Patent ID: 8442745
Filing Date: 2013-05-14
Classification: F02D

Abstract:
1. A fuel supply apparatus for an internal combustion engine, having a fuel injection valve that performs fuel injection into the internal combustion engine, a delivery passage that delivers fuel to the fuel injection valve, a fuel tank that stores the fuel, and a fuel pump that regulates the fuel from the fuel tank to a desired pressure and pumps the fuel to the delivery passage, comprising: a check valve that is disposed in a position that allows the fuel to flow out of the delivery passage into the fuel tank, that opens when a fuel pressure on the delivery passage side with respect to the check valve is higher than a fuel pressure on the fuel tank side with respect to the check valve by at least a set pressure set at a fuel pressure permitted to act on the fuel injection valve when the fuel injection by the fuel injection valve is stopped, and that while open allows the fuel to flow in an amount that enables the fuel pumped into the delivery passage by the fuel pump to be regulated to the desired pressure; a fuel pressure sensor that is attached to the delivery passage to detect the fuel pressure in the delivery passage; and a control unit that, when the fuel pressure detected by the fuel pressure sensor is lower than a diagnosis lower limit pressure being higher than the set pressure in a case where the fuel injection by the fuel injection valve is to be stopped in a state where an execution condition for an abnormality diagnosis on the check valve, in which the presence of an abnormality in the check valve is diagnosed by confirming a reduction in the fuel pressure detected by the fuel pressure sensor, is established, controls the fuel pump so that the fuel pressure in the delivery passage rises to or above the diagnosis lower limit pressure, and executes the abnormality diagnosis on the check valve after the fuel pressure detected by the fuel pressure sensor has reached or exceeded the diagnosis lower limit pressure.