毕业设计(论文)外文资料翻译
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外文出处：English For Electromechanical
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Engineering
附件： 1.外文资料翻译译文；2.外文原文。
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此翻译文章简单介绍了各机床的加工原理，并详细介绍了各机床的构造，并对方各机床的加工方法法进行了详细的描述，翻译用词比较准确，文笔也较为通顺，为在以后工作中接触英
文资料打下了基础。
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年月日注：请将该封面与附件装订成册。
附件1：外文资料翻译译文
机床
机床是用于切削金属的机器。工业上使用的机床要数车床、钻床和铣床最为重要。其它类型的金属切削机床在金属切削加工方面不及这三种机床应用广泛。
车床通常被称为所有类型机床的始祖。为了进行车削，当工件旋转经过刀具时，车床用一把单刃刀具切除金属。用车削可以加工各种圆柱型的工件，如：轴、齿轮坯、皮带轮和丝杠轴。镗削加工可以用来扩大和精加工定位精度很高的孔。
钻削是由旋转的钻头完成的。大多数金属的钻削由麻花钻来完成。用来进行钻削加工的机床称为钻床。铰孔和攻螺纹也归类为钻削过程。铰孔是从已经钻好的孔上再切除少量的金属。
攻螺纹是在内孔上加工出螺纹，以使螺钉或螺栓旋进孔内。
铣削由旋转的、多切削刃的铣刀来完成。铣刀有多种类型和尺寸。有些铣刀只有两个切削刃，而有些则有多达三十或更多的切削刃。铣刀根据使用的刀具不同能加工平面、斜面、沟槽、齿轮轮齿和其它外形轮廓。
牛头刨床和龙门刨床用单刃刀具来加工平面。用牛头刨床进行加工时，刀具在机床上往复运动，而工件朝向刀具自动进给。在用龙门刨床进行加工时，工件安装在工作台上，工作台往复经过刀具而切除金属。工作台每完成一个行程刀具自动向工件进给一个小的进给量。
磨削利用磨粒来完成切削工作。根据加工要求，磨削可分为精密磨削和非精密磨削。精密磨削用于公差小和非常光洁的表面，非精密磨削用于在精度要求不高的地方切除多余的金属。
车床
车床是用来从圆形工件表面切除金属的机床，工件安装在车床的两个顶尖之间，并绕顶尖轴线旋转。车削工件时，车刀沿着工件的旋转轴线平行移动或与工件的旋转轴线成一斜角移动，将工件表面的金属切除。车刀的这种位移称为进给。车
刀装夹在刀架上，刀架则固定在溜板上。溜板是使刀具沿所需方向进行进给的机构。用于操纵车床手柄可使车刀实现进给，也可以借助专门的传动装置实现自动进给。
车床的最大部件称为床身，它的两端分别装有床头箱和尾座。床身表面有专门的导轨，溜板和尾座可以在导轨上滑行。
车床的两个顶尖分别装在两根主轴中：活顶尖装在床头箱主轴中，另一个死顶尖则装在尾座的主轴中。
车床卡盘用于夹紧工件，其目的在于使工件在车削时不摇晃。通常，安装在床头箱主轴上的卡盘可具有不同的尺寸和结构。如果工件是一完整的圆，可将其夹紧在所谓的三爪通用卡盘中，卡盘的三个爪靠转动螺旋机构能同时向中间移动。但是如果工件系非完整的圆，则应使用四爪相互独立的四爪卡盘。
车床在车削不同材料和不同直径的工件时，必须以不同的速度运转。装在床头箱内的齿轮系统能使车床以不同的速度运转。
车床在车削工件前，它的顶尖要对准，即两个顶尖的轴线必须在同一直线上。
为检验车床顶尖的同轴度，可进行一次车削，然后用千分尺测量车削物的两端。
并非所有的工件都必须装夹在车床的两个顶尖之间。短工件的车削可不使用死顶尖，而是简单的将其适当夹紧在床头箱的主轴上。
钻头和钻床
麻花钻头是一种高效率的刀具，它通常由扁钢锻造后扭转出凹槽，或由圆柱
棒料铣削而成，一般用高速钢制作。高速钢的成本虽然较高，但用它制作的刀具在耐热性方面要比用普通工具钢制作的刀具好得多。
麻花钻可分做三个主要部分：钻体、钻柄和钻尖。螺旋槽是位于钻头侧面的螺旋形凹槽，钻头制成两条、三条或四条螺旋槽。带有三条或四条螺旋槽的钻头用于较小钻头钻孔后继续钻孔的场合，或对已钻好的孔进行扩孔，而不宜在实体坯料上钻孔。
螺旋槽主要有四个好处：
（1）螺旋槽使钻头的切削刃有正确的前角；
（2）螺旋槽可以卷紧切屑，使其占有最小的空间；
（3）螺旋槽可以构成若干通道，切屑能借助这些通道从孔内排出；
（4）螺旋槽可以使润滑剂顺利地流向切削刃。
刃带（棱边）是螺旋槽切削刃上的狭带。刃带部分实际上是钻头的最大直径处，它伸展到螺旋槽的全长，它的表面是圆柱体的一部分。紧靠刃带的钻体部分其直径略小于刃带的直径，减小的直径称做钻体间隙。钻体间隙用来减少钻头和孔壁间的摩檫，而刃带则用来保证孔的准确尺寸。
钻头的一端是钻柄，它被安装在钻套、钻床的主轴或钻夹头中。通常只有锥柄钻头才带柄舌。
钻床是仅次于车床的最古老的机床，它的发明略迟于车床，它是一种最普通和最有用的机床。钻床可分为三大类：立式钻床、多轴钻床和摇臂钻床。立式钻床有三种类型：重型钻床、普通钻床和高速手压台钻。
钻床除了钻孔外，还可完成下列工作：如攻螺纹（加工内螺纹）、铰孔（用绞刀精加工孔）、尖底锪钻、平底锪钻、镗孔和锪端面等。
铣床
铣床是一种当工件向铣刀进给时，铣刀旋转着从工件表面切除金属的机床。铣刀安装在刀杆上并由衬套或轴套定位。刀杆的一端安装在主轴上，而另一端则可在安装在刀杆支架的轴承里旋转。
铣刀通常有高速钢制成，有不同的尺寸和形状。铣刀可分为圆柱铣刀、立铣刀（铣端面）、成形铣刀、角度铣刀、三面刃铣刀、锯片铣刀等。这些铣刀的铣削方向可能不同，例如，在切削时，它们可以顺时针转动，也可以逆时针转动。
在铣床可以加工规则的或不规则的工件，铣床结构的不同取决于要加工工件的类型特点。根据主轴的位置，铣床可分为立式铣床和卧式铣床两大类。铣床可分为许多种。
根据总体结构的不同，铣床可分为升降台式铣床、专用铣床、龙门铣床；根据工作台的结构，铣床可分为万能铣床和普通铣床。
铣床主要的零部件有启动手柄、主轴、立柱、升降台、升降螺杆、工作台、分度台、调速手柄、进给手柄、工作台移动手柄、床身和刀杆支架。
铣床主轴由电动机通过安装在立柱里的一系列齿轮驱动。普通铣床的工作台只能沿垂直于主轴的方向运动，而万能铣床在铣削轮齿、螺纹等时，工作台可以在横向滑板上转动。
铣床上所用的各种附件增加了铣床的加工范围。
分度头是一种在工件圆周方向上进行等分，以及切削时把工件夹持在所需位置的装置。
铣床用各种虎钳来夹持工件，最常见的是平口钳及旋转座虎钳。
龙门刨床
龙门刨床是用于往复切削运动的最大的机床之一。它在一连窜的直线切削过程中加工平面或成形面。龙门刨床的加工效率高于牛头刨床。
龙门刨床上的工件装在工作台上，并在刨刀下面做往复运动，刨刀装在横轨上。龙门刨床的床身一定要比工作台长一倍左右，以便工作台在行程中的每一个位置都得到支承。双立柱龙门刨床有两根立柱，用来支承横轨的两端。单立柱龙门刨床只在一边有立柱。单立柱龙门刨床适用于那些宽度超过两立柱间距离的工件。然而，双立柱龙门刨床刚性较高。
有一些以前用龙门刨床加工的工件，现在可用龙门铣床加工，因为前者的效率不如后者高。不过，还是有许多工件在龙门刨床上加工比在其它机床上加工更为有利和经济。例如，斜面通常在龙门铣床上加工较为容易。狭长表面的加工用龙门刨床也最为有效。此外，龙门刨床常用来在表面粗糙的锻件和铸件上进行重要的初切，以便为后面的加工建立一个基准面。
