Research On The Design And Optimization Of Heavy Truck Air Suspension System

Suspension system has great influence on vehicle ride comfort and handling stability.With its excellent performance,air suspension system can make the vehicle obtain ideal natural frequency,good ride comfort and stability.At the same time,it can reduce the damage to road,ensure the integrity of goods,facilitate the docking of trailers and cargo handing.It has been widely used in heavy trucks abroad.For a long time,air suspension is seldom used in heavy trucks in China.However,with the increasing demand of consumers for comfort of trucks,air suspension system has attracted the attention of automobile companies,especially the promulgation of relevant national regulations,which further promotes the application of air suspension in heavy trucks.In order to meet the market demand and adapt to the changes of relevant laws and regulations,a 6×4 heavy truck with air suspension needs to be developed.In this paper,the design,development and optimization of air suspension system for heavy truck are studied in combination with the development process of the suspension system of the heavy truck.Firstly,starting with air spring,this paper expounds the difference and application occasion of bellows type and rolling lobe air spring,as well as the criterion of arranging air spring in the design process,studies the fitting method of constant pressure characteristic of air spring and the calculation method of stiffness,and compiles the calculation program based on MATLAB software.Then,the variation of axle load and wheel load under acceleration and roll conditions is analyzed,and the design checks of main components of suspension system are carried out,including the matching of front suspension leaf spring,rear air suspension pipeline and air spring,the matching checks of stabilizer bar and shock absorber,and the checking calculation of vehicle roll angle is also carried out.The three-dimensional model of air suspension system is established in the three-dimensional design software.According to the geometric parameters of the suspension of the three-dimensional model,the multi-body dynamic model of air suspension system is established in ADAMS/Car.The parallel travel analysis and opposite travel analysis is carried out.The simulation results of vertical stiffness,roll stiffness and alxe angle are obtained.In order to optimize the guide mechanism,the response surface method is used to optimize the hard-point of the rod,which reduces the change of axle angle and longitudinal displacement.The simulation analysis of the optimized model is carried out to obtain the load of the lower rod bracket.Finally,HyperWorks is used to optimize the structure of the lower reaction bar bracket.According to the results of the topology optimization,the structure design is carried out and the bracket sample is made.The reliability test of 6×4 heavy truck assembled with air suspension system was carried out to verify the reliability of the air suspension system designed and developed.