基于CAD模型的装配精度预测

发布时间：2018-07-29 18:23

【摘要】：计算机辅助公差设计(Computer Aided Tolerancing,简称CAT)是利用计算机技术对制造过程中产品的公差进行设计和优化,从而实现生产周期、制造成本和产品质量的精确控制。在产品的装配设计阶段或者产品的装配实施阶段,利用计算机辅助工具,分析产品的设计公差或者产品的实际加工误差,预测出产品的装配精度,利用预测值来评价装配质量与产品性能,比较装配结果是否满足设计要求和使用需求,进而达到避免装配方案错误、减少装配调整次数的目的。本文首先在分析Pro/ENGINEER装配模型的结构特点的基础上,设计装配精度信息的数据结构,并探究如何从CAD装配模型中提取相关装配信息。然后,设计智能搜索算法以获得准确的装约链。研究解决尺寸位置提取、其它信息的计算等问题的方法,实现装配尺寸链自动生成。然后,本文以装配尺寸链的精度计算为出发点,建立三维装配尺寸链图,综合分析了不同的公差分析方法,并修正了三维装配尺寸链的计算公式,通过综合考虑影响装配精度的尺寸公差、形位误差、环境温度以及公差分析方法等方面影响因素,建立了装配精度预测的数学模型。最后,基于Pro/ENGINEER利用Microsoft Visual Studio开发了装配精度预测原型系统,并设计装配精度比较实验。该原型系统在CAD环境下得到的预测值与实际测量值的偏差、预测值与设计要求值的偏差均在可允许范围内。
[Abstract]:Computer aided tolerance Design (Computer Aided Tolerancing,) is the use of computer technology to design and optimize the product tolerance in the manufacturing process, so as to achieve accurate control of production cycle, manufacturing cost and product quality. In the stage of product assembly design or product assembly implementation, the design tolerance of product or the actual processing error of product are analyzed by means of computer aided tools, and the assembly accuracy of product is predicted. The prediction value is used to evaluate the assembly quality and product performance, and to compare whether the assembly results meet the design requirements and the application requirements, so as to avoid the assembly scheme errors and reduce the assembly adjustment times. On the basis of analyzing the structural characteristics of Pro/ENGINEER assembly model, this paper designs the data structure of assembly precision information, and probes into how to extract relevant assembly information from CAD assembly model. Then, the intelligent search algorithm is designed to obtain accurate reduction chain. The methods to solve the problems of dimension location extraction and other information calculation are studied to realize the automatic generation of assembly dimension chain. Then, taking the precision calculation of assembly dimension chain as the starting point, the three-dimensional assembly dimension chain diagram is established, the different tolerance analysis methods are comprehensively analyzed, and the calculation formula of three-dimensional assembly dimension chain is revised. The mathematical model of assembly accuracy prediction is established by taking into account the influence factors such as dimension tolerance, shape and position error, ambient temperature and tolerance analysis method. Finally, an assembly precision prediction prototype system based on Pro/ENGINEER and Microsoft Visual Studio is developed, and the assembly accuracy comparison experiment is designed. The deviation between the predicted value and the actual measured value and the deviation between the predicted value and the design requirement value of the prototype system under CAD environment are all within the allowable range.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH164;TG95

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