外文翻譯--機(jī)床坐標(biāo)軸-數(shù)控機(jī)床

1、<p>　　14. CNC MACHINES</p><p>　　? Computer Numerical Control machines use a computer to guide a process that might otherwise be done manually. </p><p>　　14.1 MACHINE AXES</p><p&g

2、t;　　14.2 NUMERICAL CONTROL (NC)</p><p>　　? The use of numerical data to drive a machine for processes such as,</p><p><b>　　- milling</b></p><p><b>　　- turning</

3、b></p><p>　　- drilling</p><p>　　- grinding</p><p>　　- shot peening</p><p>　　- tube bending</p><p>　　- flame cutting</p><p>　　- automated kn

4、itting machines</p><p>　　- automatic riveting</p><p><b>　　- etc.</b></p><p>　　? Basic components of NC systems,</p><p><b>　　- program</b></p&

5、gt;<p>　　- controller unit</p><p>　　- machine tool</p><p>　　? Most suited to,</p><p>　　- parts are pr ocessed frequently in small lot sizes</p><p>　　- complex pa

6、rt geometry</p><p>　　- close tolerances on workpart</p><p>　　- many oper ations on part in processing</p><p>　　- large amounts of metal to be removed</p><p>　　- enginee

7、ring design will possibly change</p><p>　　- parts that are too expensive for mistakes</p><p>　　? The methods for developing NC programs include,</p><p>　　- manual part programming&l

8、t;/p><p>　　- computer-assisted part programming</p><p>　　- computer gener ated programs</p><p>　　? The manual and computer aided methods use various NC programming languages,</p>

9、<p>　　- APT (Automatically Programmed Tools)</p><p>　　- AUTOSPOT (Automatic System for Positioning Tools)</p><p>　　- SPLIT (Sundstrand Processing Language Internally Translated)</p>

10、<p>　　- COMPACT II</p><p>　　- ADAPT (ADaptation of APT)</p><p>　　- EXAPT (Extended Subset of APT)</p><p><b>　　- UNIAPT</b></p><p>　　? These language

11、s are used by a parts programmer to define the motion of the cutting tool.</p><p>　　? The languages may be preprocessed, and then used for a number of various control types, </p><p><b>　　s

12、uch as,</b></p><p>　　- punched paper tape</p><p>　　- Computer Numerical Control (CNC)</p><p>　　- Direct Numerical Control (DNC)</p><p>　　? The automatic methods w

13、ork with geometry created in a CAD program.</p><p>　　14.2.1 NC Tapes</p><p>　　? NC Progr ams are preprocessed on computers, and punched onto paper or mylar tapes.</p><p>　　? Simple

14、NC machines can use a tape reader to direct the machine.</p><p>　　? Problems,</p><p>　　- required storage, transportation, and manual loading of NC tapes</p><p>　　- has to reread th

15、e tape for each new part</p><p>　　- tapes tend to wear, and become dirty, thus causing misreadings</p><p>　　- the mechanical parts in the readers reduced reliability</p><p>　　- test

16、ing had to be done on the NC machine</p><p>　　- no program editing abilities (increased lead time)</p><p>　　? The end of tapes was the result of two competing developments</p><p>　　

17、- DNC used remote computers to replace tape readers, these were displaced in most cases by CNC</p><p>　　- CNC allowed the use of a local computer to overcome problems with tapes, and the problems with dista

18、nt computers. While CNC was used to enhance tapes for a while, they eventually allowed the use of other storage media, and cur rently program transfer media are not required.</p><p>　　14.2.2 Computer Numeric

19、al Control (CNC)</p><p>　　? A computer controller is used to drive an NC machine directly.</p><p>　　? Characteristics are,</p><p>　　- controls a single machine</p><p>　

20、　- located very close to machine tool</p><p>　　- allows storage/retrieval/entry of NC programs without preprocessing of NC code</p><p>　　? Advantages of CNC,</p><p>　　- progr am is

21、only entered into memory once, so it is more reliable</p><p>　　- the programs can be tested and altered at the machine</p><p>　　- increased flexibility and control options on the local computer&

22、lt;/p><p>　　- easy to integrate into FMS systems</p><p>　　? The Background,</p><p>　　- the problems with NC tapes were approached using DNC networks</p><p>　　- the communi

23、cation problems with DNC systems became obvious, and local computers were added to act as tape readers which would read tapes once, and play them back to the NC machine indefinitely</p><p>　　- CNC controller

