| 摘要 |
PROBLEM TO BE SOLVED: To improve exhaust emission when switching an injection condition (an injection mode or the fuel injection timing) of a cylinder injection engine. SOLUTION: The injection mode is switched between an intake stroke one time injection mode of injecting fuel by one time in an intake stroke of respective cylinders, a compression stroke one time injection mode of injecting the fuel by one time in a compression stroke of the respective cylinders and a divided injection mode of dividedly injecting the fuel in a plurality of times in one cycle of the respective cylinders in response to an engine operation state. When switching the injection mode and when largely switching the fuel injection timing in the same stroke in the same injection mode, fuel injection quantity correcting processing is performed for correcting a fuel injection quantity corresponding to the injection condition after switching so as to restrain a variation in the air-fuel ratio in a period when a wet quantity and an injection characteristic gradually change in response to switching of the injection condition. Thus, the air-fuel ratio can be prevented from temporarily varying in the lean direction and the rich direction when switching the injection condition. COPYRIGHT: (C)2007,JPO&INPIT
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