| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the amount of inert gas used in an induction hardening apparatus. SOLUTION: In the induction hardening apparatus 10 for executing the hardening by induction-heating a work W above the liquid surface of hardening oil L with an induction heating coil 400 and dipping the work together with a work supporting part 200 for supporting the work W into the hardening oil L stored in a storing tank 100, an inert gas blowing-out mechanism 500 is provided and the blowing-out holes 510 in this blowing-out mechanism 500 is arranged at a position almost surrounding the induction heating coil 400 and the work supporting part 200 arranging the induction heating coil 400. Then, the blowing-out mechanism 500 is intermittently worked while interlocking the movement of the work supporting part 200 arranging the induction heating coil 400. Further, fire is detected with a fire alarming means 550 for detecting the burning of the hardening oil L stored in the storing tank 100, and in the case of judging that the detected result of the fire alarming means 550 is the fire, the blowing-out mechanism 550 is forcedly worked for a prescribed time.</p> |
