Products and solutions, 2000-03-20, 01:00 AM
Automotive segment: New twist beam axle delivers up to 25 percent cost and 30 percent weight savings
A new twist beam axle design devised by the Brackwede, Germany plant of Thyssen Umformtechnik + Guss GmbH (TUG) cuts costs by up to 25 percent and reduces weight by as much as 30 percent. The design is being developed to production maturity in a joint project with a German auto manufacturer. The key innovation is a new twist beam with a significantly lower wall thickness than comparable conventional components.
The twist beam and the trailing links welded to each end are the core components of twist beam axles. To date, the most common production method for the beams has been to bend five to seven millimeter thick sheet metal blanks into components with a V-shaped cross section. TUG's new design can be realized with thicknesses from only 1.5 millimeters. A high-strength dual-phase steel is used with a strength of 600 newtons per square millimeter.
However, the key to the wall thickness reduction is the shape of the beam, which TUG has submitted for patent: steel strip is roll-formed to a component with a double-U cross section and a cavity between the inner and outer shells. This cross section provides a distinctly superior torsional moment of inertia to conventionally formed twist beams. The new design even makes it possible to dispense with the stabilizer bar, which is inserted into conventional twist beams as a reinforcing element - especially on vehicles with powerful engines - and welded to the two trailing links.
Another new aspect of the TUG twist beam axle are the trailing links, which comprise flangeless welded half shells. While the majority of trailing links are currently made from tubes, TUG's design offers greater design latitude for reducing weight and integrating further functions. For example, the shape of the sheet metal shells is adapted to load conditions, rendering reinforcing or supporting elements between the twist beam and trailing links unnecessary. Also, the connections for spring seat and shock absorber mount can be integrated in the trailing links.
The new twist beam axle design is a product of the pre-development department set up in 1997 at TUG's Brackwede plant. TUG Brackwede was one of the first automotive suppliers to establish its own team to advise customers in the design phase of new models.