METHOD AND DEVICE FOR PRODUCING PRESSURE-ROLLED PIPES WITH THICKENED INNER WALL SECTIONS AT THE ENDS

摘要

The invention concerns a method of producing pressure-rolled pipes (3) with a pressure mandrel (1) and one or a plurality of pressure rollers (2), the pipe (3) being disposed between the pressure mandrel (1) and the pressure rollers (2) and being plastically deformed by the force applied by the pressure rollers (2). In order to produce pipes with thickened wall sections at the ends, according to the invention, a first pressure mandrel (1a) with a stepped portion (4) at the tailstock end is used in a first operating step. The pressure rollers (2) commence their deforming action at the stepped portion (4) at the tailstock end, operating in the direction of the machine spindle. The semi-finished pipe (3a) is then removed from the first pressure mandrel (1a). In a second operating step, at the end where a thickened wall section (5) has already been produced, the semi-finished pipe (3a) is clamped in a rotary chuck (6) (clamping mandrel or the like) mounted in the pressure roller machine. A second pressure mandrel (1b), which is secured at the tailstock end and has an outer diameter (d2) corresponding to the inner diameter of the thickened wall section, is inserted into the semi-finished pipe (3a). The pressure rollers (2) then shape the second thickened wall section from the tailstock end towards the machine spindle side.