| 摘要 |
Proposed are a heat treatment method capable of molding, by mobile quenching of induction quenching, an outer joint member of a tripod type constant velocity universal joint excellent in a strength thereof without forming hardened layers in larger radially-inner portions, and the outer joint member and the tripod type constant velocity universal joint which are manufactured by the above-mentioned heat treatment method. Mobile quenching is performed in such a manner that a high-frequency induction heating coil (51) is moved in an axial direction relative to an outer joint member (21), and thus hardened layers (S) are formed on the roller guide surfaces (27) of the outer joint member (21). Magnetic field line cut-out bodies (A) for cutting out magnetic field lines generated through the high-frequency induction heating coil are arranged on the high-frequency induction heating coil (51), and each of the larger radially-inner portions (46) of the outer joint member (21) becomes an unquenched portion (50) by cutting out the magnetic field lines with the magnetic field line cut-out bodies (A). |
