JP2005146949A - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine capable more rapidly solving a problem of fuel adhesion in a cylinder due to accidental fire. <P>SOLUTION: This control device of an internal combustion engine stops supplying fuel to an accidental fire cylinder and igniting mixture in the cylinder when accidental fire is recognized, and forcedly opens an intake valve and an exhaust valve in a compression stroke and an expansion stroke of the cylinder. Thereby, in the accidental fire cylinder, in addition to the intake and exhaust strokes, air is taken and exhausted in compression and exhaust strokes. Because ventilation in the cylinder can be significantly improved, fuel adhesion such as at electrodes of an ignition plug due to accidental fire can be solved at an early stage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device applied to a four-cycle internal combustion engine.

  In a spark ignition type internal combustion engine that ignites fuel through spark discharge from the spark plug, fuel that has not been burned due to misfire adheres to the electrode portion of the spark plug, and ignitability deteriorates. In such a state, if the fuel supply to the cylinder is continued, a so-called plug fogging with a large amount of fuel adhering to the spark plug electrode portion, and the fuel ignition in the cylinder cannot be performed for a long time. May end up. In particular, in a situation where the temperature in the cylinder is low, such as during cold start, the fuel that has once adhered is difficult to vaporize, so such plug fog is likely to occur.

Therefore, conventionally, for example, Patent Document 1 discloses a control device for an internal combustion engine that detects the occurrence of misfire in each cylinder at the time of starting the engine and corrects the fuel supply amount to the cylinder in which the misfire is detected, or stops the fuel supply. Has been described. In this control device, the amount of fuel supplied to the cylinder in which misfire has occurred is reduced, and further fuel adherence to the spark plug electrode portion is suppressed. Can do.
JP-A-3-271538

  Even in such a conventional technique, the elimination of the plug fog is not limited to waiting for the fuel adhering to the spark plug electrode portion to be vaporized according to the ventilation of the in-cylinder gas accompanying the intake and exhaust during the intake and exhaust strokes. However, there was a limit to its advancement.

  Even in a compression ignition type internal combustion engine such as a diesel engine, when a misfire occurs, a part of the fuel supplied into the cylinder adheres to the wall surface of the combustion chamber and remains in the cylinder without being discharged in the exhaust stroke. Resulting in. If the fuel supply to the cylinder is continued in such a state, the air-fuel ratio of the air-fuel mixture in the cylinder becomes overrich, and the ignition performance is deteriorated. Therefore, even in a compression ignition type internal combustion engine, the deterioration of ignition performance can be suppressed by reducing the fuel supply to the cylinder in accordance with the confirmation of misfire as in the conventional technique. However, even in such a case, the removal of the fuel adhering to the wall surface of the combustion chamber has to wait for vaporization according to the ventilation of the in-cylinder gas accompanying the intake and exhaust in the intake and exhaust strokes.

  The present invention has been made in view of such circumstances, and a problem to be solved is to provide a control device for an internal combustion engine that can further accelerate the elimination of fuel adhesion in a cylinder due to misfire. is there.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
According to the first aspect of the present invention, in the control device for an internal combustion engine applied to a four-cycle internal combustion engine, when it is confirmed that the engine is in a misfire state, the engine is subjected to the compression stroke and the expansion stroke of the cylinder in which the misfire is confirmed. The gist is to force the valve to open.

  In the above configuration, it is confirmed whether or not the engine is misfired during engine operation, that is, whether or not misfire has occurred, or whether or not misfire such as the plug fogging is likely to occur. When such a misfire condition is confirmed, in the cylinder (misfire cylinder) in which the misfire condition is confirmed, the intake valve and the exhaust valve, which are engine valves, are forced to the compression stroke and the expansion stroke that are originally closed. The valve is opened. As a result, in the misfire cylinder, intake and exhaust are performed also in the original compression stroke and expansion stroke, and intake and exhaust are continuously performed without substantially taking the compression stroke and expansion stroke into account. . That is, in the misfire cylinder, the intake stroke and the exhaust stroke are repeated twice in one cycle through the forced opening of the engine valve.

  Therefore, in the above configuration, the ventilation performance in the misfire cylinder is improved, and the vaporization of the fuel adhering to the cylinder is promoted. Therefore, according to the above configuration, it is possible to accelerate the elimination of fuel adhesion in the cylinder due to misfire.

