JP2008267292A - Control system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of restraining deterioration in emission and the operational deterioration in a functional component in a cylinder caused when a combustion stroke is not normally finished in any cylinder of an internal combustion engine. <P>SOLUTION: When detecting that the combustion stroke of any cylinder of the internal combustion engine is not normally finished by a misfire (S102), the ignition timing is advanced forward more than MBT in the combustion stroke after its cylinder, and a peak value of the temperature in the cylinder is raised (S103), to thereby promote oxidation or vaporization of fuel remaining in the cylinder of causing the misfire. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a system for controlling a spark ignition type internal combustion engine, and more particularly, to a system for performing processing when a combustion stroke is not normally terminated in any cylinder of the internal combustion engine.

  In an internal combustion engine, combustion of fuel in a combustion chamber may become unstable and misfire may occur due to various factors such as fuel properties, incomplete ignition system / fuel system functions, and abnormal engine components. In addition, the engine speed may decrease sharply due to the above-mentioned causes, air-fuel ratio mismatch, a sudden increase in load, and the like, and engine stall may occur. When such a misfire or engine stall occurs, the combustion stroke in the cylinder of the internal combustion engine does not end normally, so the fuel supplied to the combustion chamber remains in the cylinder without being used for combustion. In some cases, unburned fuel was discharged as HC, which worsened emissions. In some cases, the fuel adheres to the spark plug or the fuel injection valve and hinders their normal operation.

  Regarding such misfire of the internal combustion engine, misfire is detected for each cylinder, fuel cut control for a cylinder with a high misfire rate, control for stopping fuel feedback control and fuel learning control, and initializing a correction amount, A technique has been proposed in which ignition timing retardation control is performed to suppress an increase in catalyst temperature (see, for example, Patent Document 1).

However, in the above-described prior art, the fuel supplied into the cylinder where the combustion stroke did not end normally remains without being used for combustion, which causes deterioration in emissions and functional components. It has not been avoided.

On the other hand, in a spark ignition type internal combustion engine, the ignition timing is advanced ahead of MBT (Minimum spark advance for Best Torque), thereby promoting an increase in the temperature of the cooling water, thereby increasing the warm-up performance of the internal combustion engine. Techniques for improving are known (see, for example, Patent Document 2). Although this prior art considers the warm-up performance of the internal combustion engine, it does not consider the removal of fuel remaining in the cylinder where the combustion stroke has not ended normally.
JP 2006-152955 A JP 2000-240547 A

  The present invention has been made in view of the above-described circumstances, and the object thereof is to reduce the emission caused by the combustion stroke not completing normally in any cylinder of the internal combustion engine, It is to provide a technology capable of suppressing the deterioration of operation of functional parts.

  In order to solve the above-described problems, the present invention sets the ignition timing in the combustion stroke after the cylinder when it is detected that the combustion stroke of any cylinder of the internal combustion engine has not ended normally. The greatest feature is to advance ahead of the MBT and raise the peak value of the temperature in the cylinder.

More specifically, an over-advance means for advancing the ignition timing of the spark ignition type internal combustion engine before MBT;
An incomplete combustion detection means for detecting that the combustion stroke has not ended normally for each cylinder of the internal combustion engine;
If the incomplete combustion detection means detects that the combustion stroke of any cylinder has not ended normally, the over-advance means in the subsequent combustion stroke in the cylinder where the combustion stroke has not ended normally And an incomplete combustion cylinder over-advance control means for advancing the ignition timing ahead of MBT;
It is characterized by providing.

  That is, if the combustion stroke does not end normally in the combustion stroke of any cylinder of the internal combustion engine due to misfire or engine stall, the fuel supplied to the cylinder remains in the cylinder without being used for combustion. Will be. As a result, the unburned fuel may be discharged as HC, resulting in a worse emission. Further, the fuel may adhere to the functional parts in the cylinder and hinder normal operation. For example, when fuel adheres to the spark plug, or when the adhering fuel accumulates as carbon deposits, the insulation of the insulating portion of the spark plug may deteriorate, and normal spark ignition may be difficult. .

