多路换向阀稳态液动力分析与结构优化

Steady-State Flow Power Analysis and Structure Optimization of Multi-way Directional Valve

对于多路换向阀而言,稳态液动力过大会导致阀芯运动卡滞、换向阀操纵性下降。通过AMESim与Fluent软件联合仿真,发现稳态液动力峰值往往在阀口小开度时出现,且方向趋于阀口关闭;在阀芯复位过程中,稳态液动力在操纵力中最大占比为25.12%,阀芯在稳态液动力的影响下会获得过大的操纵力,破坏阀芯行程与复位弹簧力本身具有的线性关系。针对这种情况,基于流道改造法与特殊阀腔法,提出一种滑阀稳态液动力补偿方法,即在阀芯上设置一种挡流凸台。对改进后阀芯进行流场仿真分析,结果表明:凸台直径越大,降低稳态液动力的效果越明显,最多可以降低65.18%。但是过大的凸台直径会改变多路换向阀对应阀口的通流面积和水力直径,影响换向阀的压力特性,使得改进效果不理想。

For the multi-way directional valve,excessive steady-state flow power will cause the spool clamping and the operability of the directional valve to decrease.Base on AMESim and Fluent co-simulation,it is found that the peak of steady-state flow power usually occurs when the valve opening is small,tending to close the valve port;steady-state flow force accounts for 25.12%of the maximum operating force in reset process of spool valve;under the influence of steady-state flow force,the spool will obtain too large control force,which destroys the linear relationship between spool stroke and the reset spring force.Aiming at this situation,based on flow passage reconstruction method and special valve cavity method,a steady-state hydraulic power compensation method was proposed for spool valve,which was to set a kind of baffle boss on the valve core.The flow field simulation results of the improved spool show that the larger the diameter of the baffle boss is,the more obvious the effect of reducing the steady-state hydraulic force is,which can be reduced by 65.18%at most;however,too large diameter of the baffle will change the pressure characteristics of the multi-way directional valve,which makes the improvement effect not ideal.