JP6024603B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine.

  For example, Patent Document 1 discloses an internal combustion engine mounted on a vehicle such as an automobile that automatically stops engine operation when the vehicle is temporarily stopped, and automatically restarts engine operation when the vehicle starts. Yes.

  The internal combustion engine of Patent Document 1 includes an in-cylinder injection valve. In this internal combustion engine, cranking by a starter is started at the time of automatic restart, and the first fuel injection and ignition at the time of automatic restart are executed for the cylinders in the compression stroke to cause an initial explosion. This realizes early restart.

JP 2007-309276 A

  By the way, the ignition in each cylinder is executed based on the crank angle calculated based on the signal output from the crank angle sensor. The crank angle used for such ignition control is calculated as follows, for example. That is, the crank angle sensor outputs a pulse signal corresponding to a plurality of protrusions formed on the crank rotor that rotates integrally with the crankshaft. And a control apparatus calculates a crank angle by counting the pulse signal which the crank angle sensor output. In addition, a part of the crank rotor is provided with a toothless part with a missing protrusion, and the control unit detects the calculated crank angle when the pulse signal output interval becomes longer. Is updated to a value indicating the crank angle that should be calculated. That is, since the missing tooth portion is provided only in a part of the crank rotor, the output interval of the pulse signal is only momentarily increased when passing the crank angle where the missing tooth portion is provided. Therefore, if there is a deviation between the calculated crank angle and the actual crank angle, it will be calculated when a missing tooth part where the output interval of the pulse signal becomes momentarily long is detected. The deviation is corrected by updating the existing crank angle to a value indicating the crank angle that should be calculated when the missing tooth portion is detected.

  On the other hand, there is a possibility that a deviation has occurred between the calculated crank angle and the actual crank angle until the missing tooth portion is detected. In other words, when the engine is restarted, there is a possibility that there is a difference between the calculated crank angle and the actual crank angle until the crankshaft rotates to some extent and the missing tooth portion is detected.

  In this regard, in the internal combustion engine disclosed in Patent Document 1, a cylinder stopped in the compression stroke is detected based on the crank angle stored when the engine is stopped, and the first fuel injection and ignition at the time of automatic restart are detected for this cylinder. Is done. Therefore, since the period from the start of cranking to the first ignition is short and the rotation amount of the crankshaft until the first ignition is executed is small, the first ignition is executed in a state where the missing tooth portion is not detected. There is a high possibility. Therefore, if there is a difference between the stored crank angle and the actual crank angle, there is a possibility that ignition will be executed at an inappropriate time.

  Further, in the internal combustion engine of Patent Document 1, the second and subsequent ignitions at the time of automatic restart are executed in a state where no missing portion is detected depending on the amount of rotation of the crankshaft so far. Become. Therefore, in the internal combustion engine of Patent Document 1, improper ignition may be continuously executed during automatic restart.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to achieve early completion of engine start at the time of engine start and control that inappropriate ignition is continuously performed. To provide an apparatus.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A control device for an internal combustion engine for solving the above problems drives a crankshaft by a starter and executes ignition when starting the engine. This control device is provided with a confirmation means for confirming that the estimated value of the crank angle is an appropriate value, and is a compression stroke injection that performs fuel injection and ignition from the in-cylinder injection valve to a cylinder in the compression stroke. In the case of starting, the first ignition is executed for the cylinder that can cause the first explosion among the cylinders of the internal combustion engine based on the crank angle stored when the engine is stopped. Then, on the condition that the estimated value of the crank angle is confirmed to be an appropriate value by the confirmation means , the ignition is permitted for the cylinder that changes the ignition timing following the cylinder that performed the first ignition. .

  Since it is estimated that the rotation of the crankshaft is stopped while the engine is stopped, the crank angle calculated when the rotation of the crankshaft is stopped when the engine is stopped is determined as the crank angle at the start of the engine start. Can be substituted. In the above configuration, the first ignition at the time of starting the engine is executed for the cylinder that can cause the first explosion earliest based on the crank angle stored when the crankshaft is stopped when the engine is stopped. . That is, ignition is performed using the crank angle estimated using the crank angle stored when the engine is stopped. Therefore, if there is no deviation between the stored crank angle and the actual crank angle when the engine is stopped, the stored crank angle is used to ignite at an appropriate time, so that an appropriate initial explosion occurs early, Early start can be realized.

  Further, in the above configuration, for a cylinder that changes the ignition timing following the cylinder that first ignited when the engine is started, if the estimated value of the crank angle is not confirmed to be an appropriate value, Is prohibited. As a result, even if the first ignition is executed at an inappropriate time based on a crank angle that does not have an appropriate value, it is possible to prevent the next ignition from being executed at an inappropriate time. In this way, it is possible to suppress the inappropriate ignition from being continuously performed when the engine is started.

  When ignition is performed at an inappropriate time in each cylinder, torque that acts in the reverse rotation direction on the crankshaft may be generated by this ignition. In this regard, in the case of the compression stroke injection start, since the first ignition is performed for the cylinders that have stopped in the compression stroke in many cases, it is compared with the second and subsequent combustion in which combustion is performed through the intake stroke. Even if the amount of air in the cylinder is small and a torque in the reverse rotation direction acts on the crankshaft due to ignition at an incorrect timing, the torque is often small. Therefore, even if the initial ignition using the crank angle when the engine is stopped is performed at an inappropriate time, reverse rotation of the crankshaft can be suppressed by driving the crankshaft by the starter. That is, even when the first ignition is performed at an inappropriate time, the problem caused by the ignition is not so great. When the ignition is performed at an appropriate time, an early start can be realized.

  On the other hand, in the cylinder that changes the ignition timing following the cylinder that executed the first ignition, the compression stroke is changed after the intake stroke and the ignition timing is changed. Therefore, the reverse rotation torque generated when improper ignition is performed growing. In this regard, in the above configuration, ignition is not executed in a cylinder whose ignition timing is set subsequent to the cylinder in which the initial ignition is performed, unless it is confirmed that the estimated value of the crank angle is an appropriate value. . Therefore, it is possible to suppress a large reverse rotation torque from acting on the crankshaft due to inappropriate ignition.

According to the above configuration, it is possible to complete early start-up as described above, and to suppress the continuous execution of inappropriate ignition.
The control apparatus for an internal combustion engine includes a crank angle sensor that outputs a pulse signal corresponding to the passage of a plurality of protrusions provided on a crank rotor that rotates integrally with the crankshaft, and the pulse output from the crank angle sensor When detecting a missing tooth portion in which the protrusion of the crank rotor is missing based on a change in the signal interval, and when updating the estimated value of the crank angle to the specified value when the missing tooth portion is detected, The confirmation means can adopt a mode in which it is confirmed that the estimated value of the crank angle is an appropriate value based on the detection of the missing tooth portion.

  When the estimated value of the crank angle is updated by detecting the missing tooth portion, the estimated value of the crank angle is a value that matches the actual crank angle. Therefore, when the missing tooth portion is detected, it can be confirmed that the estimated value of the crank angle is an appropriate value based on that. In the above configuration, the specified value means a value corresponding to a crank angle that should be estimated when a missing tooth portion is detected.

  Further, as the cam signal, a first cam signal corresponding to a portion where the protrusion of the cam rotor that rotates integrally with the cam shaft is provided and a second cam signal corresponding to a portion where the protrusion is not provided are output. In the case where the cam angle sensor is provided, the confirmation unit is configured to rotate the crankshaft until the rotation of the crankshaft is estimated to be completed when the engine is started. When the missing tooth portion is detected and the cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal, the estimated value of the crank angle is within a specified range. It is possible to adopt a mode in which it is confirmed that the estimated value of the crank angle is an appropriate value based on the fact that the logical sum condition is satisfied.

  The crankshaft and the camshaft are connected via a timing chain or the like. For this reason, there is a certain correlation between the cam signal output from the cam angle sensor and the crank angle. Specifically, the crank angle when the cam signal is switched between the first cam signal and the second cam signal becomes a specific value. Therefore, if the estimated value of the crank angle is within the specified range when the cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal, the estimated value of the crank angle Can be confirmed to be at an appropriate value. In the above configuration, the specified range means an allowable range including a crank angle that should be estimated when the output of the cam signal is switched. Therefore, as described above, when the missing tooth portion is detected and the cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal, the crank angle is changed. If a configuration that confirms that the estimated value of the crank angle is an appropriate value based on the fact that the logical sum condition that the estimated value is within the specified range is satisfied, the missing tooth portion is detected. In the meantime, it can be confirmed that the crank angle is almost an appropriate value.

  On the other hand, when the crankshaft rotates by an amount of rotation that is estimated to have completed detection of the missing tooth portion, the missing tooth portion has already been detected, and the estimated value of the crank angle is updated to the specified value. Can be estimated. Therefore, in the above configuration, the condition that the missing tooth portion is detected for a cylinder whose ignition timing is set after the crankshaft has been rotated by an amount of rotation that is estimated to be completed. Ignition based on the estimated crank angle is executed. According to such a configuration, in a situation where a missing tooth portion should be detected if no abnormality has occurred, confirmation is made on the condition that detection of the missing tooth portion is more accurate than confirmation using a cam signal. Therefore, the accuracy of checking the crank angle can be increased.

Further, in an internal combustion engine to which the above control device is applied, when the intake stroke injection start that causes the initial explosion is performed after the fuel is injected into the cylinder in the intake stroke and then the ignition is performed, the confirmation is performed. It is preferable to prohibit ignition until the estimated value of the crank angle is confirmed to be an appropriate value by the means.

  In the case of an intake stroke injection start in which fuel is injected after injecting fuel to a cylinder in the intake stroke and an initial explosion is caused, an air-fuel mixture that is homogeneously mixed through the intake stroke is ignited. Compared to the first explosion caused by starting the compression stroke injection, the torque obtained is large. Therefore, in the case of the intake stroke injection start, the reverse rotation torque generated when improper ignition is performed increases. For this reason, when performing the intake stroke injection, it is preferable to prohibit the execution of ignition until it is confirmed that the estimated value of the crank angle is an appropriate value. If such a configuration is adopted, the cylinder that can cause the first explosion will not be ignited until it is confirmed that the estimated value of the crank angle is an appropriate value. It is possible to suppress a large reverse rotation torque from acting on the crankshaft due to the ignition.

  Moreover, the said control apparatus can also be applied to the control apparatus of the internal combustion engine which controls an internal combustion engine provided with the port injection valve which injects a fuel to an intake port. In this case, the fuel can be injected from the port injection valve when the intake stroke injection start is executed.

  In the control device for an internal combustion engine, the compression stroke injection start is prohibited when the pressure of the fuel supplied to the in-cylinder injection valve is less than the lower limit pressure for executing the fuel injection in the compression stroke. It is preferable to execute the intake stroke injection start.

  When the internal combustion engine has a port injection valve, an intake stroke injection start is performed in which fuel is injected by the port injection valve when the pressure of the fuel supplied to the in-cylinder injection valve is less than the lower limit pressure. It is possible to adopt a mode such as.

The control apparatus for an internal combustion engine includes an abnormality confirmation unit that confirms that the estimated value of the crank angle is not an appropriate value. In the case of the compression stroke injection start, the crank angle is estimated by the abnormality confirmation unit . It is preferable to prohibit the fuel injection to the cylinder that sets the ignition timing following the cylinder that has performed the first ignition, on the condition that the value is confirmed to be not an appropriate value .

  According to the above-described configuration, when it is confirmed that the estimated value of the crank angle is not an appropriate value, fuel injection is prohibited for the cylinder whose ignition timing is set subsequent to the cylinder that performed the first ignition. Therefore, it is possible to suppress execution of inappropriate injection.

  In addition, as an abnormality confirmation means, the structure which utilizes a cam signal similarly to the confirmation means mentioned above is applicable. For example, when the cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal, the crank angle is estimated based on the fact that the estimated value of the crank angle is outside the specified range. It can be confirmed that the estimated value is not an appropriate value.

Further, in the control device for an internal combustion engine, when performing an intake stroke injection start for initiating ignition after injecting fuel to a cylinder in the intake stroke, the abnormality confirmation means by the condition that the estimated value of the crank angle is made confirmation that no appropriate value, it is preferable to prohibit also the fuel injection for the cylinder that is capable of causing a most early initial explosion.

  Since the combustion performed through the intake stroke injection is homogeneous combustion, more fuel is burned and the generated torque is larger than the combustion performed through the compression stroke injection. Therefore, if ignition is executed at an inappropriate time, a large torque in the reverse rotation direction may act on the crankshaft. In this regard, according to the above-described configuration, when the intake stroke injection start is executed, when it is confirmed that the estimated value of the crank angle is not an appropriate value, the cylinder that can cause the first explosion is earliest. Fuel injection is also prohibited. Therefore, it is possible to suppress the occurrence of a large reverse rotation torque due to the execution of injection or ignition at an inappropriate time from the first time.

When the internal combustion engine control device has an idle stop function that automatically stops the internal combustion engine when the idle stop condition is satisfied and automatically restarts the internal combustion engine when the idle stop condition is not satisfied, When performing the compression stroke injection start from the automatic stop state by the idle stop function, the first explosion is caused the earliest among the cylinders of the internal combustion engine based on the crank angle stored at the time of the last engine stop. In the case of starting the engine due to the ignition switch being operated while the first ignition is executed for the cylinder that can be made, it is confirmed that the estimated value of the crank angle is an appropriate value by the confirmation means It is preferable to execute individual fuel injection and ignition for each cylinder under the above conditions.

  In the case of automatic restart from the automatic stop state by the idle stop function, the crank angle is estimated based on the crank angle memorized at the time of the last engine stop, and the first explosion is caused first among each cylinder of the internal combustion engine. The above-described configuration can also be applied to a control device for an internal combustion engine that performs initial ignition for a cylinder that can be used. In the case of automatic restart, since it is desirable to complete the start at an early stage, the crank angle stored at the time of the last automatic stop may be used to perform injection or ignition at the time of automatic restart. In this case, if the above-described configuration is adopted, improper ignition is continuously executed when there is a deviation between the stored crank angle and the actual crank angle while completing early start-up. Can be suppressed.

  Another aspect of the control device for an internal combustion engine for solving the above problems is a crank angle sensor that outputs a pulse signal corresponding to the passage of a plurality of protrusions provided on a crank rotor that rotates integrally with the crankshaft. And detecting a missing tooth portion lacking a projection of the crank rotor based on a change in the interval of the pulse signal output from the crank angle sensor, and estimating the crank angle when the missing tooth portion is detected. Update the value to the default value. In the case of the compression stroke injection start in which fuel injection from the in-cylinder injection valve and ignition are performed on the cylinders in the compression stroke, the crankshaft is driven by the starter and stored at the last engine stop. Based on the angle, the first ignition is performed on the cylinder that can cause the first explosion among the cylinders of the internal combustion engine based on the angle, and the first tooth is detected on the condition that the missing tooth portion is detected. The execution of ignition is permitted for the cylinder whose ignition timing is set subsequent to the cylinder that executed the ignition.

  In the above configuration, the specified value means a value corresponding to a crank angle that should be estimated when a missing tooth portion is detected. Also with this configuration, it is possible to achieve early start-up completion and to suppress the continuous execution of inappropriate ignition.

  In the control device for an internal combustion engine according to the other aspect, the first cam signal corresponding to the portion where the protrusion of the cam rotor that rotates integrally with the cam shaft is provided as the cam signal, and the protrusion is not provided. A cam angle sensor that outputs a second cam signal corresponding to the portion until the rotation of the crankshaft, which is estimated to have completed the detection of the missing tooth portion as the engine starts. The crank angle is estimated when the cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal even if the missing tooth portion is not detected. When the value is within a specified range, it is preferable to permit the execution of ignition to a cylinder that is ready for ignition timing following the cylinder that has performed the first ignition.

  In the above configuration, the specified range means an allowable range including a crank angle that should be estimated when the output of the cam signal is switched.

