JP5896288B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that is applied to an internal combustion engine having a cylinder injection valve and a port injection valve and configured to perform split injection.

Spark ignition type internal combustion engines include direct injection gasoline engines having a supercharger and an in-cylinder injection valve that injects fuel directly into the cylinder. In a direct injection gasoline engine with a supercharger, it is known to inject fuel in both an intake stroke and a compression stroke.
Some turbocharged gasoline engines have a port injection valve that injects fuel into an intake port in addition to the in-cylinder injection valve.

  Patent document 1 is disclosing the injection control apparatus of the gasoline engine with a supercharger which has a cylinder injection valve and a port injection valve. In this injection control device, for example, a high rotation high load region is defined as a combustion noise region, and when the engine operating state is in this combustion noise region, combustion speed reduction control is performed to suppress the combustion noise. Specifically, the ECU performs control to drive the ignition plug (igniter) to retard the ignition timing, or to split the fuel injection by the in-cylinder injection valve (split injection) to reduce the combustion speed. To do.

And when this deterioration of a combustion state is detected, this injection control apparatus performs control (fuel injection form switching control) which switches a fuel injection form so that a cylinder injection valve fuel injection ratio may fall.
According to Patent Document 1, it is said that the fuel injection mode switching control can suitably suppress the deterioration of the combustion state caused by the reduction in the combustion speed while suppressing the combustion noise.

Japanese Patent Laying-Open No. 2005-146884 (paragraph numbers 0044, 0045, 0050, etc.)

  By the way, as the inventor knows, in an internal combustion engine having a supercharger and an in-cylinder injection valve, when split injection is performed during acceleration, smoke and particulate matter are generated in the latter half of the acceleration. It is desirable that the amount and number of smoke and particulate matter released be as small as possible.

  The present invention has been made in view of the above circumstances, and an object thereof is to suppress the generation of smoke and particulate matter in the late stage of acceleration in an internal combustion engine having a supercharger, an in-cylinder injection valve, and a port injection valve. An object of the present invention is to provide a control device for an internal combustion engine.

In order to achieve the above object, according to one aspect of the present invention, a supercharger, in-cylinder fuel injection means for directly injecting fuel into a combustion chamber, and port injection for injecting fuel into an intake port are performed. When accelerating an internal combustion engine having a port fuel injection means, a split injection is performed in which fuel is injected into the combustion chamber by the in-cylinder fuel injection means in both the intake stroke and the compression stroke of the internal combustion engine. In the control device for an internal combustion engine, when the one parameter selected from the charging efficiency, the volumetric efficiency, the load, and the intake pressure is equal to or greater than a first threshold value, the split injection is executed to the in-cylinder fuel injection means a split injection control means for said parameters to execute the port injection to the port fuel injection means when less than the first threshold value is the second threshold value or more is larger than the first threshold value To come, the split injection and in parallel, causes execute the port injection, and a port injection control means for prohibiting the port injection when it is within a predetermined range of less than the first threshold and the second threshold value A control device for an internal combustion engine is provided.

  In the control apparatus for an internal combustion engine according to one aspect, the port injection is executed together with the divided injection when one parameter selected from the charging efficiency, the volume efficiency, the load, or the intake pressure is equal to or more than the second threshold value. According to the port injection, the homogenization of the mixed state of fuel and air is promoted, and the combustion state is improved as compared with the case of only the split injection. For this reason, according to this control apparatus, generation | occurrence | production of smoke and a particulate matter in the late stage of acceleration is suppressed.

When the threshold value corresponding to the boundary between the non-supercharged region and the supercharged region that is larger than the first threshold value and smaller than the second threshold value is set as the third threshold value, the port injection control unit has the parameter It may be configured to cause the port fuel injection means to execute the port injection in parallel with the divided injection when it is equal to or more than the threshold value and less than the third threshold value.
According to this configuration, the combustion state is improved even when the parameter is greater than or equal to the first threshold and less than the third threshold.