磨床
磨削，或研磨加工，是制造业发展最快的金属切削方法。很多以前由传统铣床，车床和刨床作的机械加工作业，现在由各种磨床来完成。
磨床的总类很多。常见的有刀具磨床、普通磨床、无心磨床、外圆磨床、内圆磨床及工具磨床。
在磨床上可进行五种类型的磨削：
（1）平面磨削。平面磨削是用于加工平面，角平面和不规则的表面。在平面磨削过程中，砂轮在轴上旋转，工件安装在一个往复移动或转动的工作台上，工件被带动与砂轮互相接触。
（2）外圆磨削。外圆磨削是磨削圆柱体的外表面的过程。这些表面可以是圆柱面的，圆锥形的和外轮廓曲面。外圆磨削操作类似车床车削的操作。当工件是很硬或当需要极高精度和较高光洁度时，外圆磨削可代替车床。工件旋转，砂轮与工件
旋转方向相反且转速更快，被带到与工件接触的部件。工件与工作台往复运动，当与砂轮接触就对材料进行磨削。
（3）无心外圆磨削。无心外圆磨床运行不需要中心孔或夹紧装置。在无心外圆磨床上，工件停在静止的刀形托板上，且被另一个称为导轮的轮子支撑着。在刀形支撑上，砂轮推动工件向下，且靠在调节轮上。调节轮经常用橡胶结合耐磨材料做成，旋转的方向与主动轮相同，同时当实质一个微小的倾斜角度时，能控制工件的纵向进给。改变这个角度和砂轮的速度，工件的进给速度也能改变。
（4）内圆磨床。内圆磨床是被用于完成精准的圆柱形的，圆锥形的和成形孔的加工。大多数通用的内圆磨床的操作与车床上的镗孔操作非常相似。工件是被工件夹具所夹持，工件夹具通常是卡盘或套爪卡盘夹紧由主轴箱驱动旋转。一台单独的电动机与工件同一个方向驱动砂轮旋转。它能进退工件也能调整切削深度。
（5）特种磨削加工。特种磨床是加工特殊类型的工件及具有特殊操作功能的磨削设备。比较常见的特殊种类概括如下：
工具和刀具磨床：人们设计这些磨削机床以锋利铣刀，绞床，丝攻和其他的机械切割刀具。
一般的刀具磨床是最通用万能的刀具磨削机床。其各种配件能使绝大多数的切割刀具变得锋利。
坐标磨床：坐标磨床机开发是用来定位和精确磨削锥形和圆柱形的孔。坐标磨床机有一个能安装和驱动砂轮的高速立轴。和坐标镗床一样，它们使用相同的精确定位系统。
螺纹磨床：这种特殊磨削机与外圆磨削机相似。它们有一个精确的引导丝杆以便在工件上加工出正确的螺距或导程。螺纹磨床还可加工及精修砂轮的切削面，以便在工件上加工出精确的螺旋线。
镗床
镗孔也可以称为内车削，是增大圆孔内径的方法。镗削之前的孔是钻孔或在铸件上的一个孔。
镗孔有以下三个目的：
（1）达到尺寸：钻孔可以得到合适精度的孔。
（2）直线度：镗孔能提高原有凿的孔和铸件的直线度。
（3）同心度：受卡盘和夹具的精度影响镗削会使孔和外圆柱偏心。
镗削工序一般分两步完成，即粗镗和精镗。粗镗工序的目的是快速、高效地去除多余的金属；而精镗工序的目的是获得所需的尺寸、光洁表面度和孔的位置。孔的尺寸通过使用试切割程序而获得。孔的直径可以用内卡尺和千分尺测量。测量仪表或内千分尺可用于直接测量直径。
肩、沟槽、轮廓、锥度和螺纹也应该在孔内镗出。内槽是用与外部开槽工具相似的工具切削。镗削内槽的步骤非常类似于车削肩部的步骤。大的肩部使用前导装置定位的镗孔工具进行刮削，使用横向滑板进给刀具。内部轮廓使用车床上的描摹附件加工。仿形板附件安装在横向滑板上，靠模指跟随标准剖面样板的轮廓线运动。这种刀具以对应于标准剖面样板的轮廓线的路径进行移动。这样标准剖面样板的轮廓就在孔内得到复制。标准剖面样板精确安装在一个专用的滑板上，滑板可以在两个方向上进行精确调整以使刀具与工件以正确的关系对正。正常的车削是在主轴逆时针转动时进行的；镗削是在主轴顺时针方向或“向后”转动时进行的。
附件2：外文原文（复印件）
Machine Tools
Machine Tools are machines for cutting metals.The most important of machine tools used in industry are lathes,drilling machines and milling machines.Other kinds of metal working machines are not so widely used in machining metals as these three.
The lathe is commonly called the father of the entire machine tool family.For turning operations,the lathe uses a single point cutting tool,which removes metal as it travels past the revolving work-piece.Turning operations are required to make many different cylindrical shapes,such as axes,gear blanks,pulleys,and threaded shafts.Boring operations are performed to enlarge,finish,and accurately locate holes.
Drilling is performed with a rotating tool called a drill.Most drilling in metal is done with a twist drill.The machine used for drilling is called a drill press.Operations,such as reaming and tapping,are also classified as drilling.Reaming consists of removing a small amount of metal form a hole already drilled.
Tapping is the process of cutting a thread inside a hole so that a cap screw or bolt may be threaded into it.
Milling removes metal with a revolving,multiple cutting edge tools called milling https://www.doczj.com/doc/706795548.html,ling cutters are made in many styles and size.Some have as few as two cutting edges and others have 30 or https://www.doczj.com/doc/706795548.html,ling can produce flat,angled surfaces,groves,slots,gear teeth,and other profiles,depending on the shape of the cutters being used.
