JPH07109948A - Crank angle judging device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a crank angle judging device which can correctly judge the crank angle with the simple constitution. CONSTITUTION:On a crank side disc 23 fixed on a crankshaft 20, a cut tooth part 29 is formed before a projection 25a corresponding to the TDC of a cylinder, and two continuous cut tooth parts 29b and 29c are formed before a projection 25b corresponding to the TDC of the cylinder. The number of times of continuation of the cut tooth part 29 is counted through an electromagnetic pick-up type crankshaft sensor 21, and an ignited cylinder is judged. Accordingly, independently of the variation of the number of engine revolution, the crank angle can be judged correctly. No cut tooth part exists in the vicinity of a projection 25c corresponding to the TDC of the cylinder, and the TDC is judged on the basis of the variation of the revolution. Accordingly, the quantity of the cut tooth parts 29 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank angle discriminating device for discriminating a crank angle of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as this type of apparatus, for example, an apparatus described in Japanese Patent Laid-Open No. 56-87860 is known. In this device, a disk is provided that is coaxially fixed to the crankshaft and rotates integrally with the crankshaft.Furthermore, a large number of projections are formed at even intervals over almost the entire circumference of the disk, and ignition timing is adjusted. The intervals of the protrusions are formed wider at the corresponding predetermined portions than at other portions. Then, the interval between the protrusions is detected by the sensor, and when the wide interval (unequal interval part) is detected, the ignition is executed at a predetermined timing.

In recent years, in a multi-cylinder internal combustion engine, which cylinder group (a set of cylinders in which pistons slide in the same phase)
It is also considered that the intervals of the unequal intervals are made different depending on whether the ignition timing corresponds to. For example, in a four-cylinder internal combustion engine, the protrusion interval may be set to two equal intervals depending on which of the ignition timings in the first and second cylinder groups corresponds.
It is conceivable that it is doubled or tripled.

[0004]

However, in this type of device, as the number of cylinders increases, the relative difference between the cylinder groups in the non-equidistant portions becomes smaller, which causes a change in the engine speed due to acceleration / deceleration. Sometimes, it became difficult to identify the cylinder group.

Therefore, for example, Japanese Patent Laid-Open No. 3-172558.
As described in the publication, a sensor that outputs a rotation signal at equal intervals according to the rotation of a cam shaft, and a rectangular pulse having a different width depending on a cylinder group when the crank shaft rotates to a crank angle corresponding to ignition timing. And a sensor that outputs
An apparatus has been proposed that determines a cylinder group based on the correspondence between the output of a rectangular pulse and the output of a rotation signal.

However, in this apparatus, since two types of sensors are used, the structure is complicated and the production cost is increased. Further, in fields other than the ignition cylinder discriminating device, a device having a simple structure and capable of accurately discriminating a large number of crank angles has not yet been developed. Therefore, the present invention has been made for the purpose of providing a crank angle determining device having a simple structure and capable of accurately determining a crank angle.

[0007]

SUMMARY OF THE INVENTION The present invention, which has been made to achieve the above-mentioned object, has a different crank angle according to the rotation of the crankshaft, as shown in FIG. In a crank angle discriminating apparatus for an internal combustion engine, comprising: pulse signal generating means for generating pulse signals at equal intervals; and crank angle discriminating means for discriminating a crank angle based on the generation intervals of the pulse signals. The generating means includes a means for generating a pulse signal having unequal intervals that are consecutive different times according to the crank angle,
The gist of the crank angle determining device for an internal combustion engine is characterized in that the crank angle determining means includes means for determining a crank angle based on the number of times of unequal intervals of the pulse signal.

[0008]

In the present invention thus constructed, the pulse generating means generates the pulse signal having the unequal intervals which are continuous different times according to the crank angle, and the crank angle discriminating means generates the pulse signal of the pulse signal. The crank angle is discriminated based on the number of times the equidistant portion is continuously formed. The number of consecutive non-equidistant portions can be counted relatively accurately regardless of changes in the engine speed. For example, it is less likely to be affected by the engine speed as compared with the case of counting the size of unequal intervals. Further, according to the present invention, it suffices to change the generation method of the pulse signal and the method of determining the crank angle, and it is not necessary to newly install a sensor or the like in the conventional device. Therefore, according to the present invention, it is possible to accurately determine the crank angle with a simple structure.

