机械工程英语 最终无敌词典.doc

考试必备(1)Engine lathes(1)普通车床(2)Toolroom lathes(2)万能车床(3)Turret lathes(3)转塔车床(4)Vertical turning and boring mills(4)立式车床(5)Automatic lathes(5)自动车床(6)Special-purpose lathes(6)特殊车床A bilateral tolerance is one where the tolerance range is disposed on both sides of the nominal dimension. 双向公差是在公称尺寸两侧都有公差带的公差。A bulk of the remaining sand and cores can be removed by mechanically striking the part. 大量的剩余型砂和砂芯要通过机械敲击零件来去除。A ceramic is often broadly defined as any inorganic nonmetallic material陶瓷通常被概括地定义为无机的非金属材料。A chip is variable both in size and shape in actual manufacturing practice. 在实际加工过程中切屑的尺寸和形状都是变化的。A compaction stage is typically used to ensure good coverage and solid molds. 通常要采取压紧步骤来保证良好的覆盖和坚固的铸型。A distinction may be made between open-die forging, usually in the form of hammer forging, and closed-die forging. 锤锻中常用的开式模锻与闭式模锻是有区别的。A drill jig is a device for ensuring that a hole to be drilled, tapped, or reamed in a workpiece will be machined in the proper place.钻模是一种确保在工件正确位置进行钻孔、攻丝或铰孔加工的装置。A fixture holds the work during machining operations but does not contain special arrangements for guiding the cutting tool ,as drill jigs do.夹具在机加工作业时夹持工件，但它不象钻模那样包含引导切削刀具的特殊布置。A football player counts on this when he trusts that his facemask wont shatter.橄榄球运动员据此相信他的面罩不会裂成碎片。A forged metal can result in the following: 锻造金属可以导致下列结果：A glass is an inorganic nonmetallic material that does not have a crystalline structure. 玻璃是没有晶体状结构的无机非金属材料。A good procedure to follow is to heat-quench a number of small specimens of the steel at various temperatures and observe the result, either by hardness testing or by microscopic examination. 要遵循的合适步骤是将这种钢的一些小试件加热到不同的温度后淬火，再通过硬度试验或显微镜检查观测结果。A hole in the body acts as a conduit to transmit coolant under considerable pressure to the tip of the drill.钻头体中有个孔作为导管在相当大的压力下将冷却液传送到钻头顶端。A host of suppliers of auxiliary equipment, molds, instruments, and controls service this major segment of the polymer industry许多辅助设备、模具、仪器和控制系统供应商在为聚合物工业的这一主要部分服务。A large majority (above 80%) of all the machine tools used in the manufacturing industry have undergone metal cutting. (2) 用于制造业的全部机床中的大多数(多于80%)都经历过金属切削。A large variety of cutting tool materials has been developed to cater to the variety of materials used in these programmes. 多种切削刀具材料被开发出来以满足这些方案中使用材料的多样性。A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges.车床是主要用于生成旋转表面和平整边缘的机床。A machine with a 10,000-ton capacity has been built to mold 264-gallon HDPE trash containers. 一台能力为10,000吨用于成型264加仑高密度聚乙烯垃圾箱的机械也已制成。 A machining (finish) allowance is made for this type of defect. 对这类缺陷采用机加工(最后一道工序)的余量。A modern lathe usually has a quick-change gearbox located under the headstock and driven from the spindle through a train of gears. 现代车床一般在主轴箱下装备快速变换齿轮箱，通过一系列齿轮由主轴驱动。A number of attempts have been made in understanding the metal cutting process and using this knowledge to help improve manufacturing operations which involved metal cutting. 在了解金属切削过程并运用这些知识帮助改善与金属切削有关的制造作业方面已经做了许多努力。A number of developments have occurred in the current century. 在最近的百年里产生了许多进展。A part has many voids that can be impregnated. 零件有许多可供填充的空间。 A part surface can be infiltrated with a low melting point metal to increase density, strength, hardness, ductility and impact resistance.Plating, heat treating and machining operations can also be used.零件表面能被低熔点金属渗透以增大密度、强度、硬度、延展性和抗冲击能力。仍然可以进行电镀、热处理和机加工作业。A piece of hot metal sufficient to slightly overfill the die shape is placed in the bottom die, and the top die is forced against it, so that the metal takes the internal shape of the die. 