JPH03213663A - Ignition timing control method and its device for internal combustion engine - Google Patents

Abstract

PURPOSE:To properly control ignition timing by counting pulse signals in 3 kinds of numbers about the rotating angle of an engine, and thereby obtaining ignition timing measurement time which is equal to the time from time when counting the pulse signals in the third number has been over to time for target ignition timing. CONSTITUTION:Pulse signals for measuring the rotating angle of an engine are generated by a means 1. Reference signals for the rotating angle are generated by a generator 2. Furthermore, during the time when the pulse signals in the third number are being counted by a means 7, ignition timing measurement time which is equal to the time from time when measurement by the means 7 has been over to time for target ignition timing operated by a means 8, is operated by a means 9 based on information on revolution speed which is obtained from the difference between time when counting the pulse signals in the second number by a means 5 has been over and time when counting the pulse signals in the first number by a means 3 has been over. The means 7 starts measuring the ignition timing measurement time from time when counting the pulse signals in the third number has been over, and when the measurement is over, an ignition signal is thereby sent to an ignition device 10 by a means 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ignition timing control method for determining an ignition timing and an ignition timing control device used to implement the method.

[Prior Art] When controlling the ignition timing using a microcomputer, the average rotational speed of the engine is detected by measuring the time interval of signals generated by the internal combustion engine attached to the internal combustion engine. Assuming that the engine is rotating at the detected rotational speed, the target ignition timing (
It is determined by a microcomputer according to the rotation speed, throttle opening, etc. ) is determined as the ignition timing measurement time (the time required for the engine to rotate from the reference position to the ignition position). Then, set this ignition timing measurement time in the ignition timing determination timer, start the timer when the internal combustion engine generates a specific signal (reference position), and when the timer times up, the ignition system for the internal combustion engine An ignition signal is given to cause the ignition operation to occur.

Internal combustion engines usually generate a signal at the maximum or minimum advance position to determine, but in most cases, ignition timing is measured with reference to the maximum advance position.

[Problems to be Solved by the Invention] FIG. 13 shows variations in rotational speed for determining two-cycle three-cylinder operation. As seen in the figure, in a two-stroke engine, the rotational speed decreases the most at the end of the compression stroke, and the rotational speed reaches its maximum at a position of 30 to 60 degrees after ignition due to explosion.

Furthermore, if the gas in the cylinder is not replaced well during the scavenging stroke, combustion will not be performed well during the subsequent explosion stroke, resulting in a low maximum rotational speed. When the gas is successfully replaced in the next scavenging stroke, combustion is performed well in the subsequent explosion stroke, and the rotational speed increases. Therefore, the rotational speed varies with each rotation.

In order to accurately control the ignition timing, it is preferable to determine the ignition timing based on the rotational speed at a time as close as possible to each ignition timing.

In the conventional ignition timing control method, the average value of the engine rotational speed is determined from the time interval of signals obtained from the internal combustion engine, and the ignition timing measurement time is determined based on the rotational speed. Since each ignition timing measurement time was determined based on the speed of rotation caused by the previous ignition, the ignition timing could not be accurately controlled.

In the conventional method, for example, as shown in FIG. 13, the time from time t1 immediately after ignition to time t2 immediately after the next ignition is measured, and a timer for measuring ignition timing is started at time t2. Then, while the ignition timing measurement timer is performing counting operation, the average value of the rotation speed is calculated from the time from time t1 to t2 and the rotation angle during that time, and the ignition timing at that time is calculated based on this rotation speed. The target ignition timing measurement time required to determine the target ignition timing measurement time is calculated, and the end time of the ignition timing measurement time is set in the ignition timing measurement timer. When the ignition timing measurement timer times up, an ignition signal is given to the ignition circuit to cause the ignition operation to occur.

In this way, in the conventional method, the rotational speed generated by the previous ignition was used as the rotational speed data used to determine each ignition timing, so the rotational speed generated by the previous ignition was used. There was no correlation with the rotational speed data, and the ignition timing could not be controlled accurately.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ignition timing control method and method for determining a target ignition timing based on the rotation speed detected immediately before, thereby making it possible to accurately control the ignition timing. An object of the present invention is to provide an ignition timing control device used for implementing the above.

[Means for Solving the Problems] In the ignition timing control method of the present invention, a pulse signal generating means is provided that generates a pulse signal every time the internal combustion engine rotates by a minute angle, and at a predetermined rotational angle position. An internal combustion engine is provided that generates a reference signal. Every time a reference signal is generated, counting of pulse signals is started and a first number N1 is obtained.
memorize the time T1 when the pulse signals of are counted;
Counting of pulse signals is further started from the time when counting of the first number of pulse signals is completed, and time T2 when the second number of pulse signals is counted is stored. Further, the counting of the third number of pulse signals is started at a time after the time TI when the counting of the first number of pulse signals is finished, and the counting of the third number of pulse signals is started until the counting of the third number of pulse signals is finished. Based on the rotational speed information obtained from the difference between the time T2 at which the counting of the pulse signals of the second number N2 is completed and the time T1 at which the counting of the pulse signals of the first number N1 is completed, the third number of pulses is calculated. An ignition timing measurement time equal to the time from time T3 when counting of the signals ends to target ignition timing Ti is determined, and measurement of the ignition timing measurement time is started from the time when counting of the third number of pulse signals ends to reach the target ignition timing Ti. When the measurement of the measurement time is completed, the ignition device for the internal combustion engine is caused to perform the ignition operation.

