【作者】 王哲兴；

【导师】 杨将新； 曹衍龙；

【作者基本信息】 浙江大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 本文结合国家自然科学基金项目“基于产品几何技术规范的集成公差设计理论与方法”(50275136)和浙江省自然科学基金项目“面向CAPP的工序公差设计研究”(502016)，开展了三维CAD系统中装配尺寸链自动提取及软件实现技术的研究，在三维CAD系统SolidWorks下开发了相应的原型系统。论文的主要研究内容如下： 第一章：回顾了计算机辅助公差技术的发展历史和研究现状，分析了其中的关键技术，提出了本文的研究内容和总体框架。 第二章：分析了ISO／TC 213公差语义，介绍了产品几何技术规范(GPS)对特征的定义及其检测过程，阐述了其中的二元原则，研究了特征的各种属性。 第三章：阐述了TTRS理论中几何特征的分类，分析了参数化三维CAD系统(SolidWorks)的约束机制。根据变动几何约束理论，给出了配合回路的生成规则，提出了面向尺寸链的变动几何约束网络的生成方法。 第四章：采用数据库来表达装配尺寸链信息，给出该数据库结构的定义，构建了一种面向装配尺寸链的数据库。 第五章：提出了基于三维装配图的尺寸链自动生成策略。在装配图上指定封闭环后，系统根据配合树在装配图中提取装配约束关系以及相关尺寸信息，生成面向尺寸链的变动几何约束网络，然后搜索其最短路径并构建面向尺寸链的装配数据库，根据数据库自动生成装配尺寸链。 第六章：在分析开发平台(SolidWorks)、开发工具(SolidWorks API)和开发语言(VB)特点的基础上，根据前面章节所述的理论和方法，开发了嵌入在SolidWorks中的装配尺寸链提取原型系统，并给出实例验证。 第七章：对本文的研究内容进行总结，对需要进一步解决的问题和以后应开展的工作进行了探讨和展望。更多还原

【Abstract】 Binding projects supported by National Nature Science Foundation of China (50275136) and Natural Science Foundation of Zhejiang (502016), the research on generation method of assembly dimension chain and its realization based on 3D CAD system is carried out. A prototype system based on the SolidWorks is developed to validate the method.In chapter 1, the development and the recent status of the CAT research are presented. Based on the analysis of the key technologies, the research content and the thesis structure are given.In chapter 2, tolerance semantics defined by ISO/TC 213 is analyzed. The geometrical feature definition of the GPS (Geometrical Product Specifications) and verification operation is introduced. The characteristics of the feature are studied.In chapter 3, the feature classification of TTRS (Technologically and Topologically Related Surface) and the constraint method of SolidWorks are analyzed. Based on the VGC(Variational Geometric Constraints) theory, a rule to set up the loop circuit for assembly dimension chain is put forward. The generation method of VGC network for assembly dimension chain is presented.In chapter 4, the information of the assembly dimension chain is expressed by means of database. The database structure is given. A database for assembly dimension chain is set up.In chapter 5, generation principle of the assembly dimension chain is presented faced to 3D CAD drawing. The dimension and assembly information is acquired from the 3D assembly drawing after the closing loop is specified by user. Based on the VGC network, the shortest path in the network is searched. The tolerance chain is generated from the database.In chapter 6, the character of design tool(SolidWorks API), platform(SolidWorks) and programming language(Visual Basic) are introduced. A generation prototype system of assembly dimension chain is developed. A sample is given to prove the effectiveness of the system.In chapter 7, all of the research work is summarized, and the future research work is presented.更多还原