现代设计与制造中英文资料

Modern Design and Manufacturing
1.The Computer and Manufacturing
The computer is bringing manufacturing into the Information Age. This new tool, long a familiar one in business and management operations, is moving into the factory, and its advent is changing manufacturing as certainly as the steam engine changed it 100 years ago. The basic metalworking processes are not likely to change fundamentally, but their organization and control definitely will
Inone respect, manufacturing could be said to be coming full circle. The fist manufacturing was a cottage industry: the designer was also the manufacturer, conceiving and fabricating products one at a time. Eventually, the concept of the interchangeability of parts was developed, production was separated into specialized functions, and identical parts were produced thousands at a time .
Today, although the designer and manufacturer may not become one again, the functions are being drawn close in the movement toward an integrated manufacturing system.
It is perhaps ironic that, at a time when the market demands a high
degree of product diversification, the necessity for increasing productivity and reducing coats is driving manufacturing toward inegration into a coherent system, a continuous process in which parts do not spent as much as 95% of production time being moved around or waiting to be worked on .
The computer is the key to each of these twin requirements. It is the only tool that can provide the quick reflexes, the flexibility and seed, to meet a diversified market. And it is the only tool that enables the detailed analysis and the accessibility of accurate data necessary for the integration of the manufacturing system.
It may well be that, in the future, the computer may be essential to a company’s surv ial. Many of today’s businesses will fade away to be replaced by more-productive combinations. Such more-productive combinations are superquality, superproductivity plants. The goal is to design and operate a plant that would produce 100% satisfactory parts wich good productivity.
A sophisticated, competitive world is requiring that manufacturing begin to settle for more, to become itself sophisticated. To meet competition, for example, a company will have to meet the somewhat conflicting demands for greater product diversification, higher quality, improved productivity , higher quality, improved
productivity and prices.
The company that seeks to meet these demands will need a sophisticated tool, one that will allow it to respond quickly to customer needs while getting the most out of its manufacturing resources.
The computer is that tool.
Becoming a “superquality, superproductivity” plant requires the integration of an extremely complex system .This can be accomplished only when all extremely complex system. This can be accomplished only when all elements of manufacturing-design, fabrication and assembly, quality assurance, management, materials handing-are computer integrated.
In product design, for example, interactive computer-aided-design(CAD) systems allow the drawing and analysis tasks to be performed in a fraction of the time allow the drawing and analysis tasks to be performed in a fration of the time previously required and greater accuracy. And programs for prototype testing testing and evaluation further speed the design process.
In manufacturing planning, computer-aided process planning permits the selection, from thousands of possible sequences and schedules,of the optimum process.
On the shop floor, distributed intlligence in the form of microprocessors controls, runs automated loading and unloading equipment, and collects data on current shopconditions.
But such isolated revolutions are not enough. What is nended is a totally automated system, linked by common software from front door to back.
The benefits range thoughout the system. Essentially, computer integration provides widely and instantaneously available, accurate information, improving communication between departments, permitting tighter control, and generally enhancing the overall quality and efficiency of the entire system.
Improved communication can mean, for example, designs that are more producible. The NC programmer and the tool designer have a chang to influence the product designer, and vice versa.
Engineering changes,can be reduced,and those that are required can be handled more efficiently.Not only dose the computer permit them to be specicified more quickly, but it also alers subsequent users of the data to the fact that a change has been made.
The instantaneous updating of production-control data permits better planning and more-effective scheduling . Expensive equipment, therefore, is used more productively, and parts move more efficiently through production, reducing work-in-process coats.
Product quality, too, can be improved. Not only are more-accurate designs produced, for example,but the use of design data by the quality-assurance department helps eliminate errors due to misunderstandings.
People are enabled to do their jobs better.By eliminating tedious calculations and paperwork—not to mention time wasted searching for information—the computer not only allows workers to be more productive but also frees them to do what only human being can do: think creatively.
Computer integration may also lure new people into manufacturing. People are attracted because they want to work in a modern, technologically sophisticated enviroment.
