JP2012184662A - Control apparatus for internal combustion engine - Google Patents

Abstract

An object of the present invention is to prevent pumping up of an exhaust valve and to smoothly drive the valve.
An exhaust control valve and a valve actuator are provided in a branch passage of the exhaust manifold. The ECU 80 detects the exhaust pressure of the engine 10 and the in-cylinder pressure of the cylinder (target cylinder) in which the exhaust valve 54 is closed, and calculates a value obtained by subtracting the in-cylinder pressure from the exhaust pressure as an index of the cylinder. When this index becomes equal to or greater than a predetermined value at which pump-up is easily induced or accelerated, the valve actuator 34 of the target cylinder is driven to close the exhaust control valve 32. Thereby, it can suppress that the exhaust pressure of another cylinder acts on the exhaust valve 54 of an object cylinder in the valve opening direction, and can eliminate pump-up reliably.
[Selection] Figure 1

Description

  The present invention relates to an internal combustion engine control device, and more particularly, to an internal combustion engine control device in which a bypass passage is provided at each branch portion of an exhaust manifold.

  As a conventional technique, for example, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2007-56848), a control device for an internal combustion engine in which a bypass passage is provided in each branch portion of an exhaust manifold is known. . In the prior art, a bypass passage is connected to each branch portion of the exhaust manifold, and the downstream side of each bypass passage is connected to the downstream side of the joining portion of the exhaust manifold.

  Each bypass passage is provided with an electromagnetic on-off valve that opens and closes the branch between the exhaust manifold and the bypass passage. In the conventional technology, when the exhaust valve is incompletely opened due to pumping up of the lash adjuster in any cylinder, the open / close valve of each cylinder is opened to bypass the exhaust pressure in the exhaust manifold. It is configured to escape from the passage. As a result, in the prior art, the exhaust pressure of the other cylinders is suppressed from acting on the exhaust valve that is in an incompletely opened state, thereby eliminating the pump-up.

JP 2007-56848 A JP-A-10-89108

  In the above-described prior art, when the exhaust valve is in an incompletely opened state in any cylinder, the pump-up is eliminated by releasing the exhaust pressure in the exhaust manifold from the bypass passage. However, even if the control of the prior art is performed, the reflected wave of the exhaust pressure is generated at the junction of the exhaust manifold, and this reflected wave acts on the exhaust valve that is incompletely opened. There is a problem that it is difficult to solve.

  The present invention has been made to solve the above-described problems. The object of the present invention is to reliably eliminate pump-up even when the exhaust valve is in an incompletely opened state. An object of the present invention is to provide a control device for an internal combustion engine that can smoothly drive the engine.

The first invention has a plurality of branch passages that are respectively connected to a plurality of cylinders of the internal combustion engine and individually discharge the exhaust gas of each cylinder, and these branch passages merge on the downstream side; and
A plurality of exhaust control valves respectively provided in the branch passages of the cylinders and capable of individually opening and closing the branch passages;
Index acquisition means for acquiring, for each cylinder, a parameter corresponding to the exhaust pressure as an index of the cylinder when the exhaust valve is closed in each cylinder;
Valve control means for closing the exhaust control valve when any of the cylinders is equal to or greater than a predetermined value that easily induces or promotes pump-up in any cylinder;
It is characterized by providing.

  According to a second aspect of the present invention, there is provided in-cylinder pressure detecting means for detecting an in-cylinder pressure while the exhaust valve is closed in each cylinder, and the index acquisition means calculates a difference obtained by subtracting the in-cylinder pressure from the exhaust pressure. It is set as the structure calculated as.

A third invention is a supercharger that supercharges intake air by a compressor;
An intake pressure detecting means for detecting an intake pressure downstream of the compressor,
The index calculation means is configured to calculate a difference obtained by subtracting the intake pressure from the exhaust pressure as the index.

  According to the fourth invention, the valve control means opens the exhaust control valve of the target cylinder, which is an arbitrary cylinder, together with the exhaust valve of the target cylinder, and then reaches the exhaust stroke next to the target cylinder. The cylinder is closed when the exhaust valve of the cylinder reaches the maximum opening.