When discriminating a large number of crank angles,
It becomes necessary to make a large number of unequal intervals continuous. In such a case, a new operating state change detecting means for detecting a change in the operating state that fluctuates according to the rotation of the crankshaft is newly provided, and the operating state change detecting means has a predetermined operating state at the equal intervals of the pulse signal. It is preferable that the crank angle discriminating means discriminates another predetermined crank angle different from the crank angle when the fluctuation is detected. With such a configuration, one predetermined crank angle can be determined even at the equidistant portions of the pulse signal, so that it is possible to reduce the number of consecutive non-equidistant portions corresponding to other predetermined crank angles. .

Further, the determination of the crank angle based on such a change in the operating state is performed when the rotation speed of the internal combustion engine is a predetermined value or more, the battery voltage is a predetermined value or more, or the internal combustion engine is in the cranking state. It may be performed only when. When the rotation speed of the internal combustion engine is low or when the battery voltage is low, the fluctuation of the operating state, which varies according to the rotation of the crankshaft, becomes irregular. Therefore, by prohibiting the determination of the crank angle based on the fluctuation of the operating state in these cases, it is possible to prevent the erroneous determination of the crank angle more favorably. Further, in the cranking state in which the crankshaft is rotated by the driving force of the starter, the correspondence between the variation in the operating state and the crank angle becomes better. Therefore, it is possible to more accurately determine the crank angle by determining the crank angle based on the change in the operating state only in the cranking state.

Also in the case of such a configuration, according to the present invention, it is only necessary to change the generation method of the pulse signal and the method of discriminating the crank angle, and it is not necessary to newly install a sensor or the like in the conventional device.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram schematically showing the configuration of the embodiment. The crank angle determination device for an internal combustion engine according to the present embodiment is installed in a 6-cylinder internal combustion engine having unillustrated first to sixth cylinders (hereinafter, referred to as cylinders 1 to 6).
The ignition timing of No. 6 is determined based on the crank angle of the internal combustion engine. Further, in the internal combustion engine of this embodiment, the cylinder 1
And 6, cylinders 2 and 5, and cylinders 3 and 4 form a so-called cylinder group in which their respective pistons slide in the same phase. For example, when one cylinder of the cylinder group is in the explosion stroke, the other cylinder Is in the intake stroke.

A crankshaft sensor 21 shown in FIG. 1 is mounted near the crankshaft 20 of the internal combustion engine. A crank side disc 23 that rotates integrally with the crank shaft 20 is coaxially fixed to the crank shaft 20, and the crank shaft sensor 21 has protrusions 25 formed around the crank side disc 23 at equal intervals. It is an electromagnetic pickup type detector for detecting

The protrusion 25 has a compression shaft top dead center of the cylinder 1 or 6 of the crankshaft 20 (hereinafter referred to as TDC1 and TDC6,
The same applies to the other cylinders) The protrusion 25a facing the crankshaft sensor 21 when rotated to the crank angle corresponding to
4 to 5 teeth in the rotation direction of the crankshaft 20 are missing, and the toothless portion 29a is present in this portion.
Are formed. In addition, the protrusions 2 are provided by one tooth, two teeth, four teeth, and five teeth before the protrusion 25b facing the crankshaft sensor 21 at TDC2 and TDC5.
5 is missing, and toothless portions 29b and 29c are formed in this portion. In addition, a toothless portion is not formed in the vicinity of the protrusion 25c facing the crankshaft sensor 21 at TDC3 and TDC4.

