Patent ID: 10012160

Abstract:
It is possible to prevent the stability of an engine from deteriorating even when degrees of changes over time of injection characteristics are different in each fuel injection valve. An inter-cylinder air-fuel ratio variation detection unit 1100 calculates an air-fuel ratio variation index (Ind_imb) which indicates a degree of variation in an air-fuel ratio between cylinders from an exhaust air-fuel ratio, engine rotation speed, or the like. Unlike in a case where the air-fuel ratio variation index (Ind_imb) is lower than a set value, when the air-fuel ratio variation index (Ind_imb) is higher than the set value, a fuel injection pulse width limitation unit 2100 sets a (allowable) minimum value (Min_TI) of a fuel injection pulse width so as to be greater. In addition, a fuel injection pulse width calculation unit 3100 calculates fuel injection pulse widths (TI_1, TI_2, TI_3, and TI_4) of cylinders so as not to be lower than the minimum value (Min_TI).