The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 2025
Filed:
Feb. 02, 2022
Hitachi Astemo, Ltd., Hitachinaka, JP;
Moritsugu Akiyama, Hitachinaka, JP;
Shigehiko Omata, Hitachinaka, JP;
Atsushi Takaoku, Hitachinaka, JP;
Satoshi Usui, Hitachinaka, JP;
Minoru Hashida, Hitachinaka, JP;
Hitachi Astemo, Ltd., Hitachinaka, JP;
Abstract
The present invention provides a fuel pump capable of preventing the occurrence of cavitation near a seat member in a valve mechanism. The fuel pump includes a plunger adapted to reciprocate, a pressurizing chamber adapted to increase and decrease its volumetric capacity through the reciprocation of the plunger, and a relief valve mechanism adapted to return a fuel to the pressurizing chamber. The relief valve mechanism includes a relief valve, and a seat member having a valve contact portion for seating the relief valve thereon. The relief valve is disposed closer to the plunger than the seat member. The seat member has an annular groove portion which forms a space communicating with the pressurizing chamber, between the annular groove portion and a second chamber (a fixing portion) surrounding the outer peripheral surface of the seat member. The space is provided at a position farther from the plunger than the valve contact portion.