When the above internal combustion engine is a multi-cylinder internal combustion engine, the internal combustion engine generates a reference signal for each cylinder, and the reference signals corresponding to two specific cylinders are made to correspond to the cylinders, and the internal combustion engine outputs The cylinder to be ignited is determined by comparing the time interval between the reference signals generated and the time interval between the cylinder discrimination signal and the previously generated reference signal.

As shown in FIG. 1, the ignition timing control device that implements the above method includes 1 pulse signal generating means 1 that generates a pulse signal for measuring the rotation angle every time the internal combustion engine rotates by a minute angle.
, an internal combustion engine 2 that generates a reference signal at a predetermined rotational angle position for determining the rotation angle, and a first engine that starts counting pulse signals every time the reference signal is generated and counts a first number N1 of pulse signals. Pulse counting means 3 and first time storage means 4 for storing time T1 at which the first pulse counting means finishes counting.
a second pulse counting means 5 which further starts counting pulse signals from the time when the counting of the first number N1 of pulse signals is finished and counts a second number N2 of pulse signals; a second memory for storing time T2 at which the counting means has finished counting;
and a third pulse counter that starts counting operation after time T1 when counting of the first number of pulse signals ends and counts the pulse signals until a third number of pulse signals is counted. A time T2 at which the counting of the second number N2 of pulse signals is completed while the means 7, the ignition timing calculating means 8 for calculating the target ignition timing, and the third pulse counting means 7 are counting the pulse signals. and the time T1 at which the counting of the first number N1 of pulse signals ends, based on the rotational speed information obtained from the time T3 at which the third pulse counting means finishes counting, to the target ignition timing Ti. The ignition timing measurement time calculation means 9 for calculating equal ignition timing measurement times and the third number pulse counting means start measuring the ignition timing measurement time from time T3 when they finish counting, and the measurement of the measurement time ends. The ignition signal supply means 11 provides an ignition signal to the ignition device 10 for an internal combustion engine when the ignition device 10 is activated.

When the internal combustion engine is a multi-cylinder internal combustion engine, the internal combustion engine ignition device has an ignition signal input terminal for each cylinder. In this case, the internal combustion engine is configured to generate a reference signal for each cylinder and to correspond to a cylinder between two predetermined reference signals corresponding to two cylinders. In this case, as shown in FIG. 2, the cylinder discriminating means 12 determines the reference signal generated next to the cylinder discriminating signal as the reference signal corresponding to a specific cylinder, thereby discriminating the cylinder in which the ignition operation is to be performed.
The ignition signal supply means 111 is configured to supply an ignition signal to the ignition signal input terminal corresponding to the cylinder discriminated by the cylinder discrimination means 12.

If a flywheel magnet generator is attached to the output shaft for determining the power, and an iron ring gear is provided on the outer periphery of the flywheel, the ring gear and the inductor type signal generator will A pulse signal generating means is configured.

Further, the internal combustion engine includes an inductor magnetic pole part provided in a part of the flywheel, a signal coil wound around an iron core having a magnetic pole part facing the inductor magnetic pole part, and a magnet that causes magnetic flux to flow through the iron core. In this case, the ring gear is preferably positioned with respect to the flywheel so that the relationship between the phase of the pulse signal and the phase of the reference signal is constant.

Note that if the flywheel is not provided with a ring gear, an encoder that rotates synchronously with the engine may be provided, and a pulse signal generated at each minute rotation angle may be obtained from the encoder.

[Effect] Examining the fluctuations in the rotational speed at each instant to determine the effect, the speed during the explosion stroke varies considerably depending on the combustion state, but in the region where the engine is rotating due to inertia, that is, the rotational speed gradually decreases. The speed is relatively stable in the compression stroke region.

In order to reduce the difference between the actual ignition timing and the target ignition timing, it is preferable to detect the rotational speed in an area as close as possible to the position where measurement of the ignition timing is started.

As described above, each time the reference signal is generated from the internal combustion engine, counting of pulse signals is started, and the first number N1 to the third number N3 of pulse signals are counted, and the second number of pulse signals is counted. Information on the rotation speed is obtained from the difference between time T2 when the pulse signal is counted and time T1 when the first number of pulse signals is counted, and based on the information on the rotation speed, the pulse signal of the third number is calculated. If the ignition timing measurement time is determined to be equal to the time from the time T3 at which counting ends to the target ignition timing Ti, the rotational speed can be adjusted by appropriately setting the first number N1 according to the characteristics of engine speed fluctuations. From time T1 to T2 to obtain information on
The period up to this point can be set to a region where the rotational speed has the least variation.

