JP5999930B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device.

  Conventionally, when the predetermined stop condition is satisfied, the engine is automatically stopped, and when the predetermined start condition is satisfied, the engine is automatically started. Only an engine control device that stops the engine is known.

  According to such an engine control device, it is possible to improve environmental performance and suppress consumption of useless fuel by suppressing useless exhaust gas emission while the vehicle is stopped.

  By the way, in such an engine control device, since the engine is started more frequently than other engine control devices that do not automatically stop and start the engine, it is necessary to reduce power consumption required for starting the engine.

  Further, in such an engine control device, when the vehicle resumes running, there is a risk of causing traffic congestion unless the engine is automatically started quickly, so it is necessary to reduce the time required to start the engine.

  For this reason, for example, in the apparatus described in Patent Document 1, the starter is rotated at a rotational speed slower than the normal rotational speed when the engine is started when the engine is difficult to rotate, such as in a low temperature state. After starting the engine, the time required for starting is shortened by increasing the rotation speed of the starter to the normal rotation speed.

  Further, in the apparatus described in Patent Document 2, when a start condition is established before the automatically stopped engine is completely stopped, the engine is restarted without waiting for the engine to stop rotating. The time required is shortened.

  Specifically, in the device described in Patent Document 2, first, the starter is idled, and the starter and the engine are interlocked and connected when the rotation of the starter and the rotation of the engine are synchronized, thereby stopping the rotation of the engine. The engine is restarted without waiting.

  Further, in the apparatus described in Patent Document 3, when the start condition is satisfied before the automatically stopped engine is completely stopped, the rotation speed of the engine is reduced to a rotation speed at which the starter and the engine can be interlocked. The engine is restarted by interlocking and coupling the starter and the engine and rotating the starter.

  According to the device described in Patent Document 3, since the starter is not idled during the automatic engine start, the power consumption required for restarting the engine can be suppressed as compared with the device described in Patent Document 2. Moreover, the automatic start can be started before the engine is completely stopped.

  As described above, in the apparatus described in each patent document, the time required for starting the engine is shortened and the power required for starting the engine is reduced by changing the operation state of the starter during the period of automatic starting of the engine. Yes.

  By the way, the engine control device cannot restart the engine when the voltage of the battery that supplies power to the starter is less than the voltage necessary for starting the engine. For this reason, a device has been devised that prohibits automatic engine stop when the voltage of the battery at the time of starting the engine is lower than a preset voltage (see, for example, Patent Document 4).

JP 2002-147320 A Japanese Patent Laying-Open No. 2005-330813 JP 2010-84754 A Japanese Patent Laid-Open No. 10-47105

  However, the determination of prohibition of automatic engine stop as described above does not take into consideration that the operation state of the starter is changed during the starter driving at the time of starting the engine as described in Patent Documents 1 to 3. There is a problem that the prohibition determination regarding the automatic engine stop may not be appropriately performed.

  For example, in the technique described in Patent Document 1, when the rotation of the starter is started at a lower rotational speed than usual, the battery voltage first decreases, and then the starter rotation is switched by switching the starter drive control. Even when the speed is increased, the voltage changes in a complicated manner such that the battery voltage decreases.

  The voltage of the battery at the time of driving the starter is not only affected by the state of the battery, but is also affected by, for example, the change in the driving load depending on the crank angle position of the engine. In the configuration that detects the minimum voltage, it is difficult to accurately detect the battery state.

  In addition, since it is difficult to accurately detect the battery state, if the voltage for determining prohibition of the automatic stop of the engine is set high in order to surely avoid the state where the automatic start of the engine cannot be performed, the automatic stop of the engine is performed. Will be less frequent.

  For this reason, how to realize an engine control device that can appropriately perform the prohibition determination regarding the automatic engine stop is a big problem.

  The present invention has been made in view of the above, and an object of the present invention is to provide an engine control device that can appropriately perform a prohibition determination regarding automatic engine stop.

  In order to solve the above-described problems and achieve the object, the present invention provides an engine that can be switched between a connected state in which a starter motor and an engine rotation shaft are connected and an unconnected state that is not connected. An engine control device is provided in a vehicle having a start mechanism, and automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition is satisfied. An engine that performs starter drive control for driving the starter motor using electric power from a battery and connection control for changing the start mechanism from a non-connected state to a connected state using electric power from the battery when starting. And detecting a voltage of the battery when the engine is started by the start control means and the engine start control means. A battery state detecting unit for detecting a battery state based on a voltage; and an automatic stop prohibiting unit for prohibiting an automatic stop of the engine based on the battery state detected by the battery state detecting unit. The start control means performs a first start control for performing the connection control in a state where the starter motor is driven by the starter drive control, and a second start control for performing the starter drive control after performing the connection control. The battery state detection means is configured to detect the battery state when the first start control is performed by the engine start control means and when the second start control is performed. It is characterized by making different.

  The engine control apparatus according to the present invention can appropriately perform the prohibition determination regarding the automatic engine stop by performing the prohibition determination regarding the automatic engine stop in consideration of the operation state of the starter changed at the time of starting the engine. There is an effect.

FIG. 1 is a block diagram showing an engine control apparatus according to the first embodiment. FIG. 2 is an explanatory diagram illustrating an example of the configuration of the starter according to the first embodiment. FIG. 3 is a timing chart showing voltage detection start timing when the start control unit according to the first embodiment performs the first start control. FIG. 4 is a timing chart showing voltage detection start timing when the start control unit according to the first embodiment performs the second start control. FIG. 5 is a flowchart illustrating processing executed by the control unit according to the first embodiment. FIG. 6 is a flowchart illustrating processing executed by the control unit according to the first embodiment. FIG. 7 is a diagram illustrating a correspondence relationship between the engine speed and the voltage correction coefficient according to the first embodiment. FIG. 8 is a diagram showing an outline of the engine control method according to the second embodiment. FIG. 9 is a diagram showing an outline of the configuration of the apparatus described in Patent Document 1. FIG. 10 is a diagram showing an outline of the configuration of the apparatus described in Patent Document 3. As shown in FIG. FIG. 11 is a block diagram showing the configuration of the engine control apparatus according to the second embodiment. FIG. 12 is a diagram illustrating a change in the voltage of the battery when starting an engine in which the rotation according to the second embodiment is not completely stopped. FIG. 13 is a diagram illustrating an example of the operation of the automatic stop prohibiting unit according to the second embodiment. FIG. 14 is a flowchart illustrating processing executed by the control unit according to the second embodiment. FIG. 15 is a diagram illustrating the operation of the automatic stop prohibiting unit according to the modification.

  Hereinafter, an engine control device according to an embodiment will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

(First embodiment)
FIG. 1 is a block diagram showing an engine control apparatus 1 according to the first embodiment. As shown in FIG. 1, the engine control device 1 according to this embodiment is connected to a sensor SE, an engine E, a starter ST, and a battery B, and includes a control unit 2 and a storage unit 3. The sensor SE connected to the engine control device 1 includes a plurality of detection devices that detect the state of the vehicle.

  Specifically, the sensor SE detects the number of revolutions of the engine E, the speed of the vehicle, the acceleration of the vehicle, the position of the shift lever, the operation state of the accelerator, the operation state of the brake, etc. Output to 1. The engine E is an internal combustion engine that drives the vehicle, and the battery B is a power source that supplies power to various electronic devices mounted on the vehicle.

  The starter ST is an engine starter provided with a starter mechanism for starting the engine E by transmitting the rotational force of a starter motor (hereinafter simply referred to as “motor”) to the rotation shaft of the engine E. The starter ST has a configuration capable of switching between a connected state in which the motor and the rotating shaft of the engine E are connected and a disconnected state in which the motor and the rotating shaft of the engine E are not connected. .

  Here, an example of the configuration of the starter ST will be described with reference to FIG. The starter ST is not limited to the one shown in FIG. FIG. 2 is an explanatory diagram illustrating an example of the configuration of the starter ST according to the first embodiment.

  As shown in FIG. 2, the starter ST includes a motor M that starts the engine E, and a solenoid switch 42 that meshes a pinion gear 41 driven by the motor M with a ring gear 51 that is linked to the rotation shaft of the engine E. ing.

  The solenoid switch 42 includes a solenoid 43 and a plunger 44 that operates by energizing the solenoid 43. The plunger 44 is connected to the rotation shaft of the pinion gear 41 via the interlocking member 45.

  Further, the solenoid switch 42 is connected to the battery B via a first switch 61 that switches ON / OFF of energization of the solenoid switch 42 according to a control signal input from the control unit 2.

  In addition, the motor M is connected to the battery B via a second switch 62 that switches ON / OFF of energization of the motor M and switching of the energization amount of the motor M according to a control signal input from the control unit 2. . That is, when the engine E is started, the control unit 2 performs starter drive control that drives the motor M using the electric power from the battery B.

  In the starter ST, when the solenoid 43 is not energized, the plunger 44 is retracted into the solenoid 43 (hereinafter referred to as “OFF state”), and the pinion gear 41 is not engaged with the ring gear 51. Retained.

  On the other hand, when the solenoid 43 is energized, the plunger 44 is advanced from the solenoid 43 (hereinafter referred to as “ON state”), and the pinion gear 41 is engaged with the ring gear 51.

  As described above, the starter ST can switch between a connected state in which the motor M and the rotation shaft of the engine E are connected and a non-connected state in which the motor M and the rotation shaft of the engine E are not connected. E starting mechanism is provided.

  The switching between the ON state and the OFF state of the plunger 44 is performed by the control unit 2 switching the first switch 61 between ON and OFF. That is, when the engine E is started, the control unit 2 performs connection control for changing the start mechanism from the non-connected state to the connected state using the electric power from the battery B.

