special english 5.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Reading Special English,Engineering Collage,Heilongjiang August First Land Reclamation University,Hu,jun,E-mail:hjgj7275,（一）常见的前缀,3.,表示时间，序列关系的前缀,1)ante-,anti-,表示“先前，早于，预先”,antecedent,anticipate,2),ex-,表示“先，故，旧”,expresident,exhusband,3),fore,-,表示“在前面，先前，前面forward,forecast,foretell(,预言,),4)mid-,medi,-,表示“中，中间”,midnight,midsummer,5),post-,表示“在后，后”,postwar,6)pre-,pri,-,表示“在前，事先，预先”,preheat,prewar,prehistory,prehistoric civilization,7)pro-,表示“在前，先，前”,prologue(,序言、序幕,),，,prophet(,预言家、先知,),8)re-,表示“再一次，重新”,retell,rewrite,4.,表示比较程度差别关系的前缀,1)by-,表示“副，次要的”,byproduct,bywork,(,副业,),2)extra-,表示“超越，额外”,extraordinary,3)hyper-,表示“超过，极度”,hypersonic(,超声波,),hypertension(,高血压,),4),out-,表示“超过，过分”,outdo(,超过,),outbid(,出价过高的人,),5),over-,，表示“超过，过度，太”,overeat,overdress,oversleep,6),sub-,suc,-,sur,-,表示“低，次，副，亚”,subeditor,subordinate,subtropical(,亚热带,),7)super-,sur,-,表示“超过”,supernature,superpower,surplus,surpass,8)under-,表示“低劣，低下”,undersize,undergrown,underproduction(,生产不足,),9),vice-,表示“副，次”,vicepresident,vicechairman,Reading skills of scientific and technical English,Reading for Main Idea(,获取主题思想,),我们可以把获取主题思想的阅读技巧分四步,1.,辨认主题名词,identify subject word,2.,找出主题词,find subject word,3.,获取主题思想,gain main idea,4.,避免不相关的内容,avoid,disrelated,content,New Words,1.lathe n,车床,vt,用车床加工,A machine for shaping a piece of material,such as wood or metal,by rotating it rapidly along its axis while pressing against a fixed cutting or abrading tool.,车床：通过压紧一种固定的切割或打磨工具并迅速沿轴线转动的办法来塑造一件材料（如木头或金属）的机器,2.swing(swung)vi,（绕轴心、铰链等）回转、旋转,3.spindle n,心轴,4.pulley n,滑轮，轱辘，皮带轮,5.clamp n,夹钳，夹子,vt,（用夹钳）夹住，夹紧,6.taper n,拨销,7.reamer n,绞刀，绞床,8.saddle n,座板，滑动座架，滑板,9.apron n,挡板，机床拖板箱,10.tapping n,攻螺丝,11.quill n,套管轴,Unit 4 Machine Tools,The Engine Lathe,（普通车床）,Engine lathe:the versatile engine lathe ranges in size and design,from,small bench and speed lathes,to,large floor types.,The,workpiece,may be held between tapered centers and rotated with the powder spindle by means of a clamping device,or it may be held in a chuck,or even fixed to a rotating plate.,When the work is swung between centers,the tailstock is clamped firmly in place.,普通车床：多用途的车床，其大小和设计多种多样，有小的台式车床、高速车床，大的落地式车床。,工件支在两个锥形顶尖之间。通过夹紧装置且与主轴一起转动，或者工件装在夹盘上，甚至可固定在一个转盘上。,当工件在两个顶尖之间转动时，尾轴则保持不动。,Spindle:a short shaft.It may be slender or tapered,a spindle is capable of rotating or of having a body rotate upon it.,主轴：主轴是一个较短的轴，可能是细长的，也可能是锥形的，主轴能转动，或者有一物体绕其转动。,Lathe size is determined by the swing and the length of the bed,（,Fig,4-1,）,The swing is twice the distance from the live center point of the spindle to the top of the bed,，,or the largest diameter that can be turned over the ways of a lathe,机床的尺寸是由其可加工工件回转直径和床身长度决定的（如图,1,所示），加工工件回转直径是从是车床心轴中心点到床身顶部距离的两倍。,Fig4-1,size is indicated by swing and the length of the bed,For example,，,a 10-in.lathe will turn a l0-in.diameter,workpiece,over the ways,，,but not over the carriage cross-feed slide,Sometimes two numbers are used to indicated swing,，,such as 17-12,The 17-in.swing would be over the bed and the 12-in,swing over the cross slide,例如,10,英寸的车床可以加工,10,英寸的工件，但其尺寸不能超过横向进刀滑座。有时两个数字被用来表示回转直径，比如,17-12,，,17,英寸回转直径将要超出床身，而,12,英寸回转直径超出了横向进刀滑座。,The length of the bed includes the part the,headstock,rests on,It determines also the distance between,centers,床身长度包括安装床头箱部分。它也决定了两中心的距离。,(2)Headstock,：,a part of a lathe that holds the revolving spindle and its attachment.,主轴箱：车床的一部分，其上安装有主轴及附件。,Center,：,one of two tapered metal rods that support work in a lathe or,grinking,machine and about or with which the work revolves.,顶尖：车床或磨床上两个锥形金属棒中的一个，它用来支持工件围绕着顶尖转动，或依靠顶尖转动。