JP2596155B2 - Method and apparatus for controlling ignition timing of internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ignition timing control method for an internal combustion engine and an ignition timing control device used for implementing the method.

[Prior Art] When controlling the ignition timing of an internal combustion engine using a microcomputer, the microcomputer measures the time interval of a signal generated by a signal generator attached to the internal combustion engine and calculates the average rotational speed of the engine. Assuming that the engine is rotating at the detected rotational speed, the signal generator generates a specific signal from the position (reference position) to the target ignition timing (microcomputer according to the rotational 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 timing). The ignition timing measurement time is set in an ignition timing determination timer, and the timer is started when the signal generator generates a specific signal (reference position). When the timer expires, the ignition for the internal combustion engine is started. An ignition signal is provided to the device to perform an ignition operation.

The signal generator usually generates a signal at the maximum advance position or the minimum advance position of the internal combustion engine, but in most cases, the measurement of the ignition timing is performed based on the maximum advance position.

[Problems to be Solved by the Invention] FIG. 13 shows fluctuations in the rotational speed of a two-cycle three-cylinder internal combustion engine. As shown in the figure, in the two-stroke engine, the rotation speed decreases at the end of the compression stroke, and reaches a maximum at 30 to 60 degrees after ignition due to an explosion. In addition, if the gas in the cylinder is not sufficiently replaced in the scavenging stroke, the combustion is not properly performed in the subsequent explosion stroke, and the maximum value of the rotation speed is reduced. When the replacement of the gas is successfully performed in the next scavenging stroke, the combustion is favorably performed in the subsequent explosion stroke, and the rotation speed increases. Therefore, the rotation speed changes for each rotation.

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

In the conventional ignition timing control method, the average value of the rotation speed of the engine is obtained from the time interval of the signal obtained from the signal generator, and the ignition timing measurement time is obtained based on the rotation speed. Since each ignition timing measurement time is determined based on the speed of rotation generated by the last two ignitions, the ignition timing cannot be controlled accurately.

In the conventional method, for example, as shown in FIG. 13, the time from time t1 immediately after ignition to time t2 immediately after ignition is measured, and a timer for measuring the ignition timing is started at time t2. Then, while the ignition timing measurement timer is performing the measurement operation, the average value of the rotation speed is calculated from the time from time t1 to time t2 and the angle rotated during that time, and the ignition timing at that time is calculated based on this rotation speed. Is calculated, and the end time of the ignition timing measurement time is set in an ignition timing measurement timer. When the timer for measuring the ignition timing has timed out, an ignition signal is supplied to the ignition circuit to cause an ignition operation to be performed.

As described above, in the conventional method, since the rotation speed generated by the ignition two times before is used as the rotation speed data used when determining each ignition timing, it is used to determine each ignition timing and the ignition timing. There was no correlation between the rotation speed data and the ignition timing could not be properly controlled.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition timing control method for an internal combustion engine, which is capable of determining a target ignition timing based on a rotational speed detected immediately before, so that ignition timing can be controlled accurately. 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 for generating a pulse signal every time the internal combustion engine rotates by a small angle is provided, and the internal combustion engine is controlled at a predetermined rotational angle position. A signal generator for generating a reference signal is provided. Each time the reference signal is generated, the counting of the pulse signal is started and the first number N1
The time T1 at the time when the pulse signal of the first number was counted is stored, and the counting of the pulse signal is further started from the time when the counting of the first number of the pulse signals is completed, and the pulse signal of the second number N2 is counted. The time T2 at the time is stored. At the time after the time T1 when the counting of the pulse signal of the first number N1 is completed, the third number
A time T2 at which the counting of the pulse signals of the second number N2 is completed and a pulse of the first number N1 are completed until the counting of the pulse signals of the third number is completed and the counting of the pulse signals of the third number is completed. Based on the information on the rotational speed obtained from the difference from the time T1 at which the counting of the signals has been completed, the angle corresponds to the angle from the rotational angle position when the counting of the pulse signal of the third number N3 is completed to the target ignition timing Qi. The ignition timing measurement time Ti to be measured is determined, the measurement of the ignition timing measurement time Ti is started from the time when the counting of the third number N3 of pulse signals is completed, and when the measurement of the measurement time is completed, the ignition device for the internal combustion engine is used. Is caused to perform an ignition operation.

