JPH0861197A - Ignition device for capacitor discharge type internal combustion engine - Google Patents

Abstract

PURPOSE: To provide an ignition device for a capacitor discharge type internal combustion engine by which ignition performance can be prevented from deteriorating at spark advance time. CONSTITUTION: A capacitor 4 is charged with positive half cycle voltage generated by an exciter coil 1, and when the exciter coil generates negative half cycle voltage, an ignition signal is given to a thyristor 7 from an ignition signal supply device 23. Electric charge of the capacitor 4 is discharged to a primary coil 5a of an ignition coil 5 by electric continuity of the thyristor 7, and ignition operation is performed. A transistor 24 is arranged to bypass the ignition signal from the thyristor 7, and when the exciter coil 1 generates positive half cycle voltage, the transistor 24 is held in an electrically continuous condition, and the ignition signal is prevented from being given to the thyristor 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor discharge type ignition device for an internal combustion engine.

[0002]

2. Description of the Related Art As an ignition device of a capacitor discharge type, an exciter coil provided in a magnet generator installed in an internal combustion engine, an ignition coil, and an exciter coil are charged to one polarity with a positive half cycle output voltage. For storing the ignition energy, a discharge switch that conducts when an ignition signal is given and discharges the charge of the ignition energy storage capacitor to the primary coil of the ignition coil, and a discharge switch at the ignition position of the internal combustion engine. An ignition signal supply device that supplies an ignition signal to an ignition signal input terminal of a switch is often used.

This type of ignition device generates an ignition voltage even when the engine rotates in the reverse direction. Therefore, when this ignition device is applied to a two-cycle engine, the engine is started or stopped. At this time, if the engine rotates in the opposite direction due to the reaction due to the compression pressure in the cylinder, an ignition voltage may be generated and the engine may continue to rotate in the reverse direction.

In order to prevent this, in a capacitor discharge type ignition device used in a two-cycle engine, a reverse rotation prevention circuit for preventing an ignition signal from being supplied to a discharge switch when the engine rotates in the reverse direction. Is provided.

FIG. 6 shows a conventional capacitor discharge type ignition device provided with a reverse rotation prevention circuit. In FIG.
Is an exciter coil which is provided in a magnet generator attached to an internal combustion engine (not shown) and has one end grounded,
A diode 2 with its anode facing the ground side is connected in parallel to both ends of the exciter coil 1. The non-grounded side terminal of the exciter coil 1 is connected to one end of the ignition energy storage capacitor 4 through the diode 3, and the other end of the capacitor 4 is connected to one end of the primary coil 5a of the ignition coil 5. The other end of the primary coil 5a of the ignition coil is grounded, and a thyristor 7 whose cathode is directed to the ground side is connected between one end of the capacitor 4 and the ground. The thyristor 7 constitutes a discharge switch, and a resistor 8 is connected between the gate and cathode of the thyristor. One end of the secondary coil 5b of the ignition coil 5 is connected to a non-grounded side terminal of an ignition plug 6 attached to a cylinder of the engine, and the other end of the secondary coil 5b is grounded together with the other end of the primary coil 5a. .

In FIG. 6, 11 is a signal coil provided in a signal generator that rotates in synchronization with the engine. This signal coil is shown in FIG. 7 (B) during the period when a positive half cycle voltage is generated in the exciter coil 1. Negative direction signal as shown in
Signal signal Vp1 in the direction indicated by the broken line arrow) and a positive direction signal (signal in the direction indicated by the solid line arrow in FIG. 6) Vp2 in one cycle.

A diode 12 is provided at one end of the signal coil 11.
, 51 and the cathode of the diode 13 are connected in common, and the cathode of the diode 12 has a waveform shaping circuit 18 including a parallel circuit of a resistor 16 and a capacitor 17.
Is connected to the gate of the thyristor 7 as a discharge switch.

A diode 14 is provided at the other end of the signal coil 11.
And 52 and the cathode of the diode 15 are connected in common, and the cathode of the diode 14 is connected to the gate of the thyristor 7 through the Zener diode 19 and the waveform shaping circuit 22 formed of the parallel circuit of the resistor 20 and the capacitor 21. There is. The anodes of the diodes 13 and 15 are grounded, and the cathodes of the diodes 51 and 52 are commonly connected to the non-grounded side terminal of the exciter coil 1.

