Study On Structural Parameters And Dynamic Characteristics Of Gas-hydraulic Buffer

With the rapid development of high-speed rail technology,as of 2020,the maximum speed of high-speed trains has reached 420km/h,which has led more and more researchers to pay more attention to the passive safety devices of trains,among which the buffer is the most critical functional component.The function of the buffer is to absorb longitudinal impact force during the startup,braking,operation,acceleration and deceleration of rail vehicles,and in the event of collision accidents,thereby protecting the safety of passengers and goods inside the carriage.At present,the gas-hydraulic buffers used in high-speed train sets in China mainly rely on expensive imports from abroad,and domestically manufactured gas-hydraulic buffers cannot meet the operational needs of trains.Therefore,conducting research on the structural parameters and dynamic characteristics of gas-hydraulic buffers in this article has important theoretical significance and engineering practical value.Gas-hydraulic buffers are widely used in high-speed train sets due to their stable performance,large capacity,and small volume.However,due to the complexity of their structure and nonlinear dynamic characteristics,it is difficult to establish accurate simulation models.This article establishes a dynamic model of the working process of a typical gas-hydraulic buffer by analyzing its structure and working principle.A multi body dynamic model of impact trolley,track,rigid wall,and simplified gas-hydraulic buffer was established in the multi body dynamics software RecurDyn.The hydraulic and pneumatic circuits of the gas-hydraulic buffer were established in AMESim,and finally,the simulation calculation of gas-hydraulic mechanical coupling of the gas-hydraulic buffer was achieved through joint simulation.Through simulation analysis of the dynamic characteristics of gas-hydraulic buffer under different impact velocities,it was found that the buffering displacement,impedance force,and absorbed energy of the gas-hydraulic buffer increase with the increase of impact velocity.In order to judge whether the simulation model can simulate the collision process of the real gas-hydraulic buffer,a dynamic impact test was conducted in the railbus laboratory of Changchun Railway Bus Co.On the basis of the simulation model,the influence law of different impact conditions,structural parameters and working medium parameters on the dynamic characteristics of the gas-hydraulic buffer was studied by changing the simulation parameters,and the results showed that the mass and speed of the impactor,the width of the throttle damping ring slit and the viscosity of the hydraulic oil had a great influence on the performance of the gas-hydraulic buffer.The buffering displacement of the gas-hydraulic buffer increases with the increase of the width of the throttling damping ring gap,and its impedance force decreases with the increase of the width of the throttling damping ring gap.The effect of hydraulic oil viscosity on the gas-hydraulic buffer is opposite.In addition,the buffering displacement and impedance force of the gas-hydraulic buffer increase with the increase of the mass and velocity of the impactor.The simulation model of gas-hydraulic buffer established in this article can simulate the real working conditions of train collision process,and has important reference value for achieving independent development and optimization design of gas-hydraulic buffer.