JPS6210471Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an engine stopping device using a semiconductor switch.

Traditionally, to stop the engine, a mechanical
An ON-OFF type switch was used, and this switch was attached to the primary circuit when a contact type ignition device was used, and to the ignition charging circuit when a non-contact type ignition device was used.

However, when this mechanical switch is used in a snowmobile or the like, there is a drawback that the switch must be kept closed until the engine stops.

To compensate for this drawback, semiconductors such as thyristors have recently been used. For example, when a thyristor is used, a stop switch is provided to transmit a signal to the gate of the thyristor. By closing this stop switch, the anode and cathode of the thyristor are A device has been proposed that stops the ignition until there is continuity between the two and the engine stops. (For example, see Utility Model Application No. 50-4130 and Utility Model Application No. 50-4131).

However, since the stop switch in the above device is a conventional mechanical ON-OFF type switch, if it is installed in a place prone to rainwater or other water intrusion, the insulation of the stop switch will deteriorate due to water ingress, resulting in electrical leakage. This poses a problem in that the stop switch becomes conductive and the engine stop mechanism is automatically activated, necessitating the use of expensive waterproof switches in areas prone to flooding.

The present invention has been devised in view of the above, and provides an engine stop device that will not stop the engine due to electrical leakage even if the stop switch is flooded with rainwater or other water.

The present invention includes a mechanical ON-OFF type stop switch, a stop signal detection unit that is connected in series to a power supply unit via the stop switch and detects a stop signal caused by closing the stop switch, and a stop signal detection unit that detects a stop signal when the stop switch is closed. a semiconductor switch section that is interposed in the ignition stop wire of the non-contact ignition device in the circuit and becomes conductive upon receiving the output of the stop signal detection section, and the stop signal detection section The switch is characterized by having a Zener diode in which the voltage drop due to leakage of the switch is greater than the difference between the power supply voltage and the Zener voltage.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In Fig. 1, 1 is the ignition circuit of the engine, 2
3 is an engine stop circuit, 3 is a magneto generator, 4 is a regulator that adjusts the voltage and current generated by the magneto generator to appropriate values, and 5 is a battery.

The ignition circuit 1 is configured such that a signal from a non-contact ignition device 6 is transmitted to an ignition coil 7, which generates high voltage on the secondary side of the ignition coil 7, causing a spark plug 8 to perform an ignition operation.

In the stop circuit 2, when a mechanical ON-OFF type stop switch 9 is closed, a voltage signal from a battery (power supply section) 5 is output as a stop signal to the stop signal detection section 1.
0 and detected by the detection section 10 is transmitted to the semiconductor switch section 14 via the shunt section 11, the rectifier 12, and the charging section 13, the semiconductor switch section 14 becomes conductive, The ignition stop wire 15 of the ignition circuit 1 is grounded to stop the engine.

Further, a specific example of the stop circuit 2 is as shown in FIG.
and a resistor 17 are connected in series to a stop signal detection section 10. The Zener voltage of the Zener diode 16 is lower than the terminal voltage (power supply voltage) of the battery, and the voltage drop due to leakage of the stop switch 9 is greater than the difference between the terminal voltage and the Zener voltage. A diode 18 and a grounded resistor 19 are connected in parallel to the stop signal detection section 10. Furthermore, the diode 18 has a resistor 20 and a capacitor 21 provided in parallel in the charging section 13 and the semiconductor switch section 14.
2 are provided in parallel. The resistor 22 is connected to the gate of the thyristor 23 of the semiconductor switch section 14, its anode is connected to the ignition stop line 15 of the non-contact ignition device 6 via the resistor 24, and its cathode is grounded.

Note that if the capacitor 21 is charged even after the engine is stopped, the thyristor 23 becomes conductive even if you try to restart the engine immediately after the engine stops, and the ignition operation is not performed. It is for discharging.

Furthermore, 25 is a leak resistance that is thought to occur when the stop switch 9 is submerged in water (virtual resistance when current flows to the stop switch 9 due to electrical leakage), and A measures the current flowing into the gate, which will be described later. This is the position where the ammeter was installed in series.

