外文翻譯-----cam和cnc

1、<p>　　CAM and CNC</p><p>　　CAM systems have changed the job of the CNC programmer from one manually producing CNC code to one maximizing the output of CNC machines. Since CNC machine tools are made by a

2、 great number of manufacturers, many different CNC control units are in use. Control units from different manufacturers use a variety of program formats and codes. Many CNC code words are identical for different controll

3、ers, but a great number vary from one to another.</p><p>　　To produce an identical part on CNC machine tools with different controllers such as one by FANCU, OKUMA or DYNAPATH, would require completely diffe

4、rent CNC codes. Each manufacturer is constantly improving and updating its CNC controllers. These improvements often include additional code words plus changes in how the existing code works.</p><p>　　A CAM

5、systems allows the CNC programmer to concentrate on the creation of an efficient machining process, rather then relearning changed code formats. A CNC programmer looks at the print of a part and then plans the sequence o

6、f machining operations necessary to make it (Figure O-3). This plan includes everything, from the selection of possible CNC machine tools, to which tooling to use, to how the part is held while machining takes place. The

7、 CNC programmer has to have a thorough understanding o</p><p>　　Another area of major importance to the programmer is the knowledge of machining processes. An example would be the selection of the surface fi

8、nish requirement specified in the part print. The sequence of machining processes is critical to obtain acceptable results. Cutting tool limitations have to be considered and this requires knowledge of cutting tool mater

9、ials, tool types, and application recommendations.</p><p>　　A good programmer will spend a considerable amount of time in researching the rapidly growing volume of new and improved tools and tool materials.

10、Often the tool that was on the cutting edge of technology just two years ago is now obsolete. Information on new tools can come from catalogs or tool manufacturers' tooling engineers. Help in tool selection or optimu

11、m tool working conditions can also be obtained from tool manufacturer software. Examples would be Kennametal's "TOOLPRO", software design</p><p>　　Software for a machining center application wo

12、uld be Ingersoll Tool Company's "Actual Chip Thickness", a program used to calculate the chip thickness in relation to feed-per-tooth for a milling cutter, especially during a shallow finishing cut. Ingerso

13、ll's "Rigidity Analysis" software ealculates tool deflection for end mills as a function of tool stiffness and tool force.</p><p>　　To this point we looked at some general qualifications that a

14、 programmer should possess. Now we examine how a CAM system works. Point Control Company's SmartCam system uses the following approach. First, the programmer makes a mental model of the part to be machined. This incl

15、udes the kind of machining to be performed-turning or milling. Then the part print is studied to develop a machining sequence, roughing and finishing cuts, drilling, tapping, and boring operations. What work-holding devi

16、ce </p><p>　　This line of information describes the tool by number, type, and size and includes the appropriate cutting speed and feed rate. After all the selected tools are entered, the file is saved.</p

17、><p>　　The second programming step is the making of the part. This represents a graphic modeling of the projected machining operation. After selecting a tool from the prepared JOBPLAN, parameters for the cuttin

18、g operation are entered. For a drill, once the coordinate location of the hole and the depth are given, a circle appears on that spot. If the location is incorrect, the UNDO command erases this entry and allows you to gi

19、ve new values for this operation. When an end mill is being used, cutting mov</p><p>　　At any time during programming, the command SHOWPATH will show the actual toolpath for each of the programmed tools. The

20、 tools will be displayed in the sequence in which they will be used during actual machining. If the sequence of a tool movement needs to be changed, a few keystrokes will to that.</p><p>　　Sometimes in CAM t

21、he programming sequence is different from the actual machining order. An example would be the machining of a pocket in a part. With CAM, the finished pocket outline is programmed first, then this outline is used to defin

22、e the roughing cuts to machine the pocket. The roughing cuts are computer generated from inputs such as depth and width of cut and how much material to leave for the finish cut. Different roughing patterns can be tried o

23、ut to allow the programmer to select the m</p><p>　　A CAM system lets the programmer view the graphics model from varying angles, such as a top, front, side, or isometric view. A toolpath that looks correct

24、from a top view, may show from a front view that the depth of the cutting tool is incorrect. Changes can easily be made and seen immediately.</p><p>　　When the toolpath and the sequence of operations are sat

25、isfactory, machine ready code has to be made. This is as easy as specifying the CNC machine that is to be used to machine the part. The code generator for that specific CNC machine during processing accesses four differe

26、nt files. The JOBPLAN file for the tool information and the GRAPHICE file for the toolpath and cutting sequence. It also uses the MACHINE DEFINE file which defines the CNC code words for that specific machine. This file

27、also</p><p><b>　　CAM和CNC</b></p><p>　　CAM系統(tǒng)改變了CNC程序員的工作，即從手工編制CNC代碼到CNC車床的輸出最大值。自從手工CNC車床被一大批廠家生產(chǎn)以來，許多不同的CNC控制單元就被使用了。各個(gè)不同的廠家的控制單元使用各個(gè)不相同的程序與代碼。許多CNC代碼語句可被不同的控制器識(shí)別。但其間還有眾多的區(qū)別。為了在有著不同

