数控车床主传动系统毕业设计外文翻译

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CA6140无级变速车床主传动系统毕业设计 外文翻译

CA6140无级变速车床主传动系统毕业设计 外文翻译

车削中恒定切削力的自组织模糊控制Received: 13 October 2004 / Accepted: 3 January 2005 / Published online: 17 August 2005 Springer-Verlag London Limited 2005摘要:在现代制造中,恒定力的控制逐渐成为一项重要技术。

特别是恒定切削力的控制,它是一种提高金属切削质量与车削工具寿命的有效方法。

但是,车削系统一般有非线性和不确定性的动态特征。

设计恒定切削力的模拟控制器是很困难的,因为一个准确的数学模型在车削系统中是很难建立的。

因此,这项研究利用了一个自由模型的模糊控制器控制车削系统以便得到恒定的切削力。

然而,设计传统的模糊控制器(TFC) 时,数据库与TFC固定后,其设计很难及时的进行调节并且根据系统做出相应的输出响应,取得理想的控制效果。

为了解决上述问题,这里建立了自组织模糊控制器(SOFC)为恒定切削力的控制系统。

SOFC在车削控制过程中不断更新,它从零初始的模糊控制表开始,克服了TFC设计时的困难,但是也要在车削控制系统中建立相应的支持模糊控制器模糊控制表,从而确定所提出的智能控制器的适应性,这项工作对旧的车床车削系统作了翻新改进从而达到恒定切削力的控制。

实验成果已经证实,SOFC比TFC在恒定切削力上有更好的控制能力。

关键词:恒定切削力控制、自组织模糊控制器、车削系统。

1.引言在生产力和降低劳动成本的需要下,数控机床(CNC)已广泛应用于工业生产,其加工的零件具有很高的精度和形状复杂性。

在数控系统中用数值控制器(NC)设计电脑程序时,要求快速准确的控制车削刀具,这给生产力带来很大提高:统一的零件加工,而且较少依赖经验知识和熟练的机械操作。

在加工过程中,数控程序员通常选择组合机床类型及主轴速度。

按常规,数控程序员保守的选定机床参数及主轴速度是为了防止任何对刀具物理性的破坏。

这样一来降低了加工效率。

数控车床毕业设计外文翻译

数控车床毕业设计外文翻译

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 heavy construction 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 isthe 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 are heavy-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 to 3658mm(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 statements similar 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 computer numerical 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.The 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, andthe 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.车床车床主要是为了进行车外圆、车端面和镗孔等项工作而设计的机床。

机械类数控车床外文翻译外文文献英文文献数控

机械类数控车床外文翻译外文文献英文文献数控

机械类数控车床外文翻译外文文献英文文献数控原文来源:Zhao Chang-ming Liu Wang-ju (CNC Machining Process and equipment, 2002,China)一、摘要Equip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment. Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry,Keywords:Numerical ControlTechnology, E quipment,industry二、译文数控技术和装备进展趋势及计策装备工业的技术水平和现代化程度决定着整个国民经济的水平和现代化程度,数控技术及装备是进展新兴高新技术产业和尖端工业〔如信息技术及其产业、生物技术及其产业、航空、航天等国防工业产业〕的使能技术和最差不多的装备。

