3 Fundamentals of press design

540 Solid forming (Forging)
To comply with the very highest quality requirements and when producing
difficult and complex reliefs, it is possible to use an oscillating
technique with varying press forces (Fig. 6.8.30).
The hydraulic double-action press comprises a press frame with a
closed frame structure, an integrated drive cylinder and separate power
drive. The press slide (coining cylinder) is CNC-controlled and has a
multiple-surface design.
Based on the principle of differential pressure surfaces, optimum levels
of output are achieved with low energy consumption. The ejector
cylinder, also controllable by CNC, is integrated underneath in the
press frame. The cheeks of the press yoke are positioned directly against
the die system and are slightly larger than the piston rod, so guaranteeing
optimum rigidity. The traversing motions are controlled by means
of servo control valves with incremental setpoint inputs and mechanical
actual value feedback.
Fig. 6.8.29 Hydraulic medal minting press
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998