機械設計制造與自動化專業(yè)英語翻譯

1、<p>　　Unit 1 Metals金屬</p><p>　　Unit 2 Selection of Construction Materials</p><p><b>　　工程材料的選擇</b></p><p>　　淬透性：指在規(guī)定條件下，決定鋼材淬硬深度和硬度分布的特性。即鋼淬火時得到淬硬層深度大小的能力，它表示鋼接受淬火的

2、能力。鋼材淬透性好與差，常用淬硬層深度來表示。淬硬層深度越大，則鋼的淬透性越好。鋼的淬透性是鋼材本身所固有的屬性，它只取決于其本身的內部因素，而與外部因素無關。鋼的淬透性主要取決于它的化學成分，特別是含增大淬透性的合金元素及晶粒度，加熱溫度和保溫時間等因素有關。淬透性好的鋼材，可使鋼件整個截面獲得均勻一致的力學性能以及可選用鋼件淬火應力小的淬火劑，以減少變形和開裂。 </p><p>　　淬透性主要取決于其臨界冷

3、卻速度的大小，而臨界冷卻速度則主要取決于過冷奧氏體的穩(wěn)定性，影響奧氏體的穩(wěn)定性主要是：</p><p>　　1.化學成分的影響 碳的影響是主要的，當C％小于1.2％時，隨著奧氏體中碳濃度的提高，顯著降低臨界冷卻速度，C曲線右移，鋼的淬透性增大；當C％大于時，鋼的冷卻速度反而升高，C曲線左移，淬透性下降。其次是合金元素的影響，除鈷外，絕大多數(shù)合金元素溶入奧氏體后，均使C曲線右移，降低臨界冷卻速度，從而提高鋼的淬透性

4、。</p><p>　　2.奧氏體晶粒大小的影響 奧氏體的實際晶粒度對鋼的淬透性有較大的影響，粗大的奧氏體晶粒能使C曲線右移，降低了鋼的臨界冷卻速度。但晶粒粗大將增大鋼的變形、開裂傾向和降低韌性。</p><p>　　3.奧氏體均勻程度的影響 在相同冷度條件下，奧氏體成分越均勻，珠光體的形核率就越低，轉變的孕育期增長，C曲線右移，臨界冷卻速度減慢，鋼的淬透性越高。</p>&

5、lt;p>　　4.鋼的原始組織的影響 鋼的原始組織的粗細和分布對奧氏體的成分將有重大影響。</p><p>　　5.部分元素，例如Mn，Si等元素對提高淬透性能起到一定作用，但同時也會對鋼材帶來其他不利的影響。</p><p>　　可鍛性(forgeability)</p><p>　　金屬具有熱塑性，在加熱狀態(tài)(各種金屬要求溫度不同)，可以進行壓力加工，稱為

6、具有可鍛性?？慑懶裕褐附饘俨牧显趬毫庸r，能改變形狀而不產生裂紋的性能。它包括在熱態(tài) 或 冷態(tài)下能夠進行錘鍛，軋制，拉伸，擠壓等加工?？慑懶缘暮脡闹饕c金屬材料的化學成分有關</p><p>　　[討論] 元素在鋼中的形成物對可鍛性的影響</p><p>　　Unit 3 Mechanical Properties of Materials</p><p>　　U

7、nit5 Design of machine and machine elements</p><p>　　機器和機器零件的設計</p><p>　　Machine design機器設計</p><p>　　Machine design is the art of planning or devising new or improved machines to a

8、ccomplish specific purposes. In general, a machine will consist of a combination of several different mechanical elements properly designed and arranged to work together, as a whole. During the initial planning of a mach

9、ine, fundamental decisions must be made concerning loading, type of kinematic elements to be used, and correct utilization of the properties of engineering materials. Economic considerations are usuall</p><p&g