外文翻译--数控车床

外文翻译--数控车床

CNCWhat is CNC?Computer numerical control is a very broad term that encompasses a variety of types of machines—all with different sizes, shapes, and functions. But the easiest way to think about CNC is to simplyunderstand that it’s all about using a comp uter as a means to control a machine that carves usefulobjects from solid blocks of material. For example, a CNC machine might begin with a solid block ofaluminum, and then carve away just the right material to leave you with a bicycle brake handle.CNC machines can be divided into two groups: turning machines and milling machines. A turningmachine is generally made up of a device that spins a workpiece at high speed and a tool (sharp edge)that shaves off the undesired material from the workpiece (where the tool is moved back and forth andin and out until the desired form is achieved). A milling machine is a machine that has a spindle (adevice similar to a router) with a special tool that spins and cuts in various directions and moves in threedifferent directions along the x, y, and z axes.Historically, you wouldn’t actually need a computer to create forms with a turning machine or amilling machine. Adding a computer to the mix allows you to design a product on a computer first andthen specify how the machine should cut this product. To design the product is to produce acomputeraideddesign (CAD) file. Then you specify how the machine should cut the product, and the result of thatstep is a computer-aided manufacturing (CAM) file (or G-Code file, or .NC file—there are many namesfor this type of file). This CAM file remembers all of the operations that the milling machine must followto cut out the parts for the product. The computer tells the CNC machine how to build the part byinterpreting the CAM file into signals that the CNC machine can understand.Industrial UsesIndustrial applications for CNC machines have been chiefly based around the removal of metal to create adesired form. Metal is widely used for producing almost everything we see around us, even though these things may not be made of metal themselves. Some of the most obvious products that are made ofmetal are cars. The engine block and the parts within the transmission are directly produced from a CNCmachine because tight tolerances are necessary (a tolerance is a range in dimensioning to which themachine must adhere). However, most of the parts of a car are not made by a CNC machine, but theyhave a latent connection to one. For example, how do you make a quarter panel? There is a hydraulicpress with a thing called a die to create an impression in a sheet of metal. Most of the parts of thehydraulic press were made from a CNC machine. The die, the part that carries the negative form of thequarter panel and that can be replaced when design changes, was also made by a CNC machine, andthen tempered for hardening and heat resistance. Even the plastic parts of a car have some connectionto a CNC machine. Many of these parts were made from a mold that was created using a CNC machineBecause CNC machines have very high precision and they can provideinformation back to thecomputer, they are also used in dimensional testing. If a switch (probe) is fastened to the location of thetool, it can analyze the measurements of a part that was produced. The machine runs this probe all overthe part to confirm its desired form and measurements.For more information on industrial uses of CNC machines, visitPersonal UsesThere is a large following by various hobbyists and DIYers around the globe interested in the concept ofCNC machines. Roboticists, craftsmen, handymen, home machinists, small business owners, techenthusiasts, backyard scientists, and artists have all discovered how a CNC machine can open doors tonew designs and more detailed creations. A roboticist, for instance, will use a CNC machine to create thestructural components of the robot with very high precision. Making these components by hand wouldbe tedious and very time consuming. Using a CNC machine, the parts come out beautifully and fittogether with great precision.For the typical handyman, a great example of using a CNC machine might be designing and making cabinets for around the house. Typically, cabinets share many of the same dimensions and can be cut bya CNC machine over and over. Imagine cutting all of the drawers and cabinet lids by hand! The parts arenumerous and the work would be quite tedious. But with a CNC machine, the individual pieces are cutand the cabinets assembled; no driving around looking for the right cabinets, having to special orderthem, and then waiting for delivery from the home improvement store. (The cabinets will needassembly, too, but with your own CNC machine, you’ll find that the high cost of buying them in t he storecan be eliminated.) CNC machines for personal use can be purchased from a variety of manufacturers, but many DIYers suffer from sticker shock the first time they begin shopping for a CNC machine. Prices of $3,000 andhigher are typical for small,de sktop versions that often come with a 12"×18" workspace, meaning you’llbe limited to working on materials that fit in that small space. CNC machines with workspaces that allowfor materials of 2'×4', for example, start around $7,000, and prices go much higher for larger workspacetables.For most DIYers, owning their own CNC machine is still out of reach financially. But no longer—thisbook brings CNC within easy reach. If you can afford to spend $700 to $800, then you can afford to buildyour very own CNC machine.Your DIY CNC MachineWith your DIY CNC machine, you’re going to be able to do some amazing things—cut, drill, etch, and sculpt—with a variety of materials. In fact, author Patrick Hood-Daniel uses his own CNC machines to make more CNC machines! He has a machine cut and drill the MDF (medium-density fiberboard) parts used to build more CNC machines. (You can do this, too, but first you’ll need to build your own DIY CNC machine—it all starts there.)Your DIY CNC machine is made of MDF, a rigid material that holds up well to cutting and drilling, as well as being extremely strong and dimensionally stable (itdoesn’t shrink or expand with fluctuations in the weather or humidity). The MDF parts you’ll be cutting and drilling are bolted together using a varie ty of sizes of bolts, nuts, washers, and other hardware. Finally,you’ll be adding a mix of electronics and one computer to bring your DIY CNC machine to life and amaze your friends and family (who will,unfortunately, come up with all kinds of requests for you and your machine).The DIY CNC machine isn’t something with vague dimensions and a random mixture of hardware.We’ll tell you exactly what to buy. You’ll be cutting and drilling material from plans created by authorPatrick Hood-Daniel and tested and used to build three machines; one by James Floyd Kelly, one by Darrell Kelly, and one by Jim Burt (not to mention the number of machines built by Patrick himself).When you’re done, however, you’re not really done. CNC is a growing and changing technology, so the limits of what you can do with your machine are really up to you. While this book will give you the basic information to build and use your machine, you’ll want to continue to improve your skills by delving deeper into the software and pushing the limits of your machine. (We’ll provide you with some good resources for further research and learning later in the book.)If you’re like us, you’re ready to begin. But trust us when we say that one of the best things you cando before starting to build your own CNC machine is this: read the entire book through at least once.Doing so will give you a glimpse of the final machine and a better understanding of how you’ll get there.You may find, as we did, that half the fun of owning your own DIY CNC machine comes from building it. HISTORY OF THE DIY CNC MACHINE, FROM PATRICK HOOD-DANIEL My desire to hop on the bandwagon of this great hobby started as a means to an end. The end has not beenrealized because I became more interested in the CNC machine itself and want to provide simpler designs and ,instruction to others who wouldn’t otherwise have the means to own a traditional CNC machine.The DIY CNC community has been around for a long time; pretty much ever since the boom of the Internet. I learned most of what I know from the information on the Internet. With my prior design training, I spent quite a bit of time improving what others had created.Through my effort to create an initial CNC machine from resources on the Internet, I found that the materialsdid not hold up well with use and tended to exhibit undesirable flexing. I learned through trying and experimenting. . . and discovered many things that worked and didn’t work. I quickly learned, for example, to stick with MDF asthe material of choice for making my CNC machines.Over the years, I made hundreds of trips to the home improvement store (my laboratory of ideas). The components that I used to start my CNC journey included round metal bar stock and a bunch of very cheap MDF.I thought that the metal stock would have some pretty good rigidity—I mean . . . it’s metal! But I was very wrong.After putting an assembly together and using the bar stock as the rail, I noticed quite a bit of flexing in the assembly. This was not going to work, so I came up with abetter way. (I was deathly afraid of trying something ,that was not illustrated on the Internet in fear that if it wasn’t done before, it wouldn’t work. But I did it anyway.) I used aluminum angles as the rails and MDF as the midsection between the rails to provide the necessary rigidity.Initially, I tried the bar stock with this technique, but the bars would still flex. The aluminum rails wrapping the MDF worked perfectly and the machine was rigid and stable—perfect! Well, perfect is a subjective word here, but it was good enough for me. And I think by the time you’re done following this book’s instructions and building your own machine, you’ll agree.Everything from that point on became intuitive. The mechanics and motion of the machine were all designedso that the parts could be cut, drilled, and assembled using nothing more than a few simple hand tools. (I’m notkidding—the early machines were cut and drilled with nothing more than a mitre box, a small saw, and a batterypowered drill.)This book documents my design; you’ll be able to skip th e frustration that I faced because this is the design Ideveloped that worked. The DIY CNC machine fulfills my desire to provide others with a simple, elegant, and fullyfunctional CNC machine. The ToolsWe cannot predict what tools you’ll have available dur ing the building of your machine. We can, however,tell you the tools we used. Some of these tools, especially the power tools, can easily be rented (by the dayor hour) at hardware stores and home centers, while others may be slightly difficult to find. And if you have ,access to a tool or two not mentioned here, that could make your work even easier. Just keep in mind,however, that this machine was designed so that it could be built with a minimum number of tools—if you find yourself lacking a tool described followinga nd cannot find it (for purchase or rent), don’t let that stop you; just improvise with the tools you do have. The CNC machine built in this book is extremely forgiving when it comes to small deviations in cutting and drilling; be as accurate as you can, use what you have available, and make the best of it.Following is a list of our tools, with a few photos for clarification:• Table saw: This is useful for cutting long lengths of MDF accurately. Depending on your skill, youcan also cut multiple MDF pieces at once, guaranteeing they match in dimensions.• Metal band saw: This is used for cutting the aluminum angled rail and lead screws • Hack saw: If a band saw is not available, this is the saw to use for cutting the aluminum angled rail and lead screws.• Mitre box: This is useful for making accurate cuts in small MDF pieces.• Hammer: This is for hammering things, obviously• Cordless screwdrivers: You’ll need a Phillips and a slot head.• Regular screwdrivers: Again, you’ll need a Phillips and a slot head.• Forstner drill bits: Forstner bits (see Figure 2-1) are extremely useful for counterboring as well as drilling large, smooth holes; regular drill bits can be used to drill counterbored holes, but thesework much betterFigure 2-1. Forstner drill bits in various sizes• Brad point drill bits: These drill a flat-bottomed hole and have a sharp, centered tip that creates a“dimple” that can be used to center other drill bits for later drilling.• Twisted drill bits: These are your standard drill bits and co me in a range of sizes. • Spade drill bits: This is another common variety of drill bit that is perfectly acceptable for drilling holes.• Transfer punches: Transfer punches (see Figure 2-2) are available in different diameters. These tools have a sharp point on the end; inserting them into existing drilled holes will allow you to make a “dimple” in a second piece of MDF, giving youan accurate point to drill on the secondpiece of MDF.Figure 2-2. Transfer punches let you mark other pieces accurately for drilling. • Magnetic bowl: This is a small bowl that can keep your nuts and bolts from falling all over the floor.• 1/2" power drill: Having a drill that can handle larger-diameter drill bits will be very useful during the build.• Drill press: Useful for drilling straight holes (vertically) through material. A drill press also provides a small table to clamp MDF and aluminum rail to when drilling. • Wrenches: You’ll need wrenches for 1/4" nuts.• Detail metal ruler: This is a special type of ruler (see Fi gure 2-3) with marks that allow you to make extremely straight lines for cutting and points for drilling. Measuring and marking increments of 1/8", 1/16", 1/32", and 1/64" are possible withthese rulers.Figure 2-3. These rulers are from Incra and are extremely accurate.数控车床一、什么是计算机数控计算机数控是一种非常广泛的专业术语,它包含各种类型的机器,比如各种大小,形状和功能的机器。

