JP2879518B2 - Capacitor charge / discharge igniter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversal misfire circuit with a timer circuit for a capacitor charge / discharge type ignition device.

[0002]

2. Description of the Related Art A capacitor charge / discharge ignition device having a reverse misfire function focuses on the fact that the polarity of a voltage generated by an exciter coil changes depending on the rotation direction of an engine. Only by providing a semiconductor switching means for supplying a pulser signal to a semiconductor switching element for controlling primary ignition current, the engine is prevented from being ignited at the time of reverse rotation and the reverse rotation of the engine is prevented (Japanese Patent Publication No. 51-9084). .

[0003]

2. Description of the Related Art However, due to the recent increase in the polarity and the spread of the advance angle of the magnet generator, the output voltage of the exciter coil and the pulser signal from extremely low (2) rotation to high rotation are increased. It has become difficult to adjust the output phase by forward rotation and reverse rotation.

[0004]

The object of the present invention is to solve the above-mentioned problems.
It is an object of the present invention to provide a capacitor charge / discharge type ignition device having a stable reverse misfire function irrespective of the number of poles of an exciter-coil output and a lead angle characteristic by adding a simple one-shot timer circuit to the reverse misfire circuit. .

[0005]

SUMMARY OF THE INVENTION The present invention is based on a main circuit for discharging a charge of a capacitor charged by an output of an exciter coil to an ignition coil via a thyristor, and an output polarity of the exciter coil. A reverse rotation detection circuit, switching means for short-circuiting the gate circuit of the thyristor by an output signal of the reverse rotation detection circuit, and holding means for holding the output signal for one or more revolutions of the engine.

[0006]

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIGS. 2, 3 and 4 are waveform diagrams of respective parts for explaining the operation of the present invention. In FIG. 1, 1 is a main circuit and 6 is an exciter coil EX.
T output negative half-wave short-circuit diode 7 is a positive half-wave of an exciter coil 10 (hereinafter referred to as EXT) for ignition capacitor 9
Is a thyristor for controlling the primary current of the ignition coil Ign, and point C is EX.
T is an output voltage output unit. Reference numeral 2 denotes an ignition timing control circuit of an ignition device having an advance angle characteristic.
(Hereinafter, PC) is a PC width output unit that outputs from the positive rise to the negative fall of the output signal. 3 is the EXT
A reverse rotation detection circuit for detecting normal rotation or reverse rotation of the engine based on the phase of the output voltage output point C and the phase of the pulser width detection force b. 4
(3) A holding circuit (one-shot timer circuit) 5 for extending the reverse rotation signal detected by the reverse rotation detection section for one cycle or more of the PC output signal is output from the one-shot timer circuit at the time of reverse rotation. And the thyristor S1
Switching means (a misfiring transistor) for short-circuiting the gate input signal and preventing conduction of 8.

[0007]

Next, the present invention will be described with reference to FIGS. In FIG. 2, (a) shows a pulser-coil PC output signal, and (6) shows a general ignition timing of an ignition device having an advance angle characteristic. As the rotational speed increases from N0 to N1 and N2, the ignition timing advances from the PC output signal Q0 to Q1. 3 and 4 are waveform phase diagrams at the time of forward rotation and reverse rotation, respectively, wherein a is a pulser-PC output signal, Q0 is the ignition timing before advance, Q1 is the ignition timing after advance, and b is the pulser.
The coil PC width detection output, C is the exciter-EXT output, d is the output of the reverse rotation detection unit, and e is the one-shot timer-circuit output unit.

During forward rotation (FIG. 3), EXT positive side output C and PC
Since the width detection output b does not overlap, the reverse rotation detection output d remains Lo, so that the reverse misfire section does not function and performs normal ignition. Next, as shown in FIG. 4, at the time of reverse rotation, the EXT positive side output C and the PC width detection output b overlap, and the reverse rotation detection output becomes Hi (d) only at the overlapped portion. However, in this case, as is apparent from FIG. 4, since the EXT output does not overlap with all of the PC width detection outputs, a non-overlapping portion S is generated and the reverse rotation detection output d
When the transistor 5 is turned on, ignition occurs at the point of the advance end ignition timing Q1, and the reverse misfire does not function at the advance end rotation speed or higher.

Here, if the phase of the EXT output d and the PC output signal is shifted, it is possible to cause the reverse misfire beyond the advance rotation speed, but this time, the phase does not match during the low rotation before the start of the advance and the reverse misfire cannot be performed. Or EXT output during normal rotation,
The PC width detection outputs overlap and cause a misfire.
As described above, when the number of poles of the EXT output increases and (4) the lead angle width also becomes diversified, the phase cannot be easily matched as before, and the phase matching has often become impossible. . In the present invention, a one-shot timer section 4 is provided after the reverse rotation detection output section 3 as shown in FIG. 1, and if the misfire signal is extended to the next PC output signal section Y as shown in FIG. Until then, stable reversal misfire characteristics can be obtained. Although the ignition device having the advance function has been described above as an example, the same applies to an object having a retard function and an object having a combination of advance and retard.

[0010]

As described above, according to the present invention, it is possible to obtain a stable reverse misfire characteristic without being affected by the number of poles of the exciter coil and the ignition timing characteristic, and it is particularly effective for preventing the reverse misfire of a two-cycle engine. It is.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a diagram illustrating the operation of the present invention (representative ignition timing characteristics).

FIG. 3 is a diagram for explaining the operation of the present invention (a diagram of each waveform during normal rotation).

FIG. 4 is an explanatory diagram of the operation of the present invention (a diagram of each waveform at the time of reverse rotation).

[Explanation of symbols]

 Reference Signs List 1 main circuit 2 ignition timing control circuit 3 reverse rotation detection circuit 4 holding circuit (one-shot timer circuit) 5 switching means (transistor) 6, 7 diode (5) 8 thyristor 9 capacitor 10 exciter coil (EXT) 11 pulser -Coil (PC) 12 Ignition coil (Ign)

Claims (2)

(57) [Claims] A main circuit for discharging a charge of a capacitor charged by an output of an exciter coil to an ignition coil through a thyristor;
A reverse rotation detection circuit 3 based on the output polarity of the exciter coil 10; switching means 8 for short-circuiting the gate circuit of the thyristor 8 by an output signal of the reverse rotation detection circuit 3; A charging / discharging type ignition device comprising: 2. The capacitor charge / discharge type ignition device according to claim 1, wherein a one-shot timer circuit is used as the holding means.