Patent ID: 9127613
Filing Date: 2015-09-08
Classification: F02D,Y02T

Abstract:
1. A fuel pressure waveform acquisition device applied to a fuel injection system that has a fuel injector that injects fuel for combustion in an internal-combustion engine from an injection hole, and a fuel pressure sensor that detects a change of a fuel pressure in a fuel path to the injection hole that changes resulting from the injection of the fuel from the injection hole, comprising: a detected waveform acquisition device that acquires a pressure waveform detected by the fuel pressure sensor while performing a multi-stage injection that injects the fuel a plurality of times per one combustion cycle of the internal-combustion engine as a detected waveform at the time of the multi-stage injection; a model waveform memorizer where a model waveform, which is used as a standard of the pressure waveform when an injection that is preceding a target injection is performed without performing the target injection, is memorized when any one of an injection of a second stage or later is considered as the target injection among multi-stage injections; a waveform extractor that extracts the pressure waveform resulting from the target injection by deducting the model waveform from the detected waveform at the multi-stage injection; a corrector that corrects the model waveform used for an extraction by a ratio according to a maximum injection rate in the injection of the preceding stage; and the larger maximum injection rate in the injection of the preceding stage, the more the corrector enlarges the ratio.