On the other hand, in the vicinity of the camshaft 30 of the internal combustion engine, as shown in FIG.
The cam shaft sensor 31 shown in is attached. Cam shaft 30
Includes a cam side disc 33 that rotates integrally with the cam shaft 30.
Are fixed coaxially, and the cam shaft sensor 31 is an electromagnetic pickup type detector that detects the protrusions 35a, 35b, 35c formed around the cam side disc 33. The projections 35a, 35b, and 35c have a cam shaft 30 that is TDC2,
It is formed at a position 30 ° ahead of the outer circumferences 33a, 33b, and 33c of the cam-side disc 33 facing the camshaft sensor 31 when rotated to positions corresponding to TDC4 and TDC6, in the rotation direction of the camshaft 30. Has been done.
In addition, the camshaft 30 has TDC1, TDC3, and TDC.
No protrusion is formed in the vicinity of the outer perimeters 33d, 33e, and 33f of the cam-side disc 33 that faces the camshaft sensor 31 when rotated to the position corresponding to 5.

Returning to FIG. 2, detection signals (hereinafter referred to as NE signal and G signal) of the projections 25 and 35 by the crankshaft sensor 21 and the camshaft sensor 31 are passed through the input buffer 110 including a waveform shaping section. It is input to the CPU 150. The CPU 150 performs calculation processing such as cylinder discrimination, reference position, and rotation speed based on the NE signal and the G signal.

In addition to the above, the CPU 150 has other operating state detection switches 41 to 41 such as a starter switch for detecting a starting state and an idle switch for detecting an idle state.
The output of 43 is input via the digital input buffer 130. In addition, an air flow meter 5 that detects the intake air amount
1. Information about the operating state of the internal combustion engine, such as the output voltage of the battery 52 and the water temperature sensor 53 that detects the cooling water temperature,
It is input to the CPU 150 via the A / D converter 140.

The CPU 150 has operating state sensors 41-41.
Optimal ignition timing and fuel injection amount are calculated based on the operating state information from 43, 51 to 53 and the above-mentioned NE signal and G signal. Then, an ignition signal is output via the output buffer 160, the igniter 200 is driven, the ignition coils 210 to 260 of a predetermined cylinder are energized, and the energization is cut off at the calculated ignition timing. The high voltage is applied to the ignition plug (not shown) of each cylinder to ignite and burn the air-fuel mixture in each cylinder.

Further, the CPU 150 has an output buffer 160.
And outputs an injection signal via the fuel injection valve 310 of each cylinder.
Fuel is injected into the intake manifold from ~ 360. Thus, in this embodiment, the CPU 150 and the output buffer 1
A control circuit for outputting a control signal is constituted by 60 and the like.

Next, the CPU 150 executes the processing shown in FIG. 5 and thereafter to control the ignition of each cylinder. First, FIG. 5 and FIG.
Are cylinders 1, 2, 5, corresponding to the toothless portions 29a to 29c.
6 is a flowchart showing a first ignition control process for determining TDC of No. 6; It should be noted that this process is executed every time the NE signal is input.

When the processing is started, first, step 100
At a, it is determined whether the G latch counter GC is 0 or not. Immediately after the start, GC = 0 is initially set, so that an affirmative decision is made and the routine goes to the subsequent step 100b. Step 1
At 00b, it is determined whether or not the G signal is input between the end of the previous processing and the start of this processing. If no G signal is input (step 10)
0b: NO), the process directly proceeds to step 101, and if there is (step 100b: YES), step 10
After setting the G latch counter GC to 6 at 0c, the process proceeds to step 101.

If GC = 6 is set in step 100c, a negative determination is made in step 100a when the next process is started, the G latch counter GC is decremented in step 100d, and the process proceeds to step 101. Therefore, when the G signal is input by the series of processes of steps 100a to 100d, it is possible to hold GC> 0 from the first NE signal input to the seventh NE signal input.

Next, when the process proceeds to step 101, FIG.
As illustrated in, the current value Tn of the time interval of the NE signal
And the value Tn-2 at the time before the previous processing is compared, and whether the ratio is larger than a predetermined value Kh (2 <Kh <3), that is,
Whether or not the crankshaft sensor 21 faces the toothless portion 29 is determined depending on whether or not Tn / Tn-2> Kh.
If they do not face each other, a negative decision is made and the routine proceeds to step 103, where it is judged whether or not the missing tooth counter KC for counting the number of consecutive missing teeth portions 29 is 1. Immediately after the start, KC is initialized to 0, so a negative determination is made and the processing is temporarily terminated.