  According to a fifth aspect of the invention, the valve control means opens the exhaust control valve of the target cylinder every time the exhaust valve of each cylinder that reaches the exhaust stroke after the next cylinder is opened. The valve is closed every time the maximum opening is reached.

  According to the first invention, when the exhaust pressure of the other cylinder becomes a predetermined value or more, the exhaust pressure acts in the valve opening direction on the exhaust valve of the target cylinder, so that the pump up is performed in the target cylinder. It is likely to occur. Therefore, in this case, the exhaust control valve of the target cylinder can be closed to suppress the exhaust pressure of the other cylinder from acting on the exhaust valve of the target cylinder. That is, since the exhaust pressure of the other cylinders can be shut off by the exhaust control valve, even if a reflected wave of the exhaust pressure occurs in the exhaust passage or the exhaust valve is in an incompletely opened state, the pump can be surely pumped up. Therefore, the valve can be driven smoothly.

  According to the second invention, the exhaust pressure of the other cylinder acts in the valve opening direction and the in-cylinder pressure of the own cylinder acts in the valve closing direction on the exhaust valve of the target cylinder. Therefore, by subtracting the in-cylinder pressure from the exhaust pressure, it is possible to obtain only the pressure in the valve opening direction that causes the pump-up as an index, and it is possible to more accurately determine the ease of occurrence of the pump-up. .

  According to the third invention, the exhaust pressure of the other cylinder acts in the valve opening direction and the intake pressure acts in the valve closing direction on the exhaust valve of the target cylinder. In particular, when the supercharger is operating, the intake pressure (supercharging pressure) supercharged by the supercharger acts on the exhaust valve of the target cylinder in the valve closing direction. Therefore, by subtracting the intake pressure from the exhaust pressure, it is possible to acquire only the pressure in the valve opening direction that causes the pump-up as an index, and it is possible to more accurately determine the ease of occurrence of the pump-up. .

  According to the fourth invention, first, in the exhaust stroke of each cylinder (target cylinder), the exhaust control valve can be opened together with the exhaust valve, and the exhaust can be performed smoothly. Further, the exhaust control valve of the target cylinder can be closed at the timing when the opening degree of the exhaust valve of the next cylinder becomes the maximum opening degree, that is, the timing when the exhaust pressure generated in the next cylinder increases. For this reason, even if surging remains in the exhaust valve of the target cylinder, it is possible to avoid the exhaust pressure generated in the next cylinder from acting on the exhaust valve. Therefore, it is possible to prevent the self-surging and the exhaust pressure of the next cylinder from acting synergistically on the exhaust valve of an arbitrary cylinder, and pump-up can be more stably suppressed.

  According to the fifth aspect of the invention, the exhaust control valve can be opened and closed at an accurate timing according to the state of the exhaust pressure acting on the target cylinder from other cylinders, and the opening / closing timing is set to a small value can do. As a result, it is possible to respond to the pressure change in the exhaust passage with high responsiveness, and the exhaust control valve can be controlled with higher accuracy. Further, for example, when a normally closed valve mechanism is used as the exhaust control valve, the energization can be stopped more frequently, so that the power consumption can be reduced.

It is a whole block diagram for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is sectional drawing which fractures | ruptures and shows one cylinder of an engine. In Embodiment 1 of this invention, it is a flowchart of the control performed by ECU. 6 is a timing chart showing opening / closing timings of an exhaust valve and an exhaust control valve in the second embodiment. In Embodiment 3, it is a timing chart which shows the opening and closing timing of an exhaust valve and an exhaust control valve.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
The first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an overall configuration diagram for explaining a system configuration according to the first embodiment of the present invention. As shown in this figure, the system of the present embodiment includes an engine 10 made of, for example, an L-type four-cylinder engine as an internal combustion engine. The engine 10 includes an intake passage 12 that sucks intake air into each cylinder, and the downstream side of the intake passage 12 is branched into a plurality of passages and connected to an intake port 44 (FIG. 2 described later) of each cylinder. The intake manifold 14 is configured. The intake passage 12 is provided with an electronically controlled throttle valve 16 that adjusts the intake air amount and an intercooler 18 that cools the intake air.

