JPH06129297A - Misfire detection device of internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a misfire detection device of an internal combustion engine capable of precisely making a misfire judgement even in the case when a driving state of the internal combustion engine suddenly changes. CONSTITUTION:This device is furnished with a crank angle detection means M2 connected to an internal combustion engine 1 having a plural number of cylinders and to detect rotation of this internal combustion engine 1 and a misfire detection menas M3 connected to this crank angle detection means M2 and to detect flame-out cuased in each of the cylinders of the internal combustion engine 1 in accordance with an output signal of the crank angle detection means M2. Additionally, it is furnished with a driving state detection means M4 connected to the internal combustion engine 1 and to detect a driving state of this internal combustion engine 1, and the misfire detection means M3 is constituted so as to nullify a judged result of misfire detection at the time when an output signal of the driving state detection means M4 suddenly changes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a misfire detection device for an internal combustion engine, and more particularly to a misfire detection device for an internal combustion engine for detecting a misfire due to an abnormality of an ignition system, a fuel system, etc. of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a misfire detecting device for an internal combustion engine of this type, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 2-414000. This is to detect the rotation of the internal combustion engine using a crank angle sensor, and determine the misfire from the fluctuation in the rotation that occurs depending on the presence or absence of the misfire. In this misfire detecting device, a time ratio detecting means for detecting a time ratio of required times of front and rear predetermined angle sections based on a predetermined crank angle of the internal combustion engine, and an acceleration of the time ratio is obtained, and from this acceleration A misfire determining means for determining misfire is provided, and the misfire determining means compares the acceleration with a predetermined value corresponding to a predetermined misfire to determine the presence or absence of misfire.

[0003]

However, in such a conventional apparatus, attention is paid to the rotational fluctuation of the internal combustion engine, and the misfire is judged by detecting that the rotational cycle of the misfiring cylinder at the time of misfire of the internal combustion engine is detected. Therefore, if the operating state changes suddenly, the angular velocity of the crankshaft of the internal combustion engine also changes suddenly.
There was a problem in that the difference in angular velocity behavior between normal combustion and misfire could not be determined, and misfire determination was erroneous.

The present invention has been made in order to solve such a problem, and provides a misfire detecting device for an internal combustion engine, which can accurately determine misfire even when the operating state of the internal combustion engine suddenly changes. With the goal.

[0005]

A misfire detecting device for an internal combustion engine according to a first aspect of the present invention is connected to an internal combustion engine having a plurality of cylinders, and crank angle detecting means for detecting the rotation of the internal combustion engine, Connected to this crank angle detection means,
Misfire detection means for detecting misfire occurring in each cylinder of the internal combustion engine based on the output signal of the crank angle detection means,
And an operating state detecting means connected to the internal combustion engine for detecting an operating state of the internal combustion engine, wherein the misfire detecting means invalidates the determination result of the misfire detection when the output signal of the operating state detecting means suddenly changes. And so on.

A misfire detection device for an internal combustion engine according to a second aspect of the present invention is connected to an internal combustion engine having a plurality of cylinders,
Crank angle detecting means for detecting the rotation of the internal combustion engine,
Misfire detection means connected to the crank angle detection means for detecting misfire occurring in each cylinder of the internal combustion engine based on an output signal of the crank angle detection means, and operation of the internal combustion engine connected to the internal combustion engine. And a misfire detecting means for detecting the condition, wherein the misfire detecting means invalidates the determination result of misfire detection when the amount of change in the output signal of the operating condition detecting means is equal to or more than a predetermined value.

A misfire detecting device for an internal combustion engine according to a third aspect of the present invention is connected to an internal combustion engine having a plurality of cylinders,
Crank angle detecting means for detecting the rotation of the internal combustion engine,
Misfire detection means connected to the crank angle detection means for detecting misfire occurring in each cylinder of the internal combustion engine based on an output signal of the crank angle detection means, and operation of the internal combustion engine connected to the internal combustion engine. An operating state detecting means for detecting the state is provided, and the misfire detecting means invalidates the determination result of the misfire detection for a predetermined period of time after the operating state changes abruptly.

