Variable-valve-actuation apparatus for internal combustion engine

摘要

In a VVA apparatus for an internal combustion engine wherein the position of contact of a cam face of a VO cam with respect to the top face of a valve lifter is changed in accordance with a change in a rocking fulcrum of a rocker arm to alter the valve lift, the maximum valve lift is obtained in a first rotated position of a control shaft where an axis of a control cam is adjacent to a driving shaft. The minimum valve lift is obtained in a second rotated position of the control shaft where the axis of the control cam is positioned near a first pivotal point of the rocker arm and a crank arm with respect to a first line connecting the axis of the control shaft and the axis of the control cam upon the maximum valve lift.