JP7207268B2 - Vehicle internal combustion engine controller - Google Patents

Description

The present invention relates to a control system for a vehicle internal combustion engine.

Patent Literature 1 discloses a control device that controls an onboard internal combustion engine that performs idling stop control that suppresses continuation of idling by automatically stopping and restarting the internal combustion engine. In a vehicle that executes such idling stop control, oxygen is stored in the catalyst device while the operation of the internal combustion engine is stopped. Decreased ability. Therefore, in the control device described in Patent Document 1, when restarting, the fuel injection amount is increased so that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio, and the exhaust gas containing excess fuel is introduced into the catalyst device. Rich reduction control is being executed to reduce the oxygen stored in the device.

JP 2012-036849 A

In order to recover the exhaust purification ability by such rich reduction control, it is desired to quickly complete the reduction of oxygen and quickly recover the purification ability.

Means for solving the above problems and their effects will be described below.
A control device for a vehicle internal combustion engine for solving the above problems includes a fuel injection valve, an ignition device, a turbocharger equipped with a wastegate valve that controls boost pressure by opening and closing a wastegate port, an exhaust passage, and an exhaust passage. and a catalyst device that is arranged downstream of the turbine of the turbocharger in the above, has an oxygen storage capacity, and purifies exhaust gas. The control device includes an injection control unit that controls the fuel injection valve and performs fuel cut control to stop the supply of fuel to the combustion chamber during deceleration, an ignition control unit that controls the ignition device, an engine An idling stop control unit that performs idling stop control that suppresses continuation of idling operation by automatically stopping and restarting the operation, and a supercharging control unit that controls opening and closing of the waste gate valve. . In this control device, when the fuel supply to the combustion chamber is restarted and the engine operation is restarted, the injection control unit executes rich reduction control to make the air-fuel ratio richer than the stoichiometric air-fuel ratio. A control device for an engine, in which the supercharging control unit closes the waste gate valve while the fuel cut control is being executed, and the release condition is established as the engine is operated thereafter. The closed valve hold control is executed to hold the valve closed until the valve is closed.

When the wastegate valve is kept closed, gas flowing through the exhaust passage passes through the turbine wheel of the turbocharger. The gas passing through the turbine wheel and flowing downstream reaches the catalyst device as a swirling flow as the turbine wheel rotates. Therefore, if the closed valve hold control is executed, the exhaust containing excess fuel passes through the turbine wheel when the engine operation is restarted and the rich reduction control is executed, causing the exhaust to become a swirling flow. It will be introduced into the catalytic unit. In this case, the centrifugal force causes the exhaust gas to diffuse in the exhaust passage, and the exhaust gas containing the fuel is more likely to be uniformly introduced into the catalyst device. Further, in the case of swirling flow, compared with the case where the exhaust gas flows straight toward the downstream side without swirling, it is possible to secure the time for contact between the catalyst and the fuel. Therefore, according to the above configuration, oxygen in the catalyst device can be efficiently reduced by the rich reduction control.

Further, according to the above configuration, after the wastegate valve is closed by the closed-state holding control, the wastegate valve is held in the closed state until the release condition is satisfied with subsequent engine operation. be. Therefore, when the engine operation is restarted, the wastegate valve is already closed. Therefore, the exhaust gas starts to pass through the turbine wheel from the start of the rich reduction control, and the swirling flow described above can be produced.

Therefore, according to the above configuration, the swirling flow promotes the reduction reaction in the catalyst device, and upon restarting the engine, it is possible to quickly complete the reduction of excess oxygen and quickly recover the purification capability.

In one aspect of the control device for a vehicle-mounted internal combustion engine, the supercharging control unit starts the closed valve holding control to close the waste gate valve when the fuel cut control is started.

As long as the fuel cut control is executed, even if the waste gate valve is closed, the output torque of the internal combustion engine does not increase. Therefore, the waste gate valve can be closed in advance in preparation for the rich reduction control. According to the above configuration, since the closed valve holding control is started at the time when the fuel cut control is started, the waste gate valve can be closed from the earliest time in preparation for subsequent rich reduction control.

During execution of fuel cut control, fuel supply to the combustion chamber is stopped, so combustion does not occur. negative pressure. Therefore, if the wastegate valve is closed during fuel cut control, the opening of the wastegate valve becomes smaller, and the wastegate valve tends to vibrate due to such negative pressure and exhaust pulsation when the seat is approached. Become. As a result, the wastegate valve collides with the seating surface, generating noise. The sound of the wastegate valve colliding with the seat is easily noticeable.

On the other hand, in one aspect of a control device for a vehicle-mounted internal combustion engine, the supercharging control unit controls the waste gate valve prior to execution of the fuel cut control when conditions for executing the fuel cut control are satisfied. is closed, and closed valve hold control is executed to keep the valve closed until the release condition is satisfied with subsequent engine operation.

According to such a configuration, the wastegate valve is closed before the fuel cut control is executed, and the fuel cut control is started while the wastegate valve is closed. That is, the wastegate valve is closed when combustion is performed in the internal combustion engine, vibration of the wastegate valve is unlikely to occur, and the sound of the wastegate valve colliding with the seat surface is not noticeable. This makes it difficult for passengers to hear the sound of the wastegate valve colliding with the seat.

Further, even with this configuration, after the wastegate valve is closed by the valve-closed retention control, the wastegate valve is kept closed until the release condition is satisfied with subsequent engine operation. be done. Therefore, when the engine operation is restarted, the wastegate valve is already closed. Therefore, the exhaust gas starts to pass through the turbine wheel from the start of the rich reduction control, and the swirling flow described above can be produced.

In one aspect of the controller for a vehicle-mounted internal combustion engine that is applied to the vehicle-mounted internal combustion engine having an air-fuel ratio sensor downstream of the catalyst device, the supercharging control unit restarts supply of fuel to the combustion chamber. After the engine operation is restarted, the closed valve holding control is terminated on condition that the air-fuel ratio sensor detects that the air-fuel ratio is richer than the stoichiometric air-fuel ratio.

When the fuel introduced together with the exhaust gas by the rich reduction control is exhausted by the reduction of the oxygen stored in the catalytic device, exhaust gas containing no fuel reaches the air-fuel ratio sensor. On the other hand, when the reduction of oxygen progresses and the amount of oxygen stored in the catalytic device decreases, the fuel passes through the catalytic device and reaches the air-fuel ratio sensor without being completely consumed. Therefore, as in the above configuration, if a configuration is adopted in which the closed valve holding control is terminated on the condition that the air-fuel ratio sensor detects that the air-fuel ratio is richer than the stoichiometric air-fuel ratio, the detection result of the air-fuel ratio sensor Based on this, it is possible to confirm that the reduction of oxygen is progressing until the fuel is not exhausted, and to end the valve-closed holding control.

In one aspect of the control device for a vehicle-mounted internal combustion engine, the ignition control unit executes ignition retardation control for retarding the ignition timing while executing the rich reduction control.
NOx generation can be suppressed by retarding the ignition timing. According to the above configuration, while the rich reduction control is not completed, the ignition timing is retarded to suppress the emission of NOx. Therefore, the emission of NOx is suppressed until the purification capability of the catalyst device is recovered. be able to.

