Cold-rolling mill for large tubes

摘要

Cold cross-rolling mill with internal planetary rolls for the production of large tubes, especially thin-walled large tubes, consisting of a machine frame with a slideway, a drive motor, a main shaft mounted in bearing pedestals, a drive shaft, a die head mounted on the machine frame, connected frictionally to the driveshaft and having, mounted in it, an annular die which can be moved axially with the die head along the slideway in order to adjust the wall thickness and diameter of the finished tube. In this arrangement, the inner surface of the die is essentially conical and three or more work rolls are arranged uniformly on the circumference around the rolling centre line on a machine head projecting into the blank, the arrangement beign such that the roll axes intersect the rolling centre line in the space at a cross-rolling angle, and, in addition, an axially movable adjusting cone and a set of compensating springs are mounted on the machine head, thereby allowing the axial position of the rolls to be adjusted in relation to the rolling centre line to allow the blank to be introduced into the interspace between the machine head and the die and/or the wall thickness of the finished tube to be adjusted. It is possible to produce thin-walled large tubes with diameters of 200-2000 mm or above at a high production rate, with good quality and with a good surface finish of @7@8. The machine is of simple construction, practical as far as adjustment is concerned, easy to automate... Original abstract incomplete. <IMAGE>