The schematic diagram which shows the relationship between the control apparatus of the internal combustion engine concerning 1st Embodiment, and an internal combustion engine. (A)-(c) is a timing chart which shows the crank signal which the crank angle sensor in the same embodiment outputs, the calculated value of a crank angle, and the cam signal which a cam angle sensor outputs. The flowchart which shows the execution procedure of the setting process of the index value of the crank angle confirmation condition in the embodiment. The timing chart which shows the change of the stroke in each cylinder with respect to the change of the crank angle in the same embodiment. The flowchart which shows the execution procedure of the ignition control at the time of the automatic restart in the same embodiment. The flowchart which shows the execution procedure of the fuel-injection control at the time of the automatic restart in the same embodiment. The timing chart which shows the change of the stroke in each cylinder with respect to the change of the crank angle in 2nd Embodiment. The flowchart which shows the execution procedure of the ignition control at the time of the automatic restart in the same embodiment. The flowchart which shows the execution procedure of the fuel-injection control at the time of the automatic restart in the same embodiment. The schematic diagram which shows the relationship between the control part in the control apparatus of the internal combustion engine concerning 3rd Embodiment, a cam angle sensor, and a cam rotor. (A)-(c) is a timing chart which shows the crank signal which the crank angle sensor in the same embodiment outputs, the calculated value of a crank angle, and the cam signal which a cam angle sensor outputs. The timing chart which shows the change of the stroke in each cylinder with respect to the change of the crank angle in the same embodiment. The flowchart which shows the execution procedure of the ignition control at the time of the automatic restart in the same embodiment. The timing chart which shows the change of the stroke in each cylinder with respect to the change of the crank angle in 4th Embodiment.

(First embodiment)
Hereinafter, a first embodiment of a control device for an internal combustion engine will be described with reference to FIGS.
As shown in FIG. 1, the control device for the internal combustion engine 10 includes a control unit 50 and various sensors 71 to 78 that detect various states of the internal combustion engine 10. The control unit 50 controls the internal combustion engine 10 based on signals output from the various sensors 71 to 78. The internal combustion engine 10 of this embodiment is an in-line four-cylinder gasoline engine.

  The control unit 50 includes a central processing unit (CPU) that executes various arithmetic processes for controlling the internal combustion engine 10, a calculation program and a calculation map, a read-only memory (ROM) in which various data are stored, calculation results, and the like. Is provided with a random access memory (RAM) or the like for temporarily storing.

As shown in FIG. 1, the following various sensors are connected to the control unit 50.
The accelerator position sensor 71 detects the amount of depression of the accelerator pedal by the driver. The throttle position sensor 72 detects the throttle opening, which is the opening of the electronically controlled throttle valve 13. The air flow meter 73 detects the temperature of the air introduced into the internal combustion engine 10 and the amount of intake air that is the amount thereof. The water temperature sensor 74 detects the engine cooling water temperature, which is the temperature of the cooling water that cools the internal combustion engine 10. The brake switch 77 detects whether or not the brake pedal is depressed. The vehicle speed sensor 78 detects the speed of the vehicle.

  The crank angle sensor 75 outputs a signal corresponding to a change in the rotation angle of the crankshaft 20 of the internal combustion engine 10. Specifically, a crank rotor 21 is fixed to the crankshaft 20. The crank rotor 21 includes a plurality of protrusions 22 formed on the outer periphery at intervals of 10 ° in the circumferential direction, and a missing tooth portion 23 in which the protrusions 22 are missing at one position on the outer periphery. The missing tooth portion 23 has a width corresponding to three protrusions (30 ° width). The crank angle sensor 75 outputs a pulse signal corresponding to the passage of the plurality of protrusions 22 of the crank rotor 21 that rotates integrally with the crankshaft 20. Then, the control unit 50 calculates the crank angle by counting the pulse signal, and when the pulse signal is output after the pulse signal is not continuously output for the period of three output intervals, Based on this, the missing tooth portion 23 is detected. Then, the calculated crank angle is updated to a specified value, that is, a crank angle value that should be calculated when the missing tooth portion 23 is detected. That is, in the present embodiment, the missing tooth portion 23 is provided only at one location on the outer periphery of the crank rotor 21, so the missing tooth portion 23 is detected by the crank provided with this missing tooth portion 23. Only when passing the corner. Therefore, when the missing tooth portion 23 is detected, the calculated crank angle is updated to the crank angle that should be calculated when the missing tooth portion 23 is detected. If there is a deviation from the actual crank angle, the deviation is corrected. The control unit 50 calculates the crank angle in this way, and calculates the engine rotation speed indicating the rotation speed of the crankshaft 20 per unit time.

  An exhaust cam angle sensor 76 (hereinafter simply referred to as “cam angle sensor”) outputs a cam signal corresponding to a change in the rotation angle of the exhaust cam shaft 30 (hereinafter simply referred to as “cam shaft”) of the internal combustion engine 10. . Specifically, a cam rotor 31 is fixed to the cam shaft 30. The cam rotor 31 includes three convex portions (protrusions) 32, 33, 34 having different occupying ranges in the circumferential direction, and the convex portions 32, 33, 34 positioned between the convex portions 32, 33, 34. Concave portions (portions where no protrusions are provided) 35, 36, and 37 that are recessed with respect to 34 are provided.

  The largest first convex portion 32 is formed over an angle of 90 ° in the circumferential direction of the cam rotor 31. On the other hand, the smallest second convex portion 33 is formed so as to extend over 30 ° in angle, and the third convex portion 34 is formed so as to extend over 60 °. The first concave portion 35 between the first convex portion 32 and the second convex portion 33 is provided over 90 ° in the circumferential direction of the cam rotor 31, and the second convex portion 33 and the third convex portion 33 are provided. The second concave portion 36 between the convex portion 34 is provided over 60 ° in the circumferential direction of the cam rotor 31. The third concave portion 37 between the first convex portion 32 and the third convex portion 34 is provided over 30 ° in the circumferential direction of the cam rotor 31.

  The cam angle sensor 76 is disposed toward the peripheral edge of the cam rotor 31 at a position that can face the convex portions 32, 33, and 34 of the cam rotor 31. The cam angle sensor 76 is a magnetoresistive element type sensor. When the cam rotor 31 rotates as the cam shaft 30 rotates, an H signal that is a first signal corresponding to the convex portions 32, 33, and 34 is generated. The L signal that is the second signal corresponding to the recesses 35, 36, and 37 is output to the control unit 50.

  The internal combustion engine 10 is provided with an in-cylinder injection valve 11 that directly injects fuel into the cylinder, a spark plug 12, and a throttle valve 13 provided in the intake passage. The drive units 11 to 13 of the internal combustion engine 10 are driven and controlled by the control unit 50.

  One in-cylinder injection valve 11 is provided for each cylinder of the internal combustion engine 10 and opens based on a drive command output from the control unit 50 to inject fuel into each cylinder. . In the present embodiment, fuel is injected into the cylinder in the compression stroke by the in-cylinder injection valve 11.

  One spark plug 12 is provided for each cylinder, and ignites the air-fuel mixture in the combustion chamber based on an ignition command output from the control unit 50. The throttle valve 13 is driven to open and close based on a drive command output from the control unit 50 to adjust the intake air amount of the internal combustion engine 10.

The control unit 50 is connected to a starter 14 that drives the crankshaft 20 when the engine is started.
The control unit 50 grasps the state of each part of the engine based on the signals output from the various sensors 71 to 78, and introduces an amount of air corresponding to the amount of fuel supplied to each cylinder into the combustion chamber. In order to form an ideal air-fuel ratio mixture, the throttle valve 13 is controlled to adjust the intake air amount.

  Further, the control unit 50 adjusts the valve opening timing and valve opening period of the in-cylinder injection valve 11 to control the amount of fuel supplied to each cylinder and the fuel injection timing. Further, the ignition timing in each cylinder is adjusted by adjusting the timing at which an ignition command is output to the spark plug 12 in order to realize efficient engine operation by good combustion. Specifically, the control unit 50 calculates the crank angle by counting the pulse signals output from the crank angle sensor 75, and determines the fuel injection and ignition timing for each cylinder based on the calculated crank angle. To do. Then, a drive signal is output to the in-cylinder injection valve 11 and the spark plug 12 so that fuel injection and ignition are executed at the determined timing.

  The internal combustion engine 10 of the present embodiment has a so-called idling stop function that automatically stops the engine operation without depending on the operation of the driver when the vehicle stops due to a signal waiting or the like.

  The control unit 50 automatically stops the engine operation through the idling stop control when the idle stop condition is satisfied. The idle stop condition is set to determine whether the vehicle is stopped due to a signal waiting or the like. For example, the vehicle is stopped (the vehicle speed is “0”), and the accelerator operation amount is “0”. And that all requirements such as that the brake pedal is depressed are satisfied. Then, when the idle stop condition is not satisfied after that, the internal combustion engine 10 is automatically restarted.

  In the present embodiment, the normal start of the internal combustion engine 10 by turning on the ignition switch is performed as follows. First, cranking for rotating the crankshaft 20 by the starter 14 is performed under the control of the control unit 50. When the missing tooth portion 23 is detected based on the output of the crank angle sensor 75 while the crankshaft 20 is rotating by cranking, the control unit 50 completes the cylinder discrimination based on this. And after such cylinder discrimination | determination is completed, the separate fuel injection and ignition with respect to each cylinder are performed according to a crank angle.

  On the other hand, since the automatic restart is a start for starting the vehicle from a stopped state due to a signal waiting or the like, the start completion is required earlier than the normal start. Therefore, in the present embodiment, at the time of automatic restart, the crankshaft 20 is rotationally driven by the starter 14 and the first fuel injection and ignition are performed on the cylinder that can cause the initial explosion earliest. Yes. Specifically, the first fuel injection and ignition are performed on the cylinders that are ready for the fuel injection timing of the compression stroke at the time of automatic restart.

  In addition, when the first ignition at the time of automatic restart is performed for the cylinder that first reaches the fuel injection timing of the compression stroke at the time of automatic restart, the period from the start of automatic restart to the first ignition is short. Therefore, the amount of rotation of the crankshaft 20 until the first ignition is executed is small, and there is a high possibility that the missing tooth portion 23 is not detected until the first ignition is executed. Further, the subsequent ignition is executed in a state where the missing tooth portion 23 is not detected depending on the rotation amount of the crankshaft 20 until then, and the estimation accuracy of the crank angle calculated by the above-described mode is low. Become. When ignition based on the calculated crank angle is executed in such a state that the estimation accuracy of the crank angle is low, inappropriate ignition is continuously executed.

  Therefore, in the present embodiment, in order to realize early start-up while suppressing such inappropriate ignition from being continuously executed, the control unit 50 performs automatic restart as described in detail below. Ignition control and fuel injection control are executed.

Hereinafter, the control at the time of the automatic restart performed by the control part 50 is demonstrated with reference to FIGS.
In the present embodiment, the crank angle calculated when the crankshaft 20 stops due to automatic stop is stored, and the stored crank angle is used to start the next automatic restart. The first explosion is caused early by executing the ignition. In addition, for cylinders whose ignition timing follows the cylinder that performed the first ignition, the estimated crank angle value calculated in the above manner is an appropriate value that matches the actual crank angle. On the condition that it is confirmed, the execution of the ignition is permitted to prevent the ignition from being executed at an inappropriate time. In the present embodiment, since ignition may be prohibited after the first explosion occurs, the engine rotation speed at which the starter 14 stops driving the crankshaft 20 is higher than the engine rotation speed obtained by the first explosion. Set to a high value. As a result, since the rotation of the crankshaft 20 by the starter 14 is continued after the first explosion, even if ignition is prohibited after the first explosion occurs, the startability of the internal combustion engine 10 can be ensured. it can.

  In the present embodiment, the control unit 50 uses the signal output from the crank angle sensor 75 and the cam signal output from the cam angle sensor 76 as the confirmation unit and the abnormality confirmation unit, so that the calculated crank angle is appropriate. Confirm that it is in the value and not in the proper value. With reference to FIG. 2, the crank signal output from the crank angle sensor 75, the calculated crank angle based on the crank signal, and the cam signal output from the cam angle sensor 76 will be described.

  As shown in FIG. 2A, in this embodiment, every time the crankshaft 20 rotates by 10 ° CA, the crank angle sensor 75 outputs a pulse signal corresponding to the protrusion 22 of the crank rotor 21. Further, the case where the crank angle is 120 to 140 ° CA and the case where the crank angle is 480 to 500 ° CA correspond to the missing tooth portion 23 of the crank rotor 21. That is, as described with reference to FIG. 1, since the missing tooth portion 23 is provided at one place on the outer periphery of the crank rotor 21, the crankshaft 20 rotates once as shown in FIG. Every 360 ° CA, a period corresponding to the missing tooth portion 23 in which the output interval of the pulse signal becomes long appears.

  Then, as shown in FIG. 2 (b), the crank angle is incremented by 10 ° CA according to the output of the pulse signal, and when the missing tooth portion 23 is detected, the calculated crank angle is The crank angle is updated to a specified value that should be calculated when the missing tooth portion 23 is detected. Specifically, in the present embodiment, it is calculated at 170 ° CA and 530 ° CA after 30 ° CA from the crank angle (120 to 140 ° CA, 480 to 500 ° CA) at which the missing tooth portion 23 is provided. The crank angle is updated. That is, when the pulse signal that has been continuously output is not output for 30 ° CA, and the pulse signal is output three times thereafter, the missing tooth portion 23 is detected based on the pulse signal and is calculated at that time. The crank angle is updated to the crank angle (170 ° CA, 530 ° CA) when the missing tooth portion 23 is detected. As described above, when the missing tooth portion 23 is detected when the pulse signal is output three times from the situation where the pulse signal is not output by 30 ° CA, the engine speed at which the rotation speed of the crankshaft 20 is likely to change is changed. In this case, the missing tooth portion 23 can be detected more accurately.

  When the calculated crank angle value is counted up to 710 ° CA according to the output of the pulse signal, the calculated crank angle value is reset to 0 ° CA by the output of the next pulse signal. In the present embodiment, the crank angle is calculated in this way.

  Further, in this embodiment, every time the rotation of the crankshaft 20 stops with the automatic stop, the crank angle calculated at that time is stored in the RAM of the control unit 50. By doing so, the crank angle when the rotation of the crankshaft 20 is stopped when the automatic stop is last performed at the time of the next automatic restart is stored. Therefore, at the time of automatic restart, the stored crank angle becomes an initial value, and the crank angle is calculated by adding 10 ° CA each time a pulse signal is output. Thereafter, when the missing tooth portion 23 is detected, the crank angle is updated to a specified value of the crank angle that should be calculated when the missing tooth portion 23 is detected.

  In addition, as shown in FIG. 2C, the cam signal alternately outputs the H signal and the L signal. As described above, the H signal corresponds to the convex portions 32, 33, and 34 of the cam rotor 31, and the L signal corresponds to the concave portions 35, 36, and 37. Here, the camshaft 30 and the crankshaft 20 are connected via a timing chain or the like, and the camshaft 30 makes one revolution every time the crankshaft 20 makes two revolutions. Therefore, since the first convex portion 32 of the cam rotor 31 is formed over 90 ° in the circumferential direction of the rotor 31, the H signal corresponding to the first convex portion 32 is 180 ° of 0 to 180 ° CA. It is output as an H signal for CA. Moreover, since the 1st recessed part 35 adjacent to the 1st convex part 32 is formed over 90 degrees of the circumferential direction of the cam rotor 31, the L signal corresponding to the 1st recessed part 35 is the 1st convex part. 32 is output following the H signal corresponding to 32, and is output as an L signal corresponding to 180 ° CA of 180 to 360 ° CA. Similarly, the H signal corresponding to the second convex portion 33 is output as an H signal corresponding to 60 ° CA of 360 to 420 ° CA, and the L signal corresponding to the second concave portion 36 is 420 to 540 °. It is output as an L signal for 120 ° CA of CA. The H signal corresponding to the third convex portion 34 is output as an H signal corresponding to 120 ° CA of 540 to 660 ° CA, and the L signal corresponding to the third concave portion 37 is 660 to 720 ° CA (0 ° CA) and an L signal corresponding to 60 ° CA.

