JP7073974B2 - Internal combustion engine control device - Google Patents

Description

The present invention relates to an internal combustion engine control device applied to a spark ignition type internal combustion engine.

Patent Document 1 describes an example of an internal combustion engine using gasoline as fuel. The exhaust purification device of the internal combustion engine includes a three-way catalyst provided in the exhaust passage and a particulate filter arranged downstream of the three-way catalyst in the exhaust passage.

In the internal combustion engine described in Patent Document 1, combustion in the cylinder may be stopped when the load applied to the internal combustion engine is low when the required torque for the internal combustion engine is reduced due to the cancellation of the accelerator operation or the like. be. In such a combustion stop period, a fuel cut process for stopping the fuel injection of the fuel injection valve and a fuel introduction process for injecting fuel from the fuel injection valve and causing the fuel to flow out from the cylinder to the exhaust passage without being burned. One of the processes is selected and executed. According to Patent Document 1, when the particulate filter is regenerated during the combustion stop period, the fuel introduction process is executed. On the other hand, when the regeneration is not performed during the combustion stop period, the fuel cut process is executed.

In the fuel introduction process, the fuel injected from the fuel injection valve flows through the exhaust passage together with the air. Then, when the fuel is introduced into the three-way catalyst, the temperature of the three-way catalyst rises due to the combustion of the fuel. Then, the high-temperature gas flows into the particulate filter, and the temperature of the particulate filter rises. As a result, the particulate matter collected in the particulate filter is burned.

The required value of the fuel injection amount calculated during the execution of the fuel introduction process is calculated to be smaller than the required value calculated when the combustion is performed in the cylinder.

U.S. Patent Application Publication No. 2014/0041362

When the fuel introduction process is being executed during the combustion stop period, the condition for restarting the combustion in the cylinder may be satisfied. In this case, the execution of the fuel introduction process is terminated when the condition is satisfied.

Here, when combustion is performed in the cylinder, the time when the fuel is injected from the fuel injection valve is the time on the advance side of the time when the spark discharge is performed by the ignition device. The time when spark discharge is performed to burn the air-fuel mixture in the cylinder is called the combustion ignition timing. That is, when combustion is restarted in the cylinder because the above condition is satisfied during the execution of the fuel introduction process, the condition may be satisfied between the fuel injection timing of the fuel injection valve and the combustion ignition timing. ..

When the execution of the fuel introduction process is completed because the above conditions are satisfied, in the cylinder into which the fuel injected from the fuel injection valve is introduced by the execution of the fuel introduction process, the ignition device provided in the cylinder is used. Combustion is performed by spark discharge. In this case, since the amount of fuel in the cylinder is an amount corresponding to the required value of the fuel injection amount calculated during the execution of the fuel introduction process, the air-fuel ratio in the cylinder is on the lean side as compared with the theoretical air-fuel ratio. Is the value of. Therefore, the exhaust property deteriorates when the combustion in the cylinder is restarted.

The control device for an internal combustion engine for solving the above problems is applied to an internal combustion engine that burns an air-fuel mixture containing fuel injected from a fuel injection valve in a cylinder by spark discharge of an ignition device. The control device of the internal combustion engine injects fuel from the fuel injection valve when the combustion in the cylinder is stopped under the condition that the crank shaft of the internal combustion engine is rotating, and the fuel is not burned. The fuel introduction process of flowing out from the inside of the cylinder to the exhaust passage is executed as it is. The control device of the internal combustion engine has an ignition control unit that controls the ignition device, and the fuel so that the fuel injection amount is smaller when the fuel introduction process is executed than when combustion is performed in the cylinder. It includes an injection valve control unit that controls the injection valve, and a stop determination unit that determines whether or not the combustion stop condition in the cylinder is satisfied. Of the time when the ignition device discharges sparks, the time when combustion in the cylinder becomes possible is referred to as the combustion ignition timing. When the ignition control unit restarts combustion in the cylinder, fuel is supplied by injection of the fuel injection valve after the stop determination unit does not determine that the stop condition is satisfied. When combustion is performed in the cylinder, the spark discharge of the ignition device at the ignition timing for combustion is restarted.

