JPS6155618B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal combustion engine ignition system.

Conventionally, this type of ignition device, for example, a capacitor charging/discharging type ignition device, has been widely used for engine starting, etc., but in outboard motors equipped with this engine, the drive gear position (neutral gear, drive Ignition is possible regardless of gear, etc. For this reason, if the engine is started with the drive gear etc. in the condition, the outboard motor etc. may unexpectedly fly out, which is not only dangerous but also causes an accident. In view of the above, the present invention provides a highly safe ignition device that has a function of disabling engine starting when the drive gear is in a position other than a predetermined position. Explain. 1 and 2 are circuit diagrams of an embodiment of the present invention device and operation waveform diagrams of each part thereof. In the figures, 1 is a kill switch for stopping the engine, 2 and 18 are
3 is a generating coil and a signal generating coil (hereinafter referred to as a balsa coil) of a magnetic generator rotated by an engine (not shown); 3 is a diode for shorting the reverse voltage of the generating coil 2; 4 is for preventing discharge of a capacitor to the generating coil side, which will be described later. Diodes 5, 6, and 19 form a closed circuit, including a thyristor (SCR), a capacitor (first), and an ignition coil, n1, n2.
are the primary and secondary windings of the coil 19, 7, 8, and 9 are diodes, resistors, and capacitors (second) forming a series circuit, and the connection point ○A and A of the capacitor 6 and the ignition coil n1 are , the coil n
The other end of 1 is connected between ○ and B. 15 and 17 are semiconductor switching elements (hereinafter referred to as transistors) and switches forming a parallel circuit;
is interlocked with a driving gear of the engine (not shown), and is closed when the gear is in the "neutral" position and opened when the gear is in the "drive" position. 16 is a reverse voltage prevention diode for the pulsar coil 18, and the transistor 15 to the pulsar coil 18 form a gate circuit of the thyristor 5. Next, 12 is a transistor whose base and emitter are connected to the other end of the capacitor 9 via resistors 10 and 11, and whose collector is connected to the base of a transistor 15 via resistors 13 and 14, so that the transistor 15 becomes conductive. Form a holding circuit. The circuit of the present invention is configured as described above.

Next, the operation will be explained.

<Engine starting operation> First, when the engine drive gear is in the neutral position, the switch 17 is closed (ON) and the kill switch 1 is also opened. At this time, when the crankshaft (not shown) rotates, an alternating current voltage is generated across the generator coil 2.
The capacitor 6 is charged by the positive half-cycle voltage along the path of the coil 2 → diode 4 → capacitor 6 → ignition coil n1 → coil 2.
On the other hand, since the pulsar coil 18 is set in advance to generate a signal (pulse) in synchronization with the generating coil 2 when the voltage of the generating coil 2 is in the negative half cycle, the pulsar coil 18→ An ignition signal is sent along the path of diode 16 -> switch 17 -> gate and cathode of thyristor 5 -> pulsar coil 18, thereby turning the thyristor into a conductive state. Therefore, the charge in the capacitor 6 is discharged along the path of capacitor 6 → thyristor 5 → ignition coil n1 → capacitor 6, resonates between the capacitor 6 and ignition coil n1, and is discharged along the path and the capacitor 6 → ignition coil n1. It vibrates along the path of ignition coil n1 → diode 3 → diode 4 → capacitor 6, and the voltage shown in FIG. The spark plug 20 generates a discharge and generates a spark.

<Load Drive Operation> In the above operation, when the engine is started and the driver or the like switches the drive gear to the drive gear position, the switch 17 is opened (OFF).