  According to the control by the control unit 2, the starter ST performs different starting operations depending on whether the rotation of the engine E to be started is not completely stopped or when the rotation is completely stopped.

  Specifically, when the rotation of the engine E to be started is not completely stopped, the starter ST first drives the motor M while the plunger 44 is in an OFF state to cause the pinion gear 41 to idle. Hereinafter, the state in which the starter ST rotates the pinion gear 41 while keeping the plunger 44 in the OFF state is referred to as a first state.

  Subsequently, when the rotation of the pinion gear 41 and the rotation of the engine E are synchronized, the starter ST turns on the plunger 44 and increases the rotation speed of the motor M to start the engine E. Hereinafter, the state in which the starter ST rotates the pinion gear 41 with the plunger 44 turned on is referred to as a second state.

  According to the starter ST, the engine E can be restarted before the rotation of the engine E is completely stopped, so that the time required for restarting the engine E can be shortened. In addition, the synchronization determination of the rotation of the pinion gear 41 and the rotation of the engine E is performed by the control unit 2.

  Here, in the first state and the second state, the power consumption of the motor M is larger in the second state than in the first state. That is, when starting the engine E whose rotation is not completely stopped, the starter ST consumes more power than the first state after driving the motor M in the first state where the power consumption is relatively small. In the second state, the motor M is driven to start the engine E.

  On the other hand, when the rotation of the engine E to be started is completely stopped, the starter ST starts the engine E by driving the motor M in the second state from the beginning. That is, the starter ST first turns on the plunger 44, engages the pinion gear 41 whose rotation has stopped and the ring gear 51 whose rotation has stopped, and then starts driving the motor M to start the engine E. Start up.

  Returning to FIG. 1, the description of the engine control device 1 will be continued. The engine control device 1 stores a control unit 2 that performs automatic stop and automatic start of the engine E, start / stop condition information 31 that is used for automatic stop and automatic start of the engine E, automatic stop permission information 32, and threshold information 33. And a storage unit 3.

  Here, the start / stop condition information 31 is information indicating a stop condition and a start condition of the engine E. Specifically, the storage unit 3 stores, as stop conditions, conditions such as the number of revolutions of the engine E being idling, the vehicle speed and acceleration being 0, the accelerator being OFF, the brake being ON, and the shift position being neutral or parking. doing.

  Then, the control unit 2 automatically stops the engine E when all the stop conditions are satisfied in a state where the automatic stop of the engine E is permitted.

  In addition, the storage unit 3 stores conditions such as the shift position being shifted from neutral or parking to drive while the brake is ON, as the start condition. Then, when the start condition is satisfied after the engine E is automatically stopped, the control unit 2 automatically restarts the engine E.

  The automatic stop permission information 32 is information indicating whether the automatic stop of the engine E is permitted or prohibited. The automatic stop permission information 32 is referred to by the control unit 2 when the engine E stop condition is satisfied. The threshold information 33 is information indicating a threshold to be compared with the voltage of the battery B when the control unit 2 performs the prohibition determination regarding the automatic stop of the engine E.

  When the control unit 2 performs start control for starting the engine E, the control unit 2 compares the voltage of the battery B with the threshold value stored as the threshold information 33, and prohibits the next automatic stop of the engine E. Determine whether or not. The start control executed by the control unit 2 will be described later with reference to FIGS. 3 and 4, and the process executed by the control unit 2 will be described later with reference to FIGS. 5 and 6.

  The control unit 2 controls the overall operation of the engine control device 1 and includes an information processing device having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Yes.

  The control unit 2 includes a plurality of processing units that function when the CPU reads various programs from the ROM and executes them using the RAM as a work area. Specifically, the control unit 2 includes a start / stop determination unit 21, a stop control unit 22, a start control unit 23, a voltage detection unit 24, and an automatic stop prohibition unit 25.

  The start / stop determination unit 21 determines whether the stop condition or the start condition of the engine E is established based on each detection result input from the sensor SE and the start / stop condition information 31 stored in the storage unit 3. It is a processing unit for determining whether or not.

  The start / stop determination unit 21 outputs the determination result to the stop control unit 22 when it is determined that the stop condition of the engine E is satisfied. On the other hand, when the start / stop determination unit 21 determines that the start condition of the engine E is satisfied, the start / stop determination unit 21 outputs the determination result to the start control unit 23.

  The stop control unit 22 is a processing unit that automatically stops the engine E. When the determination result indicating that the stop condition is satisfied is input from the start / stop determination unit 21, the stop control unit 22 refers to the automatic stop permission information 32 stored in the storage unit 3 and performs automatic stop. If it is permitted, the engine E is automatically stopped.

  The start control unit 23 is a processing unit that automatically starts the engine E. The start control unit 23 automatically starts the engine E when a determination result indicating that the start condition is satisfied is input from the start / stop determination unit 21.

  At this time, if the rotation of the engine E is not completely stopped, the start control unit 23 drives the motor M in the first state described above, and then consumes more power than the first state. First start control is performed to start the engine E by driving in the second state described above. On the other hand, when the rotation of the engine E is completely stopped, the start control unit 23 performs the second start control for starting the engine E by driving the motor M in the above-described second state.

  That is, the start control unit 23 performs the first start control for performing the above-described connection control in the state where the motor M is driven by the above-described starter drive control, and the first start control for performing the above-described starter drive control after performing the above-described connection control. It functions as an engine start control means capable of performing 2 start control.

  The voltage detection unit 24 functions as a battery state detection unit that detects the voltage of the battery B when the engine E is started and detects the state of the battery B (battery state) based on the detected voltage. Then, the voltage detection unit 24 outputs the detected minimum voltage of the battery B to the automatic stop prohibition unit 25 as a battery state.

  The voltage detection unit 24 varies the way of detecting the battery state depending on whether the start control unit 23 performs the first start control on the starter ST or the second start control. For example, the voltage detection unit 24 switches the voltage detection start timing of the battery B during the drive period of the motor M between when the first start control is performed and when the second start control is performed. Different periods for detecting voltage.

  Here, the voltage detection start timing by the voltage detection part 24 is demonstrated using FIG. 3 and FIG. FIG. 3 is a timing chart showing voltage detection start timing when the start control unit 23 according to the first embodiment performs the first start control, and FIG. 4 is a start control unit 23 according to the first embodiment. 6 is a timing chart showing voltage detection start timing when performing the second start control.

  3 and 4, in order from the bottom, the time axis, the transition of the voltage of the battery B, the transition of the rotation speed of the engine E, the transition of the state of the plunger 44, the transition of the driving state of the motor M, the voltage detection unit 24 shows the transition of the voltage detection state by 24.

  As shown in FIG. 3, for example, when the engine E is stopped at the time T1, and then the start condition is satisfied before the rotation of the engine E stops at the time T2, the start control unit 23 is at the timing of the time T2. The first start control is started.

  Specifically, the start control unit 23 turns on the motor M at the timing of time T2 and starts driving. At this time, the pinion gear 41 idles because the plunger 44 is in the OFF state. Further, since the battery B supplies electric power for causing the pinion gear 41 to idle to the motor M, the voltage decreases.

  Thereafter, when the rotation of the pinion gear 41 and the rotation of the engine E are synchronized at time T3, the start control unit 23 switches the state of the plunger 44 to the ON state at the timing of time T3. As a result, the pinion gear 41 of the motor M and the ring gear 51 of the engine E mesh with each other, and the load applied to the motor M increases. Thereby, since the power consumption of the motor M increases, the voltage of the battery B decreases more than at the time T2.

  Thereafter, when the start of the engine E is completed at time T4, the start control unit 23 turns off the motor M at the timing of time T4, switches the plunger 44 to the OFF state, and ends the first start control. Thereby, in battery B, the voltage returns to the steady state.

  Thus, when starting the engine E whose rotation is not stopped, the voltage of the battery B is more at the time T3 when the plunger 44 is switched to the ON state than at the time T2 when the driving of the motor M is started. Is greatly reduced. That is, the voltage drop amount of the battery B is larger when the motor M is driven in the second state than when the motor M is driven in the first state.

  Moreover, when the ring gear 51 is rotated by the pinion gear 41 and the voltage of the battery B falls below the voltage at which the engine E can be started, the engine E cannot be started. That is, whether or not the voltage of the battery B during the period of driving the motor M in the second state can start the engine E more than the voltage of the battery B during the period of driving the motor M in the first state. Greatly affects.

  Therefore, when the first start control is performed, the voltage detection unit 24 does not detect the voltage of the battery B during the period in which the motor M is driven in the first state, and does not detect the voltage of the motor M in the second state. The voltage detection of the battery B is started at the time T3 when the driving is started. And the voltage detection part 24 complete | finishes voltage detection at the timing when starting of the engine E was completed at the time T4.

  As described above, when the first start control is performed, the voltage detection unit 24 does not perform the driving start timing of the motor M, but the timing at which the state of the motor M is switched from the first state to the second state. Voltage detection is started, and the voltage detection ends after the start of the engine E is completed.

  As a result, the voltage detection unit 24 does not detect the voltage of the battery B for an unnecessarily long time, so that the process of determining the minimum voltage from the detected voltage can be accelerated.

  On the other hand, as shown in FIG. 4, for example, when the engine E is stopped at time T1 and then the start condition is satisfied with the rotation of the engine E stopped at time T2, the start control unit 23 The second start control is started at the timing.

  Specifically, the start control unit 23 switches the plunger 44 to the ON state at the timing of time T2. At this time, since the battery B supplies power for driving the plunger 44 to the starter ST, the voltage temporarily decreases.

