JPS624694Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an engine stopping device for stopping the engine in which the engine is ignited by the engine's ignition circuit.

Conventionally, in order to stop an engine, disabling the engine's ignition circuit has been carried out. One such method is shown in FIG. This Figure 1 shows a capacitor discharge type ignition circuit. In the figure, 1 is a generating coil of a magnet generator driven by an engine (not shown), and 2 is a signal coil that generates an ignition signal at the ignition timing of the engine. , for example, built into a magnet generator.

One end of each of the generating coil 1 and signal coil 2 is grounded, and the other end of the generating coil 1 is grounded via a stop switch 10, a diode 3, a capacitor 4, and a primary winding of an ignition coil 6. The stop switch 10 is for stopping the engine by blocking the power generation output. Also,
The diode 3 is for rectifying the generated output of the generator coil 1, and the capacitor 4 is charged by this rectified output.

The secondary winding of the ignition coil 6 is grounded via the ignition plug 8. The spark plug 8 receives the secondary voltage of the ignition coil 6 and generates a spark discharge.
Further, a diode 5 is connected between the connection point between the stop switch and the diode 3 and the ground. The diode 5 is for short-circuiting a half cycle of the power generation output of the power generation coil 1 that does not contribute to charging the capacitor 4 .

On the other hand, the other end of the signal coil 2 is connected to the gate of the thyristor 7 through a diode 9. This thyristor 7 is connected between the connection point between the diode 3 and the capacitor 4 and the ground, and is a semiconductor switching device that receives the ignition signal from the signal coil 2 at the ignition timing of the engine and discharges the charge in the capacitor 4 to the ignition coil 6. It is element. In addition, the diode 9 rectifies the ignition signal of the signal coil 2 and connects it to the thyristor 7.
This is to prevent reverse voltage from being applied between the gate and the cathode.

The stop switch 10 is designed to stop the engine by opening the switch in order to prevent theft of motorcycles, snowmobiles, outboard motors, etc. equipped with the engine, and as a safety device.

Next, the operation of the capacitor discharge type ignition circuit shown in FIG. 1 will be explained. First, by turning on the stop switch 10, the generated output of the generating coil 1 is rectified by the diode 3 and charges the capacitor 4. Half cycles that do not contribute to the charging of capacitor 4 are short-circuited by diode 5. The ignition signal generated in the signal coil 2 at the ignition timing of the engine is rectified by the diode 9 and applied to the gate of the thyristor 7, which becomes conductive.
The charge in the capacitor 4 is discharged through the thyristor 7 to the primary coil of the ignition coil 6. This results in
A secondary voltage is generated in the secondary coil of the ignition coil 6, causing spark discharge at the ignition plug 8. In this way, spark discharge occurs in the spark plug 8 at the ignition timing of the engine, so the engine continues to operate.

As described above, the engine is operated, but in order to stop the engine while it is in operation, the stop switch 10 can be opened. That is, stop switch 1
When 0 is opened, the power generation output of the power generation coil 1 is cut off, no charge is accumulated in the capacitor 4, and therefore no spark discharge occurs in the ignition plug 8, so the engine stops.

By the way, in the case of the capacitor discharge type ignition circuit shown in FIG. 1, when the stop switch 10 is opened and when the stop switch 10 is closed, that is, when the engine is running, the voltage between the terminals of the stop switch 10 and between the terminal of the stop switch 10 and the ground is is the power generation output of generator coil 1 (generally several hundred V)
is applied directly. Therefore, although the stop switch 10 is insulated, if water or seawater splashes between the terminals of the stop switch 10 or between the terminals and the ground, the insulation resistance between the terminals of the stop switch 10 or between the terminals and the ground decreases. If the voltage applied between the terminals or between the terminal and the ground is high, the leakage current will increase, and this current may cause the stop switch 10 to malfunction, such as dielectric breakdown, making it impossible to stop or restart the engine. There is a flaw.

Moreover, even if these problems do not occur, there is a defect that the stop switch 10 may be exposed to water or seawater, and if a worker touches it with wet hands, an electric shock may occur.

Instead of the above means, another method of disabling the engine's ignition circuit is to use a capacitor discharge type ignition circuit as shown in FIG.

In FIG. 2, parts that are the same as those in FIG. 1 are given the same reference numerals and explanations thereof will be omitted, and only parts that are different from those in FIG. 1 will be described. In the case of FIG. 2, a diode 5 and a thyristor 12, which is a semiconductor switching element, are connected in parallel to the generating coil 1, and the generating coil 1 and the diode 3 are directly connected. Further, a series circuit of a resistor 11 and a stop switch 10 is connected between the connection between the diode 3 and the generating coil 1 and the ground, and the connection point between this resistor and the stop switch 10 is connected to the gate of the thyristor 12.

Next, the operation shown in FIG. 2 will be explained. When the stop switch 10 is closed, all terminals of the stop switch 10 are at ground voltage, so there is no leakage or electric shock. In this case, since the gate of the thyristor 12 is grounded, the current flowing through the resistor 11 flows directly to the ground, so the thyristor 12 is in a non-conducting state, and therefore the voltage of the generating coil 1 is not short-circuited, so the engine is Do not stop.

