HEATING COIL FOR ONE SHOT QUENCHING IN PERIPHERAL SURFACE

摘要

PURPOSE:To efficiency execute quenching treatment only to the whole surface of peripheral wall to be quenched by constituting heating coil with a hollow tube forming the whole surface side of the peripheral wall to be quenched with conductive plate material and wall surface side to be not-quenched with non-conductive material and boring cooling fluid injecting holes to the conductive plate material. CONSTITUTION:The heating coil C composing of the hollow tube forms the whole surface of the part facing the peripheral wall IF to be quenched for ring-like member W with the outer peripheral conductive forming material 1 and arranges plural number of the cooling fluid injecting holes (s). Further, the end face non-conductive forming material 4 is arranged at the wall face OF side evading the quenching in the member W and an upper cover 2 and the inner peripheral forming material 3 are made of the non-conductive material. At the time of conducting the current in this coil C, the current is conducted only to the outer peripheral forming material 1, and the inner peripheral surface IF in the member W facing to the outer peripheral forming material 1 raises the temp. but outer surface OF in bending part (wc) does not raise the temp. because there is apart from the outer peripheral forming material 1. When the temp. of the inner peripheral surface IF raises to the prescribed temp., the current is stopped and cooling fluid is supplied through the hose 7 and injected from the injected holes (s) to rapidly cool the whole surface of the inner peripheral surface IF and the quenching is executed.