JPS6024949Y2 - Stop circuit in non-contact ignition device for internal combustion engine - Google Patents

Description

[Detailed description of the invention] The present invention relates to a stop circuit connected to the ignition circuit of a non-contact ignition device for an internal combustion engine. The purpose is to automatically return to a state where it can be restarted once it has completely stopped.

Currently, many non-contact ignition devices using semiconductor elements are used as ignition devices for internal combustion engines, but these non-contact ignition devices have a function to stop the internal combustion engine to protect the safety of the driver and the internal combustion engine. Parts are often attached.

There are many types of stop function parts based on various operating principles, but among these, the one that stops the ignition circuit's ignition operation and stops the internal combustion engine utilizes the electrical operation of a non-contact ignition device. Effective and simple.

A typical conventional example of a stop circuit in this non-contact ignition system is to insert a snap switch type stop switch between both terminals of the primary winding of the ignition coil, and turn on this stop switch to turn on the primary winding. The ignition operation is stopped by shorting both terminals of the wire.

This conventional example can reliably stop the ignition operation of the ignition device and stop the internal combustion engine, but on the other hand, the voltage applied between both terminals of this stop switch is extremely high, so the rated A large switch must be used, and its contacts are subject to severe wear.Furthermore, when restarting the system, users tend to forget to reset the stop switch, which is inconvenient in use.

The present invention was devised to eliminate the drawbacks of the conventional examples described above, and utilizes part of the reverse voltage induced in the primary winding to activate the ignition circuit while the internal combustion engine is rotating. It is held in such a way that the ignition operation is disabled.

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

The ignition circuit 1 to which the stop circuit 2 according to the present invention is attached includes:
When a forward voltage is generated between the base of the transistor circuit 5 which turns on according to the forward voltage induced in the primary winding 40 of the ignition coil 39 and causes a primary short circuit current to flow through the primary winding 40, and the primary winding 40, The semiconductor rectifying element 6 with a control terminal inserted between the negative side terminal B (in the illustrated embodiment, a thyristor is used, so it will be referred to as thyristor 6 in the following explanation) is set to the value of the primary short-circuit current. The plug 38 connected to the secondary winding 41 of the ignition coil 39 is turned on, and the transistor circuit 5 is turned off by turning on the thyristor 6. By turning off the transistor circuit 5, the primary short-circuit current is abruptly cut off.
The structure is such that a spark discharge is generated.

That is, in the illustrated embodiment, the plug 3 is connected to the secondary winding 41.
A series circuit consisting of a resistor 8 having a high resistance value, a transistor 4, and a capacitor 7 is connected between both terminals of a primary winding 40 of an ignition coil 39 connected to a transistor circuit 5 (in the illustrated embodiment, this transistor Circuit 5 is a Darlington circuit, but this may be a single power transistor) and a series circuit of a resistor 9 with a low resistance value,
A series circuit of a resistor 10 with a high resistance value and a thyristor 6 is inserted and connected in parallel, the base of the transistor circuit 5 is connected to the anode of the thyristor 6, and the transistor 4 is connected to the base of the transistor circuit 5.
The base of the transistor 4 is connected to the emitter of a transistor circuit 5, and the collector of the transistor 4, which is connected to a resistor 8, is connected to the gate of a thyristor 6.

Note that the resistor 12 inserted between the gate and cathode of the thyristor 6 in the figure is a gate stabilizing resistor of the thyristor 6, and the resistor 11 inserted between the collector of the transistor 4 and the gate of the thyristor 6 is a current limiting resistor. It is for use.

Further, the series circuit of the diode 13 and the resistor 14 in the opposite direction inserted between the base of the transistor circuit 5 and the terminal B of the primary winding 40 causes a reverse voltage to be induced in the primary winding 40. According to this reverse voltage, the primary winding 4
The Zener diode 15 inserted between the collector and the base of the transistor circuit 5 is a circuit for preventing pre-ignition by flowing a reverse current through the transistor circuit 5. It also functions to protect the transistor circuit 5 from the high surge voltage generated between both terminals of the primary winding 40 during the ignition operation, that is, when the primary short-circuit current is cut off.

