在80年代的初期,工程师们曾经认为要加快产品的研制开发,必须进行大量的研究工作。结果是实际上只进行了较少的研究工作,这是因为产品开发周期的缩短,促使工程师们尽可能地利用现有的技术。研制开发一种创新性的技术并将其应用在新产品上,是有风险的,并且易于招致失败。在产品开发工程中采用较少的步骤是一种安全的和易于成功的方法。
对于资金和人力都处于全球性环境中的工程界而言,缩短产品研制开发周期也是有益的。能够设计和制造各种产品的人可以在世界各地找到。但是,具有创新思想的人则比较难找.对于你已经进行了6个月的研制开发工作,地理上的距离已经不再是其他人发现它的障碍。如果你的研制周期较短,只要你仍然保持领先,这种情况并不会造成严重后果。但是如果你正处于一个长达6年的研制开发过程的中期,一个竞争对手了解到你的研究工作的一些信息,这个项目将面临比较大的麻烦。
工程师们在解决任何问题时都需要进行新的设计这种观念很快就过时了.在现代设计中的第一步是浏览因特网或则其他系统,看其他人是否已经设计了一种类似于你所需要的产品,诸如传动装置或者换热器等。通过这些信息系统,你可能发泄有些人已经有了制造图纸,数控纸带和制造你的产品所需要的其他所有东西。这样,工程师们就可以把他们的职业技能集中在尚未解决的问题上。
在解决这类问题时,利用工作站和进入信息高速公路可以大大增强工程小组的能力和效率。这些信息时代的工具可以使工程小组利用大规模的数据库。数据库中有材料性能,标准,技术和成功的设计方案等信息。这些经过验证的设计可以通过下载直接应用,或者通过对其进行快速,简单的改进来满足特定的要求.将产品技术要求通过网络送出去的远程制造也是可行的。你可以建立一个没有任何加工设备的虚拟公司。你可以指示制造商,在产品加工
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完成后,将其直接送给你的客户。定期访问你的客户可以保证你设计的产品按照设计要求进行工作。尽管这些研制开发方式不可能对每个公司都完全适用,但是这种可能性是存在的。
过去客户设计的产品通常是由小公司来制造。大公司不屑于制造这种产品,
他们讨厌与特殊定向产品市场,或者是客户设计的小批量产品打交道。\"这就是我的产品”,一家大公司这样说:\"这是我们能够制造出来的最好产品,你应该喜欢它。如果你不喜欢,顺这条街走有一家小公司,它会按你的要求去做。”
今天,因为客户们有较大的选择余地,几乎所有的市场都是特殊定向产品市场.如果你不能使你的产品满足某些特定客户的要求,你将失去你市场份额中的一大部分,或者失掉全部份额。由于这些定向产品市场是经常变化的,你的公司应该对时常的变化作出快速的反应。
定向产品市场和根据客户要求进行设计这种现象的出现改变了工程师研究工作的方式。今天,研究工作通常是针对解决特定问题进行的。现在许多由政府资助或者由大公司出资开发的技术可以在非常低的成本下被自由使用,尽管这种情况可能是暂时的。在对这些技术进行适当改进后,它们通常能够被直接用于产品开发,这使得许多公司可以节省昂贵的研究经费。在主要的技术障碍被克服后研究工作应该主要致力于产品的商品化方面,而不是开发新的,有趣的,不确定的替换产品。
采用上述观点看问题,工程研究应该致力于消除将已知技术快速商品化的障碍。工作的重点是产品的质量和可靠性,这些在当今的顾客的头脑中是最重要的。很明显,一个质量差的声誉是一个不好企业的同义词。企业应该尽最大的努力来保证顾客得到合格的产品,这个努力包括在生产线的终端对产品进行严格的检验和自动更换有缺陷的产品。
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研究工作应该着重考虑诸如可靠性等因素对成本带来的益处。当可靠性提高时,制造成本和系统的最终成本将会降低。如果在生产线的终端产生了30%的废品,这不仅会浪费金钱,也会给你的竞争对手创造一个利用你的想法制造产品,并将其销售给你的客户的良机。
提高可靠性和降低成本这个过程的关键是深入,广泛地利用设计软件。设计软件可以使工程师们加快每一阶段的设计工作。然而,仅仅缩短每一阶段的设计时间,可能不会显著地缩短整个设计过程的时间。因而必须致力于采用并行工程软件,这样可以使所有设计组的成员都能使用共同的数据库。
随着我们步入信息时代,要取得成功,工程师们在技术开发和技术管理方面都应该具有一些独特的知识和经验。成功的工程师们不但应该具有宽广的知识和技能,而且还应该是某些关键技术或学科的专家,他们还应该在社会因素和经济因素对市场影响方面有敏锐的洞察能力。将来,花在解决日常工程问题上的费用将会减少,工程师们将会在一些更富有挑战性,更亟待解决的问题上协同工作,大大缩短解决这些问题所需要的时间。我们已经开始了工程实践的新阶段。计算机和网络工程师们具有了越来越强的解决问题的能力,这也给他们的工作带来了很大的希望和喜悦。为了确保成功,我们所使用的工具的性能和对更好的产品与系统的不断追求应该与标志着在过程方面所有巨大努力的创新工作所带来的喜悦相适应。机械工程是一个伟大的行业,在我们尽可能多地利用了信息时代所提供的机遇后,它将变得更加伟大。
