机械专业英语课件

1、Unit 24 Drilling Operations,Specialized English,Paragraph 1,1.Drilling involves producing through or blind holes in a workpiece by forcing a tool, which rotates around its axis, against the workpiece. 钻是利用绕轴旋转的钻头在工件上生成通孔或盲孔的加工工艺。 2.Consequently, the range of cutting from that axis of rotation is equ

2、al to the radius of required hole. 因此，旋转轴的切削范围就等于所钻孔的半径。 3.In practice, two symmetrical cutting edges that rotate about the same axis are employed. 实际上是利用绕同一轴的旋转的两个对称切削刃(棱边)来进行加工的,Paragraph 2,1.Drilling operations can be carried out by using either hand drills or drilling machines. The latter differ

3、 in size and construction. 钻削加工有手钻和钻床两种方式。钻床的大小和结构各不相同。 2.Nevertheless, the tool always rotates around its axis while the workpiece is kept firmly fixed. This is contrary to drilling on a lathe. 然而，钻床加工中钻头总是绕轴旋转而工件保持固定。这与车床上的钻加工相反,Paragraph 3,1.In drilling operations, a cylindrical rotary-end cuttin

4、g tool, called a drill, is employed. 在钻加工中，采用了一种圆柱形的、端面旋转的刀具，称为钻头。 2.The drill can have either one or more cutting edges and corresponding flutes, which can be straight or helical. 钻头可能有一个或多个切削刃(棱边)以及直立的或螺旋状的排屑槽,Paragraph 3,3.The function of the flutes is to provide outlet passages for the chips gen

5、erated during the drilling operations and also to allow lubricants and coolants to reach the cutting edges and the surface being machined. Following is a survey of the common used drills. 排屑槽的作用就是为钻加工过程中产生的碎片提供出口通道，同时允许润滑剂和冷却剂流到切削刃和被加工的工件表面上。下面是平常所使用钻头的概况,Paragraph 4,1.Twist drill. The twist drill i

6、s the most common type of drill. 螺旋钻(麻花钻).麻花钻是最常用的钻头。 2.It has two cutting edges and two helical flutes that continue over the length of the drill body. 麻花钻具有两个切削刃(棱边)以及两道沿钻体的螺旋槽。 3.The drill also consists of a neck and a shank that can be either straight or tapered. 钻头也包括一个钻颈和一个可为直柄或锥柄的柄部,Paragraph

7、 4,4.In the latter case, the shank is fitted by the wedge action into the tapered socket of the spindle and has a tang, which goes into a slot in the spindle socket, thus acting as a solid means for transmitting rotation. 对于后者，柄部可通过楔紧作用将其固定在主轴的锥形孔中，柄部还有一个柄脚，柄脚插入到主轴锥形孔的插槽中，这样就可以可靠的方式传递扭矩,Paragraph 4,

8、5.On the other hand, straight-shank drills are held in a drill chunk that is, in turn, fitted into the spindle socket in the same way as tapered shank drills. 另一方面，直柄钻被固定到钻夹中，同理，钻夹以与锥柄钻相同的方式固定到主轴孔中,Paragraph 5,1.Twist drills are usually made of high-speed steel, although carbide-tipped drills are al

9、so available. The size of twist drills used in industrial range from 0.01 up to 3.25 in. (i.e., 0.25 up to 80 mm). 尽管在加工中有硬质合金的钻头，但麻花钻通常由高速钢作成。在工业生产实践中，麻花钻的尺寸大小通常在0.01至3.25英寸的范围内。(即是0.25到80毫米,Paragraph 6,1.Core drills. A core drill consists of the chamfer, body, neck, and shank.扩孔钻：扩孔钻由倒角槽、钻体、钻颈和钻柄组

10、成。 2.This type of drill may have either three or four flutes and equal number of margins, which ensure superior guidance, thus resulting in high machining accuracy.这种类型的钻具有三个或四个出屑槽以及相同数量的刃带，这些可确保准确的导向，从而获得较高的机加工精度,Paragraph 7,3.A core drill has flat end. The chamfer can have three or four cutting ed

11、ges or lips, and the lip angle may between 90。 and 120。 扩孔钻有一个扁形的柄脚。倒角槽有三四个切削刃或刀刃，刀刃角从90度到120度大小不等。 4.Core drills are employed for enlarging previously made holes and not for originating holes. 扩孔钻是用来扩孔而不是用来钻孔的,Paragraph 7,5.This type of drill is characterized by greater productivity, high machining

