HIGH PRESSURE FUEL SUPPLY PUMP

PROBLEM TO BE SOLVED: To provide a relief valve structure which stably exerts high fuel release properties, and a high pressure fuel supply pump mounting the same, with a small and low-cost configuration.SOLUTION: In a body of a high pressure fuel supply pump, a suction passage, a pressurizing chamber, and a discharge passage are formed sequentially from an upstream side, a solenoid-valve for determining a fuel amount is arranged in the suction passage, a discharge valve for limiting a circulation direction of the fuel is arranged in the discharge passage, and a relief valve is provided in a relief passage formed between the upstream and the downstream of the discharge valve. In the relief valve, a seat part is formed for sealing the fuel by a valve body and a valve seat part provided in the relief passage coming into contact, and other than the seat part, a fluid passage is provided for including a part of the valve body and for forming a fluid throttle. The relief valve also includes a cylindrical wall part formed in the relief passage, and a guide part for sliding in the wall part and formed integrally with the valve body, and eccentricity of the valve body in a radial direction is suppressed by the guide part.SELECTED DRAWING: Figure 1 【課題】安定して高い燃料開放特性を発揮するリリーフ弁構造と、それを搭載した高圧燃料供給ポンプを、小型かつ安価な構造により提供する。【解決手段】ボディ内に、上流側から吸入通路、加圧室、吐出通路が順次形成されて吸入通路には燃料量を決定する電磁弁、吐出通路には燃料の流通方向を制限する吐出弁が配置され、吐出弁の上流と下流間に形成されたリリーフ通路にリリーフ弁が設けられ、リリーフ弁は、リリーフ通路内に備えられた弁体と弁座部が接触することで燃料をシールするシート部が形成され、かつシート部の他に弁体の一部を含み流体絞りを形成する流体通路が設けられている高圧燃料供給ポンプであって、リリーフ弁は、さらにリリーフ通路内に形成された筒状の壁部と、壁部内を摺動し弁体と一体に形成されたガイド部を備え、ガイド部により弁体の径方向への偏芯を抑制する。【選択図】図１