The port injection control means prohibits execution of port injection by the port fuel injection means when the parameter is greater than or equal to the third threshold and less than the second threshold, and the split injection control means is configured such that the parameter is greater than or equal to the third threshold and second When it is less than the threshold value, the in-cylinder fuel injection unit may be configured to execute split injection.
According to this configuration, when the parameter is greater than or equal to the third threshold value and less than the second threshold value, only split injection is executed, and good acceleration performance is ensured.
The port injection control means sets the ratio of the injection amount of the port fuel injection means to the total injection amount of the in-cylinder fuel injection means and the port fuel injection means to the first ratio when the parameter is equal to or greater than the second threshold value. The port injection is executed, and when the parameter is less than the first threshold value, the ratio of the injection amount of the port fuel injection means is set to the second ratio that is larger than the first ratio, and the port injection is executed. It may be configured.

  ADVANTAGE OF THE INVENTION According to this invention, in the internal combustion engine which has a supercharger, an in-cylinder injection valve, and a port injection valve, the control apparatus of an internal combustion engine which suppresses generation | occurrence | production of the smoke of late acceleration and a particulate matter is provided.

It is a figure for demonstrating the structure of the control apparatus of the internal combustion engine which concerns on 1st Embodiment. It is a flowchart which shows the schematic procedure of the division | segmentation injection control method which the control apparatus of FIG. 1 performs. 3 is a schematic timing chart when the divided injection control method of FIG. 2 is executed, where (a) is an accelerator opening change amount, (b) is ON / OFF of divided injection, (c) is a port injection ratio, ( d) shows the charging efficiency, (e) shows the torque, and (f) shows the time change of the smoke generation amount. It is a flowchart which shows the schematic procedure of the division | segmentation injection control method which the control apparatus of the internal combustion engine which concerns on 2nd Embodiment performs. 5 is a schematic timing chart when the divided injection control method of FIG. 4 is executed, where (a) is an accelerator opening change amount, (b) is ON / OFF of divided injection, (c) is a port injection ratio, ( d) shows the charging efficiency, (e) shows the torque, and (f) shows the time change of the smoke generation amount. It is a figure for demonstrating the structure of the control apparatus of the internal combustion engine which concerns on 3rd Embodiment. It is a figure for demonstrating the structure of the control apparatus of the internal combustion engine which concerns on 4th Embodiment. It is a figure for demonstrating the structure of the control apparatus of the internal combustion engine which concerns on 5th Embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

(First embodiment)
FIG. 1 shows a schematic configuration of an internal combustion engine 10 and a control device 12 of the internal combustion engine 10 according to the first embodiment. The internal combustion engine 10 and the control device 12 are mounted on a vehicle (not shown).

  The internal combustion engine 10 includes a crankcase 14 and a cylinder block 16, and one or more cylinders 18 are defined inside the cylinder block 16. A crankshaft 20 is rotatably disposed in the crankcase 14, and a piston 22 is reciprocally disposed in each cylinder 18. The piston 22 is connected to the crankshaft 20 via a connecting rod 24.

  A cylinder head 26 is attached to the cylinder block 16. The cylinder head is disposed so as to close the open end of the cylinder 18, and a combustion chamber 28 is formed between the piston 22 and the cylinder head 26.

  The cylinder head 26 is provided with an intake port 30 and an exhaust port 32 communicating with the fuel chamber 28 corresponding to the cylinder 18, and an intake valve 34 and an exhaust valve 36 are provided at the intake port 30 and the exhaust port 32, respectively. It has been. The intake valve 34 is reciprocated by an intake cam 38 to open and close the intake port 30. The exhaust valve 36 is reciprocated by the exhaust cam 40 to open and close the exhaust port 32.

  Further, in-cylinder injection valves (in-cylinder fuel injection valves) 42 are attached to the cylinder head 26 corresponding to the respective cylinders 18. The in-cylinder injection valve 42 constitutes an in-cylinder fuel injection unit that directly injects fuel into the combustion chamber 28. The fuel is gasoline, and fuel is supplied to the in-cylinder injection valve 42 from a fuel tank through a feed pump and a high-pressure pump, although not shown. The in-cylinder injection valve 42 opens and closes according to a command from the control device 12 and injects fuel into the combustion chamber 28 with a predetermined injection amount.

