JPH01257766A - Device for controlling ignition timing of internal combustion engine - Google Patents

Abstract

PURPOSE:To minimize the delay in response by obtaining the present ignition timing from an engine speed calculated in an interval one period before and correcting same by the engine speed in the interval immediately before the present ignition timing. CONSTITUTION:The edge of a signal from a crank reference position detector 3 and a shaping circuit 4 is detected by an ingot edge detector 10, an interrup tion signal is sent to a CPU 7 while sending a latch signal to a latch circuit 11 to latch the value of the timer (free running counter) 12 at that time. From these signals, the CPU 7 measures the period between crank reference position signals P, etc., and obtains the optimum ignition position, etc., from the required time in this interval and by adding the input time of the signal P thereto, houses same into a latch circuit 13. Further, by correcting the optimum ignition posi tion, etc. by the value of the timer 12 from the signal P to the ignition timing, i.e., the engine speed immediately before the ignition timing and at the point of time when the values of the timer 12 and latch circuit 13 agreed, an ignition signal is outputted from a comparator 14. Thereby, the delay of response can be restricted to the minimum, always obtaining accurate ignition timing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ignition timing control device for internal combustion engines such as gasoline engines, and in particular, a relatively small and high-output device with excellent responsiveness to rotational speed control. The present invention relates to an ignition time control device suitable for high speed gasoline engines.

[Prior Art] In order to control the ignition timing of an internal combustion engine such as a gasoline engine, it is necessary to detect the rotational speed of the engine and calculate the ignition advance amount based on the detected rotational speed.

Incidentally, engines for motorcycles and other vehicles are often of the high-output, high-speed rotation type and have excellent speed control response, and as a result, in most cases, the driving characteristics are relatively high in rotational pulsation. Become.

Therefore, conventionally, for such ignition timing control of a gasoline engine, for example, Japanese Patent Application Laid-open No. 62-4,409 has been proposed.
As disclosed in Publication No. 5, the rotational position of the engine crankshaft is divided into a plurality of sections, and in order to detect the rotational speed for ignition timing control, the ignition timing of the above-mentioned plurality of sections is divided. A method was adopted in which the engine rotational speed calculated based only on the rotational angular velocity of the crankshaft in the included section was used, thereby avoiding the influence of the rotational pulsation described above.

[Problems to be Solved by the Invention] The above-mentioned conventional technology has a problem with the responsiveness of ignition timing control because it does not take into account when the engine is subjected to sudden acceleration/deceleration control.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ignition timing control device for an internal combustion engine that has excellent transient response in ignition timing control and can always perform ignition timing control with high accuracy.

[Means for Solving the U Problem] The above purpose is to calculate the engine rotational speed based on the rotational angular velocity of the crankshaft in an adjacent section before this section, in addition to the section including the ignition timing, and calculate the engine rotational speed in the same section. This problem is solved by calculating the rotational speed fluctuation by comparing it with the engine rotational speed calculated one cycle before, and correcting the ignition timing based on the calculation result.

[Operations] In the conventional example, the current ignition timing is determined by the engine rotation speed calculated in the section one cycle before, resulting in a delay in response; however, in the present invention, the current ignition timing is determined immediately before the current ignition timing. Since it is corrected based on the engine rotational speed in the section, response delay is minimized and sufficient transient response can be provided.

[Embodiment 1] Hereinafter, the ignition timing control device for an internal combustion engine according to the present invention will be explained in detail with reference to an embodiment shown in the drawings.

FIG. 2 shows an embodiment of the present invention, in which the present invention is applied to a 4-stroke, 4-cylinder, two-cylinder simultaneous ignition gasoline engine for motorcycles. , ] indicates a batch, which is connected to the power supply circuit 2 that supplies power to each block.

=3- 3 is a crank reference position detector, which is composed of a magnetic rotating body 3o that rotates in synchronization with the crankshaft of the engine and a magnetic pink-up sensor 31. The magnetic rotating body 30 has eight protrusions arranged at an angle of 45 degrees, one of which
One is made with a wider protrusion than the other, and is used to detect the reference point that determines the period of the crankshaft. When these protrusions pass near the sensor 31, positive and negative pulses are generated from the sensor 31 at both ends of the protrusions, and when these pulses pass through the shaping circuit 4, the pulses shown in FIG. The crank reference position signal P is used to divide the rotational angular position into eight sections A to H, with one rotation of the crankshaft being one cycle.

