【作者】 赵杨；

【导师】 陈天星；

【作者基本信息】 西南交通大学 ， 机械工程， 2013， 硕士

【摘要】 近年来,随着计算机辅助设计和计算机管理技术的发展,工程技术人员开始引入三维数字化模型对产品进行定义,区别于以往利用二维工程图进行产品定义的方法。MBD (Model Based Definition),即“基于模型的定义”技术,是一种基于产品三维数字化模型的、面向计算机应用的产品定义技术,其核心理念是采用一个集成的三维数字化模型来完整地表达产品定义信息,将产品的几何形状、尺寸、公差、注释以及与产品定义相关的非几何信息共同定义到产品的三维数字化模型中,不再使用二维工程图,实现面向制造的设计,并保证产品数据的唯一性。论文的主要研究内容如下：1.论述和分析采用二维工程图定义产品的特点和存在的不足,以及采用三维数字化模型进行产品定义的优点。介绍国内外企业和研究机构利用三维数字化模型进行产品定义取得的突出成果。2.分析和研究国外数字化产品定义技术标准ASME Y14.41-2003、ISO16792-2006及我国数字化产品定义技术标准GB/T24734-2009,详细分析了采用3DMBD技术进行产品定义时采用的新方法。3.UG PMI模块是UG NX软件中实现数字化产品定义技术的模块。本文运用PMI模块,遵循GB/T24734-2009标准,对产品零件进行标注。4.研究PMI标注中不符合标准规定的问题。针对模型旋转时某些标注因为观察角度而显示不清的问题,提出更换标注显示平面使标注显示得到优化的解决办法,以Visual Studio2008C++为软件开发平台进行UG二次开发,实现标注显示的优化。更多还原

【Abstract】 With the development of Computer Aided Design and Computer Management technology, engineers start to use3D digital model to define a product, which is different from the traditional engineering drawing method.Model Based Definition (MBD) is an advanced digital product definition technology which is based on products’3D digital model and can meet the application requirements of computers. Its core idea is by using an integrated3D digital model solely to represent a product’s information completely. The3D digital model covers a product’s all aspects of information which include its form, dimension, tolerance, note and other related non-geometric information, and no longer use engineering drawings to define a product any more. MBD can be fully implemented in the manufacture-oriented design method and guarantee the product definition’s unambiguity and originality.The major contents of this paper are described as follow:1. Both the advantages and disadvantages of traditional engineering drawing for product definition, and the advantages of using a3D digital model to define a product are described and analyzed. The major achievements obtained by corporations and research institutions with MBD technology are introduced in this paper.2. Foreign technique standards ASME Y14.41-2003, ISO16792-2006and domestic standard GB/T24734-2009are analyzed. The new methods employed in product definition with3DMBD technology are analyzed in detail.3. UG PMI function can be used in digital product definition. The UG PMI is employed to annotate on products’3D digital model in accordance with standard requirements of GB/T24734-2009.4. The problems which UG PMI is unable to meet the standard requirements are analyzed. With some annotations can’t be displayed clearly due to user’s viewing angle while model rotations, a solution to optimize annotations’display results by switching annotations’display plane is proposed. By employing Visual Studio2008C++as programing platform with UG redevelopment method, the annotation display is optimized.更多还原