机械毕业设计外文翻译---数控机床
机械外文翻译中英文-机床【范本模板】
英文原文Basic Machining Operations and Cutting TechnologyBasic 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 work piece 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。
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。
数控机床编程外文文献翻译、中英文翻译、外文翻译
英文原文CNC machine toolsWhile 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 workpiece. 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 workpieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate workpieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine tools is 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 (feedrate) 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 t he linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3.Though 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 systems .It 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 for the 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.All discussions to this point assume that the absolute mode of programming is used. 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), end points 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 incrementa lly. 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 move ment 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 possibly at 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.A 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 the central computer. Instead, instructions from the central computer are passed to the cell controller.2. The cell is limited in the number of part families it can manufacture.The following elements are normally found in an FMC: • Cell controller• Programmable logic controller (PLC) • More than one machine tool• A 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. 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: Rough machining and semi-finishing of the material in its soft (annealed ) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrode s 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, cermet, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves a combination 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 is 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 HSM SurvivalThe 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 this area. 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 new and optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs haveto be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpieces that have to be machined (medical equipment, electronics, products for defence, computer parts)Production equipmentThe strong development of cutting materials, holding tools, machine tools, controlsand 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..."Given 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 verify this 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 per minute or roughly 3 300 to 33 000 feet per minute. Speeds above10 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 troubleshootingMaintenance for a horizontal MCThe following is a list of required regular maintenance for a Horizontal Machining Center as shown in fig.5. 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.DailyTop 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. Weekly• Check for proper operation of auto drain on filter regulator.On 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 pumpfrom 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 use solvents.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. Annually• Replace 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. Troubles hootingThis 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 mis-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 don't replace the spindle drive 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 it WON'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.中文译文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。
(完整版)机械毕业设计外文翻译7243268
Introduciton of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process . For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, Machining the second purpose is the establishment of the and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its generalshape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。
(数控加工)机械类数控外文翻译外文文献英文文献数控精编
（数控加工）机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufactur ingtechnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachine toolsweremanualoperatedandcontrolled.Amongthemanylimitationsassoc iatedwithmanualcontrolmachinetools,perhapsnoneismoreprominentthan thelimitationofoperatorskills.Withmanualcontrol,thequalityoftheproducti sdirectlyrelatedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrep resentsthefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufact uringsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Ra therthanoperatingamachinetool,anNCtechnicianwritesaprogramthatissue soperationalinstructionstothemachinetool,Foramachinetooltobenumeric allycontrolled,itmustbeinterfacedwithadeviceforacceptinganddecodingth ep2ogrammedinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanop erator,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanm anuallyoperatedmachines,theycanproducepartsmoreuniformly,theyarefas