In this example, the signal coil 11, the diodes 12 to 15, the Zener diode 19, and the waveform shaping circuits 18 and 22 send an ignition signal to the ignition signal input terminal of the discharge switch (between the gate and cathode of the thyristor 7 in this example). An ignition signal supply device 23 is provided.

The magnitude of the signal voltage generated in the signal coil 11 increases as the engine speed increases. In the ignition device shown in FIG. 6, the negative direction signal Vp1 generated by the signal coil 11 when the engine speed exceeds the set value N1.
The peak value of the zener voltage V of the zener diode 19
The output characteristic of the signal coil 11 and the Zener voltage of the Zener diode 19 are selected so as to have a value of z or more.

In the above circuit, when the engine is rotating normally, when the signal coil 11 generates a signal, the exciter coil 1 generates a positive half-cycle voltage in the direction of the solid arrow. A reverse voltage is applied to the diodes 51 and 52. When the rotational speed of the engine is lower than the set value N1, the negative direction signal V generated first by the signal coil 11 as shown by the solid line waveform in FIG. 7 (B).
The magnitude of p1 is the Zener voltage V of the Zener diode 19.
Since it is lower than z, the signal coil 1 is generated when the forward direction signal Vp2 generated next reaches a predetermined threshold voltage (determined by the voltage across the capacitor 17) at the position of the angle θ2.
1 → diode 12 → waveform shaping circuit 18 → thyristor 7
An ignition signal is given to the thyristor 7 through the path between the gate-cathode circuit of the device, the diode 15 and the signal coil 11. As a result, the thyristor 7 becomes conductive to discharge the electric charge of the capacitor 4 to the primary coil of the ignition coil 5 and induce a high voltage (ignition voltage) V2 for ignition in the secondary coil of the ignition coil. Therefore, when the rotational speed of the engine is lower than the set value N1, the ignition operation is performed at the angular position θ2.

When the rotational speed of the engine exceeds the set value N1,
As indicated by the broken line in FIG. 7B, the negative-direction signal Vp1 generated by the signal coil 11 increases, and the signal Vp1 increases in angle θ.
Since the Zener voltage of the Zener diode 19 is exceeded at the position of 1, the signal coil 11 is at the position of the angle θ1.
→ diode 14 → zener diode 19 → waveform shaping circuit 22 → gate-cathode circuit of thyristor 7 → ignition signal is given to the thyristor 7 through the path of the diode 13 and the thyristor 7 is conducted at the position of the angular position θ1 to perform the ignition operation. Done. Therefore, as shown in FIG. 3, the ignition position of the engine advances stepwise from θ2 to θ1 when the rotational speed reaches the set value N1.

The voltage across the ignition energy storage capacitor 4 is, for example, as shown in FIG.
The waveform Vc shown by the solid line in (C) is obtained, and the charging voltage during the ignition operation is Vcm. However, when the engine speed exceeds the set value N1, the charging voltage of the capacitor 4 becomes as shown in FIG.
A waveform Vc 'shown by a broken line in (C) is obtained, and the charging voltage during the ignition operation is Vcm'(<Vcm). for that reason,
When the ignition position is advanced when the rotation speed reaches the set value N1, the ignition voltage V2 generated in the secondary coil of the ignition coil decreases as shown by a broken line curve b in FIG. descend.

When the engine rotates in the reverse direction, the polarity of the AC voltage generated in the exciter coil 1 is opposite to that in the normal rotation, so that when the signal coil 11 generates a signal, the dashed arrow shown in the figure shows the exciter coil 1. A negative half cycle voltage in the direction is generated. Therefore, the signal coil 1
1 generated positive direction signal Vp2 in the direction of the solid arrow shown in the figure is
Signal coil 11 → diode 51 → exciter coil 1
→ Diode 15 → By the path of the signal coil 11, it is bypassed from between the gate cathode of the thyristor 7 (between the ignition signal input terminals). The negative direction signal Vp1 generated by the signal coil 11 in the direction of the broken arrow in the drawing is bypassed from the gate cathode of the thyristor 7 by the route of the signal coil 11 → diode 52 → exciter coil 1 → diode 13.

