外文翻译--基于CATIA的汽车改装式升降台数字样机建模及应用研究

附 录 附录 A Modified Car Lifting Platform Based on CATIA Modeling and Application of Digital Prototyping Describes the use of CATIA V5 mechanical parts i and zero-dimensional modeling, virtual assembly of the basic process components and steps, and worm assembly, for example in detail. The effect of improving the mechanical design to improve design efficiency and shorten the design cycle time, has some practical significance 1 Overview CATIA software from IBM and Dassault company to launch high-end CAD / CAM software, has become the international aviation industry preferred design software. With its strong surface design features in the machinery, aircraft, automobile, shipbuilding and other widely used design, CATIA surface modeling capabilities is reflected in the features and advantages it provides a very rich modeling tools to support the user modeling needs. As its unique high-order Bezier curve and surface features, the number can reach 15, can well meet specific industry demanding requirements of surface smoothness. Application CATlA constructed solid model can be directly applied to other analysis software ANSYS finite element analysis CATIA software with three-dimensional CAD software and other standard data interface for easy data conversion model. CATIA V5 is based on the Windows platform, and to fully parametric feature modeling technology as the core feature-based modeling software, which is consistent with the Windows-style menu bar, standard shortcuts, contextual menus, multi-document interface, you can make the difference Windows applications to share data, OLE integration, so work quickly and efficiently, can significantly reduce training time. CATIA parts assembly is basic, but also the most advantages and features function modules, including the creation of an assembly, add the specified components or parts to the assembly, the assembly relationship between components to create, move and layout of the assembly members, generated an explosion of products diagram, assembly interference and gap analysis and other major features?. 2 three-dimensional modeling based on CATIA and assembly 2.1 Design sketches Sketch design is the starting point of three-dimensional design, and its essence is a two-dimensional line, surface design, software design with a traditional two-dimensional functions. Parametric design of the basic approach is to start from scratch design, size and geometric constraints imposed by creating a sketch feature, then apply the size-driven technology to automatically generate parts of the three-dimensional solid model, in the use of technology to generate two-dimensional contour sketches do not have to outline the exact size of the input , the parameters in the future to get the design process. Thus, during the product design, you can always adjust the design size, without a clear early in the design of the design size, enhance the ease of CAD software, to better achieve a user-friendly design, but also for the design of series improvement of products and original products and parts borrowed are convenient. 2.2 to generate three-dimensional part blank CATIA has a strong three-dimensional solid modeling functionality, the user plane in the sketch, after drawing two-dimensional graphics, into the part design (Part Design) modules, you can rotate, stretch, lofting, stiffened, and other methods to generate the draft three-dimensional parts to be rough. Constraints can also use parameterized functions to be modified according to need. Designers can change for the body part blank to achieve the design process by drawing to design changes, and CATIA V5 provides three-dimensional model of the specific features make the design more similar to the production process, better to achieve a combination of design and processing. 2.3 complete the three-dimensional modeling CATIA V5 provides feature-based design, will feature as a design element, the characteristics of the product as a combination, through the object from the class to be achieved step by step description of the specific shape of the design. After generating the rough three-dimensional parts can be used to drilling, slotting, shells, chamfer, plus convex sets, such as T with internal and external threads on the rough to processing, the final completion of mechanical parts solid modeling. 