| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an induction heating coil capable of performing the uniform heating so as to form a uniform hardened layer pattern on a surface continuous to first and second stepped parts from a small diameter shaft part of a stepped shaft-like member without fitting any magnetic material (a magnetic flux focusing member) such as a dust core and a silicon steel plate. SOLUTION: A straight first small diameter shaft part heating conductor 37 is disposed so as to pass a part corresponding to a space between an arc-like second small diameter shaft part heating conductor 38 in the axial direction of the small diameter shaft part and an arc-like third small diameter shaft part heating conductor 40, and the inequalityα>=βis satisfied, whereαis the arc length (circumferential length) of the arc-like first stepped part heating conductor 33 disposed correspondingly to a first stepped part 1a provided on a relatively large diameter shaft part, andβis the arc length (circumferential length) of the arc-like second stepped part heating conductor 36 disposed correspondingly to a second stepped part 1b provided on a relatively small diameter shaft part.</p> |