In manufacturing engineering, CAD/CAM decreases
tool-design,NC-programming, and planning times while speeding the response rate, which will eventually permit in-hous staff to perform work that is currently being contracted out.
2.CAD/CAM
CAD/CAM is a term which means computer-aided and computer-aided manufacturing .it is the technology concerned with the use of digital computers to perform certain functions in design and production .This technology is moving in the direction of greater integration of design and manufacturing,two activities which have traditionally been treated as distinct and separate functions in a production firm .Ultimately,CAD/CAM will provide the technology base for the computer-integrated factory of the future .
Computer-aided design(CAD) can be defined as the use of computer stytems to assist in the creation ,modification ,analysis,or optimization of a design. The computer systems consist of the hardware and software to perform the specialized design functions required by the particular user firm. The CAD hardware typically included the computer,one or more graphics display terminals,keyboards,and other peripheral equipment.The CAD software consists of the computer programs to implement computer graphics to facilitate the engineering functions of the user company.Examples of these application programs include stress-strain analysis of
components,dynamic response of mechanisms,heat-transfer calculations, and numerical control part programming The collection of application programs will vary from oneuser firm to the next because their product lines, manufacturing processes,and customer markets are different These factors give rise to differences in CAD system requirements.
Computer-aided manufacturing(CAM) can be defined as the use of computer systems to plan,manufacturing plant through either direct or indirect computer interface with the plan’s production resources. As indicated by t he definition,the applications of computer-aided manufacturing fall into two broad categories:puter monitoring and control.2.Manufacturing support applications. The distinction between the two categories is fundamental to an understand-ing of computer-aided manufacturing.
In addition to the applications involving a direct computer-processinterface for the purpose of process monitoring and control,computer-aided manufacturing also includes indirect applications in which the computer serves a support role in the manufacturing operations of the plant. In these applications,the computer is not linked directly to the manufacturing process. Instead,the computer is used “off-line” to provide plans,schedules,forecasts, instructions,and information by which the firm’s production resources can be managed more effectively. The form of the relationship between the computer and the process is represented symbolically in the figure given below.Dashed lines are used to indicate that the communication and control link is an off-line connection,with human beings often required to consummate the inerface. However,human beings are presently required in the application either to provide input to the computer programs or to interpret the computer output and implement the required action.
3.V oice NC Programming
V oice programming of NC machines(abbreviated VNC) involves vocal communication of the machining procedure to a voice-input NC tape-preparation of the maching procedure to a voice-input NC tape-prepartion system. VNC allows the programmer to avoid steps such as One of the principal companies specializing in voice-input systems is Threshold Technology, Inc ,of Delran,New jersey. “turn”, To perform the part programming process with VNC,the operator speaks into a headband microphone designed to reduce background acoustical noise. Communication of the programming instructions is in shop language with such terms
as “turn”, “thead”,and “mill line ”,together with numbers to provide dimensional and coordinate data.Before the voice-input system can be used,It must be “trained”to recognize and accept the individual programmer’s voice pattern. This is accomplished by repeating each word of the vocabulary about five times to provide a reference set which can subsequently be compared to voice commands given during actual programming.The entire vocabulary for the thres hold system contains about 100 words.Most NC programming jobs can be completed by using about 30 of these vocabulary words.
In talking to the system, the programmer must isolate each word by pausing before and after the word. by pausing before and after the word. The pause must be only one-tenth of a second or longer.This allows the speech recognition system to indentify boundaries for the boundaries for the uttered command so that its wave characteristics can be compared with words in the reference set for that programmer. typical word input rates under this restriction are claimed to be about 70 per minute.As the words are spoken,a CRT terminal in front of the next command.
When all of the programming instructions have been entered and verified,the system prepares the punched tape for the job.
TheAdvantages of VNC lie principally in the the savings in programming time and resulting improvements in manufacturing lead time.Savings in programming time up to 50% are claimed. Improvents in accuracy and lower computer-skill requirements for the programmer are also given as benefits of VNC.
译文：
现代设计与制造
一、计算机与制造业：
计算机正在将制造业带入信息时代。

