JPH045737Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a capacitor discharge type ignition device for an internal combustion engine.

[Prior Art] A capacitor discharge type ignition device for an internal combustion engine is provided with an ignition coil, an exciter coil, and the primary side of the ignition coil, and is charged to one polarity by the output of the positive half cycle of the exciter coil. an ignition energy storage capacitor, a discharge control thyristor provided to discharge the charge of the ignition energy storage capacitor to the primary coil of the ignition coil when conductive, and a signal coil that outputs an ignition timing determination signal. and a trigger circuit that supplies a trigger signal to the discharge control thyristor using the output of the signal coil.

In a capacitor discharge type ignition system, as shown by the broken line in Fig. 3, the characteristics of the ignition timing α with respect to the engine rotational speed are such that the ignition timing is almost constant from low to high speeds of the engine. There is a risk that the engine rotation speed will increase too much and the engine may seize.

Therefore, an ignition system has been proposed that delays the ignition timing when the engine is running at high speed to prevent the engine's rotational speed from becoming excessive.

An ignition device that delays the ignition timing at high speeds is disclosed in Japanese Patent Application Laid-open No. 57-360. This ignition device includes a circuit that provides a trigger signal to the discharge control thyristor using the positive output of the signal coil, and a power supply circuit that charges a power supply capacitor with the positive output of the signal coil and obtains a DC voltage across the capacitor. , a capacitor that is charged by the voltage across the power supply capacitor each time the signal coil outputs a positive polarity signal, and a capacitor for ignition timing control that is charged by the voltage obtained by adding the voltage across the capacitor to the voltage of the power supply circuit. A collector-emitter circuit is connected in parallel between the capacitor, a circuit for discharging the ignition timing control capacitor at a constant time constant, and a gate cathode of the discharge control thyristor, and a base current is supplied by the output of the power supply circuit. and a transistor cutoff circuit that cuts off the signal bypass transistor when the voltage across the ignition timing control capacitor drops below a predetermined level.

In this ignition system, when the engine speed is lower than the set value, the voltage across the ignition timing control capacitor has already fallen below a predetermined level by the time the signal coil gives the trigger signal to the discharge control thyristor. Since the signal bypass transistor is in the cutoff state, when the positive signal output of the signal coil reaches the trigger level of the discharge control thyristor, a trigger signal is given to the discharge control thyristor. This causes the ignition energy storage capacitor to discharge through the thyristor to the primary coil of the ignition coil, and ignition is performed. In this way, in a region where the rotational speed of the engine is lower than the set value, the ignition operation is performed when the positive polarity signal output of the signal coil reaches the trigger level of the thyristor.

When the rotation speed exceeds the set value, the voltage across the ignition timing control capacitor still exceeds the predetermined level when the positive polarity signal of the signal coil reaches a level that can trigger the discharge control thyristor. Become. In this state, when a trigger signal is about to be given from the signal coil to the discharge control thyristor, the signal bypass transistor is still in a conductive state, so the trigger signal is bypassed from the thyristor, and the conduction of the thyristor is interrupted. thwarted. When a predetermined period of time passes after the positive signal output of the signal coil reaches a level that can trigger the discharge control thyristor, the discharge of the ignition timing control capacitor progresses and its terminal voltage falls below a predetermined level. The signal bypass transistor is cut off,
A trigger signal is now given to the discharge control thyristor from the signal coil. In this way, in the region above the set rotation speed, the trigger signal is given to the discharge control thyristor at a time later than the time when the positive polarity signal of the signal coil reaches the trigger level of the thyristor, so the ignition timing is delayed. .

