基于双速缓冲阀推移系统的压力特性研究

Pressure characteristics of two-speed buffer valve pushing system

综采工作面液压支架推移系统的定位控制由智能化开采的关键技术支撑,井下高压大流量工况下,现有支架开关换向阀启闭瞬间会引起系统压力流量突变,影响元件寿命以及执行机构运动的精度和平稳性。为此,设计了用于液压支架推移回路的双速缓冲阀结构。首先,展开了对推移系统及双速缓冲阀的理论研究,分析了双速缓冲阀对系统启动、运行过程压力的影响;其次,建立了阀及推移回路的SimulationX模型,仿真分析了关键参数对阀压降以及液压执行系统速度的影响;最后,搭建了模拟实验台,研究了不同供液压力流量下双阀串联推移系统的压力特性。研究结果表明:启用双速缓冲阀后,减小了系统的压力和速度变化幅值,降低了阀前压力波动及其对系统压力的影响;在不同的系统压力、流量下,改善了阀后压力特性,增强了稳态压力抗干扰性;验证了方案的有效性,为井下阀控缸方案及后续阀的优化提供依据。

The positioning control of hydraulic support pushing system in fully mechanized mining face is the key technical support to realize intelligent mining.The opening and closing of the existing support switch reversing valve will cause sudden change of system pressure and flow under the condition of high pressure and large flow,which will affect the life of components,the precision and stability of the actuator movement.To solve the problem,the structure of two-speed buffer valve for hydraulic support pushing circuit was designed.Firstly,through theoretical research on the pushing system and the two-speed buffer valve,the pressure characteristics during the start-up and operation of the system after adding the two-speed buffer valve were analyzed.Then,the valve and hydraulic circuit were modeled by SimulationX to analyze the influence of key parameters on valve pressure drop and speed of hydraulic execution system.Finally,an experimental platform was built to study the pressure characteristics of double valve series pushing system under different pressure flow of liquid supply.The research results show that when the two-speed buffer valve is used,the pressure and velocity change thresholds of the system are reduced,which reduces the pressure fluctuation in front of the valve and its effect on the system pressure.At the same time,under different system pressure and flow,the downstream pressure characteristics of the valve are improved,the steady-state pressure anti-interference is enhanced.Therefore,the effectiveness of the scheme is verified,and the basis is provided for the optimization of the downhole valve control cylinder scheme and the subsequent valve.