Kabushiki Kaisha Riken

Nissan Motor Company Limited

Nippon Itf, Inc

Takashi Matsui

Masaki Moronuki

Yutaka Mabuchi

Takahiro Hamada

Tomoyuki Koike

Yoshiharu Utsumi

Hisanori Ohara

Katsuhiro Tsuji

Hiroyuki Izumi

An amorphous hard carbon film comprising a first amorphous carbon layer substantially consists only of carbon formed on a substrate surface and a second amorphous carbon layer substantially consists only of carbon formed on the surface of the first amorphous carbon layer, wherein the transmission electron microscope image of the first amorphous carbon layer is brighter than that of the second amorphous carbon layer when the cross section is observed.

Hard amorphous carbon film

A valve lifter, in which an amorphous hard carbon film is coated at least on the surface that slides against a cam, is characterized in that the surface of a base material (substrate) has an arithmetic mean roughness of Ra 0.01 to 0.03 micrometers, and the maximum length of the scratch on the base surface is made to be equal to or shorter than 250 micrometers.

Valve lifter

Growing community of inventors

Kumagaya, Japan

Takashi Matsui