2.4 complete the virtual assembly Virtual assembly is using virtual assembly technology, three-dimensional computer model will be assembled together, it can avoid the application of physical prototypes, but also for parts for clearance and interference testing, reduce the sample error rate. In the product design process can use various techniques such as analysis, evaluation, simulation, and give full consideration to the assembly areas and related products during the various possible factors. Product performance and functionality to meet the conditions to improve the product assembly structure, the design of the product not only assembly, and minimize assembly cost and total product costs, shorten design cycles. CATIA-based virtual assembly model has parallel, bottom-up and top-down approach to product development, this article focuses on bottom-up design. Construct the first module in the parts of parts of the three-dimensional model, then components in the assembly module to create constraints between the position, orientation relationships, about the relationship between parts to quantify the actual with the virtual assembly process between the various components entities location constraint relationship. In this way, parts of the geometry is being used in the assembly process, and not simply be copied to the assembly, to truly realize the part of the virtual assembly. CATIA assembly workbench provides a flexible and intuitive tool to determine the relationship between parts. Workbench allows users to assemble the component parts and various sub-assemblies combined together to form the final assembly in the assembly environment, according to the defined constraints, parts can be modified, analysis, and relocation HJ. CATIA features with a single database, regardless of how editors edit parts and components where the whole assembly of parts to maintain the consistency of association, if you modify the components, assemblies that reference it automatically updated, real-time components reflect the latest change. Virtual assembly steps: the assembly provided in CArllA bench, leaders need to assemble the parts and components (CATIA provides the main method of inserting parts into parts, into the products, parts and insert new components into existing, etc.) . Then, the constraints on the components and the establishment of appropriate assembly relationship, according to the requirements of the different parts of the assembly, use a different constraint relations, and finally get a complete assembly model. And Pro / E compared to the assembly process using CATIA has automatically created two parts to be assembled their design basis points of overlap between components to facilitate the designer a clear design basis between the assembly and parts between the base difference. 3 Design Example The worm drive, for example, the use of CATIA modeling and assembly process and methods described. 3.1 to create three-dimensional model worm Analysis of the structure of the worm part, clearly the main features of the structure to determine the modeling steps. By rotating the worm body, composed of the alveolar and keyway parts, the basic characteristics of a rotating body. 3.1.1 Create three-dimensional model of the worm part (1) in draft mode to draw shapes according to the rough shape of the worm rough sketches, the establishment of size constraints, such as size changes, chamfer, etc. (of course, also in the formation of rough chamfer after the entity). (2) In the design mode, the use of rotating parts (Shaft) tool to generate worm blank. (3) According to the worms parameters, to calculate the alveolar pitch worm and the worm screw according to the mode of curves and surfaces generated a worm wrapped around the spiral, as the slot scanning wire. (4) Since the end of cylindrical worm Archimedes Archimedes spiral, oblique axial plane to a straight line , so the worm shaft can choose almost plane, in draft mode, draw a trapezoid (must be a closed curve), its distance from the axis of the bottom margin is just the worm tooth root radius, both sides of the edge and face angle of 20. (Note: The pitch at both sides of the edge distance should be the pitch circle space width). (5) in the part design mode using the narrow slot (Slot) tool to generate an alveolar； use the whole array of tools to worm out of the alveolar process. (6) in draft mode to draw shapes keyway, the use of stretch cutting (Pocket) tool to generate key slot, to complete the three-dimensional construction of the worm Mode. 3.1.2 create three-dimensional model worm parts Analysis of worm parts of the structure, clearly a major component characteristics to determine the modeling steps. As the worm gear and ring gear teeth by the core 2 parts, so the ring gear and the tooth should be separated from the core model, and then assembled. Parts using CATIA modeling platform provided by the ring gear and the worm were generated tooth core. 3.2 parts of the assembly 3.2.1 Import Parts Assembly in CATIA provides the product structure workbench tool bar, use of existing parts into the function of the prior conductivity has been designed worm and worm parts. 