ter,andthelong-runtoolingcostsarelower.ThedevelopmentofNCledtothede velopmentofseveralotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduc eawidevarietyofpar4s,eachinvolvinganassortmentofundertaketheproducti onofproductsthatwouldnothavebeenfeasiblefromaneconomicperspective usingmanuallycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesofthe MassachusettsInstituteofTechnology.TheconceptofNCwasdevelopedinthe early1950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCm achineswereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobe programmedtoundertakeaseriesofhorizontalandverticalstepstoproducea curve.Theshorteristhestraightlinesmakingupthestep,thesmootheris4hecu rve.Eachlinesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgram medTools(APT)languageforNCthatusesstatementssimilartoEnglishlangua getodefinethepartgeometry,describethecuttingtoolconfiguration,andspe cifythenecessarymotions.ThedevelopmentoftheAPTlanguagewasamajors tepforwardinthefurtherdevelopmentofNCtechnology.TheoriginalNCsyste mwerevastlydifferentfromthoseusedpunchedpaper,whichwaslatertorepla cedbymagneticplastictape.Atapereaderwasusedtointerprettheinstruction swrittenonthetapeforthemachine.Together,all/fthisrepresentedgiantstepf orwardinthecontrolofmachinetools.However,therewereanumberofproble mswithNCatthispointinitsdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwas commonforthepapercontainingtheprogrammedinstructionstobreakortea rduringamachiningprocess,Thisproblemwasexacerbatedbythefactthateac hsuccessivetimeapartwasproducedonamachinetool,thepapertapecarryin gtheprogrammedinstructionshadtorerunthoughtthereader.Ifitwasnecessa rytoproduce100copiesofagivenpart,itwasalsonecessarytorunthepapertap ethoughtthereader100separatetimes.Fragilepapertapessimplycouldnotwi thstandtherigorsofshopfloorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapert apecarriedtheprogrammedinstructionsasaseriesofholespunchedinthetap e,theThismostimportantofthesewasthatitwasdifficultorimpossibletochang etheinstructionsenteredonthetape.Tomakeeventhemostminoradjustment sinaprogramofinstructions,itwasnecessarytointerruptmachiningoperation sandmakeanewtape.Itwasalsostillnecessarytorunthetapethoughtthereade rasmanytimesastherewerepartstobeproduced.Fortunately,computertechn ologybecomearealityandsoonsolvedtheproblemsofNC,associatedwithpun chedpaperandplastictape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethe paperandplastictapeproblemsassociatedwithnumericalcontrolbysimplyeli minatingtapeasthemediumforcarryingtheprogrammedinstructions.Indire ctnumericalcontrol,machinetoolsaretied,viaadatatransmissionlink,toahost computerandfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedta peandplastictape.However,itissubjecttothesamelimitationasalltechnologi esthatdependonahostcomputer.Whenthehostcomputergoesdown,thema chinetoolsalsoexperiencedowntime.Thisproblemledtothedevelopmentofc omputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofpr ogrammablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnolo giesallowedforthedevelopmentofcomputernumericalcontrol(CNC).WithC NC,eachmachinetoolhasaPLCoramicrocomputerthatservesthesamepurpo se.Thisallowsprogramstobeinputandstoredateachindividualmachinetool. CNCsolvedtheproblemsassociateddowntimeofthehostcomputer,butitintr oducedanotherproblemknownasdatamanagement.Thesameprogrammig htbeloadedontendifferentmicrocomputerswithnocommunicationamongt hem.Thisproblemisintheprocessofbeingsolvedbylocalareanetworksthatco nnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinma nyways,likefilteringandspectralanalysis,Designinganaloghardwaretoperfo rmthesefunctionsispossiblebuthasbecomelessandpractical,duetoincrease dperformancerequirements,flexibilityneeds,andtheneedtocutdownondev elopment/testingtime.Itisinotherwordsdifficultpmdesignanaloghardware analysisofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignalprocessingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDi gitalSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanym anufacturers,eachonedesignedforaparticularprice/performance/usagegro up.Manyofthelargestmanufacturers,likeTexasInstrumentsandMotorola,off erbothspecialisedDSP’sforcertainfieldslikemotor-controlormodems,and generalhigh-performanceDSP’sthatcanperformbroadrangesofprocessin gtasks.Developmentkitsan`softwarearealsoavailable,andtherearecompani esmakingsoftwaredevelopmenttoolsforDSP’sthatallowstheprogrammer toimplementcomplexprocessingalgorithmsusingsimple“drag‘n’drop ”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingar chitecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessorst endtohaveanaccumulatorarchitec ture,withonlyone“generalpurpose”re gister,makingthemquitetrickytoprogramandmoreimportantly,makingC-c ompilersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecomm ongeneral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,an ditisdifficulttask findingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupaco nstraintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufacturersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT &TandAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintoth eDSPwhichperformsthedecoding,thenthedecodedsampleshavetobeconv ertedbackintotheanalogdomain,andtheresultingsignalfedanamplifierorsi