3 Fundamentals of press design

Process technology and example applications
pressclosure
fillingwith
pressuremedium
applicationofhori ontal
cylinders,waterpressure
control,controlof
counterpressurepunch
pressopening,
e ectionofpart
Fig. 5.2.2 Production of a T-piece
counterpressure punch
The component and material-specific process parameter curves
(Fig. 5.2.3) are used to control the forming process. If an existing hydroforming
line is intended for the manufacture of a different workpiece,
the die is changed and a different program accessed in the machine’s
control system.
Expansion takes place under axial material flow, which is accomplished
by compression in the axial or radial direction (Fig. 5.2.4). Subsequently,
the component which has already been largely finish formed
is calibrated against the wall of the die.
The active forming forces are applied both by the moving die elements
and also by the pressurized medium. In the die-related method,
the formed part is pressed against the wall of a contoured die which
thus determines the final shape of the part.
After hydroforming, the components possess a high degree of dimensional
stability and high strength values. As a result of the three-dimen-
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
tube
contoured die hal es
seal punch
secondary contour
T-fitting
407