机床改造工艺夹具类外文文献翻译、中英文翻译、外文翻译
镗削加工和镗床机床工艺夹具外文文献翻译、中英文翻译、外文翻译
中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械制造设计及其自动化姓名：李旭学号： 052115012015年 4 月 2 日英文翻译原文:(一)镗削加工和镗床像车床加工零件一样，镗床能在中空的工件或由钻削加工或其它工艺所加工的孔上进行内轮廓圆的加工。
镗削是由那些类似车削的刀具完成的。
因为镗头必须达到镗杆的全长，刀具将发生弯曲，因此，尺寸精度的保持性成为了一个重大问题。
镗杆必须有足够的刚度——刀杆是由较高弹性模量的材料制造的，比如碳化钨（硬质合金）——去减小弯曲和避免摇动和振动。
镗杆被设计有减振的能力。
镗床既能加工在车床上加工的较小工件，镗铣床又能加工巨大的工件。
这类机械既有立式的又有卧式的并且能够完成如：车削、车端面、切槽、和倒角。
一台立式的镗床类似一台车床，但它有一根垂直的工件旋转轴。
刀具（通常用于切削的单独切削点是由M-2和M-3高速钢和C-8硬质合金制造的）被安装于能垂直运动（用于镗削和车削）和径向运动（用于车端面）并由十字导轨导向的刀头上。
刀头能够旋转去加工圆锥形表面。
在卧式镗床上工件被装夹在能在水平面内两个轴向和径向上移动的工作台上，刀具被安装于能做垂直和纵向两方向上运动的主轴箱上。
钻头、铰刀、螺纹刀和铣刀都能安装于机床主轴上。
镗床具有许多优良的性能，它所加工工件的直径是1m-4m(3ft-12ft)，工件尺寸达到20m(60ft)的可在专用的立式镗床上加工。
机床功率范围可达到150kw(200hp)。
这些可用于所有运动都能编程的数字控制加工。
利用这些控制，只需要很少的相关操作，并且稳定性和生产率大大提高了。
镗床的切削速度和进给速度和车床比较相似。
坐标镗床是属于具有较高精度支撑的立式镗床。
尽管它们可用于各类尺寸的工件加工和拥有夹紧合安装的刀具空间。
它们正被多功能的数控机床取代。
镗床的设计要求：导轨的效率，类似于车削的经济型操作，另外，应该考虑以下因素：a.无论何时，应尽可能注意是加工通孔而并盲孔。
牛头刨床、钻床和铣削机床夹具外文文献翻译、中英文翻译、外文翻译
中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械设计制造及其自动化*名：***学号： ******** 2015 年 4 月 1 日Shapers, Drilling and Milling MachinesA shapers utilizes a single-point tool on a tool holder mounted on the end of the ram. Cutting is generally done on the forward stroke. The tool is lifted slightly by the clapper box to prevent excessive drag across the work, which is fed under the tool during the return stroke in preparation for the next cut. The column houses the operating mechanisms of the shaper and also serves as a mounting unit for the work-supporting table. The table can be moved in two directions mutually perpendicular to the ram. The tool slide is used to control the depth of cut and is manually fed. It can be rotated through 90 deg, on either side of its normal vertical position, which allows feeding the tool at an angle to the surface of the table.Two types of driving mechanisms for shapers are a modified Whitworth quick-return mechanism and a hydraulic drive. For the Whitworth mechanism, the motor drives the bull gear, which drives a crank arm with an adjustable crank pin to control the length of stroke. As the bull gear rotates, the rocker arm is forced to reciprocate, imparting this motion to the shaper ram.The motor on a hydraulic shaper is used only to drive the hydraulic pump. The remainder of the shaper motions are controlled by the direction of the flow of the hydraulic oil. The cutting stroke of the mechanically driven shaper uses 220 deg. Of rotation of the bull gear, while the return stroke uses 140 deg. This gives a cutting stroke to return stroke ratio of 1.6 to 1. The velocity diagram for a hydraulic shaper shows that for most of the tool during cutting stroke is never constant, while the velocity diagram for a hydraulic shaper shows that for most of the cutting stroke the cutting speed is constant. The hydraulic shaper has an added advantage of infinitely variable cutting speeds. The principal disadvantage of this type of machine is the lack of a definite limit at the end of the ram stroke, which may allow a few thousandths of an inch variation in stroke length.A duplicating device that makes possible the reproduction of contours from a sheet-metal template is available. The sheet metal template is used in conjunction with hydraulic control.Upright 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 orcumbersome 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 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 0.5µm 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 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 Ⅱ 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 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 toolsand 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 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 highquantities 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.牛头刨床、钻床和铣削刨床是刀具特有者利用单点刀具将其安装在滑头的末梢。
机床加工外文文献翻译
机床加工外文文献翻译(含：英文原文及中文译文)文献出处：Shunmugam M. Basic Machining Operations and Cutting Technology[J]. Journal of the Institution of Engineers, 2014, 1(2):22-32. 英文原文Basic Machining Operations and Cutting TechnologyShunmugam MBasic Machining OperationsMachine was developed from the early Egyptian pedal car and John Wilkinson's trampoline. They provide rigid support for workpieces and tools and can precisely control their relative position and relative speed. Basically, metal cutting refers to a sharpened pry tool that removes a very narrow metal from the surface of a tough workpiece. Chips are discarded products. Compared with other workpieces, the chips are shorter, but there is a certain increase in the thickness of the uncut parts. The geometry of the workpiece surface depends on the shape of the tool and the path of the tool during machining operations.Most machining processes produce parts of different geometries. If a rough workpiece rotates on the central axis and the tool cuts into the workpiece surface parallel to the center of rotation, a rotating surface is created. This operation is called turning. If a hollow tube is machined onthe inner surface in the same way, this operation is called boring. When the diameter is evenly changed, a conical outer surface is produced, which is called taper turning. If the tool contact point moves in a way that changes the radius, then a workpiece with a contour like a ball is produced; or if the workpiece is short enough and the support is very rigid, then the forming tool normally feeds one outside the axis of rotation. Surfaces can be produced, and short tapered or cylindrical surfaces can also be formed.Flat surfaces are often required and they can be produced by radial turning of tool contact points with respect to the axis of rotation. It is easier to fix the tool and place the workpiece under the tool for larger workpieces while planing. The tool can feed reciprocally. The forming surface can be produced by a forming tool.Multi-blade cutters can also be used. Using a double-edged groove drilling depth is 5-10 times the hole diameter. Regardless of whether the drill rotates or the workpiece rotates, the relative motion between the cutting edge and the workpiece is an important factor. During milling, a rotating tool with many cutting edges comes into contact with the workpiece and the workpiece slowly moves relative to the tool. Flat or shaped surfaces may occur depending on the tool geometry and feed method. A horizontal or vertical axis rotation can be generated and can be fed in any of three coordinate directions.Basic machineThe machine tool produces parts with special geometry and precise dimensions by removing chips from plastic material. The latter is waste, which is a change from the long continuous strip of plastic material such as steel, which is useless from a processing point of view. It is easy to handle cracked chips produced from cast iron. The machine performs five basic metal removal processes: turning, planing, drilling, and milling. All other metal removal processes are modified from these five basic procedures. For example, boring is internal turning; reaming, tapping and counterboring are further machining of drilled holes; gear machining is based on Milling operation. Polishing and sanding are deformations that grind and remove the abrasive process. Therefore, there are only four basic types of machine tools that use specially controllable cutting tools: 1. Lathes, 2. Drilling machines, 3. Milling machines, 4. Grinding machines. The grinding process forms chips, but the geometry of the abrasive particles is uncontrollable.The amount and speed of material removal through various processing steps is enormous, just as high facets are removed in large turning operations, or in extremely small grinding and ultra-precision machining. A machine tool fulfills three major functions: 1. It supports work pieces or fixtures and tools 2. It provides relative motion to work pieces and tools 3. In each case provides a range of feeds and generallyup to 4-32 species Speed choices.Processing speed and feedSpeed, feed, and depth of cut are three major variables in economic processing. The other quantities are tapping and tool material, coolant and tool geometry. The speed of the metal removal and the power required are dependent on these variables.Depth of cut, feed, and cutting speed are the mechanical parameters that must be established in any metalworking process. They all affect the force, speed and speed of metal removal. The cutting speed can be defined as the radius of the velocity recording surface that spreads radially at any instant during one revolution, or the distance between two adjacent grooves. The depth of cut is the depth of entry and the depth of the trench.Turning in the center of the latheBasic operations completed on a motorized bed have been introduced. Those operations that use a single point tool on the outside surface are called turning. In addition to drilling, reaming, and grinding of internal surfaces, the operation is done by a single point tool. All machining operations, including turning, can be categorized as roughing, finishing or semi-finishing. Finishing removes a large amount of material as quickly and efficiently as possible, while a small part of the material left on the workpiece is used for finishing. Finishing isThe workpiece gets the final size, shape and surface accuracy. Sometimes semi-finishing leaves a predetermined amount of material for finishing, which is prior to finishing.In general, longer workpieces are simultaneously supported by one or two lathe centers. Conical holes, so-called center holes, are drilled at both ends for the center of the lathe - usually along the axis of the cylindrical workpiece. The end of the workpiece near the frame is usually supported by the center of the tailstock. At the end near the main bearing is the center of the main bearing or clamped by the jaw plate. This method can firmly tighten the workpiece and can smoothly transmit the force to the workpiece. The auxiliary support provided by the chuck to the workpiece reduces the chattering tendency during cutting. If the chuck can be carefully and accurately used to support the workpiece, then Accurate results can be obtained.Supporting the workpiece between two centers can give very accurate results. One end of the workpiece has been machined, then the workpiece can be turned. The other end is machined on a lathe, and the center hole serves as a precise positioning surface and a supporting surface for carrying the weight of the workpiece and resisting the cutting force. When the workpiece is removed from the lathe for any reason, the center hole will accurately return the workpiece to this lathe or another lathe or a cylindrical grinder. Workpieces are not allowed to be clampedon the main bearing by the chuck and lathe center. However, the first thing that comes to mind is a method of quickly adjusting the workpiece on the chuck, but this is not allowed because it is impossible to hold the center of the lathe while holding it by the chuck. The adjustment provided by the center of the lathe will not continue and the claw plate pressure will damage the center hole and lathe center, and even the lathe spindle. The floating claw plate provides an exception to the above statement. It is used almost exclusively for high production work. These chucks are real job drivers and are not used for the same purpose as ordinary three-jaw, four-jaw chucks.While large-diameter workpieces are fashioned in two centers, they are preferably held by the panel at the tail of the main bearing for smooth energy conversion; many lathe chucks do not provide sufficient energy conversion, although they can be used as special energy conversions.Mechanical processing introductionAs a method of producing a shape, machining is the most commonly used and the most important method in all manufacturing processes. The machining process is a process of producing a shape in which the drive device removes some of the material on the workpiece as chips. Although in some cases, the workpiece is supported using mobile equipment without support, most machining operations are performed by equipment that supports both the workpiece and the tool.Small batch, low cost. Machining has two applications in the manufacturing industry. Casting, forging, and pressure work produce each special shape, even one part, almost always with a higher mold cost. The shape of the weld depends largely on the raw material. By using equipment that has a high overall cost but does not have a special mold, machining is possible; starting from almost any kind of raw material, the shape is designed from any material as long as the external dimensions are large enough. Processing is therefore the preferred method. When producing one or several parts or even in mass production, the design of the parts logically leads to the casting, forging or stamping of the product. High precision, surface accuracy. The second application of mechanical machining is based on the possible high precision and surface accuracy. If mass production occurs in other processes, many low-volume components will produce low but acceptable tolerances. On the other hand, many parts produce general shapes from some large deformation processes and are only machined on selected surfaces with very high accuracy. For example, the inside process is seldom produced by any other machining method and the hole on the part may be processed immediately after the pressure operation.The main cutting parametersThere are four factors that fully describe the relationship between the basic tooling work during cutting: tool geometry, cutting speed and depthof cut. The tool must be made of a suitable material; it must have a certain strength, roughness, hardness and fatigue resistance. The tool geometry is described by face and angle and is correct for each cutting operation. Cutting speed refers to the speed at which the cutting edge passes through the work surface, which has been expressed in feet per minute. For machining efficiency, the cutting speed must be of an appropriate scale relative to the particular working combination. In general, the harder the work, the lower the speed. Feed is the rate at which the tool enters the workpiece. When the workpiece or tool rotates, the feed rate is in inches per revolution. When the tool or workpiece moves back and forth, the unit of feed is inches. In general, the feed rate is inversely proportional to the cutting speed in other similar situations. The cutting speed is expressed in inches and is represented by the distance the tool enters the workpiece. It refers to the width of the chips when turning or the thickness of the chips when cutting in a straight line. The depth of cut during roughing is greater than the depth of cut during finishing.Effect of Cutting Parameter Change on Cutting TemperatureIn metal cutting operations, heat is generated in the primary and secondary deformation zones and these results in complex temperatures throughout the tool, workpiece, and chips. A typical isothermal as shown in the figure, it can be seen that as predicted, when the workpiece materialundergoes major deformation and is reduced, there is a very large temperature gradient throughout the entire width of the chip. When the chips in the second deformed zone still have a short distance, the maximum temperature is reached.Because almost all of the work is done with metal cutting converted to heat, it can be predicted that the increased energy consumption per unit volume of metal removed will increase the cutting temperature. Therefore, when all the other parameters are unchanged, the rake angle becomes larger and the energy and cutting temperature per unit volume of metal removed will be reduced. When considering the increase in the thickness and speed of the non-formed chips, the situation is even more complicated. Increasing the thickness of the cut will often greatly affect the amount of heat transferred to the workpiece, the number of tools, and will keep the chips at a fixed amount, and at the same time the change in cutting temperature will be small. However, increasing the cutting speed will reduce the amount of heat transferred to the workpiece. This will increase the temperature rise of the main deformation of the chips. In addition, the second deformation zone is relatively small, and in this deformation zone it will increase the temperature. The other changes in cutting parameters hardly affect the removal of energy consumption per unit volume and the cutting temperature. It has thus been shown that even small changes in cutting temperature have a significant effect on toolwear rate, and it is appropriate to estimate the cutting temperature from the cutting data. The most direct and accurate method of testing high-speed steel tools, Trent gave detailed information on the temperature distribution of high-speed steel tools. This technique is based on the data detection of high-speed steel tools and is related to the microscopic changes in thermal history.Trent has described the measurement of cutting temperature and the temperature distribution of high-speed steel tools when machining a wide range of workpieces. Using scanning electron microscopy to study fine-scale microstructure changes, this technique has been further developed. This technique is also used to study the temperature distribution of high-speed steel single-point turning tools and twist drills.Tool wearBrittle fractures have been treated and there are basically three types of tool wear. Back flank wear, boundary wear and flank wear. Face wear occurs at the major and minor cutting edges. The main cutting edge is responsible for the removal of large amounts of metal, which increases the cutting force and temperature, and if left unchecked the vibration of the tool and the workpiece can be caused, and this can no longer be cut efficiently. The secondary cutting edge determines the workpiece size and surface finish. Wear of the flank causes poor surface accuracy in a large number of products. According to the actual cutting conditions, the mainreason for the unacceptable use of the tool is that the wear of the main flank before the secondary flank is very large, which results in the generation of an unacceptable portion. Due to the stress distribution of the tool, the frictional force in the sliding area is maximized between the chip and the surface at the beginning of sliding, and the final frictional force is zero. Therefore, abrasive wear occurs in this area. More wear occurs between the chip and the disengagement area adjacent to the area, which is more than adjacent to this point.This results in a localized pitting of the tool face at a certain distance from the face, which is usually partly arc-shaped. In many respects and based on actual cutting conditions, the boundary wear is a less severe wear than the flank, so that the wear of the face is a relatively common blunt standard. Then, as various authors have shown, with the increase of cutting speed, the increase of surface temperature is more than the increase of the blade surface, and because the temperature change seriously affects any type of wear rate, boundary wear usually occurs at higher cutting speeds. Situation.Where the tool is in contact with the uncut surface, the wear of the trailing portion of the main flank is more pronounced than that along the remaining wear surface. This is because the local influences such as the uncut surface are caused by the work hardening caused by the previous cutting, oxidation scale, and local high temperature. This localized wearis generally related to the wear of the boundary and is sometimes severe. Although the occurrence of a notch does not seriously affect the cutting performance of the tool, the notch is often deeper, and it is likely that the cutting tool will break if it continues.If any form of gradual wear continues to make its dramatic existence, the tool will face catastrophic failures, such as the cutting tool can not be cut, in good condition, the workpiece is scrapped, at worst, the mechanical tool may cause damage. For cemented carbide tools and various types of wear and tear, the maximum service life limit is reached before a catastrophic failure occurs. However, wear on high-speed steel cutting tools is uneven. It has been found that when wear continues and even catastrophic failure occurs, the most meaningful and reproducible results are obtained, but in practice, the cutting time is much less. At the time of failure. Several phenomena occur when a catastrophic failure occurs. The most common is a sudden increase in cutting force, a bright ring in the workpiece, and a significant increase in noise.Surface finishing mechanismThere are five basic mechanisms that affect the processed product: (1) The basic geometry of the cutting process, the single-point turning tool will advance axially a constant distance, the resulting surface will be on it, and the tool will feed in the vertical direction. A series of sharp points form the basic shape of the cutting tool. (2) The efficiency ofcutting. It has already been mentioned that an unstable tumor will produce a face that contains hardened tumor segments. This fragment reduces the surface finish. It can also be proved that under heavy cutting conditions, large feed rates, small rake angles and low cutting speeds can be used. In addition to these, the production conditions can also lead to unstable BDE products. The cutting process becomes unstable rather than continuous cutting in the shear zone. , Shattered, uneven discontinuous chips appear, and the surface is not smooth enough. This is especially true when working with ductile materials. (3) The stability of the machine tool. According to certain combinations of cutting conditions, workpiece dimensions, clamping methods and stiffness relative to the machine structure, instability is a tool-induced chatter. Under certain conditions, this kind of vibration will reach and maintain a certain amplitude, and vibrations based on other conditions will also be generated, unless the cutting prevents considerable damage or both the cutting tool and the workpiece may vibrate. This phenomenon is called chattering.Axial turning features a long spiral band on the workpiece and short pitch fluctuations on the temporary machined surface. (4) Remove the effectiveness of cuttings. In intermittent chip production processes, such as milling and turning of brittle materials, it is expected that whether due to gravity or cutting fluid, chips will leave the cutting zone and in any case will not affect the cutting surface. Consecutive chips are obvious,and if no measures are taken to control the chips, they may affect the cutting surface and leave marks. Inevitably, this marks only expectations.