Tandem Suspension System Design And Ride Comfort Analysis Of Heavy Duty Tractor

Leaf spring tandem suspension system is a kind of suspension structure widely used in heavy duty multi-axles commercial vehicles.On the one hand,it enhances the loading capacity of the vehicle,improves the adhesion performance of the tires and distributes the vertical load between middle and rear axle wheels equally,on the other hand,it is closely related to the ride comfort,handling stability and reliability.However,at present,in the process of product development,the domestic heavy truck enterprises do not design and match the parts of the tandem suspension system reasonably,the analysis of the motion law and operation conditions are not sufficient,and lack the further research of the dynamic characteristics,which restricts the improvement of the ride comfort and reliability of the system.In view of the above background and problems,this paper takes the tandem suspension system of a tractor as the research object,and adopts the study ideas from parts to system,then to the whole vehicle to carry out system design and match,dynamic analysis and vehicle ride comfort simulation and test.The main research content include:(1)This paper analyzes the structure and working principle of the tandem suspension system,introduces the technical requirements and design process of the forward design of the tandem suspension system,expounds the structure and matching calculation method of the key parts and assemblies,and completes the relevant design,bench test and vehicle verification.(2)By using CATIA software,the eight degree of freedom kinematic model of the tandem suspension mechanism is constructed,and the motion under four working conditions is simulated visually;the vehicle suspension system package test is completed,and the results show that the simulation results of the model are in good agreement with the test data,the maximum error is less than 2%,which provides an effective method and a practical reference model for the design and kinematic analysis of vehicle tandem suspension mechanism.(3)The topological structure of the tandem suspension system is analyzed.The virtual prototype model is established by using Adams / Car Truck.The K& C characteristics of the tandem suspension system are analyzed for five typical working conditions.The analysis results show that the hardpoint setting of the system is reasonable and the K & C characteristics of the mechanism meet the design requirements.(4)In this paper,the simplified modeling conditions of the tandem suspension system are proposed,the three degree of freedom dynamic model is established by using Lagrange equation,the amplitude frequency characteristics of the system vibration response are analyzed,and the effects of stiffness and damping on the suspension performance are studied.(5)The half vehicle eight degree of freedom dynamic model is established,and the ride comfort of the whole vehicle is simulated and analyzed by MATLAB software.The ride comfort test and data processing are carried out according to the national standards based on random input driving test method.By comparison,it is found that the simulation results are consistent with the test results.The model has certain theoretical significance and practical application value.