機(jī)械工程英語(yǔ)(上) 主編 劉鎮(zhèn)昌 1-15課后答案

1、第一課1）機(jī)械工業(yè)用于制造產(chǎn)品的材料，可以分為金屬材料、聚合物、陶瓷和復(fù)合材料。 The materials used for manufacturing products can be divided into four categories: metallics, polymerics, ceramics and composites. 2）金屬可以分為有色金屬和黑色金屬。 Metallics can be classified into non-ferrous and ferrous metallics. 3）塑料可以分為熱固性塑料和熱塑性塑料。 Plastics cab be grou

2、ped into thermosets (thermosetting plastics) and thermoplastics. 4）復(fù)合材料可以由兩種或兩種以上性質(zhì)不同的材料組合，保留各自的特點(diǎn)，得到單一材料無(wú)法比擬的、優(yōu)越的綜合性能。 A composite consists of two more kinds of different materials, with each material keeping its own property, to get the superior synthetical (combined) performance which is unparall

3、eled (unmatched) by that of the individual material. 5）當(dāng)其所處的工作環(huán)境變化時(shí)，智能材料能改變其性能、顏色和形狀等。An intelligent material can change its property, color, shape and so on when its working environment changes.第二課1) 材料的特性可分為物理特性和化學(xué)特性兩大類。 The properties of a material can be divided into two main groups: physical an

4、d chemical property. 2) 塑性材料在拉伸載荷的作用下應(yīng)力達(dá)到屈服強(qiáng)度時(shí)，產(chǎn)生塑性變形。When the stress of a material under the action of tensile load reaches yield strength, it will produce plastic deformation. 3) 除軟鋼等材料有明顯的屈服點(diǎn)外，合金鋼和有色合金等塑性材料無(wú)明顯的屈服點(diǎn)。 Except that materials such as mild steel have obvious yielding point, plastic mate

5、rials such as alloy steel and non-ferrous alloys have no obvious yielding point. 4) 脆性材料拉伸時(shí)，以抗拉強(qiáng)度為極限應(yīng)力，壓縮時(shí)以抗壓強(qiáng)度為極限應(yīng)力。 When a brittle material is stretched, the tensile strength is used as its ultimate stress, and when the material is compressed, compressive strength is used as its ultimate stress. 5

6、) 蠕變是指材料在恒定溫度和恒定應(yīng)力的長(zhǎng)期作用下，隨著時(shí)間的延長(zhǎng)會(huì)緩慢的發(fā)生塑性變形的現(xiàn)象。 Creep is referred to the phenomena that under the long-time action of constant temperature and load, the material will slowly produce plastic deformation with the extension of time.第三課 1）為特定產(chǎn)品選擇一種理想的材料是一個(gè)非常復(fù)雜的過(guò)程。 It is a complicated process to select an

7、 ideal material for a specific product. 2）要達(dá)到正確選材，合理用材，加強(qiáng)新材料應(yīng)用技術(shù)的研究，對(duì)于發(fā)展和擴(kuò)大其應(yīng)用都是十分有用的。 To make a correct selection and use of materials, strengthening the study of technology on new materials and their applications is very useful to develop and expand their application fields. 3）選擇材料時(shí)要注意材料的物理化學(xué)性能、工藝

8、性能、經(jīng)濟(jì)性和可獲得性。 When selecting a material, what should be noted include the physical and chemical properties, processability , cost and its availability . 4）在材料的各種性能指標(biāo)中，如只取強(qiáng)度極限或疲勞極限一個(gè)指標(biāo)作為選擇材料的依據(jù)，常常不夠合理。 It is often unappropriated to select a material only in accordance with ultimate strength or fatigue

9、 strength chosen from various performance criteria of material. 5）對(duì)于大批量生產(chǎn)，材料的選用與供應(yīng)的可能性有關(guān)。 For large scale production, selection for a type of material is associated with the possibility of its supply.第四課1）對(duì)材料循環(huán)每一階段的研究有助于認(rèn)識(shí)材料的重要性及其對(duì)人類社會(huì)的影響。 Studying each of the stages of material cycle aids us with i

10、nsight into the importance of materials and their effects on our society. An explanation of each of the stages will provide us with insight into the importance of materials, how they affect our lives, and their total impact on society. (課文中相似句)2）從鋁礦石中提煉鋁消耗大量電力。 It takes large amounts of electricity

11、to extract Al from bauxite ore. 3）設(shè)計(jì)人員確定產(chǎn)品對(duì)材料性能要求，材料工程師可制備滿足其需要的材料。 Designers specify desired properties of the materials required by products and material engineers create the materials to suit the needs. 4）制造工程是將材料轉(zhuǎn)變成最終產(chǎn)品和系統(tǒng)的一門技術(shù)學(xué)科。 Manufacturing engineering is the study of techniques to turn bulk