[0008]

According to the present invention, the operating condition detecting means connected to the internal combustion engine for detecting the operating condition of the internal combustion engine is provided, and the output signal of the operating condition detecting means is rapidly changed by the misfire detecting means. At this time, the determination result of misfire detection is invalidated to prevent erroneous determination and enhance the accuracy of misfire detection.

According to the second aspect of the present invention, there is provided an operating state detecting means connected to the internal combustion engine to detect the operating state of the internal combustion engine, and the misfire detecting means provides a predetermined amount of change in the output signal of the operating state detecting means. When the value is equal to or larger than the value, the misfire detection determination result is invalidated to prevent erroneous determination and improve the misfire detection accuracy.

According to another aspect of the present invention, there is provided an operating condition detecting means connected to the internal combustion engine for detecting the operating condition of the internal combustion engine, and the operating condition continues for a predetermined time after the operating condition is suddenly changed by the misfire detecting means. Then, the determination result of the misfire detection is invalidated to prevent the erroneous determination immediately after the operating state is returned to the steady state during the period in which the operating state is rapidly changing, thereby further improving the detection accuracy of the misfire.

[0011]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram of the present invention. In the figure, M1 is an engine as an internal combustion engine having a plurality of cylinders, M2 is connected to the engine M1, and the engine M
Crank angle detecting means for detecting the position of the reference crank angle used for ignition control with reference to a predetermined crank angle of 1, M
Reference numeral 3 is connected to the crank angle detecting means M2, and the time required for each section before and after the reference crank angle corresponding to each cylinder of the engine M1 based on the output signal of the crank angle detecting means M2 (not shown). A misfire detection unit that includes a time ratio detection unit that detects a ratio and a misfire determination unit that determines a misfire based on an output signal of the time ratio detection unit.

The misfire detector M3 detects the specific reference angle of the engine M1, for example, the time ratio of the reference cycle signals before and after the top dead center, from the output signal from the crank angle detection device M2 by the time ratio detection device. , Misfire is determined from the angular velocity of this time ratio. M4 is an operating state detecting means that is connected to the engine M1, detects operating states such as engine load and rotation speed, and outputs the detection information to the misfire detecting section M3.

FIG. 2 is a block diagram showing an embodiment of the present invention which is an implementation of FIG. In the figure, reference numeral 1 is a four-cylinder engine having # 11 to # 4 cylinders 11 to 14, and 2 is an air flow disposed in an intake passage (not shown) of the engine 1 for detecting the amount of air taken into the engine 1. The sensor 3 is a crank angle sensor that is attached to a crank shaft (not shown) of the engine 1 and detects the rotation of the engine 1. Reference numeral 4 denotes a distributor mounted on a cam shaft (not shown) of the engine 1 and having a built-in cylinder identification sensor 41. Reference numeral 5 denotes an intake air amount signal from the air flow sensor 2, a rotation signal from the crank angle sensor 3 and the cylinder identification sensor 41. A control unit to which a cylinder identification signal from the control unit 5 is supplied, 6 is a control unit 5
Is an injector for injecting fuel into each cylinder of the engine 1, 7 is an igniter as an ignition device connected to the control unit 5, and 8 is an alarm lamp connected to the control unit 5 for warning a misfire. .

The control unit 5 receives various signals (not shown) (for example, a slot opening signal, a water temperature signal, etc.) in addition to the intake air amount signal, the rotation signal, and the cylinder identification signal to drive the injector 6 and the igniter 7. It has a function of controlling fuel and ignition, and a misfire detection function of detecting misfire and turning on the alarm lamp 8.

The control unit 5 is an analog interface 5 to which the intake air amount signal from the air flow sensor 2 is input.
1, a digital interface 52 to which the rotation signal from the crank angle sensor 3 and the cylinder identification signal from the cylinder identification sensor 41 are input, and these interfaces 51 and 5
The output signal from the control unit 5 is processed based on the output signal from the control unit 5 by processing the output signal from the control unit 5 through a driver, which will be described later, and controlling the fuel, ignition control, misfire detection, and display control. , An igniter 7 and an alarm lamp 8, respectively, an injector driver 54, an ignition driver 55, and a lamp driver 56. Further, the microcomputer 53 includes a processing procedure, a memory 531 that stores control information, a timer counter (free running counter) 532 that counts up every fixed time clock, a CPU 533 that executes each arithmetic processing, and the like.

