JP2020023898A - Control device for internal combustion engine - Google Patents

Abstract

To suppress a variation in the amount of fuel to be introduced into a three-way catalyst.SOLUTION: In an exhaust passage of an internal combustion engine, the three-way catalyst is arranged for purifying exhaust gas. In the exhaust passage at its portion on the further downstream side than the three-way catalyst, a particulate filter is arranged for trapping particulate matters included in exhaust gas. To an intake passage of the internal combustion engine, a purge passage is connected for introducing evaporated fuel generated in a fuel tank into a cylinder. In the purge passage, a purge valve is mounted for adjusting the amount of the evaporated fuel distributing in the purge passage. When stopping combustion in the cylinder in such a situation that a crank shaft of the internal combustion engine is rotated, a control device applied to the internal combustion engine executes fuel introduction processing for allowing fuel to be injected from a fuel injection valve and flow out of the cylinder into the exhaust passage as it is unburnt. When the fuel introduction processing is being executed, a valve control part of the control device controls the opening of the purge valve to be zero.SELECTED DRAWING: Figure 3

Description

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

  The internal combustion engine of Patent Literature 1 includes a cylinder that burns fuel. An intake passage for introducing intake air to the cylinder is connected to the cylinder. Further, an exhaust passage for discharging exhaust gas from the cylinder is connected to the cylinder. The exhaust passage is provided with a three-way catalyst for purifying exhaust gas. Further, a particulate filter for collecting particulate matter in the exhaust gas is provided downstream of the three-way catalyst in the exhaust passage. Further, a fuel injection valve for introducing the fuel pumped from the fuel tank to the fuel passage into the cylinder is attached to the cylinder.

  In the internal combustion engine of Patent Literature 1, combustion may be stopped in a cylinder when the load applied to the internal combustion engine is small when the required torque for the internal combustion engine is reduced due to cancellation of the accelerator operation or the like. 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 the fuel from the fuel injection valve and allowing the fuel to flow out of the cylinder into the exhaust passage without burning. Select one of the processes. Then, in the internal combustion engine of Patent Document 1, when the particulate filter is regenerated, the fuel introduction process is selected and executed. On the other hand, in the internal combustion engine of Patent Literature 1, when the particulate filter is not regenerated, the fuel cut process is selected and executed.

  In the fuel introduction process, the fuel injected from the fuel injection valve flows through the exhaust passage together with the intake air. 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 out to the particulate filter, and the temperature of the particulate filter rises. As a result, the particulate matter trapped in the particulate filter is burned.

US Patent Application Publication No. 2014/0041362

  Generally, an internal combustion engine as disclosed in Patent Document 1 includes a purge passage for introducing evaporated fuel generated in a fuel tank into a cylinder, and an opening / closing valve for adjusting the amount of evaporated fuel flowing through the purge passage. I have. Here, when the above-described fuel introduction process is being performed, if the evaporated fuel is introduced through the purge passage, the evaporated fuel is also introduced into the three-way catalyst in addition to the fuel from the fuel injection valve. Become. Therefore, when the amount of the evaporated fuel introduced varies, the amount of the fuel introduced into the three-way catalyst fluctuates. If the amount of fuel introduced into the three-way catalyst fluctuates excessively, the temperatures of the three-way catalyst and the particulate filter may deviate from target temperatures.

  A control device for an internal combustion engine for solving the above-mentioned problems is arranged in a cylinder that burns fuel, an intake passage that introduces intake air to the cylinder, an exhaust passage that discharges exhaust from the cylinder, and an exhaust passage. A three-way catalyst for purifying exhaust gas, a particulate filter disposed downstream of the three-way catalyst in the exhaust passage and collecting particulate matter contained in the exhaust gas, and a fuel tank. A fuel injection valve for introducing fuel into the cylinder, a purge passage for introducing evaporative fuel generated in the fuel tank to the cylinder, and an on-off valve for adjusting an amount of evaporative fuel flowing through the purge passage. When the combustion in the cylinder is stopped while the crankshaft of the internal combustion engine is rotating, the fuel injection A control device for an internal combustion engine that executes a fuel introduction process for injecting fuel from a valve and causing the fuel to flow out of the cylinder into the exhaust passage without burning the fuel, the valve control being configured to control an open / close state of the open / close valve. The valve control unit controls the opening of the on-off valve to zero when the fuel introduction process is being performed.

