Research On Variable Damping Hydraulic Shock Absorber For Express Wagon

With the rapid development of our country's economy,the improvement of people's living standards and the emergence of a new Internet e-commerce model,the demand for goods transportation characterized by timeliness,diversification and high added value has increased sharply.The standard of convenience,completeness and economy of goods transportation in the market is also getting higher and higher.Accordingly,higher requirements are put forward for the safety and stability of wagon.As an important part of wagon suspension system,shock absorber can restrain and attenuate vehicle vibration.The performance of traditional friction shock absorber is not stable and can not meet the dynamic performance requirement of wagon bogie.At present,express wagons in our country are at the stage of research and test,and the dampers mostly rely on foreign imports.In order to realize the transformation development of railway freight transportation,it is necessary to study the shock absorber suitable for express wagons in China.In this context,primary vertical shock absorbers for 160km/h express wagons is systematically studied in this paper.Considering the empty and heavy vehicle characteristics of express wagons,the shock absorber should have two-stage damping characteristics.After summarizing the development and technical characteristics of bogies and shock absorbers for express wagons at home and abroad,this paper determines that passive displacement-related hydraulic shock absorbers are suitable for installation on fast freight cars in China.Firstly,this paper takes the traditional two-way reciprocating flow damper as the research object,analyses its structure and working principle,builds a model in AMESim,and completes the corresponding performance test of the damper bench,which verifies the correctness of the model.On this basis,by adding a bypass groove to the inner wall of the working cylinder,the two-stage damping of the shock absorber can be adjusted with the piston displacement.The influence of structural parameters on the external characteristics of the shock absorber is studied by using AMESim software.Furthermore,according to a 160km/h express wagon in China,a dynamic model of express wagon was established based on SIMPACK.Finally,in the Simulink environment,the AMESim/SIMPACK co-simulation platform was built to realize the coupling between the hydraulic model of shock absorber and the dynamic model of express wagon.The dynamic performance of the joint simulation model is predicted according to the evaluation index in GB5599-85.The results show that express wagon needs different vertical damping in the condition of empty and heavy vehicle,and the passive displacement related shock absorber can meet the requirements of the characteristics of empty and heavy vehicle.