Furthermore, by starting the measurement of the ignition timing measurement time after counting the third number N3, not only can the ignition timing measurement time be calculated during that time, but also information on the rotational speed can be obtained at time T2. It is possible to correct errors caused by speed fluctuations that occur during the period from then until time T3 when measurement of the ignition timing measurement time is actually started. That is, time T2
Assuming that the rotational speed increases from to time T3,
The calculated ignition timing measurement time will be too long, but
In this case, since the position at which the measurement of the ignition timing measurement time starts is advanced, the deviation between the actual ignition timing and the target ignition timing can be reduced.

If the rotation speed decreases between time T2 and time T3, the calculated ignition timing measurement time will be too short, but in this case, the position at which the ignition timing measurement time starts will be delayed. The deviation between the actual ignition timing and the target ignition timing can be reduced.

As described above, according to the present invention, by appropriately setting the first number N1, it is possible to set the period for obtaining rotational speed information to the most desirable range, and also to start measuring the ignition timing measurement time. Since information on the rotational speed can be obtained close to the time when the actual ignition timing occurs, the deviation between the actual ignition timing and the target ignition timing can be reduced.

In addition, instead of starting the measurement of the ignition timing measurement time from the time when the internal combustion engine generates a specific signal, the ignition timing is started at the end time of counting of the third number N3, which is later than the time T2 at which the rotational speed information was obtained. Since the measurement of the timing measurement time is started, it is possible to compensate for errors caused by speed fluctuations that occur between obtaining the rotation speed information and starting the measurement of the ignition timing measurement time. Coupled with the ability to accurately obtain information, it is possible to accurately control ignition timing.

If the flywheel is provided with a ring gear, the pulse signal can be easily obtained by using the teeth of the ring gear. In this case, if the number of teeth of the ring gear is not divisible by the number of cylinders to be determined, the number of pulse signals generated between the plurality of reference signals corresponding to the plurality of cylinders will be different. In that case, it is necessary to make the count values N1 to N3 different for each cylinder.

This count value can be changed by switching the numbers N1 to N3 set in the register when counting pulse signals to determine the ignition timing of each cylinder in conjunction with cylinder discrimination. In this case, in order to prevent errors from occurring, it is desirable that the phase relationship between the pulse signal and the reference signal does not vary from product to product. Therefore, it is desirable that the positional relationship between the teeth of the ring gear and the magnetic pole portion of the rotor of the internal combustion engine does not vary from product to product. When using an internal combustion engine consisting of an inductor magnetic pole formed in a part of the flywheel and a signal generator facing the inductor magnetic pole (so-called pulser with a built-in magnet generator), a ring gear is attached to the flywheel. When installing the ring gear, the positional relationship between the teeth of the ring gear and the inductor magnetic pole portion provided on the flywheel may be maintained constant.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 schematically shows the configuration of an ignition timing control device that implements the method of the present invention, and in this embodiment, a three-cylinder, two-stroke internal combustion engine is ignited.

The internal combustion engine ignition system 10 includes three ignition coils 15a to 15c, each corresponding to three cylinders of the engine, and an ignition circuit 16 that controls the primary current of these ignition coils.
It consists of spark plugs Pa to Pc installed in the first to third cylinders of the engine, respectively, and connected to the secondary coils of ignition coils 15a to 15c, respectively. The ignition circuit 16 has ignition signal input terminals 17a to 17c corresponding to the first to third cylinders, respectively, and when an ignition signal is input to these ignition signal input terminals, one of the corresponding ignition coils is activated. The secondary current is controlled to suddenly change, and a high voltage for ignition is generated in the secondary coil of the ignition coil.

The pulse signal generating means 1 includes an iron ring gear 19 provided on the outer periphery of a cup-shaped flywheel 18 attached to the output shaft of the engine, and an inductor-shaped signal disposed opposite to the teeth of the ring gear 19. It consists of a generator 20.

Although not shown, a permanent magnet is attached to the inner periphery of the flywheel 18. The flywheel and the permanent magnet constitute a magnet rotor, and the magnet rotor and a stator (not shown) constitute a magnet. A generator is configured.

The signal generator 20 includes an iron core having a magnetic pole portion facing the teeth of the ring gear 19, and a signal coil wound around the iron core.
A well-known type equipped with a permanent magnet that causes magnetic flux to flow through the iron core,
Every time each tooth of the ring gear 19 faces a magnetic pole portion of the iron core of the signal generator 20, a pulse-like signal is induced in the signal coil.