  On the other hand, in the spark ignition type internal combustion engine, when the ignition timing is advanced to the front of the MBT (hereinafter also referred to as “over-advance angle”), the phenomenon that the peak value of the in-cylinder temperature can be increased is observed. It was issued. This is because when the ignition timing is over-advanced, the amount of the air-fuel mixture that burns before the compression top dead center increases. This is thought to be due to a synergistic effect with the temperature effect.

  The control system for an internal combustion engine according to the present invention uses the effect of this advance angle to promote the oxidation and vaporization of the fuel remaining in the cylinder where the combustion stroke has not ended normally. That is, when it is detected by the incomplete combustion detection means that the combustion stroke of one of the cylinders has not ended normally, the ignition timing is advanced to a position before the MBT in the subsequent combustion stroke in that cylinder. The peak value of the internal temperature is raised from the normal value, and the unburned fuel remaining in the cylinder is oxidized or vaporized.

  According to this, when the combustion stroke does not end normally in any cylinder of the internal combustion engine, it is possible to suppress the discharge of HC from the cylinder and the adhesion of fuel to the functional components in the cylinder. it can.

  Further, in the present invention, the over-advance angle means is configured such that, in the subsequent combustion stroke in the cylinder in which the combustion stroke has not ended normally, the torque generated in the combustion stroke of the cylinder after the advance is The ignition timing of the internal combustion engine may be advanced to an ignition timing that is equivalent to the torque to be generated in the combustion stroke of the cylinder.

  Here, the magnitude of the torque generated in the combustion stroke of one cylinder varies depending on the ignition timing in the combustion stroke. That is, when the ignition is performed by MBT, the generated torque becomes maximum, and the generated torque decreases even if the ignition timing is retarded or advanced from MBT. Further, in a normal operation state, the ignition timing is often set on the retard side from the MBT. Therefore, in the present invention, the ignition timing is set to be retarded from the MBT in the normal operation state, and the ignition timing is set to be higher than the MBT in the subsequent combustion stroke in the cylinder in which the combustion stroke has not ended normally. You may make it advance to the ignition timing which is the ignition timing of the advance side, and can obtain the torque equivalent to the torque obtained in a normal driving | running state.

  This makes it possible to more reliably oxidize or vaporize the fuel remaining in the cylinder in which the combustion stroke has not ended normally in the subsequent combustion stroke of the cylinder, and to make the generated torque equal to that of other cylinders. Thus, torque fluctuation as an internal combustion engine can be suppressed.

  In the present invention, when the ignition timing is over-advanced, the over-advance means means that the pressure in the cylinder of the internal combustion engine in the subsequent combustion stroke in the cylinder where the combustion stroke did not end normally. You may make it advance the ignition timing of the said internal combustion engine to the ignition timing which becomes the maximum in TDC vicinity.

  Here, it is understood that the peak value of the in-cylinder temperature can be substantially maximized when the ignition timing of the internal combustion engine is set before the MBT and the ignition timing at which the pressure in the cylinder of the internal combustion engine becomes maximum near TDC. ing. Therefore, when the ignition timing is over-advanced in the present invention, the ignition timing of the internal combustion engine is advanced to an ignition timing that is before MBT and at which the pressure in the cylinder of the internal combustion engine becomes maximum near TDC. Thus, it is possible to oxidize or vaporize the fuel remaining in the cylinder whose combustion stroke has not ended normally more efficiently.

  The means for solving the problems in the present invention can be used in combination as much as possible.

  According to the present invention, it is possible to suppress the deterioration of the emission and the deterioration of the operation of the functional components in the cylinder, which are caused by the combustion stroke not completing normally in any cylinder of the internal combustion engine.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of an internal combustion engine control system according to the present embodiment. An internal combustion engine 1 shown in FIG. 1 is a four-stroke cycle spark ignition type internal combustion engine (gasoline engine) having a plurality of cylinders 2. The cylinder 2 of the internal combustion engine 1 is connected to the intake passage 30 through the intake port 3 and is connected to the exhaust passage 40 through the exhaust port 4.