There is also an ignition device that delays the ignition timing at high speeds, as shown in Utility Model Application No. 188958/1983. This ignition device includes a power supply circuit that charges a power supply capacitor with the positive polarity output of the signal coil to obtain a DC voltage across the capacitor, and a power supply circuit that charges the power supply capacitor with the positive polarity output of the signal coil and obtains a DC voltage across the capacitor. A capacitor that is charged, an ignition timing control capacitor that is charged with a voltage obtained by adding the voltage of the capacitor to the voltage of a power supply circuit, a circuit that discharges the ignition timing control capacitor at a fixed time constant, and a thyristor for controlling discharge. A collector-emitter circuit is connected in parallel between the gate and cathode of the signal bypass transistor, which is turned on by supplying a base current with the output of the power supply circuit, and the voltage across the ignition timing control capacitor is at a predetermined level. A signal supply transistor conducts to provide a trigger signal to the discharge control thyristor when the voltage decreases to below, and the signal bypass transistor is cut off when the negative output of the signal coil reaches a predetermined level. It is equipped with a transistor cutoff circuit.

In this ignition system, when the engine speed is lower than the set value, the ignition timing control capacitor has enough time to discharge, so the negative output signal of the signal coil is at a level that turns off the signal bypass transistor. Before reaching the ignition timing control capacitor, the voltage across the ignition timing control capacitor has fallen below a predetermined level, and the signal supply transistor has become conductive. Therefore, at the same time that the negative polarity signal output of the signal coil turns off the signal bypass transistor, a trigger signal is given to the discharge control thyristor. This causes the ignition energy storage capacitor to discharge through the thyristor to the primary coil of the ignition coil, and ignition is performed. In this way, in a region where the rotational speed of the engine is lower than the set value, the ignition operation is performed when the negative polarity signal output of the signal coil reaches a level that turns off the signal bypass transistor.

When the rotation speed exceeds the set value, the voltage across the ignition timing control capacitor still exceeds the predetermined level when the negative output signal of the signal coil reaches a level that cuts off the signal bypass transistor. Be in a state of being. In this state, since the signal supply transistor is in the cutoff state, no trigger signal is given to the discharge control thyristor even if the signal bypass transistor is cut off. When a predetermined period of time passes after the negative output signal of the signal coil turns off the signal bypass transistor, the discharge of the ignition timing control capacitor progresses and its terminal voltage falls below a predetermined level, causing the signal The supply transistor becomes conductive, and a trigger signal is applied from the signal coil to the discharge control thyristor through the signal supply transistor. In this way, in the region where the rotation speed exceeds the set value, the signal supply transistor becomes conductive at a time later than the time when the negative polarity signal of the signal coil turns off the signal bypass thyristor, and the signal supply transistor is turned on for discharge control. Since a trigger signal is given to the thyristor, the ignition timing is delayed.

[Problem to be solved by the invention] In the conventional ignition system for an internal combustion engine disclosed in Japanese Patent Application Laid-open No. 57-360, in order to charge the ignition timing control capacitor, there is a power supply circuit and a power supply circuit that is charged by the power supply circuit. This requires a capacitor for controlling the ignition timing, and a circuit for charging the ignition timing control capacitor with the voltage obtained by adding the voltage of the capacitor to the voltage of the power supply circuit.
The complexity of the device configuration was unavoidable.

In addition, in this ignition device, a circuit that supplies charging current from the signal coil to the capacitor of the power supply circuit and a circuit that provides a trigger signal from the signal coil to the discharge control thyristor are connected in parallel, and a trigger signal is sent to the discharge control thyristor. Since the capacitor in the power supply circuit was charged with the same signal as the output signal of the signal coil that gives A problem like this arises. In other words, in order to lower the starting rotational speed of the engine (the rotational speed at which ignition operation begins) and make engine starting easier, the impedance of the circuit that provides the trigger signal to the discharge control thyristor is lowered to lower the impedance of the signal coil. If a trigger signal is given to the discharge control thyristor even when the output is low, the charging voltage of the capacitor in the power supply circuit will be low, making it difficult to reliably operate the control circuit that retards the ignition timing. Become. In addition, in order to make the charging voltage of the capacitor in the power supply circuit sufficiently high, if the impedance of the circuit that gives the trigger signal to the discharge control thyristor is made high, the discharge control thyristor will not be activated until the output of the signal coil becomes high. Since no trigger signal is given, the starting speed of the engine becomes high.

