| 摘要 |
<p>The method involves bending a metal sheet between dies (16B) and a matrix (30), first with the edge of the blank held by a clamp die (15), and then with its edge released. The sheet metal blank is subjected to a number of stamping operations between dies and matrices of different shapes. Each stage increasing its concavity and depth, leaving an edge (24) which lies perpendicular to its base to form a cylindrical collar for one end of the container.</p> |
