Patent ID: 6067947
Filing Date: 2000-05-30
Classification: F01L,F02B

Abstract:
A valve driving apparatus for an engine comprising:a camshaft rotatably supported by the engine;a combustion chamber having a pair of ports;a pair of valves associated with the ports, respectively, for selectively opening and closing the respective ports, wherein the valves each have a longitudinal axis, a head end, and an outer end, which is opposite to the head end;a cam provided on the camshaft for operating the valves, wherein the cam lifts the valves along their axes in response to rotation of the camshaft, the cam having a cam nose for lifting the valves, wherein the radius of the cam nose varies in the axial direction so that the valves are driven with a variable amount of valve lift;a cam follower for transmitting movement of the cam to the valves, wherein the cam follower contacts the cam at a contact position;a valve lifter structure located between the follower and the valves, whereinthe valve lifter structure is connected to each valve;a side surface of the lifter structure is shaped like at least one circle so that the lifter structure fits into a correspondingly shaped opening that is formed entirely by drilling or boring;the lifter structure includes a pair of valve lifters respectively mounted on the pair of valves, each lifter having a cylindrical shape, and a bracket for connecting the pair of valve lifters with each other; andthe cam follower is pivotally supported on the bracket; andan actuator for moving the cam relative to the valves in the axial direction of the camshaft to vary the amount of valve lift of each valve, wherein the movement of the cam varies the contact position of the cam follower on the cam.