计算机长期以来在商业和管理方面得到了广泛的应用，它正在作为一种新的工具进入到工厂中，而且它如同蒸汽机在100年前使制造业发生改变那样，正在使制造业发生着变革。

尽管基本的金属切削过程不太可能发生根本的改变，但是他们的组织形式和控制方式将发生改变。

从某一方面可以说，制造业正在完成一个循环。

最初的制造业是家庭手工业：设计者本身也是制造者，产品的构思与加工由同一人完成。

后来，形成了零件的互换性这个概念，生产被依照专业功能分割开来，可以成批的生产数以千计的相同的零件。

今天，尽管设计者与制造者不可能再是同一个人，但在向集成制造系统前进的途中，这两种功能已经越来越靠近了。

可能具有讽刺意味的是，在市场需求高度多样化的产品的时候，提高生产率和降低成本的必要性促使着制造业朝着集成为单调关联系统方向变化。

这是一个连续的过程，在其中零件不需要花费多达95%的生产时间用在运输和等待加工上。

计算机是满足这两项要求中任何一项的关键。

它是能够提供快速反应能力、柔性和满足多样化市场的唯一工具。

而且，它是实现制造系统集成所需要的、能够进行详细分析和利用精确数据的唯一工具。

在将来计算机可能会是一个企业生存的基本条件，许多现今的企业将会被生产能力更高的企业组合所取代。

这些生产能力更高的企业组合是一些具有非常高的质量、非常高的生产率的工厂。

目标是设计和运行一个能够以高生产率的生产方式100%合格产品的工厂。

一个采用先进的、竞争的世界正在促使制造业开始做更高的工作，使其本身采用先进的技术。

为了适应竞争，一个公司会满足一些在某种程度上相互矛盾的要求，诸如产品多样化、提高质量、增加生产率、降低价格。

在努力这些要求的过程中，公司需要一个采用先进技术的工具，一个能够对顾客的需求作出快速反应，而且从制造资源中获得最大收益的工具，计算机就是这个工具。

成为一个具有“非常高的质量、非常高的生产率”的工厂，需要对一个非常复杂的系统进行集成。

这只有通过采用计算机对机械制造的所有组成部分—设计、加工、装配、质量保证、管理和材料装卸及输送进行集成才能完成。

例如，在产品设计期间，交互式的计算机辅助设计系统使得完成绘图和分析
工作所需要的时间比原来减少了几倍，而且精确程度得到了很大的提高。

此外，样机的实验与评价程序进一步加快了设计过程。

在制订制造计划时，计算机辅助编制工艺规程可以从数以千计的工序和加工过程中选择最好的加工方案。

在车间里，分布式智能以微处理器这种形式来控制机床、操纵自动装卸料设备和收集关于当前车间状态的信息。

但是这些各自独立的改革还远远不够。

我们所需要的是有一个共同的软件从始端到终端进行控制的全部自动化的系统。

整个系统都会从中受益。

基本上，计算机集成可以提供广泛的、及时的和精确的信息，可以改进各部门之间的交流与沟通，实施更严格的控制，而且通常能增强整个系统的全面质量和效率。

例如，改进交流和沟通意味着会使设计具有更好的可制造性。

数控编程人员和工艺装备设计人员有机会向产品设计人员提出意见，反之亦然。

因而可以减少技术反面的变更，而对于那些必要的变更，可以更有效地进行处理。

计算机不仅能够更快地对变更之处做出详细说明，而且还能把变更之后的数据告诉随后的使用者。

利用及时更新的生产控制数据可以制订更好的工艺规程和更有效率的生产进度。

因而，可以使昂贵的设备更好的利用，提高零件在生产过程中运送效率，减少在制品的成本。

产品质量也可以得到改进。

例如，不仅可以提高设计精度，还可以使质量保证部门利用设计数据，避免由于误解而产生错误。

可以使人们更好的完成他们的工作。

通过避免冗长的计算和书写工作—这还不算查找资料所浪费的时间—计算机不仅使人们更有效的工作，而且还能把他们解放出来去做只有人类才能做工作：创造性思考。