  Further, the engine 10 includes an exhaust passage 20 that discharges exhaust gas of each cylinder, and an upstream side of the exhaust passage 20 is configured by an exhaust manifold 22. The exhaust manifold 22 is formed by branching the upstream side into a plurality of branch passages 24, and these branch passages 24 are respectively connected to exhaust ports 46 of cylinders described later. On the downstream side of the exhaust manifold 22, a merging portion 26 where the branch passages 24 merge is provided. Further, a catalyst 28 for purifying the exhaust gas is provided on the downstream side of the exhaust passage 20. On the other hand, a known supercharger (turbocharger) 30 is provided between the intake passage 12 and the exhaust passage 20. The supercharger 30 has a turbine provided in the exhaust passage 20 and a compressor provided in the intake passage 12. In the supercharger 30, the turbine receives the exhaust pressure to drive the compressor, and supercharges the intake air by the compressor.

  The engine 10 also includes a plurality of exhaust control valves 32 that individually open and close the branch passages 24 of the exhaust manifold 22 and valve actuators 34 that individually drive the exhaust control valves 32. The exhaust control valve 32 is configured by a butterfly valve or the like, for example, and is disposed in each branch passage 24. The exhaust control valve 32 of each cylinder is configured to open at least during the exhaust stroke of the cylinder. The valve actuator 34 drives the exhaust control valve 32 to a fully open position and a fully closed position. The valve system of the exhaust control valve 32 and the valve actuator 34 can be opened and closed multiple times during one cycle of the engine, for example. It is made up of a possible high-speed operating system.

  Next, the structure of each cylinder will be described with reference to FIG. FIG. 2 is a sectional view showing one cylinder of the engine in a cutaway view. As shown in this figure, each cylinder of the engine 10 includes a combustion chamber 42 formed by a piston 40, and an intake port 44 and an exhaust port 46 that open to the combustion chamber 42. Each cylinder has a fuel injection valve 48 that injects fuel into the intake port 44, an ignition plug 50 that ignites the air-fuel mixture, and an intake air that opens and closes the intake port 44 with respect to the combustion chamber 42 (inside the cylinder). The intake valve 52 and the exhaust valve 54 having a valve 52 and an exhaust valve 54 for opening and closing the exhaust port 46 with respect to the inside of the cylinder are driven by the engine via a crankshaft and a camshaft. When the intake stroke, the explosion / expansion stroke, and the exhaust stroke arrive in sequence, they are opened and closed at a predetermined timing with respect to these strokes.

  Next, the control system of the system will be described with reference to FIG. 1 and FIG. The system according to the present embodiment includes a sensor system including sensors 60 to 70 described later, and an ECU (Engine Control Unit) 80 that controls operation of the engine 10. First, the sensor system will be described. The crank angle sensor 60 outputs a signal synchronized with the rotation of the crankshaft, the cam angle sensor 62 outputs a signal synchronized with the rotation of the camshaft, and the airflow sensor 64 receives the suction. It detects the amount of air.

  The in-cylinder pressure sensor 66 individually detects the in-cylinder pressure of each cylinder, and is provided for each cylinder (only one is shown). The intake pressure sensor 68 detects intake pressure (supercharging pressure) on the downstream side of the compressor of the supercharger 30. The exhaust pressure sensor 70 detects the exhaust pressure of the engine, and is disposed, for example, at the junction 26 of the exhaust manifold 22. In addition to this, the sensor system includes various sensors necessary for driving the engine and the vehicle. The in-cylinder pressure sensor 66 and the intake pressure sensor 68 constitute the in-cylinder pressure detection unit and the intake pressure detection unit of the present embodiment, respectively.

  As shown in FIG. 2, the ECU 80 includes an arithmetic processing unit (CPU) 82, a storage circuit 84 including a ROM, a RAM, and the like, an input port 86, and an output port 88. Each sensor of the sensor system is connected to the input port 86 via an A / D conversion circuit or the like. Various actuators including the throttle valve 16, the valve actuator 34, the fuel injection valve 48, the spark plug 50, and the like are connected to the output port 88.

  The ECU 80 controls the operation by driving each actuator based on the engine operation information detected by the sensor system. Specifically, the engine speed and the crank angle are detected based on the output of the crank angle sensor 60, and the intake air amount is detected by the air flow sensor 64. The engine load is calculated based on the engine speed and the intake air amount, the fuel injection amount is calculated based on the intake air amount, the engine load, etc., and the fuel injection timing and the ignition timing are determined based on the crank angle. To do. Then, the fuel injection valve 48 is driven when the fuel injection timing comes, and the spark plug 50 is driven when the ignition timing comes. Thereby, the air-fuel mixture is combusted in the combustion chamber 42 of each cylinder, and the engine can be operated.