milaraudioequipment.Thisdigitaltoanalogconversion(DCA)isperformedby acircuitwiththesamename&DifferentDCA’sprovidedifferentperformance andquality,asmeasuredbyTHD(Totalharmonicdistortion),numberofbits,lin earity,speed,filtercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocessor digitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.The ’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontro la pplications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeproce ssingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontro lsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstruc turebutdifferenton-chipmemoryandperipheralconfigurations.Spin-offdev icesusenewcombinationsofOn-chipmemoryandperipheralstosatisfyawide rangeofneedsintheworldwideelectronicsmarket.Byintegratingmemoryand peripheralsontoasinglechip,TMS320devicesreducesystemcostsandsavecir cuitboardspace.The16-bit,fixed-point DSPcoreofthe‘C24xdevicesprovidesanalogde signersadigitalsolutionthatdoesnotsacrificetheprecisionandperformance oftheirsystemperformancecanbeenhancedthroughtheuseofadvancedcont rolalgorithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andsta tecontrol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Anal ogcontrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperien ceperformancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upt ables.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastradition al8-and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyoursoftwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgen eration,sourcecodecompatiblewiththe’C2xgeneration,andupwardlysour cecodecompatiblewiththe‘C5xgenerationofDSPsfro mTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignals.I tusesa16-bitwordlengthalongwith32-bitregistersforstoringintermediatere sults,andhastwohardwareshiftersavailabletoscalenumbersindependentlyo ftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,andi ncreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightincl udeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranesti mationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadva ntageofansetofperipheralfunction sthatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordi fferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirs tstandarddeviceintroducedinthe‘24xseriesofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrolle r.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimple cycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple 8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsam plingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutio nformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrat ing.Alsoincludedareseveralpower-downmodesforfurtherpowersavings.So meapplicationsthatbenefitfromtheadvancedprocessingpowerofthe‘240i nclude:---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts ---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oando therperipherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.Thisapplication-optimizedperipheralunit,coupledwiththehighperfor manceDSPcore,enablestheuseofadvancedcontroltechniquesforhigh-preci sionandhigh-efficiencyfullvariable-speedcontrolofallmotortypes.Includei ntheeventmanagerarespecialpulse-widthmodulation(PWM)generationfu nctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMs tatemachinefor3-phasemotorsthatprovidesstate-of-the-artmaximumeffic iencyintheswitchingofpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister, supportthegenerationofasymmetric(noncentered)aswellassymmetric(cen tered)PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophisticatio ninthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusuall ycapableofadaptingtoavarietyofoperatingconditionsandisabletorespondt oaclassofinputssatisfactorily.However,notanytypeofcontrolsystemhasthea ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebea ringontheindoortemperature.Thisalcopointstoanimportantdisadvantageo ftheperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofadaptingtovariationsinenvironmentalconitionsortoexternaldisturban ces.Inthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovi decontrolforacertaindesiredtemperatureinthehouse;butidthedoorsorwin dowsareopenedorclosedintermittentlyduringtheoperatingperiod,thefinal temperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loop control.Anelectricwashingmachineisanothertypicalexampleofanopen-loops ystem,becausetheamountofwashtimeisentirelydeterminedbythejudgmen tandestimationofthehumanoperator.Atrueautomaticelectricwashingmach ineshouldhavethemeansofcheckingthecleanlinessoftheclothescontinuous lyandturnitsedtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmo readaptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesyste m.Inordertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefe dbackandcomparedwiththereferenceinput,andanactuatingsignalproporti onaltothedifferenceoftheoutputandtheinputmustbesentthroughthesyste mtocorrecttheerror.Asystemwithoneormorefeedbackpat(slikethatjustdesc ribediscalledaclosed-loopsystem.humanbeingareprobablythemostcompl exandsophisticatedfeedbackcontrolsysteminexistence.Ahumanbeingmay beconsideredtobeacontrolsystemwithmanyinputsandoutputs,capableofc arryingouthighlycomplexoperations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasa sensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedist ancebetweenthehandandtheobjectistheerror,whichiseventuallybroughtto zeroasthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontr ol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecano nlyreachtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustra tiveexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftheru ddercontrolsystemofThebasicalementsandtheblocadiagramofaclosed-loo pcontrolsystemareshowninfig.Ingeneral,theconfigurationofafeedbackcon trolsystemmaynotbeconstrainedtothatoffig&.Incomplexsystemstheremay bemultitudeoffeedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控（NC）。