Next, the operation will be described. First, the relationship between the crank angle sensor 3, ignition and combustion will be described. FIGS. 3 (a) and 3 (b) show the pressure change of each cylinder 11-12 with respect to the crank angle of the four-stroke cycle four-cylinder engine and the waveform of each part. In FIG. 5A, the solid line is the pressure waveform of the first cylinder # 1 of the engine 1, BDC is the bottom dead center, TDC.
Is the top dead center. Also, the broken line is the pressure waveform of the third cylinder # 3, the alternate long and short dash line is the pressure waveform of the second cylinder # 2, and the alternate long and two short dashed line is the pressure waveform of the fourth cylinder # 4. As shown in FIG. 3, in a 4-cylinder engine, the combustion cycle of each cylinder has a phase difference of a crank angle of 180 degrees. In addition, in FIG. 3, the pressure waveform of the first cylinder # 1 continuously shows the stroke of one cycle of intake, compression, explosion, and exhaust, but the second cylinder # 2 and the third cylinder # 1.
Regarding the pressure waveforms of the third and fourth cylinders # 4, only the compression and explosion strokes are described, and the intake and exhaust strokes are omitted.

As shown in FIG. 3B, the crank angle sensor 3 corresponds to the ignition timing of each of the cylinders 11 to 14 at a cycle of 180 degrees with respect to the position 6 degrees before TDC, for example, at a cycle of 180 degrees. 110 degree Low section (hereinafter referred to as L) and 7
An ignition cycle signal distributed to a 0 degree High section (hereinafter referred to as H) and a cylinder identification signal for identifying the number of the ignition cylinder are generated at a timing corresponding to the H section of the first cylinder of this ignition cycle signal. To do. In general, ignition control refers to this cylinder identification signal to control the energization of an ignition coil (not shown).

That is, taking the first cylinder # 1 as an example, the energization of the ignition coil is started in the H section of the compression stroke at the crank angle of 180 to 360 degrees, and the ignition timing determined corresponding to the rotational speed load. With reference to the output signal of the crank angle sensor 3 which changes from H to L near TDC, the ignition coil is de-energized and the high voltage generated thereby is applied to the ignition plug to ignite it. Corresponding to this, as shown by the solid line in FIG. 3 (a), the in-cylinder pressure has a crank angle of 360 degrees to 54 degrees.
Ignition occurs in the explosion stroke at 0 degree, and the combustion pressure increases.
Similarly, the ignition sequence # 1 → # 3 is repeated every 180 degrees.
The combustion cycle is repeated as → # 4 → # 2 → # 1.

Next, a specific method for detecting misfire will be described. Figures 3 (a) and 3 (c) show the relationship between combustion and angular velocity. still,
This figure shows the case where the engine speed is 1000 rpm. In the first cylinder # 1 shown by the solid line in FIG. 3A, the waveform centering on the crank angle of 360 degrees is the case of normal combustion, and the air-fuel mixture charged in the intake stroke is pressurized in the compression stroke and compressed. TDC
It is ignited in the vicinity, rapidly expanded in the explosion stroke, and discharged outside the cylinder in the exhaust stroke.

Next, the misfire state that occurs when ignition fails or the mixing ratio of air and fuel is inappropriate will be described. The pressure waveform centered around a crank angle of 1080 degrees corresponds to this, and T
It becomes symmetrical about DC. In the case of this example, there is no combustion at all, that is, the state of complete misfire is shown. However, if the extent of misfire is slight, the pressure transition in the explosion stroke is at the normal crank angle of 360 to 540 degrees. It becomes an intermediate value of the pressure waveform. Further, as shown in the crank angle of 0 to 1080 degrees in FIG. 3 (c), the angular velocity has a characteristic that the angular velocity increases in accordance with the torque increase due to the explosion of each cylinder and decreases in accordance with the compression. Here, when a misfire occurs, the torque increase due to the explosion cannot be obtained as shown after the crank angle of 1080 degrees, so the angular velocity decreases, and the next third
It keeps decreasing until the explosion of cylinder # 3 occurs. Therefore,
Focusing on this point, the present invention intends to determine the misfire from the fluctuation of the angular velocity in a predetermined section of the crank angle caused by the presence or absence of the misfire.

