3 Fundamentals of press design

Organization of stamping plants
When producing small sheet metal components such as drawer
slides, disc carriers for automatic transmissions, wishbones, bicycle
brake levers etc., the coil stock can be fed directly to the press by a coil
line (cf. Fig. 4.3.1).The sheet metal forming process takes place in a compact
piece of equipment, generally a high-speed press (cf. Fig. 4.6.6), a
universal (cf. Fig. 4.4.1) or transfer press (cf. Fig. 4.4.23).
The finished parts are palletized either manually or by using a stacking
device (cf. Fig. 4.4.41) and made ready for downstream processing,
for example welding, painting or hemming. At the same time, scrap disposal
takes place.
For the introduction of new dies for large parts and transfer presses,
try-out presses (cf. Fig. 4.1.19 and 4.1.20) and simulators (cf. Fig. 4.1.24)
are employed. These are used by the die shop to prepare tooling as well
as try-out of the dies before the final try-out on the actual production
press.
This shortens the die try-out time on the production presses substantially
for obtaining the first OK parts. Consequently, this procedure
shortens the time necessary to produce the first OK parts and increases
the machine utilization rate.
4.9.2 Layout
The following provides a detailed description of a typical example stamping
plant layout. To simplify matters somewhat, our explanation is based
on the assumption of ideal conditions and new installation of the complete
equipment (Greenfield plant). This is a typical task to establish
manufacturing facilities for the production of medium-sized and large
car body panels such as doors, roofs, hoods, floor panels, side panels,
fenders etc. for a particular car type. There are three press systems available:
tri-axis transfer presses (cf. Fig. 4.4.27), crossbar transfer presses (cf.
Fig. 4.4.38) and press lines (cf. Fig. 4.4.19) of various bed sizes.
Before preparing the plant layout, it is first necessary to determine
which parts are to be outsourced and which are produced in-house. The
following parts are generally produced in-house:
– outer panels whose surface could be damaged during transport,
– joining parts with narrow gap tolerances for precise matching,
– parts of large volume resp. size which are difficult to stack or transport.
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