Abstract

The invention relates to a method and a system for creating a butt joint between rotationally symmetrical members (2, 3), e.g. flange-pipe-flange, flange-pipe or pipe arrangements, using friction stir welding. The aim of the invention is to improve the butt joint of friction stir welded rotationally symmetrical members (2, 3) in such a way that differences in the out-of-roundness and straightness in the butt region of the rotationally symmetrical members (2, 3) are eliminated, measurement and set-up processes can be dispensed with, the quality is improved, production times are reduced, and less material is required. Said aim is achieved in that following the centering process, the butt region of the members (2, 3) that are retained using axial clamping forces is locally deformed by radially pressing the members to obtain the inner shape thereof and straightening the members using a centering, inner-shape-forming, straightening and clamping disk, the centering force being boosted in the manner of a toggle lever to an inner-shape-forming force causing the local deformation, and said inner-shape-forming force being maintained in the butt region of the members (2, 3) until the end of the friction stir welding process.

IPC Classes  ?

• B23K 20/12 - Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by frictionFriction welding
• B23K 37/053 - Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass for holding or positioning work aligning cylindrical workClamping devices therefor
• B23K 37/06 - Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass for positioning the molten material, e.g. confining it to a desired area

Abstract

The invention relates to a device (10) for centering, pressing to form the inner shape of, straightening and clamping rotationally symmetrical hollow articles, e.g. on a flange-pipe-flange, flange-pipe, or pipe-pipe arrangement, which are joined at the butt joint using friction stir welding or fusion welding, said device comprising a clamping member (10) that includes a drive unit (21), can be adjusted to the internal diameter of the hollow articles, and is placed centrally in relation to the axis of the hollow articles. The clamping member (10) is designed as a weld pool holding element in the form of a centering, inner-shape-forming, straightening and clamping disk which is subdivided into circular-segment-shaped primary and secondary jaws (14, 16), on each of which hammer-shaped forked retention elements (17) are radially mounted in the direction of the axis of the hollow articles. Each forked retaining element (17) is guided in a recess (35) of a support element (36) and is connected in a radially pivotable manner, similar to a toggle lever, to a tappet (20) of the drive unit (21) by means of a primary or secondary lever (18, 19).

IPC Classes  ?

• B23K 20/12 - Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating the heat being generated by frictionFriction welding
• B23K 37/053 - Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass for holding or positioning work aligning cylindrical workClamping devices therefor
• B23K 37/06 - Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass for positioning the molten material, e.g. confining it to a desired area
• F16L 37/12 - Couplings of the quick-acting type in which the connection between abutting or axially-overlapping ends is maintained by locking members using hooks, pawls, or other movable or insertable locking members
• B23K 9/035 - Seam weldingBacking meansInserts with backing means disposed under the seam