许多工程师的职责是进行产品设计,而产品是通过对材料的加工制造而生产出来的。设计工程师在材料选择——制造方法等方面起着关键的作用.一个设计工程师应该比其他的人更清楚地知道他的设计需要达到什么目的。他知道他对使用载荷和使用要求的假设,产品的使用环境,产品应该具有的外观形貌。为了满足这些要求,他必须选择和规定所使用的材料。通常,为了利用材料并使产品具有所期望的形状,设计工程师知道应该采用哪些制造方
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法。在许多情况下,选择了某种特定材料就可能意味着已经确定了某种必须采用的加工方法。同时,当决定采用某种加工方法后,很可能需要对设计进行修改,以使这种加工方法能够被有效而经济地应用。某些尺寸公差可以决定产品的加工方法。总之,在将设计转变为产品的过程中,必须有人做出这些决定.在大多数情况下,如果设计人员在材料和加工方法方面具有足够的知识,他会在设计阶段做出最为合理的决定。否则,做出的决定可能会降低产品的性能,或则使产品变得过于昂贵。显然,设计工程师是制造过程中的关键人物,如果他们能够进行面向生产(即可以进行高效率生产)的设计,就会给公司带来效益。
制造工程师们选择和调整所采用的加工方法和设备,或者监督和管理这些加工方法和设备的使用。一些工程师进行专用工艺装备的设计,以使通用机床能够被用来生产特定的产品。这些工程师们在机床,工艺能力和材料方面必须具有广泛的知识,以使机器在没有过载和损坏,而且对被加工材料没有不良影响的情况下,更为有效地完成所需要的加工工序。这些制造工程师们在制造业中也起到重要作用。
少数工程师们设计在制造业中使用的机床和设备。显然,他们是设计工程师。而且对于他们的产品而言,他们同样关心设计,材料和制造方法之间的相互关系。然而,他们更多地关心他们所设计的机床将要加工的材料的性能和机床与材料之间的相互作用。
还有另外一些工程师——材料工程师,他们致力于研制新型和更好的材料,他们也应该关心这些材料的加工方法和加工对这些材料性能的影响。
尽管工程师们所起的作用可能有很大的差别,但是,大部分工程师们都必须考虑材料与制造工艺之间的相互关系。低成本制造并不是自动产生的.在产品设计,材料选择,加工工艺装备选择和设计之间都有着非常密切的相互依赖关系。这些步骤中的每一个都必须在开始制造前仔细地加以考虑,规划和协调。这种从产品设计到实际生产的准备工作,特别是对于复
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杂产品,可能需要数月甚至数年的时间,并且可能花费很多钱。典型的例子有,对于一种全新的汽车,从设计到投产所需要的时间大约为2年,而一种现代化飞机则可能需要4年。
随着计算机和由计算机产生的纸带与由计算机本身控制的机器的出现,我们进入了一个生产计划的新时代。采用计算机将产品的设计功能与制造功能集成,被称为CAD/CAM(计算机辅助设计/计算机辅助制造).这种设计被用来制定加工工艺规程和提供加工过程本身的编程信息。可以根据供设计由于制造用的中心数据库内的信息绘制零件图,需要时可以生成加工这些零件时所使用的程序。此外,对加工后的零件的计算机辅助试验与检测也得到了广泛的应用。随着计算机价格的降低和性能的提高,这种趋势将毫无疑问地得到不断加速的发展。
Mechanical Engineering in the Information Age
In the early 1980s, engineers thought that massive research would be needed to speed up product development. As it turns out, less research is actually needed because shortened product development cycles encourage engineers to use available technology for use in a new product is risky and prone to failure. Taking short steps is a safer and usually more successfully approach to product development.
