JPH03271564A - Control device of cylinder direct injection gasoline engine - Google Patents

Abstract

PURPOSE:To facilitate control, by setting a pulse of a crank angle sensor to agree with the start time fuel injection timing, providing accuracy of ignition timing or the like even when an engine speed is fluctuated, improving ignitability and startability and further determining the ignition timing thereafter based on fuel injection. CONSTITUTION:When a starter switch 32 is turned on, starting is decided in a starting decision part 42 of a control unit 40, and a starting time fuel injection pulse width is calculated in a starting time fuel injection amount arithmetic part 44 based on the decision of starting. On the other hand, a reference position of a crank pulse A is judged by inputting the crank pulse A from a crank angle sensor 30 and a pulse B from a cylinder discriminating sensor 31 to a control unit 40. Fuel is directly injected by an injector 6 by outputting a fuel injection signal from a fuel injection control part 46 in the point of time the crank pulse A is generated. Thereafter the above-mentioned spray performs stratified combustion by a spark of an electrode 7a by outputting an ignition signal to a spark plug 7 from a starting time ignition timing determining part 45 in the point of time after the atomization time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a direct-in-cylinder gasoline engine that injects fuel directly into a cylinder by an injector. Regarding timing control.

[Conventional technology]

The applicant of the present invention has already proposed a number of two-stroke engines with in-cylinder direct injection. In the low load range, including during startup, the fuel from the injector is injected toward the electrode of the spark plug just before the ignition timing, maintaining a rich mixture spray near the electrode to achieve good stratified combustion. It shows the technical idea. Therefore, at the time of starting, the fuel injection time (e.g. 3 msec) and the optimal atomization time for fuel stratification (e.g. 2 msec) must be taken into consideration before the appropriate ignition timing (e.g. 10 degrees BTDC). , it is necessary to set the fuel injection timing earlier than these times.

On the other hand, to control the timing of these three fuel injection ignitions, generally in a crank in-cylinder direct injection gasoline engine using an electromagnetic pickup, the pulse of the crank angle sensor is set to match the fuel injection timing at startup, and the fuel injection The subsequent atomization 1 ignition timing is also accurate even if there are rotational fluctuations, improving ignition and starting performance.

Furthermore, since the in-cylinder direct injection type allows fuel atomization time at startup to be accurately set, stratified combustion is performed well.

Furthermore, since the ignition timing is determined after the fuel injection, control becomes easier.

Furthermore, by injecting fuel in synchronization with the crank pulse, the fuel injection is particularly good at the initial stage of starting, which helps shorten the starting time.

Furthermore, the position of the crank pulse is, for example, BTDC1.
5 degrees and does not cause any inconvenience when shifting to normal control.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a block diagram showing an embodiment of the control device for a direct injection gasoline engine of the present invention, and Fig. 2 is a diagram showing the timing of fuel injection and ignition timing at startup. .

Claims (2)

[Claims] (1) Place the injector and spark plug electrode in the combustion chamber,
In a direct-in-cylinder gasoline engine that is installed to enable stratified combustion at low load, the control system injects fuel just before the ignition timing using a pulse from a crank angle sensor at startup. The direct injection gasoline engine is characterized in that the starting ignition timing is controlled at a predetermined time point after the fuel injection synchronized with the above-mentioned fuel injection timing. Control device. (2) The ignition timing at the time of starting is set to the time after the generation of the crank pulse, the width of the fuel injection pulse at the time of starting, and the atomization time for stratification. Control device for injection gasoline engine.