When the crankshaft sensor 21 faces one of the tooth-missing portions 29 (step 101: YES), the process proceeds to step 105 to increment the tooth-missing counter KC, and in the following step 107, is KC = 2? Determine whether or not. When you move to step 107 for the first time, KC
Since = 1, a negative decision is made and the processing is terminated.

When the crankshaft sensor 21 faces the toothless portion 29a, an affirmative decision is made only once in step 101, and a negative decision is made in step 101 in the next process (when the next NE signal is input), and a step is made. Move to 103. Since KC = 1 at this time (step 103: YE
S), shift to step 111, and increment the NE signal counter NC initially set to 0. In the following step 113, it is determined whether NC = 3. Since NC = 1 when the process proceeds to step 113 for the first time, a negative determination is made and the process is temporarily terminated. continue,
Similarly, the processes of steps 101, 103, 111 and 113 are repeated until NC = 3 (step 113: YE
S), that is, the crankshaft sensor 21 has the protrusion 25a.
When facing (corresponding to TDC1 and TDC6), the process proceeds to step 115. In step 115, it is determined whether or not there is a G latch based on whether or not GC> 0. If yes, the determination is affirmative and step 117 is performed. If not, the determination is negative and the process proceeds to step 119. To do.

Here, as shown in FIG. 7, when the G signal is input, the G latch is continuously output from the NE signal input immediately after that to the seventh NE signal input. It is a rectangular pulse. Therefore, TDC2, TDC
4, TDC6 is arranged between the G latches.

Therefore, when there is a G latch (step 115: YES), it is judged to be TDC6 in step 117, and when there is no G latch (step 115: N).
O), it is determined in step 119 that TDC1.
Following steps 117 and 119 are steps 121 and 123.
To the NE signal counter NC and the missing tooth counter K.
After C is sequentially reset, the process ends.

Further, the crankshaft sensor 21 has a protrusion 25b.
When it is opposed to (corresponding to TDC2 and TDC5), step 105 is continuously performed twice according to the toothless portions 29c and 29b.
Move to. Then, KC = 2 and step 107
A positive determination is made in step S125, and the process proceeds to step 125. In step 125, it is judged whether or not there is a G latch depending on whether or not GC> 0, and if it is (step 125: YE
S) is TDC2 at step 127, and if there is no (step 125: NO), TDC5 at step 129.
And judge each. After steps 127 and 129, the process proceeds to step 123 described above.

By the above processing, the TDC of the cylinders 1, 2, 5, 6 (TDC1, TDC2, TDC5, TDC6) can be discriminated. Further, according to another routine not shown, TDC1, TDC2, TDC5, and TDC
When determining 6, the ignition signal IGt is turned ON, and the corresponding ignition coil (any of 210 to 260) is energized. Then, the ignition signal IGt is set to O when the next NE signal is input.
As the FF, the electric power stored in the ignition coils 210 to 260 is discharged to ignite the corresponding cylinder (see FIG. 7).

Next, FIGS. 8 and 9 are a time chart and a flow chart showing the second ignition control process for discriminating the TDC of the cylinders 3 and 4 in which the toothless portion is not formed. There is a relationship illustrated in FIG. 8 between the cranking angle from the start and the instantaneous engine speed T at each cranking angle. That is, since the internal combustion engine of this embodiment has 6 cylinders, 60 ° BTDC (60 ° before top dead center)
(CA) has the highest engine speed T in the vicinity of
The engine speed T becomes the smallest in the vicinity of. Therefore,
Change Ts of engine speed T detected every 10 ° CA
Looking at the change of (= Tn-1−Tn), Ts changes from negative to positive between 60 ° BTDC and 50 ° BTDC,
Ts changes from positive to negative between TDC and 10 ° ATDC (10 ° CA after top dead center). Further, the engine speed T and the amount of change Ts thereof show substantially the same change not only during cranking but also during operation of the internal combustion engine. Therefore, in this routine, the TDCs of the cylinders 3 and 4 in which the toothless portion is not formed are determined as follows based on the change in the sign of Ts. The engine speed T is calculated based on the NE signal interval by another routine (not shown).

