3 Fundamentals of press design

354 Sheet metal forming and blanking
11
11
8
10 7 7
14
5
2 3
18
6 4
15
18
1
13
7 7
12
Fig. 4.7.23 Moving punch system, complete blanking die:
1 blanking punch; 2 blanking plate; 3 ejector; 4 guide/vee-ring plate;
5 inner form punch; 6 inner form ejector pin; 7 pressure pins; 8 back-up plate;
9 holding ring; 10 piercing punch retaining plate; 11 pressure pad;
12 punch base; 13 ejector bridge; 14 base plate; 15 latch bolt;
16 upper frame; 17 lower frame; 18 gib unit
positioned by means of the press frame's column gib 18. The blanking
and guide plate are fixed using the latch bolt 15.
Thefixed punch systemis suitable for all die types – in particular for the
manufacture of thick, large parts (Fig. 4.7.24). The blanking punch 1 is
positioned on a hardened pressure plate 9 on the upper die-set 16, and
is permanently positioned and fastened to the upper die-set 16. The precisely
fitted guide plate 15 and the vee-ring plate 8, which bear the latch
bolts 14, guarantee the fitting precision of the blanking punch 1 relative
to the blanking plate 2 by means of the column gib unit 18 of the frame.
The inner form slugs are stripped from the blanking punch 1 by the
inner form ejectors 6 and 7. Pressure is applied on the ejectors 6 and 7
and the vee-ring plate 8 by the vee-ring piston of the press via pressure
pins 13. Pressure pins 13 transmit the force of the vee-ring during the
blanking process and the stripping force during the stripping cycle.
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
9
17
16