| 摘要 |
PURPOSE:To protect the optical fiber and to improve the durability of the reflecting mirror by irradiating the laser beam while rotating the torch head inside the piping of small diameter. CONSTITUTION:A torch 1 is inserted into a piping X, and the laser beam irradiating position of the laser beam in the longitudinal direction is determined by activating a moving means connected to the torch 1. A torch body 2 is positioned to the center of the piping X by a positioning means 3 so that a torch head 5 may be rotated about the center axis of the piping X. The cooling fluid and the assist gas are supplied into the torch 1 from a cooling fluid supplying source 22 and an assist gas supplying source 38. Under this condition, irradiation of the laser beam is executed from a cooling oscillator 39 through an optical fiber 6, and at the same time, the torch head 5 is rotated at a constant speed by driving a driving means 4. The laser beam is converged by a lens 7, refracted by a reflecting mirror 9, and emitted from a small hole 8 of the torch head 5 onto the inner wall surface of the piping X to form the converging point P. |