  With the above configuration, the flow of the evaporated fuel in the purge passage is restricted when the fuel introduction process is being performed. Thus, it is possible to suppress a change in the amount of fuel introduced into the three-way catalyst due to a variation in the amount of fuel vapor introduced through the purge passage.

FIG. 1 is a schematic diagram of a hybrid vehicle. FIG. 1 is a schematic diagram of an internal combustion engine and an internal combustion engine control unit applied to the internal combustion engine. 5 is a flowchart showing a processing procedure for controlling a fuel injection valve and a purge valve. (A) is a time chart which shows the change of the combustion state in a cylinder. (B) is a time chart showing a change in the execution state of motoring. (C) is a time chart showing changes in the engine speed of the internal combustion engine. (D) is a time chart showing a change in the state of execution of the fuel introduction process. (E) is a time chart showing a change in the fuel injection amount. (F) is a time chart showing a change in the open / closed state of the purge valve. (G) is a time chart showing a change in the amount of introduced fuel vapor. (H) is a time chart showing a change in the temperature of the three-way catalyst. (I) is a time chart showing a change in the temperature of the particulate filter.

Hereinafter, an embodiment of a control device for an internal combustion engine will be described with reference to FIGS.
As shown in FIG. 1, the hybrid vehicle includes an internal combustion engine 10, a power distribution integration mechanism 40 connected to the crankshaft 14 of the internal combustion engine 10, and a first motor generator connected to the power distribution integration mechanism 40. 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 integration 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 of the pinion gears 43 is supported by the carrier 44 so that the pinion gears 43 can freely rotate and revolve. The first motor generator 71 is connected to the sun gear 41. The crankshaft 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 and the ring gear 42. 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 electric power.

  On the other hand, when the first motor generator 71 functions 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. When the output torque of the first motor generator 71 is input to the crankshaft 14 via the carrier 44, the crankshaft 14 can be rotated. In the present embodiment, rotating the crankshaft 14 by driving the first motor generator 71 in this manner is referred to as “motoring”.

  The reduction gear 50 is a planetary gear mechanism, and includes 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. I have. The ring gear shaft 45 is connected to the ring gear 52. 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. Each pinion gear 53 is rotatable but non-revolvable.

  When the vehicle is decelerated, the regenerative braking force corresponding to the amount of power generated by the second motor generator 72 can be generated in the vehicle by causing the second motor generator 72 to function as a generator. When the second motor generator 72 functions 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. Is done. As a result, the drive wheels 62 can be rotated, that is, the vehicle can run.

  First motor generator 71 exchanges power with battery 77 via first inverter 75. The second motor generator 72 exchanges power with the battery 77 via the second inverter 76.

  As shown in FIG. 2, the internal combustion engine 10 includes a cylinder 11 for burning fuel. The cylinder 11 houses a piston 12 that reciprocates in the cylinder 11 in response to combustion of fuel. The piston 12 is connected to a crankshaft 14 via a connecting rod 13.

  An intake passage 15 for introducing intake air to the cylinder 11 is connected to the cylinder 11. An intake valve 18 for opening and closing the connection between the intake passage 15 and the cylinder 11 is attached to the connection between the intake passage 15 and the cylinder 11. In the middle of the intake passage 15, a throttle valve 16 that rotates to adjust the amount of intake air into the cylinder 11 is attached. A fuel injection valve 17 for introducing fuel into the cylinder 11 is attached to a portion of the intake passage 15 downstream of the throttle valve 16.

  An exhaust passage 21 for discharging exhaust from the cylinder 11 is connected to the cylinder 11. An exhaust valve 20 for opening and closing the connection between the exhaust passage 21 and the cylinder 11 is attached to the connection between the exhaust passage 21 and the cylinder 11. A three-way catalyst 22 for purifying exhaust gas is arranged in the middle of the exhaust passage 21. In a portion of the exhaust passage 21 downstream of the three-way catalyst 22, a particulate filter 23 for collecting particulate matter contained in the exhaust gas is disposed.