  Further, a port injection valve (port fuel injection valve) 43 is attached to the cylinder head 26 corresponding to each cylinder 18. The port injection valve 43 constitutes a port fuel injection unit that injects fuel into the intake port 30. Although not shown, the port injection valve 43 is supplied with fuel from a fuel tank via a feed pump. The port injection valve 43 opens and closes in accordance with a command from the control device 12 and injects fuel at a predetermined injection amount. The fuel injected from the port injection valve 43 is supplied into the combustion chamber 28 through the intake port 30.

  Furthermore, a spark plug 44 is attached to the cylinder head 26 corresponding to each cylinder 18, and the spark plug 44 ignites and burns an air-fuel mixture containing fuel in the combustion chamber 28.

An intake passage 46 is connected to the intake port 30. The intake passage 46 is a passage for supplying air to the combustion chamber 28 and is constituted by piping or the like. The intake passage 46 includes an air filter 48 for purifying air, a compressor 50 for compressing air, an intercooler 52 for cooling the compressed air, and a throttle valve for adjusting the flow rate of air. 54 is provided.
The throttle valve 54 is, for example, an electronic control valve (ETV) that can electronically control the opening degree, and the throttle valve 54 is driven by a throttle valve actuator 55.

  An exhaust passage 56 is connected to the exhaust port 32. The exhaust passage 56 is a passage for exhausting exhaust gas from the combustion chamber 28, and is configured by piping or the like. The exhaust passage 56 is provided with an exhaust turbine 58 driven by exhaust, a catalyst 60 for purifying exhaust, and a muffler 62 for silencing.

  The exhaust turbine 58 is connected to the compressor 50, and the power of the exhaust turbine 58 driven by the exhaust is used as power for the compressor 50 to compress air. That is, the compressor 50 and the exhaust turbine 58 constitute a supercharger 64 composed of an exhaust turbocharger, and the internal combustion engine 10 is a direct injection gasoline engine having the supercharger 64.

The internal combustion engine 10 has a plurality of types of sensors.
Specifically, the internal combustion engine 10 includes an air flow rate sensor 66, a throttle valve opening sensor, a crank rotation angle sensor 68, and an accelerator opening sensor 69.
The air flow sensor 66 is provided in a portion of the intake passage 46 downstream of the air filter 48 and detects the flow rate of the intake air.

  The throttle valve opening sensor is a sensor for measuring the opening of the throttle valve 54. In the present embodiment, the throttle valve actuator 55 also serves as the throttle valve opening sensor. Therefore, the throttle valve actuator 55 is also referred to as a throttle valve opening sensor 55.

The crank rotation angle sensor 68 is provided in the vicinity of the crankshaft 20 and detects the rotation angle of the crankshaft 20.
The accelerator opening sensor 69 is provided in the vicinity of the accelerator pedal, and can detect the accelerator opening and the amount of change per unit time of the accelerator opening, that is, the changing speed of the accelerator opening.

  Intake flow rate, throttle valve opening, crankshaft rotation angle detected continuously or intermittently by the air flow sensor 66, throttle valve opening sensor 55, crank rotation angle sensor 68, and accelerator opening sensor 69, The detected value of the accelerator opening and the change rate of the accelerator opening are input to the control device 12 continuously or intermittently.

The control device 12 is configured by, for example, an ECU (electronic central control device), and is configured by a CPU (central processing unit), a memory, an external storage device, an input / output device, and the like.
The control device 12 is a control unit that controls the entire vehicle including the internal combustion engine 10.

  The control device 12 determines the amount of fuel supplied into the combustion chamber 28 by the in-cylinder injection valve 42 and the port injection valve 43 according to the input accelerator opening and the detected value of the change rate of the accelerator opening, and The amount of intake air supplied into the combustion chamber 28 through the throttle valve 54 is adjusted. The control device 12 also controls the fuel supply timing (injection timing) and the ignition timing of the spark plug 44 based on the input detected value of the rotation angle of the crankshaft 20.

  Here, FIG. 1 schematically shows a functional configuration of the control device 12 of the present embodiment. The control device 12 includes an acceleration request determination unit 70, a filling efficiency determination unit 72, a divided injection control unit (divided injection control unit) 74, a port injection control unit (port injection control unit) 76, and an acceleration end determination unit 78. .

