Optimization Of Alignment Parameter And Steeringsystem Base On Reducing Tyre Wear

Vehicle’s camber and toe-in are the two most important parameters. According tofront wheels’ side slip mechanism, an research on the optimum matching of thecamber and the toe-in is done by considering the properties of tires and the constructparameters of vehicle. Then a new formula of matching is developed. By analyzingthe steering moments on the vehicle steering wheels, formulas of aligning torque andsteering resisting torque are introduced. According to these formulas, the relationbetween rudimental yaw and alignment parameter, and the relation between manualsteering effort and wheel turning angle are gotten by way of functions. Based on thesefunctions、 GB/T6323.4-94、 GB/T6323.5-94and QC/T480-1999(2005), themathematical computations of the Returnability Test and the Steering Efforts Test arebrought out. Finally, the demonstration tests are made for a light-truck(1042)asexamples. Based on function of residual yaw-rate, camber incremental, caster andkingpin inclination, and a new calculation of camber and toe-in，a method foroptimization of caster and kingpin inclination is brought out. By analyzing the slipangle of steering wheels and the spatial motion of Ackermann steering linkage,calculation model of the spatial motion and Ackermann factor is introduced.Considering influence of velocity, an optimization scheme whose objective isAckermann factor is put forward. Finally, an actual optimal analysis is made for acoach(6608) as an example. According to the case of tyre abnormal wear of thecoach(6608), alignment parameter and mechanism of steering system and suspensionsystem, the reasons of tyre abnormal wear are found. Due to these reasons, Theoptimizations of alignment parameter and Ackermann steering linkage are brought out.It is proved by test results that the coach(6608) with optimized alignment parameterhas better Handing and Stability, the tyre abnormal wear of t coach(6608)is solved.