In this way, when the engine reverses, the positive and negative signals generated by the signal coil 11 are bypassed between the ignition signal input terminals of the discharge switch, so that the ignition signal input terminals are ignited. No signal provided. As a result, the ignition operation at the time of reverse rotation of the engine is blocked, so that the reverse rotation of the engine is prevented.

In the example shown in FIG. 6, the diodes 51 and 52 and the exciter coil 1 constitute a reverse rotation prevention circuit.

[0017]

In order to prevent reverse rotation of the engine, the reverse rotation of the engine is performed by bypassing the signal voltage generated in the signal coil during reverse rotation of the engine from the signal input terminal of the main ignition circuit through the exciter coil. In the conventional ignition device having the reverse rotation prevention circuit for preventing the above, it is necessary to generate the ignition signal during the period in which the positive half cycle voltage is generated in the exciter coil during the normal rotation of the engine.

Therefore, as described above, when the rotational speed reaches the set value N1 and the ignition position is advanced, the charging voltage of the capacitor for storing the ignition energy during the ignition operation is lowered and the ignition performance is lowered. was there.

An object of the present invention is to prevent the engine from rotating in the reverse direction by bypassing the ignition signal from the ignition signal supply device from the ignition signal input terminal of the discharge switch when the engine tries to rotate in the reverse direction. An object of the present invention is to provide a capacitor discharge type ignition device for an internal combustion engine, which prevents the charging voltage of the ignition energy storage capacitor from decreasing when cornering and prevents the ignition performance from decreasing.

[0020]

DISCLOSURE OF THE INVENTION The present invention is an exciter coil which is provided in a magnet generator installed in an internal combustion engine and which outputs an alternating voltage of a plurality of cycles per revolution of the engine in synchronization with the rotation of the engine. An ignition coil, 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 voltage of the exciter coil, and conducting when an ignition signal is given. A capacitor discharge internal combustion engine provided with a discharge switch for discharging the electric charge of the capacitor to the primary coil of the ignition coil, and an ignition signal supply device for providing an ignition signal to an ignition signal input terminal of the discharge switch at an ignition position of the internal combustion engine. The present invention relates to an ignition device for a vehicle.

In the present invention, the ignition signal bypass switch is provided so as to bypass the ignition signal from the ignition signal input terminal of the discharge switch when conducting, and the output voltage of the negative half cycle of the exciter coil. To keep the ignition signal bypass switch in the cut-off state when occurs, and to keep the ignition signal bypass switch in the conductive state when the positive half cycle output voltage of the exciter coil is generated, An ignition signal side path switch control circuit for controlling the ignition signal side path switch according to the polarity of the output voltage of the exciter coil is provided. In the present invention, the ignition signal supply device is configured so as to generate an ignition signal when the exciter coil generates a positive half-cycle voltage when the internal combustion engine rotates normally.

The ignition signal bypass switch can be constructed by an NPN transistor having a collector-emitter circuit connected in parallel between the ignition signal input terminals of the main ignition circuit. In this case, the ignition signal side switch control circuit includes a DC power supply circuit that outputs a DC voltage, a base current supply circuit that supplies a base current from the DC power supply circuit to the transistor, and an exciter coil that outputs a negative half cycle. It can be configured by a circuit including a reverse bias circuit that reversely biases the base-emitter of a transistor when a voltage is generated to bring the transistor into a cutoff state.

In the reverse bias circuit, a forward current is supplied to the diode with the anode connected between the base and the emitter of the transistor with the anode directed toward the emitter side of the transistor and the negative half cycle output of the exciter coil. And a circuit.

[0024]

With the above construction, an ignition signal is generated when the exciter coil is generating a voltage of a negative half cycle when the engine is rotating forward, and an ignition signal is generated when the engine is rotating reversely when the engine is rotating backward. The ignition signal is generated while the voltage is being generated. When the agitator coil is generating a negative half-cycle voltage, the ignition signal side road switch control circuit keeps the ignition signal side road switch off so that the ignition signal is generated when the engine is rotating forward. Then, the ignition signal is supplied to the discharge switch, and the ignition operation is performed without any trouble.

