Mechanical-Hydraulic, Adaptive Stabilizer Bar with Frequency–Selective Damping

The chassis of a passenger vehicle has a long history of development and seems to have reached its optimum in the cost-benefit ratio. On the one hand, the cost pressure is increasing, because the raw materials are becoming more expensive; on the other hand, high-end systems must clearly demonstrate the necessity of their use from a functional, weight, consumption, cost and strategic point of view. Caused by this reasons a large field opens between conventional, passive and fully active stabilizers.

As a new technical concept is presented an adaptive stabilizer, whereby a frequency-selective damping valve is connected in parallel to the torsion bar,see Fig. 1. The operating principle describes the use of the difference in angle of rotation of the two halves of the stabilizer to adjust a hydraulic piston, whereby a volume of oil is passed through a valve system and generates a frequency-selective damping. The stabilizer halves are connected on the one hand to the housing on the other hand to the shaft. The internal, passive application torsion bar connected to both sides is always engaged. The concept has been developed and prototype parts have been installed into a BMW X4. Due to the first positive driving impressions the basic concept could therefore be confirmed.