Next, the angular acceleration used for the actual misfire determination will be described with reference to FIG. In the figure,
T is the ignition cycle of each cylinder for each crank angle of 180 degrees,
TU is the required time for the L section of 110 degrees, and TL is the required time for the H section of 70 degrees. The subscript i indicates the current value, and i
-1 indicates the previous value. In reciprocating circular motion, angular acceleration α
(Rad / s ² ) is expressed by the following equation.

Α = (ω _i −ω _i−1 ) / T _i (1)

Here, ω _i is the angular velocity in the period T _i , and T _i is the period between ignitions. The angular velocity ω _i is expressed by the following equation.

Ω _i = 4π / c × (1 / T _i ) (2)

Here, c is the number of cylinders. From the above equations (1) and (2), when the angular velocity ω _i decreases, the angular acceleration α
If the polarity is selected to be positive, then

Α = 4π / c × (1 / T _i ) × [T _i / T _i ² − {T _i−1 / (T _i−1 ) ² }] (3)

Here, T _i-1 = T _i + ΔT _i, and ΔT _i ²
If «1, the angular acceleration α in the above equation (3) is approximately represented by the following equation.

Α = 4π / c × (T _i-1 −T _i-1 ) / T _i ³ (4)

Further, the period Ti between each ignition and the time ratio TU /
The relationship with TL is T _i = TL + TU, and the term of TL is information on the amount of filled air included in the compression stroke, which means that TU is normalized on the basis of the amount of air. Here, if the filling air amounts of the adjacent cylinders are constant, TL _i = TL _i−1 , and ΔT _i = T _i−1 −T _i = TU _i−1 −TU _i
The angular acceleration α is given by the following equation.

Α = 4π / c × (TL _i / T _i ³ ) × {TU _i / TL _i − (TU _i-1 / TL _i-1 )} (5)

In the arithmetic expression used in this embodiment, the term of 4π / c is deleted, and the acceleration (1 / s ² ) is calculated as an approximate expression of the angular acceleration.
Uses the acceleration β expressed by the following equation to determine the angular velocity fluctuation caused by a misfire as the acceleration β.

Β = (TL _i / T _i ³ ) × {TU _i / TL _i − (TU _i-1 / TL _i-1 )} (6)

FIG. 3 (d) is a diagram showing the relationship between misfire and acceleration (1 / s ² ). In the figure, the solid line indicates each cylinder # 1.
Accelerations calculated respectively corresponding to # 4. If a value of 5 (1 / s ² ) shown by a broken line in the figure is set as the misfire determination value, the first cylinder centered at a crank angle of 1080 degrees #
It is clear that the misfire can be determined from the acceleration because the acceleration increases corresponding to the misfire of 1 and becomes equal to or higher than the determination value.

Next, a case where the engine operating state changes abruptly will be described with reference to FIGS. 4 and 5. FIG. 4 is a time chart showing a state where the load is rapidly increased, and is an example of erroneous detection in which misfire is determined despite normal combustion. Further, FIG. 5 is a time chart showing a state in which the load is sharply reduced, which is an example of undetected misfire. 4 and 5, the parts corresponding to those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 4 shows a state in which the load is rapidly increased, and this situation occurs when the accelerator pedal interlocked with a throttle valve (not shown) is depressed after a shift change. The Ce value (charging efficiency) was used as an index of the load, which is the value of the fresh air amount actually sucked in with respect to the fresh air weight occupying the stroke volume of the cylinder calculated from the information of the mass flow rate of the intake air from the air flow sensor 2. This Ce value shown in FIG. 4A takes a value of 0 to 1 and represents a state in which the load changes rapidly from a low load to a high load.

