JPS6336426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact ignition device for an internal combustion engine constructed using a semiconductor switching element. The purpose of this is to immediately stop the engine in the event of an accident.

A large number of small general-purpose engines are used in many fields, and the biggest problem with these small general-purpose engines at present is that they are illegally driven in the opposite direction.

If the engine is driven in the opposite direction, not only will normal operation be impossible, but it will also be extremely dangerous.

For this reason, this type of internal combustion engine is equipped with an emergency stop function so that the engine can be stopped immediately if a malfunction such as reverse rotation occurs in the engine.

However, the risk of driving in the opposite direction is extremely high, and the shock caused by the movement in the opposite direction is intense, so the operation to stop the engine described above cannot be accomplished quickly. There was a high risk of a major accident.

The present invention was devised to eliminate the drawbacks of the conventional examples described above, and in a high-voltage magnet generator for an internal combustion engine, the direction of the generated voltage is set in a fixed sequential pattern according to the driving direction of the internal combustion engine. Taking advantage of this fact, the driving direction of the internal combustion engine is determined based on the sequential pattern of the generated voltage, and depending on the direction of the generated voltage, when driving in the opposite direction, the ignition operation itself is electrically disabled. It is configured to do so.

An embodiment of the present invention will be described below with reference to the drawings.

In the ignition device for an internal combustion engine according to the present invention, a first resistor R1 having a high resistance value is connected between both terminals of a primary winding T1 of an ignition coil T having a plug P connected to a secondary winding T2.
and transistor 1 and first capacitor C1
a series circuit of the transistor circuit 2 and a second resistor R2 with a low resistance value, a third resistor R3 of a high resistance value, and a silicon-controlled rectifier element 3 in which a gate circuit is inserted between the gate and cathode. (hereinafter simply referred to as thyristor 3) are connected in parallel, the base of the transistor 1 is connected to the emitter of the transistor circuit 2, the collector of the transistor 1 is connected to the gate of the thyristor 3, and the The base of the transistor circuit 2 is connected to the anode of the thyristor 3, a semiconductor switching element 4 with a control terminal is connected in parallel with the gate circuit, and a resistor and a control terminal of the semiconductor switching element are connected in parallel with the first capacitor C1. and a second capacitor inserted and connected between the cathode terminal and the cathode terminal.

The configuration of the gate circuit of the thyristor 3 is completely different depending on whether it is a self-trigger type or an external trigger type, but in the present invention, the configuration of the gate circuit of the thyristor 3 is as follows. It may be of any type, and the illustrated embodiment shows a case where it is constructed only of the gate resistor R5, which has the simplest structure.

In the device of the present invention described above, the first resistor R
1, a transistor 1, a first capacitor C1, a transistor circuit 2, a second resistor R2, a third resistor R3, and a thyristor 3 constitute the main body of the ignition device, and a semiconductor switching element 4, a resistor R6 The second capacitor C2 constitutes a part that prevents the engine from rotating in reverse.

Further, the semiconductor switching element 4 is not particularly limited, but the most desirable ones are a field effect transistor and an ordinary transistor.

1 and 3 show examples of circuit configurations using field effect transistors as semiconductor switching elements 4, and FIGS. 2 and 4 show examples of circuit configurations using ordinary transistors.

As is clear from the embodiments shown in FIGS. 1 to 4, in the case of the present invention, when a field effect transistor is used as the semiconductor switching element 4, the circuit is more efficient than when an ordinary transistor is used. The configuration is simple.

The embodiment shown in FIG. 1 shows an example of the simplest circuit configuration when a field effect transistor is used as the semiconductor switching element 4. The reverse orientation Zener diode ZD inserted and connected to the transistor circuit 2 is for protecting the transistor circuit 2 from the surge voltage generated during the ignition operation, and is connected to the base of the transistor 1.
The diode D1, whose cathode is connected, conducts current in the reverse direction through the transistor 1 to the primary winding T1.
This is to prevent pre-sparking from occurring.

