METHOD AND BENDING DEVICE FOR BENDING FLAT METAL WORKPIECES

摘要

The invention relates to a method and device for bending flat metal workpieces (b), especially sheet steel, by air bending over edges along a bending line and at straight, linear movement of the tool, the bending edges being arranged in parallel to the longitudinal direction of the sheet and the tool being displaced along the width of the sheet. The method according to the invention is characterized by the following steps: inserting a punch (a) between the bending edges of a swage die (c), holding the punch (a) at the lowest position of the bend, applying a compressive stress in order to level out the stresses in the shaping zone produced by bending and incrementally superimposing the tensile stress with a compressive stress that is effective along the bending line in the direction of the sheet width of the bent workpiece (b), the tool producing the compressive stress being displaced along the bending line in the direction of the sheet width. The bending device according to the invention is characterized by comprising, arranged between the swage die sets and below the punch (a), a carriage that can be displaced in the direction of the bending axis (i.e. in the sheet width) and that comprises a pressure roller (d). Said pressure roller is effective in the punch axis and has a groove in the plane of intersection with the punch axis.