基于边界分析的最大实体要求和最小实体要求混合设计与标注  

Hybrid design and annotation of MMR and LMR based on boundary analysis

作　　者：徐旭松 吴德辉 XU Xusong;WU Dehui(College of Mechanical Engineering,Jiangsu University of Technology,Changzhou 213001,China;Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province,Hangzhou 310027,China;BOSCH Power Tools(China)Co.,Ltd.,Hangzhou 310052,China)

机构地区：[1]江苏理工学院机械工程学院,江苏常州213001 [2]浙江省先进制造技术重点实验室,浙江杭州310027 [3]博世电动工具(中国)有限公司,浙江杭州310052

出　　处：《计算机集成制造系统》2020年第4期1052-1062,共11页Computer Integrated Manufacturing Systems

基　　金：国家自然科学基金资助项目(51475219)。

摘　　要：针对如何对尺寸要素使用最大实体要求(MMR)和最小实体要求(LMR)的问题,分析了从保证零部件可装配性(或装配间隙)和尽量放松公差要求出发,对被测要素应采用最大实体要求,使得被测要素获得公差补偿;若零件的定位特征作为基准要素时,应同时对该基准要素采用最大实体要求,使得被测要素获得基准偏移补偿,从而尽可能的放松公差要求。提出了实际装配实效边界和最小装配实效边界的概念,指出为了保证装配互换性,最小装配实效边界在任何工况下均不得被超出。研究并提出对于装配连接工艺不允许利用定位特征之间的间隙来调整装配的场合,不应对基准要素采用最大实体要求,而应在权衡零件合格率与检验成本之后,选择对基准要素采用独立原则或是最小实体要求。Aiming at the problem of how to add Maximum Material Requirement(MMR)modifier and Least Material Requirement(LMR)modifier to a feature of size,a case study demonstrated that the MMR modifier should be added to the toleranced feature to guarantee assemblability or assembly clearance between two parts.And,if the positioning feature of the part was used as datum feature to control the other geometrical features,the MMR modifier should also be added to the datum feature,for the possible Datum Shift(DS)could be compensated to the toleranced feature.New concepts of Actual Assemble Virtual Boundary(AAVB)and Minimum Assemble Virtual Boundary(MAVB)were put forward.It was pointed out that the MAVB should not be exceeded under any working conditions to ensure assembly interchangeability.When the clearance between the positioning features was not allowed for adjusting assembling,MMR modifier should not be added to the datum feature,but the independence principle or the LMR modifier could be used after weighing the qualification rate of parts and the cost of inspection.

关 键 词：最大实体要求 最小实体要求 公差边界 装配实效边界 公差设计 

分 类 号：TG801[金属学及工艺—公差测量技术]