On the other hand, when the voltage generated by the ignition coil 19 is positive, that is, when the capacitor 6 side of the primary winding n1 is polar as shown in the shaded area in FIG. It is charged along the route. When the charging voltage of the capacitor 9 (FIG. 2a) reaches the voltage between the base and emitter of the transistor 12 (VBE), the capacitor 9 is discharged via the resistors 10 and 11 and the base and emitter of the transistor 12. and makes the transistor 12 conductive, thereby making the transistor 1 conductive.
5 is also conductive. Therefore, the ignition signal of the pulsar coil 18 is sent to the gate of the thyristor 5 via the diode 16 → the transistor 15, and the thyristor becomes conductive in the same manner as described above, forming a discharge path for the capacitor 6, so that the engine Maintained driving. In other words, the parallel circuit of switch 17 and transistor 15 functionally constitutes a logic circuit (OR circuit), and if either one is ON, the engine can be started, and if starting in neutral gear, transistor 15 is always activated. Since it is in a conductive state, the engine can continue operating without stopping. Note that the discharge time constant of the capacitor 9 in the conduction protection circuit, that is, the discharge time constant of the capacitor 9 and the resistor 10 to maintain conduction of the transistor 12, is set to be equal to or longer than the discharge interval of the capacitor 6 in a closed circuit. It is necessary. This prevents the ignition plug 20 from causing a discharge failure and failure in operation unless the thyristor 5 is reliably maintained in a conductive state when the capacitor 6 is discharged.

<Engine starting operation 2> When the driving gear is in the drive gear position when the engine is started, the switch 17 is opened and is in the OFF state. On the other hand, since the capacitor 9 is charged by the voltage generated by the ignition coil 19, there is no charge in the previous state, that is, when the engine is stopped. (The charge in the capacitor 9 immediately after the operation is stopped is discharged to zero after a predetermined period of time (1 to several seconds).) Therefore, the transistors 12 and 15 are in a non-conducting state, and the switch 17 in the parallel circuit and transistor 15 are both OFF. Therefore, even if the crankshaft is rotated, the signal from the pulsar coil 18 is not sent to the thyristor 5, and the thyristor 5 is still in the OFF state and the engine does not start.

As described above, according to the present invention, by adding to the gate circuit of the thyristor 5 a switch that operates in conjunction with the drive gear and a logic circuit of a semiconductor switching element that operates by detecting the operation of the engine, the drive gear can be controlled. The engine cannot be started when the position is other than the predetermined position (neutral position), and the engine can be started and operated when it is in the predetermined position. Although the above embodiment has been described using a transistor as a semiconductor switching element, the present invention can be similarly implemented using a thyristor or the like.

As is clear from the above description, according to the present invention, a highly safe ignition device that can prevent an outboard motor from flying out can be provided at a low cost, and therefore has great practical effects.

[Brief explanation of the drawing]

FIGS. 1 and 2 are circuit diagrams of an embodiment of the present invention and operation waveform diagrams of each part thereof. In the figure, 1 is a mole switch for stopping the engine, 2 is a generator coil 3,
4, 7 and 16 are diodes, 5 is a thyristor,
6 is a capacitor (first), 8, 10, 11, 1
3 and 14 are resistors, 9 is a capacitor (second), 12
is a transistor, 15 is a semiconductor switching element (transistor), 17 is a switch, 18 is a signal generation (pulsar) coil, 19 is an ignition coil, n1 and n2 are primary and secondary windings, and 20 is a spark plug. .

Claims (1)

[Claims] 1. A closed circuit formed by a capacitor (first), an ignition coil, a thyristor, etc., a circuit that charges the capacitor with the voltage generated by the generator coil, and no load connected to the engine. It includes a parallel circuit of a switch that operates by detecting the state and a semiconductor switching element that operates by detecting the operation of the engine, and the ignition signal of the ignition signal generating coil can be sent to the gate of the thyristor by the operation of the switch or the semiconductor switching element. a capacitor (second) charged by the primary voltage of the ignition coil for detecting operation of the engine; and a capacitor (second) that maintains conduction of the semiconductor switching element by the voltage of the capacitor (second). 1. An internal combustion engine ignition device comprising: a discharge time constant of a capacitor (second) in the continuity holding circuit is set to be longer than a discharge interval of the capacitor (first) in the closed circuit. 2. Claim 1, characterized in that a series circuit of a diode and a capacitor (second) is connected between the connection point of the capacitor (first) and the ignition coil and the other end of the ignition coil. Internal combustion engine ignition system as described. 3. A patent claim characterized by using a continuity maintaining circuit in which the base and emitter of a transistor are connected through a resistor between both ends of a capacitor (second), and the collector is connected to a control pole of a semiconductor switching element. 2. The internal combustion engine ignition system according to item 2.