The fuel injection amount of the fuel injection valve during the execution of the fuel introduction process is smaller than the fuel injection amount when the air-fuel mixture is burned in the cylinder. Therefore, when the fuel injected from the fuel injection valve is introduced into the cylinder by executing the fuel introduction process, if the ignition device is made to perform spark discharge at the ignition timing for combustion, the combustion in the cylinder becomes lean combustion. Become. Lean combustion is combustion in the cylinder when the air-fuel ratio of the air-fuel mixture is on the lean side of the stoichiometric air-fuel ratio. In this case, the exhaust property deteriorates.

According to the above configuration, when the combustion in the cylinder is restarted, the cylinder to which the fuel is supplied by the injection of the fuel injection valve before the determination that the above stop condition is satisfied is not satisfied is burned. Spark discharge is not performed at the ignition timing. As a result, it is possible to suppress the occurrence of lean combustion in the cylinder, so that deterioration of the exhaust property can be suppressed. Then, when the combustion is performed in the cylinder to which the fuel is supplied by the injection of the fuel injection valve after the determination that the above stop condition is not satisfied is not made, the spark of the ignition device at the ignition timing for combustion is generated. Discharge is resumed. In this case, the air-fuel ratio in the cylinder is closer to the theoretical air-fuel ratio than in the case where the fuel injected from the fuel injection valve is introduced into the cylinder by executing the fuel introduction process. Therefore, it becomes possible to restart the combustion in the cylinder while suppressing the deterioration of the exhaust property.

FIG. 6 is a configuration diagram showing an outline of a control device including an internal combustion engine control unit which is a control device of the internal combustion engine of the embodiment and a hybrid vehicle equipped with the control device. The figure which shows the functional composition of the internal combustion engine control unit, and the schematic structure of the internal combustion engine mounted on the hybrid vehicle. The flowchart which shows the processing procedure for controlling a fuel injection valve. A flowchart showing a processing procedure for controlling an ignition device. Timing chart when the condition to stop the combustion of the air-fuel mixture in the cylinder is not satisfied while the fuel introduction process is being executed.

Hereinafter, an embodiment of the control device for an internal combustion engine will be described with reference to FIGS. 1 to 5.
FIG. 1 illustrates a schematic configuration of a hybrid vehicle. As shown in FIG. 1, the hybrid vehicle includes an internal combustion engine 10, a power distribution integration mechanism 40 connected to the crank shaft 14 of the internal combustion engine 10, and a first motor generator connected to the power distribution integration mechanism 40. It is equipped with 71. A second motor generator 72 is connected to the power distribution integration mechanism 40 via a reduction gear 50, and a drive wheel 62 is connected via a reduction mechanism 60 and a differential 61.

The power distribution integrated mechanism 40 is a planetary gear mechanism, and has a sun gear 41 of an external gear and a ring gear 42 of an internal gear coaxially arranged with the sun gear 41. A plurality of pinion gears 43 that mesh with both the sun gear 41 and the ring gear 42 are arranged between the sun gear 41 and the ring gear 42. Each pinion gear 43 is supported by the carrier 44 in a state where it can rotate and revolve freely. A first motor generator 71 is connected to the sun gear 41. A crank shaft 14 is connected to the carrier 44. A ring gear shaft 45 is connected to the ring gear 42, and both the reduction gear 50 and the reduction mechanism 60 are connected to the ring gear shaft 45.

When the output torque of the internal combustion engine 10 is input to the carrier 44, the output torque is distributed to the sun gear 41 side and the ring gear 42 side. That is, by inputting the output torque of the internal combustion engine 10 to the first motor generator 71, the first motor generator 71 can generate electricity.

On the other hand, when the first motor generator 71 is made to function as an electric motor, the output torque of the first motor generator 71 is input to the sun gear 41. Then, the output torque of the first motor generator 71 input to the sun gear 41 is distributed to the carrier 44 side and the ring gear 42 side. Then, the output torque of the first motor generator 71 is input to the crank shaft 14 via the carrier 44, so that the crank shaft 14 can be rotated. In the present embodiment, rotating the crank shaft 14 by driving the first motor generator 71 in this way is referred to as "motoring".