On the other hand, when the engine is rotating in reverse, the exciter coil generates a positive half cycle voltage when the ignition signal is generated, and the ignition signal side path switch control circuit operates the ignition signal side path switch. The ignition signal is bypassed from the ignition signal input terminal of the discharge switch because it is held conductive. Therefore, the ignition operation is not performed, and the engine cannot continue reverse rotation.

Further, during the normal rotation of the engine, when the ignition signal is generated, the ignition energy storage capacitor is sufficiently charged by the output voltage of the positive half cycle immediately before the exciter coil. The charging voltage of the ignition energy storage capacitor during the ignition operation does not change even if the generation position of is changed. Therefore, it is possible to prevent the charging voltage of the capacitor from decreasing and the ignition performance to deteriorate at the time of advancing, and it is possible to obtain good ignition performance over the entire rotation range of the engine.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which the same parts as those of the conventional example shown in FIG. In FIG. 1, reference numeral 1 denotes an exciter coil provided in a magnet generator attached to an internal combustion engine (not shown), and the exciter coil generates an AC voltage of a plurality of cycles per revolution of the engine in synchronization with the rotation of the internal combustion engine. In this embodiment, the magneto-generator is composed of four poles, and the exciter coil 1 induces an AC voltage Ve of 2 cycles per rotation as shown in FIG. 2 (A). The output voltage of the exciter coil 1 is applied to the ignition energy storage capacitor 4 through the diode 3, and the capacitor 4 is charged to the polarity shown by the positive half cycle output voltage of the exciter coil 1 in the direction of the solid arrow in the figure.

When an ignition signal is applied from the ignition signal supply device 23 to the gate of the thyristor 7 as a discharge switch, the electric charge of the capacitor 4 is discharged to the primary coil 5a of the ignition coil 5 through the thyristor and the ignition coil 2 The other-field ignition voltage V2 is induced in the next coil 5b. Since this ignition voltage is applied to the spark plug 6, a spark is generated in the spark plug and the engine is ignited.

Similar to the ignition device shown in FIG. 6, the signal coil 11, the diodes 12 to 15, the zener diode 19, the waveform shaping circuit 18 including a parallel circuit of the resistor 16 and the capacitor 17, the resistor 20, and the capacitor. An ignition signal supply device 23 including a waveform shaping circuit 22 including a parallel circuit 21 is provided, and an output terminal of the ignition signal supply device is connected to the gate of the thyristor 7.

The signal coil 11 is provided, for example, in the signal generator arranged opposite to the reluctor formed on the outer circumference of the flywheel magnet rotor of the magneto generator in which the exciter coil 1 is provided. When the reluctor passes through the position of the magnetic pole of the emitted electrons, as shown in FIG. 2B, the signal Vp1 in the negative direction (the direction of the broken arrow in FIG. 1) and the positive direction (FIG.
Signal voltage Vp2 (in the direction of the broken line arrow) is generated for one cycle. In this embodiment, the output voltage of the exciter coil 1 is set so that the signals Vp1 and Vp2 are generated during the period in which the exciter coil 1 generates a voltage of a negative half cycle in the direction of the broken line arrow at the time of positive rotation of the engine. The phase relationship with the signal voltage is set. Further, the magnitude of the signal voltage induced in the signal coil 11 increases as the rotational speed of the period increases, but in this embodiment, when the rotational speed of the engine reaches the set value N1, the peak value of the negative direction signal Vp1 becomes the zener. In order to reach the Zener voltage Vz of the diode 19,
The output characteristic of the signal coil 11 and the Zener voltage of the Zener diode 19 are selected.

The collector-emitter circuit of the NPN transistor 24 is connected between the gate and cathode of the thyristor 7 via the diode 25. Transistor 24
Constitutes an ignition signal bypass switch for bypassing the ignition signal from the ignition signal input terminal of the discharge switch (thyristor 7) when the transistor is turned on.

In order to control the transistor 24, a DC power supply circuit 26 that outputs a DC voltage using the exciter coil 1 as a power supply, a base current supply circuit 27 that supplies a base current from the DC power supply circuit to the transistor 24, and the exciter coil 1 When a negative half cycle output voltage is generated, a reverse bias circuit 28 reverse biases the base-emitter of the transistor 24 to shut off the transistor 24.
Is provided.

