摘 要：为建立有效的电磁阀线圈故障诊断方法，设计了电磁阀线圈疲劳寿命试验，提出一种多物理场耦合作用下的线圈渐进性失效诊断方法：首先，基于有限元仿真平台（ANSYS Workbench）建立直动电磁阀三维有限元分析模型，计算电磁阀温度场；然后，在机械应力场的模型求解中引入温度载荷，得到由机械应力和热应力耦合作用下的应力场；最后，搭建线圈疲劳寿命试验平台，采集不同驱动电压载荷下温度、电流、电阻等线圈重要特征参量的全寿命周期数据，通过对比分析试验数据和数值仿真结果，得出线圈缓变失效机制。研究表明：线圈通电产生的高温易破坏包裹线圈的绝缘橡胶，同时应力的耦合效应会在橡胶间产生一定的挤压作用，当在高温条件下破损的绝缘橡胶相互挤压时，线圈将会发生短路，造成线圈阻值的3次突降和温度的3次突增，这种叠加效应会加剧橡胶的破损和线圈的短路，直至电磁阀失效。该方法可适用于其它类型电磁阀线圈的故障诊断，对提高电磁阀的可靠性具有一定意义。

Abstract:Aiming at the lack of effective means to analyze faults of solenoid valve coils,an accelerated life test of solenoid valve coils is designed,and a mechanism with gradual failure for solenoid valves based on multiphysics coupling is put forward. Firstly,a three dimensional finite element model for direct acting solenoid valves based on Workbench is built to calculate the temperature field of coils. Then,the temperature is added to the mechanical stress field as the new load and the coupling stress distribution is received based on the combined action of thermal stress and mechanical stress. Finally,an accelerated life test of coils is built,and the life cycle data of key characteristic parameters are gathered such as temperature,current,and resistance. Then the gradual failure mechanism for coils is concluded by comparing and analyzing the simulation results and the gradual failure data of coils from the accelerated life test. The result shows the high temperature of coils produced by driving current can fail the insulation between coil wires. Meanwhile,the coupling effect of stress will squeeze coils. When the coils which have failed by high temperature squeeze against each other,shortcircuit of coils appears,causing three times of sudden decrease in resistance and three times of sudden increase in temperature. This superimposed effect will aggravate the failure of insulation and the shortcircuit of coils until the failure of the solenoid valve. This method can be applied to the fault diagnosis of the other types of solenoid valve coils and is of significance to improve the reliability of solenoid valve.

TP211.3