| 摘要 |
1290620 Welding by pressure; breaking EUROPEAN ATOMIC ENERGY COMMUNITY 10 Dec 1970 [10 Dec 1969] 58677/70 Headings B3E and B3R In welding a plug 1 in the end of a tube 10 by magnetic pulse welding, i.e. welding wherein a pulse of current is supplied to an induction coil to produce a magnetic field which induces current in one member to be welded and wherein the induced current produces a further magnetic field which reacts with the first field to produce an impulse force on the one member, a circumferential weakened portion 5 is formed in the tube 10, a centring device 2 is attached to one end of the plug, the plug and device are positioned, plug first, in the tube with the one end of the plug adjacent the weakened portion 5 of the tube and a current is passed through a coil about the tube to drive the tube radially inwardly to weld the plug to the tube and snap off the tube at the weakened portion 5. The plug 1 with a cylindrical portion and frustoconical portions 11, 12 is screwed by a threaded spigot into a threaded hole in the centring device 2 having orifices 4. The plug and device 2 are placed in the tube with a circumferential notch 5 in the tube located adjacent a space 16 between the plug and device 2. Current passed through a coil about the tube creates a sudden magnetic field which contracts the tube, thus welding the tube to the plug and snapping the tube at notch 5. Air is expelled from the orifices 4. A conductive sleeve 6 may be provided if the tube is a poor electrical conductor and the device 2 may be screwed into the plug 1. The device 2 may alternatively have radial projections extending from a central portion. |
