| 摘要 |
PURPOSE: To improve purifying efficiency by generating a main fuel injection command for generating an engine output in the vicinity of the top dead center of compression, and a post injection command for supplying hydrocarbon to a catalyst device at an expansion stroke or an exhaust stroke. CONSTITUTION: A diesel engine 40 in which a catalyst device for reducing and purifying NOx is arranged in an exhaust passage 45 is provided with a fuel injection control means 30 including an ECU 31 which receives output of a sensor 32 for detecting an exhaust gas temperature. A main fuel injection command for generating output of an engine in the vicinity of the top dead center of compression and a post injection command for supplying hydrocarbon to a catalyst device 15 at an expansion stroke or an exhaust stroke are generated, and the solenoid valve 12 of a fuel injection means is driven by each command. At this time, the post injection command is generated has times than that of the main fuel injection command, namely the post injection command is generated only to one cylinder of four cylinders. It is thus possible to improve purifying efficiency in the catalyst device 15 since fuel having round amounts is post- injected.
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