(5) The effective relief angle of the cutting tool. For small cutting edges and relief angles with a certain geometry, it is possible to cut at the main cutting edge and polish at the secondary cutting edge. This will result in good surface accuracy, but of course this combination of strictly metal forming cannot be recommended as an actual cutting method. However, due to occasional occurrence of these conditions, tool wear can cause changes in the surface properties.Limits and tolerancesMechanical parts are manufactured so they are interchangeable. In other words, each mechanical part or device is made to a size and shape suitable for other types of machines. In order to make the parts interchangeable, each part is dimensioned to fit the corresponding part in the right way. This is not only impossible, but it is impractical to make many parts into one size. This is because the machine is not perfect and the tool wears. A slight deviation from the correct size is usually allowed. The size of this deviation depends on the type of part being manufactured. For example, a part may be 6 inches and the upper and lower deviation is 0003 inches (one thousandth of a thousandth). So this deviation can be between 5,997 inches and 6003 inches and still maintain the correct size. This is bias. The difference between the upper and lower deviations is theThe tolerance is the maximum amount of change in part size, and the basic size is the size limit derived from the allowable variation and tolerance range. Sometimes the deviation allows only one direction to change. It allows the tolerance to change in the hole or axis without seriously affecting the fit. When the tolerance changes in both directions, it is called full deviation (positive and negative). The full deviation is separate and there will be on each side of the basic size. The limit size is only the largest size and the smallest size. Therefore, the to lerance is the difference between these two dimensions.Surface accuracy and size controlProducts have been completed in their proper shape and size, and often require some type of surface accuracy to enable them to perform their own functions. In some cases, in order to resist scratching and scratching, it is necessary to improve the physical properties of the surface material. In many manufacturing processes, dirt, chips, grease or other harmful substances are left on the surface of the product. Mixtures of different materials, the same materials processed in different ways, may require some special surface treatment to provide a uniform appearance.基本加工工序和切削技术Shunmugam M基本加工的操作机床是从早期的埃及人的脚踏动力车和约翰·威尔金森的镗床发展而来的。
夹具设计英文文献
夹具设计英文文献In the realm of manufacturing, fixture design is acritical component that ensures precision and efficiency inthe production process. It involves creating devices that securely hold workpieces in place during machining operations.The design process begins with a thorough understandingof the workpiece's geometry and the specific machining requirements. This understanding guides the selection of materials, the determination of size, and the configurationof the fixture's components.Innovative fixture designs often incorporate adjustable features to accommodate a variety of workpieces, thereby enhancing the flexibility of the manufacturing setup. This adaptability is key to reducing production time andminimizing costs.Safety is paramount in fixture design, with mechanisms ensuring that both the operator and the workpiece areprotected from potential hazards. Ergonomic considerationsalso play a role, with the fixture's design facilitating ease of use for the operator.Advancements in technology have led to the integration of computer-aided design (CAD) and simulation software infixture design. These tools allow designers to virtually test and optimize fixture performance before physical prototyping.Sustainability is becoming an increasingly important aspect of fixture design, with a focus on using recyclable materials and minimizing waste throughout the manufacturing process.The future of fixture design looks towards automation and robotics, where fixtures can dynamically adjust to different workpieces, further streamlining the production line and reducing the need for manual intervention.In conclusion, fixture design is a multifaceteddiscipline that requires a deep understanding of materials, mechanics, and manufacturing processes. As technology continues to evolve, so too will the sophistication and capabilities of fixtures in the industry.。
机床加工外文文献翻译
机床加工外文文献翻译(含：英文原文及中文译文)文献出处：Shunmugam M. Basic Machining Operations and Cutting Technology[J]. Journal of the Institution of Engineers, 2014, 1(2):22-32. 英文原文Basic Machining Operations and Cutting TechnologyShunmugam MBasic Machining OperationsMachine was developed from the early Egyptian pedal car and John Wilkinson's trampoline. They provide rigid support for workpieces and tools and can precisely control their relative position and relative speed. Basically, metal cutting refers to a sharpened pry tool that removes a very narrow metal from the surface of a tough workpiece. Chips are discarded products. Compared with other workpieces, the chips are shorter, but there is a certain increase in the thickness of the uncut parts. The geometry of the workpiece surface depends on the shape of the tool and the path of the tool during machining operations.Most machining processes produce parts of different geometries. If a rough workpiece rotates on the central axis and the tool cuts into the workpiece surface parallel to the center of rotation, a rotating surface is created. This operation is called turning. If a hollow tube is machined on the inner surface in the same way, this operation is called boring. Whenthe diameter is evenly changed, a conical outer surface is produced, which is called taper turning. If the tool contact point moves in a way that changes the radius, then a workpiece with a contour like a ball is produced; or if the workpiece is short enough and the support is very rigid, then the forming tool normally feeds one outside the axis of rotation. Surfaces can be produced, and short tapered or cylindrical surfaces can also be formed.Flat surfaces are often required and they can be produced by radial turning of tool contact points with respect to the axis of rotation. It is easier to fix the tool and place the workpiece under the tool for larger workpieces while planing. The tool can feed reciprocally. The forming surface can be produced by a forming tool.Multi-blade cutters can also be used. Using a double-edged groove drilling depth is 5-10 times the hole diameter. Regardless of whether the drill rotates or the workpiece rotates, the relative motion between the cutting edge and the workpiece is an important factor. During milling, a rotating tool with many cutting edges comes into contact with the workpiece and the workpiece slowly moves relative to the tool. Flat or shaped surfaces may occur depending on the tool geometry and feed method. A horizontal or vertical axis rotation can be generated and can be fed in any of three coordinate directions.Basic machineThe machine tool produces parts with special geometry and precise dimensions by removing chips from plastic material. The latter is waste, which is a change from the long continuous strip of plastic material such as steel, which is useless from a processing point of view. It is easy to handle cracked chips produced from cast iron. The machine performs five basic metal removal processes: turning, planing, drilling, and milling. All other metal removal processes are modified from these five basic procedures. For example, boring is internal turning; reaming, tapping and counterboring are further machining of drilled holes; gear machining is based on Milling operation. Polishing and sanding are deformations that grind and remove the abrasive process. Therefore, there are only four basic types of machine tools that use specially controllable cutting tools: 1. Lathes, 2. Drilling machines, 3. Milling machines, 4. Grinding machines. The grinding process forms chips, but the geometry of the abrasive particles is uncontrollable.The amount and speed of material removal through various processing steps is enormous, just as high facets are removed in large turning operations, or in extremely small grinding and ultra-precision machining. A machine tool fulfills three major functions: 1. It supports work pieces or fixtures and tools 2. It provides relative motion to work pieces and tools 3. In each case provides a range of feeds and generally up to 4-32 species Speed choices.Processing speed and feedSpeed, feed, and depth of cut are three major variables in economic processing. The other quantities are tapping and tool material, coolant and tool geometry. The speed of the metal removal and the power required are dependent on these variables.Depth of cut, feed, and cutting speed are the mechanical parameters that must be established in any metalworking process. They all affect the force, speed and speed of metal removal. The cutting speed can be defined as the radius of the velocity recording surface that spreads radially at any instant during one revolution, or the distance between two adjacent grooves. The depth of cut is the depth of entry and the depth of the trench.Turning in the center of the latheBasic operations completed on a motorized bed have been introduced. Those operations that use a single point tool on the outside surface are called turning. In addition to drilling, reaming, and grinding of internal surfaces, the operation is done by a single point tool. All machining operations, including turning, can be categorized as roughing, finishing or semi-finishing. Finishing removes a large amount of material as quickly and efficiently as possible, while a small part of the material left on the workpiece is used for finishing. Finishing isThe workpiece gets the final size, shape and surface accuracy.Sometimes semi-finishing leaves a predetermined amount of material for finishing, which is prior to finishing.In general, longer workpieces are simultaneously supported by one or two lathe centers. Conical holes, so-called center holes, are drilled at both ends for the center of the lathe - usually along the axis of the cylindrical workpiece. The end of the workpiece near the frame is usually supported by the center of the tailstock. At the end near the main bearing is the center of the main bearing or clamped by the jaw plate. This method can firmly tighten the workpiece and can smoothly transmit the force to the workpiece. The auxiliary support provided by the chuck to the workpiece reduces the chattering tendency during cutting. If the chuck can be carefully and accurately used to support the workpiece, then Accurate results can be obtained.Supporting the workpiece between two centers can give very accurate results. One end of the workpiece has been machined, then the workpiece can be turned. The other end is machined on a lathe, and the center hole serves as a precise positioning surface and a supporting surface for carrying the weight of the workpiece and resisting the cutting force. When the workpiece is removed from the lathe for any reason, the center hole will accurately return the workpiece to this lathe or another lathe or a cylindrical grinder. Workpieces are not allowed to be clamped on the main bearing by the chuck and lathe center. However, the firstthing that comes to mind is a method of quickly adjusting the workpiece on the chuck, but this is not allowed because it is impossible to hold the center of the lathe while holding it by the chuck. The adjustment provided by the center of the lathe will not continue and the claw plate pressure will damage the center hole and lathe center, and even the lathe spindle. The floating claw plate provides an exception to the above statement. It is used almost exclusively for high production work. These chucks are real job drivers and are not used for the same purpose as ordinary three-jaw, four-jaw chucks.While large-diameter workpieces are fashioned in two centers, they are preferably held by the panel at the tail of the main bearing for smooth energy conversion; many lathe chucks do not provide sufficient energy conversion, although they can be used as special energy conversions.Mechanical processing introductionAs a method of producing a shape, machining is the most commonly used and the most important method in all manufacturing processes. The machining process is a process of producing a shape in which the drive device removes some of the material on the workpiece as chips. Although in some cases, the workpiece is supported using mobile equipment without support, most machining operations are performed by equipment that supports both the workpiece and the tool.Small batch, low cost. Machining has two applications in themanufacturing industry. Casting, forging, and pressure work produce each special shape, even one part, almost always with a higher mold cost. The shape of the weld depends largely on the raw material. By using equipment that has a high overall cost but does not have a special mold, machining is possible; starting from almost any kind of raw material, the shape is designed from any material as long as the external dimensions are large enough. Processing is therefore the preferred method. When producing one or several parts or even in mass production, the design of the parts logically leads to the casting, forging or stamping of the product. High precision, surface accuracy. The second application of mechanical machining is based on the possible high precision and surface accuracy. If mass production occurs in other processes, many low-volume components will produce low but acceptable tolerances. On the other hand, many parts produce general shapes from some large deformation processes and are only machined on selected surfaces with very high accuracy. For example, the inside process is seldom produced by any other machining method and the hole on the part may be processed immediately after the pressure operation.The main cutting parametersThere are four factors that fully describe the relationship between the basic tooling work during cutting: tool geometry, cutting speed and depth of cut. The tool must be made of a suitable material; it must have acertain strength, roughness, hardness and fatigue resistance. The tool geometry is described by face and angle and is correct for each cutting operation. Cutting speed refers to the speed at which the cutting edge passes through the work surface, which has been expressed in feet per minute. For machining efficiency, the cutting speed must be of an appropriate scale relative to the particular working combination. In general, the harder the work, the lower the speed. Feed is the rate at which the tool enters the workpiece. When the workpiece or tool rotates, the feed rate is in inches per revolution. When the tool or workpiece moves back and forth, the unit of feed is inches. In general, the feed rate is inversely proportional to the cutting speed in other similar situations. The cutting speed is expressed in inches and is represented by the distance the tool enters the workpiece. It refers to the width of the chips when turning or the thickness of the chips when cutting in a straight line. The depth of cut during roughing is greater than the depth of cut during finishing.Effect of Cutting Parameter Change on Cutting TemperatureIn metal cutting operations, heat is generated in the primary and secondary deformation zones and these results in complex temperatures throughout the tool, workpiece, and chips. A typical isothermal as shown in the figure, it can be seen that as predicted, when the workpiece material undergoes major deformation and is reduced, there is a very largetemperature gradient throughout the entire width of the chip. When the chips in the second deformed zone still have a short distance, the maximum temperature is reached.Because almost all of the work is done with metal cutting converted to heat, it can be predicted that the increased energy consumption per unit volume of metal removed will increase the cutting temperature. Therefore, when all the other parameters are unchanged, the rake angle becomes larger and the energy and cutting temperature per unit volume of metal removed will be reduced. When considering the increase in the thickness and speed of the non-formed chips, the situation is even more complicated. Increasing the thickness of the cut will often greatly affect the amount of heat transferred to the workpiece, the number of tools, and will keep the chips at a fixed amount, and at the same time the change in cutting temperature will be small. However, increasing the cutting speed will reduce the amount of heat transferred to the workpiece. This will increase the temperature rise of the main deformation of the chips. In