小型液压挖掘机动臂联阀口的流量特性  

The Research on Flow Characteristic of Orifice in the Boom Circuit of Mini-hydraulic Excavator

作　　者：官通 郭勇[1,2] 尹升[1] 陈桂芳 

机构地区：[1]中南大学高性能复杂制造国家重点实验室,长沙410012 [2]山河智能装备股份有限公司,长沙410100

出　　处：《机械设计与研究》2014年第2期115-118,127,共5页Machine Design And Research

基　　金：湖南省科技厅重大专项资助项目(2012KJ0201)

摘　　要：为了解决动臂下降过慢的问题,提高其可控性,以小型挖掘机多路阀动臂联阀为研究对象,采用CFD软件对节流槽及阀内流动进行仿真,表明P^A的流量过小且流量系数变化区间较大。通过试验对改进后的阀芯进行流量特性的测试。获得了P^A口和P^T口流量系数随阀芯位移的变化规律。结果表明:流量系数是随阀芯位移的变化而变化的,对于P^A口,在小开度时,流量系数为负值,而在大开度时也只能到达0.24;同一阀芯,不同节流口,流量系数的变化不一样,P^T口流量系数变化呈现先增大后减小的趋势;改变通过节流口的流量对阀口流量系数的影响不大;通过合理配置P^A口和P^T口过流面积的大小,可以使阀口流量系数的变化更平缓。In order to improve falling speed of the boom and its controllability, computational fluid dynamics （CFD） software is used to simulate orifice and the flowing inside the valve in boom circuit of mini-hydraulic excavator. The results show that the flow rate of P-A is small and the interval of flow coefficient changes largely. An experiment is conducted to test the flow coefficient on the improved valve core, in which the rule of the flow rate of P-A port and P- T port changed with the spool displacement is obtained. The result explains that： the flow coefficient changes with spool displacement： for P-A, with the small opening the flow coefficient is negative, while even with the large opening the coefficient can only reach 0.24 ; with the same spool but different orifice port, the flow coefficient changes in different trend. The flow coefficient in P-T port witnesses an increase at first but then declines ; the flow of orifice port have no significant effect on the flow coefficient of valve port ; an rational allocation of the flow area passage of the P-A port and the P-T port leads to a gentle trend of the changing in flow coefficient of valve port. This research has great theoretical significance and shows positive effect on the design of high quality hydraulic valve.

关 键 词：多路阀 节流槽 阀口 流量系数 

分 类 号：TH137[机械工程—机械制造及自动化]