销/孔定位结构公差设计中的功能边界分析法

Functional Boundary Analysis Method in Pin/Hole Location Structure Tolerancing

为了更好地运用公差标准中的边界理论进行机械精度设计,介绍了边界、实效条件边界和功能边界的概念和特点。以一面两孔(销)定位结构的尺寸与公差标注为例,分析了功能边界在定位销/孔的几何尺寸与公差分析和配置中的应用,探讨了销/孔定位精度分析和计算方法,从改进定位结构的角度分析了提高一面两孔定位精度的措施和原因。利用功能边界分析法能有效地优化产品几何规范、公差配置和结构,对合理保证零件的功能和可装配性、提高经济性有重要意义。

In order to make better use of the boundary theory for the design of mechanical precision under current tolerance standards.The concepts of boundary,virtual condition boundary and functional boundary were introduced.The application of function boundary in analyzing and allocating geometric dimension and tolerance were analyzed based on a case of one side and two holes(pin)locating structure.The method of calculating pin/hole positioning accuracy was elaborated.The measures of improving the positioning accuracy of one plane and two holes location structure were analyzed from the view of changing positioning structure.It shows that functional boundary analysis can be used to optimize the geometric specification,tolerance configuration and the structures of the products.It is of great significance to make proper use of functional boundary for the design of tolerance,which can guarantee the functionality and assemblability of parts,and can improve the economy.