机械类数控外文翻译外文文献英文文献数控
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 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.Numerical control means the control of machine tools and other manufacturing systems though 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 p2ogrammed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operator , 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:1.Electrical discharge machining.ser cutting.3.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 variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools 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 make 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 is the straight lines making up the step ,the smoother is 4he 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 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 further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this represented 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 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 rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigors of shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make 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 thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve 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 and fed to the machine tool as 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 limitation as all technologies that depend on a host computer. When the host computer goes down , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connectDigital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP’s for certain fields like motor-control or modems ,and general high-performance DSP’s that can perform broad ranges of processingtasks. Development kits an` software are also available , and there are companies making software development tools for DSP’s that allows the programmer to implement complex processing algorithms using simple “drag ‘n’ drop” methodologies.DSP’s more or less fall into t wo categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose” register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP’s behave more like common general-purpose CPU’s ,with register-files.There are thousands of different DSP’s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA’s provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits, linearity , speed, filter characteristics and other things.The TMS320 family DQP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (D[Ps) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The’ F/C240 is a number of the’C2000DSP platform , and is optimized for control applications. The’C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications:--- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the ‘C24x devices provides analog designers a digital solution that does not sacrifice the precision and performance of their system performance can be enhanced through the use of advanced control algorithms for techniquessuch as adaptive control , Kalman filtering , and state control. The ‘C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwired solutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purp ose‘C2xx generation ,source code compatible with the’C2x generation , and upwardly source code compatible with the ‘C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The ‘C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marke tplace.The TMS320F/C240 is the first standard device introduced in the ‘24x series of DSP controllers. It sets the standard for a single-chip digital motor controller. The ‘240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The ‘240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the ‘240 include:---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climatecontrol---Appliance and HV AC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own compare register, suppo rt the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A humanbeing may be considered to be a control system with many inputs and outputs, capable of carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there may be multitude of feedback loops and element blocks.数控在先进制造技术领域最根本的观念之一是数控（NC）。
毕业设计(论文)外文资料翻译(崔涛)
毕业设计(论文)外文资料翻译学院：机械工程学院专业：机械设计制造及其自动化姓名：崔涛学号： 090501614外文出处： Robotics and Computer-IntegratedManufacturing 25 (2009) 73-80 附件： 1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文科学指南机器人和计算机集成制造25（2009）73–80一个外旋轮线专用的固定循环数控铣床Sotiris L. Omirou a, , Andreas C. Nearchou b——弗雷德里克大学机械工程系，尼科西亚，塞浦路斯，塞浦路斯——希腊帕特雷大学工商管理系发表于2006年9月20日，修改更新从2007年7月23日到2007年9月10日。
摘要提出了一个加工外旋轮线边界的特定的铣床组策略，该方法适用于被集成到一个控制器的数控铣床，对于旋转式内燃发动机（汪克尔），旋转活塞泵和一般外旋轮线形外壳的加工设计特别有用。
方案可以提供较高的精度，其中铣机是通过利用数控插补算法实现的，表面质量控制，是通过粗加工和精加工来实现，整个加工任务可以被编程在一块。
最后，该方法的有效性通过仿真试验验证所产生的刀具路径来实现。
关键词：数控；程序加工；刀具路径生成；偏移曲线；外旋轮线1介绍智能周期提供了一种数控机床来完成重复使用的G / M代码语言的新的加工操作的编程方法。
从本质上讲，智能周期是一个指令被预先设定并永久存储的集机控制器。
它们的使用，消除了许多编程的繁琐需要，减少了编程时间，并简化了整个编程过程。
所有数控加工控制是智能的，这些固定循环可以执行一定的代码，输入任何所需的变量信息。
钻，反钻，深孔钻或槽的加工是标准智能循环应用的例子。
然而，标准智能循环在数量和能力有限，无法容纳复杂的几何形状的日益增加的应用需求。
在加工一个外旋轮线构造特征的情况下，不能用标准智能循环处理。
尽管有其重要的加工应用，现代数控系统仍缺乏类似的专用智能周期。
机床——机械类外文文献翻译、中英文翻译
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。
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。
毕业论文外文翻译-数控技术
数控技术数控技术是一种利用程序实现自动控制的技术，加工制造设备采用数控技术后能由数字、字符和符号等进行控制。
这些数字、字符和符号等北边麻城按一定格式定义的指令程序，用于特定的加工或工作。
这种指令可采用两种二进制编码的数字系统中的任意一种进行定义，这两种二进制编码的数字系统分别为电工协会代码和美国标准信息交换代码。
一般来说，ASCII编码的机床控制系统不能接受EIA编码的指令，反之亦然。
当然，这样的问题已经逐渐得到解决。
数控加工制造目前已经广泛地应用于几乎所有的金属加工机床；车床，铣床，钻床，镗床，磨床，回转冲床，电火花或线切割机床以及焊接机床，甚至弯管机也可采用数控加工技术。
数控技术的基本组成一个数控系统主要由以下3个部分组成：(1)程序指令(2)加工控制单元(3)制造装备程序指令由一条一条的详细指令组成，制造装备按要求执行这些指令。
最常用的指令形式可以按要求使机床刀具主轴位于工作台上的具体位置，工作台是用于固定加工零件的。
许多更高级的指令还包括主轴速度选择，道具选择及其他的一些功能。
加工控制单元包括一些用于阅读和解释程序指令并将其转换为机床刀具或其他制造装备的机械动作的电子和控制硬件。
制造装备是一种进行金属加工的数控技术装备，在常用的数控技术领域中，制造装备用于进行机械制造。
制造装备包括工作台、主轴、电机及控制驱动单元。
数控技术的类型数控技术系统主要有两种类型：点对点数控系统和轮廓线数控系统。
点对点数控系统也称为位置数控系统，比轮廓线数控系统简单，其主要的原理是移动刀具或工件从一个程序控制点到另一个程序控制点，通常像钻床这样的加工功能，每个点都可以通过NC程序中的指令进行控制。
点对点数控系统适用于钻孔，沉孔加工、沉孔镗孔、铰孔和攻螺纹等。
其他冲孔机床、电焊机和装配机床等也都采用点对点数控系统。
轮廓线数控系统也称为轮廓线路径数控系统，定位和切割操作都是以不同的速度沿着控制的路径进行的。
由于刀具沿路径进行切削，因此刀具的运动和速度的精确控制盒同步性能是非常重要的。
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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What Is CNCCNC stands for Computer Numerical Control and has been around since the early 1970''s. Prior to this, it was called NC, for Numerical Control. (In the early 1970''s, computers were introduced in these controls, hence the name changed)While people in most walks of life have never heard of this term, CNC has touched almost every form of manufacturing process in one way or another. If you''ll be working in manufacturing, it''s likely that you''ll be dealing with CNC on a regular basis.Before CNCWhile there are exceptions to this statement, CNC machines typically replace (or work in conjunction with) some existing manufacturing process/es. Take one of the simplest manufacturing processes, drilling holes, for example.A drill press can of course be used to machine holes. (It''s likely that almost everyone has seen some form of drill press, even if you don''t work in manufacturing.) A person can place a drill in the drill chuck that is secured in the spindle of the drill press. They can then (manually) select the desired speed for rotation (commonly by switching belt pulleys), and activate the spindle. Then they manually pull on the quill lever to drive the drill into the workpiece being machined.As you can easily see, there is a lot of manual intervention required to use a drill press to drill holes. A person is required to do something almost every step along the way! While this manual intervention may be acceptable for manufacturing companies if but a small number of holes or workpieces must be machined, as quantities grow, so does the likelihood for fatigue due to the tediousness of the operation. And do note that we''ve used one of the simplest machining operations (drilling) for our example. There are more complicated machining operations that would require a much higher skill level (and increase the potential for mistakes resulting in scrap workpieces) of the person running the conventional machine tool. (We commonly refer to the style of machine that CNC is replacing as the conventional machine.)By comparison, the CNC equivalent for a drill press (possibly a CNC machining center or CNC drilling & tapping center) can be programmed to perform this operation in a much more automatic fashion. Everything that the drill press operator was doing manually will now be done by the CNC machine, including: placing the drill in the spindle, activating the spindle, positioning the workpiece under the drill, machining the hole, and turning off the spindle.How CNC worksThere is another article included in this web site called The Basics of CNC that explains how to program, setup, and operate CNC machines in greater detail. Additionally, we offer a series of products aimed at helping you learn how to use CNC machines. Here we''re relating how CNC works in very general terms.As you might already have guessed, everything that an operator would be required to do with conventional machine tools is programmable with CNC machines. Once the machine is setup and running, a CNC machine is quite simple to keep running. In fact CNC operators tend to get quite bored during lengthy production runs because there is so little to do. With some CNC machines, even the workpiece loading process has been automated. (We don''t mean toover-simplify here. CNC operators are commonly required to do other things related to the CNC operation like measuring workpieces and making adjustments to keep the CNC machine running good workpieces.)Let''s look at some of the specific programmable functions.Motion controlAll CNC machine types share this commonality: They all have two or more programmable directions of motion called axes. An axis of motion can be linear (along a straight line) or rotary (along a circular path). One of the first specifications that implies a CNC machine''s complexity is how many axes it has. Generally speaking, the more axes, the more complex the machine.The axes of any CNC machine are required for the purpose of causing the motions needed for the manufacturing process. In the drilling example, these (3) axis would position the tool over the hole to be machined (in two axes) and machine the hole (with the third axis). Axes are named with letters. Common linear axis names are X, Y, and Z. Common rotary axis names are A, B, and C.Programmable accessoriesA CNC machine wouldn''t be very helpful if all it could only move the workpiece in two or more axes. Almost all CNC machines are programmable in several other ways. The specific CNC machine type has a lot to do with its appropriate programmable accessories. Again, any required function will be programmable on full-blown CNC machine tools. Here are some examples for one machine type.Machining centersAutomatic tool changerMost machining centers can hold many tools in a tool magazine. When required, the required tool can be automatically placed in the spindle for machining.Spindle speed and activationThe spindle speed (in revolutions per minute) can be easily specified and the spindle can be turned on in a forward or reverse direction. It can also, of course, be turned off.CoolantMany machining operations require coolant for lubrication and cooling purposes. Coolant can be turned on and off from within the machine cycle.The CNC programThink of giving any series of step-by-step instructions. A CNC program is nothing more than another kind of instruction set. It''s written in sentence-like format and the control will execute it in sequential order, step by step.A special series of CNC words are used to communicate what the machine is intended to do. CNC words begin with letter addresses (like F for feedrate（馈送率）, S for spindle speed, and X, Y & Z for axis motion). When placed together in a logical method, a group of CNC words make up a command that resemble a sentence.For any given CNC machine type, there will only be about 40-50 words used on a regular basis. So if you compare learning to write CNC programs to learning a foreign language having only50 words, it shouldn''t seem overly difficult to learn CNC programming.The CNC controlThe CNC control will interpret a CNC program and activate the series of commands in sequential order. As it reads the program, the CNC control will activate the appropriate machine functions, cause axis motion, and in general, follow the instructions given in the program.Along with interpreting the CNC program, the CNC control has several other purposes. All current model CNC controls allow programs to be modified (edited) if mistakes are found. The CNC control allows special verification functions (like dry run) to confirm the correctness of the CNC program. The CNC control allows certain important operator inputs to be specified separate from the program, like tool length values. In general, the CNC control allows all functions of the machine to be manipulated.What is a CAM system?For simple application (like drilling holes), the CNC program can be developed manually. That is, a programmer will sit down to write the program armed only with pencil, paper, and calculator. Again, for simple applications, this may be the very best way to develop CNC programs.As applications get more complicated, and especially when new programs are required on a regular basis, writing programs manually becomes much more difficult. To simplify the programming process, a computer aided manufacturing (CAM) system can be used. A CAM system is a software program that runs on a computer (commonly a PC) that helps the CNC programmer with the programming process. Generally speaking, a CAM system will take the tediousness and drudgery out of programming.What is a DNC system?Once the program is developed(either manually or with a CAM system), it must be loaded into the CNC control. Though the setup person could type the program right into the control, this would be like using the CNC machine as a very expensive typewriter. If the CNC program is developed with the help of a CAM system, then it is already in the form of a text file . If the program is written manually, it can be typed into any computer using a common word processor (though most companies use a special CNC text editor for this purpose). Either way, the program is in the form of a text file that can be transferred right into the CNC machine. A distributive numerical control (DNC) system is used for this purpose.A DNC system is nothing more than a computer that is networked with one or more CNC machines. Until only recently, rather crude serial communications protocol (RS-232c) had to be used for transferring programs. Newer controls have more current communications capabilities and can be networked in more conventional ways (Ethernet, etc.). Regardless of methods, the CNC program must of course be loaded into the CNC machine before it can be run.中文翻译：什么数控机床数控机床代表计算机数字控制机床，并且从20世纪70年代以来一直受到人们的关注。