When the stop switch 10 is opened, the thyristor 12 is triggered by the voltage applied to its gate through the resistor 11 and becomes conductive, so that the generated output of the generating coil 1 is short-circuited by the thyristor 12. Therefore, the capacitor 4 is not charged and no spark discharge occurs, so the engine stops.

In this case, only the low trigger voltage (approximately 0.5 to 0.7 V) required to make the thyristor 12 conductive is applied between the terminals of the stop switch 10, and even if water or seawater adheres, leakage current will not occur. Since this is extremely small, there is no dielectric breakdown of the stop switch 10 or electric shock, there is no loss of power generation output from the generating coil 1, and there is no possibility of ignition failure due to a drop in the generated voltage.

However, in FIG. 2, the generated output of the generator coil 1 flows to the stop switch 10 via the resistor 11 while the engine is in operation. The resistor 11 is connected to the current (several mA) required to trigger the thyristor 12 in order to reduce the loss of the power generated by the generating coil
The resistance value is set to a large value so that only a certain amount (below) is allowed to flow.

Therefore, only a current of several mA or less flows through the stop switch 10, and the applied voltage is approximately 0.5~
Since the voltage is as low as 0.7V, if an insulating film is formed at the contact of the stop switch 10, the current flowing through it is small, so that there is no contact cleaning effect due to the breakdown of the insulating film caused by the current.
Therefore, there is a defect that makes it impossible to restart the engine.

Furthermore, if the value of the resistor 11 is decreased in order to increase the current flowing through the stop switch 10 and improve the above-mentioned defect, the loss of power generated by the generator coil 1 will increase, and the charge necessary for engine ignition will accumulate in the capacitor 4. There is a defect that the engine cannot be operated.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional method. A thyristor is provided as a semiconductor switching element for bypassing the output of the generating coil, and the gate and cathode of the thyristor are turned on and off by a stop switch. In addition, a diode is provided to bypass the current flowing from the cathode to the gate, and by passing the short-circuit current to the stop switch during the half cycle of the generated output of the generator coil that does not contribute to charging the capacitor, the semiconductor switching element is activated when the stop switch is opened. prevent destruction,
An object of the present invention is to provide an engine stopping device capable of eliminating stop switch failures.

Hereinafter, embodiments of the engine stopping device of this invention will be described based on the drawings. FIG. 3 is a circuit diagram showing the configuration of one embodiment. In FIG. 3, in order to avoid duplication when describing the configuration, parts that are the same as those in FIG. 2 are given the same reference numerals and their explanations are omitted, and parts that are different from those in FIG. 2 will be mainly described.

In FIG. 3, a thyristor 12 as a semiconductor switching element and a series circuit of a resistor 11 and a diode 13 are connected in parallel to the power generating coil 1. A connection point between the resistor 11 and the diode 13 is connected to the gate of the thyristor 12.
Furthermore, a series circuit of a diode 5 and a stop switch 10 is connected between the connection point between the generator coil 1 and the diode 3 and the ground. The connection point between stop switch 10 and diode 5 is resistor 1.
1 and the diode 13. The other configurations are the same as in FIG. 2.

The diode 13 is used to bypass the current flowing from the cathode to the gate of the thyristor 12. Further, the diode 5 short-circuits a half cycle in which the power generation output of the power generation coil 1 does not contribute to charging the capacitor 4.

Next, the operation of the engine stop device of this invention constructed as described above will be explained. First, when the stop switch 10 is closed, one half cycle of the generated output of the generating coil 1 is rectified by the diode 3, charging the capacitor 4 and energizing the stop switch 10 through the resistor 11.

Here, only the current required to trigger the thyristor 12 needs to flow through the resistor 11, so it can have a relatively large value.Therefore, the current value flowing through the resistor 11 and the stop switch 10 can be small, so
The load on the power generation output of the power generation coil 1 is reduced,
There is almost no decrease in the charge on the capacitor 4.

The other half cycle of the generator coil 1, that is, the half cycle that does not contribute to the charging of the capacitor 4, flows through the diode 5 via the stop switch 10 and is short-circuited. In this case, the short circuit current flowing through the stop switch 10 and the diode 5 is several hundreds.
Since the current flows in excess of mA, this current causes breakdown of the contact insulation film, which has a contact cleaning effect. For this reason, there is no contact failure at the contacts, and it is never impossible to restart the engine.

Further, since the stop switch 10 is in a closed state and one end is grounded, there is no voltage between the terminals, and there is no possibility of dielectric breakdown of the stop switch 10 or electric shock.

As described above, when the stop switch 10 is closed, the capacitor 4 is reliably charged by the generated output of the generator coil 1, the thyristor 7 is triggered by the output of the signal coil 2, and the charge in the capacitor 4 is transferred to the primary of the ignition coil 6. The coil is discharged, a spark discharge is generated at the spark plug 8, and the engine is operated.