,A typical size might be a 3-foot bed with a distance of 23 in,between centers,Lathe beds are offered in many different lengths,for,each available swing size,典型尺寸是一个,3,英尺床身（长度）两中心间距离应是,23,英寸。,对于每种不同回转直径的车床，都可以有许多不同的床身长度。,A lathe should have,a swing capacity and distance between centers,that,is at least 10 percent greater,than,needed to do any,job,that,may be required,车床的回转直径和两中心间的距离至少要比其完成任何作业所需的尺寸大,10%,，,标准的车床有不同的设计、不同的类型，也可能是其回转直径由,9,英寸变化到,53,英寸。,它们通常被分为小型、中型或大型回转径的车床。,Standard lathes come in a variety of designs and styles and may have a swing changing from about 9 to 53 in,They are generally,classified as,small,，,medium swing,，,and heavy duty,The bed is the,base or foundation,of the lathe,It is a heavy,，,rigid casting made in one piece,It is the,backbone,of the lathe and,holds or supports,all the other parts,床身是车床的基础部分，它是一体的较重的、刚性铸件。它是车床的“脊骨”，支撑车床的所有其它零部件。,Located on the top of the bed areways.,More expensive lathes have a combination of,V ways,and flat ways,Less expensive lathes have flat ways only,Construction of ways varies according to the make,安装于床身顶部的是导轨。具有“,V”,形轨和平轨的组合导轨的车床价格要更贵，而只有平导轨的车床其价格要相对便宜。,导轨的结构依其型式而不同。,Some builders use ways made of hardened steel that can be replaced if necessary,Others use,flamehardened,ways that are an integral part of the bed section,一些车床采用必要可以被替代的硬化了的钢制导轨；,其它车床采用与床身制成一体的烧硬的导轨。,The headstock assembly is permanently fastened to the left end of the lathe,It contains the headstock spindle,，,which is rotated by gears or by a combination of gears and pulleys,床头箱组件设永久地固定于车床的左侧。,它包括齿轮组驱动或齿轮与皮带轮联合驱动的主轴。,The spindle holds the attachments which,，,in turn,，,hold and turn the,workpiece,Spindles come in several quality ratings and are supported in headstocks by three to five,bearings,.,主轴支撑固定和转动工件的一些附件。主轴有几种质量规格，在床头箱内有,3-5,个轴承支承着主轴。,Since the accuracy of the work done on a lathe,depends on,the axis of rotation of the spindle holding the,workpiece,，,the spindle and all its,accessories,must be built and,assembled,with the greatest possible care,由于机床工作的精度依赖于固定工件的主轴的旋转同轴度，所以主轴及其附件的制造和安装必须尽可能地仔细。,The tailstock can be moved along the bed ways and clamped in position.It consists of two castings or main parts,车床尾座能够沿着床身导轨的运动，并且可固定在一定的位置，它由两个铸件或主要部件组成。,The lower part,rests,directly,on,the ways,，,and the upper part rests on the lower part.,Adjusting screws hold the parts together,下部的部件直接安装在导轨上，上部的部件装在下面的部件上。,调节螺纹把部件固定在一起。,The upper casting can be moved toward or away from the operator to offset the tailstock for taper turning and to realign the tailstock center for straight turning,The tailstock spindle moves,in and out,of the upper casting when the tailstock,handwheel,is turned.,上面的铸件能够移近或移离操纵者，故可在锥形车削时调整尾架顶尖，在直线车削时对尾架主轴进行重对中。当转动尾座手轮时，尾座中心轴可以从上部铸件中伸缩。,This spindle has a taper hole into which the dead center or other tools such as drills and reamers fit,Only tools having the same taper as the tailstock spindle should be placed in the spindle hole.,中心轴有一个锥形孔，钻头或铰刀等工具可以安装在锥形孔中。,只有那些具有与车床尾座中心轴同样锥度的工具才能装进中心轴孔中。,To remove tools from the spindle,，,it is only necessary to back up on the,handwheel,until the spindle end is nearly inside the casting,The end of the screw that moves the spindle loosens the taper shank so it can be removed,若要把工具从中心轴上卸下来，只需转动手轮后退中心轴，直至中心轴刚刚要进到铸件内部时，移动中心轴的螺纹端使锥形孔松动。这样可以使工具从中心孔中退出。,The,carriage,consisting of the saddle and apron is the movable part which slides between the headstock and tailstock,It controls and supports the cutting tool,由滑动底座及拖板箱组成的刀架是可以在床头箱及车床尾轮间滑动的可移动部件。,它控制和支撑着刀具。,