數(shù)控專業(yè)英語

1、Unit 1 Introduction to Computer Introduction to Computer Numerical Control ManufacturingNumerical Control Manufacturing第第1 1單元單元 計算機數(shù)控加工簡介計算機數(shù)控加工簡介Reading TargetReading TargetAfter reading this unit, you should be able to explain what computer numerical control (CNC) is and what basic components com

2、prise CNC systems.TextText 1.1Definition of Computer Numerical Control and its components A computer numerical control (CNC) machine is an NC machine with the added feature of an on-board computer. The on-board computer is often referred to as the machine control unit or MCU. 1.1 CNC的定義及其系統(tǒng)組成的定義及其系統(tǒng)

3、組成 計算機數(shù)控機床就是在計算機數(shù)控機床就是在NC機床的基礎上附加一個內機床的基礎上附加一個內置式計算機，這種內置式計算機通常被稱為機床控制單元置式計算機，這種內置式計算機通常被稱為機床控制單元或或MCU。NC機床的控制單元通常由硬件構成，也就是說機床的控制單元通常由硬件構成，也就是說機床的功能是由控制器內置的物理電子元件控制的。機床的功能是由控制器內置的物理電子元件控制的。 TextTextControl units for NC machines are usually hard wired. This means that a machine functions are controll

4、ed by the physical electronic elements that are built into the controller. Simply put, numerical control is a method of automatically operating a manufacturing machine based on a code of letters, numbers, and special characters. NC機床的控制單元通常由硬件構成，也就是說機床的功機床的控制單元通常由硬件構成，也就是說機床的功能是由控制器內置的物理電子元件控制的。簡單地說

5、，能是由控制器內置的物理電子元件控制的。簡單地說，數(shù)字控制是基于代碼自動操作制造類機床的一種方法，數(shù)字控制是基于代碼自動操作制造類機床的一種方法，這些代碼由字母、數(shù)字和特殊字符組成。這些代碼由字母、數(shù)字和特殊字符組成。 A complete set of coded instructions for executing an operation is called a program. Such programs are stored in RAM or the random-access memory portion of the computer. They can be played b

6、ack, edited, and processed by the control. Thus, the machine functions are encoded into the computer at the time of manufacture. 所謂的程序就是用于執(zhí)行某一操作的一整套代碼表示的所謂的程序就是用于執(zhí)行某一操作的一整套代碼表示的指令，而這些程序是存放在計算機的隨機存儲器中的，控指令，而這些程序是存放在計算機的隨機存儲器中的，控制器可以對它們進行重新調用，編寫以及處理等操作。因制器可以對它們進行重新調用，編寫以及處理等操作。因此，我們可以通過對計算機進行編碼從而在加工時實

7、現(xiàn)機此，我們可以通過對計算機進行編碼從而在加工時實現(xiàn)機床操作的各種功能。床操作的各種功能。TextText The components found in many CNC systems are shown in Figure 1-1 . Machine control unit: generates, stores and processes CNC programs. The machine control unit also contains the machine motion controller in the form of an executive software progr

8、am. NC machine: responds to programmed signals from the machine control unit and manufactures the part. CNC系統(tǒng)中常見的組成部分如圖系統(tǒng)中常見的組成部分如圖1-1所示。所示。 機床控制單元：生成、存儲和處理機床控制單元：生成、存儲和處理CNC程序。機床程序。機床控制單元還包括機床運動控制器，該控制器是一個可執(zhí)控制單元還包括機床運動控制器，該控制器是一個可執(zhí)行的軟件程序。行的軟件程序。NC機床：響應來自機床控制單元的程序機床：響應來自機床控制單元的程序信號并對零件進行加工。信號并對零件進行加

9、工。 TextTextTextTextFig 1-1 Components of modern CNC system 現(xiàn)代現(xiàn)代CNC系統(tǒng)的組成系統(tǒng)的組成1.2Types of CNC equipment Machining centers are the latest development in CNC technology. These systems come equipped with automatic tool changers with the capability of changing up to 90 or more tools. Many are also fitted