One aspect of a vehicle internal combustion engine control device applied to a vehicle internal combustion engine provided with an intake side variable valve timing mechanism for changing the opening/closing timing of an intake valve and an exhaust side variable valve timing mechanism for changing the opening/closing timing of an exhaust valve a valve timing control unit for controlling the intake-side variable valve timing mechanism and the exhaust-side variable valve timing mechanism, wherein the valve timing control unit controls the exhaust-side variable valve timing while the rich reduction control is being executed; Both the exhaust valve and the intake valve are opened by adjusting the valve opening timing of the intake valve with the intake side variable valve timing mechanism while the closing timing of the exhaust valve is retarded to the maximum by the mechanism. Exhaust most retarded angle control is executed to control the valve overlap, which is the period during which the valve is open.

NOx and HC emissions can be reduced by recirculating the exhaust into the combustion chamber using valve overlap. If the valve overlap is adjusted by adjusting the opening timing of the intake valve while the closing timing of the exhaust valve is retarded to the maximum as in the above configuration, the target valve overlap can be obtained. It is possible to reduce the actual compression ratio by delaying the closing timing of the intake valve as much as possible while achieving a large compression ratio. Therefore, according to the above configuration, it becomes easier to achieve both the Atkinson cycle by delaying the closing timing of the intake valve and the target valve overlap. As a result, the Atkinson cycle can reduce pumping loss, suppress fuel consumption, and suppress NOx and HC emissions.

1 is a schematic diagram showing the configuration of a control device according to an embodiment and a vehicle-mounted internal combustion engine that is controlled by the control device; FIG. FIG. 2 is a cross-sectional view of a turbine housing in a turbocharger; 4 is a flow chart showing the processing flow of a routine for determining the start of rich reduction control; 4 is a flow chart showing the processing flow of a routine for determining the end of rich reduction control; 4 is a flow chart showing the flow of processing of a routine for determining the start of valve-closed holding control; 4 is a flowchart showing the flow of processing of a routine for determining the end of valve-closed holding control; 4 is a timing chart showing the relationship between execution timings of each control; 9 is a flow chart showing the flow of processing of a routine for determining start of valve-closed holding control in the second embodiment. FIG. 11 is a flow chart showing the processing flow of a routine for determining the start of fuel cut control in the second embodiment; FIG. FIG. 11 is a timing chart showing the relationship between the execution timing of valve-close holding control and the execution timing of fuel cut control in the second embodiment; FIG.

(First embodiment)
A first embodiment of a vehicle internal combustion engine control apparatus will be described below with reference to FIGS. 1 to 7. FIG.

As shown in FIG. 1 , a turbocharger 50 having a wastegate valve 60 is mounted on an internal combustion engine 10 controlled by a control device 100 . The turbocharger 50 includes a compressor housing 51 arranged in the intake passage 12 of the internal combustion engine 10 and a turbine housing 52 arranged in the exhaust passage 19 of the internal combustion engine 10 .

An airflow meter 33 for detecting the amount of intake air and the temperature of the intake air is provided in a portion of the intake passage 12 upstream of the compressor housing 51 . On the other hand, an intercooler 70, a throttle valve 31, and an intake pressure sensor 36 are provided in order from the upstream side in a portion downstream of the compressor housing 51 in the intake passage 12. As shown in FIG. Intercooler 70 cools intake air by heat exchange with cooling water. The throttle valve 31 is driven by a motor and adjusts the amount of intake air.

Further, the internal combustion engine 10 is provided with a port injection valve 14, which is a fuel injection valve that injects fuel into intake air flowing through the intake port 13, at the intake port 13, which is a connection portion of the intake passage 12 to the combustion chamber 11. there is Further, in the combustion chamber 11, an in-cylinder injection valve 15, which is a fuel injection valve that directly injects fuel into the combustion chamber 11, and an air-fuel mixture introduced into the combustion chamber 11 are ignited by spark discharge. An ignition device 16 is provided. An exhaust passage 19 in which a turbine housing 52 is installed is connected to the combustion chamber 11 via an exhaust port 22 .

The internal combustion engine 10 is an in-line four-cylinder internal combustion engine and includes four combustion chambers 11, only one of which is shown in FIG. When the air-fuel mixture burns in the combustion chamber 11, the piston 17 reciprocates and the crankshaft 18, which is the output shaft of the internal combustion engine 10, rotates. After combustion, exhaust gas is discharged from the combustion chamber 11 to the exhaust passage 19 .

An intake valve 23 is provided in the intake port 13 . An exhaust valve 24 is provided in the exhaust port 22 . These intake valves 23 and exhaust valves 24 open and close with the rotation of an intake camshaft 25 and an exhaust camshaft 26 to which the rotation of the crankshaft 18 is transmitted.

The intake camshaft 25 is provided with an intake side variable valve timing mechanism 27 that changes the opening/closing timing of the intake valves 23 by changing the phase of the intake camshaft 25 with respect to the crankshaft 18 . The exhaust camshaft 26 is also provided with an exhaust side variable valve timing mechanism 28 that changes the opening/closing timing of the exhaust valve 24 by changing the phase of the exhaust camshaft 26 with respect to the crankshaft 18 .

A timing chain 29 is wound around the intake side variable valve timing mechanism 27 , the exhaust side variable valve timing mechanism 28 , and the crankshaft 18 . As a result, when the crankshaft 18 rotates, the rotation is transmitted via the timing chain 29, the intake camshaft 25 rotates together with the intake side variable valve timing mechanism 27, and the exhaust side variable valve timing mechanism 28 together with the exhaust camshaft 26 rotates. Rotate.

A catalyst device 80 carrying a three-way catalyst that oxidizes CO and HC in the exhaust gas and reduces NOx is provided in the exhaust passage 19 downstream of the turbine housing 52 . Note that the catalyst device 80 has an oxygen storage capacity of storing oxygen contained in the gas flowing through the exhaust passage 19 .

As shown in FIG. 2 , an upstream exhaust pipe 20 and a downstream exhaust pipe 21 that form the exhaust passage 19 are connected to the turbine housing 52 . A turbine wheel 54 is accommodated in the turbine housing 52 . The turbine wheel 54 is connected via a compressor wheel 53 housed in a compressor housing 51 and a shaft 55 housed in a bearing housing 56 . Therefore, when the turbine wheel 54 rotates due to the flow of exhaust introduced into the turbine housing 52 through the upstream exhaust pipe 20 , the compressor wheel 53 also rotates, compressing the intake air and sending it into the combustion chamber 11 .

The turbine housing 52 is provided with a waste gate port 57 that bypasses the turbine wheel 54 and allows the exhaust gas to flow downstream of the turbine wheel 54 . The wastegate valve 60 controls boost pressure by opening and closing the outlet of the wastegate port 57 . That is, if the wastegate valve 60 is held in a fully closed state, the exhaust introduced into the turbine housing 52 through the upstream exhaust pipe 20 passes through the turbine wheel 54 and flows into the downstream exhaust pipe 21. Wheel 54 and compressor wheel 53 rotate to increase the boost pressure. On the other hand, when the wastegate valve 60 is opened, the exhaust introduced into the turbine housing 52 through the upstream side exhaust pipe 20 flows into the downstream side exhaust pipe 21 through the wastegate port 57 bypassing the turbine wheel 54. and the boost pressure becomes low.

The wastegate valve 60 is driven by an actuator 61. As shown in FIG. The actuator 61 may be an electric motor, or may be operated using pneumatic pressure or hydraulic pressure.

