JPH109109A - Ignition timing controlling device for ignition device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition timing controlling device for an ignition device of the internal combustion engine, for which it is possible to obtain, an ignition section signal for determining the change width of the generation position of the ignition signal with a simple constitution. SOLUTION: When a first and second signals Vs1 and Vs2 generated by a signal coil 1 reach a first and second thresholds respectively at the maximum spark advance position and the minimum spark advance position of the internal combustion engine, a first and second waveform shaping circuits 2 and 3 generate a first and second pulses Vp1 and Vp2 to generate, from an ignition section signal generating circuit 4, an ignition section signal Vq which lasts from the first pulse generation position to the second pulse generation position. When the number of revolutions of the internal combustion engine is smaller than the preset value, the first threshold is set so as not to generate the first pulse Vp1 at the level of the first signal Vs1 at such a moment, and the second threshold is set so as to generate the second pulse Vp2 even when the number of revolutions is smaller than the present value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing for determining the ignition timing of an internal combustion engine by appropriately changing an ignition signal between a maximum advance position and a minimum advance position of the engine in accordance with the rotational speed. The present invention relates to an ignition timing control device for an internal combustion engine ignition device to be controlled.

[0002]

2. Description of the Related Art As an apparatus for controlling the ignition timing of an internal combustion engine, a first signal and a second signal having a phase delayed from the first signal are used.
A signal generator that generates the first signal in synchronization with the rotation of the internal combustion engine, a first waveform shaping circuit that outputs a first pulse when the first signal reaches a first threshold level, , Second
A second waveform shaping circuit that generates a second pulse when the signal reaches a second threshold level, and a second waveform shaping circuit that receives the first and second pulses as input and generates a second pulse from the first pulse generation position. An ignition section signal generation circuit that generates an ignition section signal that lasts for the section up to the pulse generation position, and a signal that changes the generation position with the maximum change width in the section in which the ignition section signal is generated is used to determine the ignition timing of the internal combustion engine. There is known an apparatus including an ignition signal generation circuit that outputs an ignition signal to be determined. In this type of ignition timing control device, the position where the first signal reaches the first threshold level matches the maximum advance position of the internal combustion engine, and the second signal reaches the second threshold level. The signal generator is configured such that the position corresponds to the minimum advance position of the internal combustion engine. The ignition signal generation circuit includes an integration circuit that sets an interval in which the ignition interval signal is generated as an integration interval, and a comparison circuit that compares an output of the integration circuit with a reference voltage.

In this type of ignition timing control device, an ignition interval signal is generated halfway when the engine is started, and the integration circuit of the ignition signal generating circuit may perform the integration operation halfway, so that the initial ignition timing is incorrect. In some cases, an ignition signal is generated at a timing that is earlier than the normal ignition timing at a low speed, and the ignition timing is advanced at the time of starting. Also, when the engine is at an extremely low speed (for example, at a low speed of 1000 rpm or less), the angular velocity of the rotating shaft of the engine greatly changes during one rotation, and the angular velocity changes considerably before and after ignition. 2, the time interval of the ignition section signal does not become a regular length at each rotation speed, and the operation of the integration circuit of the ignition signal generation circuit is disturbed. There were times when it was off.

When the ignition timing is advanced at the time of starting the engine as described above, a so-called Ketchin phenomenon in which the engine tries to reverse is caused. In particular, in the case of an engine which performs a rope start or a kick start, the reaction of the engine causes the driver to react. Risk of injury.

Therefore, as shown in Japanese Patent Publication No. 2-31791, the ignition signal is generated by the second pulse generated at the minimum advance position without generating the ignition section signal when the engine is at extremely low speed. Thus, there has been proposed an ignition timing control device which prevents the ignition timing from advancing when the engine is started or at an extremely low speed.

In this conventional ignition timing control device, the ignition section signal generation circuit includes a first switch triggered by a second pulse, and a first capacitor charged when the first switch is triggered. A discharge circuit for discharging the first capacitor with a constant time constant, and a second circuit that conducts when the terminal voltage of the first capacitor is at or above a predetermined trigger level when the first pulse is input. A second switch connected to the first switch for charging almost instantaneously when the second switch is turned on and discharging almost instantaneously through the first switch when the first switch is turned on. And a terminal voltage of the second capacitor or a voltage corresponding to the terminal voltage is output as an ignition interval signal. In the ignition section signal generation circuit, the terminal voltage of the first capacitor is reduced to a value lower than a predetermined trigger level when the first pulse is generated at an extremely low speed of the engine, so that the second switch Is kept in the cut-off state so that the ignition section signal is not generated. Further, the ignition signal generating circuit is provided with a circuit for outputting an ignition signal when the second pulse is generated, so that the ignition signal is output at the minimum advance position at an extremely low speed of the engine where no ignition section signal is generated. ing.

