To control a stable idling rotating speed for fluctuation of the rotating speed and load input when stratified combustion is performed at the time of engine cool down, or stratified combustion is performed after warming-up by providing a means for increasing and decreasing basic fuel injection amount for controlling the rotation during idling and/or correcting load.
During the operation of an engine, in a target rotating speed generating means 122, a water temperature TW is input to obtain a rotating speed as a basis for idling from a table, and an extra rotating speed is determined according to the load SW, which is added to the basic rotating speed to generate a target rotating speed the. Subsequently, in an idling rotating speed control means 116, a deviation eNe between the obtained target rotating speed the and the actual engine rotating speed Ne is obtained, and PID control is conducted by the proportional part, the differential part and the integral part to output a reference change amount ΔTp2 of the reference fuel injection amount Tp2, and the output is reflected in the reference injection amount Tp2'. Thus, the fuel quantity is increased to increase the intake air quantity.
HOSOKAWA KOJI
ATAGO TAKESHI