将一块大小足以充填模腔并能稍有溢出的加热金属放入底模，并将顶模加压合拢，这块金属便获得该模腔的形状。A polymer has a repeating structure, usually based on a carbon backbone. 聚合物具有一般是基于碳链的重复结构。A proper lubricant is necessary for making good forgings. 制造良好的锻件必须有合适的滑润剂。A range of atmospheres, including vacuum, are used to sinter different materials depending on their chemical compositions. 根据不同材料的化学成分，烧结的环境包括真空状态也各不相同。A reciprocating screw injection molding machine combines the functions of an extruder and a compressive molding press.往复螺旋注射成型机把压出机和成型压力机的功能结合起来。A riser is an extra void created in the mold to contain excessive molten material. 冒口是在铸模内部增加的额外空间，用于容纳过多的熔化金属。A Second pressing operation, repressing, can be done prior to sintering to improve the compaction and the material properties.在烧结前可以进行二次挤压作业(再挤压)以改善压实状态和材料性能。A shaft might have a nominal size of 2.5in.(63.5mm), but for practical reasons this figure could not be maintained in manufacturing without great cost. 一根轴可能的名义尺寸为2.5in.(63.5mm)，但由于实际原因不用大成本是不能在制造中保持这个数字的，因此要增加确定的公差。 A similar technique is to “glue” the small percentage of alloying element onto the iron powder. 另一种类似的技术是把小百分比的合金元素“粘合”到铁微粒上。A simplified diagram, such as the one in Fig.2.1, focuses on the eutectoid region and is quite useful in understanding the properties and processing of steel. 如图2.1所示的简化铁碳状态图将焦点集中在共析区，这对理解钢的性能和处理是十分有用的。A Simplified Iron-carbon Diagram简化铁碳状态图A single full turn of the workpiece generates a circle whose center falls on the lathe axis; this motion is then reproduced numerous times as a result of the axial feed motion of the tool.工件旋转一整圈产生一个圆心落在车床主轴上的圆；由于刀具的轴向进给运动这种动作重复许多次。A steel with varying carbon content and, consequently, different critical temperatures requires a special heat treatment. 含碳量变化的钢具有不同的临界温度，因此需要特殊的热处理。A substantial precipitation of cementite begins at 600(315), which produces a decrease in hardness. 渗碳体的大量析出开始于600(315)，这使硬度下降。A system of tolerances is necessary to allow for the variations in accuracy that are bound to occur during manufacture, and still provide for interchangeability and correct function of the part.为了允许在制造过程中必然会发生的精度变化，并提供零件的互换性和正确功能，一个公差系统是必需的。A third tempering treatment may be used to reduce strains.第三次回火处理可用于减少应变。A tolerance is the difference in a dimension in order to allow for unavoidable imperfections in workmanship. 公差是为了允许工艺上不可避免缺陷而存在的尺寸上的不同。 A typical cutting tool in simplified form is shown in Fig.7.1. The important features to be observed are follows. 典型切削刀具的简化形式如图7.1所示。要注意的重要特征如下A unilateral tolerance is one where the tolerance zone is on one side only of the nominal dimension, in which case the nominal dimension may form one of the limits.单向公差是仅在公称尺寸一侧有公差带的公差，在这种情况下公称尺寸成了两个极限中的一个。A variation from this type is planetary internal grinding, which is recommended for heavy workpieces that cannot be held in chucks. 这种方法的一个变体是行星式内表面磨削，当工件较重不能用卡盘固定时推荐使用。A very large clearance angle reduces the strength of the tool tip, and hence normally an angle of the order of 56is used.很大的后角会削弱刀尖的强度，因此一般采用56的后角。A wide variety of milling cutters is available in industry. 工业上可采用的铣刀类型众多。Above this point the hardness can be increased only slightly, because steels above the eutectoid point are made up entirely of pearlite and cementite in the annealed state. 高于此点，由于超过共析点钢完全由珠光体和退火状态的渗碳体组成，硬度增加并不多。Abrasive disks for cutoff and slotting operations. (thickness 0.02 up to 0.2in. (0.5 to 5mm). 4)用于切断和开槽作业的砂轮片(其厚度从0.02到0.2英寸(0.5到5毫米)。