数控车床主传动系统毕业设计外文翻译

数控车床主传动系统毕业设计外文翻译

数控车床主传动系统毕业设计外文翻译数控车床在先进制造技术领域最根本的观念之一是数控(NC)。

数控来临之前,所有机床是手工操作和控制。

手动控制机床有许多限制,或许没有比操作者的技能更突出。

用手动控制,产品质量直接相关,并仅限于操作者的技能。

车床主要是为了进行车外圆、车端面和镗孔等项工作而设计的机床。

车削很少在其他种类的机床上进行,而且任何一种其他机床都不能像车床那样方便地进行车削加工。

由于车床还可以用来钻孔和铰孔,车床的多功能性可以使工件在一次安装中完成几种加工。

因此,在生产中使用的各种车床比任何其他种类的机床都多。

车床的基本部件有:床身、主轴箱组件、尾座组件、溜板组件、丝杠和光杠件在各种速度下回转。

主轴箱基本上由一个安装在精密轴承中的空心主轴和一系列变速齿轮(类似于卡车变速箱)所组成。

通过变速齿轮,主轴可以在许多种转速下旋转。

大多数车床有8~12种转速,主轴箱安装在内侧导轨的固定位置上,一般在床身的左端。

它提供动力,并可使工一般按等比级数排列。

而且在现代机床上只需扳动2~4个手柄,就能得到全部转速。

一种正在不断增长的趋势是通过电气的或者机械的装置进行无级变速由于机床的精度在很大程度上取决于主轴,因此,主轴的结构尺寸较大,通常安装在预紧后的重型圆锥滚子轴承或球轴承中。

主轴中有一个贯穿全长的通孔,长棒料可以通过该孔送料。

主轴孔的大小是车床的一个重要尺寸,因此当工件必须通过主轴孔供料时,它确定了能够加工的棒料毛坯的最大尺寸。

这个问题导致了1959年自动编程工具(APT)语言的发展,使用类似数控英文语句来定义几何零件,描述刀具配置,并制定所需的方案。

新的APT语言的发展是重大的一步,推动数控技术的进一步发展。

原来的数控系统广泛使用穿孔纸,后来由磁性塑料带代替。

一个使用穿孔纸的人解释了该机器的磁带使用说明作为知名的数控概念发展(DNC)解决了纸张和塑料带与数控相关作为执行指令的编程语言磁带的问题。

在直接数字控制下,精密机床的束缚,通过数据传输链路,连接在主机和机器工具,通过数据传输连接需要。

机械专业毕业设计外文翻译--机械传动系统介绍

机械专业毕业设计外文翻译--机械传动系统介绍

Transmission System introducedThe important position of the wheel gear and shaft can’t falter in traditional machine and modern machines. The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, used for many situations respectively. so we must be the multilayers to the understanding of the wheel gear and shaft in many ways.In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoids.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor interesting. The teeth of crossed-helical fears have point contact with each other which changes to line contact as the gears wear in. for this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed helical gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is, a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles ate equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some ofbevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing this means that shaft deflection can be more pronounced and have a greater effect in the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squrgears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution The tooth action between such gears is a combination of rolling and has much in common with that of worm gears.A shaft is a rotating or stationary member usually of circular cross section, having mounted upon it such elementsas gears pulleys flywheels, cranks sprockets and other power-transmission elements Shaft may be subjected to bending tension compression or torsional loads acting singly or in combination with one another .When they are combined one may expect to find both static and fatigue strength to be important design considerations since a single shaft may be subjected to static stresses completely reversed, and repeated stresses, all acting at the same timeThe word “shaft” covers numerous wariations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating nor subjected to torsion load. Ashirt rotating shaft is often called a spindle.When either the lateral or the tosional deflection of shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses The reasonfor this is that if the shift is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are within acceptable limits. Whenever possible the power-transmission elements such as gears or pullets, should be located close to the supporting bearings. This reduces the bending moment, and hence the deflection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably come closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias I1and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for each geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the hear-dissipating surfaces. The various types of clutches and brakes may be classified as fallows:Rim type with internally expanding shoesRim type with internally contracting shoesBand typeDisk or axial typeCone typeMiscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:1. Assume or determine the distribution of pressure on the frictionalsurfaces.2. Find a relation between the maximum pressure and the pressure at any point3. apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscellaneous clutches include several type, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws re used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.Although positive clutches are not used to the extent the frictional-contact type, they do have important applications where synchronous operation is required.Devices such as linear driver or motor-operated screw drivers must run to definite limit and then come to a stop. An over load-release rype of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” because the driver is stopped or because another source of power increase the speed of the driven. This type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedding the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. Bu varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.机械传动系统介绍在传统机械和现代机械中齿轮和轴的重要地位是不可动摇的。