The reduction gear 50 is a planetary gear mechanism and has a sun gear 51 of an external gear to which a second motor generator 72 is connected and a ring gear 52 of an internal gear coaxially arranged with the sun gear 51. There is. A ring gear shaft 45 is connected to the ring gear 52. Further, a plurality of pinion gears 53 that mesh with both the sun gear 51 and the ring gear 52 are arranged between the sun gear 51 and the ring gear 52. Although each pinion gear 53 is rotatable, it cannot revolve.

Then, when the vehicle is decelerated, the second motor generator 72 functions as a generator, so that the vehicle can generate a regenerative braking force according to the amount of power generated by the second motor generator 72. When the second motor generator 72 is made to function as an electric motor, the output torque of the second motor generator 72 is input to the drive wheels 62 via the reduction gear 50, the ring gear shaft 45, the reduction mechanism 60, and the differential 61. Will be done. As a result, the drive wheels 62 can be rotated, that is, the vehicle can be driven.

The first motor generator 71 transfers electric power to and from the battery 77 via the first inverter 75. The second motor generator 72 transfers power to and from the battery 77 via the second inverter 76.

As shown in FIG. 2, the internal combustion engine 10 has four cylinders 11. A piston connected to the crank shaft 14 via a connecting rod is housed in each cylinder 11 in a reciprocating manner. Further, air is introduced into each cylinder 11 via the intake passage 15. Further, the internal combustion engine 10 has the same number of fuel injection valves 17 as the cylinder 11. Each fuel injection valve 17 is an injection valve that injects fuel into the intake passage 15. The fuel and air injected from the fuel injection valve 17 are introduced into each cylinder 11 via the intake passage 15. Then, in each cylinder 11, the air-fuel mixture containing fuel and air is burned by the spark discharge of the ignition device 19. Of the time when the ignition device 19 performs spark discharge, the time when the air-fuel mixture can be burned in the cylinder 11 is called "combustion ignition timing". The ignition timing for combustion is appropriately finely adjusted according to the operating condition of the internal combustion engine 10.

The exhaust generated in each cylinder 11 due to the combustion of the air-fuel mixture is discharged to the exhaust passage 21. The exhaust passage 21 is provided with a three-way catalyst 22 and a particulate filter 23 arranged on the downstream side of the three-way catalyst 22. The particulate filter 23 has a function of collecting particulate matter contained in the exhaust gas flowing through the exhaust passage 21.

An air-fuel ratio sensor 81 for detecting the oxygen concentration in the gas flowing through the exhaust passage 21, that is, the air-fuel ratio of the air-fuel mixture is arranged upstream of the three-way catalyst 22 in the exhaust passage 21. Further, a temperature sensor 82 for detecting the temperature of the gas flowing through the exhaust passage 21 is arranged between the three-way catalyst 22 and the particulate filter 23 in the exhaust passage 21.

In the internal combustion engine 10, combustion of the air-fuel mixture in the cylinder 11 may be stopped when the vehicle is running and the crank shaft 14 is rotating. The period during which combustion in the cylinder 11 is stopped while the crank shaft 14 is rotating is referred to as a "combustion stop period CSP". In the combustion stop period CSP, each piston reciprocates in synchronization with the rotation of the crank shaft 14. Therefore, the air introduced into each cylinder 11 through the intake passage 15 flows out to the exhaust passage 21 without being subjected to combustion.

In the combustion stop period CSP, a fuel cut process for stopping the fuel injection of each fuel injection valve 17 and a fuel injection from each fuel injection valve 17 are performed, and the fuel is injected from the inside of each cylinder 11 into the exhaust passage 21 without being burned. One of the fuel injection processes to be discharged is selected and executed. When the fuel introduction process is executed, the fuel injected from each fuel injection valve 17 flows through the exhaust passage 21 together with the air. Then, the fuel is introduced into the three-way catalyst 22. At this time, when the temperature of the three-way catalyst 22 is equal to or higher than the activation temperature, if a sufficient amount of oxygen is present in the three-way catalyst 22 to burn the fuel, the fuel is burned by the three-way catalyst 22. As a result, the temperature of the three-way catalyst 22 rises. Then, the high-temperature gas flows into the particulate filter 23, and the temperature of the particulate filter 23 rises. When oxygen is supplied to the particulate filter 23, when the temperature of the particulate filter 23 becomes equal to or higher than the combustible temperature, the particulate matter collected in the particulate filter 23 is burned.

