Hitachi, Ltd.

Hitachi Car Engineering Co., Ltd.

Hitachi Automotive Systems, Ltd.

Toru Onose

Hiroyuki Yamada

Satoshi Usui

Masami Abe

Atsuji Saito

Hiroshi Odakura

Kenichiro Tokuo

Minoru Hashida

Masayoshi Kotaki

Masayuki Suganami

Junichi Shimada

Sunao Takahashi

Hideaki Yamauchi

Kazuichi Ishige

Tohru Himoto

Masami Hitachi Car Eng Co Ltd Abe

A high-pressure fuel pump includes a pressurizing chamber for pressurizing fuel, an outlet valve for discharging the fuel pressurized in the pressurizing chamber to an outlet passage, a relief passage for connecting the outlet passage located downstream of the outlet valve and the pressurizing chamber with each other while bypassing the outlet valve. A relief valve device is provided in the relief passage and adapted to open when an internal pressure of the outlet passage becomes higher than that of the pressurizing chamber, thereby providing communication between the outlet passage and the pressurizing chamber. The relief valve includes a relief spring mechanism for pressing a relief valve to a relief valve seat. At least the relief spring mechanism among members of the relief valve device is provided outside the pressurizing chamber in the pump body.

High-pressure fuel pump

A high-pressure fuel pump includes a pump body, a plunger, a retainer, a spring that is configured to energize the plunger in a direction opposite to a direction of the pressurizing chamber, and a tappet covering the retainer from a side of an end portion of the retainer and the plunger. The retainer is provided with a projection portion protruding to a side of the tappet. The projection portion is separated from the tappet by a predetermined distance along an axial direction of the plunger.

A high-pressure fuel pump is comprises of: a plunger which slidably fits to a cylinder and reciprocates for pressurizing and discharging a fuel taken in a pressurizing chamber; an inlet valve device for taking in a fuel into the pressurizing chamber; an outlet valve device for discharging the pressurized fuel from the pressurizing chamber; and a communicating pass which comprises a hole or a groove formed in the cylinder, and communicates between a pressurized fuel area and a gap between the cylinder and the plunger.

A high pressure fuel pump for an internal combustion engine having a cylinder, a plunger slidably fitted in the cylinder and a seal mechanism for blocking fuel leakage from an end of a sliding portion between the cylinder and the plunger and also for preventing an lubricant for a driving mechanism of the plunger from entering into the cylinder from the end of the sliding portion of the cylinder and the plunger. A holder surrounding the end of the sliding portion of the cylinder and the plunger is provided. The seal mechanism comprises two mutually independent seal devices mounted with a specific spacing in a longitudinal direction from the end of the sliding portion of the cylinder and the plunger along a circumference of the plunger. The two seal devices are held on the circumference of the plunger by the holder surrounding the end of the sliding portion of the cylinder and the plunger while keeping the specific spacing.

High pressure fuel pump for internal combustion engine

A fuel feed system capable of feeding a fuel to fuel injection valves at a fuel pressure with improved stability is provided. A fuel feed system for an internal combustion engine including a fuel tank and a low-pressure pump for feeding the fuel in the fuel tank to fuel injection valves, is provided with a diaphragm type damper having a wave-shape cross section at a position in contact with the fuel. Also, in a high-pressure fuel feed pump including a pressurizing chamber for pressurizing the fuel, a plunger for pumping the fuel within the pressurizing chamber, an intake valve provided at a fuel inlet of the pressurizing chamber, a discharge valve provided at a fuel outlet of the pressurizing chamber, and a low-pressure chamber provided in an upstream of the intake valve, a mechanism for reducing fuel pressure pulsation is disposed in a space of the low-pressure chamber provided in the upstream of the intake valve, and a fuel pressure sensor for measuring the fuel pressure is mounted near the mechanism for reducing fuel pressure pulsation.

High pressure fuel pump provided with damper

Fuel feed system

A simple structured high-pressure fuel pump. A fuel pump comprises a reciprocably-supported cylinder, a pressurizing chamber using part of the outer surface of the cylinder as the wall surface which move to change the internal volume, a fuel intake passage forming a fuel passage which introduces fuel to the pressurizing chamber, a fuel discharge passage for the compressed fuel coming out from the pressurizing chamber. A fuel intake valve is provided in fuel intake passage. A fuel discharge valve is provided in said fuel discharge passage. A connecting passage connects upstream side of the intake valve in the fuel intake passage and the downstream side of it. A check valve which flows fuel from the fuel discharge flow passage to the fuel intake passage is provided in the connecting passage.

Growing community of inventors

Ibaraki, Japan

Toru Onose