3 Fundamentals of press design

514 Solid forming (Forging)
Horizontal presses with modified knuckle-joint
If longer forming strokes are necessary, a modified knuckle-joint drive
system can be used as a special variation of the standard knuckle-joint
power unit. The force-stroke curve and the slide velocity correspond to
the vertical press shown in Fig. 6.8.3.
6.8.3 Hydraulic presses
Hydraulic presses are also designed in vertical and horizontal layouts.
They enjoy extremely universal application in solid forming both on a
single-station and multiple-station basis, either with manual operation
for small batch sizes or fully automatically for production rates of up to
1.8 million pressed parts per year. They are frequently used as presses
for long shafts and shaft-type parts, or for large parts with weights of up
to approx. 15 kg.
As in mechanical presses, the selection of the necessary press size is
made on the basis of part geometry, workpiece material and of the
required manufacturing process. The basic principles are described in
Sects. 3.3 and 6.5.
Vertical design
The hydraulic components and oil tanks are generally accommodated
in the press crown (Fig. 6.8.8). A service platform offers convenient
maintenance of the easily accessible units. The uprights are generally
configured in the form of a welded monobloc or panel structure (cf.
Fig. 3.1.1).
In special cases (for example in the event of space problems or to
reduce noise), the pumps and motors can also be mounted in the foundation
or in a separate room. Vertical hydraulic presses are generally
used for cold forming. However, it is not unusual for them to also be
used for hot forming under certain circumstances (cf. Sect. 6.8.5). Particularly
where large parts are involved (weights above 5 kg), hydraulic
presses are frequently used for hot forging. The usual press forces lie
between 1,600 and 36,000 kN, and presses with slide strokes of up to
1.5 m have already been manufactured.
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998