  Here, as described above, since the camshaft 30 is connected to the crankshaft 20 via a timing chain or the like, there is a certain correlation between the cam signal and the crank angle, and the H signal of the cam signal. And the crank angle value when the L signal is switched become a specific value. In the present embodiment, the ROM of the control unit 50 includes a crank angle (H → L: 180 ° CA, 420 ° CA, 660 ° CA, L → H: 0 °) when the H signal and the L signal are switched. CA, 360 ° CA, 540 ° CA) is stored in advance. Therefore, when the switching of the cam signal is detected, the calculated crank angle value is within a specified range, that is, the crank angle that should be calculated when the cam signal output is switched (the crank angle stored in the ROM). ) Is within an allowable range, it can be estimated that the calculated crank angle is at an appropriate value. On the other hand, when the switching of the cam signal is detected, if it is not within the specified range, it can be estimated that the calculated crank angle is not an appropriate value.

  Here, when the calculated crank angle is updated by detection of the missing tooth portion 23, it can be confirmed that the calculated crank angle is at an appropriate value. Further, by detecting the switching between the H signal and the L signal of the cam signal, it can be confirmed whether or not the calculated crank angle is at an appropriate value. Therefore, in this embodiment, the control unit 50 confirms that the calculated crank angle is an appropriate value based on the signal output from the crank angle sensor 75 and the signal output from the cam angle sensor 76. At the same time, based on the signal output from the cam angle sensor 76, it is confirmed that the calculated crank angle is not an appropriate value.

  Table 1 shows an index value indicating a confirmation state that the calculated crank angle is at an appropriate value or is not at an appropriate value. This index value is set by the control of the control unit 50, and the latest index value set last is stored in the RAM of the control unit 50.

As shown in Table 1, the index value is set to “0” when the crank angle has not been confirmed at the time of automatic restart. In addition, when the automatic restart is already detected, the switching between the H signal and the L signal of the cam signal is detected, and when it is confirmed that the crank angle calculated based on this detection is not an appropriate value, It is set to “1” indicating that the check result by the cam signal is NG. On the other hand, if it is confirmed that the calculated crank angle is an appropriate value based on the detection of cam signal switching, the cam signal check has been completed, and the calculated crank angle is an appropriate value. Is set to “2” indicating that Further, at the time of automatic restart, the missing tooth portion 23 is detected by the crank angle sensor 75, and when the calculated crank angle is updated, it is set to “3” indicating that the missing tooth has been detected.

  The index value of the crank angle confirmation status is set according to the processing procedure shown in the flowchart of FIG. This process is executed as an interrupt process by the control unit 50 every time the crank angle sensor 75 outputs a pulse signal.

  As shown in FIG. 3, when this process, which is an index value setting process for the crank angle confirmation status, is started, it is first determined in step S11 whether or not automatic restart is being performed. In step S11, for example, immediately after the control unit 50 grasps that the idle stop condition is no longer established based on information from various sensors, a drive signal is sent to the starter 14 to rotate the crankshaft 20. It is determined that the automatic restart is in progress on the condition that the data is output. In step S11, when it is during normal operation of the internal combustion engine 10, it is determined that it is not at the time of automatic restart (step S11: NO), the process proceeds to step S21. In step S21, the index value indicating the crank angle confirmation status is set to “0” indicating undecided. That is, since the automatic restart is not currently being performed, the index value is set to “0” because the crank angle is not confirmed at the time of automatic restart.

  On the other hand, when it is determined in step S11 that the automatic restart is being performed (step S11: YES), the process proceeds to step S12, and it is determined whether or not the index value is “3”. When it is determined in step S12 that the index value is “3” (step S12: YES), the control unit 50 once ends this process. That is, the index value “3” should be calculated when the missing tooth portion 23 has already been detected since the automatic restart is started and the calculated crank angle is detected. It is shown that the crank angle is updated to the specified value. Accordingly, since the accuracy of the calculated crank angle is the highest, it is not necessary to change the index value thereafter, and thus this processing is terminated.

  On the other hand, when it is determined in step S12 that the index value is not “3” (step S12: NO), the process proceeds to step S13, and it is determined whether or not the missing tooth portion 23 is detected. If it is determined in step S13 that the missing tooth portion 23 is not detected (step S13: NO), the process proceeds to step S16, and it is determined whether the index value is “0” or “2”. When the index value is set to “1”, since it is determined in step S16 that the index value is not “0” or “2” (step S16: NO), the control unit 50 performs this process. Exit once. That is, when the index value is “1”, switching between the H signal and the L signal in the cam signal has already been detected, and based on this, it has been confirmed that the crank angle is not at an appropriate value. Until the missing tooth portion 23 is detected, it is estimated that the deviation between the calculated crank angle and the actual crank angle cannot be resolved. Therefore, in a situation where it is determined that the missing tooth portion 23 has not been detected, if the index value is “1”, this processing is temporarily terminated.

  On the other hand, when it is determined in step S16 that the index value is “0” or “2” (step S16: YES), the process proceeds to step S17 to determine whether or not switching of the cam signal is detected. That is, when the index value is “0” or “2”, the cam signal is not yet output at the time of automatic restart (index value “0”), or the cam signal that has already been detected is switched. Based on this, it is confirmed that the crank angle is at an appropriate value (index value “2”). Therefore, the processing after step S17 is executed to perform confirmation based on the switching of the cam signal.

  If it is determined in step S17 that the switching of the cam signal has not been detected (step S17: NO), whether or not the calculated crank angle is an appropriate value is determined based on the switching of the cam signal. Since it cannot confirm, the control part 50 once complete | finishes this process.

  On the other hand, if it is determined in step S17 that the switching of the cam signal is detected (step S17: YES), the process proceeds to step S18, where the calculated crank angle is within the specified range, that is, the switching of the cam signal is detected. It is determined whether or not it is within an allowable range including the crank angle that should be calculated. In the present embodiment, this allowable range is set to ± 20 ° CA. That is, here, the crank angle calculated in steps of 10 ° CA is 160 to 190 ° CA, 340 to 370 ° CA, 400 to 430 ° CA, 520 to 550 ° CA, 640 to 670 ° CA, 700 to 10 When it is ° CA (that is, 700 ° CA, 710 ° CA, 0 ° CA, 10 ° CA), it is determined that it is within the allowable range. The permissible range is, for example, mechanical deviation due to elongation or assembly tolerance of a timing chain connecting the crankshaft 20 and the camshaft 30, and the convex portions 32, 33, 34 and concave portions 35, 36 of the cam rotor 31. , 37 is set based on, for example, a phase shift between the H signal and L signal boundaries of the cam signal. Therefore, the allowable range can be appropriately set according to the characteristics of the internal combustion engine 10 and the cam angle sensor 76, and the value is not limited to ± 20 ° CA.

  Then, when it is determined in step S18 that the calculated crank angle is within the specified range (step S18: YES), the process proceeds to step S19, the index value is set to “2”, and the control unit 50 This process is temporarily terminated. That is, if an affirmative determination is made in step S18, it can be estimated that the calculated crank angle is an appropriate value, and therefore the index value is set to “2”.

  On the other hand, when it is determined in step S18 that the calculated crank angle is not within the allowable range from the crank angle based on the cam signal (step S18: NO), the process proceeds to step S20 and the index value is set to “1”. Then, the control unit 50 once ends this process. That is, if a negative determination is made in step S19, the deviation between the calculated crank angle and the actual crank angle exceeds the allowable range, and the calculated crank angle is not an appropriate value. Since it can be determined, the index value is set to “1”.

When the index value is set in steps S19 and S20, the control unit 50 once ends this process.
If it is determined in step S13 that the missing tooth portion 23 is detected (step S13: YES), the process proceeds to step S14, and the calculated crank angle is calculated when the missing tooth portion 23 is detected. Update to the specified crank angle value. Then, the process proceeds to step 15, the index value is set to “3”, and the control unit 50 once ends this process. That is, the index value is set to “3” indicating that the missing tooth portion 23 has been detected.

As described above, this processing is repeatedly executed every time the crank angle sensor 75 outputs a pulse signal.
Therefore, the index value is “0” at the start of the automatic restart, and the index value changes to “2” or “3” during the automatic restart. Further, after the index value is set to “3”, the value is maintained until the automatic restart is finished and the operation is shifted to the normal operation. When the normal operation is started, the index value is set to “0” again. Reset to. Also, the index value may be set to “1” before the index value changes to “3” during automatic restart. In this way, the index values shown in Table 1 are set at the time of automatic restart, and the set index values are used for determining whether to permit or prohibit fuel injection and ignition at the time of automatic restart.

  Table 2 shows the conditions for permitting ignition during automatic restart in the present embodiment. The setting mode of the ignition permission conditions in Table 2 will be described with reference to FIG.

FIG. 4 shows the relationship between the stroke of each cylinder and the crank angle. The time indicated by the solid arrow A indicates the crank angle at which the switching of the cam signal from the L signal to the H signal is detected, and the solid arrow B Indicates the crank angle at which switching of the cam signal from the H signal to the L signal is detected. A crank angle in a range indicated by an arrow C corresponds to the missing tooth portion 23, and a crank angle indicated by a broken arrow D after 30 ° CA is a crank angle at which the missing tooth portion 23 is detected. In each cylinder, the fuel injection timing is 30 ° CA before the compression top dead center (broken arrow), and the compression top dead center is 10 ° CA from 10 ° CA before the compression top dead center (solid arrow). The period until is the energization timing of the spark plug 12.

  In FIG. 4, for example, when the crankshaft 20 is stopped due to automatic stop, the cylinder stopped in the compression stroke is advanced from the fuel injection timing (before 40 ° CA before the compression stroke top dead center). ), The first fuel injection and ignition can be performed on the cylinders stopped in the compression stroke. Therefore, if fuel injection and ignition are performed on the cylinders that are stopped in the compression stroke, the first explosion can be caused the fastest. In this embodiment, 40 ° CA or more from the top dead center in the compression stroke. If there is a cylinder that is stopped in front, the first fuel injection and ignition are performed on this cylinder. In addition, when the cylinder stopped in the compression stroke is stopped at the fuel injection timing or at a retarded angle side (after 30 ° CA before compression top dead center), the first fuel injection is performed for the cylinder. Can not be done. For this reason, in this case, the cylinder for which the ignition timing is set next becomes the cylinder that causes the first explosion earliest, and the first fuel injection and ignition are executed for the cylinder. In the following description, the cylinder in which the first fuel injection and ignition is performed is referred to as “the cylinder that first determines the ignition timing”, and the cylinder that first performs the compression stroke after the cylinder that first determines the ignition timing. Is described as “the second cylinder for which the ignition timing is to be changed”.

  As shown in Table 2, whether or not the ignition permission condition is set to the index value “0” or more and the calculated crank angle is an appropriate value for the cylinder whose ignition timing is initially set is determined. Ignition is permitted even if no confirmation is made. In addition, for the cylinders whose ignition timings are second and third, since the ignition permission condition is set to the index value “2” or more, the ignition is permitted when the index value is “2” or more. Ignition is prohibited when there is no confirmation that the crank angle is at an appropriate value. Further, for the cylinders whose ignition timing is changed from the fourth onward, the ignition permission condition is set to the index value “3”. Therefore, the ignition is permitted at the index value “3” and the missing tooth portion 23 is not detected. In situations, ignition is prohibited.

  For the cylinders whose ignition timing is to be changed after the fourth, the ignition permission condition is set to the index value “3”. In the present embodiment, unless an abnormality or the like of the crank angle sensor 75 occurs, the fourth ignition timing is the latest. This is because the missing tooth portion 23 is detected and the calculated crank angle is updated based on the detection of the missing tooth portion 23.

  That is, as shown in FIG. 4, for example, when the cylinder whose ignition timing is first changed is the first cylinder, the missing tooth portion 23 is detected in the compression stroke of the third cylinder whose ignition timing is changed second. Therefore, the missing tooth portion 23 is detected by the third ignition timing in the fourth cylinder. Further, when the cylinder whose ignition timing is first changed is the fourth cylinder, the missing tooth portion 23 is detected in the compression stroke of the second cylinder whose ignition timing is changed second, so that the third cylinder in the first cylinder is detected. The missing tooth portion 23 is detected by the ignition timing.

  However, when the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 may not be detected by the third ignition timing. This is due to the following reason. For example, when the cylinder whose ignition timing is initially set is the third cylinder, the first explosion occurs in the third cylinder, but when the cylinder is stopped at a crank angle of 90 ° CA or more during automatic stop, the third cylinder The missing tooth portion 23 of 120 to 140 ° CA cannot be detected in the compression stroke. In order to recognize the missing tooth portion 23, the output period of the pulse signal output before that is required to be stable, but immediately after the cranking starts, the engine speed is slow and the pulse signal This is because the output period tends to be longer. When stopping at a crank angle of 90 ° CA or more during automatic stop, the number of times that the pulse signal output until the missing tooth portion 23 is detected is small and the output interval is long. The part 23 cannot be detected accurately. Therefore, when the third cylinder is a cylinder that is initially subjected to ignition timing, the missing tooth portion 23 may not be detected in the compression stroke of the third cylinder. When the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 is detected even at 530 ° CA. However, since this timing is the same as the ignition timing in the second cylinder (the timing at which the ignition plug 12 is energized) that takes the third ignition timing, by the second cylinder ignition timing, which is the third ignition timing. Therefore, the detection of the missing tooth portion 23 at 480 to 500 ° CA is not performed. Therefore, when the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 may not be detected until the third ignition timing. Similarly, when the cylinder whose ignition timing is initially set is the second cylinder, the missing tooth portion 23 may not be detected by the third ignition timing in the third cylinder. However, even if the first cylinder whose ignition timing is changed is the third cylinder or the second cylinder, the crank angle at which the missing tooth portion 23 should be detected before the fourth ignition timing is changed. Will definitely pass. Therefore, in any case, the missing tooth portion 23 is detected until the fourth ignition timing is reached, and the index value of the crank angle confirmation status is set to “3”.

  That is, no matter which cylinder is stopped in the compression stroke, the missing tooth portion 23 is detected by the fourth ignition timing at the latest, and if no abnormality has occurred, the crank angle confirmation status is The index value is set to “3”. For this reason, in the present embodiment, the ignition permission condition is set to the index value “3” for the cylinders whose ignition timing is to be reached after the fourth.

  In the present embodiment, as described above, the missing tooth portion 23 is detected by the fourth ignition timing. Therefore, if the fourth ignition timing is changed, the crank is increased as the engine starts. The shaft 20 is rotated by an amount of rotation estimated that the detection of the missing tooth portion 23 is completed. Therefore, in the present embodiment, the ignition permission condition is greater than or equal to the index value “2” until the rotation of the crankshaft 20 that is estimated to have completed the detection of the missing tooth portion 23 as the engine is started. On the other hand, it can be said that the ignition permission condition is set to the index value “3” after the crankshaft 20 has been rotated by the amount of rotation estimated that the detection of the toothless portion 23 is completed. .

  In this embodiment, even if the rotation starts from any stop position, detection of the missing tooth portion 23 can be completed if the crankshaft 20 rotates by 440 ° CA. That is, the most disadvantageous condition in detecting the missing tooth portion 23 is a case where automatic restart is started from a state where it stops before 30 ° CA immediately before the missing tooth portion 23. However, even in this case, after the crank angle sensor 75 outputs the pulse signal twice (20 ° CA), a period (30 ° CA) corresponding to the missing tooth portion 23 appears, and then rotates once. After the period corresponding to the missing tooth portion 23 appears (360 ° CA), the missing tooth portion 23 is detected when the pulse signal is output three times (30 ° CA). During this time, 20 ° CA until the crankshaft 20 reaches the missing tooth portion 23, 30 ° CA until the crankshaft 20 passes through the missing tooth portion 23, and 330 ° corresponding to the interval until the crankshaft 20 reaches the missing tooth portion 23 again. The rotation is 440 ° CA, which includes CA, 30 ° CA that passes through the missing tooth portion 23 again, and 30 ° CA that passes through the missing tooth portion 23 until the pulse signal is output three times. . Therefore, if the crankshaft 20 rotates at least 440 ° CA, it can be estimated that the detection of the missing tooth portion 23 is completed based on this.

