外文翻譯--機床設計

附錄 1 Design of Machine Tool Designing starts with a need real. Existing apparatus may need improvements in durability, efficiency, weight, speed, or cost. New apparatus may be needed to perform a function previously. 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 impractical ideas, also can in the design early time, namely in front of the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts. When the general shape and a few dimensions of the several components become apparent, analysis can begin in earnest. The analysis will have as its objective satisfactory or superior performance, plus safety and durability with minimum weight, and a competitive cost. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strengths of the several components. Materials and their treatment will be chosen. These important objectives can be attained only by analysis based upon the principles of mechanics, such as those of static for reaction forces and for the optimum utilization or friction； of dynamics for inertia, acceleration, and energy； of elasticity and strength of materials for stress and deflection； of physical behavior of materials； and of fluid mechanics for lubrication and hydrodynamic drives. The analyses may be made by the same engineer who conceived the arrangement of mechanisms, or un a large company, they may be made by a separate analysis division or research group. Design is a reiterative and cooperative process, whether done formally or informally, and the analyst can contribute to phases other than his own. Product design requires much research and development. Many Concepts of an idea must be studied, tried, and then either used or discarded. Although the content of each engineering problem is unique, the designers follow the similar process to solve the problems. Product liability suits designers and forced in material selection, using the best program. In the process of material, the most common problems for five (a) dont understand or not use about the latest application materials to the best information , (b) failed to foresee and consider the reasonable use material may (such as possible, designers should further forecast and consider due to improper use products. In recent years, many products liability in litigation, the use of products and hurt the plaintiff accused manufacturer, and won the decision), (c) of the materials used all or some of the data, data, especially when the uncertainty long-term performance data is so, (d) quality control method is not suitable and unproven, (e) by some completely incompetent persons choose materials. Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding. Finally, a design based upon function, and a prototype may be built. If its tests are satisfactory, the initial design will undergo certain modifications that enable it to be manufactured in quantity at a lower cost. During subsequent years of manufacture and service, the design is likely to undergo changes as new ideas are conceived or as further analyses based upon tests and experience indicate alterations. Sales appeal. Some Rules for Design In this section it is suggested that, applied with a creative attitude, analyses can lead to important improvements and to the conception and perfection of alternate, perhaps more functional, economical, and durable products. To stimulate creative thought, the following rules are suggested for the designer and analyst. The first six rules are particularly applicable for the analyst. 1. A creative use of need of physical properties and control process. 2. Recognize functional loads and their significance. 3. Anticipate unintentional loads. 4. Devise more favorable loading conditions. 5. Provide for favorable stress distribution and stiffness with minimum weigh. 6. Use basic equations to proportion and optimize dimensions. 7. Choose materials for a combination of properties. 8. Select carefully, stock and integral components. 9. Modify a functional design to fit the manufacturing process and reduce cost. 10. Provide for accurate location and noninterference of parts in assembly. The complete design of a machine is a complex process. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineering material, materials mechanics and machine manufacture technology has the deep elementary knowledge. One of the first steps in the design of any product is to select the material from which each part is to be made. Numerous materials are available to todays designers. The function of the product, its appearance, the cost of the material, and the cost of fabrication are important in making a selection. A careful evaluation of the properties of a. material must be made prior to any calculations. Careful calculations are necessary to ensure the validity of a design. In case of any part failures, it is desirable to know what was done in originally designing the defective components. The checking of calculations (and drawing dimensions) is of utmost importance. The misplacement of one decimal point can ruin an otherwise acceptable project. All aspects of design work should be checked and rechecked. The computer is a tool helpful to mechanical designers to lighten tedious calculations, and provide extended analysis of available data. Interactive systems, based on computer capabilities, have made possible the concepts of computer aided design (CAD) and computer-aided manufacturing (CAM). How does the psychologist frequently discuss the machine which the people adapt to operate. Design personnel basic responsibility is diligently causes the machine 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 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 stage, 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. If front sues, the machine design goal is the production can meet the human 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, must first determine whether the people do need this kind of product. Grasps the project elementary knowledge 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 wrong a decimal point position, also can cause the correct design to turn wrongly. Machinery design covers the following contents. 1. Provides an introduction to the design process, problem formulation, and safety factors. 2. Reviews the material properties and static and dynamic loading analysis, Including beam, vibration and impact loading. 3. Reviews the fundamentals of stress and defection analysis. 4. Introduces fatigue-failure design, which is commonly used in the design of rotation machinery. 5. Discusses thoroughly the phenomena of wear mechanisms, surface contact stresses, and surface fatigue. 6. Investigates shaft design using the fatigue-analysis techniques. 7. Discusses fluid-film an rolling-element bearing theory and application 8. Gives a thorough introduction to the kinematics, design and stress analysis of spur gears, and a simple introduction to helical, bevel, and worm gearing. 9. Discusses spring design including compression, extension and torsion springs. 10. Deals with screws and fasteners including power screw and preload fasteners. 11. Introduces the design and specification of disk and drum clutches and brakes. 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 the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons absolutely many, knows very well the method for the people. Because many person of conservativeness does this certainly is not an easy matter. 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. 附錄 2 機 床設計 設計開始之前就要想到機器的實際性，現(xiàn)存的機器需要在耐用性、效率、重量、速度或成本上加以改進。 在設計的初始階段，應該允許設計人員充分發(fā)揮創(chuàng)造性，不受到任何約束。即使產生了許多不切實際的想法，也會在設計的早期，即在繪制圖紙之前被改正掉。只有這樣，才不至于阻斷創(chuàng)新的思路。通常，還要提出幾套設計方案，然后加以比較。很有可能在這個計劃最后決定中，使用了某些不在計劃之內的一些想法。 一般的當外型特點和組件部分的尺寸特點分析的透徹時，就可以全面的設計和分析。接著還要客觀的分析機器性能和優(yōu)越性，以及它的安全、重量 、耐用性，并且競爭力的成本也要考慮在分析結果之內。每一個至關重要的部分優(yōu)化它的比例和尺寸，同時也要保持與其他組成部分相協(xié)調。也要選擇原材料和處理原材料的方法。通過力學原理來分析和實現(xiàn)這些重要的特性，如那些靜態(tài)反應的能量和摩擦力的最佳利用，像動力慣性、加速動力和能量；包括彈性材料的強度、應力和剛度等材料的物理特性，以及流體潤滑和驅動器的流體力學。設計的過程是重復和合作的過程，無論是正式或非正式的進行，對設計者來說每個階段都很重要。最后，以圖樣為設計標準，并建立將來的模型。如果它的測試時符合事先要求的，則再將對 初步設計進行某些修改，使它能夠在制造成本上有所降低。產品的設計需要不斷探索和發(fā)展。許多方案必須被研究、試驗、完善，然后決定使用還是放棄。雖然每個工程學問題的內容是獨特的，但是設計師可以按照類似的步驟來解決問題。 產品的責任訴訟迫使設計人員和公司在選擇材料時，采用最好的程序。在材料過程中，五個最常見的問題為：（ 1）不了解或不會使用關于材料應用方面的最新最好的信息資料；（ 2）未能預見和考慮材料的合理用途；（ 3）所使用的材料的數(shù)據(jù)不完全或是有寫數(shù)據(jù)不確定，尤其是當其性能數(shù)據(jù)長期不更新；（ 4）質量控制方法不適當和未 經驗證；（ 5）由一些完全不稱職的人員選擇材料。 通過對上述五個問題的分析，可以得出這些問題是沒有充分理由而存在的結論。對這些問題的研究分析可以為避免這些問題的出現(xiàn)而指明方向。盡管采用最好的材料選擇方法也不能避免發(fā)生產品責任訴訟，設計人員和工業(yè)界按照適當?shù)某绦蜻M行材料選擇，可以大大減少訴訟的數(shù)量。 從以上的討論可以看出，材料選擇的人們應該對材料的性質，特點和加工方法有一個全面而基本的了解。 在隨后生產和售后服務的幾年中，要接受新觀念的變化，或者由試驗和經驗為基礎，進一步分析并改進。 一些設計規(guī)則 : 在本節(jié)中， 建議運用創(chuàng)造性的態(tài)度來替代和改進。也許會創(chuàng)造出更實用、更經濟、更耐用的產品。 為了激發(fā)創(chuàng)造性思維，下列是設計和分析的建議和規(guī)則。前六個規(guī)則對設計者來說特別適用。 1、 要有創(chuàng)造性的利用所需要的物理性質和控制過程。 2、 認識負載產生的影響及其意義。 3、 預測沒有想到的負載。 4、 創(chuàng)造出對載荷更為有利的條件。 5、 提供良好的應力分布和最小的剛度條件。 6、 運用最簡單的方程來優(yōu)化體積和面積。 7、 選擇組合材料。 8、 仔細選擇所備的原料和不可缺少的組件。 9、 調整有效的設計方案，以適應生產過程和降低成本。 10、規(guī)定好準確的位置條件為了使組件安裝時不干 涉。 一臺完整機器的設計是一個復雜的過程。機械設計是一項創(chuàng)造性的工作。設計工程師不僅在工作上要有創(chuàng)造性，還必須在機械制圖、運動學、工程材料、材料力學和機械制造工藝學等方面具有深厚的知識基礎。 任何產品在設計時第一步就是選擇產品每個部分的構成材料。許多的材料被今天的設計師所使用。對產品的功能，它的外觀，材料的成本、制造的成本做出必要的選擇是十分重要的，對材料的特性必須事先做出仔細的評估。 仔細精確的計