液压支架用电液换向阀的动态特征及流场特性仿真分析

为了提高液压支架的机械控制能力,利用电液换向阀完成支架控制箱动作控制。该文采用流体动力学仿真了电液换向阀的动态特征及流场特性。研究结果表明:当时间到达0.14 s时二级阀芯发生运动,出口流量快速增大至一个峰值状态;随着阀芯到达一个稳定运动状态后,换向阀也达到1013 L/min的稳定出口流量。换向阀在高压大流量系统内工作时将会快速到达峰值压力,产生液压冲击作用并使支架立柱受到破坏。当流体由阀套流至阀芯时因为过流断面的面积会迅速降低,使压力下降4.1 MPa,形成压力集中损失的区域,同时在阀芯的主流道区域还会形成均匀的压力分布状态。从阀口的下游最初进入阀芯的主通道位置时将达到最大流速,等于109 m/s,表明该部位形成了最小的过流面积。

Simulation Analysis of Dynamic Characteristics and Flow Field Characteristics of Electro-hydraulic Directional Valve for Hydraulic Support

In order to improve the mechanical control ability of the hydraulic support,electro-hydraulic directional control valve is used to complete the action control of the support control box.In this paper,the dynamic characteristics and flow field characteristics of electro-hydraulic directional valve are simulated by fluid dynamics.The results show that when the time reaches 0.14 s,the secondary spool moves and the outlet flow increases rapidly to a peak state.After the spool reaches a stable motion state,the reversing valve also reaches a stable outlet flow rate of 1013 L/min.The reverse valve will quickly reach the peak pressure when working in the high pressure and large flow system,which will produce the hydraulic impact and destroy the support column.When the fluid flows from the valve sleeve to the spool,the area of the flow cross section will be rapidly reduced,resulting in a pressure drop of 4.1 mpa,forming a pressure loss concentration area,and at the same time,a uniform pressure distribution state will be formed in the mainstream channel area of the spool.The maximum flow rate,equal to 109 m/s,will be reached when entering the main channel of the spool from the downstream of the valve orifice,indicating that the minimum flow area is formed at this position.