組合機床設計外文翻譯

1、<p>　　畢 業(yè) 設 計（論 文）外 文 參 考 資 料 及 譯 文</p><p>　　譯文題目： TRANSFER AND UNIT MACHINE </p><p>　　組合機床 </p><p>　　學生姓名： 學　　號： </p&

2、gt;<p>　　?！　I(yè)： 機械設計制造及其自動化 </p><p>　　所在學院： </p><p>　　指導教師： </p><p>　　

3、職　　稱： 講師 </p><p>　　2012年 11月 23 日</p><p><b>　　說明：</b></p><p>　　要求學生結合畢業(yè)設計（論文）課題參閱一篇以上的外文資料，并翻譯至少一萬印刷符（或譯出3千漢字）以上的譯文。譯文原則上要求打印（如手寫，一律用

4、400字方格稿紙書寫），連同學校提供的統(tǒng)一封面及英文原文裝訂，于畢業(yè)設計（論文）工作開始后2周內(nèi)完成，作為成績考核的一部分。</p><p>　　TRANSFER AND UNIT MACHINE </p><p>　　While the specific intention and application for transfer and unit machine vary from o

5、ne machine type to another, all forms of transfer and unit machine have common benefits. Here are but a few of the more important benefits offered by TRANSFER AND UNIT MACHINE equipment.</p><p>　　The first b

6、enefit offered by all forms of transfer and unit machine is improved automation. The operator intervention related to producing workpieces can be reduced or eliminated. Many transfer and unit machine can run unattended d

7、uring their entire machining cycle, freeing the operator to do other tasks. This gives the transfer and unit machine user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, an

8、d consistent and predictable machining time for e</p><p>　　The second major benefit of transfer and unit machine technology is consistent and accurate workpieces. Today's transfer and unit machines boast

9、 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.</p>

10、<p>　　rd benefit offered by most forms of transfer and unit machine tools is flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program.

11、 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 ver

12、y easy to set up and run, and since programs can be easily loaded, they </p><p>　　Motion control - the heart of transfer and unit machine</p><p>　　The most basic function of any transfer and uni

13、t 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, transfer and unit machines allow moti

14、on control in a revolutionary manner2. All forms of transfer and unit machine equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of

15、travel. The t</p><p>　　Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, transfer and unit machines allow motions to be commanded through programmed com

16、mands. 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 transfer and unit machine tools.</p>

17、<p>　　A transfer and unit machine 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 dr

18、ives the 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. Refer to fig.1.</p><p><b>　　Fig.1</

19、b></p><p>　　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

20、the vise. By comparison, a linear axis on a transfer and unit machine machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.<

21、;/p><p>　　How axis motion is commanded - understanding coordinate systems</p><p>　　It would be infeasible for the transfer and unit machine user to cause axis motion by trying to tell each axis dri

22、ve 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 in

23、ch!) Instead, all transfer and unit machine controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate sys</p><p>　　The program zero point establis

24、hes the point of reference for motion commands in a transfer and unit machine program. This allows the programmer to specify movements from a common location. If program zero is chosen wisely, usually coordinates needed

25、for the program can be taken directly from the print.</p><p>　　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 command

26、ed. 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

27、 to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer t</p><p><b>　　Fig.2</b></p><p><b>　　Fig.3

28、</b></p><p>　　All discussions to this point assume that the absolute mode of programming is used6. The most common transfer and unit machine word used to designate the absolute mode is G90. In the abso

29、lute 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

30、way of specifying end points for axis motion.</p><p>　　In the incremental mode (commonly specified by G91), end points for motions are specified from the tool's current position, not from program zero. W

31、ith 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

32、more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode.</p><p>　　Be careful when making motion commands. Beginners have the tendency to think in

33、crementally. 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 to

34、ols current position.</p><p>　　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 com

35、mands. In the absolute mode, if a motion mistake is made in one command of the program, only one movement will be incorrect. On the other hand, if a mistake is made during incremental movements, all motions from the poin

36、t of the mistake will also be incorrect.</p><p>　　Assigning program zero</p><p>　　Keep in mind that the transfer and unit machine control must be told the location of the program zero point by o

37、ne means or another. How this is done varies dramatically from one transfer and unit machine and control to another8. One (older) method is to assign program zero in the program. With this method, the programmer tells th

38、e 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</p><p>　　Another, newer and better way

39、 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

40、 offsets used to assign program zero for each tool geometry offsets.</p><p>　　Fig. 4 </p><p>　　Flexible manufacturing cells</p><p>　　A flexible manufacturing cell (FMC) can be co

41、nsidered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS:</p><p>　　An FMC is not under the direct control of thecentral computer. Instead, instructions fro

