工序尺寸换算中假废品的判定及补救措施研究  

Research on identification and remedial measure of false waste product in process dimension calculation

作　　者：冯文慧 马晓三 FENG Wen-hui;MA Xiao-san(College of Mechanical and Electronic Engineering,Huanghe Jiaotong University,Jiaozuo 454950,China;School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454000,China)

机构地区：[1]黄河交通学院机电工程学院,河南焦作454950 [2]河南理工大学机械与动力工程学院,河南焦作454000

出　　处：《工程设计学报》2021年第1期33-40,共8页Chinese Journal of Engineering Design

基　　金：河南省智能制造技术与装备工程技术研究中心资助项目(3118210370)。

摘　　要：在工艺基准和设计基准不重合的情况下,在零件加工过程中采用极值法计算工艺尺寸链时经常会出现工序尺寸不合格而最终设计尺寸可能合格的“假废品”现象。为此,以工艺尺寸链极值法计算的特点为基础,对假废品产生的原因进行了分析。为了便于在零件加工过程中判定假废品,通过将工序尺寸作为封闭环尺寸,建立并计算新的尺寸链,得到间接保证设计尺寸合格的必要不充分条件,并结合先于工序尺寸生成的组成环尺寸的实际偏差,提出了一种新的判定假废品工序尺寸公差范围的计算方法和流程。为了避免假废品转化为设计尺寸不合格的真废品,提出了一种对后续加工尺寸进行公差压缩的补救措施。根据工艺尺寸链中各组成环尺寸的相互补偿关系,分析了后续加工工序中公差压缩后尺寸极限偏差和公差的计算方法和流程。研究结果可为实际生产中假废品的判定和补救提供指导。In the case that the technological datum does not coincide with the design datum,when the extremum method is used to calculate the technological dimension chain during the part processing,the false waste product with unqualified process dimension but probably qualified design dimension often occurs.For this reason,based on the characteristics of the calculation of technological dimension chain by the extremum method,the occurrence reason of the false waste product was analyzed.In order to facilitate the identification of the false waste product during the part processing,a new dimension chain was established and calculated by taking the process dimension as the closed link dimension,so the necessary and insufficient condition to indirectly guarantee qualified design dimension was obtained.Then,a novel calculation method and flow of the process dimension tolerance range for identifying the false waste product were proposed by incorporating the actual deviations of composition loop dimensions generated before the process dimension.In order to avoid the conversion of the false waste product into a real waste product with an unqualified design dimension,a remedial measure based on the tolerance compression of dimensions in the subsequent processing was proposed.According to the mutual compensation relationship among the dimensions of each composition loop in the technological dimension chain,the calculation method and flow of the limit deviation and the tolerance of the dimension after tolerance compression in the subsequent processing were analyzed.The research results can provide guidance for the identification and remedy of the false waste product.

关 键 词：假废品 工序尺寸 工艺尺寸链 极值法 补救措施 

分 类 号：TH162[机械工程—机械制造及自动化]