| 摘要 |
PROBLEM TO BE SOLVED: To make wide lag of an ignition timing and combustion stability compatible with each other and realize rising of an exhaust gas temperature at the time of a cold machine and reduction of an amount of HC emission. SOLUTION: In a warming up completion state where a cooling water temperature exceeds 80°C, usual layered combustion operation and homogeneous combustion operation are performed. In a cold state that it is below 80°C, fuel injection is effected as a top dead center injection operation mode for promotion of activation of a catalyst converter and reduction of an HC discharge amount and fuel injection is effected astride a top dead center such that an injection start timing ITS becomes before a compression top dead center and an injection end timing ITE becomes after a top dead center. An ignition timing ADV becomes after a top dead center. At the top dead center, swirl and tumble are attenuated and minute turbulence is activated and since the position change of a piston 3 is also scarce, stable combustion can be realized. When air density of a high ground and the like is low, generated torque is further reduced and there is a possibility that an engine is stopped, and thereby a top dead center injection operation mode is prohibited. COPYRIGHT: (C)2006,JPO&NCIPI
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