Method and device for folding along a generatrice of a sheet metal blank has a multilayer structure and metallic a multilayer structure obtained by this

摘要

The procedure consists of bending the sheet, made from two layers (2, 3) of metal with a layer (4) of a polymer material between, along the generating line of the fold to form a rib (5) on the inside and a hollow along the outside of the fold. The depth of the hollow is between 0,5 and 1.5 times the thickness of the metal sheet, and its width is between 0.5 and 3 times the sheet thickness. After forming the rib on a lengthwise projection (22) on the sheet-bending matrix, the sheet material is transferred to a second part of the matrix with a V-section recess (26), into which it is forced by a die (10). The die is in two sections (11, 12) which squeeze the sides of the inner rib together as the outer layer of the sheet is bent to the required angle.