According to the procedure used, steel can be hardened to resist cutting action and abrasion, or it can be softened to permit machining. 按所采用的步骤，钢可以通过硬化来抵抗切削和磨损，也可以通过软化来允许机加工。Accuracy is ensured by machining suitable location features as early as possible, and using them for all location, unless other considerations mean that other location features must be used. 除非有必要采用另外定位要素的其它考虑，精度可通过尽可能早地加工合适的定位要素并采用它们进行所有定位来保证。Actually, analysis of photomicrographs shows that this built-up edge is held in place by the static friction force until it becomes so large that the external forces acting on it cause it to dislodge, with some of it remaining on the machined surface and the rest passing off on the back side of the chip, Fig.7.3c. 实际上，对显微照片的分析显示这种切屑瘤受到静摩擦力抑制直至它变得大到作用在它上面的外力使其移动，一些留在机加工表面上而另一些延伸到切屑的背面，见图7.3c。Adding other metals can affect the density, strength, fracture toughness, plastic deformation, electrical conductivity and environmental degradation.加一些其它金属能影响密度、强度、断裂韧性、塑性变形、导电性以及环境侵蚀。Additional tables give the values for basic sizes above 500 mm and for “Commonly Used Shafts and Holes” in two categories“General Purpose” and “Fine Mechanisms and Horology”.对基本尺寸大于500毫米和在“一般用途”和“精密机械和钟表”两个类别中的“常用的轴和孔”而言，由附加的表格给出数值。Additionally there are extensions to the gating system called vents that provide the path for the built-up gases and the displaced air to vent to the atmosphere. 除此之外，还有称为排放口的浇注系统延长段，它为合成气体和置换空气排放到大气提供通道。Advantages优点After compaction the components pass through a sintering furnace. 零件压实后通过烧结炉。After injection moulding, the plastic binder material is removed to leave a metal skeleton which is then sintered at high temperature. 注塑成型后，去除塑料粘合材料剩下金属骨架，然后在高温下烧结。After the workpiece has been marked out, it is still necessary to position it with respect to the machine movements, and to clamp it in that position before machining is started.工件划线后，仍有必要将其相对于切削运动定位，并在机加工开始前把它装夹到位。After this, the entire pattern is placed in an oven and the wax is melted away. 完成后把整个型模放在烤箱里融化石蜡。Again, at economical working pressures, products are not fully dense and usually need additional working such as hot extrusion, hot rolling or forging to fully density the material.此外使用经济工作压力的产品不是充分致密的，一般需要增加诸如热挤压、热轧或锻之类的额外工序来使材料达到全密度。Again, recommended values for feeds, which can be taken as guidelines, are found in handbooks and in information booklets provided by cutting tool manufacturers.再者，作为指导方针的进给推荐值可以从手册和切削刀具生产商提供的资料小册子上找到。Alignment pins may also be used for mating the molds later. 为了以后铸模匹配还要用到定位销。All dimensions must be governed by the general tolerance on the drawing unless otherwise stated. 除非另行说明，所有尺寸都必须受图上的通用公差控制。All these characteristics may not be found in a single tool material. Improved tool materials have been giving a better cutting performance. 所有这些特性不可能存在于单一刀具材料中。改进的刀具材料已经被赋予较好的切削性能。Allowance, which is sometimes confused with tolerance, has an altogether different meaning. 允差，有时会跟公差混淆，但其具有完全不同的含义。 Alloy steel owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadium, and copper. 合金钢的性质取决于其所含有的除碳以外的一种或多种元素，如镍、铬、锰、钼、钨、硅、钒和铜。Alloys are compounds consisting of more than one metal. 合金是由一种以上金属组成的混合物。Alloys contain more than one metallic element. 合金包含不止一种金属元素。Also coating operations such as plating or painting are straightforward due to a good surface, which needs very little preparation. 另外由于锻件良好的表面，像电镀或油漆之类的涂装工序就很简单，几乎不需要做准备工作。Also, adding some chromium to steel will slow the rusting process, but will make it more brittle.同样，在钢里加一些铬能减缓它的生锈过程，但也将使它更脆。