| 摘要 |
PURPOSE:To uniformize the quality of a circular surface already applied with the heat treatment by condensing laser beam to an annular state corresponding to the circular surface of a material to be worked, in the heat treatment method of circular surface using the laser beam as heat source. CONSTITUTION:For example, the laser beam 2 outputted from a laser beam generator 1 is changed in the direction by a reflecting mirror 3 and made incident on a conical lens 5 arranged in the inner part of a machining head 4. The generator 1 uses a carbon dioxide gas laser beam generator and wave length of the outputted laser beam is 10.6mum. The quality of the lens 5 in ZnSe and has >=99% transmissivity to 10.6mum wave length. Further, the conical part 6 of the lens 5 is arranged so that the center of the laser beam 2 corresponds to the apex in the reverse side to the incident side of the laser beam 2. The incident laser beam 2 on the lens 5 is emitted as the annular laser beam 8 according to the inclination of the conical part and irradiates the bottom surface 12 of an annular groove 11 in the material 9 to be worked, and temp. of the irradiating part is raised, and after this part reaches the quenching temp., the irradiation of the laser beam 8 is stopped. |
