| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel and a method of manufacturing the same, in which over heat is prevented when high-frequency hardening is performed for a lightened hub wheel by strength improvement by hardening of cold forging. <P>SOLUTION: A wheel attachment flange 6 is configured from a plurality of partial flanges 6a. A hub wheel 4 is formed by a hot forging step and a cold forging step which is partially applied after the hot forging step such that, in the hot forging, the root section of the wheel attachment flange 6 is formed thicker than a tip section, and it is made thinner in the cold forging, to form a nearly uniform thickness, and a high frequency coil 32 to be a heating conductor is inserted while facing the outer face of the hub wheel 4. In a state that an outlet tool 33 made of a conductor between the partial flanges 6a is inserted via a predetermined magnetic gap, high frequency heating is performed by supplying high frequency current to the high frequency coil 32, and thereby, a predetermined hardening layer 13 is formed in the hub wheel 4. <P>COPYRIGHT: (C)2013,JPO&INPIT |
