Patent ID: 7631621

Claim:
An engine valve operating system comprising a rocker arm ( 63 , 111 ) which has a cam abutting portion ( 65 , 114 ) abutting against a valve operating cam ( 69 ) and is interlocked and connected to an engine valve ( 19 ), a first link arm ( 61 , 112 ) having one end turnably connected to the rocker arm ( 63 , 111 ) and the other end turnably supported at a fixed position of the engine body ( 10 ), a second link arm ( 62 , 113 ) having one end turnably connected to the rocker arm ( 63 , 111 ) and the other end turnably supported by a displaceable movable support shaft ( 68 a , 134 ), and driving means ( 72 ) connected to the movable support shaft ( 68 a , 134 ) to enable a position of the movable support shaft ( 68 a , 134 ) to be displaced in order to continuously vary the lift amount of the engine valve ( 19 ), wherein the rocker arm ( 63 , 111 ) having a valve connecting portion ( 63 a , 111 a ) into which tappet screws ( 70 ) abutting against a pair of engine valves ( 19 ) are screwed so that their advance/retract positions can be adjusted and a first and second support portions ( 63 b , 63 c ; 111 b , 111 c ) to which the one ends of the first and second link arms ( 61 , 62 ; 112 , 113 ) are turnably connected is formed so that the valve connecting portion ( 63 a , 111 a ) has a larger width in a direction along a rotating axis of the valve operating cam ( 69 ) than in a remaining part.