  After that, when the pinion gear 41 of the starter ST meshes with the ring gear 51 of the engine E at time T3, the start control unit 23 turns on the motor M and starts driving. That is, the start control unit 23 starts driving the motor M in the second state at time T3. Thereby, since the power consumption of the motor M increases, the voltage of the battery B decreases more than at the time T2.

  Thereafter, when the start of the engine E is completed at time T4, the start control unit 23 turns off the motor M at the timing of time T4, switches the state of the plunger 44 to the OFF state, and ends the second start control. Thereby, in battery B, the voltage returns to the steady state.

  As described above, when starting the engine E whose rotation has stopped, the voltage of the battery B is greater at the time T3 when the driving of the motor M is started than at the time T2 when the state of the plunger 44 is switched to the ON state. Is greatly reduced. That is, when driving the motor M in the second state, the voltage of the battery B is the lowest.

  Moreover, when the ring gear 51 is rotated by the pinion gear 41 and the voltage of the battery B falls below the voltage at which the engine E can be started, the engine E cannot be started. That is, the voltage of the battery B during the period in which the motor M is driven in the second state greatly affects whether or not the engine E can be started.

  Therefore, when the second start control is performed, the voltage detection unit 24 does not detect the voltage of the battery B and starts driving the motor M in the second state during the period in which the plunger 44 is switched to the ON state. The voltage detection of the battery B is started at the timing of time T3. And the voltage detection part 24 complete | finishes voltage detection at the timing when starting of the engine E was completed at the time T4.

  Thus, when the second start control is performed, the voltage detection unit 24 reduces the minimum voltage of the battery B during the period in which the motor M is driven in the second state that greatly affects whether or not the engine E can be started. Can be detected.

  Thus, the voltage detection part 24 starts the voltage detection of the battery B at the timing when the drive of the motor M was started, when 2nd starting control is performed. On the other hand, when the first start control is performed, the voltage detection unit 24 does not detect the battery at the timing when the state of the plunger 44 is switched to the ON state after the driving of the motor M is started, but at the timing when the driving of the motor M starts. B voltage detection is started.

  That is, the voltage detection unit 24 switches the voltage detection timing of the battery B during the driving period of the motor M between the case where the start control unit 23 performs the first start control and the case where the start control is performed. Detect voltage.

  Thereby, the voltage detection unit 24 determines whether or not the engine E can be started next time, that is, whether or not the engine E should be automatically stopped next time, according to the operation state of the starter ST that is changed when the engine E is started. A voltage suitable as a determination material can be detected.

  Returning to FIG. 1, the description of the control unit 2 will be continued. The automatic stop prohibiting unit 25 of the control unit 2 is a processing unit that functions as an automatic stop prohibiting unit that prohibits the automatic stop of the engine E based on the battery state detected by the voltage detection unit 24. The automatic stop prohibition unit 25 determines whether to prohibit automatic stop based on the minimum voltage of the battery B input from the voltage detection unit 24 and the threshold value of the threshold information 33 stored in the storage unit 3. To do.

  Specifically, the automatic stop prohibition unit 25 permits the next automatic stop of the engine E when the minimum voltage of the battery B input from the voltage detection unit 24 is equal to or higher than the threshold stored in the storage unit 3. The automatic stop permission information 32 indicating that the data is to be stored is stored in the storage unit 3.

  On the other hand, when the minimum voltage of the battery B input from the voltage detection unit 24 is less than the threshold value stored in the storage unit 3, the automatic stop prohibition unit 25 prohibits the next automatic stop of the engine E. The automatic stop permission information 32 shown is stored in the storage unit 3.

  Note that the threshold value that the automatic stop prohibiting unit 25 compares with the minimum voltage is determined to an optimum value by performing a simulation in advance. For example, the automatic stop prohibiting unit 25 determines whether to stop automatically while changing each threshold value, and when automatic stop is permitted, the engine E is automatically stopped and then the engine E is restarted. Repeat in advance. As a result of the simulation, the lowest value among the threshold values set when the engine E is successfully started is determined as the threshold value.

  As described above, in the control unit 2, the minimum voltage suitable as a determination material for determining whether or not the automatic stop of the engine E should be permitted according to the operation state of the starter ST that is changed when the engine E is started. Is output to the automatic stop prohibition unit 25.

  Then, the automatic stop prohibiting unit 25 determines whether to prohibit the next automatic stop of the engine E based on the minimum voltage input from the voltage detecting unit 24. Thereby, according to the engine control apparatus 1, the prohibition determination regarding the automatic stop of the engine E can be performed appropriately.

  In the present embodiment, the voltage detection unit 24 detects the voltage of the battery B when the engine E is started as the battery state, but detects the charged state or the deteriorated state of the battery B when the engine E is started as the battery state. The voltage detector 24 may be configured as described above.

  In such a configuration, the storage unit 3 stores in advance information that associates the voltage of the battery B with a predetermined value indicating the state of charge or deterioration of the battery B, and a predetermined threshold regarding the state of charge or deterioration of the battery B. Remember me.

  The voltage detection unit 24 detects the voltage of the battery B when the engine E is started, and outputs a value indicating the charging state or the deterioration state associated with the voltage to the automatic stop prohibiting unit 25 as the battery state.

  On the other hand, the automatic stop prohibiting unit 25 compares the value indicating the state of charge or the deterioration state input from the voltage detection unit 24 with a predetermined threshold and determines that the state of charge of the battery B is insufficient, or When it is determined that the battery B has deteriorated, the next automatic stop of the engine E is prohibited.

  In addition, as a method for making the voltage detection unit 24 detect the battery state differently when the first start control is performed and when the second start control is performed, for example, the voltage detection period of the battery B is different. Alternatively, a method of making the battery state different or a method of calculating the battery state may be used.

  Next, the process which the control part 2 of the engine control apparatus 1 performs is demonstrated using FIG. 5 and FIG. FIG. 5 and FIG. 6 are flowcharts showing processing executed by the control unit 2 according to the first embodiment.

  As shown in FIG. 5, the control unit 2 determines whether or not a stop condition is satisfied while the vehicle is traveling (step S101), and determines that the stop condition is not satisfied (No in step S101). The process is terminated.

  On the other hand, when it determines with the stop condition having been satisfied (step S101, Yes), the control part 2 determines whether the automatic stop is permitted (step S102). If the control unit 2 determines that the automatic stop is not permitted (No at Step S102), the process ends.

  On the other hand, when it determines with the automatic stop being permitted (step S102, Yes), the control part 2 stops the engine E automatically (step S103), and determines whether the starting condition of the engine E was satisfied. (Step S104).

  When the control unit 2 determines that the start condition is not satisfied (step S104, No), the process proceeds to step S104, and when it is determined that the start condition is satisfied (step S104, Yes), the engine E Is automatically started (step S105), and the process is terminated.

  Moreover, the control part 2 performs the process shown in FIG. 6, when starting the engine E automatically in step S105. That is, when starting the automatic start of the engine E, as shown in FIG. 6, the control unit 2 first determines whether or not the first start control is selected (step S201).

  Here, the control unit 2 determines that the first start control is selected when the rotation of the engine E is not completely stopped, and when the rotation of the engine E is completely stopped, It is determined that the first start control is not selected.

  And when it determines with the 1st start control having been selected (step S201, Yes), the control part 2 drives the motor M in a 1st state (step S202). That is, the control unit 2 causes the pinion gear 41 to idle without being meshed with the ring gear 51.

  Thereafter, the control unit 2 drives the motor M in the second state at the timing when the rotation of the pinion gear 41 and the rotation of the engine E are synchronized, and starts detection of the lowest voltage of the battery B (step S203).

  That is, the control unit 2 moves the pinion gear 41 to a position where it engages with the ring gear 51 and starts the engine E by the rotation of the motor M. In addition, the control part 2 complete | finishes the detection of the minimum voltage, when starting of the engine E is completed.

  Subsequently, the control unit 2 determines whether or not the minimum voltage detected in step S203 is equal to or greater than a threshold value stored in the storage unit 3 (step S204). If the control unit 2 determines that the minimum voltage is equal to or higher than the threshold value (Yes at Step S204), the control unit 2 permits the next automatic stop of the engine E (Step S205), and ends the process.

  On the other hand, when it determines with the minimum voltage being less than a threshold value (step S204, No), the control part 2 prohibits the next automatic stop of the engine E (step S206), and complete | finishes a process.

  Further, when it is determined that the first start control is not selected in Step S201 (Step S201, No), the control unit 2 starts the second start control and drives the motor M in the second state. Detection of the minimum voltage of the battery B is started (step S207).

  That is, the control unit 2 starts driving the motor M and starts the engine E after meshing the pinion gear 41 with the ring gear 51 without idling. In addition, the control part 2 complete | finishes the detection of the minimum voltage, when starting of the engine E is completed.

  Subsequently, the control unit 2 determines whether or not the minimum voltage detected in step S207 is equal to or greater than a threshold stored in the storage unit 3 (step S208). And when it determines with the minimum voltage being more than a threshold value (step S208, Yes), the control part 2 permits the next automatic stop of the engine E (step S209), and complete | finishes a process.

  On the other hand, when it determines with the minimum voltage being less than a threshold value (step S208, No), the control part 2 prohibits the next automatic stop of the engine E (step S210), and complete | finishes a process.

  By the way, the voltage detection unit 24 can be configured to further divide the period during which the motor M is driven in the second state into a plurality of divided periods and detect the lowest voltage of the battery B in each divided period. .

