JP2002039007A - Misfire control system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent misfire by correcting combustion conditions when misfire is detected in an internal combustion engine. SOLUTION: An ECU 16 controls an engine 2 based on control of a fuel injection quantity by an injector 8 and ignition timing of a spark plug 9. A crank angle sensor 22 for detecting a rotation angle of a crankshaft of the engine 2 compares a time from the ignition timing to a predetermined range among a plurality of cylinders 3 to check whether or not misfire occurs in a particular cylinder 3. When the judgment shows that misfire occurs in the particular cylinder 3, the misfire is eliminated by executing compensation through increasing the fuel injection quantity via the injector 8 or by executing compensation through delaying the ignition timing of the spark plug 9. However, when the misfire is not eliminated even by the compensation beyond the predetermined upper limit, the compensation is reset to zero, and a diagnosis code showing misfire detection is displayed on a display 34 to prompt a driver to consult a specialist of a service shop, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a misfire control device for an internal combustion engine used for an engine of an automobile for preventing misfire.

[0002]

2. Description of the Related Art Conventionally, in the engine control of automobiles, there have been many demands for satisfying exhaust gas regulations, reducing fuel consumption, and improving driving performance and drivability as automobiles. Electronic control is being performed to meet this. Various performances related to the vehicle engine
It is determined on the premise that combustion is normally performed in a combustion chamber as an internal combustion engine. In engine control,
Failure to ignite or explode successfully results in a condition known as misfire. If a misfire occurs, surging will occur and emission will deteriorate. Surging is also called breathing and the like, and the rotation of the engine is not performed smoothly. Even at a constant speed running on a flat ground, the driver gives an unpleasant feeling due to vibration or shaking, and reduces drivability. Emission deterioration is caused by an increase in various harmful gases discharged from the engine, and in particular, a situation in which the content of a gas to be controlled is out of the regulation range is likely to occur. Conventionally, when such a state occurs, the replacement of parts on the hardware side of the engine, the change of constants and the execution of programs by an electronic control unit (hereinafter sometimes abbreviated as “ECU”), especially an ECU for engine control, are performed. In order to correct software such as a change, it is necessary to replace a component such as a ROM in which the software is stored.

The prior art of detecting a misfire of an engine, increasing the fuel injection amount for the cylinder in which the misfire is detected, and decreasing the fuel injection amount for the other cylinders to maintain a predetermined fuel injection amount as a whole is known. For example, Japanese Patent Application Laid-Open No. 64-59
No. 46, JP-A-5-133254 and the like. Japanese Patent Application Laid-Open No. H10-148154 discloses a concept in which when a misfire is detected, a correction is made to increase the amount of fuel in the cylinder, and the correction is made to correspond to the engine coolant temperature and the number of revolutions. Japanese Patent Application Laid-Open No. 5-113147 discloses a concept of correcting the ignition timing to a retarded or advanced side when the occurrence of misfire is detected. Japanese Patent Application Laid-Open No. 3-151544 discloses a concept in which, when performing a correction for making the air-fuel ratio appropriate, when the correction value reaches a preset limit value, the content of the abnormality is determined and displayed. JP-A-8-21016
No. 5, JP-A-64-32037 or JP-A-63-263242 discloses a concept of determining misfire in connection with control for preventing knocking. Japanese Patent Application Laid-Open No. Hei 6-93943 discloses a concept of controlling the ignition timing to be retarded while the temperature of the internal combustion engine is low.

[0004]

Continuing to use the engine of a motor vehicle in a state where misfire has occurred may deteriorate the emission and may also adversely affect the exhaust gas purifying catalyst. It is not preferable.
In the United States and Europe, regulations stipulate that an electronic control unit or engine parts should be replaced whenever a misfire occurs. However, there is some margin in the range of the combustion conditions of the internal combustion engine that satisfies the conditions such as the exhaust gas regulation. Even if a misfire occurs, the misfire may be prevented by changing the combustion condition. In such a case, misfires are prevented by modifying the software of the electronic control unit, replacing the ROM that stores the software, or using an electrically rewritable nonvolatile memory. I am trying to rewrite.

