中國(guó)地質(zhì)大學(xué)長(zhǎng)城學(xué)院本科畢業(yè)設(shè)計(jì)外文資料翻譯系 別： 工程技術(shù)系 專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 姓 名： 王碩 學(xué) 號(hào)： 05211611 2015年 4 月 4 日1機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯附錄一Drilling and Milling MachinesUpright drilling machines or drill presses are available in a variety of sizes and types, and are equipped with a sufficient range of apindle speeds and automatic feeds to fit the neds of most industries. Speed ranges on a typical machine are from 76 to 2025 rpm., with drill feed from 0.002 to 0.020 in.per revolution of the spindle.Radial drilling machines are used to drill workpieces that are too large or cumbersome to conveniently move. The spindle with the speed and feed changing mechanism is mounted on the radial arm; by combining the movement of the radial arm around column and the movement of the spindle assembly along the arm, it is possible to align the spindle and the drill to any position within reach of the machine. For work that is too large to conveniently support on the base, the spindle assembly can be swung out over the floor and the workpiece set on the beside the machine. Plain radial drilling machines provide only for vertical movement of the spindle; universal machines allow the spindle to swivel about an axis normal to the radial arm and the radial arm to rotate about a horizontal axis, thus permitting drilling at any angle.A multispindle drilling machine has one or more heads that drive the spindles through universal joints and telescoping splined shafts. All spindles are usually driven by the same motor and fed simultaneously to drill the desired number of holes. In most machines each spindle is held in an adjustable plate so that it can be moved relative to the others. The area covered by adjacent spindles overlap so that the machine can be set to drill holes at any location within its range.The milling operation involves metal removal with a rotating cutter. It includes removal of metal from the surface of a workspiece, enlarging holes, and form cutting, such as threads and gear teeth.Within an knee and column type of milling machine the column is the main supporting member for the other components, and includes the base containing the drive motor, the spindle, and the cutters. The cutter is mounted on an arbor held in the spindle, and supported on its outer extremity by a bearing in the overarm. The knee is held on the column in dovetail slots, the saddle is fastened to the knee in dovetail slots, and the table is attached to the saddle. Thus, the build-up the knee and column 2機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯machine provides three motions relative to the cutter. A four motion may be provided by swiveling the table around a vertical axis provided on the saddle.Fixed-bed milling machines are designed to provide more rigidity than the knee and column type. The table is mounted directly on the machine base, which provides the rigidity necessary for absorbing heavy cutting load, and allows only longitudinal motion to the table. Vertical motion is obtained by moving the entire cutting head.Tracer milling is characterized by coordinated or synchronized movements of either the paths of the cutter and tracing elements, or the paths of the workpiece and model. In a typical tracer mill the tracing finger follow the shape of the master pattern, and the cutter heads duplicate the tracer motion.The following are general design considerations for milling:1. Wherever possible, the part should be designed so that a maximum number of surfaces can be milled from one setting.2. Design for the use of multiple cutters to mill several surfaces simultaneously.3. The largest flat surface will be milled first, so that all dimensions are best referred to such surface.4. Square inside corners are not possible, since the cutter rotates.Grinding Machines and Special Metal-removal ProcessRandom point-cutting tools include abrasives in the shape of a wheel, bonded to a belt, a stick, or simply suspended in liquid. The grinding process is of extreme importance in production work for several reasons.1.It is most common method for cutting hardened tool steel or other heat-treated steel. Parts are first machined in the un-heat-treated condition, and then ground to the desired dimensions and surface finish.2.It can provide surface finish to 0.5m without extreme cost.3.The grinding operation can assure accurate dimensions in a relatively short time, since machines are built to provide motions in increments of ten-thousandths of an inch, instead of thousandths as is common in other machines. 