Patent ID: 8406982
Filing Date: 2013-03-26
Classification: F02D,F02M

Abstract:
1. A fuel injection detecting device detecting a fuel injection condition, the fuel injection detecting device being applied to a fuel injection system in which a fuel injector injects a fuel accumulated in an accumulator, the fuel injection detecting device comprising: a fuel pressure sensor provided in a fuel passage fluidly connecting the accumulator and a fuel injection port of the fuel injector, the fuel pressure sensor detecting a fuel pressure which varies due to a fuel injection from the fuel injection port; a falling-modeling means for modeling a falling waveform of the fuel pressure by a falling-modeling function during a period in which the fuel pressure decreases due to a fuel injection rate increase; a rising-modeling means for modeling a rising waveform of the fuel pressure by a rising-modeling function during a period in which the fuel pressure increases due to a fuel injection rate decrease; an intersection timing computing means for computing an intersection timing at which a first line expressed by the falling-modeling function and a second line expressed by the rising-modeling function intersect with each other, an intersection pressure computing means for computing an intersection pressure at which a first line expressed by the falling-modeling function and a second line expressed by the rising-modeling function intersect with each other; a reference pressure computing means for computing a reference pressure based on a fuel pressure right before the falling waveform is generated; a determination means for determining whether a pressure difference between the reference pressure and the intersection pressure is smaller than or equal to a specified value; and a changing point computing means for computing