磁热耦合下的比例电磁铁热稳健性再设计

Thermal Robustness Redesign of Proportional Electromagnet Under Magneto-Thermal Coupling

针对工程机械比例阀用电磁铁的耐久性问题,为提高在随机载荷条件下抵抗热失效的能力,综合多物理场耦合理论与稳健性优化理论,提出了比例电磁铁的参数化再设计模型。以一种具有盆式吸合结构的比例电磁铁为研究对象,通过稳态电磁测试和温度分布测试,验证了所提出的参数化模型的有效性,并在保证电磁算力精度的前提下,标定了系统中量值模糊的导磁、传热等参数;以电磁铁和线圈主要结构参数为控制因子,以生产工艺条件不确定性导致的线圈漆包铜导线线径随机误差为噪声因子,基于田口方法设计正交试验,定义了多因素加权的比例电磁铁热稳健性再设计评价函数;以挖掘机现场试验获得的比例电磁铁热负载作为响应计算热源,在不导致线圈绝缘破损失效的许用温升约束下,进行关键结构参数在噪声扰动下系统响应变异最小的再设计。研究结果表明:线圈长度和匝数是影响电磁铁热稳健性的主要因素,由绕线工艺决定的线圈窗口形态决定了系统的导磁、传热能力。文中提出的比例电磁铁热稳健性再设计方法对于磁热耦合下的机电产品定制化设计具有工程化参考价值。

Aiming at the durability problem of electromagnets for proportional valves of construction machinery,in order to improve the resistance of electromagnets to thermal failure under random load conditions,a parametric redesign model of proportional electromagnets was proposed based on multi-physical field coupling theory and robust optimization theory.By taking a proportional electromagnet with basin-type suction structure as the research object,the effectiveness of the proposed parametric model was verified through steady-state electromagnetic test and temperature distribution test.Under the premise of ensuring the accuracy of electromagnetic calculation,the parameters such as magnetic conductivity and heat transfer with fuzzy magnitude in the system were calibrated.With the main structural parameters of electromagnet and coil as control factors,and with the random error of wire diameter of coil enameled co-pper wire caused by the uncertainty of production process as noise factor,orthogonal tests were designed based on Taguchi method,and the evaluation function of the thermal robustness redesign of multi-factor weighted proportional electromagnet was defined.Then,with the thermal load of the proportional electromagnet obtained in the field test of the excavator as the response calculation heat source,the redesign of the key structural parameters with the minimum system response variation under noise disturbance was carried out,under the constraint of allowable temperature rise that does not cause the coil insulation failure.The results show that the coil length and the number of turns are the main factors affecting the thermal robustness of the electromagnet,and that the coil window shape determined by the winding process determines the magnetic permeability and heat transfer capability of the system.The thermal robustness redesign method of proportional electromagnet proposed in this paper is of engineering reference value for the custo-mized design of electromechanical products under magneto-thermal coupling.