To effectively raise temperature (activate) exhaust emission purifying catalyst by increasing rate of component having high reaction property in unburned component when raising temperature of exhaust emission purifying catalyst to improve emission.
Opening area of a fuel injection valve is increased to increase fuel injection rate and stratified air-fuel mixture is changed (S23) so that air-fuel ratio of the stratified air-fuel mixture becomes rich to raise temperature of the exhaust emission purifying catalyst. Injection start time ITs and fuel injection period TI of the fuel injection valve are calculated (S24, S25), respectively. Ignition time is set (S26) in such a way that air-fuel mixture is burned before fuel injected from the fuel injection valve reaches a wall face of a combustion chamber by taking them into account.
TSUCHIDA HIROBUMI
TAYAMA AKIRA
HOTTA ISAMU
SHIRAISHI TAISUKE