  The intake passage 30 is provided with a throttle valve 6 that controls the amount of air flowing through the intake passage 30. An intake pressure sensor 7 that measures the pressure (intake pressure) in the intake passage 30 is provided in the intake passage 30 downstream of the throttle valve 6. An air flow meter 8 that measures the amount of air flowing through the intake passage 30 is provided in the intake passage 30 upstream of the throttle valve 6.

  On the other hand, an exhaust purification device 9 is disposed in the exhaust passage 40. The exhaust purification device 9 includes a catalyst such as a three-way catalyst as an exhaust purification catalyst, and purifies exhaust when it is in a predetermined activation temperature range.

  Further, the internal combustion engine 1 is provided with an intake valve 10 that opens and closes an open end of the intake port 3 facing the cylinder 2 and an exhaust valve 11 that opens and closes an open end of the exhaust port 4 facing the cylinder 2. The intake valve 10 and the exhaust valve 11 are driven to open and close by an intake camshaft 12 and an exhaust camshaft 13, respectively.

  A spark plug 14 for igniting the air-fuel mixture in the cylinder 2 is disposed at the upper part of the cylinder 2. Further, a direct injection type fuel injection valve 5 that directly injects fuel into the cylinder 2 is disposed. Further, a piston 15 is slidably inserted into the cylinder 2. The piston 15 is connected to the crankshaft 17 via a connecting rod 16.

  A crank position sensor 18 that detects a rotation angle of the crankshaft 17 is disposed in the vicinity of the crankshaft 17. Furthermore, a water temperature sensor 19 for measuring the temperature of the cooling water circulating through the internal combustion engine 1 is attached to the internal combustion engine 1.

  The internal combustion engine 1 configured as described above is provided with an ECU 20. The ECU 20 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like. The ECU 20 is electrically connected to various sensors such as the air flow meter 8, the intake pressure sensor 7, the crank position sensor 18, and the water temperature sensor 19 described above, and can input measurement values of the various sensors. The ECU 20 electrically controls the fuel injection valve 5, the throttle valve 6, the spark plug 14 and the like based on the measured values of the various sensors described above.

  Here, in the internal combustion engine 1, fuel combustion in the cylinder 2 becomes unstable due to heavy fuel properties and malfunctions of the operation of the spark plug 14 and the fuel injection valve 5, causing misfire. Sometimes. Further, due to the above-mentioned causes, incompatibility of the air-fuel ratio, a sudden increase in load, etc., the engine speed of the internal combustion engine 1 may rapidly decrease and engine stall may occur. When such a misfire or engine stall occurs, the combustion stroke in the cylinder 2 of the internal combustion engine 1 does not end normally, so the fuel supplied in the cylinder 2 remains in the cylinder 2 without being used for combustion. . Then, there is a possibility that this fuel is discharged as HC and the emission is deteriorated, or this fuel adheres to functional parts such as the spark plug 14 and hinders their normal operation.

  On the other hand, in this embodiment, it is detected that a misfire has occurred in any cylinder 2 of the internal combustion engine 1, and if a misfire has been detected, ignition in the next combustion stroke of the cylinder 2 in which the misfire has occurred. The timing is advanced to before MBT, the peak value of the in-cylinder temperature in the next combustion stroke of the cylinder 2 is increased, and the remaining fuel is oxidized or vaporized.

  FIG. 2 is a graph showing how the relationship between various parameters in the cylinder 2 and the crank angle changes depending on the ignition timing in the cylinder 2. The horizontal axis represents the crank angle of the internal combustion engine 1, and the vertical axis represents each parameter in the cylinder 2. In FIG. 2, the graph when the ignition of the spark plug 14 is performed on the advance side (hereinafter referred to as “over-advance angle”) before the MBT is indicated by a solid line, and the graph when the ignition is performed by the MBT. Is indicated by a broken line, and a graph when ignition is performed at the compression top dead center (TDC) is indicated by a one-dot chain line.

  When the ignition timing is over-advanced, the air-fuel mixture burned before the compression top dead center is compared to when the ignition timing is set to MBT and when the ignition timing is set to compression top dead center (TDC). The amount of increases. For this reason, the peak of heat energy generated by the combustion of the air-fuel mixture (see the heat generation rate, generated heat amount, and combustion mass ratio in FIG. 2) shifts to before the compression top dead center.