The CPU 150 executes the second ignition control process of FIG. 9 every time the NE signal is input. When the processing is started, first, at step 201, it is judged whether or not the sign of Ts has changed. If it has not changed, a negative decision is made and the routine moves to step 203. In step 203, KC =
It is determined whether it is 0 or not. When the missing tooth portion 29 is not detected and KC = 0, it is determined whether the counter I is 1 or less. Since the counter I is initially set to 0, when the process proceeds to step 205 for the first time, an affirmative decision is made and the process proceeds to step 207. In step 207, it is determined whether or not I = 1, and if I ≠ 1, the processing is temporarily terminated.

Next, when Ts changes from negative to positive at 50 ° BTDC, an affirmative decision is made in step 201. In the following step 211, it is determined whether or not Ts has changed positively, and affirmative determination is made in this step as well, and steps 212, 213 and 2 are performed.
Move to 15. In steps 212, 213 and 215, it is determined whether or not the starter switch is on (STA = ON), the battery voltage B is equal to or higher than a predetermined value B0, and the engine speed T is equal to or higher than a predetermined value T0. If a negative determination is made in any of steps 212, 213 or 215, the processing is ended as it is, and steps 212, 21 are executed.
If both affirmative determinations are made at steps 3 and 215, the process proceeds to the following step 217. In step 217, the counter I is set to 4 and then the process is terminated.

Next, when the processing is executed (40 ° BTD
C), the negative judgment is again made at step 201, but I = 4
Therefore, a negative determination is made in step 205. Then,
In step 221, the counter I is decremented and the processing is temporarily terminated. Hereinafter, steps 201, 203, 20
The counter I is decremented each time the NE signal is input (every 10 ° CA in the vicinity of TDC3 and TDC4) while repeating the processings of 5 and 221.

When I = 1, (10 ° BTD
C) An affirmative decision is made in steps 205 and 207, and the routine moves to step 223. In step 223, the ignition signal IG
After t is turned on and the counter I is reset in the following step 225, the process is temporarily terminated. If the missing tooth portion 29 is detected while the counter I is being decremented, KC
When ≠ 0, the process directly proceeds from step 203 to step 225 to reset the counter I. That is, TDC
Ignition signal I for 1, TDC2, TDC5, TDC6
Since Gt is controlled by the above-mentioned first ignition control processing, the control of the ignition signal IGt by this routine is prohibited.

When Ts changes negatively at 10 ° ATDC (step 201: YES, step 211: N)
O) Go to step 229, turn off ignition signal IGt
After that, the process ends. Then, according to another routine (not shown), the cylinder 4 is ignited when the G latch is present, and the cylinder 3 is ignited when the G latch is not present.

In this routine, B <B0 or T
When <T0 (step 213: NO, or step 215: NO), the counter I is not set. For this reason,
Next, when the process proceeds to step 207, a negative determination is made and the cylinders 3 and 4 are not ignited, but this is due to the following reason. That is, as illustrated by ◯ in FIG. 10, when the battery voltage B is low, the waveform of the engine speed T and its variation Ts tends to advance with respect to the normal waveform illustrated by ●. Therefore, the accurate ignition timing cannot be determined by the second ignition control process, and the ignition of the corresponding cylinder is stopped. Also, the engine speed T
Similarly, when the value is low, the accurate determination cannot be performed, so the ignition to the corresponding cylinder is stopped.

As described above, in the crank angle discriminating apparatus of the present embodiment, the ignition timings of the cylinders 1, 2, 5, 6 are discriminated by the number of consecutive toothless portions 29. Therefore, it is possible to perform accurate determination regardless of changes in the engine speed and the like, compared to a conventional device that determines based on the length of the toothless portion. Further, the present embodiment can be implemented by changing the configurations of the crank side disk 23 and the program in the electronic control circuit with respect to the conventional device. Therefore, in this embodiment, it is possible to accurately determine the ignition cylinder with a simple configuration.