数控专业毕业设计外文翻译

数控专业毕业设计外文翻译

Conventional Machining ProcessesConventional machining is the group of machining operations that use single- or multi-point tools to remove material in the form of chips. Metal cutting involves removing metal through machining operations. Machining traditionally takes place on lathes, drill presses, and milling machines with the use of various cutting tools. Most machining has very low set-up cost compared with forming, molding, and casting processes. However, machining is much more expensive for high volumes. Machining is necessary where tight tolerances on dimensions and finishes are required.Turning is one of the most common of metal cutting operations. In turning, a workpiece is rotated about its axis as single-point cutting tools are fed into it, shearing away excess material and creating the desired cylindrical surface. Turning can occur on both external and internal surfaces to produce an axially-symmetrical contoured part. Parts ranging from pocket watch components to large diameter marine propeller shafts can be turned on a lathe.Apart from turning, several other operations can also be performed on lathe.Boring and internal turning. Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools. If the initial workpiece is solid, a drilling operation must be performed first. The drilling tool is held in the tailstock, and the latter is then fed against the workpiece. When boring is done in a lathe, the work usually is held in a chuck or on a face plate. Holes may be bored straight, tapered, or to irregular contours. Boring is essentially internal turning while feeding the tool parallel to the rotation axis of the workpiece.Facing is the producing of a flat surface as the result of a tool’s being fed across the end of the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be faced, it must be turned around after the first end is completed and then the facing operation repeated. The cutting speed should be determined from the largest diameter of the surface to be faced.Facing may be done either from the outside inward or from the center outward. In either case, the point of the tool must be set exactly at the height of center of rotation.Because the cutting force tends to push the tool away from the work, it is usually desirable to clamp the carriage to the lathe bed during each facing cut to prevent it from moving slightly and thus producing a surface that is not flat. In the facing of casting or other materials that have a hard surface, the depth of the first cut should be sufficient to penetrate the hard material to avoid excessive tool wear.Parting is the operation by which one section of a workpiece is severed from the remainder by means of cutoff tool. Because cutting tools are quite thin and must have considerable overhang, this process is less accurate and more difficult. The tool should be set exactly at the height of axis of rotation, be kept sharp, have proper clearance angles, and be fed into the workpiece at a proper and uniform feed rate.Threading can be considered as turning since the path to be travelled by the cutting tool is helical. However, there are some major differences between turning and threading. While in turning, the interest is in generating a smooth cylindrical surface, in threading the interest is in cutting a helical thread of a given form and depth which can be calculated from the formulae. There are two basic requirements for thread cutting. An accurately shaped and properly mounted tool is needed because thread cutting is a form-cutting operation. The resulting thread profile is determined by the shape of the tool and its position relative to the workpiece.The second by requirement is that the tool must move longitudinally in a specific relationship to the rotation of workpiece, because this determines the lead of the thread. This requirement is met through the use of the lead screw and the split unit, which provide positive motion of carriage relative to the rotation of spindleLathe bed is foundation of the engine lathe, which heavy, rugged casting is made to support the working parts of the lathe. The size and mass of the bed gives the rigidity necessary for accurate engineering tolerances required in manufacturing. On top of the bed are machined slideways that guide and align the carriage and tailstock, as they are move from one end of the lathe to the other.Headstock is clamped atop the bed at left-hand end of the lathe and contains the motor that drives the spindle whose axis is parallel to the guideways through a series of gears housed within the gearbox. The function of gearbox is to generate a number of different spindle speeds. A spindle gear is mounted on the rear of the spindle to transmit power through the change gears to the feeding box that distributes the power to the lead screw for threading or to the feed rod for turning.The spindle has a through hole extending lengthwise through which bar stocks can be fed if continuous production is used. The hole can hold a plain lathe center by its tapered inner surface and mount a chuck, a face plate or collet by its threaded outer surface.Carriage assembly is actually an H-shaped block that sits across the guideways and in front of lathe bed. The function of the carriage is to carry and move the cuttingtool longitudinally. It can be moved by hand or by power and can be clamped into position with a locking nut. The carriage is composed of the cross slide, compound rest, tool saddle, and apron.The cross slide is mounted on the dovetail guideways on the top of the saddle and it moved back and forth at 90°to the axis of the lathe by the cross slide lead screw. The lead screw can be hand or power activated.The compound rest is mounted on the cross slide and can be swiveled and clamped at any angle in a horizontal plane. The compound is typically used for cutting chamfers or tapers, but must also be used when cutting thread. The compound rest can only be fed by hand. There is no power to compound rest. The cutting tool and tool holder are secured in the tool post which is mounted directly to the compound rest.The tool saddle is an H shaped casting mounted on the top of the guideways and houses the cross slide and compound rest. It makes possible longitudinal, cross and angular feeding of the tool bit.The apron is attached to the front of the carriage and contains the gears and feed clutches which transmit motion from the feed rod or lead screw to carriage and cross slide. When cutting screw threads, power is provided to the gearbox of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage.Tailstock is composed of a low base and the movable part of the tail-stock proper, the transverse adjustments being made with a cross screw furnished with a square head. The two parts are hold together by the holding-down bolts which secure the tailstock to the bed.。

关于数控车床编程外文文献翻译中英文翻译外文翻译

关于数控车床编程外文文献翻译中英文翻译外文翻译

关于数控车床编程外文文献翻译、中英文翻译、外文翻译英文原文On the NC latheCNC 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 inthe numericalcontrol 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, rigidity, can choose the am ount of processing good, high productivity (3~5 times as common machine);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 operators of higher quality, higher demands for the repair ofthe 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 convertedinto 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 feeddrive 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 millingcompound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining isgreatly improved. \processing factory\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: automaticallyadjust 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 precisionmachining 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 micronlevel (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 nanometer 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 andtemperature, 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 system 1, stepping motor servo system Generally used for NC machine tools. 2, DC servo motor servo systemPower is stable, but because of the brush, the wear resulting in use needto change. Generally used for middle-grade CNC machine tools. 3, AC servomotor 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 system 1, the ball screw nut pairNC machining, the rotary motion into linear motion, so the use of screwnut transmissionmechanism. NC machine tools are commonly used on the ball screw, as shownin Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmissionside 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 indispensablepart 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 the instructions 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 characteristicis 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 positioning 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, stepprocessing 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 form 1, 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 rotary cutter.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, reducetool change time, improve The ATC reliability. 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.感谢您的阅读,祝您生活愉快。