Further, the internal combustion engine 2 includes a boss portion 1 of the flywheel 18.
A rotor 21 configured by providing inductor magnetic pole parts 21a and 21b of different lengths in 8A, a signal coil wound around an iron core having a magnetic pole part opposite to these inductor magnetic pole parts at the tip, and a signal coil wound around the iron core. The signal generator 22 includes a magnet for causing magnetic flux to flow, and the signal generator 22 generates a pulse signal as shown in FIG. 8(A). Of the pulse signals shown in the figure, Vp3 and Vpl are generated when the longer inductor magnetic pole portion 21a starts to oppose the signal generator 22, and when the inductor magnetic pole portion 21a leaves the state of facing the signal generator 22, respectively. The pulse signals Vpa and Vp2 are generated when the shorter inductor magnetic pole portion 21b begins to oppose the signal generator 22, and when the inductor magnetic pole portion 21b begins to oppose the signal generator 2, respectively.
Occurs when exiting the state of facing 2. Among these signals, the pulse signals Vpl, Vp2 and Vpa are used as first to third reference signals corresponding to the first to third cylinders for determining the pulse signal Vpl corresponding to the first cylinder, respectively. The pulse signal Vpa generated between the first cylinder and the nox signal Vp2 corresponding to the second cylinder is used as the cylinder discrimination signal. In this embodiment, the first to third reference signals Vpl to Vpa are the first to third reference signals of the engine, respectively.
This occurs at a position 5 degrees before the top dead center (minimum advance position) of the first to third cylinders.

The signals Vpl, Vpa, Vp2 and Vpa are input to the first waveform shaping circuit 25 and converted into pulse signals of equal polarity, and these pulse signals are input to the input port a1 of the microcomputer 30 through the OR circuit 26. .

The pulse signal generated from the pulse signal generating means 1 is input to the second waveform shaping circuit 27, and only the pulse signal of one polarity is extracted. That is, the waveform shaping circuit 27 outputs pulse signals of equal polarity and the number of pulses generated per rotation equal to the number of teeth of the ring gear, as shown in FIG. 8(B). This pulse signal is transmitted to the microcomputer 30
is input to the input port a2.

The microcomputer 30 includes a CPU 30a, a ROM 30b storing a predetermined program, a RAM 30c into which data is written at any time, a register 30d into which the ignition timing measurement time is input, a timer counter 30e which counts clock pulses, and a timer counter 30e which counts clock pulses. A comparator 30f that outputs a signal when the contents of the register 30d and the count value of the timer counter 30e match, and an input port a from the OR circuit 26.
A latch means 30g that latches the counted value of the timer counter 30e every time a signal is applied to the input port a2, a counter 30h that counts pulse signals for measuring the rotation angle when a signal is applied to the input port a2, and first to third counters. It includes a second register 30i into which numerical values N1 to N3 are sequentially input, and a comparator 30j which provides a signal from the output port Ao to the OR circuit 26 when the counted value of the counter 30h matches the contents of the second register 30i, These are interconnected by an internal bus.

In the microcomputer, the function realizing means 3 to 9 and 10 to 12 shown in FIG. 2 are configured according to a predetermined program according to an algorithm to be described later, and the ignition timing of the first to third cylinders of the engine is controlled. When each measurement is made, ignition signals for the first to third cylinders are output to the output ports A1 to A3 through the input/output (10) interface 30k, respectively. These output capos
) The ignition signals obtained from Al to A3 are input to the ignition signal input terminals 17a to 17C of the ignition circuit 16, respectively. The primary currents of the ignition coils 15a to 15c for the three cylinders are controlled to induce a high voltage for ignition on the secondary side of each ignition coil.

The programs stored in the ROM of the microcomputer are created according to the control algorithms shown in FIGS. 4 to 7. The main routine is as shown in FIG. 4. When the program is started, initial settings of each part are first performed, and then interrupts are permitted. Reference signals Vpl to Vp3 and cylinder discrimination signal V are input to input port a1.
When either one of .pa and .pa is input, the interrupt routine shown in FIG. The count value of Oe (the time when the signal was input to the input port a1) is latched, and the value is stored in the RAM. Further, the difference between this time and the time when the signal was last applied to the input port al is calculated as cylinder discrimination data and stored in the RAM, and this data is used to discriminate the cylinder.

That is, the times when the reference signals Vpl to Vp3 are inputted are respectively Tol to Toa, and the cylinder discrimination signal Vp is
If the time when a is input is Toa, the time difference TOI-
TO3, TOa-TOI, TO2-TOa, - are sequentially calculated and stored. These time differences are compared, and if the cylinder discrimination signal Vpa is generated between the first reference signal Vp1 and the second reference signal Vp2 as shown in FIG. 8(A), T Ol-T 03 ≧k(TOa−To
l) When it is detected that the next input port-h
It is determined that the reference signal Vp2 input to al is the reference signal corresponding to the second cylinder. This cylinder discrimination is performed for each rotation. The coefficient is set to an appropriate value (to increase the difference between TOI and TOa) so that the cylinder can be identified even if (TOa-Tol) fluctuates when starting an engine with unstable rotation. Generally, it is set to k×1).