Further, in the present embodiment, the ignition timings of the cylinders 3 and 4 are determined based on the change in the engine speed T. Therefore, the cylinders can be discriminated even in the equally spaced portions of the protrusions 25, and the ignition timings of a large number of cylinders 1 to 6 can be discriminated by providing three toothless portions 29. Therefore, the toothless portion 2
9 can be lengthened to more accurately determine the ignition cylinder.

In the above embodiment, the crank side disk 23 and the crankshaft sensor 21 correspond to pulse signal generating means, and the CPU 150 corresponds to crank angle determining means. Further, the process of calculating the amount of change Ts of the engine speed T is performed by the operating state fluctuation detecting means, the process of calculating the engine speed T is performed by the speed detecting means, and the battery voltage B is calculated.
The process of reading in corresponds to the battery voltage detecting means.

In the above embodiment, the T of each of the cylinders 1 to 6 is T.
Although the DC and thus the ignition timing are determined, the present invention can be applied to various other devices for determining the crank angle. It can also be applied to internal combustion engines having various numbers of cylinders such as 8 cylinders and 10 cylinders. Further, in the above embodiment, the toothless portions 29a to 29c are provided on the crank side disk 23, but instead of providing the toothless portions 29a to 29c, the projection 2
The intervals of 5 may be close. Furthermore, the NE signal may be generated by a magnetized drum and a Hall element.

In the second ignition control process of the above embodiment, the crank angle (T
Although DC3 and TDC4) are discriminated, the crank angle can be discriminated based on various operating states.
For example, as illustrated in FIG. 11, the battery voltage B also changes according to the crank angle. Therefore, the crank angle may be determined based on the fluctuation of the battery voltage B. Also in this case, as illustrated by ◯ in FIG. 11, when the battery voltage B is low, the fluctuation waveform thereof advances as compared with the waveform at the normal time. Therefore, it is desirable to prohibit the discrimination when B <B0.

Further, the engine speed T and the battery voltage B
Fluctuations correspond better to the crank angle during cranking of the internal combustion engine. Therefore, in the above embodiment, the crank angle is determined based on the variation of the engine speed T only when the starter switch is turned on and cranking is being performed. Therefore, the crank angle can be determined more accurately,
The process of step 212 in FIG. 9 may be omitted. Furthermore,
In the above embodiment, the ignition control is prohibited when B <B0 or T <T0. However, as shown in FIG.
(Compatible with TDC2 and TDC5) and protrusion 25c (TDC
3 and TDC4) are separated by 12 protrusions 25. Therefore, in the first ignition control process, TDC2 or TD
After determining C5, 12 NE signals may be counted, and the ignition control may be performed by determining TDC4 or TDC3 at that time.

Further, in the above embodiment, the crank-side disc 2
Although the number of sensors is reduced by forming the toothless portions 29a to 29c in No. 3, another sensor structure, for example, two crankshaft sensors are provided as described in Japanese Patent Laid-Open No. 62-87649. The second ignition control process may be performed on the object. Also in this case, it is possible to determine the cylinders of other cylinders without changing the sensor structure.

[0044]

As described above in detail, in the crank angle discriminating apparatus for the internal combustion engine of the present invention, the crank angle discriminating means discriminates the crank angle on the basis of the number of consecutive non-equidistant portions. It is possible to accurately determine the crank angle regardless of changes in the number. Further, the present invention can be implemented only by changing the generation method of the pulse signal and the method of determining the crank angle. Therefore, according to the present invention, the crank angle can be accurately determined with a simple configuration.