addition, the second deformation zone is relatively small, and in this deformation zone it will increase the temperature. The other changes in cutting parameters hardly affect the removal of energy consumption per unit volume and the cutting temperature. It has thus been shown that even small changes in cutting temperature have a significant effect on tool wear rate, and it is appropriate to estimate the cutting temperature fromthe cutting data. The most direct and accurate method of testing high-speed steel tools, Trent gave detailed information on the temperature distribution of high-speed steel tools. This technique is based on the data detection of high-speed steel tools and is related to the microscopic changes in thermal history.Trent has described the measurement of cutting temperature and the temperature distribution of high-speed steel tools when machining a wide range of workpieces. Using scanning electron microscopy to study fine-scale microstructure changes, this technique has been further developed. This technique is also used to study the temperature distribution of high-speed steel single-point turning tools and twist drills.Tool wearBrittle fractures have been treated and there are basically three types of tool wear. Back flank wear, boundary wear and flank wear. Face wear occurs at the major and minor cutting edges. The main cutting edge is responsible for the removal of large amounts of metal, which increases the cutting force and temperature, and if left unchecked the vibration of the tool and the workpiece can be caused, and this can no longer be cut efficiently. The secondary cutting edge determines the workpiece size and surface finish. Wear of the flank causes poor surface accuracy in a large number of products. According to the actual cutting conditions, the main reason for the unacceptable use of the tool is that the wear of the mainflank before the secondary flank is very large, which results in the generation of an unacceptable portion. Due to the stress distribution of the tool, the frictional force in the sliding area is maximized between the chip and the surface at the beginning of sliding, and the final frictional force is zero. Therefore, abrasive wear occurs in this area. More wear occurs between the chip and the disengagement area adjacent to the area, which is more than adjacent to this point.This results in a localized pitting of the tool face at a certain distance from the face, which is usually partly arc-shaped. In many respects and based on actual cutting conditions, the boundary wear is a less severe wear than the flank, so that the wear of the face is a relatively common blunt standard. Then, as various authors have shown, with the increase of cutting speed, the increase of surface temperature is more than the increase of the blade surface, and because the temperature change seriously affects any type of wear rate, boundary wear usually occurs at higher cutting speeds. Situation.Where the tool is in contact with the uncut surface, the wear of the trailing portion of the main flank is more pronounced than that along the remaining wear surface. This is because the local influences such as the uncut surface are caused by the work hardening caused by the previous cutting, oxidation scale, and local high temperature. This localized wear is generally related to the wear of the boundary and is sometimes severe.Although the occurrence of a notch does not seriously affect the cutting performance of the tool, the notch is often deeper, and it is likely that the cutting tool will break if it continues.If any form of gradual wear continues to make its dramatic existence, the tool will face catastrophic failures, such as the cutting tool can not be cut, in good condition, the workpiece is scrapped, at worst, the mechanical tool may cause damage. For cemented carbide tools and various types of wear and tear, the maximum service life limit is reached before a catastrophic failure occurs. However, wear on high-speed steel cutting tools is uneven. It has been found that when wear continues and even catastrophic failure occurs, the most meaningful and reproducible results are obtained, but in practice, the cutting time is much less. At the time of failure. Several phenomena occur when a catastrophic failure occurs. The most common is a sudden increase in cutting force, a bright ring in the workpiece, and a significant increase in noise.Surface finishing mechanismThere are five basic mechanisms that affect the processed product: (1) The basic geometry of the cutting process, the single-point turning tool will advance axially a constant distance, the resulting surface will be on it, and the tool will feed in the vertical direction. A series of sharp points form the basic shape of the cutting tool. (2) The efficiency of cutting. It has already been mentioned that an unstable tumor willproduce a face that contains hardened tumor segments. This fragment reduces the surface finish. It can also be proved that under heavy cutting conditions, large feed rates, small rake angles and low cutting speeds can be used. In addition to these, the production conditions can also lead to unstable BDE products. The cutting process becomes unstable rather than continuous cutting in the shear zone. , Shattered, uneven discontinuous chips appear, and the surface is not smooth enough. This is especially true when working with ductile materials. (3) The stability of the machine tool. According to certain combinations of cutting conditions, workpiece dimensions, clamping methods and stiffness relative to the machine structure, instability is a tool-induced chatter. Under certain conditions, this kind of vibration will reach and maintain a certain amplitude, and vibrations based on other conditions will also be generated, unless the cutting prevents considerable damage or both the cutting tool and the workpiece may vibrate. This phenomenon is called chattering.Axial turning features a long spiral band on the workpiece and short pitch fluctuations on the temporary machined surface. (4) Remove the effectiveness of cuttings. In intermittent chip production processes, such as milling and turning of brittle materials, it is expected that whether due to gravity or cutting fluid, chips will leave the cutting zone and in any case will not affect the cutting surface. Consecutive chips are obvious, and if no measures are taken to control the chips, they may affect thecutting surface and leave marks. Inevitably, this marks only expectations.(5) The effective relief angle of the cutting tool. For small cutting edges and relief angles with a certain geometry, it is possible to cut at the main cutting edge and polish at the secondary cutting edge. This will result in good surface accuracy, but of course this combination of strictly metal forming cannot be recommended as an actual cutting method. However, due to occasional occurrence of these conditions, tool wear can cause changes in the surface properties.Limits and tolerancesMechanical parts are manufactured so they are interchangeable. In other words, each mechanical part or device is made to a size and shape suitable for other types of machines. In order to make the parts interchangeable, each part is dimensioned to fit the corresponding part in the right way. This is not only impossible, but it is impractical to make many parts into one size. This is because the machine is not perfect and the tool wears. A slight deviation from the correct size is usually allowed. The size of this deviation depends on the type of part being manufactured. For example, a part may be 6 inches and the upper and lower deviation is 0003 inches (one thousandth of a thousandth). So this deviation can be between 5,997 inches and 6003 inches and still maintain the correct size. This is bias. The difference between the upper and lower deviations is the tolerance.The tolerance is the maximum amount of change in part size, and the basic size is the size limit derived from the allowable variation and tolerance range. Sometimes the deviation allows only one direction to change. It allows the tolerance to change in the hole or axis without seriously affecting the fit. When the tolerance changes in both directions, it is called full deviation (positive and negative). The full deviation is separate and there will be on each side of the basic size. The limit size is only the largest size and the smallest size. Therefore, the tolerance is the difference between these two dimensions.Surface accuracy and size controlProducts have been completed in their proper shape and size, and often require some type of surface accuracy to enable them to perform their own functions. In some cases, in order to resist scratching and scratching, it is necessary to improve the physical properties of the surface material. In many manufacturing processes, dirt, chips, grease or other harmful substances are left on the surface of the product. Mixtures of different materials, the same materials processed in different ways, may require some special surface treatment to provide a uniform appearance.中文译文基本加工工序和切削技术Shunmugam M基本加工的操作机床是从早期的埃及人的脚踏动力车和约翰·威尔金森的镗床发展而来的。
车床机床夹具类外文文献翻译、中英文翻译、外文翻译
中北大学信息商务学院本科毕业设计英文参考资料题目 Lathes系名专业姓名学号指导教师2016年6 月2 日译文标题车床简介原文标题Lathes作者(Serope kalpakjian)译名卡尔帕基安国籍美国原文出处/原文：LathesLathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool.The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod.The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed.The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavyconstruction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle.The tailsticd assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw.The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers.Engine lathes are the type most frequently used in manufacturing. They areheavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances up to3658mm(12 feet) are not uncommon. Most have chip pans and a built-in coolant circulating system. Smaller engine lathes-with swings usually not over 330 mm (13 inches ) –also are available in bench type, designed for the bed to be mounted on a bench on a bench or cabinet.Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the work piece, thy are not suitable for quantity production. Often the actual chip-production tine is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operator’s time is consumed by simple, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing.2 Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC). Prior to the advent of NC, all machine tools ere manually operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool. For a machine tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:Electrical discharge machining,Laser cutting,Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tolls and processes.Like so many advanced technologies, NC was born in the laboratories of the Massachusetts Institute of Technology. The concept of NC was developed in the early 1950s with funding provided by the U.S. Air Force. In its earliest stages, NC machines were able to made straight cuts efficiently and effectively.However, curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter the straight lines making up the steps, the smoother is the curve, Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming language for NC that uses statementssimilar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the fur ther development from those used today. The machines had hardwired logic circuits. The instructional programs were written on punched paper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium. It was common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to be rerun through the reader. If it was necessary to produce 100 copies of a given part, it was also necessary to run the paper tape through the reader 100 separate tines. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions as a series of magnetic dots. The plastic tape was much stronger than the paper tape, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To made even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many times as there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problems of NC associated with punched paper and plastic tape.The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host computer. Programs for operating the machine tools are stored in the host computer and fed to the machine tool an needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend on a host computer. When the host computer goes down, the machine tools also experience downtime. This problem led to the development of computernumerical control.3 TurningThe engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered.Th e engine lathe has been replaced in today’s production shops by a wide variety of automatic lathes such as automatic of single-point tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today.Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used.Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating.In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the optimum tolerances possible on the turrets lathe, the designer should strive for a minimum of operations.Automatic Screw Machines Generally, automatic screw machines fall into several categories; single-spindle automatics, multiple-spindle automatics and automatic chucking machines. Originally designed for rapid, automatic production of screws and similar threaded parts, the automatic screw machine has long since exceeded the confines of this narrow field, and today plays a vital role in the mass production of a variety of precision parts. Quantities play an important part in the economy of the parts machined on the automatic screw machine. Quantities less than on the automatic screw machine. The cost of the parts machined can be reduced if the minimum economical lot size is calculated and the proper machine is selected for these quantities.Automatic Tracer Lathes Since surface roughness depends greatly on material turned, tooling , and feeds and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances.In some cases, tolerances of 0.05mm are held in continuous production using but one cut . groove width can be held to 0.125mm on some parts. Bores and single-point finishes can be held to 0.0125mm. On high-production runs where maximum output is desirable, a minimum tolerance of 0.125mm is economical on both diameter and length of turn。
加工工艺工装夹具基本加工工序和切削技术外文文献翻译、中英文翻译、外文翻译
附录Basic Machining Operations and Cutting TechnologyMachine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson's boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation.Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed.Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswisefeed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools.Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions.Basic Machine ToolsMachine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable.The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed.A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case.Intr oduction 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 two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he 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, by machining; to start with nearly any form of raw material, so tong 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 press working 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 otherhand, many parts are given their general 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 press worked parts may be machined following the press working operations.Primary Cutting ParametersThe basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut.The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute.For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed.Feed is the rate at which the cutting tool advances into the workpiece. "Where the workpiece or the tool rotates, feed is measured in inches per revolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions.The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very largetemperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data.The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history.Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills.Wears of Cutting ToolDiscounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in an oversized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component.Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cuttingspeed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds.At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture.If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable of cutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset of catastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level.Mechanism of Surface Finish ProductionThere are basically five mechanisms which contribute to the production of a surface which have been machined. These are:1．The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the workpiecc and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut.2．The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. This situation is particularly noticeable when machining very ductile materials such as copper and aluminum.3．The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface.4．The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless stepsare taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking.5．The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics.Limits and TolerancesMachine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part. The basic size is that size from which limits of size arc derived by the application of allowances and tolerances. Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateraltolerance (plus and minus). Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions.基本加工工序和切削技术机床是从早期的埃及人的脚踏动力车和约翰·威尔金森的镗床发展而来的。
X62W铣床数控化改造外文文献翻译、中英文翻译、外文翻译