  Fuel and air are introduced into the cylinder 11 through the intake passage 15 when the intake valve 18 is open. Then, in the cylinder 11, a mixture containing the air introduced through the intake passage 15 and the fuel injected from the fuel injection valve 17 is burned by the spark discharge of the ignition device 19. The exhaust gas generated in the cylinder 11 by the combustion of the air-fuel mixture is discharged to the exhaust passage 21 when the exhaust valve 20 is open.

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

  The fuel supply device 30 of the internal combustion engine 10 includes a fuel tank 31 for storing fuel to be burned in the cylinder 11, an electric feed pump 32 for pumping the fuel in the fuel tank 31, and a fuel discharged from the feed pump 32. And a flowing fuel passage 33. The fuel injection valve 17 is connected to the fuel passage 33. That is, the fuel injection valve 17 injects fuel pumped from the fuel tank 31 to the fuel passage 33 by the operation of the feed pump 32. Further, the fuel supply device 30 is provided with a fuel pressure sensor 83 for detecting a supply fuel pressure which is a fuel pressure of the fuel passage 33.

  The fuel tank 31 is connected to an evaporative fuel processing device 90 for suppressing the release of evaporative fuel generated in the fuel tank 31 to the atmosphere. The fuel vapor processing device 90 includes a canister 92 that adsorbs fuel vapor generated in the fuel tank 31. One end of a vapor passage 91 for introducing the fuel vapor into the canister 92 is connected to the canister 92. The other end of the vapor passage 91 reaches the inside of the fuel tank 31. In the middle of the vapor passage 91, a closing valve 96 for switching the flow passage of the vapor passage 91 between an open state and a closed state is attached.

  The outside air introduction passage 93 for introducing outside air to the canister 92 is connected to the canister 92. In the middle of the outside air introduction passage 93, an outside air introduction valve 97 for switching the flow path of the outside air introduction passage 93 to one of an open state and a closed state is attached.

  One end of a purge passage 94 for introducing the fuel vapor into the cylinder 11 is connected to the canister 92. The other end of the purge passage 94 is connected to a portion of the intake passage 15 downstream of the throttle valve 16. In the middle of the purge passage 94, a purge valve 98 for switching the flow path of the purge passage 94 between an open state and a closed state is attached.

  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 crankshaft 14 is rotating. The period during which the combustion of the air-fuel mixture in the cylinder 11 is stopped while the crankshaft 14 is rotating is referred to as a “combustion stop period”. During the combustion stop period, the piston 12 reciprocates in synchronization with the rotation of the crankshaft 14. Therefore, the air introduced into the cylinder 11 via the intake passage 15 flows out to the exhaust passage 21 without being subjected to combustion.

  In the combustion stop period, a fuel cut process for stopping the fuel injection of the fuel injection valve 17 and a fuel introduction for injecting the fuel from the fuel injection valve 17 and allowing the fuel to flow out of the cylinder 11 to the exhaust passage 21 without burning. Any one of the processes is selected and executed. When the fuel introduction process is executed, the fuel injected from the 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, if the temperature of the three-way catalyst 22 is equal to or higher than the activation temperature, the fuel is burned by the three-way catalyst 22 if a sufficient amount of oxygen is stored in the three-way catalyst 22 to burn the fuel. You. As a result, the temperature of the three-way catalyst 22 increases. Then, the high-temperature gas flows into the particulate filter 23, and the temperature of the particulate filter 23 rises. When oxygen is introduced into the particulate filter 23 in a situation where the temperature of the particulate filter 23 is somewhat high, the particulate matter collected by the particulate filter 23 can be burned. .

Next, a control configuration of the hybrid vehicle will be described with reference to FIGS.
As shown in FIG. 1, the control device 100 of the hybrid vehicle calculates a required torque that is a 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 the amount of operation 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 each of the motor generators 71 and 72 based on the calculated required torque.

