Patent ID: 6099084
Filing Date: 2000-08-08
Classification: B60B,B60G

Abstract:
A motor vehicle rear axle of the twist-beam axle type having unitary control arm assembly comprising an opposed pair of longitudinal control arms (2) of a high flexural strength and torsional stiffness, each for supporting a wheel carrier plate for a wheel, and a transverse strut (3) which is resistant to bending but resilient relative to torsional stress and which has a profiled cross-section and which twists to change the location of the shear center thereof, opposed ends of said strut being integral with a said control arm at a joining zone, characterized in that the transverse strut (3) consists of an aluminum extrusion having the following composition: Magnesium 0.4-1.4% Silicon 0.4-1.5% Copper 0.01-1.0% Iron 0.1-0.8% Manganese 0.01-1.0% Chromium max. 0.3% Zirconium max. 0.3%  balance aluminum and unavoidable impurities and having an extrusion structure extending in the longitudinal direction of the transverse strut, said extrusion structure of said transverse strut comprising primary precipitates of an aluminum alloy selected from the group consisting of AlMn, AlMnFe and AlFe.