FUEL SUPPLY DEVICE FOR AN INTERNAL COMBUSTION ENGINE, AND FUEL SUPPLY CONTROL METHOD

摘要

Disclosed is a fuel supply device provided with: a low-pressure fuel pump which siphons fuel from a fuel tank; a high-pressure pump which pressurizes the siphoned fuel; an accumulation chamber which accumulates the pressurized fuel; a fuel injection valve which directly injects the fuel from the accumulation chamber into a cylinder; a relief valve which limits the maximum fuel pressure in the accumulation chamber (3); a high-pressure fuel pressure sensor which measures the fuel pressure in the accumulation chamber; and a control unit. The control unit sets a target fuel injection pressure and controls the high-pressure fuel pump such that the fuel pressure in the accumulation chamber reaches said target fuel injection pressure. If the control unit detects a malfunction in the high-pressure fuel pressure sensor, the control unit substitutes the current target fuel injection pressure for the measurement value from the high-pressure fuel pressure sensor and either stops the high-pressure fuel pump or runs same with the discharge amount set to maximum. Thus, fuel can be injected with an injection pulse width appropriate to the actual fuel pressure even if the high-pressure fuel pressure sensor becomes unable to measure the fuel pressure in the accumulation chamber, such as due to an electrical disconnection.