  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 a “control device for an internal combustion engine” in the present embodiment. When the fuel introduction process is performed during the combustion stop period, the drive of the first motor generator 71 is controlled by the motor control unit 120 to perform the motoring. That is, the rotation speed of the crankshaft 14 during the combustion stop period can be controlled through the execution of the motoring.

  As shown in FIG. 2, the internal combustion engine control unit 110 includes, as functional units, an ignition control unit 111 that controls the ignition device 19, an injection valve control unit 112 that controls the fuel injection valve 17, a shutoff valve 96, and outside air introduction. A valve control unit 113 for controlling the open / close state of the valve 97 and the purge valve 98 is provided.

  When burning the air-fuel mixture in the cylinder 11, the ignition control unit 111 causes the ignition device 19 to perform spark discharge at the timing when the piston 12 reaches the vicinity of the compression top dead center. On the other hand, the ignition control unit 111 does not cause the ignition device 19 to perform spark discharge during the combustion stop period.

  The valve control unit 113 controls the open / close state of the shutoff valve 96, the outside air introduction valve 97, and the purge valve 98 to adjust the amount of fuel vapor flowing through the purge passage 94. Specifically, when the purge valve 98 is controlled to be closed and the closing valve 96 and the outside air introduction valve 97 are controlled to be opened, the fuel vapor generated in the fuel tank 31 is adsorbed inside the canister 92. . When the purge valve 98 is in the closed state as described above, the flow of the gas such as the evaporated fuel in the purge passage 94 is restricted by blocking the flow passage of the purge passage 94. On the other hand, when the purge valve 98, the closing valve 96, and the outside air introduction valve 97 are controlled to be open, outside air is introduced into the canister 92 through the outside air introduction passage 93 due to the negative pressure of the intake passage 15. Then, the evaporated fuel and the outside air that have been adsorbed inside the canister 92 are introduced into the intake passage 15 via the purge passage 94. When the purge valve 98 is in the open state as described above, the flow of the gas such as the evaporated fuel in the purge passage 94 is permitted by communicating the flow passage of the purge passage 94. Therefore, the purge valve 98 is an opening / closing valve that adjusts the amount of fuel vapor flowing through the purge passage 94.

  Next, a processing procedure executed by the control device 100 to control the fuel injection valve 17 and the purge valve 98 will be described with reference to FIG. The control device 100 turns off the system start switch from the time when the system start switch (also referred to as a start switch, a main switch, or the like) of the hybrid vehicle is turned on and the control device 100 starts operating. Until the control device 100 completes its operation, the series of processes shown in FIG. 3 is repeatedly executed. Note that a prohibition flag described below is OFF when the control device 100 starts operating.

  As shown in FIG. 3, when a series of processes is started, the internal combustion engine control unit 110 in the control device 100 performs the process of step S11. In step S11, the internal combustion engine control unit 110 determines whether a condition for stopping combustion of the air-fuel mixture in the cylinder 11 is satisfied. For example, when the required value of the output torque for the internal combustion engine 10 is equal to or less than “0 (zero)”, it is determined that the condition for stopping the combustion is satisfied. On the other hand, when the required value of the output torque for the internal combustion engine 10 is larger than “0 (zero)”, it is determined that the condition for stopping the combustion is not satisfied. If it is determined in step S11 that the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is satisfied (S11: YES), the control device 100 advances the process to step S12.

  In step S12, the valve control unit 113 of the internal combustion engine control unit 110 controls the opening of the purge valve 98 to “0 (zero)”. Here, if the purge valve 98 is open at the time of step S12, the purge valve 98 is switched to the closed state, and the opening of the purge valve 98 becomes “0 (zero)”. On the other hand, if the opening of the purge valve 98 is “0 (zero)” at the time of step S12, the opening of the purge valve 98 is maintained at “0 (zero)”. Further, the valve control unit 113 in the internal combustion engine control unit 110 turns on a prohibition flag that prohibits the opening of the purge valve 98 from becoming larger than “0 (zero)”. That is, when the prohibition flag is ON, the opening of the purge valve 98 is prohibited regardless of the operation state of the internal combustion engine 10, and the opening of the purge valve 98 is controlled to “0 (zero)”. Thereafter, control device 100 causes the process to proceed to step S13.