As shown in FIG. 1, in the portion of the exhaust passage 19 between the turbine housing 52 and the catalytic device 80, a sensor for outputting a detection value corresponding to the oxygen concentration of the gas flowing through the exhaust passage 19, that is, an air-fuel mixture sensor. An upstream A/F sensor 34, which is an air-fuel ratio sensor that detects the fuel ratio, is installed. A downstream A/F sensor 35 , which is an air-fuel ratio sensor similar to the upstream A/F sensor 34 , is installed in a portion of the exhaust passage 19 downstream of the catalyst device 80 .

The control device 100 controls the internal combustion engine 10, and controls the throttle valve 31, the port injection valve 14, the in-cylinder injection valve 15, the ignition device 16, the intake side variable valve timing mechanism 27, the exhaust side variable valve timing mechanism 28, and the waste gate. The internal combustion engine 10 is controlled by operating various devices to be operated such as the valve 60 .

In the control device 100, an accelerator position sensor 30 inputs a detection signal of a driver's accelerator operation amount, and a vehicle speed sensor 41 inputs a detection signal of a vehicle speed, which is the running speed of the vehicle.

In addition to the airflow meter 33, the upstream A/F sensor 34, the downstream A/F sensor 35, and the intake pressure sensor 36, detection signals from various sensors are input to the control device 100. FIG. For example, the throttle position sensor 32 detects the opening of the throttle valve 31 . A crank position sensor 38 detects the rotational phase of the crankshaft 18 . A water temperature sensor 37 detects a cooling water temperature, which is the temperature of the cooling water of the internal combustion engine 10 . Note that the control device 100 calculates the engine rotation speed, which is the rotation speed of the crankshaft 18 of the internal combustion engine 10, from the detection signal of the crank position sensor 38. FIG. An intake cam position sensor 39 detects the rotation phase of the intake camshaft 25 . The control device 100 calculates the phase of the intake camshaft 25 with respect to the crankshaft 18 indicating the opening/closing timing of the intake valve 23 from the detection signal of the intake side cam position sensor 39 and the detection signal of the crank position sensor 38 . The exhaust cam position sensor 40 detects the rotational phase of the exhaust camshaft 26 . The control device 100 calculates the phase of the exhaust camshaft 26 with respect to the crankshaft 18 indicating the opening/closing timing of the exhaust valve 24 from the detection signal of the exhaust side cam position sensor 40 and the detection signal of the crank position sensor 38 .

The control device 100 takes in the output signals of these various sensors, performs various calculations based on these output signals, and executes various controls related to engine operation according to the calculation results.

The control device 100 includes, as control units for performing these various controls, an injection control unit 101 that controls the port injection valve 14 and the in-cylinder injection valve 15, an ignition control unit 102 that controls the ignition device 16, and an intake side variable valve. A valve timing control unit 103 that controls the timing mechanism 27 and the exhaust side variable valve timing mechanism 28 is provided. Further, the control device 100 includes a supercharging control unit 104 that drives the actuator 61 to control the waste gate valve 60, and an idling stop control that suppresses continuation of the idling operation by automatically stopping and restarting the engine operation. It also has an idling stop control unit 105 that executes.

The injection control unit 101 calculates a target fuel injection amount, which is a control target value for the fuel injection amount, based on the accelerator operation amount, vehicle speed, intake air amount, engine speed, engine load factor, and the like. The engine load factor is the ratio of the inflow air amount per cylinder per combustion cycle to the reference inflow air amount. Here, the reference inflow air amount is the inflow air amount per combustion cycle of one cylinder when the opening degree of the throttle valve 31 is maximized, and is determined according to the engine speed. The injection control unit 101 basically calculates the target fuel injection amount so that the air-fuel ratio becomes the stoichiometric air-fuel ratio. Then, control target values for the injection timing and the fuel injection time for the port injection valve 14 and the in-cylinder injection valve 15 are calculated. The port injection valve 14 and the in-cylinder injection valve 15 are driven to open in accordance with these control target values. As a result, an amount of fuel suitable for the operating state of the internal combustion engine 10 at that time is injected and supplied to the combustion chamber 11 . In the internal combustion engine 10, which fuel injection valve to inject fuel from is switched according to the operating state. Therefore, in the internal combustion engine 10, in addition to the case where fuel is injected from both the port injection valve 14 and the in-cylinder injection valve 15, there are cases where fuel is injected only from the port injection valve 14, and fuel is injected only from the in-cylinder injection valve 15. may be injected. Further, the injection control unit 101 stops fuel injection to stop the supply of fuel to the combustion chamber 11 during deceleration when the operation amount of the accelerator is zero, thereby reducing the fuel consumption rate. Also performs cut control.

The ignition control unit 102 calculates ignition timing, which is the timing of spark discharge by the ignition device 16, and operates the ignition device 16 to ignite the air-fuel mixture.
The valve timing control unit 103 calculates a target value of the phase of the intake camshaft 25 with respect to the crankshaft 18 and a target value of the phase of the exhaust camshaft 26 with respect to the crankshaft 18 based on the engine speed and the engine load factor, and The intake side variable valve timing mechanism 27 and the exhaust side variable valve timing mechanism 28 are operated. Thereby, the valve timing control unit 103 controls the opening/closing timing of the intake valve 23 and the opening/closing timing of the exhaust valve 24 . As an example, the valve timing control unit 103 controls valve overlap, which is a period during which both the exhaust valve 24 and the intake valve 23 are open.

The supercharging control unit 104 calculates the target opening of the wastegate valve 60 based on the vehicle speed, accelerator operation amount, engine rotation speed, engine load factor, etc., and drives the actuator 61 to open the wastegate valve 60. control the degree. That is, the supercharging control unit 104 controls opening and closing of the waste gate valve 60 .

The idling stop control unit 105 issues a command to the injection control unit 101 and the ignition control unit 102, stops fuel supply and ignition when the vehicle is stopped, automatically stops engine operation, and starts the vehicle. automatically restarts fuel supply and ignition to resume engine operation. That is, the idling stop control unit 105 performs idling stop control to suppress continuation of the idling operation by automatically stopping and restarting the engine operation.

By the way, when fuel cut control is executed and the vehicle is coasting, air flows into the catalyst device 80 through the exhaust passage 19 . When the vehicle is subsequently stopped and the engine operation is stopped by idling stop control or the like, the catalyst device 80 continues to be exposed to the air. As a result, the catalyst device 80 stores a large amount of oxygen, and when the internal combustion engine 10 is restarted, there is a possibility that the amount of oxygen stored in the catalyst device 80 becomes excessively large and the exhaust purification capability is reduced. be. Therefore, in the control device 100, when the fuel supply to the combustion chamber 11 is restarted and the engine operation is restarted, the injection control unit 101 executes rich reduction control to make the air-fuel ratio richer than the stoichiometric air-fuel ratio. . By executing the rich reduction control in this way, the excess fuel is introduced into the catalyst device 80 together with the exhaust gas, and the oxygen stored in the catalyst device 80 is reduced by the reaction with the fuel.

Next, a series of processes related to this rich reduction control will be described with reference to FIGS. 3 and 4. FIG. The flowchart shown in FIG. 3 shows the flow of processing in a routine for determining the start of rich reduction control. This routine is repeatedly executed by the control device 100 while the control device 100 is in operation.

As shown in FIG. 3, when this routine is started, the control device 100 first determines in the process of step S100 whether or not it is time to restart the internal combustion engine 10 by idling stop control. That is, the control device 100 determines whether or not the internal combustion engine 10 is being restarted after being automatically stopped by the idling stop control.

