| 摘要 |
<p>The invention makes the production of bent tubes possible by cold drawing of a hollow tube blank (10) in one operation for reduction of the outer diameter and the wall thickness. It is characterized in that a straight tube blank (10) is drawn through a drawing tool comprising a drawing die (13) and a straight mandrel (12) which is short relative to the tube blank and applied centrally in the tube blank. Drawing means (15, 16) attached to the tube end draw the tube along a pre-determined curved path, suitably in surface contact with a guiding device (17) with a pre-determined curved surface (18). The drawing die (13) is turned along a predetermined curved path simultaneously as the tube is drawn through the drawing die. Hereby production of tubes with a curvature adjusted to each purpose becomes possible.</p> |