In step S13, control device 100 determines whether or not the motoring execution condition is satisfied. Here, the execution conditions of the motoring will be described. In the present embodiment, it is determined that the execution condition is satisfied when both of the following two conditions are satisfied.
(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 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 in some cases. Therefore, a specified temperature is set as a criterion for determining whether unburned fuel introduced into the three-way catalyst 22 can be burned. That is, the specified temperature is set to the activation temperature of the three-way catalyst 22 or a temperature slightly higher than the activation temperature.

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

  In step S13, when it is determined that the motoring execution condition is not satisfied (S13: NO), control device 100 causes the process to proceed to step S21. That is, when the control device 100 determines that the motoring execution condition is not satisfied, the control device 100 executes the fuel cut process from step S21.

  In step S21, the motor control unit 120 in the control device 100 stops motoring for rotating the crankshaft 14 by driving the first motor generator 71. If the motoring has already been stopped at the time of step S21, the stopped state of the motoring is maintained. Thereafter, control device 100 causes the process to proceed to step S22.

  In step S22, the injection valve control unit 112 in the internal combustion engine control unit 110 sets the required value QPR of the fuel injection amount to “0 (zero)”. Thereafter, control device 100 causes the process to proceed to step S23.

  In step S23, the injection valve control unit 112 in the internal combustion engine control unit 110 controls the fuel injection valve 17 based on the calculated required value QPR of the fuel injection amount. That is, in the fuel cut process, since the required value QPR of the fuel injection amount is “0 (zero)”, the fuel is not injected from the fuel injection valve 17 and the combustion of the fuel is stopped. After that, the control device 100 ends this series of processing.

  On the other hand, if it is determined in step S13 that the motoring execution condition is satisfied (S13: YES), control device 100 causes the process to proceed to step S32. In step S32, the motor control unit 120 of the control device 100 starts execution of motoring for rotating the crankshaft 14 by driving the first motor generator 71. Thereafter, control device 100 causes the process to proceed to step S33.

  In step S33, the motor control unit 120 of the control device 100 determines whether or not the engine speed, which is the speed of the crankshaft 14 of the internal combustion engine 10 per predetermined time, is equal to or higher than a preset reference speed. . Here, the reference rotation speed is an engine rotation speed of the internal combustion engine 10 in which a predetermined amount or more of intake air is introduced from the intake passage 15 to the cylinder 11 side per predetermined time by the piston 12 driven by the rotation of the crankshaft 14. It is determined, for example, by experiments and simulations.

  In step S33, when it is determined that the engine speed of the internal combustion engine 10 is smaller than the preset reference speed (S33: NO), the control device 100 advances the process to step S22. That is, in this case, the fuel cut process is performed while the motoring is performed. On the other hand, when it is determined in step S33 that the engine speed of the internal combustion engine 10 is equal to or higher than the preset reference speed (S33: YES), the control device 100 advances the process to step S34. That is, control device 100 executes the fuel introduction process after step S34.

  In step S34, the injection valve control unit 112 in the internal combustion engine control unit 110 calculates the required value QPR of the fuel injection amount. Here, the required value QPR of the fuel injection amount when the fuel introduction process is being executed is smaller than the required value QPR of the fuel injection amount 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 of the fuel injection amount calculated in step S34, the air-fuel ratio in the cylinder 11 becomes This value is leaner than the air-fuel ratio when the air-fuel mixture is burned. Thereafter, control device 100 causes the process to proceed to step S35.

  In step S35, the injection valve control unit 112 in the internal combustion engine control unit 110 controls the fuel injection valve 17 based on the calculated required value QPR of the fuel injection amount. After that, the control device 100 ends this series of processing.

  On the other hand, if it is determined in step S11 that the condition for stopping combustion of the air-fuel mixture in the cylinder 11 is not satisfied (S11: NO), the control device 100 advances the process to step S41.

