JPH09170542A - Igniter for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent accident from taking place by prevention of such a danger as suddenly driven load caused by start of an engine under its state of an engaged clutch by providing a safety circuit composed of a clutch condition detecting circuit, an ignition blocking circuit and an ignition blocking control circuit. SOLUTION: A clutch condition detecting circuit 8 is provided in a safety circuit 7. In addition, such an ignition checking control circuit 10 is provided for detecting any ignition pulse generated in the primary coil of an ignition coil 5 at the action time of ignition, and blocking any drive signal to be given to the ignition blocking switch of an ignition blocking circuit 9 when such a state as detecting ignition pulses continues at a time interval shorter than the set time, and allowing the drive signal to be given to an ignition blocking switch when such a state as detecting no ignition pulse continues for a period exceeding the set time. Thereby, any igniting action of an ignition circuit 6 is blocked when engine start operation is practiced with a clutch 3 in its linked condition so as to prohibit start of the engine for preventing generation of any accident.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device for an internal combustion engine equipped with a safety circuit that prevents the engine from starting while the clutch is engaged.

[0002]

2. Description of the Related Art Generally, an internal combustion engine ignition device includes an ignition coil and an ignition circuit for controlling a primary current of the ignition coil so as to induce a high voltage for ignition in a secondary coil of the ignition coil during an ignition operation. Is equipped with.

In a vehicle such as a two-wheeled vehicle having a clutch and a transmission between an output shaft of an internal combustion engine and a load (a driving wheel in the case of a two-wheeled vehicle), when the clutch is disengaged when the engine is started. , Or a safety circuit that allows engine ignition only when the transmission is in the neutral position and prohibits engine ignition when the clutch is engaged or when the transmission is in a position other than the neutral position. Is provided in the ignition device to prevent the engine from starting when the clutch is engaged or the transmission is in a position other than the neutral position.

[0004]

If the safety circuit as described above is provided, it is possible to prevent the vehicle from suddenly starting and causing an accident immediately after the start operation, so that the safety is improved. Can be made.

However, in vehicles and other devices (for example, mowers) where only the clutch is provided between the output shaft of the engine and the load, the clutch is engaged because the safety circuit as described above is not provided. If the engine was started in this state, the device suddenly actuated and an accident could occur.

It is an object of the present invention to prevent ignition of the engine when the engine is started while the clutch is engaged, to prevent the engine from starting with the clutch engaged, and to start the engine. Another object of the present invention is to provide an ignition device for an internal combustion engine, which is provided with a safety circuit in which the ignition operation is performed even when the clutch is engaged so that the engine can be operated without hindrance.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an ignition coil and an ignition circuit that controls the primary current of the ignition coil to induce a high voltage for ignition in the secondary coil of the ignition coil during an ignition operation. And a safety circuit that inhibits the ignition operation of the ignition circuit and prohibits the engine from starting when the engine is started while the clutch provided between the output shaft of the engine and the load is engaged. And an ignition device for an internal combustion engine.

In the ignition device targeted by the present invention,
It is assumed that a power generation coil provided in a magneto power generator attached to an internal combustion engine is used as an ignition power source for supplying a primary current to the ignition coil.

According to the present invention, the safety circuit detects the state of a clutch provided between the output shaft of the internal combustion engine and the load, and outputs a clutch-on signal when the clutch is engaged. An ignition blocking circuit that includes a detection circuit and an ignition blocking switch that operates using a clutch-on signal as a drive signal, and that shorts or disconnects a part of the ignition circuit by the operation of the ignition blocking switch to block the ignition operation. , The ignition pulse generated in the primary coil of the ignition coil during the ignition operation is detected, and the drive signal is given to the ignition prevention switch when the state in which the ignition pulse is detected at the interval shorter than the set time continues. And the drive signal is supplied to the ignition prevention switch when the ignition pulse is not detected for a period exceeding the set time. Ignition blocking control circuit and by configured for.

In general, the ignition circuit includes a semiconductor switch that operates (ON operation or OFF operation) when a trigger signal (ignition signal) is given to the ignition timing of the internal combustion engine, and the primary operation of the ignition coil is performed by the operation of the semiconductor switch. By making a rapid change in the current, a high voltage for ignition is induced in the secondary coil of the ignition coil. In the present invention, the "ignition pulse generated in the primary coil of the ignition coil" means a pulsed voltage induced in the primary coil of the ignition coil when the primary current of the ignition coil is rapidly changed.

Techniques for blocking the ignition operation by short-circuiting or disconnecting a part of the ignition circuit by an ignition-blocking switch are already known. The location where the ignition blocking switch short-circuits or disconnects may be any location as long as the ignition operation is not performed due to the short-circuiting or disconnection. The places where the ignition blocking switch short-circuits are, for example, between the input terminals of the trigger signal of the semiconductor switch that controls the primary current of the ignition coil, both ends of the semiconductor switch, both ends of the power generation coil used as the ignition power source, and the like.

The drive signal for the ignition prevention switch is a signal given to the control terminal of the switch circuit for making the ignition prevention switch conductive or cut off. In a switch for ignition prevention, for example, when using a transistor as a switch element to turn on the transistor,
The base current given to the transistor becomes a drive signal.

In the above ignition device, when the engine is started, the ignition blocking control circuit is in a state in which the drive signal is supplied to the ignition blocking switch. When the engine is started with the clutch engaged,
Since the clutch-on signal is generated and the drive signal is given to the ignition prevention switch, the ignition prevention switch operates.
As a result, the ignition operation is blocked, so that the engine goes into a misfire state and the engine is blocked from starting.

On the other hand, when the engine is started with the clutch disengaged, the clutch-on signal is not generated, and the drive signal is not given to the ignition prevention switch, so that the ignition operation is performed. It is not blocked and the engine can be started without any problems.

Once the engine is started, the ignition pulse is generated within the set time, so that the ignition prevention control circuit is in a state of preventing the drive signal from being applied to the ignition prevention switch. In this state, the drive signal is not given to the ignition preventing switch even when the clutch is engaged and the clutch-on signal is generated, so that the ignition operation is performed and the operation of the engine is performed without trouble.

As described above, according to the present invention, when the engine is started while the clutch is engaged,
Since it is possible to prevent the ignition operation from being performed, it is possible to prevent the engine from starting while the clutch is engaged and suddenly drive the load, and it is possible to prevent an accident from occurring.

When the internal combustion engine is stopped, the electric charge accumulated in the time setting capacitor is discharged through the discharge circuit, so that the safety circuit can be normally operated again when the engine is restarted.

The ignition prevention control circuit discharges the time setting capacitor charged with an ignition pulse induced in the primary coil of the ignition coil during the ignition operation and the time setting capacitor with a predetermined time constant, for example. A drive provided so as to bypass the drive signal supplied to the ignition prevention switch by conduction when the voltage across the discharge circuit and the time setting capacitor exceeds a predetermined level. Equipped with a signal side path switch, the drive signal side path switch is turned on to prevent ignition when the ignition pulse is detected at an interval shorter than the set time determined by the time constant of the discharge circuit. The drive signal is blocked from being supplied to the drive switch, and when the ignition pulse is not detected for more than the set time, the drive signal bypass Pitch and in the cut-off state can be formed by an ignition blocking control circuit to allow the drive signal is applied to the ignition blocking switch.

