高温下应力不对称及热变形对射流管伺服阀零位的影响  

Influence of Stress Asymmetry and Thermal Deformation on Zero Position of Jet Pipe Servo Valve at High Temperature

作　　者：夏天 陈誉 张晋[2] XIA Tian;CHEN Yu;ZHANG Jin(School of Mechanical Engineering,Nanjing Institute of Technology,Jiangsu,Nanjing 211167;School of Mechanical Engineering,Yanshan University,Hebei,Qinhuangdao 066004)

机构地区：[1]南京工程学院机械工程学院,南京江苏211167 [2]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《液压与气动》2023年第8期155-166,共12页Chinese Hydraulics & Pneumatics

摘　　要：高温环境下射流管伺服阀呈现出诸多如温漂、小信号曲线局部增益激增、小信号流量曲线锯齿状波动、全信号曲线不平滑等影响其工作性能的问题,且这些现象具有不规则性、不可重复性。基于系统级参数化仿真和元件级有限元数值模拟方法,针对射流管伺服阀存在应力不对称的情况下温度变化导致的零漂问题,推导了气隙长度、磁性材料物性和油液黏度关于温度的参数化模型,运用AMESim仿真分析并揭示等效应力不对称对伺服阀零位的影响规律;同时为解决高温下射流管伺服阀热变形改变整阀形位尺寸变化导致的零漂问题,综合考虑介质密度、黏度、比热容、导热系数等参数随温度、压力变化,运用热-流-固耦合仿真方法探究分析前置级热变形对零位的影响。对比两种结果表明:射流管伺服阀零位受应力不对称影响较小,造成过大零漂和零位特性不确定的原因是伺服阀热变形导致的形位误差。The jet pipe servo valve under high temperature shows many deficiencies that impact its working performance,including temperature drift,local gain surge in the small signal curve,zigzag fluctuation in the small signal flow curve,and uneven full-signal curve.The system-level parametric simulation and the element-level finite element numerical simulation were adopted in this paper,to establish a parameterized model about the relationship between the air gap length,the physical properties of the magnetic material,the oil viscosity and temperature for the zero-drift problem caused by the temperature change when the jet pipe servo valve is under asymmetrical stress.The impact of equivalent stress asymmetry on the zero position of the servo valve was analyzed and simulated by using AMESim.In order to solve the problem of zero drift due to the changes in the valve form and position caused by the thermal deformation of the jet pipe servo valve under high temperature,the changes of the medium density,viscosity,specific heat capacity,thermal conductivity and other parameters along with temperature and pressure were taken into account to explore and analyze the influence of the pre-stage thermal deformation on the zero position by using the heat-fluid-solid coupling simulation.The comparison results indicate that the zero position of the jet pipe servo valve is less affected by the stress asymmetry,and the form and position deviations caused by the thermal deformation of the servo valve lead to the excessive zero drift and the uncertain characteristic of the zero position.

关 键 词：射流管伺服阀 应力不对称 温漂 各级不对称 零位特性 

分 类 号：TH137[机械工程—机械制造及自动化]