When the cylinder discrimination is completed, the process returns to the main routine shown in FIG. In the main routine, the target ignition timing is calculated in accordance with the throttle opening (detected by a detection means every time the throttle opening is changed and stored in the RAM as digital information). In addition, for safety, the engine is checked for abnormalities such as overheating and overspeeding.
When there is an abnormality, the ignition timing is retarded, the ignition sparks are thinned out, or the ignition of a specific cylinder is caused to misfire in order to suppress the rotational speed during the period below the safe speed, but this point is the gist of the present invention. Since it deviates from the above, a detailed explanation will be omitted. Note that this process for ensuring safety can also be omitted.

The count value of the pulse signal of the counter 30h is the second register 3.
When the signal matches the first number N1 input to 0i, a signal is applied from the output port AO to the input port a1 through the OR circuit 26, and the count value of the timer counter 30e at that time (the count of the first number N1 pulse signals (Time TI)
is latched.

Further, each time the count value of the counter 30h matches the contents of the second register 301, the interrupt routine shown in FIG. 6 is executed. In this interrupt routine, it is first determined whether or not counting of the third number N3 pulse signals has been completed, and then the second
It is determined whether or not the counting of the first number N2 of pulse signals has been completed, but at the stage where the counting of the first number N1 of pulse signals has been completed, the second number N2 and the third number N3 have been counted. Since the counting has not ended, the process proceeds to a step of storing the counted value of the timer counter 30e. As a result, the time T1 when counting of the first number N1 is completed is stored. Then the second
The second number N2 is set in the register 30i and the process returns to the main routine. When the counted value of the counter 30h matches the second number N2 input to the second register 30i, the counted value of the timer counter 30e is latched, and the interrupt routine of FIG. 6 is executed again and latched. The count value of the timer counter 30e (time T2 when counting of the second number N2 ends) is stored. Next, after setting the third number N3 in the second register 30i, a process of calculating the ignition timing measurement time is performed. In this process, the difference between the time T2 when the counting of the second number N2 pulse signals is finished and the time T1 when the counting of the first number N1 pulse signals is finished and the angle rotated during that time (the number of teeth of the ring gear The information on the engine rotational speed is obtained from
It is converted into "ignition timing measurement time" which is equal to the time from the time when the counting in step 3 is completed to the ignition timing Ti. Then return to the main routine.

Next, when the count value of the counter 30h matches the third number N3 set in the second register 30i, the count value of the timer counter 30e is latched and the interrupt routine of FIG. 6 is executed again. At this time, in the interrupt routine of FIG. 6, the already calculated ignition timing measurement time is set in the second register 301, and the counter 3
Reset 0h to stop and return to the main routine.

When the counted value of the timer counter 30e matches the contents of the second register 301, the interrupt routine shown in FIG. 7 is executed.
An ignition signal is applied to the ignition signal input terminal of the cylinder being discriminated.

Figure 8 (D) shows how the count value of the timer counter increases and how it is latched when a signal is applied to the input port and when counting of the first number N1 and the second number N2 is completed. The count value of the timer counter is shown. Although the count values TI and T2 differ for each cylinder (for each reference signal), the same symbols are used for each cylinder to simplify the display.

In the above embodiment, the first number N1 in FIG.
is set in the second register 30i to cause the counter 30h to count pulse signals, the first pulse counting means 3 is realized, and the count value of the counter 30h becomes the first number N1.
The first time storage means 4 is realized in the process of saving the count value of the timer counter 30e when the timer counter 30e matches the timer counter 30e.

In addition, in FIG. 6, the second number N2 is stored in the second register 30i.
In the process of setting the counter 30h to count pulse signals, the second pulse counting means 5 is realized, and when the counted value of the counter 30h matches the second number N2, it calculates the counted value of the timer counter 30e. The second time storage means 6 is realized in the process of saving.

Furthermore, in FIG. 6, the third number N3 is stored in the third register 30i.
The third pulse counting means 7 is realized in the process of setting the counter 30h to count pulse signals.

Further, in the process of calculating the ignition timing in the main routine of FIG. 4, the ignition timing calculation means 8 is realized, and in the process of calculating the ignition timing measurement time of FIG. 6, the ignition timing measurement time calculation means 9 is realized.

Furthermore, the ignition signal supply means 1 is activated by the interrupt routine shown in FIG.
1 is realized, and the cylinder discriminating means 12 is configured in the process of discriminating the cylinders shown in FIG.

Note that when the internal combustion engine is a single cylinder, it is natural that the cylinder discrimination means is omitted as shown in FIG.

In the above embodiment, the rotational speed information is obtained from the time from time T1 when counting of the first number N1 of pulse signals ends to time T2 when counting of the second number N2 of pulse signals ends. It is desirable to set the period for obtaining this rotational speed information to a period in which the instantaneous rotational speed of the engine is relatively stable (with little change from rotation to rotation). Further, it is desirable that this period be close to the time when measurement of the ignition timing is actually started. In the present invention, by appropriately setting the first number N1, the period (
(period for counting the second number N2 of pulse signals) can be set at any position.