Similarly, the conventional ignition system for an internal combustion engine disclosed in Utility Model Application Publication No. 57-188958 also includes a power supply circuit, a capacitor charged by the power supply circuit, and a power supply circuit for charging the ignition timing control capacitor. Since a circuit for charging the ignition timing control capacitor with a voltage obtained by adding the voltage of the capacitor to the voltage of the capacitor is required, the configuration of the device inevitably becomes complicated.

In addition, in this ignition system, the positive polarity output of the signal coil (signal of the previous half cycle) charges the capacitor of the power supply circuit, which has a considerably large capacity, so the large armature is charged during the positive half cycle of the signal coil output. A reaction occurs, which tends to delay the rise of the signal coil's negative polarity signal (the later half-cycle signal that occurs following the positive polarity signal). As a result, the time when the signal bypass transistor becomes cut off is delayed, causing a problem in that the ignition timing is delayed even before the engine rotational speed reaches the set value.

The purpose of this invention is to delay the ignition timing or cause a misfire when the engine is running at high speed, without delaying the ignition timing during steady operation when the engine speed does not reach the set value, and without complicating the circuit configuration. An object of the present invention is to provide an ignition device for an internal combustion engine that can prevent the rotation speed of the engine from becoming excessive.

[Means for Solving the Problems] As shown in FIG. 1 showing an embodiment of the present invention, an ignition coil 1 and an exciter coil 7 are provided.
and an ignition energy storage capacitor 3 which is provided on the primary side of the ignition coil and is charged to one polarity by the output of one half cycle of the exciter coil 7.
and a discharge control thyristor 4, which is provided to discharge the charge of the ignition energy storage capacitor 3 to the primary coil 1a of the ignition coil 1 when conductive, and outputs a signal of one cycle per engine revolution. In an ignition system for an internal combustion engine, which includes a signal coil 11 and a trigger circuit that supplies a trigger signal to a discharge control thyristor 13 using the output of the previous half cycle of the signal coil, the ignition timing is delayed in the high speed region of the engine. This is to prevent the rotational speed of the motor from becoming excessive.

Therefore, in the present invention, the signal shorting thyristor 13 is connected in parallel to the signal coil 11 in such a direction that the output of the previous half cycle of the signal coil is applied in the forward direction, and the signal shorting thyristor 13 is current limiting element 12 connected in series with
, an ignition timing control capacitor 19 that is charged to one polarity by the output of the subsequent half cycle of the signal coil 11, a discharge circuit that discharges the charge of the ignition timing control capacitor 19 at a constant time constant, and a signal coil. The ignition timing control capacitor 19 is connected in parallel between the ignition signal supply circuit that supplies the ignition signal to the signal shorting thyristor 13 with the output of the previous half cycle and the gate cathode of the signal shorting thyristor 13. A signal bypass switch circuit 25 that is controlled by the terminal voltage of and conducts when an ignition signal is supplied with the terminal voltage below a set level and bypasses the ignition signal from the signal short circuit thyristor 13.
It is equipped with

[Operation of the device] In the above ignition system, when the engine speed is below the set value, the terminal voltage of the ignition timing control capacitor falls below the set value before the output of the signal coil 11 for the previous half cycle rises. Therefore, the signal bypass switch 25 is connected to the signal short circuit thyristor 1.
Each time an ignition signal to thyristor 3 is generated, the ignition signal becomes conductive to prevent the ignition signal from being supplied to the signal shorting thyristor 13. Therefore, when the rotational speed of the engine is below the set value, the signal short circuit thyristor 13 is not conductive, and the output of the previous half cycle of the signal coil 11 supplies a trigger signal to the discharge control thyristor 4, and the ignition operation is performed. .

