滚珠丝杠压扭型2D电液比例方向阀动态特性研究

摘要

提出了一种滚珠丝杠型压扭联轴器,该联轴器能将输出力放大约20倍,有效地解决了因比例电磁铁磁饱和造成直动比例方向阀无法实现大流量的问题.该联轴器将2D方向阀和比例电磁铁相连接,利用压扭放大驱动技术,将电磁力转化为阀芯左右两端不平衡的液压力,以克服摩擦力、卡紧力和液动力等非线性因素的影响.对主阀P-A处与导控级的压力分布和流场分布进行了仿真分析,理论与实验研究表明:压扭联轴器有效地放大了电磁力,在流量约为210 L/min的情况下,阀的阶跃响应约为0.35 s,该阀-90°频率为4 Hz左右.叠加一定颤振对改善阀的阶跃响应不明显,但能较好保证阀芯位移与电磁铁位移之间的跟随性.%A ball-screw type axial compression-torsion coupling was proposed herein.This design achieved an output force amplifications for about 20 times,which effectively overcome the disadvanta-ges of small flows of proportional directional valves caused by proportional solenoid magnetic satura-tion.The coupling connected 2D directional valves and proportional electromagnets by compression-torsion amplification drive technology.The electromagnetic forces were transformed into the pressure differences from both ends of the spools,which was sufficiently capable of overcoming the frictional forces,clamping forces and nonlinear hydrodynamic forces etc.The pressure distribution and flow field distribution from the main valve P-A and the pilot stage,the steady-state fluid force were simula-ted and analyzed.Theoretical and experimental studies show that the compression-torsion coupling ef-fectively enlarges the electromagnetic forces.The step response of the valves is about 0.35 s,and the frequency characteristics at -90°is about 4 Hz at a flow rate of about 210 L/min.The step character-istics is not improved obviously by superposing dithering,but the latter may effectively satisfy the fol-lowing features between the spool displacement and the electromagnet displacement.