机械设计外文翻译(中英文)

1、机械设计理论机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科 学。它涉及工程技术的各个领域，主要研究产品的尺寸、形状和详细结构的基本 构思，还要研究产品在制造、销售和使用等方面的问题。进行各种机械设计工作的人员通常被称为设计人员或者机械设计工程师。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制 图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。 如前所诉，机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处，只有当它们被应用在产品上才能产生效 益。因而，应该认识到在一个特定的产品进行

2、设计之前， 必须先确定人们是否需 要这种产品。应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公 式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决 定的。另一方面，应该认真精确的进行所有运算。例如，即使将一个小数点的位 置放错，也会使正确的设计变成错误的。一个好的设计人员应该勇于提出新的想法， 而且愿意承担一定的风险，当新的方 法不适用时，就使用原来的方法。因此，设计人员必须要有耐心，因为所花费的时间和努力并不能保证带来成功。 一个全新的设计，要求屏弃许多陈旧的，为 人们所熟知的方法

3、。由于许多人墨守成规，这样做并不是一件容易的事。一位机 械设计师应该不断地探索改进现有的产品的方法，在此过程中应该认真选择原有 的、经过验证的设计原理，将其与未经过验证的新观念结合起来。新设计本身会有许多缺陷和未能预料的问题发生， 只有当这些缺陷和问题被解决 之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也 伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法， 就没 有必要仅仅为了变革的目的而采用新方法。在设计的初始阶段，应该允许设计人员充分发挥创造性， 不受各种约束。即使产 生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有 这样，才不

4、致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。心理学家经常谈论如何使人们适应他们所操作的机器。设计人员的基本职责是努 力使机器来适应人们。这并不是一项容易的工作，因为实际上并不存在着一个对 所有人来说都是最优的操作范围和操作过程。另一个重要问题，设计工程师必须能够同其他有关人员进行交流和磋商。 在开始 阶段，设计人员必须就初步设计同管理人员进行交流和磋商， 并得到批准。这一 般是通过口头讨论，草图和文字材料进行的。为了进行有效的交流 ，需要解决 下列问题：（1）所设计的这个产品是否真正为人们所需要？（2）此产品与其

5、他公司的现有同类产品相比有无竞争能力？（3）生产这种产品是否经济？（4）产品的维修是否方便？（5）产品有无销路？是否可以盈利？只有时间能对上述问题给出正确答案。但是， 产品的设计、制造和销售只能在 对上述问题的初步肯定答案的基础上进行。设计工程师还应该通过零件图和装配 图，与制造部门一起对最终设计方案进行磋商。通常，在制造过程中会出现某个问题。可能会要求对某个零件尺寸或公差作一 些更改，使零件的生产变得容易。但是，工程上的更改必须要经过设计人员批准， 以保证不会损伤产品的功能。有时，在产品的装配时或者装箱外运前的试验中才 发现设计中的某种缺陷。这些事例恰好说明了设计是一个动态过程。 总是存在着

6、 更好的方法来完成设计工作，设计人员应该不断努力，寻找这些更好的方法。近些年来，工程材料的选择已经显得重要。 此外，选择过程应该是一个对材料的 连续不断的重新评价过程。新材料不断出现，而一些原有的材料的能够获得的数 量可能会减少。环境污染、材料的回收利用、工人的健康及安全等方面经常会对 材料选择附加新的限制条件。为了减轻重量或者节约能源，可能会要求使用不同 的材料。来自国内和国际竞争、对产品维修保养方便性要求的提高和顾客的反馈 等方面的压力，都会促使人们对材料进行重新评价。由于材料选用不当造成的产 品责任诉讼，已经产生了深刻的影响。此外，材料与材料加工之间的相互依赖关 系已经被人们认识得更清楚