An object of the present invention is to provide a misfire control device for an internal combustion engine that can automatically perform a misfire countermeasure by itself when the misfire can be prevented by modifying software.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a misfire control apparatus for an internal combustion engine which has a plurality of combustion chambers and controls a fuel injection quantity for each combustion chamber to prevent a misfire. The misfire determining means for determining whether or not a misfire has occurred for each combustion chamber, and the amount of fuel injected into the combustion chamber determined to have a misfire by the misfire determination means are increased by a predetermined correction amount. And a misfire prevention means for controlling the misfire of the internal combustion engine.

According to the present invention, the internal combustion engine has a plurality of combustion chambers, and the fuel injection amount can be controlled for each combustion chamber. The misfire control device for an internal combustion engine includes misfire determination means and misfire prevention means. The misfire determining means determines whether or not a misfire has occurred for each combustion chamber. The misfire prevention means controls the fuel injection amount to the combustion chamber, which is determined by the misfire determination means to have a misfire, so as to increase by a predetermined correction amount. Since the fuel injection amount is usually set to the minimum necessary, when the misfire occurs, the possibility of preventing the misfire can be increased by increasing the fuel injection amount by the device itself. Since the increase in the fuel injection amount is controlled by a predetermined correction amount, the correction amount can be stopped within a range that satisfies the exhaust gas regulations imposed on the internal combustion engine, and misfire can be prevented.

Further, the present invention relates to a misfire control device for an internal combustion engine which has a plurality of combustion chambers and controls the ignition timing of each combustion chamber to prevent misfire. Misfire determining means for determining the presence or absence of a misfire every time; and misfire preventing means for controlling the ignition timing in the combustion chamber determined to have a misfire by the misfire determining means so as to be delayed by a predetermined correction amount. And a misfire control device for an internal combustion engine.

According to the present invention, the internal combustion engine has a plurality of combustion chambers, and the ignition timing can be controlled for each combustion chamber. The misfire control device for an internal combustion engine includes misfire determination means and misfire prevention means. The misfire determining means determines whether or not a misfire has occurred for each combustion chamber. The misfire prevention means controls the ignition timing in the combustion chamber, which is determined by the misfire determination means to have a misfire, by a predetermined correction amount. Generally, the ignition timing is set earlier so that the energy generated by the ignition of the fuel introduced into the combustion chamber can be effectively used. When it is determined that there is a misfire, the possibility that the ignition can be reliably performed can be increased by delaying the ignition timing by the device itself. Since the correction amount of the ignition timing delay is determined in advance, the correction amount can be determined within a range that satisfies the exhaust gas regulations of the internal combustion engine.

Further, the present invention relates to a misfire control apparatus for an internal combustion engine which includes a plurality of combustion chambers and controls a fuel injection amount and an ignition timing for each combustion chamber to prevent a misfire. A misfire determining means for determining whether or not a misfire has occurred for each combustion chamber; and a fuel injection amount and an ignition timing for the combustion chambers which are determined to have a misfire by the misfire determination means.
A misfire control device for an internal combustion engine, comprising: a misfire prevention unit that controls each of the compensation amounts to be increased and delayed by a predetermined correction amount.

According to the present invention, the internal combustion engine has a plurality of combustion chambers, and the fuel injection amount and the ignition timing can be controlled for each combustion chamber. The misfire control device for an internal combustion engine includes misfire determination means and misfire prevention means. The misfire determining means determines whether or not a misfire has occurred for each combustion chamber. The misfire prevention means controls the fuel injection amount and the ignition timing to the combustion chamber, which are determined by the misfire determination means to have a misfire, so as to increase and delay by a predetermined correction amount, respectively. Normally, in a combustion chamber of an internal combustion engine, the fuel injection amount is minimized and the ignition timing is set earlier in order to efficiently extract power from a fixed fuel. When it is determined that misfire has occurred, the possibility of avoiding misfire can be increased by increasing the fuel injection amount by itself and delaying the ignition timing. Since the correction amount of the increase in the fuel injection amount and the delay of the ignition timing is predetermined, it can be set as a correction amount within a range in which the internal combustion engine satisfies the exhaust gas regulations and the like.

