| 摘要 |
PROBLEM TO BE SOLVED: To materialize rise of exhaust gas temperature and reduction of HC emission at a time of cold engine by compatibly establishing large delay of ignition timing and combustion stability. SOLUTION: Normal stratified combustion operation and homogeneous combustion operation are performed under warm up completion condition. Fuel injection is performed over top dead center to make injection start timing IT before compression top dead center and injection end timing after top dead center as a top dead center injection operation mode is performed for accelerating activation of a catalytic converter and HC emission reduction under a cold engine condition. Ignition timing ADV is after top dead center. Since swirl and tumble are attenuated at compression top dead center and minute turbulence is activated and position change of a piston is small at compression top dead center, stable combustion can be materialized. When transient rotation drop occurs during idling operation, ignition timing ADV is advanced together with fuel injection timing IT like B, C. Torque increases with good response without waiting increase of intake air quantity by approaching MBT point. COPYRIGHT: (C)2007,JPO&INPIT
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