X62W CNC milling machine transformation1 general CNC transformation of the need for analysisOur about 3200000 existing machine tools, the machine tool technol ogy status of ageing is serious, according to statistics, about 30% of the total country equipment in more than 16 years, of which nearly 30% of age more than 26 years, all these show the present our country did no t go mainly rely on progress of science and technology of machine tools to transform track. In addition, with the development of science and tec hnology, production is dependent on the degree of equipment increases i ncreasingly, the crop of the enterprise, quality, efficiency, cost, safety an d environmental protection and labor emotions get equipment restrict, rea lize the modernization of enterprise oneself be imperative. But according to the data, our metal cutting machine tool production only accounted for similar equipment to have an amount 1 / 28, such as the annual produ ction of all the machines used to replace the old machine tool needs 28 years so, our country is solved at present equipment technical progress is the main way of machine tools.2 domestic and foreign research present situationIn today's world, industrial developed country to machine tool industr y height seriously, competing for the development of mechanical and ele ctrical integration, high precision, high efficiency, high automation and ad vanced machine tool, in order to accelerate the industrial and economic development. For a long time, Europe and the United States, Asia in the international market are in fierce competition, has formed an invisible fr ont, especially with microelectronics, computer technology, numerical cont rol machine tools in the nineteen eighties later accelerated development, put forward more requirements of all users, had become the four big int ernational machine tool exhibition to display machine tool manufacturers advanced technology, for the user, enlarge the market focus. The more f amous control system : Japan FANUC series, Mitsubishi series, OKUNIA series, SODICK series, series of Hitachi, Germany SIEMENS series, DE CKEL series, Heidenhain series, HELLER series, the United States ALLE N-BRADLEY ( AB ) series, CINCINNANTI series, Num series, FIDIA seri es of France, Italy, Spain, Switzerland FAGOR series, AG series of dom estic series.In the United States, Japan and Germany and other developed coun tries, they will machine transformation as a new economic growth sector, the business scene, is in the golden age. As the machine tool and the continuous advancement of technology, machine tools transformation is a "timeless" issue. Transformation of China's machine tool industry, but a lso from the old to the industry into the digital technology-based new industries. In the United States, Japan, Germany, with machine tool of num erical control technical reformation and production line has a broad mark et, has formed a production line of CNC machine tool and the new indu stry. In the United States, reconstruction of machine tool industry called machine regeneration ( Remanufacturing ) industry. Engaged in renewabl e industry's well-known companies: Bertsche engineering company, ayton machine tool company, Devlieg-Bullavd ( PO ) services group, US equi pment company. The United States company has been in China for the company. Rebuilding of machine tool industry in Japan called machine m odified ( Retrofitting ) industry. Engaged in refitting industry well-known c ompanies have: Doomsday engineering group, three post machinery com pany, Chiyoda engineering machine company, Nozaki engineering compa ny, Hamada engineering company, Yamamoto engineering company.Catch up with the pace of computer system structure, accelerate the development of NC system for NC development speed, has become the main trend. The fourth generation computer engineering structure and m icroelectronic technology as the basis, make full use of existing computer hardware, software resources, development of bus type, module type, o pen type, embedded on a flexible NC system, which is suitable for mach ining complex parts, vertical machine tool with CNC system, but also for future automation upgrades the function may be expanded requirements.China 's NC system development has the following 3 features:( 1 ) system of high-grade numerical control technology has been a breakthrough. As of I type numerical control system, with multi axis linka ge function, fast feed speed in 1.67m / s above, have stronger communi cation, management function.( 2) universal CNC system is a mature technology. Beijing Machine Tool Research Institute BS9l system, these systems are generally equipp ed with CRT display, can be configured to DC and AC servo drive, 2 ~ 4 shaft linkage.( 3) the economic type CNC system still has vast market prospect. As a result of this kind of system has the advantages of simple structur e, cheap price, very suitable for small and medium enterprises in China,is still the most widely applied in CNC system. A typical Nanjing gener ous JWK series.Our country is big country of production of machine tools, it is the u se of power. NC machine tool is the key to the development of machine ry industry products, China's CNC machine tool in machine tool products in the proportion of the overall low level of. But our country is a develo ping country, a lot of enterprises financial weakness, not likely to spend a lot of money on a lot of new CNC machine tools, while a large numb er of universal machine tool can not be all eliminated.Therefore, the transformation of general machine tools CNC machine is a effective way to improve the rate of NC machine tools transformati on, less cost, reform targeted, time is short, after the transformation of t he machine tool are able to overcome the original machine faults and pr oblems, high production efficiency.3 basic scheme comparison and selectionNC transformation of the main general plan shall include the followin g contents: the servo drive system, numerical control device selection, el ectrical equipment, mechanical design, CNC hardware system. Show cent to narrate as follows.The 3.1 servo drive systemServo system is a important part of NC machine tool, its performanc e will directly affect the machining accuracy, surface quality and producti on efficiency, it can be divided into 3 kinds, namely, open loop, closed l oop, loop.3.1.1 open loop systemOpen loop system is the most simple servo, stepper motor as the o pen loop system main device, it has the advantages of simple structure ( electrical control and drive circuit is simple ), small volume, light weight, low price, convenient repair and maintenance characteristics3.1.2 closed loop systemClosed loop system, its structure is complex, technical difficulty is gr eat, testing and repair more difficult, cost is high. Closed loop control ca n achieve good accuracy of machine tools, to compensate for mechanica l transmission system in a variety of error, eliminate the gap, interferenc e on the accuracy of processing, generally applied to the high requireme nts of NC equipment.3.1.3 semi closed loop systemSemi closed loop system with closed-loop system similar to, the posi tion detection device is mounted on the execution component, but mount ed on the drive motor end or the end of the drive rod, indirectly measur ed actuator position or displacement. Due to its wide range of speed ( 0.1 - 3OOO R / rain ), strong overload capacity, and the feedback control, the precision can reach 0.01 ~ 0.001nlln, as fast as 0.5 m / s, so its p erformance is far superior to the stepping motor open loop control, and t he feedback link does not include most of mechanical transmission comp onents, simple debugging ratio closed loop, the system stability can be e asily ensured, than the closed loop is easy to realize. Therefore, using a closed-loop system, is more reliable and feasible.3.1.4 AC, DC servo motor comparisonClosed loop, half closed loop system can be AC or DC servo motor, the AC speed regulation gradually expanding the scope of application, s eems to have replaced DC servo trend. But AC servo control of complic ated structure, high technical difficulty, popularity is not wide, and the pri ce is high ( DC servo motor 1.5 ~ 20000 yuan / Taiwan, AC servo mot or is 2 - 30000 ) in addition, compared to the DC servo motor AC serv o motor with large inertia, the small inertia, debugging difficulty big, whe n the sources are more difficult to repair components. DC servo motor p rinciple similar to DC motor, control system technology is more mature, spread wide, its main drawback is the large volume, large weight, but als o with the commutator and brush, increased repair workload.Through the comparison, the success rate, technical difficulty, precisi on and investment and other factors, decided to adopt DC servo loop co ntrol.3.2 numerical control deviceNumerical control device also has a variety of scheme selection. For example, can all of its own design, production; can use SBCs or STD module control; can use readily available numerical control device for a small number of applicable changes or matching. In the factory's practica l application, generally use the following 2 kinds of solution. A kind of cir cumstance is required for the function and requirement of ready-made C NC device can meet, then used mostly to buy ready-made products solu tion, because of own design is not only a waste of time, investment is n ot necessarily can save investment, more often, and quality do not nece ssarily guarantee. Another kind of circumstance is not to buy off-the-shelf products to achieve some special function, then mostly adopt buy price performance ratio as high performance close to the device, and then to supplement or transformation, at least also bought STD template or indu strial control computer, single board computer to make.According to the selected DC servo drive and processing requiremen ts, the numerical control device can realize closed loop ( loop ) of contr ol, provides the analog control signal, receives the half closed loop feed back signal to control; three coordinate axis of motion, wherein at least t o simultaneously control linkage to complete the arc differential complem ent; in the processing of can use different size cutter, CNC device with cutting tool radius and length compensation in NC machining, so accordi ng to the contour programming and can adapt to the size of tool change, in order to meet the needs of future development and clear structure, d ecided to adopt the STD template, modular design.3.3 other electrical devicesIn numerical control transformation, also needs to be combined with the numerical control device and servo drive configuration characterized by other electrical parts, including the strong and weak electrical signal c onversion, transmission or processing necessary. The input / lucky bird o ut interface to consider whether isolation, shielding requirements; in additi on, but also configure the needed power, all kinds of protection circuit, a uxiliary circuit detecting display.3.4 mechanical partsIn the equipment of numerical control transformation, although is the core part of CNC, involve more is microelectronics and electrical, but n ot of all. If you ignore the mechanical aspects according to the character istics of CNC machine tools for the corresponding necessary changes, or in the transformation of the design and manufacture of endless and rea sonable, the results will give numerical control transformation brings beat all difficulties, and may even lead to failure because of mechanical prob lems.3.5 CNC numerical control systemThe CNC system is composed of CPU memory template; servo mot or interface circuit board; the keyboard, display interface circuit board an d a switch quantity input, output interface circuit board. Each template m ain function is as follows.3.5.1CPU memory boardThe board carried out various data operations, timer in the interventi on, timing execution system program, coordination, management of vario us parts of the circuit to work.In addition, also has a power down protection, power on reset and generates a pulse signal and other functions. At the same time, board m emory, for storing system software, computing the results of staging and storage parts processing program. Plate communicationInterface for the boards and peripherals to provide a convenient com munication.3.5.2 servo motor interface circuit boardThe plate is connected to the servo motor and the CPU bridge. CP U issued a servo motor control instruction code, through the template D / A conversion, operational amplifier after being sent to the motor drive s ource, thus realizing the electrical automatic control. At the same time th e motor running state, through the detecting device of the pulse, in the plate after processing, in the form of code into CPU, CPU adjust motor control instruction, thereby forming displacement closed loop system. If th e pulse signal by F / V conversion, can get the speed control unit feedb ack voltage, which constitute a closed loop system.X62W铣床数控化改造1.普通机床数控化改造的必要性分析我国现有机床320多万台，这些机床技术状况老化严重，据统计，全国30%左右设备在16年以上，其中近30%的役龄超过了26年，这些都说明目前我国还没有走上主要依靠科技进步对机床进行改造的轨道。
数控加工外文翻译文献
数控加工外文翻译文献(文档含中英文对照即英文原文和中文翻译)原文:Basic Machining Operations and CuttingTechnologyBasic Machining OperationsMachine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson's boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation.Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed.Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady andreciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools.Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions.Basic Machine ToolsMachine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cuttingtools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable.The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed.A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case.Speed and Feeds in MachiningSpeeds, feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed (V) is represented by the velocity of- the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the difference in position between two adjacent grooves. The depth of cut is the penetration of the needle into the record or the depth of the grooves.Turning on Lathe CentersThe basic operations performed on an engine lathe are illustrated. Those operations performed on external surfaces with a single point cutting tool arecalled turning. Except for drilling, reaming, and lapping, the operations on internal surfaces are also performed by a single point cutting tool.All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stock on the work-piece to be removed by the finishing operation.Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece provided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck.Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver plate mounted on the spindle nose. One end of the Workpiece is mecained;then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the cutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately alignthe workpiece back in the lathe or in another lathe, or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center, and perhaps even the lathe spindle. Compensating or floating jaw chucks used almost exclusively on high production work provide an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four-jaw chucks.While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be made as a special. Faceplate jaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have.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 two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he produced by welding depend to a large degree on the shapes ofraw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining; to start with nearly any form of raw material, so tong 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 press working 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 parts are given their general 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 press worked parts may be machined following the press working operations.Primary Cutting ParametersThe basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut.The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute.For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed.Feed is the rate at which the cutting tool advances into the workpiece. "Where the workpiece or the tool rotates, feed is measured in inches perrevolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions.The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondarydeformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data.The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history.Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills.Wears of Cutting ToolDiscounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in anoversized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component.Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cutting speed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds.At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture.If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable ofcutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset of catastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level. Mechanism of Surface Finish ProductionThere are basically five mechanisms which contribute to the production of a surface which have been machined. These are:(l) The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the workpiecc and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut.(2) The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. Thissituation is particularly noticeable when machining very ductile materials such as copper and aluminum.(3) The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface.(4)The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps are taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking.(5)The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics.Limits and TolerancesMachine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. Tomake the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part.The basic size is that size from which limits of size arc derived by the application of allowances and tolerances.Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateral tolerance (plus and minus).Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions.Surface Finishing and Dimensional ControlProducts that have been completed to their proper shape and size frequently require some type of surface finishing to enable them tosatisfactorily fulfill their function. In some cases, it is necessary to improve the physical properties of the surface material for resistance to penetration or abrasion. In many manufacturing processes, the product surface is left with dirt .chips, grease, or other harmful material upon it. Assemblies that are made of different materials, or from the same materials processed in different manners, may require some special surface treatment to provide uniformity of appearance.Surface finishing may sometimes become an intermediate step processing. For instance, cleaning and polishing are usually essential before any kind of plating process. Some of the cleaning procedures are also used for improving surface smoothness on mating parts and for removing burrs and sharp corners, which might be harmful in later use. Another important need for surface finishing is for corrosion protection in a variety of: environments. The type of protection procedure will depend largely upon the anticipated exposure, with due consideration to the material being protected and the economic factors involved.Satisfying the above objectives necessitates the use of main surface-finishing methods that involve chemical change of the surface mechanical work affecting surface properties, cleaning by a variety of methods, and the application of protective coatings, organic and metallic.In the early days of engineering, the mating of parts was achieved by machining one part as nearly as possible to the required size, machining the mating part nearly to size, and then completing its machining, continually offering the other part to it, until the desired relationship was obtained. If it was inconvenient to offer one part to the other part during machining, the final work was done at the bench by a fitter, who scraped the mating parts until the desired fit was obtained, the fitter therefore being a 'fitter' in the literal sense. J It is obvious that the two parts would have to remain together, and m the event of one having to be replaced, the fitting would have to be done all over again. Inthese days, we expect to be able to purchase a replacement for a broken part, and for it to function correctly without the need for scraping and other fitting operations.When one part can be used 'off the shelf' to replace another of the same dimension and material specification, the parts are said to be interchangeable.A system of interchangeability usually lowers the production costs as there is no need for an expensive, 'fiddling' operation, and it benefits the customer in the event of the need to replace worn parts.Automatic Fixture DesignTraditional synchronous grippers for assembly equipment move parts to the gripper centre-line, assuring that the parts will be in a known position after they arc picked from a conveyor or nest. However, in some applications, forcing the part to the centre-line may damage cither the part or equipment. When the part is delicate and a small collision can result in scrap, when its location is fixed by a machine spindle or mould, or when tolerances are tight, it is preferable to make a gripper comply with the position of the part, rather than the other way around. For these tasks, Zaytran Inc. Of Elyria, Ohio, has created the GPN series of non- synchronous, compliant grippers. Because the force and synchronizations systems of the grippers are independent, the synchronization system can be replaced by a precision slide system without affecting gripper force. Gripper sizes range from 51b gripping force and 0.2 in. stroke to 40Glb gripping force and 6in stroke. GrippersProduction is characterized by batch-size becoming smaller and smaller and greater variety of products. Assembly, being the last production step, is particularly vulnerable to changes in schedules, batch-sizes, and product design. This situation is forcing many companies to put more effort into extensive rationalization and automation of assembly that was previouslyextensive rationalization and automation of assembly that was previously the case. Although the development of flexible fixtures fell。
