带有K型节流槽的液压支架换向阀改进设计

针对煤矿综采工作面现有液压支架换向阀阀口过流面积梯度大、仅能够实现开关型控制功能的现状,以及由此造成的支架供液系统内液压冲击剧烈问题,提出在阀芯径向过流孔凸肩位置增设K型节流槽的换向阀改进设计方案。得出了K型节流槽等效阀口过流面积计算方法,采用AMESim软件搭建了换向阀液压仿真模型;并对现有开关型换向阀和改进换向阀进行了对比研究。结果表明:带有K型节流槽的换向阀改进方案可实现阀芯开启过程中的阀口过流面积分段线性增大规律,在阀芯开度小于5. 5 mm时,阀口过流面积梯度较小;在阀芯开度大于5. 5 mm后,该梯度数值增大至与现有换向阀相当;阀口通流流量和阀口压力可相应实现分段增大规律。改进设计思路对于面向支架不同工艺动作的换向阀结构优化具有借鉴意义。

Improved Design for Directional Valve with K-Shaped Throttling Grooves Used in Hydraulic Supports

The existing directional valve of hydraulic supports used in fully mechanized coal mining face has a large gradient of flow area and can only realize switching control function, which consequently results in severe hydraulic impact in the hydraulic supports flow supply system. An improved design methodology of directional valve by added K-shaped throttling grooves at the shoulder of valve core is proposed in this paper.The calculation method of equivalent valve orifice area of K-shaped throttling grooves has obtained, the hydraulic simulation model of directional valve has built by AMESim software, the comparative analysis has completed about the existing switching directional valve and the improved directional valve.The results show that the improved design methodology of directional valve with K-shaped throttling grooves can successfully realize piecewise linear increase of flow area in the process of spool opening; when the valve opening is less than 5.5 mm, the gradient of the orifice flow area is small; when the valve opening is greater than 5.5 mm, the gradient increases to the same value as the existing directional valve; the flow rate though valve orifice and the pressure at the valve port can achieve piecewise growth consequently.The improved design methodology proposed by this paper can be used for reference to optimize the structure of the directional valve for different technological actions of the hydraulic supports.