Patent EP-2561947-A1 (EP)
Inventor: HOLENWEG BEAT
IPC: H01B9/06
Filed: 2011-08-24
Abstract: Apparatus for assembling rotationally symmetrical bodies, e.g. pipe-pipe connection, to a compressed gas-tight assembly, comprises: directly driven rotary recordings, between which the rotationally symmetrical body is aligned according to its longitudinal axis; an axially clamped butt joint; a rotating capping (12) provided with a screw (17); a friction stir welding tool (10) having a friction stir welding probe (13); and a counter holder arranged under the butt joint. The capping exhibits a spiral form that winds from the rotational axis to the extending edge of friction surface and grooves. Apparatus for assembling rotationally symmetrical bodies, preferably pipe-pipe, flange-pipe, flange-pipe-flange and/or flange-flange connection of similar or dissimilar light metal alloys to a compressed gas-tight assembly, comprises: directly driven rotary recordings, between which the rotationally symmetrical body is aligned according to its longitudinal axis; an axially clamped butt joint to execute a rotation around its longitudinal axis; a rotating capping (12) provided with a screw (17); a friction stir welding tool (10) having a friction stir welding probe (13), which with contact pressure penetrates perpendicularly into the butt joint between the rotationally symmetrical bodies, above the longitudinal axis, and whose material regions soften, stirred and interconnects the arrangement within a circulation; and a counter holder arranged under the butt joint, for receiving the contact pressure. The capping exhibits a spiral form that winds from the rotational axis to the extending edge of friction surface and grooves. The width of the friction surface first increases radially outwardly and decreases to the edge, and the width of the groove remain constant. The friction stir welding probe has a screw with a cutting edge having an undercut of 10-15[deg] , and elongated through the probe height. The width of the screw thread is constant. The ratio of the capping diameter to the probe length is greater than 2. A form wedge is provided in alignment of the tangent planes extending above the longitudinal axis through the butt joints, and which is starts and withdraws during running rotation of the assembly. The friction stir welding probe moves out from the joined butt joint without forming a recess in the friction stir welding. Independent claims are also included for: (1) assembling rotationally symmetrical bodies to a compressed gas-tight assembly, where (i)at least one flange and a tube, or tubes or the flanges are materially connected with each other at their ends in the butt joint, (ii) the tube and the flange fixed to the front ends to one another according to their longitudinal axes, are axially clamped against each other and are driven in rotation, (iii) the friction stir welding probe of the friction stir welding tool is lowered into the butt joint with contact pressure, and (iv) the reactive force is applied from the counter holder associated under the butt joint for the contact pressure, and which penetrates into the butt joint, whose material regions are plasticized, stirred and interconnected, comprising (a) grinding the multiple scissors of the plasticized material and the oxide layer through the gaps in the cutting edge and the transitional channels between the friction surfaces of the capping, with a contact pressure of 6000-10000 N, a rotation speed of the tool of 1000-1800 min -> 1>and a feed rate of 0.3-1 m/minute, and a rotation of the arrangement by 360[deg] , (b) homogeneously dispersing the components of the joint partners and the ground oxide particles, within the plasticized material region over the gaps and transition channels, (c) starting and pressing the form wedge adapted to the diameter of the rotationally symmetrical body, on the rotating assembly in the alignment of the horizontally extending tangent, by the butt joint located above the longitudinal axis, and suppressing the form wedge in grinding when the arrangement has executed a rotation by 350-358[deg] , preferably 355[deg] , and remains on the rotating assembly, and stopping the rotation of the arrangement, when the angular position is reached at 362-370[deg] , preferably 365[deg] , simultaneously driving the friction stir welding tool with friction stir welding probe, into the form wedge in tangential direction, and the recess left behind the friction stir welding probe, is filled by the material of the form wedge, and removing the form wedge from the assembly, and (d) dissolving the axial capping and removing the finished assembled arrangement; and (2) compressed gas density arrangement of rotationally symmetrical bodies, where the connection between the rotationally symmetrical bodies is blunt shock friction stir welded and the assembly is used as a gas-insulated casing for transmission lines in high-voltage range.