中英文中英文文献翻译-关于数控车床和换刀系统
英文原文On the NC lathe and tool changing systemCNC machine tool numerical control machine tools (Computer numerical control machine tools) abbreviation, is provided with a program control system of automatic machine tools. The logic control system can deal with the control code or other symbolic instruction specified program, and decoding the digital code, said information carrier, through the numerical control device input. After processing by CNC device control signals, control the machine movements, by drawing the shape and size requirements, will be automatically processed by the parts.Features: CNC machine tool operation and monitoring of all completed in the numerical control unit, it is the brain of CNC machine tools. Compared with the general machine tools, CNC machine tools has the following characteristics:● the processing object adaptability, adapt to the characteristics of mold products such as a single production, provide the appropriate processing method for die and mould manufacturing;● high machining accuracy, processing with stable quality;● can coordinate linkage, processing complex shape parts;● machining parts change, only need to change the program, can save the preparation time of production;● the machine itself high precision, rigi dity, can choose the amount of processing good, high productivity (typically 3 to 5 times that of ordinary machine tool);The machine is a high degree of automation, reducing labor intensity;● conducive to the production management modernization. The use of CNC machine tools and the standard code of digital information processing, information transmission, the use of computer control method, has laid the foundation for the integration of computer aided design, manufacturing and management;● on the operato rs of higher quality, higher demands for the repair of the technical staff;● high reliability.Composition: CNC machine tools in general by the input medium, man-machine interactive equipment, CNC equipment, feed servo drive system, spindle servo drive system, the auxiliary control device, feedback apparatus and adaptive control device etc.. [4] in NC machining, NC milling processing is the most complex, need to solve most problems. NC programming of NC line in addition to CNC milling, cutting, CNC EDM, CNC lathe, CNC grinding, each with its own characteristics, servo system is the role of the motion signal is converted into the machine moving parts from the numerical control device of pulse. Concrete has the following parts: the structure of CNC machine tools.Driver: he is driving parts of CNC machine tools, actuator, including spindle drive unit, feeding unit, spindle motor and feed motor. He through the electric or electro-hydraulic servo system to realize the spindle and feed drive under the control of numerical control device. When several feed linkage, can complete the positioning, processing line, plane curve and space curve.The main performance(1) the main dimensions.(2) the spindle system.(3) feed system.(4) tool system.(5) electrical. Including the main motor, servo motor specifications and power etc..(6) cooling system. Including the cooling capacity, cooling pump output.(7) dimensions. Expressed as length * width * height.Development trend of CNC lathe:High speed, precision, complex, intelligent and green is the general trend in the development of CNC machine tool technology, in recent years, made gratifying achievements in practicality and industrialization. Mainly in the:1 machine tool composite technology to further expand with the CNC machine tool technology, composite processing technology matures, including milling - car compound, car milling compound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining is greatly improved. "One machine is a processing factory", "one card, complete processing" concept is being accepted by more people, the development of compound processing machine tool is the trend of diversified.Intelligent technology 2 CNC machine tools have a new breakthrough, in the performance of NC system has been reflected more. Such as: automatically adjust the interference anti-collision function, after the power of workpiece automatically exit safety power-off protection function, machining parts detection and automatic compensation function of learning, high precision machining parts intelligent parameter selection function, process automatic elimination of machine vibration functions into the practical stage, intelligent upgrade the function of machine and quality.The 3 robots enable flexible combination of flexible combination of higher efficiency of robot and the host are widely used, make flexible line more flexible, extending the function, flexible line shorten further, more efficient. Robot and machining center, milling composite machine, grinder, gear processing machine tool, tool grinding machine, electric machine, sawing machine, punching machine, laser cutting machine, water cutting machine etc. various forms of flexible unit and flexible production line has already begun the application.4 precision machining technology has the machining precision of CNC metal cutting machine tools from the yarn in the original (0.01mm) up to micron level (0.001mm), some varieties has reached about 0.05 μ M. Micro cutting and grinding machining of ultra precision CNC machine tools, precision can reach about 0.05 μ m, shape precision can reach about 0.01 μ M. Special processing precision by using optical, electrical, chemical, energy can reach nanomete r level (0.001 μ m). By optimizing the design of machine tool structure, machine tool parts of ultra precision machining and precision assembly, using high precision closed loop control and temperature, vibration and other dynamic error compensation technology, improve the geometric accuracy of machine tool processing, reduce the shape of error, surface roughness, and into the submicron, nano super finishing tiThe 5 functional component to improve the performance of functional components are at a high speed,high precision, high power and intelligent direction, and obtain the mature application. A full digital AC servo motor and drive device, high technology content of the electric spindle, linear motor, torque motor, linear motion components with high performance, application of high precision spindle unit and other function parts, greatly improving the technical level of CNC machine tools.The feed drive system of CNC lathe:Effect of feed drive system,The feed drive system of CNC machine tools will be received pulse command issued by the numerical control system, and the amplification and conversion machine movements carry the expected movement.Two, the feeding transmission system requirementsIn order to guarantee the machining accuracy of NC machine tool is high, the feed drive system of transmission accuracy, sensitivity high (fast response), stable work, high stiffness and friction and inertia small, service life, and can remove the transmission gap.Category three, feed drive system1, stepping motor servo systemGenerally used for NC machine tools.2, DC servo motor servo systemPower is stable, but because of the brush, the wear resulting in use need to change. Generally used for middle-grade CNC machine tools.3, AC servo motor servo systemThe application is extremely widespread, mainly used in high-end CNC machine tools.4, the linear motor servo systemNo intermediate transmission chain, high precision, the feed speed, no length limit; but the poor heat dissipation, protection requirements are particularly high, mainly used for high-speed machine.Driving component four, feed system1, the ball screw nut pairNC machining, the rotary motion into linear motion, so the use of screw nut transmission mechanism. NC machine tools are commonly used on the ball screw, as shown in Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmission side of high efficiency, small friction, and can eliminate the gap, no reverse air travel; but the manufacturing cost is high, can not lock, size is not too big, generally used for linear feed in small CNC machine tool.2, rotary tableIn order to expand the scope of the process of NC machine tools, CNC machine tools in addition to make linear feed along the X, Y, Z three coordinate axes, often also need a circumferential feed movement around Y or Z axis. Circular feed motion of CNC machine tools in general by the rotary table to realize, for machining center, rotary table has become an indispensable part of.Rotary table of commonly used CNC machine tools in the indexing table and NC rotary table.(1) indexing tableIndexing table can only finish dividing movement, not circular feed, it is in accordance with theinstructions in the NC system, when indexing will work together with the workpiece rotation angle. When indexing can also use manual indexing. Provisions of indexing table is generally only rotary angle (such as 90, 60 and 45 degree).(2) NC rotary tableNC rotary table appearance similar to the indexing table, but the internal structure and function is not the same. The main function of the NC rotary table is based on the numerical control device sends command pulse signal, complete circumferential feed movement, various arc processing and surface processing, it can also be graduation work.3, guideRail is an important part of feed drive system, is one of the basic elements of the structure of machine tool, rigidity, precision and accuracy of NC machine tool which determines to a large extent retention. At present, guide the NC machine tool are sliding rail, rolling guideway and hydrostatic guideway.(1) sliding guideSliding guide rail has the advantages of simple structure, easy manufacture, good stiffness, vibration resistance and high performance, widely used in CNC machine tools, the use of most metal plastic form, known as the plastic guide rail, as shown in figure 1-26.On characteristics of the plastic sliding guide: friction characteristic is good, good wear resistance, stable movement, good manufacturability, low speed.(2) rolling guideRolling guide is placed in the rail surface between the ball, roller or needle roller, roller, the rolling friction instead of sliding surface of the guide rail between wipe.Rolling guide rail and the sliding rail, high sensitivity, small friction coefficient, and the dynamic, static friction coefficient is very small, so the motion is uniform, especially in the low speed movement, the stick-slip phenomenon is not easy to occur; high posit ioning accuracy, repeatability positioning accuracy is up to 0.2 μ m; traction force is small, wear small, portable in movement; good precision, long service life. But the vibration of rolling guide, high requirements on protection, complicated structure, difficult manufacture, high cost Automatic tool changer:One, the function of automatic tool changerAutomatic tool changing device can help save the auxiliary time of CNC machine tools, and meet in an installation completed procedure, step processing requirements.Two, on the requirement of automatic tool changerNumerical control machine tool for automatic tool changer requirement is: tool change quickly, time is short, high repetitive positioning accuracy, tool storage capacity is sufficient, small occupation space, stable and reliable work.Three, change the knife form1, rotary cutter replacementIts structure is similar to the ordinary lathe turret saddle, according to the processing of different objects can be designed into square or six angle form, consists of the NC system sends out the instruction to the rotarycutter.2, the replacement of the spindle head tool changeThe spindle head pre-loaded required tools, in order to machining position, the main motor is switched on, drives the cutter to rotate. The advantage of this method is that eliminates the need for automatic clamping, cutting tool, clamping and cutting tool moving and a series of complex operation, reduce tool change time, improve the reliability of the tool change.3, the use of changing toolThe processing required tools are respectively arranged in the standard tool, adjust the size of the machine after certain way add to the knife, the exchange device from the knife and the spindle take knife switch.Four, the tool switching deviceAutomatic tool change device, device for knife library and the main shaft transmission and handling tool for tool exchange device. Tool exchange often have two kinds: mechanical hand tool exchange and by relative motion of knife and machine tool spindle exchange tool (cutter to the spindle tool change or movement of the spindle to the knife knife tool change position), the mechanical hand tool change is most common.Five, the knifeThe knife is one of the most important parts in automatic tool changer, have great influence on the overall design of NC machine tool and its capacity, layout and structure.1, the capacity of the tool storageA number of knife inventory cutters, generally depending on the processing requirements. The capacity of small knife, can not meet the processing needs; capacity is too large, will make the knife database size, covers an area of large, tool selection process for a long time, and the knife library utilization rate is low, the structure is too complex, causing great waste.2, the knife typeGenerally, the chain disc and drum type knife several.Disc cutter tool was circular arrangement, low utilization of space, size is not large but simple structure.Chain magazine compact structure, large capacity, link shape can also be random bed made of various forms and flexible layout, but also will change the cutter location prominent for tool change, widely used.Drum type or lattice type knife, covers an area of small, compact structure, large capacity, but cutter selection, tool movements are complicated, for centralized knife system for FMS.3, tool selectionOften order tool selection and random selection tool two.The order of tool selection is before processing, the processing required tools to process sequence of insert knife knife, order not wrong, processing adjust knife in order. The work piece changes, the need to reset the tool sequence, the operation is simple, and the processing tool with a workpiece can not be repeated use.A knife is the cutting tool has its own code, optional and can be repeatedly used in processing, also do not put in the fixed knife, knife, the knife is convenient.Technology file is the guiding file workers during processing, process scheme is reasonable, not only affect the efficiency of NC machining, and will directly affect the machining quality. Therefore, before NCprogramming, NC machining process follows the process of certain principles and combined with the characteristics of CNC lathe seriously and develop in detail the good parts.In the CNC lathe processing parts, should according to the principle of dividing process concentrated, in a fixture as far as possible to complete the most or even all of the surface processing. Part positioning, according to the structure of different shapes, usually cylindrical, face or end clamping, and strive to design basis, process reference and programming the unification datum.The main contents are: analysis of NC machining technology of part drawings, clear processing content; determination method, workpiece on lathe the surface processing sequence and tool feed line and cutting tools, fixtures and cutting the amount of choice.Analysis, part drawing processIn the machining process planning of parts, first of all to carry on in-depth analysis to the processing object. For NC turning process should consider the following aspects:1 reading part drawing, analysis of geometric conditions of part contourIn turning process of manual programming, to calculate each node coordinates; in automatic programming, to define the components outline all geometric elements. Therefore, in the analysis of parts should pay attention to:Parts of the map is missing a dimension, the geometric conditions are not sufficient to constitute the part outline, influence;Map location map parts of the ambiguity or dimension is not clear, so that the program can't start;The part drawing geometry given is not reasonable, resulting in mathematical difficulties.The part drawing dimensioning methods should adapt to the characteristics of CNC lathe processing, should size or directly given coordinate dimension with the same standard.2 dimensional accuracy requirementsAnalysis of the pattern of parts size precision requirements, to determine whether achieve the turning process, and determine the process method to control the dimension precision. In the analysis process, but also can convert some dimensions such as size, incremental and absolute size and dimension chain calculation. In the use of NC lathe turning parts, average value of components often required size and maximum and minimum limit of size size as the basis of programming.3 shape and position accuracy requirementsPattern of parts tolerance of shape and location given is important foundation to ensure the parts precision. When machining parts, to determine the location reference and measurement reference according to the requirements, can also carry out some technical processing according to the special needs of CNC lathe parts, in order to control effectively the shape and position accuracy.4 requirements of surface roughnessSurface roughness is an important requirement of micro precision parts of the surface, but also the reasonable selection of NC lathe, cutting tools and cutting the amount determined on the basis of.5 material and heat treatment requirementsThe part drawing on material and heat treatment given requirements, is the choice of cutter, CNC lathe,cutting the amount determined on the basis of model.Automatic tool changing system is mainly to process the required tools, transmitted to the spindle clamping mechanism from the knife. A TC system by knife library, manipulator, which consists of a driving system. Basic requirements: tool 1 short change time 2 tool with high repeat positioning accuracy of 3 sufficient storage capacity of 4 knife library covers an area of small (compact) 5 safe and reliable.The knife is a knife storage device provides the required automatic machining process and tool changing needs; the automatic tool change mechanism and can put the tool storage of the knife. Controlled by the computer program, can complete a variety of machining different needs, such as milling, drilling, boring, tapping etc.. Shorten the process, reduce the production cost.The knife is a knife storage location, and according to the control program, to determine the correct tool to position, to exchange tool; tool change mechanism is the implementation of tool exchange action. The knife must exist at the same time and tool change mechanism, if no knife library processing required tools can't reserve; without tool change mechanism, then the processing