  In such a case, a threshold value to be compared with the voltage detected in each divided period is stored in advance in the storage unit 3 for each divided period. Each threshold value is determined for each divided period by performing a simulation in advance.

  For example, the automatic stop prohibiting unit 25 determines whether to stop automatically while changing the threshold value associated with each divided period. When automatic stop is permitted, the engine E is automatically stopped and then the engine E is turned off. Repeat the simulation to be restarted in advance. As a result of the simulation, the threshold value of the lowest value among the threshold values of the divided periods set when the engine E is successfully started is determined as the threshold value of each divided period.

  Then, the automatic stop prohibition unit 25 compares the minimum voltage of the battery B detected in each divided period with a threshold corresponding to each divided period, and determines whether to stop automatic stop.

  For example, the voltage detection unit 24 is a period (hereinafter referred to as “rushing period”) until a predetermined time elapses from the time when the driving of the motor M is started in the second state (time T3 shown in FIGS. 3 and 4). The minimum voltage of the battery B (hereinafter referred to as “minimum voltage upon entry”) is detected. The predetermined time here is, for example, 100 ms.

  Subsequently, the voltage detection unit 24 is a period from the end of the entry period to the time when the start of the engine E is completed (time T4 shown in FIGS. 3 and 4) (hereinafter referred to as “period after entry”). The lowest voltage of the battery B (hereinafter referred to as “minimum voltage after entry”) is detected.

  Then, the voltage detection unit 24 outputs the lowest voltage upon entry and the lowest voltage after entry to the automatic stop prohibition unit 25. The automatic stop prohibition unit 25 determines whether or not the inrush minimum voltage input from the voltage detection unit 24 is equal to or greater than a threshold value associated with the inrush period. Furthermore, the automatic stop prohibition unit 25 determines whether or not the minimum voltage after rush input from the voltage detection unit 24 is equal to or greater than a threshold value associated with the period after rush.

  The automatic stop prohibiting unit 25 permits the next automatic stop of the engine E when the lowest voltage at the time of entry and the lowest voltage after entry are equal to or greater than the threshold value associated with the detected divided period. On the other hand, if it is less than the threshold value associated with the detected divided period in either the inrush minimum voltage or the inrush minimum voltage, the automatic stop prohibiting unit 25 prohibits the next automatic stop of the engine E. .

  Therefore, the automatic stop prohibiting unit 25 prohibits the next automatic stop of the engine E, for example, when the inrush minimum voltage is equal to or greater than the threshold and the inrush voltage is less than the threshold. Thereby, in the engine control apparatus 1, for example, when the battery B can rotate the ring gear 51, but the rotation speed cannot be increased to a speed at which the engine E can be started, the next automatic It is possible to prevent the stoppage from being permitted.

  In the above-described embodiment, the case where the minimum voltage of the battery B that is starting the engine E is compared with the threshold value to perform the prohibition determination regarding the automatic stop of the engine E has been described. However, the present invention is not limited to this.

  For example, the engine control apparatus 1 may be configured to determine whether or not the voltage of the battery B is sufficient to start the engine E for each rotation speed of the engine E during the start. According to such a configuration, the prohibition determination regarding the automatic stop can be determined more accurately and finely.

  However, when the engine E is started by the starter ST, the amount of decrease in the voltage of the battery B varies depending on the rotational speed of the engine E being started. Therefore, in order to determine whether or not the voltage of the battery B is sufficient to start the engine E for each rotation speed of the engine E in the middle of starting, it is optimal to compare the voltage for each rotation speed of the engine E. It is desirable to store a threshold value.

  However, if it is attempted to store all optimum threshold values to be compared with the voltage for each rotation speed of the engine E, it is necessary to increase the storage capacity accordingly, which leads to an increase in circuit scale and manufacturing cost.

  Therefore, when the engine control device 1 is configured so as to determine whether the voltage of the battery B is sufficient to start the engine E for each rotation speed of the engine E during the start, Based on the corrected voltage of the battery B, the automatic stop prohibition determination is performed.

  Hereinafter, the automatic stop prohibiting unit 25 corrects the voltage detected from the battery B by using FIG. 7 according to the rotation speed of the engine E to be started, and determines whether to prohibit the automatic stop of the engine E based on the corrected voltage. The case of performing will be described.

  FIG. 7 is a diagram illustrating a correspondence relationship between the rotation speed of the engine E and the voltage correction coefficient according to the first embodiment. When permitting or prohibiting automatic stop based on the corrected voltage, the engine control device 1 stores, for example, a voltage correction table shown in FIG.

  The voltage correction table shown in FIG. 7A-1 is a table used when starting the engine E whose rotation is completely stopped. As shown in FIG. 7A-1, in the voltage correction table, the rotation speed (rpm) of the engine E and the detected voltage of the battery B during the period in which the starter ST and the engine E are linked and connected. A correction coefficient to be multiplied is associated.

  When such a voltage correction table is set, as shown in FIG. 7A-1, the correction coefficient 1 is associated with the rotation speed of the engine E being 0 (rpm), and the higher the rotation speed of the engine E, the higher the rotation speed of the engine E becomes. Set so that the value of the correction coefficient is small. This is because the voltage drop of the battery B tends to become smaller as the rotational speed of the engine E becomes higher.

  Then, when the engine E is started by the starter ST, the automatic stop prohibiting unit 25 sets a correction coefficient corresponding to the rotational speed of the engine E with respect to the voltage detected by the voltage detecting unit 24 based on the voltage correction table. Calculate the corrected voltage by multiplication.

  Subsequently, the automatic stop prohibiting unit 25 compares the corrected voltage with one preset threshold value, and permits the automatic stop of the engine E when the corrected voltage is equal to or greater than the threshold value. As described above, by using the voltage correction table, it is possible to appropriately determine whether automatic stop is permitted or prohibited according to the number of revolutions of the engine E without storing a plurality of types of threshold values to be compared with the voltage in advance. .

  Further, the engine control device 1 replaces the voltage correction table shown in FIG. 7A-1 with the correspondence between the engine E rotation speed and the voltage correction coefficient as shown in FIG. 7A-2. It is also possible to store function information indicating the relationship.

  7 indicates a correction coefficient value corresponding to each rotation speed described in the voltage correction table shown in FIG. 7A-1. If such function information is stored, the engine control apparatus 1 can calculate a correction coefficient corresponding to an arbitrary rotation speed using the function information, and therefore stores a correction coefficient for each rotation speed of the engine E. There is no need.

  Moreover, the engine control apparatus 1 can also store a voltage correction table shown in FIG. 7B-1 as a table used when starting the engine E whose rotation has not completely stopped.

  It should be noted that the voltage correction table shown in FIG. 7B-1 is also set so that the value of the correction coefficient decreases as the rotational speed of the engine E increases. However, when setting such a voltage correction table, the value of the correction coefficient at the same rotational speed is set smaller than that of the voltage correction table shown in FIG.

  For example, as shown in FIG. 7 (A-1), when the correction coefficient when the rotation speed is 200 is set to 0.97 in the voltage correction table used for starting the engine E whose rotation is stopped, In the voltage correction table shown in 7 (B-1), 0.92 smaller than 0.97 is set as the correction coefficient when the rotation speed is 200.

  This is because the voltage drop when the rotation speed of the rotating engine E is increased to 200 (rpm) is lower than the voltage decrease amount when the rotation speed of the engine E is increased from 0 to 200 (rpm). This is because it can be predicted that the amount is smaller.

  By using the voltage correction table shown in FIG. 7 (B-1), the automatic stop prohibiting unit 25 is starting the engine E by the starter ST even if a plurality of types of threshold values to be compared with the voltage are not set in advance. In addition, the automatic stop can be appropriately permitted and prohibited.

  Further, the engine control apparatus 1 can store function information shown in FIG. 7B-2 instead of the voltage correction table shown in FIG. Note that □ shown in FIG. 7B-2 indicates the value of the correction coefficient corresponding to each rotation speed described in the voltage correction table shown in FIG. 7B-1.

  If such function information is stored, the engine control device 1 can calculate a correction coefficient corresponding to an arbitrary rotational speed while starting the engine E by the starter ST. Therefore, the engine control apparatus 1 can appropriately permit and prohibit the automatic stop of the engine E even during the period when the engine E is being started by the starter ST.

  Here, a case has been described in which the voltage detected by the voltage detection unit 24 is corrected so as to decrease as the rotational speed of the engine E during startup increases. However, one type of threshold value is stored and the voltage is stored. You may correct | amend the threshold value according to the rotation speed of the engine E, without correct | amending.

  In such a case, the threshold value is corrected so that the threshold value increases as the rotational speed of the engine E during startup increases. Even in this case, the engine control device 1 does not need to store a plurality of types of threshold values for each rotation speed of the engine E to be started, and permits and prohibits automatic stop as in the case of correcting the voltage. Can be done appropriately.

  As described above, the engine control device 1 according to the embodiment is a device that automatically stops the engine E when a predetermined stop condition is satisfied, and automatically starts the engine E when a predetermined start condition is satisfied.

  Then, the engine control device 1 is driven by the electric power of the battery B to drive the motor M that starts the engine E in the first state, and then switches to the second state in which the power consumption is larger than that in the first state. The engine start is switched between the first start control for starting the engine E by driving and the second start control for starting the engine E by starting the drive of the motor M from the second state according to the state of the engine E. Control means (starting control unit 23) is provided.

  Further, the engine control device 1 switches the voltage detection start timing of the battery B during the driving period of the motor M between the case where the first start control is performed by the engine start control means and the case where the second start control is performed. A voltage monitoring unit (voltage detection unit 24) for detecting the voltage of the battery B; an automatic stop prohibiting unit (automatic stop prohibiting unit 25) for prohibiting automatic stop of the engine E based on the voltage detected by the voltage monitoring unit; Is provided.