[0007]

[Problems to be Solved by the Invention]
In the conventional ignition timing control device shown in FIG. 1, the first switch is triggered by the second pulse in order to prevent the ignition signal from being generated at a position advanced from the normal ignition timing at an extremely low speed of the engine. A first capacitor that is charged when
It is necessary to provide a discharge circuit for discharging the first capacitor with a constant time constant in the ignition interval signal generation circuit, and when the first pulse is inputted, the terminal voltage of the first capacitor is set to a predetermined trigger. It was necessary to make the second switch conductive only when it was above the level. Therefore, there is a problem that the ignition section signal generation circuit becomes complicated, the number of components increases, and the manufacturing cost of the device increases.

An object of the present invention is to make it possible to form an ignition interval signal generation circuit with a smaller number of circuit components than in a conventional ignition timing control device of this type, and to generate an ignition interval signal at an extremely low speed of the engine. An object of the present invention is to provide an ignition timing control device for an internal combustion engine ignition device which can generate an ignition signal at a minimum advance position without causing the possibility that the ignition timing will advance at the time of starting or at an extremely low speed.

[0009]

According to the present invention, there is provided a signal generator for generating a first signal and a second signal having a phase delayed from the first signal in synchronization with rotation of an internal combustion engine. A first waveform shaping circuit that outputs a first pulse when the first signal reaches a first threshold, and a second waveform shaping circuit that outputs a second pulse when the second signal reaches a second threshold level A second waveform shaping circuit for generating a first pulse and a first
An ignition section signal generating circuit for generating an ignition section signal that lasts for a section from the pulse generation position to the second pulse generation position, and the generation position changes with the maximum change width in the section in which the ignition section signal is generated. An ignition signal generating circuit for outputting a signal as an ignition signal for determining an ignition timing of the internal combustion engine, wherein a position at which the first signal reaches a first threshold level coincides with a maximum advance position of the internal combustion engine. The ignition timing control device for an internal combustion engine ignition device, wherein the signal generator is configured such that the position where the second signal reaches the second threshold level coincides with the minimum advance position of the internal combustion engine. The configuration of the signal generation circuit is simplified, and the ignition timing is prevented from being advanced due to the ignition section signal being generated halfway during starting.

According to the present invention, a first switch which is turned on when triggered by a first pulse, a capacitor which is charged when the first switch is turned on, and a second switch which turn on the ignition interval signal generating circuit by a first pulse; A second switch that is triggered by the pulse to conduct and discharge the capacitor. Then, a first threshold level is set so that the first pulse is not generated at the level of the first signal when the rotation speed of the internal combustion engine is equal to or lower than the set value. Also generates a second pulse.
Set the threshold level for

The ignition signal generating circuit is provided with a low-speed ignition signal output circuit for outputting an ignition signal when a second pulse is generated in a rotation speed region where an ignition section signal is not generated.

With the above configuration, in the region where the rotation speed exceeds the set value, both the first pulse and the second pulse are generated and the ignition interval signal is output from the ignition interval signal generation circuit, so that the ignition The signal generation circuit outputs an ignition signal whose generation position changes between a maximum advance position and a minimum advance position. In the region where the rotation speed is equal to or lower than the set value, the level of the first signal does not reach the first threshold level, and the first pulse is not generated. The signal generation circuit does not output the ignition interval signal. Therefore, in this case, the second advance is
When the pulse is generated, the ignition signal is output from the low-speed ignition signal output circuit.

As described above, according to the present invention, when the rotational speed of the engine is extremely low below the set value, the first threshold level is set so that the first pulse does not occur at the level of the first signal. The ignition interval signal can be prevented from being generated at extremely low speeds only by setting, and the phenomenon that the ignition timing is advanced at the time of starting the engine and at extremely low speeds by using the ignition interval signal generation circuit having a simple circuit configuration. Can be prevented.

