| 摘要 |
<p>The invention concerns a tool for regulating the surface pressure on a blank constituting a metal plate which forms the starting item for shaping a finished item in a press. The blank is placed between a draw ring (23) and a blank holder ring (24). Besides, the tool comprises a shimming plate (1, 5, 10) provided with chambers (2, 3, 4, 6, 7, 8, 9, 11, 12, 13, 14) which are delimited by the shimming plate itself and by a flexible membrane (27). The shimming plate is placed between a tool bottom part (17), alternatively a tool top part (16), and the blank holder ring, alternatively the draw ring. A pressure medium like hydraulic oil may be led to the chambers. Thereby it is possible locally and individually to increase the surface pressure on the blank depending on the number of chambers, the design of chambers and the location of the chambers in the shimming plate. Furthermore, it is possible to regulate the pressure during the shaping process itself.</p> |
