To prevent rotational reduction, misfire and engine stall by eliminating a fuel correction to the lean side of the air-fuel ratio such as exceeding a combustion limit at the low temperature of an engine.
An operation control device has an air-fuel ratio state determining means for determining whether a state of the air-fuel ratio detected by an air-fuel ratio detecting means is rich or lean, a characteristic holding means for holding an integral gain characteristic and a proportional gain characteristic of determining a value by an engine speed and intake pipe pressure and a cooling water temperature factor characteristic of determining a cooling water temperature factor of correcting integral gain in response to the cooling water temperature, and a fuel correction quantity operation means for multiplying the integral gain by the cooling water temperature factor when determining a correction value of a fuel injection quantity by using a sign, the integral gain and proportional gain provided by a determining result of the air-fuel ratio state determining means. The cooling water temperature factor of the cooling water temperature factor characteristic is set smaller than a steady value in an area lower than the steady temperature in the cooling water temperature.
Michiharu Soga
Hidetoshi Furukawa
Suzuki Kenchi
Kajinami order
Nakamura Rei
Next Patent: PUMP AND PUMP SYSTEM