[0014]

FIG. 1 shows an example of a configuration of a main part of an ignition timing control device according to the present invention. FIG. 2 shows signal waveforms of respective parts in FIG. The waveform shown by the broken line in FIG. 2 indicates that the rotation speed of the internal
m) The following shows the waveform at the time of extremely low speed, and the waveform shown by the solid line shows the waveform when the rotation speed of the internal combustion engine exceeds the set value.

In FIG. 1, reference numeral 1 denotes a signal coil provided in a signal generator which is attached to an internal combustion engine and rotates synchronously with the engine. As shown in FIG. A first signal Vs1 at which the position θ1 reaching the threshold level Vth1 coincides with the maximum advance position of the engine, and a second signal V2 at which the position θ2 reaching the second threshold level Vth2 coincides with the minimum advance position of the engine. Signal Vs2. In this example, the first signal Vs1 is a signal having a negative polarity, and the second signal Vs2 is a signal having a positive polarity. In FIG. 2, the angle of each position on the horizontal axis indicates an angle measured from the top dead center to the advanced side (left side of the horizontal axis in FIG. 2) from the top dead center TDC of the engine as zero.

In FIG. 1, reference numeral 2 denotes a first waveform shaped as shown in FIG. 2B when the first signal Vs1 reaches the first threshold level Vth1 at the maximum advance position θ1. This is a first waveform shaping circuit that outputs a pulse (a negative pulse in this example) Vp1. This first waveform shaping circuit 2 includes an NPN
A transistor TR1, a resistor R1 connected between the base and the emitter of the transistor, a resistor R2 having one end connected to the collector of the transistor TR1, and a transistor T1.
A resistor R3 having one end connected to the base of R1;
3, a capacitor C1 connected between the other end of the capacitor C1 and the ground, a resistor R4 connected in parallel to both ends of the capacitor C1, an anode connected to the emitter of the transistor TR1, and a cathode connected to the non-ground terminal of the signal coil 1. The other end of the resistor R2 is the non-grounded output terminal of the waveform shaping circuit.

In the first waveform shaping circuit 2, the first
When the level of the signal Vs1 is equal to or lower than the first threshold level Vth1, the transistor TR1 does not conduct, so that the first pulse Vp1 is not output. When the level of the first signal Vs1 reaches the first threshold level Vth1, the transistor TR1 conducts and outputs a first pulse Vp1 (a negative pulse in the example shown). First threshold level Vth1
Is the first signal V when the rotational speed of the engine is equal to or less than the set value.
At the level of s1, the magnitude is set so as not to generate the first pulse Vp1.

Reference numeral 3 denotes a second waveform shaping circuit. The waveform shaping circuit 3 includes a capacitor C2 and a diode D2, one ends of which are connected to the non-ground side terminal of the signal coil 1, and a second end of the capacitor C2 and the resistor R5. The diode D2 has an anode connected in common, resistors R6 and R8 having one end connected to the cathode of the diode D2, and a resistor R7 connected between the other end of the resistor R6 and ground. The other end is an output terminal on the non-ground side of the waveform shaping circuit.

The second waveform shaping circuit 3 converts the second signal Vs2 generated by the signal coil 1 to a second threshold level Vth2.
When the second pulse V is reached as shown in FIG.
p2 (a positive pulse in the illustrated example) is output. In the present invention, the second signal Vs2 reaches the second threshold value Vth2 even when the rotational speed of the engine is equal to or lower than the set value, so that the second pulse Vp2 is generated. The magnitude of threshold value Vth2 is set sufficiently small. In the illustrated example, the magnitude of the second threshold value Vth2 is substantially determined by the voltage across the capacitor C2 and the forward voltage drop of the diode D2.

