| 摘要 |
PURPOSE:To decrease a burning chance of a mirror, and also to decrease danger in an irradiating path of CO2 laser beams by irradiating said beam to a weld zone through an optical fiber of silver chloride. CONSTITUTION:An edge part 2 of a steel band (tubular body) 1 formed tubularly by a forming roll group which is not shown in the figure is butted by a squeeze roll 3 and presents a wedge shape in which a welding point W is the top. The welding point W is heated by an eddy current of the tubular body 1 based on a high frequency current flowing to a work coil 4 provided on the upstream of the roll 3. On the other hand, a laser beam from a CO2 laser irradiating device 5 is guided between the edge parts 2 by an optical fiber 6 consisting of a single crystal of silver chloride and irradiated on the welding point W from the optical fiber 6 as indicated with an arrow F. By Joule heat by said eddy current and energy of the laser beam, the welding point W is heated to a welding temperature and welded. Since the optical fiber 6 is used, the number of mirrors to be used is decreased, a burning chance of the mirror is also decreased, and the laser beam can be irradiated from a narrow part, too. |