required tools not knife Kuyi order replacement, and reduce non-cutting time to lose.Rotary motion of the knife is composed of a three-phase asynchronous motor with brake of the power source, the three-phase power supply through the AC contactor is supplied to the motor brake open, then the knife library operation, cut off the three-phase power supply brake locking, knife immediately stop running. Through the logical combination of indexing disk motion and related test element group, can make each Daotao accurate stop at the tool change position. Knife stopped at the tool change position, controlled by the cylinder sleeve in horizontal or vertical state, to facilitate mechanical hand for the knife, knife indexing table can be clockwise or counterclockwise rotation, which can search in the shortest possible time to the tool to change. The driving system of NC machine tool automatic tool changing system with hydraulic mechanism, pressure mechanism, electric cam mechanism. Nowadays the cam tool changer is used widely. Really fast, but no other consumable parts and maintenance requirements change, the failure rate at least, life of more than one million times. Speed changer system for rapid automatic tool changing technology is mainly aimed to reduce the processing time, the comprehensive consideration of various factors of machine tools, complete the technical method of tool exchange in the shortest possible time. The machine has the following features: 1 knife arm is short 2 knife arm is not necessarily linear 3 two knife may mutually perpendicular 4 cam box is small and mobile. Its main purpose is to let the knife, the movable parts of small moment of inertia, in order to achieve the purpose of quick change knife. Foundation to improve the automatic changing device in the traditional method of knife cutter changing speed of increase movement speed, or the mechanism action faster and a driving element. For example, change the knife speed mechanical cam structure is higher than that of hydraulic and pneumatic structure. According to the high speed machine tool structure design of knife and the knife changing device of form and position. For example, the knife machine tools and tool replacing device installed at the side of an upright post, in the high speed machine tool is more feeding movable column, in order to reduce the mass of the moving parts, the knife and tool replacing device should not be installed on the upright post. The formation of the optimal cutting parameters. Machining and turning centers is composed of mechanical equipment and CNC system, high efficiency, high precision of automatic machine for machiningof complex parts. This machine can be installed several knife, automatic tool change, installed in a card, to complete the milling, boring, vehicle processing, drilling, expansion joints, tapping. The reason why this kind of processing capacity, it is because it has a set of automatic tool changer. Automatically switch to the device in a variety of forms, is the main component of the knife, a manipulator and a driving device, although the tool change, tool selection, tool storage structure, mechanical hand types are different, but all is in the numerical control device and the programmable controller control, by the motor or hydraulic or pneumatic actuator driven knife base and the manipulator and the exchange tool selection. We refer to this as continuous processing to achieve a variety of process, the processing center or turning center, device selection and exchange for tool called automatic knife device (automatic tool change ATC). The main part of ATC is the knife, a manipulator and a driving device. The knife is the function of storage tool and knife next to be used accurately to the tool change position, in exchange for tool changing manipulator to complete the old and new tool. When the tool storage capacity is large, often far away from the main configuration and integral movement is not easy, it needs between the spindle and the tool library configuration tool change mechanism to perform the action of changing knife.The manipulator assembly is the current research focus, foreign study used camera and a force sensor and a microcomputer connected together, can identify the parts of the range to reach the aim of inlaid. At present the industry manipulator is mainly used for machining, casting, heat treatment, regardless of the number, variety and performance still can not meet the needs of industrial development. The main is to gradually expand the scope of application, mechanical hand to focus on the development of casting, heat treatment, in order to reduce labor intensity, improve working conditions, the application of special mechanical hand at the same time, the development of general machinery corresponding hand, has the condition to develop teaching manipulator, computer control of manipulator and the combination of manipulator. The motion of the manipulator components, such as expansion, swing, lifting, shifting, pitch mechanism and a clamping mechanism of different types according to the design into a common mechanism, typical, so according to the different requirements of different types of clamping mechanism, can form different manipulator path. Both for the design and manufacture, is convenient for the replacement of the workpiece, expand the scope of application. At the same time to improve speed, reduce the impact, correct positioning, in order to better play the role of manipulator. In addition to research on servo type, memory reappearance type, as well as with tactile, visual properties such as mechanical hand, and consider the connected with computer, and gradually become a basic unit of the whole machinery manufacturing system. In the mechanical manufacturing industrial manipulator is used more, faster development. Now mainly used for machine, horizontal forging press feeding and discharging, and spot welding, paint spraying operations, which can be used to complete the operation in advance in accordance with the specified procedure. In addition, the development trend of foreign manipulator is developing manipulator has some kind of intelligence. It has the ability to change sensor, can feedback to external conditions, make corresponding changes. Such as the location of a deviation, which can correct and self detection, focus on visual function and tactile function research. At present, have made certain achievements. Visual function is mounted on a manipulator has a TV camera and optical rangefinder (i.e. distance sensor) and micro computer. Work is a television camera will object image into the video signal, andthen sent to the computer, in order to analyze the types of objects, size, color and location, and sends out the instruction to control the manipulator to work. Tactile function is tactile feedback control device is mounted on a manipulator. When the mechanical hand first finger to find work, produce the tactile effect through the pressure sensitive element is arranged on the finger, and then into the front, seize the workpiece. Hand grasping force control through the sensitive element is arranged on the finger, to achieve automatic adjustment grip size. In short, as the capacity of assembly work development of mechanical sensing technology will also further improve the hand. More important is the manipulator, the flexible manufacturing system and flexible manufacturing unit combination, so as to fundamentally change the current manufacturing system operation state.中文译文关于数控车床和换刀系统数控机床是数字控制机床（Computer numerical control machine tools）的简称，是一种装有程序控制系统的自动化机床。
数控技术类外文文献翻译、中英文翻译、外文翻译
外文原文：NC Technology1、Research current situation of NC lathe in our timesResearch and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that people's knowledge plays is more outstanding, and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times:（1）、Pay more attention to new technology and innovationWorldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc.. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly.（2）、Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center, are improving rigidity of the lathe, reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe, repeat precision, working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate, software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed.（3）、Improve the research of the machine tooling productivityWorld NC lathe, machining center and corresponding some development of main shaft, electrical machinery of straight line, measuring system, NC system of high speed, under the prerequisite of boosting productivity.（4）、What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedlyA、Intelligent research of the numerical control systemMainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control, adaptive operation , discerning automatically load selects models automatically, since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc..B、The numerical control system melts and studies openMainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety, different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm, disposing the norm, operation platform, numerical control systematic function storehouse and numerical control systematic function software developing instrument, etc. are the core of present research to pass through.C、Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it is a basic unit of realizing the new manufacture mode too.2、Classification of the machining center（1）Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center.Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up. Horizontal machining center for 3-5 sport coordinate axis, acommon one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the working bench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece. Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, the price is high.Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the working bench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally, can find a room for one horizontal numerical control revolving stage (the 4th axle) of axle process the spiral part at working bench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures, can carry on the processing of most work pieces.Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine.Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting, can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest, save 2 times install and insert working, thus improve production efficiency, reduce the process cost.（2）Classify by craft useIs it mill machining center to bore, is it mill for vertical door frame machining center, horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction.（3）Classify by special functionSingle working bench, a pair of working bench machining center;Single axle, dual axle, three axle can change machining center, main shaft of case;Transfer vertically to the tower machining center and transfer;One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers;One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center.3、Development trend of the current numerical control latheAt present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultrafast cutting , ultraprecision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions.（1）. The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe, it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile, adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability, namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe working bench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology, make it lag behind error reduce greatly, thus improve the machining accuracy cut in corner not to track.For meet ultrafast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc.. At present, ceramic cutter and diamond coating cutter have already begun to get application.（2）. Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100 of the above ) automatically tofurnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe, realize so-called "the front desk processes, the backstage supporter is an editor ". In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too.（3）. Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state , thus get the higher machining accuracy and roughness of smaller surface , can improve the service life of the cutter and production efficiency of the equipment at the same time . Diagnose by oneself, repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down, adopt the measure of shutting down etc. immediately, carry on the fault alarm, brief on position, reason to break down, etc.. Can also make trouble module person who take off automatically, put through reserve module ,so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires, its development trend adopts the artificial intelligence expert to diagnose the system.（4）.Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD draw process pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great differencetheir programming necessary processing technology parameter needn't by artificial to participate in most, get from CAPP database in system directly.（5）. The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time. The numerical control system will adopt the circuit chip of higher integrated level, will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts, to improve dependability. Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module, standardization, universalization and seriation of the structure lathe noumenon of the hardware at the same time, make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on. Still through operating and starting many kinds of diagnostic programs of diagnosing, diagnosing, diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware, software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part " redundantly ", in order to realize the trouble resumes by oneself; Utilize various kinds of test, control technology, excess of stroke, knife damages, interfering, cutting out, etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically.（6）. Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine, electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installation method , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more.本文出自：Shigley J E. Mechanical Engineering Design. New York: McGraw-Hill, 1998译文：数控技术1、当前世界NC机床的研究现状世界各国对数控机床、加工中心以至FMS、CIMS等各种新技术的研究与发展进程，是与世界经济形势紧密相连的。
精密机械加工工艺外文文献翻译、中英文翻译、外文翻译
1．圆偏心轮的工作原理
2．圆偏心轮的夹紧行程及工作段
3.偏心轮的自锁条件
αmax≤Φ1+Φ2
推导得：f1≥2e／D
当f= 0.1时，e／D≥20当f= 0.15时，e／D≥14
四、定心夹紧机构
2.杠杆式定心夹紧机构
杠杆式三爪自定心卡盘中，滑套作轴向移动时，圆周均布的三个钩形杠杆便绕轴转动，拨动三个滑块沿径向移动，从而带动其上卡爪将工件定心并夹紧或松开。
这种定心夹紧机构具有刚性大、动作快、增力倍数大、工作行程也比较大等特点，但其定心精度较低。一般为0.1mm左右，它主要用于工件的粗加工。由于杠杆机构不能自锁，所以这种机构自锁要靠气压或其它机构。
3.使用性好。夹紧装置的操作应当方便、安全、省力。
三、基本夹紧机构
原始作用力转化为夹紧力是通过夹紧机构来实现的。在众多的夹紧机构中以斜楔、螺旋、偏心以及由它们组合而成的夹紧机构应用最为普遍。
1.斜楔夹紧机构
采用斜楔作为传力元件或夹紧元件的夹紧机构称为斜楔夹紧机构。直接采用斜楔夹紧时，斜楔的自锁条件是：斜楔的升角小于斜楔与工件、斜楔与夹具体之间的摩擦角之和.即：
4.弹簧筒夹式定心夹紧机构
这种定心夹紧机构常用于安装轴套类工件。
弹性定心夹紧机构的结构简单、体积小、操作方便迅速，因而应用十分广泛。其定心精度可稳定在0.04mm0.010mm之间。除上述介绍的定心夹紧机构外，常用的还有膜片卡盘机构、波纹套定心夹紧机构以及液性塑料夹紧机构等。
夹具是机械加工中不可缺少的部件，在机床技术向高速、高效、精密、复合、智能、环保方向发展的带动下，夹具技术正朝着高精、高效、模块、组合、通用、经济方向发展。
机床数控化改造外文文献翻译、中英文翻译
外文资料First, CNC of the need for transformation1.1, microscopic view of the necessity ofFrom the micro perspective, CNC machine tools than traditional machines have the following prominent superiority, and these advantages are from the NC system includes computer power.1.1.1 can be processed by conventional machining is not the curve, surface and other complex partsBecause computers are superb computing power can be accurately calculated instantaneous each coordinate axis movement exercise should be instantaneous, it can compound into complex curves and surfaces.1.1.2 automated processing can be achieved, but also flexible automation to increase machine efficiency than traditional 3 to 7 times.Because computers are memory and storage capacity, can be imported and stored procedures remember down, and then click procedural requirements to implement the order automatically to achieve automation. CNC machine tool as a replacement procedures, we can achieve another work piece machining automation, so that single pieces and small batch production can be automated, it has been called "flexible automation."1.1.3 high precision machining parts, the size dispersion of small, easy to assemble, no longer needed "repair."1.1.4 processes can be realized more focused, in part to reduce the frequent removal machine.1.1.5 have automatic alarm, automatic control, automatic compensation, and other self-regulatory functions, thus achieving long unattended processing.1.1.6 derived from the benefits of more than five.Such as: reducing the labor intensity of the workers, save the labor force (onecan look after more than one machine), a decrease of tooling, shorten Trial Production of a new product cycle and the production cycle, the market demand for quick response, and so on.These advantages are our predecessors did not expect, is a very major breakthrough. In addition, CNC machine tools or the FMC (Flexible Manufacturing Cell), FMS (flexible manufacturing system) and CIMS (Computer Integrated Manufacturing System), and other enterprises, the basis of information transformation. NC manufacturing automation technology has become the core technology and basic technology.1.2, the macro view of the necessityFrom a macro perspective, the military industrial developed countries, the machinery industry, in the late 1970s, early 1980s, has begun a large-scale application of CNC machine tools. Its essence is the use of information technology on the traditional industries (including the military, the Machinery Industry) for technological transformation. In addition to the manufacturing process used in CNC machine tools, FMC, FMS, but also included in the product development in the implementation of CAD, CAE, CAM, virtual manufacturing and production management in the implementation of the MIS (Management Information System), CIMS, and so on. And the products that they produce an increase in information technology, including artificial intelligence and other content. As the use of information technology to foreign forces, the depth of Machinery Industry (referred to as information technology), and ultimately makes their products in the international military and civilian products on the market competitiveness of much stronger. And we in the information technology to transform traditional industries than about 20 years behind developed countries. Such as possession of machine tools in China, the proportion of CNC machine tools (CNC rate) in 1995 to only 1.9 percent, while Japan in 1994 reached 20.8 percent, every year a large number of imports of mechanical and electrical products. This also explains the macro CNC transformation of the need.Second, CNC machine tools and production lines of the transformation of the market2.1, CNC transformation of the marketMy current machine total more than 380 million units, of which only the total number of CNC machine tool 113,400 Taiwan, or that China's CNC rate of less than 3 percent. Over the past 10 years, China's annual output of about 0.6 CNC machine tools to 0.8 million units, an annual output value of about 1.8 billion yuan. CNC machine tools annual rate of 6 per cent. China's machine tool easements over age 10 account for more than 60% below the 10 machines, automatic / semi-automatic machine less than 20 per cent, FMC / FMS, such as a handful more automated production line (the United States and Japan automatic and semi-automatic machine, 60 percent above). This shows that we the majority of manufacturing industries and enterprises of the production, processing equipment is the great majority of traditional machine tools, and more than half of military age is over 10 years old machine. Processing equipment used by the prevalence