Shaping and planing produce flat surfaces with a single point cutting tool.In shaping,the cutting tool on a shaper reciprocates or moves back and forth while the work is fed automatically towards the tool.In planing,the work-piece is attached to a worktable that reciprocates past the cutting
tool.The cutting tool is automatically fed into the work-piece a small amount on each stroke.
Grinding makes use of abrasive particles to do the cutting.Grinding operations may be classified as precision or non-precision,depending on the purpose.Precision grinding is concerned with grinding to close tolerances and very smooth finish.Non-precision grinding involves the removals of metal where accuracy is not important.
Lathe
A lathe is a machine tool for cutting metal form the surface of a round work fastened between the two lathe centers and turning around its axis.In turning the work a cutter moves in the direction parallel to the axis of rotation of the work or at an angle to this axis,cutting off the metal from the surface of the work.This movement of the cutter is called the feed.The cutter is clamped in the tool post which is mounted on the carriage.The carriage is the mechanism feeding the cutter in the needed direction.The lathe hand may feed the cutter by hang or may make it be fed automatically by means of special gears.
The largest part of the lathe is called the bed on which the headstock and the tailstock are fastened at opposite ends.On the upper part of the bed there are special ways upon which the carriage and the tailstock silde.
The two lathe centers are mounted in two spindles:one(the live center)is held in the headstock spindle,while the other (the dead center)in the tailstock spindle.
The lathe chuck is used for chucking the work,which is for clamping it so that it will rotate without wobbling while turning.The
chuck,usually,mounted on the headstock spindle,may have different sizes and construction.If the work is perfectly round,it may be chucked in the
so-called three-jaw universal chuck,all the jaws of which are moved to the center by turning the screw.But if the work is not perfectly round,the
four-jaw independent chuck should be used.
In turning different materials and works of different diameters,lathes must be run at different speeds.The gearbox contained in the headstock makes it possible to run the lathe at various speeds.
Before turning a work in the lathe,the lathe centers are to be aligned;that means that the axes of both centers must be on one line.
The alignment of the lathe center may be tested by taking a cut and then measuring both ends of the cut with a micrometer,
Not all works should be fastened between the two centers of the lathe.A short work may be turned without using the dead center,by simply chucking it properly at the spindle of the headstock.
Drills and Drilling Machines
The twist drill is a very efficient tool.It is generally formed by forging and twisting grooves in a flat strip of steel or by milling a cylindrical piece of steel,high-speed steel being commonly used.High-speed steel costs more but tools made of it withstand heat much better than those made of ordinary tool steel.