Briefly explaining the ignition operation of the ignition circuit 1 of the embodiment illustrated above, a part of the reverse voltage induced in the primary winding 40 prior to the forward voltage is caused by the reverse leakage current of the transistor 4 to the capacitor 7. The battery will be charged with the polarity shown in the diagram.

In this state, when the induced voltage in the primary winding 40 is reversed and a forward voltage begins to be induced, part of the reverse voltage charged in the capacitor 7 is transferred from the resistor 9 to the base of the transistor 4 and then to the emitter of the transistor 4. is discharged through the transistor 4, so that the transistor 4 is in the triggered state.

Current flows into the base of the transistor circuit 5 through the resistor 10 in accordance with the forward voltage of the primary winding 40, so the transistor circuit 5 turns on, causing a primary short circuit current to flow through the primary winding 40, and at the same time, this transistor circuit 5 turns on. A portion of the next short-circuit current flows into the base of transistor 4, turning transistor 4 on.

By turning on this transistor 4, the capacitor 7
As the discharge of the voltage is promoted, the voltage is reversed and the forward voltage starts to be charged.

When the value of the primary short-circuit current reaches around the maximum value, the transistor 4 is turned off by the action of the capacitor 7, or the current value flowing into the gate of the thyristor 6 through the resistor 11 exceeds a predetermined value, so that the thyristor 6 is turned off. It turns on and pulls the base potential of the transistor circuit 5 to negative.

Therefore, the transistor circuit 5 is turned off to cut off the primary short-circuit current, thereby performing the ignition operation.

The present invention is assembled into the ignition circuit 1 as described above,
It forms part of the control terminal circuit of the thyristor 6 of the ignition circuit 1, that is, the semiconductor rectifying element 6 with a control terminal.

That is, a capacitor 20 is connected to the base of a transistor 16 inserted between the gate and cathode of the thyristor 6 via a resistor 22, and the resistor 2 of this capacitor 20
A diode 17 is inserted between the electrode C on the side connected to the capacitor 2 and the terminal B of the primary winding 40, and the diode 17 forms a part of the charging circuit for the reverse voltage to the capacitor 20 in a reverse direction. A resistor 23 forming part of the discharge circuit of the capacitor 20 is inserted between the other electrode of the capacitor 20 and the emitter of the transistor 16, and the electrode of the capacitor 20 and the other terminal A of the primary winding 40 are connected to each other. A push/button type stop switch 21 is inserted between the capacitors 20 and 20 to form part of a charging circuit for the capacitor 20, and the capacitor 20 is charged with a reverse voltage via a semiconductor rectifier in parallel with the stop switch 21. It is constructed by connecting a charge holding circuit 3 which becomes conductive due to this.

The charge holding circuit 3 may be connected in parallel with the stop switch 21 via a diode 19, as shown by the solid line, or a Zener diode 15 may be used in the ignition circuit 1, as shown by the dotted line. If so, the Zener diode 15 may be used to reduce the number of circuit components used.

Although various configurations are possible for the charge holding circuit 3, specific examples thereof will be explained with reference to FIGS. 2 to 4.

In the case of the embodiment shown in FIG. 2, the planar type N-gate thyristor 24 (hereinafter referred to as PUT 24) is located between the terminal E of the charge holding circuit 3 and the electrode C of the capacitor 20 and has a large resistance value. A series circuit with the resistor 26 is inserted, a resistor 27 with a large resistance value is inserted between the gate of the PUT 24 and the electrode of the capacitor 20, and a series circuit with the resistor 26 is inserted.
It is constructed by inserting a diode 25 in a reverse orientation between the anode and the electrode of the UT 24.

Note that a capacitor 28 inserted between the anode and gate of the PUT 24 in FIG. 2 is a so-called high frequency bypass capacitor for preventing malfunction of the PUT 24.

In the embodiment shown in FIG. 2, when the capacitor 20 is charged with a reverse voltage with the polarity shown in FIG. , this turns on PUT 24.

