JPH0343424Y2 - - Google Patents

Description

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

[Prior Art] In equipment that emphasizes ease of operation, such as agricultural machinery and small engine generators, a magnet generator is constantly connected to the ignition circuit of the internal combustion engine to perform rope starts and other operations without using a key switch. A quick start allows the engine to start immediately.
When the power source is constantly connected to the ignition circuit in this way, it is necessary to take special measures to stop the engine. Figure 1 shows an example in which the stop device proposed earlier by the present applicant (Utility Model Application No. 126187/1987) is applied to an engine using a capacitor discharge type ignition system. grounded 1
The ignition coil 2 has a primary coil 1a and a secondary coil 1b, and 2 is a spark plug attached to a cylinder of an engine (not shown) and connected in parallel to both ends of the secondary coil. Reference numeral 3 denotes an ignition energy storage capacitor whose one end is connected to the non-grounded terminal of the primary coil 1a, and a capacitor discharging control capacitor whose cathode faces the grounding side is connected to both ends of the series circuit between the capacitor and the primary coil. Thyristors 4 are connected in parallel. The cathode of a diode 5 is connected to the connection point between the thyristor 4 and the capacitor 3, and the other end of an exciter coil 6 serving as an ignition power supply coil whose one end is grounded is connected to the anode of the diode 5.
The above-mentioned parts constitute a capacitor discharge type ignition device.

In this ignition system, the exciter coil 6 is placed in a magnet generator (not shown) driven by the engine, and generates an alternating current voltage in synchronization with the rotation of the engine. When the exciter coil 6 generates a voltage in the direction of the arrow shown in the figure, the capacitor 3 is charged through the diode 5 to the polarity shown. Next, when an ignition signal is applied to the thyristor 4 from a signal coil (not shown), the thyristor becomes conductive, and the charge in the capacitor 3 is discharged through the thyristor 4 to the primary coil 1a. This causes a large magnetic flux change in the iron core of the ignition coil, and a high voltage is generated in the secondary coil.
Therefore, a spark is produced in the spark plug 2, and the engine is ignited.

In order to stop the engine, an engine stopping thyristor 7 is connected in parallel to the exciter coil 6, and one end of an engine stopping capacitor 9 is connected to the gate of the thyristor 7 via a current limiting resistor 8. The other end of the engine stop capacitor 9 is connected to the cathode (ground) of the thyristor 7, and the cathode of a diode 10 is connected to the connection point between the capacitor 9 and the resistor 8. The anode of the diode 10 is connected to one end of a stop command switch 11, and the other end of the switch 11 is connected to the exciter coil 6.
connected to the non-grounded terminal of the The diode 10 constitutes a circuit that gives an ignition signal to the thyristor 7 when the stop command switch is closed, and this circuit, the thyristor 7, the resistor 8, and the capacitor 9 constitute an internal combustion engine stop device 12. .

When the switch 11 is closed in the above-mentioned stop device, when a voltage having the polarity in the direction of the arrow shown in the figure is generated in the exciter coil 6, the capacitor 9 is charged through the diode 10 to the polarity shown in the figure. When charging of the capacitor 9 is completed, an ignition signal is given to the thyristor 7 through the current limiting resistor 8 and the thyristor 7 becomes conductive, so that the exciter coil 6
is short-circuited through thyristor 7. Therefore, charging of the capacitor 3 is blocked and ignition operation is blocked, causing the engine to misfire and its rotational speed to decrease. When the thyristor 7 becomes conductive, the voltage drop between the gate and cathode of the thyristor charges the capacitor 9 through the resistor 8 to the polarity shown. Capacitor 9 starts discharging through resistor 8 when the voltage between the gate and cathode of thyristor 7 exceeds its peak. The discharge time constant of this capacitor is set so that after the exciter coil 6 generates an output for a half cycle in the direction opposite to the illustrated arrow, the discharge continues until the output for the next half cycle rises. Therefore, when an output in the direction of the arrow shown in the figure is generated in the exciter coil, an ignition signal is applied to the thyristor 7 and the thyristor becomes conductive. The conduction of the thyristor 7 charges the capacitor 9 again, and the above-described operation is repeated. Therefore, while the engine is rotating and a voltage is induced in the exciter coil, the thyristor 7 repeatedly conducts during the half cycle of the exciter coil in the direction of the arrow shown in the figure (the half cycle that contributes to the ignition operation) and short-circuits the exciter coil. Then, the ignition is blocked and the engine is stopped.