  Therefore, in-cylinder pressure during the period from the compression stroke to the expansion stroke is obtained by a synergistic effect of the temperature increase / pressure increase effect due to the combustion of the air-fuel mixture and the compression effect due to the piston ascending operation (operation from bottom dead center to top dead center) In addition, the peak value of the in-cylinder temperature increases significantly. Note that, since the excessive advance angle of the ignition timing before the MBT is executed according to a command from the ECU 20, the excessive advance means includes the ECU 20 in this embodiment.

  FIG. 3 shows a graph of the relationship between the ignition timing and torque in the cylinder 2 and the maximum in-cylinder temperature. The horizontal axis represents the ignition timing of the spark plug 14, and the vertical axis represents the torque and the maximum temperature in the cylinder. As can be seen from FIG. 3, when the ignition timing is advanced from MBT, the torque decreases, while the in-cylinder maximum temperature increases and reaches the highest in ST1.

In this way, by causing the ignition timing of the spark plug 14 to advance excessively before MBT,
The maximum temperature in the cylinder 2 can be raised, and the fuel remaining without being burned in the cylinder 2 where misfire has occurred can be efficiently oxidized or vaporized.

  In this embodiment, the target ignition timing when the ignition timing is over-advanced is particularly an ignition that can obtain a torque equivalent to the torque at the ignition timing during normal operation, as shown in the lower graph of FIG. Time ST2 is assumed. If it does so, the torque which generate | occur | produces in the next combustion stroke of the cylinder 2 which misfired can be made equivalent to the other cylinders 2. Accordingly, it is possible to suppress HC discharge from the cylinder 2 in which misfire has occurred and further malfunction of the spark plug 14 while suppressing torque fluctuation as the whole internal combustion engine 1.

  Next, FIG. 4 shows a flowchart of the misfire cylinder over-advance control routine in the present embodiment. This routine is a program stored in the ROM of the ECU 20, and is executed by the ECU 20 for each cylinder 2 independently for each predetermined period while the internal combustion engine 1 is in operation.

  When this routine is executed, first, in S101, it is determined whether or not the cooling water temperature of the internal combustion engine 1 is less than 60 ° C. Specifically, it is determined by reading the output signal of the water temperature sensor 19 into the ECU 20. Here, when the cooling water temperature is 60 ° C. or higher, the cylinder 2 of the internal combustion engine 1 is sufficiently warmed up, so that even if a misfire occurs in any of the cylinders 2, it remains without being used for combustion. Since it is determined that the fuel is sufficiently oxidized or vaporized, the process proceeds to S104. On the other hand, when the cooling water temperature is lower than 60 ° C., the process proceeds to S102.

  In S102, it is determined whether or not misfiring has occurred in the previous combustion stroke of the cylinder 2 (hereinafter, abbreviated as “target cylinder 2”) that is the control target of this routine. Specifically, the fluctuation of the engine speed at the timing corresponding to the combustion stroke of the target cylinder 2 is acquired from the output signal of the crank position sensor 17. Then, the occurrence of misfire in the target cylinder 2 may be detected based on whether or not the rotational speed has dropped at a timing corresponding to the previous combustion stroke of the target cylinder 2. Alternatively, the predetermined misfire detection flag may be turned on only during a period from when the misfire in the target cylinder 2 is detected until the next combustion stroke, and in S102, the value of the misfire detection flag may be read into the ECU 20 for determination. . If it is determined in S102 that misfire has occurred in the previous combustion stroke of the target cylinder 2, the process proceeds to S103. On the other hand, if it is determined that no misfire has occurred in the previous combustion stroke of the cylinder 2, the process proceeds to S104.

  In S103, the ignition timing of the spark plug 14 of the target cylinder 2 is advanced to ST2. Thereby, the peak value of the in-cylinder temperature of the target cylinder 2 is increased, and the fuel remaining in the target cylinder 2 from the time of misfire is oxidized or vaporized.

