Kabushiki Kaisha Riken

Other

Toshikatsu Hayashi

Kouhei Sugimoto

Hayato Sasaki

Yoshinari Watanabe

Akira Kunimoto

Takashi Ono

Yunzhi Gao

Hiroshi Kawamoto

Shigeo Inoue

Ryou Obara

Jun Satou

Yasushi Sakai

Kazuo Shimada

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.

A fuel cell separator having excellent corrosion resistance, electric conductivity and durability comprising a substrate made of austenitic stainless steel, and a nitride layer formed on a surface of the substrate in contact with an oxygen electrode or a current collector on the oxygen electrode side, the nitride layer comprising a solid solution compound phase composed of an FeN crystal, in which part of Fe is substituted by at least Cr and Ni.

Separator for fuel cell with austenitic stainless steel substrate

The present invention provides a flame-retardant electromagnetic wave absorber that exhibits excellent formability and electromagnetic wave-absorbing properties, and can be easily assembled and constructed. The electromagnetic wave absorber comprises a wave-absorbing body and a base plate supporting the bottom thereof, wherein the wave-absorbing body is formed in a pyramid shape by fitting polygonal wave-absorbing plates into each other.

Electromagnetic wave absorber

A radio wave absorber unit includes two or more molded bodies in a pyramid or wedge shape whose radius at the tip end is from 0.5 mm to 7.5 mm and a base. A radius at the trough between adjacent molded bodies is 7.5 mm or less. A unit including molded bodies and the base is integrally formed from propylene-based conductive expanded beads. The bases of adjacent units are connected by fitting their recessed and raised portions to each other. The expanded bead size is in the range from 2 mm to 10 mm, and beads with two or more different bead diameters can be used. A hollow molded body can be formed by providing a hollow structure inside.

Radio wave absorber

A composite electromagnetic wave absorber capable of restricting the height of a pyramidal electromagnetic wave absorber and being applied to a compact anechoic chamber, wherein an upper absorber ( ) is fabricated by dispersing ferrite powder in a general-purpose resin having a permittivity of not higher than 4.9.

Composite electromagnetic wave absorber and method of fitting the same

A wave absorber is provided which has a wave absorption characteristic of 20 dB in a frequency band of 1 GHz to 20 GHz, is nonflammable, compact and lightweight, and has excellent durability. A porous ferrite is produced as the base material for which is an Ni--Zn type ferrite which has an excellent wave absorption characteristic in the high frequency range, and this serves as a wave absorber formed in the shape of a pyramid or triangular prism.

Growing community of inventors

Kashiwazaki, Japan

Toshikatsu Hayashi