When the internal combustion engine is a multi-cylinder internal combustion engine, while generating a reference signal for each cylinder from the signal generator,
A cylinder discrimination signal is generated between reference signals corresponding to two specific cylinders, a time interval between the reference signals output from the signal generator, and a time between the cylinder discrimination signal and a reference signal generated before the cylinder discrimination signal. By comparing with the interval, the cylinder in which the ignition operation is performed is determined.

As shown in FIG. 1, the ignition timing control device for performing the above method includes a pulse signal generating means 1 for generating a pulse signal for measuring a rotation angle every time the internal combustion engine rotates by a small angle.
A signal generator 2 for generating a reference signal at a predetermined rotation angle position of the internal combustion engine, and a first signal generator 2 for starting counting pulse signals and counting a first number N1 of pulse signals each time the reference signal is generated. Pulse counting means 3, and first time storage means 4 for storing the time T1 at which the first pulse counting means has finished counting,
Second pulse counting means 5 for starting counting of pulse signals from the time when counting of the pulse signals of the first number N1 is completed and counting pulse signals of the second number N2; and second pulse counting means A second time storing means for storing a time T2 at which the counting of the pulse signals is completed, and a time T1 at which the counting of the first number of the pulse signals is completed.
Thereafter, a third pulse counting means 7 for counting the pulse signals until a third number N3 of pulse signals are counted by starting a counting operation, and an ignition timing calculating means 8 for calculating a target ignition timing.
And the time T2 at which the counting of the pulse signals of the second number N2 is completed while the third pulse counting means 7 is counting the pulse signals, and the time at which the counting of the pulse signals of the first number N1 is completed. T1
Timing measurement time for calculating an ignition timing measurement time corresponding to the angle from the rotation angle position to the target ignition timing Qi when the third pulse counting means completes counting based on the rotation speed information obtained from the difference between From the time T3 when the calculating means 9 and the third number of pulse counting means finish counting, the ignition timing measurement time Ti
And an ignition signal supply means 11 for supplying an ignition signal to the internal combustion engine ignition device 10 when the measurement of the measurement time is started and the measurement of the measurement time is completed.

When the internal combustion engine is a multi-cylinder internal combustion engine, the ignition device for the internal combustion engine has an input terminal for an ignition signal for each cylinder. In this case, the signal generator generates a reference signal for each cylinder, and generates a cylinder discrimination signal between reference signals corresponding to two predetermined cylinders. In this case, as shown in FIG. 2, the cylinder discriminating means 12 for discriminating the reference signal generated next to the cylinder discrimination signal as the reference signal corresponding to the specific cylinder and discriminating the cylinder for performing the ignition operation is provided. The ignition signal supply means 111 is provided to supply an ignition signal to an input terminal of an ignition signal corresponding to the cylinder determined by the cylinder determination means 12.

When a flywheel magnet generator is attached to the output shaft of the internal combustion engine, and an iron ring gear is provided on the outer periphery of the flywheel, by the ring gear and an inductor-type signal emitting device, A pulse signal generating means is configured.

In addition, the signal generator includes an inductor magnetic pole portion provided on a part of the flywheel, a signal coil wound around an iron core having a magnetic pole portion facing the inductor magnetic pole portion, and a magnet for flowing magnetic flux through the iron core. In this case, it is preferable that 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 kept constant.

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

[Operation] When examining the state of the fluctuation of the instantaneous rotational speed of the internal combustion engine, the speed in the explosion stroke fluctuates considerably depending on the combustion state, but the region where the engine is rotating due to inertia, that is, the rotational speed gradually decreases. In some regions (compression stroke), the speed is relatively stable. In order to reduce the difference between the actual ignition timing and the target ignition timing, it is preferable to detect the rotation speed in a region as close as possible to the position where the measurement of the ignition timing is started.

As described above, every time a reference signal is generated from the signal generator, the counting of pulse signals is started, the pulse signals of the first number N1 to the third number N3 are counted, and the pulse of the second number N2 is counted. Rotation speed information is obtained from the difference between the time T2 when the signal is counted and the time T1 when the first number N1 of pulse signals are counted, and a third number N3 is obtained based on the rotation speed information. From the rotation angle position when the counting of the pulse signal of
When the ignition timing measurement time Ti corresponding to the angle up to Qi is obtained, the first number N1
Is appropriately set, the period from time T1 to time T2 when the information on the rotational speed is obtained can be set to an area where the fluctuation of the rotational speed is the least.