12、 materials into final products and systems. 5）為了保護(hù)環(huán)境和自然之源，必須進(jìn)一步重視材料的回收和再利用。 More attention must be paid to material recycling for protecting environment and natural resources.第五課1） 將金屬?gòu)牡V石中分離出來(lái)的過(guò)程叫冶煉。 The process in which metal is separated from ore is called smelting. 2）幾乎所有的黑色金屬中都含有碳。 Almost all th

13、e ferrous metallics contain carbon. 3） 影響鑄件質(zhì)量的因素很多。 The factors that affect the quality of a casting are numerous. 4） 通常認(rèn)為金屬鑄造是藝術(shù)與科學(xué)的結(jié)合。 It is usually believed that metal casting is a combination of art and science. 5）熔模鑄造具有很多獨(dú)特的優(yōu)點(diǎn)。 Investment casting has many peculiar advantages.第六課1）今天，在鍛造工藝中，金屬的成

14、形并非總是采用加熱和鍛打的方法。Today，in forging process, metal forming does not always use the method of heating and hammering. 2）液壓機(jī)鍛錘被廣泛地用于鍛造工藝中。 Hydraulic presses and the hammer are widely used in forging process. 3）隨著鍛造技術(shù)的進(jìn)步，許多以前認(rèn)為不可能鍛的材料現(xiàn)在也可通過(guò)常規(guī)鍛造工藝進(jìn)行加工。 With the development of forging technology, many materi

15、als which was believed that it was impossible to be forged can now be forged with the regular forging process. 4）鍛造就是要使金屬材料變形為所需要的形狀，而不同的材料對(duì)外界所施加的變形力的反應(yīng)極不相同。 The purpose of forging is to make the shape of metal to be changed into what is needed, and the responses of different materials to the deform

16、ing force exerted by outsides are extremely different. 5）鍛造設(shè)備的行為是鍛造技術(shù)發(fā)展的一個(gè)重要課題，因?yàn)樗苯佑绊懼懺旃に嚨男Ч?The behavior of forging equipments is an important topic in the development of forging technology, because it directly influences the effects of forging process.第七課1）焊弧溫度的測(cè)量值通常在5000-30000K之間。 The measured

17、 value of welding arc temperature is usually between 5000 and 30000K. 2) 焊接已成為加工和維修金屬產(chǎn)品的主要手段之一。 Welding has become one of the main methods to fabricate and repair metal- products. 3) 當(dāng)工件被加熱到所需溫度時(shí)，就將它們移至砧座上鍛打到一起。 When the work-pieces are heated to the required temperature, they will be moved onto an

18、anvil and united by forging. 4) 除此之外，還可以用激光進(jìn)行焊接。In addition to that，laser can also be used in welding. 5) 鍛焊是最早的焊接方法，并且，這種方法作為唯一的焊接方法持續(xù)了幾個(gè)世紀(jì)。 Forging welding is the first form of welding and lasted for several centuries as the only welding method.第八課1）加熱時(shí),工件的斷面越厚保溫時(shí)間應(yīng)該越長(zhǎng),以使其內(nèi)部溫度趨于均勻。 When heated, th

19、e thicker the section of a work-piece, the longer the temperature should be kept，so that the temperature tends to be even throughout the work-piece。2）金屬的溫度還可以通過(guò)觀察其顏色來(lái)判斷。 Metal temperature could also be judged by watching its color. 3）退火的主要目的是使鋼件的硬度變軟，以便于進(jìn)行機(jī)械加工，即冷加工。 Annealing is designed to reduce t

20、he hardness of a steel part, so that it can be machined or cold-processed easily. 4）對(duì)鋼件進(jìn)行加熱和冷卻可以增加其硬度和抗拉強(qiáng)度。 Heating and cooling a steel part can increase its hardness and tensile strength. 5）在許多熱處理工藝中，加熱速度都是應(yīng)該注意的重要因素。 In many heat-treatment processes, the rate of heating is an important factor to wh

21、ich we should pay attention.第九課1）螺桿用來(lái)傳遞運(yùn)動(dòng)和力。 Screw threads are used to transmit motion and force. 2）鉚接既可以是搭接也可以是對(duì)接。 Rivet joints can be either a lap or a butt joint. 3.）焊接殘余應(yīng)力是由于熱膨脹和收縮不均勻產(chǎn)生的。 Welding residual stress is produced by the uneven thermal expansion or contraction 4）在焊接設(shè)計(jì)時(shí)，要考慮安全因素。 Safety

22、factors should be taken into consideration in welding design. 5）膠接連接的強(qiáng)度取決于樹(shù)脂對(duì)金屬表面的粘附力和樹(shù)脂本身分子之間的結(jié)合力。 The strength of adhesive joint is determined by the adhesion of the resin to the metal surfaces, and the cohesion between the molecules of the resin itself.第十課1）帶傳動(dòng)和鏈傳動(dòng)聯(lián)接兩個(gè)或多個(gè)軸來(lái)傳遞旋轉(zhuǎn)運(yùn)動(dòng)和運(yùn)動(dòng)。 Belt drive a

