JPS6016785Y2 - engine ignition system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a semiconductor type internal combustion engine ignition device.

Various current interrupt type engine ignition devices have been proposed in the past, and they are used as a means to increase ignition energy by short-circuiting a resistor provided in series with an ignition coil during engine startup or high-speed operation.

Additionally, in conjunction with exhaust control, it is also required to increase ignition energy during deceleration and the like.

However, there is also a type of engine ignition system that does not significantly change the ignition energy by using an external resistor, that is, it attempts to keep the energization time to the ignition coil constant regardless of the operating state of the engine. In order to perform highly accurate control, it has become necessary to control the energization time of the ignition coil according to the operating state of the engine.

This idea provides a concrete means for realizing it.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a circuit breaker contact that opens and closes in conjunction with an engine (not shown), and has an open period of (1-x)%.

2 is a first pulse generating circuit that generates a time-width pulse triggered by the circuit of the circuit breaker contact 1; 3 is the difference between the opening time of the circuit breaker contact 1 and the pulse time of the first pulse generating circuit 2; time pulse (T(1x) t.

] (where f is the ignition signal period), 4 is the time pulse of the first logic circuit X/(1
-x) a second pulse generation circuit that generates twice as many pulses, 5
6 is a second logic circuit that generates a pulse with a duration equal to the sum of the opening time of the circuit breaker contact 1 and the output of the second pulse generating circuit 4, and prohibits conduction of the ignition coil during that time; This is a control signal generation circuit that changes the pulse width of the first pulse generation circuit accordingly.

In the configuration as described above, the conduction time Ton of the ignition coil is calculated as follows: 1 1 XI Ton=7-- (A(1-x) +1 , (,
-x)-to)) =-t.

-x Therefore, it has nothing to do with the engine rotation speed.

However, X is the circuit breaker contact 1 that gives the closing rate,
This is determined by the cam angle of the power distributor, and cannot be changed depending on the operating condition of the engine.
This is the output pulse width of the pulse signal generating circuit 2, and since it is constructed from an electric circuit such as a monostable multi-channel circuit, it can be controlled from the outside.

The conduction time Ton of the ignition coil can be changed by changing the output pulse width of the first pulse signal generating circuit 2 according to the operating state of the engine detected by the control signal generating circuit 6, and is independent of the rotational speed of the engine. In addition, the operating status of the engine (e.g. temperature, EGR (exhaust gas recirculation) amount, load size)
The ignition energy can be changed according to the

The first pulse generation circuit can be configured with a monostable multi-channel circuit as described above.

The output pulse of the second pulse generation circuit 4 discharges the capacitor charged by the output pulse of the first logic circuit with a discharge current that is (1-x)/x times the charging current, and the voltage level is detected. This can be achieved by doing this.

Furthermore, in the present invention, the control range is limited to above idle, and the current is limited below idle, which has the effect of simplifying the circuit.

As described above, according to this invention, the ignition energy can be changed by making the conduction time of the ignition coil independent of the rotational speed of the engine other than when the engine is idling, and changing it according to the operating status of other engines, and the current is limited when the engine is idling. Therefore, it is possible to ignite with the optimum ignition energy depending on the engine operating state, and also to minimize heat loss in the ignition system.

[Brief explanation of the drawing]

The figure is an electrical circuit diagram showing an embodiment of this invention. In the figure, 1 is a circuit breaker contact, 2 is a first pulse generation circuit, 3 is a first logic circuit, 4 is a second pulse generation circuit,
5 is a second logic circuit, and 6 is a control signal generation circuit.

Claims (1)

[Scope of utility model registration request] It opens and closes in conjunction with the rotation of the engine, and the ignition signal generation period (1)
a first pulse generating circuit that is triggered by the opening of this interrupter contact and generates a pulse of time duration t; the opening time of said interrupter and the first pulse generation; a first logic circuit that generates a pulse with a time difference between the output pulses of the circuit; a second pulse generation circuit that generates a pulse with a time x/(1-x) times the output pulse of the first logic circuit; a second logic circuit that generates a control pulse to interrupt the ignition coil current for a time equal to the sum of the opening time of the ignition coil contact and the pulse time of the second pulse generation circuit; Equipped with a control signal generation circuit that changes the time width of the output pulse of the pulse generation circuit, the control signal is controlled by current limiting when the engine is in an idling state, and the control signal is generated when the engine is in a state other than idling. An engine ignition system characterized in that the energization time of an ignition coil is changed according to the operating state of the engine by changing the time width of the output pulse of the first pulse generating circuit using the output of the circuit.