Patent ID: 9285032
Filing Date: 2016-03-15
CPC Classification: F02F,F16J

Claim Text:
1. A piston ring having a resin-based coating formed on at least one of an upper surface and a lower surface of a piston ring body, wherein the resin-based coating comprises a first resin-based coating containing a plate-like filler having a mean particle diameter of 2 μm to 20 μm and an aspect ratio of 20 to 200, and a second resin-based coating located closer to the piston ring body than the first resin-based coating and containing hard particles having a mean particle diameter of 0.01 μm to 1 μm, a surface immediately under the second resin-based coating has a plateau structure having plateau portions and valley portions, a mean width of the valley portions is approximately the same as the mean particle diameter of the hard particles in the second resin-based coating, and some of the hard particles are inserted in the valley portions of the plateau structure and protrude from the surface of the plateau portions.