| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress the facility cost and to reduce the number of hardening processes by simultaneously applying high frequency induction hardening to portions at a plurality of positions of a work having different shapes. SOLUTION: When the high frequency induction hardening is simultaneously applied to the portions (journal parts 2J, 4J) at a plurality of positions of a work 100 having different shapes with a single set of generator 6, the high frequency induction heating is first applied to the position 4J having a large heating capacity, and after the lapse of a prescribed time, this heating is stopped for a short period of time. Subsequently, the portion 2J having a small heating capacity and the portion 4J having a large heating capacity are simultaneously heated, and after the lapse of a prescribed time, the simultaneous heating is stopped. Thereafter, the portions 2J, 4J of the work 100 having different heating capacities are simultaneously hardened by simultaneously cooling the heated portions 2J, 4J.</p> |
