| 摘要 |
<p>PURPOSE:To prevent an increase of pre-load hydraulic pressure of a pressure uniforming device, and to always obtain an article with a stable quality. CONSTITUTION:In a pressure uniforming device of a press through a hydraulic cylinder 1 applying a pre-load hydraulic pressure between a cushion pin and a die cushion pad supporting a blank holder from a lower side, a valve means 8 which takes out temporarily the pre-load hydraulic pressure in the hydraulic cylinder l during a slide is ascending between a hydraulic pump 5 feeding the pre-load hydraulic pressure to the hydraulic cylinder 1 and the hydraulic cylinder 1, because the pre-load hydraulic pressure is re-set on every one cycle, the increase of the pre-load hydraulic pressure caused by pumping action can be prevented.</p> |