23、nd chain drive are used to connect two or more shafts for transmission of rotation and power. 2）鏈傳動(dòng)的傳動(dòng)比計(jì)算跟齒輪的傳動(dòng)一樣，即與齒數(shù)成反比。 The speed ratio of a chain drive is the same as that of a gear drive, namely, the inverse ratio of the tooth number. 3）鏈長(zhǎng)必須是節(jié)距即一個(gè)連節(jié)的長(zhǎng)度的倍數(shù)，節(jié)距的數(shù)目最好是偶數(shù)。 The chain length must be a

24、multiple of the length of one shackle and it is preferable that the number of pitches is even. 4）行星輪系在較小的空間內(nèi)能得到較大的傳動(dòng)比。 Planetary gear trains can get larger speed ratio in a small package. 5）凸輪機(jī)構(gòu)能把旋轉(zhuǎn)運(yùn)動(dòng)轉(zhuǎn)換成直線運(yùn)動(dòng)或擺動(dòng)。 Cam mechanism can convert rotary motion into linear or oscillating (angular) motion. 第十一

25、課1） 軸承的潤(rùn)滑有油潤(rùn)滑、水潤(rùn)滑、脂潤(rùn)滑、或氣潤(rùn)滑（如空氣）。 The lubricants used in bearings include oil, water, grease or gas (such as air). 2）軸承材料要有好的耐壓強(qiáng)度和疲勞強(qiáng)度、高的熱傳導(dǎo)率、好的延展性、對(duì)軸和箱體材料有化學(xué)惰性等性能要求。 The bearing materials should have good compressive and fatigue strength, high heat conductivity, good ductility, and have some require

26、ments on the chemical inertness of shaft and housing materials. 3）軸承或多或少有氣孔，這取決于制造時(shí)受到的壓力。 Depending upon the pressure subjected in manufacturing, a bearing is more or less porous. 4）電磁軸承最初是為地球衛(wèi)星上的應(yīng)用而開(kāi)發(fā)的，后來(lái)開(kāi)始在工業(yè)裝備中應(yīng)用。 Electromagnetic bearings were originally developed for earth-orbit satellites and t

27、hen begin to be used in industrial equipment.5）滾動(dòng)接觸軸承沒(méi)有粘滑效應(yīng)，其動(dòng)力矩小，運(yùn)行摩擦力小。Bearings with rolling contact have no slip-stick effect，low starting torque and running friction.第十二課1）為了生產(chǎn)出滿意的齒輪驅(qū)動(dòng)系統(tǒng)，必須要有齒輪設(shè)計(jì)的知識(shí)，包括設(shè)計(jì)的限制條件。 To produce a satisfactory gear drive system, one must have a working knowledge of gear

28、 design, including design limitations. 2）如果要正確運(yùn)轉(zhuǎn)的話，兩個(gè)嚙合齒輪的齒距必須相等。 The circular pitches of meshing gears must be equal if they are to operate properly. 3）非金屬齒輪比金屬齒輪強(qiáng)度低，熱傳導(dǎo)率低。 Non-metallic gears are weaker than metallic gears and have low heat conductivity. 4）精密齒輪需要磨削，修整或其它精密成形加工。Precision gears need

29、being ground，shaved or otherwise accurately shaped. 5）錐齒輪可以有任意傳動(dòng)比，但通常不超過(guò)6。 The speed ratio of a pair of bevel gears could be arbitrarily chosen, but it is usually not over 6.第十三課1）液壓系統(tǒng)有動(dòng)力源、執(zhí)行原件、控制元件和輔助系統(tǒng)組成。 A hydraulic system consists of power source, actuators, control devices and auxiliary system.

30、 2）根據(jù)動(dòng)力源的不同，液壓系統(tǒng)可分為恒流系統(tǒng)和恒壓系統(tǒng)。 Depending on the power resource, a hydraulic system can be divided into a constant flow system and a constant pressure system. 3)齒輪泵是容積泵種結(jié)構(gòu)最簡(jiǎn)單但效率較高的一種泵。 A gear pump is the simplest type of positive displacement pump and its efficiency is higher than others. 4)液壓系統(tǒng)中另一種重要

31、元件是閥，主要有三種類型的閥：溢流閥、流量控制閥和方向控制閥。 Another important device in hydraulic system is valve. There are mainly three types of valve: relief valve, flow control valve and direction control valve.第十四課1) 在車床加工中，工件的旋轉(zhuǎn)為主運(yùn)動(dòng)，刀具的運(yùn)動(dòng)為進(jìn)給運(yùn)動(dòng)。 In turning machining, the turning of the work-piece is primary motion and the motion of the tool is feed motion. 2)常用的銑床有以下幾種：1）立式銑床；2）臥式銑床；3）龍門銑床。 The commonly used milling machines are as the following kinds: 1) Horizontal milling machine; 2) Vertical milling