利用ANSYS软件建立了小型直流电磁继电器热电耦合分析模型。热源包括电磁线圈与触头回路,其中触头接触处按接触电阻相等的原则等效为小圆柱体,触头引出脚处外接导线的发热及散热按热通量相等进行当量折合,导电部件均考虑了电阻率随温升的变化。散热分析中计入了热传导、对流及辐射的影响,并考虑导热系数及对流传热系数随温度的变化。运用所建模型,对直流继电器带外壳和不带外壳时,在不同线圈电压下进行稳态热分析,得到了继电器各部分的温度场。根据有限元计算结果计算了各种情况下的线圈平均温升,并与实验数据进行了比较,结果表明两者能较好吻合。%The thermal-electric analysis model of a miniature DC electromagnetic relay is worked out with the software ANSYS.The heat generation by coil and contact circuit is considered,in which the contact area of the contacts is treated as an equivalent small cylinder with the same resistance as the contact resistance.Meanwhile,thermal effects of connected wires are equivalently reduced to the heat generator according to its heat flux.Heat conductivity,convention and radiation are all taken into account in the thermal analysis,in which the coefficients of heat conductivity and convention are considered as variables of temperature.With the above model,steady thermal analysis is performed for the DC electromagnetic relays with and without shell under different coil voltage.The temperature fields of every part of the relays are obtained.And the average temperature rises of the coil are calculated according the FEA results and in good agreement with the experiment results by comparison.
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