  In S104, the ignition timing of the ignition plug 14 of the target cylinder 2 is set to the normal ignition timing, specifically, the ignition timing retarded from the MBT. When the process of S103 or S104 ends, this routine is temporarily ended.

  As described above, in this embodiment, for each cylinder 2, it is determined whether or not misfire has occurred in the previous combustion stroke, and if it is determined that misfire has occurred in the previous combustion stroke, Therefore, the ignition timing of the spark plug 14 of the cylinder 2 is over-advanced before MBT. As a result, the peak value of the in-cylinder temperature of the cylinder 2 can be increased, and the fuel remaining in the cylinder 2 can be oxidized or vaporized. This is caused by the deterioration of emission and the adhesion of fuel to the spark plug 14. The deterioration of the ignition operation can be suppressed.

Further, in this embodiment, when the ignition timing of the spark plug 14 is over-advanced, the ignition timing after the advance is set to an ignition timing at which the generated torque is equivalent to that of the normal ignition timing before the advance. Therefore, the torque fluctuation as the internal combustion engine 1 due to the excessive advance angle can be suppressed.

  Further, in this routine, the ignition timing of the spark plug 14 is over-advanced only when the coolant temperature is less than 60 ° C. As a result, the warm-up of the internal combustion engine 1 has been completed, and even if misfire has occurred in the previous combustion stroke, the excessive advance is performed in a situation where the remaining fuel is naturally oxidized or vaporized. Can be suppressed.

  In addition, ECU20 which performs the process of S102 of this routine is corresponded to an incomplete combustion detection means in a present Example. Further, the ECU 20 that executes the process of S103 corresponds to an incomplete combustion cylinder over-advance control means in this embodiment. In the present embodiment, the occurrence of misfire in the cylinder 2 corresponds to the fact that the combustion stroke in the cylinder 2 did not end normally.

  Further, in this routine, in the cylinder 2 in which misfire has occurred, the ignition timing over-advance angle is executed in the next combustion stroke of the combustion stroke in which misfire has occurred. However, the combustion stroke in which the ignition timing is advanced excessively is not limited to the next time. The advance angle may be performed in a plurality of combustion strokes including the next combustion stroke in which misfire has occurred. According to this, the fuel remaining in the cylinder can be oxidized or vaporized more reliably.

  In S101 of this routine, when the cooling water temperature is 60 ° C. or higher, the cylinder 2 of the internal combustion engine 1 is sufficiently warmed up, so that even if a misfire occurs in any of the cylinders 2, Although it is determined that the fuel remaining without being supplied is sufficiently oxidized or vaporized as it is, the cooling water temperature as a threshold for this determination is not limited to 60 ° C. An appropriate value can be determined by experiments or the like according to the specifications of the internal combustion engine 1.

  Next, a second embodiment of the present invention will be described. In the present embodiment, when the engine stall is restarted immediately after the internal combustion engine 1 is cold-started, a cylinder whose misfire or combustion is unstable at the engine stall is detected, and the next combustion stroke of such a cylinder is detected. Now, an example will be described in which the ignition timing of the spark plug is advanced to an angle before MBT and the fuel remaining in the cylinder is oxidized or vaporized. The internal combustion engine and its intake / exhaust system and control system in this embodiment are the same as those shown in FIG.

  Here, when the internal combustion engine 1 is cold-started, for example, if the fuel is heavy and has low volatility, combustion becomes unstable and sufficient torque cannot be secured, causing engine stall. May end up. In such a case, unburned fuel may remain in the cylinder 2 because combustion is incomplete. As in the case of misfire, this residual fuel causes the deterioration of emissions and the deterioration of the function parts. Therefore, in the present embodiment, when there is an engine stall during the cold start of the internal combustion engine 1, the ignition timing over-advanced angle is executed for the cylinder 2 in which combustion instability has been confirmed.

  FIG. 5 shows a flowchart of the post-end over-advance angle control routine in this embodiment. This routine is a program stored in the ROM of the ECU 20 and is executed by the ECU 20 for each cylinder 2 independently for each predetermined period while the internal combustion engine 1 is in operation.

