JPH02204681A - Starting ignition circuit for engine - Google Patents

Abstract

PURPOSE:To make engine starting impossible if allowing such a fact that wire connecting a condenser discharge ignition(CDI) circuit and an ignition switch is cut off by assembling an internal element of the CDI circuit in the ignition switch. CONSTITUTION:When an engine is started, a moving contact 16 of an ignition switch 4 is made contact with a RUN contact 17. With this contact, since a condenser 9 is connected to the output side of a CDI circuit 2 in series with a primary side coil 11 of an ignition coil 3, charging and discharging are repeated by a current interrupting the primary side coil 11 through on-off operation of a thyristor 10, including a high voltage in a secondary side coil 12 of the ignition coil 3, thereby starting an engine. When the moving contact 16 of the ignition switch 4 is made contact with an OFF contact to stop the engine, output voltage of a magnet 1 comes to charge the condenser 9 in consequence, but it will not flow into the primary side coil 11 of the ignition coil 3, so that ignition comes impossible and the engine is thus not started.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine starting ignition circuit using the CDI ignition system.

(Prior art) The CDI ignition system charges a capacitor with electromotive force generated by a flywheel magnet (hereinafter simply referred to as magneto) attached to the engine crankshaft, and when this charge is discharged at a predetermined timing, this energy is released. is applied to the primary coil of the ignition transformer to generate a high voltage in the secondary coil. Unlike the battery ignition method, the engine can be started without a battery, so it is often used in outboard motors for motorcycles and small boats.

In the case of the CDI ignition system, the magneto generates electricity when the engine crankshaft is rotated, so for example, in the case of a motorcycle, it is possible to start the engine by stepping on the kick pedal or pushing the vehicle body, making it possible to prevent theft. This is not preferable in terms of prevention, so when an ignition switch is installed and the key is placed in the off contact, even if the engine crankshaft is rotated by an external force, the electromotive force generated in the magneto will be transferred to the ground circuit ( This problem is solved by shorting the circuit connected to the negative output end of the magneto.

This type of conventional circuit will be explained with reference to FIG. 2. This circuit is roughly divided into magneto 1. It consists of a CDI circuit 2, an ignition coil 3, and an ignition switch 4. The magneto 1 generates an alternating current electromotive force in the main coil 5 when a magnet (not shown) is rotated by a crankshaft. The magneto l is also provided with a pulser coil 6 for timing detection. A part of a charging/discharging capacitor 9 is connected to the output side of the main coil 5 via a rectifying diode 7.8.

And at this connection point, the anode side of the thyristor lO is connected.
Further, one end of the primary coil II of the ignition coil 3 is connected to the output side. The cathode side of the thyristor ■ and the other end of the primary coil ■ are connected to the ground circuit. Secondary coil 12 of ignition coil 3
Spark plug 3 is connected to.

A gate of a thyristor 10 is connected to the output side of the pulser coil 6 via a diode 14 and a resistor 15. As a result, when a magnet (not shown) passes near the pulser coil 6, an electromotive force is induced in the pulser coil 6, and this electromotive force turns on the thyristor lO.

When the thyristor 10 is turned on, the charge stored in the capacitor 9 is discharged. The ignition switch 4 is a single-pull, double-throw type, and the movable contact I6 is connected to a ground circuit. and the RU that the movable contact 16 selectively contacts.
The RUN contact 17 of the 7FF contacts 18 above the N contact is not connected, and the OFF contact 18 has a diode 9 in the middle.
It is connected to the output end of the main coil 5 by a wire 20 with an interposed wire 20 .

In this circuit configured in this way, when the engine is started, the movable contact 16 of the ignition switch 4 is brought into contact with the R11N contact I7, and the crankshaft is rotated by a starter motor, kick pedal, coil starter, etc. (not shown). Then, a voltage is generated in the main coil 5, which is rectified by the diode 7.8 and flows to the series circuit of the capacitor 9 and the primary coil H. As a result, the capacitor 9 is charged. When the six-rotating magnet passes near the pulser coil 6, an electromotive force is generated in the pulser coil 6, so the thyristor IO is turned on and the charge accumulated in the capacitor 9 is instantly discharged. discharge. At this time, a high voltage is generated in the secondary coil +2 of the ignition coil 3, the spark plug 13 ignites, and the engine starts.