If the measurement of the ignition timing measurement time is started after the third number N3 is counted, not only can the calculation of the ignition timing measurement time be performed during that time, but also the rotation speed information can be obtained at time T2. After that, it is possible to correct the error due to the speed fluctuation occurring until time T3 when the measurement of the ignition timing measurement time is actually started. That is, if the rotation speed increases from time T2 to time T3, the calculated ignition timing measurement time will be too long.In this case, the position at which the measurement of the ignition timing measurement time is started is advanced.
The deviation between the actual ignition timing and the target ignition timing can be reduced.

Also, if the rotation speed is reduced from time T2 to time T3, the calculated ignition timing measurement time will be too short, but in this case, the position where the measurement of the ignition timing measurement time is started is 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, the period for obtaining the information on the rotational speed can be set to the most desirable region, and the measurement of the ignition timing measurement time is started. Since the information on the rotational speed can be obtained at a point near the time at which the ignition timing is performed, the difference between the actual ignition timing and the target ignition timing can be reduced.

Also, instead of starting the measurement of the ignition timing measurement time from the time when the signal generator generates a specific signal, the counting end time of the third number N3 which is further delayed from the time T2 when the information on the rotational speed was obtained. Since the measurement of the ignition timing measurement time is started, it is possible to compensate for the error due to the speed fluctuation that occurred between the time when the information on the rotation speed was obtained and the time when the measurement of the ignition timing measurement time was started. In addition to the fact that the above information can be obtained accurately, the ignition timing can be controlled accurately.

When a ring gear is provided on the flywheel, a 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 of the internal combustion engine, the number of pulse signals generated between the plurality of reference signals respectively 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 change of the count value may be performed by switching the numbers N1 to N3 set in the register when counting the pulse signal for determining the ignition timing of each cylinder in conjunction with the determination of the cylinder. In this case, in order to prevent an error 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 poles of the rotor of the signal generator does not vary from product to product. When a signal generator including an inductor magnetic pole formed in a part of a flywheel and a signal generator facing the inductor magnetic pole (a so-called pulsar with a built-in magnet generator) is used, a ring is attached to the flywheel. When attaching the gear, it is sufficient to manage the positional relationship between the teeth of the ring gear and the magnetic pole portion of the inductor provided on the flywheel so as to be always constant.

Embodiment An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 3 schematically shows the configuration of an ignition timing control device for implementing the method of the present invention. In this embodiment, a three-cylinder two-cycle internal combustion engine is ignited.

The internal combustion engine ignition device 10 includes three ignition coils 15a to 15c respectively corresponding to three cylinders of a period, an ignition circuit 16 for controlling a primary current of these ignition coils, and first to third cylinders of the engine. And ignition plugs Pa to Pc respectively connected to the secondary coils of the ignition coils 15a to 15c. The ignition circuit 16 has an ignition signal input terminal corresponding to each of the first to third cylinders.
17a to 17c, when the ignition signal is input to these ignition signal input terminals, the primary current of the corresponding ignition coil is controlled to change suddenly, and the secondary coil of the ignition coil is used for ignition. Generates high voltage.

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 type signal arranged corresponding to the teeth of the ring gear 19. It consists of 20 generators. Although not shown, a permanent magnet is attached to the inner periphery of the flywheel 18, and a magnet rotor is constituted by the flywheel and the permanent magnet, and a magnet is formed by the magnet rotor and a stator (not shown). A generator is configured.

The signal generator 20 is a well-known type including an iron core having a magnetic pole portion facing the teeth of the ring gear 19, a signal coil wound around the iron core, and a permanent magnet flowing a magnetic flux through the iron core. Each time each tooth of the ring gear 19 faces the magnetic pole portion of the signal generator 20 and the iron core, a pulse signal is induced in the signal coil.

The signal generator 2 is provided with a boss portion of the flywheel 18.
A rotor 21 constituted by providing inductor magnetic pole portions 21a and 21b having different lengths on 18A, a signal coil wound around an iron core having a magnetic pole portion opposed to these inductor magnetic pole portions at its tip, and a The signal generator 20 includes a magnet for flowing a magnetic flux, and the signal generator 22 generates a pulse signal as shown in FIG. 8 (A). V _p3 and V among the pulse signals shown in FIG.
_p1 is the longer inductor magnetic pole part 21a and the signal emission 22
The pulse signal V is generated when the inductor magnetic pole portion 21a exits the state where the inductor magnetic pole portion 21a faces the signal emission 22.
_Pa and V _p2 are generated when the shorter inductor magnetic pole portion 21b starts to face the signal emission 22 and when the inductor magnetic pole portion 21b comes out of the state of facing the signal emission 22. Among these signals, the pulse signals V _p1 , V _p2 and V _p3 are used as first to third reference signals corresponding to the first to third cylinders of the internal combustion engine, respectively, and correspond to the first cylinder. pulse signal V _pa generated between the pulse signal V _p1 and a pulse signal V _p2 corresponding to the second cylinder is used as a cylinder discrimination signal. In this embodiment, the first to third reference signals V
Each of _p1 to _Vp3 is generated at a position (minimum advance position) 5 degrees before the top dead center of the first to third cylinders of the engine.