Reference numeral 4 denotes first and second pulses Vp1 and Vp1 outputted by the first and second waveform shaping circuits 2 and 3, respectively.
Using p2 as input, the maximum advance position θ1 to the minimum advance position θ2
This is an ignition section signal generation circuit that outputs an ignition section signal Vq (FIG. 2D) that lasts for the section up to. The illustrated ignition section signal generation circuit 4 has an emitter connected to a positive output terminal of a DC power supply circuit (not shown) that outputs a DC voltage Vcc, and has a base connected to the other end (the first terminal) of the resistor R2 of the first waveform shaping circuit 2. PNP transistor TR2 connected to the non-ground side output terminal of the waveform shaping circuit, a capacitor C3 connected between the collector and ground of the transistor TR2, and a resistor R6 of the second waveform shaping circuit whose emitter is grounded and whose base is grounded. And an NPN transistor TR3 connected to the other end of the
A diode D having an anode and a cathode connected to the collector of R2 and the collector of transistor TR3, respectively;
It consists of three. In the example shown in FIG. 1, the transistor TR2 triggers the first pulse Vp1 to conduct and the first switch 40 which charges the capacitor C3.
1 and the transistor TR3 constitutes a second switch 402 which is triggered by the second pulse Vp2 to conduct and discharge the capacitor C3.

In the illustrated ignition section signal generation circuit 4, when the first pulse Vp1 is inputted at the maximum advance position θ1, the transistor TR2 is turned on by the first pulse and the capacitor C3 is almost instantaneously turned on. Charged. When the second pulse Vp2 is input at the minimum advance position .theta.2, the transistor TR3 is turned on and the electric charge of the capacitor C3 is discharged almost instantaneously through the diode D3 and the transistor TR3. Therefore, between the both ends of the capacitor C3, FIG.
As shown in (D), a rectangular wave voltage that lasts in the section from the maximum advance position θ1 to the minimum advance position θ2 is generated, and the rectangular wave voltage is output as the ignition section signal Vq. If the first pulse Vp1 is not input at the maximum advance position θ1, the transistor TR2 does not conduct, so that the ignition section signal V1 is not generated.

Reference numeral 5 denotes an ignition signal generation circuit which receives the ignition section signal Vq as an input. The ignition signal generation circuit includes a section from the maximum advance position θ1 to the minimum advance angle θ2 to which the ignition section signal Vq is input. Is the maximum change width (maximum advance width), and the signal Vg '(the solid line waveform in FIG. 2E) whose generation position changes.
Is output as an ignition signal Vg for determining the ignition timing of the engine.

The ignition signal generating circuit 5 also generates a signal Vp2 '(the dashed waveform in FIG. 2E) having the same shape as the second pulse Vp2 obtained from the second waveform shaping circuit 3 when the second pulse Vp2 is generated. A low-speed ignition signal output circuit for outputting an ignition signal Vg is provided.

In the ignition timing control device shown in FIG. 1, when the rotational speed of the engine is equal to or lower than the set value (at an extremely low speed), the level of the second signal Vs2 induced in the signal coil 1 is changed to the second threshold. Although the second pulse Vp2 is generated at the minimum advance position .theta.2 when the signal level exceeds the value level Vth2, the level of the first signal Vs1 does not reach the first threshold level Vth1, so that
Does not occur. Therefore, the transistor TR
2 does not conduct and the capacitor C3 is not charged, so that no ignition interval signal Vq is generated. In this case, when the second pulse Vp2 is generated at the minimum advance position, the low-speed ignition signal output circuit in the ignition signal generation circuit 5 ignites a signal Vp2 'having the same shape as the second pulse Vp2. Output as signal Vg. Therefore, when the rotational speed of the engine is lower than the set value, the engine is ignited at the minimum advance position θ2.

When the engine speed rises and exceeds the set value, the level of the first signal Vs1 exceeds the first threshold level Vth1, so that the first and second waveforms are obtained. The shaping circuits 2 and 3 respectively operate the first pulse Vp1 and the second pulse Vp1 at the maximum advance position θ1 and the minimum advance position θ2.
Outputs P2. Therefore, the ignition section signal generation circuit 4 outputs an ignition section signal Vq that lasts for the section from the maximum advance position θ1 to the minimum advance position θ2, and the ignition signal generation circuit 5
Maximum advance angle θ1 and minimum advance angle θ2 according to rotation speed
And the ignition signal Vg, the signal Vg 'whose position changes between
Output as Therefore, in a region where the engine speed exceeds the set value, the ignition position is changed according to the change in the engine speed.

As described above, in the present invention, when the rotational speed of the engine is extremely low at or below the set value, the first pulse Vp1 is not output from the first waveform shaping circuit, thereby generating the ignition section signal. Since the ignition section signal Vq is not generated in the circuit and the ignition signal is generated at the minimum advance position, the configuration of the ignition section signal generation circuit can be simplified. In addition, the ignition section signal Vq is not generated halfway when the engine is started, and the time width of the ignition section signal is not deviated due to a change in the angular velocity of the rotating shaft of the engine at an extremely low speed immediately after the start. It is possible to prevent the ignition timing from being excessively advanced at a low speed.