  The acceleration request determination unit 70 compares the input detection value ΔAPS of the latest accelerator opening change rate with a predetermined acceleration request determination threshold value ΔAPSth. Then, when the detected value ΔAPS becomes equal to or greater than the acceleration request determination threshold ΔAPSth, the acceleration request determination unit 70 determines that the driver requests acceleration, and the detected value ΔAPS is less than the predetermined acceleration request determination threshold ΔAPSth. If there is, it is determined that the driver does not request acceleration.

The charging efficiency determination unit 72 calculates the charging efficiency based on the input detection value AF of the air flow rate. Then, the charging efficiency determination unit 72 determines whether or not the calculated value Ec of the charging efficiency obtained by the calculation is equal to or greater than a predetermined first threshold value Ecth1. Further, the charging efficiency determination unit 72 determines whether or not the calculated value Ec of the charging efficiency obtained by the calculation is equal to or greater than a predetermined second threshold value Ecth2. The second threshold Ecth2 is greater than the first threshold Ecth1 (Ecth2> Ecth1).
In the present embodiment, as an example, the first threshold Ecth1 is in the range of 0.6 to 1.0, and the second threshold Ecth2 is in the range of 1.2 to 1.6.

When it is determined that the calculated value Ec is less than the first threshold value Ecth1 when the driver is requesting acceleration, the split injection control unit 74 causes the in-cylinder injection valve 42 to perform intake injection, and the calculated value Ec. Is determined to be equal to or greater than the first threshold value Ecth1, the in-cylinder injection valve 42 is caused to perform divided injection.
Here, the intake air injection means that fuel is injected into the combustion chamber 28 during the intake stroke.
The split injection is to inject fuel (compression injection) into the combustion chamber 28 in the compression stroke following the intake stroke after performing the intake injection in the intake stroke. That is, split injection is a combination of intake injection and compression injection. The ratio of the fuel injection amount (Qc) in the compression injection to the total injection amount (Qi + Qc) of the fuel injection amount in the intake injection and the compression injection in the divided injection (compression injection ratio: Qc / (Qi + Qc)) is predetermined. For example, it is set to 0.3.

  In the internal combustion engine 10, the four strokes of the intake stroke, the compression stroke, the combustion stroke, and the exhaust stroke are repeated. With regard to the position of the piston 22, in the intake stroke, the piston 22 moves from the top dead center to the bottom dead center. In the compression stroke, the piston 22 is located from the bottom dead center to the top dead center.

  When it is determined that the calculated value Ec is greater than or equal to the first threshold value Ecth1 and less than the second threshold value Etch2 when the driver requests acceleration, the port injection control unit 76 injects fuel (port Injection) is prohibited, and when it is determined that the calculated value Ec is the second threshold value Etch2, port injection is executed.

Therefore, when it is determined that the calculated value Ec is the second threshold value Etch2, the divided injection by the in-cylinder injection valve 42 and the port injection by the port injection valve 43 are performed in parallel, and port injection combined divided injection is performed.
In such port injection combined split injection, fuel is injected separately into port injection, intake injection, and compression injection. The total fuel injection amount in the port injection combined split injection is based on the detected value APS of the accelerator opening and the traveling state of the vehicle, as in the case of only the intake injection and the case of only the split injection. Determined by.

  When it is determined that the calculated value Ec is equal to or greater than the second threshold value Etch2, the ratio of the fuel injection amount (Qp) in the port injection to the total fuel injection amount (Qd + Qp) in the port injection combined split injection (Qp) The port injection ratio: Rport = Qp / (Qd + Qp)) is set to a preset ratio R1.

  The acceleration end determination unit 78 determines that the driver's request for acceleration has ended when the input detection value APS of the latest accelerator opening is less than a predetermined acceleration end determination threshold APSth. When it is determined that the driver's request for acceleration has ended, the split injection control unit 74 ends the split injection, and the control device 12 executes only the intake injection.

  On the other hand, when it is determined that the acceleration request by the driver has ended, the port injection control unit 76 stops the port injection or changes the port injection ratio Rport as necessary according to the driving situation, and then changes the port injection ratio Rport. Continue jetting.

