面向精密装配的零件形状误差评价参数确定方法

Precision Assembly Oriented Method to Determine the Evaluation Parameters for Surface Form Error

针对传统的以最小包容原则为基础的形状误差评价方法不足以定量描述形状误差分布和装配精度关系的现状,提出了面向装配精度的零件表面形状误差评价参数的确定方法.首先通过分析实际加工表面的检测参数确定非高斯模拟的输入参数,以非高斯平面模拟方法生成切削加工表面,以小波滤波获得表面形状误差,建立并提取能够表征表面形状误差分布的表征参数;将滤波后的表面通过接触点搜索的方法来模拟装配,计算装配后的第二个零件的空间方位变化的分布参数;通过相关分析确定零件形状误差表征参数和装配后零件空间方位分布参数的关系,确定形状误差评价参数,实现表面几何分布表征参数与装配精度关系的定量描述,为优化装配工艺从而提高装配精度提供科学依据.

The traditional form error evaluation methods, based on the principles of a minimum tolerance, are inadequate to quantitatively describe the vital influence of the distribution of the surface form error on the assembly precision. In this paper, a method was proposed to determine the potential evaluation parameters of surface form error for assembly precision. Firstly, non- Gaussian surface construction was used to simulate machining surface, and wavelet analysis with the selected base function was used to obtain the surface form error. The input parameters of non Gauss simulation were determined by analyzing the test parameters of the ＂real machined surface＂, and the candidate parameters characterizing the surface form error distribution were selected. Then the virtual assembly of the filtered surface with ideal smooth surface was conducted, hence the ideal surface spatial location was calculated. The relationship between the surface parameters and the second surface spatial location was established by correlation analysis to determine the form error evaluation parameters with a certain criteria. Finally a case was used to verify the feasibility proposed method. The method can provide a scientific basis for optimizing the assembly process to improve assembly precision.