[Problem to be solved by the invention] In the internal combustion engine stopping device as described above, in order to confirm that the operation of the stopping device has started when the switch 11 is closed to stop the engine, a stopping operation is required. It is preferable to display what is being done.

Therefore, a stopping device has been proposed in which a light emitting diode is connected in series with an engine stopping thyristor, and a short-circuit current of a power supply coil is caused to flow through the series circuit of the engine stopping thyristor and the light emitting diode. However, since light-emitting diodes generally have a small current capacity, if a light-emitting diode is connected in series to an engine stop thyristor, an overcurrent may flow through the light-emitting diode when the power supply coil is short-circuited, causing damage to the light-emitting diode. There was a problem in that if the light emitting diode was damaged and its resistance value became infinite, it would be impossible to stop the engine. In addition, when a light emitting diode is connected in series to the cathode side of the engine stop thyristor, the voltage applied across the light emitting diode reaches a predetermined threshold level (usually about 0.6 volts).
Unless it exceeds the threshold, the gate current cannot flow through the thyristor, so the trigger level of the thyristor becomes high. Therefore, it became necessary to charge the engine stop capacitor to a high voltage, making it difficult to design the trigger circuit for the engine stop thyristor.

In addition, in the device shown in FIG. 1, the resistance value of the resistor 8 is set considerably large so that the discharge of the capacitor 9 continues when the voltage of the exciter coil 6 rises for half a cycle in the direction of the arrow. Therefore, the time constant for charging the capacitor 9 by the gate-cathode voltage of the thyristor 7 becomes considerably large. Therefore, in the device of FIG.
could not be charged to the peak value of the gate-to-cathode voltage of the thyristor 7, and the charging voltage of the capacitor 9 could not be increased. In this case, the discharge of the capacitor 9 is continued and the thyristor 7
In order to perform the trigger without any trouble, it is necessary to use a large capacitor 9 with a large capacity, which poses a problem of increased cost.

The purpose of the present invention is to make it possible to display that an engine stop operation is being performed without damaging the light emitting diode, and to increase the charging voltage of the engine stop capacitor than before to increase the charging voltage of the capacitor. An object of the present invention is to provide an internal combustion engine stopping device that can be used with a small capacity device.

[Means for solving the problem] The present invention provides a power supply coil 6 for an ignition device for an internal combustion engine.
The anode is connected to the non-grounded terminal of the current limiting resistor 14, and the cathode is grounded through the current limiting resistor 14.
A thyristor 7 for engine stopping is connected in parallel to the power supply coil 6 via a current limiting resistor 8, one end of which is connected to the gate of the thyristor 7, and a current limiting resistor 8 is connected between the other end of the current limiting resistor 8 and ground. Thyristor 7
The engine stop capacitor 9 is charged by the voltage between the gate cathode of the engine stop capacitor 9, the stop command switch 11 is closed when the internal combustion engine is stopped, and an ignition signal is given to the thyristor 7 when the stop command switch 11 is closed. The target is an internal combustion engine stop device equipped with a circuit.

In the present invention, a diode 17 is connected in parallel to both ends of a current limiting resistor with the anode facing the gate side of the thyristor, and the anode is connected to the non-grounded terminal of the current limiting resistor 14 via a resistor 16, and the cathode is grounded. A light emitting diode 15 was provided.

[Function] With the above configuration, when the engine stop thyristor becomes conductive, the light emitting diode 15 emits light due to the voltage appearing across the current limiting resistor 14 connected between the cathode of the thyristor and the ground, so the engine stops. It is possible to display that the operation is being performed.

Further, since the current limiting resistor 14 is connected in series between the cathode of the thyristor and the ground, a gate current can be passed through the engine stop thyristor regardless of the threshold level of the light emitting diode 15. Therefore, the engine stop thyristor can be triggered even if the charging voltage of the engine stop capacitor 9 is lower than when the light emitting diode 15 is connected in series to the cathode side of the thyristor 7 (current limiting resistor 14 is omitted). The triggering of the thyristor can be ensured.

