Study On The Dynamic Characteristics Of Variable Stiffness Suspension

Automobile suspension is the name of power transmission connection device, which is used to transfer the force and moment between the wheel and the frame, and buffer the impact force of the frame and the wheel caused by road, so it is closely related with the comfort and comfort of vehicle. The rigidity of spring is the only factor affecting suspension’s the natural frequency.The content of the subject is subsidized by C hongqing science and technology research project(applied technology research and development),named“air suspension system of automobile core technology research and industrialization”(project number is cstc2012gg- yyjs0867).the paper is the basic research of the dynamic characteristics of variable stiffness suspension.In this paper,it taken 1/4 vehicle as the research object, taken quality of single freedom vibration system as the research model,and based on the transfer function to deduce formulas of elastic characteristics 、 stiffness characteristics and frequency characteristics of the constant stiffness suspension、the deputy spring suspension、the multi-stage variable stiffness suspension and the air suspension.First of all,with leaf spring as the research object,it is concluded that the necessity of the design variable stiffness suspension, from the angle of the inherent frequency. Compared two kinds of design method of the main and auxiliary suspension,which are the geometric average method and average load method,found that the geometric average method is the optimal design method in the view of lower the range of natural frequency. Through analysis and study of multi-stage variable stiffness of suspension,it is concluded that the change law of the elastic properties, and deduce the relevant formula of elastic characteristics、stiffness characteristics and frequency characteristics.Secondly, with the air spring as the research object, in order to study the elastic characteristics、stiffness characteristics and frequency characteristics of air suspension,which is simplified as four vibration model in the method of step by step, and got the relevant formula.