三级喷嘴挡板伺服阀喷嘴堵塞故障分析

Analysis of Nazzle Clogging Trouble in Three Stage Nazzle Baffle Servo Valve

为排除三级喷嘴挡板伺服阀的故障,对其结构组成和工作原理进行了分析,该阀由两级先导阀及主阀构成。两级先导阀,第一级为喷嘴挡板结构,固定节流孔和喷嘴挡板可变节流孔构成了一个液压全桥;第二、三级为滑阀结构。通过对故障阀进行空载流量测试发现,先导阀流量输出异常和三级伺服阀阀芯位移反馈不变。据此判断,伺服阀先导级可能存在卡阻,破坏了液压全桥的正常工作。对伺服阀拆解后发现,喷嘴挡板机构部分堵塞。对该阀进行清洗后重新组装,检测空载流量、滞环等指标,均在控制范围内,故障排除。

In order to eliminate the three stage nozzle baffle servo valve failt,For its structure composition and working principle are analyzed,The valve is composed of two stage pilot valve and main valve.Two stage pilot valve,The first stage is nozzle baffle structure,fixed orifice and variable orifice nozzle baffle from a total hydraulic bridge;The two and third stage are slide valve structure.It is found by testing zero load flow of the fault valve,The pilot valve has abnormal flow output and the three stage servo valve valve core displacement feedback is unchanged.And judging by that,The pilot valve of servo valve could be blocking removement,Disruption of the total hydraulic bridge normal operation.Disassembly servo valve discovery,The mechanism of nazzle baffle partly blocking.The valve is cleaned and assembled,tested zero load flow、hysteresis other indexes,all within control,trouble shooting.