APPARATUS AND METHOD FOR DETERMINING ABNORMALITY OF INDUCTION HARDENING

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and a method for determining abnormality of induction hardening, allowing the induction hardening to be appropriately performed.SOLUTION: An apparatus 20 for determining abnormality of induction hardening is an apparatus attached to a high frequency circuit in which a heating coil 14 and a capacitor 12 are connected to a high frequency inverter 11. The apparatus for determining abnormality of induction hardening includes: a current sensor 21 for detecting an output current from the high frequency inverter 11; a voltage sensor 22 for detecting a voltage produced in the heating coil 14; a calculation part 23d for calculating load impedance on the basis of a detection signal of the current sensor 21 and the voltage sensor 22; and a determining part 23e for determining whether a workpiece has been already subjected to induction hardening treatment, from temporal change of a load impedance calculated in the calculation part 23d and a detection signal from the current sensor 21.