The ignition prevention control circuit also uses, as a drive signal, a power supply capacitor charged to one polarity by the negative half cycle output voltage of the generator coil and an ignition pulse induced in the primary coil of the ignition coil during the ignition operation. A pump-up switch circuit that conducts and transfers the charge of the power supply capacitor to the time setting capacitor, a discharge circuit that discharges the charge of the time setting capacitor with a constant time constant, and a voltage across the time setting capacitor And a drive signal bypass switch that is provided so as to bypass the drive signal supplied to the ignition prevention switch when the ignition control switch is turned off from the ignition prevention switch.

As described above, when the power source capacitor is charged with the negative half cycle output voltage of the power generating coil and the time setting capacitor is charged with the charge of the power source capacitor, the energy of the ignition pulse generated at the time of starting is increased. Even when is small, the time setting capacitor can be sufficiently charged to operate the safety circuit normally.

In the pump-up switch circuit, for example, when the collector-emitter circuit is connected between the power supply capacitor and the time setting capacitor, the charge of the power supply capacitor is transferred to the time setting capacitor when the circuit becomes conductive. And a second transistor which is turned on when an ignition pulse is applied and causes a base current to flow through the first transistor.

The pump-up switch circuit also includes
A programmable unijunction transistor (hereinafter referred to as UJT) that transfers the charge of the power supply capacitor to the time setting capacitor when the anode-cathode circuit is connected between the power supply capacitor and the time setting capacitor and becomes conductive.
That. ), And a trigger transistor that is turned on when an ignition pulse is applied and applies a trigger signal to the gate of the UJT.

Further, the pump-up switch circuit is
The thyristor that transfers the electric charge of the power supply capacitor to the time setting capacitor when the circuit between the anode and the cathode is connected between the power supply capacitor and the time setting capacitor, and the gate of the thyristor when an ignition pulse is given. It can also be configured with a trigger signal supply circuit that gives a trigger signal.

As described above, the PUT serves as a switch for transferring the electric charge of the power supply capacitor to the time setting capacitor.
Alternatively, if a thyristor is used, the PUT or thyristor, once made conductive when an ignition pulse occurs, waits until the potential of the positive polarity side terminal of the power supply capacitor becomes lower than the potential of the positive polarity side terminal of the time setting capacitor. Since the conduction state is maintained, the safety circuit can be normally operated by sufficiently charging the time setting capacitor even when the pulse width of the ignition pulse is narrow.

The clutch state detection circuit is provided with a detection switch that is closed when the clutch is engaged, and is configured to output a clutch-on signal through the detection switch with a positive half cycle output voltage of the magneto coil. You can

The clutch state detection circuit may also be provided with a detection switch that is closed when the clutch is engaged, and the clutch-on signal may be output through the detection switch at the charging voltage of the power supply capacitor.

A current interruption type circuit can be used as the ignition circuit. When using a current interruption type ignition circuit, it is often the case that at least a primary coil of an ignition coil is provided in a magnet generator so that the primary coil also serves as a generator coil as an ignition power source. In this case, the current cut-off type ignition circuit has a base circuit, for example, when the collector-emitter circuit is connected in parallel to the primary coil of the ignition coil and a positive half-cycle output voltage is induced in the primary coil of the ignition coil. A primary current control transistor that is supplied with current and conducts, and a cutoff that is triggered to turn off the primary current control transistor when the voltage across the primary coil of the ignition coil reaches a set value. It is composed of a control switch.

A capacitor discharge type ignition circuit may be used as the ignition circuit. The capacitor discharge type ignition circuit includes, for example, 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 generator coil, and is triggered during the ignition operation. And a discharge switch for discharging the electric charge of the ignition energy storage capacitor to the primary coil of the ignition coil.

When a capacitor discharge type circuit is used as the ignition circuit, the ignition prevention control circuit provided in the safety circuit is
The power supply capacitor charged with a constant time constant by the positive half cycle output voltage of the magneto coil, the time setting capacitor charged with a constant time constant by the voltage across the power capacitor, and the voltage across the power capacitor The charging current bypass switch for bypassing the charging current supplied from the power supply capacitor to the time setting capacitor by the drive signal is supplied to the primary coil of the ignition coil during the ignition operation. The charge current bypass switch cutoff circuit that detects the induced ignition pulse and turns off the charge current bypass switch while the ignition pulse is generated, and the charge of the time setting capacitor with a constant time constant Ignition prevention switch that conducts when the voltage across the discharge circuit and the time setting capacitor exceeds a specified level The drive signal provided to can be constituted by the driving signal side road switch provided so as to bypass the switch ignition blocking.

[0030]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a basic configuration of an internal combustion engine ignition device according to the present invention. In the figure, 1 is an internal combustion engine, 2 is a load driven by the internal combustion engine 1, 3 is a clutch provided between the output shaft of the internal combustion engine 1 and the load 2, and 4 is ignition for the internal combustion engine according to the present invention. It is a device.

The ignition device 4 comprises an ignition coil 5 composed of a primary coil and a secondary coil wound around an iron core, and an ignition coil 5 for inducing a high voltage for ignition in the secondary coil of the ignition coil 1 during an ignition operation. An ignition circuit 6 that controls the primary current of the coil and a safety circuit 7 that inhibits the ignition operation of the ignition circuit 6 and prohibits the engine from starting when the engine is started with the clutch 3 engaged. Composed.

The ignition circuit 6 includes a power generation coil as an ignition power source that outputs an AC voltage in synchronization with the rotation of the internal combustion engine, and a semiconductor switch that operates when the ignition signal is given by using the power generation coil as a power source. A primary current control circuit that causes a sudden change in the primary current of the ignition coil by the operation of the semiconductor switch, and an ignition signal supply circuit that provides an ignition signal to the semiconductor switch of the primary current control circuit at the ignition timing of the internal combustion engine. It

The ignition signal supply circuit is of a simple structure that detects the ignition timing from the change in the voltage across the power generation coil as the ignition power source to obtain the ignition signal. There are various types, including complicated configurations for controlling the.

The ignition circuit 6 currently used is divided into a current cut-off type circuit and a capacitor discharge type circuit, depending on how to control the primary current.

In the current interrupting type circuit, when a positive half-cycle voltage is induced in the generator coil, a semiconductor switch provided in parallel with the generator coil is turned on so that a short-circuit current flows through the generator coil. A high voltage is induced in the generator coil by turning off the semiconductor switch at the ignition timing. This voltage is further boosted by the ignition coil to obtain a high voltage for ignition.

The capacitor discharge type ignition circuit is provided on the primary side of the ignition coil, and has an ignition energy storage capacitor charged to one polarity by the positive half cycle output voltage of the magneto coil of the magneto-generator, and an ignition energy storage capacitor. A discharge switch that conducts when a signal is given to discharge the electric charge of the ignition energy storage capacitor to the primary coil of the ignition coil;
An ignition timing control circuit that gives an ignition signal to the discharge switch at the ignition timing of the internal combustion engine.

As an ignition power source for supplying a primary current to the ignition coil 5, a magneto coil provided in a magneto generator (not shown) attached to the internal combustion engine 1 is used. Particularly when a current interruption type ignition circuit is used, the ignition coil 5 itself is provided in the magnet generator without providing the generator coil separately from the ignition coil, and the primary coil of the ignition coil is synchronized with the rotation of the engine. In many cases, the primary current is passed through the ignition coil with a voltage of a positive half cycle of the AC voltage induced in the ignition coil.In that case, the primary coil of the ignition coil also serves as the generator coil as the ignition power source. Become. In the ignition device according to the present invention, the power generation coil as the ignition power source may be provided separately from the ignition coil, or the primary coil itself of the ignition coil may be used as the power generation coil as the ignition power source.

