Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Masashi Nemoto

Satoshi Usui

Kenichiro Tokuo

Hideki Machimura

Shunsuke Aritomi

Shigehiko Omata

Moritsugu Akiyama

Akihiro Munakata

Hiroyuki Yamada

Noriyuki Maekawa

Kiyotaka Ogura

Masayuki Suganami

Tatsuo Kawano

Daisuke Kitajima

Shigenori Tahara

Hideaki Yamauchi

Takafumi Ito

Takanori Oginuma

The present invention suppresses wear of a rod or a component with which the rod is in contact. An electromagnetic suction valve mechanism (electromagnetic valve mechanism) includes a suction valve (valve body), a rod engaged with the suction valve, and a magnetic attraction force generation unit that generates a magnetic attraction force for moving the rod in an axial direction. The rod is provided with a low friction portion. The low friction portion is set to a friction coefficient such that a frictional force generated between the rod and the rod contact component with which the rod is in contact is smaller than a rotational propulsive force of the rod.

Electromagnetic valve mechanism and fuel pump

Provided is a high-pressure fuel pump that ensures oil tightness even at high fuel pressure and has a small and lightweight inexpensive discharge valve structure. Therefore, a high-pressure fuel pump according to the present invention includes: a discharge valve arranged on a discharge side of a pressurizing chamber; a discharge valve seat on which the discharge valve is seated; and a facing member configured independently as a separate member from the discharge valve seat and located on an opposite side of the discharge valve seat with the discharge valve interposed therebetween, in which a stroke direction regulating portion that regulates displacement of the discharge valve in a stroke direction is formed on a tapered surface of the facing member.

High-pressure fuel pump

There is provided a discharge valve mechanism provided at an outlet of a pressurizing chamber of a high-pressure fuel supply pump that aims to reduce a backflow amount of fuel from a discharge valve and to prevent cavitation erosion. There are provided a discharge valve disposed on a discharge side of a pressurizing chamber, a discharge valve seat that closes a discharge side flow passage of the pressurizing chamber by seating the discharge valve, and a discharge valve spring that presses the discharge valve toward the discharge valve seat. It is configured such that, in a case where a minimum seat diameter of a seat portion in which the discharge valve is seated on the discharge valve seat is set to D and a spring force of the discharge valve spring at a time of setting is set to F, a coefficient K obtained by dividing the spring force F by the minimum seat diameter D is set to be 0.2 or more.

High-pressure fuel supply pump

A high-pressure fuel supply pump which has no probability of discontinuity of a thin film of fuel at a sliding portion even when the fuel is not needed to be compressed to a high pressure is obtained. Two low-pressure fuel ports are provided on the high-pressure fuel supply pump in addition to a high-pressure discharge port to a high-pressure fuel capacity chamber. One of the two low-pressure fuel ports is connected to a low-pressure fuel capacity chamber and remaining one is connected to a low-pressure fuel supply pump. Accordingly, the interior of the high-pressure fuel supply pump is always filled with fresh fuel even in a mode in which a high-pressure fuel injecting valve does not inject fuel and only a low-pressure fuel injection valve injects fuel, so that a temperature rise of a plunger and a cylinder is prevented and locking of the plunger and the cylinder can be prevented.

A fluid pressure pulsation damper mechanism includes: a metal damper having two metal diaphragms joined together with a hermetic seal for forming a sealed spacing filled with a gas between the two metal diaphragms, an edge part overlapping along outer peripheries thereof, a main body having a damper housing in which the metal damper is accommodated, and a cover attached to the main body to cover the damper housing and isolate the damper housing from outside air.

Fluid pressure pulsation damper mechanism and high-pressure fuel pump equipped with fluid pressure pulsation damper mechanism

An object of the present invention is to reduce the pressure loss in a relief valve employed for a high-pressure liquid supply pump. Disclosed is a high-pressure liquid supply pump for pressurizing a liquid and supplying the pressurized liquid from a low-pressure side to a high-pressure side. The pump includes a relief path which releases the pressurized liquid from the high-pressure side to the low-pressure side, and a relief valve which is positioned in the relief path and equipped with an intermediate chamber, a valve seat positioned toward the high-pressure side of the intermediate chamber, a ball valve that is attachable to and detachable from the valve seat, and a ball valve retainer for pressing the ball valve against the valve seat. The relief path is configured so that an inflow path to the intermediate chamber and an outflow path from the intermediate chamber both produce a restriction effect. The ball valve retainer has a pressure reception surface for receiving the pressure from the intermediate chamber. A first pressure reception area, which detaches the ball valve from the valve seat upon receipt of liquid pressure of the pressurized liquid from a high-pressure section when the relief valve closes, is smaller than a second pressure reception area, which lifts the ball valve and the ball valve retainer upon receipt of liquid pressure from the intermediate chamber.

High-pressure liquid supply pump

Growing community of inventors

Hitachinaka, Japan

Masashi Nemoto