When control device 100 determines in the process of step S100 that it is time to restart under idling stop control (step S100: YES), the process proceeds to step S110. Then, in the process of step S110, the injection control unit 101 of the control device 100 starts rich reduction control. In the rich reduction control, the injection control unit 101 makes the air-fuel ratio richer than when the rich reduction control is not executed, and increases the target fuel injection amount so that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio. Inject fuel.

Then, in the subsequent process of step S120, the ignition control unit 102 of the control device 100 starts ignition timing retardation control. In the ignition timing retardation control, the ignition control unit 102 corrects the ignition timing to the retard side compared to when the ignition timing retardation control is not executed, and retards the ignition timing more than the ignition timing when the ignition timing retardation control is not executed. Spark discharge of the ignition device 16 is performed at the timing of the corner side.

Furthermore, in the process of step S130 following step S120, the valve timing control unit 103 of the control device 100 starts the most retarded exhaust control. In the exhaust most retarded angle control, the valve timing control unit 103 sets the opening/closing timing of the exhaust valve 24 to the most retarded side by the exhaust side variable valve timing mechanism 28 . With the opening/closing timing of the exhaust valve 24 set to the most retarded side, the intake side variable valve timing mechanism 27 adjusts the opening/closing timing of the intake valve 23 to control the valve overlap. That is, when the most retarded exhaust angle control is being executed, the valve timing control unit 103 sets the opening/closing timing of the exhaust valve 24 to the most retarded side, which is the same as when the most retarded exhaust angle control is not being executed. The opening/closing timing of the intake valve 23 is adjusted so as to realize valve overlap.

When the rich reduction control, the ignition timing retardation control, and the exhaust maximum retardation control are started through the processing of steps S110 to S130, the control device 100 ends this routine.

Further, as shown in FIG. 3, when the control device 100 determines in the process of step S100 that it is not the time of restart by the idling stop control (step S100: NO), the process of steps S110 to S130 is executed. without exiting this routine. That is, the control device 100 does not execute the rich reduction control, the ignition timing retardation control, and the exhaust maximum retardation control unless the engine is restarted by the idling stop control.

The flowchart shown in FIG. 4 shows the flow of processing in a routine for determining the end of rich reduction control. This routine is repeatedly executed by control device 100 when rich reduction control is being executed.

As shown in FIG. 4, when this routine is started, the controller 100 first determines whether the rear A/F value detected by the downstream A/F sensor 35 is equal to or less than the rich judgment value in step S200. determine whether The rich judgment value is a threshold for judging that unburned fuel is contained in the exhaust downstream of the catalyst device 80 based on the fact that the rear A/F value is equal to or less than the rich judgment value. It is set to a value slightly smaller than the value indicating the air-fuel ratio, that is, a value indicating a rich air-fuel ratio.

When control device 100 determines in the process of step S200 that the rear A/F value is equal to or less than the rich determination value (step S200: YES), the process proceeds to step S210.

Then, the control device 100 ends the rich reduction control in the process of step S210. That is, in the process of step S210, the injection control unit 101 of the control device 100 ends the rich reduction control. As a result, the injection control unit 101 stops increasing the fuel injection amount by rich reduction control and executes fuel injection according to the target fuel injection amount.

Then, in the subsequent processing of step S220, the ignition control unit 102 of the control device 100 ends the ignition timing retardation control. As a result, the ignition control unit 102 stops correcting the ignition timing to the retarded side by the ignition timing retarding control, and performs spark discharge of the ignition device 16 at the ignition timing not corrected by the ignition timing retarding control. become.

Furthermore, in the process of step S230 following step S220, the valve timing control unit 103 of the control device 100 ends the most retarded exhaust control. As a result, the valve timing control unit 103 cancels the state in which the opening/closing timing of the exhaust valve 24 is set to the most retarded side. Accordingly, the valve timing control unit 103 sets a target value of the phase of the intake camshaft 25 with respect to the crankshaft 18 and a target value of the phase of the exhaust camshaft 26 with respect to the crankshaft 18 based on the engine speed and the engine load factor. Then, the intake side variable valve timing mechanism 27 and the exhaust side variable valve timing mechanism 28 are operated. That is, the valve timing control unit 103 controls valve overlap by operating both the opening/closing timing of the exhaust valve 24 and the opening/closing timing of the intake valve 23 .

When the rich reduction control, the ignition timing retardation control, and the exhaust maximum retardation control are thus terminated through the processing of steps S210 to S130, the control device 100 terminates this routine.

Further, as shown in FIG. 4, when control device 100 determines in the process of step S200 that the rear A/F value is greater than the rich determination value (step S200: NO), Exit this routine without performing any processing.

That is, the control device 100 is executing rich reduction control, but the rear A/F value is higher than the rich determination value, and the exhaust downstream of the catalyst device 80 does not contain unburned fuel. is estimated, the rich reduction control, the ignition timing retardation control, and the exhaust maximum retardation control are not terminated. In short, in the control device 100, the injection control unit 101 reduces the oxygen stored in the catalyst device 80 by the rich reduction control, and the fuel passes through the catalyst device 80 without being completely consumed by the reduction reaction in the catalyst device 80. The rich reduction control is continued until the downstream A/F sensor 35 is reached.

It should be noted that, in order to restore the exhaust purification ability by such rich reduction control, it is preferable to quickly complete the reduction of oxygen in the catalytic device 80 and quickly recover the purification ability. Therefore, in the control device 100, in order to promote the reduction of oxygen by the rich reduction control, the waste gate valve 60 is kept in the closed state.

Next, the closed valve holding control will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 shows the flow of processing in a routine for determining the start of valve-closed holding control. This routine is repeatedly executed by the control device 100 while the control device 100 is in operation.

As shown in FIG. 5, when this routine is started, control device 100 first determines in the process of step S300 whether or not fuel cut control is being performed. When control device 100 determines in the process of step S300 that fuel cut control is being performed (step S300: YES), the process proceeds to step S310.

Then, in the process of step S310, the supercharging control unit 104 of the control device 100 starts the valve closing holding control. In the closed valve hold control, the supercharging control unit 104 closes the waste gate valve 60 and holds it in the closed state. Note that when it is determined that the fuel cut control is being performed in the process of step S300, the closed valve holding control has already started, and if the closed valve holding control is being carried out, in the process of step S310 Without doing anything, the closed valve holding control is continued.

On the other hand, if it is determined in the process of step S300 that fuel cut control is not being performed (step S300: NO), control device 100 ends this routine without executing the process of step S310.

By repeatedly executing this routine while the internal combustion engine 10 is running, the closed valve hold control is started at the time when the fuel cut control is started.
The flowchart shown in FIG. 6 shows the flow of processing in the routine for determining the end of the valve-closed holding control. This routine is repeatedly executed by the control device 100 when the closed valve holding control is being executed.

As shown in FIG. 6, when this routine is started, the control device 100 first determines whether or not the rear A/F value is equal to or less than the rich determination value in the process of step S400. When control device 100 determines in the process of step S400 that the rear A/F value is equal to or less than the rich determination value (step S400: YES), the process proceeds to step S410.