10 is an input edge detector that detects the rising and falling edges of the signal output from the shaping circuit 4, and
8 interrupt signals and 1 latching signal on the first latch circuit. When this latch circuit 11 receives a latch signal, it latches the value of the timer 12 at that time and continues to hold it until the next latch signal is input. In other words, shaping circuit 4
The values of the timer 12 at the rising and falling edges of the crank reference position signal outputted from the crank reference position signal are held until the next rising and falling edges of the crank reference position signal arrive.

Note that the timer 12 is a free running counter that constantly counts at a constant cycle.

The CPU 7 receives these signals, measures the period between the crank reference position signals, etc. using a program stored in advance in the ROM 5, and stores each measured period in the RAM 6.

As shown in FIG. 1, the crank reference position signal P is
This is the output from the shaping circuit 4 shown in the figure. In addition,
The numbers attached to the waveforms are for the purpose of making it easier to understand the operation using this reference position signal P.

By the way, as described above, such an internal combustion engine has rotational pulsation, and therefore, the variation in the rotation speed during one revolution of the crankshaft is as shown in the crank rotation variation amount in the figure. That is, in section 8-1 (referred to as A) and section 1-2 (B), an increase in rotational speed due to an explosion in one of the cylinders is observed, and on the contrary, in section 2-3 (C)
, section 3-4. In (D), a decrease in rotational speed due to compression can be seen. A similar situation is seen in the next section 4-8 (designated E, F, G, and H, respectively).

The CPU 7 determines the optimum ignition position, the time to the optimum energization start position, and TADV based on the time required in these sections.
, (TADV-ONMAP) are calculated, and the time when the crank reference position signal P is input is added and stored in the latch circuit 13. Thereafter, when the count values of the timer 12 and the latch circuit 13 match, the comparator 14 generates an interrupt signal to the CPU 7 and a clock signal to the D flip-flop 20.

Further, the CPU 7 determines whether to perform energization start processing or ignition processing based on the interrupt signal, and sets data D that becomes an ignition signal to the D flip-flop 2o.
In the case of ignition processing, output processing of distribution signals a and b is also performed.

Q output of D flip-flop 20 and distribution signals a, b
are input to AND gates 30 and 31, where they are distributed as ignition signals a and b. The output ignition signal is sent to the switching element 40.41, and the ignition coil 50.5
Controls energization and shutoff of 1. This causes a spark to fly to the spark plug.

Next, a method for calculating TADV will be explained.

In Fig. 1, if the advance angle is zero, the sparks will fly at the rising points of 8 and 4 of the reference position signal P, but in reality the angle is almost advanced, so in that case, 8, 4 The spark must be emitted before the spark moves to the left in Figure 1. Therefore, the ignition signal shown in the figure shows a state in which the ignition angle is advanced to some extent.

In FIG. 1, the intervals that include the ignition timing are the interval H and the width of the previous interval or H under the same conditions, that is, the width of the reference position signal P of 8. Search for the time T between 1 or between 3 and 4,
Based on this time T, the rotation speed N within the section is calculated using equation (1).

Next, the optimum ignition timing at this rotational speed N is searched from the ROM 5.

In this way, the retrieved ignition timing data is converted into a section or a ratio of H to the time width T using equation (2).

In the above formula, the ignition timing is based on the crank reference position signal 8 or 4.
This indicates that the position is T1 in front of (on the left side in FIG. 1). Therefore, when converted to the time from 7 or 4 of the crank reference position signal P, it becomes as shown in equation (3).

T2=T-Tl (
3) Now that we have found the time T2 required from crank reference position signal P 7 or 4 to ignition timing, we need to convert this time T2 to crank reference position signal P 7 or 4.
In addition to the value of the timer 12 when the signal appears, that is, the value of the latch circuit 11 at the time of a rising signal, the latch circuit 13 needs to be set.

By doing this, even when there is a lot of rotational pulsation,
It is possible to output the energization start timing and ignition time more accurately than when the rotational speed is sampled every crank rotation or randomly.

