| 摘要 |
PROBLEM TO BE SOLVED: To prevent an injection operation from becoming unstable due to a shortage of capacitor voltage in a drive circuit for driving a fuel injection nozzle of each cylinder during the catalyst early warming control (during post- injection) of a direct injection engine. SOLUTION: During the catalyst early warming control of the direct injection engine, a post-injection is performed in an expansion stroke after a main injection is performed for generating an engine output in a compression stroke by switching an operation mode to a stratified combustion mode. By an injection interval between the post-injection of a former cylinder and the main injection of a latter cylinder, it is judged whether or not the distance is shorter than a capacitor charging time required to drive a fuel injection nozzle. If the injection interval is judged to be shorter than the capacitor charging time, a main injection timing in the compression stroke is corrected to assure the charging time of the capacitor. Thus, the injection interval can be prevented from becoming shorter than the capacitor charging time while a post-injection timing is set to a proper timing capable of providing a sufficient exhaust temperature rising effect.
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