3 Fundamentals of press design

76 Fundamentals of press design
– Forces are generated through the action of the hydraulic fluid.
– Displacements are achieved by the supply of hydraulic fluid.
– Press (slide) speed is proportional to volumetric flow rates.
– Forward and reverse motions are controlled by the direction of
fluid flow.
Design of hydraulic systems in presses
The hydraulic system is subdivided into several functional assemblies
(Fig. 3.3.3). The hydraulic fluid is stored in the oil tank. All suction pipes
to the pumps or cylinders are supplied with fluid from the reservoir. The
fluid tank is suspended at the press crown to ensure that the cylinders are
filled when the press closes at high speed. The hydraulic drive system,comprised
of pumps and motors, forms a structural unit together with the
clutch and connecting flange. The pumps used are either immersion
M
3
slide
cylinder
P
slide
control
pressure
and pump
control
oil tank
secondary
systems
al econtrol
pressure
accumulator
pump dri e
Fig. 3.3.3 Arrangement of a press hydraulic system
heating
cooling
filtration
primary circuit secondary circuit oil maintenance
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
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