  Thereby, the engine control apparatus 1 detects the voltage of the battery B at an appropriate timing according to the operation state of the starter ST changed according to the state of the engine E to be started, and automatically stops the engine E based on the detected voltage. Prohibition determination can be made. Therefore, according to the engine control apparatus 1, the prohibition determination regarding the automatic stop of the engine E can be performed appropriately.

(Second Embodiment)
Next, an engine control apparatus according to a second embodiment will be described. In the following, an outline of the engine control method according to the second embodiment will be described with reference to FIG. 8, and then an engine control device to which the engine control method according to the second embodiment is applied will be described. FIG. 8 is a diagram showing an outline of the engine control method according to the second embodiment.

  The engine control method according to the second embodiment (hereinafter referred to as “the present control method”) automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition is satisfied. It is something to be made.

  For example, in the present control method, a stop operation by the driver is performed, so that the engine is automatically stopped when the vehicle is stopped, and so-called idling stop is performed in which the engine is automatically started when the start operation is performed by the driver. Here, the engine stop condition and start condition are the same as those in the first embodiment.

  In this control method, based on the voltage of the battery (hereinafter referred to as “power supply voltage”) that changes depending on the state of the engine starter (hereinafter referred to as “engine start load”) that becomes the load of the battery when starting the engine. Then, when the vehicle is stopped next time, it is determined whether or not the automatic engine stop is prohibited.

  Specifically, in this control method, a power supply voltage (hereinafter referred to as “first voltage”) during a first period in which the engine starting load is driven in the first load state is detected ((1 in FIG. 8). )reference). Subsequently, in the present control method, the first voltage detected in the first period is compared with a predetermined threshold (see (2) in FIG. 8).

  Thereafter, in this control method, when the engine start load drive control is switched to the second load state in which the power consumption of the engine start load is different from the first load state, the engine start load is driven in the second load state. The power supply voltage during the second period (hereinafter referred to as “second voltage”) is detected (see (3) in FIG. 8).

  Subsequently, in the present control method, the second voltage detected in the second period is compared with a predetermined threshold (see (4) in FIG. 8). At this time, the predetermined threshold value compared with the first voltage and the predetermined threshold value compared with the second voltage are set to different values.

  When setting such a predetermined threshold, for example, an engine automatic start test is repeatedly performed in advance, and each time the automatic start is successful, the first voltage and the second voltage detected at the previous automatic start are recorded. The lowest voltage of the recorded first voltage and second voltage is obtained.

  The lowest value of the first voltage acquired in this way is set as a predetermined threshold value to be compared with the first voltage, and the lowest value of the acquired second voltage is set as the predetermined threshold value to be compared with the second voltage.

  In this control method, when the first voltage is equal to or higher than the predetermined threshold for the first voltage and the second voltage is equal to or higher than the predetermined threshold for the second voltage (see (5) in FIG. 8), The automatic stop of the engine is permitted (see (6) in FIG. 8).

  On the other hand, in the present control method, when either one of the first voltage and the second voltage is less than the corresponding predetermined threshold, the next automatic engine stop is prohibited.

  As described above, in the present control method, the voltage detected during the period when the engine start load is driven in the first load state and the voltage detected during the period during which the engine start load is driven in the second load state, Based on the result compared with the different threshold value, the automatic engine stop is prohibited.

  For this reason, according to this control method, even when starting control is performed such that the driving state of an engine starting load such as a starter is switched during the engine starting period, the prohibition determination regarding the automatic engine stop is appropriately performed. be able to.

  Thereby, in this control method, even if the state of the battery is a state where the engine can be restarted, the automatic stop of the engine is prohibited, and the vehicle can be prevented from consuming fuel wastefully. .

  In addition, in this control method, it is possible to prevent the vehicle from being in a failure state where the engine cannot be restarted because the automatic stop of the engine is permitted even though the state of the battery cannot restart the engine. .

  Further, in the case where the engine start load described above is a starter provided with a motor that starts the engine, in this control method, the state of the battery is determined based on the voltage of the battery when the starter is driven.

  In such a case, since the voltage drops most immediately after starter driving is started, it is basically preferable to determine the state of the battery based on the voltage (minimum voltage) immediately after starter driving is started. However, even in the same battery state, for example, due to a change in driving load depending on the crank angle position of the engine at the start of starter driving, a change in the state of battery drop occurs.

  For this reason, in this control method, when the starter is in a driving state, a voltage at a predetermined time immediately after the start of the starter driving and a voltage after the predetermined time have elapsed are detected, and each voltage is set to a preset voltage. As a result, it is possible to improve the battery state determination accuracy.

  Next, an engine control apparatus according to a second embodiment to which the present control method described with reference to FIG. 8 is applied will be described. The engine control apparatus according to the present embodiment is a device that automatically stops the engine when a predetermined stop condition is satisfied, and automatically starts the engine when a predetermined start condition is satisfied.

  In particular, the engine control device according to the present embodiment is an engine starter that changes the operating state of the starter within a period of automatic start of the engine, such as the devices described in Patent Documents 1 to 3 described in the background art. Permits and prohibits automatic engine stop.

  Further, the engine control device according to the present embodiment independently performs automatic engine stop and automatic start similar to the devices described in Patent Documents 1 to 3, and further permits permission for automatic engine stop performed by the own device and You may comprise so that prohibition may be performed.

  Here, prior to the description of the engine control device according to the present embodiment, the configuration of the devices described in Patent Documents 1 to 3 will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram illustrating an outline of the configuration of the device described in Patent Document 1, and FIG. 10 is a diagram illustrating an overview of the configuration of the device described in Patent Document 3.

  The configuration of the device described in Patent Document 2 is similar to the device described in Patent Document 3. For this reason, about the apparatus of patent document 2, after explaining the apparatus of patent document 3, it demonstrates using FIG.

  As shown in FIG. 9, the apparatus 100 described in Patent Document 1 includes two switches 103 and 104 connected in series between a motor 101 and a battery 101 that supplies power to a motor 102 of a starter that starts an engine. Has been.

  Of these two switches 103 and 104, the switch 103 provided on the battery 101 side is a switch that is switched ON / OFF by an ignition key (hereinafter referred to as “key switch 103”).

  On the other hand, a switch 104 provided on the motor 102 side is a switch (hereinafter referred to as “state changeover switch 104”) that is switched ON / OFF by an ECU (Engine Control Unit). The device 100 described in Patent Document 1 includes a resistor 106 that reduces the power supplied from the battery 101 to the motor 102.

  When the key switch 103 is turned on, the device 100 described in Patent Document 1 first drives the motor 102 in the first state, and then enters the second state in which the power consumption is different from the first state. The engine is started by switching the drive control to drive the motor 102.

  Specifically, in the device 100 described in Patent Document 1, after the key switch 103 is turned on, the ECU 105 controls the state changeover switch 104 to connect the battery 101 and the resistor 106, thereby passing through the resistor 106. Then, electric power is supplied from the battery 101 to the motor 102.

  As a result, the motor 102 rotates at a lower rotational speed than when the state changeover switch 104 is turned on to run the engine. Subsequently, in the device 100 described in Patent Document 1, the ECU 105 controls the state changeover switch 104 to directly connect the battery 101 and the motor 102, so that power is transmitted from the battery 101 to the motor 102 without passing through the resistor 106. Is supplied.

  As a result, the motor 102 rotates at a higher rotational speed than when the engine is running and starts the engine. As described above, the device 100 described in Patent Document 1 is configured to switch the drive state of the starter (here, the motor 102) during the period of starting the engine.

  In the device 100 described in Patent Document 1, when the engine is automatically started, when a predetermined start condition is satisfied, the ECU 105 automatically controls the state changeover switch 104 to connect the battery 101 and the resistor 106, Thereafter, the battery 101 and the motor 102 are directly connected to automatically start the engine.

  In the engine control device according to the present embodiment, when the device for automatically starting the engine is the device described in Patent Document 1, the motor 102 is driven by electric power supplied from the battery 101 via the resistor 106. The voltage of the battery 101 in the first period is detected.

  Subsequently, the engine control apparatus according to the present embodiment detects the voltage of the battery 101 in the second period in which the motor 102 is driven by the electric power supplied from the battery 101 without passing through the resistor 106.

  Then, the engine control apparatus according to the present embodiment permits the automatic stop of the engine based on the comparison result obtained by comparing the voltage detected in the first period and the voltage detected in the second period with different threshold values. And determine the prohibition.

  Next, the apparatus described in Patent Document 3 will be described with reference to FIG. As shown in FIG. 10, the device 200 described in Patent Document 3 is a device that starts the engine 220 by controlling the operation of the starter 201.

  The starter 201 includes a motor 202 that starts the engine 220 and a solenoid switch 210 that meshes a pinion gear 203 driven by the motor 202 with a ring gear 221 that is linked to the crankshaft of the engine 220.

  The solenoid switch 210 includes a solenoid 211 and a movable member 212 that operates by energizing the solenoid 211. The movable member 212 is connected to the rotation shaft of the pinion gear 203 via the interlocking member 213.

  In such a starter 201, when the solenoid 211 is not energized, the pinion gear 203 is held at a position where it does not mesh with the ring gear 221, and when the solenoid 211 is energized, it moves to a position where the pinion gear 203 meshes with the ring gear 221. To do.

  The device 200 described in Patent Document 3 that controls the operation of the starter 201 includes a first switch 231 that switches ON / OFF of energization to the solenoid 211 and a second switch 232 that switches ON / OFF of energization to the motor 202. And.