Further, the present invention is a misfire control apparatus for an internal combustion engine which includes a plurality of combustion chambers and controls the internal combustion engine capable of controlling a fuel injection amount and an ignition timing for each combustion chamber to prevent a misfire. A misfire determining means for determining whether or not a misfire has occurred for each combustion chamber; and a correction amount which is determined in advance by the misfire determining means to determine one of a fuel injection amount or an ignition timing into the combustion chamber which is determined to have a misfire. And misfire prevention means for controlling the fuel injection amount or the ignition timing to increase or delay by a predetermined correction amount after the correction amount reaches the upper limit. A misfire control device for an internal combustion engine, characterized in that:

According to the present invention, the internal combustion engine has a plurality of combustion chambers, and the fuel injection amount and the ignition timing can be controlled for each combustion chamber. The control device for the internal combustion engine includes a misfire determination unit and a misfire prevention unit. The misfire determining means determines whether or not a misfire has occurred for each combustion chamber. The misfire prevention means controls to increase or delay one of the fuel injection amount and the ignition timing into the combustion chamber, which is determined by the misfire determination means as having a misfire, by a predetermined correction amount. Usually, the fuel injection amount to be supplied to the combustion chamber is set to a minimum and the ignition timing is set earlier so that power can be effectively extracted from the fuel. When a misfire occurs, the apparatus itself can correct one of the increase of the fuel injection amount and the delay of the ignition timing, and can try to prevent the misfire at a stage where the change from the original state is as small as possible. If the misfire cannot be prevented by correcting the fuel injection amount or the ignition timing to one upper limit, the other of the fuel injection amount and the ignition timing is corrected to increase the possibility of preventing the misfire.

Further, the present invention further comprises a temperature detecting means for detecting a temperature of a fluid for cooling a combustion chamber of the internal combustion engine, wherein the misfire preventing means is adapted to detect a temperature of the fluid detected by the temperature detecting means. The correction amount is changed.

According to the present invention, the temperature of the fluid for cooling the combustion chamber of the internal combustion engine, for example, the temperature of engine cooling water is detected by the temperature detector. The operating state of the internal combustion engine also changes depending on the temperature of the combustion chamber, and the temperature of the cooling fluid in the combustion chamber can be considered to accurately reflect the temperature of the combustion chamber. Since the correction amount when a misfire has occurred is changed according to the temperature of the fluid, misfire can be prevented with an appropriate correction amount according to the temperature of the combustion chamber.

Further, in the present invention, the misfire prevention means returns the correction amount to 0 when the misfire determination means determines that a misfire has occurred even if the correction amount reaches a preset upper limit. And outputting a self-diagnosis result indicating that the error has occurred.

According to the present invention, an upper limit is previously set for the amount of correction when controlling to prevent misfire by the misfire prevention means. Therefore, the amount of correction is set to a range that does not satisfy the exhaust gas regulations of the internal combustion engine. Can be prevented from increasing.
When it is necessary to make correction beyond the upper limit, it is difficult to satisfy the regulations such as exhaust gas of the internal combustion engine and prevent misfire by modifying only the software. It outputs a self-diagnosis result to the effect that the electronic control unit and the parts are replaced.

Further, in the present invention, the misfire prevention means retains a history of processing relating to the correction amount.

According to the present invention, since the misfire prevention means leaves a history of the processing relating to the correction amount, the history can be read out at a service factory or the like to obtain information about the occurrence of misfire.

Further, the present invention is characterized in that the misfire determination means does not judge whether or not the misfire has occurred if an abnormality has occurred in the fuel supply system.

According to the present invention, when an abnormality occurs in the fuel supply system, not only misfire occurs but also emission deteriorates, and the correction of the fuel injection amount into the combustion chamber and the correction of the ignition timing are not performed. Impossible. In such a case, since it is not determined whether or not a misfire has occurred, useless misfire prevention control can be avoided.

Further, the present invention further includes operation determination means for determining an operation state of the internal combustion engine, wherein the misfire prevention means is provided based on a correspondence between a preset operation state of the internal combustion engine and the correction amount. , The correction amount is determined.

According to the present invention, the operating state of the internal combustion engine, for example, the idling state, the acceleration / deceleration state, or the engine speed is determined by the operation determining means. Since the misfire prevention means determines the correction amount based on the preset correspondence between the operating state of the internal combustion engine and the correction amount, the misfire prevention means prevents the misfire with an appropriate correction amount corresponding to the operating state of the internal combustion engine. be able to.

Further, the present invention further includes knocking control means for performing ignition timing delay control for preventing knocking of the internal combustion engine, and the misfire determination means performs ignition timing delay control by the knocking control means. During the operation, the determination of the occurrence of the misfire is not performed.

