Design And Research Of The New-style Hydro-pneumatic Buffer For Train

With the rapid development of the railway transportation industry,the buffer,which is used to achieve the connection between the vehicles and keep a certain distance,is one of the key components of the train.It can transmit and mitigate the longitudinal force and impact force generated by the train during operation or during shunting.The modernization process has forced the development of mechanical devices to become larger and faster,and for the safety components of mechanical devices,the performance requirements of buffers are getting higher and higher,and there is an urgent need to adapt to large load and high performance buffers to meet the needs of the mechanical industry.Therefore,it is urgent to develop high-performance and high-stability buffers.Compared with other types of buffers,the hydro-pneumatic buffer has the advantages of small size,low price,stable performance,excellent buffering effect and high energy absorption rate.A hydro-pneumatic buffer designed in this paper can be used with the No.15 coupler and applied to the 25T trunk coach.Its structure mainly uses the plunger as the main component to withstand the impact,the throttle damping ring and the throttle damping hole are used together as the damping structure.The through hole at the end of the plunger and the throttle damper together form a throttle damper ring,its end structure is provided with a throttle orifice for connecting the oil chamber 1 to the oil chamber 2.The check valve controls the switch of the throttle orifice,and the gas chamber is filled with compressed nitrogen as a reset element of the buffer.It avoids the rebound and fatigue that can occur with the spring as a reset element.This paper describes the working principle of the buffer.Based on the theory of fluid dynamics(CFD),the internal flow field of the buffer is modeled by the Fluent module of ANSYS Workbench.the dynamic mesh model and numerical simulation method are used to obtain the curve of impedance versus displacement when the compression speed is different,so the static and dynamic characteristics of the buffer are explored.This paper also explores the effect of the structural parameters of the buffer on the dynamic impedance curve of the buffer.The results show that with the increase of the size of the throttling damping ring and the aperture of throttle orifice,the resistance force of the buffer is gradually reduced,as the displacement increases,the resistance force shows an instantly increase-stationary-re-increasing trend,The throttle orifice length has little effect on the resistance.Reasonable design of the structural parameters of the buffer can adjust the dynamic characteristic curve of the buffer,improve the performance and stability of the buffer,and provide a reference for rational design of the structural parameters of the buffer.Finally,the fluid-solid coupling simulation of the throttle damper of the buffer is carried out.When the impact velocity is different,the stress and deformation of the throttling damper under the action of the fluid are explored.Comparing the maximum stress value of the throttle damper with the material properties.Ensure that the strength of the part meets the requirements while achieving the maximum impact speed it can withstand.