Shorter product development cycles are also beneficial in an engineering world in which both capital and labor are global. People who can design and manufacture various products can be found anywhere in the world, but containing a new idea is hard. Geographic distance is no longer a barrier to others finding out about your development six months into the process. If you’ve got a short development cycle, the situation is not catastrophic —as long as you maintain you
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lead. But if you’re in the midst of a six year development process and a competitor gets wind of your worker, the project could be in more serious trouble.
The idea that engineers need to creat a new design to solve every problem is quickly becoming obsolete. The first step in the modern design process is to browse the Internet or other information systems to see if someone else has already a new transmission, or a heat exchanger that is close to what you need. Through these information system, you may discover that someone already has manufacturing drawings, numerical control tapes ,and everything else required to manufature your product. Engineers can then focus their professional competence on unsolved problems.
In talckling such problems, the availability of wokstations and access to the information hignway dramatically enhance the capability of the engineering team and its productivity. These information age tools can give the team access to massive databases of material properties, standards, technologies, and successful designs. Such protested designs can be downloaded for direct use or quickly modified to meet specific needs. Remote manufacturing, in which productions are sent out over a network, is also possible. You could end up with a virtual company where you don’t have to see any hardware. When the product is completed you can direct the manufaturer to drop-ship it to your customer. Periodic visits to the customer can be made to ensure that the product you designed working according to the specification. Although all of the developments won’t apply equally to every company, the potential is there.
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Custom design used to be left to small company. Big companies sneered at it—they hated the idea of dealing with niche markets small-valum custom solutions. “Here is my product,” one of the big companies would say:“This is the best we can make it —you ought like it. If you don’t, there’s smaller company down the street that will work on your problem.”
Today, nearly every market is a niche market, because customers are selective. If you ignore the potential for tailoring your product to specific customers’ needs, you will lose the major part of your market share. Since these niche markets are transient, your company needs to be in a positiong to respond to them quickly.
The emgergence of niche markets and design on demand has altered the way engineers conduct research. Today, research is commonly directed toward sovling particular problems. Although this situstion is probably temporary, much uncommitted technology, developed at government expense or written off by major corporationgs, is available today at very low cost. Following modest modificationgs, such technology can ofen be used directly in product development, which allows many organizations to avoid the expense of an extensive research effort. Once the technology is free of major obstacles, the research effort can focus on overcoming the barriers to commercializationg rather than on pursuing new and interesting, but undefined, alternatives.
When view in this prospective, engineering research must focus primarily on removing the barriers to rapid commercilizationg of known technologies. Much of this effort must address quality and reliability concerns, which are foremost in the
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minds of today’s consumers. Clearly, a reputationg for poor quality is synonymous with bad business. Everything possible—including thorough inspection at the end of the manufacturing line and automatic replacement of defective products—must be dong to assure that the customer receives a properly functionging product.
Research has to focus on the cost benefit of fators such as reliability. As reliability increases, manufanturing costs and the final costs of the system will decrease. Having 30%junk at the end of a production line not only costs a forturn but also creats an opportunity for a competitor to take your idea and sell it to your customers.
Central to the process of improving reliability and lowing costs is the intensive and widespread use of design software, which allows engineers to speed up every stage of the design process. Shortening each stage, however ,may not sufficiently reduce the time required for the entire process. Therefore, attention must also be devoted to concurrent engineering software with shared databases can be accessed by all members of the design team.
