| 摘要 |
<p>PURPOSE:To prevent the damage to a work and a heating coil by preventing the generation of short circuit between the heating coil and the work through chips even if the chips are remained in an oil hole in the work. CONSTITUTION:Before executing induction hardening to a journal part 11 of a crank shaft with the heating coil 21, by injecting the quenching liquid L to a part 15a where the oil hole 15 of the journal part 11 is opened from jackets 25, 25, the chips in the oil hole 15 are flowed out by the injected quenching liquid L. Thereafter, the induction quenching is executed to the journal part 11.</p> |
