Patent ID: 6588084
Filing Date: 2003-07-08
Classification: B21D,B23K,Y10T

Abstract:
A process for producing a circumferentially closed hollow profile, which is of frustoconical form in sections, from a sheet-bar blank, comprising the steps of:cutting a sheet bar to size to form a blank having a rectangular section and a ring segment, a summit of which adjoining a center of one side of the rectangle, an outer, longer arc, which faces the rectangle, having approximately the same length as a length of the side of the rectangle, sheet-bar material being left on the blank outside the summit between the ring segment and the side of the rectangle and joining the ring segment with the side of the rectangle integrally at all locations and joining corners of the ring segment and the rectangle that are closest together to form a rounded edge contour; bending the side edges of the blank into abutment with one another about a longitudinal center axis of the blank to form a cylindrical hollow-profile section and a frustoconical hollow-profile section adjoining the cylindrical hollow-profile section; joining together the edges of the blank bent into abutment with one another in the bending step only by a longitudinal seam weld to form a preform of the hollow profile; and deforming the preform, which approximates to a final form of the hollow profile, achieved in the joining step into the final form by internal high-pressure fluid.