FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To provide a fuel injector for an internal combustion engine which can achieve the improved responsiveness to the target fuel pressure as well as the improved control performance even when the fuel pressure is greatly decreased. SOLUTION: The fuel injector for an internal combustion engine comprises: a high pressure pump 103 for pressure-feeding high pressure fuel of the internal combustion engine; a fuel rail 105 for accumulating the fuel pressure-fed by the high pressure pump; an injection valve 106 for injecting, into a cylinder, the fuel accumulated in the fuel rail; a fuel pressure sensor 104 for detecting the pressure of the fuel that is accumulated in the fuel rail; an solenoid relief valve 107 for discharging the accumulated fuel of the fuel rail; and an ECU 110 for controlling opening and closing of the solenoid relief valve 107. The ECU 110 repeats the opening and closing of the relief valve to release the fuel pressure in stages so that the fuel pressure in the fuel rail is decreased down to the target fuel pressure. COPYRIGHT: (C)2009,JPO&INPIT