  The gist of the invention according to claim 2 is that, in the control device for an internal combustion engine according to claim 1, the fuel supply amount for the cylinder in which the misfire is confirmed is corrected together with the forced valve opening. .

In the above configuration, further fuel adhesion in the misfire cylinder is suppressed, so that the elimination can be performed more effectively.
The gist of the invention according to claim 3 is that, in the control apparatus for an internal combustion engine according to claim 1, together with the forced opening, the fuel supply to the cylinder where the misfire is confirmed is stopped.

In the above configuration, since further fuel adhesion in the misfire cylinder is avoided, the elimination can be performed more effectively.
According to a fourth aspect of the present invention, in the control device for an internal combustion engine according to any one of the first to third aspects, the forced valve opening is executed on condition that the engine is being started.

  In the above configuration, the engine valve is forcibly opened during the compression stroke and the expansion stroke of the misfire cylinder only during the engine start. During engine start-up, particularly during cold start, the in-cylinder temperature is low, and the fuel that has once adhered is difficult to vaporize as it is, so the fuel adhesion in the cylinder due to misfire may cause a significant decrease in ignitability. . On the other hand, during normal engine operation, the in-cylinder temperature is high, and even if fuel adheres to the cylinder due to misfire, the adhering fuel is vaporized relatively quickly. Even if the forced valve opening is not executed, it is possible to avoid the ignition failure due to the adhered fuel. Therefore, according to the said structure, execution of unnecessary forced valve opening can be suppressed and the fuel adhesion accompanying misfire can be eliminated efficiently.

The gist of the fifth aspect of the invention is the control device for an internal combustion engine according to any one of the first to fourth aspects, wherein the internal combustion engine is a spark ignition type internal combustion engine.
In a spark ignition type internal combustion engine that ignites fuel through spark discharge, since the electrode for spark discharge is exposed in the combustion chamber, the fuel adheres to the electrode due to misfiring and easily causes ignition failure. Therefore, the present invention can achieve a more remarkable effect when applied to such a spark ignition type internal combustion engine.

The gist of the present invention is that the engine valve is forcibly opened during the compression-expansion stroke according to the confirmation of the misfire state.
In the above configuration, when a misfire state is confirmed, the engine valve is forcibly opened during the compression-expansion stroke, and the intake into the cylinder is also performed during the compression-expansion stroke, which is the original valve closing period of the engine valve. Alternatively, exhaust from the cylinder is performed. As a result, the gas flow in and out of the cylinder is increased and the ventilation is improved, so that vaporization of the attached fuel is promoted. Therefore, according to the above configuration, it is possible to quickly eliminate fuel adhesion in the cylinder due to misfire.

  Hereinafter, an embodiment of a control device for an internal combustion engine according to the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a spark ignition type four-cycle engine such as a gasoline engine will be described.

  FIG. 1 shows a schematic structure of a main part of an internal combustion engine to which the present embodiment is applied and its control device. The internal combustion engine 10 shown in the figure is configured as a multi-cylinder internal combustion engine having a plurality of cylinders 11 (cylinders).

  A piston 12 is disposed in each cylinder 11 of the internal combustion engine 10 so as to be able to reciprocate (up and down operation). The piston 12 is connected via a connecting rod 13 to a crankshaft 14 that is an engine output shaft. The crankshaft 14 is rotated in accordance with the lifting / lowering operation of the piston 12. The crankshaft 14 is cranked by an engine starter motor (starter) 15 in response to an engine start operation (starter switch on), and is rotated by the motor 15.

  On the other hand, each cylinder 11 has a combustion chamber 16 in which an air-fuel mixture is combusted by a wall surface and a top surface of the piston 12. In each combustion chamber 16 of each cylinder 11, an electrode plug is exposed in the combustion chamber 16 and a spark plug 17 is provided.

  The combustion chamber 16 of each cylinder 11 is connected to an intake port 19 via an intake valve 18 and to an exhaust port 21 via an exhaust valve 20. The combustion chamber 16 is opened and closed with respect to the intake port 19 and the exhaust port by the intake valve 18 and the exhaust valve 20, respectively.

