Study of Car Multi-Link Rear Axle Considering Their Kinematic Incompatibilities

Abstract

Multi-link rear axles offer some important advantages relative to vehicle handling. But the structure of the multilink split type generally determines kinematic incompatibilities in its operation. The paper studies some aspects surrounding constructive solutions that could minimize these kinematic incompatibilities. Some rear axle mechanisms from different cars were measured and analyzed as component shape by authors; this process allows the geometrical modeling and animation of systems using specialized software (Autodesk Inventor Professional 8). The effects of these modeled structures (the variations of track width and wheel camber angle) have been studied using the above-mentioned software. The variation of track width caused by the studied mechanisms along the compression and relaxation of the suspension spring defines the trajectory of the tyre contact patch. The results are contextualized in diagrams showing that the modifications of the analyzed parameters are very important, with a negative influence on car stability and the comfort of passengers. The interpretation of these diagrams allows the choice of favorable constructive solutions to increase car performance.

Influence of compliance for an elastokinematic model of a proposed rear suspension

“…The analysis of operation of double wishbone front suspension mechanisms gives their influence on the guiding of front wheels is appreciated through the variations of the track half-width and the camber angle depending on the wheel vertical displacement. Dobre et al (2011) present research starting from the analysis of an existing variant (Ford and Volkswagen cars) of multi-link rear axles leading to a multi-link rear axle structure proposed by authors. The models have incompatibilities resulting from different causes (inaccurate measurement, used types of joints -rigid or semi-elastic, supplemental arm, etc.).…”