| 摘要 |
PROBLEM TO BE SOLVED: To stably secure a firm joined part by making the joining surface in the case of a liquid phase diffusion welding between tubes or via a connecting sleeve the taper surface in contact with each other. SOLUTION: The outer peripheral taper 1t reducing the diameter in the direction of the end surface is formed in the end part outer periphery of metal tubes 1a, 1b to be joined, and the outer peripheral taper 1t is engaged with the inner peripheral taper 2t expanding the diameter in the direction of the end surface formed in the inner periphery of the both side part of the connecting sleeve 2 having the larger outer diameter than metal tubes. A joining material 3a of the liquid phase diffusion welding is interposed in the joining surface. Also, the both end surfaces of metal tubes are butted via the joining material 3b within the connecting sleeve 2 in order to make the end surface of metal tubes 1a, 1b the joining surface as well. Under this state, a compressing stress is applied with a pressing device 5 provided with a clamp mechanism 5c and a compressing stress providing mechanism 5p while heating the joining part and its peripheral part with a heating device 4 arranged outside the connecting sleeve 2, the joining materials 3a, 3b interposed in the joining surface are molten to weld by the liquid phase diffusion, whereby the structure of the liquid phase diffusion welding of metal tubes is obtained. |