of poor quality products, less variety, low-grade, high cost, supply a long period, in view of the international and domestic markets, lack of competitiveness, and a direct impact on a company's products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously raise the rate of CNC machine tools.2.2, import equipment and production lines of the transformation of NC marketSince China's reform and opening up, many foreign enterprises from the introduction of technology, equipment and production lines for technological transformation. According to incomplete statistics, from 1979 to 1988 10, the introduction of technological transformation projects are 18,446, about 16.58 billion US dollars.These projects, the majority of projects in China's economic construction play a due role. Some, however, the introduction of projects due to various reasons, not equipment or normal operation of the production line, and even paralyzed, and the effectiveness of enterprises affected by serious enterprise is in trouble. Some of the equipment, production lines introduced from abroad, the digestion and absorption of some bad, spare parts incomplete, improper maintenance, poor operating results; onlypay attention to the introduction of some imported the equipment, apparatus, production lines, ignore software, technology, and management, resulting in items integrity, and potential equipment can not play, but some can not even start running, did not play due role, but some production lines to sell the products very well, but not because of equipment failure production standards; because some high energy consumption, low pass rate products incur losses, but some have introduced a longer time, and the need for technological upgrading. Some of the causes of the equipment did not create wealth, but consumption of wealth.These can not use the equipment, production lines is a burden, but also a number of significant assets in stock, wealth is repaired. As long as identifying the main technical difficulties, and solve key technical problems, we can minimize the investment and make the most of their assets in stock, gain the greatest economic and social benefits. This is a great transformation of the market.Third, NC transformation of the content and gifted missing3.1, the rise of foreign trade reformIn the United States, Japan and Germany and other developed countries, and their machine transform ation as new economic growth sector, the business scene, is in a golden age. The machine, as well as technology continues to progress, is a machine of the "eternal" issue. China's machine tool industry transformation, but also from old industries to enter the CNC technology mainly to the new industries. In the United States, Japan, Germany, with CNC machine tools and technological transformation of production lines vast market, has formed a CNC machine tools and production lines of the new industry. In the United States, transforming machine tool industry as renewable (Remanufacturing) industry. Renewable industry in the famous companies: Borsches engineering company, atoms machine tool company, Devlieg-Bullavd (Bo) services group, US equipment companies. Companies in the United States-run companies in China. In Japan, the machine tool industry transformation as machine modification (Retrofitting) industry. Conversion industry in the famous companies: Okuma engineering group, Kong 3 Machinery Company, Chiyoda Engineering Company, Nozaki engineering company, Hamada engineeringcompanies, Yamamoto Engineering Company.3.2, the content of NCMachine tools and production line NC transformation main contents of the following:One is the restoration of the original features of the machine tools, production line of the fault diagnosis and recovery; second NC, in the ordinary machine augends significant installations, or additions to NC system, transformed into NC machine tools, CNC machine tools; its Third, renovation, to improve accuracy, efficiency and the degree of automation, mechanical, electrical part of the renovation, re-assembly of mechanical parts processing, restore the original accuracy of their production requirements are not satisfied with the latest CNC system update; Fourth, the technology updates or technical innovation, to enhance performance or grades, or for the use of new technology, new technologies, based on the original technology for large-scale update or technological innovation, and more significantly raise the level, and grades of upgrading.3.3, NC transformation of the gifted missing3.3.1 reduce the amount of investment, shorter delivery timeCompared with the purchase of new machine, the general can save 60% to 80% of the costs and transforming low-cost. Especially for large, special machine tools particularly obvious. General transformation of large-scale machine, spent only the cost of the new machine purchase 1 / 3, short delivery time. But some special circumstances, such as high-speed spindle, automatic tray switching systems and the production of the installation costs too costly and often raise the cost of 2 to 3 times compared with the purchase of new machine, only about 50 percent of savings investment.3.3.2 stable and reliable mechanical properties, structure limitedBy the use of bed, column, and other basic items are heavy and solid casting components, rather than kind of welding components of the machine after the high-performance, quality, and can continue to use the new equipment for many years. But by the mechanical structure of the original restrictions, it is not appropriate to thetransformation of a breakthrough.3.3.3 become familiar with the equipment, ease of operation and maintenanceThe purchase of new equipment, new equipment do not know whether to meet the processing requirements. Transformation is not, can be used to calculate the machine processing capacity; In addition, since the use of many years, the operator of the machine has long been understood that in the operation, use and maintenance of the training time is short, quick. Transformation of the machine tools installed, we can achieve full load operation.3.3.4 can take full advantage of the existing conditionsTake full advantage of the existing foundation, not like buying new equipment as necessary to build a foundation.3.3.5 can be used as control technologyAccording to the development speed of technological innovation and in a timely manner increased level of automation in production equipment and efficiency, improve the quality of equipment and grades, and the old machine will be replaced by the current level of machine.Fourth, the main steps of CNC machine tools4.1, for the determination of transformationThrough analysis of the feasibility of transforming the future, we can against a Taiwan or a few machines determine the current status of reform programmes, which are generally include:4.1.1 mechanical and electrical repair of combiningGenerally speaking, the need for a transformation of the electrical machine, are subject to mechanical repairs. Repairs to determine the requirements, scope, content must be decided by electrical machinery required to transform the structure of the request; transformation to determine electrical and mechanical repair, alteration between the staggered time requirements. The mechanical properties of intact electrical transform the basis of success.4.1.2 easy first, and to the overall situation after the first localThe removal of the original system must control the original drawings, carefully, to make drawings in a timely manner marked to prevent the demolition or omission (of local circumstances). In the process of demolition will discover some new system design in the gaps, and that should be promptly added, removed and parts of the system should be disaggregated, safekeeping, in case of failure or partial failure reinstated. There is a definite value, and can be used for spare parts for other machines. Must not extravagantly used and misplaced.4.2 reasonable arrangements for a new location and routing systemUnder the new system design drawings and reasonable new system configurations, including fixed box, panel installation, alignments, and the fixed position adjustment components, sealing and necessary, such as decoration. Connection must be a clear division of work, it was reviewed inspection to ensure connectivity of norms, diameter appropriate, accurate, reliable handsome.4.3 DebuggingCommissioning must be identified in advance by the steps and requirements. Debugging should be cool-headed, keep records, in order to identify a nd solve problems. Commissioning of the first test sensitivity security protection systems to prevent physical, equipment accidents. Debugging the scene must be cleaned, no superfluous items; coordinates extension units in the campaign centre of the whole trip; empty can test, first empty after loading; can simulate the test, after the first real dynamic simulation; can manually the upper hand After moving automatically.4.4, acceptance and post-workAcceptance of the work to employ the staff to join, has been developed in accordance with the acceptance criteria. The transformation of the late work is also very important, it is conducive to enhancing the level of technical projects and equipment as soon as possible so that production. Acceptance and post include:4.4.1 machine mechanical properties acceptanceAfter mechanical repairs and maintenance as well as a full transformation, the mechanical properties of the machine tools should meet the requirement, in the geometric accuracy should be within the limits prescribed.4.4.2 electrical control function and control accuracy acceptanceElectrical control the various functions of action must be normal, sensitive and reliable. Application control accuracy of the system itself functions (such as stepping dimensions, etc.) and standard measurement apparatus (such as laser interferometer, coordinate measurement machines) inspection, the scope of accuracy achieved. At the same time also and the transformation of the former machine tool accuracy of the various functions and to contrast, poor access to quantifiable indicators.4.4.3 specimen cutting AcceptanceYou can refer to the CNC machine tool cutting at home and abroad specimen standards, qualified operatives, with the programming staff to test cutting. Acceptance specimen cutting machine stiffness can be cutting, noise, trajectory, and other related actions, the general should not be used for product components specimen use.4.4.4 drawings, information acceptanceMachine transformation of the latter should be timely drawings (including schematics, layout plans, wiring diagram, ladder diagram, etc.), information (including various brochures), the transformation of files (including the transformation before and after the various records) summary, collating, transfer to stall. Maintain data integrity, effective, continuous, and that the future stability of the equipment running is very important.4.4.5 summing up, enhancingAfter the end of each should be promptly summed up, helps improve the operational level of technical personnel, but also conducive to the whole enterprise technical progress.中文译文一、机床数控化改造的必要性1.1、微观看改造的必要性从微观上看，数控机床比传统机床有以下突出的优越性，而且这些优越性均来自数控系统所包含的计算机的威力。
数控机床外文文献翻译、中英文翻译
数控机床外文文献翻译、中英文翻译原文一CNC machine toolsOutdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool，JohnWiley & sons, 2001While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing work pieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each work piece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing work pieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate work pieces. T oday's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical work pieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine toolsis flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements.Motion control - the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion control. Rather than applying completely mechanical devices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (federate) are programmable with almost all CNC machine tools.A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw.And the ball screw drives the linear axis (slide). A feedbackdevice (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1.fig.1 typical drive system of a CNC machine toolThough a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded - understanding coordinate systemsIt would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount4. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the more popular of these two is the rectangular coordinate system.The program zero point establishes the point of reference for motion commands in a CNC program. This allows the programmer to specify movements from a common location. If program zero is chosen wisely, usually coordinates needed forthe program can be taken directly from the print.With this technique, if the programmer wishes the tool to be sent to a position one inch to the right of the program zero point, X1.0 is commanded. If the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3.fig.2, 3.Understanding absolute versus incremental motionAll discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion.In the incremental mode (commonly specified by G91), endpoints for motions are specified from the tool's current position, not from program zero. With this method of commanding motion, the programmer must always be asking "How far should I move the tool?" While there are times when the incremental mode can be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode.Be careful when making motion commands. Beginners have the tendency to think incrementally. If working in the absolute mode (as beginners should), the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position.Aside from making it very easy to determine the current position for any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one command of the program, only one movement will be incorrect. On the other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect.Assigning program zeroKeep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. With this method, the programmer tells the control how far it is from the program zero point to the starting position of the machine. This is commonly done with a G92 (or G50) command at least at the beginning of the program and possiblyat the beginning of each tool.Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets.fig.4 assign program zero through G54Flexible manufacturing cellsA flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS:1.An FMC is not under the direct control of thecentral computer. Instead, instructions from the centralcomputer are passed to the cell controller.2.The cell is limited in the number of part families itcan manufacture.The following elements are normally found in an FMC:Cell controllerProgrammable logic controller (PLC)More than one machine toolA materials handling device (robot or pallet)The FMC executes fixed machining operations with parts flowing sequentially between operations.High speed machiningThe term High Speed Machining (HSM) commonly refers to end milling at high rotational speeds and high surface feeds. For instance, the routing of pockets in aluminum airframe sections with a very high material removal rate1. Refer to fig.5 for the cutting data designations and for mulas. Over the past 60 years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the production of components with specific surface topography requirements and machining of materials with hardness of 50 HRC and above. With most steel components hardened to approximately 32-42 HRC, machining options currently include:Fig.5 cutting datarough machining and semi-finishing of the material in its soft (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting tools) finishing and super-finishing of cylindrical/flat/cavity surfaces with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves acombination of these options and in the case of dies and moulds it also includes time consuming hand finishing. Consequently, production costs can be high and lead times excessive.It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering.The main criteria are the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy.One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times.Main economical and technical factors for the development of HSMSurvivalThe ever increasing competition in the marketplace is continually setting new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions...MaterialsThe development of new, more difficult to machine materials has underlined the necessity to find new machining solutions.The aerospace industry has its heat resistant and stainless steel alloys. The automotive industry has different bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The die and mould industry mainly has to face the problem of machining high hardened tool steels, from roughing to finishing.QualityThe demand for higher component or product quality is the result of ever increasing competition. HSM, if applied correctly, offers a number of solutions in thisarea. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry.ProcessesThe demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes can also be reduced or eliminated with HSM.Design & developmentOne of the main tools in today's competition is to sell products on the value of novelty. The average product life cycle on cars today is 4 years, computers and accessories 1.5 years, hand phones 3 months... One of the prerequisites of this development of fast design changes and rapid product development time is the HSM technique.Complex productsThere is an increase of multi-functional surfaces on components, such as new design of turbine blades giving newand optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpiece that have to be machined (medical equipment, electronics, defense products, computer parts).Production equipmentThe strong development of cutting materials, holding tools, machine tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5.Definition of HSMSalomon's theory, "Machining with high cutting speeds..." on which, in 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than in conventional machining), the chip removal temperature at the cutting edge will start to decrease...".See fig.6.Fig.6 chip removal temperature as a result of the cutting speedGiven the conclusion:" ... seems to give a chance to improve productivity in machining with conventional tools at high cutting speeds..."Modern research, unfortunately, has not been able to verifythis theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials.The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors.Given today's technology, "high speed" is generally accepted to mean surface speeds between 1 and 10 kilometers perminute, or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being used. One trend which is very evident today is the use of very large cutter diameters for these applications - and this has important implications for tool design.There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshooting Maintenance for a horizontal MCThe following is a list of required regular maintenance for a Horizontal Machining Center as shown in fig.7. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty.Fig. 7 horizontal machining centerDailyTop off coolant level every eight hour shift (especially during heavy TSC usage).Check way lube lubrication tank level.Clean chips from way covers and bottom pan.Clean chips from tool changer.Wipe spindle taper with a clean cloth rag and apply light oil.WeeklyCheck for proper operation of auto drain on filter regulator. See fig. 8Fig. 8 way lube and pneumaticsOn machines with the TSC option, clean the chip basket on the coolant tank.Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank. Do this monthly for machines without the TSC option.Check air gauge/regulator for 85 psi.For machines with the TSC option, place a dab of grease on the V-flange of tools. Do this monthly for machines without the TSC option.Clean exterior surfaces with mild cleaner. DO NOT usesolvents.Check the hydraulic counterbalance pressure according to the machine's specifications.Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools".MonthlyCheck oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank.Clean pads on bottom of pallets.Clean the locating pads on the A-axis and the load station. This requires removing the pallet.Inspect way covers for proper operation and lubricate with light oil, if necessary.Six monthsReplace coolant and thoroughly clean the coolant tank.Check all hoses and lubrication lines for cracking.AnnuallyReplace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil.Check oil filter and clean out residue at bottom for the lubrication chart.Replace air filter on control box every 2 years.Mineral cutting oils will damage rubber based components throughout the machine.TroubleshootingThis section is intended for use in determining the solution to a known problem. Solutions given are intended to give the individual servicing the CNC a pattern to follow in, first, determining the problem's source and, second, solving the problem.Use common senseMany problems are easily overcome by correctly evaluating the situation. All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault.Don't suspect machine accuracy if the vise bends the part. Don't claim hole miss-positioning if you don't first center-drill the hole.Find the problem firstMany mechanics tear into things before they understand the problem, hoping that it will appear as they go. We know this from the fact that more than half of all warranty returned parts are in good working order. If the spindle doesn't turn, remember that the spindle is connected to the gear box, which is connected to the spindle motor, which is driven by the spindle drive, which is connected to the I/O BOARD, which is driven by the MOCON, which is driven by the processor. The moral here is doing replace the spindle drives if the belt is broken. Find the problem first; don't just replace the easiest part to get to.Don tinker with the machineThere are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, reconnect and reload, and if you make one mistake or bend one tiny pin itWON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better.译文一数控机床虽然各种数控机床的功能和应用各不相同，但它们有着共同的优点。
