| 摘要 |
<p>A valve actuating mechanism is disposed in a four-stroke cycle engine comprises a rotatable rocker shaft (11) having eccentric large-diameter portions formed as bushings (12,13) on the way of the rocker shaft, a rocker arm assembly including a first rocker arm (7) rotatably mounted directly on the rocker shaft (11) and second and third rocker arms (8,9) rotatably mounted on the eccentric bushings of the rocker shaft with the first rocker arm being interposed therebetween, and a cam assembly including first, second and third cam members (3,4,5) which drives the first, second and third rocker arms, (7,8,9) respectively. The first rocker arm is provided with a branched distal end and the second and third rocker arms each is provided with a distal end which are laid upon each other. The second and third cams have the same cam profiles and the first cam has a cam profile different from those of the second and third cams. A play adjusting screw means (33,34) is provided for either one of the support portion of the first rocker arm and the support portions of the second and third rocker arms and a screw means receiving portion is provided for other one of the suportion of the first rocker arm and the support portions of the second and third rocker arms in a manner such that a clearance between a distal end of the play adjusting means and the screw receiving portion is adjusted. <IMAGE></p> |