  The device 200 described in Patent Document 3 includes a key switch 233 that switches ON / OFF of the first switch 231 and the second switch 232 by operating an ignition key.

  The device 200 described in Patent Document 3 includes a delay circuit 234 and a key switch 233 that turn on the second switch 232 after a lapse of a predetermined time after the first switch 231 is turned on when the key switch 233 is turned on. Instead of this, an ECU 235 that sequentially turns on the first switch 231 and the second switch 232 is provided.

  Then, when a predetermined start condition is satisfied before the engine 220 is completely stopped, the device 200 first drives the starter 201 in the first state, and then the second power consumption is different from that in the first state. The drive control is switched to this state to drive the motor 202, and the engine 220 is started.

  Specifically, in the device 200 described in Patent Document 3, when a predetermined start condition is satisfied, when the rotational speed of the engine 220 decreases to a rotational speed at which the pinion gear 203 can be engaged with the ring gear 221, The ECU 235 turns on the first switch 231.

  As a result, the solenoid switch 210 is driven, the pinion gear 203 moves to a position where the pinion gear 203 meshes with the ring gear 221, and the starter 201 enters the first state. Subsequently, in the apparatus 200 described in Patent Document 3, the ECU 235 turns on the second switch 232 after a predetermined time has elapsed. Thereby, the motor 202 is driven, the starter 201 is in the second state, and the engine 220 is started.

  In the engine control device according to the present embodiment, when the device for automatically starting the engine 220 is the device described in Patent Document 3, the starter 201 is driven in the first state of the battery 230 in the first period. Detect voltage. Subsequently, the engine control apparatus according to the present embodiment detects the voltage of the battery 230 in the second period in which the starter 201 is driven in the second state.

  The engine control apparatus according to the present embodiment relates to the automatic stop of the engine 220 based on a comparison result obtained by comparing the voltage detected in the first period and the voltage detected in the second period with different threshold values. Determine permission and prohibition.

  Next, the apparatus described in Patent Document 2 will be described. The apparatus described in Patent Document 2 is different from the apparatus 200 described in Patent Document 3 except that the delay circuit 234 is not provided and the control procedure of the first switch 231 and the second switch 232 by the ECU 235 is different. It is the same composition.

  In the apparatus described in Patent Document 2, when a predetermined start condition is satisfied before the engine 220 is completely stopped, first, the starter 201 is driven in the first state, and then the power consumption is the first state. The driving control is switched to the second state with different motors to drive the motor 202, and the engine 220 is started.

  Specifically, in the device described in Patent Document 2, when a predetermined start condition is satisfied, the ECU 235 first turns on the second switch 232. As a result, the pinion gear 203 starts idling, and the starter 201 enters the first state.

  Subsequently, in the device described in Patent Document 2, when the ECU 235 determines that the rotation of the pinion gear 203 and the rotation of the engine 220 are synchronized, the first switch 231 is turned on. As a result, the solenoid switch 210 is driven, the pinion gear 203 moves to a position where the pinion gear 203 meshes with the ring gear 221, the starter 201 enters the second state, and the engine 220 is started.

  In the engine control device according to the present embodiment, when the device that automatically starts the engine 220 is the device described in Patent Document 2, the starter 201 is driven in the first state of the battery 230 in the first period. Detect voltage. Subsequently, the engine control apparatus according to the present embodiment detects the voltage of the battery 230 in the second period in which the starter 201 is driven in the second state.

  The engine control apparatus according to the present embodiment relates to the automatic stop of the engine 220 based on a comparison result obtained by comparing the voltage detected in the first period and the voltage detected in the second period with different threshold values. Determine permission and prohibition.

  Next, the configuration of the engine control apparatus according to the present embodiment will be described with reference to FIG. FIG. 11 is a block diagram showing a configuration of an engine control device 1a according to the second embodiment. In the following, the devices described in Patent Documents 1 to 3 described above will be described as engine starting devices that automatically stop and start the engine.

  The engine control device 1a shown in FIG. 11 causes the engine start device to automatically stop the engine when a predetermined stop condition is satisfied, and then causes the engine start device to switch the engine when the predetermined start condition is satisfied. It is a device that performs automatic starting.

  As shown in FIG. 11, the engine control device 1a is connected to a sensor SEa, an engine Ea, an engine start load (hereinafter referred to as “starter STa”), and a battery Ba. The starter STa corresponds to the motor 102 shown in FIG. 9 when the engine starting device is the device described in Patent Document 1, and shown in FIG. 10 when the engine starting device is the device described in Patent Document 2 or 3. This corresponds to the starter 201.

  In FIG. 11, for simplicity of explanation, the starter STa and the engine control device 1 a are illustrated as being directly connected. However, actually, the starter STa and the engine control device 1 a are the engine starter devices. The ECUs 105 and 235 are connected.

  That is, the engine control device 1a outputs a control signal for starting the engine Ea to the ECUs 105 and 235 of the engine starting device, thereby causing the ECUs 105 and 235 to control the operation of the starter STa to start the engine Ea.

  The sensor SEa includes a plurality of detection devices that detect the state of the vehicle. Specifically, the sensor SEa detects the number of revolutions of the engine Ea, the speed of the vehicle, the acceleration of the vehicle, the position of the shift lever, the operation state of the accelerator, the operation state of the brake, etc. Output to 1a.

  The engine Ea is an internal combustion engine that drives the vehicle, and the battery Ba is a power source that supplies electric power to various electronic devices mounted on the vehicle including the starter STa.

  Further, the engine control device 1a includes a control unit 2a for automatically stopping and automatically starting the engine Ea, start / stop condition information 31a, automatic stop permission information 32a, and threshold information 33a used for automatically stopping and automatically starting the engine Ea. And a stored storage unit 3a.

  The start / stop condition information 31a is information indicating a stop condition and a start condition of the engine Ea. Specifically, the storage unit 3a stores, as stop conditions, conditions such as the number of revolutions of the engine Ea being idle, the vehicle speed and acceleration being 0, the accelerator being OFF, the brake being ON, and the shift position being neutral or parking. doing.

  Then, the control unit 2a automatically stops the engine Ea when all of the stop conditions are satisfied in a state where the automatic stop of the engine Ea is permitted.

  In addition, the storage unit 3a stores conditions such as a shift position being shifted from neutral or parking to drive while the brake is ON as a start condition. Then, when the start condition is satisfied after the engine Ea is automatically stopped, the control unit 2a automatically restarts the engine Ea.

  The automatic stop permission information 32a is information indicating whether automatic stop of the engine Ea is permitted or prohibited. The automatic stop permission information 32a is referred to by the control unit 2a when a stop condition for the engine Ea is satisfied.

  The threshold information 33a is information indicating a threshold to be compared with the voltage of the battery Ba during the period in which the starter STa is driven. Specifically, the storage unit 3a uses, as the threshold information 33a, a threshold (hereinafter referred to as “threshold Th”) used when starting the engine Ea whose rotation is stopped, and the rotation is completely stopped. The threshold value used when starting the engine Ea which is not present is stored.

  In particular, the storage unit 3a uses a threshold value (hereinafter referred to as “a threshold value” used for a first period in which the starter STa is driven in the first state as a threshold value used when starting the engine Ea whose rotation has not stopped. Threshold value Th1a ") and a threshold value (hereinafter referred to as" Th2a ") used in the second period in which the starter STa is driven in the second state.

  The storage unit 3a corresponds to the time elapsed after starting the starter STa in the first state, the time elapsed after starting the starter STa in the second state, the rotational speed of the engine Ea when automatically starting, and the like. It is also possible to store different threshold values.

  The control unit 2a controls the overall operation of the engine control apparatus 1a, and includes an information processing apparatus having a CPU, a ROM, and a RAM. The control unit 2a includes a plurality of processing units that function when the CPU reads various programs from the ROM and executes them using the RAM as a work area. Specifically, the control unit 2a includes a start / stop determination unit 21a, a stop control unit 22a, a start control unit 23a, a voltage detection unit 24a, and an automatic stop prohibition unit 25a.

  The start / stop determination unit 21a determines whether the stop condition or the start condition of the engine Ea is satisfied based on each detection result input from the sensor SEa and the start / stop condition information 31a stored in the storage unit 3a. It is a processing unit for determining whether or not.

  When the start / stop determination unit 21a determines that the stop condition of the engine Ea is satisfied, the start / stop determination unit 21a outputs the determination result to the stop control unit 22a. On the other hand, when it is determined that the start condition of the engine Ea is satisfied, the start / stop determination unit 21a outputs a determination result to the start control unit 23a.

  The stop control unit 22a is a processing unit that automatically stops the engine Ea. When a determination result indicating that the stop condition is satisfied is input from the start / stop determination unit 21a, the stop control unit 22a refers to the automatic stop permission information 32a stored in the storage unit 3a, and the automatic stop is performed. If it is permitted, the engine Ea is automatically stopped.

  The start control unit 23a is a processing unit that automatically starts the engine Ea. The start control unit 23a automatically starts the engine Ea when a determination result indicating that the start condition is satisfied is input from the start / stop determination unit 21a.

  The voltage detection unit 24a is a processing unit that functions as a voltage monitoring unit that detects the voltage of the battery Ba during a period in which the starter STa is being driven, and outputs a detection result to the automatic stop prohibition unit 25a.

  The automatic stop prohibition unit 25a is a processing unit that determines whether or not automatic stop of the engine Ea is prohibited. The automatic stop prohibition unit 25a determines whether or not automatic stop is prohibited based on the voltage of the battery Ba input from the voltage detection unit 24a and the threshold values Th1a and Th2a stored in the storage unit 3a. The operation of the automatic stop prohibiting unit 25a will be described later with reference to FIG.