The signals V _p1 , V _pa , V _p2 and V _p3 are inputted to a first waveform shaping circuit 25 and converted into pulse signals having the same polarity, and these pulse signals are passed through an OR circuit 26 to an input port a1 of the microcomputer 30. Has been entered.

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

The microcomputer 30 includes a CPU 30a, a ROM 30b storing a predetermined program, and a RAM 3 in which data is written as needed.
0c and the first register 30d to which the ignition timing measurement time is input
And the timer counter 30e counting the clock pulse
And a comparator 30f for outputting a signal when the content of the first register 30d matches the count value of the timer counter 30e, and the count value of the timer counter 30e every time a signal is supplied from the OR circuit 26 to the input port a1. Means 30g for latching the rotation angle measurement pulse signal supplied to the input port a2, a second register 30i to which the first to third count values N1 to N3 are sequentially input, a counter 30h
Comprising a from the count value of the output ports A ₀ when it matches the contents of the second register 30i and comparator 30j that gives a signal to the OR circuit 26, which are connected to one another by an internal bus.

In the microcomputer, the function realizing means 3 to 9 and 10 to 12 shown in FIG. 2 are constituted by a predetermined program according to an algorithm described later, and the ignition timing of the first to third cylinders of the engine is set. When each is measured, an ignition signal for the first to third cylinders is output to the output ports A1 to A3 through the input / output (I / O) interface 30k. These output ports A1 to A3
Are input to the ignition signal input terminals 17a to 17c of the ignition circuit 16, respectively. The ignition circuit 16 outputs signals for the first to third cylinders when the ignition signals are input to the input terminals 17a to 17c, respectively. One of the ignition coils 15a to 15c
The secondary current is controlled to induce a high voltage for ignition on the secondary side of each ignition coil.

The program stored in the ROM of the microcomputer is created in accordance with the control algorithm shown in FIGS. The main routine is as shown in FIG. 4. When the program is started, initial setting of each section is first performed, and then interruption is permitted. When any of the reference signals V _p1 to V _p3 and the cylinder discrimination signal V _pa is input to the input port a1, the interrupt routine shown in FIG. 5 is executed, and the first number N1 is set in the second register 30i. At the same time, the count value of the timer counter 30e (the time when a signal is input to the input port a1) is latched, and the value is
Stored in M. The difference between this time and the time when the signal was previously supplied to the input port a1 is calculated as cylinder discrimination data and stored in the RAM, and the cylinder is discriminated using this data.

That is, _assuming that the times at which the reference signals V _p1 to V _p3 are respectively input are T ₀₁ to T ₀₃ and the time at which the cylinder discrimination signal V _pa is input is T _0a , the time differences T ₀₁ −T ₀₃ , T _0a −T _01. , T ₀₂
-T _0a ,... _Are sequentially calculated and stored. These time differences are compared, when the cylinder discrimination signal V _pa between the Figure 8 the first reference as indicated in (A) signal V _p1 and a second reference signal V _p2 is generated, T ₀₁ When it is detected that −T ₀₃ ≧ k (T _0a −T ₀₁ ), it is determined that the reference signal V _p2 input to the input port a1 next is the reference signal corresponding to the second cylinder. . The determination of the cylinder is performed for each rotation. Note that the coefficient k is (T _0a −T ₀₁ ) when the engine whose rotation is unstable starts.
Is appropriate (so that the difference between T _{01 and} T ₀₃ is large) (generally k <1) so that the cylinder can be determined even if the value fluctuates.
Is set to

Upon completion of the cylinder determination, the process returns to the main routine in FIG. In the main routine, the target ignition timing Qi is calculated in accordance with the throttle opening (detected by the detecting means every time the throttle opening is changed and stored in the RAM as digital information). For safety, it is checked for abnormalities such as overheating and overspeed of the engine.If there is an abnormality, the ignition timing is retarded or the ignition spark is thinned in order to keep the rotational speed during the period below the safe speed. However, the ignition of a specific cylinder is misfired. However, since this point is out of the gist of the present invention, a detailed description is omitted. In addition, the process for ensuring this safety can be omitted.