3.2.2 the establishment of binding As part of the import process CAITA has established a worm in the worm and the axial profile width of 1 / 2 of the face overlap constraint relations, has pledged its profile in the worm drive of the main (center section) on the alignment, in The only other two to determine the direction of the constraint relationship. Center distance worm gear in accordance with requirements (center distance worm and worm gear during physical modeling, based on the geometric parameters of worm and worm calculated), the establishment of the worm and worm wheel axis offset between the axis of restraint to ensure that the difference between the distance to meet the design requirements. Along the axis of the worm to establish worm constraint relation, which is to ensure in the middle of the worm and worm gear worm side of the axis of symmetry perpendicular to the plane and worm width 1 / 2 symmetry on the alveolar surface profile coincidence (Note: during the worm and worm wheel solid modeling calculations must be accurate, otherwise it will not be accurate worm and worm wheel working position) to ensure that the worm and worm gear installed in the corresponding position. Generated as shown in Figure 1 worm drive assembly model. 4 Conclusion CATIA 3D design software design tools provide a complete and convenient user interface, the interface and options designed with a consistent style with Microsoft products, greatly reducing the user for the software to learn and adapt to the cycle, to a large extent improved the operation of complex 3D modeling software defects. Meanwhile, CATIA feature-based 3D modeling functions it has the following advantages: (1) inherited the use of solid modeling software for product design, the user can directly see on the screen the true three-dimensional model of the product characteristics, to model their ideas closer to the body composition, more intuitive design. (2) parametric design changes to facilitate the graphic size, quickly plotted, relative to the two-dimensional graphics methods, designed to greatly reduce the workload, especially in the subsequent parametric design for the technical staff provides an easy design, easy to modify the platform, facilitating product serial design. (3) The feature-based modeling idea, the use of Boolean operators seeking intersecting lines, intersecting lines, the engineering drawing speed faster, more accurate line. (4) assembly method using a virtual machine, you can directly check the product design space mechanical system components and assembly of interference and to further visualize the design and analysis, concurrent engineering has a certain significance. 附录 B 基于 CATIA 的汽车改装式升降台数字样机建模及应用研究 介绍了利用 CATIA V5 进行机械零件 i 维造型以及零、部件虚拟装配的基本过程与步骤，并以蜗轮蜗杆装配为例进行详细说明。对于改善机械设计的效果、提升设计效率、 缩短设计加工周期，具有一定的现实意义 1 概述 CATIA 软件是 IBM 公司和 Dassault 公司合作推出的高端 CAD CAM 软件，现已成为国际航空工业首选的设计软件。它以其强大的曲面设计功能在机械、飞机、汽车、造船等设计领域得到广泛应用， CATIA 的曲面造型功能的特点和优势体现在它提供了极丰富的造型工具来支持用户的造型需求。如其特有的高次Bezier 曲线曲面功能，次数能达到 15，能很好地满足特殊行业对曲面光滑性的苛刻要求。应用 CATlA 构造的实体模型可直接应用于 ANSYS 等分析软件中进行有限元分析。 CATIA 软件具有与其他三维 CAD 软件标准的数据接口，方便模型数据的转换。 CATIA V5 是基于 Windows 平台的全参数化和以特征建模技术为核心的特征造型软件，它与 Windows 保持一致风格的菜单条、标准的快捷键、上下关联的菜单、多文档界面、可以使不同的 Windows 应用程序共享数据的 OLE 集成，使工作快速高效，可显著减少培训时间。零件装配是 CATIA 基本的、也是最具优势和特色的功能模块，包括创建装配体、添加指定的部件或零件到装配体、创建部件之间的装配关系、移动和布置装配成员、生成产品的爆炸图、 装配干涉和间隙分析等主要功能 ?。 2 基于 CATIA 的三维造型与装配 2 1 草图设计 草图设计是三维设计的起点，其实质是二维线、面设计，具有传统二维软件设计的功能。参数化设计的基本方法是从草图设计开始，通过施加尺寸和几何约束生成草图特征，再应用尺寸驱动技术自动生成零件的三维实体模型，在利用草图技术生成二维轮廓时不必输入轮廓的准确尺寸，可以在以后的参数设计过程中得到。这样，在进行产品设计时，可以随时根据需要调整设计尺寸，而不必在设计之初就明确各设计尺寸，增强了 CAD 软件的易操作性，更 好地实现了人性化设计，而且对于设计系列产品及原产品的改进和零部件的 借用 都方便。 2 2 生成三维零件毛坯 CATIA 具有很强的三维实体建模的功能，当用户在草图平面绘制二维图形后，进入零件设计 (Part Design)模块，可以通过旋转、拉伸、放样、加肋、拔模等方法生成所需的三维零件毛坯。同时还可利用参数化约束功能，根据需要随时进行修改。设计者可以直接针对零件毛坯进行形体改变，实现了设计过程由绘图 向 设计 的转变，而且 CATIA V5 提供的各项具体功能使三维模型的设计更类似于生产加工过 程，较好地实现设计与加工的结合。 2 3 完成三维造型 CATIA V5 提供基于特征的设计，即将特征作为设计的单元，将产品视为特征的有机结合，通过由类到对象的逐步描述来实现具体的形状设计。在生成三维零件毛坯后，可利用打孔、开槽、抽壳、倒角、加凸台、内外螺纹等 T 具对 毛坯 进行 加工 ，最终完成机械零件实体造型。 2 4 完成虚拟装配 虚拟装配是利用虚拟装配技术，在计算机上将三维模型装配到一起，这样可避免物理原型的应用，也可对零部件进行间隙和干涉检验，减少样品差错率。能在产品设计 过程中利用各种技术手段如分析、评价、仿真等，并充分考虑产品的装配环节及其相关过程中各种可能因素的影响。在满足产品性能与功能的条件下改进产品的装配结构，使设计出的产品不但可以装配，并尽可能降低装配成本和产品总成本，大大缩短设计周期。 基于 CATIA 的虚拟装配模式有并行、自下而上和自上而下的产品开发方法，本文重点介绍自下而上的设计方法。先在零件模块中构造各零件的三维模型，然后在装配模块中建立零部件之间的位置约束、定位关系，即将零件间的实际配合关系量化为虚拟装配过程中的各零部件实体之间的位置约束关系。这样 ，零部件的几何体是在装配过程中被利用，而并不是简单地被复制到装配中，真正地实现了零件的 虚拟 装配。 CATIA 的装配工作台提供灵活、直观的工具，用来确定各零件间的关系。装配工作台允许用户将各个组成零件和各种子装配件组合到一起形成最终的装配体，在装配环境中，根据定义的约束，零件可以被修改、分析以及重定位 HJ。CATIA 具有单一数据库的特性，不管如何编辑零部件和在何处编辑零部件，整个装配部件保持关联的一致性，如果修改整个零部件，则引用它的装配件自动更新，实时反映零部件的最新变化。虚拟装配的步骤：在 CArllA 所提供的装配工作台上，导人需装配的零、部件 (CATIA 提供的插入部件的方法主要有插入部件、插入产品、插入新部件和插入已存在的部件等 )。然后，对零部件进行适当的约束并建立装配关系，根据不同零件的装配要求，选用不同的约束关系，最后得到完整装配模型。 与 Pro E 相比，使用 CATI