In a two-cycle engine, it is preferable to set the period for counting the second number N2 of pulse signals in a region (compression stroke) in which the rotation of the engine relies on inertia and the rotational speed decreases. In order to bring the area for counting the second number N2 to the optimum area according to the characteristics of the engine and the rotational speed of the engine, the first number N1 is (obtained from the time for counting pulse signals) can be changed as appropriate.

Also, the time for counting the first number N1 of pulse signals, and the time for counting the pulse signals of the first number N1,
The time to count the number N2 of pulse signals and the third number N3
It is necessary to set each count value so that the sum of the time for counting the pulse signals of is shorter than the time from when each reference signal is generated until the cylinder corresponding to that reference signal is ignited. Since the time from when each reference signal is generated to when the cylinder corresponding to that reference signal is ignited changes as the rotation speed changes, the values of the first to third numbers N1 to N3 are soft. It is preferable to change the rotation speed according to the rotation speed.

As described above, after counting the second number N2 of pulse signals and obtaining rotation speed information at time T2, the ignition timing measurement starts from time T3 when the third number N3 of pulse signals is further counted. By doing so, not only can the ignition timing measurement time be calculated during that time, but also the calculation can be performed between the time when the rotation speed information is obtained at time T2 and the time T3 when the ignition timing measurement time is actually started. Errors due to speed fluctuations that occur can be corrected. That is, if the rotational speed increases between time T2 and time T3, the calculated ignition timing measurement time will be too long, but in this case, the position at which the ignition timing measurement time starts will be moved earlier.
The deviation between the actual ignition timing and the target ignition timing can be reduced.

If the rotation speed decreases between time T2 and time T3, the calculated ignition timing measurement time will be too short, but in this case, the position at which the ignition timing measurement time starts will be delayed. The deviation between the actual ignition timing and the target ignition timing can be reduced.

When obtaining pulse signals using a ring gear as in the above embodiment, if the number of teeth on the ring gear is not divisible by the number of cylinders, the number of pulse signals generated between the reference signals will differ. It turns out.

In this case, the first to third numbers N1 to N3, which are set in the second register 30i (set for each cylinder) after the reference signal for each cylinder is generated on the software, are made different for each cylinder. There is a need.

In this way, the first to third numbers N set for each cylinder
If the relationship between the reference signal generation phase and the pulse signal generation phase varies from product to product, if the ignition timing or N3 is different, the ignition timing will deviate, making it impossible to perform accurate ignition timing control. It disappears. Therefore, when attaching the ring gear to the flywheel, it is necessary to maintain a constant positional relationship between the teeth of the ring gear and the inductor magnetic pole of the internal combustion engine, which is provided on a part of the flywheel. It is.

In the above embodiment, a ring gear is used to obtain a pulse signal, but in the present invention, it is sufficient to obtain a pulse signal generated at each minute rotation angle of the engine, and a member that rotates synchronously with the engine, for example, A pulse signal generated at each minute rotation angle may be obtained by configuring an encoder with a code plate attached to the flywheel and a sensor for reading the code provided on the code plate.

In the above embodiment, in order to enable the ignition operation even if the microcomputer fails, the reference signal Vpl
It is desirable to provide a circuit for inputting Vp3 to Vp3 (which occurs at the maximum retard position) as an ignition signal to the ignition circuit without going through a microcomputer.

In the above embodiment, the first to third numbers N1 to N3
is counted by one counter 30h,
Since a plurality of counters are usually provided in a microcomputer, the third number N3 may be counted by another counter. In this case, the third number N
3 may be started after the counting of the first number Nl has finished, but normally, as shown by the solid line in Figure 10 (D), counting of the second number N2 has finished. Either start counting the third number N3 at time T2, or start counting the third number N3 at time T2, or
), it is preferable to start counting the third number N3 at time T1 when counting of the first number N1 ends.

Counting of the third number N3 may be started at a time other than these, for example, at an appropriate time within the period in which the counting of the second number N2 is being performed, but in that case, the counting of the third number N3 In order to specify the time to start counting, a means for measuring the time from the end of counting the first number N1 to the start of counting the third number N3 is required.

Note that the counting end time of the third number N3 needs to be set after the time when the calculation of the rotational speed and the calculation of the ignition timing measurement time end after the counting of the second number N2 is completed. Of course.

FIG. 9 shows the configuration of an apparatus used in an embodiment in which the third number N3 is counted by another counter. In this embodiment, a counter corresponding to the counter 30h in FIG. 3 is used. A tenth counter 30h is added, a second counter 30m, a third register 30n, and a comparator 30p that outputs a signal when the count value of the second counter matches the contents of the third register 30n. . Comparator 30
The output of p is input to the OR circuit 26 through the output port Ao'. Further, the output of the second waveform shaping circuit 27 is input to the second counter 30m through the input port a3.

