| 摘要 |
<p>PURPOSE:To harden the outer peripheral surface of a bent work to a uniform hardness, by heating and hardening the outer peripheral surface of the bent work such as a crank shaft having different rotation centers while it is rotating on its own axis with a loop-shaped high frequency induction coil having an internal shape which is nearly equal to that of the bent work. CONSTITUTION:A bent work 1 of irregular shape such as a crank shaft is attached to the top end of a supporting rod 14 which revolves around the rotating axis 13 and the work 1 is rotated on its own axis. The bent work 1 is heated by a high frequency induction coil 7 and is quenched in a cooling fluid 15. The high frequency induction coil composed of a pair of circumferential coils 8, 8' and a pair of axial coils 9, 9', and both the coils are connected alternately and surround the work 1. The axial coils 9, 9' are nearly equal in shape to the outer peripheral breadth of the outer peripheral locus of the work 1, the locus which becomes most distant from an axis 2 when the work 1 rotates around the center axis 2. The outer peripheral surface of the work 1 which rotates on its own axis is heated uniformly, hence it is hardened to a uniform hardness all over the work 1.</p> |
