DEVICE FOR CONTROLLING LIFT OF INTAKE AND EXHAUST VALVES IN INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To reduce variations in lift of intake and exhaust valves upon changing of the lift to reduce knocking sound in a valve lift control device in which a lift control cam changes the inclined angle of a lever to change the fulcrum position of a rocker arm, by providing damping sections in front and rear of each stable position of the control cam. CONSTITUTION:One end of a lever 25 supporting the rear surface of a rocker arm, for controlling the lift of a valve in association with changes in its inclined angle, is positioned in association with the rotation of a control cam 30. The control cam 30 has a plurality of stable positions a1 through a5 for determining the maximum lift of the valve, and the stable positions are connected with each other through the intermediary of damping sections A1 through A5 each having a smooth curve. Due to the provision of the damping section no large variations in the lift of the valve are effected upon change-over of the control cam 30 so that knocking sound may be reduced, and control torque necessary for initiating the rotation of the control cam may be reduced.