| 摘要 |
In a dual-fuel injection operation involving direct injection and port injection in an engine (1), when a fuel injection time (TAUD) by a direct injector (7) as determined on the basis of a direct fuel pressure is less than a minimum value (TAUDmin), the dual-injection is performed as follows. The dual-injection is performed with a duel injection rate such that the amount of fuel injected by the direct injector (7) is greater than when the dual-injection is performed with a duel injection rate (K) which is determined in accordance with an engine operation state. Thus, the amount of fuel injected by the direct injector (7) is increased, so that the high-temperature fuel that has remained in a high-pressure fuel pipe (33) connected to the injector (7) is rapidly injected and consumed. As a result, the direct fuel pressure can be rapidly lowered, whereby the fuel injection time (TAUD) by the direct injector (7) for implementing an amount of fuel injection in accordance with a direct injection command value (QD) can be rapidly increased to the minimum value (TAUDmin). |