Next, the control configuration of the hybrid vehicle will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, the control device 100 of the hybrid vehicle calculates the required torque TQR, which is the torque to be output to the ring gear shaft 45, based on the accelerator opening ACC and the vehicle speed VS. The accelerator opening ACC is an operation amount of the accelerator pedal AP by the driver of the vehicle, and is a value detected by the accelerator opening sensor 84. The vehicle speed VS is a value corresponding to the moving speed of the vehicle and is detected by the vehicle speed sensor 85. The control device 100 controls the internal combustion engine 10 and the motor generators 71 and 72 based on the calculated required torque TQR.

The control device 100 includes an internal combustion engine control unit 110 that controls the internal combustion engine 10, and a motor control unit 120 that controls the motor generators 71 and 72. The internal combustion engine control unit 110 corresponds to an example of the “internal combustion engine control device” in the present embodiment. When the fuel introduction process is executed during the combustion stop period CSP, the motor control unit 120 controls the drive of the first motor generator 71 for motoring. That is, the rotation speed of the crank shaft 14 can be controlled during the combustion stop period CSP through the execution of motoring.

FIG. 2 illustrates the functional configuration of the internal combustion engine control unit 110. The internal combustion engine control unit 110 has an ignition control unit 111 that controls the ignition device 19, an injection valve control unit 112 that controls the fuel injection valve 17, and a stop determination unit 113 as functional units. The control of the fuel injection valve 17 and the control of the ignition device 19 will be described later.

The stop determination unit 113 determines whether or not the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is satisfied. For example, the stop determination unit 113 determines that the stop condition is satisfied when the required value of the output torque for the internal combustion engine 10 is “0” or less. On the other hand, when the required value of the output torque for the internal combustion engine 10 is larger than "0", the stop determination unit 113 does not determine that the stop condition is satisfied, that is, determines that the stop condition is not satisfied. do. Then, when the stop condition 113 is changed from the state where the stop condition is satisfied to the state where the stop condition is not satisfied, the stop determination unit 113 requests the restart of the combustion of the air-fuel mixture in the cylinder 11.

Next, with reference to FIG. 3, a processing procedure for driving the fuel injection valve 17 under the control of the injection valve control unit 112 will be described. The series of processes shown in FIG. 3 is executed for each fuel injection valve 17.

In the first step S11 in the series of processes shown in FIG. 3, it is determined whether or not the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is satisfied. The determination process in step S11 is performed based on the result of the process of the stop determination unit 113. Then, when the stop determination unit 113 does not determine that the stop condition is satisfied (S11: NO), the process proceeds to the next step S12. In step S12, the first calculation process for calculating the required value QPR of the fuel injection amount of the fuel injection valve 17 is performed. In the first calculation process, for example, the required value QPR is calculated so that the air-fuel ratio detection value AFS becomes the air-fuel ratio target value AFTr. The air-fuel ratio detection value AFS is the air-fuel ratio detected by the air-fuel ratio sensor 81. When the air-fuel mixture is burned in the cylinder 11, the air-fuel ratio target value AFTr is set to, for example, the theoretical air-fuel ratio or a value near the theoretical air-fuel ratio. Then, when the required value QPR is calculated, the process proceeds to the next step S13. In step S13, the drive of the fuel injection valve 17 is controlled based on the required value QPR calculated in step S12. Subsequently, in the next step S14, the combustion prohibition flag is set to off. The combustion prohibition flag is a flag that is set to on when the combustion of the air-fuel mixture in the cylinder 11 is prohibited, and is set to off when the combustion is permitted. Then, a series of processes is temporarily terminated.

