Zexel Gmbh

Bosch Automotive Systems Corporation

Akinori Yamazaki

Hideya Kikuchi

Etsuro Hozumi

Takeo Kushida

Akinao Minegishi

Hitoshi Okuyama

Kazumasa Kasahara

The present invention provides a pressure relief valve, which achieves a reliable sealed structure in a valve holder without the valve holder jutting far out from a common rail, assures stability of operation of a valve spring in a valve holder and is capable of being manufactured at low cost and can be made compact. A first invention relates to a pressure relief valve, which focuses on making the low-pressure portion side end portion of a valve holder a closed structure, and which has a valve spring that is housed inside the valve holder spring seats on which a valve spring is seated; a valve seat that is mounted to the valve holder and a valve body which is lifted from the valve seat by fluid pressure, this pressure relief valve being characterized in that there is formed a closed end portion which makes the low-pressure portion side end portion B of the valve holder a closed state, and, in addition, is constituted so as to enable a valve spring to be seated between the inner wall surface of closed end portion and a spring seat A second invention focuses on making the spring seats of valve spring a cup shape, and is characterized in that spring seats are housed in a slidable condition inside a valve holder as cup-shaped spring seats

Pressure relief valve

The plunger pump according to the present invention discharges fuel by reciprocation of a plunger, and comprises metallic diaphragm type dampers, provided at a fuel inlet side and a fuel outlet side, respectively, for reducing pressure pulsation of fuel. Each metallic diaphragm type damper comprises a pressure chamber for receiving fuel pressure, a back pressure chamber into which gas is charged, and a metallic diaphragm for defining the pressure chamber and the back pressure chamber. Since the metallic diaphragm type dampers are provided at the fuel inlet side and the fuel outlet side, respectively, noise and vibration caused by pressure pulsation are reduced at the fuel inlet side and the fuel outlet side. Also, since the diaphragms are metallic diaphragms, deterioration thereof generated by fuel liquid and back pressure gas is low, reliability is high, and the lifetime is long.

Plunger pump

Growing community of inventors

Saitama Prefecture, Japan

Akinori Yamazaki