[Features of Embodiment 1]
In each cylinder, the exhaust valve 54 basically opens and closes according to the rotation angle (exhaust cam profile) of the exhaust camshaft. However, the exhaust valve 54 may be slightly opened even during the period in which the valve should be closed (the base circle period of the cam) depending on the engine operating state, the exhaust pressure of other cylinders, the change over time of the valve drive system, and the like. There is. For example, when the exhaust brake is operated, when back pressure pulsation occurs, or when the engine is running at high speed, so-called valve jump or valve surging occurs, and the exhaust valve opens even during the base circle period. There is.

  When the exhaust valve opens during the base circle period, a gap is formed between the stem end of the exhaust valve and the rocker arm, and the plunger spring of the lash adjuster extends to fill this gap. As a result, the plunger and the push rod are pushed up, and expansion (decompression) of the pressure chamber occurs. As a result, the check valve is opened and oil flows from the reservoir chamber into the pressure chamber, so that the lash adjuster is in an extended state due to the plunger being pushed up, so-called pump-up occurs.

  In this way, when pump-up occurs, the lash adjuster functions as a new valve closing position of the exhaust valve at the excessively extended position. It becomes. During engine operation, pumping up is induced or promoted when the exhaust pressure of other cylinders acts on the exhaust valve in the valve opening direction in the cylinder where pumping up is likely to occur as described above.

  Therefore, in this embodiment, in each cylinder, it is determined whether or not pump-up is likely to occur based on the following indices (1) to (3). The exhaust control valve 32 of the cylinder is closed. In the present embodiment, for example, the case where three indices (1) to (3) are used is exemplified, but the present invention does not need to control the exhaust control valve 32 based on all these indices. That is, it is good also as a structure which performs control based on any one or two among parameter | index (1)-(3).

(1) Exhaust pressure The ECU 80 detects the exhaust pressure using the exhaust pressure sensor 70 as an index when the exhaust valve 54 is closed in each cylinder, that is, during the base circle period of the exhaust cam of the cylinder. This detection process is executed for each cylinder, and the detected exhaust pressure (index) corresponds to the exhaust pressure of other cylinders excluding the cylinder in each cylinder. In any cylinder (target cylinder), when the index is equal to or greater than a predetermined value at which pump-up is easily induced or promoted, the valve actuator 34 of the target cylinder is driven to close the exhaust control valve 32. To do. The predetermined value is determined in advance by measurement with a real machine, theoretical calculation, or the like.

  When the exhaust pressure of the other cylinder becomes equal to or higher than the predetermined value, the exhaust pressure acts in the valve opening direction on the exhaust valve 54 of the target cylinder, so that the target cylinder is likely to be pumped up. Therefore, in this case, the exhaust control valve 32 of the target cylinder is closed to suppress the exhaust pressure of the other cylinder from acting on the exhaust valve 54 of the target cylinder. As a result, it is possible to prevent pumping up due to the exhaust pressure of the other cylinders.

(2) The difference obtained by subtracting the in-cylinder pressure from the exhaust pressure When the exhaust valve 54 is closed in each cylinder, the ECU 80 detects the exhaust pressure by the exhaust pressure sensor 70 and the in-cylinder pressure sensor 66 detects the exhaust pressure of the cylinder. In-cylinder pressure is detected. Subsequently, a difference obtained by subtracting the in-cylinder pressure from the exhaust pressure is calculated as an index of each cylinder. Then, in any cylinder (target cylinder), when the index is equal to or greater than a predetermined value at which pump-up is easily induced or promoted, the exhaust control valve 32 of the target cylinder is closed.

  On the exhaust valve 54 of the target cylinder, the exhaust pressure of the other cylinder acts in the valve opening direction, and the in-cylinder pressure of the own cylinder acts in the valve closing direction. Therefore, by subtracting the in-cylinder pressure from the exhaust pressure, it is possible to obtain only the pressure in the valve opening direction that causes the pump-up as an index, and it is possible to more accurately determine the ease of occurrence of the pump-up. .

