Research On Dynamics Of Coupler Buffer Device Of Emu Based On Magnetorheological Technology

With the continuous increase of train speed and traction weight,the longitudinal impulse of the train continues to increase.Excessive longitudinal impulse will shorten the life of train and vehicle parts,and even cause accidents such as vehicle derailment and broken hooks.Therefore,the performance of the buffer has a key impact on the train shunting operation,running speed,and the safety and comfort of the train.More attention has been paid to the research on buffer performance in recent years,The thesis studies and designs a coupler buffer based on magnetorheological technology to alleviate the longitudinal shock of the train.The main research work includes the following aspects:(1)Understand the similarities and differences between the parametric and non-parametric mechanical models of magnetorheological dampers,and compare and analyze the application of each mechanical model in different environments.In this dissertation,the mechanical model of the damper selects the Bingham parameterized model to study magnetorheological dampers.Magnetorheological effects in three basic working modes,and further derive the functional relationship between the output damping force of the magnetorheological damper in the three working modes and other parameters,which lays a preliminary foundation for the structural design and magnetic circuit design analysis of the buffer damper of the EMU Theoretical basis.(2)According to the different structural forms of the basic flow path and piston rod of the magnetorheological damping unit,combined with the working environment of the EMU coupler buffer device,the annular flow path and the single rod structure are selected as the damper structure;according to the structure design of the magnetorheological damper Principles and buffer design requirements,preliminary design of structural parameters such as damping gap,piston rod radius,piston effective length,piston effective area,and accumulator gas;according to the damping gap magnetic induction intensity saturation principle,the piston,cylinder,magnetic Appropriate materials are selected for rheological fluid and coils,the number of turns of the coil is determined by Ohm’s law of the magnetic circuit,and the influence of changes in the damping gap,piston flange width,piston rod diameter and piston diameter on the maximum damping force is analyzed,and further optimized for The structural parameters of the damping longitudinal impulse damper of the EMU.(3)Using ANSYS electromagnetic module software to simulate the electromagnetic effect of the magnetorheological damper under different excitation currents,the simulation results of the magnetic induction intensity under different excitation currents are obtained.When the coil of the piston head is a two-stage coil,the average magnetic induction intensity in the damping channel It is better than the single-stage coil structure,and optimizes the distribution of magnetic field intensity and magnetic induction intensity in the channel gap.(4)Based on the previous structural design,electromagnetic simulation and functional relationship of the damper,a SIMULINK model of a magnetorheological damper with a maximum damping force of 800 k N was established to analyze the output characteristics of the damper under specific working conditions;the SIMPACK dynamic software was used to establish a single freedom The degree four-vehicle model uses the characteristic fitting curve of the EMU buffer as input to analyze the simulation of vehicle impact when the EMU train collides on a straight track.The simulation results show that the shock absorber can effectively absorb impact energy,and the maximum longitudinal acceleration of the vehicle is lower than the 5g limit specified in the EN15227-2008 standard.The research results of this dissertation can provide a theoretical basis for the design of magnetorheological damper for EMUs in the future.