(Problem to be Solved by the Invention) In order to prevent WJl of a vehicle, etc. (including an outboard motor) in the above circuit, the movable contact 16 of the ignition switch 4 is brought into contact with the OFF contact side 8, and in that state, The key (not shown) will have to be removed. If the key is removed, even if an external force rotates the crankshaft and generates an electromotive force in the main coil 5 of the magneto L, the electromotive force will be transferred to the ground circuit via the diode I9, the OFF contact 18, and the movable contact I6. Since the current flows and the capacitor 9 is not charged, the engine is not started.

However, this circuit has the following drawbacks. In other words, this circuit was designed to prevent theft by bringing the movable contact 16 of the ignition switch 4 into contact with the OFF contact 18 and removing the key. If an output voltage is generated, the engine can be started.

Therefore, even if part of the line 20 is cut as indicated by the symbol in the figure, the engine can be started. For this reason, it was difficult to say that the anti-theft mechanism was perfect.

The present invention has been made in view of this point, and CI)1
To provide an engine starting ignition circuit in which the engine cannot be started by cutting a line connecting a circuit 2 and an ignition switch 4.

(Means for Solving Problem A) The present invention, as a means for solving the above problem, charges a capacitor 9 with the voltage generated in the magneto L, and uses the discharge current of the capacitor 9 to charge the ignition coil 8.
CDI that induces A1ff1 pressure in the secondary coil 12 of
In the ignition type engine, the internal elements of the CDI circuit 2 are incorporated into the ignition switch 4.

(Function) In such a configuration, that is, as an internal element of the CDI circuit 2, for example, the capacitor 9 is connected to the ignition switch 4.
Even if the wire connecting the CDI circuit 2 and the ignition switch 4 is cut, the CDI circuit 2 will not operate and the engine will not be able to start.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 1, in which the same members as in FIG. The element is incorporated into the ignition switch 4. That is, the capacitor 9 as an internal element of the CDI circuit 2 is built into the ignition switch 4, and the wiring between this and the CDI circuit 2 is such that the diode 19 in the CDI circuit 2 and the OFF contact 18 of the ignition switch 4 are connected in the middle. They are connected by a wire 20 with a current limiting resistor 2I interposed therebetween, and a capacitor 9 is connected between the movable contact 16 of the ignition switch 4 and the ground circuit. In the circuit shown in Figure 2, the ignition coil 3 which was grounded
One end of the primary coil II is connected to the RUN contact of the ignition switch 4 by wire 22! 7 is connected. Note that a resistor 23 for discharging the capacitor 9 is connected between the OFF contact 18 of the ignition switch 4 and the ground circuit.

The operation of this circuit configured in this way will be explained. To start the engine, the movable contact 16 of the ignition switch 4 is brought into contact with the RUN contact 17. As a result, the capacitor 9 is connected to the output side of the CDI circuit 2 in series with the primary coil 11 of the ignition coil 3.
The primary coil II is turned on and off by turning on and off the thyristor IO.
Charging and discharging are repeated with the intermittent current, and a high voltage is induced in the secondary coil 12 of the ignition coil 3, and the engine starts.

Ignition switch 4 to stop the engine
If the movable bridge point 16 of the magneto 1 is brought into contact with the OFF contact 18, the output voltage of the magneto 1 will charge the capacitor 9, but it will not flow to the primary coil 11 of the ignition coil 3, so ignition will not occur. The engine will not start.

(Effects of the Invention) Since the present invention is an engine starting ignition circuit configured as described above, it is not possible to start the engine by external operations such as cutting the wiring as in conventional circuits. , which has a great effect on preventing theft. Furthermore, since the circuit is simple, it has the advantage that it can be easily applied to automobiles, motorcycles, and marine engines.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional circuit. 1... Magneto 2 - CD 1 circuit 3... Ignition coil 4 - Ignition switch 5 - Main coil 9 - Capacitor 10 - Thyristor 11 - Primary coil + 2 - Secondary coil + 3 - Spark plug

Claims (1)

[Claims] (1) CDI is the voltage generated in the flywheel magnet.
In an engine of the CDI ignition system, in which a capacitor in the circuit is charged and a high voltage is induced in the secondary coil of the ignition coil by the discharge current of the capacitor, the internal elements of the CDI circuit are incorporated into the ignition switch. An engine starting ignition circuit characterized by: