Research On Low Dynamic Bogie Of120KM/H A Type Metro Vehicle

As the City expanding in China, several long station spacing subway line have been built already, then the120km/h A type metro which have faster speed and heavier axle loads have running successful. But with the increasing speed and raising axle load, the wheel/rail interaction in both vertical and lateral are unavoidably reinforced. Initiatives to reduce the wheel/rail interaction can improve vehicle’s ride quality, reduce derailments, lower the shock between wheel and rail, reduce wheel and rail failures; so that the vehicle system can keep in good condition and long-term efficient operation. It’s the key point to acquire low dynamic interation when design metro vehicles.According to120km/h A-type metro vehicles and the characteristics and the condition of metro lines. Considering the vehicle/track interaction as a overall system based on the theory of the vehicle-track coupling dynamics model, A vehicle traffic system dynamic model has been established by SIMPACK multi-body system dynamics software, so as to investigate the effects of suspension and structure parameters of the train and structure parameters of the track on wheel-rail interaction. Much technical measurement is put forward to make the type of metro vehicle to get low lateral wheel-rail dynamic feature for urban rail vehicle designers reference. Analysis results show that:Within the rail parameters, the overall vertical stiffness of the track has much effect on the wheel/rail interaction, the overall lateral stiffness of the track and the overall damping of the track has less effect, however the overall lateral damping has no effect on the wheel/rail interaction almost. The overall vertical stiffness of track affects the wheel/rail interaction in both vertical and lateral direction, and the reability of the wheel/rail interaction caused by the overall vertical stiffness of track is obviously large. It’s very available for dynamic reduction to reduce the vertical stiffness of the fastening on the premise of keep the rail stability. The increasing of the track’s overall vertical damping is beneficial to reducing the wheel/rail vertical force P1、P2, rail vibration acceleration. The increasing of the track’s overall lateral stiffness will cause increasing of wheel/rail lateral interaction, and make the wheel/rail wear phenomenon worse, but it will not disturb the vehicle’s lateral stability.Within the parameters of vehicle structure and suspension, which will disturb wheel/rail interaction includes:unsprung mass, the vertical stiffness of the first suspension’s axle box’s spring, the longitudinal and vertical stiffness of the axle box rotary arm positioning mode, the damping of the first suspension vertical damper. Reducing the unsprung mass is an efficient approach to lower wheel/rail’s vertical and lateral interaction. The vertical stiffness of the first suspension’s axle box’s spring(Kpz) will affect the high frequency force-P1, when Kpz increasing, the high frequency force P1decreased significantly; meanwhile the Kpz has limited influence on the lateral wheel/rail interaction, an oversized Kpz will lead the wheel/rail lateral dynamic performance to deteriorate. It’s available for improving the wheel/rail lateral dynamic performance to decrease the longitudinal and vertical stiffness of the axle box rotary arm positioning mode if the vehicle lateral stability is reasonable. Increasing the damping of the first suspension damper(Cp2) in a reasonable range is an efficient approach to reduce the high frequency force P1,and which can maintain the low frequency force P2at a low level at the same time, a oversize Cp2will cause P2increasing rapidly and make the vertical wheel/rail interation deterioration. It’s unremarkable for the dynamic reduction to change the stiffness values of the second suspendion, so much investigation should be focused on the ride performance of the train in the process of the design.