CA6140车床的数控-毕业设计机械外文翻译

CA6140车床的数控-毕业设计机械外文翻译

The machinability of materialThe machinability of a material usually defined in terms of four factors:(1). Surface finish and integrity of the machined part;(2). Tool life obtained;(3). Force and power requirements;(4). Chip control.Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone.Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below.1. Machinability Of SteelsBecause steels are among the most important engineering materials , their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels.Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels.Phosphorus in steels has two major effects. It strengthens the ferrite, causing increased hardness. Harder steels result in better chip formation and surface finish. Note that soft steels can be difficult to machine, with built-up edge formation and poor surface finish. The second effect is that increased hardness causes the formation of short chips instead of continuous stringy ones, thereby improving machinability.Leaded Steels. A high percentage of lead in steels solidifies at the tip of manganese sulfide inclusions. In non-resulfurized grades of steel, lead takes the form of dispersed fine particles. Lead is insoluble in iron, copper, and aluminum and their alloys. Because of its low shear strength, therefore, lead acts as a solid lubricant and is smeared over the tool-chip interface during cutting. This behavior has been verified by the presence of high concentrations of lead on the tool-side face of chips when machining leaded steels.When the temperature is sufficiently high-for instance, at high cutting speeds and feeds —the lead melts directly in front of the tool, acting as a liquid lubricant. In addition to this effect, lead lowers the shear stress in the primary shear zone, reducing cutting forces and power consumption. Lead can be used in every grade of steel, such as 10xx, 11xx, 12xx, 41xx, etc. Leaded steels are identified by the letter L between the second and third numerals (for example, 10L45). (Note that in stainless steels, similar use of the letter L means “low carbon,” a condition that improves their corrosion resistance.)However, because lead is a well-known toxin and a pollutant, there are serious environmental concerns about its use in steels (estimated at 4500 tons of lead consumption every year in the production of steels). Consequently, there is a continuing trend toward eliminating the use of lead in steels (lead-free steels). Bismuth and tin are now being investigated as possible substitutes for lead in steels.Calcium-Deoxidized Steels. An important development is calcium-deoxidized steels, in which oxide flakes of calcium silicates (CaSo) are formed. These flakes, in turn, reduce the strength of the secondary shear zone, decreasing tool-chip interface and wear. Temperature is correspondingly reduced. Consequently, these steels produce less crater wear, especially at high cutting speeds.Stainless Steels. Austenitic (300 series) steels are generally difficult to machine. Chatter can be s problem, necessitating machine tools with high stiffness. However, ferritic stainless steels (also 300 series) have good machinability. Martensitic (400 series) steels are abrasive, tend to form a built-up edge, and require tool materials with high hot hardness and crater-wear resistance. Precipitation-hardening stainless steels are strong and abrasive, requiring hard and abrasion-resistant tool materials.The Effects of Other Elements in Steels on Machinability. The presence of aluminum and silicon in steels is always harmful because these elements combine with oxygen to form aluminum oxide and silicates, which are hard and abrasive. These compounds increase tool wear and reduce machinability. It is essential to produce and use clean steels.Carbon and manganese have various effects on the machinability of steels, depending on their composition. Plain low-carbon steels (less than 0.15% C) can produce poor surface finish by forming a built-up edge. Cast steels are more abrasive, although their machinability is similar to that of wrought steels. Tool and die steels are very difficult to machine and usually require annealing prior to machining. Machinability of most steels is improved by cold working, which hardens the material and reduces the tendency for built-up edge formation.Other alloying elements, such as nickel, chromium, molybdenum, and vanadium, which improve the properties of steels, generally reduce machinability. The effect of boron is negligible. Gaseous elements such as hydrogen and nitrogen can have particularly detrimental effects on the properties of steel. Oxygen has been shown to have a strong effect on the aspect ratio of the manganese sulfide inclusions; the higher the oxygen content, the lower the aspect ratio and the higher the machinability.In selecting various elements to improve machinability, we should consider the possible detrimental effects of these elements on the properties and strength of the machined part in service. At elevated temperatures, for example, lead causes embrittlement of steels (liquid-metal embrittlement, hot shortness), although at room temperature it has no effect on mechanical properties.Sulfur can severely reduce the hot workability of steels, because of the formation of iron sulfide, unless sufficient manganese is present to prevent such formation. At room temperature, the mechanical properties of resulfurized steels depend on the orientation of the deformed manganese sulfide inclusions (anisotropy). Rephosphorized steels are significantly less ductile, and are produced solely to improve machinability.2. Machinability of Various Other MetalsAluminum is generally very easy to machine, although the softer grades tend toform a built-up edge, resulting in poor surface finish. High cutting speeds, high rake angles, and high relief angles are recommended. Wrought aluminum alloys with high silicon content and cast aluminum alloys may be abrasive; they require harder tool materials. Dimensional tolerance control may be a problem in machining aluminum, since it has a high thermal coefficient of expansion and a relatively low elastic modulus.Beryllium is similar to cast irons. Because it is more abrasive and toxic, though, it requires machining in a controlled environment.Cast gray irons are generally machinable but are. Free carbides in castings reduce their machinability and cause tool chipping or fracture, necessitating tools with high toughness. Nodular and malleable irons are machinable with hard tool materials.Cobalt-based alloys are abrasive and highly work-hardening. They require sharp, abrasion-resistant tool materials and low feeds and speeds.Wrought copper can be difficult to machine because of built-up edge formation, although cast copper alloys are easy to machine. Brasses are easy to machine, especially with the addition pf lead (leaded free-machining brass). Bronzes are more difficult to machine than brass.Magnesium is very easy to machine, with good surface finish and prolonged tool life. However care should be exercised because of its high rate of oxidation and the danger of fire (the element is pyrophoric).Molybdenum is ductile and work-hardening, so it can produce poor surface finish. Sharp tools are necessary.Nickel-based alloys are work-hardening, abrasive, and strong at high temperatures. Their machinability is similar to that of stainless steels.Tantalum is very work-hardening, ductile, and soft. It produces a poor surface finish; tool wear is high.Titanium and its alloys have poor thermal conductivity (indeed, the lowest of all metals), causing significant temperature rise and built-up edge; they can be difficult to machine.Tungsten is brittle, strong, and very abrasive, so its machinability is low, although it greatly improves at elevated temperatures.Zirconium has good machinability. It requires a coolant-type cutting fluid, however, because of the explosion and fire.3. Machinability of Various MaterialsGraphite is abrasive; it requires hard, abrasion-resistant, sharp tools.Thermoplastics generally have low thermal conductivity, low elastic modulus, and low softening temperature. Consequently, machining them requires tools with positive rake angles (to reduce cutting forces), large relief angles, small depths of cut and feed, relatively high speeds, andproper support of the workpiece. Tools should be sharp.External cooling of the cutting zone may be necessary to keep the chips from becoming “gummy” and sticking to the tools. Cooling can usually be achieved with a jet of air, vapor mist, or water-soluble oils. Residual stresses may develop during machining. To relieve these stresses, machined parts can be annealed for a period of time at temperatures ranging from C ︒80 to C ︒160 (F ︒175to F ︒315), and then cooled slowly and uniformly to room temperature.Thermosetting plastics are brittle and sensitive to thermal gradients during cutting. Their machinability is generally similar to that of thermoplastics.Because of the fibers present, reinforced plastics are very abrasive and are difficult to machine. Fiber tearing, pulling, and edge delamination are significant problems; they can lead to severe reduction in the load-carrying capacity of the component. Furthermore, machining of these materials requires careful removal of machining debris to avoid contact with and inhaling of the fibers.The machinability of ceramics has improved steadily with the development of nanoceramics and with the selection of appropriate processing parameters, such as ductile-regime cutting .Metal-matrix and ceramic-matrix composites can be difficult to machine, depending on the properties of the individual components, i.e., reinforcing or whiskers, as well as the matrix material.4. Thermally Assisted MachiningMetals and alloys that are difficult to machine at room temperature can be machined more easily at elevated temperatures. In thermally assisted machining (hotmachining), the source of heat—a torch, induction coil, high-energy beam (such as laser or electron beam), or plasma arc—is forces, (b) increased tool life, (c) use of inexpensive cutting-tool materials, (d) higher material-removal rates, and (e) reduced tendency for vibration and chatter.It may be difficult to heat and maintain a uniform temperature distribution within the workpiece. Also, the original microstructure of the workpiece may be adversely affected by elevated temperatures. Most applications of hot machining are in the turning of high-strength metals and alloys, although experiments are in progress to machine ceramics such as silicon nitride.SUMMARYMachinability is usually defined in terms of surface finish, tool life, force and power requirements, and chip control. Machinability of materials depends not only on their intrinsic properties and microstructure, but also on proper selection and control of process variables.材料的可机加工性一种材料的可机加工性通常以四种因素的方式定义:(1)、分的表面光洁性和表面完整性。