  In step S41, the valve control unit 113 in the internal combustion engine control unit 110 turns off a prohibition flag that prohibits the opening of the purge valve 98 from becoming larger than “0 (zero)”. That is, when the prohibition flag is turned off in this way, the opening of the purge valve 98 is allowed to be larger than “0 (zero)”. Thereafter, control device 100 causes the process to proceed to step S42.

  In step S42, the motor control unit 120 in the control device 100 stops the motoring that rotates the crankshaft 14 by driving the first motor generator 71. If the motoring has already been stopped at the time of step S42, the stopped state of the motoring is maintained. Thereafter, control device 100 causes the process to proceed to step S43.

  In step S43, the injection valve control unit 112 in the internal combustion engine control unit 110 calculates a required value QPR of the fuel injection amount of the fuel injection valve 17. That is, the required value QPR of the fuel injection amount is calculated by the injection valve control unit 112 such that the detected air-fuel ratio value becomes the target air-fuel ratio value. The air-fuel ratio detection value is an air-fuel ratio detected by the air-fuel ratio sensor 81. Thereafter, control device 100 causes the process to proceed to step S44.

  In step S44, the injection valve control unit 112 in the internal combustion engine control unit 110 controls the fuel injection valve 17 based on the required value QPR of the fuel injection amount calculated in step S43. After that, the control device 100 ends this series of processing.

The operation and effect of the present embodiment will be described. In the following description, it is assumed that the temperature of the three-way catalyst 22 is equal to or higher than a specified temperature.
In the example shown in FIG. 4A, the combustion of the air-fuel mixture is performed in the cylinder 11 before the time t1. Therefore, exhaust gas generated by combustion of the air-fuel mixture in the cylinder 11 flows through the exhaust passage 21. When the exhaust gas flowing through the exhaust passage 21 flows into the particulate filter 23, the particulate matter in the exhaust gas is collected by the particulate filter 23. Then, the collection amount of particulate matter in the particulate filter 23 gradually increases.

  At time t1, when the required value of the output torque becomes “0 (zero)” or less according to the accelerator pedal AP by the driver, the condition for stopping the combustion of the air-fuel mixture in the cylinder 11 is satisfied. Then, as shown in FIG. 4A, the spark discharge of the ignition device 19 is stopped, and the combustion of the fuel in the cylinder 11 is stopped.

  Further, as shown by a solid line in FIG. 4F, at time t1, the opening of the purge valve 98 is controlled to “0 (zero)”. Further, a prohibition flag for prohibiting the opening of the purge valve 98 from becoming larger than “0 (zero)” is turned on.

  Here, at time t1, the estimated value of the amount of particulate matter collected in the particulate filter 23 is less than the determination collection amount, so that the motoring execution condition is not satisfied. Therefore, as shown in FIG. 4E, at time t1, the fuel cut processing is executed, and the fuel injection amount of the fuel injection valve 17 becomes “0 (zero)”.

  At time t2, when the estimated value of the trapped amount of particulate matter in the particulate filter 23 is equal to or greater than the determined trapped amount, all the motoring execution conditions are satisfied. Then, as shown in FIG. 4B, at time t2, execution of motoring by the first motor generator 71 is started, and the engine speed of the internal combustion engine 10 is increased by the driving of the first motor generator 71. Start to become. Then, oxygen is supplied to the three-way catalyst 22 and the particulate filter 23 through the intake passage 15, the cylinder 11, and the exhaust passage 21. Further, as shown in FIG. 4C, the engine speed of the internal combustion engine 10 gradually increases between the time t2 and the time t3.

  As shown in FIG. 4C, when the engine speed of the internal combustion engine 10 becomes larger than the reference speed at time t3, the fuel introduction process is performed as shown in FIG. 4D. Then, as shown in FIG. 4E, fuel is injected from the fuel injection valve 17. Here, during the combustion stop period after time t1, the spark discharge of the ignition device 19 is stopped. Therefore, the fuel injected from the fuel injection valve 17 flows through the exhaust passage 21 together with the air without being burned. When such unburned fuel is introduced into the three-way catalyst 22, the fuel is burned by the three-way catalyst 22, and the temperature of the three-way catalyst 22 increases. Thereafter, when the high-temperature gas that has passed through the three-way catalyst 22 flows into the particulate filter 23, the temperature of the particulate filter 23 increases. When the temperature of the particulate filter 23 rises to a temperature required for regeneration of the particulate filter 23, the particulate matter trapped in the particulate filter 23 is burned.