Next, a split injection control method executed by the control device 12 of the internal combustion engine 10 will be described with reference to FIG. FIG. 2 is a flowchart showing a schematic procedure of the split injection control method.
In the split injection control method, first, an acceleration request determination step S10 is performed. In the acceleration request determination step S10, the input detection value ΔAPS of the latest accelerator opening change speed is compared with a preset acceleration request determination threshold value ΔAPSth.

If the detection value ΔAPS is smaller than the acceleration request determination threshold value ΔAPSth as a result of the comparison in the acceleration request determination step S10, the acceleration request determination step S10 is repeated. If the detection value ΔAPS is equal to or greater than the acceleration request determination threshold value ΔAPSth, The filling efficiency calculation step S12 is executed.
In the charging efficiency calculation step S12, the charging efficiency calculation value Ec is calculated based on the input detection value AF of the latest intake flow rate.

Then, the first filling efficiency determination step S14 is executed. In the first filling efficiency determination step S14, it is determined whether or not the calculated value Ec is greater than or equal to the first threshold value Ecth1. As a result of the determination, if the calculated value Ec is greater than or equal to the first threshold value Ecth1, the second filling efficiency determination step S16 is executed.
In the present embodiment, the first filling efficiency determination step S14 and the second filling efficiency determination step S16 are distinguished, but the first filling efficiency determination step S14 and the second filling efficiency determination step S16 may be performed simultaneously. .

In the second filling efficiency determination step S16, it is determined whether or not the calculated value Ec is greater than or equal to the second threshold value Ecth2. As a result of the determination, if the calculated value Ec is less than the second threshold value Ecth2, the port injection ratio Rport is set to 0 (zero) (S18). Then, the divided injection on step S20 is executed, and divided injection is started.
On the other hand, if the result of determination in the second filling efficiency determination step S16 is that the calculated value Ec is equal to or greater than the second threshold value Ecth2, the port injection ratio Rport is set to the ratio R1 (S22). Then, the port injection combined split injection on step S24 is executed, and the port injection combined split injection is started.

  After the split injection on step S20 and the port injection combined split injection on step S24, an acceleration end determination step S26 is executed. Further, as a result of the determination in the first filling efficiency determination step S14, the acceleration end determination step S26 is also executed when the calculated value Ec of the charging efficiency is less than the first threshold value Ecth1.

  In the acceleration end determination step S26, it is determined whether or not the input detection value APS of the latest accelerator opening is equal to or greater than the acceleration end determination threshold APSth. As a result of the determination, if the detected value APS is less than the acceleration end determination threshold APSth, the divided injection off step S28 is executed.

  In the split injection off step S28, when only split injection is performed, split injection by the in-cylinder injection valve 42 is terminated, and only normal intake injection by the in-cylinder injection valve 42 is performed. On the other hand, in the split injection off step S28, when the split injection with the port injection is performed, the split injection by the in-cylinder injection valve 42 is at least terminated, the in-cylinder injection valve 42 performs the intake injection, and the port injection valve 43 The port injection by is stopped or continued after changing the port injection ratio Rport as necessary.

  If the detection value APS is equal to or greater than the acceleration end determination threshold APSth as a result of the determination in the acceleration end determination step S26, the charging efficiency calculation step S12 is executed again, and the detection value APS becomes less than the acceleration end determination threshold APSth. Steps S12 to S26 are repeated.

FIG. 3 is an example of a timing chart when the control device 12 executes the divided injection control method of FIG.
As shown in FIG. 3 (a), the detected value ΔAPS of the change rate of the accelerator opening is equal to or greater than the acceleration request determination threshold value ΔAPSth, and as shown in FIG. 3 (d), the calculated value of the charging efficiency is calculated. When Ec becomes equal to or greater than the first threshold value Ecth1, the divided injection is turned on as shown in FIG. 3B, and the divided injection is started.

  On the other hand, in the range where the calculated value Ec is greater than or equal to the first threshold value Ecth1 and less than the second threshold value Ecth2, as shown in FIG. 3C, port injection is not performed but only divided injection is performed. In the example of FIG. 3C, when the calculated value Ec is less than the first threshold value Ecth1, the port injection is executed with the port injection ratio Rport being set to the predetermined ratio R2, and the calculation is performed. When the value Ec reaches the first threshold value Ecth1, the port injection is stopped.

