JPS58174166A - Ignition system for multicylinder engine - Google Patents

Abstract

PURPOSE:To prevent smoldering of fuel in a combustion chamber under the ignited condition of abnormal intake and compression by stopping ignition operation until a crankshaft rotates at least one revolution in the start of an engine. CONSTITUTION:A stopping means 10 is constituted from a counter circuit 12, a muting circuit 14 and an one shot multivibrator 15 so that the output of the counter circuit 12 is changed over by the input of reset signal. Thus, a switching element 5 in an ignition circuit 1 is held non-conducting by the operation of the muting circuit 14 to stop ignition operation of the ignition circuit, and thereafter when the second pulse is sent to the input of the counter 12 by at least one revolution of a crankshaft, the muting circuit 14 is operated reversely so that the ignition operation is given by the conduction of the switching element at a predetermined phase.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition 811 in a multi-cylinder engine, particularly a four-stroke multi-cylinder engine with two or more cylinders.

Conventional CO2 engines have the disadvantage that the air-fuel mixture is ignited at startup without being properly inhaled and compressed, which tends to cause smoldering in the combustion chamber.The present invention solves this disadvantage and provides nine wrinkles. In a multi-cylinder engine having two or more cylinders, the engine is equipped with a stopping means for opening and stopping the ignition operation of the large point circuit of the engine at the time of starting the engine until the crankshaft is rotated at least once. Next, one example of implementing the present invention will be explained with reference to the attached drawings.

The drawing shows an example in which the present invention is applied to a 4-stroke, 2-cylinder engine. In the drawing, (1) is an ignition circuit equipped with an output side spark plug (2). , a switching element (5) at a predetermined phase for each rotation of the crankshaft by a pulse from an ignition pulser (4) cooperating with a retractor (3) interlocked with the crankshaft.
ignition filter (2).
The configuration is such that energization is applied to the primary side of.

Two spark plugs (6) (6) provided for one cylinder and the other are commonly connected to the secondary value of the cough ignition coil (2), and both spark plugs (6) are connected when the primary side is energized. (
61 is configured so that a spark discharge is applied at the same time.

In the drawing, (7) indicates a starting switch, and the switch (7)
When the switch is closed, the starting motor (9) is activated via the relay switch (8) to start the engine.

Although the above is the same as the conventional one, according to the present invention, the point large circuit (11) is provided with a stop means (II) for opening and stopping the ignition operation at the time of starting the engine until the crankshaft is rotated at least once. After the crankshaft has made one rotation or more, a spark discharge is applied at the longitudinal plate f (6) (6). , the above-mentioned ignition valve-
Counter circuit α2 inputs 11i pulses from (4) through the waveform shaper aυ for each rotation of the crankshaft.
and a two-tinder circuit Q41 which inputs the output me from the circuit α2 via the latch circuit α4, and inputs the counter circuit (13 to 7) signal when the start switch (7) is closed. One Shijitsu)! It consists of a multivibrator (5), and according to the input of the cough signal, the counter aii
The output of ua is switched from a low level signal to a high level signal, and according to this high level output signal, the above-mentioned ignition circuit (1) is activated by the operation of the mutinder circuit 0.
The switching element (5) is kept non-conductive to stop the ignition operation of the ignition circuit (1).
When the 2Il-th pulse is input to the switching element (5), a p-level output signal is generated from the gta path H, the muting circuit a4 becomes inactive, and the switching element (5)
Ignition operation by conduction at a predetermined phase as described above is provided.

Next, to explain its operation, in a 4-cycle two-cylinder engine, there is a phase difference of 560' between the inner cylinders, and the engine is started in a phase state in which one cylinder is in the intake process and the other cylinder is in the explosion process. In some cases, one cylinder is started in a phase state where one cylinder is in the compression process and the other cylinder is in the exhaust process. In the former case, normal intake is not performed in the intake process immediately after startup, so the intake The intake air in one cylinder that is started in the process is over 1!
KM<If ignition is given at the end of the compression process, it will cause smoldering in the fuel-rich state; If given, smoldering may occur due to ignition of residual gas.

However, according to the present invention, since the ignition operation is stopped by the stopping means α@ until the crankshaft is rotated one rotation or more as described above, in any of the above cases, the compression immediately after starting: iIi is the final stage. Since the ignition is always given after the intake air is compressed through the exhaust process, the above-mentioned smoldering does not occur.

The present invention is applicable not only to a 14-cycle 2-cylinder engine but also, for example, to a 4-stroke 4-cylinder engine. In this case, one exit coil is used for each two cylinders, but in this case, the stop hand J90Qlii and the crankshaft are It is preferable to configure the ignition operation so that the ignition operation is applied after two rotations 1. For example, the above-mentioned counter rotation M port 2
The configuration is such that a Loreherno output is generated by inputting the pulse ii of the t-receiver 7N1.

Further, when the ignition operation is stopped by the stop hand RQQl, the decompressor (not shown) may be operated at the same time.

As described above, according to the present invention, the stopping means stops the ignition operation during the period t''1'' during which the crankshaft 7) rotates one revolution or more after starting.
It has the effect of primarily preventing the occurrence of smoldering within the combustion chamber of #.

[Brief explanation of drawings]

The drawing is a block diagram showing an example of implementing the invention. (1)...Ignition circuit 11α...
Stopping means patent applicant: Honda Motor Co., Ltd.
Coffee person Kin Kitamura -□・1, 2 other people

Claims (1)

[Claims] A multi-cylinder engine having two or more cylinders, characterized in that it is equipped with a stopping means for opening and stopping the ignition operation of the ignition circuit of the engine at the time of engine starting until the crankshaft is rotated one revolution. igniter.