Drawing equipment producing multiple-channel tubes - has drawing die with angle between compression zone generatrix and die axis in excess of forty five degrees

摘要

The method by which multiple-channel tubes are produced uses a thin-walled cylindrical shell (1) into which a rod (2) with radially positioned ribs (3) are initially introduced. By drawing, the peripheral tips of the ribs (3) are permanently fixed on the inner surface of the shell. For the drawing operation a drawing die is used with an angle (alpha) enclosed by the generatrix cf the upsetting zone and the geometrical axis of the die in excess of 45 degrees. The length of the projection of the upsetting zone on the axis (b) equals six times the thickness of the rib (3).