| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a cam shaft in which the surfaces of the first cam and the second cam with different cam profiles are heated and heat-treated with heating coils, thus hardened layers having the same depth are formed by a simple constitution.SOLUTION: A pump cam C2 is provided between two valve cams C1, C1, and the surfaces of the cams C1, C2 are heated and hardened with a heating coil H to produce a cam shaft C formed with hardened layers Q having a prescribed depth. The method comprises: a step of molding a part to form into an axial part between a part c1 to be formed into the valve cam and a part c2 to be formed into th pump cam c2 in a crude material c to a length L in the axial direction through which a magnetic flux M generated with the heating coil H can uniformly pass; and a step of subsequently heating the surfaces of the part c1 to be formed into the vale cam and the part c2 to be formed into te pump cam in the crude material c with the heating coil H and performing quenching. |
