INDUCTION HEATING COIL AND INDUCTION HEATING METHOD

摘要

To heat a workpiece having a recess portion provided along a longitudinal axis of the workpiece, the workpiece is inserted into an induction heating coil, and the induction heating coil or the workpiece is along an axial direction of the workpiece. The induction heating coil has a conductor configured to surround the workpiece around the axis of the workpiece. The conductor has a protruding portion protruding inwardly to face the recess portion of the workpiece.