On the other hand, if the engine speed exceeds the set value, the terminal voltage of the ignition timing control capacitor 19 will still be higher than the set value when the output of the signal coil for the previous half cycle rises. ,
When the output of the previous half cycle of the signal coil 11 rises, the signal bypass switch is in the cutoff state. Therefore, when the rotational speed of the engine exceeds the set value, the signal coil generates the output of the previous half cycle, and when the output reaches a level that can trigger the signal short circuit thyristor, the thyristor conducts and the signal short circuits. The output of the coil is short-circuited to prevent the ignition signal from being supplied to the discharge control thyristor. The holding current of the signal shorting thyristor is limited by a current limiting element connected in series with the thyristor,
When this holding current becomes less than a predetermined value, the signal shorting thyristor becomes cut off. When the signal short-circuit thyristor enters the cut-off state in this manner, a trigger signal is given to the discharge control thyristor by the output of the previous half cycle of the signal coil, and an ignition operation is performed. Therefore, when the rotational speed of the engine exceeds the set position, the ignition timing is delayed by the period during which the signal shorting thyristor is conductive, and an increase in the rotational speed of the engine is suppressed.

Furthermore, if the rotation speed increases further for some reason, the signal shorting thyristor remains conductive for almost the entire period during which the signal coil outputs the previous half-cycle signal, so the thyristor is not triggered. A signal higher than the level is no longer given, and ignition operation is no longer performed.

As described above, according to the present invention, the ignition timing of the engine can be delayed or a misfire can be caused when the engine rotation speed exceeds a set value, so that the engine rotation speed can be prevented from becoming excessive. It can be prevented.

In addition, as in the present invention, among the positive and negative half-cycle signals generated by the signal coil, the previous half-cycle signal provides a trigger signal to the discharge control thyristor, and the second half-cycle signal provides a trigger signal to the ignition timing control capacitor. By charging the ignition timing control capacitor, the ignition timing control capacitor can be directly charged by the output of the signal coil without the need for a special power supply circuit for charging the ignition timing control capacitor. The configuration can be simplified.

Furthermore, as described above, if the ignition timing control capacitor is charged with a signal different from the signal that provides the trigger signal to the discharge control capacitor, a trigger signal is sent to the discharge control thyristor regardless of the charging voltage of the ignition timing control capacitor. It is possible to set the impedance of the circuit that supplies the Therefore, the impedance of the circuit that provides a trigger signal to the discharge control thyristor can be lowered, and the rotational speed at which the ignition operation starts can be lowered, making it possible to improve the startability of the engine.

Furthermore, as described above, if the ignition timing control capacitor is charged by the signal of the latter half cycle of the positive and negative half cycle signals generated from the signal coil, the signal of the latter half cycle and the next signal Since there is a considerable time interval between the signal of the previous half cycle generated from the coil, the armature reaction of the signal generator caused by charging the ignition timing control capacitor generates the signal of the previous half cycle of the signal coil. It has little effect on the signal. Therefore, there is no possibility that the problem of ignition timing being delayed in a region where the rotational speed is lower than the set value will occur.

[Embodiments] Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 indicates a primary coil 1a and a secondary coil 1.
The ignition coil 2 has an ignition coil 1b, and the ignition plug 2 is attached to a cylinder of an engine (not shown) and connected to a secondary coil 1b of the ignition coil. One end of the primary coil 1a and the secondary coil 1b are connected in common, and one end of the ignition energy storage capacitor 3 is connected to the other end of the primary coil 1a. capacitor 3
The other end is connected to the anode of a discharge control thyristor 4, and the cathode of this thyristor is connected to a common line (usually grounded) 5 connected to a common connection point of the primary coil 1a and secondary coil 1b. ing. A cathode of a diode 6 is connected to the connection point between the anode of the thyristor 4 and the capacitor 3, and an exciter coil 7 is connected between the anode of the diode 6 and the common line 5. A diode 8 with its anode facing the common line 5 side is connected to both ends of the exciter coil 7, a resistor 9 is connected between the gate and cathode of the thyristor 4, and a resistor 9 is connected between the anode and the anode of a diode 10 whose cathode is connected to the gate of this thyristor. A signal coil 11 is connected between the common line 5 and the common line 5 .