  Further, in the present embodiment, as shown in FIG. 4, since the cam signal switching is detected by the ignition timing of the cylinder whose ignition timing is second, the calculated crank angle is appropriate. If the value is a negative value, the second and third ignitions are executed unless the cam angle sensor 76 is abnormal.

  Ignition at the time of automatic restart is executed according to the processing procedure shown in the flowchart of FIG. This process is executed by the control unit 50 as an interrupt process at predetermined intervals when the ignition switch is in the on state.

  As shown in FIG. 5, when this process is started, first, in step S31, it is determined whether or not it is during automatic restart. The determination in step S31 is performed in the same manner as in step S11 in FIG. If it is determined in step S31 that it is not at the time of automatic restart (step S31: NO), the control unit 50 ends this process. That is, when it is not at the time of automatic restart, it is not necessary to perform ignition control at the time of automatic restart, and thus this processing ends.

  If it is determined in step S31 that the automatic restart is being performed (step S31: YES), the process proceeds to step S32, and it is determined whether or not it is an ignition determination in a cylinder that first changes the ignition timing at the time of automatic start. The If an affirmative determination is made in step S32 (step S32: YES), the process proceeds to step S39, and ignition is permitted based on the calculated crank angle. That is, the RAM of the control unit 50 stores the crank angle calculated when the crankshaft 20 stops with the last automatic stop. Therefore, at the time of automatic restart, the control unit 50 determines the ignition timing based on the crank angle calculated using the stored crank angle, and performs ignition at the determined timing. A drive command is output to the plug 12. And the control part 50 once complete | finishes this process.

  On the other hand, if it is determined in step S32 that it is not the ignition determination time in the cylinder whose ignition timing is initially changed (step S32: NO), the process proceeds to step S33, and the ignition in the cylinder whose ignition timing is changed second or third is determined. It is determined whether it is a determination time. If an affirmative determination is made in step S33 (step S33: YES), the process moves to step S38, and it is determined whether or not the index value for crank angle determination is set to “2” or more. That is, as shown in Table 2, in the cylinder whose ignition timing is second or third, the ignition permission condition is the index value “2” or more. Therefore, in step S38, it is determined whether or not this permission condition is satisfied. If it is determined in step S38 that the index value is “2” or more (step S38: YES), the ignition permission condition is satisfied, and the routine proceeds to step S36, where ignition is permitted. That is, the control unit 50 determines the ignition timing in the cylinder whose ignition timing is second or third based on the calculated crank angle, and the ignition plug so that ignition is executed at the determined timing. A drive command is output to 12. On the other hand, when it is determined in step S38 that the index value is not “2” or more (step S38: NO), the process proceeds to step S37 and ignition is prohibited. In other words, when the index value is not “2” or more, the ignition permission condition is not satisfied in the cylinders whose ignition timings are second and third, and thus ignition is prohibited. After the processing of step S36 and step 37, the control unit 50 once ends this processing.

  If it is determined in step S33 that it is not at the time of ignition determination in the cylinder that changes the ignition timing second or third (step S33: NO), the process proceeds to step S34, and the ignition determination in the cylinder that changes the ignition timing after the fourth. It is determined whether it is time. If a negative determination is made in step S34 (step S34: NO), it is not the ignition determination time, so the control unit 50 once ends this process.

  On the other hand, if it is determined in step S34 that it is the ignition determination time in the cylinder whose ignition timing is to be changed after the fourth (step S34: YES), the process proceeds to step S35, and the index value of the crank angle confirmation status is set to “3”. It is determined whether it is set. That is, as shown in Table 2, the ignition permission condition is the index value “3” in the fourth and subsequent cylinders whose ignition timing is to be changed. Therefore, in step S35, it is determined whether or not this permission condition is satisfied. If it is determined in step S35 that the index value is “3” (step S35: YES), the ignition permission condition is satisfied, so the routine proceeds to step S36, where ignition is permitted. That is, the control unit 50 determines the ignition timing in the cylinder whose ignition timing is to be changed from the fourth onward based on the calculated crank angle, and the ignition plug 12 so that ignition is performed at the determined timing. A drive command is output to. On the other hand, when it is determined in step S35 that the index value is not “3” (step S38: NO), the process proceeds to step S37 and ignition is prohibited. That is, when the index value is not “3”, the ignition permission condition is not satisfied in the cylinders whose ignition timing is to be reached after the fourth time, and thus ignition is prohibited. After the processing of step S36 and step 37, the control unit 50 once ends this processing. As described above, ignition control at the time of automatic restart is executed.

  Next, fuel injection permission conditions during automatic restart will be described with reference to Table 3.

As shown in Table 3, the fuel injection to the cylinder whose ignition timing is first changed at the time of automatic restart is such that the permission condition is an index value “0” or more, and the fuel injection of the cylinder whose ignition timing is changed after the second is When the index value is other than “1”, it is permitted. That is, the injection to the cylinder whose ignition timing is to be changed after the second is prohibited only when it is confirmed that the calculated crank angle is not an appropriate value, and this confirmation is not made (index value “ 0 "," 2 "and" 3 "), fuel injection is performed. In the second and subsequent cylinders, the index value “0” is also a condition for permitting fuel injection. Even if it is not confirmed that the calculated crank angle is an appropriate value, the fuel value is Injection will be permitted. However, even if the fuel injection is executed at an inappropriate time, the subsequent ignition is executed on the condition that the calculated crank angle is at an appropriate value, so that inappropriate combustion does not occur. . In the case of the index value “1”, since it has already been confirmed that the calculated crank angle is not an appropriate value, inappropriate fuel injection based on the calculated crank angle is executed. In order to suppress this, fuel injection is prohibited.

  The fuel injection at the time of automatic restart is executed according to the processing procedure shown in the flowchart of FIG. 6 based on the permission conditions shown in Table 3. This process is executed by the control unit 50 as an interrupt process at predetermined intervals when the ignition switch is in the on state.

  As shown in FIG. 6, when this process is started, first, in step S41, it is determined whether or not it is an automatic restart time. The determination in step S41 is performed in the same manner as in step S11 in FIG. When it is determined in step S41 that it is not during automatic restart (step S41: NO), the control unit 50 ends this process. That is, when it is not at the time of automatic restart, it is not necessary to perform fuel injection control at the time of automatic restart, and thus this processing ends.

  On the other hand, when it is determined in step S41 that the automatic restart is being performed (step S41: YES), the process proceeds to step S42, and it is determined whether or not it is the time for determining the fuel injection in the cylinder whose ignition timing is initially set. Determined. If an affirmative determination is made in step S42 (step S42: YES), the process proceeds to step S47 and fuel injection is permitted. That is, the control unit 50 determines the fuel injection timing based on the crank angle calculated using the crank angle stored at the time of the last automatic stop, and performs the in-cylinder injection valve to execute the fuel injection at that timing. 11 outputs a drive command. And the control part 50 once complete | finishes this process.

  On the other hand, if it is determined in step S42 that it is not the time of fuel injection determination in the cylinder whose ignition timing is first changed (step S42: NO), the time of fuel injection determination in the cylinder whose ignition timing is changed after the second time is determined. It is determined whether or not. If a negative determination is made in step S42 (step S43: NO), the control unit 50 once ends this process because it is not the time of determination of fuel injection.

  On the other hand, if an affirmative determination is made in step S43 (step S43: YES), since it is the time of determination of fuel injection in the cylinder that changes the ignition timing after the second, the process proceeds to step S44, and the index value of the crank angle confirmation situation Is determined to be “1”. That is, as shown in Table 3, in the cylinders whose ignition timings are to be changed after the second, the permission condition for fuel injection is determined to be other than the index value “1”. Therefore, in step S44, it is determined whether or not this permission condition is satisfied. If it is determined in step S44 that the index value is “1” (step S44: YES), the process proceeds to step S46, and the fuel injection permission condition is not satisfied, and thus fuel injection is prohibited. On the other hand, if it is determined in step S44 that the index value is not “1” (step S44: NO), the process proceeds to step S45, where fuel injection is permitted. That is, the control unit 50 determines the fuel injection timing based on the calculated crank angle, and outputs a drive command to the in-cylinder injection valve 11 to execute fuel injection at that timing. And the control part 50 once complete | finishes this process after the process of step S45 or step 46. FIG. As described above, fuel injection control during automatic restart is executed.

Next, the operation of this embodiment will be described.
In the present embodiment, the first ignition at the start of the engine uses the crank angle stored when the crankshaft 20 is stopped with the automatic stop for the cylinder that can cause the first explosion earliest. It is executed based on the calculated crank angle. In addition, for cylinders whose ignition timing is set after the cylinder that first ignited when starting the engine, the calculation is performed when it is confirmed that the calculated crank angle is an appropriate value. Ignition based on the crank angle is performed. On the other hand, when it is not confirmed that the calculated crank angle is at an appropriate value, ignition is prohibited.

In the embodiment described above in detail, the following effects can be obtained.
(1) If there is no deviation between the stored crank angle and the actual crank angle when the engine is stopped, the first ignition is performed at an appropriate time by using the stored crank angle. It is possible to generate early and realize early start.

  Further, in the present embodiment, it is a condition that it is confirmed that the calculated crank angle, that is, the estimated value of the crank angle is an appropriate value for the cylinder whose ignition timing is to be set for the second and subsequent cylinders. The ignition is prohibited when it is permitted and is not confirmed. Therefore, even if the first ignition is executed at an inappropriate time based on a crank angle that is not at an appropriate value, the next ignition can be suppressed from being executed at an inappropriate time. In this way, it is possible to suppress the inappropriate ignition from being continuously performed when the engine is started.

  When ignition is performed at an inappropriate time in each cylinder, torque that acts in the reverse rotation direction on the crankshaft 20 may be generated by this ignition. In this regard, in the case of the compression stroke injection start in which the fuel injection and ignition from the in-cylinder injection valve 11 are performed on the cylinder in the compression stroke, the first ignition is often the cylinder that has stopped in the compression stroke. Is executed against. Therefore, even if the amount of air in the cylinder is small compared to the second and subsequent combustion in which the combustion is performed through the intake stroke, and if a torque in the reverse rotation direction acts on the crankshaft 20 due to ignition at an incorrect timing, The torque is often small. Therefore, even if the initial ignition using the crank angle when the engine is stopped is performed at an inappropriate time, the reverse rotation of the crankshaft 20 can be suppressed by driving the crankshaft 20 by the starter 14. That is, even when the first ignition is performed at an inappropriate time, the problem caused by the ignition is not so great. When the ignition is performed at an appropriate time, an early start can be realized.

  On the other hand, in the cylinder that changes the ignition timing following the cylinder that executed the first ignition, the compression stroke is changed after the intake stroke and the ignition timing is changed. Therefore, the reverse rotation torque generated when improper ignition is performed growing. In this regard, in the present embodiment, in the cylinder in which the ignition timing is set subsequent to the cylinder in which the initial ignition is performed, the ignition is performed when it is not confirmed that the calculated crank angle is an appropriate value. Not executed. Therefore, it is possible to suppress a large reverse rotational torque from acting on the crankshaft 20 due to inappropriate ignition.

As described above, early start-up can be completed and inappropriate ignition can be suppressed from being continuously performed.
(2) When the calculated crank angle is updated to the specified value by detecting the missing tooth portion 23, the calculated crank angle is a value that matches the actual crank angle. Therefore, when the missing tooth portion 23 is detected, it can be confirmed that the crank angle calculated based on that is at an appropriate value. In the present embodiment, the index value is set to “3” after the crankshaft 20 has been rotated by an amount of rotation that is estimated to have detected the missing tooth portion 23 as the engine is started. Yes. Therefore, using the relationship between the detection of the missing tooth portion 23 and the crank angle update as described above, it is confirmed that the crank angle is an appropriate value based on the index value being “3”. Can do.

  (3) The amount of rotation that the crankshaft 20 is estimated to have detected the missing tooth portion 23 as the engine is started by the time of the ignition determination in the cylinder that takes the third ignition timing during automatic restart. Since it is not rotating, the missing tooth portion 23 may not be detected. Therefore, until the second and third cylinders have the ignition timing, the ignition permission condition is set to the index value “2” or more, and the crank angle value calculated when the cam signal output is switched is within the specified range. That is, ignition is permitted even when the output is within the allowable range including the crank angle that should be calculated when the output of the cam signal is switched. Therefore, it is possible to confirm that the crank angle is approximately an appropriate value and allow ignition until the missing tooth portion 23 is detected.

  On the other hand, the crankshaft 20 has been rotated by an amount of rotation that is estimated to have detected the missing tooth portion 23 by the time of ignition determination in the cylinder that takes the fourth ignition timing during automatic restart. It can be estimated that the missing tooth portion 23 has already been detected and the calculated estimated value of the crank angle has been updated to the specified value when the missing tooth portion 23 is detected. In this respect, in the present embodiment, ignition based on the estimated value of the crank angle is executed on the condition that the missing tooth portion 23 is detected for the fourth and subsequent cylinders whose ignition timing is set. According to such a configuration, in a situation where the missing tooth portion 23 should be detected if no abnormality has occurred, confirmation is made on the condition that the missing tooth portion 23 is detected more accurately than the confirmation using the cam signal. As a result, the accuracy of checking the crank angle can be increased.

  (4) In the present embodiment, the crank angle value calculated when the cam signal output from the cam angle sensor 76 is switched between the H signal and the L signal is outside the specified range. Confirm that the calculated crank angle is not an appropriate value. Then, when it is confirmed in the compression stroke injection start that the calculated crank angle is not an appropriate value, the control unit 50 performs the ignition following the cylinder that performed the first ignition with the engine start. Fuel injection is prohibited for cylinders that are ready for timing. Therefore, it is possible to suppress execution of inappropriate fuel injection.

(Second Embodiment)
Next, a second embodiment of the control device for an internal combustion engine will be described with reference to FIG. 1 and FIGS.

In the present embodiment, in addition to the control of the first embodiment, control for switching the fuel injection mode is performed based on the fuel pressure supplied to the in-cylinder injection valve 11 at the time of automatic restart.
That is, when the pressure in the delivery pipe that supplies fuel to the in-cylinder injection valve 11 during the automatic stop decreases, the fuel injection in the compression stroke cannot be properly executed during the automatic restart. Note that the fuel supply pipe is provided with a check valve so that the pressure of the delivery pipe is maintained above the lower limit pressure at which in-cylinder injection can be performed even during automatic stop. When the fuel in the delivery pipe leaks over a long period of time, there may be a situation in which the pressure of the delivery pipe becomes less than the lower limit pressure.

  Therefore, the control device of the present embodiment includes a pressure sensor 79 that detects the pressure in the delivery pipe, as indicated by a broken line in FIG. When the pressure in the delivery pipe detected by the pressure sensor 79 becomes less than the lower limit pressure, the control unit 50 prohibits the compression stroke injection start and fuels the cylinder in the intake stroke. The in-cylinder injection valve 11 and the spark plug 12 are controlled so that the ignition is executed after the injection is performed and the intake stroke injection start that causes the initial explosion is executed. The lower limit pressure is set to a pressure that is slightly higher than the lower limit pressure at which fuel injection can actually be performed in the compression stroke.

  Further, when the pressure in the delivery pipe is equal to or higher than the lower limit pressure for executing fuel injection in the compression stroke, fuel injection in the compression stroke is executed at the time of automatic restart. Based on the permission conditions shown in Fig. 5, control is performed by partially changing the flowcharts of Figs.