According to the present invention, the knocking control means performs ignition timing delay control for preventing knocking on the internal combustion engine. The misfire determining means does not judge whether or not a misfire has occurred while the ignition timing delay control is being performed by the knocking control means, so that the control for preventing knocking and the control for preventing misfire interfere with each other. The control for preventing knocking can be controlled so as not to be disturbed by the control for preventing misfire.

[0026]

FIG. 1 shows a schematic configuration of a misfire control apparatus 1 for an internal combustion engine according to an embodiment of the present invention. The misfire control apparatus 1 for an internal combustion engine according to the present embodiment performs control on the engine of an automobile, which is an internal combustion engine, to prevent misfires while controlling exhaust gas, reducing fuel consumption, improving drivability, and the like. The engine 2 includes a plurality of cylinders 3 as combustion chambers for each cylinder.
A piston 4 and a connecting rod 5 are provided therein, and fuel can be explosively burned in a space inside the cylinder 3 to take out rotational power from a crankshaft connected to the piston 4 and the connecting rod 5.

Air is introduced into the cylinder 3 from an intake pipe 7 through an intake valve 6, and fuel is injected from an injector 8 provided near the intake valve 6 through the intake pipe 7.
The fuel and air injected by the injector 8 are introduced into the cylinder 3 in a mixed state. Cylinder 3
A spark plug 9 is attached to the upper part of the, and can electrically ignite a mixer of air and fuel. The burned fuel becomes exhaust gas, which is discharged to the exhaust pipe 11 by opening the exhaust valve 10.

The intake pipe 7 includes a pressure detector 12, a throttle valve 13, a valve opening detector 14, and an intake air temperature detector 15
Is provided. The pressure detector 12 detects the pressure of air supplied from the intake pipe 7 to the cylinder 3. Throttle valve 1
3 adjusts the flow rate of the air taken into the intake pipe 7. The valve opening detector 14 is a throttle valve 1 for adjusting the flow rate of air.
3 is detected. The intake air temperature detector 15 is connected to the intake pipe 7.
Detects the temperature of the air taken into the air. Pressure detector 12,
The detection outputs of the valve opening detector 14 and the intake air temperature detector 15 are input to the ECU 16 and used for controlling the fuel injection amount from the injector 8 and the ignition timing by the spark plug.

The control of the fuel injection amount by the injector 8 and the control of the ignition timing by the spark plug 9 are performed by detecting an oxygen concentration detector 17 provided in the exhaust pipe 11 and detecting a temperature of a cooling water as a fluid for cooling the cylinder 3. The output of the detector 18 is also used and input to the ECU 16. Distributor 19
Switches according to the rotation of the engine 2 and connects the output from the ECU 16 to an appropriate spark plug 9. ECU16
The operation state of a starter switch (hereinafter, abbreviated as "starter SW") 20 is also input to. In addition, an output from a knock sensor 21 for performing knocking prevention control and a crank angle sensor 22 for detecting a rotation angle of a crankshaft connected to the connecting rod 5 are also input. Knock sensor 21 is formed of a piezoelectric element, is provided near cylinder 3, and outputs the magnitude of vibration of engine 2 as a voltage. The crank angle sensor 22 calculates the amount of angular displacement corresponding to the rotation of the crankshaft,
Output with high accuracy.

The ECU 16 includes a processing circuit 30 including a microcomputer for performing control and data processing.
It includes an input interface 31 provided on the input side of the processing circuit 30 and an output interface 32 provided on the output side. Further, a memory 33 for storing a history of misfire processing by the processing circuit 30 and a light emitting diode (LED) or a liquid crystal display (LCD) for displaying a result of a diagnosis as a self-diagnosis processing performed by the processing circuit 30 are provided. The display 34 and the memory 33 at the service factory of the vehicle, etc.
Is provided with a connector 35 for reading the history stored in the.