One end of a resistor 12 as a current limiter is connected to one end of the signal coil 11 on the opposite side from the common line 5, and a signal short circuit is established between the other end of this resistor 12 and the common line 5 with the cathode facing the common line side. A thyristor 13 for use is connected. An anode of a diode 14 is connected to one end of the signal coil 11, and a cathode of the diode 14 is connected to the gate of a thyristor 13 via a resistor 15. The gate and cathode of thyristor 13 each have
The collector and emitter of the PNP transistor 16 are connected, and a resistor 17 is connected in parallel between the collector and emitter of the transistor 16. The drain and source of a field effect transistor 18 are connected to the base and collector of the transistor 16, respectively, and an ignition timing control capacitor 19 is connected between the gate and source of the field effect transistor 18. A variable resistor 20 is connected to both ends of the capacitor 19, and the variable resistor constitutes a discharge circuit that discharges the charge of the capacitor 19 at a constant time constant. A Zener diode 21 is connected to both ends of the variable resistor 20 with its cathode facing the common line, and the terminal voltage of the capacitor 19 is limited to the Zener voltage of this Zener diode. One end of a resistor 22 is also connected to the gate of the field effect transistor 18, and the other end of this resistor 22 is connected to the anode of a diode 23 whose cathode is connected to one end of the signal coil 11.

In the above embodiment, the signal coil 11, the diode 10, and the resistor 9 constitute a trigger signal supply circuit that supplies a trigger signal to the discharge control thyristor 4 using the output of the signal coil 11. Furthermore, the diode 14 and the resistor 15 cause the thyristor 13 to be connected to the previous half cycle output of the signal coil 11.
An ignition signal supply circuit is configured to supply an ignition signal to the ignition signal. Further, in the above embodiment, the transistor 16 and the field effect transistor 18 are connected in parallel to the gate and cathode of the signal shorting thyristor, and the ignition timing control capacitor 19 is connected to the ignition timing control capacitor 19.
A signal bypass switch circuit is controlled by the terminal voltage of the terminal and conducts when the ignition signal is supplied with the terminal voltage being less than a set value level to bypass the ignition signal from the signal short circuit thyristor. It is configured.

Next, the operation of the above embodiment will be explained. In the above ignition system, the exciter coil 7 is disposed within a magnet generator driven by the engine, and induces an alternating current voltage in synchronization with the rotation of the engine as shown in FIG. 2A. Further, the signal coil 11 is provided in a signal generator (not shown), and induces one cycle of signal voltages V _s1 and V _s2 per one revolution of the engine, as shown in FIG. 2B. In this embodiment, the voltage of the positive half cycle that occurs earlier in the signal voltage of one cycle is
V _s1 is used as a signal for determining ignition timing.

Exciter coil 7 has a positive half-cycle voltage
When V _e1 is output, the ignition energy storage capacitor 3 is charged to the illustrated polarity through the diode 6 and the primary coil 1a of the ignition coil.

Ignition timing control capacitor 19 is connected to signal coil 1
The Zener diode 2 is connected through the diode 23 and the resistor 22 by the output V _s2 of the half cycle after 1.
It is charged to the Zener voltage of 1 with the polarity shown.
The charge in the capacitor 19 is discharged at a constant time constant through a discharge circuit consisting of a variable resistor 20.

