| 摘要 |
In a method and apparatus for shaping hollow-section workpieces such as tubes of metal, the workpiece is introduced into a pressing mold whose internal contour corresponds to the workpiece shape to be produced. After closure of the pressing mold a pressure medium in the form of solid matter particles or elements such as steel balls is pressed by means of a bar into the workpiece, applying it against the internal contour of the pressure mold. In that operation an upsetting movement of the workpiece is superimposed on the bar movement. The bar can be pressed into the workpiece in two or more steps, in which case the pressure medium is further advanced by means of a pressure cylinder between the respective steps after a respective withdrawal movement of the bar.
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