12、 accuracy, and superior quality of the drilled surfaces. 这种类型的钻具有高效率、高机加精度和好的表面质量,Paragraph 8,1.Gun drills. Gun drills are used for drilling leap holes. All gun drills are straight-flutes, and each has a single cutting edge.深孔钻：深孔钻是用来钻削深孔。所有的深孔钻都是直槽并有一个单刃。 2.A hole in the body acts as a conduit to t

13、ransmit coolant under considerable pressure to the tip of the drill.深孔钻体的孔的作用相当于一个导管，在钻顶部的压力下把冷却液输送到底部,Paragraph 9,1.There are two kinds of gun drills, namely, the center-cut gun drill used for drilling blind holes and the trepanning drill. 深孔钻分为两种，即用于钻削盲孔的中心钻和套孔钻。 2.The latter has a cylindrical gro

14、ove at its center, thus generating a solid core, which guides the tool as it proceeds during the drilling operation. 套孔钻的中心有一个圆柱孔，钻孔时可在工件上形成一个芯子，当钻头连续进给进行钻孔时，芯子对钻头起导向作用,Paragraph 10,1.Spade drills. Spade drills are used for drilling large holes of 3.5 in.(90mm) or more. 扁钻：扁钻用于钻削3.5英寸或更大的孔。 2.Their

15、design results in a marked saving in cost of the tool as well as a tangible reduction in its weight, which facilitates its handling. Moreover, this type of drill is easy to be grind. 它们的设计明显降低了钻头的生产成本、切实的减轻了重量，以便于钻头的操纵。而且，这种类型钻头易于磨削,Other Types of Drilling Operations 钻孔的其它类型 In addition to conventio

16、nal drilling, there are other operations that are involved in the production of holes in the industrial practice. Following is a brief description of each of these operations. 除了常规钻孔以外，有其他加工工序涉及到工业实践中的孔加工。以下是这些工序的简短描述,机械工程专业英语教程,29.12.2020,16,Boring Boring involves enlarging a hole that has already

17、been drilled. It is similar to internal turning and can, therefore, be performed on a lathe. There are also some specialized machine tools for carrying out boring operations. Those include the vertical boring machine, the jig boring machine, and the horizontal boring machine. 镗孔 镗孔涉及到对已经被钻出的孔的扩大。类似于

18、车内圆，因此能在车床上进行。也有一些进行镗孔加工的专用机床。包括立式镗床、坐标镗床和卧式镗床,机械工程专业英语教程,29.12.2020,17,Counterboring As a result of counterboring, only one end of a drilled hole is enlarged. This is illustrated in Figure 1 (a). This enlarged hole provides a space in which to set a bolt head or a nut so it would be entirely below

19、the surface of the part. 锪沉孔 锪沉孔时钻好的孔只有一端被扩大。如插图1(a)中所示。孔被扩大的部分提供了安装螺栓头或螺母的空间，因此它应该整个低于零件表面。 (a) Counterboring (b) Spot facing (c) Countersinking Figure 1 Operations related to drilling.5,机械工程专业英语教程,29.12.2020,18,Spot Facing Spot facing operation is performed to finish off a small surface area aroun

20、d the opening of a hole. As can be seen in Figure 1 (b), this process involves removing a minimal depth of cut and is usually performed on castings or forgings. 锪端面 锪端面用于在孔的开口周围加工出一个小平面区域。如图1(b)所示，其工艺包含去除一个最小的切削深度，常用于铸件和锻件,机械工程专业英语教程,29.12.2020,19,Countersinking As shown in Figure 1 (c), countersink

21、ing is done to enable accommodating the conical seat of a flathead screw so that the screw does not appear above the surface of the part. 锪锥孔 如图1(c)所示，锪出的锥孔能容纳平头螺钉的锥形安装位置，以使螺钉不会露出零件表面。 Reaming Reaming is actually a sizing process, by which an already drilled hole is slightly enlarged to the desired

22、size. As a result of a reaming operation, a hole has a very smooth surface. The cutting tool used in this operation is known as the reamer. 铰孔 铰孔实际上是一个矫正工艺，通过它可以将已钻好的孔轻微扩大到需要的尺寸。铰孔加工可以得到具有非常光滑表面的孔。用于铰孔的刀具被称为铰刀,机械工程专业英语教程,29.12.2020,20,Classification of Drilling Machines 钻床的分类 Drilling operations can

23、 be carried out by employing either portable small machines or appropriate machine tools. The latter differ in shape and size, although they have common features. For instance, they all involve one or more twist drills, each rotating around its own axis while the workpiece is kept firmly fixed. 钻削加工

