The high-pressure fuel pump

PROBLEM TO BE SOLVED: To provide a high-pressure fuel pump with extremely simple structure which suppresses the deterioration of the volumetric efficiency of the pump when operated while releasing fuel in an accumulator to a compression chamber to maintain fuel pressure in the accumulator at a prescribed level when the high-pressure pump is stopped. SOLUTION: The high-pressure fuel pump 3 includes: a compression chamber 18; a discharge passage 83 communicating with a delivery pipe 4; a discharge valve 20 provided midway through the discharge passage 83; a return passage 85 making the delivery pipe 4 side of the discharge valve 20 communicate with the compression chamber 18 side thereof; and a relief valve 30 provided midway through the return passage 85.The relief valve 30 has a fuel channel 41 for circulating fuel flowing in the return passage 85. The fuel channel 41 has a valve seat 44 and a valve needle 47 housed therein. The valve needle 47 is slidably supported by the fuel channel 41, and a sliding gap S1 is formed between the sliding portion 50 of the valve needle 47 and the inner wall 46 of the fuel channel 41 to limit the flowing amount of the fuel. COPYRIGHT: (C)2009,JPO&INPIT