On the other hand, if it is determined by the stop determination unit 113 that the stop condition is satisfied in step S11 (YES), the process is shifted to the next step S15. In step S15, a second calculation process for calculating the required value QPR of the fuel injection amount of the fuel injection valve 17 is performed. In the second calculation process, when the fuel cut process is executed, the required value QPR is set to "0". On the other hand, in the second calculation process, when the fuel introduction process is being executed, the required value QPR is calculated to be a value larger than "0". However, the required value QPR of the fuel injection amount when the fuel introduction process is executed is smaller than the required value QPR when burning the air-fuel mixture in the cylinder 11. Therefore, when the fuel injected from the fuel injection valve 17 is introduced into the cylinder 11 based on the required value QPR calculated in step S15, the air-fuel ratio in the cylinder 11 burns the air-fuel mixture in the cylinder 11. It is a value on the lean side compared with the air-fuel ratio (that is, the theoretical air-fuel ratio) at the time of making the fuel.

Here, a method of selecting a fuel cut process and a fuel introduction process during the combustion stop period CSP will be described. That is, after the combustion stop period CSP is started, when at least one of the following two conditions is not satisfied, the fuel cut process is executed. On the other hand, when both of the following two conditions are satisfied during the combustion stop period CSP, the fuel introduction process is executed.
(Condition 1) It can be determined that the temperature of the three-way catalyst 22 is equal to or higher than the specified temperature.
(Condition 2) The estimated value of the collected amount of the particulate matter in the particulate filter 23 is equal to or larger than the determined collected amount.

Even if unburned fuel is introduced into the three-way catalyst 22, if the temperature of the three-way catalyst 22 is low, the fuel may not be burned. Therefore, a specified temperature is set as a criterion for determining whether or not the unburned fuel introduced into the three-way catalyst 22 can be burned. That is, the specified temperature is set to a temperature slightly higher than the activation temperature or the activation temperature of the three-way catalyst 22.

The larger the amount of particulate matter collected by the particulate filter 23, the more the clogging of the particulate filter 23 progresses. Therefore, the determined collection amount is set as a criterion for determining whether or not the clogging has progressed to the extent that the particulate filter 23 needs to be regenerated. As the collection amount increases, the differential pressure between the portion between the three-way catalyst 22 and the particulate filter 23 in the exhaust passage 21 and the portion downstream of the particulate filter 23 in the exhaust passage 21 tends to increase. Therefore, for example, an estimated value of the collected amount can be calculated based on the differential pressure.

When the required value QPR is calculated in step S15, the process shifts to the next step S16. In step S16, the drive of the fuel injection valve 17 is controlled based on the required value QPR calculated in step S15. That is, when the fuel cut process is executed, the required value QPR is "0", so that fuel is not injected from the fuel injection valve 17. On the other hand, when the fuel introduction process is executed, the required value QPR is larger than "0", so that fuel is injected from the fuel injection valve 17. Subsequently, in the next step S17, the combustion prohibition flag is set to ON. Then, a series of processes is temporarily terminated.

Next, with reference to FIG. 4, a processing procedure for driving the ignition device 19 under the control of the ignition control unit 111 will be described. The series of processes shown in FIG. 4 is executed for each ignition device 19.

In the series of processes shown in FIG. 4, in the first step S21, it is determined whether or not the combustion prohibition flag is set to ON. For example, in the case of processing for the cylinder 11 having the cylinder number "# 1", it is determined whether or not the combustion prohibition flag for the cylinder 11 is set to ON. The combustion prohibition flag for the cylinder 11 having the cylinder number "# 1" is a flag set when calculating the required value QPR of the fuel injection amount of the fuel injection valve 17 corresponding to the cylinder 11. When the combustion prohibition flag is set to ON, the required value QPR is a value calculated by the second calculation process. Therefore, the air-fuel ratio in the cylinder 11 is a value on the lean side of the theoretical air-fuel ratio. On the other hand, when the combustion prohibition flag is set to off, the required value QPR is a value calculated by the first calculation process. Therefore, the air-fuel ratio in the cylinder 11 is close to the theoretical air-fuel ratio.

If it is determined in step S21 that the combustion prohibition flag is set to ON (YES), the process proceeds to the next step S22. In step S22, non-combustion ignition control is performed so that the ignition device 19 does not perform spark discharge at the combustion ignition timing. Specifically, in the non-combustion ignition control, the spark discharge of the ignition device 19 is stopped. In this case, the air-fuel mixture is not burned in the cylinder 11. Then, a series of processes is temporarily terminated.

