3 Fundamentals of press design

16 Basic principles of metal forming
Fig. 2.1.19 Embossing
punch
workpiece
die
Forming by bending
In bending with a linear die movement the die components move in a
straight line (cf. Sect. 4.8.1). The most important process in this subcategory
is die bending,in which the shape of the part is impacted by the
die geometry and the elastic recovery (Fig. 2.1.20). Die bending can be
combined with die coining in a single stroke. Die coining is the restriking
of bent workpieces to relieve stresses, for example in order to reduce
the magnitude of springback.
Bending with rotary die movement includes roll bending, swivel bending
and circular bending. During roll bending, the bending moment is
applied by means of rolling. Using the roll bending process, it is possible
to manufacture cylindrical or tapered workpieces (Fig. 2.1.21). The
roll bending process also includes roll straightening to eliminate undesirable
deformations in sheet metal, wire, rods or pipes (Fig. 2.1.22 and
cf. Sect. 4.8.3) as well as corrugating and roll forming (Fig. 2.1.23 and
cf. Sect. 4.8.2).
Fig. 2.1.20 Die bending
punch
workpiece
bending die
Udie Vdie
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998