Further, a new operating state change detecting means for detecting a change in the operating state which fluctuates according to the rotation of the crankshaft is newly provided, and the operating state change detecting means has a predetermined operating state at the equal intervals of the pulse signal. When detecting the fluctuation, the crank angle discriminating means may discriminate another predetermined crank angle different from the crank angle. In this case, the following new effect can be obtained. With this configuration, one predetermined crank angle can be determined even in the equidistant portion of the pulse signal, so that the number of consecutive non-equidistant portions can be reduced and a large number of crank angles can be discriminated well. Becomes

Further, the determination of the crank angle based on such a change in the operating state is performed when the rotation speed of the internal combustion engine is a predetermined value or more, the battery voltage is a predetermined value or more, or the internal combustion engine is in the cranking state. If you do it only when
It is possible to more accurately determine the crank angle. Also in the case of such a configuration, the present invention can be implemented by only changing the generation method of the pulse signal and the crank angle determination method.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a configuration around a crankshaft sensor according to an embodiment.

FIG. 2 is a block diagram schematically showing a configuration of an example.

FIG. 3 is an explanatory diagram illustrating a configuration around a cam shaft sensor according to an embodiment.

FIG. 4 is a time chart showing the behavior of the crankshaft sensor detection signal of the embodiment.

FIG. 5 is a flowchart showing a first ignition control process of the embodiment.

FIG. 6 is a flowchart showing a first ignition control process of the embodiment.

FIG. 7 is a time chart showing the operation of a G latch in the electronic control circuit of the embodiment.

FIG. 8 is a time chart showing a second ignition control process of the embodiment.

FIG. 9 is a flowchart showing a second ignition control process of the embodiment.

FIG. 10 is a time chart showing a difference in engine speed variation due to a battery voltage.

FIG. 11 is a time chart showing a change in battery voltage according to a crank angle.

FIG. 12 is a diagram illustrating the configuration of the present invention.

[Explanation of symbols]

1, 2, 3, 4, 5, 6 ... Cylinder 10 ... Internal combustion engine
21 ... Crankshaft sensor 23 ... Crank side disk 25 ... Protrusion 29a,
29b, 29c ... missing tooth portion 31 ... cam shaft sensor 33 ... cam side disk 35
a, 35b, 35c ... Protrusion 52 ... Battery 150 ... CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02P 5/15 7/067 302 C 17/00 G01M 15/00 Z

Claims (5)

[Claims] 1. A pulse signal generating means for generating pulse signals at different intervals at a predetermined crank angle and at equal intervals at other crank angles according to the rotation of a crankshaft, and based on the generation intervals of the pulse signals. In a crank angle discriminating device for an internal combustion engine, which comprises a crank angle discriminating means for discriminating a crank angle, the pulse signal generating means generates a pulse signal having unequal intervals consecutively different times according to the crank angle. A crank angle discriminating apparatus for an internal combustion engine, comprising: a means for discriminating a crank angle based on the number of consecutive unequal intervals of the pulse signal. 2. A driving state fluctuation detecting means for detecting fluctuations in the driving status which fluctuates according to the rotation of the crankshaft, wherein the driving status fluctuation detecting means detects a predetermined driving condition at equal intervals of the pulse signal. The crank angle discriminating means for an internal combustion engine according to claim 1, wherein the crank angle discriminating means includes means for discriminating another predetermined crank angle different from the predetermined crank angle when a variation is detected. apparatus. 3. A crank based on the fluctuation of the operating condition, which is provided with a rotation speed detecting means for detecting the rotation speed of the internal combustion engine, and wherein the crank angle determining means is based on the fluctuation of the operating state only when the detected rotation speed is a predetermined value or more. The crank angle discriminating apparatus for an internal combustion engine according to claim 2, further comprising means for discriminating an angle. 4. A crankshaft based on a variation of the operating state, comprising battery voltage detection means for detecting a battery voltage of the internal combustion engine, wherein the crank angle discrimination means is based on the fluctuation of the operating state only when the detected battery voltage is a predetermined value or more. The crank angle discriminating apparatus for an internal combustion engine according to claim 2, further comprising means for discriminating an angle. 5. A cranking angle detection means for detecting a cranking state of the internal combustion engine, wherein the crank angle determination means determines a crank angle based on a change in the operating state only when the cranking state is detected. The crank angle discriminating apparatus for an internal combustion engine according to claim 2, further comprising: