基于形变检测的弱微零件过盈装配控制

Interference fit control for weak micro-parts based on deformation detection

针对过盈微装配中弱微零件易损的问题,以激光惯性约束聚变(Inertial Confinement Fusion,ICF)研究中微靶关键部件—冷冻罩(Thermomechanical Package,TMP)组件装配作为研究对象,开展弱微零件过盈装配方法研究。首先,针对装配空间狭小及存在视觉遮挡,导致难以实现装配过程中硅臂形变检测的问题,提出了基于灰度变化的形变检测方法并建立了小爪灰度—形变模型;然后,针对受到显微视觉检测精度影响,硅臂与套筒微小位姿偏差不易检测的问题,基于硅臂受力变形情况分析,提出了硅臂与套筒位姿偏差定性判断方法,实现两者微小位姿偏差的检测;最后,基于零件灰度变化及几何分析,提出了微装配过程位姿偏差定量计算方法并设计了过盈装配控制策略。实验结果证明了所提方法的有效性,并且实现了过盈20~26μm的TMP组件无损装配。该方法适用于微机电系统制造中微轴孔过盈装配。

To address the problem of weak micro-parts vulnerable to interference fit damage in MEMS manufacturing,an interference fit control method for weak micro-parts was studied.The micro-assembly process of the thermomechanical package component(key component in inertial confinement fusion research)was our research topic.First,to address difficulty in detecting deformation of the silicon arm in the assembly process owing to the small assembly space and visual occlusion,a detection method based on gray-scale variations was proposed,and a model of the relationship between gray-scale and deformation was established.Next,to address difficulty in detecting the tiny pose deviation between the silicon arm and the sleeve owing to limited microscopic visual detection accuracy,a qualitative method of judging the pose deviation,based on pressure deformation analysis,is presented.Finally,a quantitative method for assessing the pose deviation was proposed based on gray-scale variations and geometric analysis of parts,completing the overall control strategy design.Experimental results indicated that the proposed method is effective,and thermomechanical package assemblies with interference of 20μm~26μm were realized.This method is suitable for interference fit of micro-axis and micro-hole parts in MEMS manufacturing.