Then, the control device 100 terminates the valve closing holding control in the process of step S410. That is, in the process of step S410, the supercharging control unit 104 of the control device 100 terminates the closed valve holding control. As a result, the supercharging control unit 104 calculates the target opening of the wastegate valve 60 based on the vehicle speed, accelerator operation amount, engine rotation speed, engine load factor, etc., and drives the actuator 61 so that the wastegate valve 60 to control the opening of the

Further, as shown in FIG. 6, when the control device 100 determines in the process of step S400 that the rear A/F value is larger than the rich determination value (step S400: NO), it executes the process of step S410. without exiting this routine. That is, after the supply of fuel to the combustion chamber 11 is restarted and the engine operation is restarted, the supercharging control unit 104 detects that the air-fuel ratio is richer than the stoichiometric ratio by the downstream side A/F sensor 35. on the condition that the closed valve holding control is ended.

In this way, the control device 100 executes the valve-closed holding control, but the rear A/F value is higher than the rich judgment value, and the exhaust downstream of the catalyst device 80 contains unburned fuel. If it is estimated that the valve is not closed, the closed valve holding control is not terminated. In short, in the control device 100, the detection of the air-fuel ratio being richer than the stoichiometric air-fuel ratio by the downstream A/F sensor 35 is a condition for releasing the closed valve hold control. In the control device 100, the oxygen stored in the catalyst device 80 is reduced by the rich reduction control, and the fuel passes through the catalyst device 80 without being completely consumed by the reduction reaction in the catalyst device 80, and is discharged to the downstream A/F sensor 35. The closed valve holding control is continued until reaching .

Next, operation of the first embodiment will be described with reference to FIG. FIG. 7 is a timing chart showing the transition of each control when the vehicle decelerates, stops, and then restarts.
As shown in FIG. 7, when the vehicle starts decelerating, fuel cut control is started at time t10 (step S300: YES), and valve closed holding control is started (step S310), and the waste gate valve 60 is closed. will be retained. When the fuel cut control is executed, the supply of fuel is stopped and the air passes through the combustion chamber 11 and flows through the exhaust passage 19. Both the F value and the rear A/F value detected by the downstream A/F sensor 35 are values indicating lean. As fuel-free air passes through the catalytic converter 80, the catalytic converter 80 stores oxygen.

At time t11, as the vehicle speed decreases, the fuel cut control is stopped, and when the engine shifts to idling operation, fuel supply is resumed, so the front A/F value and the rear A/F value are richer than the stoichiometric air-fuel ratio. changes to the value of

When the vehicle stops at time t12 and the operation of the internal combustion engine 10 is stopped by the idling stop control, the fuel supply is stopped. The front A/F value and the rear A/F value change to values near the theoretical air-fuel ratio. While the operation of the internal combustion engine 10 is stopped in this way, the catalyst device 80 is exposed to the air in the exhaust passage 19 . Therefore, the catalyst device 80 stores oxygen.

At time t13, when the operation stop by the idling stop control is canceled and the internal combustion engine 10 is restarted (step S100: YES), rich reduction control, ignition timing retardation control, and exhaust re-retardation control are performed. is started (step S110, step S120, step S130). As a result, the fuel is supplied in an increased amount so that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio, and exhaust gas containing surplus fuel is introduced into the catalyst device 80 . Therefore, at this time, the front A/F value becomes a value on the rich side. Immediately after the rich reduction control is started, the fuel contained in the exhaust gas is consumed by the reduction of the oxygen stored in the catalytic device 80 and does not reach the downstream A/F sensor 35, so the rear A/F value is The value is close to the theoretical air-fuel ratio. When the rich reduction control is continued and the reduction of oxygen progresses and the amount of oxygen stored in the catalyst device 80 decreases, the fuel passes through the catalyst device 80 and reaches the downstream A/F sensor 35 without being completely consumed. will come to

Then, when the lean A/F value becomes equal to or less than the rich judgment value at time t14 (step S200: YES, step S400: YES), the rich reduction control is terminated (step S210), and the closed valve hold control is also terminated (step S410). ). At the same time, the ignition timing retardation control and the exhaust maximum retardation control are terminated (steps S2220 and S230).

As described above, in the control device 100, the closed valve holding control is started from the time when the fuel cut control is started. Therefore, when the rich reduction control is started, the waste gate valve 60 is already held closed. Then, while the rich reduction control is being executed, the closed valve holding control continues and the waste gate valve is held in the closed state.

Further, while the rich reduction control is being executed, the ignition timing retardation control is executed, and the engine is operated with the ignition timing being retarded. Further, while rich reduction control is being executed, exhaust re-retarding control is executed, and overlap control is performed with the opening/closing timing of the exhaust valve 24 set to the most retarded side.

Effects of the control device 100 of the first embodiment will be described.
(1) When the wastegate valve 60 is kept closed, gas flowing through the exhaust passage 19 passes through the turbine wheel 54 of the turbocharger 50 . As the turbine wheel 54 rotates, the gas passing through the turbine wheel 54 and flowing downstream becomes a swirling flow and reaches the catalytic device 80 . Therefore, if the closed valve holding control is being executed, the exhaust containing excess fuel passes through the turbine wheel 54 and becomes a swirling flow when the engine operation is restarted and the rich reduction control is being executed. will be introduced into the catalyst device 80 . In this case, the centrifugal force causes the exhaust gas to diffuse in the exhaust passage 19 , and the exhaust gas containing fuel is more likely to be uniformly introduced into the catalyst device 80 . Further, in the case of swirling flow, compared with the case where the exhaust gas flows straight toward the downstream side without swirling, it is possible to secure the time for contact between the catalyst and the fuel. Therefore, according to the above configuration, oxygen in the catalyst device 80 can be efficiently reduced by the rich reduction control.

(2) When the fuel cut control is started, the closed valve hold control is started, and after the waste gate valve 60 is closed by the closed valve hold control, the release condition is satisfied with the subsequent engine operation. During this time, the wastegate valve 60 is kept closed. Therefore, when the engine operation is restarted, the wastegate valve 60 is already closed. Therefore, the exhaust gas begins to pass through the turbine wheel 54 from the start of the rich reduction control, and the effect of the swirling flow described above can be produced. Therefore, according to the above configuration, the reductive reaction in the catalyst device 80 is promoted by the swirling flow, and the reduction of excess oxygen can be quickly completed at the time of restarting, so that the purifying ability can be recovered quickly.

(3) If the fuel cut control is being executed, the output torque of the internal combustion engine 10 will not increase even if the waste gate valve 60 is closed. Therefore, the waste gate valve 60 can be closed in advance in preparation for the rich reduction control. In the above configuration, since the closed valve holding control is started at the time when the fuel cut control is started, the waste gate valve 60 can be closed from the earliest time in preparation for subsequent rich reduction control.

(4) When the fuel introduced together with the exhaust gas by the rich reduction control is exhausted by the reduction of the oxygen stored in the catalytic device 80, the downstream A/F sensor 35 detects exhaust gas containing no fuel. reach. On the other hand, when the reduction of oxygen progresses and the amount of oxygen stored in the catalytic device 80 decreases, the fuel passes through the catalytic device 80 and reaches the downstream A/F sensor 35 without being completely consumed. Therefore, as in the above configuration, if the downstream side A/F sensor 35 detects that the air-fuel ratio is richer than the stoichiometric air-fuel ratio, the closed valve holding control is terminated. Based on the detection result of the /F sensor 35, it is possible to confirm that the reduction of oxygen is progressing until the fuel is not exhausted, and to end the valve closing holding control.

(5) Generation of NOx can be suppressed by retarding the ignition timing. According to the above configuration, while the rich reduction control is not completed, the ignition timing retardation control is executed to retard the ignition timing to suppress NOx emissions, so the purification capability of the catalyst device 80 is restored. It is possible to suppress NOx emissions during the period.

