DRIVE CAM AND VALVE OPERATING SYSTEM IN ENGINE

摘要

Provided are a drive cam having an improved wear resistant sliding surface that gives the drive cam enhanced durability and a valve operating system in an engine with such a drive cam. The drive cam 13a of the present invention, made of a nitriding steel, has on its sliding surface, a hardened surface formed by nitrocarburizing wherein the hardened layer lies on top of the sliding surface. It is preferred that the driven mechanism 33 used in combination with the drive cam 13a has, in its sliding surface against which the drive cam slides, a chrome-plated layer and thereon a diamond-like carbon coating.