  Next, the voltage change of the battery Ba when starting the engine Ea whose rotation has not completely stopped will be described with reference to FIG. FIG. 12 is a diagram illustrating a voltage change of the battery Ba when starting the engine Ea in which the rotation according to the second embodiment is not completely stopped.

  As shown in FIG. 12 (A), after the engine Ea is automatically stopped at time T1, as shown in FIG. 12 (B), if the start condition is satisfied before the rotation of the engine Ea stops at time T2, The starter STa is driven (ON) in the first state, and the voltage of the battery Ba decreases at time T2, as shown in FIG.

  After that, as shown in FIG. 12C, when the load state of the starter STa is switched (ON) at time T3 and the starter STa is driven in the second state, the voltage of the battery Ba is changed to FIG. As shown in FIG. 4, the voltage drops at time T3.

  Thereafter, as shown in FIG. 12A, the engine Ea is successfully started at time T4, and when the starter STa is stopped at time T4 as shown in FIGS. 12B and 12C, As shown in FIG. 12D, the voltage of the battery Ba returns to the voltage before driving the starter STa.

  Thus, when starting the engine Ea whose rotation has not completely stopped, the voltage of the battery Ba is set at the time T2 when the starter STa starts to be driven in the first state and the starter STa is in the second state. It greatly decreases at time T3 when driving is started (see FIG. 12D).

  Further, as shown in FIG. 12D, the periods T2 to T3 (hereinafter referred to as “first period”) in which the starter STa is driven in the first state, and the starter STa is driven in the second state. In the period T3-T4 (hereinafter referred to as “second period”), the voltage variation state of the battery Ba is different.

  Therefore, the engine control device 1a is configured to permit and prohibit automatic stop in consideration of the voltage drop of the battery Ba in the first period and the voltage drop of the battery Ba in the second period.

  Next, the operation of the automatic stop prohibiting unit 25a will be described with reference to FIG. FIG. 13 is a diagram illustrating an example of the operation of the automatic stop prohibiting unit 25a according to the second embodiment. Note that the voltage change of the battery Ba shown in FIG. 13 corresponds to FIG.

  First, the automatic stop prohibiting unit 25a first determines the lowest value of the voltage of the battery Ba (hereinafter referred to as “first”) input from the voltage detecting unit 24a during the first period T2 to T3 when the starter STa is driven in the first state. (Referred to as (1) in FIG. 13).

  Subsequently, the automatic stop prohibiting unit 25a includes a minimum value of the voltage of the battery Ba (hereinafter referred to as “first”) input from the voltage detection unit 24a during the second period T3 to T4 in which the starter STa is driven in the second state. 2 ”(refer to (2) in FIG. 13).

  Subsequently, the automatic stop prohibiting unit 25a has the first minimum voltage V1a equal to or higher than the threshold Th1a stored in the storage unit 3a, and the second minimum voltage V2a is equal to or higher than the threshold Th2a stored in the storage unit 3a. If there is (see (3) in FIG. 13), the automatic stop permission information 32a indicating that the next automatic stop is permitted is stored in the storage unit 3a (see (4) in FIG. 13).

  On the other hand, the automatic stop prohibition unit 25a prohibits the next automatic stop when the first minimum voltage V1a is not less than the threshold Th1a and the second minimum voltage V2a is not less than the threshold Th2a. The automatic stop permission information 32a indicating that the data is to be stored is stored in the storage unit 3a.

  In the engine control device 1a, the threshold value Th1a to be compared with the first lowest voltage V1a and the threshold value Th2a to be compared with the second lowest voltage V2a are different values (see (5) in FIG. 13).

  Such threshold values Th1a and Th2a are determined based on the result of simulation in advance. For example, the automatic stop prohibition unit 25a performs automatic stop permission determination while changing each of the threshold values Th1a and Th2a, and after the engine Ea is automatically stopped according to the determination result, a simulation for starting the engine Ea is performed in advance.

  As a result of such simulation, the combination of threshold values Th1a and Th2a having the lowest value among the combinations of threshold values Th1a and Th2a set when the engine Ea is successfully started is stored in the storage unit 3a as threshold information 33a.

  As described above, the engine control device 1a can appropriately permit and prohibit automatic stop by storing different optimal values as the threshold values Th1a and Th2a in the storage unit 3a as the threshold information 33a.

  Next, the process which the control part 2a of the engine control apparatus 1a performs is demonstrated. Here, the control unit 2a executes processing according to the flowchart shown in FIG. 5, but executes processing different from that of the engine control device 1 according to the first embodiment when the engine Ea is automatically started in step S105. .

  For this reason, below, the process performed when the control part 2a performs the automatic start of the engine Ea is demonstrated using FIG. FIG. 14 is a flowchart illustrating processing executed by the control unit 2a according to the second embodiment.

  When the engine Ea is automatically started in step S105, the control unit 2a first determines whether or not the first start control is selected as shown in FIG. 14 (step S301). Here, the first start control is drive control in which the starter STa is driven in the second state after being driven in the first state described above.

  Specifically, in the first start control, when the engine start device is the device 100 described in Patent Document 1, the motor 102 is driven to rotate at a lower speed than usual so as to run the engine. Drive control for starting the engine by increasing the rotational speed of the engine.

  Further, in the first start control, when the engine starter is the device described in Patent Document 2, after the starter 201 is idling, the idling pinion gear 203 is moved to the ring of the engine 220 (here, engine Ea). This is drive control for starting the engine 220 by moving it to a position where it engages with the gear 221.

  Further, in the first starting control, when the engine starting device is the device 200 described in Patent Document 3, the pinion gear 203 of the starter 201 is moved to a position where it meshes with the ring gear 221 of the engine 220 (in this case, the engine Ea). After that, the motor 202 is driven to start the engine 220 (here, the engine Ea).

  And when it determines with the 1st start control having been selected (step S301, Yes), the control part 2a starts the drive (1st start control) by the 1st state of starter STa (step S302), The first lowest voltage V1a is acquired (step S303).

  Subsequently, the control unit 2a drives the starter STa by switching to the second load state, which is a different load state (step S304), and obtains the second minimum voltage V2a (step S305).

  Thereafter, when it is determined that the start of the engine Ea is completed, the control unit 2a stops driving the starter STa and ends the start control (step S306). Subsequently, the control unit 2a determines whether or not the first lowest voltage V1a is equal to or higher than the threshold Th1a and the second lowest voltage V2a is equal to or higher than the threshold Th2a (Step S307).

  When the control unit 2a determines that the first minimum voltage V1a is equal to or higher than the threshold Th1a and the second minimum voltage V2a is equal to or higher than the threshold Th2a (step S307, Yes), the automatic stop of the engine Ea is permitted. (Step S308), and the process ends.

  On the other hand, when either one of the conditions that the first lowest voltage V1a is equal to or higher than the threshold Th1a and the second lowest voltage V2a is equal to or higher than the threshold Th2a is not satisfied (No in step S307), the control unit 2a Is automatically stopped (step S309), and the process is terminated.

  Moreover, when it determines with the 1st start control not being selected in step S301 (step S301, No), the control part 2a starts 2nd start control (step S310). Note that the first start control is not selected in step S301, for example, if the engine start device is the device 100 described in Patent Document 1, the start temperature of the engine at the time of start is high and there is no need to run the starter. Is the case.

  In addition, the first start control is not selected in step S301 if the engine start device is the device described in Patent Document 2 or the device 200 described in Patent Document 3, the engine 220 to start (here, the engine Ea) This is a case where the rotation of the motor has stopped completely.

  And the control part 2a performs the following 2nd starting controls in step S310. That is, when the engine starting device is the device described in Patent Literature 1, the control unit 2a starts the engine by energizing the starter through a path that does not go through the resistor 106 from the beginning.

  Alternatively, the control unit 2a reduces the resistance value of the resistor 106 in the first state (implemented by configuring the resistor 106 with a variable resistor or the like), and goes to the starter in the first state and the second state. The engine is started with almost no difference in the resistance value of the energization path.

  When the engine starting device is the device described in Patent Document 2, the control unit 2a starts driving the motor 202 after meshing the pinion gear 203 with the ring gear 221 without idling, and the engine 220 (here Now, the engine Ea) is started.

  Further, when the engine starting device is the device 200 described in Patent Document 3, the control unit 2 sets the pinion of the starter 201 (here, the starter STa) in a state where the engine 220 (here, the engine Ea) is completely stopped. After the gear 203 is moved to a position where it engages with the ring gear 221 of the engine 220 (here, engine Ea), the motor 202 is driven to start the engine 220 (Ea).

  Subsequently, the control unit 2a obtains the minimum voltage of the battery Ba (step S311). When determining that the start of the engine Ea is completed, the control unit 2a stops driving the starter STa and ends the start control (step S312). Then, the control unit 2a determines whether or not the acquired minimum voltage is equal to or higher than a predetermined threshold Th (Step 313).

  At this time, the threshold value Th to be compared with the voltage is a value different from the above-described threshold values Th1a and Th2a, and is the value of the voltage of the battery Ba that is the minimum necessary for starting the engine Ea whose rotation has completely stopped.

  If the control unit 2a determines that the voltage of the battery Ba is equal to or higher than the threshold value Th (step S313, Yes), the automatic stop of the engine Ea is permitted (step S314), and the process is terminated. On the other hand, if the control unit 2a determines that the voltage of the battery Ba is less than the threshold Th (step S313, No), the control unit 2a prohibits the automatic stop of the engine Ea (step S315) and ends the process.