The DC power supply circuit 26 used in this embodiment has a diode 30 whose anode is connected to the non-grounded side terminal of the exciter coil 1, and a capacitor 32 which is connected through a resistor 31 between the cathode of the diode 30 and ground. Zener diode 3 connected in parallel with capacitor 32
3 which is well-known, the capacitor 32 is charged to the Zener voltage of the Zener diode 33 by the positive half cycle output voltage of the exciter coil 1 so that a constant DC voltage is obtained across the capacitor. ing.

The base current supply circuit 27 of this embodiment is composed of a resistor 34 connected between the output terminal of the DC power supply circuit 26 and the base of the transistor 24.

The reverse bias circuit 28 includes a transistor 24.
A diode 35 connected between the base-emitters of the transistors with the anode facing the emitter side of the transistor, and the cathode of the diode facing the exciter coil side between the cathode of the diode and the non-ground side terminal of the exciter coil 1. In this embodiment, a forward current is passed through the diodes 35 and 36 by the negative half cycle output of the exciter coil 1.

Next, the operation of the above embodiment will be described with reference to FIGS. In the present embodiment, the magnet generator is configured with four poles, and the exciter coil 1 generates an AC voltage of 2 cycles per rotation as shown in FIG. 2 (A). When the positive half cycle output voltage in the direction of the solid line arrow is generated in the exciter coil 1, the ignition energy storage capacitor 4 is charged to the illustrated polarity by the positive half cycle output voltage, and the DC power supply circuit 26 The capacitor 32 is charged to the polarity shown in the figure, and the DC voltage obtained across the capacitor is output from the DC power supply circuit 26.

When the positive half-cycle output voltage of the exciter coil 1 is generated, the base current is supplied from the DC power supply circuit 26 to the transistor 24 through the resistor 34, and the transistor 24 is kept conductive. When a negative half cycle output voltage of the exciter coil 1 in the direction of the broken arrow in the figure is generated, a current flows through the diode 2 due to the negative half cycle output voltage, and a forward current flows through the diode 35 and the diode 36. And a forward voltage drop across the diode 35 causes reverse bias between the base and emitter of the transistor 24. Thus, transistor 24 is held in the off state when the exciter coil is inducing a negative half cycle voltage.

When the rotational speed of the engine in the positive direction is lower than the set value N1, the ignition energy storage capacitor 4 is charged with two positive half cycle voltages of the exciter coil 1, and the voltage across the capacitor is Figure 2
It rises like the waveform Vc shown by the solid line in (C). During the negative half cycle of the exciter coil 1, the charging voltage of the capacitor 4 is maintained at a substantially constant value Vcm.

During normal rotation of the engine, the exciter coil 1
When a negative half-cycle voltage is generated in the signal coil 11, the signal coil 11 generates the negative direction signal Vp1 and the positive direction signal Vp2 shown by the solid lines in FIG. When the rotational speed of the engine is low, the magnitude of the negative direction signal Vp1 is equal to the magnitude of the Zener diode 19
Signal Vp1 is blocked by the Zener diode 19 because it is lower than the Zener voltage Vz. Next, when the forward signal Vp2 is generated, the signal coil 11 → diode 12 →
An ignition signal is given to the thyristor 7 through a path from the waveform shaping circuit 18 to the gate-cathode circuit of the thyristor 7 to the gate of the thyristor 7. At this time, since the transistor 24 is in the cutoff state, an ignition signal is given to the gate of the thyristor 7 so that the thyristor becomes conductive at the angular position θ1.
As a result, the capacitor 4 that has been charged to the charging voltage Vcm
Is discharged to the primary coil 5a of the ignition coil 5 to generate an ignition voltage V2 in the secondary coil 5b.

When the rotational speed of the engine rises and exceeds the set value N1, the voltage across the ignition energy storage capacitor 4 rises, for example, as a waveform Vc 'shown by a broken line in FIG. The charging voltage of the capacitor is almost constant Vcm
Held in ´. When the rotation speed exceeds the set value N1, the magnitudes of the negative direction signal Vp1 and the positive direction signal Vp2 generated by the signal coil 11 become large as shown by the broken line in FIG. It becomes higher than the Zener voltage Vz.

