HEAT TREATMENT APPARATUS FOR LONG WORK AND METHOD FOR CONTROLLING HEAT TREATMENT FOR LONG WORK USED IN THIS APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a long work heating treatment device, etc., with which the heat treatment can be applied to the long work into a hardening depth within the specification range while executing the control of extension. SOLUTION: This heat treatment apparatus is provided with a high frequency induction heating coil body 911, an electric source part D for supplying the electric power to this coil body, a shifting mechanism 930 for shifting the coil body 911 along the work W, a length measuring instrument 953 for measuring the whole length of the work W during heating and a control unit (not show in the figure) for controlling the supplied electric power to control the heating quantity to the incompleting part of heating in the work W by using the extending data measured with the length measuring instrument 953. The control unit has a storing part for storing the reference data of the extension measured at the time when a work for obtaining pre-data as the same as the actual work W is hardened into a prescribed hardened depth, the electric power at this time, the shifting speed of the coil body 911 at this time and the electric power, with which the hardened depth in this shifting speed becomes the allowable max. value and the allowable min. value, and a comparing control part for comparing the extension data of the actual work W measured during heating-stopping and shifting-heating with the reference data and changing the electric power so as to equalize with the reference data, etc.