10、with the movable rectangular worktables called pallets. The pallets are used to automatically load and unload work pieces. 1.2 CNC設備的類型設備的類型 加工中心在加工中心在CNC技術中屬于最前沿的。它們裝有自技術中屬于最前沿的。它們裝有自動換刀裝置，可換刀具數(shù)高達動換刀裝置，可換刀具數(shù)高達90把甚至更多。許多加工把甚至更多。許多加工中心還裝有可移動的長方形工作臺，即托盤系統(tǒng)。這種中心還裝有可移動的長方形工作臺，即托盤系統(tǒng)。這種托盤系統(tǒng)用來自動裝卸工件。托盤系統(tǒng)用來自

11、動裝卸工件。TextText At a single setup machining centers can perform such operations as milling, drilling, tapping, boring, and so on. Additionally by utilizing indexing heads, some centers are capable of executing these tasks on many different faces of a part and at specified angles. Machining centers sa

12、ve production time and cost by reducing the need for moving a part from one machine to another. 加工中心只需一次裝卡就可以完成銑、鉆、攻絲、鏜加工中心只需一次裝卡就可以完成銑、鉆、攻絲、鏜等多種加工操作。此外，一些加工中心利用分度頭可等多種加工操作。此外，一些加工中心利用分度頭可以對零件不同的面和特定的角度進行加工。通過減少以對零件不同的面和特定的角度進行加工。通過減少零件在機床間轉移，加工中心能夠節(jié)省生產時間與成零件在機床間轉移，加工中心能夠節(jié)省生產時間與成本。本。TextTextTextText

13、 Turning centers with increased capacity tool changers are also making strong appearance in modern production shops. These CNC machines are capable of executing many different types of lathe cutting operations simultaneously on rotating part. 具有大容量刀庫的車削中心在現(xiàn)代制造廠中占據(jù)具有大容量刀庫的車削中心在現(xiàn)代制造廠中占據(jù)著顯著位置。這些著顯著位置。這

14、些CNC機床能對旋轉的工件同時進機床能對旋轉的工件同時進行多種車削加工。行多種車削加工。TextText In addition to machining centers and turning centers, CNC technology has also been applied to many other types of manufacturing equipment. Among these are wire electrical discharge machines (wire EDM) and laser cutting machines. 除加工中心和車削中心之外，除加工中心

15、和車削中心之外，CNC技術還被廣技術還被廣泛用于其他許多類型的設備，其中包括線切割機床泛用于其他許多類型的設備，其中包括線切割機床和激光切割機。和激光切割機。TextText Wire EDM machines utilize a very thin wire as an electrode. The wire is stretched between two rollers and cuts the part like a band-saw. Material is removed by the erosion caused by a spark that moves horizontall

16、y with the wire. CNC is used to control horizontal table movements. 線切割機是用一根很細的切割絲做電極。切割線切割機是用一根很細的切割絲做電極。切割絲在兩個導輪之間拉緊，像帶鋸一樣切割工件。切絲在兩個導輪之間拉緊，像帶鋸一樣切割工件。切割絲水平移動所產生的電火花會將材料腐蝕掉，而割絲水平移動所產生的電火花會將材料腐蝕掉，而CNC就是用來控制水平工作臺的移動。就是用來控制水平工作臺的移動。 TextText Laser cutting CNC machines utilize an intense beam of focused

17、 laser light to cut the part. Material under the laser beam undergoes a rapid rise in temperature and is vaporized. If the beam power is high enough, it will penetrate through the material. Because no mechanical cutting forces are involved, lasers cut parts with a minimum of distortion, they have be

18、en very effective in machining slots and drilling holes. 激光切割激光切割CNC機床能利用一束強烈的聚焦光線來切機床能利用一束強烈的聚焦光線來切割工件。材料在光線的照射下溫度會驟然上升并汽化。若割工件。材料在光線的照射下溫度會驟然上升并汽化。若光束能量足夠高就會將材料穿透。由于沒有機械切削力，光束能量足夠高就會將材料穿透。由于沒有機械切削力，所以激光加工的工件變形非常小，激光切割機對加工窄槽所以激光加工的工件變形非常小，激光切割機對加工窄槽和鉆孔非常有效和鉆孔非常有效 。Key TermsComputer Numerical Control 計算機數(shù)字控制計算機數(shù)字控制MCU Machine control unit 機床控制單元機床控制單元electronic element 電子元件電子元件controller 控制器控制器RAM random-access memory 隨機存儲器隨機存儲器machining center 加工中心加工中心pallet 托盤托盤ATC automatic tool changer 自動換刀裝置自動換刀裝置work piecework