24、s began using other storage media like magnetic tapes, and floppy disks</p><p>　　- CNC now offers features like,</p><p>　　- local programming,</p><p>　　- communication over interfac

25、es,</p><p>　　- hard disk storage,</p><p>　　- program simulation</p><p><b>　　- etc.</b></p><p>　　? ASIDE: Direct Numerical Control is similar to CNC, except

26、a remote computer is used to control a number of machines. This gives the advantage of more computer power. This approach is no longer popular, as the dropping cost of computers offsets any advantages.</p><p&g

27、t;　　? Some companies use proprietary NC Languages,such as the example of DYNA Mill NC code shown later</p><p>　　? These machines are often programmed by downloading NC code from a computer, or manually progr

28、amming the controller computer.</p><p>　　? Future trends involve,</p><p>　　- adaptive feed rates to increase speeds as the metal removal rate varies</p><p>　　- tool wear detection&

29、lt;/p><p>　　14.2.3 Direct/Distributed Numerical Control (DNC)</p><p>　　? Uses a few methods,</p><p>　　- the oldest methods used modems, and a mainframe which emulated a tape reader, to

30、 control the NC machine (no storage)</p><p>　　- a more recent advance used a local computer which acts as a storage buffer. Programs are downloaded from the main DNC computer, and then the local controller

31、feeds instructions to the hardwired NC machine, as if they have been read from tape.</p><p>　　- the newer methods use a central computer which communicates with local CNC computers (also called Direct Numeri

32、cal Control)</p><p>　　? DNC controllers came before CNC machines, but as computer technology impr oved it became practical to place a computer beside the NC machine, and DNC changed in form.</p><

33、p>　　? Characteristics of modern DNC systems are,</p><p>　　- uses a server (with large storage capacity) to store a large number of part programs。</p><p>　　- the server will download part prog

34、rams on demand to local machines</p><p>　　- may have abilities to,</p><p>　　- display and edit part programs</p><p>　　- transmit operator instructions and other data needed at the m

35、achines</p><p>　　- collect and process machine status information for management purposes</p><p>　　? Advantages are,</p><p>　　- eliminates the need for NC tapes (the advantages are

36、obvious)</p><p>　　- design changes are immediate</p><p>　　- NC programs may be edited quickly</p><p>　　- can be used to support an FMS system</p><p>　　- increase effici

37、ency of individual machine tools</p><p>　　- more shop up-time than with stand alone machines</p><p>　　- simplifies implementation of group technology, computer aided process planning, and other

38、 CIM concepts</p><p>　　-reduces peripheral costs with NC tapes</p><p>　　? A Brief History,</p><p>　　? Mid 60’s</p><p>　　- concept proved by Cincinnati Milacron and G.E.

39、</p><p>　　- telephone links used to send instructions from large computers to hard wired NC machines. Basically replaced a tape reader.</p><p><b>　　? 1970</b></p><p>　　-

40、 several commercial DNC systems announced.</p><p>　　? Mid 70’s</p><p>　　- Aerospace companies used DNC because of the large number of distributed </p><p>　　-machines in their facil

41、ities.</p><p>　　? Initial resistance to DNC technology was (previously) based on,</p><p>　　- high cost of computer hardware</p><p>　　- the number of machines which could be controll

42、ed by one computer was limited</p><p>　　- computer sof tware was limited for maintenance, scheduling, control, and data collection</p><p>　　- a backup computer was usually required</p>&l

43、t;p>　　- was hard to justify on the basis of downloading parts programs</p><p>　　? when downloading programs there are two popular opinions,</p><p>　　- a program should only be downloaded in p

44、art, this accommodates easy engineering </p><p>　　changes in a real-time environment.</p><p>　　- many programs should be downloaded to the local controller to provide protection </p><

45、;p>　　against system failure, and eliminating the cost of real-time response in the DNC </p><p>　　centr al computer.</p><p>　　14.3 EXAMPLES OF EQUIPMENT</p><p>　　? The number of N

46、C machines available commercially will be well into the thousands. </p><p>　　14.3.1 EMCO PC Turn 50 </p><p>　　? This is a small desktop lathe capable of turning parts in metal. </p><

47、;p>　　? The basic physical specifications are, </p><p>　　Cutting volume radial travel 48mm rad axial travel 228mm</p><p>　　Max.holding volume radial 30-65mm axial 300mm 12mm by 12mm &l

48、t;/p><p>　　Max.tool size max 80mmm dia</p><p>　　Chuck 130-3000rpm</p><p>　　Spindle 0.001mm</p><p>　　Resolution 0-750mm/min<

49、;/p><p>　　Feed <=600N below 500mm/min</p><p>　　Feed force 100/110/230VAC,0-6KVA</p><p>　　Power 840 by 695 by 345 mm</p><p>　　?