  Specifically, in step S31 in FIG. 5, only the determination as to whether or not it is during automatic restart is performed. However, in the present embodiment, it is determined whether or not it is during automatic restart due to compression stroke injection. The That is, in conjunction with the determination of whether or not it is during automatic restart, when the pressure sensor 79 detects that the pressure of the delivery pipe is equal to or higher than the lower limit pressure, the control unit 50 determines the start by the compression stroke injection. A determination is made whether or not. The other steps are the same as those described above with reference to FIG. Also in step S41 in FIG. 6, it is determined whether or not it is during automatic restart by compression stroke injection. And since it is the same as the content demonstrated based on FIG. 6 previously in another step, description is abbreviate | omitted.

  Table 4 shows the conditions for permitting ignition when the intake stroke injection is performed during the automatic restart, that is, when the intake stroke injection is started.

As shown in Table 4, when the intake stroke injection start is performed, the permission condition is set to the index value “2” or more from the time of the first ignition determination. This is due to the following reason. That is, in the case of the intake stroke injection start, since the air-fuel mixture that is homogeneously mixed through the intake stroke is ignited, the torque obtained is larger than that in the initial explosion by the compression stroke injection start. Therefore, in the case of the intake stroke injection start, the reverse rotation torque generated when improper ignition is performed increases. Therefore, when the intake stroke injection start is executed, the execution of ignition is prohibited until it is confirmed that the estimated value of the crank angle calculated by the above mode is an appropriate value. As a result, ignition is not performed even for the cylinder that can cause the first explosion as soon as it is confirmed that the calculated crank angle is an appropriate value. As a result, it is possible to suppress a large reverse rotation torque from acting on the crankshaft 20. For these reasons, when the compression stroke injection start is performed, the first ignition permission condition is set to the index value “0” or more, whereas when the intake stroke injection start is performed, the index value “ 2 ”or higher.

The setting mode of the ignition permission conditions in Table 4 will be described with reference to FIG.
FIG. 7 shows the relationship between the stroke of each cylinder and the crank angle. The timing at which the cam signal switching is detected and the timing at which the missing tooth portion 23 is detected are shown in the same manner as in FIG. Show. Further, the first fuel injection at the time of automatic restart is executed after 120 ° CA of the intake top dead center in the cylinder in the intake stroke (broken line arrow), and subsequently in the cylinder for which the ignition timing is set, the intake top dead center is set. Fuel injection is performed after 60 ° CA. FIG. 7 shows only the injection timing when the fuel injection is first performed in each cylinder. In each cylinder, the period from the 10 ° CA before compression top dead center (solid arrow) to the compression top dead center of 10 ° CA is the energization timing of the spark plug 12.

  In the start of the intake stroke injection, the first fuel injection timing is set to 120 ° CA after the intake top dead center for the following reason. That is, when the fuel injection timing is set immediately after the intake top dead center, even if there is a cylinder stopped in the intake stroke at the start of automatic restart, the crank angle at the stop position already corresponds to the fuel injection timing. There is also a high possibility that the angle is retarded from the crank angle, and the first fuel injection may not be executed for the cylinder. Therefore, in such a case, the first explosion cannot be caused early. On the other hand, if the fuel injection timing is in the vicinity of the intake bottom dead center, the injected fuel is not homogenized well, and the combustion state of the first explosion is deteriorated. Therefore, in the present embodiment, the fuel injection timing is set to the intake top dead center in order to execute the first fuel injection as much as possible while maintaining good fuel homogenization for the cylinders stopped in the intake stroke. After 120 ° CA.

  In FIG. 7, for example, when the crankshaft 20 stops due to automatic stop, any cylinder stops on the advance side of the fuel injection timing in the intake stroke (before 110 ° CA before the intake top dead center). In this case, the first fuel injection and ignition can be performed on the cylinders that are stopped in the intake stroke. Therefore, if fuel injection and ignition are performed on a cylinder that is stopped in the intake stroke, the first initial explosion can be caused the earliest, so in this embodiment, the intake top dead center is 110 ° in the intake stroke. If there is a cylinder that is stopped before the CA, this cylinder is the cylinder that first determines the fuel injection timing and ignition timing. In addition, when the cylinder stopped in the intake stroke is stopped at the fuel injection timing or at the retarded angle side (after 120 ° CA after the intake top dead center), the first fuel injection is performed. Since this cannot be performed on the cylinder, the cylinder that is the next in the intake stroke is the cylinder that first determines the fuel injection timing and the ignition timing. In the following description, the cylinder that first enters the intake stroke after the cylinder that changes the fuel injection timing and ignition timing and then changes the ignition timing will be described as “the cylinder that changes the ignition timing second”.

  As described with reference to Table 4, the ignition permission condition in all the cylinders is set to an index value “2” or more so as to suppress the generation of a large reverse rotation torque due to the intake stroke injection. Specifically, since the ignition permission condition is set to the index value “2” or more for the cylinders whose ignition timing is first and second, the ignition is permitted while the index value “2” or more is calculated. Ignition is prohibited when it is not confirmed that the crank angle is at an appropriate value. Further, for the cylinders whose ignition timing is to be reached after the third, since the ignition permission condition is set to the index value “3”, the ignition is permitted at the index value “3” and the missing tooth portion 23 is not detected. In situations, ignition is prohibited.

  For the cylinders whose ignition timing is to be changed from the third onward, the ignition permission condition is set to the index value “3”. In this embodiment, the third ignition timing is the latest at the latest unless the crank angle sensor 75 is abnormal. This is because the missing tooth portion 23 is detected and the calculated crank angle is updated based on the detection of the missing tooth portion 23. The reason why the missing tooth portion 23 is detected by the third ignition timing at the latest is that the missing tooth portion 23 is reached by the ignition timing of the cylinder that changes the ignition timing fourth in the first embodiment in the case of the compression stroke injection start. The reason is the same as the reason described as the reason for detecting the error.

  That is, as shown in FIG. 7, for example, when the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 is detected in the compression stroke of the third cylinder, so that the ignition is performed second. The missing tooth portion 23 is detected before the ignition timing of the fourth cylinder for which the timing is reached. In addition, when the cylinder whose ignition timing is first changed is the second cylinder, the missing tooth portion 23 is detected in the compression stroke of the second cylinder, so the ignition timing of the first cylinder whose timing is changed second. By this time, the missing tooth portion 23 is detected. On the other hand, if the first cylinder whose ignition timing is changed is the first cylinder and the stop position at the start of automatic restart is a crank angle after 450 ° CA, the second cylinder whose ignition timing is changed is second. The missing tooth portion 23 cannot be detected by the ignition timing of the third cylinder, but the missing tooth portion 23 can be detected by the ignition timing of the fourth cylinder that changes the ignition timing third. Similarly, even when the cylinder whose ignition timing is initially changed is the fourth cylinder, the missing tooth portion 23 may not be detected by the ignition timing of the second cylinder whose ignition timing is changed second, but third. The missing tooth portion 23 can be detected before the ignition timing of the first cylinder that changes the ignition timing. Therefore, at the start of intake stroke injection in the present embodiment, the missing tooth portion 23 is detected by the third ignition timing at the latest unless an abnormality or the like of the crank angle sensor 75 occurs. The ignition permission condition in the cylinder that is in the third intake stroke is “3”.

  In the present embodiment, as shown in FIG. 7, since the cam signal switching is detected by the first ignition timing, when the calculated crank angle is at an appropriate value, Unless the cam angle sensor 76 is abnormal, it is executed from the first ignition.

  Ignition at the time of automatic restart is executed according to the processing procedure shown in the flowchart of FIG. 8 based on the permission conditions shown in Table 4. This process is executed by the control unit 50 as an interrupt process at predetermined intervals when the ignition switch is in the on state.

  As shown in FIG. 8, when this process is started, first, in step S51, it is determined whether or not it is during automatic restart by intake stroke injection. The determination in step S51 is that the automatic restart is being performed, and that the pressure sensor 79 detects that the delivery pipe pressure is less than the lower limit pressure at the start of the restart. An affirmative determination is made on the condition that the start is determined. In step S51, if it is not at the time of automatic restart or if it is the compression stroke injection start even at the time of automatic restart, a negative determination is made (step S51: NO), and the control unit 50 ends this process. . That is, when it is not during automatic restart, ignition control during normal operation is performed, and when it is during automatic restart due to compression stroke injection start, the ignition control shown in FIG. 5 is executed.

  On the other hand, if it is determined in step S51 that the automatic restart is performed by the intake stroke injection (step S51: YES), the process proceeds to step S52, and the ignition is determined in the cylinder whose ignition timing is first or second. It is determined whether or not. If an affirmative determination is made in step S52 (step S52: YES), the process moves to step S56, and it is determined whether or not the index value for crank angle determination is set to “2” or more. That is, as shown in Table 4, the ignition permission condition is the index value “2” or more in the cylinder whose ignition timing is first or second. Therefore, in step S56, it is determined whether or not this permission condition is satisfied. If it is determined in step S56 that the index value is “2” or more (step S38: YES), the ignition permission condition is satisfied, and the process proceeds to step S55, where ignition is permitted. That is, the control unit 50 determines the ignition timing in the cylinder whose ignition timing is first or second based on the calculated crank angle, and the ignition plug 12 so that ignition is executed at the determined timing. A drive command is output to. On the other hand, when it is determined in step S56 that the index value is not “2” or more (step S56: NO), the process proceeds to step S57, and ignition is prohibited. In other words, when the index value is not “2” or more, the ignition permission condition is not satisfied in the cylinders whose ignition timing is first and second, and thus ignition is prohibited. After the processing of step S55 and step 57, the control unit 50 once ends this processing.

  If it is determined in step S52 that it is not the ignition determination time for the cylinder whose ignition timing is changed first or second (step S52: NO), the process proceeds to step S53, and the ignition determination for the cylinder whose ignition timing is changed for the third time and thereafter. It is determined whether or not. If a negative determination is made in step S53 (step S53: NO), the control unit 50 once ends this process because it is not an ignition determination time.

  On the other hand, if it is determined in step S53 that it is the ignition determination time in the cylinder whose ignition timing is to be changed after the third time (step S53: YES), the process proceeds to step S54, and the index value of the crank angle confirmation status is set to “3”. It is determined whether it is set. In other words, as shown in Table 2, the ignition permission condition is the index value “3” in the third and subsequent cylinders whose ignition timing is to be changed. Therefore, in step S54, it is determined whether or not this permission condition is satisfied. If it is determined in step S54 that the index value is “3” (step S54: YES), the ignition permission condition is satisfied, and thus the process proceeds to step S55, where ignition is permitted. That is, the control unit 50 determines the ignition timing in the cylinder whose ignition timing is to be changed from the third onward based on the calculated crank angle, and the ignition plug 12 is ignited so that ignition is executed at the determined timing. A drive command is output. On the other hand, when it is determined in step S54 that the index value is not “3” (step S38: NO), the process proceeds to step S57, and ignition is prohibited. That is, when the index value is not “3”, the ignition permission condition is not satisfied in the cylinder whose ignition timing is to be reached after the third time, and thus ignition is prohibited. After the processing of step S36 and step 37, the control unit 50 once ends this processing.

  As described above, the intake stroke injection start is executed only when it is confirmed that the calculated crank angle is an appropriate value (index value “2” or “3”) from the first ignition. Is allowed. The third and subsequent ignitions are executed only when the missing tooth portion 23 is detected (index value “3”). Therefore, when the intake stroke injection is performed at the time of automatic restart, the execution of ignition is prohibited until it is confirmed that the calculated crank angle is an appropriate value. When the permission conditions shown in Table 4 are not satisfied, ignition in the cylinder is prohibited.

  Table 5 shows the fuel injection permission conditions at the start of the intake stroke injection.

As shown in Table 5, the fuel injection condition is set to other than “1” at the start of the intake stroke injection. That is, at the time of automatic restart by intake stroke injection, if it is confirmed that the calculated crank angle is not an appropriate value from the first fuel injection, fuel injection is prohibited, and this confirmation is made. When there is no index (index values “0”, “2” and “3”), fuel injection is performed. Therefore, when the calculated crank angle is an inappropriate value, it is possible to suppress the fuel injection from being executed based on the crank angle. Thereby, it is possible to suppress the occurrence of a large reverse rotation torque due to the fuel injection being performed at an inappropriate time from the first time.

  The fuel injection at the time of automatic restart is executed according to the processing procedure shown in the flowchart of FIG. 9 based on the permission conditions shown in Table 5. This process is executed by the control unit 50 as an interrupt process at predetermined intervals when the ignition switch is in the on state.

  As shown in FIG. 9, when this process is started, first, in step S61, it is determined whether or not it is during automatic restart by intake stroke injection. In step S61, the same determination as in step S51 of FIG. 8 is performed. Therefore, in step S61, if it is not at the time of automatic restart, or if the compression stroke injection is started even at the time of automatic restart, a negative determination is made (step S61: NO), and the control unit 50 performs the main determination. The process ends.

  On the other hand, when it is determined in step S61 that it is an automatic restart due to the intake stroke injection start (step S61: YES), the process proceeds to step S62, and it is determined whether or not it is a fuel injection determination time in each cylinder. . If a negative determination is made in step S62 (step S62: NO), the control unit 50 once ends this process because it is not the ignition determination time.

  On the other hand, if it is determined in step S62 that it is time to determine the fuel injection in each cylinder (step S62: YES), the process proceeds to step S63, and it is determined whether or not the index value of the crank angle confirmation status is “1”. Is done. That is, as shown in Table 5, in all cylinders, the fuel injection permission condition is to be other than the index value “1”. Therefore, in step S63, it is determined whether or not this permission condition is satisfied. If it is determined in step S63 that the index value is “1” (step S63: YES), the fuel injection permission condition is not satisfied, so the routine proceeds to step S65, where fuel injection is prohibited. On the other hand, when it is determined in step S63 that the index value is not “1” (step S63: NO), the process proceeds to step S64 and fuel injection is permitted. That is, the control unit 50 determines the fuel injection timing based on the calculated crank angle, and outputs a drive command to the in-cylinder injection valve 11 to execute fuel injection at that timing. And after the process of step S64 or step 65, the control part 50 once complete | finishes this process. As described above, fuel injection control during automatic restart is executed.

Next, the operation of this embodiment will be described.
In the present embodiment, when the intake stroke injection start is executed, the execution of ignition is prohibited until the control unit 50 confirms that the calculated crank angle is at an appropriate value. Therefore, until the confirmation that the calculated crank angle is an appropriate value is made, ignition is not performed even for the cylinder that can cause the first explosion earliest.

In the embodiment described above in detail, in addition to the effects (1) to (4) described in the first embodiment, the following effects can be obtained.
(5) When performing the intake stroke injection start, even for the cylinder that can cause the first explosion the earliest until confirmation that the calculated crank angle is an appropriate value is made. Since the ignition is not performed, it is possible to suppress an inappropriate ignition and a large reverse rotation torque from acting on the crankshaft 20.

  (6) When the pressure of the fuel supplied to the in-cylinder injection valve 11 is less than the lower limit pressure for executing fuel injection in the compression stroke, the control unit 50 prohibits the compression stroke injection start and performs intake. Control is performed so that the stroke injection start is executed. Therefore, even when the pressure is less than the lower limit pressure for executing fuel injection in the compression stroke, the internal combustion engine 10 can be started by executing fuel injection when starting the engine.

  (7) When performing the intake stroke injection start that causes the first explosion, the first explosion occurs the earliest, provided that it is confirmed that the calculated crank angle is not an appropriate value. The fuel injection to the cylinders that can be made is also prohibited. Therefore, it is possible to suppress the occurrence of a large reverse rotation torque due to the execution of injection or ignition at an inappropriate time from the first time.

(Modification of the second embodiment)
In the second embodiment, fuel injection is performed by the in-cylinder injection valve 11 even when the intake stroke injection is started.