Therefore, the signal coil 11 is driven by the negative direction signal.
-> Diode 14-> Zener diode 19-> waveform shaping circuit 22-> between gate and cathode of thyristor 7-> diode 13-> signal coil 11 gives an ignition signal to thyristor 7 and advances to angular position θ1 beyond angular position θ2.
Then, the thyristor 7 becomes conductive. As a result, the charging voltage Vcm '
The electric charge of the capacitor 4 that has been charged to the discharge is discharged and the ignition voltage V2 is generated in the ignition coil 5.

As described above, in the present embodiment, the exciter coil 1 is adapted to induce the alternating voltage of 2 cycles per one rotation, and the ignition energy is generated by the output voltage of the two positive half cycles of the exciter coil. Since the ignition signal is generated after the storage capacitor 4 is charged and the charging voltage is maintained at a substantially constant value, the ignition position is advanced when the rotation speed reaches the set value N1. Also, the charging voltage of the capacitor 4 does not drop during the ignition operation, and good ignition performance can be obtained over the entire rotation range.

FIG. 4 shows a comparison between the characteristics of the embodiment of the present invention shown in FIG. 1 and the conventional example shown in FIG. 6 showing the relationship between the ignition voltage V2 and the rotational speed N of the engine. so,
In the figure, a curve a shows the characteristics obtained by the ignition device of this embodiment, and a curve b shows the characteristics obtained by the conventional ignition device. As is apparent from FIG. 4, according to the present invention, as shown in FIG. 3, the engine speed is set to the set value N1.
Even if the ignition position is advanced when the value reaches, the ignition voltage does not decrease and the ignition performance does not decrease.

In the ignition device of this embodiment, when the internal combustion engine rotates in the reverse direction, the polarity of the AC voltage induced in the exciter coil 1 and the polarity of the signal voltage induced in the signal coil 11 are opposite to those in the normal rotation. . FIG. 5A shows a waveform Ve of the AC voltage induced in the exciter coil 1 at the time of forward rotation.
(Solid line) and a waveform Ver (dashed line) during reverse rotation, and FIG. 5B shows a waveform Vp (solid line) during forward rotation of the signal voltage induced in the signal coil 11 and a waveform Vpr during reverse rotation. In these figures, the rotational angle position is shown to change from left to right during normal rotation and from right to left during reverse rotation. As can be seen from the figure, at the time of reverse rotation of the engine, the signal voltage Vpr is generated within the period in which the positive half cycle output voltage of the exciter coil 1 is generated. Therefore, in this case, the transistor 24 is in the conductive state when the negative direction signal and the positive direction signal are generated, and the ignition signal supply device 2
The ignition signal given to the discharging thyristor 7 from 3 is bypassed through the transistor 24, so that the thyristor 7 does not conduct. Therefore, even if the engine tries to reverse, no ignition voltage is generated and the reverse rotation of the engine is not maintained.

In the above embodiment, the ignition signal supply device 23
Is configured to supply an ignition signal by a negative direction signal and a positive direction signal generated in the signal coil 11, and when the rotation speed of the engine reaches the set value N1, the ignition position is θ2.
It is designed to advance from θ1 to θ1,
The ignition signal supply device 23 may be any one as long as it generates an ignition signal within the angular range in which the exciter coil 1 generates a negative half cycle output voltage when the engine is rotating normally, and is the one shown in the above embodiment. Not limited to. For example, a well-known arithmetic circuit using an integrating circuit whose integration section is determined by a signal voltage obtained from a signal coil, which generates an ignition signal for advancing or retarding within the above angle range, or a CPU is used. Alternatively, the ignition signal may be generated at the ignition position.

In the above embodiment, the transistor 2
4, a DC power supply circuit 26 for supplying a base current to
Although the exciter coil 1 is used as a power source for a circuit for outputting a DC voltage, the DC power source circuit is not limited to the above-described embodiment. For example, a DC power supply circuit that outputs a DC voltage using a battery or another power generation coil provided in a magnet generator installed in the engine as a power supply may be used.