  Thereafter, when the acceleration proceeds and the calculation value Ec of the charging efficiency becomes equal to or greater than the second threshold value Ecth2, the port injection is executed in combination with the divided injection. That is, the port injection ratio Rport is set to a predetermined ratio R1, and port injection is started.

According to the control device 12 of the first embodiment described above, when the calculated value Ec of the filling efficiency is equal to or greater than the second threshold value Ecth2, the port injection is used in addition to the divided injection, and the generation of smoke and particulate matter is suppressed. The
More specifically, the solid line in FIG. 3 (f) shows the temporal change in the amount of smoke generated when the port injection is used in the region where the calculated value Ec of the charging efficiency is equal to or larger than the second threshold value Ecth2, and FIG. The alternate long and short dash line in f) shows the change over time in the amount of smoke generated when only the divided injection is performed without using the port injection in the region of the second threshold value Ecth2 or more.

As shown in FIG. 3 (f), when the port injection is used in a region where the calculated value Ec of the charging efficiency is equal to or greater than the second threshold value Ecth2, the amount of smoke generated is reduced by ΔS compared to the case where the port injection is not used together. ing.
On the other hand, FIGS. 3 (d) and 3 (e) show changes in charging efficiency and torque over time, respectively. When port injection is used in a region where the calculated value Ec is equal to or greater than the second threshold value Ecth2, it is not used together. Compared to the case, the charging efficiency is reduced by ΔEc, and the torque is reduced by ΔT. The reduction amount ΔEc of the charging efficiency and the reduction amount ΔT of the torque are small and do not have a great influence on the acceleration performance.

(Second Embodiment)
Hereinafter, a second embodiment will be described. In the description of the embodiments described later, the same or similar configurations as those of the preceding embodiments are denoted by the same names or reference numerals, and the description thereof is omitted or simplified.

Since the configuration of the control device 80 of the second embodiment is substantially the same as the configuration 12 of the control device of the first embodiment, the configuration of the control device 80 will be described with reference to FIG.
In the control device 80, the filling efficiency determination unit 72 compares the calculated value Ec of the filling efficiency with a third threshold value Ecth3 that is larger than the first threshold value Ecth1 and smaller than the second threshold value Ecth2, and port injection control is performed. The unit 76 is different from the control device 12 of the first embodiment in that the port injection is performed in parallel with the divided injection in a region where the calculated value Ec is not less than the first threshold Ecth1 and less than the third threshold Ecth2.

  FIG. 4 is a flowchart showing a schematic procedure of the divided injection control method executed by the control device 80. In this divided injection control method, the third filling efficiency determination step S30 for comparing the calculated value Ec with the third threshold value Ecth3. And a step S32 for setting the port injection ratio Rport to a predetermined ratio R2, and a port injection combined split injection process S34 for turning on the port injection combined split injection at the ratio R2.

  In the present embodiment, the first filling efficiency determination step S14, the second filling efficiency determination step S16, and the third filling efficiency determination step S30 are distinguished from each other. However, the first filling efficiency determination step S14 and the second filling efficiency determination step S30 are distinguished from each other. The determination step S16 and the third filling efficiency determination step S30 may be performed simultaneously.

  FIG. 5 is an example of a timing chart when the control device 80 executes the divided injection control method of FIG. As shown in FIG. 5C, the port injection is executed at the ratio R2 in the region where the calculated value Ec is not less than the first threshold and less than the third threshold. In the present embodiment, the port injection is performed at the ratio R2 even in the region where the calculated value Ec is less than the first threshold value Ecth1.

  Similarly to the control device 12 of the first embodiment, the control device 80 of the second embodiment also executes the port injection combined split injection in a region where the calculated value Ec of the charging efficiency is equal to or greater than the second threshold value Ecth2. Thus, the generation of smoke and particulate matter is suppressed.

In the control device 80 of the second embodiment, the combustion state is improved by using the port injection together in the region where the calculated value Ec of the charging efficiency is not less than the first threshold value Ecth1 and less than the third threshold value Ecth3.
Further, in the control device 80 of the second embodiment, when the calculated value Ec of the charging efficiency is not less than the third threshold value and less than the second threshold value, port injection is prohibited and only divided injection is performed. Performance is ensured.

