磁流变阀控液压缸系统性能分析

摘要

磁流变液作为智能流体,在磁场的作用下可在毫秒时间内实现从液体到固体之间的转换,且这种转换是可逆的,而磁场的大小又可通过电流的大小来控制,具有可控性.利用磁流变液这种特性,设计了一种由4个磁流变阀代替传统液压阀组成的磁流变阀控液压缸系统,这种结构类似于惠斯通电桥,通过介绍其结构特点和工作原理,分析系统工作效率及执行器效率,推导出磁流变阀组的工作效率,建立该结构的数学模型,并通过仿真对其进行理论分析.仿真结果表明磁流变阀控液压缸系统性能与无名义参数δ和μ有关;当通过磁流变阀的电流增大时,无名义阻尼间隙厚度δ增大,系统驱动力F增大,效率也增大;而当黏度比μ越小,系统性能越好,效率越高.%Magnetorheological fluid (MRF),as a smart fluid,can be transformed from liquid state to solid state in several millisecond by applying magnetic fields,and the transformation is reversible,then the size of magnetic field can be controlled smoothly via changing the applied current,which is controllable.Based on the characteristic of MRF,a novel magnetorheological (MR) valve controlled hydraulic cylinder system which used four MR valves in place of conventional mechanical valves is designed.This structure was similar to that of the Wheatstone bridge,its structure characteristics and work principle were introduced,the working efficiency of the system was deduced and the efficiency of the actuator was derived,the working efficiency of MR valve set was deduced,the mathematic model of its structure was established and theoretical analysis was carried out by simulatuion.The simulation results show that the performance of a MR valve controlled hydraulic cylinder system is related to nondimensional parameters,namely δ and μ.On increasing the current to MRV,nondimensional plug thickness δ will increase as well as driving force F,this caused an increase in the efficiency.While the performance and efficiency of system become better with decreasing of viscosity ratio μ.