FIG. 4 (b) shows the pressure waveform of each cylinder. As the load in FIG. 4 (a) increases, the pressure in the cylinder also changes in a 180 degree cycle at # 1 → # 3 → # 4 → # 2. It increases with the repeated ignition in the ignition order of. Further, in the figure, the combustion is normal and there is no misfiring cylinder. Figure 4
(D) shows a change in the angular velocity due to combustion, and during acceleration after the shift change, irregular combustion occurs due to an increase in the amount of fuel, and the angular velocity increases while periodically increasing and decreasing-a waveform. FIG. 4 (e) shows the relationship of the acceleration (1 / s ² ), in which the solid line is the acceleration calculated for each of the cylinders # 1 to # 4, and the broken line is shown in FIG. As shown in FIG. 3, the value of acceleration 5 (1 / s ² ) is set as the misfire determination value, as in FIG.

Here, paying attention to the acceleration, at the crank angle 900 (deg), the acceleration of the second cylinder # 2 exceeds the misfire determination value 5 (1 / s ² ) although the misfire does not occur. This is because the change in the angular velocity of the crankshaft increases due to the increase in the load, but the irregular combustion occurs and the angular velocity decreases slightly. This is erroneously determined to be the decrease in the angular velocity due to misfire. Therefore, if the load increases rapidly,
It is difficult to determine the behavior of the angular velocity during normal combustion and during misfire, and accurate misfire determination cannot be performed. Therefore, this part must be excluded from the range for misfire determination.

FIG. 5 shows an undetected example that occurs when the load sharply decreases, and the waveform of the Ce value shown in FIG. 5A shows a state in which the load sharply decreases from high load to low load. Represents This situation occurs when the accelerator pedal, which is linked to a throttle valve (not shown), is released before the shift change. FIG. 5B shows a pressure waveform of each cylinder.
As the load in (a) decreases, the pressure in the cylinder also becomes 1
It decreases with the repeated ignition in the order of # 1 → # 3 → # 4 → # 2 in the cycle of 80 degrees. Further, in the figure, the third cylinder # 3 having a crank angle of 1080 (deg) is symmetric with respect to the crank angle of 1080 degrees, and thus indicates a misfire state.

FIG. 5D shows a change in the angular velocity due to combustion, and the angular velocity decreases as the load decreases.
FIG. 5 (e) shows the relationship of the acceleration (1 / s ² ), in which the solid line is the acceleration calculated for each of the cylinders # 1 to # 4, and the broken line is shown in FIG. As shown in FIG. 3, the value of acceleration 5 (1 / s ² ) is set as the misfire determination value, and the acceleration of the crank angle 1080 (deg) is the misfire determination value even though the misfire has occurred. 5 (1 / s
² ) Below. This means that if the load drops sharply,
The angular velocity decreases due to the misfire, and the cylinder next to the misfiring cylinder (crank angle 1260 (deg)) also decreases due to the decrease in the load. This is because they become equal and there is no significant difference in angular velocity, so detection becomes impossible. Therefore, when the load is suddenly reduced, accurate misfire determination cannot be performed, so this portion must be excluded from the range of misfire determination.

Next, the operation for preventing erroneous misfire determination due to a sudden change in operating state will be described with reference to FIG. This operation prohibits a misfire determination for a predetermined period after a sudden change in the driving state and for a predetermined time after the sudden change in the driving state if the amount of change in the driving state is equal to or more than a predetermined value, and this routine is executed every predetermined time.

First, in step S1, the microcomputer 53 performs a predetermined calculation by the CPU 533 at predetermined time intervals based on the output signals of the air flow sensor 2, the crank angle sensor 3 and the cylinder identification sensor 41 to detect misfire. Further, the microcomputer 53 at step S2, based on the output signals of the air flow sensor 2, the crank angle sensor 3, and the cylinder identification sensor 41, the engine 1 at predetermined time intervals.
The operating conditions such as the load and the number of revolutions are detected and stored in the memory 531. Next, in step S3, this process
After starting the program, the CPU checks whether it is the first time.
If it is the first time, the process is terminated, and if it is the second time or later, the process proceeds to step S4, the previous operating state and the current operating state are read from the memory 531, and the CPU 5
At 33, the change amount of the operating state is calculated, and if the change amount is not less than the predetermined value, the process proceeds to step S5.

