3 Fundamentals of press design

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Fig. 4.6.9 Influence of the press stroking rate on the penetration depth of the blanking punch in
the female die
cal rigidity is provided by the solid press body, by the slide drive system
using a double fork connecting rod in short presses and two generously
dimensioned connecting rods in long presses, and by the bending resistance
of the slide. However, as the stroking rate-dependent increase in
penetration depth has a physical cause and does not depend on the static
and dynamic behavior of the press, a control device is frequently
used on high-speed presses. This device detects the increase in penetration
depth and automatically corrects it to the set value (Fig. 4.6.10).
Even when working at extremely high stroking rates, this system allows
to achieve a die service life that is similar to that achieved when blanking
in the lower stroking ranges.
In addition to the behavior of the press in the vertical direction, the
vibration characteristics of the slide in the horizontal directionalso influence
die life. As the blanking clearance between the punch and female die
amounts to only a few hundredths of a millimeter, highly stringent
demands are made on accuracy of slide guidance and on the horizontal
rigidity of the press body. The degree of horizontal vibration is also
directly influenced by play and by the elastic behavior of the press. The
horizontal play can be eliminated through the use of slide gibs with
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