Patent ID: 6102009
Filing Date: 2000-08-15
Classification: F02B,F02D,Y02T

Abstract:
A fuel injection method for engines comprising the steps of:storing fuel delivered by a fuel pump in a common rail;injecting the fuel from the common rail into combustion chambers through nozzle holes formed in injectors driven by an injection command signal;selecting a basic target injection timing corresponding to a present engine operating state from among predetermined basic target injection timing data as related to engine operating states;determining, by using a predetermined function having as variables at least a timing after the start of fuel injection at which the common rail pressure starts to fall, an injection delay time that elapses from an output timing of the injection command signal to a fuel injection timing at which the fuel injection from each of the injectors is started; anddetermining the output timing of the injection command signal from the basic target injection timing and the injection delay time;wherein, using a graph with time and the common rail pressure as coordinate axes, the timing at which the common rail pressure starts to fall due to fuel injection is determined as a time coordinate of an intersection between a straight line approximating a common rail pressure falling curve before reaching a first minimal value and a straight line approximating the common rail pressure before the start of fuel injection.