Valve operation changing system of internal combustion engine

摘要

A valve operation changing system of an internal combustion engine comprises first and second cams formed on a camshaft. The first and second cams are different in cam profile from each other. At least one of the cams has a plurality of cam faces which are axially separate from each other. Additionally, a rocker arm is provided with a follower section contactable with the cam face of the first and second cams. The follower section has a plurality of contact faces at least one of which is contactable with the cam face of the first cam when the rocker arm is in a first position, while with the cam face of the second cam when the rocker arm is in a second position, thereby reducing the moving distance of the rocker arm to improve the response in valve timing change of an engine valve.