数控技术 外文翻译 外文文献 英文文献 数控技术的发展与维修
Development and maintenance of CNC technology Numerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in "sophisticated" technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.Part I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliabilityHigh speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. CompositeComposite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. IntelligentIntelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integratedThe world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology.Second, personalization is the adaptability of the market trendsToday's market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the user's individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend isThe core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface.CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine MaintenanceCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use.CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails,Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation.Second, the fault information collation, analysis. For some simple fault, because not alot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse ①②drive is not enough time to move the state line to control the spindle components ③④damage to the spindle motor short-circuit, causing the spindle thermal relay protection ⑤ not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one.Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier.CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination methodRoutine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the "first post outside of" the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function methodModern CNC system has yet to achieve a high degree of intelligence. But already has a strong self-diagnostic function. CNC ready to monitor the hardware and software is working. Once the abnormal, immediately displayed on the CRT alarm or fault LEDs indicate the approximate cause. Using self-diagnosis function, but also shows the interface signals between the system and the host state, in order to determine the fault occurred in themechanical part or parts of NC system, and indicate the approximate fault location. This method is currently the most effective maintenance methods.3. Functional program testing methodSo-called functional program testing method is commonly used in the numerical control system functions and special features, such as linear positioning, circular interpolation, helical cut, fixed cycle, such as the user macro programming by hand or automatic programming methods, the preparation of test procedures into a functional program , into the numerical control system, and then start the CNC system to make it run, to check the im time the first boot of CNC whether a programming error or operational error or machine4. Spare parts substitutionSpare parts replacement method is a simple method to determine the scene is one of the most commonly used. The so-called spare substitution is generally the cause of failure in the analysis of the case, maintenance personnel can use the alternate PCB, templates, integrated circuit chip or replace the questionable parts of components, which narrowed the fault to a printed circuit board or chip level. It is actually in the verification analysis is correct. However, before switching the standby board should carefully check the spare board is intact, and should check the status of reserve board should be fully consistent with the original board the state. This includes checking with the board selection switch, set the location and the short rod potentiometer position. In short, we must strictly in accordance with the system's operation, maintenance requirements manual operation.In determining the replacement of a part to, should carefully check the relevant connected to electrical lines and other related, confirming that no failure up to the new replacement to prevent failures caused by external damage to replace the parts up.5. Transfer ActThe so-called transfer method is to have the same numerical control system features two printed circuit boards, templates, integrated circuit chips or components to exchange, observed failure phenomena be transferred. In this way, the system can quickly determine the fault position. This method is actually a kind of spare parts substitution. Therefore, the considerations described in the same spare parts substitution.6. Parameter check methodKnown parameters can directly affect the numerical performance of CNC machine tools. Parameters are usually stored in the magnetic bubble memory, or stored in batteries to be maintained by the CMOS RAM, once the battery is low or because of outside interference and other factors, some parameters will be lost or change in chaos, so that the machine does not work. At this point, through the proofreading, correction parameters, will be able to troubleshoot. When the machine idle for a long time to work again for no reason that there is no normal or failure without warning, it should be based on fault characteristics, inspection and proof-reading the relevant parameters.After a long run of CNC machine tools, wear and tear due to its mechanical drive components, electrical component performance changes and other reasons, also need to adjust the parameters of its. Some machine tool failure is often not timely because the parameters change due to some not meet. Of course, these failures are the fault of the areas are soft.7. Measurement of Comparative LawCNC system in the design of printed circuit board manufacturing plant, in order to adjust, repair facilities, in the printed circuit board designed a number of test terminals. Users can also use normal printed circuit board terminals comparing the measured and the difference between the printed circuit board failure. These terminals can detect the voltage and waveform measurements, analyze the causes of failure and failure location. Even on a normal printed circuit board can sometimes artificially create "fault", such as broken connection or short circuit, unplug the components, in order to determine the real cause of failure. Therefore, maintenance personnel should be in the usual accumulation of key parts of the printed circuit board or failure-prone parts of the right in the normal waveform and voltage values. Because the CNC system manufacturer often does not provide the information in this regard.8. Percussion methodWhen the CNC system failures showed Ruoyouruowu, often used method for detecting the fault struck the site lies. This is because the numerical control system is composed by the multi-block printed circuit boards, each board has a lot of solder joints, plates or between modules and is connected through the connectors and cables. Therefore, any cold solder joint or bad, may cause a malfunction. When the tap with the insulation and poor contact with Weld doubt at fault must be repeated reproduction.9. Local heating methodAfter a long running CNC system components are to be aging, performance will deteriorate. When they are not fully damaged, failures will become from time to time. Then heat can be used such as a hair dryer or electric iron is suspected to local heating components, accelerating the aging so thoroughly exposed fault components. Of course, using this method, be sure to pay attention to components of the temperature parameters, do not roast the original device is a good or bad.10. Principle of analysisThe composition according to principles of numerical control system can be analyzed from various points of logical levels and logical parameters (such as voltage or waveform) and then with a multimeter, logic pen, only the oscilloscope or logic analyzer to measure, analyze and compare, and thus failure positioning. Using this method, which requires maintenance personnel to be on the whole system or the principle of each circuit have a clear, deep understanding.Based on the above principles and methods, we may be itemized on the check it and eliminate the causes.The first possible failure for the system output pulse time is not enough, we adjust the M-code system, start the spindle output time, found the problem still exists, and then find the next possible cause may be in the drive to move the state, refer to the manual drive , set parameters start the spindle, the problem still exists we suspected spindle motor short-circuit, resulting in thermal relay protection. Then find the cause of the short, so that the spindle thermal relay reset the start and found that the normal operation of the spindle, the problem solved.Fourth, do a lessons learned and recorded. After troubleshooting, repair work can not be considered complete, still need technical and management aspects of the underlying causes of failure have to take appropriate measures to prevent failures from happening again. Underfield conditions when necessary use of mature technologies to transform and improve the equipment. Finally, the failure of the maintenance of the phenomenon, cause analysis, resolution process, the replacement of components, legacy, etc. to make a record.数控技术的发展与维修数控技术及装备是发展新兴高新技术产业和尖端工业的使能技术和最基本的装备。
机械制造专业外文翻译--机床夹具的分类与构成
外文原文：Machine classification and pose fixture1 fixture in the role of machiningWorkpiece clamping fixture is a kind of process equipment, it is widely used in mechanical machining of the manufacturing process, heat treatment, assembly, welding and testing processes. In the use of metal-cutting machine tools collectively referred to as the jig fixture. n a modern production machine is an indispensable fixture of the process equipment, machining of the workpiece, the processing requirements in order to ensure. First of all to the workpiece and the machine tool relative to a correct position, and this location during processing does not change the impact of external forces. To this end, during the pre-machining, workpiece clamping must be good. There are two ways to clamp workpiece: one is directly clamping the workpiece in the machine table or on the chuck; The other is the workpiece in the fixture on the fixture. The first method used when the workpiece clamping, the general design requirements have to press lines in the surface to draw the size and location, clamping, or when the needle is zoned dial indicator to find is after the clamping. This method need special equipment, but low efficiency, are generally used for one-piece and small batch production. Large quantities, mostly with the workpiece clamping fixture. With the merits of the workpiece clamping fixtures are as follows: (l) Guarantee the stability of the machining accuracy of workpiece. Workpieces with clamping fixture, the workpiece relative to the location of tool and machine tool to ensure the accuracy of the fixture from the technical level of workers, so that a number of workpiece machining accuracy of the line.(2) To improve labor productivity. Workpiece clamping fixture can facilitate the user easily、rapidly, and the workpiece does not need to find is crossed, can significantly reduce the supplementary working hours, to improve labor productivity; workpiece in the fixture after the fixture to improve the rigidity of the workpiece, thus cutting the amount of increase, to improve labor productivity; can use more pieces of multi-workpiece clamping fixture, and the use of efficient clamping bodies, to further improve labor productivity.(3) To expand the use of machine tools. Machine tools in general use a dedicated machine tool fixture can expand the scope of the process and give full play to the potential of machine tools to achieve a multi-machine use. For example, the use of adedicated fixture can be easily Lathe processing small box to the workpiece. Even in the lathe out of oil, a reduction of expensive dedicated machines, reducing the cost, which is particularly important for small and medium-sized factories.(4) To improve the operator's working conditions. As the pneumatic, hydraulic, electro-magnetic power source, such as the application in the fixture, on the one hand to reduce the labor intensity of workers; the other hand, it guarantees the reliability of the workpiece clamping, and to achieve the interlocking machine, to avoid accidents, ensure the operator safety and machine tool equipment(5) To reduce costs. In mass production after the use of fixture, from stem to increase labor productivity, lower level technical workers, as well as lower scrap and other reasons, obviously to reduce the production costs.Fixture manufacturing cost-sharing in a group of workpieces, each workpiece to increase the cost is very minimal, far less than as a result of increased labor productivity and reduce costs. The greater volume of workpiece, fixture made to use has become more significant economic benefits.2 Fixture Category2.1 General characteristics of the fixture by CategoryAccording to the production in different types of fixtures in the common characteristics of machine tool fixture fixture can be divided into general, special fixtures, adjustable clamp, and automatic line of modular fixture fixture, such as: (l) General Fixture. Universal fixture refers to the structure, size has been standardized, and has a certain universal fixture. This type of fixture adaptable, can be used to setup the scope of a certain shape and size of various parts.(2)A dedicated fixture. This type of fixture is designed for a particular part of the processing procedures and the design and manufacture. Relatively stable in the product, the production of larger quantities, used a variety of special fixtures, access to higher productivity and machining accuracy. (3) Adjustable fixture. Adjustable fixture for general fixture and special fixture and the defects developed a new kind of fixture. Of different types and sizes of the workpiece, simply adjust or replace the fixture at the original location of the individual components and will be used to clamp components. （4) Modular Fixture. Modular fixture is a modular fixture. Standard components of the module with high precision and resistance to abrasion, can be assembled into a variety of fixtures. Removable fixture used to clean the assembly after the new fixture left. （5) Automatic line fixture. Automatic line clamp generally divided into two categories:fixed-type fixture, which is similar to a dedicated fixture; other accompanying a fixture for the use of the workpiece in the fixture, together with the movement, and automatic workpiece along the line from a move to the next position position for processing.2.2 Classification by the use of machine tools ClassificationBy the use of machine tools can be divided into lathe jig fixtures, milling fixtures, drilling fixtures, hang-bed fixture, jig gear machine, CNC machine tool fixture, automatic machine tool fixtures, accompanied by automatic line, and other fixtures, such as machine tools. This is a special fixture design of the classification method used. Dedicated fixture design, the machine group, the type and the main parameters have been determined. Their difference is the cutting forming machine tool movements, so the connection fixture with the machine in different ways. Machining accuracy of their different requirements.2.3 Clamping fixture according to the power sourceClamping fixture according to the power source can be divided into manual fixture, pneumatic fixtures, hydraulic fixtures, gas fixtures by force, electromagnetic fixture, vacuum fixtures, fixture, such as centrifugal force.3 the composition of fixtureAlthough the structure of machine tool fixture range, but their components can be summarized as the following sections.(1) Positioning components. Typically, when the shape of the workpiece datum position established, the position will be the basic components of the structure identified(2) Clamping device. Positioning of the workpiece in the fixture, the need to clamp the workpiece before processing to ensure that the workpiece during processing is not due to external force and undermine its position.(3) The specific folder. Fixture and the skeleton matrix, all the components through the fixture it will constitute a whole.(4) Of the knife or the guide. Tool used to determine position relative to the correct position of components. Of the knife device common in milling fixture. Used to adjust the cutter knife block position before machining.(5) To connect components. Connected components in the machine tool fixture is todetermine the correct position on the component, therefore, can double as a specific folder to connect components. Lathe fixture on the transition plate, the positioning ofmilling machine fixture on key components are connected.(6) Other devices or components. According to the processing needs, some degree fixture device were used by mode device, the whole device, and the balance of the top block and so on. These components or devices specially designed need.中文译文：机床夹具的分类与构成1机床夹具在机械加工中的作用夹具是一种装夹工件的工艺装备，它广泛地应用于机械制造过程的切削加工、热处理、装配、焊接和检测等工艺过程中。
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毕业设计(论文)外文资料翻译系部：专业：姓名：学号：外文出处：English For Electromechanical(用外文写)Engineering附件： 1.外文资料翻译译文；2.外文原文。
指导教师评语：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。
签名：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。