| 摘要 |
PROBLEM TO BE SOLVED: To provide a shim for a valve mechanism, which is interposed between a pad surface of a rocker arm and a stem of a valve, which has a shim top surface to be in contact with the pad surface, the shim top surface having been rotated about a center thereof to be cut and been provided with a center hole at the center thereof because the cutting cannot be performed at the center, and which prevents the occurrence of abnormal wear at a corner of an opening edge of the center hole when the rocker arm swings to bring its pad surface into contact with the shim top surface while moving the contact point.SOLUTION: A shim top surface 13 is set into such a shape that when a rocker arm 3 swings, a pad surface 6 of the rocker arm does not come into contact with an intersection line (a) between an inner peripheral surface of a center hole 14 and the shim top surface 13. The shim top surface 13 is shaped in such a manner that an intermediate diameter part b having a predetermined intermediate diameter Db is the highest and that the height decreases from the intermediate diameter part b toward the intersection line (a). |
