METHOD FOR SUPPORTING SHAFT BODY IN HARDENING APPARATUS

摘要

PURPOSE:To prevent a parallel or eccentric shaft body from producing a strain during local hardening or hardening under movement by putting a center shaft having a sphere on the tip into the center hole in the shaft body and by hardening the shaft body while supporting it. CONSTITUTION:A center shaft C having a sphere Cs which can be put into the center hole Ch in a shaft body W on the tip is prepd. The shaft body W is subjected to local hardening, hardening under movement or one-shot hardening over the full length by an induction heating means while supporting the shaft body W by the shaft C. During the hardening, the position of the circumferential linear contact of the inner wall of the hole Ch with the spherical surface of the sphere Cs is automatically changed on the spherical surface in accordance with the expansion and contraction of the shaft body.