In this embodiment, a third number N3 is input to the third register 30n, the second counter 30m counts pulse signals, and the counted value of the pulse signal matches the content of the third register 30n. When the timer counter 30e
Latch the count value and apply an internal interrupt,
The interrupt routine shown in either FIG. 11 or FIG. 12 is executed.

The interrupt routine in FIG. 11 is similar to the interrupt routine shown in FIG. 11, except that the third number N3 is set in the third register, and the counter that is stopped after setting the ignition timing measurement time in the third register is the first counter 30h. This is similar to the interrupt routine shown in FIG. When using the interrupt routine shown in FIG. 11, as shown by the solid line in FIG. 10(D), the third number N2 is
A count of 3 is performed.

In addition, the interrupt routine in FIG. 12 has two points: after setting N2 to the second register 30i, the third number N3 is set to the third register 30n, and when the counting of the second number N2 is finished, the timer counter is This is the same as the example shown in FIG. 6, except that the ignition timing measurement time is calculated immediately after the count value is saved.

When using the interrupt routine of FIG. 12, as shown by the broken line in FIG. 10(D), counting of the third number N3 starts at time TI when counting of the first number Nl ends. Ru. In this case, the time at which counting of the third number N3 ends is
It is set after the time at which the calculation of the rotational speed and the calculation of the ignition timing measurement time are completed after the counting of the second number N2 is completed.

As mentioned above, the third number N3 of pulse signals is counted as the first
If the counting is performed using a counter separate from the counter that counts the pulse signals of the number Nl and the second number N2, the time from the start of counting of the first number N1 until the end of counting of the third number N3 is The rotation angle is the reference signal Vpl, V92.・
...The mutual rotation angle (120 degrees in the case of 3 cylinders) may be exceeded.

Normally, the reference signal is the engine's minimum advance position (for example, 1 minute before top dead center).
However, with the above configuration, the position at which counting of the third number N3 ends can be set at a position further behind 10 degrees before top dead center (a position close to top dead center). Even when the ignition operation is performed at a position further delayed than the position where the reference signal is generated, the ignition operation can be performed stably.

Further, since there is no need to limit the counting start time of the third number N3 to the counting end time of the second number N2, the degree of freedom in program design can be increased.

[Effects of the Invention] As described above, according to the present invention, each time a reference signal is generated from an internal combustion engine, counting of pulse signals is started and the first number N is calculated.
1. Count the second number N2 and third number N3 of pulse signals, and time T when the second number of pulse signals is counted.
2 and time T1 when the first number of pulse signals are counted.
Information on the rotational speed is obtained from the difference between the rotational speed and the ignition timing measurement time equal to the time from time T3 at which counting of the third number of pulse signals is completed to target ignition timing T1 is determined based on the information on the rotational speed. Therefore, by appropriately setting the first number N1 according to the characteristics of engine speed fluctuations, the period from time T1 to T2 for obtaining rotational speed information can be set to an area where the rotational speed fluctuations are the least. The rotation speed information can be obtained accurately. In addition, since the rotational speed caused by the previous ignition is accurately detected and the ignition timing measurement time is calculated based on the rotational speed, the ignition timing can be controlled accurately. can.

Furthermore, since the measurement of the ignition timing measurement time is started after counting the third number N3, the period from obtaining the rotational speed information at time T2 to time T3 when actually starting the measurement of the ignition timing measurement time is This has the advantage that it is possible to correct errors caused by speed fluctuations that occur during that time, and it is possible to reduce errors in ignition timing caused by instantaneous speed fluctuations.

[Brief explanation of drawings]

1 and 2 are claim correspondence diagrams showing the structure of the invention of claims 5 and 6, respectively, FIG. 3 is a block diagram schematically showing the structure of an apparatus used in an embodiment of the present invention, and FIG. 4 7 to 7 are flowcharts showing the control algorithm of the embodiment of the present invention, FIG. 8 is a diagram for explaining signal waveforms and counting operations of the counter and timer in the embodiment of the present invention, and FIG. 9 is a diagram showing the control algorithm of the embodiment of the present invention. Fig. 10 is a diagram showing the signal waveform in the embodiment of Fig. 9, and Figs. 11 and 12 are diagrams showing the configuration of the device used in another embodiment. Flow chart showing an example, part 1
FIG. 3 is a diagram showing rotational fluctuations for determination. DESCRIPTION OF SYMBOLS 1... Pulse generation means for rotational speed measurement, 2... Internal combustion engine, 3... First pulse counting means, 4... First time storage means, 5... Second pulse counting Means, 6...
- Second time storage means, 7... Third pulse counting means, 8... Ignition timing calculation means, 9... Ignition timing measurement time calculation means, 10... Ignition device for internal combustion engine, 11・・・
・Ignition Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 1 Fig. 1 2 Fig. ← times ■ secret Q

Claims (1)