The twist drill may be divided into three principal parts:body,shank,and point.The flutes are the spiral grooves that are formed on the side of a drill,drills being made with two,three,or four flutes.Those having three or four flutes are used for following smaller drills or for enlarging holes already drilled,and are not suited for drilling into solid stock.
Spiral flutes have four main advantages:
(1) They give the correct rake to the lip of a drill.
(2) They cause the chip to curl so tightly that it occupies the minimum amount of space.
(3) They form channels through which chips escape from the hole.
(4) They allow the lubricant to flow easily down to the cutting edge.
The margin is the narrow strip on the cutting edge of the flute.It is
practically the full diameter of the drill and extends the entire length of the flute,its surface being a part of a cylinder.The portion of the body next to the margin is of less diameter than the margin.This lessened diameter,called body clearance,reduces the friction between the drill and the walls of the hole,while the margin insures the hole being of accurate size.
The shank is the end of the drill which fits into the socket,spindle,or chuck of the drill press.The tang is usually found only on tapered shank tools.
The drilling machine is the second oldest machine tools,having been invented shortly after the lathe,and is one of the most common and useful machines.The drilling machines may be classified into three general types:vertical spindle,multiple spindle,and radial spindle machine.The vertical spindle drilling machine comes in three types:heavy duty,plain,and sensitive.
Besides the drilling of holes,such operations may be performed on the drilling machine:drilling,tapping(internal threading),reaming(finishing the hole with a reamer),countersinking,counterboring,boring and
spot-facing.
Milling Machines
The milling machine is a machine that removes metal from the work with a revolving milling cutter as the work is fed against it.The milling cutter is mounted on an arbor where it is held in place by spacers or bushing.The arbor is fixed in the spindle with one end,while the other end of the arbor rotates in the bearing mounted on the arbor yoke.
The milling cutter are generally made from high speed steel and are available in different sizes and shapes.There are such kinds of milling cutters as cylindrical cutters,end milling cutters(for face milling),from milling cutters,angular,side and face cutter,slitting saw,ect.These
cutters may differ in the direction of their operation,i.e.they may cut revolving either clockwise or counter-clockwise.
Regular or irregular shaped work may be produced on a milling machine,designs varying according to the particular class of work wanted.According to the position of the spindle,the milling machines may be divided into two groups of vertical spindle milling machines and horizontal spindle milling https://www.doczj.com/doc/706795548.html,ling machines may be grouped into various classes.
According to the variation in general design as the"column and knee type",the manufacturing types,and the planner type of milling
machine.According to the table design,the milling machines may be classified as universal and plain milling machines.
The most important parts of the milling machine are starting levers,spindle,column,knee,elevating screw,table,index head,speed levers,feed movement,table movement levers,foot stock,arbor yoke.
The spindle of the milling machine is driven by an electric motor through a train of gears mounted in the column.The table of the plain milling machine may travel only at right angles to the spindle,while the universal milling machine is provided with a table that may be swiveled on the transverse slide for milling gear teeth,threads,ect.
Various attachments are used for increasing the range of work that can be performed on a milling machine.
The dividing head(also called an index head)is a device used to divide the periphery of a piece of work into any number of equal parts,and to hold the work in the required position while the cuts are being made.
Various kinds of vises may be used for holding the work in a milling machine,the most common being the plain vise,and the swivel vise.
The Planer
The planer is one of the biggest machine tools that employ a
reciprocating cutting action.It generates flat or contoured surfaces in a series of straight cuts.Its efficiency is higher than that of the shaper.
The work on the planer is held on the machine table and moves under the tool which is carried on the rail.The bed must be approximately twice as long as the table to support it at all positions during the stroke.The double-housing on one side only.Open-side planers are designed for
work-pieces which are so wide that they can pass between the housings of double-housing planers.The double-housing machine,however,offers greater rigidity.
Some of the work that was formerly done on the planer is now done on the planer-type milling machine since the former is not so efficient as the latter.However,there are still many jobs that can be carried out better and more economically on the planer than on any other machines.For example,angular surfaces are often easier to machine on a planer.Planning is also most effective in the machining of long and narrow surfaces.In addition,the planer usually takes the important first cut on the rough forging or casting to establish a reference surface for subsequent machining.
Grinding Machines
Grinding,or abrasive machine,is one of the most rapidly growing metal removal processes in manufacturing.Many machining operations,previously done on conventional milling machines,lathes and shapers,are now performed on various types of grinding machines.
There is a great variety of grinding machines.The machines that are generally used are cutter grinder,surface grinder,centerless
grinder,external grinder,internal grinder,and tool grinder.
Five types of grinding operations are performed on grinding machines:
（1）Surface grinding.Surface grinding are used to produce flat,angular and irregular surfaces.In the surface grinding process,the grinding wheel revolves on a spindle;and the workpiece,mounted on either a reciprocating or a rotary table,is brought into contact with the grinding wheel.
（2）Cylindrical grinding.Cylindrical grinding is the process of grinding the outside surface of a cylinder.These surfaces may be straight,tapered or contoured.Cylindrical grinding operations resemble lathe turning operations.They replace the lathe when the workpiece is hardened or when extreme accuracy and superior finish are required.As the workpiece revolves,the grinding wheel,rotating much faster in the opposite direction,is brought into contact with the part.The workpiece and table reciprocate while in contact with the grinding wheel to remove material.
（3）Centerless grinding.Centerless grinding machines eliminate the need to have center holes for the work or to use workholding devices.In centerless grinding,the workpiece rests on a workrest blade and is backed up by a second wheel,called the regulating wheel.The rotation of the grinding wheel pushes the workpiece down on the workrest blade and against the regulating wheel.The regulating wheel,usually made of a rubber bonded abrasive,rotates in the same direction as the grinding wheel and controls the longitudinal feed of the work when set at a slight angle.By changing this angle and the speed of the wheel,the workpiece feed rate can be changed.