When the engine rotational speed is below the set value Ns, the time for the capacitor 19 to discharge is sufficiently long, and as shown by the solid line in Fig. 2C, the output V _s1 of the previous half cycle of the signal coil rises. capacitor 1
Since the terminal voltage of the transistor 9 is lower than the set value V _F (the cut-off level of the field effect transistor 18), the field effect transistor 18 becomes conductive at the same time as the signal V _s1 rises, and the transistor 16 also becomes conductive. Therefore, each time the signal coil 11 outputs the output V _s1 of the previous half cycle, the transistor 18 conducts and bypasses the firing signal to the signal shorting thyristor 13 from the thyristor. Therefore, when the engine speed is below the set value Ns, the signal short-circuit thyristor 1
3 is not conductive, and a trigger signal is supplied to the discharge control thyristor 4 through the diode 10 with the output of the previous half cycle of the signal coil 11.

When the thyristor 4 becomes conductive, the charge in the capacitor 3 is transferred to the thyristor 4 and the primary coil 1a of the ignition coil.
As a result, a high voltage is induced in the secondary coil of the ignition coil, a spark is generated in the ignition plug 2, and the engine is ignited.

In this case, the ignition timing is the timing when the output signal V _s1 of the previous half cycle of the signal coil 11 reaches the trigger level of the thyristor 4, and if the signal V _s1 rises early, the engine rotation speed N is less than the set value Ns. In this case, the ignition timing is approximately constant with respect to the engine rotational speed N, as shown in FIG.

Note that if the signal V _s1 has a waveform with a relatively slow rise, the signal V _s1
The phase that reaches the trigger level of engine rotational speed N
As the rotational speed N increases, the ignition timing advances as the rotational speed N increases.

On the other hand, when the rotational speed of the engine exceeds the set value Ns, the time during which the capacitor 19 can discharge becomes shorter, and when the output signal V _s1 of the previous half cycle of the signal coil 11 rises, the terminal voltage of the capacitor 19 still remains. is higher than the set value (the cutoff level of the field effect transistor 18), so the field effect transistor 18 and the transistor 16 are in a cutoff state when the signal V _s1 rises.
In this way, if the transistor 16 is in the cut-off state when the signal V _s1 of the previous half cycle of the signal coil 11 rises, the signal is short-circuited before the discharge control thyristor 4 is triggered by the signal V _s1 . thyristor 13 is triggered.
That is, when the rotational speed of the engine exceeds the set value, as shown in FIG. 4, after the signal coil 11 generates the signal V _s1 of the previous half cycle, the signal coil 11 generates the signal V s1 at point a shown in FIG. 4. When the signal reaches a level Vt that can trigger the signal shorting thyristor 13, the thyristor 13 becomes conductive. Since the trigger level of the discharge control thyristor 4 is set higher than the voltage at point a, the thyristor 4 is still in the cutoff state when the thyristor 13 becomes conductive. Thyristor 13
When conductive, the voltage between the gate and cathode of the discharge control thyristor 4 decreases to the sum of the voltage across the current limiting element 12 and the voltage drop between the anode and cathode of the thyristor 13.
The gate-to-cathode voltage of the thyristor is prevented from reaching the trigger level of the thyristor. Since the anode current of the signal shorting thyristor 13 is limited by the current limiting element 12 connected in series with the thyristor, as the signal V _s1 decreases, a certain point, for example b shown in FIG. Thyristor 13 at the point
The anode current of becomes below the holding current. When the anode current of the signal shorting thyristor 13 becomes equal to or less than the holding current, the thyristor 13 enters the cutoff state. When the signal shorting thyristor 13 enters the cut-off state, the current flowing from the signal coil 11 through the current limiting element 12 and the thyristor 13 is cut off, so a high pulse-like voltage is induced in the signal coil 11, and this voltage A trigger signal is given to the discharge control thyristor 4 to perform an ignition operation. Therefore, when the engine rotational speed exceeds the set value Ns, the ignition timing is delayed in steps during the period when the signal shorting thyristor 13 is conductive, as shown in Figure 3, to prevent the engine rotational speed from increasing. suppress.