  In the internal combustion engine 10, the intake valve 18 and the exhaust valve 20 that are engine valves are configured as electromagnetically driven valves. That is, the intake valve 18 and the exhaust valve 20 are driven to open and close by the electromagnetic attractive force generated by the electromagnets 22 and 23 provided respectively. Therefore, the intake valve 18 and the exhaust valve 20 of the internal combustion engine 10 can be opened and closed at any time through the energization control of the electromagnets 22 and 23.

  An injector 24 is disposed in each intake port 19 of each cylinder 11. Each cylinder 11 is individually provided with a fuel pressure sensor 25 for detecting the in-cylinder pressure.

  Various controls of the internal combustion engine 10 are performed by the electronic control unit 26. The electronic control unit 26 includes a CPU that executes various arithmetic processes related to the control of the internal combustion engine 10, a memory that stores programs and data for the control, and an input port and an output port that exchange signals with the outside. Etc. are provided.

  Various sensors for detecting the engine operating state are connected to the input port of the electronic control unit 26, including the fuel pressure sensor 25. For example, a crank angle sensor that detects the rotation angle (crank angle) of the crankshaft 14, an accelerator sensor that detects an operation amount of an accelerator pedal, an air flow meter that detects an intake air amount, and the like are connected to the input port.

  On the other hand, drive circuits such as the spark plug 17 and the injector 24 are connected to the output port of the electronic control unit 26. The electronic control unit 26 executes fuel injection control, ignition timing control, and the like by controlling the spark plug 17, the injector 24, and the like based on the engine operating state input from each sensor. The output port is also connected to drive circuits for the electromagnets 22 and 23 of the intake valve 18 and the exhaust valve 20. The electronic control unit 26 controls the intake valve 18 and the exhaust valve through energization control of the electromagnets 22 and 23. 20 open / close control is also performed.

The internal combustion engine 10 configured as described above is normally operated while repeating the following intake stroke, compression stroke, expansion stroke, and exhaust stroke, as shown in FIG.
(1) Intake stroke: When the intake valve 18 is opened while the piston 12 is being lowered toward the bottom dead center (BDC) in the cylinder 11, air is supplied to the intake port 19 by a pumping action. be introduced. The injector 24 injects and supplies fuel into the air thus introduced into the intake port 19. The fuel / air mixture supplied by injection is sucked into the combustion chamber 16 via the opened intake valve 18.

  (2) Compression stroke: The piston 12 lowered to the bottom dead center starts to move upward toward the top dead center (TDC). Here, the intake valve 18 is closed, whereby the intake air-fuel mixture is compressed in the combustion chamber 16.

  (3) Expansion stroke: When the piston 12 is raised to the vicinity of the top dead center, the spark plug 17 performs a spark discharge from the electrode portion. As a result, the sufficiently compressed air-fuel mixture is ignited and burned. The piston at this time is pushed down toward the bottom dead center by the combustion pressure generated by the combustion of the air-fuel mixture. Thereby, a rotational driving force of the crankshaft 14 is generated.

  (4) Exhaust stroke: The piston 12, which has been lowered to the bottom dead center, starts to rise again toward the top dead center. At this time, the exhaust valve 20 is opened, and the combustion gas in the combustion chamber 16 generated by the combustion of the air-fuel mixture is discharged to the exhaust port 21. Thereafter, the piston 12 that has risen to the top dead center is moved downward again toward the bottom dead center. Here, the exhaust valve 20 is closed and the intake valve 18 is opened, whereby the intake stroke is started again.

  On the other hand, the internal combustion engine 10 is started in the following manner. That is, when the starter switch is turned on, the electric motor 15 is cranked to the crankshaft 14 and generates a rotational driving force for the crankshaft 14. Thus, when the crankshaft 14 is rotated and the piston 12 of each cylinder 11 starts to move up and down accordingly, the fuel injection from the injector 24 and the spark ignition of the air-fuel mixture by the spark plug 17 are performed in each cylinder 11. Is started. When the engine speed increases sufficiently, the cranking is canceled and the internal combustion engine 10 is operated independently, and the engine start is completed.

  During such engine start-up, the temperature in the cylinder is low, so misfire may occur even if spark discharge is made from the electrode portion of the spark plug 17. If fuel injection from the injector 24 is continued in such a state, a large amount of fuel adheres to the electrode part of the spark plug 17 and the like, so that a so-called plug fogging state occurs, and the ignitability of the air-fuel mixture deteriorates. Startability may be significantly impaired.