（4）Internal grinding.Internal grinders are used to accurately finish straight,tapered or formed holes.The most popular internal grinder is similar in operation to a boring operation in a lathe.The work-piece is held by a workholding device,usually a chuck or collet,and revolved by a motorized headstock.A separate motor head in the same direction as the workpiece revolves the grinding wheel.It can be fed in and out of the work and also adjusted for depth of cut.
（5）Special grinding processes.Special types of grinders are grinding machines made for specific types of work and operations.A brief description
of the more commonly used special types follows:
Tool and cutter grinders:There grinding machines are designed to sharpen milling cutters,reamers,taps and other machine tool cutters.
The general purpose cutter grinder is the most popular and versatile tool grinding machine.Various attachments are available for sharpening most types of cutting tools.
Jig grinding machines:Jig grinders were developed to locate and accurately grind tapered or straight holes.Jig grinders are equipped with a high speed vertical spindle for holding and driving the grinding wheel.They utilize the same precision locating system as do jig borers.
Thread grinding machines:These are special grinders that resemble the cylindrical grinder.They must have a precision lead screw to produce the correct pitch,or lead,on a threaded part.Thread grinding machines also have a means of dressing or truing the cutting periphery of the grinding wheel so that it will produce a precise thread form on the part.
Boring Machine
Boring,also called internal turning,is used to increase the inside diameter of a hole.The original hole is made with a drill,or it may be a cored hole in a casting.Boring achieves three things:
Sizing:Boring brings the hole to the proper size and finish.
Straightness:Boring will straighten the original drilled or cast hole.
Concentricity:Boring will make the hole concentric with the outside diameter within the limits of the accuracy of the chuck or holding device.
The boring operation is generally performed in two steps;namely,rough boring and finish boring.The objective of the rough-boring operation is to remove the excess metal rapidly and efficiently,and the objective of the finish boring operation is to obtain the desired size,surface finish,and location of the hole .The size of the hole is obtained by using the trial-cut procedure.The diameter of the hole can be measured with inside calipers and
outside micrometer calipers.Basic Measuring Instruments,or inside micrometer calipers can be used to measure the diameter directly.
Shoulders,grooves,contours,taper,and threads are also bored inside of holes.Internal grooves are cut using a tool that is similar to an external grooving tool.The procedure for boring internal shoulders is very similar to the procedure for turning https://www.doczj.com/doc/706795548.html,rge shoulders are faced with the boring tool positioned with the nose leading,and using the cross slide to feed the tool.Internal contours can be machined using a tracing attachment on a lathe.The tracing attachment is mounted on the cross slide and the stylus follows the outline of the master profile plate.This caused the cutting tool to move in a path corresponding to the profile of the master profile plate.Thus,the profile on the master profile plate is reproduced inside the bore.The master profile plate is accurately mounted on a special slide which can be precisely adjusted in two directions,in order to align the cutting tool in the correct relationship to the work.Normal turning cuts are taken with the spindle rotating counterclockwise.The boring cut is taken with the spindle revolving in a clockwise direction,or "backwards".
红外数据通信技术外文翻译文献(文档含中英文对照即英文原文和中文翻译) Infrared Remote Control System Abstract Red outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique, drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos
etc. characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage. Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application. The purpose that design this system is transmit customer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish customer’s operation demand. Keywords: Infrared dray；Code；Decoding；LM386；Red outside transceiver 1 Introduction 1.1 research the background and significance Infrared Data Communication Technology is the world wide use of a wireless connection technology, by the many hardware and software platforms supported. Is a data through electrical pulses and infrared optical pulse switch between the wireless data transceiver technology.
通信工程专业英语翻译 JXTA is a crystallization by Sun company's chief scientist Bill Joy's more than twenty years of brewing."JXTA technology is a platform for Network programming and calculation.To solve the modern distribution calculation especially peer-to-peer (Peer to Peer, P2P) in the calculation of the problem".[1] JXTA research project,which will provide a new framework that make the user more convenient to access to connect on the Internet's personal computer resources, thus further expand Internet 's space. At the same time JXTA is also the Sun's "ONE Internet" strategic continuance, and will take a more positive attitude to compete with the .net strategy of Microsoft and Hailstorm plan . JXTA agreement defines a set of six agreement based on XML, the organization of node into node group, release and found some resources, communication and mutual monitoring provides standardized method.(Endpoint Routing Protocol,ERP) is used for node found routing.To send a message to other nodes, and through the potential firewall and connection.(Rendezvous Protocol,RVP) s used for the nodes in the group to spread information.(Peer Resolver Protocol,PRP) is Used to one or more points to send general inquiries, and receive the response of inquiries.