FIG. 2 shows a misfire control apparatus 1 for an internal combustion engine shown in FIG.
1 shows a control procedure including misfire prevention for each cylinder 3 performed by the engine. The procedure starts from step a1. In step a2, fuel is injected from the injector 8 at a preset crank angle based on the output from the crank angle sensor 22.
Next, in step a3, when the crank angle reaches a predetermined angle, a voltage is applied to the spark plug 9 to perform ignition.
In step a4, misfire detection is performed from the time when the crank angle sensor 22 reaches a predetermined angle. The misfire is detected, for example, by measuring the time required for the crankshaft to be angularly displaced from the ignition timing in step a3 to an angle of 30 °, comparing with the time measured for the ignition timing of the other cylinders 3, and If the time is longer than the predetermined range, it is detected as misfire. At step a5, it is determined that there is a misfire. The misfire detected in step a4 is not determined to be a misfire only once, for example, 20 out of 100 misfires
It is better to judge that there is a misfire when the misfire is detected about once. If it is determined in step a5 that there is a misfire, the fuel injection amount by the injector 8 is increased by a fixed amount, for example, 1% only in the cylinder 3 in which the misfire is detected in step a6. In step a7, it is determined whether or not the increased value by the correction of the fuel injection amount exceeds a preset upper limit, for example, 5%. When it is determined that the upper limit has not been exceeded, the process returns to step a2, and in the next fuel injection, fuel injection increased by the correction amount is performed.

When it is determined in step a7 that the correction amount of the fuel injection amount exceeds the upper limit, the ignition timing of only the cylinder in which misfire is detected in step a8 is retarded by, for example, 1 °. In step a9, it is determined whether or not the correction amount due to the ignition timing retard exceeds the upper limit. If it does not exceed the upper limit, the process returns to step a2, and the ignition is performed at a timing delayed by the corrected retard angle at the time of the ignition in step a3. If it is determined in step a9 that the correction amount of the ignition timing retard exceeds the upper limit, step a10
Then, the correction amount is returned to 0, the diagnostic code indicating the self-diagnosis result of the misfire detection is displayed on the display 34 in FIG. 1 in step a11, and the procedure is ended in step a12.

In this embodiment, the correction of the increase in the fuel injection amount is performed first, and the correction based on the retard of the ignition timing is performed.
If the misfire still does not disappear, the correction amount is returned to 0 and the misfire detection diagnostic code is displayed. As a result, the driver of the vehicle or the like can know that a misfire has occurred in the engine 2 and that the driver should go to a service factory or the like to receive an expert's diagnosis.

In the engine 2 according to the present embodiment, both the fuel injection amount by the injector 8 and the ignition timing by the spark plug 9 can be adjusted, so that the increase in the fuel injection amount is corrected first. Correction based on the ignition timing retard is performed later to try to prevent the misfire. If misfire can be prevented by correcting the fuel injection amount, the ignition timing is not corrected, so that the fuel can be effectively changed to power. When the misfire cannot be prevented only by correcting the fuel injection amount, the retard of the ignition timing is also corrected, and the possibility of preventing the misfire can be increased. In order to increase the possibility of misfire prevention, the correction of the fuel injection amount and the correction of the ignition timing may be performed simultaneously. When priority is given to reduction of fuel consumption, correction by retarding the ignition timing may be performed first, and correction by increasing the fuel injection amount may be attempted later.

FIG. 3 shows a control procedure of the engine 2 by the misfire control apparatus 1 for an internal combustion engine according to another embodiment of the present invention. In the present embodiment, steps b1 to b
5, the same processes as those in steps a1 to a5 in FIG. 2 are performed. When it is determined in step b5 that there is a misfire, the water temperature detector 18 is determined in step b6.
To detect the engine water temperature. In step b7, the fuel injection amount of the cylinder in which the misfire has been detected is increased in accordance with the engine coolant temperature. Step b8 to step b1
Steps up to 1 are equivalent to steps a7 and steps a10 to a12 in FIG.

In this embodiment, the correction amount of the fuel injection amount is changed according to the engine water temperature. In general, the engine water temperature of about 85 ° C. is standard for the gasoline engine 2 for automobiles. When the engine 2 is started in a cold region, it may take time for the engine water temperature to reach 85 ° C. When the engine coolant temperature THW <60 ° C., even if there is a misfire, the correction amount is set to 0 and no correction is performed. This is because if the fuel injection amount is increased, the fuel contained in the exhaust gas may also increase, and the three-way catalyst connected to the exhaust pipe 11 may be damaged. When 60 ≦ THW ≦ 80 ° C., the correction amount is increased by 2%. This is to eliminate the misfire as soon as possible to obtain an appropriate operating state of the engine 2. T
When HW ≦ 80 ° C., the correction amount is reduced by 0.5%. This is because if the engine water temperature falls within an appropriate range and the correction amount is slightly increased, the possibility of preventing misfire increases.