7、。因此，为了能在合理的成本和确保质量的前提下获 得满意的结果，设计工程师的制造工程师都必须认真仔细地选择、确定和使用材 料。制造任何产品的第一步工作都是设计。 设计通常可以分为几个明确的阶段：（a） 初步设计；（b）功能设计；（c）生产设计。在初步设计阶段，设计者着重考 虑产品应该具有的功能。通常要设想和考虑几个方案，然后决定这种思想是否可 行；如果可行，则应该对其中一个或几个方案作进一步的改进。在此阶段，关于 材料选择唯一要考虑的问题是：是否有性能符合要求的材料可供选择； 如果没有 的话，是否有较大的把握在成本和时间都允许的限度内研制出一种新材料。在功能设计和工程设计阶段，要做出一个切实可行

8、的设计。在这个阶段要绘制出 相当完整的图纸，选择并确定各种零件的材料。通常要制造出样机或者实物模型， 并对其进行试验，评价产品的功能、可靠性、外观和维修保养性等。虽然这种试 验可能会表明，在产品进入到生产阶段之前，应该更换某些材料，但是，绝对不 能将这一点作为不认真选择材料的借口。 应该结合产品的功能，认真仔细地考虑 产品的外观、成本和可靠性。一个很有成就的公司在制造所有的样机时，所选用 的材料应该和其生产中使用的材料相同，并尽可能使用同样的制造技术。这样对 公司是很有好处的。功能完备的样机如果不能根据预期的销售量经济地制造出 来，或者是样机与正式生产的装置在质量和可靠性方面有很大不同，则这种

9、样机就没有多大的价值。设计工程师最好能在这一阶段完全完成材料的分析、选择和 确定工作，而不是将其留到生产设计阶段去做。 因为，在生产设计阶段材料的更 换是由其他人进行的，这些人对产品的所有功能的了解不如设计工程师。在生产设计阶段中，与材料有关的主要问题是应该把材料完全确定下来， 使它们 与现有的设备相适应，能够利用现有设备经济地进行加工， 而且材料的数量能够 比较容易保证供应。在制造过程中，不可避免地会出现对使用中的材料做一些更改的情况。 经验表明， 可采用某些便宜材料作为替代品。 然而，在大多数情况下，在进行生产以后改换 材料要比在开始生产前改换材料所花费的代价要高。 在设计阶段做好材料选择

10、工 作，可以避免多数这样的情况。在生产制造开始后出现了可供使用的新材料是更 换材料的最常见的原因。当然，这些新材料可能降低成本、改进产品的性能。但 是，必须对新材料进行认真的评价，以确保其所有性能都满足要求。应当记住， 新材料的性能和可靠性很少像现有材料那样为人们所了解。 大部分的产品失效和 产品责任事故案件是由于在选用新材料作为替代材料之前，没有真正了解它们的长期使用性能而引起的。产品的责任诉讼迫使设计人员和公司在选择材料时，采用最好的程序。在材料过 程中，五个最常见的问题为：（a）不了解或者不会使用关于材料应用方面的最 新最好的信息资料；（b）未能预见和考虑擦黑年品可能的合理用途（如有可能

11、， 设计人员还应进一步预测和考虑由于产品使用方法不当造成的后果。在近年来的许多产品责任诉讼案件中，由于错误地使用产品而受到伤害的原告控告生产厂 家，并且赢得判决）；（c）所使用的材料的数据不全或是有些数据不确定，尤其 是当其长期性能数据是如此的时候；（d）质量控制方法不适当和未经验证；（e）由 一些完全不称职的人员选择材料。通过对上述五个问题的分析，可以得出这些问题是没有充分理由存在的结论。 对 这些问题的研究分析可以为避免这些问题的出现指明方向。尽管采用最好的材料选择方法也不能避免发生产品责任诉讼，设计人员和工业界按照适当的程序进行 材料选择，可以大大减少诉讼的数量。从以上的讨论可以看出，选

12、择材料的人们应该对材料的性质，特点和加工方法有 一个全面而基本的了解。Machine design theoryThe mach ine desig n is through desig ns the new product or improves the old product to meet the huma n n eed the applicati on tech ni cal scie nee. It invo Ives the project tech no logy each doma in, main ly studies the product the size, the s

13、hape and the detailed structure basic idea, but also must study the product the personnelwhich in aspect the and so onmanu facture, sale and use questio n.Carries on each kind of mach ine desig n work to be usually called desig ns the personnelor machine design engineer. The machine design is acreat

14、ive work. Project engin eer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engin eerigmaterial, materials mecha nicsand mach inemanu facturetech no logy has the deep eleme ntary kno wledge.If front sues, the mach ine desig n goal is t

15、he product ioncan meet thehuman need the product. The invention, the discovery and technical kno wledge itself certa inly not n ecessarily can bring the adva ntage to the huma nity, only has whe n they are applied can produce on the product the ben efit. Thus, should realize to carries on before the

16、 desig n in a specific product, must first determ ine whether the people do n eed this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulati onproduct manu facture tech no logygood op

17、port un ity.Grasps the project elementary knowledgeto have to memorize somedata and the formula is more importantthan. The merely service dataand the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all o

18、perations.For example, even if places wrong a decimalpoint positi on, also can cause the correct desig n to tur n wron gly.A good design personnelshould dare to propose the new idea,moreover is willing to undertake the certain risk, when the new methodis not suitable, use orig inal method. Therefore

19、, desig ns the pers onnel tohave to have to have the patienee, because spends the time and the endeavor eertainly cannot guarantee brings successfully. A brand-new desig n, the request scree n aba ndons obsoletely many, knows very well the method for the people. Because many pers on of con servative

20、 ness, does this certa inly is not an easy matter. A mecha ni cal desig ner should unceasinglyexplore the improvementexistingproduct the method,should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Ne

21、wly desig ns itself can have the questi on occurre nee which many flaws and has not been able to expect, only has after these flaws and the questi on are solved, can manifest new goods come into the market the product superiority. Therefore, a performa nee superior product is born at the same time,

22、also is following a higher risk. Should emphasize, if desig ns itself does not request to use the brand-new method, is not unn ecessary merely for the goal which tran sform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, no

23、t each kind of restraint. Even if has had many impractical ideas, also can in the desig n early time, n amely in front of the pla n bluepri nt is corrected. Only the n, only the n does not send to stops up the inno vati on the men tality. Usually, must propose several sets of design proposals, then

24、perform the comparison.Has the possibilityvery much in the pla n which fin ally desig nated, has used certa in not in pla n some ideas which accepts.How does the psychologist freque ntly discuss causes the mach ine whichthe people adapts them to operate. Desig ns pers onn el''sbasicresp on s

25、ibility is dilige ntly causes the machi ne to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operatingarea and theoperat ing process.Ano ther importa nt questi on, project engin eer must be able to carry on

26、the excha nge and the con sultatio n with other concerned pers onn el. I n the in itial stage, desig ns the pers onnel to have to carry on the excha nge and the con sultati on on the prelim inary desig n with the adm ini strative pers onn el, and is approved. This gen erally is through the oral disc

27、ussi on, the schematic diagram and the writing material carries on. In order to carry on the effective excha nge, n eeds to solve the followi ng problem:(1) desig ns whether this product truly does n eed for the people? Whether there is competitive ability(2) does this product compare with other com

28、panies''existing similarproducts?(3) produces this kind of product is whether econo mical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above questi on. But, the product desig n, the

29、 manu facture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manu facture to the fin ally desig n proposal.

30、Usually, can have some problem in the manufacture process. Possibly can request to some comp onents size or the com mon differe nee makes some cha nges, causes the comp onents the producti on to cha nge easily.But, in the project cha nge must have to pass throughdesig ns thepersonnelto authorize,gua

31、ranteedcannot damage the product thefunction. Sometimes,when in front of product assembly or in thepack ing foreig n shipme nt experime nt only the n discovers in the desig n some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the

32、 design work, desig ns the pers onnel to be supposed un ceas in gly dilige ntly, seeks these better method.Rece nt year, theengin eerigmaterial choice already appearedimportantly. In addition, the choice process should be to the material continuouslythe unceasing again appraisal process. The new mat

33、erialun ceas in gly appears, but some orig inal materials can obta in the qua ntity possibly can reduce. The environmentalpollution,material recyclingaspect and so on use, worker''s health and security freque ntly can attach the new limiting condition to the choice of material. In order to r

34、educe the weight or saves the energy, possibly can request the use different material. Comes from domestic and intern atio nalcompetiti on, toproduct service maintenance convenience request enhancementandcustomer''s aspect the and so on feedback pressure, can urge the people to carry on to t

35、he material reappraises. Because the material does not select whe n created the product resp on sibility lawsuit, has already had the profo und in flue nee. In additi on, the material and betwee nthematerial processing interdependenceis already known by the peopleclearly. Therefore, in order to can

36、and guarantees the quality in the reas on able cost un der the premise to obta in satisfact ion the result, project engineermakes engineers all to have earnestly carefully tochoose, the determ in atio n and the use material.Makes any product the first step of work all is desig ns. Desig ns usually m

37、ay divide into several explicit stages: (a) preliminarydesign; (b)fun cti onal desig n; (c) product ion desig n. In the prelimi nary desig n stage, the desig ner emphatically con sidered the product should have fun cti on.Usually must con ceive and con sider several pla ns, the n decided this kind o

38、f thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performa nee to conform to the request material to be possible to supply the choice; If

39、no, whether has a bigger assura nee all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineeringdesign stage, needs tomake a practical feasible design. Must draw up the quite complete bluepri nt inthis stage,chooses anddeterm ines e

40、achkind ofcomponentsthe material.Usually mustmake theprototype or thework ing model, and carries on the experime nt to it, the appraisal product fun cti on,the reliability, the outwardappeara neeand the servicemaintenance and so on. Although this kind of experime nt possibly can in dicate, en ters i

41、n the product to the product ion base in front of, should replacecertain materials, but,absolutelycannot thispointtake notearn estly chooses the material the excuse. Should unify the product the fun cti on, earn estly carefullycon sidersthe product theoutwardappeara nee, the cost and the reliability

42、. Has the achieveme nt very much the companywhen manufacture all prototypes, selects the materialshould the material which uses with its production in be same, and uses the similar manu facture tech no logy as far as possible. Like this has the adva ntage very much to the compa ny. The function comp

43、lete prototype if cannot act accord ing to the an ticipated sales volume econo mically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer

44、 is best can completely complete the material in this stage the an alysis, the choice and the determ ination work, but is not remai ns it to the production desig n stage does. Because, is carries on in the producti on desig n stage materialreplacementby other people, these people are inferior toproj

45、ect engin eer to the product all fun cti ons un dersta ndin g. I n the producti on desig n stage, is should completely determ ine with the material related main question the material, causes them to adapt with the existi ng equipme nt, can use the existi ng equipme nt econo mically to carry on the p

46、rocessing, moreover the material quantitycan quite beeasy to guara ntee the supply.In the manu facture process, in evitably can appear to uses the material to make some changes the situation. The experienee indicated that, mayuse certain cheap materials to take the substitute. However, in the majori

47、ty situati on, in will carry on the product ionlater to cha nge thematerial to have in to start before the productionto change the pricewhich the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situati ons. Started aft

48、er the product ion manu facture to appear has bee n possible to supply the use the new material is replaces the material the most com mon reas on. Certai nly, these new materials possibly reduce the cost, the improvement product performanee. But, must carry on the earnest appraisal to the new materi

49、al, guarantees its all performance all to an swer the purpose. Must remember that, the new material performa nce and the reliable very few pictures materials on hand such un derstood for the people. The majority of products expirati on and the product accident caused by negligence case is because in

50、 selects the new material to take in front of substituti on material, not truly un derstood their Ion g-term operatio nal performa nce causes.The product resp on sibility lawsuit forces desig ns the pers onnel and the companywhen the choice material, uses the best procedure. In thematerial process, five most com