COOLING JACKET FOR INTERNAL HARDENING OF CYLINDRICAL WORKPIECE, AND ARRANGEMENT STRUCTURE OF HEATING COIL AND COOLING JACKET OF HIGH FREQUENCY INDUCTION HARDENING DEVICE

摘要

To provide a cooling jacket for the internal hardening of a cylindrical workpiece capable of satisfactorily subjecting the internal face of a cylindrical workpiece to high frequency induction hardening, and the arrangement structures of the heating coil and cooling jacket of a high frequency induction hardening device.SOLUTION: Provided is a high frequency induction hardening device 1 comprising: a heating coil 7; and a cooling jacket 3 for internal hardening. The heating coil 7 is provided with: straight line parts 8a, 8b composed of a series of conductors and entering the inside from the opening 22a of a cylindrical workpiece 20; and straight line parts 9a, 9b returning to the side of the opening 22a by the same number. The respective straight line parts 8a, 8b, 9a, 9b are separated each other, and the respective straight line parts 8a, 8b, 9a, 9b are close to the inside internal face of the cylindrical workpiece 20. The cooling jacet 3 for internal hardening is separated from the internal face of the cylindrical workpiece 20 than the respective straight line parts 8a, 8b, 9a, 9b. A cooling liquid 13 jetted from the jacket 3 for internal hardening reaches the internal face through the spaces of the respective straight line parts 8a, 8b, 9a, 9b and cools the internal face.SELECTED DRAWING: Figure 1