The set rotation speed at which the generation of the first pulse Vp1 and thus the generation of the ignition interval signal Vq is started is determined by the magnitude of the first threshold level Vth1. In the above embodiment, the magnitude of the first threshold level Vth1 can be appropriately adjusted by adjusting the resistance value of the resistor R3. When the resistance value of the resistor R3 is increased, the set rotation speed is increased. If the resistance value of the resistor R3 is reduced, the set rotation speed can be reduced.

FIG. 3 shows a specific configuration example of the ignition signal generation circuit 5 used in the ignition timing control device, together with a configuration example of an ignition circuit to which an ignition signal is given by the ignition timing control device. FIG. 4 shows the signal waveforms of the respective parts.

In the ignition device shown in FIG. 3, the ignition signal generating circuit 5 includes a transistor TR4, a programmable unijunction transistor PU1, and a capacitor C4.
To C6, resistors R9 to R14, and diode D4
It is composed of Here, the capacitors C5 and C6 are first and second integration capacitors, respectively. At the same time when the ignition section signal Vq is generated at both ends of the capacitor C3, the transistor TR4 is turned on to instantaneously charge the first integration capacitor C5. When the terminal voltage of the capacitor C5 reaches a value obtained by dividing the terminal voltage of the capacitor C3 by the resistors R9 and R10, the transistor TR4 is turned off, and thereafter the capacitor C5 is kept constant through the resistor R11 by the voltage across the capacitor C3. It is additionally charged with a time constant.
The electric charge of the capacitor C5 is discharged to the second position at the minimum advance position θ2.
When the transistor TR3 is turned on by the generation of the pulse Vp2, the resistor R11, the diode D3 and the transistor TR3 are turned on.
3 Discharge almost instantaneously through. Therefore, the capacitor C
5 shows the waveform of the first integrated voltage Vc5 obtained at both ends of FIG.
As shown in (C), the waveform instantaneously rises to a constant voltage at the maximum advance position θ1, rises with a constant gradient, and instantly returns to zero at the minimum advance position θ2.

The second integrating capacitor C6 is charged with a constant time constant from the DC power supply circuit 6 through the resistor R12, and is instantaneously discharged through the diode D4 and the transistor TR3 when the transistor TR3 is turned on at the minimum advance position θ2. I do. Accordingly, the waveform of the second integrated voltage Vc6 obtained at both ends of the capacitor C6 is as shown in FIG.
From the minimum advance position θ2 to the next minimum advance position θ2, the waveform rises from zero with a constant gradient.

The first and second integrated voltages Vc5 and Vc6
Are applied between the grounded anode and the grounded gate of the programmable junction transistor PU1, respectively, and are compared. The programmable junction transistor PU1 is turned on when the first integrated voltage Vc5 becomes equal to or higher than the second integrated voltage Vc6, and the signal Vg '(FIG. 4)
D) and supplies the signal Vg 'to the ignition circuit 7 as an ignition signal Vg. The angular position at which the first integrated voltage Vc5 becomes equal to or higher than the second integrated voltage Vc6 advances as the engine speed increases, and the position at which the ignition signal Vg is generated (ignition timing) increases as the engine speed increases. Advancing with it.
The advance width of the ignition signal Vg is determined by the width of the ignition section signal Vq, and does not advance beyond the maximum advance position θ1.

The ignition interval signal Vq is not generated when the engine rotational speed is extremely low below the set value. In this case, as described above, when the second pulse Vp2 is generated at the minimum advance position θ2, this signal is generated. A pulse Vp2 '(FIG. 4E) having the same shape as the second pulse Vp2 is supplied to the ignition circuit 7 as an ignition signal Vg.
Therefore, at extremely low speeds, ignition always occurs at the minimum advance position,
The advance of the ignition timing is prevented.

The ignition circuit 7 shown in FIG. 3 is a known capacitor discharge type circuit, and comprises an ignition coil IG, an exciter coil Le, an ignition energy storage capacitor C8,
Thyristor S1, resistor R16, diodes D6 and D
7 and a spark plug P attached to a cylinder of the engine.