On the other hand, if it is not determined in step S21 that the combustion prohibition flag is set to ON (NO), the process proceeds to the next step S23. In step S23, combustion ignition control for causing the ignition device 19 to perform spark discharge at the combustion ignition timing is performed. The combustion ignition timing is, for example, the timing in which the piston is located near the compression top dead center in the cylinder 11. In this case, the air-fuel mixture is burned in the cylinder 11. Then, a series of processes is temporarily terminated.

Next, with reference to FIG. 5, the operation and effect of the present embodiment will be described. FIG. 5 shows an example in which the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is not satisfied under the condition that the fuel introduction process is being executed. In FIG. 5, the white squares represent the execution timing of the fuel injection of the fuel injection valve 17 based on the required value QPR of the fuel injection amount calculated by the second calculation process. On the other hand, the black squares represent the execution time of the fuel injection of the fuel injection valve 17 based on the required value QPR calculated by the first calculation process. Further, the triangle represents the ignition timing for combustion. Specifically, among the triangles, the white triangles indicate that the spark discharge is not performed at the combustion ignition timing, while the black triangles indicate that the spark discharge is performed at the combustion ignition timing.

As shown in FIG. 5, at the timing t12 under the condition that the fuel introduction process is being executed, the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is not satisfied. Therefore, at the timing t12, it is required to restart the combustion of the air-fuel mixture in the cylinder 11. In the example shown in FIG. 5, fuel is injected from the fuel injection valve 17 corresponding to the cylinder 11 having the cylinder number “# 4” at the timing t11 before the timing t12. At the timing t11, since the above restart request has not yet been made, the fuel injection valve 17 is driven based on the required value QPR of the fuel injection amount calculated by the second calculation process. Therefore, the air-fuel ratio in the cylinder 11 having the cylinder number "# 4" is a value on the lean side of the theoretical air-fuel ratio.

The timing t14 in FIG. 5 is the ignition timing for combustion in the cylinder 11 having the cylinder number “# 4”. However, at the timing t14, fuel injection is performed in the cylinder 11 having the cylinder number "# 4" based on the required value QPR calculated by the first calculation process, even though the restart of combustion has already been requested. Therefore, the combustion prohibition flag for the cylinder 11 having the cylinder number "# 4" is set to ON. That is, the fuel injected from the fuel injection valve 17 based on the required value QPR calculated by the second calculation process is introduced into the cylinder 11 having the cylinder number "# 4". Therefore, spark discharge is not performed by the implementation of non-combustion ignition control. As a result, the air-fuel mixture is not burned in the cylinder 11 having the cylinder number "# 4".

As described above, the air-fuel ratio in the cylinder 11 having the cylinder number "# 4" is a value on the lean side as compared with the stoichiometric air-fuel ratio. If the air-fuel mixture is burned in the cylinder 11 in such a state, the exhaust property deteriorates. On the other hand, in the present embodiment, the fuel injected from the fuel injection valve 17 is introduced based on the required value QPR calculated by the second calculation process even after the combustion restart is requested. The air-fuel mixture is not burned in the cylinder 11. That is, lean burn is not performed in the cylinder 11. Therefore, deterioration of the exhaust property at the time of restarting combustion can be suppressed.

At the timing t13 after the timing t12 for which the restart of combustion is requested, fuel is injected from the fuel injection valve 17 corresponding to the cylinder 11 having the cylinder number "# 1". Then, the combustion prohibition flag for the cylinder 11 having the cylinder number "# 1" is set to off. In this case, the fuel injection valve 17 is driven based on the required value QPR of the fuel injection amount calculated by the first calculation process. Therefore, the air-fuel ratio in the cylinder 11 having the cylinder number “# 1” is a value near the air-fuel ratio target value AFTr.

