Stamping process used during manufacture of road vehicle bodywork for producing shallow or deep drawn bulges with thinned and weakened edges uses stamp of larger diameter than matrix

摘要

The sheet metal shaping tool (4) uses a stamp (6) which may be cylindrical, with a flat bottom surface and a rounded edge (10). The sheet metal vehicle body part (1), of a given thickness (a) is held between a matrix (3) and a ring (2) surrounding the stamp. A circular portion of the sheet metal workpiece (7) is pushed downwards into a circular aperture (8) in the matrix. The aperture has rounded edges (11), and the sheet metal is stretched thin (a 1) at this point (12). The diameter (dm) of the aperture in the matrix is less than the diameter (ds) of the stamp.