数控技术-毕业设计外文资料翻译

数控技术-毕业设计外文资料翻译

外文资料译文数控技术数控技术是现代制造技术的基础,它的广泛应用使普通机械被数控机械所代替,使全球制造业发生了根本变化。

数控技术的水准、拥有和普及程度已经成为衡量一个国家综合国力和工业现代化水平的重要标志之一。

为适应这种形势,需要大量培养数控专业技术人才。

数控机床是一种用计算机来控制的机床,用来控制机床的计算机,不管是专用计算机、还是通用计算机都统称为数控系统。

数控机床的运动和辅助动作均受控于数控系统发出的指令。

而数控系统的指令是由程序员根据工件的材质、加工要求、机床的特性和系统所规定的指令格式编制的。

数控系统根据程序指令向伺服装置和其它功能部件发出运行或终断信息来控制机床的各种运动。

当零件的加工程序结束时,机床便会自动停止。

任何一种数控机床,在其数控系统中若没有输入程序指令,数控机床就不能工作。

机床的受控动作大致包括机床的起动、停止;主轴的启停、旋转方向和转速的变换;进给运动的方向、速度、方式;刀具的选择、长度和半径的补偿;刀具的更换,冷却液的开起、关闭等。

CNC(数控机床)是计算机数字控制机床(Computer numerical control)的简称,是一种由程序控制的自动化机床。

该控制系统能够逻辑地处理具有控制编码或其他符号指令规定的程序,通过计算机将其译码,从而使机床动作并加工零件。

通过刀具切削将毛坯料加工成半成品成。

CNC加工(CNC Machining)数控加工是指用数控的加工工具进行的加工。

CNC指数控机床由数控加工语言进行编程控制,通常为G代码。

数控加工G 代码语言告诉数控机床的加工刀具采用何种笛卡尔位置坐标,并控制刀具的进给速度和主轴转速,以及工具变换器、冷却剂等功能。

数控加工相对手动加工具有很大的优势,如数控加工生产出的零件非常精确并具有可重复性;数控加工可以生产手动加工无法完成的具有复杂外形的零件。

数控加工技术现已普遍推广,大多数的机加工车间都具有数控加工能力,典型的机加工车间中最常见的数控加工方式有数控铣、数控车和数控EDM线切割(电火花线切割)。

毕业设计_外文翻译=cnc数控技术=5000字符 精品

毕业设计_外文翻译=cnc数控技术=5000字符 精品

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姓名:何飞学号:052083082012年 4 月 15 日外文资料翻译译文CNC技术数控(NC)是可编程的自动化的一种形式。

其加工设备由一系列的数字、字母和其他符号控制。

这些数字、字母和符号被编成一定的格式,以便为一个特定的工步或者工作定义一个指令程序。

当工作改变时,指令程序也随之改变。

这种改变程序的能力使NC适应小、中批量生产。

编写新的程序要比大批量调换生产设备容易的多。

1.NC的基本组成部分一个数控系统包括以三个组成部分:指令编程、机械控制单元、加工设备。

三者之间的关系是:程序导入控制单元,控制单元直接指导加工设备的动作。

指令程序是细化的一步步的命令,它控制加工设备。

在它的一般形式中,命令涉及到机床主轴和放置工件的工作台的相对位置。

许多先进的指令包含有选择主轴速度,切削工具等功能。

程序编在一个适当的媒介中,再导入到控制单元中。

在几十年前最常用的媒介是一英尺宽的穿孔纸带。

由于穿孔纸带的广泛应用,NC也叫做“纸带控制”。

现在磁带和软盘得到了广泛的应用。

加工设备的NC系统的第三个基本组成部分。

它是有效工作的执行部分。

在许多数控的例子中,加工设备包括工作台、主轴和驱动和控制它们的设备。

2.控制系统的种类在NC中有两种基本控制类型:点到点和仿型定位。

在点到点系统中(也叫做点定位),机床的每一个轴都单独驱动。

为了减少不加工时间,机床一最大的速度运动。

但刀具达到定位点时开始减速。

因此在一个加工过程中,比如钻削或冲压,加工过程和回程独立完成。

在孔被钻出或冲出后,刀具撤回,移动到另一个地方,继续下一次加工。

从一点到另一点的路径在一个放面十分重要:为提高效率,所需时间必须最小。

点定位主要用于钻削、虫牙和立式洗削加工。

在仿型定位系统中(也被称为沿路径加工系统),定位和加工都沿着指定的路径,但速度不一样。

因此刀具沿着指定的路径运动,速度和运动的同步精确控制十分重要。

数控车床主轴部件机械外文文献翻译、中英文翻译、外文翻译

数控车床主轴部件机械外文文献翻译、中英文翻译、外文翻译

数控车床主轴部件机械外文文献翻译、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姓名:王泽民学号: 052116362015年4月30日外文原文翻译数控车床主轴部件车床是主要用于生成旋转表面和平整边缘的机床。

根据它们的使用目的、结构、能同时被安装刀具的数量和自动化的程度,车床—更确切地说是车床类的机床,可以被分成以下几类:(1)普通车床(2)万能车床(3)转塔车床(4)立式车床(5)自动车床(6)特殊车床虽然车床类的机床多种多样,但它们在结构和操作原理上具有共同特性。

