HIGH PRESSURE PUMP

摘要

A valve seat member, which partitions between a supply passage and a pressurizing chamber, includes an inner flow path, which communicates between the supply passage and the pressurizing chamber, and an outer flow path, which is placed on a radially outer side of the inner flow path. An inner valve is seatable against an inner valve seat formed in an opening of the inner flow path. An outer valve is contactable with an end surface of the inner valve, which is opposite from the inner valve seat. The outer valve is seatable against an outer valve seat, which is formed in an opening of the outer flow path.

主权项

1. A high pressure pump comprising:
a plunger that is reciprocatable; a pump body that includes:
a pressurizing chamber, in which fuel is pressurized through reciprocation of the plunger; anda supply passage, which supplies the fuel to the pressurizing chamber; a valve seat member that partitions between the supply passage and the pressurizing chamber, wherein the valve seat member includes:
an inner flow path, which communicates between the supply passage and the pressurizing chamber; andan outer flow path, which is placed on a radially outer side of the inner flow path and communicates between the supply passage and the pressurizing chamber; a valve member that has a cylindrical outer peripheral surface and is seatable and liftable relative to the valve seat member, wherein:
in one operational state where the valve member is seated against the valve seat member, communication between the supply passage and the pressurizing chamber through the inner flow path and the outer flow path of the valve seat member is disabled; andin another operational state where the valve member is lifted away from the valve seat member, the communication between the supply passage and the pressurizing chamber through the inner flow path and the outer flow path of the valve seat member is enabled; a stopper member that is formed separately from the valve seat member and is placed on a side of the valve seat member, at which the pressurizing chamber is placed, and the valve member is placed between the valve seat member and the stopper member, wherein:
the stopper member includes a stopper, which limits a lift amount of the valve member at a time of lifting the valve member away from the valve seat member;the cylindrical outer peripheral surface of the valve member is slidably guided by a plurality of guide surfaces of the stopper member when the valve member is reciprocated between the valve seat member and the stopper of the stopper member, and each of the plurality of guide surfaces is formed as an inner peripheral surface of a corresponding one of a plurality of radial projections, which radially inwardly project from a peripheral wall of the stopper member; andthe valve member defines an outer flow path, which is located between the valve member and the stopper member in a radial direction of the valve member, and an inner flow path, which is located on a radially inner side of the outer flow path defined by the valve member; and a rod that is received through the inner flow path of the valve seat member and controls movement of the valve member.