The timing t15 is the ignition timing for combustion in the cylinder 11 having the cylinder number “# 1”. At the timing t15, since the combustion prohibition flag for the cylinder 11 having the cylinder number “# 1” is set to off, spark discharge is performed by executing the combustion ignition control. That is, combustion ignition is performed when combustion is performed in the cylinder 11 to which fuel is supplied by the injection of the fuel injection valve 17 after the stop determination unit 113 does not determine that the stop condition is satisfied. The spark discharge of the ignition device 19 at the timing is restarted. As a result, the air-fuel mixture is burned in the cylinder 11 having the cylinder number "# 1". In this case, since the air-fuel ratio in the cylinder 11 having the cylinder number "# 1" is close to the stoichiometric air-fuel ratio, the exhaust properties are better than in the case where lean combustion is performed.

After the timing t13, any of the fuel injection valves 17 is controlled based on the required value QPR calculated by the first calculation process. Therefore, after the timing t15, spark discharge is performed at the ignition timing for combustion in any of the cylinders 11. Therefore, in the present embodiment, it is possible to restart the combustion of the air-fuel mixture in the cylinder 11 while suppressing the deterioration of the exhaust property.

The above embodiment can be modified and implemented as follows. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the non-combustion ignition control, if the spark discharge is not performed at the combustion ignition timing, the ignition device 19 may be made to perform the spark discharge at the time when the air-fuel mixture does not burn in the cylinder 11. For example, when the spark discharge is performed when the piston is located near the bottom dead center, the air-fuel mixture is not burned in the cylinder 11 where the spark discharge is performed. Therefore, even if spark discharge is performed during the fuel introduction process, the fuel injected from the fuel injection valve 17 can be discharged from the cylinder 11 to the exhaust passage 21 without being burned.

The internal combustion engine to which the control device of the internal combustion engine is applied may include an in-cylinder injection valve which is a fuel injection valve that directly injects fuel into the cylinder 11. In this case, during the execution of the fuel introduction process, the fuel is injected into the cylinder 11 from the in-cylinder injection valve, and the fuel is discharged to the exhaust passage 21 without being burned. As a result, unburned fuel can be introduced into the three-way catalyst 22.

-The system of the hybrid vehicle may be a system different from the system shown in FIG. 1 as long as the rotation speed of the crank shaft 14 can be controlled by driving the motor.

-The internal combustion engine to which the control device of the internal combustion engine is applied may be an internal combustion engine having an arbitrary number of cylinders other than four (for example, three or six).
-The control device for an internal combustion engine may be embodied as a device for controlling an internal combustion engine mounted on a vehicle having no power source other than the internal combustion engine. Even in an internal combustion engine mounted on such a vehicle, combustion of the air-fuel mixture in the cylinder may be stopped under the condition that the crank shaft 14 is rotating due to inertia. If the execution condition of the fuel introduction process is satisfied during the combustion stop period CSP, the fuel introduction process is executed.

10 ... Internal combustion engine, 11 ... Cylinder, 14 ... Crank shaft, 17 ... Fuel injection valve, 19 ... Ignition device, 21 ... Exhaust passage, 110 ... Internal combustion engine control unit, 111 ... Ignition control unit, 112 ... Injection valve control unit, 113 ... Stop determination unit.

Claims (1)

It is applied to an internal combustion engine that burns an air-fuel mixture containing fuel injected from a fuel injection valve in a cylinder by spark discharge of an ignition device.
When the combustion in the cylinder is stopped while the crank shaft of the internal combustion engine is rotating, fuel is injected from the fuel injection valve, and the fuel is left unburned from the cylinder to the exhaust passage. In the control device of the internal combustion engine that executes the fuel introduction process of flowing out and regenerating the particulate filter provided in the exhaust passage .
An ignition control unit that controls the ignition device,
When the fuel introduction process is being executed, an injection valve control unit that controls the fuel injection valve so that the fuel injection amount is smaller than that when combustion is performed in the cylinder.
A stop determination unit for determining whether or not the combustion stop condition in the cylinder is satisfied is provided.
When the ignition timing for combustion is defined as the time when the ignition device discharges sparks and the combustion in the cylinder is possible.
When the ignition control unit restarts combustion in the cylinder executing the fuel injection process, the fuel after the stop determination unit does not determine that the stop condition is satisfied. A control device for an internal combustion engine, characterized in that, when combustion is performed in the cylinder to which fuel is supplied by injection of an injection valve, the spark discharge of the ignition device at the ignition timing for combustion is restarted.

Images