这些特性可以通过普通车床这一最常用的代表性类型来最好地说明。

下面是关于图11.1所示普通车床的主要部分的描述。

车床床身:车床床身是包含了在两个垂直支柱上水平横梁的主骨架。

为减振它一般由灰铸铁或球墨铸铁铸造而成。

它上面有能让大拖板轻易纵向滑动的导轨。

车床床身的高度应适当以让技师容易而舒适地工作。

主轴箱:主轴箱固定在车床床身的左侧,它包括轴线平行于导轨的主轴。

主轴通过装在主轴箱内的齿轮箱驱动。

齿轮箱的功能是给主轴提供若干不同的速度(通常是6到18速)。

有些现代车床具有采用摩擦、电力或液压驱动的无级调速主轴箱。

主轴往往是中空的,即纵向有一通孔。

如果采取连续生产,棒料能通过此孔进给。

同时,此孔为锥形表面可以安装普通车床顶尖。

主轴外表面是螺纹可以安装卡盘、花盘或类似的装置。

尾架:尾架总成基本包括三部分,底座、尾架体和套筒轴。

底座是能在车床床身上沿导轨滑动的铸件,它有一定位装置能让整个尾架根据工件长度锁定在任何需要位置。

这通过使用手轮和螺杆来达到,与螺杆啮合的是一固接在套筒轴上的螺母。

套筒轴开口端的孔是锥形的,能安装车床顶尖或诸如麻花钻和镗杆之类的工具。

套筒轴通过定位装置能沿着它的移动路径被锁定在任何点。

大拖板:大拖板的主要功能是安装刀具和产生纵向和/或横向进给。

它实际上是一由车床床身V形导轨引导的、能在车床床身主轴箱和尾架之间滑动的H形滑块。

数控技术课程毕业设计外文文献翻译、中英文翻译、外文翻译

数控技术课程毕业设计外文文献翻译、中英文翻译、外文翻译

数控技术数字控制与计算机数字控制的发展历史数字控制是按照含有机床(刀具)运动信息程序所指定的顺序自动执行操作的加工过程。

数控这一概念是由密歇根洲特拉华城的约翰·帕森于20世纪四十年代后期提出的。

为了在工件上加工光滑的轮廓,帕森提出了一种自动的机床控制方式,它能够引导铣床刀具加工出一种“过轴曲线”。

1949年,美国空军与帕森签署了合同,要求开发一种能够提高生产率的新型机床。

帕森委托麻省理工学院(MIT)来开发一种新概念机床,麻省理工学院的科学家和工程师研制出了一种用穿孔纸带作为输入媒介的二轴联动铣床控制系统。

在较短时间内,当时所有主要的机床生产商都生产了一些数控机床,但直到20世纪七十年代后期,基于计算机的数字控制才被得到广泛的使用。

只有价格低廉且功能强大的微处理芯片代替了计算机数控系统中的硬连线逻辑发生器后,NC才真正成为一门自动化技术。

当数控机床在计算机监控下工作时,它就被称为计算机数控机床(CNC)。

计算机是CNC机床的控制单元,它们内嵌于数控机床或者通过通讯渠道与数控机床联接,当程序员编程时,通过纸带或磁盘将一些信息输入,计算机将对一些必要的数据进行计算的完成工作。

由于第一台数控机床的数据是由纸带控制的,因此数控系统被称为纸带控制机床。

它们只能控制由输入到机床内的纸带或磁带所规定的单一操作,输入到机床内的程序是不能被编辑的,要改变程序必须重做新纸带。

当今的系统都由计算机来控制数据,因而称之为计算机数控机床(简称CNC机床)。

NC和CNC系统两者的工作原理一样,仅仅控制执行的方式不同。

新型的数控系统通常速度更快、功率更大、功能更齐全。

数字控制与计算机数字控制的应用数控技术自创立以来就得到了广泛的应用,包括车床和车削中心、铣床和加工中心、冲床、电火花(EDM)加工机床、线切割机床、磨床以及测试检测装置等。

最复杂的计算机数控机床是车削中心,图4—1所示一个具有十转位的刀架能进行快速换刀的现代车削中心,立式加工中心如图4—2所示(刀具库在机床的左边。

数控车床主轴部件机械外文文献翻译、中英文翻译、外文翻译

数控车床主轴部件机械外文文献翻译、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姓名:王泽民学号: 052116362015年4月30日外文原文翻译数控车床主轴部件车床是主要用于生成旋转表面和平整边缘的机床。

根据它们的使用目的、结构、能同时被安装刀具的数量和自动化的程度,车床—更确切地说是车床类的机床,可以被分成以下几类:(1)普通车床(2)万能车床(3)转塔车床(4)立式车床(5)自动车床(6)特殊车床虽然车床类的机床多种多样,但它们在结构和操作原理上具有共同特性。