The polarities of the positive and negative half cycles of the AC voltage induced in the generator coil are relative, and one of the two half cycles of the AC voltage output by the generator coil is positive. If it is a cycle, the other half cycle is a negative half cycle. In the present invention, the half cycle used to pass the primary current through the ignition coil is a positive half cycle. When using a capacitor discharge type ignition circuit that charges the ignition energy storage capacitor with the output of a half cycle of the generator coil and discharges the charge of the capacitor to the primary coil of the ignition coil, a capacitor discharge type ignition circuit is used. The half cycle of charging the energy storage capacitor is the positive half cycle.

In the present invention, the safety circuit 7 detects the state of the clutch 3 provided between the output shaft of the internal combustion engine 1 and the load 2 and outputs a clutch-on signal when the clutch is engaged. Outputting clutch state detection circuit 8
And an ignition blocking circuit 9 that includes an ignition blocking switch that operates using the clutch-on signal as a drive signal, and that blocks the ignition operation by the operation of the ignition blocking switch, and is generated in the primary coil of the ignition coil 5 during the ignition operation. Ignition pulse V
p is detected and the ignition pulse V is generated at an interval shorter than the set time.
When a state in which p is detected continues, a drive signal is prevented from being given to the ignition blocking switch, and when a state in which the ignition pulse Vp is not detected continues for a period exceeding the set time, the ignition blocking switch is provided. And an ignition prevention control circuit 10 which allows a drive signal to be given.

In order to prevent the ignition operation by the operation of the ignition prevention switch, the ignition prevention switch is turned on or off when the drive signal is given by the clutch-on signal, and the ignition prevention switch switches the ignition circuit. It suffices if a part of them is short-circuited or separated. As the ignition prevention switch, a switch circuit using a switch element such as a transistor, an FET, or a thyristor capable of on / off control is used.

The clutch state detection circuit 8 is provided with a detection switch which detects the operation of the clutch and turns on when the clutch is engaged and turns off when the clutch is disengaged. It can be configured by a circuit that outputs a clutch-on signal through a detection switch. When the clutch is engaged and disengaged, the detection switch is in an off state and an on state, respectively, and when the detection switch is in an on state, it is in an off state, and the detection switch is in an off state. It is also possible to configure the clutch state detection circuit 8 with a semiconductor switch that is turned on.

The ignition prevention control circuit 10 discharges the time setting capacitor charged with an ignition pulse induced in the primary coil of the ignition coil during the ignition operation and the electric charge of the time setting capacitor with a predetermined time constant, for example. A drive signal bypass switch for bypassing a drive signal, which is conducted when the voltage between both ends of the discharge setting circuit and the time setting capacitor exceeds a predetermined level, and is applied to the ignition prevention switch, from the ignition prevention switch. And a circuit including and.
In this case, when the ignition pulse is detected at an interval shorter than the set time determined by the time constant of the discharge circuit, the drive signal bypass switch is turned on to apply the drive signal to the ignition prevention switch. To prevent the ignition signal from being applied to the ignition blocking switch by turning off the drive signal bypass switch when the ignition pulse is not detected for a period exceeding the set time. .

The ignition prevention control circuit 10 also uses, as drive signals, a power supply capacitor charged to one polarity by the negative half cycle output voltage of the generator coil and an ignition pulse induced in the primary coil of the ignition coil during ignition operation. A pump-up switch circuit that conducts and transfers the charge of the power supply capacitor to the time setting capacitor, a discharge circuit that discharges the charge of the time setting capacitor with a constant time constant, and a voltage across the time setting capacitor And a drive signal bypass switch that is provided so as to bypass the drive signal supplied to the ignition prevention switch when the ignition prevention switch is turned off. You can also In this case as well, when the ignition pulse continues to be generated at an interval shorter than the set time determined by the time constant of the discharge circuit, the drive signal side switch is turned on and the drive signal is supplied to the ignition prevention switch. When the state in which the ignition pulse is not generated continues for a period exceeding the set time, the drive signal bypass switch is turned off to allow the drive signal to be supplied to the ignition prevention switch.

Hereinafter, specific examples of the configuration of each part of the ignition device for an internal combustion engine according to the present invention will be described in detail with reference to various embodiments.

[0045]

FIG. 2 shows a first embodiment of the present invention. In FIG. 2, the ignition coil 5 comprises a primary coil 5a and a secondary coil 5b wound around an iron core 5c.
One ends of the primary coil 5a and the secondary coil 5b are commonly connected and grounded. The non-grounded terminal of the secondary coil 5b is connected to the non-grounded terminal of the spark plug 11 provided in the cylinder of the internal combustion engine via a high voltage cord. In this example, the ignition coil 5 is provided in a magnet generator attached to the output shaft of the internal combustion engine, and an AC voltage is induced in the primary coil 5a in synchronization with the rotation of the engine. That is, in this example,
The primary coil 5a of the ignition coil also serves as a power generation coil as an ignition power source.

The ignition circuit 6 is a current cutoff type circuit, the emitter of which is grounded and the collector of which is the primary coil 5a of the ignition coil.
NPN transistor (primary current controlling transistor) TR1 connected to the non-grounded terminal of NPN transistor TR2 (emitter control switch) whose emitter is grounded and whose collector is connected to the base of transistor TR1
And a resistor R connected between the base of the transistor TR1 and the non-grounded side terminal of the primary coil 5a and between the base of the transistor TR2 and the non-grounded side terminal of the primary coil 5a, respectively.
1 and R2 and a resistor R3 connected between the base of the transistor TR2 and ground.

In this ignition circuit 6, the primary coil 5
When a voltage of a positive half cycle in the direction of the arrow in the figure is induced in a, a base current is given to the transistor TR1 through the resistor R1, so that the transistor becomes conductive and the primary current flows from the primary coil 5a between the collector and emitter of the transistor TR1. (Short circuit current) flows. When the voltage across the primary coil 5a reaches a predetermined level with an increase in the primary current, the base current given to the transistor TR2 through the resistor R2 reaches a size that makes the transistor TR2 conductive, so that the transistor TR2 becomes conductive. TR2 becomes conductive. When the transistor TR2 becomes conductive, the resistance R1
Most of the current flowing through the transistor TR2 flows between the collector and emitter of the transistor TR2, and almost no base current flows through the transistor TR1. Therefore, the transistor TR1 is cut off and the primary current flowing through the primary coil 5a is cut off. At this time, in the primary coil 5a,
A high pulse voltage (ignition pulse) Vp in a direction in which the current that has been flowing up to that time is kept flowing is induced. This voltage is further boosted by the ignition coil 5, and the secondary coil 5b
A high voltage for ignition is induced in. Since this high voltage is applied to the spark plug 11, a spark is generated in the spark plug 11,
The engine is ignited.

In the example shown in FIG. 2, the transistor TR2 is used as the cutoff control switch. In this switch, the cathode is grounded, the anode is connected to the base of the transistor TR1, and the gate is the resistor R2 and A thyristor connected to the connection point of R3 may be used.

The clutch state detection circuit 8 detects the state of the clutch provided between the output shaft of the engine and the load,
Equipped with a detection switch 8a that is turned on and off when the clutch is engaged and disengaged respectively, and ignites when the detection switch 8a is on (when the clutch is engaged). From the generator coil (primary coil 5a) as a power source to the detection switch 8
A high level clutch-on signal Von is output through a.