10、t;　　機器設計為了特定的目的而發(fā)明或改進機器的一種藝術。一般來講，機器時有多種不同的合理設計并有序裝配在一起的部件構成的，在最初的機器設計階段，必須基本明確負載、元件的運動情況、工程材料的合理使用性能。負責新機器的設計最初的最重要的是經濟性考慮。一般來說，選擇總成本最低的設計方案，不僅要考慮設計、制造、銷售、安裝的成本。還要考慮服務的費用，機械要保證必要的安全性能和美觀的外形。制造機器的目標不僅要追求保證只用功能的合理壽命，還要保證足

11、夠便宜以同時保證其經濟的可行性。</p><p>　　The engineer in charge of the design of a machine should not only have adequate technical training, but must be a man of sound judgment and wide experience, qualities which are usua

12、lly acquired only after considerable time has been spent in actual professional work.</p><p>　　負責設計機器的工程師，不僅要經過專業(yè)的培訓，而且必須是一個準確判斷而又有豐富經驗的人，具有一種有足夠時間從事專門的實際工作的素質。</p><p>　　Design of machine elemen

13、ts機器零件的設計</p><p>　　The principles of design are, of course, universal. The same theory or equations may be applied to a very small part, as in an instrument, or, to a larger but similar part used in a piece

14、of heavy equipment. In no ease, however, should mathematical calculations be looked upon as absolute and final. They are all subject to the accuracy of the various assumptions, which must necessarily be made in engineeri

15、ng work. Sometimes only a portion of the total number of parts in a machine are designed on </p><p>　　相同的理論或方程可應用在一個一起的非常小的零件上，也可用在一個復雜的設備的大型相似件上，既然如此，毫無疑問，數(shù)學計算是絕對的和最終的。他們都符合不同的設想，這必須由工程量決定。有時，一臺機器的零件全部計算僅僅是

16、設計的一部分。零件的結構和尺寸通常根據(jù)實際考慮。另一方面，如果機器和昂貴，或者質量很重要，例如飛機，那麼每一個零件都要設計計算。</p><p>　　The purpose of the design calculations is, of course, to attempt to predict the stress or deformation in the part in order that it ma

17、y sagely carry the loads, which will be imposed on it, and that it may last for the expected life of the machine. All calculations are, of course, dependent on the physical properties of the construction materials as det

18、ermined by laboratory tests. A rational method of design attempts to take the results of relatively simple and fundamental tests such as tension, c</p><p>　　當然，設計計算的目的是試圖預測零件的應力和變形，以保證其安全的帶動負載，這是必要的，并且其也許影響到

19、機器的最終壽命。當然，所有的計算依賴于這些結構材料通過試驗測定的物理性能。國際上的設計方法試圖通過從一些相對簡單的而基本的實驗中得到一些結果，這些試驗，例如結構復雜的及現(xiàn)代機械設計到的電壓、轉矩和疲勞強度。</p><p>　　In addition, it has been amply proved that such details as surface condition, fillets, notches

20、, manufacturing tolerances, and heat treatment have a market effect on the strength and useful life of a machine part. The design and drafting departments must specify completely all such particulars, must specify comple

21、tely all such particulars, and thus exercise the necessary close control over the finished product.</p><p>　　另外，可以充分證明，一些細節(jié)，如表面粗糙度、圓角、開槽、制造公差和熱處理都對機械零件的強度及使用壽命有影響。設計和構建布局要完全詳細地說明每一個細節(jié)，并且對最終產品進行必要的測試。</p&g

22、t;<p>　　As mentioned above, machine design is a vast field of engineering technology. As such, it begins with the conception of an idea and follows through the various phases of design analysis, manufacturing, mar

23、keting and consumerism. The following is a list of the major areas of consideration in the general field of machine design:</p><p>　　綜上所述，機械設計是一個非常寬的工程技術領域。例如，從設計理念到設計分析的每一個階段，制造，市場，銷售。以下是機械設計的一般領域應考慮的主要方面的清

24、單：</p><p>　?、?Initial design conception; 最初的設計理念</p><p>　?、?Strength analysis;受力分析</p><p>　?、?Materials selection;材料的選擇 </p><p>　?、?Appearance; 外形</p><p>　