Furthermore, as mentioned above, if a light-emitting diode is connected via a resistor to both ends of the current-limiting resistor connected in series to the cathode side of the engine stop thyristor, the voltage applied to the light-emitting diode will be equal to that of the current-limiting resistor with a smaller resistance value. Since the voltage appearing at both ends is low and the current of the light emitting diode is limited by the resistance, it is possible to eliminate the risk of the light emitting diode being damaged by overcurrent.

In addition, in the present invention, a diode 17 with its anode facing the thyristor gate side is connected across the current limiting resistor 8 connected between the engine stop capacitor and the thyristor gate.
The time constant for charging the capacitor 9 by the gate-cathode voltage of the thyristor 7 can be made very small. Therefore, the capacitor 9 can be charged to approximately the peak value of the gate-to-cathode voltage of the thyristor 7, and the charging voltage of the capacitor 9 can be made higher than in the past. Therefore, it is possible to use a capacitor 9 with a smaller capacitance than conventional capacitors, and it is possible to reduce costs and downsize the device.

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

Fig. 2 shows an embodiment in which the present invention is applied to a stop device of the type shown in Fig. 1. In Fig. 2, parts equivalent to those in Fig. 1 are designated with the same reference numerals. There is. In this embodiment, a current limiting resistor 14 having a sufficiently small resistance value is inserted between the cathode of the engine stop thyristor 7 and the ground, and a light emitting diode 15 is provided in parallel with the resistor 14. In this embodiment, the cathode of the light emitting diode 15 is grounded, and the anode is connected to the cathode of the thyristor 7 via a resistor 16. Further, a diode 17 with an anode facing the gate of the thyristor 7 is connected to both ends of the current limiting resistor 8, and a resistor 18 is connected in parallel to both ends of the series circuit of the diode 10 and the capacitor 9. The rest of the structure is similar to that of the apparatus shown in FIG.

In the embodiment described above, the ignition operation is similar to the device of FIG. When the switch 11 is closed to stop the engine, when a voltage is generated in the exciter coil 6 in the direction of the arrow shown in the figure, the capacitor is charged through the exciter coil 6-diode 10-capacitor 9-exciter coil 6 path.
When the output voltage of the exciter coil in the direction of the arrow passes the peak, the charge in the capacitor 9 is discharged between the resistor 8 and the gate cathode of the thyristor 7 and through the resistor 14, so that an ignition signal is given to the thyristor 7. Thyristor 7 is therefore conductive and exciter coil 6 is essentially short-circuited through thyristor 7 and resistor 14. This prevents the capacitor 3 from charging, causing the engine to misfire. When the thyristor 7 becomes conductive, the capacitor 9 is charged to the polarity shown through the diode 17 by the sum of the voltage drop between its gate and cathode and the voltage drop across the resistor 14. Thereafter, similar to the device shown in FIG. 1, a firing signal is repeatedly applied to the thyristor 7, which causes the thyristor 7 to repeatedly conduct and stop the engine. When the thyristor 7 is conducting during one half cycle of the output of the exciter coil 6, the light emitting diode 15 emits light due to the voltage generated across the resistor 14, indicating that the engine is being stopped, that is, the engine has misfired. Show what you are doing. Since the light emitting diode emits light during the entire period of one half cycle of the exciter coil 6, the stop operation can be clearly displayed.

In the present invention, when giving a command to stop the engine by manual operation, a self-resetting manual switch such as a push button switch is used as the stop command switch 11. In addition, if the engine is to be automatically stopped when a condition that requires stopping the engine occurs, an appropriate detection switch (a non-contact switch is also acceptable) that detects the conditions for stopping the engine is activated by the stop command switch 11. used as For example, when stopping the engine when the amount of oil in the engine becomes low, an oil level detection switch that is closed when the amount of oil becomes less than a specified amount is used as the stop command switch. In this embodiment, a diode 17 is connected in parallel to the current limiting resistor 8, and the charging time constant of the capacitor 9 is very small. Electricity is generated almost instantaneously up to the peak value of the voltage corresponding to the sum of the terminal voltage. Therefore, the capacitor 9 should have a small capacity (approximately 1/1/2 of the conventional capacitor).
10), the capacitor can be discharged for a sufficiently long time, and an inexpensive capacitor can be used. The resistor 18 is provided to prevent the ignition signal from being given to the thyristor 7 when the contacts of the switch 11 are immersed in water. It is set to a sufficiently low value for the small resistance between the contacts of the switch 11 so that the voltage appearing across the resistor 18 does not reach the trigger level of the thyristor 7 when the switch 11 is immersed in water. ing.