28、控制器（如FAWC、OKUMA、或DYNAPATH）生產(chǎn)一個(gè)可互換的零件，將需要完全不同的CNC代碼。每個(gè)制造商在不斷地提高和更新其CNC控制。這些改進(jìn)通常包括附加的代碼語句在已有代碼如何工作上的變化。CAM系統(tǒng)允許CNC程序員在高效的加工過程的建立上濃縮、精選、而不重新學(xué)習(xí)已改變的代碼格式。一個(gè)CNC程序員看著一個(gè)零件的圖紙，并且設(shè)計(jì)必要的車床操作來制造這個(gè)零件（如圖O-3）。這個(gè)設(shè)計(jì)包括以下每個(gè)因素，從可能使用的CNC車床的選擇，到

29、車床的使用選擇，再到加工時(shí)的零件裝夾的選擇。CNC程序員必須對這個(gè)即將寫入程序的CNC車床的能力和局限有一個(gè)完全的了解。車床主參數(shù)如馬力主軸馬力、最大轉(zhuǎn)速、工作臺(tái)的重量、工具的尺寸限制、加工變化能力等只是值得考慮的影響程序的因素中的一些。對程序員要求的另一個(gè)最重要領(lǐng)域是制</p><p>　　為加工中心使用的軟件是ENGERSOLL CUTTING TOOL公司的ACTUAL CHIP THICKNESS。程序被

30、用來計(jì)算磨床每次進(jìn)的給量，特別是在微量的光潔度加工中。ENGERSOLL的“精密分析”軟件作為車床剛度和車床力的功能來。在這一點(diǎn)上我們觀察一些廣泛的設(shè)計(jì)人員應(yīng)掌握的規(guī)格?，F(xiàn)在我們測試CAM系統(tǒng)怎樣工作。點(diǎn)控公司（POINT CPNTROLL COMPANY）的SMARTCAM 系統(tǒng)使用接下來的手段：首先設(shè)計(jì)人員使用一個(gè)金屬零件模型去加工。這包括的加工方式是------車或磨。接著這個(gè)零件圖被研究來做成車床加工工序，粗加工或精加工、鉆、沖

31、、磨等操作。被使用的裝夾夾具是虎鉗，抓盤還是卡盤？這些考慮之后，計(jì)算機(jī)輸出就可開始了。首先還是工藝卡的建立。這個(gè)工藝卡由各種記錄（例如：英制或公制，車床類型、零件卡、切削材料類型、安裝記錄、和所需要車床的描述</p><p>　　其第二個(gè)編程的步驟是零件的制造。這描述了一個(gè)所設(shè)計(jì)車床操作的生動(dòng)模型。從已準(zhǔn)備好的JOBPLAN中選好車床后，切削加工的參數(shù)就被編入。對鉆床而言，一旦孔的位置坐標(biāo)和深度被給出，一個(gè)孔就給

32、出現(xiàn)在那點(diǎn)。如果其位置是錯(cuò)的，其撤消命令選擇這一記錄，并允許你給這個(gè)工序新的值。當(dāng)端面磨時(shí)，切削運(yùn)動(dòng)通常被定義為弧。當(dāng)一條直線被編入程序， TOOLPATH就會(huì)生動(dòng)的顯示，其錯(cuò)誤也可立即被糾正。</p><p>　　在程序運(yùn)行的任意時(shí)刻，命令SHOWPATH會(huì)顯示當(dāng)前的刀具軌跡，也會(huì)顯示刀具在實(shí)際加工時(shí)的使用順序。當(dāng)?shù)毒哌\(yùn)動(dòng)順序需要改變時(shí)，可用一個(gè)按鍵來實(shí)現(xiàn)它。</p><p>　　有時(shí)，

33、CAM的程序順序和實(shí)際加工的順序是各不相同的。某部件的孔的加工就是一個(gè)例子。首先，在CAM中編譯已加工孔的外部輪廓，再把外部輪廓當(dāng)成粗基準(zhǔn)來加工內(nèi)孔。根據(jù)輸入切削的寬和深以及完成切削需切去的材料，計(jì)算機(jī)產(chǎn)生粗切削的加工程序。程序員嘗試各種粗基準(zhǔn)，以便選出最有效的切削加工方法。由于用不同的顏色代表不同的刀具，所以觀察不同刀具的軌跡是很容易的。一個(gè)CAM系統(tǒng)可讓程序員從不同的角度觀察圖形，比如說從頂部、正面、側(cè)面或立體圖。俯視中正確的刀具軌

34、跡，在正視圖中，切削的深度是不正確的，其變化顯而易見。</p><p>　　當(dāng)?shù)毒呗窂郊捌漤樞蚨ê煤?，車床的代碼應(yīng)被做好。這和詳細(xì)指明加工這個(gè)部件的CNC車床一樣容易。運(yùn)行時(shí)，指定車床的代碼發(fā)生器相當(dāng)于四個(gè)不同的鍵。JOBPLAN文件運(yùn)行時(shí)，表示刀具信息，GRAPHICS文件表示刀具路徑和切削順序。也用MACHINE DEFINE文件表示CNC代碼命令。這個(gè)文件可提供最大的進(jìn)給速度、轉(zhuǎn)速、加工時(shí)間等等。當(dāng)代碼發(fā)生