基于全面析因试验设计的永磁微加速度开关接触可靠性分析

Study on Contact Reliability of Micro Magnetic Acceleration Switch Based on Full Factorial Experimental Method

针对一种新型磁力微加速度开关设计方案,建立了该开关系统的动力学方程,给出了影响开关动作的永磁力、表面接触力计算公式。采用四阶Runge-Kutta法对加速度激励下开关工作过程中永磁力、质量块与触点接触压力等参数的变化规律进行了仿真,对接触压力进行了极差分析和方差分析。选取微加速度开关的3个结构参数(悬臂梁宽度、质量块质量和永磁铁体积)作为关键因素,基于全面析因试验方法设计了该开关27种不同结构参数的水平组合,结果表明:微加速度开关3个结构参数中对接触可靠性影响大小的顺序为永磁铁体积V、悬臂梁宽度W、质量块质量m;可靠性最高的最佳结构参数水平组合为W3m3V1,即W=0.70mm、m=2.00g、V=5.38mm3;在置信度为99%的情况下,悬臂梁宽度W、永磁铁体积V和质量块质量m对微加速度开关接触可靠性均有显著的影响。

A dynamics model of a novel micro acceleration switch of permanent magnetic force was established. The equations of the permanent magnetic forces and the contact forces between the mass and the conductors were presented. The variation of the magnetic forces and the contact forces in the working process were simulated with the 4th order Runge-Kutta method. The range analysis and the variance analysis were given based on the simulation results of the contact forces. The breadth of the cantilevers,the mass in the micro switch,and the volume of the permanent magnet were selected as the major process parameters and 27 acceleration switches with every kind of combinations of the process parameters were designed firstly based on the full factorial experimental method. The results reveal that the impact sequence of the three major structure parameters from high to low is as the volume of the permanent magnet, the cantilever breadth and the mass. The best combination of the process parameters is W3m3V1 in which the mass is of 2.00g, the cantilever breadth of 0.7mm and the permanent magnet volume of 5.38mm^3. With 99 % confidence, the cantilever breadth W, the permanent magnet volume V and the mass rn have effects on the contact reliability.