Figure 3 shows another embodiment of the present invention.
In this embodiment, the anode of the diode 10 is NPN.
The collector of transistor 20 is connected.
The emitter of the transistor 20 is grounded, and the stop command switch 11 is connected in parallel between the base of the transistor 20 and the ground. In addition, a diode 2 is connected to the other end of the exciter coil 6 whose one end is grounded.
A resistor 22 is connected between the cathode of the diode 21 and the collector of the transistor 20 . Further, a resistor 23 is connected between the cathode of the diode 21 and the base of the transistor 20, and in this embodiment, the diode 1
0, 21, transistors 20, resistors 22, 23, and stop command switch 11 constitute an initial charging circuit that charges capacitor 9 from the power supply coil side when the stop command switch is closed. In this initial charging circuit, the diode 21, the resistor 22, and the diode 10 constitute a coupling circuit that couples the connection point between the resistor (current limiting resistor) 8 and the capacitor 9 to the other end of the exciter coil 6. Further, the diode 21 and the resistor 23 constitute a base current supply circuit that supplies the base current from the exciter coil 6 to the transistor 20.

In this embodiment, when the stop command switch 11 is open, when a voltage in the direction of the arrow shown in the figure is generated in the exciter coil 6, the voltage between the exciter coil 6 - the diode 21 - the resistor 23 - the base emitter of the transistor 20 - the exciter coil 6 A base current flows through the transistor 20 through the path, and the transistor 20 becomes conductive. In this case, therefore, all the current flowing from the exciter coil 6 through the diode 21 and the resistor 22 flows through the transistor, and no charging of the capacitor 9 and no ignition signal being supplied to the thyristor 7 takes place. Therefore, at this time, the engine ignition is performed normally.

To stop the engine, switch 1 for stop command
1, the base and emitter of the transistor 20 are short-circuited, so that the transistor 20 cannot conduct. Therefore, when a voltage in the direction of the arrow shown in the figure is induced in the exciter coil 6, the diode 2
1, the capacitor 9 is charged through the resistor 22 and the diode 10, and at the same time a firing signal is applied to the gate of the thyristor 7 through the resistor 8. As a result, the thyristor 7 becomes conductive, and the exciter coil 6
is substantially short-circuited through the thyristor 7 and the small resistor 14. Therefore, the capacitor 3 is no longer charged and the engine misfires. When the thyristor 7 becomes conductive, the engine stop capacitor 9 is charged through the diode 17 by the sum of the voltage drop between its gate and cathode and the voltage drop across the resistor 14. In this invention, resistor 8 is used as a current limiting resistor.
A diode 17 is connected in parallel to the capacitor 9, and the charging time constant of the capacitor 9 is very small. It is charged almost instantly to the peak voltage value. Therefore, in this case as well, a capacitor 9 having a small capacity can be used to discharge the capacitor for a sufficiently long time, and an inexpensive capacitor can be used. Furthermore, in this invention,
When the stop command switch 11 is open, the transistor 20 is conductive, and when the switch 11 is open, the transistor 20 is conductive.
When thyristor 7 is closed, thyristor 7 conducts and short-circuits exciter coil 6, so transistor 20 has (R1 + R2) × Igt (however, R1 is
Only a low voltage (R2 is the resistance value of the resistors 8 and 14, respectively, and Igt is the gate current of the thyristor 7) is applied. Therefore, an inexpensive transistor with a low breakdown voltage can be used as the transistor 20, and costs can be reduced. Furthermore, in this embodiment, one end of the switch 11 can be grounded, so the structure of the switch can be simplified. Note that in FIG. 3, the diode 21 is used to prevent the reverse voltage of the exciter coil from being applied to the transistor 20, but if the transistor 20 can withstand the reverse voltage of the exciter coil, this diode 21 is omitted. can do.

