Denso Corporation

Nippon Soken, Inc.

Tatsuro Koga

Noriya Matsumoto

Masatoshi Kuroyanagi

Shinobu Oikawa

Osamu Hishinuma

Seiji Tanizawa

In a high-pressure pump, a relief valve seating surrounds an opening of a relief valve passage of a valve seat main body in a first space, A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

High-pressure pump

In a high-pressure pump, a relief valve seat surrounds an opening of a relief valve passage of a valve seat main body in a first space. A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve member is provided in the first space so as to be reciprocable in an axial direction. A relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

In a high-pressure pump, a relief valve main body has a rod shape. A relief valve seat portion is integrated with an end of a relief valve main body so as to be capable of contacting a relief valve seat. The relief valve main body is inserted into a guide hole portion of a support portion. The guide hole portion slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve main body in the axial direction. A fuel guide portion is provided at an end portion of the relief valve main body facing the pressurizing chamber and can guide a flow of the fuel in a direction radially outward of the relief valve main body on the way from the pressurizing chamber toward the valve seat portion.

A valve body is provided with a discharge relief portion. A relief valve outlet is formed in an end face thereof on a central axis of the valve body. Discharge valve inlets are point-symmetrically formed with respect to the central axis. A discharge valve outlet is formed in another end face thereof and relief valve inlets are point-symmetrically formed with respect to the central axis. A discharge valve outlet and the discharge valve inlets communicate with each other. A flow of fuel from a pressurization chamber to a fuel discharge port is restricted by a discharge valve member capable of closing the discharge valve outlet. The relief valve outlet and the relief valve inlets communicate with each other. A flow of fuel from the fuel discharge port to the pressurization chamber is restricted by a relief valve member capable of closing the relief valve outlet.

High pressure pump having unitary discharge and relief valve

At least one choked flow passage communicates between one side of the movable member and the other side of the movable member and limits an amount of fuel, which passes from the one side of the movable member to the other side of the movable member, when the movable member is moved by an urging force of a relief spring toward a valve element. A larger amount of fuel, which is larger than the amount of fuel that is passable through the at least one choked flow passage, flows from a first return flow passage to a second return flow passage, when the movable member is moved toward the other side, which is opposite from the valve element, against the urging force of the relief spring.

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Kariya, Japan

Tatsuro Koga