In this ignition circuit, an exciter coil Le is arranged in a magnet generator (not shown) driven by the engine, and the output of the positive half cycle of the exciter coil is connected to a capacitor C8 through diodes D6 and D7.
Is charged to the illustrated polarity. The voltage Vc8 across the capacitor C8 is shown in FIG. When the ignition signal Vg (Vg 'or Vp2') is supplied to the gate of the thyristor S1, the thyristor S1 conducts, and the electric charge of the capacitor C8 is discharged through the thyristor S1 and the primary coil of the ignition coil IG. As a result, a high voltage is induced in the secondary coil of the ignition coil, a spark is generated in the ignition plug P, and the engine is ignited.

The DC power supply circuit 6 comprises a circuit in which a series circuit of a diode D5, a resistor R15 and a capacitor C7 is connected to both ends of an exciter coil Le, and a DC voltage Vcc obtained across both ends of a capacitor C7 is connected to an emitter of a transistor TR2. It is supplied between the ground and between one end of the resistor R12 and the ground.

In the example shown in FIG. 3, the ignition timing includes the ignition circuit 7, the DC power supply circuit 6, the signal coil 1, the waveform shaping circuits 2 and 3, the ignition section signal generation circuit 4, and the ignition signal generation circuit 5. An ignition device for an internal combustion engine is configured by the control device.

FIG. 5 shows the configuration of another ignition device using the ignition timing control device according to the present invention. FIG. 6 shows signal waveforms at various points in the same drawing.

In the ignition device shown in FIG. 5, the ignition signal generating circuit 5 includes an integrating capacitor C9 and a transistor TR5.
, TR6, resistors R17 to R24, comparator CP1
And diodes D8 to D10. Other points are the same as the example shown in FIG.

In the ignition signal generating circuit 5 used in the ignition device of FIG. 5, the integrating capacitor C9 is charged by the output of the DC power supply circuit 6 through the resistor R22 and the transistor TR5, and its terminal voltage Vc9 has a constant gradient. Going up. When the ignition section signal Vq is generated at the maximum advance position θ1, the transistor TR6 is turned on to discharge the capacitor C9 through the resistor R19 with a constant time constant. When the ignition section signal Vq becomes zero at the minimum advance angle θ2, the transistor TR
6 is cut off. At this time, the second pulse Vp2 is generated, so that the transistor TR3 is turned on and the charge of the integrating capacitor C9 is discharged instantaneously through the diode D10 and the transistor TR3. Therefore, the integrated voltage Vc9 obtained at both ends of the integrating capacitor C9 is, as shown in FIG.
A waveform that rises at a constant gradient from the minimum advance position θ2 to the maximum advance position θ1, falls at a constant gradient from the maximum advance position θ1 to the minimum advance position θ2, and instantly returns to zero at the minimum advance position. become.

The integrated voltage Vc9 is compared with the reference voltage Vr obtained at both ends of the resistor R24 by the comparator CP1. When the falling slope of the integrated voltage Vc9 becomes lower than the reference voltage Vr, the signal Vg 'from the comparator CP1 is output. Is output. This signal Vg 'is supplied as the ignition signal Vg to the gate of the thyristor S1 of the ignition circuit 7 through the diode D8. The position at which the falling slope of the integrated voltage Vc9 becomes equal to or lower than the reference voltage Vr advances as the engine speed increases, and therefore the signal Vg '
The position of occurrence advances with an increase in the rotation speed, and an advanced angle characteristic is obtained. Since the ignition section signal Vq is not generated at an extremely low speed of the engine, the signal Vp2 'simultaneously generated at the minimum advance position .theta.2 and simultaneously with the second pulse Vp2 is supplied to the ignition circuit through the diode D9 as the ignition signal Vg.

In the examples shown in FIGS. 3 and 5, the ignition circuit 7 is a capacitor discharge type circuit. However, another type of circuit, for example, a current cutoff type ignition circuit 7 shown in FIG. Can also be used. In this ignition circuit, a collector-emitter circuit of a transistor TR7 whose emitter is grounded is connected in series to a primary coil of an ignition coil IG, and a voltage of a battery B is connected across the series circuit of the primary coil and the transistor TR7. Is applied.
When this ignition circuit is used, a rectangular wave signal Vg is supplied from the ignition signal generation circuit 5 to the base of the transistor TR7. This square wave signal rises before the ignition timing and falls to zero at the ignition timing, and the falling edge of the square wave signal becomes the ignition signal. While the square wave signal Vg is applied to the base of the transistor TR7, the transistor conducts and a primary current flows through the ignition coil. When the rectangular wave signal Vg falls at the ignition timing, the transistor TR7 is turned off, so that a high voltage is induced in the primary coil of the ignition coil IG so as to continue to flow the current that has been flowing so far. It is further boosted and the ignition coil 2
A high voltage for ignition is induced in the next coil.