  Therefore, in the present embodiment, the electronic control unit 26 monitors the occurrence of misfire in each cylinder 11 during engine startup, and when a misfire is confirmed, the fuel adhering to the electrode portion or the like with respect to the misfire cylinder is detected. Ventilation control to promote vaporization is executed. Details of the ventilation control in this embodiment will be described below with reference to FIGS.

(Details of ventilation control)
In the present embodiment, the occurrence of misfire in each cylinder 11 during engine startup is confirmed based on the detection result of the fuel pressure sensor 25 provided for each cylinder 11. Here, the details of confirmation of such misfires are explained first.

  FIG. 3 shows the transition in the cylinder before and after the ignition timing. As indicated by the solid line in the figure, when the combustion is normally performed, the in-cylinder pressure greatly increases after ignition because of the combustion pressure of the air-fuel mixture. On the other hand, when a misfire occurs, the in-cylinder pressure after ignition does not increase significantly as shown by the broken line in FIG. Therefore, the presence or absence of misfire can be confirmed by observing the transition of the in-cylinder pressure after ignition of each cylinder 11, that is, the transition of the combustion pressure.

  More specifically, the electronic control unit 26 according to the present embodiment calculates the average value of the combustion pressure of the corresponding cylinder in the immediately preceding engine cycle or the combustion pressure of the corresponding cylinder in the immediately preceding predetermined engine cycle, and the same cylinder in the current engine cycle. Whether or not misfire has occurred is determined by comparison with the combustion pressure. In the present embodiment, the fuel pressure sensor 25 is individually provided in each cylinder 11 so that the cylinder (misfire cylinder) in which the occurrence of misfire is confirmed can be determined.

  When a misfire is confirmed in this way, the electronic control unit 26 starts ventilation control for the misfire cylinder. FIG. 4 shows an example of the control mode of such ventilation control. FIG. 4 shows the transition of the piston position in the misfire cylinder before and after the occurrence of misfire, the transition of the valve lift amounts of the intake valve 18 and the exhaust valve 20, and the execution mode of fuel injection and ignition.

  As shown in the figure, when the ventilation control is started, the electronic control unit 26 first performs fuel injection from the injector 24 to the misfire cylinder and ignition of the air-fuel mixture by the spark plug 17 in the misfire cylinder. Stop both. As a result, further fuel adherence such as an electrode portion of the spark plug 17 to which fuel adheres due to misfire is avoided.

  Further, when the ventilation control is started, the electronic control unit 26 forcibly opens the intake valve 18 and the exhaust valve 20 during the compression stroke and the expansion stroke of the misfire cylinder. Here, during the ventilation control, the electronic control unit 26 opens the exhaust valve 20 during the compression stroke in the same manner as the exhaust stroke, and opens the intake valve 18 during the expansion stroke in the same manner as the intake stroke. Yes.

  Due to the forced opening of the intake valve 18 and the exhaust valve 20 in the compression stroke and the expansion stroke, intake and exhaust are performed in the original compression stroke and the expansion stroke in the misfire cylinder, and the compression stroke and the expansion stroke are substantially taken. Intake and exhaust are continuously performed without any problems. That is, in the misfire cylinder, the intake stroke and the exhaust stroke are repeated twice in one engine cycle through the forced opening of the engine valve. As a result, in the misfire cylinder, the period during which intake and exhaust are performed, that is, the ventilation period in the cylinder is doubled as usual, and the ventilation performance is greatly improved, so that vaporization of the attached fuel is promoted.

  This ventilation control is continued from the start until a predetermined time (ventilation period) elapses. After the ventilation period is completed, the electronic control unit 26 resumes the fuel supply and ignition in the misfired cylinder to which the ventilation control is applied, and normally performs the opening / closing operation of the intake valve 18 and the exhaust valve 20 of the cylinder. Return to.

FIG. 5 is a flowchart showing a processing procedure related to such ventilation control. The electronic control unit 26 periodically and repeatedly executes the process of the flowchart after the start of the engine start.
When the processing with this flowchart is started, the electronic control unit 26 first determines in step 100 whether or not the engine is being started (cranking). Here, if the engine is being started (YES), the electronic control unit 26 proceeds with the process to step 110, and if not (NO), the process in the current control cycle is terminated.

