LASER WELDING EQUIPMENT FOR FINE TUBE

PURPOSE:To weld the necessary place only concentrically and to reduce the welding time by inserting the optical fiber which leads a laser beam and a conical concave mirror into a fine tube with their combination. CONSTITUTION:A heat transfer tube 1 and sleeve 5 are closely fitted by expanding the sleeve 5 with its inserting into the inner face close to the defective part 4 of the fine tube like the heat transfer tube 1, etc. A concave mirror 11 is then held on the inner face of the sleeve 5 by a stabilizer 12 by inserting the conical concave mirror 11. When a laser beam generator 16 is turned on in this state, the laser beam is irradiated on all the periphery of the inner face of the sleeve 5 after the laser beam passing through an optical fiber 14 and being reflected by the concave mirror 11. Consequently, the heat transfer tube 1 and sleeve 5 are instantaneously welded.