However, as it is, the ignition timing and energization timing are calculated using data before the crank rotates 180 degrees (or an integer multiple of this), as in the conventional example described above. For setting errors, shortening the energization time, or sudden deceleration.

Problems such as over-advanced ignition may occur.

In particular, overadvanced angle may lead to the destruction of the engine.

Therefore, correction control at the time of sudden acceleration/deceleration is essential, but in this embodiment, this is done by calculating the amount of change in the time width of the interval C or G one position before the ignition timing output interval or H, and using the formula ( 3
), which improves responsiveness.

Now, if the first ignition timing setting interval is D or H, the amount of change T3 is: T3 - (Current C or G time @t□) - (Previous C
or time width tz of G)...(4), and adding equation (4) to equation (3) yields TADV= (T-TI)
+73...(5). formula(
Rewriting 5) results in .

Therefore, the latch circuit (2) 13 should be calculated by adding the acceleration/deceleration correction amount T3 to the required time T2 from the crank reference position signal to the ignition timing.

However, what should be noted here is that if the engine has variations in pulsation depending on the number of engine cylinders or engine displacement, care must be taken when sampling section data used for acceleration/deceleration correction. This is because, no matter how many sections under the same conditions are sampled, there is a risk that the optimum acceleration/deceleration correction cannot be made due to engine performance, etc. For this reason, it is important to secure the optimum amount of correction by changing the sampling location from the data under the same conditions one cycle ago or the data under the same conditions two cycles ago.

FIG. 3 shows the fluctuations in the crank rotation speed, and shows the difference between the fluctuations during constant speed rotation and during acceleration, and is shown using the crank reference position signal as a reference.

From FIG. 3, it can be seen that during acceleration, if the ignition timing is output within section D' based on the cycle of section H', the ignition position in section D' will be delayed due to the rotational difference. is obvious. According to this embodiment, this delay is corrected.

Next, using FIG. 4, the operation of this embodiment using a microcomputer will be explained.

The routine 100 shown in FIG. 4(a) is an interrupt processing routine that is activated by an interrupt signal output from the input edge detector 10 every time the crank reference position signal P appears. In step '-05, it is determined whether this interrupt occurs at the rising edge or the falling edge of the reference position signal.

If it is a falling edge, the top dead center is detected in step 110, and the interrupt processing is terminated. If it is a rising edge, step 115 and subsequent steps are executed.

In step 115, the period between the crank reference position signals is measured and stored in the RAM 6. In step 125,
Calculate TADV. Here, it is determined in which section the ignition timing is located, and data used for calculation (period, acceleration correction amount, etc.) is called out from the RAM 6 and calculations are performed.

In step 130, it is determined whether ignition timing processing or energization start timing processing should be performed, and processing is assigned.

Step 135 is a routine that sets the energization start timing process. In this setting, by subtracting ONMAP from TADV calculated in step 125, the time until energization starts can be obtained, and the reference position signal is added to this. The time obtained by adding the time of entry (SVFRC) is the energization start time.

TONSET=TAVD-ONMAP+5VFRC==
=(7) Therefore, this step 135 calculates equation (7), and the next step 145 stores the data in the latch circuit 13, and ends the process.

Next is step 140, which is the process of setting the ignition timing.
However, this is also a process of finding the ignition timing using equation (8).

TIGSET=TADV+5VFRC---(8)C
PU7 calculates equations (7) and (8) and performs step 14.
5, the latch circuit 13 is turned on, but at the same time, D=1 is output to the D input of the D flip-flop 2o when the energization is set, and when the ignition timing is set, D==
It is designed to output O.

Next, a routine 200 shown in FIG. 4(b) is an output comparison interrupt routine operated by an interrupt signal output from the comparator 14 when the latch circuit 13 and the timer 12 match. Therefore, this routine is an interrupt routine that runs at each energization start timing and at each ignition timing.

First, in step 205, it is determined whether this interrupt is the energization start timing or the ignition timing timing. If it is the energization start timing, output processing for setting the ignition timing is performed. This is because if the energization start time and the ignition timing time are present at the same time between the reference position signals, only one of the times can be set from the reference position signal. In this case, the energization start is set in step 100, and the ignition timing is set as follows.
It is designed to be set at the interrupt of this energization start timing. This process is performed in step 220.

