| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the degradation of a transient exhaust condition and the occurrence of noise in transition between operation regions (H) and (D) in a direct-injection diesel engine in which advanced fuel injection is made to conduct premixed compression injection combustion at an EGR rate set at least at a 1st set value or higher in a premixed combustion region (H) on a light-load side, and diesel combustion is made at an EGR rate set at a 2nd set value or less in a diffusion combustion region (D) on a heavy-load side. <P>SOLUTION: When combustion shifts from either a premixed combustion region (H) and a diffusion combustion region (D) to the other, fuel injection timing is set at predetermined timing in an expansion stroke in a cylinder 2, and the combustion shifts into a 3rd combustion state mainly formed of premixed combustion. The fuel injection timing or the like is controlled on the basis of the predicted result of the rate of recirculated exhaust emission (actual EGR rate EGR) in intake air. In the 3rd combustion state, a fuel-injection volume is increased more than in the premixed compression ignition combustion and diesel combustion to prevent a torque shock from occurring at the time of switching combustion conditions. <P>COPYRIGHT: (C)2004,JPO |