4.Extremely small and thin parts can be finished by this method, since light pressure is used and the tendency for the part to deflect away from the cutter is minimized.On a cylindrical grinding machine the grinding wheel rotates between 5500 and 6500 rpm., while the work rotates between 60 and 125 rpm. The depth of cut is 13機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯controlled by moving the wheel head, which includes both the wheel and its drive motor. Coolants are provided to reduce heat distortion and to remove chips and abrasive dust.Material removal from ductile materials can be accomplished by using a tool which is harder than the workpiece. However during Word War the widespread use of materials which were as hard or harder than cutting tools created a demand for new material-removal methods. Since then a number of processes have been developed which, although relatively slow and costly, can effectively remove excess material in a precise and repeatable fashion. There are two types of processes. The first type is based on electrical phenomena and is used primarily for hard materials; the second depends upon chemical dissolution. Chemical milling is controlled etching process using strong alkaline or acid etchants. Aluminum, titanium, magnesium, and steel are the principal metals processed by this method. The area to remain untouched by the etchant are masked with a protective coating. For example, the entire part may be dipped in the masking material and the mask removed from those areas to be etched, or a chemically resistant prescribed time, after which the part is rinsed in cold water, the masking removed, the part inspected, and thoroughly cleaned.There are certain disadvantages to consider. Metal will erode equally in all directions, so that walls of the etched section will have a radius equal to the depth of etch. A second disadvantage is that a better finish is obtained on surfaces parallel to the direction of rolling of a sheet than on surface perpendicular to the direction of rolling. This can be compared to the surface obtained when working wood parallel to, or across the grain. A third disadvantage, not unique with this process, is the warpage that will occur in thin, previously stressed sections etched on just one side.Chemical milling, however, has many advantages over conventional metal-removal methods. There is no warpage of heavy sections such as forgings or extrusions when the etchant is applied simultaneously to all sides for reduction of section thickness. In conventional milling only one side can be worked at a time, and frequent turning of a part is necessary to prevent warpage. Chemical milling can be applied to parts of irregular shape where conventional milling may be very difficult. Light-weight construction can be obtained with chemical milling by the elimination of welding, riveting, and stiffeners; parts can be contoured to distribute the load in the most suitable manner. As an example of the potential savings of this process, as compared to machine milling, one company reports that the cost of removing 14機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯aluminum by chem.-milling is $0.27 per pound as compared to $1.00 per pound by conventional milling. The rate of metal removal for chem.-milling is 0.001in. for aluminum.Electric-discharge machining is a process in which an electrical potential is impressed between the workpiece and the tool, and the current, emanating from a point source on the workpoiece, flows to the tool in the form of a spark. The forces that accomplish the metal removal are within the workpiece proper and, as a result, it is not necessary to construct the unit to withstand the heavy pressures and loads prevalent with conventional machining methods.The frequency of the electrical discharge ranges from 20,00 cps (cycles per second) for rough machining, to 50,000 cps for finishing such items as hardened tools and dies. The current may vary from 50 