| 摘要 |
PROBLEM TO BE SOLVED: To reduce friction while increasing a degree of freedom in designing a cam.SOLUTION: A cam structure 10 for driving a tappet 11 connected to a basic end portion of an intake valve or an exhaust valve of an engine, includes a cam shaft 20 rotated in conjunction with a crank shaft of the engine, and a cam lobe 30 assembled to the cam shaft 20. The cam lobe 30 is composed of a base cam 31 composed of a base circular portion 31a having a mounting hole 31h for the cam shaft 20, and a valve lift portion 31b having a cutout portion 31n cut out at an intermediate portion in the width direction, of a tip portion 31c, and a roller 32 disposed on the cutout portion 31n, and provided with a crowning of the swollen shape projecting at an axial central portion on an outer peripheral face. The axial central portion of the roller 32 is rotationally moved through a center P of a top face 11a of the tappet 11. |
