Patent ID: 6123053
Filing Date: 2000-09-26
Classification: F01L

Abstract:
A variable valve actuation apparatus for an internal combustion engine having a plurality of cylinders, comprising:a first cylinder valve;a second cylinder valve;said first and second cylinder valves being arranged for one of the plurality of cylinders to perform one of intake and exhaust phases of the one cylinder;each of said first and second cylinder valves being biased by a valve spring toward a valve close position thereof;a camshaft adapted for rotation about a camshaft axis;a first valve operating cam cooperating with said first cylinder valve, said first valve operating cam being arranged for pivotal motion, about a pivotal axis thereof, to lift said first cylinder valve toward a valve open position thereof against the valve spring thereof;a second valve operating cam cooperating with said second cylinder valve to lift said second cylinder valve toward a valve open position thereof against the valve spring thereof;a control shaft adjustable to varying angular positions with respect to a control shaft axis; anda mechanism to convert rotational motion of said camshaft into pivotal motion of said first valve operating cam,said mechanism having different states corresponding to said varying angular positions which said control shaft is adjustable to, respectively and being continuously variable in state to one of said different states in response to a shift of said control shaft to one of said varying angular positions,said mechanism being operative to vary said first valve operating cam, in position, relative to said first cylinder valve in response to a shift between said different states,wherein said second valve operating cam being arranged for pivotal motion about a pivotal axis thereof, wherein said mechanism is operative to convert rotational motion of said camshaft into pivotal motion of said second valve operating cam, and wherein said mechanism is operative to vary said second valve operating cam, in position, relative to said second cylinder valve in response to a shift between said different states, andwherein said mechanism is operative to cause said first and second valve operating cams to provide first valve open timing and second valve open timing, respectively, with a difference between said first and second valve open timings varying against the varying angular positions to which said control shaft is adjustable.