用于多跳认知无线电网络的分布式网络编码控制信道 Alfred Asterjadhi等著 1 前言 大多数电磁频谱由政府机构长期指定给公司或机构专门用于区域或国家地区。由于这种资源的静态分配，许可频谱的许多部分在许多时间和/或位置未使用或未被充分利用。另一方面，几种最近的无线技术在诸如IEEE802.11，蓝牙，Zigbee之类的非许可频段中运行，并且在一定程度上对WiMAX进行操作;这些技术已经看到这样的成功和扩散，他们正在访问的频谱- 主要是2.4 GHz ISM频段- 已经过度拥挤。为了为这些现有技术提供更多的频谱资源，并且允许替代和创新技术的潜在开发，最近已经提出允许被许可的设备（称为次要用户）访问那些许可的频谱资源，主要用户未被使用或零星地使用。这种方法通常被称为动态频谱接入（DSA），无线电设备发现和机会性利用未使用或未充分利用的频谱带的能力通常称为认知无线电（CR）技术。 DSA和CR最近都引起了无线通信和网络界的极大关注。通常设想两种主要应用。第一个是认知无线接入（CW A），根据该认知接入点，认知接入点负责识别未使用的许可频谱，并使用它来提供对次用户的接入。第二个应用是我们在这个技术中研究的应用，它是认知自组织网络（CAN），也就是使用 用于二级用户本身之间通信的无许可频谱，用于诸如点对点内容分发，环境监控，安全性等目的，灾难恢复情景通信，军事通信等等。 设计CAN系统比CW A有更多困难，主要有两个原因。第一是识别未使用的频谱。在CW A中，接入点的作用是连接到互联网，因此可以使用简单的策略来推断频谱可用性，例如查询频谱调节器在其地理位置的频谱可用性或直接与主用户协商频谱可用性或一些中间频谱经纪人另一方面，在CAN中，与频谱调节器或主要用户的缺乏直接通信需要二级用户能够使用检测技术自己识别未使用的频谱。第二个困难是辅助用户协调媒体访问目的。在CW A中存在接入点和通常所有二级用户直接与之通信（即，网络是单跳）的事实使得直接使用集中式媒体接入控制（MAC）解决方案，如时分多址（TDMA）或正交频分多址（OFDMA）。相反，预计CAN将跨越多跳，缺少集中控制器;而对于传统的单通道多跳自组织网络而言，这个问题的几个解决方案是已知的，因为假设我们处理允许设备访问的具有成
附录A Lathe fixture design and analysis Ma Feiyue (School of Mechanical Engineering, Hefei, Anhui Hefei 230022, China) Abstract: From the start the main types of lathe fixture, fixture on the flower disc and angle iron clamp lathe was introduced, and on the basis of analysis of a lathe fixture design points. Keywords: lathe fixture; design; points Lathe for machining parts on the rotating surface, such as the outer cylinder, inner cylinder and so on. Parts in the processing, the fixture can be installed in the lathe with rotary machine with main primary uranium movement. However, in order to expand the use of lathe, the work piece can also be installed in the lathe of the pallet, tool mounted on the spindle. THE MAIN TYPES OF LATHE FIXTURE Installed on the lathe spindle on the lathe fixture
5G无线通信网络中英文对照外文翻译文献(文档含英文原文和中文翻译)
翻译： 5G无线通信网络的蜂窝结构和关键技术 摘要 第四代无线通信系统已经或者即将在许多国家部署。然而，随着无线移动设备和服务的激增，仍然有一些挑战尤其是4G所不能容纳的，例如像频谱危机和高能量消耗。无线系统设计师们面临着满足新型无线应用对高数据速率和机动性要求的持续性增长的需求，因此他们已经开始研究被期望于2020年后就能部署的第五代无线系统。在这篇文章里面，我们提出一个有内门和外门情景之分的潜在的蜂窝结构，并且讨论了多种可行性关于5G无线通信系统的技术，比如大量的MIMO技术，节能通信，认知的广播网络和可见光通信。面临潜在技术的未知挑战也被讨论了。 介绍 信息通信技术（ICT）创新合理的使用对世界经济的提高变得越来越重要。无线通信网络在全球ICT战略中也许是最挑剔的元素，并且支撑着很多其他的行业，它是世界上成长最快最有活力的行业之一。欧洲移动天文台（EMO）报道2010年移动通信业总计税收1740亿欧元,从而超过了航空航天业和制药业。无线技术的发展大大提高了人们在商业运作和社交功能方面通信和生活的能力无线移动通信的显著成就表现在技术创新的快速步伐。从1991年二代移动通信系统(2G)的初次登场到2001年三代系统（3G）的首次起飞，无线移动网络已经实现了从一个纯粹的技术系统到一个能承载大量多媒体内容网络的转变。4G无线系统被设计出来用来满足IMT-A技术使用IP面向所有服务的需求。在4G系统中，先进的无线接口被用于正交频分复用技术（OFDM），多输入多输出系统（MIMO）和链路自适应技术。4G无线网络可支持数据速率可达1Gb/s的低流度，比如流动局域无线访问，还有速率高达100M/s的高流速，例如像移动访问。LTE系统和它的延伸系统LTE-A，作为实用的4G系统已经在全球于最近期或不久的将来部署。 然而，每年仍然有戏剧性增长数量的用户支持移动宽频带系统。越来越多的
毕业设计 外文翻译 题目曲轴的加工工艺及夹具设计学院航海学院 专业轮机工程 学生佟宝诚 学号 10960123 指导教师彭中波 重庆交通大学 2014年
Proceedings of IMECE2008 2008 ASME International Mechanical Engineering Congress and Exposition October 31-November 6, 2008, Boston, Massachusetts, USA IMECE2008-67447 MULTI-OBJECTIVE SYSTEM OPTIMIZATION OF ENGINE CRANKSHAFTS USING AN INTEGRATION APPROACH Albert Albers/IPEK Institute of Product Development University of Karlsruhe Germany Noel Leon/CIDyT Center for Innovation andDesign Monterrey Institute of Technology,Mexico Humberto Aguayo/CIDyT Center forInnovation and Design, Monterrey Institute ofTechnology, Mexico Thomas Maier/IPEK Institute of Product Development University of Karlsruhe Germany ABSTRACT The ever increasing computer capabilities allow faster analysis in the field of Computer Aided Design and Engineering (CAD & CAE). CAD and CAE systems are currently used in Parametric and Structural Optimization to find optimal topologies and shapes of given parts under certain conditions. This paper describes a general strategy to optimize the balance of a crankshaft, using CAD and CAE software integrated with Genetic Algorithms (GAs) via programming in Java. An introduction to the groundings of this strategy is made among different tools used for its implementation. The analyzed crankshaft is modeled in commercial parametric 3D CAD software. CAD is used for evaluating the fitness function (the balance) and to make geometric modifications. CAE is used for evaluating dynamic restrictions (the eigenfrequencies). A Java interface is programmed to link the CAD model to the CAE software and to the genetic algorithms. In order to make geometry modifications to
中英文翻译 附件1：外文资料翻译译文 通用移动通信系统的回顾 1.1 UMTS网络架构 欧洲/日本的3G标准，被称为UMTS。 UMTS是一个在IMT-2000保护伞下的ITU-T 批准的许多标准之一。随着美国的CDMA2000标准的发展，它是目前占主导地位的标准，特别是运营商将cdmaOne部署为他们的2G技术。在写这本书时，日本是在3G 网络部署方面最先进的。三名现任运营商已经实施了三个不同的技术：J - PHONE 使用UMTS，KDDI拥有CDMA2000网络，最大的运营商NTT DoCoMo正在使用品牌的FOMA（自由多媒体接入）系统。 FOMA是基于原来的UMTS协议，而且更加的协调和标准化。 UMTS标准被定义为一个通过通用分组无线系统（GPRS）和全球演进的增强数据
技术（EDGE）从第二代GSM标准到UNTS的迁移，如图。这是一个广泛应用的基本原理，因为自2003年4月起，全球有超过847万GSM用户，占全球的移动用户数字的68％。重点是在保持尽可能多的GSM网络与新系统的操作。 我们现在在第三代（3G）的发展道路上，其中网络将支持所有类型的流量：语音，视频和数据，我们应该看到一个最终的爆炸在移动设备上的可用服务。此驱动技术是IP协议。现在，许多移动运营商在简称为2.5G的位置，伴随GPRS的部署，即将IP骨干网引入到移动核心网。在下图中，图2显示了一个在GPRS网络中的关键部件的概述，以及它是如何适应现有的GSM基础设施。 SGSN和GGSN之间的接口被称为Gn接口和使用GPRS隧道协议（GTP的，稍后讨论）。引进这种基础设施的首要原因是提供连接到外部分组网络如，Internet或企业Intranet。这使IP协议作为SGSN和GGSN之间的运输工具应用到网络。这使得数据服务，如移动设备上的电子邮件或浏览网页，用户被起诉基于数据流量，而不是时间连接基础上的数据量。3G网络和服务交付的主要标准是通用移动通信系统，或UMTS。首次部署的UMTS是发行'99架构，在下面的图3所示。 在这个网络中，主要的变化是在无线接入网络（RAN的）CDMA空中接口技术的引进，和在传输部分异步传输模式作为一种传输方式。这些变化已经引入，主要是为了支持在同一网络上的语音，视频和数据服务的运输。核心网络保持相对不变，主要是软件升级。然而，随着目前无线网络控制器使用IP与3G的GPRS业务支持节点进行通信，IP协议进一步应用到网络。 未来的进化步骤是第4版架构，如图4。在这里，GSM的核心被以语音IP技术为基础的IP网络基础设施取代。 海安的发展分为两个独立部分：媒体网关（MGW）和MSC服务器（MSS）的。这基本上是打破外连接的作用和连接控制。一个MSS可以处理多个MGW，使网络更具有扩展性。 因为现在有一些在3G网络的IP云，合并这些到一个IP或IP/ ATM骨干网是很有意义的（它很可能会提供两种选择运营商）。这使IP权利拓展到整个网络，一直到BTS(基站收发信台)。这被称为全IP网络，或推出五架构，如图五所示。在HLR/ VLR/VLR/EIR被推广和称为HLR的子系统（HSS）。 现在传统的电信交换的最后残余被删除，留下完全基于IP协议的网络运营，并
