机械英语中英对照

1、Lesson 21 CAD/CAM/CAPP 1. Words and phrases n interactive adj. 交互式的 n wire-frame models 线框模型 n surface models表面模型 n solid models实体模型 n vertex顶点，最高点 n stress-strain应力，应变 n fabricatev. 构成，伪造，虚构 n straightforward正直的，简单的，直截 了当的 n incorporate合并的，一体化的 n phenomenon 现象 n simultaneous 同时的，同时发生的 2. text nCAD计

2、算机辅助设计 n Computer aided design (CAD) can be defined as using computers to aid the engineering design process by means of effectively creating, modifying, or documenting the parts geometrical modeling. be defined as 被定义为 by means of 通过方法、手段 n 计算机辅助设计被定义为通过高效的创建、修改或记录零件的几何建模 等手段， 使用计算机来辅助工程设计过程。 nCAD

3、is most commonly associated with the use of an interactive computer graphics system. The object of the engineering design is stored and represented in the form of geometric models. n associate with 与联系在一起 n in the form of 以的形式存在 n 计算机通常与交互式计算机图形系统的使用联系在一起。工程设计的实体以几何模型 的形式进行存储和记录。 n Geometric modelin

4、g is concerned with the use of a CAD system to develop a mathematical description of the geometry of an object. The mathematical description is called a model. There are three types of models (wire-frame models, surface models, and solid models, see Fig.21.1), that are commonly used to represent a p

5、hysical objects. n be concerned with 干预，参与 n CAD系统使用几何建模来进行实体几何上的数学描绘。数学上的这种描绘称为建模。 有三种类型的建模（线框模型、表面模型、实体模型，见图21.1），它们通常用来描绘 物质实体。 n nWire-frame models, also called edge-vertex or stick-figure手工线形画 models, are the simplest method of modeling and are most commonly used to define computer models of pa

6、rts. Surface models may be constructed using a large variety of surface features. n线框模型也叫网格点或线轮廓模型，是建模最简单的方法，常用来定义零件的计算机建模。表面模 型可以应用各种表面特征来构造。 nSolid models are recorded in the computer result；1it is possible to calculate mass properties of the parts, which is often required for engineering analysis

7、 such as finite element methods, kinematics or dynamic studies, and mass or heat transfer for interference checking. n kinematics 运动学的 dynamic 动力学的，动态的 n实体模型记录在计算机的结果里面，它可能会用来计算零件的质量属性，这些质量属性通常是用以 工程分析，如有限元方法，运动学和动力学研究，进行干涉校验发生的质量和热传递。 n Models in CAD also can be classified as being two-dimensional

8、models, two- and-half dimensional models, or three-dimensional models. A 2-D model represents a flat part and a 3-D model (see Fig.21.2) provides representation of a generalized part shape. A 2.5-D model can be used to represent a part of constant section with no side-wall details. 2The major advant

9、age of a 2.5-D model is that it gives a certain amount of 3-D information about a part without the need to create the database of a full 3-D model. n generalized 广义的，无显著特点的，通用的 n CAD中的模型也可以分类为二维模型、2.5维模型、三维模型。 二维模型描 绘平面零件，三维模型描绘广义零件的形状。2.5维模型能用来描绘零件的无 侧面细节的连续部分。2.5维模型的主要优势是给出零件的一定数量三维信息， 而无需全三维模型的数据

10、库。 n After a particular design alternative has been developed, some form of engineering analysis must often be performed as a part of the design process. The analysis may take the form stress-strain calculations, heat transfer analysis, dynamic simulation etc. Some examples of the software typically

11、 offered on CAD systems are mass properties and Finite Element Method (FEM) analysis. n particular 特定的，详细的，详尽的，精确的 n take the form (of) 采取形式 n 选择性的详尽的设计形成以后，一些工程分析方式常作为零件设计进程来进行。一些 分析也许采取压力应变计算、热传递分析、动态仿真等形式进行。在CAD系统中典 型的软件提供的例子就是材质属性和有限元方法分析。 nMass properties involve the computation of such feature

12、s of a solid object as its volume, surface area, weight, and center of gravity. FEM analysis is available on most CAD systems to aid in heat transfer, stress-strain analysis, dynamic characteristics, and other engineering computations. Presently, many CAD systems can automatically generate the 2-D o

13、r 3-D FEM meshes which are essential to FEM analysis. Mesh 网状物 v. 相合，相配 n 材质属性包括实体体积、表面积、重量和重心。有限元方法分析用在多数CAD系统中， 用以辅助热传递、应力应变分析、动态特性和其他工程计算。目前，很多CAD系统 能自动生成2D或3D有限元网格，有限元网格是有限元方法分析的主要组成要素。 CAM 计算机辅助制造 nCAM can be defined as computer aided preparation manufacturing including decision-making, process

14、 and operational planning, software design techniques, and artificial intelligence, and manufacturing with different types of automation (NC machine, NC machine centers, NC machining cells, NC flexible manufacturing systems), and different types of realization (CNC single unit technology, DNC group

15、technology). Realization 意识，现实，实现，变现，变卖 n CAM可以定义为计算机辅助制造，包括制定决策、进程和操作规划，软件设计技术、 人工智能、不同类型的数控制造（数控加工、数控加工中心、数控加工单元、数控柔 性生产系统）和各种类型的实现方法（计算机数控单元技术、直接数控成组技术） n The CAM covers group technology, manufacturing database, automated and tolerance. Fig.21.3 illustrates the general scope of CAM. n CAM包含了成组技术，