[Claims] (1) In an ignition timing control method for controlling the ignition timing of an internal combustion engine by controlling the timing of applying an ignition signal to an ignition device for the internal combustion engine, a pulse signal is sent every time the internal combustion engine rotates by a minute angle. A signal generator is provided to generate a reference signal at a predetermined rotational angle position of the internal combustion engine, and each time the reference signal is generated, the pulse signal is started to be counted. A time T1 when a number N1 of pulse signals is counted is stored, and counting of pulse signals is further started from the time when counting of the first number of pulse signals is completed, and a second number of pulse signals is counted. the third number of pulse signals is started to be counted after the time when the counting of the first number of pulse signals is completed, and the counting of the third number of pulse signals is The second number N2 until the end
The time T2 at which the counting of the pulse signals of is completed and the first number N1
Based on the rotational speed information obtained from the difference from the time T1 at which the counting of the third number of pulse signals ends, the ignition timing is equal to the time from the time T3 at which the counting of the third number of pulse signals ends to the target ignition timing Ti. Determine a measurement time, start measuring the ignition timing measurement time from the time when counting of the third number of pulse signals ends, and when the measurement of the measurement time ends, cause the internal combustion engine ignition device to perform an ignition operation. A method for controlling ignition timing of an internal combustion engine, the method comprising: controlling the ignition timing of an internal combustion engine; (2) The internal combustion engine is a multi-cylinder internal combustion engine with two or more cylinders, and the signal generator generates the reference signal for each cylinder, and performs cylinder discrimination between the reference signals corresponding to two specific cylinders. The ignition operation is performed by comparing a time interval between reference signals outputted from the signal generator and a time interval between the cylinder discrimination signal and a previously generated reference signal. 2. The ignition magnetic control method for an internal combustion engine according to claim 1, further comprising determining the cylinder in which the ignition is performed. (3) In an ignition timing control device for an internal combustion engine that controls the ignition timing of an internal combustion engine by controlling the timing of applying an ignition signal for determining the ignition timing to the ignition device for an internal combustion engine, every time the internal combustion engine rotates by a minute angle, a signal generator that generates a reference signal at a predetermined rotational angle position of the internal combustion engine; and a signal generator that starts counting the pulse signal every time the reference signal is generated. a first pulse counting means for counting the number N1 of pulse signals; a first pulse storage means for storing a time T1 at which the first pulse counting means finished counting; and a first pulse storage means for counting the first number of pulse signals. a second pulse counting means that further starts counting pulse signals from the time when the counting of the signals ends and counts a second number of pulse signals; and a time T2 at which the second pulse counting means finishes counting. a second time storage means for storing, and counting pulse signals starting a counting operation after time T1 when counting of the first number of pulse signals is completed until a third number of pulse signals is counted; a third pulse counting means; an ignition timing calculation means for calculating a target ignition timing Ti; and a pulse count of the second number N2 until the third number of pulse counting means finishes counting pulse signals The time at which the third pulse counting means finishes counting based on the rotational speed information obtained from the difference between the time T2 at which the counting of the signals ends and the time T1 at which the counting of the first number N1 pulse signals ends. T
ignition timing measurement time calculation means for calculating an ignition timing measurement time equal to the time from 3 to the target ignition timing Ti; and a time T at which the third number of pulse counting means finishes counting.
ignition signal supply means for starting the measurement of the ignition timing measurement time from step 3 and supplying an ignition signal to the internal combustion engine ignition device when the measurement of the measurement time is completed. Ignition timing control device. (4) The internal combustion engine is a multi-cylinder internal combustion engine, the internal combustion engine ignition device has an ignition signal input terminal for each cylinder, and the signal generator generates the reference signal for each cylinder. The cylinder discrimination signal is also configured to be generated between reference signals corresponding to two predetermined cylinders, and the reference signal generated after the cylinder discrimination signal is determined to be the reference signal corresponding to a specific cylinder. The cylinder further comprises a cylinder discriminating means for discriminating a cylinder to perform an ignition operation, and the ignition signal supply means supplies an ignition signal to an ignition signal input terminal corresponding to the cylinder discriminated by the cylinder discriminating means. The ignition control device for an internal combustion engine according to claim 3. (5) A flywheel magnet generator is attached to the output shaft of the internal combustion engine, and the pulse signal generating means is connected to the outer periphery of the flywheel of the flywheel magnet generator in order to engage the output gear of the internal combustion engine starter. 5. The apparatus according to claim 3, further comprising an iron ring gear provided in the ring gear, and an inductor-type signal generator that induces a pulse signal by a change in magnetic flux generated by the ring gear. Ignition timing control device for internal combustion engines. (6) The signal generator includes an inductor magnetic pole part provided in a part of the flywheel, a signal coil wound around an iron core having a magnetic pole part facing the inductor magnetic pole part, and a magnetic flux flowing through the iron core. a signal generator having a magnet for causing a current to flow, and the ring gear is positioned with respect to the flywheel so that the relationship between the phase of the pulse signal and the phase of the reference signal is constant. The ignition timing control device for an internal combustion engine according to claim 5.