In step S5, the microcomputer 53 turns on a flag indicating that the misfire determination is prohibited (provisionally, this flag name is KINSHI), stores the flag state in the memory 531 and at the same time counts at regular intervals. After the timer counter 532 to be incremented is cleared, the timer counter 532 is started and the process proceeds to step S6 to prohibit the misfire determination.

On the other hand, when the amount of change in the operating state is less than the predetermined value in step S4, the process proceeds to step S7, in which the state of the KINSHI flag stored in the memory 531 is checked, and if it is OFF, the process ends. . Step S7
If the KINSHI flag is ON, the process proceeds to step S7, where the state of the timer counter 532 started in step S5 is determined, and if it is within a predetermined time, the process proceeds to step S6 and the misfire determination is prohibited. That is, the timer counter 532 is operated for a predetermined time from the time when the amount of change equal to or more than the predetermined value is generated, and the misfire determination is prohibited during the operation section of the timer counter 532. If the value of the timer counter 532 has timed up in step S8, that is, if it is not within the predetermined time, the KINSHI flag is turned off in step S9, and the process is terminated.

Example 2. In the above embodiment, the change in the operating state is determined by Ce (charging efficiency), but instead of this, although not shown, the boost pressure, which is the pressure of the suction pipe, and the rotation speed N.
It is also possible to use A / N, which is the ratio of the intake air amount A to A, throttle opening, rotational speed, and the like. Further, although the misfire determination prohibition time after the sudden change in the operating state is a fixed value, it may be a variable value according to the amount of change. Furthermore, in the above-described embodiment, the case of a four-cylinder engine has been described, but the present invention is not limited to this, and can be similarly applied to engines having other numbers of cylinders, and the same effect as that of the above-described embodiment can be obtained.

[0045]

As described above, according to the first aspect of the present invention, the crank angle detecting means, which is connected to the internal combustion engine having a plurality of cylinders and detects the rotation of the internal combustion engine, and the crank angle detecting means. And a misfire detecting means for detecting a misfire occurring in each cylinder of the internal combustion engine based on an output signal of the crank angle detecting means, and an operation for connecting to the internal combustion engine and detecting an operating state of the internal combustion engine. Since the misfire detection means is configured to invalidate the determination result of the misfire detection when the output signal of the operating state detection means changes abruptly, the misfire detection means includes an error when the operating state changes abruptly. There is an effect that the determination can be prevented and the accuracy of misfire detection can be improved.

A misfire detecting device for an internal combustion engine according to a second aspect of the present invention is connected to an internal combustion engine having a plurality of cylinders,
Crank angle detecting means for detecting the rotation of the internal combustion engine,
Misfire detection means connected to the crank angle detection means for detecting misfire occurring in each cylinder of the internal combustion engine based on an output signal of the crank angle detection means, and operation of the internal combustion engine connected to the internal combustion engine. The operation state detection means for detecting the state, wherein the misfire detection means is configured to invalidate the determination result of the misfire detection when the change amount of the output signal of the operation state detection means is a predetermined value or more. There is an effect that erroneous determination when the state changes abruptly can be prevented and misfire detection accuracy can be improved.

A misfire detecting device for an internal combustion engine according to a third aspect of the present invention is connected to an internal combustion engine having a plurality of cylinders,
Crank angle detecting means for detecting the rotation of the internal combustion engine,
Misfire detection means connected to the crank angle detection means for detecting misfire occurring in each cylinder of the internal combustion engine based on an output signal of the crank angle detection means, and operation of the internal combustion engine connected to the internal combustion engine. The operation state detection means for detecting the state is provided, and the misfire detection means is such that the determination result of the misfire detection is invalidated for a predetermined period of time after the operation state changes abruptly. There is an effect that it is possible to prevent the erroneous determination immediately after the operating state returns to the steady state, as well as the period during which the state changes to, and to further improve the detection accuracy of the misfire.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention which is an implementation of FIG.

