| 摘要 |
PURPOSE:To permit easy synchronization of upper and lower dies and to reduce the cycle time for forming by fitting freely slidablly upper and lower dies into upper and lower die sets and interposing a differential mechanism between the dies to transmit the displacement between the die sets. CONSTITUTION:A movable rack 35 is depressed and a pinion 32 rotates when a slide 2 descends upon contact of upper and lower dies 9, 22 with each other in a pair of die sets 1 and 3 in a press machine. A fulcrum shaft 31 is descended by 1/2 of the downward displacement of the slide 2 by the differential function of the pinion 32 and the lower die 22 is descended by as much as said displacement. The upper die 9 descends as well by as much as 1/2 of the downward displacement of the slide 2. On the other hand an upper punch 11 descends by the same stroke as the stroke of the upper die set 1 and a lower punch 23 is held fixed. The contact surfaces of both dies 9, 22 are therefore maintained at the ratio of the position in the initial state of the downward movement between the opposed surfaces of the punches 11, 23.
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