  Instead, in this modification, as shown by a broken line in FIG. 1, the internal combustion engine 10 also includes a port injection valve 15 that injects fuel into the intake port, and the pressure of the fuel supplied to the in-cylinder injection valve 11 Is less than the lower limit pressure, the intake stroke injection start in which fuel is injected by the port injection valve 15 is executed.

Other operations and configurations are the same as those of the second embodiment.
Even when such a configuration is adopted, the same effects as those of the second embodiment can be obtained.

(Third embodiment)
Next, a third embodiment of the control device for an internal combustion engine will be described with reference to FIGS.
The internal combustion engine to which the control device of this embodiment is applied is a V-type 6-cylinder gasoline engine provided with an in-cylinder injection valve, and compression stroke injection is performed during automatic restart. Since the internal combustion engine of this embodiment is a V-type engine, it has two banks, a right bank and a left bank. In the present embodiment, the same components as those in the first embodiment will be described using the same reference numerals. Further, the configuration that is not particularly described is the same as that of the first embodiment.

  The crank rotor 21 of the present embodiment has the same configuration as that of the first embodiment, and includes a plurality of protrusions 22 formed at intervals of 10 ° on the outer periphery thereof, and three protrusions 22 provided at one position on the outer periphery. And a missing tooth portion 23 having a width corresponding to the width of the toothed portion. However, as will be described later, since the crank angle at which the missing tooth portion 23 is provided is different from that in the first embodiment, the crank angle at which the missing tooth portion 23 is detected is different from that in the first embodiment.

  As shown in FIG. 10, the right bank and the left bank are provided with exhaust cam shafts (hereinafter simply referred to as “cam shafts”) 80 and 90, respectively, and two exhaust cam angle sensors (hereinafter simply referred to as “cams”). 88 and 98 (referred to as "angle sensors") output cam signals corresponding to changes in the rotation angles of the cam shafts 80 and 90 of each bank. The cam rotors 81 and 91 provided on the cam shafts 80 and 90 of each bank have the same shape, but are different from the cam rotor 31 of the first embodiment. As shown in FIG. 10, since the shape of each cam rotor 81, 91 is the same, only the cam rotor 81 in the right bank will be described.

  The cam rotor 81 includes three convex portions (protrusions) 82, 83, 84 having different occupying ranges in the circumferential direction, and the convex portions 82, 83, 84 located between the convex portions 82, 83, 84. Concave portions (portions having no protrusions) 85, 86, and 87 that are recessed with respect to 84 are provided.

  The largest first convex portion 82 is formed so as to spread over 90 ° in the circumferential direction of the cam rotor 81. On the other hand, the smallest second convex portion 83 is formed so as to spread over 30 ° as an angle, and the third convex portion 84 is formed so as to spread over 60 °. The first concave portion 85 between the first convex portion 82 and the second convex portion 83 is provided over 30 ° in the circumferential direction of the cam rotor 81, and the second convex portion 83 and the third convex portion 83 are provided. The second concave portion 86 between the convex portion 84 is provided over 90 ° in the circumferential direction of the cam rotor 81. The third concave portion 87 between the first convex portion 82 and the third convex portion 84 is provided over 60 ° in the circumferential direction of the cam rotor 81.

  The left bank cam rotor 91 is attached to the right bank cam rotor 81 with the rotational phase shifted by 60 ° retarded. As a result, the signal output from the cam angle sensor 98 in the left bank is delayed by 120 ° CA with respect to the signal output from the cam angle sensor 88 in the right bank.

  Also in the present embodiment, the control unit 50 calculates the crank angle calculated based on the signal output from the crank angle sensor 75 and the cam signals output from the cam angle sensors 88 and 98 as the confirmation unit and the abnormality confirmation unit. Confirm that the estimated value is at an appropriate value and not at an appropriate value. With reference to FIG. 11, the crank signal output from the crank angle sensor 75, the calculated crank angle based on the crank signal, and the cam signals output from the cam angle sensors 88 and 98 will be described.

  As shown in FIG. 11A, in this embodiment, every time the crankshaft 20 rotates by 10 ° CA, the crank angle sensor 75 outputs a pulse signal corresponding to the protrusion 22 of the crank rotor 21. Further, the case where the crank angle is 180 to 200 ° CA and the case where the crank angle is 540 to 560 ° CA correspond to the missing tooth portion 23 of the crank rotor 21. That is, since the missing tooth portion 23 is provided at one place on the outer periphery of the crank rotor 21, as shown in FIG. 11A, a pulse signal is output every 360 ° CA in which the crankshaft 20 makes one rotation. A period corresponding to the missing tooth portion 23 in which the interval becomes longer appears.

  Then, as shown in FIG. 11B, the crank angle is incremented by 10 ° CA according to the output of the pulse signal, and when the missing tooth portion 23 is detected, the calculated crank angle is The crank angle is updated to a specified value that should be calculated when the missing tooth portion 23 is detected. Specifically, in the present embodiment, it is calculated at 230 ° CA and 570 ° CA after 30 ° CA from the crank angle (180 to 200 ° CA, 540 to 560 ° CA) at which the missing tooth portion 23 is provided. The crank angle is updated. That is, when the pulse signal that has been continuously output is not output for 30 ° CA, and the pulse signal is output three times thereafter, the missing tooth portion 23 is detected based on the pulse signal and is calculated at that time. The crank angle is updated to the crank angle (230 ° CA, 570 ° CA) when the missing tooth portion 23 is detected. As described above, if the missing tooth portion 23 is detected when the pulse signal is output three times from the situation where the pulse signal is not output by 30 ° CA, the engine start in which the rotational speed of the crankshaft 20 is likely to change is started. Even at times, the missing tooth portion 23 can be detected more accurately.

  When the calculated crank angle value is counted up to 710 ° CA according to the output of the pulse signal, the calculated crank angle value is reset to 0 ° CA by the output of the next pulse signal. In the present embodiment, the crank angle is calculated in this way.

  Also in the present embodiment, every time the rotation of the crankshaft 20 stops with the automatic stop, the crank angle calculated at that time is stored in the RAM of the control unit 50. By doing so, the crank angle when the rotation of the crankshaft 20 is stopped when the automatic stop is last performed at the time of the next automatic restart is stored. Therefore, at the time of automatic restart, the stored crank angle becomes an initial value, and the crank angle is calculated by adding 10 ° CA each time a pulse signal is output. After that, when the missing tooth portion 23 is detected, the crank angle is updated to a specified value of the crank angle when the missing tooth portion 23 is detected.

  Further, as shown in FIG. 11C, the cam angle sensors 88 and 98 corresponding to the right bank and the left bank alternately output the H signal and the L signal cam signal. Similar to the cam signal in the first embodiment, the H signal corresponds to the convex portions 82, 83, 84, 92, 93, 94 of the cam rotors 81, 91, and the L signal corresponds to each of the cam rotors 91. It corresponds to the recesses 85, 86, 87, 95, 96, 97. The camshafts 80 and 90 are connected to the crankshaft 20 via a timing chain or the like, and rotate once every time the crankshaft 20 rotates twice. Therefore, the H signal is output for a crank angle that is twice the circumferential angle of each convex portion 82, 83, 84, 92, 93, 94 of each cam rotor 81, 91. Further, the L signal is output for a crank angle that is twice the circumferential angle of each recess 85, 86, 87, 95, 96, 97 of each cam rotor 81.

  More specifically, the right bank cam signal is output as an H signal corresponding to 180 ° CA of 150 to 330 ° CA, with the H signal corresponding to the first convex portion 82 of the right bank cam rotor 81 being the first concave portion. The L signal corresponding to 85 is output as an L signal corresponding to 60 ° CA of 330 to 390 ° CA. The H signal corresponding to the second convex portion 83 is output as an H signal corresponding to 60 ° CA of 390 to 450 ° CA, and the L signal corresponding to the second concave portion 86 is 180 ° of 450 to 630 ° CA. It is output as an L signal for CA. The H signal corresponding to the third convex portion 84 is output as an H signal corresponding to 120 ° CA of 630 to 30 ° CA, and the L signal corresponding to the third concave portion 87 is 120 ° of 30 to 150 ° CA. It is output as an L signal for CA.

  As described above, the left bank cam signal is output as a waveform having a 120 ° CA phase delay with respect to the right bank cam signal. Therefore, the left bank cam signal is output as an H signal corresponding to 180 ° CA of 270 to 450 ° CA corresponding to the first convex portion 92 of the left bank cam rotor 91, and is output to the first concave portion 95. The corresponding L signal is output as an L signal corresponding to 60 ° CA of 450 to 510 ° CA. The H signal corresponding to the second convex portion 93 is output as an H signal corresponding to 60 ° CA of 510 to 570 ° CA, and the L signal corresponding to the second concave portion 96 is 180 ° of 570 to 30 ° CA. It is output as an L signal for CA. The H signal corresponding to the third convex portion 94 is output as an H signal corresponding to 120 ° CA of 30 to 150 ° CA, and the L signal corresponding to the third concave portion 97 is 120 ° of 150 to 270 ° CA. It is output as an L signal for CA.

  Here, as described above, since the camshaft 30 is connected to the crankshaft 20 via a timing chain or the like, there is a certain correlation between the cam signal and the crank angle, and the H signal of the cam signal. And the crank angle value when the L signal is switched become a specific value. The ROM of the control unit 50 includes a crank angle (right bank H → L: 30 ° CA, 330 ° CA, 450 ° CA, right bank L → H: 150 ° CA, 390) when the H signal and the L signal are switched. (° CA, 630 ° CA, left bank H → L: 150 ° CA, 450 ° CA, 570 ° CA, left bank L → H: 30 ° CA, 270 ° CA, 510 ° CA) are stored in advance. Therefore, when the switching of the cam signal is detected, the calculated crank angle value is within the specified range, that is, the crank angle that should be calculated when the cam signal output is switched (the crank angle stored in the ROM). In the allowable range including the angle), it can be estimated that the calculated crank angle is at an appropriate value. On the other hand, if the calculated crank angle is not within the specified range when a cam signal change is detected, it is estimated that the calculated crank angle is not an appropriate value. Can do.

  Here, when the calculated crank angle is updated by detection of the missing tooth portion 23, it can be confirmed that the calculated crank angle is at an appropriate value. Further, by detecting the switching between the H signal and the L signal of the cam signal, it can be confirmed whether or not the calculated crank angle is at an appropriate value. Therefore, in the present embodiment, the control unit 50 confirms that the calculated crank angle is an appropriate value based on the signal output from the crank angle sensor 75 and the signals output from the cam angle sensors 88 and 98. And confirming that the calculated crank angle is not an appropriate value based on the signal output from the cam angle sensor 76.

  Also in this embodiment, at the time of automatic restart, the index value of the crank angle confirmation status is set in the same manner as in Table 1 of the first embodiment. In the present embodiment, when setting the index value of the crank angle confirmation status based on the cam signal, the cam signals of both the right bank and the left bank are used. That is, although the setting of the index value is performed in the same manner as the execution procedure shown in the flowchart of FIG. 3, it is determined in step S17 whether or not a cam signal is detected in at least one bank. Then, based on the calculated crank angle and the presence or absence of switching of the cam signal in both banks, it is determined whether or not the crank angle is an appropriate value.

  That is, if it is determined in step S17 that switching of at least one cam signal has been detected (step S17: YES), the process proceeds to step S18, and the calculated crank angle is within the specified range, that is, the cam signal. It is determined whether or not it is within an allowable range including the crank angle that should be calculated when the change of the engine is detected. In the present embodiment, this allowable range is set to ± 20 ° CA. When switching is detected only in the cam signal of the right bank, it is allowed when the crank angle calculated in 10 ° CA increments is 310 to 340 ° CA, 370 to 400 ° CA, 610 to 640 ° C. A determination is made that it is within range. Further, when switching is detected only in the cam signal of the left bank, it is allowed when the crank angle calculated in increments of 10 ° CA is 250 to 280 ° CA, 490 to 520 ° CA, 550 to 580 ° CA. A determination is made that it is within range. When switching of the cam signals of both the right bank and the left bank is detected, the crank angles calculated in increments of 10 ° CA are 10 to 40 ° CA, 130 to 160 ° CA, 430 to 460 ° CA. At some point, a determination is made that it is within an acceptable range.

As described above, also in the present embodiment, the index value of the crank angle confirmation status is set at the time of automatic restart.
Table 6 shows the conditions for permitting ignition during automatic restart in the present embodiment. The setting mode of the ignition permission conditions in Table 6 will be described with reference to FIG.

FIG. 12 shows the relationship between the stroke of each cylinder and the crank angle. The time indicated by the solid arrow AR indicates the crank angle at which the switching of the right bank cam signal from the L signal to the H signal is detected. The time indicated by the solid arrow BR indicates the crank angle at which switching of the right bank cam signal from the H signal to the L signal is detected. The time indicated by the solid line arrow AL indicates the crank angle at which switching from the L signal of the left bank cam signal to the H signal is detected, and the time indicated by the solid line arrow BL indicates the H signal of the left bank cam signal. The crank angle at which switching to the L signal is detected is shown. A crank angle in a range indicated by an arrow C corresponds to the missing tooth portion 23, and a crank angle indicated by a broken arrow D after 30 ° CA is a crank angle at which the missing tooth portion 23 is detected. In each cylinder, the fuel injection timing is 30 ° CA before the compression top dead center (broken arrow), and the compression top dead center is 10 ° CA from 10 ° CA before the compression top dead center (solid arrow). The period until is the energization timing of the spark plug 12.

  In FIG. 12, for example, when the crankshaft 20 is stopped due to automatic stop, the cylinder stopped in the compression stroke is advanced from the fuel injection timing (before 40 ° CA before the compression stroke top dead center). ), The first fuel injection and ignition can be performed on the cylinders stopped in the compression stroke. Therefore, if fuel injection and ignition are performed on the cylinders that are stopped in the compression stroke, the first explosion can be caused the fastest. In this embodiment, 40 ° CA or more from the top dead center in the compression stroke. If there is a cylinder that is stopped in front, the first fuel injection and ignition are performed on this cylinder. In addition, when the cylinder stopped in the compression stroke is stopped at the fuel injection timing or at a retarded angle side (after 30 ° CA before compression top dead center), the first fuel injection is performed for the cylinder. Can not be done. For this reason, in this case, the cylinder for which the ignition timing is set next becomes the cylinder that causes the first explosion earliest, and the first fuel injection and ignition are executed for the cylinder. In the following description, the cylinder in which the first fuel injection and ignition is performed is referred to as “the cylinder that first determines the ignition timing”, and the cylinder that first performs the compression stroke after the cylinder that first determines the ignition timing. Is described as “the second cylinder for which the ignition timing is to be changed”.

  Then, as shown in Table 6, for the cylinder whose ignition timing is initially set, whether or not the ignition permission condition is set to the index value “0” or more and the calculated crank angle is an appropriate value. Ignition is permitted even if no confirmation is made. In addition, for the cylinders whose ignition timing is second to fourth, since the ignition permission condition is set to the index value “2” or more, the ignition is permitted while the index value “2” or more is permitted. Ignition is prohibited when it is not confirmed that the crank angle is at an appropriate value. For the cylinders whose ignition timing is to be changed after the fifth, since the ignition permission condition is set to the index value “3”, the ignition is permitted at the index value “3” and the missing tooth portion 23 is not detected. In situations, ignition is prohibited.

  For cylinders whose ignition timing is to be changed from the fifth onward, the ignition permission condition is set to the index value “3”. In this embodiment, unless the crank angle sensor 75 is abnormal, the fifth ignition timing is the latest. This is because the missing tooth portion 23 is detected and the calculated crank angle is updated based on the detection of the missing tooth portion 23.

  That is, as shown in FIG. 12, for example, when the cylinder whose ignition timing is first changed is the second cylinder, the missing tooth portion 23 is detected in the compression stroke of the third cylinder whose ignition timing is changed second. Therefore, the missing tooth portion 23 is detected by the third ignition timing in the fourth cylinder. Further, when the cylinder whose ignition timing is first changed is the fifth cylinder, the missing tooth portion 23 is detected in the compression stroke of the sixth cylinder whose ignition timing is changed second, so the third cylinder in the first cylinder is detected. The missing tooth portion 23 is detected by the ignition timing.

