3 Fundamentals of press design

5 Hydroforming
5.7 General considerations
5.7.1 Production technology issues
Any comparison between hydroforming and other processes – such as
compression moulding, assembly of stamped parts, casting or assembly
of bent tubes – must take into consideration all the technical as well as
economic aspects. Preceding and subsequent work steps and the properties
of the finished component must also be included into any evaluation.
Production by means of hydroforming can, for instance, appear
uneconomical for small quantities if only the component costs are considered,
as the cycle times required are relatively long (Table 5.7.1).
However, if we compare the technical properties of the end product
with those produced using different techniques, it is possible to make
up for this drawback. Where medium and high quantities of a component
suitable for hydroforming are involved, the technical and economic
benefits of hydroforming can be brought so effectively to bear
that no other manufacturing processes can realistically be considered.
Table 5.7.1: Cycle times for different parts
Component Automation Components per stroke Cycle time
exhaust manifold with dome no 2 15 ... 25 s
exhaust manifold tube yes 2 ... 4 15 ... 20 s
side member for pick-up yes 2 40 s
instrument panel rail yes 1 35 s
T-fittings yes up to 25 13 s
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998