| 摘要 |
<p>The invention relates to a process for producing a circumferentially closed hollow profile, which is of frustoconical form in sections, from a sheet-bar blank. To produce hollow profiles of this type in as simple a manner as possible and with a reliable process, it is proposed that the sheet bar is cut to size in such a manner that a blank with a rectangular section and a ring segment, the summit of which adjoins the centre of one side of the rectangle, while Its outer arc, which faces the rectangle, is of approximately the same length as the length of the side of the rectangle, is formed, sheet-bar material also being left on the blank outside the summit, between the ring segment and the side of the rectangle, this material joining the ring segment with the side of the rectangle integrally at all locations and also joining the cornexs of ring segment and rectangle which are closest together, so as to form a rounded edge contour, Then the side edges o~ the blank are bent into abutment with one another about the longitudinal centre axis of the blank. After the bending operation, the edges of the sheet-bar blank are joined together by means of a longitudinal seam weld, so as to form a preform of the hollow profile, which is then deformed into the final form by means of internal high-pressure fluid.</p> |
