Patent ID: 7644689

Claim:
A variable valve operating device for mechanically changing the operating characteristic of a valve relative to the rotation of a camshaft, the variable valve operating device comprising: a drive cam installed over the camshaft; a control shaft that is positioned in parallel with the camshaft and capable of changing a rotation position continuously or stepwise; control means for controlling the control shaft so that it is fixed at a rotation position corresponding to a desired valve lift amount; a swing member that is installed over the control shaft and allowed to swing around the control shaft; a swing cam surface that is formed on the swing member, comes into contact with a valve support member, which supports the valve, and presses the valve in a lifting direction; a slide surface that is formed on the swing member so as to face the drive cam; an intermediate roller that is positioned between the drive cam and the swing member and comes into contact with both the slide surface and a cam surface of the drive cam; a control member that is fastened to the control shaft and has a swing fulcrum at a position eccentric to the center of the control shaft; and a coupling member that supports the intermediate roller in such a manner as to permit free rotation and couples the intermediate roller to the swing fulcrum in such a manner as to permit free swinging; wherein, the swing fulcrum is positioned closer to a position opposite to the intermediate roller with respect to the control shaft when the control shaft is fixed at a rotation position giving a large lift to the valve than when the control shaft is fixed at a rotation position giving a small lift to the valve.