Forces and stresses on tool and press
Sheet-based punching machines

On a progressive press tool, several sheet metal forming operations are carried out: cutting, bending and stamping.

However, the efforts developed by each of these operations are not of equal value. The highest forces are generally found in the die-cutting stations. It is therefore important to be able to evaluate these forces in order to dimension the tool and thus determine the overall forces of the press. The cutting force system is shown in figure 11 .

Vertical forces are the most important and are the subject of this presentation. It should be noted, however, that horizontal stress can be significant: this stress, which varies with cutting clearance and tool wear, can reach around a third of the vertical stress.

The stresses developed...