CONTROL DEVICE OF ROTATIONAL SPEED OF ENGINE

摘要

PURPOSE:To stabilize the rotational speed of an engine by quickly bringing it close to a target rotational speed by the ways of adjusting the fuel quantity or the air quantity and further adjusting the ignition timing after detecting the engine speed. CONSTITUTION:At idle running, a throttle valve 2 is controlled to open and close by the operation of an actuator 4 to adjust the fuel quantity or the air quantity passing through the intake pipe 1 of an engine. A control unit 15 makes information corresponding to the rotational speed of the engine by measuring the firing interval generated by the input of a firing signal SG from a distributor 24. In addition, the unit 15 calculates the ignition lead angle corresponding to each operating condition on the basis of each input signal and outputs the resulted signal OS to an ignitor 25. The ignition lag count by the unit 15 is reduced in synchronism with the pulse signal from a crankangle sensor 10 and at the time of zero count, an OS signal is forwarded from the unit 15 and a timing-con trolled firing signal CSG is sent to an ignition coil 26.