The ignition blocking circuit 9 includes an NPN transistor (ignition blocking switch) TR3 whose emitter is grounded, and a resistor R4 whose one end is connected to the base of the transistor, for detecting the clutch state detecting circuit 8. A drive signal (base current) is given to the transistor TR3 through the resistor R4 by the clutch-on signal given through the switch 8a. The collector of the transistor TR3 forming the ignition blocking switch is connected to the base of the transistor TR2 of the ignition circuit 6, and when the transistor TR3 becomes conductive, the base and emitter of the transistor TR2 of the ignition circuit are short-circuited. ing.

The ignition prevention control circuit 10 includes a diode D1 having an anode connected to the non-grounded terminal of the primary coil 5a of the ignition coil 5, a Zener diode ZD1 having a cathode connected to the cathode of the diode D1, and a Zener diode ZD1. A time setting capacitor C1 with one end connected to the anode of the resistor through a resistor R5 and the other end grounded
And a discharge resistor R6 connected in parallel to both ends of the capacitor C1 and a Zener diode connected in parallel to both ends of the capacitor C1 with the anode facing the ground side to limit the charging voltage of the capacitor C1 to a constant value. It consists of ZD2 and FET F1 whose source is grounded and whose drain is connected to the base of transistor TR3. The gate of the FET is connected to the non-grounded side terminal of capacitor C1. In this example, the resistor R6 constitutes a discharge circuit for the capacitor C1 and the FET F1 constitutes a drive signal side switch.

In the ignition prevention control circuit 10 shown in FIG. 2, when the ignition pulse Vp induced in the primary coil 5a of the ignition coil 5 during the ignition operation exceeds a set level substantially determined by the Zener voltage Vz1 of the Zener diode ZD1. , The Zener diode becomes conductive, and the time setting capacitor C1 is charged with a predetermined time constant. The electric charge of the time setting capacitor C1 is discharged with a constant time constant through the resistor R6. Time setting capacitor C by ignition pulse Vp
When 1 is charged, when the voltage across the capacitor C1 exceeds a predetermined trigger level, the FET F1 conducts to bypass the base current given to the transistor TR3 from the transistor TR3, and the transistor TR3 conducts. Prevent. In the present invention, the discharge time constant of the capacitor C1 is set so that the time (set time) during which the voltage across the capacitor C1 exceeds the trigger level of the FET F1 is sufficiently longer than the ignition interval at low speed of the engine. Is set.

FIGS. 3A to 3E show the voltage waveforms at various points in the embodiment of FIG. 2, and FIG. 3A shows the voltage between the diode D1 of the ignition prevention control circuit 10 and the ground (primary). The voltage across the coil 5a) V1 is shown in the figure (B).
Shows ON / OFF operation of the detection switch 8a of the clutch state detection circuit 8. 3 (C) and 3 (D) show the waveform of the voltage Vc1 across the time setting capacitor C1 and the waveform of the voltage Vds between the drain and source of the FET F1, respectively, and FIG. Transistor T
The voltage Vce between the collector of R3 and ground is shown.

When the engine is started with the clutch engaged, as shown at the left end of FIG. 3 (B),
Since the detection switch 8a is in the ON state, the clutch-on signal Von is transmitted between the base of the transistor TR3 and the ground through the detection switch 8a when a voltage of a positive half cycle in the direction of the arrow in the drawing is induced in the primary coil 5a of the ignition coil. Is applied. As a result, a base current flows through the transistor TR3, so that the transistor TR3 becomes conductive and the voltage Vce between its collector and ground becomes almost zero, and the transistor TR2 is held in the cutoff state. Therefore, the primary coil 5
The transistor TR1 is held in the conducting state for the entire positive half cycle of the voltage induced in a, and the primary coil 5
The waveform of the positive half cycle of the output voltage of a is as shown on the left end side of FIG. In this state, since the primary current of the ignition coil is not cut off, the ignition operation is blocked. If the ignition operation is not performed, the ignition pulse Vp is not generated, so that the capacitor C1 of the ignition prevention control circuit 10 is not charged and the FET is not conducted. Therefore, the FET F1 does not hinder the conduction of the transistor TR3, and the ignition blocking circuit 9 continues to block the ignition operation. As a result, starting the engine with the clutch engaged is prohibited.

When the clutch is disengaged at the time of starting the engine, or even when the starting operation is performed with the clutch being engaged, when the clutch is disengaged during the starting operation, As shown in the central portion of FIG. 3 (B), since the detection switch 8a is turned off, the base current is not given to the transistor TR3 of the ignition blocking circuit 9. In this state, when the voltage across the primary coil 5a reaches a predetermined level, the transistor T of the ignition circuit 6
Since R2 conducts and turns off the transistor TR1, the ignition operation is performed and the engine is started.

Once the ignition operation is performed, the ignition pulse V
When p exceeds the Zener level Vz1 of the Zener diode ZD1, the time setting capacitor C1 is charged and the voltage Vc1 across the capacitor C1 rises as shown in FIG. 3 (C). The voltage across the capacitor C1 is FET
When the cut-off level (trigger level) Vct of F1 is exceeded, the FET becomes conductive and the voltage V between its drain and source becomes Vct.
Since ds becomes almost zero, the transistor TR3 is turned off. The voltage across the capacitor C1 is FET F1
Since the discharge time constant of the capacitor C1 is set so that the time (set time) exceeding the trigger level of is sufficiently longer than the ignition interval at low speed of the engine, once the ignition operation is performed After that, the FET F1 is held in the conductive state, and the ignition blocking operation of the ignition blocking circuit 9 is prohibited. Therefore, after the engine is started, even if the clutch state detection circuit 8 outputs the clutch-on signal when the clutch is engaged, the transistor TR3 of the ignition prevention circuit 9 does not become conductive, and the ignition operation is performed without any trouble. Be seen.

After the engine is stopped, if the state where the ignition pulse Vp is not detected continues for a period exceeding the above set time,
Since FET F1 (switch for drive signal side path) is cut off, the transistor TR3 is turned on by the clutch-on signal.
The drive signal is allowed to be given to the (ignition prevention switch), and the ignition prevention control circuit 9 becomes operable. Therefore, when the engine is started next time, the safety circuit 7 operates normally and the engine is prohibited from being started in the state where the clutch is engaged.

As shown in FIG. 2, a Zener diode ZD2 is connected to both ends of the time setting capacitor C1.
The voltage across the capacitor C1 is set to a constant value (FET F1
The voltage across the capacitor C1 is FET
The time (set time) during which the cutoff level of F1 (trigger level of the drive signal side switch) is exceeded can be kept constant. However, the time during which the voltage across the time setting capacitor C1 exceeds the trigger level of the drive signal side switch may be set to be sufficiently longer than the ignition interval at the time of starting the engine, and is not necessarily constant. Therefore, the Zener diode ZD2 can be omitted.

FIG. 4 shows an essential part of the second embodiment of the present invention. In this example, one end of a power supply capacitor Co is connected to the cathode of a diode D2 whose anode is grounded, and the capacitor Co The other end is resistor R7 and diode D
3 is connected to the non-grounded side terminal of the primary coil 5a of the ignition coil. Capacitor Co and diode D2
A discharge resistor R8 is connected to both ends of a series circuit of the above, and an emitter of a PNP transistor TR4 is connected to a connection point between the capacitor Co and the diode D2. The base of the transistor TR4 is connected to the collector of an NPN transistor TR5 whose emitter is grounded through a resistor R9,
The base of the transistor TR5 is connected to the non-grounded side terminal of the primary coil 5a of the ignition coil through the resistor R5, the Zener diode ZD1 and the diode D1 provided in the same manner as in the embodiment of FIG. A time setting capacitor C1 and a discharging resistor R6 are connected in parallel between the collector of the transistor TR4 and the ground, and the voltage Vc1 across the time setting capacitor C1 is applied between the gate and source of the FET F1. Other configurations are similar to those of the embodiment shown in FIG.