Step 210 is a routine that is executed at the ignition timing, and performs output processing of distribution signals a and b to be sent to AND gates 30 and 31. Furthermore, ignition cutting and thinning for the purpose of preventing over-speed is also performed here by controlling the distribution signals a and b.

In step 215, the next energization timing is set at the ignition timing. This will act as a fail-safe in case the crank reference position signal fails to set the energization start.

Step 225 is a processing routine that is executed when these output proportional interrupts are completed, and performs linking processing between the side programs.

Next, the routine 300 shown in FIG. 4(c) will be explained. This routine is executed by an interrupt generated each time the timer 12 overflows. First, in step 310, the number of overflows is counted, and in step 3
At 20, engine stoppage detection, time measurement, etc. are performed.

The final step is a routine 400 shown in FIG.
In step 10, search for ignition timing and energization time, and proceed to step 4.
20 performs A/D conversion of the analog signal from the sensor. Step 430 performs processing such as setting and resetting various flags indicating the state of the engine, and determining digital input signals.

By performing acceleration/deceleration correction in this manner, it is possible to perform ignition timing control with good transient response that can sufficiently respond to sudden changes in engine speed.

In this embodiment, a case has been described in which the present invention is applied to a simultaneous ignition type four-cylinder gasoline engine for a two-wheeled vehicle, but it goes without saying that the present invention is not limited to this and can be applied.

Furthermore, in the above embodiment, the number of divisions of the rotational angular position of the crankshaft, that is, the number of sections, is 8, and as a result, a crank reference position signal is generated every 45 degrees of crank angle. It goes without saying that the number of sections is not limited to the above eight, and may be arbitrarily set depending on the required accuracy, calculation time interval, etc.

By the way, in the above embodiment, the ignition signal thinning control is easy, and as a result, the ignition cut control can be appropriately performed to prevent engine overspeed and vehicle overspeed. Therefore, this point will be explained below. I will explain about it.

Regarding such ignition cut control, for example, as proposed in the invention related to application No. 60-79245, conventionally, when the engine rotation speed exceeds a predetermined value, all ignition The cylinder's ignition was cut off.

Therefore, in the conventional method, when looking at each cylinder separately,
The ignition will be completely cut off in the cylinder where the misfire occurs, causing shock to the vehicle and frequent afterfires caused by the exhaust from the misfiring cylinder.

Therefore, in the following embodiments, while applying such ignition cut control, it is possible to sufficiently soften the shock during over-speed limiting operation and vehicle speed limiting operation, and to sufficiently suppress the adverse effects on the engine. For this purpose, rectangular wave signals with various cycles are created based on the ignition timing, and by combining them and performing an AND with the ignition signal, the ignition signal is generated according to a predetermined combination pattern. In this method, thinning is performed and this combination pattern is changed.

Therefore, according to the following embodiments, the misfire rate of the engine due to ignition cut is not fixed but is changed, so that shock is reduced and adverse effects on the engine are suppressed.

FIG. 5 shows another embodiment of the present invention, in which the above-mentioned ignition cut control is added, and a system in which an independent ignition coil 50, 51 is provided for each cylinder for a 4-stroke, 2-cylinder engine. The target is In the embodiment shown in Fig. 5, parts that are equivalent to those in the embodiment shown in Fig. 2 are given the same numbers, but since there are some functional differences, there are few differences. I will omit the explanation of the missing parts, but will repeat the explanation of the other parts.

In the embodiment of FIG. 5, 60 is a digital signal source;
Indicates the driving status of a vehicle (car, motorcycle, etc.)
For example, it includes various signal sources such as forward motion, reverse motion detection signals, and gear position signals, and the signals from these signal sources are Di.
(Digital input interface) 7 to be input to the CPU 7.

Reference numeral 3 denotes a crank reference position detector, which is composed of a magnetic rotating body 30 that rotates in synchronization with the crankshaft of the engine and a magnetic pickup sensor 31.