Also in this embodiment, the upper limit of the correction amount is guarded in step b8. The upper limit of the correction amount is, for example, about 5%. If the increase is not resolved even if the increase or decrease exceeds 5%, the correction amount is returned to 0 in step b9, and step b
A diagnostic code as a result of the self-diagnosis is displayed at 10 to urge replacement of parts, and the procedure ends at step b11. When using other fluids such as oil and air instead of water for cooling the engine 2, the temperature of the fluid may be detected instead of the water temperature.

As still another embodiment of the present invention, a method of changing the correction amount within the range of the rotation speed of the engine 2 can be adopted. For example, it is assumed that the range of the engine speed is an idling region, and the idling switch is in an ON state in this region. The rotation speed region where the idling switch is in the OFF state is a region of less than 2000 rpm, and
3000 or more as an area of not less than 00 and less than 3000 rpm
It is divided into regions of rpm or more. When the engine 2 is a four-cylinder engine having four cylinders 3 and a misfire occurs only in the second cylinder 3 among them, the correction is performed with correction values as shown in Table 1 below. That is, the correction for increasing the fuel injection amount is performed in the region where the idling switch is OFF only in the second cylinder among the four cylinders 3. The correction amount for the increase in the fuel injection amount is set to 2% only in the region, and 1% in the region.
%.

[0039]

[Table 1]

Such a change in the correction amount corresponding to the rotation speed region of the engine 2 is performed by detecting the rotation speed in place of the water temperature detection in step b6 according to the control procedure shown in FIG. The increase in the fuel injection amount may be corrected according to Table 1. Further, the correction amount of the engine water temperature may be reflected in Table 1, and the correction amount for increasing the injection amount may be reflected using both the engine water temperature and the rotation speed as parameters.

FIG. 4 shows a control procedure of the internal combustion engine misfire control apparatus 1 of FIG. 1 as still another embodiment of the present invention. Each step from step c1 to step c5 is equivalent to each step from step a1 to step a5 in FIG. 2 and each step from step b1 to step b5 in FIG. In step c6, the engine coolant temperature is detected as in step b6 of FIG. In step c7, a correction is made to retard the ignition timing only for the cylinder in which misfire has been detected. The correction amount of the retard of the ignition timing is changed according to the engine coolant temperature. When the engine water temperature THW is lower than 60 ° C., no correction is performed. 2 ° when engine water temperature is above 60 ° C and below 80 ° C
Correction is performed for each time. When the engine water temperature THW is equal to or higher than 80 ° C., the correction is performed by 1 °. In step c8, it is determined whether or not the correction amount for retarding the ignition timing exceeds a preset upper limit. If not, the process returns to step c2. If it is determined in step c8 that the correction amount of the retard exceeds the upper limit, the correction area is returned to 0 in step c9, a misfire detection diagnostic code is displayed in step c10, and the control is ended in step c11. It should be noted that the rotation speed may be detected instead of the water temperature detection in step c6, and the ignition timing correction in step c7 may be performed with the retard angle divided into the rotation speed region as in Table 1.

In the correction of the increase in the fuel injection area in step a6 in FIG. 2, the correction amount is associated with a change in the correction amount due to the detection of the water temperature as shown in FIG. It is also possible to combine the changes of the correction amounts to be obtained. Also,
The change of the correction amount of the ignition timing retard based on the engine water temperature as shown in FIG. 4 can be combined with the ignition timing retard in step a8 in FIG.

In the internal combustion engine misfire control apparatus 1 shown in FIG. 1, the knock sensor 21 also performs control for preventing knocking. If control for misfire prevention is performed while control for knocking prevention is being performed, both controls will interfere with each other,
There is also a risk that knocking cannot be effectively prevented. Therefore, the control for preventing knocking is given priority, and the control for preventing misfire is stopped. In order to stop the misfire prevention control, for example, the misfire detection in steps a4, b4, and c4 in FIGS. 2 to 4 is stopped, or the misfire determination in steps a5, b5, and c5 is stopped. do it.