  Further, for example, when the first cylinder for which the ignition timing is changed is the first cylinder, the missing tooth portion 23 is detected in the compression stroke of the third cylinder for which the third ignition timing is changed. The missing tooth portion 23 is detected by the first ignition timing. Further, when the cylinder whose ignition timing is first changed is the fourth cylinder, the missing tooth portion 23 is detected in the compression stroke of the sixth cylinder whose ignition timing is changed third, so the fourth cylinder in the first cylinder The missing tooth portion 23 is detected by the ignition timing.

  However, if the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 may not be detected by the fourth ignition timing. This is due to the following reason. For example, when the cylinder whose ignition timing is initially set is the third cylinder, the first explosion occurs in the third cylinder, but when the cylinder is stopped at a crank angle of 150 ° CA or more during automatic stop, the third explosion is performed. The missing tooth portion 23 of 180 to 210 ° CA cannot be detected in the compression stroke of the cylinder. In order to recognize the missing tooth portion 23, the output period of the pulse signal output before that is required to be stable, but immediately after the cranking starts, the engine speed is slow and the pulse signal This is because the output period tends to be longer. When stopping at a crank angle of 150 ° CA or more during automatic stop, the number of times that the pulse signal output until the missing tooth portion 23 is detected is small and the output interval is long. The part 23 cannot be detected accurately. Therefore, when the third cylinder is a cylinder that is initially subjected to ignition timing, the missing tooth portion 23 may not be detected in the compression stroke of the third cylinder. Further, when the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 is detected even at 590 ° CA. However, since this timing is the same as the ignition timing in the sixth cylinder (the timing at which the ignition plug 12 is energized), which is the fourth ignition timing, by the ignition timing of the sixth cylinder, which is the fourth ignition timing. , 540 to 570 ° CA will not be detected. Therefore, when the cylinder whose ignition timing is initially set is the third cylinder, the missing tooth portion 23 may not be detected until the fourth ignition timing. Similarly, when the cylinder whose ignition timing is initially set is the sixth cylinder, the missing tooth portion 23 may not be detected until the fourth ignition timing in the third cylinder. However, even if the first cylinder whose ignition timing is changed is the third cylinder or the sixth cylinder, the crank angle at which the missing tooth portion 23 should be detected before the fifth ignition timing is changed. Will definitely pass. Therefore, in any case, the missing tooth portion 23 is detected and the index value of the crank angle confirmation status is set to “3” until the fifth ignition timing is reached.

  That is, no matter which cylinder is stopped in the compression stroke, the missing tooth portion 23 is detected by the fifth ignition timing at the latest, and if no abnormality has occurred, the crank angle confirmation status is The index value is set to “3”. For this reason, in this embodiment, the ignition permission condition is set to the index value “3” for the cylinders whose ignition timing is to be changed after the fifth.

  In the present embodiment, as described above, the missing tooth portion 23 is detected by the fifth ignition timing. Therefore, if the fifth ignition timing is changed, the crank is increased as the engine starts. The shaft 20 is rotated by an amount of rotation estimated that the detection of the missing tooth portion 23 is completed. Accordingly, the ignition permission condition is set to the index value “2” or more until the rotation of the crankshaft 20 that is estimated to have completed the detection of the missing tooth portion 23 as the engine is started. In other words, the ignition permission condition is set to the index value “3” after the rotation of the crankshaft 20 that is estimated to have completed the detection of the missing tooth portion 23 with the engine start.

  In this embodiment, even if the rotation starts from any stop position, detection of the missing tooth portion 23 can be completed if the crankshaft 20 rotates by 440 ° CA. That is, the most disadvantageous condition in detecting the missing tooth portion 23 is a case where automatic restart is started from a state where it stops before 30 ° CA immediately before the missing tooth portion 23. However, even in this case, after the crank angle sensor 75 outputs the pulse signal twice (20 ° CA), a period (30 ° CA) corresponding to the missing tooth portion 23 appears, and then rotates once. After the period corresponding to the missing tooth portion 23 appears (360 ° CA), the missing tooth portion 23 is detected when the pulse signal is output three times (30 ° CA). During this time, 20 ° CA until the crankshaft 20 reaches the missing tooth portion 23, 30 ° CA until the crankshaft 20 passes through the missing tooth portion 23, and 330 ° corresponding to the interval until the crankshaft 20 reaches the missing tooth portion 23 again. The rotation is 440 ° CA, which includes CA, 30 ° CA that passes through the missing tooth portion 23 again, and 30 ° CA that passes through the missing tooth portion 23 until the pulse signal is output three times. . Therefore, if the crankshaft 20 rotates at least 440 ° CA, it can be estimated that the detection of the missing tooth portion 23 is completed based on this.

  Further, in the present embodiment, as shown in FIG. 12, since the cam signal switching is detected by the ignition timing of the cylinder whose ignition timing is second, the calculated crank angle is appropriate. If the value is in the correct value, the second to fourth ignitions are executed unless the cam angle sensor 76 is abnormal.

  The ignition at the time of automatic restart is executed according to the processing procedure shown in the flowchart of FIG. 13 based on the permission conditions shown in Table 6. This process is executed by the control unit 50 as an interrupt process at predetermined intervals when the ignition switch is in the on state. The flowchart in FIG. 13 is obtained by replacing the determination in step S33 in the flowchart in FIG. 5 with step S71 and replacing the determination in step S34 with step S72. The other steps are the same as those in the flowchart in FIG. Processing is performed.

  As shown in FIG. 13, when this process is started, first, in step S31, it is determined whether or not it is an automatic restart time. The determination in step S31 is performed in the same manner as in step S11 in FIG. If it is determined in step S31 that it is not at the time of automatic restart (step S31: NO), the control unit 50 ends this process.

  On the other hand, when it is determined in step S31 that the automatic restart is being performed (step S31: YES), the process proceeds to step S32, and whether or not it is the ignition determination time in the cylinder that first determines the ignition timing at the time of automatic start. Determined. If an affirmative determination is made in step S32 (step S32: YES), the process proceeds to step S39, where ignition is permitted based on the calculated crank angle, and the control unit 50 once ends this process.

  On the other hand, if it is determined in step S32 that it is not at the time of ignition determination in the cylinder whose timing is initially changed (step S32: NO), the process proceeds to step S71, where ignition is determined in the cylinder whose timing is changed to the second to fourth. It is determined whether it is time. If an affirmative determination is made in step S71 (step S71: YES), the process moves to step S38, and it is determined whether or not the index value for crank angle determination is set to “2” or more. In other words, as shown in Table 6, in the cylinders whose ignition timings are set to the second to fourth and subsequent cylinders, the ignition permission condition is the index value “2” or more. Therefore, in step S38, it is determined whether or not this permission condition is satisfied. If it is determined in step S38 that the index value is “2” or more (step S38: YES), the ignition permission condition is satisfied, and the routine proceeds to step S36, where ignition is permitted. On the other hand, when it is determined in step S38 that the index value is not “2” or more (step S38: NO), the process proceeds to step S37 and ignition is prohibited. That is, when the index value is not “2” or more, the ignition permission condition is not satisfied in the cylinder that changes the ignition timing for the second to fourth times, and thus ignition is prohibited. After the processing of step S36 and step 37, the control unit 50 once ends this processing.

  If it is determined in step S71 that it is not the ignition determination time in the cylinder that changes the ignition timing for the second to fourth times (step S71: NO), the process proceeds to step S72, and the ignition determination time in the cylinder that changes the ignition timing for the fifth time and thereafter. It is determined whether or not. If a negative determination is made in step S72 (step S72: NO), the control unit 50 once ends this process because it is not the ignition determination time.

  On the other hand, in step S72, if it is determined that it is the ignition determination time in the cylinder whose ignition timing is to be changed after the fifth (step S72: YES), the process proceeds to step S35, and the index value of the crank angle confirmation status is set to “3”. It is determined whether it is set. That is, as shown in Table 6, the ignition permission condition is the index value “3” in the cylinders whose ignition timing is to be reached after the fifth. Therefore, in step S35, it is determined whether or not this permission condition is satisfied. If it is determined in step S72 that the index value is “3” (step S35: YES), the ignition permission condition is satisfied, so the routine proceeds to step S36, where ignition is permitted. On the other hand, when it is determined in step S35 that the index value is not “3” (step S38: NO), the process proceeds to step S37 and ignition is prohibited. That is, when the index value is not “3”, the ignition permission condition is not satisfied in the cylinders whose ignition timing is to be reached after the fifth, and therefore ignition is prohibited. After the processing of step S36 and step 37, the control unit 50 once ends this processing. As described above, ignition control at the time of automatic restart is executed.

  Next, fuel injection permission conditions at the time of automatic restart will be described with reference to Table 7.

As shown in Table 7, the fuel injection permission conditions in the present embodiment are the same as the fuel injection permission conditions shown in Table 3 in the first embodiment.

  In other words, the fuel injection to the cylinder whose ignition timing is first changed at the time of automatic restart is set to an index value “0” or higher, and the fuel injection of the cylinder whose ignition timing is changed after the second is set to an index value “1”. It is permitted in cases other than “”. Therefore, the injection to the cylinder whose ignition timing is to be changed after the second time is prohibited only when it is confirmed that the calculated crank angle is not an appropriate value, and this confirmation is not made (index value “ 0 "," 2 "and" 3 "), fuel injection is performed. In the second and subsequent cylinders, the index value “0” is also a condition for permitting fuel injection. Even if it is not confirmed that the calculated crank angle is an appropriate value, the fuel value is Injection will be permitted. However, even if the fuel injection is executed at an inappropriate time, the subsequent ignition is executed on the condition that the calculated crank angle is at an appropriate value, so that inappropriate combustion does not occur. . In the case of the index value “1”, since it has already been confirmed that the calculated crank angle is not an appropriate value, inappropriate fuel injection based on the calculated crank angle is executed. In order to suppress this, fuel injection is prohibited.

  The fuel injection at the time of automatic restart is executed based on the fuel injection permission conditions shown in Table 7. As described above, since the fuel injection permission conditions shown in Table 7 are the same as the fuel injection permission conditions shown in Table 3, the fuel injection control at the time of automatic restart is the flowchart of FIG. 6 of the first embodiment. It is executed according to the processing procedure shown in FIG. Therefore, the actual control is the same as the fuel injection control at the time of automatic restart described in the first embodiment, and thus description thereof is omitted.

Also in this embodiment, the same operation as the first embodiment and the same effects (1) to (4) of the first embodiment can be achieved.
(Fourth embodiment)
In the present embodiment, in addition to the configuration of the third embodiment, control for switching the fuel injection mode is performed based on the pressure of the fuel supplied to the in-cylinder injection valve 11 at the time of automatic restart.

  Specifically, the control device of this embodiment includes a pressure sensor 79 that detects the pressure in the delivery pipe described in the second embodiment. When the pressure detected by the pressure sensor 79 is less than the lower limit pressure at which fuel injection in the compression stroke can be performed, the control unit 50 prohibits the compression stroke injection start and performs the intake stroke. The in-cylinder injection valve 11 and the spark plug 12 are controlled so that the injection start is executed.

  When the pressure in the delivery pipe is equal to or higher than the lower limit pressure for executing fuel injection in the compression stroke, fuel injection in the compression stroke is executed at the time of automatic restart, so Tables 6 and 7 In addition, substantially the same control as that described above with reference to FIGS. 6 and 13 is performed. Specifically, in step S31 in FIG. 13, only whether or not it is during automatic restart is determined, but in this embodiment, it is determined whether or not it is during automatic restart due to compression stroke injection. The That is, in conjunction with the determination of whether or not it is during automatic restart, when the pressure sensor 79 detects that the pressure of the delivery pipe is equal to or higher than the lower limit pressure, the control unit 50 determines the start by the compression stroke injection. A determination is made whether or not. Also in step S41 in FIG. 6, it is determined whether or not it is during automatic restart by compression stroke injection. The other steps are the same as those described above, and thus description thereof is omitted.

  Table 8 shows the conditions for permitting ignition when the intake stroke injection is performed during automatic restart.

As shown in Table 8, when the intake stroke injection start is performed at the time of automatic restart, the permission condition is set to the index value “2” or more from the time of the first ignition determination. The reason is the same as the reason described in the second embodiment. That is, in the case of intake stroke injection start, the reverse rotation torque generated when improper ignition is performed becomes large. Therefore, when the intake stroke injection start is executed, the calculated crank angle is appropriate. The ignition is prohibited until the value is confirmed. For these reasons, when the compression stroke injection start is performed, the first ignition permission condition is set to the index value “0” or more, whereas when the intake stroke injection start is performed, the index value “ 2 ”or higher.

The setting mode of the ignition permission conditions in Table 8 will be described with reference to FIG.
FIG. 14 shows the relationship between the stroke of each cylinder and the crank angle. The timing at which the cam signal switching is detected and the timing at which the missing tooth portion 23 is detected are shown in the same manner as in FIG. Show. Further, the first fuel injection at the time of automatic restart is executed after 120 ° CA of the intake top dead center in the cylinder in the intake stroke (broken line arrow), and subsequently in the cylinder for which the ignition timing is set, the intake top dead center is set. Although fuel injection is executed after 60 ° CA, FIG. 14 shows only the injection timing when fuel injection is first performed in each cylinder. In each cylinder, the period from the 10 ° CA before compression top dead center (solid arrow) to the compression top dead center of 10 ° CA is the energization timing of the spark plug 12.

  In the start of the intake stroke injection, the first fuel injection timing is set to 120 ° CA after the intake top dead center for the same reason as described in the second embodiment. That is, the fuel injection timing is set to 120 ° CA after the intake top dead center in order to execute the first fuel injection as much as possible while maintaining good fuel homogenization for the cylinders stopped in the intake stroke. It is said.

  In FIG. 14, for example, when the crankshaft 20 is stopped due to automatic stop, any cylinder stops on the advance side (before 110 ° CA after intake top dead center) with respect to the fuel injection timing in the intake stroke. In this case, the first fuel injection and ignition can be performed on the cylinders that are stopped in the intake stroke. Therefore, if fuel injection and ignition are performed on a cylinder that is stopped in the intake stroke, the first initial explosion can be caused the earliest, so in this embodiment, the intake top dead center is 110 ° in the intake stroke. If there is a cylinder that is stopped before the CA, this cylinder is the cylinder that first determines the fuel injection timing and ignition timing. In addition, when the cylinder stopped in the intake stroke is stopped at the fuel injection timing or at the retarded angle side (after 120 ° CA after the intake top dead center), the first fuel injection is performed. Since this cannot be performed on the cylinder, the cylinder that is the next in the intake stroke is the cylinder that first determines the fuel injection timing and the ignition timing. In the following description, the cylinder that first enters the intake stroke after the cylinder that changes the fuel injection timing and ignition timing and then changes the ignition timing will be described as “the cylinder that changes the ignition timing second”.

  As described with reference to Table 8, the ignition permission condition in all the cylinders is set to an index value “2” or more so as to suppress the generation of a large reverse rotation torque due to the intake stroke injection. Specifically, since the ignition permission condition is set to the index value “2” or more for the cylinders whose ignition timing is first and second, the ignition is permitted while the index value “2” or more is calculated. Ignition is prohibited when it is not confirmed that the crank angle is at an appropriate value. Further, for the cylinders whose ignition timing is to be reached after the third, since the ignition permission condition is set to the index value “3”, the ignition is permitted at the index value “3” and the missing tooth portion 23 is not detected. In situations, ignition is prohibited.