An ignition signal generating circuit 5 used in this ignition device
Is a rectangular wave signal Vg whose fall position (ignition timing) changes in accordance with the rotation speed with the section in which the ignition section signal Vq is generated when the engine rotation speed exceeds a set value as the maximum change width. In the extremely low speed region where the rotation speed of the engine is lower than the set value, a rectangular wave signal Vg which falls when the second pulse Vp2 is generated is generated.

[0043]

As described above, according to the present invention, when the rotational speed of the engine exceeds the set value, an ignition section signal whose generation section is determined by the first and second pulses is generated,
When the rotation speed of the engine is equal to or lower than the set value, the generation of the ignition section signal is stopped by not generating the first pulse, and the ignition signal for determining the ignition timing of the engine is generated when the second pulse is generated. Therefore, it is possible to prevent the ignition signal generation circuit from malfunctioning when the engine is started or at an extremely low speed, thereby preventing the ignition timing from being advanced. Further, according to the present invention, since the configuration of the ignition section signal generation circuit can be simplified, there is an advantage that the ignition timing control device can be manufactured at lower cost than before.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of an ignition timing control device according to the present invention.

FIG. 2 is a waveform diagram showing signal waveforms at various parts in FIG.

FIG. 3 is a circuit diagram showing a configuration example of an ignition device for an internal combustion engine using the control device of the present invention.

FIG. 4 is a waveform diagram showing signal waveforms at various parts in FIG.

FIG. 5 is a circuit diagram showing another example of the configuration of the ignition device using the control device of the present invention.

FIG. 6 is a waveform diagram showing signal waveforms at various parts in FIG.

FIG. 7 is a circuit diagram showing still another configuration example of the ignition device to which the control device of the present invention is applied.

[Description of Signs] 1 signal coil 2 first waveform shaping circuit 3 second waveform shaping circuit 4 ignition section signal generation circuit 401 first switch 402 second switch 5 ignition signal generation circuit 6 DC power supply circuit 7 ignition circuit C3 capacitor C5 First integration capacitor C6 Second integration capacitor C8 Ignition energy storage capacitor TR1 to TR7 Transistor PU1 Programmable unijunction transistor S1 Thyristor IG Ignition coil Le Exciter coil

Claims (1)

[Claims] 1. A signal generator for generating a first signal and a second signal having a phase delayed from that of the first signal in synchronization with rotation of an internal combustion engine, and wherein the first signal is a first signal. And a first waveform shaping circuit for outputting a first pulse when the second signal reaches a second threshold level, and generating a second pulse when the second signal reaches a second threshold level. A second waveform shaping circuit, and an ignition section signal generation circuit that receives the first and second pulses and generates an ignition section signal that lasts for a section from a first pulse generation position to a second pulse generation position. And an ignition signal generation circuit that outputs a signal whose position of occurrence changes with the section in which the ignition section signal is generated as the maximum change width as an ignition signal for determining the ignition timing of the internal combustion engine, wherein the first signal Of the engine reaches the first threshold level. Coincides with the maximum advance position, and the second
Wherein the signal generator reaches the second threshold level and coincides with a minimum advance position of the internal combustion engine. The signal generation circuit includes a first switch that is turned on when triggered by the first pulse, a capacitor that is charged when the first switch is turned on, and a switch that is turned on when triggered by the second pulse. A second switch for discharging the capacitor, wherein the first threshold level is the first signal level when the rotation speed of the internal combustion engine is equal to or lower than a set value.
The second threshold level is set so as to generate the second pulse even when the rotation speed is equal to or less than a set value, and the ignition signal generation circuit includes: An ignition timing control for an internal combustion engine ignition device, comprising: a low-speed ignition signal output circuit that outputs the ignition signal when the second pulse is generated in a rotation speed region where the ignition section signal is not generated. apparatus.