论文总字数：14723字

摘 要

本次毕业设计以轻型客车离合器总成为研究对象，运用三维设计的原理与方法，进行了离合器总成的三维建模、装配，并生成了二维图纸。

通过逆向工程获得了离合器总成的点云数据。离合器总成是由分离拨叉、离合器壳、膜片弹簧、扭转减振器、压盘、摩擦片、分离轴承等零件组成。首先在零件表面有规律的贴满参考点贴纸，使用三维激光扫描技术扫描各零件，通过参考点的辅助，在软件中获得了各零件的表面数据。由于扫描精度、扫描环境及零件本身材质、造型的影响，扫描数据可能不太完整或存在着大量的噪点，在使用前要先利用Geomogic Studio软件对数据进行修剪、填补等预处理后，再保存为三维建模可使用的点云数据。

在CATIA中完成了离合器总成三维模型的建立与装配。将点云数据导入CATIA，进行铺面后获得零件大致的表面形状。在建模过程中，由于零件多是回转体，所以多次使用到了“基本表面识别”这一命令，目的在于生成回转中心轴，以通过回转轴的平面截取零件的主体轮廓，编辑草图拟合轮廓，使用“回转体”命令快速构建主体。此外还频繁地使用了“凸台”、“凹槽”等命令用于构造种种细节。对于非回转体零件，则完全采用曲面重构等方法精准拟合表面，再通过填充获得实体。在对各零件进行装配时，通过查阅离合器构造的相关资料，理清了各零件的位置关系和装配顺序，装配完成后并无干涉。

在CAD中完成了对离合器总成与各零件的二维图纸编辑。在生成二维图纸过程中，首先由CATIA导出零件的主要图选择合适平面建立主视图，使用剖面线建立剖视图。在CAD中将基本视图简单处理并按标准标注尺寸、工艺基准、技术要求等。

关键词：离合器 逆向工程 三维设计 装配

Three dimensional design of light bus clutch assembly

Abstract

This graduation design takes the light bus clutch as the research object. Using the principle and method of the three-dimensional design, the 3D modeling and assembly of the clutch assembly are carried out, and the two-dimensional drawings are generated.

The point cloud data of clutch assembly are obtained through reverse engineering. The clutch assembly is made up of separated fork, clutch shell, diaphragm spring, torsion damper, pressure plate, friction disc and separated bearing. First of all, the surface of the parts is regularly filled with the reference point sticker, and the 3D laser scanning technology is used to scan the parts. The surface data of the parts are obtained in the software through the assistance of the reference point. Because of the influence of scanning precision, scanning environment and the material and modeling of parts itself, the scanned data may not be complete or have a lot of noise. Before using, we should use Geomogic Studio software to prune and fill the data, and then save it as a point cloud data that can be used in 3D modeling.

The 3D model of clutch assembly was built and assembled in CATIA. The point cloud data are imported into CATIA, and the surface shape of the parts is obtained after pavement. In the process of modeling, the order of "basic surface recognition" is used many times because the parts are mostly revolving body. The purpose is to generate the rotary center axis to intercept the main body outline of the parts through the plane of the axis of revolution, edit the sketch to fit the outline, and quickly construct the body with the "rotary body" command. In addition, commands such as "boss" and "groove" are frequently used to construct various details. For non revolving parts, surface reconstruction and other methods are used to precisely match the surface, and then fill solid. In the assembly of each part, the position relation and assembly order of each part are cleared by consulting the related data of the clutch structure, and there is no interference after the assembly is completed.

The 2D drawing editing of clutch assembly and parts was completed in CAD. In the process of generating two-dimensional drawings, the main drawing of the parts is first derived from CATIA, the appropriate plane is selected to establish the main view, and the sectional view is used to form the sectional view. In CAD, the basic view is processed simply and dimensioned according to standard, process datum, technical requirement, etc.

Key Words: Clutch;Reverse Engineering;3D Design;Assembly

目 录

摘 要 I

ABSTRACT II

第一章 绪论 1

1.1背景 1

1.2研究的意义 1

1.3国内外发展现状 1

1.3.1国内离合器发展现状 1

1.3.2国外离合器发展现状 2

1.4主要设计工作 2

1.5本章小结 2

第二章 离合器总成三维设计理论基础 4

2.1逆向工程 4

2.2三维激光扫描技术 4

2.2.1基本原理 4

2.2.2工程应用 4

2.3数据采集和预处理 4

2.3.1三维扫描 4

2.3.2点云处理 5

2.4曲面重构及实体化 6

2.4.1点云数据的导入与三角网格化 6

2.4.2建立旋转中心轴和基准平面 6

2.4.3基于特征创建曲面 6

2.4.4基于曲面的实体特征生成 6

2.5本章小结 6

第三章 离合器的三维建模 8

3.1从动盘建模 8

3.2防尘罩建模 13

3.3扭转减振器弹簧建模 15

3.4本章小结 18

第四章 离合器装配与二维图 19

4.1 离合器装配 19

4.2二维图 21

4.2.1基本视图的创建 21

4.2.2标注尺寸、公差等 23

4.3经济性分析 26

4.4本章小结 26

第五章 总结与展望 27

5.1总结 27

5.2展望 27

参 考 文 献 28

致 谢 30

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