Study On Physical Parametrical Mechanical Model Of Anti-Yaw Hydraulic Shock Absorbers

The contradiction between speed and stability of the high-speed train was more prominent, as the improvement of the operation speed. The anti-yaw hydraulic shock absorber is the important insurance of the safety and stability of the train, by which the hunting stability critical speed of high-speed train was affected significantly. It’s an important component of second suspension, the calculation model accuracy of which decided the simulation accuracy of the vehicle system dynamics. The nonlinear characteristics of shock absorbers could not be reflected well by conventional damper model. So it is imperative to develop the nonlinear physical parametrical model of the hydraulic shock absorber to reflect the dynamic characteristics of it.In this paper, the relationship between orifice valve flow and operation pressure was analyzed from the point of the working principle based on the feature of inside orifice structure. The flow-pressure equation was deduced by the theory of hydrodynamics. The influences of oil viscosity, density and the percent of mixed air volume were considered in the process of analyzing the dynamic characteristics, by which the nonlinear physical parametrical model of the hydraulic shock absorber has been established. The simulation program of the nonlinear physical parametrical model was written to simulate the nonlinear static characteristics and dynamic ones of the hydraulic shock absorber.In order to verify the correctness of the established nonlinear physical parametrical model, the bench test of one certain SACHS anti-yaw hydraulic shock absorber has been carried out. Comparing the test data and simulation results in various cases, the static characteristics could be reflected accurately by the established nonlinear physical parametrical model, as well as the dynamic characteristics in most conditions.The influencing rule to damping characteristics was studied by the correspondence between various structure parameters and damping characteristics, which has been obtained by the simulation of changing structure parameters inside the hydraulic shock absorber. It could provide the theoretical guidance for the design of the shock absorber.