| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving force transmission device capable of suppressing the occurrence of such a phenomenon that an electromagnetic clutch mechanism does not operate during energizing an electromagnet, while suppressing a cost increase.SOLUTION: A driving force transmission device 1 includes an outer housing 2 and an inner shaft 3, a main clutch 4 for connecting the outer housing 2 and the inner shaft 3 in a torque transmissive manner, a cam mechanism 5 having a main cam 51 for outputting pressing force to press the main clutch 4 and a pilot cam 52 for allowing the main cam 51 to generate cam thrust, a pilot clutch 60 for transmitting torque to rotate the pilot cam 52 relative to the main cam 51, and an armature 63 opposed to the main cam 51 in the axial direction for receiving electromagnetic force from an electromagnet 64 to press the pilot clutch 60. The main cam 51 is formed of a carburization-quenched iron based material which has an average carbon content of 0.7% or greater in a range from the surface of a contact face 514a to contact the armature 63 when the armature 63 moves to the side of the main cam 51, to a depth of 0.2 mm. |
