機械加工介紹(中英文對照)(編輯修改稿)

　

【文章內(nèi)容簡介】 s the first major step away from human control of machine tools.先進制造技術(shù)中的一個基本的概念是數(shù)字控制（NC）。在數(shù)控技術(shù)出現(xiàn)之前，所有的機床都是由人工操縱和控制的。在與人工控制的機床有關(guān)的很多局限性中，操作者的技能大概是最突出的問題。采用人工控制是，產(chǎn)品的質(zhì)量直接與操作者的技能有關(guān)。數(shù)字控制代表了從人工控制機床走出來的第一步。Numerical control means the control of machine tools and other manufacturing systems through 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 programmed instructions, known as a reader.數(shù)字控制意味著采用預(yù)先錄制的、存儲的符號指令來控制機床和其他制造系統(tǒng)。一個數(shù)控技師的工作不是去操縱機床，而是編寫能夠發(fā)出機床操縱指令的程序。對于一臺數(shù)控機床，其上必須安有一個被稱為閱讀機的界面裝置，用來接受和解譯出編程指令。Numerical control was developed to overe the limitation of human operators, 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 longrun tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:Electrical discharge machining,Laser cutting,Electron beam welding.發(fā)展數(shù)控技術(shù)是為了克服人類操作者的局限性，而且它確實完成了這項工作。數(shù)字控制的機器比人工操縱的機器精度更高、生產(chǎn)出零件的一致性更好、生產(chǎn)速度更快、而且長期的工藝裝備成本更低。數(shù)控技術(shù)的發(fā)展導(dǎo)致了制造工藝中其他幾項新發(fā)明的產(chǎn)生： 電火花加工技術(shù)、激光切割、電子束焊接Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide of parts, each involving an assortment of widely varied and plex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tolls and processes.數(shù)字控制還使得機床比它們采用有人工操的前輩們的用途更為廣泛。一臺數(shù)控機床可以自動生產(chǎn)很多類的零件，每一個零件都可以有不同的和復(fù)雜的加工過程。數(shù)控可以使生產(chǎn)廠家承擔那些對于采用人工控制的機床和工藝來說，在經(jīng)濟上是不劃算的產(chǎn)品生產(chǎn)任務(wù)。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 . Air Force. In its earliest stages, NC machines were able to made straight cuts efficiently and effectively.同許多先進技術(shù)一樣，數(shù)控誕生于麻省理工學院的實驗室中。數(shù)控這個概念是50年代初在美國空軍的資助下提出來的。在其最初的價段，數(shù)控機床可以經(jīng)濟和有效地進行直線切割。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 the straight lines making up the steps, the smoother is the curve, Each line segment in the steps had to be calculated.然而，曲線軌跡成為機床加工的一個問題，在編程時應(yīng)該采用一系列的水平與豎直的臺階來生成曲線。構(gòu)成臺階的每一個線段越短，曲線就越光滑。臺階中的每一個線段都必須經(jīng)過計算。This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming 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 fur ther development from those used today. The machines had hardwired logic circuits. The instructional programs were written on punched paper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.在這個問