The magnetic rotating body 30 is provided with four protrusions spaced apart by a crank angle of 90°, one of which is wider than the other protrusions. When these protrusions pass near the magnetic pickup sensor 3]-, positive and negative pulses are generated from the sensor 31 at both ends of the protrusions. This pulse is waveform-shaped by the shaping circuit 4, and becomes a pulsed crank reference position signal L) as shown in FIG.

A vehicle speed sensor 62 is attached to the speedometer cable and generates a signal at a period proportional to the vehicle speed. 63 is a waveform shaping circuit that shapes this signal.

12 is a timer that constantly performs a counting operation at a constant period. 10 is an edge detector which detects the rising and falling edges of the signal P and sends an interrupt signal to the CPU 7;
Sends a latch signal to latch circuit 1. This latch circuit 1
" holds the value of the timer 12 when the signal from the edge detector 10 is input. That is, the values of the timer 12 at the rising and falling edges of the signal P from the crank angle detector 3 are held until the next rising and falling edges of the signal from the detector 3 arrive.

The CPU 7 receives these input signals, takes in the rotational speed, running speed, etc. according to a program stored in the ROM 5 in advance, and performs calculations.

The rotation speed N at this time can be calculated using the following equation (9) by measuring the passing time of each 90° section in the reference position signal P shown in (A) of Fig. 6. can.

Rotation speed N=T [rpm] ・ ・
(9) T2 passing time (cycle) [seconds] From the calculation result, ignition advance angle data (ADV”) according to the rotation speed N at that time, energization time (ONMAP) hair ROM5
Search from.

Next, the elapsed time from the reference position signal P to the ignition position (ADV) is calculated and sent to the latch circuit 13 (
TADV).

TADV is determined from the following formula (10).

During this time, the timer 12 continues counting.

Also, the comparator 14 is always connected to the timer 12 and the latch circuit 13.
When the two match, a tarok is output to the D flip-flop 20 and an interrupt request signal is also generated to the CPU 7. And this interrupt signal is CP
Inside U7, it is determined whether it is an energization start timing interrupt or an ignition timing interrupt, and if it is the ignition timing, output processing of the distribution signals a and b is performed, and if it is the energization start timing, output processing for the next ignition is performed.

On the other hand, the D flip-flop 20 uses the clock output from the comparator 14 to send the signal output from the CPU 7 to the AND gate 30.3:I-.

D flip-flop 20 for AND games 1 to 30 and 31
Even if it receives the output from the D flip-flop 20 (ignition signal Q) and the distribution signal from the CPU 14, the ignition signal from the D flip-flop 20 is output only when the distribution signal is at a high level. The two systems of distribution signals a and b are used to distribute signals to the first cylinder and the second cylinder.

The outputs of the AND gates 30 and 31 are ignition signals for the first and second cylinders, respectively, and are supplied to switching elements 40 and 41 that control the energization of the ignition coils 50 and 51.

FIG. 6 shows the basic waveforms of the signals of each part of the circuit shown in FIG.

Regarding the horizontal axis of the reference position signal P shown in FIG. It shows the crank angle. The signal from the crank position detector 3 is
The signal is input as the reference position signal P to the CPU 7 through the shaping circuit 4.

The ignition signal Q shown in (B) is an output waveform of various calculation results, and is a signal output from the D flip-flop 20.

Distribution signal 1 shown in (C) and distribution signal 2 shown in (D)
are the distribution signals a and b output from the CPU 7.

The first cylinder ignition signal shown in (E) and the second cylinder ignition signal shown in (F) are signals obtained by ANDing the ignition signal Q input to the AND gate 30.31, distribution signal 1, and distribution signal 2. Each is output to switching element 40.41 to control energization of ignition coil 50.51.

Next, changes in the ignition cut (thinning) according to this embodiment will be explained.

In FIG. 7, the ignition signal Q is the same signal as the ignition signal shown in FIG. 6(B). D flip flop 20
The timing at which the ignition coil 50 outputs data “1” is
．． The timing coincides with the timing of energizing the ignition coil 51 (energization start), and on the contrary, the timing of outputting data "0" coincides with the timing of energizing the ignition coil 50.

51 (ignition).

First, when the data of the timer 12 and the latch circuit 13 match, the comparator 14 outputs a signal to the D flip-flop 20,
It has been explained that an interrupt signal is generated to the CPU 7, but this interrupt signal causes the CPU 7 to generate an ignition timing interrupt at the time of ignition.

