| 摘要 |
A fuel injection method wherein optimum fuel injection timing for a fuel-injection type gas fuel engine (10) is determined by setting fuel injection end timing to be after the start of opening of an intake valve (10a) of the engine (10). That is, when injection ends in a first half of an open period of the intake valve (10a), the volumetric efficiency eta v falls and the engine output also falls, because the injection period overlaps with a period of positive pressure arising inside an intake pipe before opening of the intake valve (10a), but when injection ends in a second half of an open period of the intake valve (10a), the volumetric efficiency eta v rises and the engine efficiency also rises, because the injection period overlaps with a period of negative pressure arising in the intake pipe during the first half of the intake valve open period. As a result, when fuel is injected during the trough in an intake port pressure, the volumetric efficiency increases and the engine output also increases by several percent. <IMAGE> |
