| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress abnormal sound generated when the roller of a locker arm drops into the decompression groove of a camshaft, and to secure engine performance by reducing the weight of a locker arm while reducing a manufacturing cost also. <P>SOLUTION: The engine includes a valve moving mechanism which drives the opening and closing of an exhaust valve by an exhaust side locker arm through the rolling of a roller 22 for an exhaust side locker arm 19 along the cam profile of an exhaust side cam 16 in the camshaft 17. In this case, a decompression shaft 31, equipped with a decompression cam 32 on one end and equipped with a decompression arm on the other end thereof, is received together with the decompression cam 32 to be turnable in the decompression groove 35 which is formed on the camshaft while including the base circle part 16A of an exhaust side cam. The groove end 35A of the decompression groove 35 is formed in the base circle part 16A of an exhaust side cam 16 while the tangents 29 of respective points in the region of the roller locus 38 of the base circle part are formed to be intersected with the axial center O of the camshaft. <P>COPYRIGHT: (C)2012,JPO&INPIT |