  By the way, as shown by the broken line in FIG. 4F, after the time t3, when the purge valve 98 is controlled to the open state and the opening degree of the purge valve 98 becomes larger than “0 (zero)”, the purge valve 94 is passed through the purge passage 94. Thus, the evaporated fuel is introduced into the intake passage 15. Then, the evaporated fuel is introduced into the three-way catalyst 22 via the intake passage 15, the cylinder 11, and the exhaust passage 21. Here, the amount of the evaporated fuel which is the amount of the evaporated fuel introduced into the intake passage 15 through the purge passage 94 is determined by the amount of the evaporated fuel adsorbed in the canister 92 and the amount of the evaporated fuel generated in the fuel tank 31. Varies depending on the amount of For this reason, as shown by the broken line in FIG. 4G, the amount of fuel vapor introduced is more likely to vary greatly than the amount of fuel injected from the fuel injection valve 17. When the amount of introduced fuel varies, the total amount of fuel injected from the fuel injection valve 17 and the amount of introduced fuel fluctuates. Then, the amount of fuel introduced into the three-way catalyst 22 via the intake passage 15, the cylinder 11, and the exhaust passage 21 varies. If the amount of the fuel introduced into the three-way catalyst 22 fluctuates excessively, the temperature of the three-way catalyst 22 may deviate from the target temperature as shown by a broken line in FIG. As indicated by the broken line in FIG. 4 (i), the temperature of the particulate filter 23 may deviate from the target temperature. If the temperature of the three-way catalyst 22 deviates from the target temperature, for example, the temperature of the three-way catalyst 22 may become excessively high and the function of the three-way catalyst 22 may be impaired. If the temperature of the particulate filter 23 deviates from the target temperature, for example, the particulate matter trapped in the particulate filter 23 may not be properly burned.

  In this embodiment, as shown by the solid line in FIG. 4F, at time t1, the opening of the purge valve 98 is controlled to “0 (zero)”. Further, a prohibition flag for prohibiting the opening of the purge valve 98 from becoming larger than “0 (zero)” is turned on. Therefore, during execution of the fuel introduction process after time t3, the opening of the purge valve 98 is maintained at “0 (zero)”. By maintaining the opening of the purge valve 98 at “0 (zero)” in this manner, the flow of the evaporated fuel in the purge passage 94 during the fuel introduction process is restricted. This suppresses a variation in the amount of fuel vapor introduced into the intake passage 15 through the purge passage 94. As a result, the amount of fuel introduced into the three-way catalyst 22 via the intake passage 15, the cylinder 11, and the exhaust passage 21 can be suppressed from varying.

This embodiment can be implemented with the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.
In the above embodiment, the amount of evaporated fuel flowing through the purge passage 94 may be limited without depending on the control of the purge valve 98. For example, during execution of the fuel introduction process, the opening degrees of the closing valve 96 and the outside air introduction valve 97 may be controlled to “0 (zero)”. As described above, when the opening degrees of the closing valve 96 and the outside air introduction valve 97 are controlled to “0 (zero)”, no evaporated fuel or outside air is introduced into the canister 92. Therefore, when the opening degrees of the closing valve 96 and the outside air introduction valve 97 are controlled to “0 (zero)”, even if the negative pressure of the intake passage 15 acts on the flow path of the purge passage 94, the purge passage The flow of gas such as evaporative fuel at 94 is restricted. In this example, the closing valve 96 and the outside air introduction valve 97 correspond to an opening / closing valve.

  In the above embodiment, the timing for controlling the opening of the purge valve 98 to “0 (zero)” and the timing for turning on the prohibition flag can be changed. For example, the opening degree of the purge valve 98 may be controlled to “0 (zero)” simultaneously with or after the execution of the motoring in step S32 and before the processing in steps S34 and S35.