50、 The basic sequence of operations for this machine are,</p><p>　　1. Unpack components.</p><p>　　2. Connect devices to power, air supply, and attach interface cables </p><p>　　3. Ins

51、tall RS-485 card in PC.</p><p>　　4. Install software.</p><p>　　5. Test basic system (Done initial setup here).</p><p>　　6. Start and initialize lathe and PC with software.</p>

52、;<p>　　7. Setup tools for new job. Find zero positions/offsets, and enter values for turret.</p><p>　　8. Load NC code.</p><p>　　9. Simulate program.</p><p>　　10.Load stock an

53、d close automatic chuck.</p><p>　　11.Close door.</p><p>　　12.Run program on Lathe.</p><p>　　13.Open door and open chuck.</p><p>　　14.If cutting a similar part go to ste

54、p 8, if doing a new setup go to step 7.</p><p>　　14.3.2 Light Machines Corp. proLIGHT Mill</p><p>　　? This is a small desktop lathe capable of turning parts in metal.</p><p>　　? Th

55、e basic physical specifications are</p><p>　　Cutting Volume </p><p>　　Max. Holding Volume</p><p>　　Max. Tool Size</p><p>　　Spindle 200-5000rpm<

56、;/p><p>　　Resolution</p><p>　　Feed 50ipm x,y and 40ipm z</p><p>　　Feed Force</p><p><b>　　Power</b></p><p>　　Dimensions</p>

57、<p><b>　　Weight</b></p><p>　　Controller IBM compatible computer</p><p>　　Control Interface IBM compatible computer</p><p>　　Programming G-Codes a

58、nd Dos softwar</p><p>　　Spindle 1 H.P. </p><p>　　? The basic sequence of operations for this machine are,</p><p>　　1. Unpack components.</p><p>　　2. Connec

59、t devices to power, air supply, and attach interface cables.</p><p>　　3. Install software.</p><p>　　4. Test basic system (Done initial setup here).</p><p>　　5. Start and initialize

60、 mill and PC with software.</p><p>　　6. Setup tool for new job. Find zero position/offset.</p><p>　　7. Load NC code.</p><p>　　8. Simulate program.</p><p>　　9. Run pr o

61、gram on Mill.</p><p>　　10. If cutting a similar part go to step 7, if doing a new setup go to step </p><p>　　14.4 PRACTICE PROBLEMS14.5 TUTORIAL - EMCO MAIER PCTURN 50 LATHE (OLD) ? The lathe i

62、s shipped with software that is meant to emulate shop floor interfaces. We donnot have the standard keyboard, so we need to use special key stroke sequences on the PC keyboard.</p><p>　　? Procedure:</p>

63、;<p>　　1. Connect the air supply to the lathe and make sure that the regulator on the lathe is between 25 and 75 psi - 50 psi is good. Ensure that the lath is connected to the PC with the DNC cable. The computer c

64、ard must also have a terminator on the second connector - this is an empty connector. Turn on the lathe, and the PC.</p><p>　　2. Once the PC is booted, run the emco control software. The screen may come up

65、with warnings. If these warnings don’t disappear when you hit ‘ESC’ call the instructor.</p><p>　　3. First we must zero the lathe. To do this first hit ‘F1’ and then ‘F7?-ZRN’. A small label </p><

66、p>　　‘ZRN’ should appear near the bottom of the screen. Press ‘4’ on the number pad of the keyboard - the lathe should move in the ‘x’ dir ection. Next, press ‘8’ on the keyboard, the lathe should move in the ‘z’ direc

67、tion. After all motion has stopped the lathe is calibrated, and it will be put in jog mode.</p><p>　　4. You can move the lathe with the keys on the number pad as well as perform other function.</p>&l

68、t;p>　　4 - move carriage left</p><p>　　6 - move carriage right</p><p>　　2 - cross slide out</p><p>　　8 - move cross slide in</p><p>　　<SFT>7 - turn spindle on&l

