JPS6054510B2 - Ignition system for internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition system for an internal combustion engine, and more particularly to an ignition system that can stop the operation of a part of the ignition circuit of a spark-ignition internal combustion engine that has a plurality of ignition circuits for each cylinder. Regarding equipment.

When you want to stop the operation of a part of multiple ignition systems,
All you have to do is stop the supply of the primary current flowing to the ignition coil, but if a transistor type ignition device is used as the ignition device, if you stop the operation of the power transistor that controls the ignition coil current at any point, the , extremely high voltage is generated on the secondary side of the ignition coil and sends ignition sparks to the ignition plug, so if the power transistor stops outside of the normal ignition time, drivability will deteriorate and engine durability will be affected. Problems such as a decrease in

SUMMARY OF THE INVENTION An object of the present invention is to provide an ignition device that eliminates the above-mentioned disadvantages and prevents the power transistor for driving the ignition coil from turning off at a position other than the normal ignition position even if an ignition stop signal is input during the ignition coil energization period. There is something to do.

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

FIG. 1 is a circuit diagram of an embodiment of the present invention, in which the ignition signal from the control circuit 10 is transmitted to the resistors 3, 4,
, an ignition circuit consisting of a transistor 24, a power transistor 16, an ignition coil 12, resistors 1 and 2, a transistor 20, a transistor 25, and a power transistor 1.
5. It is supplied to an ignition circuit consisting of an ignition coil 11. The secondary sides of the ignition coils 11 and 12 are each connected to a spark plug 13.
, connected to 14. The above configuration is similar to the known ignition circuit, but according to the present invention, the base circuit of the power transistor 15, that is, the base of the transistor 25 is connected to the collector of the common emitter transistor 22, and the emitter is grounded through the resistor 7. transistor 23
connected to the base of. The collector of transistor 23 is connected to the base of transistor 22. That is, transistors 22 and 23 constitute a type of flip-flop circuit. The base of transistor 22 is resistor 6
It is connected to the contact 17 through the resistor 5, and to the power supply V+ through the resistor 5. The contact 17 opens when the ignition stop signal is issued, and closes when there is no ignition stop signal. Next, the operation of the circuit shown in FIG. 1 will be explained with reference to the waveform diagram shown in FIG.

First, if there is no ignition stop signal, the contact 17 is closed, so the transistor 22 is in an off state, and the collector voltage of the transistor 20 is directly applied to the base of the transistor 25. Therefore, when the ignition signal shown in FIG. 2A is applied to point A in FIG. 1, voltage waveforms as shown in FIG. Currents as shown in Fig. 2 C and G flow respectively through the terminals. Now, while the power transistor 15 is on, time t1
When the ignition stop signal is generated and contact 17 is opened, the waveform at point D changes as shown in FIG. 2D, transistor 23 is turned on, and transistor 22 remains off. Therefore, power transistor 15 is not turned off at this point. Next, when the point A waveform changes from O to 1, that is, at the ignition position, the transistor 20 is turned on, and the transistor 23
is turned off, the transistor 22 is connected through the resistors 5 and 6.
A current is supplied to the base of the transistor 22, and the transistor 22 is turned on. From this point on, the transistor 22 remains on as long as the contact 17 is open, that is, as long as the ignition stop signal is present, so even if the ignition signal is repeatedly input, the power transistor 15 remains off. continue. That is, the waveforms shown by broken lines in FIGS. 2E and 2G do not occur while the contact 17 is open. When the ignition stop signal disappears and the contact 17 closes, the transistor 22 is turned off and a normal ignition signal is transmitted to the power transistor 15, so the power transistor 15 starts operating. Note that the circuit consisting of the transistors 22 and 23 can be provided in a power transistor for any ignition coil whose ignition is to be stopped.

As described above, according to the present invention, the supply of the primary current to the ignition coil is stopped after the normal ignition position, so that it is possible to prevent false ignition, improve reliability, and improve durability. It can be measured with a simple circuit configuration.

[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 of an embodiment of the present invention.
The waveforms of each part of the figure are shown. 10... Control circuit, 11, 12... Ignition coil, 15, 16... Power transistor, 1
7...Ignition stop signal contact, 20-25...
transistor.

Claims (1)

[Claims] 1. Two ignition coils that generate high voltage to the two ignition plugs provided in each cylinder of an internal combustion engine, and one control signal from the same ignition control signal generation means as the number of ignition coils. A power transistor circuit for driving an ignition coil that controls on/off according to the operating state of the internal combustion engine, and a means for outputting a signal according to the operating state of the internal combustion engine, and the two In an ignition device for an internal combustion engine, driving of a selected one of the ignition coils is stopped by turning off a power transistor circuit for driving the selected ignition coil,
The ignition coil driving power transistor circuit includes a drive control signal generating section and a power transistor section, and a drive input signal is input to the power transistor section of the ignition coil driving power transistor circuit that drives the selected ignition coil. means for grounding according to the output signal from the operating state signal output means, and further, when the output signal from the operating state signal output means overlaps with the drive input signal to the power transistor section, the grounding means an ignition device for an internal combustion engine, comprising means for holding the power transistor in a non-grounded state until the power transistor drive input signal is turned off, regardless of the operating state output signal.