| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of producing a rack for producing an oblique tooth rack or the like by high-frequency induction hardening which causes less twisting in high-frequency induction hardening.SOLUTION: A workpiece 1 is fixed to the side of a rotation axis 11 and supported by a center 12, and the side opposite to the rotation axis 11 is held between small rollers 22 among rollers 13 for braking. A braking force is applied to the vicinity of one end of the workpiece 1, and the other end of the workpiece 1 is held with a chuck 21. The workpiece 1 is rotated in the direction in which the pitch of rack teeth 2 widens. In this state, an induction heating coil 15 is brought close to the workpiece 1, and a high-frequency current is passed through the induction heating coil 15 to induction-heat the workpiece 1. When the workpiece 1 is red-heated, the electrification of the induction heating coil 15 is stopped, and the workpiece 1 is chilled quickly. The rack 30 produced by the method shows less twisting, reducing the need of after processing. |