If the rotational speed of the engine increases further for some reason, the signal short circuit thyristor 13 will remain conductive for almost the entire period when the signal coil 11 is generating the output V _s1 of the previous half cycle. A trigger signal higher than the trigger level is no longer applied to the thyristor 4, and the ignition operation is no longer performed. Therefore, in this case, the engine will misfire and the increase in rotational speed will be reliably suppressed.

In the above embodiment, a resistor 1 is used as the current limiting element.
2 was used, but the number of current limiting elements is one or more (the number is determined as appropriate depending on the required resistance value).
It can also be replaced by a diode.

[Effects of the invention] As described above, according to the invention, when the engine rotation speed exceeds a set value, the ignition timing of the engine can be delayed or a misfire can be caused. This can prevent it from becoming too large.

In particular, according to the present invention, among the positive and negative half-cycle signals generated by the signal coil, the previous half-cycle signal provides a trigger signal to the discharge control thyristor, and the second half-cycle signal provides a trigger signal to the ignition timing control capacitor. As a result, the ignition timing control capacitor can be directly charged by the output of the signal coil without the need for a special power supply circuit for charging the ignition timing control capacitor, which is more efficient than conventional ignition systems. This has the advantage of simplifying the configuration.

Furthermore, according to the present invention, since the ignition timing control capacitor is charged by a signal different from the signal that provides the trigger signal to the discharge control capacitor, the discharge control thyristor is triggered regardless of the charging voltage of the ignition timing control capacitor. It is possible to set the impedance of the circuit that supplies the signal. Therefore, the impedance of the circuit that provides a trigger signal to the discharge control thyristor can be lowered, and the rotational speed at which the ignition operation starts can be lowered, making it possible to improve the startability of the engine.

Furthermore, according to the present invention, the armature reaction of the signal generator caused by charging the ignition timing control capacitor hardly affects the next half-cycle signal generated from the signal coil. It is possible to eliminate the possibility of a problem in which the ignition timing is delayed in a region where the rotational speed is lower than the set value.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a voltage waveform diagram of each part in Figure 1, Figure 3 is a line diagram showing an example of the ignition characteristics obtained by the device of the present invention, and Figure 4 is a line diagram showing the waveform of the signal voltage in the embodiment of Figure 1. It is a diagram. 1...Ignition coil, 2...Spark plug, 3...
Ignition energy storage capacitor, 4... Thyristor for discharge control, 7... Exciter coil, 11
... Signal coil, 12 ... Resistor (current limiting element),
13...Thyristor for signal short circuit, 14...Diode, 15...Resistor, 19...Capacitor for ignition timing control, 25...Switch circuit for signal bypass.

Claims (1)

[Claims for Utility Model Registration] An ignition coil, an exciter coil, and an ignition energy storage capacitor provided on the primary side of the ignition coil and charged to one polarity by the positive half-cycle output of the exciter coil. , a discharge control thyristor provided to discharge the electric charge of the ignition energy storage capacitor to the primary coil of the ignition coil when conductive, and a signal coil that outputs a signal of one cycle per engine rotation. and a trigger circuit that supplies a trigger signal to the discharge control thyristor with the output of the previous half cycle of the signal coil, wherein the signal of the previous half cycle generated by the signal coil is a signal shorting thyristor connected in parallel to the signal coil in a forward direction; a current limiting element connected in series to the signal shorting thyristor; and a current limiting element after the signal coil. an ignition timing control capacitor that is charged to one polarity by the output of a half cycle; a discharge circuit that discharges the electric charge of the ignition timing control capacitor at a constant time constant; An ignition signal supply circuit that supplies an ignition signal to the signal shorting thyristor and a gate cathode of the signal shorting thyristor are connected in parallel to each other, and are controlled by a terminal voltage of the ignition timing control capacitor. The present invention is characterized by comprising a signal shunting switch circuit that becomes conductive when the firing signal is supplied in a state where the terminal voltage is less than a set level and bypasses the firing signal from the signal shorting thyristor. Ignition system for internal combustion engines.