The above interrupt causes the CPU 7 to create waveforms T1 to T4 shown in FIG. The method will be explained with reference to FIG. Step 800 inverts the waveform regardless of what state the waveform T1 is in. As a result, T1 is inverted every time an ignition timing interrupt occurs, so that a waveform of T1 as shown in FIG. 7 is created. In step 801, the state of the waveform of T1 is checked and “O
If it is I+, in step 802, the waveform T2 is inverted as in step 800.

On the other hand, if the waveform T1 is "1", step 8 is performed without inversion.
Move to 03. Thereafter, waveforms from T1 to T4 are created in the same manner.

Next, waveforms Q1 to Q5 in FIG. 7 will be explained. This is an ignition signal created based on the waveforms of T1 to T4.

First, here, as seen in waveform Q3, there are two misfires,
5o% of ignition twice, ignition twice, and repeated misfires.
The misfire rate is set at . This is because in the case of one embodiment, the system ignites twice per crank rotation, so in the case of a four-cycle engine, one of the two ignitions will be wasted.

Therefore, when written as a percentage of misfire rate, Q 1 =87', 5
%.

Q2=75%, Q3=50%, Q4=25%, Q5=1
2. Becomes Nishiki.

Next, a method of outputting waveforms Q1 to Q5 will be explained using FIGS. 7 and 9.

In the ignition timing interruption, first, waveforms T1 to T4 are created, and then in step 900 it is determined what percentage of ignition thinning is currently required.

This is predetermined based on the vehicle speed and the elapsed time of the vehicle speed limit, and changes over time.

In this example, they are 12.5%, 25%, and 50%.

You can choose from 5 different ignition reductions: 75% and 87.5%.

5TAGE in step 900 is a flag for selecting the above-mentioned five ways. In this embodiment, step 90
5TAGE of step 1 indicates ignition thinning of 87.5%, 5TAGE2 of step 902 is 75%, 5TAGE3 of step 903 is 50%, step 5TAGE is 25%,
5TAGE in step 905 is 12.5%, which determines the ignition thinning ratio.

First, 5TAGEI will be explained. In step 910, T2. T3. Check the state of the T4 waveform.

If any one of them is ``rrH'', ignition cut processing is performed; if not, the process ends without doing anything. As a result, the Ql waveform is output.

For 5TAGE2, T2°T3 is set in step 920.
The state of the waveform is inserted, and if any one of them is nJ (n, then the ignition cut processing is performed, and if not, no processing is performed, so the waveform of Q2 is output.

Regarding 5TAGE3, the state of T2 is checked in step 930, and if LL H++, ignition cut processing 960 is performed, and if IIL", no processing is performed. Therefore, the waveform of Q3 is output.

For 5TAGE4, T2°T3 is set in step 940.
Check the waveform state of and if both are H''', perform ignition cut processing 9.
60, and if it is different, do not process.

Therefore, the waveform of Q4 is output.

For 5TAGE5, in step 950, 2°T3
．． Looking at the waveform states of T4, if both are 11H++, ignition cut processing 960 is performed, and if they are different, no processing is performed. Therefore, the waveform of Q5 is output.

Next, the ignition cut processing in step 960 will be explained. In step 960, both distribution signals a and b are set to L.
``'' processing is performed.

As a result, the distribution signals a and b input to the AND gate 30.31 in FIG.
Continuing the state is one thing. As a result, the ignition coil 50
．． 51 is not energized and is not ignited.

Finally, the method of changing the ignition cut in this embodiment will be explained.

In FIG. 5, the CPU 7 calculates the vehicle speed based on the signal from the vehicle speed sensor 62. The calculated vehicle speed is stored in ROM5
If the vehicle speed exceeds the vehicle speed limit start speed, the CPU 7 outputs a request to start the 5TAGE4.

This controls the output of the distribution signals a and b, and at this time, an ignition signal is produced with a misfire rate of 25%. In addition, the CPU 7 issues a request to start up the 5TAGE 4, and at the same time measures the time since the misfire started.
After a certain period of time (for example, 1 second), 5TAGE3
Outputs the startup request.