The count value of the pulse signal of the counter 30h is stored in the second register 30i.
Signal is applied to the input port a1 and matching a first number N1, which is inputted through the OR circuit 26 from the output port A _0, the count of the count value (the first number N1 pulses signal of the timer counter 30e at that time T1) at which the operation ends is latched.

Each time the count value of the counter 30h matches the content of the second register 30i, the interrupt routine shown in FIG. 6 is executed. In this interrupt routine, first, it is determined whether or not the counting of the pulse signal of the third number N3 is completed, and then the second number N2 is determined.
It is determined whether or not the counting of the pulse signals of the first number N1 is completed. At the stage where the counting of the pulse signals of the first number N1 is completed, the counting of the second number N2 and the third number N3 is completed. Since it has not been performed, the process proceeds to the step of storing the count value of the timer counter 30e. As a result, the time T1 when the counting of the first number N1 is completed is stored. Next, the second number N2 is set in the second register 30i, and the process returns to the main routine. counter
When the count value of 30h matches the second number N2 input to the second register 30i, the count value of the timer counter 30e is latched, and the interrupt routine of FIG. The count value of the counter 30e (time T2 at which the counting of the second number N2 is completed) is stored. Next, after the third number N3 is set in the second register 30i, a process of calculating the ignition timing measurement time is performed. In this process, the time T2 at which the counting of the pulse signals of the second number N2 is completed and the time T1 of the first number N1 are completed.
From the time T1 at which the counting of the pulse signal is completed, and the angle rotated during this time (determined by the number N2 of ring gear teeth)
The information of the ignition timing Qi calculated in the main routine is obtained from the information of the engine rotation speed from the above, and the data corresponding to the angle from the rotation angle position to the ignition timing Qi when the counting of the third number N3 is completed. To the “ignition timing measurement time Ti”. Thereafter, the process returns 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 timer counter 30
While the count value of e is latched, 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 Ti is set in the first register 30e, the counter 30h is reset and stopped, and the process returns to the main routine.

When the count value of the timer counter 30e matches the content of the first register 30d, the interrupt routine shown in FIG. 7 is executed, and an ignition signal is given to the ignition signal input terminal of the determined cylinder.

FIG. 8 (D) shows how the count value of the timer counter rises, when a signal is given to the input port, and in the first state.
And the count value of the timer counter latched when the counting of the number N1 and the second number N2 is completed. Count value T
Although 1, T2 differs for each cylinder (for each reference signal), the same reference numeral is 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 the pulse signal, thereby realizing the first pulse counting means 3. When the count value of the counter 30h matches the first number N1, a timer counter is set. In the process of saving the count value of 30e, the first time storage means 4 is realized.

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

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

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

Further, an ignition signal supply means is provided by an interrupt routine shown in FIG.
11 is realized, and the cylinder discriminating means 12 is constituted in the process of discriminating the cylinder shown in FIG.

When the internal combustion engine is a single cylinder, the cylinder discriminating means is naturally omitted as shown in FIG.

In the above embodiment, the rotation speed information is obtained from the time from the time T1 when the counting of the pulse signal of the first number N1 ends to the time T2 when the counting of the pulse signal of the second number N2 ends. It is desirable to set the period during which the rotational speed information is obtained to a period during which the instantaneous rotational speed of the engine is relatively stable (changes at each rotation are small). It is desirable that this period is a period close to the time when the measurement of the ignition timing is actually started. In the present invention, by appropriately setting the first number N1, the period for obtaining the information on the rotational speed (the period for counting the pulse signals of the second number N2) can be set at an arbitrary position.

In a two-cycle engine, it is preferable to set the period for counting the second number N2 of pulse signals to a region (compression stroke) in which the rotation of the engine depends on inertia and the rotation speed decreases. The first number N1 is set such that the region for counting the second number N2 is set to an optimum region according to the characteristics of the engine and the rotational speed of the engine. It can also be changed appropriately according to the time required for counting the pulse signal.)

