| 摘要 |
<p>1,218,613. Explosive forming; tube expanding. ATOMIC ENERGY OF CANADA Ltd. 25 March, 1968 [3 May, 1967], No. 14260/68. Headings B3J and B3Q. [Also in-Division F2]. A method of forming a metal workpiece against a surface by means of a high-pressure wave in a fluid comprises using a back-up member to support the surface and a layer of liquid between the back-up member and the die or other member, e.g. a pipe coupling, having the surface, the back-up member being so spaced from the die or other member that during the existance of the high pressure wave it receives and defleets impulses back to the die or other member. The high pressure wave may be formed electrically, electromagnetically or by an explosive detonated in air or water. If the explosive is in contact with the workpiece, the surrounding medium and gases produced by the explosion provide the transmission fluid. Cylindrical, non-circular closed of substantially closed sections, and flat workpieces may be formed. As applied to securing a zirconium-niobium alloy tube 14, Fig. 1, in a stainless-steel end-fitting 16, the fitting is surrounded by a back-up member 22 having a sealing ring 26 at each end of an annular chamber to which water is fed through passages 29. A temporary partition 28 supports a volume of water in which the charge 12 is exploded to join the tube to the fitting by expanding the tube-end. A member (not shown) may be provided between the explosive and thetube to be expanded as part of the joint. The partition 28 may have protuberances to position the charge. In another example, Fig. 3 (not shown), a ring of explosive (112) is used for contracting a pipe (114) on to a hollow fitting (116) containing a back-up plug (122). For forming flat workpieces (214), Fig. 5 (not shown), the die (216) is supported on a back-up plate (222) by an hydraulic cushion.</p> |