(6) Emission of NOx and HC can be suppressed by recirculating exhaust gas into the combustion chamber 11 using valve overlap. If the exhaust re-retarding control is executed to adjust the valve overlap by adjusting the valve opening timing of the intake valve 23 while the closing timing of the exhaust valve 24 is retarded to the maximum as in the above configuration. Thus, the closing timing of the intake valve 23 can be delayed as much as possible while achieving the target valve overlap, thereby reducing the actual compression ratio. Therefore, according to the above configuration, it becomes easier to achieve both the Atkinson cycle by delaying the closing timing of the intake valve 23 and the target valve overlap. As a result, the Atkinson cycle can reduce pumping loss, suppress fuel consumption, and suppress NOx and HC emissions.

This embodiment can be implemented with the following modifications.
- Although the closed valve holding control is started at the time when the fuel cut control is started, the start timing of the valve open holding control may not be the time when the fuel cut control is started. If the closed valve holding control is started before the restart is performed and the rich reduction control is started, the swirl flow is used to uniformly introduce the fuel into the catalyst device 80 from the time when the rich reduction control is started. You can get the effect of

(Second embodiment)
Next, a second embodiment of a vehicle internal combustion engine control apparatus will be described with reference to FIGS. 8 to 10. FIG. Here, the same reference numerals are assigned to the configurations that are common to the first embodiment, and detailed description thereof will be omitted.

In the first embodiment, the closed valve holding control is started from the time when the fuel cut control is started. Control is started and the waste gate valve 60 is closed prior to execution of fuel cut control.

Like the control device 100 of the first embodiment, the control device 100 of the second embodiment executes rich reduction control through the processes described with reference to FIGS. 3 and 4 . In the control device 100 of the first embodiment, when the fuel cut control is started through the routine described with reference to FIG. 5, the closed valve holding control is started. Now, instead of the routine described with reference to FIG. 5, the routine shown in FIG. 8 is executed. This routine shown in FIG. 8 is repeatedly executed by the control device 100 while the control device 100 is in operation.

As shown in FIG. 8, when this routine is started, control device 100 first determines in the process of step S500 whether or not a fuel cut execution condition is satisfied. The fuel cut execution condition is a requirement for executing fuel cut control, and is a logical AND condition of the operation amount of the accelerator being zero and the engine rotation speed being equal to or higher than the fuel cut permission rotation speed. ing. When control device 100 determines in the process of step S500 that the fuel cut execution condition is satisfied (step S500: YES), the process proceeds to step S510.

Then, in the process of step S510, the supercharging control unit 104 of the control device 100 starts the closed valve holding control. In the closed valve hold control, the supercharging control unit 104 closes the waste gate valve 60 and holds it in the closed state. Note that when it is determined in the process of step S500 that the fuel cut execution condition is satisfied, the closed valve holding control has already started, and if the closed valve holding control is being carried out, the process of step S510 is performed. Then, without doing anything, the closed valve holding control is continued.

On the other hand, if it is determined in the processing of step S500 that the fuel cut execution condition is not satisfied (step S500: NO), control device 100 ends this routine without executing the processing of step S510.

By repeatedly executing this routine while the internal combustion engine 10 is running, the closed valve holding control is started at the time when the fuel cut execution condition is satisfied.
Also in the control device 100 of the second embodiment, the end timing of the valve-close holding control is determined through the routine described with reference to FIG.

Next, determination of the start timing of the fuel cut control in the control device 100 of the second embodiment will be described with reference to FIG. 9 . The flowchart shown in FIG. 9 shows the flow of processing in a routine for determining the start of fuel cut control in the control device 100 of the second embodiment. This routine is repeatedly executed by the control device 100 at predetermined intervals while the control device 100 is operating.

As shown in FIG. 9, when this routine is started, control device 100 first determines in the process of step S600 whether or not the fuel cut execution condition is satisfied in the same manner as in the process of S500. When control device 100 determines in the process of step S600 that the fuel cut execution condition is satisfied (step S600: YES), the process proceeds to step S610.

Then, the control device 100 counts up the counter CNT in the process of step S610. A counter CNT is a counter for counting the elapsed time after the fuel cut execution condition is satisfied. Specifically, control device 100 increments counter CNT by one each time the process of step S610 is executed.

Next, control device 100 executes the process of step S620. In the process of step S620, control device 100 determines whether counter CNT is greater than or equal to threshold value Cth. It should be noted that the threshold value Cth is set based on the fact that the counter CNT reaches the threshold value Cth, the fuel cut execution condition is satisfied, the closed valve holding control is started, and the wastegate valve 60 is closed after the wastegate valve 60 is started to be closed. The size is set so that it can be determined that a sufficient amount of time has elapsed before the door closes. That is, in this step S610, based on the fact that the counter CNT is greater than or equal to the threshold value Cth, it is determined that the time sufficient to close the waste gate valve 60 has passed.

When control device 100 determines in the process of step S620 that counter CNT is equal to or greater than threshold value Cth (step S620: YES), the process proceeds to step S630. In step S630, injection control section 101 of control device 100 starts fuel cut control. Then, the control device 100 resets the counter CNT to zero in the processing of the next step S640, and once terminates this routine. On the other hand, when the control device 100 determines in the process of step S620 that the counter CNT is less than the threshold value Cth (step S620: NO), the process of step S630 and the process of step S640 are not executed, and the control device 100 Terminate this routine once.

When it is determined in the process of step S600 that the fuel cut execution condition is not satisfied (step S600: NO), control device 100 does not execute the processes of steps S610 to S630, and the process of step S640 is performed. is executed, the counter CNT is reset to zero, and this routine ends.

That is, through this routine, the control device 100 starts the fuel cut control after a certain delay time TD has elapsed after the fuel cut execution condition is satisfied. A period until the counter CNT reaches the threshold value Cth corresponds to the delay time TD. The length of the delay time TD is set to a time sufficient for the waste gate valve 60 to start closing after the fuel cut execution condition is established and to close the waste gate valve 60 .

Next, operation of the second embodiment will be described with reference to FIG. FIG. 10 is a timing chart showing the transition of each control when the vehicle decelerates and stops. That is, FIG. 10 shows the state up to time t11 in FIG. Transition of each control after time t11 is the same as in the first embodiment described with reference to FIG.

As shown in FIG. 10, when the accelerator operation amount becomes zero at time t7, the fuel cut execution condition is established. In FIG. 10 , the state where the accelerator operation amount is zero is shown as the accelerator OFF state, and the state where the accelerator is being operated is shown as the accelerator ON state.

When the fuel cut execution condition is satisfied (step S500: YES, step S600: YES), the closed valve holding control is started at time t8 (step S510), and the waste gate valve 60 is closed. Further, while the fuel cut execution condition is satisfied, the counter CNT is repeatedly counted up (step S610).

At time t9, when it is determined that the counter CNT has reached or exceeded the threshold value Cth (step S620: YES), fuel cut control is started (step S630). When the fuel cut control is executed, the supply of fuel is stopped and the air passes through the combustion chamber 11 and flows through the exhaust passage 19 . 7, the front A/F value detected by the upstream A/F sensor 34 and the rear A/F value detected by the downstream A/F sensor 35 are detected. are both lean values. As fuel-free air passes through the catalytic converter 80, the catalytic converter 80 stores oxygen.