The time for counting the first number N1 of pulse signals and the second
The sum of the time for counting the pulse signals of the number N2 and the time for counting the pulse signals of the third number N3 is from the generation of each reference signal to the ignition of the cylinder corresponding to the reference signal. It is necessary to set each count value so as to be shorter than the time. Since the time from the generation of each reference signal to the ignition of the cylinder corresponding to the reference signal changes with the change of the rotation speed, the first to third numbers N1 to N3
Is preferably changed on software in accordance with the rotation speed.

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

Also, if the rotation speed is reduced from time T2 to time T3, the calculated ignition timing measurement time will be too short, but in this case, the position where the measurement of the ignition timing measurement time is started is delayed, The deviation between the actual ignition timing and the target ignition timing can be reduced.

As in the above embodiment, when a pulse signal is obtained using a ring gear, if the number of teeth of the ring gear cannot be divided by the number of cylinders, the number of pulse signals generated between the reference signals differs. Will be. In this case, the first to third numbers N1 to N3 to be set in the second register 30i (set for each cylinder) after the generation of the reference signal for each cylinder on software are made different for each cylinder. There is a need. When the first to third numbers N1 to N3 set for each cylinder are different in this way, if the relationship between the generation phase of the reference signal and the generation phase of the pulse signal varies from product to product, the ignition Timing shift occurs, and accurate ignition timing control cannot be performed. Therefore, when attaching the ring gear to the flywheel, it is necessary to manage so that the positional relationship between the teeth of the ring gear and the inductor magnetic pole part of the signal generator provided in a part of the flywheel is always constant. is necessary.

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

In the above embodiment, the reference signal V _{p1 is} used to enable the ignition operation even if the microcomputer fails.
It is desirable to provide a circuit for inputting V _p3 (generated at the maximum retard position) as an ignition signal to the ignition circuit without using a microcomputer.

In the above embodiment, the first to third numbers N1 to N3 are counted by one counter 30h. However, since the microcomputer normally has a plurality of counters, the third number The counting of N3 may be performed by another counter. In this case, the counting of the third number N3 may be started after the time when the counting of the first number N1 is completed, but usually the second number N3 is indicated by a solid line in FIG. 10 (D). At the time T2 when the counting of the number N2 is completed, the counting of the third number N3 is started, or at the time T1 at which the counting of the first number N1 is completed as indicated by a broken line in FIG. It is preferable to start counting the number N3 of three. The counting of the third number N3 may be started at a time other than these, for example, at an appropriate time within a period in which the counting of the second number N2 is performed.
In order to specify the time at which the counting of the third number N3 is started, means for measuring the time from the end of the counting of the first number N1 to the start of the counting of the third number N3 is required. Become.

It is necessary to set the counting end time of the third number N3 after the time when the calculation of the rotation speed and the calculation of the ignition timing measurement time are completed after the counting of the second number N2 is completed. Of course.

FIG. 9 shows a 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. The first counter 30h and the 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 content of the third register 30n. The output of the comparator 30p is input to the OR circuit 26 through the output port A ₀ '. Also the second
The output of the waveform shaping circuit 27 is input to the second counter 30m through the input port a3.

In this embodiment, the third register 30n stores the third number N
3 is input and the pulse signal is counted by the second counter 30m, and the counted value of the pulse signal is stored in the third register 30n.
When the value matches the content of (1), the count value of the timer counter 30e is latched and an internal interrupt is applied to execute the interrupt routine of either FIG. 11 or FIG.

The interrupt routine of FIG. 11 is the same as the interrupt routine of FIG. 11 except that the third number N3 is set in the third register and the counter for stopping after setting the ignition timing measurement time in the first register is the first counter 30h. This is the same as the interrupt routine shown in FIG. When the interrupt routine shown in FIG. 11 is used, as shown by the solid line in FIG.
The third number N3 is counted from the time when the counting of the number N2 is completed.

In the interrupt routine of FIG. 12, N2 is stored in the second register.
Set the third number N3 to the third register 30n after setting to 30i, and immediately calculate the ignition timing measurement time after saving the count value of the timer counter when the counting of the second number N2 is completed. 6 is the same as the example of FIG. When using the interrupt routine of FIG. 12,
As indicated by the broken line in FIG. 10 (D), the counting of the third number N3 is started at the time T1 when the counting of the first number N1 is completed. In this case, the time at which the counting of the third number N3 ends is the second number.
It is set after the time when the calculation of the rotational speed and the calculation of the ignition timing measurement time are completed after the counting of N2 is completed.