The embodiment shown in FIG. 2 is constructed using an ordinary transistor in place of the field effect transistor of the embodiment of FIG. and a diode D for maintaining the conduction state of the transistor.
3 and a series circuit with resistor R8 are additionally required.

The embodiment shown in FIGS. 3 and 4 uses a diode as a dedicated circuit in place of the diode D1 in the circuit shown in FIG. 1 and the circuit shown in FIG. D2 and resistor R7
A series circuit is provided.

The ignition device according to the present invention has the above-mentioned configuration.Next, the operation of the ignition device according to the present invention will be explained in order.

(Hereinafter, it will be explained according to the embodiment shown in FIG. 1)
When the internal combustion engine is driven in the normal rotation direction, the ignition coil T
An induced voltage V as shown in FIG. 5 is induced in the primary winding T1.

When the forward voltage V2 begins to be induced, the third
Since the base current flows into the base of the transistor circuit 2 through the resistor R3, the transistor circuit 2
turns on.

By turning on transistor circuit 2,
A primary short-circuit current flows through the transistor circuit 2 and the second resistor R2, but at the same time as this primary short-circuit current flows, a current also flows into the base of the transistor 1, so the transistor 1 also turns. - Turns on and charges the first capacitor C1 with the polarity shown.

When charging in the first capacitor C1 progresses and the potential of the emitter of the transistor 1 becomes approximately the same as the potential of the base, the transistor 1 enters a cut-off state.

When transistor 1 is cut off, transistor 1
The collector potential of the thyristor 3 suddenly rises to generate a voltage pulse, which is applied to the gate of the thyristor 3 through the stabilizing resistor R4, so that the thyristor 3 becomes conductive.

The conduction of the thyristor 3 causes the base current of the transistor circuit 2 to be shunted, so that the transistor circuit 2 is turned off and the 1
The next short-circuit current is abruptly cut off.

Due to this sudden interruption of the primary short circuit current, a high voltage is induced in the secondary winding T2 of the ignition coil T.
A spark discharge is then generated in the plug P, and the ignition operation is achieved.

The operation of the ignition circuit is achieved as described above, but as is clear from FIG. 5, reverse voltages V1 and V3 are induced before and after the forward voltage V2, and these two voltages V1 and V3
plays a unique role.

That is, a part of the first voltage component V1 is charged to the first capacitor C1 with a polarity opposite to that shown in the figure, and before the forward voltage component V2 is induced, the first capacitor C1→ Since the charged charge is discharged in the path of second resistor R2 → base of transistor 1 → emitter of transistor 1 → first capacitor C1, transistor 1 becomes in the triggered state and is reliably activated at the same time as transistor circuit 2 is turned on. Turning on will ensure that circuit operation is achieved.

Furthermore, the third voltage component V3 has the same effect as the first voltage component V1.

Since the first capacitor C1 has an extremely small capacity, the change in the charging voltage charged to the first capacitor C1 draws a changing waveform as shown in FIG.

That is, the voltage v1 is applied to the first capacitor C1 due to the first voltage portion V1, and the voltage v1 is applied to the first capacitor C1 due to the second voltage portion V2.
Therefore, the voltage v2 is charged by the third voltage V3, and the voltage v3 is charged by the third voltage V3.

The voltage v3 of the voltage charged in the first capacitor C1 is charged with a polarity opposite to that shown in FIG. 1, and before the next ignition operation starts, the first capacitor C1 second capacitor C
2→resistor R6→first capacitor C1 and charges the second capacitor C2 with the polarity shown.

When the second capacitor C2 is charged with the polarity shown, the semiconductor switching element 4 is kept turned off and does not influence the switching operation of the thyristor 3, so that the ignition circuit is It will function normally.

That is, when a field effect transistor is used as the semiconductor switching element 4, the potential of the gate of this field effect transistor is maintained at a lower potential than the potential of the source due to the action of the second capacitor C2. Therefore, due to this potential relationship, the field effect transistor is kept in a state where it cannot be turned on.Also, when an ordinary transistor is used as the semiconductor switching element 4, the second Due to the action of the charge stored in the capacitor C2, this transistor is held in a state where it cannot be turned on.

