3 Fundamentals of press design

12 Basic principles of metal forming
nd
punchfor2 draw
st
punchfor1 draw
as blankholder
forredraw
initialhollow
body
nd
2 drawnpart
die
Fig. 2.1.11 Multiple-draw deep drawing with telescopic punch
The most significant variation of deep drawing is done with a rigid
tool (Fig. 2.1.10). This comprises a punch, a bottom die and a blank
holder, which is intended to prevent the formation of wrinkles as the
metal is drawn into the die. In special cases, the punch or die can also
be from a soft material.
There are deep drawing methods which make use of active media
and active energy. Deep drawing using active media is the drawing of a
blank or hollow body into a rigid die through the action of a medium.
Active media include formless solid substances such as sand or steel
balls, fluids (oil, water) and gases, whereby the forming work is performed
by a press using a method similar to that employed with the
rigid tools. The greatest field of application of this technique is hydromechanical
drawing, for example for the manufacture of components
from stainless steel (Fig.2.1.13, cf. Sects. 4.2.4 and 4.2.5).
Fig. 2.1.12 Reverse drawing
st
blank holder for 1 draw
st
die for 1 draw
st
punch for1 draw as
die for reverse draw
blank holder for reverse draw
punch for reverse draw
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998