(3) The difference obtained by subtracting the intake pressure from the exhaust pressure The ECU 80 detects the exhaust pressure by the exhaust pressure sensor 70 and the intake pressure by the intake pressure sensor 68 when the exhaust valve 54 is closed in each cylinder. To detect. When a difference obtained by subtracting the intake pressure from the exhaust pressure is calculated as an index of each cylinder, and the index becomes equal to or greater than a predetermined value that easily induces or promotes pump-up in any cylinder (target cylinder) First, the exhaust control valve 32 of the target cylinder is closed.

  When the supercharger 30 is operating, the intake pressure (supercharge pressure) supercharged by the supercharger 30 acts on the exhaust valve 54 of the target cylinder in the valve closing direction. Therefore, by subtracting the intake pressure from the exhaust pressure, it is possible to acquire only the pressure in the valve opening direction that causes the pump-up as an index, and it is possible to more accurately determine the ease of occurrence of the pump-up. .

  As described above, the exhaust control valve 32 of each cylinder is multiple times in one cycle (for example, 3 in one cycle for a four-cylinder engine) based on the determination conditions using the indices (1) to (3). Times) Open and closed. In any cylinder, the exhaust control valve 32 is opened when the exhaust valve 54 of the cylinder is open, and exhaust gas discharged from the cylinder flows into the exhaust passage 20. The predetermined value may be set to a different value depending on which of the indices (1) to (3) is used.

  According to the above configuration, when the exhaust valve 54 of each cylinder is likely to be opened by the exhaust pressure of the other cylinder, the exhaust control valve 32 can block the exhaust pressure of the other cylinder. Therefore, even when a reflected wave of the exhaust pressure is generated at the merging portion 26 of the exhaust manifold 22 or the exhaust valve 54 is incompletely opened, the pump-up can be reliably eliminated and the valve can be driven smoothly. Can be done.

[Specific Processing for Realizing Embodiment 1]
Next, specific processing for realizing the above-described control will be described with reference to FIG. FIG. 3 is a flowchart of control executed by the ECU in the first embodiment of the present invention. The routine shown in this figure is repeatedly executed during the operation of the engine, and the ignition of each cylinder is performed in the order of # 1 cylinder → # 3 cylinder → # 4 cylinder → # 2 cylinder. FIG. 3 shows an example of the process for the index (2).

  In the routine shown in FIG. 3, first, at step 100, for example, whether the rotational position of the exhaust cam of the # 1 cylinder is within the base circle period, that is, whether the exhaust valve 54 of the # 1 cylinder is closed. No, and wait until this determination is satisfied. Next, in step 102, the exhaust pressure detected by the exhaust pressure sensor 70 is read. In step 104, the in-cylinder pressure of the # 1 cylinder detected by the in-cylinder pressure sensor 66 is read. In step 106, an index of the # 1 cylinder is calculated by subtracting the in-cylinder pressure from the exhaust pressure, and it is determined whether or not this index is equal to or greater than the predetermined value.

  If the determination at step 106 is established, the exhaust control valve 32 of the # 1 cylinder is closed at step 108. On the other hand, if the determination in step 106 is not established, the exhaust control valve 32 is held open in step 110. Next, in step 112, the same processing as in steps 100 to 110 is executed for the # 3 cylinder. Briefly, the index of the # 3 cylinder is calculated by subtracting the in-cylinder pressure of the # 3 cylinder from the exhaust pressure, and when the index is equal to or greater than the predetermined value, the exhaust control valve 32 of the # 3 cylinder is closed. I speak. Next, in steps 114 and 116, the same processes as in steps 100 to 110 are executed for the # 4 cylinder and the # 2 cylinder.