Therefore, this time an ignition signal is generated with a misfire rate of 50%. Further, the CPU 7 activates the 5TAGE2 after a certain period of time has elapsed after setting the three 5TAGEs on the upper cylinder, and outputs an ignition signal with a misfire rate of 75%.

Next, a method for outputting a misfire rate of 25% will be explained using FIG. In this FIG. 10, the ignition signal and waveform T1
~T4 is the same as that in FIG.

The misfire rate of 25% corresponds to 5TAGE4 in Figure 9, and in step 94.0 "T2 and T3:1 l
If YES in l, ignition cut processing is to be performed. This corresponds to the shaded portions of waveforms T2 and T3 in FIG.

By starting 5TAGE4, CPU7 inputs both the outputs of distribution signals a and b, which had been distributed regularly until now.
Set it to L++. Accordingly, even if the output of AND gate 30.31 receives the signal from D flip-flop 20, it outputs II L ++ toward switching element 40.41. For this reason, the first and second cylinder ignition signals shown in FIG. 10 disappear, resulting in such an empty state.

This series of operations is performed from the comparator 14 to the CPU 7.
The ignition timing interrupt processing in the interrupt request signal output to the ignition timing interrupt processing is performed in order.

In the case of this embodiment, based on the signal from the digital input signal section 60, the ignition is cut in different modes during forward travel and reverse travel to control the vehicle speed. For example, when moving forward...misfire rate 25% → 50% → 75% → 87.5%
When going in reverse...misfire rate goes from 12.5% to 25% to 50%.

Incidentally, in the above embodiment, only the restriction of vehicle speed has been described, but the present invention can be similarly applied to prevention of engine overspeed. In addition, in the embodiment, the waveforms T1 to T4 are created using software using a microcomputer, synthesized, and processed, but of course they can also be created using hardware using flip-flops, etc. Synthesis is also possible.

Additionally, hysteresis may be provided for each process, and the cylinders to be thinned out may be divided into all cylinders and one cylinder.

It is also possible to use only any cylinder.

[Effects of the Invention] According to the present invention, it is possible to always provide accurate ignition timing without being affected by rotational pulsation of the engine, and also without being affected by rotational changes during acceleration/deceleration, and the transient response is reduced. It is possible to reliably obtain excellent ignition control.

[Brief explanation of the drawing]

FIG. 1 is a waveform diagram explaining the operation of one embodiment of the ignition control device for an internal combustion engine according to the present invention, FIG. 2 is a block diagram of the same embodiment, FIG. 3 is a waveform diagram explaining the operation, and FIG. 5 is a block diagram showing another embodiment of the present invention, FIGS. 6 and 7 are waveform diagrams for explaining the operation, and FIGS. 8 and 9 are flowcharts for explaining the operation. 10 is a flowchart for explaining the operation, and FIG. 10 is a waveform diagram for explaining the operation. 1...Battery, 2...Power circuit, 3
...Crank reference position detector, 4...Waveform shaping circuit, ROM, 6...RA
M, 7...CPU, 10...Input edge detector, 11...Latch circuit (1), 12...
...Timer, 13...Latch circuit (2)
, 14...Comparator, 20...D flip-flop, 30°31...AND gate, 4
0.41...Switching element, 50.51.
...Ignition coil. Agent: Patent attorney Takeshi Kenjibe (1 other person) Figure 4 (a)
)

Claims (1)

[Claims] 1. One cycle is defined as an integral multiple of at least one rotation of the crankshaft of the internal combustion engine, and the rotational position of the crankshaft per cycle is divided into a plurality of sections at predetermined angles, and the ignition timing within these sections is determined. The engine rotation speed is calculated each time based on the crankshaft rotation speed in the included section, and the ignition advance amount in the section including the ignition timing one cycle later is sequentially calculated based on the engine rotation speed calculation result. In an ignition timing control device for an internal combustion engine, the rotational angular velocity of the crankshaft in the section immediately before the section including the ignition timing is sequentially detected for each cycle, and the detection result from one cycle before and the current detection result are detected. and a rotation speed fluctuation detection means that detects the amount of variation in the engine rotation speed by comparing the detection results of both of them. An ignition timing control device for an internal combustion engine, characterized in that it is configured to correct the amount of ignition timing.