INJECTION TIMING FEEDBACK CONTROL METHOD FOR DIESEL ENGINE

摘要

PURPOSE:To prevent the occurrence of overcompensation for injection timing, by finding a proportional term on the basis of a difference between desired injection timing and detected injection timing at a time when this difference is larger than a dead zone in the proportional term of feedback control. CONSTITUTION:At the time of driving an engine 10, first a duty ratio of desired injection timing is calculated on the basis of each output of a speed sensor 46 and an accelerator position sensor 20 at a electronic control unit 56. Next, when a feedback control condition is effctuated, desired ignition timing is calculated likewise, and a dead zone in a proportional term of duty control which varies according to an engine speed is calculated. Then, a difference between the desired ignition timing and the ignition timing to be detected by an ignition timing sensor 38 is found, the difference from which an integration term of the duty control is calculated, while the proportional term is calculated from the found value by subtracting the said dead zone from the said difference. And, the integration term and the proportional term are added to the said duty ratio and a control duty ratio is found, thus a timer control valve 48 is controlled.