Also, that hole has a tapered surface to allow mounting a plain lathe center. 同时，此孔为锥形表面可以安装普通车床顶尖。Also, the grinding action in this case is achieved by the end face of the grinding wheel (Fig.8.1b), contrary to the case of horizontal-spindle machines, where the workpieces ground by the periphery of the grinding wheel. 而且在这种情况下，磨削动作是通过砂轮端面完成的(图8.1b)，这与通过砂轮周边磨削工件的卧式主轴磨床正好相反。 Also, the plane angles of these tools must always be identical to those of the thread forms. 同时，这些刀具的平面角必须始终与螺纹形状的平面角保持一致。Altering the Surfaces改变表面Although most of the softening action occurs in the first few minutes after the temperature is reached, there is some additional reduction in hardness if the temperature is maintained for a prolonged time. 虽然大多数软化作用发生在达到所需温度后的最初几分钟，但如果此温度维持一段延长时间，仍会有些额外的硬度下降。Although small tolerances give higher quality work and a better operating mechanism, the cost of manufacture increases rapidly as the tolerances are reduced, as indicated by the typical curve of Fig14.1. 虽然较小公差能得到较高加工质量和较好操作机构，但随着公差的减小制造成本会迅速增加，如图14.1的典型曲线所示。Although the hydraulic forging press is a more expensive piece of equipment than a drop-forge, it has advantages beside those of giving greater strength and more uniform structure to large components. 虽然这种液压锻机比落锤锻造要昂贵得多，但它除了能给予大零件较高的强度和更均匀的组织外还有其它优点。Although this process softens steel, it differs considerably from annealing in that the process lends itself to close control of the physical properties and in most cases does not soften the steel to the extent that annealing would. 虽然这过程使钢软化，但它与退火是大不相同的，因为回火适合于严格控制物理性能并在大多数情况下不会把钢软化到退火那种程度。Aluminum in the range of 1% to 1.5% has proved to be especially suitable in steel, in that it combines with the gas to form a very stable and hard constituent. 在钢中含铝1%到1.5%被证明特别合适，它能与氨气结合形成很稳定坚固的成分。An advantage of carbonitriding is that the hardenability of the case is significantly increased when nitrogen is added, permitting the use of low-cost steels.碳氮共渗的优点之一是加入氮后外层的淬透性极大增加，为使用低价钢提供条件。An analogy car, be made to a block of ice that can be softened (i.e. turned back to liquid), poured into any shape cavity, and then cooled to become a solid again.一辆由冰块制成的模拟汽车，可以融化(即转化为液态)，倒入任何形状的空腔，然后冷却重新变成固体。An elevated temperature diffusion process referred to as sintering, sometimes assisted by external pressure, accomplishes this. 提升温度扩散工艺被称为烧结，有时还辅之以外界的压力来达到目的。An estimate showed that about 10 to 15% of all the metal produced in USA was converted into chips. (3) 有估计显示美国生产的所有金属中约10到15%转变成了切屑。An example of particle-reinforced composites is an automobile tire which has carbon black particles in a matrix of polyisobutylene elastomeric polymer.微粒加强型复合材料的一个例子是机动车胎，它就是在聚异丁烯人造橡胶聚合物基材中加入了碳黑微粒。An HSS tool is usually made in the form of a single piece, contrary to cemented carbides or ceramic, which are made in the form of tips. 高速钢刀具通常以单件形式制造，而硬质合金或陶瓷刀具则以刀尖形式制造。An optical fiber contains three layers: a core made of highly pure glass with a high refractive index for the light to travel, a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other surface imperfections, and an out polymer jacket to protect the fiber from damage. 光导纤维有三层：核心由高折射指数高纯光传输玻璃制成，中间层为低折射指数玻璃，是保护核心玻璃表面不被擦伤和完整性不被破坏的所谓覆层，外层是聚合物护套，用于保护光导纤维不受损。And cleaning operations may be used to remove oxides, etc. 可能还要用清洗作业去除氧化物等。and components can be produced with dimensions that need little or no rectification to meet the dimensional tolerances. 所以零件尺寸几乎无需校正就能满足尺寸公差。Angle milling cutter. An angle milling cutter is employed in cutting dovetail grooves, ratchet wheels, and the like. Fig.12.4e indicates a milling cutter of this type.