  In the first embodiment, step 106 in FIG. 3 shows a specific example of the index acquisition means in claims 1 and 2, and step 108 shows a specific example of the valve control means.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that the closing timing of the exhaust control valve in each cylinder is set in accordance with the opening degree of the exhaust valve of the next cylinder in the configuration and control substantially the same as in the first embodiment. . In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 2]
FIG. 4 is a timing chart showing opening / closing timings of the exhaust valve and the exhaust control valve in the second embodiment. In this figure, the thin curve shows the lift curve of the exhaust valve 54 of each cylinder, and the thick rectangular straight line shows the open / closed state of the exhaust control valve 32 of each cylinder. In the present embodiment, the exhaust control valve 32 of the target cylinder, which is an arbitrary cylinder, is opened together with the exhaust valve 54 of the target cylinder, and the exhaust valve 54 of the next cylinder that reaches the exhaust stroke next to the target cylinder. The valve is closed when becomes the maximum opening. This opening / closing process is sequentially executed for the exhaust control valve 32 of each cylinder, for example, in the order of # 1 cylinder → # 3 cylinder → # 4 cylinder → # 2 cylinder.

  As a specific example, for example, when the # 1 cylinder is the target cylinder, the exhaust control valve 32 of the # 1 cylinder is opened when (or immediately before) the exhaust valve 54 of the # 1 cylinder is opened. . The exhaust control valve 32 is held in an open state until the exhaust valve 54 of the # 3 cylinder, which is the next cylinder, reaches a maximum opening (maximum lift amount), and then closed. Similarly, the exhaust control valve 32 of the # 3 cylinder is opened together with the exhaust valve 54 of the # 3 cylinder, and is closed when the exhaust valve 54 of the # 4 cylinder reaches the maximum opening.

  According to the above control, first, in the exhaust stroke of each cylinder (target cylinder), the exhaust control valve 32 can be opened together with the exhaust valve 54, and the exhaust can be performed smoothly. Further, even if surging remains in the exhaust valve 54 of the target cylinder, it is possible to avoid the exhaust pressure generated in the next cylinder from acting on the exhaust valve 54. That is, taking # 1 cylinder and # 3 cylinder as an example, for example, the exhaust pressure generated in # 3 cylinder tends to increase particularly after the opening degree of the exhaust valve 54 of the cylinder reaches the maximum opening degree. is there. On the other hand, the exhaust control valve 32 of the # 1 cylinder is closed when the opening of the exhaust valve 54 of the # 3 cylinder reaches the maximum opening, so that the exhaust pressure of the next cylinder (# 3 cylinder) is large. Can be prevented from acting on the exhaust valve of the # 1 cylinder.

  The above-described operation and effects can be obtained in the same manner for the # 3, # 4, and # 2 cylinders as shown in FIG. Therefore, according to the present embodiment, it is possible to prevent the self-surging and the exhaust pressure of the next cylinder from acting synergistically on the exhaust valve 54 of an arbitrary cylinder. In addition to substantially the same operational effects, the pump-up can be more stably suppressed. In the second embodiment, the timing chart shown in FIG. 4 shows a specific example of the valve control means in claim 4.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, in addition to the control of the second embodiment, the opening / closing timing of the exhaust control valve of each cylinder is set not only by the next cylinder but also by the operating state of the exhaust valve of the subsequent cylinder. It is characterized by. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[Features of Embodiment 3]
FIG. 5 is a timing chart showing opening / closing timings of the exhaust valve and the exhaust control valve in the third embodiment. Since the curves and straight lines in the figure are the same as those in the second embodiment (FIG. 4), description thereof is omitted. In the present embodiment, first, similarly to the second embodiment, the exhaust control valve 32 of the target cylinder which is an arbitrary cylinder is opened together with the exhaust valve 54 of the target cylinder, and the exhaust valve 54 of the next cylinder is opened. The valve is closed when becomes the maximum opening. Further, in the present embodiment, the exhaust control valve 32 of the target cylinder is opened each time the exhaust valve 54 of each cylinder that reaches the exhaust stroke after the next cylinder is opened, and the exhaust valve 54 has the maximum opening degree. The valve is closed every time. This opening / closing process is sequentially executed for the exhaust control valve 32 of each cylinder, as in the second embodiment.

  For example, when the # 1 cylinder is the target cylinder, for example, the exhaust control valve 32 of the # 1 cylinder is opened together with the exhaust valve 54 of the # 1 cylinder, and the exhaust valve 54 of the # 3 cylinder is opened. The valve is closed when the maximum opening is reached. Next, the exhaust control valve 32 of the # 1 cylinder is opened together with the exhaust valve 54 of the # 4 cylinder, and is closed when the exhaust valve 54 reaches the maximum opening. Further, the exhaust control valve 32 of the # 1 cylinder is opened together with the exhaust valve 54 of the # 2 cylinder, and is closed when the exhaust valve 54 reaches the maximum opening. Thus, the exhaust control valve 32 of each cylinder is driven to open and close multiple times during one cycle of the engine (for example, three times during one cycle for a four-cylinder engine).