  In the above-described embodiment, during the execution of the fuel introduction process, the ignition device 19 may cause the ignition device 19 to perform spark discharge at a time when the air-fuel mixture does not burn in the cylinder 11. For example, when spark discharge is performed when the piston 12 is located near the bottom dead center, the air-fuel mixture is not burned in the cylinder 11 where the spark discharge has been performed. Therefore, during the fuel introduction process, even if spark discharge is performed, the fuel injected from the fuel injection valve 17 can flow out of the cylinder 11 to the exhaust passage 21 without burning.

  In the above embodiment, the internal combustion engine 10 may include a direct injection valve that is a fuel injection valve that directly injects fuel into the cylinder 11. In this case, during execution of the fuel introduction process, fuel may be injected into the cylinder 11 from the in-cylinder injection valve, and the fuel may flow out to the exhaust passage 21 without burning. Thus, unburned fuel can be introduced into the three-way catalyst 22.

  In the above embodiment, the system of the hybrid vehicle may be another system different from the system shown in FIG. 1 as long as the rotation speed of the crankshaft 14 can be controlled by driving the motor. Good.

  In the above embodiment, the control device 100 may be applied to an internal combustion engine mounted on a vehicle having no power source other than the internal combustion engine. Even in such an internal combustion engine mounted on a vehicle, combustion of the air-fuel mixture in the cylinder may be stopped while the crankshaft 14 is rotating by inertia. As described above, the fuel introduction process may be executed during the combustion stop period in which the crankshaft 14 is rotating by inertia.

  ACC: accelerator opening, AP: accelerator pedal, QPR: required value, VS: vehicle speed, 10: internal combustion engine, 11: cylinder, 12: piston, 13: connecting rod, 14: crankshaft, 15: intake passage, 16 ... Throttle valve 17, 17 fuel injection valve, 18 intake valve, 19 ignition device, 20 exhaust valve, 21 exhaust passage, 22 three-way catalyst, 23 particulate filter, 30 fuel supply device, 31 fuel Tank 32, feed pump 33, fuel passage 40, power distribution integration mechanism 41, sun gear 42, ring gear 43, pinion gear 44, carrier 45, ring gear shaft 50 reduction gear 51 Sun gear, 52 ring gear, 53 pinion gear, 60 reduction mechanism, 61 differential, 62 drive wheel, 71 1 motor generator, 72 second motor generator, 75 first inverter, 76 second inverter, 77 battery, 81 air-fuel ratio sensor, 82 temperature sensor, 83 fuel pressure sensor, 84 Accelerator opening sensor, 85: vehicle speed sensor, 90: evaporative fuel processing device, 91: vapor passage, 92: canister, 93: outside air introduction passage, 94: purge passage, 96: closing valve, 97: outside air introduction valve, 98 ... Purge valve, 100: control device, 110: internal combustion engine control unit, 111: ignition control unit, 112: injection valve control unit, 113: valve control unit, 120: motor control unit.

Claims (1)

A cylinder for burning fuel, an intake passage for introducing intake air to the cylinder, an exhaust passage for discharging exhaust from the cylinder, a three-way catalyst disposed in the exhaust passage for purifying exhaust gas, and the exhaust passage. A particulate filter disposed downstream of the three-way catalyst and collecting particulate matter contained in exhaust gas, and a fuel injection valve for introducing fuel from a fuel tank into the cylinder. The present invention is applied to an internal combustion engine including a purge passage for introducing the fuel vapor generated in the fuel tank into the cylinder, and an opening / closing valve for adjusting an amount of the fuel vapor flowing through the purge passage,
When the combustion in the cylinder is stopped under the condition that the crankshaft of the internal combustion engine is rotating, the fuel is injected from the fuel injection valve, and the fuel is left unburned and the exhaust passage is discharged from the cylinder. A control device for an internal combustion engine that executes a fuel introduction process for allowing fuel to flow out,
It has a valve control unit for controlling the open / close state of the open / close valve,
The control device for an internal combustion engine, wherein the valve control unit controls the opening of the on-off valve to zero when the fuel introduction process is being executed.