When this routine is executed, first, in S201, it is determined whether or not the cooling water temperature of the internal combustion engine 1 is less than 60 ° C. Specifically, it is determined by reading the output signal of the water temperature sensor 19 into the ECU 20. Here, when the cooling water temperature is 60 ° C. or higher, the cylinder 2 of the internal combustion engine 1 is sufficiently warmed up, so even if unburned combustion remains in any of the cylinders 2, the fuel is sufficient Therefore, the process proceeds to S204. On the other hand, when the cooling water temperature is lower than 60 ° C., the process proceeds to S202.

  In S202, it is determined at the time of the engine stall whether or not there has been misfire or combustion instability in the cylinder 2 that is controlled by this routine (hereinafter referred to as "target cylinder 2"). Specifically, each cylinder 2 may be provided with an in-cylinder pressure sensor (not shown), and the determination may be made by reading into the ECU 20 the output of the in-cylinder pressure sensor when the target cylinder 2 is stalled. Alternatively, the determination may be made by detecting the rotation fluctuation at the combustion stroke timing of the target cylinder 2 at the time of the stall from the output signal of the crank position sensor 17. If it is determined in S202 that the target cylinder 2 has misfired or unstable combustion at the time of the engine stall, the process proceeds to S203. On the other hand, if it is determined in the target cylinder 2 that no misfire or combustion instability has occurred in the target cylinder 2 at the time of the engine stall, the process proceeds to S204.

  In S203, the ignition timing of the spark plug 14 of the target cylinder 2 is advanced to ST2. As a result, the peak value of the in-cylinder temperature of the target cylinder 2 is increased, and the fuel remaining in the target cylinder 2 since the occurrence of the engine stall is oxidized or vaporized.

  In S204, the ignition timing of the spark plug 14 of the target cylinder 2 is set to the normal ignition timing, specifically, the ignition timing retarded from the MBT. When the process of S203 or S204 ends, this routine is temporarily ended.

  As described above, in the present embodiment, it is determined whether or not there has been misfire or combustion instability at the time of cold end for each cylinder 2, and misfire or instability of combustion has occurred at the time of cold end. If it is determined that there is, the ignition timing of the spark plug 14 of the cylinder 2 is over-advanced before MBT. As a result, the peak value of the in-cylinder temperature of the cylinder 2 can be raised, and the unburned fuel remaining in the cylinder 2 can be oxidized or vaporized. The malfunction of the ignition operation due to adhesion can be suppressed.

  Also in the present embodiment, when the ignition timing of the spark plug 14 is over-advanced, the ignition timing after the advance is set to an ignition timing with the generated torque equivalent to that in the case of the normal ignition timing. The torque fluctuation as the internal combustion engine 1 due to the advance angle can be suppressed.

  Further, in this routine, the ignition timing of the spark plug 14 is over-advanced only when the coolant temperature is less than 60 ° C. As a result, the warm-up of the internal combustion engine 1 has been completed, and even if there is a misfire or combustion instability during a cold engine stall, the remaining fuel is naturally oxidized or vaporized. It can be suppressed.

  In addition, ECU20 which performs the process of S202 of this routine is corresponded to an incomplete combustion detection means in a present Example. Further, the ECU 20 that executes the process of S203 corresponds to the incomplete combustion cylinder over-advance control means in this embodiment. In this embodiment, the fact that misfire or combustion instability occurred in the cylinder 2 corresponds to the fact that the combustion stroke did not end normally.

  In the above embodiment, the target ignition timing when the ignition timing is over-advanced is the ignition timing ST2 at which a torque equivalent to the torque at the ignition timing before the advance is obtained. However, the target ignition timing in the present invention may be an ignition timing at which the in-cylinder pressure becomes maximum at TDC as shown in FIG. This ignition timing is known to correspond to ST1 that is the ignition timing at which the in-cylinder maximum temperature becomes the highest in FIG. 3, and by setting the ignition timing in this way, fuel remains after misfire or engine stall. The remaining fuel can be oxidized or vaporized most efficiently in the existing cylinder 2.

