3 Fundamentals of press design

56 Fundamentals of press design
Fig. 3.2.4 Slide (eight-link drive system) and blank holder slide drive (toggle joint drive
system) in a double-acting deep drawing press
This kinematic characteristic offers ideal conditions for the deepdrawing
process. The slide hits the blank softly, allowing to build up
high press forces right from the start of the drawing process, and forms
the part at a low, almost constant speed. In addition, this system
ensures smooth transitions between the various portions of the slide
motion. During deformation, the drive links are stretched to an almost
extended position. Thus, the clutch torque, the gear load and the decelerating
and accelerating gear masses are between 20 and 30 % smaller
than in a comparable eccentric press. In the case of single-acting
machines, for instance, reducing the impact increases the service life of
the dies, the draw cushion and the press itself.
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998