Patent ID: 7363892

Claim:
An engine valve operating system, comprising: a rocker arm ( 63 , 63 A, 63 B) which has a cam-abutting portion ( 65 ) to abut a valve operating cam ( 69 ) and whose first end is coupled in operative association with an engine valve ( 19 ); a link mechanism ( 50 , 50 A, 50 B) equipped with a first link arm ( 61 ) which has a first connecting portion ( 61 a ) at a first end to be turnably connected to the rocker arm ( 63 , 63 A, 63 B) and has a fixed support portion ( 61 b ) at the second end to be turnably supported at a fixed position on an engine body ( 10 ) as well as with a second link arm ( 62 , 62 A, 62 B) which has a second connecting portion ( 62 a , 62 Aa, 62 Ba) at a first end to be turnably connected to the rocker arm ( 63 , 63 A, 63 B) and has a movable support portion ( 62 b , 62 Ab, 62 Bb) at the second end to be turnably supported by a movable shaft ( 68 a ) which is displaceable; and drive means ( 72 ) connected to the movable shaft ( 68 a ), being capable of displacing the movable shaft ( 68 a ) in order to vary a lift amount of the engine valve ( 19 ) continuously, characterized in that the first and second connecting portions ( 61 a , 62 a ) are arranged in parallel and relatively turnably connected to the second end of the rocker arm ( 63 , 63 A, 63 B) and the movable support portion ( 62 b , 62 Ab, 62 Bb) of the second link arm ( 62 , 62 A, 62 B) is placed nearer to the engine valve ( 19 ) than the fixed support portion ( 61 b ) of the first link arm ( 61 ).