Patent ID: 7025050
Filing Date: 2006-04-11
Classification: F02D,F02M

Abstract:
1. A fuel pressure control device for an internal combustion engine, comprising: a fuel injection valve for injecting a fuel directly into a combustion chamber of the internal combustion engine; a pressure accumulation chamber connected to the fuel injection valve for storing a high pressure fuel; a high pressure pump for pressurizing a low pressure fuel supplied from a fuel tank in a pressure chamber, and supplying the high pressure fuel to the pressure accumulation chamber; a fuel pressure control valve for controlling at least one of an amount of the fuel discharged from the high pressure pump to the pressure accumulation chamber and a fuel pressure in the pressure accumulation chamber; a fuel pressure sensor for detecting the fuel pressure in the pressure accumulation chamber; an air-fuel ratio sensor for detecting an air-fuel ratio condition in the internal combustion engine; target value calculation means for calculating a target fuel pressure and a target air-fuel ratio based on an operating condition of the internal combustion engine; fuel pressure control means for performing feedback control of the fuel pressure control valve such that the fuel pressure detected by the fuel pressure sensor matches the target fuel pressure; abnormality diagnosis means for diagnosing whether the fuel pressure sensor is in an abnormal condition or not; and fuel pressure estimation means for calculating an estimated pressure in the pressure accumulation chamber based on the air-fuel ratio condition when the abnormality diagnosis means diagnoses that the fuel pressure sensor is in the abnormal condition, wherein the fuel pressure estimation means corrects the estimated fuel pressure such that the air-fuel ratio condition is guided to the target air-fuel ratio.