69、t;/p><p>　　<SFT>6 - turn spindle off</p><p>　　<SFT>2 - turn on/off chip blower</p><p>　　<SFT>1 - turn tool turret</p><p>　　+/- - increase/decrease feed&

70、lt;/p><p>　　5. You can now put the mill in MDI mode by pressing ‘F1’ then ‘F6?-MDI’. Push the door open and hold it for a second, it will then stay open. Clear the error on the screen with ‘ESC’ and press <

71、;SFT>~ the chuck should open and close. Mount a work piece and then close the door.</p><p>　　6. Put the computer in program mode ---------------</p><p>　　14.6 TUTORIAL - PC TURN 50 LATHE DOCU

72、MENTATION: (By Jonathan DeBoer)</p><p><b>　　? SETUP:</b></p><p>　　The lathe is controlled by a computer through an RS485 port. RS485 is a serial data bus that can be chained from on

73、e device to another and must be terminated.The controlling computer must be running Windows 3.1 or 3.11 and must have the RS485 card installed. Windows 95 will not get along with the interface card, and the software ref

74、uses to use an RS232 port with an RS485 adapter. The machine should have as few peripherals as possible; if one device happens to use any of the IRQs/</p><p>　　DMAs/IO ports as the RS485 card, there will be

75、 problems. So remove sound cards, extra interface cards, etc. The RS485 card has two DB9F connectors on the back, plug the cable from the lathe in one and a terminator in the other.Install WinNC (the control software)

76、 under Windows 3.1. There are two disks; the installer and a machine data disk.The lathe needs to be plugged in to the computer, to a power outlet (of course), and to an air supply at 50-75 psi (less than 50 and there i

77、sn't enough pr</p><p>　　? POWER ON/OFF:</p><p>　　To Turn On:</p><p>　　Turn on the computer and machine. To turn on the machine, turn the key on the right side. On the computer

78、, launch Windows if neccisary. Once windows is running, launch WinNC. Make sure NumLock is on befo re launching WinNC. WinNC will then establish communication with the machine.</p><p>　　To Turn Off:</

79、p><p>　　To just shut off the lathe but not the computer, just turn the key on the lathe. An error will co me up in WinNC indicating it lo st RS485 communication. Not to worry; when the lathe is turned back on

80、 later, hit ESC and the error will go away.To turn off both, exit WinNC by hitting Alt-F4 and then exit Windows. Then Simply switch off both the machine and the computer.</p><p>　　? OPERATION:</p>&

81、lt;p>　　Some notes:</p><p>　　The EMCO software is distinguished by having the most counter-intuitive, unnatu-ral, information-withholding, and ornery interface known to man. Most technical references avai

82、lable are in German。The software periodically pops up error messages for minor and major errors. Errors can be dismissed by pressing ESC. If they don't go away, there is a problem that needs to be looked into.At the

83、 bottom of the screen is a menu of options you can select with the F3-F7 keys. This is called the "softkey </p><p>　　A note on coordinates:</p><p>　　The X axis is into/out of the material.

84、 X = 0 should be the center of rotation. As long as X is a positive value, moving along X in the positive is moving the tool out of the material and away from center. Moving along X in the negative is moving into the

85、 material and toward center.</p><p>　　The Z axis is along the length of the part (along the axis of rotation). Moving along Z in the negative direction is moving toward the spindle head (to the left, facing

86、 the machine). Moving along Z in the positive direction is moving away from the spindle head (to the right, facing the machine)。</p><p><b>　　Modes:</b></p><p>　　The software is rul

87、ed by mo des. What mode the software is in determines what it can do and what it displays. I f something doesn't work or doesn't look right, check what mode the software is in. Remember operational modes are s

88、et independently of display modes. The operational mode can be EDIT but programs cannot be edited until the view mode is set to PRGRM, and vice versa.</p><p>　　Hit F1 to get a menu of operational modes:<

89、;/p><p>　　ZRN mode is used for zeroing the tool position. This should be done the first thing afterthe machine is turned on.</p><p>　　JOG is used for manual control of the lathe.</p><p&

90、gt;　　MDI is used for changing tools, opening chuck, etc. (actually, you can do all this with JOG)</p><p>　　EDIT is used for editing, loading, and exporting programs.</p><p>　　AUTO is used for r

91、unning programs.</p><p>　　Hit F12 to get display modes:</p><p>　　Note: when you switch view modes, the menu changes.The default is ALARM mode, which displays operator messages and alarms. Hit

92、F3 to display alarms, F5 to display operator messages.POS mode displays positions.Hit F3 to display the current absolute position, F4 for the current relative position, and F5 for a variety of details.</p><p&g

93、t;　　PRGRM mode displays the program. Hit F3 to display the program code, hit F4 for a list of all the programs available. If the operational mode is EDIT, you can also edit the code when you hit F3 。</p><p&g

94、t;　　OFFSET is used for displaying and changing offset values. Hit F3 for wear adjustment and F4 for geometry. These are both parameters for tools.Data for up to 16 tools can be stored at once. Hit F5 for work shift.

