Fuel injection method and device providing simple atmospheric pressure

Abstract

An internal combustion engine has an intake system, a fuel injector for injecting fuel into the intake system, a means for supplying pressurized fuel to the fuel injector, and a means for controlling the pressure difference between the pressurized fuel and the current value of atmospheric pressure to be substantially equal to a determinate value. In this fuel injection method, an actual fuel injection time interval is calculated by determining a basic fuel injection time interval according to engine operational parameters, and subsequently: if the current value of atmospheric pressure is higher than a certain standard value, then a reduction correction amount is applied to the basic fuel injection time interval, to derive the actual fuel injection time interval, but otherwise an increase correction amount is applied. Then the fuel injector is controlled to be open for substantially the actual fuel injection time interval. A device is also disclosed for practicing this method. Optionally, in both the above cases, the absolute value of the correction amount may diminish as the absolute value of the intake system pressure diminishes; and, further, the correction may be performed by multiplying the basic fuel injection time interval by a correction coefficient determined by adding, to the product of a first and a second correction value, a third correction value, the first correction value being a function only to intake system pressure, and the second and third correction values being functions only of ambient atmospheric pressure.