计算机集成制造还会吸引新的人才进入制造业。

人才被吸引过来的原因是他们希望到一个现代化的、技术先进的环境中工作。

在制造过程中，CAD/CAM减少了工艺装备设计、数控编程和编制工艺规程所需要的时间。

而且，在同时加快了响应速度，这最终将会使目前外委加工的工作由公司内部人员完成。

二、计算机辅助设计与制造
CAD/CAM是表示计算机辅助设计和计算机辅助制造的专业术语。

它是一种使用计算机完成某些设计和生产功能的技术。

在生产企业里，人们通常把设计和制造视为两项有着明显不同职能的分工，而这项技术正朝着设计与制造的更大程度一体化方向发展。

最终，CAD/CAM将会为未来的计算机集成工厂提供技术基础。

计算机辅助设计（CAD）可定义为运用计算机系统对设计的创意、修改、分析或优化予以辅助。

这些有硬件和软件构成的计算机系统，用于完成用户公司要求的特定设计功能。

CAD硬件通常包括：一台计算机，一个或多个图形显示终端，键盘和其他外围设备。

CAD软件包括各种计算机制图程序，这些程序便于用户公司完成设计职能，如：零部件的应变分析，机构的动态响应，热传输计算和数控零件编程。

由于用户的生产流程、制造工艺和销售市场方面的差异，应用程序的配制也将因用户而异。

这些因素均导致对CAD系统要求的差异性。

计算机辅助制造（CAM）可定义为通过直接或间接于厂家生产资源相适应的计算机界面，使用计算机系统来规划、管理和控制制造工厂的运行。

正如定义所表明的那样，CAM应用程序可分为两大类：1、计算机监控程序；2、制造程序。

二者间的区别是理解计算机辅助制造的基础。

计算机辅助制造的应用程序，除了为监控制造过程而直接使用计算机处理界面的应用程序之外，还包括在工厂生产运行过程中由计算机提供支持的间接应用程序。

在这些应用程序中，计算机并不直接与制造过程相连接。

想反，在脱机状态下，计算机可用来提供计划书、进度表、预报、指令和使厂家生产管理更加有效的信息资料。

计算机和制造过程间的如下图所示。

表中虚线用来说明交流和控制处于脱机状态下，需要人来完善界面。

目前，CAM的应用需要有人来为计算机输入程序，解释计算机的输入，并采取所要求的措施。

三、语音数控编程
语音编程NC机床涉及机械加工过程和语音输入数控磁带准备系统间的语
言交流。

VNC可使编程员免除手工编程、键盘输入或打字以及人工检验等步骤。

美国新泽西州德尔兰市的斯莱肖德股份有限公司便是一家专门研发语音输入系统的大公司。

使用VNC完成零件编程，操作者头带耳机话筒录音，可减弱背静杂音。

编程指令的交流使用像“turn”,“thread”和“mill ling”等加工车间使用的专门术语，同时提供车间和坐标数据。

在使用语音输入系统前，该系统必须接受“训练”来识别和接受编程员的声音模式。

“训练”时编程员把每个行话词重复大约五遍，作为参照数据组，随后实际编程时系统将给出语音指令与参照数据组进行比较。

系统的全部行话词汇包括大约100个单词。

大部分的数控编程工作使用其中的30个左右的行话词汇便可以完成。

和系统交谈时，编程员必须在说出的词前和词后停顿来隔离每个词。

停顿时间不能少于1/10秒。

停顿使语音识别系统能确认发出的语音指令的界线以便语音指令声波特征能与该编程员参照组中的单词进行比较。

据称在这种限制下，常规的单词输入速度大约每分中70个词。

随着单词的输入，操作者面前的CRT(阴
极射线管—显示器)终端验证每一个指令并提示操作者发出下一个指令。

当输入和验证所有编程指令后，系统就会准备好穿孔纸带以备工作。

VNC的优点主要在于节省编程时间并由此缩短产品设计至实际投产时间。

准确度的提高和对编程者计算机技能要求较低也被视为VNC的优点。