倾斜铣刀：倾斜铣刀用于切削燕尾槽、棘轮之类的。图12.4e显示了这类铣刀。Annealing also relieves internal stresses previously set up in the metal.退火也释放了先前在金属中的内应力。Annealing 退火Another advantage is that skilled workers are not required when jigs are used. 另一个优点是采用钻模时不需要熟练工人。Any carbon-rich gas with ammonia can be used. The wear-resistant case produced ranges from 0.003 to 0.030 inch(0.08 0.76mm) in thickness. 可以使用任何富碳气体加氨气，能生成厚度从0.003到0.030英寸(0.08 0.76mm)的耐磨外层。Any desired depth of cut can be obtained by the cross feed of the grinding wheel. 通过砂轮的横向进给能得到任意所需的切削深度Any point on the parting surface should be less than 75from the principal parting plane. 分模面上任意点与主分模面的夹角应小于75。application of cutting fluid(3)切削液的运用ARCA pair of wires are electrically energized so that an arc is struck across the tips when brought together through a pistol. 电弧喷涂当一对金属丝通过手持喷枪连到一起时，通上电横过其末端划燃电弧。As a general rule both mechanical and physical properties improve with increasing density. 作为普遍规律，随着密度的增加机械和物理性能均改善。As a replenishment for these deposited ions, the metal from the anode is dissolved and goes into the solution and balances the ionic potential.作为这些沉淀离子的补充，来自阳极的金属被溶解并进入溶液平衡离子势能。As an example, precise atmosphere control allows iron/carbon materials to be produced with specific carbon compositions and mechanical properties.例如精确的环境控制可使铁/碳材料生成特殊碳化物和机械性能。As before, any remaining austenite transforms to pearlite upon slow cooling through this temperature.就像以前说的一样，当缓慢冷却到这温度时所有剩余奥氏体转化为珠光体。As can be seen in Fig.12.1, the two cutting edges are referred to as the lips, and are connected together by a wedge, which is a chisel-like edge. 如图12.1所示，两条切削刃就是钻唇，通过凿子状边缘的楔形体连在一起。As can be seen in Fig.8.4, the axis of the regulating wheel is tilted at a slight angle with the axis of the grinding wheel. 正如在图8.4中所看到的那样，调节轮的轴与砂轮轴倾斜一个微小角度。As engineers, we usually design materials so that they dont deform under normal conditions. 作为工程师，设计时通常要使材料在正常条件下不变形。As far as the direction of cutter rotation and workpiece feed are concerned, milling is performed by either of the following two methods. 至于涉及到铣刀转动的方向和工件的进给，铣削可以通过下列两种方法之一进行。As in most forming processes, use of undercuts should be avoided as these will make the removal of the part difficult, if not impossible. 如同大多数成型工艺，如果不是非用不可，尽量避免采用凹槽，因为凹槽会使零件难以取出。As ingots of steel weighing 30 tonnes or more are forged in this way, manual operation is impossible and it is essential that all the manipulation of the ingot is done mechanically. 由于这种情况下被锻钢坯重量大于30吨，人工操作是不可能的，钢坯的所有操作都必须是机械化的。As injection pressures are low it is possible to manufacture complex components, even some with internal screw threads, by the use of side cores and split tools.注塑压力较低使得制作复杂零件成为可能，通过采用侧面型芯和分离工具甚至可以带有内螺纹。As is the case with the plain cutter, the cutting teeth can be straight or helical.象平面铣刀的情况一样，切削齿既可以是直的也可以是螺旋的。As previously mentioned, the axial feed is automatically generated when cutting a thread by means of the lead screw, which drives the carriage. 如前所述，当依靠驱动大拖板的丝杆切削螺纹时轴向进给是自动产生的。As shown in Fig.12.4d, it is quite similar to the plain milling cutter, the difference being that this type has teeth on the sides. 正如图12.4d所示，它与平面铣刀十分相似，差别在于此类铣刀齿在侧面。As shown in Fig.4.2, grain flow is the direction of the pattern that the crystals take during plastic deformation. 如图4.2所示，晶粒流动的方向就是在塑性变形期间结晶排列的方向。As the carbon content in steel increases up to around 0.60%, the possible hardness obtainable also increases. 随着钢的含碳量增加到大约0.60%，可能得到的硬度也增加。As the carbon-rich phase forms