Patent ID: 9181944
Filing Date: 2015-11-10
Classification: F04B,F04C,F16K

Abstract:
1. A high-pressure pump comprising: a plunger configured to perform a reciprocating movement; a cylinder having a plunger accommodating hole for slidably accommodating the plunger, a pressurization chamber defined by an inner wall of the cylinder and an outer end wall of the plunger, a suction port configured to suction a fluid to the pressurization chamber, and a discharge port configured to discharge a fluid pressurized in the pressurization chamber; a housing having a first inner wall surface that forms a first discharge passage that communicates with the discharge port, a second inner wall surface that forms a second discharge passage that communicates with the first discharge passage and being larger in inside diameter than the first inner wall surface, and a stepped surface formed between the first inner wall surface and the second inner wall surface; a cylindrical member provided inside of the second inner wall surface; a valve body having a cylindrical portion accommodated inside of the cylindrical member, a flange portion extended from an end of the cylindrical portion in an outward radial direction and sandwiched between one end of the cylindrical member and the stepped surface, a valve-seat-forming portion closing the end of the cylindrical portion opposite to the pressurization chamber, a discharge valve seat formed on the wall surface of the valve-seat-forming portion opposite to the cylindrical portion, and a discharge valve passage that connects the discharge valve seat and the wall surface of the valve-seat-forming portion; a discharge valve member that is unseated from the discharge valve seat or seated on the discharge valve seat to open or close the discharge valve passage; and a discharge valve biasing portion that biases the discharge valve member in a direction in which the discharge valve member is seated on the discharge valve seat.