95、This is how the working reference point is set. See below.</p><p>　　PARAM is used for changing setup parameters and viewing system information. Hit F3 for setup see below for details. Hit F4 for diagnosti

96、cs on the RJ485 por t and the software version。</p><p>　　GRAPH is used to simulate output with a graph</p><p>　　The fact that all these modes must share the menu can cause confusion.Remember tha

97、t if you should be seeing a menu and you aren't, the menu you are looking for may be "behind" the one you are seeing. For example, when you switch to a display mode, you should see the menu f or that disp

98、lay mode. If you hit F1, that menu is "covered up" by the menu to select an operational mode. Once you select something from that menu, you will see the view mode's menu again.</p><p>　　Keybo

99、ard control:</p><p>　　Note on keyboard control: Many of the keys outlined in the manual are for German keyboards only and are mapped differently on US keyboards. Use this as reference, NOT the manual:<

100、/p><p>　　Alt-F4 - Exit</p><p>　　ESC - Dismiss error message</p><p>　　F1 - mode menu</p><p>　　F3 thru F7 - select item from current menu</p><p>　　F11 - scro

101、ll through menus when they are too wide to fit on the screen (like the MORE key on a Ti-85 calculator)</p><p>　　F12 - function key menu</p><p>　　Ctrl-\ - open/close chuck (must not be in EDIT mo

102、de, door must be open)</p><p>　　Ctrl-] - open/close door (spindle must be off)</p><p>　　Ctrl-1 - change tool (must not be in EDIT or ZRN mode, door must be closed)</p><p>　　Ctrl-2 -

103、 Turn on/off blower</p><p>　　Ctrl-6 - Turn off spindle (JOG mode)</p><p>　　Ctrl-7 - Turn on spindle (JOG mode, door must be shut)</p><p>　　arrows - move cursor in the editor</p&g

104、t;<p>　　on the numeric keypad:</p><p>　　4 - move -Z in JOG mode, or zero Z axis in ZRF mode</p><p>　　6 - move +Z in JOG mode, or zero Z axis in ZRF mode</p><p>　　2 - move -X

105、 in JOG mode, or zero X axis in ZRF mode</p><p>　　8 - move +X in JOG mode, or zero X axis in ZRF mode</p><p>　　5 - zero both axis in ZRF mode</p><p>　　From：《Integration and Automati

106、on of Manufacturing Systems》by Hugh Jack</p><p><b>　　14.數(shù)控機(jī)床</b></p><p>　　計(jì)算機(jī)數(shù)控機(jī)床使用一臺計(jì)算機(jī)引導(dǎo)一個(gè)可能需要手工完成的過程</p><p><b>　　14.1機(jī)床坐標(biāo)軸</b></p><p>　　14.2

107、數(shù)字化控制</p><p>　　?使用數(shù)字?jǐn)?shù)據(jù)驅(qū)動機(jī)器進(jìn)行的加工過程如下</p><p><b>　　-銑削</b></p><p><b>　　-車削</b></p><p><b>　　-鉆削</b></p><p><b>　　-磨削&l

108、t;/b></p><p><b>　　-噴丸加工</b></p><p><b>　　- 折彎</b></p><p><b>　　-火焰切割</b></p><p><b>　　-自動化編制機(jī)</b></p><p>&l

109、t;b>　　-自動鉚接</b></p><p><b>　　-等</b></p><p>　　?數(shù)控系統(tǒng)的基本組成部分</p><p><b>　　-程序</b></p><p><b>　　-控制器單元</b></p><p><

110、;b>　　-機(jī)床設(shè)備</b></p><p><b>　　?最適合于</b></p><p>　　-頻繁加工的小批量零件</p><p><b>　　-復(fù)雜的部分幾何體</b></p><p>　　-工件上的緊公差部分</p><p>　　-加工過程中操作量