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:
Jul. 26, 2022
Filed:
Nov. 03, 2017
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A nitriding layer () is formed on the front surface side of a base material of a cylinder block () including an opening side end surface (B) and each cylinder hole (). Then, a piston sliding surface (A) of each cylinder hole () is formed as a compound layer-removed hole () by removing a compound layer () that is located on the front surface side of the nitriding layer () by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface () is formed on a part (A) where a compound layer-removed hole () and a cylinder inlet side tapered surface (B) of each cylinder hole () intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface () is formed as a tapered-state inclined surface of an angle α.