  However, if the ignition timing is excessively advanced and exceeds the misfire limit ignition timing (STS) determined by the operating state, the risk of a new misfire increases, so the ignition timing becomes the misfire limit ignition timing (STS). ) It is necessary not to become more advanced. Similarly, if the ignition timing is advanced from the knock limit ignition timing (STN) determined by the operating state, the risk of knocking increases, so the ignition timing advances from the knock limit ignition timing (STN). It is necessary not to be on the corner side. Therefore, in this embodiment, ST1, STS, and STN are derived respectively, and the most retarded ignition timing among these three ignition timings is set to ST3, and the ignition timing of the spark plug 14 is advanced to the ignition timing ST3. It may be horned. FIG. 7 illustrates an example of the relationship between ST1, STS, STN and ST3. FIG. 8 shows an example of a graph serving as the basis of a map of the relationship between the operating state of the internal combustion engine 1 and ST1, STS, and STN, respectively.

It is a figure which shows schematic structure of the internal combustion engine, the intake / exhaust system, and the control system in the Example of this invention. It is a graph which shows the relationship between the ignition timing in the cylinder which concerns on the Example of this invention, and the state in a cylinder. It is a graph which shows the relationship between the ignition timing in the cylinder which concerns on the Example of this invention, the torque of an internal combustion engine, and the highest in-cylinder temperature. It is a flowchart which shows the misfire cylinder over-advance angle control routine which concerns on Example 1 of this invention. It is a flowchart which shows the post-end over advance angle control routine which concerns on Example 2 of this invention. It is a graph for demonstrating the difference by the ignition timing of the relationship between the crank angle and cylinder pressure in the cylinder which concerns on the Example of this invention. It is a graph which shows another example of the relationship between the ignition timing in the cylinder which concerns on the Example of this invention, the torque of an internal combustion engine, and the cylinder maximum temperature. FIG. 5 is a graph serving as a reference of a map showing the relationship between the operating state of the internal combustion engine according to the embodiment of the present invention and the ignition timing at which the in-cylinder pressure becomes maximum at TDC, the ignition timing at the misfire limit, and the ignition timing at the knock limit It is an example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder 3 ... Intake port 4 ... Exhaust port 5 ... Fuel injection valve 6 ... Throttle valve 7.・ ・ ・ ・ Intake pressure sensor 8 ・ Air flow meter 9 ・ Exhaust gas purification device 10 ・ ・ ・ ・ Intake valve 11 ・ ・ ・ ・ Exhaust valve 12 ・ ・ ・ ・ Intake side camshaft 13 ・ ・・ ・ Exhaust camshaft 14 ・ ・ ・ ・ Spark plug 15 ・ ・ ・ ・ Piston 16 ・ ・ ・ ・ Connecting rod 17 ・ ・ ・ ・ Crankshaft 18 ・ ・ ・ ・ Crank position sensor 19 ・ ・ ・ ・ Water temperature sensor 20 ・... ECU
30 ... Intake passage 40 ... Exhaust passage

Claims (3)

Over-advance means for advancing the ignition timing of the spark ignition type internal combustion engine before MBT;
An incomplete combustion detection means for detecting that the combustion stroke has not ended normally for each cylinder of the internal combustion engine;
When the incomplete combustion detection means detects that the combustion stroke of any cylinder has not ended normally, the over-advance means in the subsequent combustion stroke in the cylinder where the combustion stroke has not ended normally And an incomplete combustion cylinder over-advance control means for advancing the ignition timing ahead of MBT;
An internal combustion engine control system comprising:   In the subsequent combustion stroke in the cylinder in which the combustion stroke did not end normally, the over-advance angle means is configured such that the torque generated in the combustion stroke of the cylinder after the advance angle is the combustion stroke of the cylinder before the advance angle. 2. The control system for an internal combustion engine according to claim 1, wherein the ignition timing of the internal combustion engine is advanced to an ignition timing equivalent to a torque to be generated.   The over-advance means means the ignition timing of the internal combustion engine until the ignition timing at which the pressure in the cylinder of the internal combustion engine reaches a maximum in the vicinity of TDC in the subsequent combustion stroke in the cylinder in which the combustion stroke has not ended normally. The internal combustion engine control system according to claim 1, wherein the angle is advanced.

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