Once the PUT 24 is turned on, the electrodes of the capacitor 20 are short-circuited from the diode 25 to the terminal E via the PUT 24, so that a charging circuit for the capacitor 20 is formed and maintained.

In the embodiment shown in FIG. 3, a transistor 30 is inserted between the electrode of the capacitor 20 and the terminal E, and a transistor 29 is inserted between the emitter and base of the transistor 30.
A resistor 33 is inserted between the base and collector of the transistor 30, a resistor 31 is inserted between the base of the transistor 29 and the electrode C of the capacitor 20, and a resistor 33 is inserted between the base of the transistor 29 and the electrode C of the capacitor 20.
It is constructed by inserting a resistor 32 between it and the collector of 0.

In the embodiment shown in FIG. 3, if the capacitor 20 is not charged with the polarity shown, the transistor 29
is turned on, so that the transistor 30 is kept turned off.

When the capacitor 20 is charged with the polarity shown in this state, the transistor 29 is turned off, and the transistor 30 is thereby turned on to form and maintain a charging circuit for the capacitor 20.

Once turned on, transistor 30 remains triggered as long as capacitor 20 is charged with a voltage of the polarity shown.

In the embodiment shown in FIG. 4, a transistor 35 is inserted between the electrode of the capacitor 20 and the terminal E, and the capacitor 2
A series circuit of a transistor 34 and a resistor 37 is inserted between the electrode C of 0 and the base of the transistor 35, and a resistor 36 is further inserted between the base of the transistor 34 and the collector of the transistor 35. .

That is, the embodiment illustrated in FIG.
4.35 forms an equivalent circuit of PUT in the embodiment shown in FIG.

That is, when the capacitor 20 is charged with the polarity shown, the transistor 34 becomes conductive, and the conduction of the transistor 34 also turns on the transistor 35 to form and maintain a charging circuit for the capacitor 20.

This turn-on of both transistors 34, 35 is maintained as long as the capacitor 20 is charged with the polarity shown.

Since the stop circuit 2 according to the present invention has the above-described configuration, if for some reason it is desired to stop the ignition operation of the ignition circuit 1, the stop switch 21 is pressed to close the stop switch 21.

By closing this stop switch 21, the next winding 4
0 → diode 17 → capacitor 20 → diode 18
→ Stop switch 21 → The charging circuit of the primary winding 40 is closed, and the capacitor 20 is charged with a part of the reverse voltage induced in the primary winding 40.

The reverse voltage charged in the capacitor 20 is transferred from the capacitor 20 to the resistor 22 to the base of the transistor 16 to the transistor 36 while the forward voltage is induced in the primary winding 40.
Since the emitter of is discharged along the path of resistor 23 and capacitor 20, transistor 16 is triggered, so that when current flows into the gate of thyristor 6 of ignition circuit 1,
The inflow of this current immediately turns on the thyristor 6 and short-circuits the gate and cathode of the thyristor 6.
hold the turn-on impossible.

Since the circuit time constant of the discharging circuit of the capacitor 20 described above is set to a large value, the transistor 16 remains triggered during the period of forward voltage generation at the primary winding 4'0, so that the thyristor 6 is activated during the same period. Continues to be unable to turn on during the period.

By the way, the closing of the charging circuit by the stop switch 21 only takes a very short time, and once the capacitor 20 is charged with the reverse voltage, the pressing force on the stop switch 21 is released and the stop switch 21 is closed. You can return it to "open".

For example, once the ignition operation of the ignition circuit 1 is blocked by closing the stop switch 21 as described above, even if the internal combustion engine continues to rotate due to the inertia of the internal combustion engine,
When the above-mentioned forward voltage generation period of the primary winding 40 has passed, there is still charge left in the capacitor 20, so when a reverse voltage starts to be generated, the charging voltage remaining in the capacitor 20 causes a charge retention circuit. 3 is in a conductive state, so
A part of the reverse voltage induced in the primary winding 40 is transferred to the secondary winding 40 → diode 17 → capacitor 20 → charge holding circuit 3 → diode 19 or Zener diode 15 →
The capacitor 20 is charged again through the path of the primary winding 40,
The ignition operation of the ignition circuit 1 is stopped during the period in which a forward voltage is induced in the next primary winding 40.

