Valve system for internal combustion engine

A valve system for an internal combustion engine, comprising a valve characteristic varying mechanism which comprises a valve cam pivotally supported on a camshaft so as to open and close an engine valve composed of an intake valve or an exhaust valve, a holder pivotally supported on said camshaft, a control mechanism driven by a drive mechanism so as to swing said holder about said camshaft, and a rocker arm pivotally supported on said holder and swung by a drive cam rotated integrally with said camshaft, so as to swing said valve cam about said camshaft, said valve characteristic varying mechanism controlling the valve operation characteristics of said engine valve according to the swing position of said holder, wherein

• said control mechanism and said holder are connected so as to be capable of relative motions through a control mechanism side connection portion and a holder side connection portion, and said valve characteristic varying mechanism comprises a pressing energizing means for normally pressing said holder side connection portion against said control mechanism side connection portion in the swinging direction.