amp, during rough machining, to as low as 0.5 amp, during finishing. The process is currently applied to the machining of single-point tools, form tools, milling cutters, broaches, and die cavities. It is also applicable to the removal of broken drills, taps, and studs without damaging the workpiece in which the broken tool is imbedded. Other uses are the machining of oil holes in a hardened part, and the machining of small safety-wire holes in the heads of special alloy bolts, such as titanium.The ultrasonic machining process is applied to both conducting and non-conducting material, and relies entirely upon abrasive action for metal removal. The workpiece is submerged in slurry of finely fivided abrasive particles in a vehicle such as water. The tool is coupled to an oscillator and vibrates at frequencies between 15,000 and 30,000 cps. The vibrating tool cavitates the liquid, and the force drives the abrasive into the surface of the workpiece to remove metal chips which are carried away by the liquid. The acceleration given the abrasive grains is as much as 100,000 times the acceleration of gravity, providing a smooth and rapid cutting force.Introduction of MachiningMachining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece. Low setup cost for small quantities. Machining has tow applications in 15機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯manufacturing. For casting, forging, and pressworking, each specific shape to be p5roduced, even one part, nearly always has a high tooling cost. The shapes that may be produced, even one part, nearly always has a high tooling cost. The shapes that may be produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, bu machining, to start with nearly any form of any material, so long as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore, machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or pressworking if a high quantity were to be produced.Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many pars are given shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in pressworked parts may be machined following the pressworking operations.16機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯鉆床和銑削直式鉆床或鉆孔式印刷機(jī)可用于各種尺寸和種類，它能安裝軸速度的足夠范圍和自動(dòng)運(yùn)轉(zhuǎn)以適應(yīng)大多工業(yè)的要求。一個(gè)典型機(jī)器的速度范圍是70至2025rmp，以及鉆孔的運(yùn)轉(zhuǎn)速度是0.002到0.020英尺。旋轉(zhuǎn)鉆床用來(lái)鉆那些太大或太笨重的而不能夠移動(dòng)的工件。通過(guò)將轉(zhuǎn)臂繞立柱的轉(zhuǎn)動(dòng)和主軸組件沿轉(zhuǎn)臂的移動(dòng)組合，可使主軸鉆頭對(duì)準(zhǔn)機(jī)床可達(dá)范圍內(nèi)的任何位置，由于運(yùn)轉(zhuǎn)太大而不方便建立在此基礎(chǔ)上，主軸能夠在垂直的地上方搖擺以及工件能固定在機(jī)器旁邊的地上。普通的旋臂鉆床只提供軸的垂直運(yùn)動(dòng)和徑向轉(zhuǎn)臂，通過(guò) 軸來(lái)運(yùn)轉(zhuǎn)。此 鉆頭 于任何一個(gè) 度。一個(gè)多軸通過(guò) 能 和可 的 軸來(lái) 動(dòng)的鉆床 一個(gè)或多個(gè)頭。通 的軸 是通過(guò) 的 動(dòng)機(jī)來(lái) 動(dòng)和 運(yùn)轉(zhuǎn)， 的是鉆 的 。 多鉆床的 個(gè)軸在一個(gè)可的，以便currency1 “的件移動(dòng)。 的軸重fi的fl 的使機(jī)器能夠在它的范圍的任何地方鉆孔。床轉(zhuǎn)動(dòng)的”和移動(dòng) “。它 一個(gè)工件的 移動(dòng)， 的大和型”，和。 機(jī)床的 式柱是currency1件的主要fi。 動(dòng)機(jī)的基礎(chǔ)，軸工 。工 固定在在主軸的 上能過(guò)一個(gè) 臂的軸 在它的外的 。 通過(guò) 動(dòng) 立柱和立柱機(jī)器，提供一種工 “的 向。 一種 向可能是工 由提供的 圍繞 軸旋轉(zhuǎn)而到的。固定的 機(jī)床的設(shè)計(jì) 的是 或立柱提供 大的 度。工 直 固定在機(jī) 的 ，它能大提供度的 要。而 對(duì)工徑度的方向。垂直運(yùn)動(dòng)是通過(guò)移動(dòng)個(gè)工 能達(dá)到。型床的 是 和 件的 運(yùn)動(dòng)的 或 ，或是工件或型的運(yùn)動(dòng)的 或 典型的 型床的 型 是 型的形式，而 機(jī)頭fi fi 。下是”的總體的設(shè)計(jì) 錄：1.果可能的話，零件將被設(shè)計(jì)以便在一個(gè)工位上最大的 能被”。2.對(duì)選擇性的工 的設(shè)計(jì) 的是 ”幾個(gè) 。17機(jī)械設(shè)計(jì)制造及自動(dòng)化專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯3.應(yīng)當(dāng)首先最大的 ，這樣 的尺寸 能 好的參 這個(gè) 。4. 工 的轉(zhuǎn)動(dòng)， 形的各個(gè) 落是不可能的。刺耳的機(jī)器和特殊的金屬移動(dòng)程序隨機(jī)” 構(gòu)子形狀的，或粘結(jié)到帶子或棍子上或直 浮在液體 的研磨材料。 幾個(gè)原 研磨進(jìn)程在工件的生產(chǎn) 重要。對(duì)”硬化的 鋼材料或currency1的熱 鋼材來(lái)講它是最普通的方法。零件在沒(méi) 熱 條件下第一次機(jī)器，然后到 的尺度和 光潔度。它能在沒(méi) 極限范疇 提供 光潔度達(dá)0.5微米。研磨在 對(duì)較短的 間內(nèi)能確保精確的尺度， 機(jī)器在currency1它機(jī)器的一般精度構(gòu)造 提供的動(dòng)態(tài)是 英尺增加百fi之一的精度，而不是千fi之一。尤currency1是小而細(xì)的零件能用這個(gè)方法完，由于輕壓力被使用和零件的柔韌性 折射 的”值是最小的。研磨子在圓柱形的研磨機(jī)器上在5500和6500rmp之間轉(zhuǎn)動(dòng)，當(dāng)工件在60和125rmp之間轉(zhuǎn)動(dòng) ，”的深度運(yùn)動(dòng)由木頭控制，它 子和它的 動(dòng)動(dòng)機(jī)。冷卻液用來(lái)低熱扭曲和移動(dòng)”以及研磨材料 的灰塵。韌性的材料的運(yùn)動(dòng)通過(guò)那些材質(zhì)硬的 來(lái)完，但是在二戰(zhàn)期間材料的廣泛傳播使用，它新材料運(yùn)動(dòng)方法的” 的要求 高。 大 的過(guò)程被改進(jìn)，盡管 當(dāng)慢 費(fèi)高，它能用精確 受的方式來(lái)移動(dòng)過(guò) 的材料，這 兩種進(jìn)程式：第一種類型是建立在