In the embodiment of FIG. 4, the transistor T
R4 and TR5, resistors R6 to R9, capacitors Co and C1, diodes D1 to D3 and zener diode ZD
An ignition prevention control circuit 10 is constituted by 1 and the FET F1. In this ignition prevention control circuit, the circuit of primary coil 5a → diode D2 → power supply capacitor Co → resistor R7 → diode D3 → primary coil 5a
A power supply capacitor charging circuit is configured to charge the power supply capacitor Co with the induced voltage of the primary coil 5a in the negative half cycle of the AC voltage induced in the primary coil 5a. In addition, diode D1 and Zener diode ZD1
The resistors R5 and R9 and the transistors TR4 and TR5 form a pump-up switch circuit that is turned on when the ignition pulse Vp is generated and transfers the electric charge of the power supply capacitor Co to the time setting capacitor C1.

5 (A) and 5 (G) show the voltage waveforms and the operation of the detection switch of each part of the embodiment of FIG. 4, and FIG. 5 (A) shows the operation of both ends of the primary coil 5a of the ignition coil. The waveform of the voltage V1 is shown in FIG.
The waveform of the voltage Vco across o is shown. FIG.
(C) shows the voltage V2 between the collector of the transistor TR5 and the ground, and (D) shows the waveform of the voltage Vc1 across the time setting capacitor C1. Further, FIG. 5 (E) shows the on / off operation of the detection switch 8a of the clutch state detection circuit, and FIGS. 5 (F) and (G) respectively show FET F
1 shows the drain-source voltage Vds of 1 and the voltage Vce between the collector and the ground of the transistor TR3 constituting the ignition blocking switch.

In the embodiment of FIG. 4, the power supply capacitor Co is charged to the polarity shown by the induced voltage of the negative half cycle of the primary coil (power generation coil as an ignition power source) 5a of the ignition coil. When the ignition pulse Vp is generated in the primary coil 5a of the ignition coil during the ignition operation, the transistor T
Since R5 conducts and transistor TR4 conducts by this, the electric charge of the power supply capacitor Co changes to the transistor TR.
The voltage shifts to the time setting capacitor C1 through the emitter-collector 4 and the voltage Vc1 across the capacitor C1 rises as shown in FIG. 5 (D). Other operations are the same as those in the embodiment of FIG.

Thus, the generator coil (primary coil 5
Power capacitor Co at the negative half cycle output voltage of a)
When the time setting capacitor C1 is charged with the electric charge of the power source capacitor, the time setting capacitor C1 is sufficiently charged even if the energy of the ignition pulse Vp generated at the start is small, and the safety circuit It can operate normally.

FIG. 6 shows a third embodiment of the present invention. In this embodiment, the transistor TR of the embodiment of FIG. 4 is used.
Instead of 4, a programmable unijunction transistor (PUT) Pu1 having a self-holding function is used. The anode of the PUT Pu1 is connected to the positive terminal (terminal on the diode D2 side) of the power supply capacitor Co, and the cathode is connected to the positive terminal (non-ground terminal) of the time setting capacitor C1. , Its gate is connected to the collector of the transistor TR5 through the resistor R9. In this example, PUT Pu1, transistor TR5 and resistor R9 form a pump-up switch circuit. The other points are the same as those of the embodiment shown in FIG.

FIG. 7A to FIG. 7G show the voltage waveforms of each part of the embodiment of FIG. 6 and the on / off operation of the detection switch. 7A and 7B show the waveform of the voltage V1 across the primary coil 5a and the waveform of the potential Vco at the positive polarity side terminal of the power supply capacitor Co, respectively. In addition, FIG. 7 (C)
And (D) are the waveform of the voltage V2 between the collector and the emitter of the transistor TR5 and the time setting capacitor C, respectively.
7 shows the waveform of the voltage Vc1 at both ends of 1, and FIG. 7 (E) shows the on / off operation of the detection switch 8a of the clutch state detection circuit 8. Further, FIGS. 7 (F) and (G) show FE, respectively.
The waveform of the drain-source voltage Vds of TF1 and the waveform of the voltage Vce between the collector of the transistor TR3 and the ground are shown.

In the embodiment of FIG. 6, the power supply capacitor Co is charged to the polarity shown in the negative half cycle of the voltage V1 induced in the primary coil 5a. When the ignition pulse Vp is generated in the primary coil 5a during the ignition operation, the base current is applied to the transistor TR5 through the diode D1, the zener diode ZD1 and the resistor R5, so that the transistor TR5 becomes conductive and, as shown in FIG. , The collector potential V2 of the transistor TR5 becomes almost zero for a short time. During this time, a gate current flows through PUT Pu1 and the PUT becomes conductive. When PUT Pu1 becomes conductive, the electric charge of the power supply capacitor Co is transferred to the time setting capacitor C1 through PUT Pu1. When the voltage across the capacitor C1 exceeds the cutoff level Vct of the FET F1, F
ET F1 becomes conductive and transistor T of ignition prevention circuit 9
In order to prevent the conduction of R3, the ignition prevention operation of the ignition prevention circuit 9 is prohibited.

As described above, the PUT P is used as a switch for transferring the electric charge of the power supply capacitor to the time setting capacitor.
When u1 is used, the PUT conducts once when the ignition pulse is generated, and continues until the potential of the positive polarity side terminal of the power supply capacitor Co becomes lower than the potential of the positive polarity side terminal of the time setting capacitor C1. Since the state is maintained, even when the pulse width of the ignition pulse is very narrow, the time setting capacitor can be sufficiently charged to operate the safety circuit normally.

FIG. 8 shows a fourth embodiment of the present invention. In this embodiment, the detection switch 8a of the clutch state detection circuit 8 is a terminal on the diode D2 side of the power supply capacitor Co (a terminal on the positive polarity side). ) And the input terminal of the ignition blocking circuit 9 are connected. Other configurations are the same as those of the embodiment of FIG.

With the configuration shown in FIG. 8, the detection switch 8
Since the ignition pulse is not applied to a, the detection switch 8
The cost can be reduced by using an inexpensive material having a low breakdown voltage as a.

FIG. 9 shows a fifth embodiment of the present invention. In this embodiment, a pump-up switch circuit for transferring the electric charge of the power supply capacitor Co to the time setting capacitor C1 is constituted by the thyristor S1. ing. The thyristor S1 has its anode connected to the positive terminal of the power supply capacitor and its cathode connected to the power supply capacitor C.
The gate of the thyristor is connected in series with a resistor R9, a Zener diode ZD1 whose anode is directed to the resistor R9, and a diode D1 whose cathode is directed to the Zener diode side. It is connected to the non-grounded side terminal of the primary coil 5a through a circuit. Other configurations are the same as those of the embodiment of FIG.

