3 Fundamentals of press design

208 Sheet metal forming and blanking
impact speeds allow to extend service life considerably. Through this
optimization of working and forming conditions improved part quality
and increased tool life are achieved while increasing stroking rates.
The variety of parts which can be produced on these lines include
evaporator plates, bearing elements, hinges, hardware fittings and other
components supplied to the automotive industry as well as parts for
refrigerators, lock elements and clutch disks.
4.4.2 Production lines for the manufacture
of flat radiator plates
The combined forming and coining of large-panel press parts, such as
those needed to make the plates for flat radiators, calls for a press system
with extreme system robustness together with a generously dimensioned
die space. In view of the wide variety of radiator designs, a universally
applicable die technology concept is required.
High production output levels are only achievable using fully automated
production lines which permit set-up within a short period for
the production of different parts. Special press systems, with a nominal
press force of between 4,000 and 10,000 kN (Fig.4.4.11), have been
developed for the manufacture of flat radiator plates.
In order to achieve the largest possible system robustness, a bottom
knuckle-joint drive system was selected (cf. Fig.3.2.3). This principle is
distinguished by the highly compact, low-deflection construction of
the knuckle-joint bearing and the press bed. As blanks with large surface
area require large bed surfaces, a double knuckle-joint system is
provided to improve press bed support. This design corresponds in
principle to the single knuckle-joint system illustrated in Fig.3.2.5.
The widely spaced link joints of the double knuckle-joint ensure tiltresistant
drive of the press frame. The height position of the upper die
is adjusted by two wide power driven wedges which cover the entire die
width. Due to the reduction in forming speed and the optimized weight
of the slide frame construction, the knuckle-joint drive system ensures
a high stroking rate in conjunction with smooth, quiet press operation.
An optimized welded design of the press frame allows even wider
machines, with a frame width of up to around 2m, to be run at high
speeds. A press with a nominal press force of 7,100 kN, a frame width of
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998