  In the present embodiment, the index permission value “3” is set for the third and subsequent cylinders whose ignition timing is set. In this embodiment, the missing tooth portion 23 is detected and calculated by the third ignition timing at the latest. This is because the crank angle is updated based on the detection of the missing tooth portion 23. The reason why the missing tooth portion 23 is detected by the third ignition timing at the latest is the reason described with reference to FIG. 12 in the third embodiment, that is, the ignition of the cylinder that takes the fifth ignition timing in the intake stroke injection start. The reason is the same as the reason why the missing tooth portion 23 is detected by the time.

  That is, as shown in FIG. 14, for example, in the intake stroke injection start, when the first cylinder is subjected to the ignition timing after the intake stroke is the first cylinder, the missing tooth is reached by the ignition timing of the first cylinder. Part 23 is detected. Similarly, when the cylinder whose ignition timing is first set through the intake stroke is the fourth cylinder, the missing tooth portion 23 is detected by the ignition timing in the fourth cylinder.

  Further, when the cylinder whose ignition timing is first changed through the intake stroke is the third cylinder, the missing tooth portion 23 is detected by the ignition timing of the fourth cylinder whose timing is changed second. Similarly, when the cylinder whose ignition timing is first changed through the intake stroke is the sixth cylinder, the missing tooth portion 23 is detected by the ignition timing of the first cylinder whose timing is changed second.

  In addition, when the cylinder whose ignition timing is first set through the intake stroke is the second cylinder, when the stop position at the start of the automatic restart is a crank angle after 510 ° CA, the second ignition is performed. The missing tooth portion 23 cannot be detected by the ignition timing of the third cylinder that changes the timing, and the missing tooth portion 23 can be detected by the ignition timing of the fourth cylinder that changes the ignition timing third. Similarly, when the cylinder whose ignition timing is first changed through the intake stroke is the fifth cylinder, the missing tooth portion 23 may not be detected by the ignition timing of the sixth cylinder whose ignition timing is changed second. The missing tooth portion 23 can be detected by the ignition timing of the first cylinder that changes the ignition timing third. Therefore, as shown in Table 8, the ignition permission condition in the cylinder that is in the third intake stroke at the time of automatic restart is set to “3”.

  In the present embodiment, as shown in FIG. 14, since the cam signal switching is detected before the first ignition timing is reached after the intake stroke, the calculated crank angle is appropriate. If it is in the value, the process is executed from the first ignition as long as the cam angle sensor 76 is not abnormal.

  The ignition at the time of automatic restart is executed based on the permission conditions shown in Table 8. Since the permission conditions shown in Table 8 are the same as the permission conditions shown in Table 4, they are executed according to the processing procedure shown in the flowchart of FIG. Note that the flowchart of FIG. 8 is the same as the content described in the second embodiment, and thus the description thereof is omitted.

  As described above, the intake stroke injection start is executed only when it is confirmed that the calculated crank angle is an appropriate value (index value “2” or “3”) from the first ignition. Is allowed. The third and subsequent ignitions are executed only when the missing tooth portion 23 is detected (index value “3”). Therefore, when the intake stroke injection is performed at the time of automatic restart, the execution of ignition is prohibited until it is confirmed that the calculated crank angle is an appropriate value.

  Table 9 shows the permission conditions for fuel injection at the start of intake stroke injection.

As shown in Table 9, the fuel injection condition is set to other than “1” at the start of the intake stroke injection. Therefore, at the time of fuel injection determination for each cylinder, fuel injection is permitted if the index value is other than “1”, and fuel injection is prohibited if the index value is “1”.

  The fuel injection at the time of automatic restart is executed based on the permission conditions shown in Table 9. The permission conditions shown in Table 9 are the same as the permission conditions shown in Table 5 in the second embodiment. Therefore, the fuel injection at the start of the intake stroke injection is executed according to the processing procedure shown in the flowchart of FIG. Note that the flowchart of FIG. 9 is the same as the content described in the second embodiment, and thus the description thereof is omitted.

  As described above, at the start of intake stroke injection, it is prohibited if the calculated crank angle is confirmed to be not an appropriate value from the first fuel injection. Therefore, it is possible to suppress execution of inappropriate fuel injection based on the calculated crank angle. Thereby, it is possible to suppress the occurrence of a large reverse rotation torque due to the execution of injection or ignition at an inappropriate time from the first time.

Also in this embodiment, there exists an effect similar to the effect described in (1)-(4) of 1st Embodiment, and the effect described in (5)-(7) of 2nd Embodiment.
As for the intake stroke injection in the present embodiment, when the internal combustion engine includes the port injection valve 15, fuel injection may be performed by the port injection valve 15.

(Other embodiments)
In each of the above embodiments, the detection of the missing tooth portion is performed until the crankshaft is rotated by an amount of rotation that is estimated to be completed when the crankshaft is detected as the engine is started. Based on the fact that the logical sum condition that the estimated value of the crank angle is within the specified range when the signal is switched is confirmed, it is confirmed that the estimated value of the crank angle is an appropriate value. However, confirmation that the estimated value of the crank angle is an appropriate value may be performed only by detecting the missing tooth portion. Further, the crank angle is estimated based on the fact that the logical sum condition is satisfied even after the crankshaft has been rotated by an amount of rotation that is estimated to have completed the detection of the missing tooth portion as the engine is started. You may make it confirm that a value exists in an appropriate value. Regardless of how far the crankshaft has been rotating, the estimated crank angle is always determined by confirming that the estimated crank angle is within the specified range when the cam signal is switched. It may be confirmed that is at an appropriate value.

  In each of the above embodiments, when it is determined whether the estimated value of the crank angle is an appropriate value based on the cam signal, the cam angle is simply detected and the crank angle is estimated. It is determined whether or not the value is within the allowable range of the crank angle when switching of the cam signal is detected. On the other hand, the switching of the cam signal from the L signal to the H signal and the switching from the H signal to the L signal are detected separately, and within the specified range, that is, the crank when the cam signal switching is detected. Whether the angle is within the allowable range of the corner may be determined by distinguishing between switching from the H signal to the L signal and switching from the L signal to the H signal. That is, at the time of switching from the L signal to the H signal, it is determined whether or not the crank angle is within the allowable range of the crank angle when switching from the L signal to the H signal is detected. At the time of switching, it may be determined whether or not the crank angle is within the allowable range of the crank angle when switching from the H signal to the L signal is detected.

  ・ Furthermore, by detecting the switching from the L signal to the H signal of the cam signal and grasping the length of the L signal that was continuously output before that, the switching from the L signal to the H signal is performed. It may be determined which crank angle corresponds to whether or not the estimated value of the crank angle is within a specified range that is within the allowable range of the specified crank angle. Similarly, by detecting the switching of the cam signal from the H signal to the L signal and grasping the length of the H signal continuously output before that, the estimated value of the crank angle becomes an appropriate value. You may make it determine whether it exists.

  ・ Also, the cam signal on the camshaft on the exhaust side is used as the cam signal used for determining whether or not the estimated value of the crank angle is an appropriate value. The cam signal on the side cam shaft may be used, or both the exhaust side and intake side cam signals may be used.

Further, confirmation that the crank angle is at an appropriate value may be performed based on other signals.
In the second embodiment, its modification, and the fourth embodiment, the intake stroke injection is executed when the pressure sensor detects that the pressure of the delivery pipe is lower than the lower limit pressure. However, the compression stroke injection and the intake stroke injection at the start may be switched based on other internal combustion engine conditions such as the engine temperature.

  In each of the above embodiments, during normal start, fuel injection and ignition are executed after cylinder discrimination by missing tooth detection. However, during normal start, at least one of cam signal switching detection and missing tooth detection is performed. When it is confirmed that the estimated crank angle is at an appropriate value, fuel injection and ignition may be executed. Further, at the time of normal start, the same control as the ignition control and fuel injection control at the time of automatic restart in each of the above embodiments may be performed. Thereby, even at the time of normal start, it is possible to achieve early start-up completion and to prevent inappropriate ignition from being executed continuously.

  In each of the above embodiments, in addition to ignition control at start-up, fuel injection is also prohibited when the estimated value of the crank angle is not an appropriate value. Regardless of whether or not the estimated value of the crank angle is an appropriate value, it may be executed constantly.

  In each of the above embodiments, the crank angle is estimated by counting the pulse signal output from the crank angle sensor and calculating the crank angle. However, the crank angle estimation mode is not limited to the above mode. For example, the crank angle may be estimated based on the crank angle stored when the engine is stopped and the elapsed time since the engine is started.

  Further, the specific configurations of the internal combustion engine, the cam rotor, and the crank rotor, and the timing at which the switching of the missing tooth portion and the cam angle are detected are not particularly limited to the configurations illustrated in the above embodiments. That is, the internal combustion engine may be a gasoline engine other than the inline 4-cylinder or the V-type 6-cylinder. Further, the angle in the circumferential direction of the convex portion (projection) and the concave portion (portion where there is no projection) of the cam rotor, the crank angle at which the crank tooth missing portion is provided, and the number of the missing tooth portions are limited to the above-described embodiments. Not. In each of the above embodiments, the missing tooth portion is detected after 30 ° CA of the crank angle at which the missing tooth portion is provided. However, this detection mode is not particularly limited, for example, corresponding to the missing tooth portion. Then, the missing tooth portion may be detected at the timing when the pulse signal is first output after the output of the pulse signal is stopped. Note that the amount of rotation of the crankshaft required to detect the missing tooth portion also varies depending on the form of the missing tooth portion in the crank rotor and the manner in which the missing tooth portion is detected by the crank angle sensor. Therefore, the rotation amount estimated that the detection of the missing tooth portion is completed is not limited to the rotation amount exemplified in the above embodiments.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... In-cylinder injection valve, 12 ... Spark plug, 13 ... Throttle valve, 14 ... Starter, 15 ... Port injection valve, 20 ... Crankshaft, 21 ... Crank rotor, 22 ... Protrusion, 23 ... Missing tooth Part, 30, 80, 90 ... exhaust camshaft (camshaft) 31, 81, 91 ... cam rotor, 32-34, 82-84, 92-94 ... convex part, 35-37, 85-87, 95-97 DESCRIPTION OF SYMBOLS ... Recessed part 50 ... Control part 71 ... Accelerator position sensor 72 ... Throttle position sensor 73 ... Air flow meter 74 ... Water temperature sensor 75 ... Crank angle sensor 76, 88, 98 ... Exhaust cam angle sensor (cam angle sensor) ), 77 ... Brake switch, 78 ... Vehicle speed sensor, 79 ... Pressure sensor.

Claims (11)

A control device for an internal combustion engine that drives a crankshaft by a starter at the time of engine start and executes ignition,
A confirmation means for confirming that the estimated value of the crank angle is an appropriate value;
In the case of the compression stroke injection start in which the fuel injection and ignition from the in-cylinder injection valve are executed for the cylinder in the compression stroke,
Based on the crank angle stored when the engine is stopped, the first ignition is executed for the cylinder that can cause the first explosion among the cylinders of the internal combustion engine, and the estimated value of the crank angle is determined appropriately by the checking means . A control device for an internal combustion engine, which permits ignition of a cylinder whose ignition timing is to be continued following the cylinder that has performed the first ignition, on the condition that the value is confirmed. A crank angle sensor that outputs a pulse signal corresponding to the passage of a plurality of protrusions provided on a crank rotor that rotates integrally with the crankshaft;
Based on a change in the interval of the pulse signals output from the crank angle sensor, the missing tooth portion lacking the projection of the crank rotor is detected, and the estimated value of the crank angle is detected when the missing tooth portion is detected. Is a control device for an internal combustion engine that updates the value to a specified value,
2. The control device for an internal combustion engine according to claim 1, wherein the confirmation unit confirms that the estimated value of the crank angle is an appropriate value based on detection of the missing tooth portion. Cam angle for outputting a first cam signal corresponding to a portion where a protrusion of a cam rotor rotating integrally with a cam shaft is provided as a cam signal and a second cam signal corresponding to a portion where no protrusion is provided With sensors,
The confirmation means is until the rotation of the crankshaft is estimated to be completed when the crankshaft is detected as the engine starts.
That the missing tooth portion has been detected;
The estimated value of the crank angle is within a specified range when a cam signal output from the cam angle sensor is switched between the first cam signal and the second cam signal;
The control apparatus for an internal combustion engine according to claim 2, wherein the estimated value of the crank angle is confirmed to be an appropriate value based on the fact that the logical sum condition is established. When performing an ignition after injecting fuel to a cylinder in the intake stroke and performing an intake stroke injection start that causes an initial explosion,
The control device for an internal combustion engine according to any one of claims 1 to 3, wherein execution of ignition is prohibited until the confirmation means confirms that the estimated value of the crank angle is an appropriate value . An internal combustion engine control device that controls an internal combustion engine that includes a port injection valve that injects fuel into an intake port;
The control apparatus for an internal combustion engine according to claim 4, wherein when performing the intake stroke injection start, fuel is injected from the port injection valve. When the pressure of the fuel supplied to the in-cylinder injection valve is less than the lower limit pressure for executing fuel injection in the compression stroke, the compression stroke injection start is prohibited and the intake stroke injection start is executed. The control device for an internal combustion engine according to claim 4 or 5. An abnormality confirmation means for confirming that the estimated value of the crank angle is not an appropriate value;
In the case of the compression stroke injection start,
On the condition that the estimated value of the crank angle is not an appropriate value by the abnormality confirmation means , fuel injection to a cylinder whose ignition timing is to be continued following the cylinder that has performed the first ignition is prohibited. The control apparatus for an internal combustion engine according to any one of claims 1 to 6. When performing an ignition after injecting fuel to a cylinder in the intake stroke and performing an intake stroke injection start that causes an initial explosion,
Claim 7 wherein the abnormality by confirming means on condition that the estimated value of the crank angle is made confirmation that no appropriate value, prohibits also the fuel injection for the cylinder that is capable of causing a most early initial explosion The control apparatus of the internal combustion engine described in 1. A control device for an internal combustion engine having an idle stop function for automatically stopping the internal combustion engine when the idle stop condition is satisfied and automatically restarting the internal combustion engine when the idle stop condition is not satisfied,
When performing the compression stroke injection start from the automatic stop state by the idle stop function, the first explosion is caused the earliest among the cylinders of the internal combustion engine based on the crank angle stored at the time of the last engine stop. While performing the first ignition to the cylinder that can
In the case of engine start due to the operation of the ignition switch, the individual fuel injection and ignition for each cylinder are performed on the condition that the estimated value of the crank angle is confirmed by the confirmation means to be an appropriate value. The control device for an internal combustion engine according to any one of claims 1 to 3, wherein A crank angle sensor that outputs a pulse signal corresponding to the passage of a plurality of protrusions provided on a crank rotor that rotates integrally with the crankshaft;
Based on a change in the interval of the pulse signal output from the crank angle sensor, a missing tooth portion lacking the projection of the crank rotor is detected, and an estimated value of the crank angle is detected when the missing tooth portion is detected. A control device for an internal combustion engine that updates to a specified value,
In the case of a compression stroke injection start in which fuel injection from the in-cylinder injection valve and ignition are performed on a cylinder in the compression stroke, the crankshaft is driven by a starter and based on the crank angle stored when the engine is stopped. The first ignition is executed for the cylinder that can cause the first explosion among the cylinders of the internal combustion engine, and the first ignition is executed on condition that the missing tooth portion is detected. A control device for an internal combustion engine, which permits the execution of ignition to a cylinder whose ignition timing is subsequent to the cylinder. Cam angle for outputting a first cam signal corresponding to a portion where a protrusion of a cam rotor rotating integrally with a cam shaft is provided as a cam signal and a second cam signal corresponding to a portion where no protrusion is provided With sensors,
Until the rotation of the crankshaft, which is estimated to have completed the detection of the missing tooth portion as the engine is started,
Even if the missing tooth part is not detected,
If the estimated value of the crank angle is within a specified range when the cam signal output from the cam angle sensor switches between the first cam signal and the second cam signal, the first ignition is performed. 11. The control device for an internal combustion engine according to claim 10, wherein the execution of ignition is permitted for a cylinder whose ignition timing is set subsequent to the cylinder that has executed.