The voltage waveforms of each part and the on / off operation of the detection switch in the embodiment of FIG. 9 are shown in FIGS. 10 (A) to 10 (G). 10A and 10B show the primary coil 5 respectively.
The waveform of the voltage V1 at both ends of a and the waveform of the potential Vco at the connection point between the power supply capacitor Co and the diode D2 are shown. 10 (C) and 10 (D) show the waveform of the trigger signal Vg applied to the gate of the thyristor S1 and the waveform of the voltage Vc1 across the time setting capacitor C1, respectively, and FIG. 10 (E) shows the clutch state detection circuit. 8 shows the on / off operation of the detection switch 8a of No. 8. Furthermore, FIG.
(F) and (G) show the waveform of the drain-source voltage Vds of the FET F1 and the waveform of the voltage Vce between the collector and the ground of the transistor TR3, respectively.

In the embodiment of FIG. 9, when the ignition pulse Vp is generated, the trigger signal Vg is given to the thyristor S1 so that the thyristor becomes conductive, and the electric charge of the power supply capacitor Co is transferred to the time setting capacitor C1 through the thyristor S1. To do. Since the thyristor S1 maintains the conduction state until the potential of the positive polarity side terminal of the power supply capacitor Co becomes lower than the potential of the positive polarity side terminal of the time setting capacitor C1,
Even when the pulse width of the ignition pulse Vp is very narrow, the time setting capacitor C1 can be sufficiently charged.

In the embodiment shown in FIGS. 2, 4, 6, 8 and 9, the ignition circuit 6 is composed of a current interruption type circuit. However, when a capacitor discharge type circuit is used as the ignition circuit. The present invention can also be applied.

FIG. 11 shows a sixth embodiment of the present invention in which a capacitor discharge type circuit is used as the ignition circuit 6. In this example, the ignition coil 5 is provided outside the magnet generator. One end of the ignition energy storage capacitor Ci is connected to the non-grounded terminal of the primary coil of the ignition coil 5. The other end of the capacitor Ci is connected to the cathode of the diode D11, and an exciter coil (a power generating coil as an ignition power source) 12 provided in the magnet generator is connected between the anode of the diode D11 and the ground. A diode D12 is connected to both ends of the primary coil 5a of the ignition coil with its cathode facing the ground side. A thyristor Th whose cathode is directed to the ground side is connected between the connection point between the capacitor Ci and the diode D11 and the ground, and the ignition signal Vi is applied from the ignition signal supply circuit 13 to the gate of the thyristor Th. The ignition signal supply circuit 13 is
An ignition signal Vi is given to the thyristor Th at the ignition position of the engine by using the output of the pulser coil 14 that outputs a pulse signal at a predetermined rotation angle position in synchronization with the rotation of the engine as an input.
As the ignition signal supply circuit 13, a signal generated by the pulsar coil 14 is subjected to waveform shaping and applied to the thyristor Th as an ignition signal Vi, and rotation angle information and rotation speed information obtained from the signal generated by the pulsar coil 14 are supplied. The ignition position of the engine at each rotational speed is calculated based on the above, and the ignition signal Vi is output at the calculated ignition position.

In this example, the capacitor energy storage capacitor Ci, the diodes D11 and D12, the thyristor Th, the exciter coil 12, the pulser coil 14, and the ignition signal supply circuit 13 constitute a capacitor discharge type ignition circuit 6.

The ignition blocking circuit 9 comprises an NPN transistor TR3 whose emitter is grounded and a resistor R4, as in the embodiment of FIG. 2, and the collector of the transistor TR3 is connected to the gate of the thyristor Th.

The ignition prevention control circuit 10 includes a power supply capacitor Co and a time setting capacitor C as in the embodiment of FIG.
1 is provided, but in this example, the power supply capacitor Co
And one end of the time setting capacitor C1 are grounded, and the other end of the power supply capacitor Co is connected to the non-grounded side terminal of the exciter coil 12 through the resistor R5 and the diode D1 having the cathode directed to the resistor R5 side. . A Zener diode ZD2 for limiting the charging voltage of the power source capacitor Co to a constant value is connected in parallel to both ends of the power source capacitor Co. The non-grounded terminal of the power supply capacitor Co is an NPN transistor TR whose emitter is grounded.
It is connected to the collector of 6 through a resistor R11, and a resistor R12 is connected between the base of the transistor TR6 and the non-ground side terminal of the power supply capacitor Co.

The collector of the transistor TR6 is connected to the non-grounded side terminal of the time setting capacitor C1 through the diode D13, and when the transistor TR6 is in the cut-off state, the time set by the charging voltage of the power source capacitor Co through the resistor R11 and the diode D13. The capacitor C1 is designed to be charged. A discharging resistor R6 is connected in parallel to both ends of the time setting capacitor C1, and a discharging circuit of the time setting capacitor is constituted by the resistor R6. A diode D14 having an anode directed to the ground side is connected between the base of the transistor TR6 and the ground, and the cathode of the zener diode ZD3 is connected to the cathode of the diode D14 through a resistor R13. The anode of the Zener diode ZD3 is connected to the non-grounded side terminal of the primary coil 5a of the ignition coil 5 through the diode D15 with the anode facing the Zener diode. The non-grounded terminal of the time setting capacitor C1 is connected to the gate of the FET F1 whose source is grounded, and the drain of the FET is connected to the base of the transistor TR3.

In the embodiment of FIG. 11, the power supply capacitor Co
, Time setting capacitor C1, and transistor TR6
, FET F1, diodes D1 and D13 to D15
, Zener diodes ZD2 and ZD3, and resistor R5
, R6 and R11 to R13, the ignition prevention control circuit 10
Is configured.

Further, the transistor TR6 constitutes a charging current bypass switch for bypassing the charging current of the time setting capacitor C1 from the capacitor C1. The diodes D14 and D15, the Zener diode ZD3 and the resistor R13 perform the ignition operation. A charging current bypass switch cutoff circuit for detecting an ignition pulse induced in the primary coil 5a of the ignition coil and for turning off the charging current bypass switch (transistor TR6) while the ignition pulse is generated is constructed. Has been done.

Also in this embodiment, the discharge time constant of the capacitor C1 is set so that the time period over which the voltage across the capacitor C1 exceeds the cutoff level of the FET F1 is sufficiently longer than the ignition interval at the start of the engine. Is set.

Detection switch 8 of clutch state detection circuit 8
The a is connected between the non-grounded side terminal of the power supply capacitor Co and the input terminal of the ignition blocking circuit 9.

In the embodiment shown in FIG. 11, an AC voltage is induced in the exciter coil 12 in synchronization with the rotation of the internal combustion engine. When a positive half-cycle voltage in the direction of the arrow shown in the figure is induced in the exciter coil 12, the exciter coil 12 → diode D11 → capacitor Ci → diode D12 and the primary coil 5a → exciter coil 12 have a capacitor Ci in the path.
Is charged to the illustrated polarity. When an ignition signal is given to the thyristor Th at the ignition position of the internal combustion engine, the thyristor Th
Is conducted, the charge of the capacitor Ci is transferred to the thyristor T.
Discharge through h and the primary coil 5a of the ignition coil.
As a result, an ignition pulse Vp in a direction that prevents the discharge current from flowing through the primary coil 5a is generated.
Is further boosted to generate a high voltage for ignition in the secondary coil 5b of the ignition coil. Since this high voltage is applied to the spark plug 11, a spark is generated in the spark plug 11 to ignite the engine.

The positive half cycle output voltage of the exciter coil 12 charges the power supply capacitor Co to the polarity shown in the figure through the diode D1 and the resistor R5. Before the ignition operation is performed, the base current is applied to the transistor TR6 through the resistor R12 by the voltage across the power supply capacitor Co, so that the transistor is turned on. Therefore, the electric charge of the power supply capacitor Co is all resistor R11.
Through the transistor TR6 and the transistor TR6, and does not move to the time setting capacitor C1. Therefore, in the state before the ignition operation is performed, the FET F1 does not conduct, and the ignition prevention control circuit 10 does not hinder the ignition prevention operation of the ignition prevention circuit 9.