FIG. 4 shows still another embodiment of the present invention, in which a thyristor 25 is used in place of the diode 10 in FIG. The thyristor 25 has its anode connected to the non-grounded terminal of the exciter coil, its cathode connected to the connection point between the capacitor 9 and the resistor 8, and its gate connected to the collector of the transistor 20. In this embodiment, when the switch 11 is open and the transistor 20 is in a conductive state during a half cycle of the exciter coil in the direction of the arrow shown, no firing signal is given to the thyristor 25, so the thyristor maintains its cut-off state. are doing. Therefore, at this time, the capacitor 9 is not charged and no ignition signal is given to the thyristor 7, so that the engine is normally ignited. switch 11
is closed, and the transistor 20 is no longer conductive during the half cycle of the exciter coil 6 in the direction of the arrow shown in the drawing, an ignition signal is given to the thyristor 25 through the diode 21 and the resistor 22, and the thyristor 25 is turned off from the exciter coil 6.
The capacitor 9 is instantly charged through the capacitor 9. With this configuration, the charging time constant of the capacitor 9 can be made much smaller than when the capacitor 9 is charged through the resistor 22 as in the embodiment shown in FIG. Capacitor 9 can be reliably charged and operation can be ensured.

FIG. 5 shows still another embodiment of the present invention. In this embodiment, as in the embodiment of FIG. 18 are connected in parallel. The emitter of a PNP transistor 30 is connected to one end of the non-grounded side of the capacitor 9, and the collector of the transistor 30 is connected to the gate of the engine stop thyristor 7 via a current limiting resistor 8. The base of the transistor 30 is connected to the collector of an NPN transistor 32 via a resistor 31, and the emitter of the transistor is grounded. The base of the transistor 32 is connected to the cathode of a diode 34 via a resistor 33, and the anode of the diode 34 is connected to the non-grounded terminal of the exciter coil 6. In this embodiment, transistors 30, 32 and resistors 31, 3
3 provides a discharge control switch circuit which conducts the exciter coil 6 only during one half cycle (the half cycle contributing to the ignition operation) and allows the capacitor 9 to discharge through between the resistor 8 and the gate cathode of the thyristor 7. It is configured. Further, in this embodiment, the gate of the thyristor 7 is connected to one end of the capacitor 9 via a diode 17 whose anode is directed toward the gate of the thyristor 7. The rest of the structure is similar to that of the embodiment shown in FIG.

In this embodiment, the ignition operation is the same as in each of the embodiments described above. When the stop command switch 11 is open, the capacitor 9 is not charged and the transistor 30 is not conductive, so that no ignition signal is given to the thyristor 7. Therefore, the ignition of the engine is carried out without any problem. When the stop command switch 11 is closed to stop the engine, when a voltage is generated in the exciter coil 6 in the direction of the arrow shown, the capacitor 9 is charged through the diode 10 to the polarity shown. Also at this time, exciter coil 6
Since the base current flows from the source to the transistor 19 through the diode 34 and the resistor 33, and the emitter current flows to the transistor 30 through the switch 11 and the diode 10, the transistors 30 and 18 become conductive, and a firing signal is applied to the gate of the thyristor 7. It will be done. The thyristor 7 is therefore conductive and the exciter coil 6 is essentially short-circuited through it and the small resistor 14. This prevents the capacitor 3 from charging, causing the engine to misfire. When the thyristor 7 becomes conductive, the capacitor 9 is charged to the polarity shown in the figure through the diode 17 by the sum of the voltage drop between its gate and cathode and the voltage drop across the resistor 14. Since the resistance value of the resistor 14 is small and the charging time constant of the capacitor 9 is small, the capacitor 9 is charged to a high voltage approximately corresponding to the peak value of the gate-cathode voltage of the thyristor 7. Next, during a half cycle in which a voltage with a polarity opposite to the direction of the arrow shown in the figure is generated in the exciter coil 6, no base current is applied to the transistor 32, and the transistors 30 and 32
Since both are in the disconnected state, the capacitor 9 is not discharged and the terminal voltage of the capacitor is maintained in the charged state. Next, when a voltage is generated in the direction of the arrow shown in the exciter coil 6, the transistors 30 and 32 become conductive as described above, so that the charge in the capacitor 9 is discharged through the transistor 30 and the resistor 8 to the gate of the thyristor 7. Therefore, a firing signal is applied to the thyristor 7, which becomes conductive. These operations are repeated while the engine is rotating and a voltage is induced in the exciter coil, causing the engine to continue misfiring, thereby ensuring that the engine stops. In this way, in this embodiment, since the capacitor 9 is discharged only in one half cycle of the output of the exciter coil 6, the capacitance of the capacitor can be made much smaller than in the conventional case. According to experiments, we were able to achieve reliable operation using a capacitor with a capacity 1/1000 of that used in the conventional device shown in Figure 1. In this case, the size of the capacitor could be reduced to approximately 1/300 of the conventional size.

