JPS59176466A - magneto igniter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magneto ignition device used in a two-stroke internal combustion engine.

[Prior art and its problems]

A small two-stroke internal combustion engine called a general-purpose engine is generally used in a place with a high rotational speed, and is often used because it obtains horsepower due to the high rotational speed. This high rotational usage situation consumes a lot of gasoline, and the engine becomes hot due to the heat generated from the friction between the cylinder and piston due to the high rotational speed. Under these circumstances, if the engine oil deteriorates, the 2-cycle mixed oil is defective, the oil level decreases, etc., the engine becomes abnormally high temperature, causing the metal of the piston to seize up and burn out the engine. I end up. Conventional two-stroke engines have not taken any particular measures to prevent such accidents.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magneto ignition device that can suddenly stop the engine in response to an emergency situation that occurs during use of such a two-stroke engine at high rotation speeds.

[Key points of the invention]

In the present invention, a transistor connected in parallel on the primary side of the ignition coil is connected in anti-parallel to a magneto ignition device that generates a high voltage on the secondary side of the ignition coil. A series circuit with another transistor and a switch.

A control circuit that closes the switch and turns the other transistor from on to off when the voltage across the primary winding of the ignition coil reaches a predetermined value, and the base of each transistor is connected in series to the two transistors. , is equipped with an emic junction and a diode with polarity in the same direction, and in an emergency, by turning the other transistor on and off, the engine is ignited further lζ before the proper ignition timing, in contrast to the forward rotation of the engine. The above object is achieved by applying a force that tends to reverse the direction of C and applying the brake. The correct ignition timing for normal engine rotation is 200° when the piston reaches top dead center.
However, in the present invention, for example,
By igniting before 0°, reverse rotation torque is generated in the engine.

[Embodiments of the invention]

Secondary winding 1 of 1 ignition coil l in No. 111i11J
2 is connected to the spark plug 2. The transistor 3 and its control circuit 4 connected in parallel to the primary winding 11 in the section A are bypassed by the base current control circuit 4 of the transistor 3 at proper ignition timing as in the conventional ignition system. Primary wire 1 flowing to transistor 3
This is to cut off the 1st current and generate a discharge in the spark plug.

- A diode 5 is connected in series with the transistor 3 so that it is activated when the voltage on the ground side of the secondary winding 11 is positive. The circuit in part B is added according to the present invention, in which a transistor 6 connected to both ends of the -order winding 11 with the opposite polarity to the transistor 3 is connected via a diode 7 and a switch 8. A control circuit 9 is connected to the base. The control circuit 9 is configured, for example, as shown in FIG. When this occurs, the thyristor 1o is fired by the voltage divided by the resistors 21 and 22, thereby bypassing the base current of the transistor and thereby generating a high voltage in the ignition coil. Figure 3(a),
(bl shows the waveform of the magneto ignition coil current, (a
) is when the magnet has two poles and the coil has three poles, or the magnet has three poles and the coil has two poles.

(bl is the case where both the magnet and the coil are 2@. In both cases, the current is cut off at position C by the circuit at part A in Figure 1 to generate a secondary voltage and perform proper ignition.
If the circuit at part B is activated, it will cut off the current at position D, ignite the engine at a point even earlier than the proper ignition timing, and give the engine a force to reverse the rotation.
Can apply reverse brake. That is, under normal driving conditions, the %A operates, the ignition is ignited at the proper position, and the engine is rotating. If it is necessary to suddenly stop the engine to prevent danger due to some abnormality, closing switch 8 will start circuit B.
The engine is ignited at point D in Figure 3, and a force is generated that causes the engine to rotate in reverse. Note that the diode 5 and the diode 7 are connected so that each transistor circuit does not consume power as a load when the coil current is cut off.

〔Effect of the invention〕

The present invention adds another transistor in anti-parallel to the transistor for generating high normal pressure at the normal ignition timing in the ignition coil of a magneto ignition device, and in an emergency, the current flowing through the transistor is cut off. ignition occurs before the ignition timing.

This system generates reverse rotation torque in the engine to enable it to stop suddenly, making it extremely effective in preventing accidents at high engine speeds.

[Brief explanation of drawings]

Figure 1 is a circuit diagram of an embodiment of the present invention, Figure 2 is a circuit diagram of an example of its control circuit, and Figures 3 (a) and (b) show two types of current flowing through the ignition coil. FIG. DESCRIPTION OF SYMBOLS 1...Ignition coil, 11...-Secondary winding, 12...Secondary winding, 2...Spark plug, 3, 6...Transistor, 4.9...Control circuit, 8... switch. Moeto Patent Attorney Yamaguchi Toro (1 above? I I @ ノU ′? - 2 Brilliant 3 Brilliant

Claims (1)

[Claims] 1) Turning a transistor connected in parallel with the primary winding of the ignition coil from on to off A series circuit of a transistor and a switch, and a control circuit that closes the switch and turns the other transistor from on to off when the voltage across the primary winding of the ignition coil reaches a predetermined value l, is configured by connecting both transistors. 1. A magneto ignition device comprising a diode connected in series and having polarity in the same direction as the base and emitter junctions of each transistor.