Study On Optimal Design Of Steering Linkages Of Light Trucks

The design of steering linkage of motor vehicle has significant effects onvehicle's steering performance, tire wear and handling and stability. So, the optimaldesign of steering linkage is an important aspect in the design of vehicle's frontsuspension-steering system.In present dissertation, the optimal design methods are studied fordouble-wishbone suspension-rack & pinion steering system and rigidaxle-longitudinal leaf spring suspension-integral steering system, respectively. Asimple coordinate transfer method is used to make spatial kinematics analysis for thetwo suspension-steering systems mentioned above, which presents an accurateanalysis method for the optimization of steering linkage. Optimization objectivefunctions for the two suspension-steering systems are presented, which focus onmeeting the requirements of the steering angle relationship between inner and outerfront wheels, interference steering angle caused by suspension compression andrebounding, and steering ratio of the vehicle. The objective functions consider therequirements of reducing tire wear, improving vehicle's steering performance andhandling and stability performance. The objective functions presented are morecomprehensive and well reflect practical engineering requirements for the design ofsteering linkage of motor vehicle.The software for the optimization of steering linkages in the twosuspension-steering systems has been developed, which is based on the spatialkinematics analysis mentioned above, optimization objective functions presented andthe flexible tolerance method. The software is easy to operate, has friendly interface,good calculation accuracy and result output formats easy to understand. Theoptimization of steering linkages of light trucks can be made conveniently and rapidlywith it. Thus the software has high value of practical application.The relationships between inner and outer front wheel steering angles of 11vehicles of different type were measured and average Ackerman correction ratiosobtained by fitting the data measured, which is beneficial for selecting appropriaterelationship between inner and outer front wheel steering angles.