3 Fundamentals of press design

Principles of die manufacture
spotting cylinder slide
slide cylinder
blank holder cylinder
marking stop
deep drawing
ad ustment
stepless
slide locking
slide cushion with adapter
hydraulic
draw cushion
position sensor for
the draw cushion
Fig. 4.1.20 Design of a hydraulic try-out press
duced. In addition, a spotting fixture for the slide and blank holder can
be applied to the contours of the die with a precisely controlled speed.
The die mounting area, the stroke and the force on all try-out presses
are so designed that the press can accomodate the total range of large
size tools. Force and speed can be selected in the ratio of at least 1 : 10,
so that the dies can be tried out by starting with a very low ram speed.
As a rule, both the punch and the die must be reworked at the same
time during die try-out.
In order to facilitate the rework and save time, hydraulic try-out
presses can be equipped with a pivoting slide plate (Fig. 4.1.21). At first,
the moving bolster carrying the lower die moves out of the press. When
pivoted, the top die is rotated through 180° and lowered and centered
onto a movable pallet truck. After this, the slide, the clamping plate and
top die are lowered to a pre-defined height and locked into the roll-over
device. The quick-action clamps release the slide plate from the slide,
and the slide moves to the top dead center position. After the slide plate
and top die have been turned over, the slide places the slide plate with
the top die in the centering of the pallet truck and moves again to the
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
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