In the above embodiment, the diode 34 is for protecting the transistor 32 from the induced voltage in the direction opposite to the illustrated arrow of the exciter coil, and if the transistor has sufficient reverse breakdown voltage, the diode 34 can be omitted. can.

FIG. 6 shows another embodiment of the present invention which is a partial modification of the embodiment shown in FIG. It is connected. The collector of an NPN transistor 20 whose emitter is grounded is connected to the connection point between the resistor 22 and the diode 10, and the base of the transistor 20 is connected to the cathode of the diode 34 via the resistor 23. A stop command switch 11 is connected in parallel between the base of the transistor 20 and ground.

In the embodiment shown in FIG. 6, the stop command switch 1
1 is open, a base current is applied to the transistor 9 through the diode 34 and the resistor 23 when a voltage having the polarity in the direction of the arrow shown in the figure is generated in the exciter coil 6, and this current causes the transistor to conduct. Therefore, all the current flowing from the exciter coil through diode 34 and resistor 22 flows through transistor 20 and no charging of capacitor 9 and no ignition signal to thyristor 7 takes place. Therefore, the thyristor 7 is not conductive and the engine can be ignited without any problem. When the stop command switch is closed, the transistor 20 is turned off, so the capacitor 9 is charged from the exciter coil 6 through the diode 34, the resistor 22, and the diode 10, and at the same time, the transistor 3
An ignition signal is given to the thyristor 7 through 0 and a resistor 8. Therefore, the thyristor 7 becomes conductive and prevents the engine from igniting. The operation after the thyristor 7 becomes conductive until the engine stops is the same as in the previous embodiment. With this structure, one end of the stop command switch 11 can be grounded as in the embodiment shown in FIG. 3, so the structure of the switch can be simplified.

FIG. 7 shows yet another embodiment of the invention, in which the diode 10 of FIG. 6 is replaced by a thyristor 25. The anode of the thyristor 25 is connected to the non-grounded terminal of the exciter coil 6, and the cathode is connected to the non-grounded terminal of the capacitor 9. Thyristor 2
The gate of 5 is connected to the connection point between the resistor 22 and the collector of the transistor 20, and an ignition signal is given to the thyristor 25 only when the stop command switch 11 is closed and the transistor 20 is in the off state. The capacitor 9 is charged and the ignition signal is supplied to the thyristor 7.
With this configuration, since the capacitor 9 is initially charged through the thyristor 25 when the switch is closed, the charging time constant during the initial charging of the capacitor can be reduced to ensure the operation of the stop device. .

Although a capacitor discharge type ignition device is used in each of the above embodiments, the present invention can be similarly applied to cases where other types of ignition devices are used. For example, as shown in Fig. 8, the primary coil (also serves as an exciter coil) 1 of the ignition coil is placed in a magnet generator driven by the engine.
A switch 40 such as a transistor is connected in parallel to a.
There is a well-known current-break type ignition device which performs the ignition operation by connecting the primary coil 1a and changing the switch 40 from a conductive state to an inactive state during a half cycle in the direction of the arrow shown in the figure. The present invention can also be applied when used.

