A sophisticated axle kinematics, which allows multiple adjustments, is of fundamental importance for a balanced handling. Specifically, the uprights as the „link” between the wishbones and the wheel have to take over a number of functions, which must be reflected in the design of the components:
• Rigid inclusion of the wheel bearings to allow precise control of the wheel
• Optimized geometry for caster and camber
• Torsionless incorporation of the pivot points for the lower wishbone and the steering arm
• If possible deep arranged incorporation of the brake caliper
• Incorporation of the wheel speed sensors
• Allowance of easy adjustment of camber through graded spacers
To meet the listed criteria at the lowest possible component weight, a new design for both the front and the rear uprights for the „evo” was necessary - compromising those things by purchasing the uprights would have lead to an unsatisfiying result.
Therefore, these components were engineered in the light of the above conditions completely. The entire manufacturing of the componets was performed in-house also.
Using a 3D - design program (CATIA), the first draft has been developed. To ensure adequate dimensioning for the use of the selected material (high strength aluminum of the type „7075”) the components were analyzed using FE - simulation programs in terms of their strength. After several optimization loops, which varied in the component weight against the rigidity of the relevant points an optimal design could been found and it was transfered to the next step.
The next step was the creation of a program code for the control of the machining center, producing the complex geometries. The fact that during the manufacturing of those components almost 90% of the starting material was machined illustrates the elaborate design of the uprights with a variety of strategically placed holes and milled slots.
All other parts, which furthermore are essential for the function of the upright (eg. wheel hubs, tie rods for the central bolt, steering arm, etc.) were designed using the same process: calculation, designing and finally programming for the production. As far as possible all components are made out of high-strength aluminum or alternatively titanium resp. high strength steels.
A surface treatment in form of anodisation enhances not only the optical appierance but also the increases the surface hardness further. This type of treatment minimizes the risk of mechanical damage to the surface.
The module „upright” persists of minimum 25 highly complex components which are assembled by using bolts of a high strength titanium alloy.