As we move more fully into the Information Age, success will require that the engineer possess some unique knowledge of and experience in both the development and the management of technology. Success will require broad knowledge and skills as well as expertise in some key technologies and disciplines; it also require a keen awareness of the social and economic factors at work in the marketplace. Increasingly, in the future, routin problems will not justify heavry
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engineering expenditures, and engineers will be expected to work cooperatively in solving more challenging , more demanding problems in substantially less time. We have begun a new phase in the practice of engineering. It offers great promise and excitement as more and more problem-solving capability is placed in the hands of the computerized and wired engineer. To assure success, the capability of our tools and the unquenched thirst for better products and systems must be matched by the joy of creation that marks all great engineering endeavors. mechanical engineering is a great profession, and it will become even greater as we make the most of the opportunities offered by the Information Age.
Many engineers have as their function the designing of products that are to be brought into reality through the processing or fabrication of materials. In this capacity they are a key fator in the material selection-manufaturing procedure. A design engineer, better than any other person, should know what he or she wants a design to accomplish. He knows what assumptions he has made about service loads and requirements, what service environment the product must withstand, and what appearance he wants the final product to have. In order to meet these requirements he must select and specify the material（s）to be used. In most cases, in order to utilize the material and to enable the product to have the desired form, he knows that certain manufacturing processes will have to be employed. In many instances, the selection of a specific material may dictate what processing must be used. At the same time, when certain processes are to be used, the design may have to be modified in order for the process to be utilized effectively and economically. Certainly dimensional tolerances can dictate the processing. In any case, in the sequence of converting the design into reality, such decisions must be
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made by someone. In most distances they can be made most effectively at the design stage, by the designer if he has a reasonably adequate knowledge concerning materials and manufacturing processes. Otherwise, decisions may be made that will detragt from the effetiveness of the product, or the product may be needlessly costly. It is thus apparent that design engineers are a vital fator in the manufacturing process, and it is indeed the company if they design for producibility—that is, for effient production.
Manufacturing engineers select and coordinate specific processes and equipment to be used, or supervise and manage their use. Some design special tooling that is used so that standard machines can be utilized in producing special products. These engineers must have a broad knowledge of machine and process capabilities and of materials, so that desired operations can be done effectively and efficiently without overloading or damaging machines and without adversely affecting the materials being processed. These manufacturing engineers also play an important role in manufacturing.
A relatively small group of engineers design the machines and equipment used in manufacturing. They obviously are design engineers and, relative to their products, they have the same concerns of the interrelationship of design, materials, and manufacturing processes. However, they have an even greater concern regarding the properties of the materials that their machines are going to process and the interreaction of the materials and the machines.
Still another group of engineers—the materials engineers—devote their major
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efforts toward developing new and better materials. They, too, must be concerned with how these materials can be processed and with the effects the processing will have on the properties of the materials.
Although their roles may be quite different, it is apparent that a large proportion of engineers must concern themselves with the interrelationship between materials and manufacturing processes.
Low-cost manufature does not just happen. There is a close and interdependent relationship between the design of a product, selection of materials, selection of processes and equipment, and tooling selection and design. Each of these steps must be carefully considered, planned, and coordinated before manufacturing starts. This lead time, particularly for complicated products, may take months, even years, and the expenditure of large amount of money may be involved. Typically, the lead time for a completely new model of an automobile is about 2 years, for a modern aircraft it may be 4 years.
With the advent of computers and machines that can be controlled by either tapes made by computers or by the computers themselves, we are entering a new era of production planning. The integration of the design function and the manufacturing function through the computer is called CAD/CAM（computer aided design/computer aided manufacturing）. The design is used to determine the manufacturing process planning and the programming information for the manufacturing processes themselves. Detailed drawing can also be made from the central data base used for the design and manufature, and programs can be
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generated to make the parts as needed. In addition, extensive computer aidedtesting and inspection（CATI）of the manufactured parts is taking place. There is no doubt that this trend will continue at ever-accelerating rates as computers become chesper and smarter.
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