16、生产数据库，自动化和公差检测。图21.3列举了 CAM的总体范围。 n When a design has frozen冻结，冷冻, manufacturing can begin. Computers have an important role to play in many aspects of production. Numerically controlled machine tools need a part program to define the components being made; computer techniques exist to assist, and i

17、n some cases virtually automate the generation of part programs. Modern shipbuilding fabricates structures from welded steel plates that are cut from a large steel sheet. Computer-controlled flame cutters are often used for this task and the computer is used to calculate the optimum layout of the co

18、mponents to minimize waste metal. Numerically controlled pipe-bending machines are able to operate directly from part programs generated by pipe-routing software. n 当一个设计确定以后，生产才能开始。计算机在生产的许多方面扮演着重要的角色。 数控机床需要一个零件加工程序来确定加工的部件；计算机技术的出现提供了辅助， 在多数情况下，零件加工程序事实上是自动生成的。现代造船业从大型钢板上剪下焊 接钢板构造结构。计算机控制火焰切割机常用来

19、完成这项任务，且计算机被用来计算 最优的零部件外形使得材料的浪费达到最小。数控弯管机可以通过管道路径软件生产 的零件加工程序直接进行操作。 n Printed circuit board assembly can also be improved by computer methods. Quality is maintained by computer-controlled automatic test equipment that diagnoses faults in a particular board and rejects拒绝 defective有缺陷的 boards from t

20、he assembly line. Computers are used extensively to plot the artwork插图 used to etch蚀刻， 凿刻 printed circuit boards and also to produce part programs for NC drilling machines. n 印刷集成的电路板也可以通过计算机方法进行改进。通过计算机控制的自动检测装备 诊断特殊电路板的错误可以保证质量，从装配生产线上淘汰有缺陷的电路板。计算机 被广泛应用在绘制蚀化印刷电路板模块和生产数控钻床零件加工程序。 n One of the most

21、 important manufacturing function is stock and production control. If the original design is done on a computer, obtaining lists of material requirements is straightforward. Standard computer data processing methods are employed to organize the work flow and order components when required. n 库存和生产控制

22、是最重要的生产功能之一。如果原始设计在计算机上完成后，就可以 直接获得材料需求清单。标准的计算机数据处理方法被用在物流组织和订购所需零部 件上。 CAPP 计算机辅助工艺设计 n Computer aided process planning (CAPP) can be defined as the functions which use computers to assist the work of process planners. The levels of assistance depend on the different strategies employed to impleme

23、nt the system. Lower level strategies only use computers for storage and retrieval of the data for the process plans which will be constructed manually by process planners, as well as for supplying the data which will be used in the planners new work. In comparison with lower level strategies, highe

24、r level strategies use computers to automatically generate process plans for some work pieces of simple geometrical shapes. n CAPP被定义为使用计算机辅助工艺员的工作。辅助的程度依赖于执行在此系统上的不 同策略。低等级的策略只是通过计算机完成存储和修复工艺流程数据，这些工艺流程 可以由工艺员手工构建并为工艺员的新任务提供数据。相比于低等级策略，高等级策 略是使用计算机自动为一些简单几何形状的工件生成工艺流程。 n Sometimes a process planner

25、 is required to input the data needed or to modify plans which do not fit specific production requirements well. The highest level strategy, which is the ultimate goal of CAPP, generates process plans by computer, which may replace process planners, when the knowledge and expertise of process planni

26、ng and working experience have been incorporated into the computer programs. The database in a CAPP system based on the highest level strategy will be directly integrated with conjunctive systems, e.g. CAD and CAM. CAPP has been recognized as playing a key role in CIMS (Computer integrated manufactu

27、ring system). n 有时工艺员需要输入需要的数据或者修改不能很好的适合特殊生产的工艺流程。高级 策略的目标是CAPP的最高目标，当工艺知识、专门技术和工作经验被融合进计算机程 序中时，计算机也许会取代工艺员去完成生产工艺流程。基于最高等级策略的CAPP系 统中的数据库将被直接集成在相关系统。如CAD和CAM。CAPP被认为是CIMS（计算 机集成制造系统）的关键角色。 nMore than 20 years have elapsed since the use of computers to assist process planning tasks was first propo

28、sed. Tremendous efforts have been made in the development of CAPP systems. For the time being, the research interests for development of CAPP systems are focused on intelligent and integrated process planning systems. For increasing the intelligence of CAPP systems, some new concepts, such as neural

29、 networks, fuzzy logic, and machine learning have been explored for the new generation of CAPP systems. For increasing the integrability of CAPP system, feature based design, the roles of features, integrating process planning with scheduling, and integrating process planning with manufacturing reso

30、urces planning have been focused on. This phenomenon is entitled concurrent or simultaneous engineering. n 从首次提出用计算机来辅助工艺流程任务以来已过去了20多年。人们为CAPP的发 展作了极大的努力。随着时间的推移，研究CAPP系统的意义集中在智能化和集成工艺 流程系统上。为提高CAPP系统的智能化程度，一些新概念，如神经网络，模糊逻辑学 和机器示教在新生代CAPP系统中被探索开发。为增加CAPP系统的可积性，设计开发 的焦点集中于设计中的典型特征、典型特征的功能、工艺过程和行程安排一体化，并 集成了制造原材料计划的工艺流程。该现象能够与工程同时产生。 nSince a process plan determines the methods, machines, sequences, fixturing, and tools required in the fabrication and assembly of components, it is easy to see that process planning is one of the basic tasks to be