  As described above, in the engine control device 1a, the voltage of the battery Ba is detected for each period in which the starter STa is driven by the first, second, and third start controls, and the threshold value corresponding to each detected voltage is detected. The automatic stop is permitted or prohibited based on the comparison result.

  For this reason, according to the engine control device 1a, even when the driving state (load state) of the starter STa is switched during the start of the engine Ea, permission and prohibition regarding the automatic stop of the engine Ea are appropriately performed. be able to.

  By the way, the automatic stop prohibiting unit 25a further includes a first period in which the starter STa is driven in the first state and a second period in which the starter STa is driven in the second state. It is also possible to configure so that automatic stop is permitted and prohibited using the voltage of the battery Ba in each divided period.

  Below, the modification of the automatic stop prohibition part 25a is demonstrated using FIG. FIG. 15 is a diagram illustrating an operation of the automatic stop prohibiting unit 25a according to the modification. Note that the voltage change of the battery Ba shown in FIG. 15 corresponds to FIG.

  As shown in FIG. 15, when the starter STa starts to be driven in the first state at the time T2, the automatic stop prohibiting unit 25a according to the present modified example has a period from the time T2 to the time T21 after a predetermined time has elapsed ( The voltage of the battery Ba (first inrush voltage V1b) in the first inrush period) is acquired (see (1) in FIG. 15). The predetermined time here is, for example, 100 ms.

  Subsequently, the automatic stop prohibiting unit 25a according to the present modification includes the voltage of the battery Ba during the period from the time T21 to the time T3 when the starter STa starts to be driven in the second state (the period after the first entry) (first time). The voltage V1c after rushing is acquired (see (2) in FIG. 15).

  Subsequently, the automatic stop prohibiting unit 25a according to the present modification acquires the voltage of the battery Ba (second inrush voltage V2b) in the period from the time T3 to the time T31 after a predetermined time has elapsed (second inrush period). (See (3) in FIG. 15). The predetermined time here is also 100 ms.

  Subsequently, the automatic stop prohibiting unit 25a according to the present modification includes the voltage of the battery Ba (second post-entry voltage V2c) in the period from time T31 to time T4 when the starter STa is stopped (second post-entry period). ) Is acquired (see (4) of FIG. 15).

  Subsequently, the automatic stop prohibiting unit 25a according to the present modification compares the first inrush voltage V1b with the second inrush voltage V2b (see (5) in FIG. 15), and compares the first inrush voltage V1b and the second inrush voltage V1b. 2. The lowest voltage (the lowest inrush voltage V3b) of the inrush voltage V2b is determined (see (6) in FIG. 15).

  Subsequently, the automatic stop prohibiting unit 25a according to the present modification compares the first post-rush voltage V1c and the second post-rush voltage V2c (see (7) in FIG. 15), and the first post-rush voltage V1c and the second post-rush voltage V1c (2) The lowest voltage V2c after entry (the lowest entry voltage V3c) is determined (see (8) in FIG. 15).

  Subsequently, the automatic stop prohibiting unit 25a according to the present modified example has a case where the lowest inrush voltage V3b is equal to or higher than a preset threshold Thb and the lowest after-rush voltage V3c is equal to or higher than a preset threshold Thc (FIG. 15 (see (9)), the automatic stop of the engine Ea is permitted (see (10) in FIG. 15).

  In this modification, optimum values different from each other are set in advance as the thresholds Thb and Thc (see (11) in FIG. 15). The threshold values Thb and Thc are determined by a simulation performed in advance.

  For example, the automatic stop prohibition unit 25a performs automatic stop permission determination while changing the values of the threshold values Thb and Thc, and after the engine Ea is automatically stopped according to the determination result, a simulation for starting the engine Ea is repeatedly performed in advance. .

  As a result of the simulation, among the combinations of threshold values Thb and Thc set when the engine Ea is successfully started, the combination of the lowest threshold values Thb and Thc is determined as the threshold values Thb and Thb.

  As described above, the engine control apparatus 1a permits and prohibits automatic stop based on the result of comparing the optimum threshold values different from each other as the threshold values Thb and Thc with the lowest inrush voltage V3b and the lowest inrush voltage V3c. The automatic stop can be permitted and prohibited more accurately.

  By the way, when the engine control device 1a detects the first inrush voltage V1b, the first inrush voltage V1c, the second inrush voltage V2b, and the second inrush voltage V2c, it relates to the automatic stop of the engine Ea as follows. It can also be configured to allow and prohibit.

  For example, the engine control device 1a determines the average inrush voltage by averaging the first inrush voltage V1b and the second inrush voltage V2b, and calculates the first inrush voltage V1c and the second inrush voltage V2c. Average and determine the average post-rush voltage.

  Then, the average inrush voltage and the average inrush voltage are compared with different optimum threshold values, respectively, and when the average inrush voltage is equal to or greater than the threshold and the average inrush voltage is equal to or greater than the threshold, the engine Ea Allow automatic stop of.

  On the other hand, the engine control device 1a prohibits the automatic stop of the engine Ea when any one of the conditions that the average inrush voltage is equal to or higher than the threshold and the average after-rush voltage is equal to or higher than the threshold is not satisfied.

  Note that the threshold value to be compared with the average inrush voltage and the average post-inrush voltage can be determined by repeatedly performing a simulation in advance, similarly to the threshold values Thb and Thc. Even with this configuration, the engine control apparatus 1a can appropriately permit and prohibit automatic stop.

  Further, for example, the engine control device 1a compares the first inrush voltage V1b, the first inrush voltage V1c, the second inrush voltage V2b, and the second inrush voltage V2c with different optimum threshold values, respectively. It can also be configured to allow automatic stop of the engine Ea when all the voltages are equal to or higher than the corresponding threshold values.

  In the case of such a configuration, the engine control device 1a can cope with any one of the first inrush voltage V1b, the first inrush voltage V1c, the second inrush voltage V2b, and the second inrush voltage V2c. When it is less than the threshold value, the automatic stop of the engine Ea is prohibited.

  With this configuration, the engine control device 1a can more accurately and finely determine whether automatic stop is permitted or prohibited.

  In the second embodiment and the modification described above, the automatic stop prohibiting unit 25a permits and prohibits the automatic stop based on the measured value of the voltage detected by the voltage detecting unit 24a. You may permit and prohibit automatic stop based on the voltage corrected according to the rotation speed of Ea.

  When permitting and prohibiting automatic stop based on the voltage of the battery Ba corrected according to the rotation speed of the engine Ea, the automatic stop prohibiting unit 25a is for voltage correction shown in FIG. 7 as in the first embodiment. The voltage of the battery Ba is corrected using the table and the function information.

  If the automatic control is permitted and prohibited based on the corrected voltage, the engine control device 1a needs to store a plurality of types of threshold values to be compared with the voltage in advance as in the first embodiment. Absent.

DESCRIPTION OF SYMBOLS 1, 1a Engine control apparatus 2, 2a Control part 21, 21a Start / stop determination part 22, 22a Stop control part 23, 23a Start control part 24, 24a Voltage detection part 25, 25a Automatic stop prohibition part 3, 3a Storage part 31 , 31a Start / stop condition information 32, 32a Automatic stop permission information 33, 33a Threshold information SE, SEa Sensor E, Ea Engine ST, STa Starter M Motor 44 Plunger B, Ba Battery

Claims (6)

When a predetermined stop condition is satisfied, provided in a vehicle equipped with an engine start mechanism capable of switching between a connected state in which the starter motor and the rotation shaft of the engine are connected and a disconnected state in which the starter motor is not connected. An engine control device for automatically stopping the engine and automatically starting the engine when a predetermined start condition is satisfied,
When starting the engine, starter drive control for driving the starter motor using electric power from a battery, and connection control for changing the start mechanism from a non-connected state to a connected state using electric power from the battery. Engine start control means to perform,
Battery state detection means for detecting a voltage of the battery at the time of starting the engine by the engine start control means and detecting a battery state based on the detected voltage;
Automatic stop prohibiting means for prohibiting automatic stop of the engine based on the battery state detected by the battery state detecting means,
The engine start control means includes a first start control for performing the connection control in a state where the starter motor is driven by the starter drive control, and a second start control for performing the starter drive control after performing the connection control. Is possible and
The battery state detection means is configured to make the detection of the battery state different between when the first start control is performed by the engine start control means and when the second start control is performed. A characteristic engine control device. The battery state detection means includes
The time period during which the voltage of the battery used for detection of the battery state is detected differs between when the first start control is performed by the engine start control means and when the second start control is performed. The engine control device according to claim 1, wherein The engine start control means includes
The engine control device according to claim 1 or 2, wherein the first start control is performed when it is necessary to perform the start control of the engine when the engine is in a rotating state. The battery state detection means includes
If the first start-up control is performed by the engine start control means detects the battery state of the first period after the connection control after the starter drive control is performed is performed, the engine When the second start control is performed by the start control means, the battery state in the second period after the starter drive control is performed after the connection control is performed is detected. Item 4. The engine control device according to any one of Items 1 to 3.   The battery state detection means includes
  When the first start control is performed, the battery state of the third period in which the starter drive control is performed but the connection control is not performed is detected,
  The automatic stop prohibiting means is
  The automatic stop is prohibited in consideration of the battery state detected by the battery state detection means in the third period.
  The engine control device according to claim 4. The automatic stop prohibiting means is
When the battery state detection means detects the voltage of the battery as the battery state, the engine is automatically stopped based on a minimum value obtained by multiplying the voltage of the battery by a correction value according to the engine speed. The engine control device according to any one of claims 1 to 5 , wherein the engine control device is prohibited.

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