编号： 毕业设计(论文)外文翻译 （译文） 学院：信息与通信学院 专业：通信工程 学生姓名： 学号： 指导教师单位：信息与通信学院 姓名： 职称： 2014年 2 月9 日 Radio network planning process and methods for WCDMA Abstract This paper describes the system dimensioning and the radio network planning methodology for a third generation WCDMA system. The applicability of each method is demonstrated using examples of likely system scenarios. The challenges of
modeling the multiservice environment are described and the implications to the system performance simulations are introduced. Keywords: Telecommunication network planning, Mobile radio- communication, Code division multiple access, Wide band transmission, Multiple service network, Dimensioning, Simulator, Static model, Dynamic model, Cellular network. Resume(?) Contents I.Introduction II. Initial planning, system dimensioning III. Detailed planning process IV. Example dimensioning case and verification of dimensioning with static simulations V. Comparison of a static to a dynamic network simulator VI. Conclusion INTRODUCTION As the launch of third generation technology approaches, operators are forming strategies for the deployment of their networks. These strategies must be supported by realistic business plans both in terms of future service demand estimates and the requirement for investment in network infrastructure. Evaluating the requirement for network infrastructure can be achieved using system dimensioning tools capable of assessing both the radio access and the core network components. Having found an attractive business opportunity, system deployment must be preceded by careful network planning. The network planning tool must be capable of accurately modeling the system behaviour when loaded with the expected traffic profile. The third generation cellular systems will offer services well beyond the capabilities of today's networks. The traffic profile, as well as the radio access technology itself form the two most significant challenges when dimensioning and planning a WCDMA based third generation system. The traffic profile describes the mixture of services being used by the population of users. There are also specific system functionalities which must be modelled including fast power control and soft handover. In order to accurately predict the radio coverage the system eatures associated with WCDMA must be taken into account in the network modeling process. Especially the channel characterization, and interference control mechanisms in the case of any CDMA system must be considered. In WCDMA network multiple services co-exist. Different services (voice, data) have different processing gains, Eb/N0 performance and thus different receiver SNR requirements. In addition to those the WCDMA coverage depends on the load characterization, hand over parameterization, and power control effects. In current second generation systems' coverage planning processes the base station sensitivity is constant and the coverage threshold is the same for each base station. In the case of WCDMA the coverage threshold is dependent on the number of users and used bit rates in all cells, thus it
2604130359 CNC Cutting Technology Review Numerical control high speed cutting technology (High Speed Machining, HSM, or High Speed Cutting, HSC), is one of the advanced manufacturing technology to improve the machining efficiency and quality, the study of related technology has become an important research direction of advanced manufacturing technology at home and abroad. China is a big manufacturing country, in the world of industry transfer to accept the front instead of back-end of the transfer, to master the core technology of advanced manufacturing, or in a new round of international industrial structure adjustment, our country manufacturing industry will further behind. Imminent research on the theory and application of advanced technology. 1, high-speed CNC machining meaning High speed cutting theory put forward by the German physicist Carl.J.Salomon in the last century and early thirty's. He concluded by a lot of experiments: in the normal range of cutting speed, cutting speed if the increase, will cause the cutting temperature rise, exacerbating the wear of cutting tool; however, when the cutting speed is increased to a certain value, as long as more than the inflection point, with the increase of the cutting speed, cutting temperature can not rise, but will decline, so as long as the cutting speed is high enough, it can be solved very well in high cutting temperature caused by tool wear is not conducive to the cutting problem, obtained good processing efficiency. With the development of manufacturing industry, this theory is gradually paid more attention to, and attracted a lot of attention, on