If the clutch is engaged when the engine is started, the detection switch 8a is in the ON state, so that the base current (driving signal) is given to the transistor TR3 as an ignition prevention switch, and the transistor TR3 becomes conductive. To do. Since the gate and cathode of the thyristor Th are short-circuited by the conduction of the transistor TR3, the ignition signal supplied from the ignition signal supply circuit 13 to the thyristor Th is bypassed from the thyristor Th and the conduction of the thyristor Th is blocked. As a result, the ignition operation is prohibited, so that the engine goes into a misfire state and the starting of the engine is blocked.

When the clutch is disengaged at the time of starting the engine, the detection switch 8a is open, so that the transistor TR3 does not conduct, the ignition operation is performed without any trouble, and the engine is started. When the ignition operation is performed, when an ignition pulse Vp is generated in the primary coil 5a of the ignition coil, a current flows through the circuit of the primary coil 5a → diode D14 → resistor R13 → zener diode ZD3 → diode D15 → primary coil 5a, and the diode A forward voltage drop in the direction of the arrow shown occurs across D14. This voltage drop causes a reverse bias between the base and emitter of the transistor TR6, so that the transistor TR6 is turned off. At this time, the electric charge of the power supply capacitor Co is equal to the resistance R11 and the diode D.
13 and the time setting capacitor C1 is transferred, and the capacitor C1 is charged. When the voltage across the capacitor C1 exceeds the cutoff level of the FET F1, the FE
Since T conducts, the conduction of transistor TR3 is blocked. Since the time setting capacitor C1 is charged every time the ignition operation is performed, the FET is set once the ignition operation is performed.
F1 is kept conductive. Therefore, even if the clutch is engaged and the detection switch 8a is turned on after the engine is started, the transistor TR3 does not become conductive.
The ignition operation of the engine is performed without any trouble.

[0087]

As described above, according to the present invention, the state of the clutch provided between the output shaft of the internal combustion engine and the load is detected to output the clutch-on signal when the clutch is engaged. A clutch state detection circuit that operates, and an ignition blocking switch that operates using the clutch-on signal as a drive signal, and the ignition blocking that blocks the ignition operation by short-circuiting or disconnecting a part of the ignition circuit by the operation of the ignition blocking switch. When the ignition pulse generated in the primary coil of the ignition coil during the ignition operation is detected by the circuit and the state where the ignition pulse is detected at the interval shorter than the set time continues, the drive signal is given to the ignition blocking switch. To prevent being
Since a safety circuit consisting of an ignition prevention control circuit that allows the drive signal to be supplied to the ignition prevention switch when the ignition pulse is not detected continues for a period exceeding the set time, the clutch is engaged. It is possible to prevent the ignition operation from being performed when the starting operation of the engine is performed while the engine is on. Therefore, it is possible to prevent the engine from being started while the clutch is engaged and suddenly driving the load, and it is possible to prevent an accident from occurring.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an ignition device according to the present invention together with an internal combustion engine and its load.

FIG. 2 is a circuit diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 3 is a diagram showing voltage waveforms of respective parts and on / off operation of a detection switch in the embodiment of FIG.

FIG. 4 is a circuit diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 5 is a diagram showing voltage waveforms of respective parts and on / off operation of a detection switch in the embodiment of FIG.

FIG. 6 is a circuit diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 7 is a diagram showing voltage waveforms of respective parts and on / off operation of a detection switch in the embodiment of FIG.

FIG. 8 is a circuit diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 9 is a circuit diagram showing a configuration of a fifth exemplary embodiment of the present invention.

FIG. 10 is a diagram showing voltage waveforms of respective parts and on / off operation of a detection switch in the embodiment of FIG.

FIG. 11 is a circuit diagram showing a configuration of a sixth exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Internal Combustion Engine 2 Load 3 Clutch 4 Ignition Device for Internal Combustion Engine 5 Ignition Coil 6 Ignition Circuit 7 Safety Circuit 8 Clutch State Detection Circuit 9 Ignition Blocking Circuit 10 Ignition Blocking Control Circuit TR1 to TR6 Transistor F1 FET Pu1 PUT S1 Thyristor R1 to R9, R11 to R13 Resistance D1 to D3, D11 to D15 Diode ZD1 to ZD3 Zener diode Co Power supply capacitor C1 Time setting capacitor

Claims (11)

