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:
Oct. 02, 2018
Filed:
Jan. 30, 2015
Nippon Piston Ring Co., Ltd, Saitama-shi, Saitama, JP;
Takuya Ozaki, Ichinoseki, JP;
Hiroyuki Sugiura, Ichinoseki, JP;
NIPPON PISTON RING CO., LTD, Saitama-shi, Saitama, JP;
Abstract
A piston ring having a hard carbon film formed on at least an external peripheral sliding surface of a piston ring base material, the hard carbon film having an spcomponent ratio within a range of 40% to 80% inclusive as measured by a TEM-EELS spectrum which combines electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), a hydrogen content being in a range of 0.1 at. % to 5 at. % inclusive, and an amount of macroparticles appearing on the surface being within a range of 0.1% to 10% inclusive by area ratio. The hard carbon film is formed on a hard carbon foundation film formed under low-speed film-forming conditions on the side of the piston ring base material, and the hard carbon foundation film is formed with an arc current value 80% or less of the arc current value during the formation of the hard carbon film.