Research On Anti-kink Hydraulic System In Low-floor Trams

The anti-kink hydraulic system is a safe operation control system of the low floor trams,which can ensure the normal passage of the train when it is driving into and out of the bend curve,and has the function of lateral damping during the driving of the train,which can improve the comfort of the ride and effectively avoid the relative bending between the vehicle bodies.At present,the domestic anti-kink hydraulic system mainly depends on imports,the related research work is still in its infancy.Based on this situation,this study carried out a comprehensive analysis of the anti-kink hydraulic system structure composition,working characteristics,and the influence on the curve passing performance of the trams.Firstly,the paper introduced the development of the low floor trams and the research status of anti-kink hydraulic system at home and abroad,analyzed the structure and working principle of the anti-kink hydraulic system in detail,designed the schematic diagram of the hydraulic system to meet the working requirements,and determined the structure and working parameters of the main components.Secondly,the mathematical model of the anti-kink hydraulic system is analyzed,and the AMESim simulation model is established.The working mode and stiffness characteristics of the anti-kink hydraulic system are simulated and analyzed.The influence law of the working parameters of the main control valve group,the buffer valve group and the buffer cylinder on the stiffness characteristics of the system is further analyzed.Aiming at the lateral damping function of the anti-kink hydraulic system,the damping principle model is established,the damping characteristic curve is obtained by AMESim simulation software,and the influence law of the working parameters of throttle valve and pressure limiting valve of the buffer valve group on the damping characteristics is also analyzed,then,the accuracy of the established model is verified by experiments.Finally,the dynamic simulation model of four module 100% low floor light rail train is established by using Simpack simulation software,and the influence of anti-kink hydraulic system on vehicle dynamic performance is studied when the vehicle passes through the curve line.The results show that the anti-kink hydraulic system has the highest stiffness in the rescue mode,the steering control cylinder movement in the adjacent vehicle is consistent.The fault mode is second,the steering control cylinder in the adjacent vehicle has a very small displacement difference.The stiffness under normal mode is the smallest,and there is a large displacement difference in the steering control cylinder in the adjacent vehicle.The stiffness of the buffer cylinder spring,the diameter of the bypass throttle valve in the main control valve group,the diameter of throttle valve,the open pressure and the pressure gradient of pressure limiting valve in buffer valve group will affect the stiffness characteristics of the system.The working parameters of throttle valve and pressure limiting valve in buffer valve group directly affect the damping characteristics of anti-kink hydraulic system.When a train equipped with anti-kink hydraulic system passes through the S-type and C-type curve lines,the relative angle between the body and the bogie decreases a lot,and the train is confined to the right limit which is beneficial to improve the stability and ride comfort of the train,improve the safety of the train when passes curve line,and reduce various dynamic performance index.