| 摘要 |
PROBLEM TO BE SOLVED: To make a great time lag of ignition compatible with combustion stability and raise temperature of exhaust gas and reduce amount of HC emission when an internal combustion engine is cold. SOLUTION: In a condition in which warming-up is completed, usual stratified combustion operation and homogeneous combustion operation are performed. In a cold condition, operation mode is set to top dead center injection operation mode to perform fuel injection across the top dead center so that injection start time ITS is before compression top dead center and injection end time ITE is after the top dead center to promote activation of catalyst converter and reduce amount of HC emission. Ignition time ADV is after the top dead center. Since swirl and tumble are damped, minute disturbance is activated, and change of a position of a piston is reduced at the compression top dead center, stable combustion can be realized. When load is increased due to start of a vehicle and turning-on of an auxiliary machine, exhaust gas temperature is excessively increased and there is a possibility that thermal damage of the catalyst converter may occur. Therefore, top dead center injection operation mode is released immediately after detecting predetermined increase of load. COPYRIGHT: (C)2006,JPO&NCIPI |
