掘进机用螺纹插装式平衡阀动态性能分析

Working properties of screw-in cartridge counterbalance valve in roadheader

分析了平衡阀的工作原理和主阀芯的受力情况,建立主阀芯的运动方程,分析可知油缸负重、先导控制压力、弹簧刚度系数和预紧力对平衡阀的动态性能影响比较明显;通过对掘进机截割部受力分析,建立其静力学方程,运用MATLAB软件得到截割部油缸负载工况仿真曲线,可知负载随着截割头的升高逐渐减小,在截割头最下方和最上方两极限位置处,升降油缸受力分别为最大和最小;运用AMESim进行动态模拟,分析可知:油缸负重较大时,速度波动较大且抖动时间较长;控制油口阻尼孔直径大小对系统影响不大,但其越小,阀芯运动越平稳;较大弹簧刚度可有利于系统的稳定;过大的弹簧预紧力,不仅不利于系统稳定,且会使平衡阀内产生气蚀现象。

The working principle of balancing valve and the force of the main valve core were analyzed, and the kinematic equation of main valve core was established. Analysis showed the oil cylinder weight, pilot control pressure, coefficient of spring stiffness and pre-tightening force had significant impact on dynamic performance of balance valve. Statics equation was established for cutting unit of roadheader force analysis based on force analysis, and obtained the simulation curve of cutting oil cylinder loads with MATLAB software, showing that, the load decreases as the cutting head rises; when the cutting head in the hottom and top position, the force on lifting oil cylinder achieves maximum and minimum respectively. Dynamic simulations were conducted with AMESim, and the results show that, the speed fluctuation is more obvious and the shake time is longer, with a more load on oil cylinder; the diameter size of control oil damping hole has small impact to system, but the smaller it is, the smoother of spool motion ; large spring stiffness can be beneficial to the stability of the system; large spring pre-tightening force is unfavorable for system stability, and produces cavitation phenomenon in the balance valve.