Kabushiki Kaisha Riken

Kouhei Sugimoto

Toshikatsu Hayashi

Hayato Sasaki

Yoshinari Watanabe

Takashi Ono

Ryou Obara

Provided is a piston ring capable of maintaining an excellent effect of preventing aluminum cohesion in a high output engine over a long period of time. At least one of the upper, lower, and side faces of the piston ring is coated with a silica-based coating in which hard nanoparticles are dispersed. The coating has a Martens hardness of 1,000 to 8,000 N/mm. As the hard nanoparticles, carbon nanoparticles, nanodiamond particles, carbon nanotubes, or carbon nanofibers are used. To the coating, resin particles of a fluorine-based resin or a polyether-based resin may be added.

Piston ring

A piston ring having a resin-based film covering at least one of the upper and lower sides, wherein the resin-based film contains a fibrous filler with a mean fiber diameter of 50 to 500 nm and an aspect ratio of 30 to 500, wherein the fibrous filler in the resin-based film to align roughly parallel to the film surface.

Disclosed is a piston ring that, in an engine where high temperature is reached in the vicinity of the piston ring, is capable of sustaining an excellent effect of preventing aluminum cohesion over a prolonged period of time. The 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, the resin-based coating including a first resin-based coating containing plate-like filler having a mean particle diameter of 2 &#x3bc;m to 20 &#x3bc;m and an aspect ratio of 20 to 200 and a second resin-based coating located under the first resin-based coating and containing hard particles having a mean particle diameter of 0.01 &#x3bc;m to 1 &#x3bc;m.

Growing community of inventors

Kashiwazaki, Japan

Kouhei Sugimoto