24、可以用便携式的小机器或适当的机床来进行。尽管它们有相同的特征，后者在形状和尺寸上有不同。例如，它们都包含一个或更多的麻花钻，当工件被牢固地夹紧时绕着自身的轴线旋转,机械工程专业英语教程,29.12.2020,21,This is contrary to the drilling operation on a lathe, where the workpiece is held in and rotates with the chuck.6 Following is a survey of the commonly used types of drilling machines. 6. dril

25、ling operation 意为“钻孔工序，钻孔操作”。全句可译为： 这与在车床上进行的钻孔操作正好相反，在车床上，工件被夹紧在夹具内并随其转动。以下是常用类型钻床的情况,机械工程专业英语教程,29.12.2020,22,Bench-type Drilling Machines Bench-type drilling machines are general-purpose, small machine tools that are usually placed on benches. This type of drilling machine includes an electric mo

26、tor as the source of motion, which is transmitted via pulleys and belts to the spindle, where the tool is mounted. 台式钻床 台式钻床是通用的小型机床，通常放置在工作台上。这种钻床用电机作为动力源，通过皮带轮和带将动力传输到装有刀具的主轴上。 The feed is manually generated by lowering a lever handle, which is designed to lower (or raise) the spindle.7 7. lever h

27、andle 意为“杠杆手柄”。全句可译为： 进给是通过用手向下搬动手柄而实现的，这个手柄是被设计用来使主轴向下（或向上）运动的,机械工程专业英语教程,29.12.2020,23,The workpiece is mounted on the machine table, although a special vise is sometimes used to hold the workpiece. The maximum height of a workpiece to be machined is limited by the maximum gap between the spindle

28、and the machine table. 工件安装在机床工作台上，有时也用一个专用台钳来夹持工件。被加工工件的最大高度受到主轴和工作台之间最大间隙的限制,机械工程专业英语教程,29.12.2020,24,Upright Drilling Machines Depending upon the size, upright drilling machine tools can be used for light, medium, and even relatively heavy jobs. It is basically similar to bench-type machines, the

29、 main difference being a longer cylindrical column fixed to the base.8 8. cylindrical column fixed to the base 意为“固定在底座上的圆形立柱”。全句可译为： 立式钻床 根据尺寸，立式钻床能用于加工轻的、中等的甚至是相对重型的工件。它与台式钻床基本类似，主要的区别之处在于一根较长的固定在底座上的圆形立柱,25,机械工程专业英语教程,29.12.2020,Along that column is an additional, sliding table for fixing the wor

30、kpiece which can be locked in position at any desired height. The power required for this type is more than that for the bench-type drilling machines, since this type is employed in performing medium-duty jobs. 沿着立柱是一个附加的安装工件的滑动工作台，它能在任何需要的高度锁定位置。这种钻床所需的功率比台式钻床要大，因为它用于做中等负荷的工作,机械工程专业英语教程,29.12.2020,

31、26,There are also large drilling machines of the upright type. In this case, the machine has a box column and a higher power to deal with large jobs. Moreover, gear boxes are employed to provide different rotational spindle speeds as well as the axial feed motion, which can be preset at any desired

32、rate. 也有大的立式钻床。这种情况下，机床有一个箱型立柱和更大的功率去加工大型工件。而且，用了变速箱来提供不同的主轴转速和预设好的任何速率的轴向进给运动,机械工程专业英语教程,29.12.2020,27,Multispindle Drilling Machines Multispindle drilling machines have sturdy construction and require high power; each is capable of drilling many holes simultaneously saimlteinisli . The positions o

33、f the different tools (spindles) can be adjusted as desired. Also, the whole head (which carries the spindles and the tools) can sometimes be tilted, as required. 多轴钻床 多轴钻床有坚固的构造和需要的大功率；两者都使其能同时加工多个孔。不同刀具（主轴）的位置都能按需要调整。而且整个床头箱（携带着主轴和刀具）有时可按需要倾斜,机械工程专业英语教程,29.12.2020,28,This type of drilling machine

34、is used mainly for mass production in jobs having many holes, such as cylinder blocks. 这种钻床主要用于有多个孔的工件的大量生产，如气缸缸体。 Radial Drill A radial drill is particularly suitable for drilling holes in large and heavy workpieces that are inconvenient to mount on the table of an upright drilling machine. A radia