[Claims] 1. An ignition coil, an ignition circuit for controlling a primary current of the ignition coil to induce a high voltage for ignition in a secondary coil of the ignition coil during an ignition operation, an output shaft of an internal combustion engine, and a load. A safety circuit for inhibiting the ignition operation of the ignition circuit to prohibit the engine from starting when the engine is operated with the clutch provided therebetween being connected, and a primary current is supplied to the ignition coil. An ignition device for an internal combustion engine in which a magneto coil provided in a magneto generator attached to an internal combustion engine is used as an ignition power source for flowing the ignition circuit, wherein the safety circuit includes an output shaft and a load of the internal combustion engine. A clutch state detection circuit that detects the state of the clutch provided between the two and outputs a clutch-on signal when the clutch is engaged; and a clutch-on signal that operates as a drive signal. An ignition blocking circuit for blocking the ignition operation by short-circuiting or disconnecting a part of the ignition circuit by the operation of the ignition blocking switch, and a primary coil of the ignition coil during the ignition operation. Detecting the ignition pulse that occurs, prevents the drive signal from being given to the ignition blocking switch when the state in which the ignition pulse is detected at an interval shorter than the set time continues.
An internal combustion engine, comprising: an ignition prevention control circuit that allows a drive signal to be applied to the ignition prevention switch when a state in which the ignition pulse is not detected continues for a period exceeding the set time. Ignition device. 2. An ignition coil, an ignition circuit for controlling a primary current of the ignition coil to induce a high voltage for ignition in a secondary coil of the ignition coil during an ignition operation, an output shaft of an internal combustion engine, and a load. A safety circuit for inhibiting the ignition operation of the ignition circuit to prohibit the engine from starting when the engine is operated with the clutch provided therebetween being connected, and a primary current is supplied to the ignition coil. For an internal combustion engine in which a magneto coil installed in a magneto generator attached to an internal combustion engine is used as an ignition power source for flowing, and a positive half cycle output voltage of the magneto coil is used for flowing the primary current. An ignition device, wherein the safety circuit detects a state of the clutch and outputs a clutch-on signal when the clutch is engaged; An ignition blocking circuit that operates by using an ON signal as a drive signal, and an ignition blocking circuit that short-circuits a part of the ignition device to block the ignition operation by the operation of the ignition blocking switch; and an ignition coil of the ignition coil during the ignition operation. A time setting capacitor that is charged by an ignition pulse induced in the primary coil, a discharge circuit that discharges the electric charge of the time setting capacitor with a predetermined time constant, and the voltage across the time setting capacitor is above a predetermined level. And a drive signal bypass switch that is provided so as to bypass the drive signal supplied to the ignition prevention switch when the discharge signal reaches the time constant of the discharge circuit. When the ignition pulse is detected at an interval shorter than the set time determined by, the drive signal side switch is turned on to prevent ignition. The drive signal is blocked from being given to the switch, and when the state where the ignition pulse is not detected continues for a period exceeding the set time, the drive signal bypass switch is turned off and the drive signal is sent to the ignition block switch. An ignition device for an internal combustion engine, comprising: an ignition prevention control circuit that permits being given. 3. An ignition coil, an ignition circuit for controlling a primary current of the ignition coil to induce a high voltage for ignition in a secondary coil of the ignition coil during an ignition operation, an output shaft of an internal combustion engine, and a load. A safety circuit for inhibiting the ignition operation of the ignition circuit to prohibit the engine from starting when the engine is operated with the clutch provided therebetween being connected, and a primary current is supplied to the ignition coil. An internal combustion engine in which a magneto coil installed in a magneto generator attached to an internal combustion engine is used as an ignition power source for flowing the electric current, and a positive half cycle output voltage of the magneto coil is used for flowing the primary current. An ignition device for a vehicle, wherein the safety circuit detects a state of the clutch and outputs a clutch-on signal when the clutch is engaged, and the clutch state detection circuit. An ignition blocking circuit that operates using a thion signal as a drive signal, and an ignition blocking circuit that short-circuits a part of the ignition device to block the ignition operation by the operation of the ignition blocking switch; and a negative coil of the generator coil. A power supply capacitor charged to one polarity with an output voltage of a half cycle and an ignition pulse induced in the primary coil of the ignition coil during the ignition operation are conducted as a drive signal to transfer the electric charge of the power supply capacitor to the time setting capacitor. A pump-up switch circuit for discharging, a discharge circuit for discharging the electric charge of the time setting capacitor with a constant time constant, and conducting when the voltage across the time setting capacitor exceeds a predetermined level. A drive signal bypass switch provided so as to bypass the drive signal applied to the ignition block switch from the ignition block switch. And the drive signal bypass switch is turned on to drive the ignition block switch when the ignition pulse continues to be generated at an interval shorter than the set time determined by the time constant of the discharge circuit. A signal is blocked, and when the state in which the ignition pulse is not generated continues for a period exceeding the set time, the drive signal bypass switch is turned off and a drive signal is supplied to the ignition block switch. An ignition prevention control circuit for permitting the above, and an ignition device for an internal combustion engine, comprising: 4. The pump-up switch circuit, when the collector-emitter circuit is connected between the power supply capacitor and the time setting capacitor, transfers the electric charge of the power supply capacitor to the time setting capacitor when conducting. 1
4. The ignition device for an internal combustion engine according to claim 3, further comprising: a transistor according to claim 1; and a second transistor that conducts when the ignition pulse is applied and causes a base current to flow through the first transistor. 5. The programmable pump-up switch circuit, when the anode-cathode circuit is connected between the power supply capacitor and the time setting capacitor, is electrically programmable and transfers the electric charge of the power supply capacitor to the time setting capacitor. The ignition device for an internal combustion engine according to claim 3, further comprising a unijunction transistor, and a trigger transistor that is turned on when the ignition pulse is applied and applies a trigger signal to a gate of the programmable unijunction transistor. 6. The thyristor for transferring the electric charge of the power supply capacitor to the time setting capacitor when the anode-cathode circuit is connected between the power supply capacitor and the time setting capacitor for conduction when the pump-up switch circuit is connected. The ignition device for an internal combustion engine according to claim 3, further comprising: a trigger signal supply circuit that applies a trigger signal to the gate of the thyristor when the ignition pulse is applied. 7. The clutch state detection circuit includes a detection switch that closes when the clutch is engaged, and outputs the clutch-on signal through the detection switch with a positive half cycle output voltage of the generator coil. The ignition device for an internal combustion engine according to claim 2, 3, 4, 5, or 6, characterized in that. 8. The clutch state detection circuit includes a detection switch that closes when the clutch is engaged, and outputs the clutch-on signal through the detection switch at a charging voltage of the power supply capacitor. The ignition device for an internal combustion engine according to claim 4, 5, or 6. 9. The ignition coil is configured such that at least a primary coil of the ignition coil is provided in the magnet generator so that the primary coil also serves as a generator coil used as the ignition power source. An inter-circuit is connected in parallel to the primary coil of the ignition coil, and a primary current control transistor is provided which is provided with a base current and conducts when an output voltage of a positive half cycle is induced in the primary coil of the ignition coil. A current cut-off type switch having a cut-off control switch that is triggered when the voltage across the primary coil of the ignition coil reaches a set value to turn off the primary current control transistor. The ignition blocking switch short-circuits the trigger signal input terminals supplied to the cutoff control switch when conducting. An ignition device according to claim 7 or 8 is provided so as to bypass the trigger signal from the interruption control switch. 10. The ignition circuit is provided on a primary side of the ignition coil, and is charged with one polarity by an output voltage of a positive half cycle of the generator coil to store one polarity, and a trigger for ignition operation. And a discharge switch for discharging the electric charge of the ignition energy storage capacitor to the primary coil of the ignition coil, wherein the ignition blocking switch is the discharge switch when conducting. 9. The trigger signal input terminal according to claim 1 is provided so as to short-circuit the trigger signal input terminals to bypass the trigger signal from the discharge switch. Ignition device for internal combustion engine. 11. An ignition coil, an ignition circuit for controlling a primary current of the ignition coil to induce a high voltage for ignition in a secondary coil of the ignition coil during an ignition operation, an output shaft of an internal combustion engine and a load. A safety circuit for inhibiting the ignition operation of the ignition circuit to prohibit the engine from starting when the engine is operated with the clutch provided therebetween being connected, and a primary current is supplied to the ignition coil. An internal combustion engine in which a magneto coil installed in a magneto generator attached to an internal combustion engine is used as an ignition power source for flowing the electric current, and a positive half cycle output voltage of the magneto coil is used for flowing the primary current. Ignition energy storage device, wherein the ignition circuit is provided on the primary side of the ignition coil and is charged to one polarity by an output voltage of a positive half cycle of the generator coil. And a capacitor,
A capacitor discharge type circuit provided with a discharge switch that is triggered at the time of ignition operation to discharge the charge of the ignition energy storage capacitor to the primary coil of the ignition coil, and the safety circuit detects the state of the clutch. And a clutch state detection circuit that outputs a clutch-on signal when the clutch is engaged, and an ignition-blocking switch that operates by using the clutch-on signal as a drive signal. An ignition prevention circuit that short-circuits a part of the device to prevent ignition operation, a power supply capacitor charged with a constant time constant by the positive half cycle output voltage of the generator coil, and a voltage across the power supply capacitor. Drive signal by the time setting capacitor charged with a fixed time constant and the voltage across the power supply capacitor Is applied to the time-setting capacitor from the power supply capacitor to cause a charging current to be bypassed from the time-setting capacitor to the charging current bypass switch and the primary coil of the ignition coil during ignition operation. A charge current bypass switch cutoff circuit that detects an ignition pulse and turns off the charge current bypass switch while the ignition pulse is generated, and the charge of the time setting capacitor with a constant time constant. A discharge circuit for discharging,
The drive signal side provided so as to bypass the drive signal supplied to the ignition prevention switch when the voltage across the time limit setting capacitor exceeds a predetermined level. A road switch, and when the state in which the ignition pulse is generated at an interval shorter than the set time determined by the time constant of the discharge circuit continues, the drive signal side road switch is turned on to prevent ignition. When the drive signal is prevented from being given to the switch, and the state in which the ignition pulse is not generated continues for a period exceeding the set time, the drive signal bypass switch is turned off and the drive signal is transmitted to the ignition prevention switch. An ignition device for an internal combustion engine, comprising: an ignition prevention control circuit that permits being given.