the basis of this theory has gradually formed the field of high-speed cutting technology of NC, relatively early research on NC High-speed Machining Technology in developed countries, through the theoretical basis of the research, basic research and applied research and development application, at present applications have entered the substantive stage in some areas. The high-speed cutting processing category, generally have the following several kinds of classification methods, one is to see that cutting speed, cutting speed over conventional cutting speed is 5-10 times of high speed cutting. Also has the scholar to spindle speed as the definition of high-speed processing standards, that the spindle speed is higher than that of 8000r\/min for high speed machining. And from the machine tool spindle design point of view, with the product of DN diameter of spindle and spindle speed, if the value of DN to (5~2000) * 105mm.r\/min, is considered to be of high speed machining. In practice, different processing methods, different materials, high speed cutting speed corresponding to different. Is generally believed that the turning speed of (700~7000) m\/min, milling speed reaches m\/min (300~6000), that is in the high-speed cutting. In addition, from the practical considerations, high-speed machining concept not only contains the high speed cutting process, integration and optimization also contains the process of cutting, is a
毕业设计（论文）外文文献翻译 文献、资料中文题目：码分多址 文献、资料英文题目：Code division multiple access 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期：2017.02.14
外文原文 Code division multiple access Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. It should not be confused with the mobile phone standards called cdmaOne, CDMA2000 (the 3G evolution of cdmaOne) and WCDMA (the 3G standard used by GSM carriers), which are often referred to as simply CDMA, and use CDMA as an underlying channel access method. One of the concepts in data communication is the idea of allowing several transmitters to send information simultaneously over a single communication channel. This allows several users to share a band of frequencies (see bandwidth). This concept is called multiple access. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency. CDMA is a form of spread-spectrum signalling, since the modulated coded signal has a much higher data bandwidth than the data being communicated. Steps in CDMA Modulation Each user in a CDMA system uses a different code to modulate their signal. Choosing the codes used to modulate the signal is very important in the performance of CDMA systems. The best performance will occur when there is good separation between the signal of a desired user and the signals of other users. The separation of the signals is made by correlating the received signal with the locally generated code of the desired user. If the signal matches the desired user's code then the correlation function will be high and the system can extract that signal. If the desired user's code has nothing in common with the signal the correlation should be as close to zero as
A review and analysis of current computer-aided fixture design approaches Iain Boyle, Yiming Rong, David C. Brown Keywords: Computer-aided fixture design Fixture design Fixture planning Fixture verification Setup planning Unit design ABSTRACT A key characteristic of the modern market place is the consumer demand for variety. To respond effectively to this demand, manufacturers need to ensure that their manufacturing practices are sufficiently flexible to allow them to achieve rapid product development. Fixturing, which involves using fixtures to secure work pieces during machining so that they can be transformed into parts that meet required design specifications, is a significant contributing factor towards achieving manufacturing flexibility. To enable flexible fixturing, considerable levels of research effort have been devoted to supporting the process of fixture design through the development of computer-aided fixture design (CAFD) tools and approaches. This paper contains a review of these research efforts. Over seventy-five CAFD tools and approaches are reviewed in terms of the fixture design phases they support and the underlying technology upon which they are based. The primary conclusion of the review is that while significant advances have been made in supporting fixture design, there are primarily two research issues that require further effort. The first of these is that current CAFD research is segmented in nature and there remains a need to provide more cohesive fixture design support. Secondly, a greater focus is required on supporting the detailed design of a fixture’s physical structure. 2010 Elsevier Ltd. All rights reserved. Contents 1. Introduction (2) 2. Fixture design (2) 3. Current CAFD approaches (4) 3.1 Setup planning (4) 3.1.1 Approaches to setup planning (4) 3.2 Fixture planning (4) 3.2.1 Approaches to defining the fixturing requirement (6) 3.2.2 Approaches to non-optimized layout planning (6) 3.2.3 Approaches to layout planning optimization (6) 3.3 Unit design (7) 3.3.1 Approaches to conceptual unit design (7)