  In the present embodiment, the third threshold Ecth3 is set to a value corresponding to the boundary between the non-supercharged region and the supercharged region so that the acceleration performance does not deteriorate due to the combined use of port injection. For example, the third threshold Ecth3 is set to 0.9 to 1.1. In the non-supercharging region, even if port injection is used in combination, the torque does not decrease, so that the combustion state can be improved without reducing the acceleration performance. Since only the divided injection is executed until the calculated value Ec of the charging efficiency becomes equal to or higher than the second threshold after entering the supercharging region, good acceleration performance is ensured.

(Third embodiment)
Hereinafter, the third embodiment will be described.
The control device 90 according to the third embodiment is different from the first embodiment in that a volume efficiency calculation value Ev is determined instead of the filling efficiency calculation value Ec. That is, in the first embodiment described above, the filling efficiency is used as a parameter for determining whether or not the acceleration has entered the late acceleration period. However, the volume efficiency may be used.

  As shown in FIG. 6, in the third embodiment, a temperature sensor 92 and a pressure sensor 94 for measuring the temperature and pressure of the outside air are provided in the internal combustion engine 10 in order to calculate volumetric efficiency. The temperature sensor 92 and the pressure sensor 94 are disposed, for example, in the vicinity of the inlet of the suction passage 46, and the detected values of the outside air temperature and pressure measured continuously or intermittently by the temperature sensor 92 and the pressure sensor 94 are the control device 90. Are input continuously or intermittently.

  The control device 90 includes a volumetric efficiency determining unit 96, and the volumetric efficiency determining unit 96 calculates a volumetric efficiency value Ev based on the latest detected intake flow rate, outside air temperature, and pressure detection values. Then, the volumetric efficiency determination unit 96 compares the first threshold value Evth1 corresponding to the first threshold value Ecth1 and the second threshold value Evth2 corresponding to the second threshold value Ecth2 with the calculated value Ev, and according to the comparison result, Intake injection, split injection, or port injection combined split injection is executed.

  According to the control device 90 of the third embodiment described above, the generation of smoke and particulate matter is suppressed by performing the port injection combined split injection in the region where the calculated value Ev is equal to or greater than the second threshold value Evth2.

(Fourth embodiment)
The fourth embodiment will be described below.
The control device 100 according to the fourth embodiment is different from the first embodiment in that the load is determined instead of the calculation value Ec of the charging efficiency. That is, in the first embodiment described above, the charging efficiency is used as a parameter for determining whether or not the acceleration has entered into the latter half of the acceleration, but a load may be used.
More specifically, the total injection amount (Qtotal) of fuel injected by the in-cylinder injection valve 42 and the port injection valve 43 can be used as the load.

As illustrated in FIG. 7, the control device 100 includes a load determination unit 102, and the load determination unit 102 includes a first threshold value Qth1 corresponding to the first threshold value Ecth1 and a second threshold value corresponding to the second threshold value Ecth2. Qth2 is compared with the total injection amount Qtotal, and intake injection, split injection, or port injection combined split injection is executed according to the comparison result.
The total injection amount Qtotal can be determined with reference to previously registered map data based on the input accelerator opening detection value APS and the running state of the vehicle.

  According to the control device 100 of the fourth embodiment described above, the generation of smoke and particulate matter is suppressed by performing the port injection combined split injection in the region where the total injection amount Qtotal is equal to or greater than the second threshold value Qth2. .

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described.
The control device 110 according to the fifth embodiment is different from the first embodiment in that the intake pressure is determined instead of the calculation value Ec of the charging efficiency. That is, in the first embodiment described above, the charging efficiency is used as a parameter for determining whether or not the acceleration has entered the late acceleration period. However, the intake pressure may be used.

  As shown in FIG. 8, in the fifth embodiment, a pressure sensor 114 is attached to the surge tank 112 of the intake passage 46 in order to determine the intake pressure. The pressure sensor 114 continuously or intermittently measures the intake pressure in the surge tank 112, and the obtained intake pressure detection value Pin is input to the control device 110 continuously or intermittently.