这些特性可以通过普通车床这一最常用的代表性类型来最好地说明。

下面是关于图11.1所示普通车床的主要部分的描述。

车床床身:车床床身是包含了在两个垂直支柱上水平横梁的主骨架。

为减振它一般由灰铸铁或球墨铸铁铸造而成。

它上面有能让大拖板轻易纵向滑动的导轨。

车床床身的高度应适当以让技师容易而舒适地工作。

主轴箱:主轴箱固定在车床床身的左侧,它包括轴线平行于导轨的主轴。

主轴通过装在主轴箱内的齿轮箱驱动。

齿轮箱的功能是给主轴提供若干不同的速度(通常是6到18速)。

有些现代车床具有采用摩擦、电力或液压驱动的无级调速主轴箱。

主轴往往是中空的,即纵向有一通孔。

如果采取连续生产,棒料能通过此孔进给。

同时,此孔为锥形表面可以安装普通车床顶尖。

主轴外表面是螺纹可以安装卡盘、花盘或类似的装置。

尾架:尾架总成基本包括三部分,底座、尾架体和套筒轴。

底座是能在车床床身上沿导轨滑动的铸件,它有一定位装置能让整个尾架根据工件长度锁定在任何需要位置。

这通过使用手轮和螺杆来达到,与螺杆啮合的是一固接在套筒轴上的螺母。

套筒轴开口端的孔是锥形的,能安装车床顶尖或诸如麻花钻和镗杆之类的工具。

套筒轴通过定位装置能沿着它的移动路径被锁定在任何点。

大拖板:大拖板的主要功能是安装刀具和产生纵向和/或横向进给。

它实际上是一由车床床身V形导轨引导的、能在车床床身主轴箱和尾架之间滑动的H形滑块。

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关于可编程逻辑控制器(PLC)和微型计算机的发展使微处理器的发展。这两项技术的发展,计算机数字控制(CNC)允许的数控系统。每台机器工具,PLC或微型计算机,它为同样的目的。这允许程序自动输入和存储在每个机床上。数控解决相关的主机停机的问题,但它推出了著名的数据管理的另一个问题。同样的程序可能会被装上10种不同的微型电脑,它们之间没有沟通。此问题处理是在当地区域网络的过程中解决的connectDigital信号处理器的。
在形成了直接数字控制(DNC)这个概念之后,可以不再采用纸带或塑料带作为编程指令的载体,这样就解决了与之有关的问题。在直接数字控制中,几台机床通过数据传输线路联接到一台主计算机上。操纵这些机床所需要的程序都存储在这台主计算机中。当需要时,通过数据传输线路提供给每台机床。直接数字控制是在穿孔纸带和塑料带基础上的一大进步。然而,它敢有着同其他信赖于主计算机技术一样的局限性。当主计算机出现故障时,由其控制的所有机床都将停止工作。这个问题促使了计算机数字控制技术的产生。
DSP的或多或少取决于两类下降的基础架构的定点和浮点。定点设备操作一般在16位,而浮点器件上32-40位浮点操作。不用说,定点设备一般比较便宜。另一个重要的结构不同的地方是,定点处理器往往只有一个“通用的蓄电池架构”,这使得他们的方案很棘手,更重要的是,制造的C-编译器固有的低效率。浮点DSP的表现更像是共同的通用CPU的寄存器文件。
闭环控制系统
闭环控制缺少更准确和更适应由输出反馈提高系统的输入。为了获得更准确的控制信号必须反馈,并参考输入,以及一个驱动信号成比例的输出和输入的差异,必须通过系统发送而修正错误。与一个或更多反馈,就像是刚才所说的是被称为闭环系统。人类系统是可能是最复杂和精密的反馈控制系统的存在。一个人可以被认为是一个控制系统有许多输入和输出,开展高度复杂的操作能力。
由于机床的精度在很大程度上取决于主轴,因此,主轴的结构尺寸较大,通常安装在预紧后的重型圆锥滚子轴承或球轴承中。主轴中有一个贯穿全长的通孔,长棒料可以通过该孔送料。主轴孔的大小是车床的一个重要尺寸,因此当工件必须通过主轴孔供料时,它确定了能够加工的棒料毛坯的最大尺寸。
这个问题导致了1959年自动编程工具(APT)语言的发展,使用类似数控英文语句来定义几何零件,描述刀具配置,并制定所需的方案。新的APT语言的发展是重大的一步,推动数控技术的进一步发展。原来的数控系统广泛使用穿孔纸,后来由磁性塑料带代替。一个使用穿孔纸的人解释了该机器的磁带使用说明作为知名的数控概念发展(DNC)解决了纸张和塑料带与数控相关作为执行指令的编程语言磁带的问题。在直接数字控制下,精密机床的束缚,通过数据传输链路,连接在主机和机器工具,通过数据传输连接需要。直接数字控制穿孔纸带和塑料带的应用上是一个重大的进步。但是,它受所有技术,在主机上却有相同的限制。当主机出现故障,机器工具也会出现故障。这个问题引导了计算机数控的发展。
Numerical ControlLathes
One 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 were manual 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.
在240C具有高速信号处理和数字控制功能所必需的建筑特色,以及它需要提供一个电机控制应用的单芯片解决方案的外设。该240C使用亚微米CMOS制造技术,实现了日志的功耗等级。还包括一些掉电模式,进一步节省功耗。
要作为一个系统管理员,必须有强大的DSP芯片上的I / O和其他外围设备。该240事物管理器是不同于其他任何可以用一个数字信号处理器的处理器。此应用程序优化的周边装置,与高性能的DSP核心,可提供了高精确度和高效率的全变速控制的所有汽车类型的先进控制技术。事物管理器包括特殊的脉冲宽度调制(PWM)生成功能,如可编程死区的功能和空间矢量PWM状态机,3相马达,提供了完善的设施,最先进的最高效率开关电源晶体管。
有独立的定时器,每个与它自己比较的寄存器,支持非对称代(noncentered)以及对称(中心)的PWM波形。
开环和闭环控制系统
开环控制系统
这个词意味着有一个复杂的控制系统自动控制一定的数额。它通常意味着该系统通常是能够适应不同的作业条件,并能有令人满意的回应。然而,并非任何类型的控制系统都具有自动功能。通常情况下,自动控制功能是通过feed来完成的。
车床的基本部件有:床身、主轴箱组件、尾座组件、溜板组件、丝杠和光杠
件在各种速度下回转。主轴箱基本上由一个安装在精密轴承中的空心主轴和一系列变速齿轮(类似于卡车变速箱)所组成。通过变速齿轮,主轴可以在许多种转速下旋转。大多数车床有8~12种转速,主轴箱安装在内侧导轨的固定位置上,一般在床身的左端。它提供动力,并可使工一般按等比级数排列。而且在现代机床上只需扳动2~4个手柄,就能得到全部转速。一种正在不断增长的趋势是通过电气的或者机械的装置进行无级变速
16位定点DSP的C24x核心器件模拟设计提供了数字解决方案,不牺牲精度和系统性能,可通过为技术先进的控制算法,如适应控制使用增强,卡尔曼滤波,和国家控制。C24x DSP控制器提供的可靠性和可编程性。模拟控制系统,一方面,是硬连线解决方案和经验,可能因老化性能降低,元件容差和漂移。
高速中央处理单元(CPU)可处理的数字化设计,事实上,并不是与查表结果近似的算法。这些指令集的DSP控制器,它集成了信号处理指令和通用控制功能,具有广泛的开发时间,并提供了结合传统的8位和16位微控制器使用相同的环节。指令集还允许您保留您的软件投资在其他普通C2x上,源代码C2x代兼容,源代码与德州仪器的数字信号处理器C5x代兼容。
在C24x架构也非常适用于控制信号的处理。它用于存储中间结果的32位寄存器的16位字,并有两个硬件可用号码提供给独立的CPU。这种组合减少量化误差和截断,以及附加功能增加进化的能力。这些职能可能包括取消陷波器,可以在一个系统或一个机械共振技术,可消除系统状态的传感器。
在C24xDSP控制器考虑让德州仪器具备快速配置不同价格/性能点或各种系列的成员进行应用优化的外设功能设置的优势。这两个数字和混合信号外设库包括:
g的反馈结构,它被称为开环系统,该系统是精确控制的一个事实,就是可能不知道确切的控制,特点在于最简单,最经济,它有一个明确的轴承温度。这也指出了一个开环控制系统的性能重要的缺馅,该系统不能够适应变化的环境或外部干扰。在此控制情况下,或许是有经验的人提供了一个理想中的外室温控制,门或窗被打开或在营运期间,关闭间歇性,在房子里的最后温度不会精确的受开环控制。
---非常灵活的指令集
---固有业务灵活性
---高பைடு நூலகம்性能
---创新的并行结构
---成本效益
一代的TMS320系列器件具有相同的CPU结构,但不同的片上存储器和外设配置不同。附带了设备使用的片上存储器和外设新组合,以满足全球电子市场的需求范围。通过整合到一个单一芯片内存和外设,TMS320系列设备降低了系统成本和节省电路板空间。
在许多情况下的模拟信号会用各种方法处理问题,在很多方面像滤波和频谱分析,设计模拟硬件来执行这些职能是可能的,但已变得越来越少,由于更高的性能需求,灵活性的需求,以及需要削减减少开发/测试的时间的需求。正是在困难时,换句话说,是模拟信号的硬件设计分析改变了现状。
抽样一个信号是专门为嵌入式信号处理的操作,这种处理器被称为数字信号处理器,是数字信号处理器的代表。今天有数百个家庭的DSP从尽可能多的制造商,每一个特定的价格/性能/使用组来设计的。大的厂家很多,像德州仪器,摩托罗拉,都提供专门的DSP像马达控制或调制解调器这些领域的,和一般的高性能DSP处理,可以执行广泛的任务范围。软件开发工具包也可以,也有公司做好DSP的,允许程序员可以实现复杂的处理算法,利用简单的“拖放'和'下降”的方法的软件开发工具。
数控车床
在先进制造技术领域最根本的观念之一是数控(NC)。数控来临之前,所有机床是手工操作和控制。手动控制机床有许多限制,或许没有比操作者的技能更突出。用手动控制,产品质量直接相关,并仅限于操作者的技能。
车床主要是为了进行车外圆、车端面和镗孔等项工作而设计的机床。车削很少在其他种类的机床上进行,而且任何一种其他机床都不能像车床那样方便地进行车削加工。由于车床还可以用来钻孔和铰孔,车床的多功能性可以使工件在一次安装中完成几种加工。因此,在生产中使用的各种车床比任何其他种类的机床都多。
为了说明人类作为一个正反馈控制系统,让我们考虑该计划的目的是达成一个任务对象。眼睛作为传感装置,不断地反馈手的位置。之间的距离和对象的错误,最终到零。这是一个闭环控制的典型例子。然而,如果被告知要达到目标,然后是看不到的,只能达到对对象估计其确切位置。据国际检索单位一个闭环控制系统的算例,表明了该控制系统基本的一个闭环控制系的图框。如图所示。一般来说,一个反馈控制系统配置不得限制该feedback。在复杂的系统有可能反馈回路和元素块过多。
---定时器
---串行通信接口(SCI的,SPI)
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