As described above, the counting of the pulse signal of the third number N3 is performed by the first
When a counter separate from the counter for counting the pulse signals of the number N1 and the second number N2 is used, the first number N1
Even if the rotation angle from the start of the counting of the first number to the end of the counting of the third number N3 exceeds the rotation angle between the reference signals V _p1 , V _p2 ,... (120 degrees in the case of three cylinders) Good. Normally, the reference signal is generated at the minimum advance position of the engine (for example, 10 degrees before the top dead center). With the above configuration, the position where the counting of the third number N3 ends is set to be more than 10 degrees before the top dead center. Since the position can be set to a further delayed position (a position close to the top dead center), a stable ignition operation can be performed even when the ignition operation is performed at a position further delayed than the generation position of the reference signal.

Further, it is not necessary to limit the counting start time of the third number N3 to the counting end time of the second number N2, so that the degree of freedom in designing the program can be increased.

[Effects of the Invention] As described above, according to the present invention, each time the reference signal is generated from the signal generator, the counting of the pulse signal is started and the first number N1, the second number N2 and the third number N2 are calculated. The number N3 of pulse signals are counted, and information on the rotational speed is obtained from the difference between the time T2 when the second number of pulse signals are counted and the time T1 when the first number of pulse signals are counted. Then, the ignition timing measurement time corresponding to the angle from the rotation angle position to the target ignition timing Ti when the counting of the third number of pulse signals is completed is obtained based on the information on the rotation speed. By appropriately setting the first number N1 according to the characteristics of the speed fluctuation, the period from time T1 to time T2 at which the information on the rotation speed is obtained can be set to an area where the fluctuation of the rotation speed is the least, Information on the rotation speed can be obtained accurately. In addition, since the speed of the rotation generated by the immediately preceding ignition is accurately detected and the ignition timing measurement time is calculated based on the rotation speed, it is possible to appropriately control the ignition timing. it can.

Further, since the measurement of the ignition timing measurement time is started after the third number N3 is counted, the information of the rotation speed is obtained at time T2, and then the time T3 at which the measurement of the ignition timing measurement time is actually started is obtained. There is the advantage that errors due to speed fluctuations occurring between them can be corrected, and errors in ignition timing due to instantaneous speed fluctuations can be reduced.

[Brief description of the drawings]

FIGS. 1 and 2 are claims correspondence diagrams showing the configuration of the invention of claims 5 and 6, respectively. FIG. 3 is a configuration diagram schematically showing the configuration of an apparatus used in an embodiment of the present invention. 7 to 9 are flowcharts showing a control algorithm according to an embodiment of the present invention. FIG. 8 is a diagram for explaining signal waveforms and counting operations of a counter and a timer in the embodiment of the present invention. FIG. 10 is a configuration diagram showing the configuration of an apparatus used in another embodiment, FIG. 10 is a diagram showing signal waveforms in the embodiment of FIG. 9, and FIGS. 11 and 12 are different in control algorithm of the embodiment. FIG. 13 is a flow chart showing an example, and FIG. 13 is a diagram showing rotation fluctuation of the internal combustion engine. 1 ... Rotation speed measurement pulse generating means, 2 ... Signal generator,
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 calculating means, 9
... Ignition timing measurement time calculation means, 10 ... Ignition device for internal combustion engine, 11 ... Ignition signal supply means, 12 ... Cylinder discrimination means.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyasu Nito 3744 Ooka, Numazu City, Shizuoka Prefecture Inside Kokusai Denki Co., Ltd. (72) Inventor Kazuo Watanabe 3744 Ooka, Numazu City, Shizuoka Prefecture Kokusai Electric Co., Ltd. (72) Inventor Yasuo Sasaki 3744 Ooka, Numazu City, Shizuoka Prefecture Inside of Domestic Electric Co., Ltd. (56) References JP-A-58-211569 (JP, A) JP-A-58-70052 (JP, A) JP-A-1-315672 (JP, A)

Claims (6)

