| 摘要 |
The common-rail type fuel injection method of this invention injects a small amount of fuel during the deceleration of engine to swiftly accomplish reductions in the common rail pressure and the engine revolution speed, thus reducing the amount of NOx at the end of the deceleration. The basic fuel injection amount Qb is determined from the accelerator control input Acc and the engine revolution speed Ne (step S10). When the actual pressure Pf of the common rail is higher than the target pressure Pf0 by more than a predetermined value alpha (step S11) and also the basic fuel injection amount Qb is smaller than the second fuel injection amount, which is equal to a smaller-than-one factor k times the first fuel injection amount Qpd that stabilizes the engine revolution speed during no-load operation (step S12), then the final fuel injection amount Qfin is set to the second fuel injection amount (step S13) to lower the common rail pressure in order to avoid fuel injection at high pressure when the accelerator is depressed again. <IMAGE> |
