VALVE DRIVING DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE: To improve abrasion behavior, to form an improved lubricating film and to reduce a friction coefficient by specifying the SK value of many extremely small notches optionally arranged on the sliding surface of a cam or the sliding surface of a cam follower. CONSTITUTION: In a valve drive device 1 constituted of a cam 2 arranged on a camshaft 5 and a cam follower connected to the valve of an internal combustion engine, extremely small notches are optionally arranged on the sliding surface 10 of the cam 2 and the sliding surface of the cam follower so that the SK (grade of surface roughness distribution curve) value becomes <0. The ratio of the surface having notches against the whole sliding surface is preferably set to 10-40%. The average area of the notches is preferably set to 35-130μm<2> while the notches with the area of <7μm<2> are excluded for calculation or measurement. The advantage of the surface structure on the lubrication state for rolling contact can be utilized for the contact type valve drive device 1.