Limiting drawing ratio Second draw without intermediate annealing
5.3.5
As β1 of the first drawing stage decreases, the limiting drawing ratio βn max increases in the following draws.
At the maximum draw ratio β1 of the first drawing stage, the maximum overall drawing ratio β tot is achieved.27
Eqn. 1
| Draw ratio | β2 max | = | |||
| Draw ratio | β3 max | = | |||
| Max draw ratio | β4 max | = |
| Constant | Cβ | = | ||||
| Draw ratio | β1 | = | ||||
| Draw ratio | β2 | = | ||||
| Draw ratio | β3 | = |
Calc 1
Draw ratio redraw27
The ratio constant C β is C β = 0.4 … 0.6 for different sheet metal materials
Werkstoff | Zug 1 β0 100 | Zug 2 β1 100 |
|---|---|---|
AlMg 3 weich | 2 | 1.5 |
AlMg 3 halbhart | 2 | 1.4 |
1.4301 | 2 | 1.25 |
DC 04 | 2 | 1.3 |
Tbl. 1 Limit drawing ratios β0 β1 without intermediate annealing | ||
The limiting drawing ratio β100 refers to a punch diameter of 100 mm. If there are deviations from this diameter, this ratio must be corrected in order to correctly calculate the maximum draw ratio.8
8
Oehler; Kaiser / Schnitt-, Stanz- und Ziehwerkzeuge / Springer Verlag / Berlin / 1993 / 7. Auflage
27
Herold, G.; Kluge, M. / EFB-Forschungsbericht Nr. 61: Simulation des Formstempeltiefziehens im Weiterschlag / Europäische Forschungsgesellschaft für Blechverarbeitung e. V. / Hannover / 1994 / …