| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an apparatus for hardening a hollow rack, wherein, when hardening the hollow rack, hardening crack is hardly caused and further, the time of hardening for plurality of hollow racks can be shortened. <P>SOLUTION: The apparatus for hardening the hollow rack which has a long shape and tooth-shape formed at least one surface and has the hollow portion at a part, has a hardening station which is provided with a high frequency induction-heating coil and the heats hollow rack to the hardening temperature, and a front-step side station where the hollow rack before hardening is temporarily placed, and in the front-step side station, a heating device is arranged so as to be able to raise the temperature of the hollow rack before hardening to be lower than the hardening temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