  In step 110, the electronic control unit 26 determines whether or not the ventilation control is currently being executed. Here, the electronic control unit 26 advances the process to step 120 if the ventilation control is being performed (YES), and advances the process to step 150 if not (NO).

  In step 120, the electronic control unit 26 determines whether or not the combustion pressure of the specific cylinder is low, that is, whether or not misfire has occurred in the specific cylinder. Details of this determination are as described above. If the electronic control unit 26 determines that no misfire has occurred (NO), the electronic control unit 26 ends the process in the current control cycle.

  If it is determined that a misfire has occurred (YES), the electronic control unit 26 advances the process to step 130 and starts ventilation control for the misfire cylinder. That is, the electronic control unit 26 at this time stops the fuel supply and ignition of the misfiring cylinder in step 130, and forcibly opens the intake valve 18 and the exhaust valve 20 as described above in the compression and expansion strokes of the misfiring cylinder in step 140. Let Then, after starting the ventilation control for the misfire cylinder, the electronic control unit 26 ends the process in the current control cycle.

  On the other hand, in step 150, the electronic control unit 26 determines whether or not the ventilation period has elapsed since the currently executed ventilation control was started. Here, if the ventilation period has not yet elapsed (NO), the electronic control unit 26 advances the process to step 120. If the ventilation period has elapsed (YES), the electronic control unit 26 advances the process to step 160.

  The electronic control unit 26 that has proceeded to step 160 ends the ventilation control currently being executed. That is, the electronic control unit 26 at this time restarts the fuel injection and ignition of the cylinder that is the target of the ventilation control being executed in step 160. In step 170, the electronic control unit 26 ends the forced opening of the intake valve 18 and the exhaust valve 20 in the compression stroke and the expansion stroke in the cylinder to be controlled, and returns to the normal opening / closing operation. After thus ending the ventilation control being executed, the electronic control unit 26 advances the process to step 120 described above.

According to this embodiment described above, the following effects can be obtained.
(1) In this embodiment, when the occurrence of misfire is confirmed, the intake valve 18 and the exhaust valve 20 are forcibly opened during the compression stroke and the expansion stroke of the misfire cylinder, respectively. Therefore, the ventilation performance in the cylinder 11 where misfire has occurred is greatly improved, and the fuel adhering state such as the electrode portion of the spark plug 17 can be quickly eliminated.

  (2) In this embodiment, in addition to the forced opening, the fuel supply to the misfire cylinder is stopped and further fuel adhesion during ventilation is avoided, so that the fuel adhesion state is more effectively eliminated. Can do.

  (3) In the present embodiment, since the in-cylinder temperature is low and the ignition control due to the fuel adhesion due to misfire is particularly likely to occur, the ventilation control of the misfire cylinder by the forced valve opening is executed. Unnecessary ventilation control can be avoided.

  Note that the opening / closing drive modes of the intake valve 18 and the exhaust valve 20 related to the forced opening in the compression stroke and the expansion stroke of the misfire cylinder during ventilation control may be appropriately changed to modes other than those exemplified in the above embodiment. good. In short, if the engine valve is forcibly opened during the compression / expansion stroke, which is originally during the valve closing period, the ventilation performance in the misfired cylinder will be improved, so the fuel adhering state will be eliminated earlier. It is possible to plan. In the following, modifications of the opening / closing drive mode of the engine valve during such ventilation control are listed.

  As shown in FIG. 6, both the intake valve 18 and the exhaust valve 20 of the misfire cylinder may be held open all the time during the ventilation control. Further, only one of the intake valve 18 and the exhaust valve 20 of the misfire cylinder may be kept open all the time during the ventilation control. In this case as well, intake and exhaust are performed in the compression stroke and the expansion stroke during the ventilation control in the misfire cylinder, so that it is possible to accelerate the elimination of the fuel adhesion state as in the above embodiment.

  The intake valve 18 may be opened during the compression stroke, and the exhaust valve 20 may be opened during the expansion stroke. In this case, the exhaust gas flows through the misfire cylinder during the ventilation control from the exhaust side to the intake side in the compression stroke and the expansion stroke. If the influence of the exhaust gas recirculated to the intake system on the combustion of other cylinders can be ignored in this way, by introducing exhaust gas at a temperature higher than that of the intake gas into the misfire cylinder, vaporization of the attached fuel can be further enhanced. It becomes possible to promote. In addition, the exhaust valve 20 may be opened during the intake stroke, and the intake valve 18 may be opened during the exhaust stroke.

