Patent ID: 8375905

Claim:
A variable valve train for an internal combustion engine, said valve train comprising: a camshaft rotatably supported by a cylinder head of the engine, and operable to rotate in synchronization with rotation of a crankshaft of the engine; a drive cam operable to rotate integrally with the camshaft; a valve-operating cam swingably supported by the camshaft, and operable to perform opening/closing of an engine valve; a link mechanism supported swingably around the camshaft, and operable to transmit valve drive force of the drive cam to the valve-operating cam for swinging thereof, said link mechanism comprising a support member; a holder member having the support member of the link mechanism is arranged thereon, said holder member being operable to turn around the camshaft; and a drive mechanism operable to turn the holder member for varying a position of the support member of the link mechanism; wherein the drive mechanism comprises a ball screw provided perpendicularly to the camshaft, a slider threadably engaged with the ball screw, an arm member swingably attached to the slider, said arm member having a swing portion end; and a connecting member having one end thereof secured to the swing portion end of the arm member, and the other end thereof secured to the holder member; and wherein said link mechanism is configured such that operating characteristics of the opening/closing engine valve are varied according to a swung position of the link mechanism.