42、m the centralcomputer are passed to the cell controller.</p><p>　　The cell is limited in the number of part families itcan manufacture.</p><p>　　The following elements are normally found in an

43、 FMC:</p><p>　　Cell controller</p><p>　　Programmable logic controller (PLC)</p><p>　　More than one machine tool</p><p>　　A materials handling device (robot or pallet)&l

44、t;/p><p>　　The FMC executes fixed machining operations with parts flowing sequentially between operations. </p><p>　　High speed machining</p><p>　　The term High Speed Machining (HSM) c

45、ommonly 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

46、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 a

47、bove. With most steel c</p><p>　　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. Consequ

48、ently, production costs can be high and lead times excessive.</p><p>　　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

49、 to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering .</p><p>　　The main criteria is the quality level of the die or mould regarding dimension

50、al, 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 accu

51、racy, but it always has a negative impact on the dimensional and geometric accuracy.</p><p>　　One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for m

52、anual polishing and thus improve the quality and shorten the production costs and lead times.</p><p>　　Main economical and technical factors for the development of HSM</p><p><b>　　Survival

53、</b></p><p>　　The 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 developm

54、ent of new processes and production techniques to take place. HSM provides hope and solutions...</p><p><b>　　Materials</b></p><p>　　The development of new, more difficult to machine

55、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 Graphi

56、te 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.</p><p><b>　　Quality<

57、/b></p><p>　　The 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 f

58、inishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry.</p><p><b>　　Processes</b></p><p>　　The demands on shorter throughp

59、ut 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. C

60、ostly and time consuming EDM processes can also be reduced or eliminated with HSM.</p><p>　　Design & development</p><p>　　One of the main tools in today's competition is to sell products

61、 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 rapi

62、d product development time is the HSM technique. </p><p>　　Complex products</p><p>　　There is an increase of multi-functional surfaces on components, such as new design of turbine blades giving

63、new and optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by H

64、SM . There are also more and more examples of thin walled workpieces that have to be machined (medical equipment, electronics, products for defence, computer parts)</p><p>　　Production equipment</p>&

65、lt;p>　　The strong development of cutting materials, holding tools, machine tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techn

66、iques5.</p><p>　　Definition of HSM</p><p>　　Salomon's theory, "Machining with high cutting speeds..." on which, in 1931, took out a German patent, assumes that "at a certain c

67、utting speed (5-10 times higher than in conventional machining), the chip removal temperature at the cutting edge will start to decrease..."</p><p>　　Given the conclusion:" ... seems to give a chan

68、ce to improve productivity in machining with conventional tools at high cutting speeds..."</p><p>　　Modern research, unfortunately, has not been able to verify this theory totally. There is a relative d

69、ecrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials.</p><p>　　The decrease is small for steel and cast iron. But larger for aluminum and other non-fer

70、rous metals. The definition of HSM must be based on other factors.</p><p>　　Given today's technology, "high speed" is generally accepted to mean surface speeds between 1 and 10 kilometers per m

71、inute or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve

72、 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 d</p><p>　　There are many opinions, many myth

73、s and many different ways to define HSM.</p><p>　　Maintenance and troubleshooting</p><p>　　Maintenance for a horizontal MC</p><p>　　The following is a list of required regular maint

74、enance 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 go

75、od working order and protect your warranty.</p><p><b>　　fig. 5 </b></p><p><b>　　Daily</b></p><p>　　Top off coolant level every eight hour shift (especially d

76、uring heavy TSC usage).</p><p>　　Check way lube lubrication tank level.</p><p>　　Clean chips from way covers and bottom pan.</p><p>　　Clean chips from tool changer.</p><p

77、>　　Wipe spindle taper with a clean cloth rag and apply light oil.</p><p><b>　　Weekly</b></p><p>　　?Check for proper operation of auto drain on filter regulator. </p><p

78、>　　On machines with the TSC option, clean the chip basket on the coolant tank.</p><p>　　Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the co

79、ntroller and POWER OFF the control before working on the coolant tank . Do this monthly for machines without the TSC option.</p><p>　　Check air gauge/regulator for 85 psi.</p><p>　　For machines

80、with the TSC option, place a dab of grease on the V-flange of tools. Do this monthly for machines without the TSC option.</p><p>　　Clean exterior surfaces with mild cleaner. DO NOT use solvents.</p>&

81、lt;p>　　Check the hydraulic counterbalance pressure according to the machine's specifications.</p><p>　　Place a dab of grease on the outside edge of the fingers of the tool changer and run through all

82、tools".</p><p><b>　　Monthly</b></p><p>　　Check oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank.</p><p>　　Clean pa

83、ds on bottom of pallets.</p><p>　　Clean the locating pads on the A-axis and the load station. This requires removing the pallet.</p><p>　　?Inspect way covers for proper operation and lubricate