At time t11, as the vehicle speed decreases, the engine rotation speed decreases and becomes less than the fuel cut permission rotation speed, and the fuel cut execution condition is no longer satisfied. Then, fuel cut control is stopped and the engine shifts to idling operation. When the engine shifts to idling operation, the fuel supply is restarted, so the front A/F value and the rear A/F value change to richer values than the stoichiometric air-fuel ratio.

Subsequent transition is the same as in the case of the first embodiment described with reference to FIG.
That is, after the vehicle stops and the operation of the internal combustion engine 10 is stopped by the idling stop control, the stop of the operation by the idling stop control is canceled and the internal combustion engine 10 is restarted (step S100: YES). Then, rich reduction control, ignition timing retardation control, and exhaust re-retardation control are started (steps S110, S120, and S130). As a result, the fuel is supplied in an increased amount so that the air-fuel ratio becomes richer than the stoichiometric air-fuel ratio, and exhaust gas containing surplus fuel is introduced into the catalyst device 80 . Therefore, at this time, the front A/F value becomes a value on the rich side. When the rich reduction control is continued and the reduction of oxygen progresses and the amount of oxygen stored in the catalyst device 80 decreases, the fuel passes through the catalyst device 80 and reaches the downstream A/F sensor 35 without being completely consumed. will come to

Then, when the lean A/F value becomes equal to or less than the rich judgment value (step S200: YES, step S400: YES), the rich reduction control ends (step S210), and the closed valve holding control also ends (step S410). At the same time, the ignition timing retardation control and the exhaust maximum retardation control are terminated (steps S2220 and S230).

In the control device 100 of the second embodiment as well, after the wastegate valve 60 is closed by the closed-valve holding control, the wastegate valve 60 remains closed until the release condition is satisfied with subsequent engine operation. state. Therefore, when the engine operation is restarted, the wastegate valve 60 is already closed. Therefore, the exhaust gas starts to pass through the turbine wheel from the start of the rich reduction control, and a swirling flow can be produced in the same manner as in the first embodiment.

Further, while the rich reduction control is being executed, the ignition timing retardation control is executed, and the engine is operated with the ignition timing being retarded. Further, while rich reduction control is being executed, exhaust re-retarding control is executed, and overlap control is performed with the opening/closing timing of the exhaust valve 24 set to the most retarded side.

During execution of the fuel cut control, the supply of fuel to the combustion chamber 11 is stopped. Therefore, although combustion is not performed, intake and exhaust are performed while the amount of intake air is limited. Therefore, the pressure inside the combustion chamber 11 becomes negative. If the wastegate valve 60 is closed during execution of fuel cut control, the opening degree of the wastegate valve 60 becomes small, and when the seat surface is approached, the wastegate valve 60 vibrates due to such negative pressure and exhaust pulsation. easier. When the vibrating wastegate valve 60 collides with the seat surface, a sound is generated. However, combustion is not performed in the internal combustion engine 10 during execution of fuel cut control, and noise and vibration due to combustion are generated. Therefore, the sound of the wastegate valve 60 colliding with the seat surface tends to be noticeable.

On the other hand, in the control device 100 of the second embodiment, the supercharging control unit 104, when the fuel cut control execution conditions are satisfied, controls the fuel cut control at the time t8 prior to execution of the fuel cut control at the time t9. At the time of , the closed valve holding control is started, and the waste gate valve 60 is closed.

According to such a configuration, the wastegate valve 60 is closed before the fuel cut control is executed, and the fuel cut control is started while the wastegate valve 60 is closed.

According to the control device 100 of the second embodiment, in addition to the effects (1), (2), (4) to (6) of the first embodiment, the following effects can be obtained.
(7) The wastegate valve 60 is closed when combustion is performed in the internal combustion engine 10, vibration of the wastegate valve 60 is unlikely to occur, and the sound of the wastegate valve 60 colliding with the seat surface is not noticeable. Therefore, the sound of the wastegate valve 60 colliding with the seat surface is less likely to be heard by the occupant.

The second embodiment can be implemented with the following modifications.
- Although the counter CNT is used to determine the elapse of the delay time TD, it is not necessary to determine the elapse of the delay time TD and start the fuel cut control. Fuel cut control may be started after confirming that the waste gate valve 60 is closed by using other means. For example, when the actuator 61 stops operating after the actuator 61 starts closing the wastegate valve 60, it is determined that the wastegate valve 60 is closed, and the fuel cut control is executed. You may do so.

In addition, there are the following elements that can be changed in common in each of the above-described embodiments. Each of the embodiments and modifications described above and the modifications described below can be implemented in combination within a technically consistent range.

・As an air-fuel ratio sensor, an example of application to an internal combustion engine that employs an A/F sensor whose output value changes continuously according to changes in oxygen concentration is shown, but an air-fuel ratio sensor for detecting the air-fuel ratio is used. is not limited to the A/F sensor. For example, when the output value changes significantly across the stoichiometric air-fuel ratio and the air-fuel ratio is rich, an output value indicating rich is output, and when the air-fuel ratio is lean, an output value indicating lean is output. You may use the O2 sensor which carries out.

The example of ending the closed valve holding control on the condition that the air-fuel ratio sensor detects that the air-fuel ratio is richer than the stoichiometric air-fuel ratio has been shown, but the condition for canceling the closed valve holding control is not limited to this mode. For example, the release condition may be that the rich reduction control continues for a certain period of time while the closed valve holding control is being executed.

・Although the rich reduction control, ignition timing retardation control, exhaust re-retardation control, and valve-holding control are all terminated at the same time, the end timing of each control may not be the same. good. That is, the release conditions for each control may not be the same. For example, the rich reduction control may end before the closed valve hold control, or the closed valve hold control may end before the rich reduction control. If there is a period during which the rich reduction control is executed while the closed valve hold control is being executed, it is possible to obtain the effect of uniformly introducing the fuel into the catalytic device 80 by utilizing the swirling flow during that period.

The example in which the rich reduction control is executed at the time of restart under the idling stop control has been shown, but the rich reduction control may also be executed when the fuel cut control ends and the supply of fuel is resumed. Since oxygen is stored in the catalyst device 80 even during execution of fuel cut control, the oxygen storage amount may become excessive. Even when the fuel cut control ends and the fuel supply is restarted, if the closed valve holding control is executed as in the above embodiment, fuel is uniformly supplied to the catalyst device 80 using the swirling flow. You can get the effect of introducing it.

A configuration similar to that of the control device of the above-described embodiment can also be adopted for an internal combustion engine having two or more catalyst devices in the exhaust passage 19 . If two or more catalyst devices are provided, the enrichment reduction control may be continued until the oxygen reduction in the downstream catalyst device is completed. The action of the swirl flow generated by the valve-closed hold control reaches the most upstream catalytic device closest to the turbine wheel 54, but hardly reaches the downstream catalytic device. Therefore, in this case, the closed valve holding control may be terminated when the reduction of oxygen in the upstream catalytic device is completed.

