Sumitomo Electric Industries, Limited

Nissan Motor Company Limited

Nissin Electric Co., Ltd.

Miki Irie

Yoshiharu Utsumi

Hisanori Ohara

Haruyo Fukui

Hideki Moriguchi

Makoto Setoyama

Kiyoshi Ogata

Naoto Okazaki

Satoshi Ohtani

Satoru Kukino

Yutaka Mabuchi

Akihiko Ikegaya

Keiichi Tsuda

Yoshiteru Yasuda

Masahiko Shioda

Kazuhiko Oda

Mototaka Ishihara

Disclosed is a shim or a valve lifter for an automotive engine valve driving system that slides against a cam lobe of a camshaft to drive an intake/exhaust valve of an internal combustion engine. The shim or lifter has the top of a sliding surface thereof opposing the cam lobe and being coated with a hard carbon film. The hard carbon film has a surface hardness of 1500 to 4500 kg/mmin terms of Knoop hardness, a thickness of 0.3 to 2.0 &#x3bc;m and a surface roughness Ry (&#x3bc;m) satisfying the following equation (A):&#x3c;{(0.75&#x2212;/8000)&#xd7;&#x2003;&#x2003;(A)where h is the thickness (&#x3bc;m) of the hard carbon film; and Hk is the knoop hardness (kg/mm) of the hard carbon film. By imparting durability, reliability and a low friction coefficient to the hard carbon film that is said to be low in ductility to prevent the hard carbon film from becoming cracked and separated when applied to the sliding portion.

Automotive engine valve mechanism system shim and lifter of these and cam shaft

Amorphous carbon coated tools include substrates formed from a cubic boron nitride sintered body, a diamond sintered body, a silicon nitride sintered body, or an aluminum oxide-titanium carbide sintered body, and amorphous carbon films thereon to make the cutting edges of the tools. The amorphous carbon films contain hydrogen at 5 atomic percent or below and have a maximum thickness of 0.05 &#x3bc;m to 0.5 &#x3bc;m on the cutting edges. The amorphous carbon films are most suitable for applications to cutting tools exemplified by cutters, knives, and slitters, and to indexable inserts used for example in turning tools including drills, endmills, and reamers, and milling cutters.

Amorphous carbon coated tools and method of producing the same

An amorphous carbon coated tool includes a base material of WC base cemented carbide, and an amorphous carbon film formed on this base material. The cobalt content in the base material is at least 12% by mass. The maximum thickness of the amorphous carbon film is at least 0.05 &#x3bc;m and not more than 0.5 &#x3bc;m at the cutting edge. The amorphous carbon film is deposited with graphite as the source material by physical vapor deposition in an atmosphere substantially absent of hydrogen. The amorphous carbon film coated tool superior in wear resistance and adhesion resistance is preferably applicable to rotating tools such as drills, end mills and reamers, indexable inserts used for milling cutters and turning tools, and cutting-off tools such as cutters, knives, or slitters.

Amorphous carbon coated tool and fabrication method thereof

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Itami, Japan

Miki Irie