FIG. 3 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 4 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 5 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 6 is a calculation flowchart for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

 M1 engine M2 crank angle detecting means M3 misfire detecting section M4 operating state detecting means

[Procedure amendment]

[Submission date] May 10, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

Next, the operation will be described. First, the relationship between the crank angle sensor 3, ignition and combustion will be described. FIG. 3 (a), shows the waveform of pressure change and each part of each cylinder 11-1 4 with respect to the crank angle of the four-stroke-cycle four-cylinder engine (b). In FIG. 5A, the solid line is the pressure waveform of the first cylinder # 1 of the engine 1, BDC is the bottom dead center, TDC.
Is the top dead center. Also, the broken line is the pressure waveform of the third cylinder # 3, the alternate long and short dash line is the pressure waveform of the second cylinder # 2, and the alternate long and two short dashed line is the pressure waveform of the fourth cylinder # 4. As shown in FIG. 3, in a 4-cylinder engine, the combustion cycle of each cylinder has a phase difference of a crank angle of 180 degrees. Note that, in FIG. 3, the pressure waveform of the first cylinder # 1 continuously shows the stroke of one cycle of intake, compression, explosion, and exhaust, but the second cylinder # 2 and the third cylinder # 1.
Regarding the pressure waveforms of the third and fourth cylinders # 4, only the compression and explosion strokes are described, and the intake and exhaust strokes are omitted.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

That is, taking the first cylinder # 1 as an example, the energization of the ignition coil is started in the H section of the compression stroke at the crank angle of 180 to 360 degrees, and the ignition timing determined corresponding to the rotational speed load. With reference to the output signal of the crank angle sensor 3 which changes from H to L near TDC, the ignition coil is de-energized and the high voltage generated thereby is applied to the ignition plug to ignite it. Corresponding to this, as shown by the solid line in FIG. 3 (a), the pressure waveform has a crank angle of 360 degrees to 5 degrees.
The explosion pressure at 40 degrees ignites and the combustion pressure increases. Similarly, the ignition sequence # 1 → 180 degrees
The combustion cycle of # 3 → # 4 → # 2 → # 1 is repeated.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Α = 4π / c × (T _i −T _i−1 ) / T _i ³ (4)

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

Β = (TL _i / T _i-1 ³ ) × {TU _i / TL _i − (TU _i-1 / TL _i-1 )} (6)

Claims (3)

[Claims] 1. A crank angle detecting means connected to an internal combustion engine having a plurality of cylinders for detecting the rotation of the internal combustion engine; and a crank angle detecting means connected to the crank angle detecting means, based on an output signal of the crank angle detecting means. The misfire detection means for detecting a misfire occurring in each cylinder of the internal combustion engine, and an operating state detection means connected to the internal combustion engine for detecting an operating state of the internal combustion engine, wherein the misfire detection means is the operating state. A misfire detection device for an internal combustion engine, wherein the determination result of misfire detection is invalidated when the output signal of the detection means suddenly changes. 2. A crank angle detecting means connected to an internal combustion engine having a plurality of cylinders for detecting the rotation of the internal combustion engine, and a crank angle detecting means connected to the crank angle detecting means based on an output signal of the crank angle detecting means. The misfire detection means for detecting a misfire occurring in each cylinder of the internal combustion engine, and an operating state detection means connected to the internal combustion engine for detecting an operating state of the internal combustion engine, wherein the misfire detection means is the operating state. A misfire detection device for an internal combustion engine, wherein the misfire detection determination result is invalidated when the amount of change in the output signal of the detection means is equal to or greater than a predetermined value. 3. A crank angle detecting means connected to an internal combustion engine having a plurality of cylinders for detecting the rotation of the internal combustion engine, and a crank angle detecting means connected to the crank angle detecting means based on an output signal of the crank angle detecting means. A misfire detecting means for detecting a misfire occurring in each cylinder of the internal combustion engine, and an operating state detecting means connected to the internal combustion engine for detecting an operating state of the internal combustion engine, wherein the misfire detecting means has an operating state of A misfire detection device for an internal combustion engine, characterized in that the judgment result of misfire detection is invalidated for a predetermined time after abrupt change.