Research On Magnetorheological Fluid Coupler Buffer Device For Urban Rail Vehicles

The urban rail transit industry has been developed rapidly,while it solved the traffic congestion problem in the city and greatly improved people’s travel efficiency.However,the proximity of the adjacent subway station points of urban rail transit caused the subway trains to start and stop frequently,and the constant change of passenger flow made the load of the train change in real time,which made the train easy to produce obvious vertical impulse,not only greatly affected the passenger’s ride comfort,but also brought safety hazards if the vertical impact of the train is too large.In addition,strong vertical impact will accelerate the loss of the hook,affecting the life of the hook service.Therefore,in order to improve passenger ride comfort and improve train safety,according to the characteristics of frequent subway train start-up and excessive longitudinal impact caused by shunting conditions,the hook buffer was optimized to improve the impact problems brought about by parking start-up and shunting.In this dissertation,the domestic subway vehicle hook buffer as the research object,combined with magnetorheological fluid technology to the existing hook buffer put forward a bold innovation and improvement,the magnetorheological rheum changed fluid technology applied to the subway hook buffer.The specific realization form is: referring to the existing coupler buffer,injecting magnetorheological fluid into the cavity of the piston-cylinder coupler buffer,and installing an excitation coil in the buffer damping unit to design the magnetorheological fluid coupler buffer.According to the characteristics of magnetorheological fluid could change the viscosity state of magnetorheological fluid liquid quickly by changing the strength of magnetorheological field,the magnetorheological fluid hook buffer can automatically adjusted the current of the control excitation coil according to the impact size of the vehicle to generate magnetic field,thus generating the corresponding damping force to quickly and accurately consumed the impact of the train,and thus achieved the goal of improving the safety and comfort of subway trains.The main content of this dissertation are:(1)Based on the longitudinal dynamics theory of the train,the longitudinal impact force of the subway train was analyzed and calculated,which provided a theoretical basis for the design of the magnetorheological fluid coupler buffer device;(2)According to the basic theory of magnetorheological fluid and the design standard of coupler buffer device,the structure design of magnetorheological fluid coupler buffer device was carried out,and it was concluded that the structure design of magnetorheological fluid coupler buffer device was reasonable,the damping output and the The adjustment coefficients all met the requirements;(3)The finite element analysis of the magnetic circuit of the designed magnetorheological fluid coupler buffer device was carried out with Maxwell software,and it was concluded that the magnetic circuit design met the requirements.Set up a control group to compare and analyze the magnetic field state of the same direction current and reverse current under different working conditions,and found that the reverse current is less likely to reach magnetic saturation under the same conditions;(4)The equivalent module of the damping output of the magnetorheological fluid coupler buffer device was established with Simulink software,and the damping output of the magnetorheological fluid coupler buffer device under the conditions of inputting different currents,amplitudes and frequencies was analyzed by the control variable method.The influence of current,amplitude and frequency on the damping output shows that the current has the greatest influence on the magnetorheological fluid coupler buffer device,maximum damping output meets design requirements;(5)Simulink software was used to simulate the magnetorheological fluid coupler buffer device under the maximum impact force of the subway,and the simulation results were compared with the existing ordinary coupler buffer device to test the buffer effect of the magnetorheological fluid coupler buffer device,It proved that the designed magnetorheological fluid coupler buffer device met the standard of coupler buffer device,and has better buffering and damping effect than ordinary rubber coupler buffer device.