(57) [Claims] 1. An ignition timing control method for controlling an ignition timing of an internal combustion engine by controlling a timing of giving an ignition signal to an ignition device for an internal combustion engine, wherein the pulse signal generates a pulse signal every time the internal combustion engine rotates by a small angle. A signal generator for generating a reference signal at a predetermined rotational angle position of the internal combustion engine; and starting counting the pulse signal each time the reference signal is generated to generate a first number N1 of pulses. The time when the signal was counted
T1 is stored, and the time T2 at which the pulse signal of the second number N2 is counted by further starting the counting of the pulse signals from the time when the counting of the first number of pulse signals is completed is stored. The counting of the third number N3 of pulse signals is started after the time when the counting of the first number of pulse signals is completed, and the second number is counted until the counting of the third number of pulse signals is completed. The time T2 when the counting of the pulse signal of N2 ends and the first time
Based on the information on the rotational speed obtained from the difference from the time T1 at which the counting of the number N1 of pulse signals is completed, the target ignition timing Qi is calculated from the rotational angle position at the time when the counting of the third number of pulse signals is completed.
When the ignition timing measurement time Ti corresponding to the angle until is obtained, the measurement of the ignition timing measurement time Ti is started from the time when the counting of the third number of pulse signals is completed, and the measurement of the measurement time is completed. Causing the ignition device for an internal combustion engine to perform an ignition operation. 2. The engine according to claim 1, wherein the internal combustion engine is a multi-cylinder internal combustion engine having two or more cylinders, and the signal generator generates the reference signal for each cylinder. It is configured to generate a cylinder discrimination signal, by comparing the time interval between the reference signals output from the signal generator, the time interval between the cylinder discrimination signal and the reference signal generated before, 2. The ignition timing control method for an internal combustion engine according to claim 1, wherein a cylinder for performing an ignition operation is determined. 3. An ignition timing control device for an internal combustion engine which controls the ignition timing of the internal combustion engine by controlling the timing of giving an ignition signal for determining the ignition timing to the ignition device for the internal combustion engine. Pulse signal generating means for generating a pulse signal each time the signal is generated; a signal generator for generating a reference signal at a predetermined rotational angle position of the internal combustion engine; and starting counting the pulse signal each time the reference signal is generated. A first pulse counting means for counting a first number N1 of pulse signals, a first pulse storage means for storing a time T1 at which the first pulse counting means has finished counting, A second pulse counting means for starting counting the pulse signals further from the time when the counting of the pulse signals of N1 is completed and counting the pulse signals of the second number N2; and the second pulse counting means ends the counting. did A second time storage means for storing the time T2; a counting operation is started after the time T1 when the counting of the first number of pulse signals is completed, and a pulse is generated until the third number N3 of pulse signals are counted. Third pulse counting means for counting a signal; ignition timing calculating means for calculating a target ignition timing Qi; and the second pulse counting means until the third number of pulse counting means finishes counting pulse signals. The third pulse counting means performs counting based on information on the rotational speed obtained from the difference between the time T2 at which the counting of the pulse signals of the number N2 is completed and the time T1 at which the counting of the pulse signals of the first number N1 is completed. The ignition timing measurement time calculating means for calculating the ignition timing measurement time Ti corresponding to the angle from the rotational angle position to the target ignition timing Qi at the time of ending, and the time when the third number of pulse counting means has finished counting. T3
Starting the measurement of the ignition timing measurement time from the start, and providing an ignition signal to the ignition device for the internal combustion engine when the measurement of the measurement time is completed. Timing control device. 4. The internal combustion engine is a multi-cylinder internal combustion engine,
The ignition device for an internal combustion engine has an input terminal for an ignition signal for each cylinder, and the signal generator generates the reference signal for each cylinder, and generates a reference signal corresponding to two predetermined cylinders. A cylinder discriminating unit configured to generate a cylinder discriminating signal between the cylinder discriminating signal and a cylinder discriminating unit that discriminates a reference signal generated next to the cylinder discriminating signal as a reference signal corresponding to a specific cylinder to discriminate a cylinder to perform an ignition operation 4. The ignition timing control device for an internal combustion engine according to claim 3, further comprising: an ignition signal supply unit that supplies an ignition signal to an input terminal of an ignition signal corresponding to the cylinder determined by the cylinder determination unit. 5. A flywheel magnet generator is mounted on an output shaft of said internal combustion engine, and said pulse signal generating means is adapted to engage an output gear of a starter for the internal combustion engine with a flywheel of said flywheel magnet generator. 5. An iron-shaped ring gear provided on the outer periphery of the ring gear, and an inductor-type signal generator for inducing a pulse signal by a change in magnetic flux generated by the ring gear. An ignition timing control device for an internal combustion engine according to the above. 6. A signal generator wound around an iron core having an inductor magnetic pole portion provided on a part of the flywheel, a magnetic pole portion facing the inductor magnetic pole portion, and the signal generator. The ring gear is positioned with respect to the flywheel such 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, wherein: