机械设计理论-------英文翻译.docx

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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。创造、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

2、进行设计之前，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缺乏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，而且愿意承当一定的风险，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

3、法。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，才能表达出新产品的优越性。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，才不致于

4、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 解决以下问题：（1）所设计的这个产品是否真正为人们所需要？（2）此产品与其他公司的

5、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 存在着更好的方法

6、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。止匕外，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、工人的健康及平安等方面经常 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 反应等方面的压力，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。止匕外，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。因此，

7、为了能在合理的本钱和确保质量的前提 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，那么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本钱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的设计。在

8、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 这种试验可能会说明，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、本钱和可靠性。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，那么这种 样机就没

9、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 能够比拟容易保证供应。在制造过程中，不可防止地会出现对使用中的材料做一些更改的情况。经验 说明，可采用某些廉价材料作为替代品。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 选择工作，可以防止多数

10、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本钱、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。大局部的产品 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, 设计人员还应进一

11、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防止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防止发生产品责任诉讼，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，选择材料的人们应该对

12、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 machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed s

13、tructure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engine

14、er not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the huma

15、n need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must f

16、irst determine whether the people do need 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 formulation product manufacture technology good opportunity. Grasps the project elementary k

17、nowledge to have to memorize some data and the formula is more important than. The merely service data and 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 operations. For example, even if places

18、wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have

19、 to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matt

20、er. A mechanical designer should unceasingly explore the improvement existing product 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.Newly designs itself can have the question occur

21、rence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize,

22、if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impract

23、ical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the pl

24、an which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnels basic responsibility is diligently causes the machine to adapt the people. This certainly is

25、not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stag

26、e, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective ex

27、change, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies existing similar products?(3) produces this kind of product is whether economical?(4) product service i

28、s 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 question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Projec

29、t engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common differe

30、nce makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment e

31、xperiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method.Recent year, the engineerig ma

32、terial choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, materi

33、al recycling aspect and so on use, worker* health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product

34、 service maintenance convenience request enhancement and customers aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In add

35、ition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly car

36、efully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically

37、considered the product should have function. Usually must conceive and consider several plans, then decided this kind of 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 o

38、f material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, need

39、s to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the

40、 outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should

41、unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the

42、similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the

43、 reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because,

44、is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes the

45、m to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The expe

46、rience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Compl

47、etes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost,

48、the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The major

49、ity of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly t