Abstract: In the process of modern mechanical product assembly tolerance optimization,multi-objective tolerance optimization models were often constructed with a simple weighted summing method,which often resulted in a poor solution performance and weak applicability on practical assembly sites.To improve assembly accuracy and process technology,through considering the pose changes among different key features caused by matting error,a cumulative model for assembly error transmission and a coordinated dimension chain were constructed,then the assembly and coordination errors among multiple assemblies could be predicted accurately.Based on the error data of each manufacturing process and the accumulated data of assembly accuracy,three single objective optimization models including manufacturing cost,quality loss and repair cost were established,and then a multi-objective model weight parameter distribution formula method was proposed to avoid the imbalance of tolerance data and deviation optimization direction,as well as the multi-objective tolerance optimization allocation model.The accelerated particle-swarm optimization algorithm was taken to obtain error values for each compromised error links that could improve assembly performance.The optimization of segmented wing docking assembly for a certain type of spacecraft was verified,before improving the product positioning and clamping method,the docking flush difference of wing and repair cost were reduced by 94.68% and 83.49%,respectively.With the locating contour boards,the above two assembly indicators were reduced by 11.21% and 8.50%,which could ensure the products’ assembly accuracy and coordination quality effectively.

Key words: assembly accuracy, process optimization, tolerance allocation, fusion of parameters, docking coordination

摘要： 在现代机械产品装配容差优化过程中,多以简单加权求和的方式构建多目标容差优化模型,求解效果较差且与装配现场的适用性不强。鉴于此,以装配精度提升与工艺改进为目标导向,首先,考虑配合误差引起的零件上不同关键特征间的位姿变动,构建装配误差传递累积模型与协调尺寸链,精准预测装配误差与多装配体间的协调误差;其次,结合各制造环节误差数据与装配精度累积数据,分别建立加工成本、质量损失、修配成本3个单目标优化模型,并以此提出可避免容差数据优化失衡与优化方向偏离的多目标模型权重参数分配方法,构建多目标容差优化分配模型;最后,采用加速粒子群算法求解得到面向工艺性能提升的各组成环误差数值。以某型航天器分段式机翼对接装配优化为例,在改进产品定位装夹方式之前,机翼对接外形阶差与修配成本分别降低94.68%与83.49%;在使用外形卡板定位后,通过优化使上述两项装配指标分别降低11.21%与8.50%,有效地保障了产品型面装配精度与对接协调质量。

关键词: 装配精度, 工艺优化, 容差分配, 参数融合, 对接协调