Next, the operation of the stop circuit 2 will be explained. When the stop switch 9 is closed, the terminal voltage of the battery 5 does not drop when the engine is running and is higher than the Zener voltage of the Zener diode 16.
Current is shunted through Zener diode 16 and resistor 17 to resistor 19 and diode 18 . The current flowing into the diode 18 charges the capacitor 21 and flows into the gate of the thyristor 23 via the resistor 22, thereby making the anode and cathode of the thyristor 23 conductive. When the thyristor 23 becomes conductive, the ignition stop wire 15
is grounded through resistor 24, so the engine is stopped. After the engine is stopped, the charged capacitor 21 is discharged through the resistor 22 and the gate of the thyristor 23, and is also discharged through the resistor 20.

Furthermore, if the stop switch 9 is submerged in water, a current leakage occurs and the insulation deteriorates, which has the same effect as when a resistor 25 is provided in parallel with the stop switch 9, resulting in a conductive state. Zener diode 16, resistor 17, resistor 1
Flows to 9. However, the terminal voltage of the battery 5 drops due to the leakage of the stop switch 9 (resistance 25), and a voltage lower than the Zener voltage is applied to the Zener diode 16, so the current that flows is extremely small and does not charge the capacitor 21. . Therefore, the thyristor 23 remains non-conductive and the ignition stop wire 15 is not grounded, so the engine does not stop.

In addition, FIG. 3 shows the measured values of the ammeter connected in series between the resistor 22 and the gate of the thyristor 23 (position A) in FIG. If there is no leakage resistance (no leakage resistance), if there is a current leakage (leakage resistance 200
Ω) and the measurement results when the stop switch 9 was immersed in seawater. Since the power supply voltage of the battery 5 is 14.5V, if there is a current leakage or if the stop switch 9 is immersed in seawater,
The current flowing into the gate of the thyristor 23 is almost zero, and the resistance between the anode and cathode of the thyristor 23 is also infinite (see FIG. 3). Therefore, in those cases as well, the ignition stop line 15 is not grounded and the engine does not stop, as in the normal case when the stop switch 9 is open.

As described above, the present invention is equipped with a stop signal detection section having a Zener diode that detects the stop signal caused by closing the stop switch. Even if you use a normal mechanical ON-OFF type switch without using a type switch, the engine stop circuit will not operate due to electrical leakage such as flooding, so the engine will operate normally without stopping due to malfunction. It has the effect of

[Brief explanation of the drawing]

Figure 1 is a block diagram of the engine's ignition circuit and stop circuit, Figure 2 is the same circuit diagram, and Figure 3 shows the stop switch in the normal case, the stop switch with a 200Ω resistor in parallel, and the stop switch. 2 is a graph showing the measurement results of changes in the current value at point A in FIG. 2 and the resistance value between the anode and cathode of the thyristor as the power supply voltage changes in three types of cases where the thyristor is immersed in seawater. . 1... Ignition circuit, 2... Stop circuit, 3... Magneto generator, 4... Regulator, 5... Battery, 6... Non-contact ignition device, 7... Ignition coil,
8...Spark plug, 9...Stop switch, 10...
... Stop signal detection section, 11 ... Shunting section, 12 ... Rectifier, 13 ... Charging section, 14 ... Semiconductor switch section, 15 ... Ignition stop line, 16 ... Zener diode, 17 ... Resistor, 18 ...Diode, 19...Resistor, 20...Resistor, 21...
Capacitor, 22...Resistor, 23...Thyristor, 24...Resistor, 25...Leak resistance.

Claims (1)

[Scope of utility model registration request] A mechanical ON-OFF type stop switch, a stop signal detection unit that is connected in series to the power supply unit via the stop switch and detects a stop signal caused by closing the stop switch, and a stop signal detection unit that detects a stop signal when the stop switch is closed; a semiconductor switch section that is interposed in the ignition stop wire of the contact ignition device and becomes conductive in response to the output of the stop signal detection section, and the stop signal detection section is configured to detect that the zener voltage is lower than the power supply voltage and the stop switch has an earth leakage. An engine stopping device comprising a Zener diode whose voltage drop is greater than the difference between a power supply voltage and a Zener voltage.