Next, when the stop switch 10 is opened to stop the engine, no current flows through the stop switch 10, and voltage is applied to the gate of the thyristor 12 through the resistor 11, and current flows through the resistor 11 and the gate/cathode of the thyristor 12. becomes conductive.

As a result, the power generation output of the power generation coil 1 is short-circuited through the thyristor 12, and the capacitor 4 is no longer charged after the stop switch 10 is opened. No voltage is generated,
Therefore, the engine will definitely stop.

In this case, the voltage between the terminals of the stop switch 10 becomes the voltage drop between the gate and cathode of the thyristor 12 (approximately 0.5 to 0.7 V).

With such a low value, even if water, such as seawater, were to adhere, the leakage current would be extremely small, and there would be no dielectric breakdown of the stop switch 10 or electric shock.

Furthermore, during engine operation, a half cycle that does not contribute to charging of the capacitor 4 of the generator coil 1 is short-circuited through the diode 13 and the diode 5.
Therefore, even in this case, the stop switch 10
The voltage between the terminals of is equal to the drop voltage of diode 13 (approximately
0.7V), which is a low value, so even if water or seawater were to adhere to it, the leakage current would be extremely small, so there would be no dielectric breakdown of the stop switch 10 or electric shock.

Furthermore, the thyristor 12 is connected by the diode 13.
Since the current flowing from the cathode to the gate is shunted and short-circuited through the diode 5, it is possible to completely eliminate element destruction of the thyristor 12 due to the half-cycle power generation output that does not contribute to charging the capacitor 4 of the power generation coil 1, and to Half cycles of the coil 1 that do not contribute to charging of the capacitor 4 can be short-circuited.

In the above embodiment, the thyristor 12 was used as the semiconductor switching element, but a transistor or the like may also be used.
It goes without saying that any semiconductor element other than 13 having the same function may be used, and that it can also be applied to AC ignition circuits other than capacitor discharge type ignition circuits.

As described above, according to the engine stop device of this invention, one terminal of the stop switch is connected to the control pole of the semiconductor switching element, and a diode is connected from this terminal toward the output end of the generator coil, thereby contributing to the ignition of the generator coil. Short-circuit the half cycle of power output that does not occur through the stop switch and diode,
Also, since the diode is connected from the output end of the semiconductor switching element toward the control pole,
This prevents the semiconductor switching element from being destroyed when the stop switch is opened, and short-circuits the half cycle of power generation output that does not contribute to ignition of the power generation coil.

Furthermore, since the voltage applied between the terminals of the stop switch can always be maintained at a low voltage, even if water or seawater adheres to the stop switch and its insulation resistance decreases, the leakage current that flows between the terminals of the stop switch is extremely small. Therefore, damage to the stop switch can be completely eliminated and leakage current is reduced, so that the load on the power generation output of the generator coil is reduced, that is, there is almost no drop in the power generation output, and a stable ignition function can be obtained.

Moreover, even if an operator touches the stop switch when closing or opening it to stop the engine, the applied voltage is low, so there is no risk of electric shock.

In addition, since a short-circuit current of a half-cycle of power generation output that does not contribute to the ignition of the power generation coil flows through the stop switch, this current causes breakdown of the insulation film of the stop switch contact, which cleans the contact and eliminates contact failures of the stop switch. It has excellent practical effects. Some stop switches are open when the engine is running and closed when the engine is stopped, but such normally open switches are susceptible to rust and contact failure.

[Brief explanation of the drawing]

FIGS. 1 and 2 are circuit diagrams showing conventional capacitor discharge type ignition circuits, and FIG. 3 is a circuit diagram showing an embodiment of the engine stopping device of this invention. 1...Generating coil, 2...Signal coil, 3,
5, 9, 13... Diode, 4... Capacitor, 6... Ignition coil, 7, 12... Thyristor, 8... Spark plug, 10... Stop switch, 11... Resistor. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A first diode connected to one end of the generator coil of the magnet generator to rectify the generated output, a capacitor charged by the rectified output of this first diode, and the charge in the capacitor discharged to the ignition coil at the ignition timing. A circuit that causes the spark plug to generate a spark discharge, a semiconductor switching element that has a control pole and is connected in parallel to the power generation coil and short-circuits the power generation output to stop the engine when conductive, one end of which is connected to the other end of the power generation coil. A stop switch is connected and turned on when the engine is running and turned off when the engine is stopped.The anode is connected to the other end of the stop switch and the control pole of the semiconductor switching element, and the cathode is connected to one end of the generator coil. a second diode that shorts the generated output through the stop switch during a half cycle of the generated output that does not contribute to charging the capacitor; a resistor connected in parallel with the second diode; and an anode connected to the other end of the generating coil. and a third diode whose cathode is connected to the control pole of the semiconductor switching element and bypasses the current flowing from the other end of the generating coil of the semiconductor switching element to the control pole when the engine is stopped.