INDUCTION HARDENING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a induction hardening apparatus, in which at the time of induction-hardening the wall surface layer of a groove extended in the circular direction formed to the hollow part of a metallic parts, a time for heating this wall surface layer to the hardening temp. can be shortened and even the metallic parts having narrow hollow part can easily be applied and a sufficient cooling capacity can be obtd. SOLUTION: AC current is supplied into an induction heating coil 22 from a high frequency electric source 16 while rotating the metallic parts 16 under condition of getting an arc part 28 uniformly closer to the wall surface layer 14a to heat the wall surface layer 14a. When the wall surface layer 14a reaches the hardening temp., the supply of the AC current is stopped and also, cooling liquid is spouted from spouting holes 42a of the cooling jacket 40 to quickly cool the wall surface layer 14a.