84、with light oil, if necessary.</p><p>　　Six months</p><p>　　Replace coolant and thoroughly clean the coolant tank.</p><p>　　Check all hoses and lubrication lines for cracking.</p&

85、gt;<p><b>　　Annually</b></p><p>　　?Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil.</p><p>　　?Check oil filte

86、r and clean out residue at bottom for the lubrication chart.</p><p>　　Replace air filter on control box every 2 years.</p><p>　　Mineral cutting oils will damage rubber based components throughou

87、t the machine.</p><p>　　Troubleshooting</p><p>　　This section is intended for use in determining the solution to a known problem. Solutions given are intended to give the individual servicing th

88、e TRANSFER AND UNIT MACHINE a pattern to follow in, first, determining the problem's source and, second, solving the problem.</p><p>　　Use common sense</p><p>　　Many problems are easily over

89、come 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

90、an overextended boring bar, don't expect the machine to correct the fault.</p><p>　　Don't suspect machine accuracy if the vise bends the part. Don't claim hole mis-positioning if you don't fi

91、rst center-drill the hole.</p><p>　　Find the problem first</p><p>　　Many mechanics tear into things before they understand the problem, hoping that it will appear as they go. We know this from t

92、he 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, whic

93、h 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</p><p>　　Don tinker with the machine</p&g

94、t;<p>　　There 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 som

95、ething, 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 th

96、e board, reconnect and reload, and if you make one mistake or bend one tiny pin it </p><p><b>　　組合機床</b></p><p>　　雖然各種組合機床的功能和應用各不相同，但它們有著共同的優(yōu)點。這里是數(shù)控設備提供的比較重要的幾個優(yōu)點。</p><p&

97、gt;　　各種組合機床的第一個優(yōu)點是自動化程度提高了。零件制造過程中的人為干預減少或者免除了。整個加工循環(huán)中，很多組合機床處于無人照看狀態(tài)，這使操作員被解放出來，可以干別的工作。組合機床用戶得到的幾個額外好處是：組合機床減小了操作員的疲勞程度，減少了人為誤差，工件加工時間一致而且可預測。由于機床在程序的控制下運行，與操作普通機床的機械師要求的技能水平相比，對數(shù)控操作員的技能水平要求（與基本加工實踐相關）也降低了。</p>

98、<p>　　數(shù)控技術的第二個優(yōu)點是工件的一致性好，加工精度高?，F(xiàn)在的組合機床宣稱的精度以及重復定位精度幾乎令人難以置信。這意味著，一旦程序被驗證是正確的，可以很容易地加工出2個、10個或1000個相同的零件，而且它們的精度高，一致性好。</p><p>　　大多數(shù)組合機床的第三個優(yōu)點是柔性強。由于這些機床在程序的控制下工作，加工不同的工件易如在數(shù)控系統(tǒng)中裝載一個不同的程序而己。一旦程序驗證正確，并且運行

99、一次，下次加工工件的時候，可以很方便地重新調(diào)用程序。這又帶來另一個好處—可以快速切換不同工件的加工。由于這些機床很容易調(diào)整并運行，也由于很容易裝載加工程序，因此機床的調(diào)試時間很短。這是當今準時生產(chǎn)制造模式所要求的。</p><p>　　運動控制—TRANSFER AND UNIT MACHINE的核心</p><p>　　任何組合機床最基本的功能是具有自動、精確、一致的運動控制。大多數(shù)普通

100、機床完全運用機械裝置實現(xiàn)其所需的運動，而組合機床是以一種全新的方式控制機床的運動。各種數(shù)控設備有兩個或多個運動方向，稱為軸。這些軸沿著其長度方向精確、自動定位。最常用的兩類軸是直線軸（沿直線軌跡）和旋轉軸（沿圓形軌跡）。</p><p>　　普通機床需通過旋轉搖柄和手輪產(chǎn)生運動，而組合機床通過編程指令產(chǎn)生運動。通常，幾乎所有的組合機床的運動類型（快速定位、直線插補和圓弧插補）、移動軸、移動距離以及移動速度（進給速

101、度）都是可編程的。</p><p>　　數(shù)控系統(tǒng)中的TRANSFER AND UNIT MACHINE指令命令驅(qū)動電機旋轉某一精確的轉數(shù)，驅(qū)動電機的旋轉隨即使?jié)L珠絲杠旋轉，滾珠絲杠將旋轉運動轉換成直線軸（滑臺）運動?；_上的反饋裝置（直線光柵尺）使數(shù)控系統(tǒng)確認指令轉數(shù)已完成，參見圖1。</p><p><b>　　圖1 </b></p><p>