Piston ring and method for manufacturing same
US10458548B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 10, 2015 |
| Grant date | Oct 29, 2019 |
| Priority date | — |
| Expiry date | Dec 5, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C28/048
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Provided is a piston ring having excellent low-friction properties and abrasion resistance manufactured without the need for precision control using an ordinary film formation device that does not have a special function. A piston ring obtained by coating an amorphous carbon film on the surface of a ring-shaped substrate, the piston ring being configured so that the amorphous carbon film is formed by CVD, an increase region, in which the ratio sp2/sp3 of the sp2 bond to the sp3 bond continuously increases from the substrate surface toward the film surface, and a decrease region, in which the ratio sp2/sp3 continuously decreases, are formed in alternating fashion, a soft film in which the ratio sp2/sp3 is low and a hard film in which the ratio sp2/sp3 is high are formed so as to be layered in alternating fashion by continuous variation of the ratio sp2/sp3 in the boundary between the increase region and the decrease region, and the decrease regions are formed in equal number to or with one region less than the number of increase regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.