FIG. 9 shows a case where an ignition device of a current-reduction type different from that described above is used. In this ignition device, a collector-emitter circuit of a transistor 42 is connected to both ends of an exciter coil 6 via a diode 41. are connected in parallel. Further, a thyristor 43 is connected in series to the primary coil 1a, and the anode of the thyristor 43 is connected to the diode 4.
4 to the base of transistor 42. In this ignition device, spark plugs 2 and 2' are connected between both ends of the secondary coil of the ignition coil and the ground, respectively, and these spark plugs are connected to two cylinders in which there is no problem even if sparks are generated at the same time, e.g. Each is attached to two cylinders such that one is in the ignition timing and the other is in the exhaust stroke. In the ignition device shown in FIG. 9, the output voltage of the exciter coil 6 in the direction of the arrow shown in the figure applies a base current to the transistor 42 through the primary coil 1a and the diode 44, making the transistor conductive. Next, when an ignition signal is applied to the thyristor 43 from a signal coil (not shown), the thyristor becomes conductive and the transistor 42 is turned off. Therefore, the current flowing from the exciter coil 6 through the diode 41 and the transistor 42 is interrupted, and a high voltage is induced in the exciter coil 6. This high voltage is further boosted by the ignition coil 1 and applied to the ignition plugs 2, 2', so that sparks are generated at both ignition plugs simultaneously.

[Effect of the invention] As described above, according to the invention, when the engine stop thyristor becomes conductive, the light emitting diode emits light due to the voltage appearing across the current limiting resistor connected between the cathode of the thyristor and the ground. Therefore, it is possible to display that the engine stop operation is being performed.

Furthermore, in the present invention, since a current limiting resistor is directly connected between the cathode of the thyristor and the ground, a gate current can be passed through the engine stop thyristor regardless of the threshold level of the light emitting diode. Therefore, the engine stop thyristor can be triggered even if the charging voltage of the engine stop capacitor is lower than when the light emitting diode is connected in series to the cathode side of the thyristor (current limiting resistor is omitted). There is an advantage that the thyristor can be triggered reliably.

Further, according to the present invention, the voltage applied to the light emitting diode is a low voltage appearing across the current limiting resistor having a small resistance value, and the current of the light emitting diode is limited by the resistor connected in series with the light emitting diode. Therefore, it is possible to eliminate the risk of the light emitting diode being damaged due to overcurrent.

In addition, in this invention, a diode with the anode facing the gate of the thyristor is connected across the current limiting resistor connected between the engine stop capacitor and the gate of the thyristor. The charging time constant can be made very small.
Therefore, the capacitor can be charged to approximately the peak value of the gate-cathode voltage of the thyristor, and the charging voltage of the capacitor can be made higher than conventionally. Therefore, it is possible to use a capacitor having a smaller capacitance than conventional capacitors, which has the advantage of reducing costs and downsizing the device.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional example, and FIGS. 2 to 9 are circuit diagrams showing different embodiments of the present invention. 1...Ignition coil, 2...Spark plug, 3...
Capacitor, 4... Thyristor, 6... Exciter coil (ignition power supply coil), 7... Thyristor for engine stop, 8... Current limiting resistor, 9... Capacitor for engine stop, 11... Switch for stop command,
12... Internal combustion engine stop device, 14... Current limiting resistor,
15...Light emitting diode, 16...Resistor, 17...
...Diode, 20...Transistor, 21...
Diode, 22, 23... Resistor, 25... Thyristor, 30, 32... Transistor, 31, 3
3...Resistor, 41...Diode, 42...Transistor, 43...Thyristor, 44...Diode.

Claims (1)

[Claims for Utility Model Registration] An anode is connected to the non-ground terminal of a power supply coil 6 of an ignition device for an internal combustion engine, and a cathode is connected to a current limiting resistor 1.
4, a current limiting resistor 7 connected in parallel to the power supply coil 6 via the current limiting resistor 14; a current limiting resistor 8 having one end connected to the gate of the thyristor 7; an engine stop capacitor 9 connected between the other end of the limiting resistor 8 and ground and charged by the voltage between the gate cathode of the thyristor 7; a stop command switch 11 that is closed when stopping the internal combustion engine;
In the internal combustion engine stop device, the internal combustion engine stop device is provided with a circuit that gives an ignition signal to the thyristor 7 when the stop command switch 11 is closed, and the circuit is connected in parallel to both ends of the current limiting resistor with an anode facing the gate side of the thyristor. and a light emitting diode 15, the anode of which is connected to the non-grounded terminal of the current limiting resistor 14 via a resistor 16, and the light emitting diode 15 whose cathode is grounded.