25、?、?Manufacturing;制造</p><p>　?、?Safety;安全性</p><p>　?、?Environment effects;環(huán)境影響</p><p>　?、郣eliability and life; 可靠性及壽命 </p><p>　　Strength is a

26、 measure of the ability to resist, without fails, forces which cause stresses and strains. The forces may be;</p><p>　　在沒有破壞的情況下，強度是抵抗引起應力和應變的一種量度。這些力可能是：</p><p>　?、?Gradually applied;漸變力</p&

27、gt;<p>　?、?Suddenly applied;瞬時力</p><p>　?、?Applied under impact;沖擊力</p><p>　?、?Applied with continuous direction reversals;不斷變化的力</p><p>　?、?Applied at low or elevated temper

28、atures.溫差 </p><p>　　If a critical part of a machine fails, the whole machine must be shut down until a repair is made. Thus, when designing a new machine, it is extremely important that critical p

29、arts be made strong enough to prevent failure. The designer should determine as precisely as possible the nature, magnitude, direction and point of application of all forces. Machine design is mot, however, an exact scie

30、nce and it is, therefore, rarely possible to determine exactly all the applied forces. In addition, diff</p><p>　　如果一個機器的關鍵件損壞，整個機器必須關閉，直到修理好為止。設計一臺新機器時，關鍵件具有足夠的抵抗破壞的能力是非常重要的。設計者應盡可能準確地確定所有的性質、大小、方向及作用點。機器設計

31、不是這樣，但精確的科學是這樣，因此很難準確地確定所有力。另外，一種特殊材料的不同樣本會顯現(xiàn)出不同的性能，像抗負載、溫度和其他外部條件。盡管如此，在機械設計中給予合理綜合的設計計算是非常有用的。</p><p>　　Moreover, it is absolutely essential that a design engineer knows how and why parts fail so that reli

32、able machines which require minimum maintenance can be designed. Sometimes, a failure can be serious, such as when a tire blows out on an automobile traveling at high speeds. On the other hand, a failure may be no more t

33、han a nuisance. An example is the loosening of the radiator hose in the automobile cooling system. The consequence of this latter failure is usually the loss of some radiator cool</p><p>　　此外，顯而易見的是一個知道零件是如何

34、和為什麼破壞的設計師可以設計出需要很少維修的可靠機器。有時，一次失敗是嚴重的，例如高速行駛的汽車的輪胎爆裂。另一方面，失敗未必是麻煩。例如，汽車的冷卻系統(tǒng)的散熱器皮帶管松開。這種破壞的后果通常是損失一些散熱片，可以探測并改正過來。</p><p>　　The type of load a part absorbs is just as significant as the magnitude. Generally

35、 speaking, dynamic loads with direction reversals cause greater difficulties than static loads and, therefore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. For examp

36、le, brittle materials are considered to be unacceptable where fatigue is involved.</p><p>　　零件負載類型是一個重要的標志。一般而言，變化的動負載比靜負載會引起更大的差異。因此，疲勞強度必須符合。另一個關心的方面是這種材料是否直或易碎。例如有疲勞破壞的地方不易使用易碎的材料。</p><p>　　I

37、n general, the design engineer must consider all possible modes of failure, which include the following:</p><p>　　一般的，設計師要靠考慮所有破壞情況，其包括以下方面：</p><p>　?、?Stress;應力</p><p>　?、?Deformat

38、ion;應變 </p><p><b>　?、?Wear;外形</b></p><p>　?、?Corrosion;腐蝕</p><p>　?、?Vibration;震動 </p><p>　?、?Environmental damage;外部環(huán)境破壞 </p><p>　?、?Loosenin

39、g of fastening devices. 緊固件的松脫 </p><p>　　The part sizes and shapes selected must also take into account many dimensional factors which produce external load effects such as geometric

40、discontinuities, residual stresses due to forming of desired contours, and the application of interference fit joints.</p><p>　　零件的尺寸和外形的選擇也有很多因素。外部負荷的影響，如幾何間斷，由于輪廓而產生的殘余應力和組合件干涉。</p><p>　　Unit