PURPOSE: To join a Ti-Al double tube and a Ti tube plate effectively and with high reliability by fitting a Ti collar on the outer periphery of a double tube consisting of an Al outer tube and a Ti inner tube and welding them, and inserting it to a fitting hole of the Ti tube plate and welding them.
CONSTITUTION: An Al outer tube 4 and a Ti inner tube 2 are pressure-welded to constitute a Ti-Al double tube 2. The Al outer tube 4 is made shorter than the Ti inner tube by specified length l1 at the end a bevelling part l4 in length is formed. Then, a cylindrical Ti collar 10 of length l2 is fitted over the shortened part l1 of the Al outer tube 4 and outer bevelling part l4, and bevelling parts 12, 14 of the two are melted and welded, and the Ti collar 10 is fixed to the double tube 2 at the weld zone 16. After inserting the double tube 2 into the fitting hole 20 of the Ti tube plate 18 and placing at a specified fitting position, an end part of the Ti collar 10, the end part of the Ti inner tube 6 and the peripheral part of the fitting hole 20 are melted and welded, and the double tube 2 and Ti tube plate 18 are fixed at the weld zone.
NANBA KEIZOU
SANO KEIJI
