元动作装配单元误差传递模型及有效路径求解方法

在对机械产品进行"功能-运动-动作"结构化分解的基础上,将影响元动作装配单元装配精度的误差源分为零部件的形状误差、位置误差、装配位置误差和运动误差等四类误差源。引入误差链接模型作为元动作装配单元误差关联关系的基本封装单元,构建结构化误差关联模型——链接网络和链接矩阵,形象描述误差间的耦合嵌套关系。提出基于误差链接模型的装配误差传递路径求解方法,用老鼠迷宫算法搜索所有可能的误差传递路径,以装配精度最高作为判别依据,得到各误差分量的有效传递路径。以蜗杆转动元动作装配单元蜗杆轴线平行度误差有效传递路径为目标,对上述方法进行验证,结果表明该方法能够高效地搜索到所有误差传递路径,并快速获得有效传递路径。该方法的提出为整机装配过程质量预测与控制提供了理论依据。

Error propagation model and calculating method of effective transfer path for meta-action assembly unit

Based on the structure decomposition of machine tools as function-movement-action, the deviation source that affects precision of meta-action assembly unit was clustered into four types: form error, position error, assembly position error and kinematic error. In order to express the relationship of coupling and nesting vividly, error linkage model was introduced as the basic unit of meta-action assembly unit error relationship to construct structured error relationship model of linkage network and linkage matrix. An assembly error transfer path search method based on error linkage model was proposed, searching all possible paths by mouse maze algorithm, and the effective transfer paths of error component were obtained on the identifying basis of the highest assembly accuracy. Worm axis parallelism error of worm drive meta-action assembly unit was taken as the target to verify the method and the results show that this method is capable of searching all error transfer path efficiently and getting effective path rapidly. This method provides theoretical basis for quality prediction and control of machine assembly.