Research On Damping Characteristics Of CDC Shock Absorber

CDC?Continous Damping Control?shock absorber is a kind of shock absorber with stepless damping adjustment.The main advantage is that it can continuously adjust the damping force according to different road conditions including driving behavior,different loads,etc.,which solves the problem of not satisfying both driving comfort and safety contradiction.It is a typical representative of stepless valve-controlled shock absorbers,research on its key technologies has guiding significance for the development of semi-active shock absorbers in china.This paper studies the damping characteristics of CDC shock absorber and the main research contents and results are as follows:?1?Based on the solenoid theory,the electromagnetic field model of the pilot valve of the CDC shock absorber was established,the influences of various structural parameters on the electromagnetic force were simulated to obtain the structural parameters of the pilot valve that have a greater influence on the electromagnetic force.In order to determine the optimal parameters,the orthogonal test method was used to collaboratively optimize the selected three parameters of pilot valve.Finally,the obtained parameters were used to re-establish the model to obtain the relationship between the electromagnetic force and the input current.The results indicate that:when D₂=12.6mm,?₄=0.25mm,L₂=4mm,the electromagnet has better constant force characteristics,the electromagnetic force is proportional to the input current and the electromagnetic force is roughly 21.5 times the input current.?2?Based on the knowledge of fluid mechanics and elastic mechanics,the throttle characteristic models of the CDC valve and CDC shok absorber were respectively deduced,and the mathematical models of all the throttle characteristics were integrated to derive the overall damping force model,the indicator and speed characteristics under different working conditions were both obtained by simulation.The results demonstrate that when the speed amplitude of piston rod V=0.262m/s,there is an obvious inflection point in the indicator figure,when the speed amplitude of piston rod V=0.131m/s,V=0.052m/s,the figure shows an upwardly convex shape.when the input current I=0A,I=0.4A,I=0.8A,the damping force changes slightly,while the input current I=1.2A,I=1.6A,I=2A,the damping force changes greatly.?3?The electro-hydraulic servo experimental bench built by the research group was utilized to measure the indicator and speed characteristics under different working conditions.compared with the simulation results,it shows that the experimental value of the damping force is slightly larger than the simulation value,and the maximum deviation between the simulation and the experimental data is approximately 23.78%when the speed amplitude of the piston rod is 0.052m/s.The relative errors of simulation and experiment under other working conditions are not more than 20%.