Thereafter, the above-described operation is continued until no reverse voltage is induced in the primary winding 40, that is, until the internal combustion engine is completely stopped.

When the internal combustion engine completely stops and the reverse voltage is no longer charged to the capacitor 20, all of the voltage charged to the capacitor 20 is discharged through the discharge circuit, and the capacitor 20 becomes uncharged. The holding circuit 3 is cut off,
Therefore, the charging circuit of the reverse voltage to the capacitor 20 is cut off.

Therefore, once the internal combustion engine has stopped, the ignition circuit 1
will automatically return to a state in which ignition is possible.

As described above, the stop circuit 2 according to the present invention can reliably stop the ignition operation of the ignition circuit 1 by pressing the stop switch 21 for just a moment, and can reliably stop the internal combustion engine. When the ignition circuit 1 is stopped, the ignition circuit 1 is automatically returned to a state in which ignition operation is possible.

Therefore, restarting the internal combustion engine can be done in the usual way without requiring the troublesome work of restarting the internal combustion engine.

In addition, since the power handled by the stop circuit 2 is a small amount of electricity, the ratings of the components of the stop circuit 2, including the stop switch 21, may be small, which makes it cheaper and less likely to cause failures. can.

As is clear from the above explanation, the stop circuit 2 according to the present invention
is extremely easy to operate, and is extremely safe as it can reliably stop the internal combustion engine, can be manufactured at low cost, is easy to maintain, and is easy to install in the ignition circuit 1. It has many excellent functions and effects.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the circuit of the present invention installed in an ignition circuit. 2 to 4 show different embodiments of the charge holding circuit in the circuit of the present invention. Explanation of symbols: 1: Ignition circuit, 2: Stop circuit, 3: Charge holding circuit, 4. 6.29. 30.34°35=transistor, 5: transistor circuit, 6: semiconductor rectifier with control terminal, 7. 20. 28: Capacitor, 8, 9,
10, 11, 12, 14. 22, 23, 26, 27, 3
1, 32, 33. 36, 37: Resistance, 13. 17.
18. 19.25: Diode, 21st switch, 24: Planar type N-gate thyristor, 38 Nibrag, 39: Ignition coil, 40: Primary winding, 41: Secondary winding, A, B, E: Terminal, C9D :electrode.

Claims (1)

[Scope of utility model registration request] The pace of the transistor circuit 5 which turns on according to the forward voltage induced in the primary winding 40 of the ignition coil 39 and causes the primary short circuit current to flow through the primary winding 40 and the primary winding 4
When the primary short circuit current becomes sufficiently large, the semiconductor rectifying element 6 with a control terminal inserted between the negative side terminal B and the negative terminal B when a forward voltage of 0 is generated is turned on to turn off the transistor circuit 5. and a stop connected to the ignition circuit 1 that suddenly interrupts the primary short-circuit current by turning off the transistor circuit 5 and generates a spark discharge in the plug 38 connected to the secondary winding 41 of the ignition coil 39. In circuit 2, one electrode C of a capacitor 20 is connected via a resistor 22 to the base of a transistor 16 inserted and connected between the control terminal and the cathode terminal of the semiconductor rectifying element 6 with a control terminal. A diode 17 in a reverse orientation is inserted between one electrode of the capacitor 20 and the terminal B of the primary winding 40, and the capacitor 2
A resistor 23 is inserted between the other electrode of the capacitor 20 and the terminal B of the primary winding 40, and between the other electrode of the capacitor 20 and the other terminal A of the primary winding 40. Inserting the stop switch 21, which is a push button switch,
A stop circuit in a non-contact ignition device for an internal combustion engine, in which a charge holding circuit 3 is connected in parallel with the stop switch 21 via a semiconductor rectifying element in a reverse orientation.