Analysis Of Fluid Field And Throttle Valve Structure Of High-speed Train Shock Absorber

Reducing the vibration of the High-speed train becomes even more prominent, because the train speed up causing it body vibration increase. Shock absorber is one of the key components to ensure the train stationary, and its performance should be improved accordingly. In order to study the influence of the fluid field temperature、piston velocity and structure parameters to the shock absorber performance, the situation of shock absorber fluid field and the analysis of structure parameters affect the damping characteristic are study:1. An entire geometry model for fluid field of high-speed train shock absorber was built. The three-dimensional dynamic fluid field in the shock absorber was simulated using the method of computational fluid dynamics, combined with experimental results, obtaining the throttle valve damping hole size.2. Based on the simulation mode, when the oil temperature is-20℃、20℃and80℃, and the piston at two speeds, shock absorber dynamometer and speed characteristic curve are calculated. The results show as follows:the maximum damping force is increase with the addition to velocity or exercise frequency; the valve flakes is easily open and oil dynamic viscosity is decreased by the oil temperature increased, resulting the shock absorber damping force is reduced and the vibration reduction ability becomes weak.3. The valve flake opening force, opening speed and the maximum deformation is got by adjusting the trend of the dynamometer curve. Analysis obtained that:at the same temperature, the valve flakes opening force is substantially equal in all conditions; the valve flakes opening speed and the maximum deformation is also increase with the addition to velocity, but when the damping force reaches a fixed value, the valve flakes sometimes open and sometimes close to keep the damping force tends to the fixed value; at different temperatures, the valve opening force decreases with increasing temperature. 4. Normal-open damping hole structure parameter determine the dynamometer shape when the shock absorber at low speed. Analysis of the damping characteristic about the different normal-open damping hole, obtaining that:when the normal-open damping hole throttle passage volume is same, the more number of the step or the throttle passage, the greater damping force, the stronger throttling effect.5. The throttle valve flakes structure mainly affects the damping force when the shock absorber at high speed. Analysis the influence of valve opening speed to the damping characteristic, finding that:a small change in the rate of the opening speed will cause a great change of damping force. Then valve flakes is numerical calculated by using the finite element method. Different combinations and different materials valve flakes deformation are obtained. The results are as follows:in the same thickness, the more number of the valve flakes or the smaller elastic modulus of the valve flakes, the smaller stiffness, the larger valve opening speed, resulting that the shock absorber damping is reduced.