Zexel Gmbh

Hitoshi Okuyama

Yuji Furuya

Kenichi Iino

Hideya Kikuchi

Etsuro Hozumi

Akinao Minegishi

Akinori Yamazaki

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

A guide hole extending axially, a valve seat and an injection port are coaxially formed on an elongated valve body in this order toward a distal end of the valve body. A pressurized fuel is introduced into a basal end of the guide hole. A valve element is slidably received in the guide hole of the valve body. Inclined passages are formed in one of the valve element and the valve body. When the valve element is lifted, the pressurized fuel flows, as a swirling current, between a valve portion and the valve seat, proceeds toward an exit of the injection port while swirling along an inner peripheral surface of the injection port, and is injected from the injection port. When the valve element is in the fully lifted position, an orifice for restricting an amount of fuel injected from the injection port per unit time is formed between the valve portion and the valve seat.

Swirl type fuel injection valve

A valve seat member is fixedly received in a lower end portion of an elongated body. The valve seat member has a valve seat and an injection port at its lower end portion. A valve element is axially movably received in the body. The valve element is fully lifted from a position where a valve portion formed on the lower end of the valve element sits on the valve seat to a position where an upper end portion of the valve element is brought into abutment with a stopper of the body. This fully lifted amount is determined by the thickness of a shim interposed between a first receiving surface of the body and a second receiving surface of the valve seat member. The lower end portion of the body and the valve seat member are welded over the entire periphery.

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Saitama-ken, Japan

Hitoshi Okuyama