| 摘要 |
PROBLEM TO BE SOLVED: To reduce friction loss generated by friction between a can lobe surface and a lifter shim surface in a direct-acting valve mechanism of an internal combustion engine to convert rotation of a cam shaft into reciprocation of a valve through a lifter shim and a valve lifter. SOLUTION: In a valve mechanism for an internal combustion engine in which rotation of a cam 1 of a cam shaft is converted into reciprocation of a valve 2 through a lifter shim 4 and a valve lifter 3, the lifter shim 4 provided with hard thin film is combined with the cam 1 of the cam shaft having a surface roughness of 0.08μm or less in Ra in an axial direction of a cam lobe, a cross hatch angle of a process cross on a can lobe surface is 20 deg. or more, a surface hardness of the cam lobe is HRC 45 or more, and a surface roughness of the lifter shim 4 is 0.08μm or less in Ra.
|
