| 摘要 |
PURPOSE:To eliminate noises produced through the operation of a timer control valve, by executing a process for judging the conditions of idling operation of an engine and a process for setting a timer at a smallest advance angle position. CONSTITUTION:An electronic control unit 40 is constituted mainly by a microcomputor. An MPU41 executes calculation controlling process on the basis of programs stored in memory while a ROM42 stores therein constant data necessary for executing the programs and calculation, etc. Output signals of various engine sensors 1 are furnished to the MPU41 via an input buffer 44 and a control pulse signal for a timer control valve 8 and a spill actuator control signal are furnished to the MPU41 via an output buffer 45. In case that data relating to the aimed timer position indicates that the engine is not in its idling operation, the timing for starting fuel injection is controlled by the timer control valve 8 at the duty ratio obtained from the results of calculation. In case that the engine is in idling operation, on the other hand, a roller ring 23 is turned to a smallest advance angle position by producing a control pulse signal for setting a timer mechanism 30 at a smallest advance angle position and communicating a high-pressure oil chamber 32 of the timer mechanism 30 with its low-pressure oil chamber 33. Thus, it is enabled to eliminate noises produced by ON-OFF switching of the valve. |
