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:
Apr. 02, 2013
Filed:
Mar. 23, 2011
Kimiyasu Kono, Minami-Alpls, JP;
Keisuke Nanri, Minami-Alpls, JP;
Kimiyasu Kono, Minami-Alpls, JP;
Keisuke Nanri, Minami-Alpls, JP;
Hitachi Automotive Systems, Ltd., Ibaraki, JP;
Abstract
The bottom surface of a seal groove provided in a cylinder bore has a first slant portion and a second slant portion. A transition point between the first slant portion and the second slant portion is located closer to the opening of the cylinder bore than the center in the cylinder bore axial direction of the seal groove. A gap is formed between the outer peripheral surface of a piston seal member and the bottom surface of the seal groove, and the surface pressure applied to the bottom surface of the seal groove from the piston seal member is higher at the cylinder-bottom-side end of the piston seal member than at the cylinder-opening-side end thereof. Thus, it is possible to suppress the movement of the piston toward the cylinder bore bottom due to thermal expansion of the piston seal member.