35、l drilling machine has a main column, which is fixed to the base. 摇臂钻 摇臂钻特别适于在大型和重型工件上钻孔，这些工件不便于安装在立式钻床的工作台上。摇臂钻有一根固定在基础上的杆柱,机械工程专业英语教程,29.12.2020,29,The cantilever guide arm, which carries the drilling head, can be raised or lowered along the column and clamped at any desired position.9 9. cantilev

36、er guide arm 意为“摇臂”。全句可译为： 装有钻床主轴箱的摇臂可以沿着立柱上下移动，并且可以固定在任何合适的位置上。 The drilling head slides along the arm and provides rotary motion and axial feed motion. Again, the cantilever guide arm can be swung, thus enabling the tool to be moved in all directions according to a cylindrical coordinate system. 钻

37、头主轴箱沿摇臂滑动，提供回转运动和轴向进给运动。摇臂能够摆动，因此使刀具能移到柱面坐标系的任何位置,30,机械工程专业英语教程,29.12.2020,翻译的基本方法之二-词义的引伸 Skills of Translation-Acceptation Development,当英语句子中的某个词按词典的释义直接译出不能符合汉语的修辞习惯或语言规范时，则可以在不脱离该英语词本义的前提下灵活选择恰当的汉语词或词组译出,这种翻译处理方法叫做引伸译法。 引伸的目的在于避免由于直译而造成的生硬或离意,引伸的词义应该在意义上与原基本词义相关联，避免歪曲原意,二 、词义的引伸,在专业性文章中，某些常用基本词汇

38、已含有专业概念，可根据专业而引伸出词义。 The independent chuck has four jaws, while the universal chuck has only three. 分动卡盘有四个爪，而万能卡盘只有三个。 independent 独立的引伸为专业词义分动的,1. 使基本词义专业化,The power dissipated by the filament literally boils electrons from the surface of the filament. 灯丝所消耗的功率完全用于从灯丝表面发射电子。 （boil-沸腾, 引伸为-发射,当基本词义

39、在该句中意义含糊或比较费解时，应采用解释性语言使其明确化。 - Bronze was a better material for many purposes than either of the two metals that composed it. 在许多用途方面，青铜要比构成青铜的锡和铜更好。 （将 “two metals” 明确译为“锡和铜”,2. 使基本词义明确化,Note, therefore, that when we calibrate the scale to read in ohms, these calibrations go backward. 因此要注意，当我们把刻度

40、刻成欧姆读数时，这些刻度是从大到小的。 (these calibrations go backward 若译为“这些刻度是向后的”, 就令人费解了。因此backward 在句中应引伸为“从大到小”,英语中有的词意思很笼统，很概括。例如：“good”表示“好”，用得极其广泛，但具体“好”在哪里呢？我们应根据具体情况翻译，使语意更加清晰。 - A good example of a case where electricity is changed to power is the electric streetcar. 电变为动力的典型例子是电车。 - Rivers provide good so

41、urces of hydro-power. 河流提供丰富的水力资源。 - The workers gave the machine a good checking. 工人们对机器进行了彻底的检查,3. 使基本词义具体化,It has long been thought of making good use of the suns energy to serve the human being. 人们早就设想过充分利用太阳能来为人类造福。 - Good switches move quickly. 优质开关通断灵活。 - Laser possesses a series of remarkabl

42、e properties, which make it a better light source in a number of cases. 激光有许多显著的特性，这些特性使它在许多情况下成为一种更理想的光源。 - That engine sounds good. 那台发动机听起来很正常,3. 使基本词义具体化,A good translator can do perhaps 2000 to 3000 words a day. 一个熟练的翻译人员一天也许能译两千到三千个词。 - The tungsten shines and gives a good light. 钨丝发亮而发射出耀眼的光芒

43、。 - Engineers try to reduce friction as much as possible by good design. 工程师们试图通过完美的设计来尽可能地减少摩擦。 - The car in front of me suddenly stopped and I missed the green. 我前面的那辆车突然停了，我错过了绿灯,3. 使基本词义具体化,英语中，有的词意思很具体，但在某些场合，它已经失去原来的具体词义而表示较抽象较笼统的意思，或者被借用来表示另一方面的意思。 - At present coal is the most common food of a steam plant. 目前，煤是蒸汽动力厂的最常用的能源。 - An electric power station is a factory in which energy is converted from one form or another into electrical energy. 电站是把一种能或另一种能转变成电能的地方。 -The character of these people is a mixture of the tiger and ape. 这些人的性格既残暴，又狡猾。 - Everyone has rain an