  The control device 110 includes an intake pressure determination unit 116. The intake pressure determination unit 116106 receives the input detection value Pin of the latest intake pressure, the first threshold value Pith1 corresponding to the first threshold value Ecth1, and the second threshold value. The second threshold value Pinth2 corresponding to Ecth2 is compared, and intake injection, split injection, or port injection combined split injection is executed according to the comparison result.

  According to the control device 110 of the fifth embodiment described above, the generation of smoke and particulate matter is suppressed by performing the port injection combined split injection in the region where the detected value Pin of the intake pressure is equal to or greater than the second threshold value Pinth2. Is done.

  In the present embodiment, as an example, the first threshold Pinth1 is in the range of −30 to 20 kPa in terms of gauge pressure, and the second threshold Pinth2 is in the range of 50 to 100 kPa in terms of gauge pressure.

The present invention is not limited to the first to fifth embodiments described above, but includes forms obtained by modifying each of the first to fifth embodiments.
For example, also in the third to fifth embodiments, as in the second embodiment, the port injection combined split injection may be executed in the region that is greater than or equal to the first threshold and less than the third threshold using the third threshold. Good.
Further, for example, in the first to fifth embodiments, the port injection ratio Rport in the latter half of acceleration may be changed according to the magnitude of the detected value ΔAPS of the change rate of the accelerator opening. Specifically, as the detected value ΔAPS of the change rate of the accelerator opening approaches the acceleration level determination threshold value ΔAPSth2, that is, as the detected value ΔAPS of the change rate of the accelerator opening becomes smaller, the port injection ratio Rport at the later stage of acceleration. May be made smaller.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Control apparatus 14 Crankcase 16 Cylinder block 18 Cylinder 22 Piston 26 Cylinder head 28 Combustion chamber 34 Intake valve 36 Exhaust valve 42 In-cylinder injection valve 43 Port injection valve 44 Spark plug 64 Supercharger 66 Air flow sensor 68 Crank Rotation angle sensor 69 Accelerator opening sensor 70 Acceleration request determination unit 72 Acceleration end determination unit 74 Split injection control unit 76 Port injection control unit

Claims (4)

When accelerating an internal combustion engine having a supercharger, in-cylinder fuel injection means for directly injecting fuel into the combustion chamber, and port fuel injection means for performing port injection for injecting fuel into the intake port In the control device for an internal combustion engine configured to perform split injection in which fuel is injected into the combustion chamber by the in-cylinder fuel injection means in both the intake stroke and the compression stroke of
A split injection control means for causing the in-cylinder fuel injection means to execute the split injection when one parameter selected from the charging efficiency, the volume efficiency, the load, and the intake pressure is equal to or greater than a first threshold;
When the parameter is less than the first threshold value, the port fuel injection means performs the port injection, and when the parameter is equal to or greater than a second threshold value that is greater than the first threshold value, in parallel with the divided injection. And port injection control means for prohibiting the port injection when the port injection is executed and is within a predetermined range not less than the first threshold and less than the second threshold. A control device for an internal combustion engine. When the threshold corresponding to the boundary between the non-supercharged area and the supercharged area that is larger than the first threshold and smaller than the second threshold is the third threshold,
The port injection control means is configured to cause the port fuel injection means to execute the port injection in parallel with the split injection when the parameter is equal to or greater than the first threshold and less than the third threshold. The control apparatus for an internal combustion engine according to claim 1, wherein The port injection control means prohibits execution of the port injection by the port fuel injection means when the parameter is not less than the third threshold and less than the second threshold;
The split injection control means is configured to cause the in-cylinder fuel injection means to execute the split injection when the parameter is equal to or greater than the third threshold and less than the second threshold. The control apparatus for an internal combustion engine according to claim 2. The port injection control means sets a ratio of an injection amount of the port fuel injection means to a total injection amount of the in-cylinder fuel injection means and the port fuel injection means when the parameter is equal to or greater than the second threshold value. The port injection is performed with the ratio set, and when the parameter is less than the first threshold, the ratio of the injection amount of the port fuel injection means is set to a second ratio that is larger than the first ratio. The control device for an internal combustion engine according to claim 1, wherein the port injection is executed.

Images