For example, abnormal operation of the fuel pump or the injector 8 of the fuel system may be detected by a detection mechanism (not shown) in some cases. In such a case, the correction accompanying the misfire control is not performed. Also,
Since the operation state of the engine 2 is also rapidly changing while maintaining the acceleration and deceleration of the engine 2, the accuracy of misfire detection is reduced and the effect of misfire correction is also reduced, so that misfire correction control is not performed. In order not to perform misfire correction, it is only necessary to perform processing at the stage of misfire detection or misfire determination as described above.

Although FIG. 1 illustrates an engine 2 for an automobile as an internal combustion engine, which uses a mixture of gasoline and air as a fuel, if only the fuel injection amount is to be controlled, the ignition plug 9 is connected. Misfire control can be similarly performed for a diesel engine or the like that does not have it. Further, not only the engine 2 having the cylinder 3 as a combustion chamber but also a rotary engine or the like can be applied to the present invention to perform misfire control. Although the injector 8 injects corporate fuel such as gasoline or light oil for diesel engines, it goes without saying that gaseous fuel such as natural gas may be injected.

[0046]

As described above, according to the present invention, among a plurality of combustion chambers provided in an internal combustion engine, the fuel injection amount for a combustion chamber determined to be misfire is increased by a predetermined correction amount,
Misfire can be prevented.

Further, according to the present invention, it is possible to prevent a misfire by delaying the ignition timing of a combustion chamber determined to have a misfire among a plurality of combustion chambers provided in the internal combustion engine.

Further, according to the present invention, if any of the plurality of combustion chambers of the internal combustion engine is determined to have a misfire, the fuel injection amount is increased and the ignition timing is delayed. And increase the possibility of escape from misfire.

Further, according to the present invention, when it is determined that a misfire has occurred in the combustion chamber, one of the fuel injection amount and the ignition timing is corrected first, and the misfire is changed in a state where the change from the original state is as small as possible. Can be prevented. When the misfire cannot be prevented by one of the corrections, the other correction is also performed to effectively prevent the misfire.

According to the present invention, misfire can be prevented with an appropriate correction amount corresponding to the temperature of the combustion chamber of the internal combustion engine.

Further, according to the present invention, when the misfire cannot be prevented even if the correction amount reaches the upper limit, a self-diagnosis result indicating that the misfire has occurred is output to take measures such as replacing parts. I can tell you what to do. Even if it is possible to prevent misfire by increasing the correction amount, it is not preferable to perform correction exceeding the regulation of exhaust gas, so that it is possible to limit the correction to an allowable range.

Further, according to the present invention, since the misfire prevention means keeps a history of the processing related to the correction amount, even if the misfire can be prevented within the limit of the correction amount, or the misfire cannot be prevented. At any time, it is possible to obtain information on the tendency of misfire of the internal combustion engine by referring to the respective histories. Further, according to the present invention, when there is an abnormality in the fuel supply system, correction for preventing misfire is performed. Is not performed, unnecessary control can be avoided in a case where misfire cannot be prevented due to an increase in fuel injection amount or a delay in ignition timing due to deterioration of the fuel supply state.

Further, according to the present invention, misfire can be prevented with an appropriate correction amount according to the operating state of the internal combustion engine.

Further, according to the present invention, it is possible to prioritize the control for preventing knocking so that the control for preventing knocking does not hinder the control for preventing knocking.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration related to a misfire control apparatus 1 for an internal combustion engine as one embodiment of the present invention.

2 is an ECU 16 of the internal combustion engine misfire control apparatus 1 shown in FIG.
6 is a flowchart showing a control procedure of the first embodiment.

FIG. 3 is a flowchart showing a control procedure by an ECU 16 as another embodiment of the present invention.