[0047]

As described above, according to the present invention, the ignition energy storage capacitor is charged with the positive half cycle output voltage of the exciter coil that outputs the AC voltage of a plurality of cycles per revolution of the internal combustion engine. And
Ignition signal bypass switch is provided for bypassing the ignition signal from the ignition signal input terminal of the discharge switch, and the ignition signal bypass switch is cut off when the exciter coil generates a negative half cycle output voltage. State, and the exciter coil keeps the bypass switch conductive when the positive half cycle output voltage is being generated, so charging of the ignition energy storage capacitor is completed when the engine is rotating forward. After that, the ignition signal can be generated to prevent the deterioration of the ignition performance during the advance. When the engine reverse rotation in which the polarity of the output voltage of the exciter coil is reversed, an ignition signal is generated while the ignition signal bypass switch is conducting, so the ignition signal is bypassed from the discharge switch to ignite. It is possible to prevent the operation from being performed and prevent the engine from reversing.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a waveform diagram showing voltage waveforms of respective parts of FIG.

FIG. 3 is a diagram showing a characteristic of an ignition position with respect to a rotation speed obtained according to an embodiment of the present invention.

FIG. 4 is a diagram showing a comparison of characteristics of an ignition voltage with respect to a rotation speed in an example of the present invention and a conventional example.

FIG. 5 is a waveform diagram showing the output waveform of the exciter coil and the output waveform of the signal coil used in the embodiment of the present invention during forward rotation and reverse rotation of the engine.

FIG. 6 is a circuit diagram showing a circuit configuration of a conventional example.

FIG. 7 is a waveform diagram showing voltage waveforms at various portions in FIG.

[Explanation of symbols]

 1 Exciter Coil 4 Ignition Energy Storage Capacitor 5 Ignition Coil 7 Thyristor (Discharge Switch) 11 Signal Coil 23 Ignition Signal Supply Device 24 NPN Transistor (Ignition Signal Side Switch) 26 DC Power Supply Circuit 27 Base Current Supply Circuit 28 Reverse Bias Circuit 29 Ignition signal bypass switch control circuit

Claims (3)

[Claims] 1. An exciter coil which is provided in a magnet generator attached to an internal combustion engine and which outputs an alternating voltage of a plurality of cycles per one revolution of the engine in synchronization with the rotation of the engine,
Ignition coil, an ignition energy storage capacitor that is provided on the primary side of the ignition coil and is charged to one polarity by the positive half cycle output voltage of the exciter coil, and conducts when an ignition signal is applied. And a discharge switch for discharging the electric charge of the capacitor to the primary coil of the ignition coil, and an ignition signal supply device for supplying an ignition signal to an ignition signal input terminal of the discharge switch at an ignition position of the internal combustion engine. In a capacitor discharge type internal combustion engine ignition device, an ignition signal bypass switch provided so as to bypass the ignition signal from the ignition signal input terminal of the discharge switch when conducting, and a negative switch of the exciter coil. When the output voltage of a half cycle is generated, the ignition signal side path switch is kept in the cut-off state, and the positive half cycle of the exciter coil is The ignition signal side that controls the ignition signal side path switch according to the polarity of the output voltage of the exciter coil so that the ignition signal side path switch is kept in the conductive state when the output voltage of the ignition signal side is generated. A road switch control circuit, and the ignition signal supply device is configured to generate an ignition signal when the exciter coil generates a voltage of a positive half cycle during normal rotation of the internal combustion engine. An ignition device for a capacitor discharge type internal combustion engine, characterized in that: 2. The ignition signal side path switch comprises an NPN transistor having a collector-emitter circuit connected in parallel between ignition signal input terminals of the discharge switch, and the ignition signal side path switch control circuit comprises: A direct current power supply circuit for outputting a direct current voltage; a base current supply circuit for supplying a base current from the direct current power supply circuit to the transistor; and the transistor when the exciter coil generates a negative half cycle output voltage. 2. A capacitor discharge type internal combustion engine ignition device according to claim 1, further comprising a reverse bias circuit which reversely biases the base-emitter between the base and the emitter to shut off the transistor. 3. The reverse bias circuit includes a diode connected between the base and emitter of the transistor with the anode directed toward the emitter side of the transistor, and a negative half cycle output of the exciter coil to connect the diode to the diode. The capacitor discharge type internal combustion engine ignition device according to claim 2, comprising a circuit for supplying a forward current.