  According to the above control, the following operational effects can be obtained in addition to the operational effects of the second embodiment. That is, the exhaust control valve 32 can be opened and closed at an appropriate timing according to the state of the exhaust pressure acting on the target cylinder from each of the other cylinders, and the opening / closing timing can be set to a small value. Thereby, it is possible to respond to the pressure change in the exhaust passage 20 with high responsiveness, and the exhaust control valve 32 can be controlled with higher accuracy. In addition, when the normally closed valve mechanism that opens by energizing the valve actuator 34 is used as the exhaust control valve 32, for example, the energization can be stopped a little, so the power consumption of the valve actuator 34 Can be reduced.

  In the third embodiment, the timing chart shown in FIG. 5 shows a specific example of the valve control means in claim 5. In the first to third embodiments, the individual configurations are exemplified, but the present invention includes configurations obtained by combining these embodiments. That is, in the present invention, for example, the first and second embodiments may be combined, or the first and third embodiments may be combined.

  Moreover, in embodiment, as shown in FIG. 1, the system which mounted the supercharger 30 was illustrated. However, the present invention is not limited to this, and can be applied to an internal combustion engine not equipped with a supercharger. The present invention may be applied to an internal combustion engine equipped with a mechanical supercharger including a supercharger.

10 Engine 12 Intake passage 14 Intake manifold 16 Throttle valve 18 Intercooler 20 Exhaust passage 22 Exhaust manifold 24 Branch passage 26 Merge portion 28 Catalyst 30 Supercharger 32 Exhaust control valve 34 Valve actuator 40 Piston 42 Combustion chamber 44 Intake port 46 Exhaust port 48 Fuel injection valve 50 Spark plug 52 Intake valve 54 Exhaust valve 60 Crank angle sensor 62 Cam angle sensor 64 Air flow sensor 66 In-cylinder pressure sensor (in-cylinder pressure detecting means)
68 Intake pressure sensor (Intake pressure detection means)
70 Exhaust pressure sensor 80 ECU

Claims (5)

Each having a plurality of branch passages connected to a plurality of cylinders of the internal combustion engine for individually discharging the exhaust gas of each cylinder, and these branch passages merged downstream;
A plurality of exhaust control valves respectively provided in the branch passages of the cylinders and capable of individually opening and closing the branch passages;
Index acquisition means for acquiring, for each cylinder, a parameter corresponding to the exhaust pressure as an index of the cylinder when the exhaust valve is closed in each cylinder;
Valve control means for closing the exhaust control valve when any of the cylinders is equal to or greater than a predetermined value that easily induces or promotes pump-up in any cylinder;
A control device for an internal combustion engine, comprising: In-cylinder pressure detecting means for detecting the in-cylinder pressure while the exhaust valve is closed in each cylinder,
The control apparatus for an internal combustion engine according to claim 1, wherein the index acquisition means is configured to calculate a difference obtained by subtracting the in-cylinder pressure from the exhaust pressure as the index. A supercharger that supercharges intake air with a compressor;
An intake pressure detecting means for detecting an intake pressure downstream of the compressor,
2. The control device for an internal combustion engine according to claim 1, wherein the index calculation means calculates a difference obtained by subtracting the intake pressure from the exhaust pressure as the index.   The valve control means opens the exhaust control valve of the target cylinder, which is an arbitrary cylinder, together with the exhaust valve of the target cylinder, and opens the exhaust valve of the next cylinder that reaches the exhaust stroke next to the target cylinder to the maximum. The control device for an internal combustion engine according to any one of claims 1 to 3, wherein the control device is configured to close the valve when it reaches a certain degree.   The valve control means opens the exhaust control valve of the target cylinder every time the exhaust valve of each cylinder that reaches the exhaust stroke after the next cylinder opens, and every time the exhaust valve reaches the maximum opening degree. The control device for an internal combustion engine according to claim 4, wherein the control device is configured to be closed.

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