FIG. 4 shows an ECU 1 as still another embodiment of the present invention.
6 is a flowchart illustrating a control procedure according to a sixth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Misfire control device of internal combustion engine 2 Engine 3 Cylinder 7 Intake pipe 8 Injector 9 Spark plug 11 Exhaust pipe 13 Throttle valve 14 Valve opening detector 15 Intake temperature detector 16 ECU 17 Oxygen concentration detector 18 Water temperature detector 21 Knock sensor 22 Crank angle sensor 30 Processing circuit 33 Memory 34 Display 35 Connector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 45/00376 F02D 45/00 376F 41/22 301 41/22 301C 330 330A 43/00 301 43/00 301B 301H F02P 5/152 G01M 15/00 A 5/153 F02P 5/15 D 5/15 B 17/12 17/00 F G01M 15/00 RF term (reference) 2G087 AA13 BB12 BB14 DD13 DD20 3G019 AA05 AB01 AC04 AC05 BA05 DA02 DA04 DC07 GA01 GA02 GA09 GA14 GA16 3G022 AA03 DA02 DA04 DA10 EA01 EA02 EA08 EA09 FA08 GA01 GA02 GA08 GA09 GA13 GA16 3G084 AA01 AA03 BA13 BA17 BA33 CA04 CA06 DA27 DA28 EA11 EB06 FA30 FA02 FA02 FA02 FA02 FA02 3G301 HA01 HA02 HA06 JA22 JA23 JB09 JB10 KA12 KA16 LA00 MA11 NC01 NC04 NE17 PA07Z PA10Z PA11Z PB00Z PC08Z PC09Z PD02Z PE03Z PE04Z PE 08Z

Claims (10)

[Claims] A misfire control device for an internal combustion engine that includes a plurality of combustion chambers and controls a fuel injection amount for each combustion chamber so as to prevent a misfire. Misfire determining means for determining whether or not a misfire has occurred; and misfire preventing means for controlling the fuel injection amount to the combustion chamber, which is determined by the misfire determining means to have a misfire, so as to increase by a predetermined correction amount. A misfire control device for an internal combustion engine, comprising: 2. A misfire control device for an internal combustion engine having a plurality of combustion chambers and performing control to prevent a misfire for an internal combustion engine capable of controlling an ignition timing for each combustion chamber. Misfire judging means for judging the presence or absence of occurrence of misfire, and misfire prevention means for controlling the ignition timing in the combustion chamber determined to have misfire by the misfire judgment means so as to be delayed by a predetermined correction amount. A misfire control device for an internal combustion engine, comprising: 3. A misfire control device for an internal combustion engine which includes a plurality of combustion chambers and controls a fuel injection amount and an ignition timing for each combustion chamber to prevent a misfire. Misfire determining means for determining whether or not a misfire has occurred for each combustion chamber; and increasing and delaying a fuel injection amount and an ignition timing into the combustion chamber determined to have a misfire by the misfire determination means by a predetermined correction amount. And a misfire prevention unit for controlling the misfire of the internal combustion engine. 4. A misfire control device for an internal combustion engine that includes a plurality of combustion chambers and controls a fuel injection amount and an ignition timing for each combustion chamber to prevent a misfire. Misfire determining means for determining whether or not a misfire has occurred for each combustion chamber; and increasing or decreasing a fuel injection amount or an ignition timing to the combustion chamber determined to have a misfire by the misfire determining means by a predetermined correction amount. And a misfire prevention means for controlling the fuel injection amount or the ignition timing to increase or delay by a predetermined correction amount after the correction amount reaches the upper limit. Misfire control device for an internal combustion engine. 5. The temperature control device according to claim 1, further comprising a temperature detection unit configured to detect a temperature of a fluid that cools a combustion chamber of the internal combustion engine, wherein the misfire prevention unit controls the correction amount according to a temperature of the fluid detected by the temperature detection unit. The misfire control apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein: 6. The misfire prevention means returns the correction amount to 0 when the misfire determination means determines that misfire has occurred even if the correction amount reaches a preset upper limit, and the misfire occurs. The misfire control device for an internal combustion engine according to any one of claims 1 to 5, wherein the self-diagnosis result is output. 7. The misfire control device for an internal combustion engine according to claim 6, wherein said misfire prevention means keeps a history of processing relating to said correction amount. 8. The internal combustion engine according to claim 1, wherein the misfire determination unit does not determine whether or not the misfire has occurred when an abnormality has occurred in a fuel supply system. Misfire control device. 9. An operation determination unit for determining an operation state of the internal combustion engine, wherein the misfire prevention unit performs the correction based on a correspondence relationship between a preset operation state of the internal combustion engine and the correction amount. The misfire control device for an internal combustion engine according to any one of claims 1 to 8, wherein the amount is determined. 10. The engine according to claim 1, further comprising: knocking control means for performing ignition timing delay control for preventing knocking of the internal combustion engine, wherein the misfire determining means performs the ignition timing delay control by the knocking control means. The misfire control device for an internal combustion engine according to any one of claims 1 to 9, wherein it is not determined whether or not the misfire has occurred.