10 Internal combustion engine 11 Combustion chamber 12 Intake passage 13 Intake port 14 Port injection valve 15 In-cylinder injection valve 16 Ignition device 17 Piston 18 Crankshaft 19 Exhaust Passage 20 Upstream exhaust pipe 21 Downstream exhaust pipe 22 Exhaust port 23 Intake valve 24 Exhaust valve 25 Intake camshaft 26 Exhaust camshaft 27 Intake variable valve timing Mechanism 28 Exhaust side variable valve timing mechanism 29 Timing chain 30 Accelerator position sensor 31 Throttle valve 32 Throttle position sensor 33 Airflow meter 34 Upstream A/F sensor 35 Downstream Side A/F sensor 36... Intake pressure sensor 37... Water temperature sensor 38... Crank position sensor 39... Intake side cam position sensor 40... Exhaust side cam position sensor 41... Vehicle speed sensor 50... Turbocharger 51 Compressor housing 52 Turbine housing 53 Compressor wheel 54 Turbine wheel 55 Shaft 56 Bearing housing 57 Wastegate port 60 Wastegate valve 61 Actuator 70 Intercooler 80 Catalyst device 100 Control device 101 Injection control unit 102 Ignition control unit 103 Valve timing control unit 104 Supercharging control unit 105 Idling stop control unit.

Claims (6)

A turbocharger equipped with a fuel injection valve, an ignition device, and a wastegate valve that controls boost pressure by opening and closing a wastegate port; and a catalyst device that has a storage capacity and purifies exhaust gas, and is applied to a vehicle internal combustion engine,
An injection control unit that controls the fuel injection valve and performs fuel cut control to stop the supply of fuel to the combustion chamber during deceleration, an ignition control unit that controls the ignition device, and an engine operation that automatically stops An idling stop control unit that performs idling stop control that suppresses continuation of idling operation by restarting, and a supercharging control unit that controls opening and closing of the waste gate valve, and supplies fuel to the combustion chamber. is resumed and the engine operation is resumed, the injection control unit executes rich reduction control to make the air-fuel ratio richer than the stoichiometric air-fuel ratio, wherein
The supercharging control unit closes the wastegate valve while the fuel cut control is being executed, and holds the wastegate valve in a closed state until a cancellation condition is satisfied with subsequent engine operation. A control device for an onboard internal combustion engine that performs valve retention control,
The ignition control unit executes ignition retardation control for retarding ignition timing while the rich reduction control is being executed.
A control device for an internal combustion engine in a vehicle . A turbocharger equipped with a fuel injection valve, an ignition device, and a wastegate valve that controls boost pressure by opening and closing a wastegate port; An in-vehicle vehicle comprising a catalyst device having a storage capacity to purify exhaust gas, an intake side variable valve timing mechanism for changing the opening/closing timing of the intake valve, and an exhaust side variable valve timing mechanism for changing the opening/closing timing of the exhaust valve. applied to internal combustion engines,
An injection control unit that controls the fuel injection valve and performs fuel cut control to stop the supply of fuel to the combustion chamber during deceleration, an ignition control unit that controls the ignition device, and an engine operation that automatically stops An idling stop control unit that executes idling stop control that suppresses continuation of idling operation by restarting, a supercharging control unit that controls opening and closing of the waste gate valve, the intake side variable valve timing mechanism and the exhaust side variable a valve timing control unit for controlling a valve timing mechanism , wherein the injection control unit controls the air-fuel ratio to be richer than the stoichiometric air-fuel ratio when the fuel supply to the combustion chamber is restarted and the engine operation is restarted. A control device for an in-vehicle internal combustion engine that executes rich reduction control to
The supercharging control unit closes the wastegate valve while the fuel cut control is being executed, and holds the wastegate valve in a closed state until a cancellation condition is satisfied with subsequent engine operation. A control device for an onboard internal combustion engine that performs valve retention control,
While the rich reduction control is being executed, the valve timing control unit delays the closing timing of the exhaust valve to the maximum by the exhaust side variable valve timing mechanism, and the intake side variable valve timing mechanism By adjusting the valve opening timing of the intake valve by adjusting the valve overlap, which is the period in which both the exhaust valve and the intake valve are open, the most retarded exhaust control is performed.
A control device for an internal combustion engine in a vehicle . 3. The control of the vehicle-mounted internal combustion engine according to claim 1, wherein the supercharging control unit starts the closed valve holding control to close the waste gate valve when the fuel cut control is started. Device. A turbocharger equipped with a fuel injection valve, an ignition device, and a wastegate valve that controls boost pressure by opening and closing a wastegate port; and a catalyst device that has a storage capacity and purifies exhaust gas, and is applied to a vehicle internal combustion engine,
An injection control unit that controls the fuel injection valve and performs fuel cut control to stop the supply of fuel to the combustion chamber during deceleration, an ignition control unit that controls the ignition device, and an engine operation that automatically stops An idling stop control unit that performs idling stop control that suppresses continuation of idling operation by restarting, and a supercharging control unit that controls opening and closing of the waste gate valve, and supplies fuel to the combustion chamber. is resumed and the engine operation is resumed, the injection control unit executes rich reduction control to make the air-fuel ratio richer than the stoichiometric air-fuel ratio, wherein
The supercharging control unit closes the waste gate valve prior to execution of the fuel cut control when the fuel cut control execution condition is satisfied, and the release condition is satisfied as the engine is operated thereafter. A control device for an in-vehicle internal combustion engine that executes valve closed hold control to hold the valve closed until
The ignition control unit executes ignition retardation control for retarding ignition timing while the rich reduction control is being executed.
A control device for an internal combustion engine in a vehicle . A turbocharger equipped with a fuel injection valve, an ignition device, and a wastegate valve that controls boost pressure by opening and closing a wastegate port; An in-vehicle vehicle comprising a catalyst device having a storage capacity to purify exhaust gas, an intake side variable valve timing mechanism for changing the opening/closing timing of the intake valve, and an exhaust side variable valve timing mechanism for changing the opening/closing timing of the exhaust valve. applied to internal combustion engines,
An injection control unit that controls the fuel injection valve and performs fuel cut control to stop the supply of fuel to the combustion chamber during deceleration, an ignition control unit that controls the ignition device, and an engine operation that automatically stops An idling stop control unit that executes idling stop control that suppresses continuation of idling operation by restarting, a supercharging control unit that controls opening and closing of the waste gate valve, the intake side variable valve timing mechanism and the exhaust side variable a valve timing control unit for controlling a valve timing mechanism , wherein the injection control unit controls the air-fuel ratio to be richer than the stoichiometric air-fuel ratio when the fuel supply to the combustion chamber is restarted and the engine operation is restarted. A control device for an in-vehicle internal combustion engine that executes rich reduction control to
The supercharging control unit closes the waste gate valve prior to execution of the fuel cut control when the fuel cut control execution condition is satisfied, and the release condition is satisfied as the engine is operated thereafter. A control device for an in-vehicle internal combustion engine that executes valve closed hold control to hold the valve closed until
While the rich reduction control is being executed, the valve timing control unit delays the closing timing of the exhaust valve to the maximum by the exhaust side variable valve timing mechanism, and the intake side variable valve timing mechanism By adjusting the valve opening timing of the intake valve by adjusting the valve overlap, which is the period in which both the exhaust valve and the intake valve are open, the most retarded exhaust control is performed.
A control device for an internal combustion engine in a vehicle . Applied to the in-vehicle internal combustion engine having an air-fuel ratio sensor downstream of the catalyst device,
The supercharging control unit detects that the air-fuel ratio is richer than the stoichiometric air-fuel ratio by the air-fuel ratio sensor after the fuel supply to the combustion chamber is restarted and the engine operation is restarted. 6. The control device for a vehicle-mounted internal combustion engine according to any one of claims 1 to 5 , which terminates the valve-close holding control.

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