Next, if the internal combustion engine is illegally driven in the opposite direction, the induced voltage in the primary winding T1 becomes the inverted polarity of the voltage waveform in FIG. 5, as shown in FIG. As shown in FIG. 8, the voltage charged to the first capacitor C1 also has the polarity of the voltage waveform shown in FIG. 6 inverted.

Therefore, at the time when one ignition operation is completed, the polarity of the charge in the first capacitor C1 is as follows.
This means that the battery is charged with the polarity opposite to the above state, that is, with the polarity shown.

Therefore, the second capacitor C2, which charges the discharged charge of the first capacitor C1, is charged with the third voltage v3 with a polarity opposite to that shown in the drawing.

By charging the second capacitor C2 with a polarity opposite to that shown in the figure, the semiconductor switching element 4 is held in the triggered state, so that the gate and cathode of the thyristor 3 are always kept in a short-circuited state. Therefore, the ignition circuit becomes unable to accomplish its ignition operation.

Therefore, as soon as the internal combustion engine is driven in the reverse direction, the ignition operation stops, and the internal combustion engine cannot be driven in the reverse direction, causing the internal combustion engine to stop.

As described above, the ignition device according to the present invention is configured to monitor the form of the induced voltage in the primary winding T1 and stop the operation of the ignition circuit by reversing the potential relationship corresponding to this change in form. The operation is reliable, which results in safer operation of the internal combustion engine.

In addition, its circuit configuration includes a semiconductor switching element 4, a resistor R6, and a second
Since the structure is simply an addition of a series circuit with capacitor C2, the circuit configuration is not only simple but also inexpensive to manufacture, and the present invention can be easily implemented in existing ignition circuits. You can.

Furthermore, since the function of the device according to the present invention is activated when an induced voltage is generated in the primary winding T1, it will be activated as soon as an illegal reversing operation occurs in the internal combustion engine. This means that the internal combustion engine can be stopped with almost no adverse effects caused by reverse rotation of the internal combustion engine.

As is clear from the above description, the ignition device according to the present invention has a simple structure, so it is easy to manufacture and can be manufactured at low cost, and its reversal prevention function is accurate and reliable. Since this is achieved automatically, it exhibits many excellent effects such as being able to operate the internal combustion engine extremely safely.

[Brief explanation of the drawing]

1 to 4 are electrical circuit diagrams showing embodiments of the present invention. FIG. 4 shows an example in which an ordinary transistor is used as a semiconductor switching element. Figures 5 to 8
The figures are voltage waveform diagrams for explaining the operation of the device of the present invention. Figures 5 and 6 show the state when the internal combustion engine is normally operating, and Figures 7 and 8 show the state when the internal combustion engine is normally operating. shows the state when the internal combustion engine is driven in the opposite direction. Explanation of symbols: 1; transistor; 2; transistor circuit; 3; transistor; 4; semiconductor switching element; R1, R2, R3, R4, R5, R
6, R7, R8, R9; Resistor, C1, C2; Capacitor, V1, V2, V3; Voltage, v1, v
2, v3; voltage.

Claims (1)

[Claims] 1 1 of the ignition coil with the plug connected to the secondary winding
A series circuit of a first resistor having a high resistance value, a transistor, and a first capacitor is connected between both terminals of the next winding;
A series circuit of a transistor circuit and a second resistor with a low resistance value, and a series circuit of a third resistor with a high resistance value and a silicon-controlled rectifier with a gate circuit inserted and connected between the gate and cathode are connected in parallel. The base of the transistor is connected to the emitter of the transistor circuit connected to the second resistor, and the collector of the transistor connected to the first resistor is connected to the gate of the silicon-controlled rectifying element, A base is connected to the anode of a silicon-controlled rectifying element connected to the third resistor, a semiconductor switching element with a control terminal is connected in parallel with the gate circuit, and a first capacitor is connected to the emitter of the transistor. An ignition device for an internal combustion engine comprising a series circuit connected in parallel with a resistor and a second capacitor inserted and connected between the control terminal and the cathode terminal of the semiconductor switching element with a control terminal.