  -During ventilation control, only one of the intake valve and the exhaust valve of the misfire cylinder may be forcibly opened. Further, the intake / exhaust valve may be forcibly opened only in one of the compression stroke and the expansion stroke of the misfire cylinder. Also in these cases, the ventilation performance in the misfire cylinder is improved and the elimination of the fuel adhering state is accelerated as compared with the case where the normal opening / closing drive is continued during the ventilation control.

Furthermore, the said embodiment can also be changed and implemented as follows.
In the above embodiment, the ventilation control is executed for the misfire cylinder only during the engine start, but the same ventilation control may be executed in other operating situations.

  In the above embodiment, the fuel supply to the misfire cylinder is completely stopped during the ventilation control, but the fuel supply amount to the misfire cylinder may be corrected to decrease. Also in this case, further fuel adhesion in the misfire cylinder is suppressed, and the fuel adhesion can be effectively eliminated as compared with the case where the normal fuel supply is continued.

  -Even during forced ventilation control, normal fuel supply to the misfired cylinder is continued, and even if the engine valve is forcibly opened during the compression and expansion strokes, the ventilation performance in the misfired cylinder is improved, so early fuel adhesion There is a cancellation effect.

  In the above embodiment, the presence or absence of misfiring of each cylinder 11 is confirmed based on the detection result of the fuel pressure sensor 25, but such confirmation is performed by other methods such as a transition of the engine rotation speed in the expansion stroke of each cylinder 11, for example. May be performed.

  In the above embodiment, the case where the present invention is applied to a spark ignition type internal combustion engine has been described. However, the present invention can also be applied to a compression ignition type internal combustion engine such as a diesel engine. That is, even in the case of a compression ignition type internal combustion engine, if a large amount of fuel adheres to the cylinder due to misfire, the air-fuel ratio of the air-fuel mixture in the cylinder may become overrich and cause ignition failure. Therefore, even if it is a compression ignition type internal combustion engine, the ventilation control is executed in a manner similar to or equivalent to that of the above-described embodiment, the ventilation performance in the misfire cylinder is improved, and the elimination of fuel adhesion in the cylinder is accelerated, It is possible to suppress ignition failure.

The schematic diagram of the principal part of the internal combustion engine to which one Embodiment of this invention is applied, and its control apparatus. 6 is a timing chart illustrating a normal control mode of the internal combustion engine of the embodiment. The timing chart which illustrates the transition mode of the in-cylinder pressure at the time of normal combustion and misfire. The timing chart which shows an example of the control aspect of ventilation control in the embodiment. The flowchart of the ventilation control process in the embodiment. The timing chart which shows an example of the control aspect of the ventilation control about the modification of the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder, 12 ... Piston, 13 ... Connecting rod, 14 ... Crankshaft, 15 ... Electric motor (starter) for engine start, 16 ... Combustion chamber, 17 ... Spark plug, 18 ... Intake valve, 19 DESCRIPTION OF SYMBOLS ... Intake port, 20 ... Exhaust valve, 21 ... Exhaust port, 22, 23 ... Electromagnet, 24 ... Injector, 25 ... Fuel pressure sensor, 26 ... Electronic control apparatus.

Claims (6)

In a control device for an internal combustion engine applied to a four-cycle internal combustion engine,
A control apparatus for an internal combustion engine, characterized in that when it is confirmed that the engine is misfired, the engine valve is forcibly opened during a compression stroke and an expansion stroke of the cylinder where the misfire is confirmed.   The control apparatus for an internal combustion engine according to claim 1, wherein the fuel supply amount reduction correction is performed together with the forced valve opening for the cylinder in which the misfire is confirmed.   The control device for an internal combustion engine according to claim 1, wherein the fuel supply to the cylinder where the misfire is confirmed is stopped together with the forced valve opening.   The control device for an internal combustion engine according to any one of claims 1 to 3, wherein the forced valve opening is executed on condition that the engine is being started. The internal combustion engine control device according to any one of claims 1 to 4, wherein the internal combustion engine is a spark ignition type internal combustion engine.   A control device for an internal combustion engine that forcibly opens an engine valve during a compression to expansion stroke in response to confirmation of a misfire state.

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