英语翻译Numerical control(NC) is a method of controlling the mov

英语翻译
Numerical control(NC) is a method of controlling the movements of machine components by directly inserting coded instructions in the form of numerical data (numbers and data) into the system.The system automatically interprets these data and converts it to output signals.These signals,in turn control various machine components,such as turning spindles on and off,changing tools,moving the workpiece or the tools along specific paths,and turning cutting fluids on and off.
In order to appreciate the importance of numerical control of machines,let’s briefly review how a process such as machining has been carried out traditionally.After studying the working drawing of a part,the operator sets up the appropriate process parameters(such as cutting speed,feed,depth of cut,cutting fluid,and so on),determines the sequence of operations to be performed,clamps the workpiece in a workholding device such as a chuck or collet,and proceeds to make the part.Depending on part shape and the dimensional accuracy specified,this approach usually requires skilled operators.Furthermore,the machining procedure followed may depend on the particular operator,and because of the possibilities of human error,the parts produced by the same operator may not all be identical.Part quality may thus depend on the particular operator or even the same operator on different days or different hours of the day.Because of our increased concern with product quality and reducing manufacturing costs,such variability and its effects on product quality are no longer acceptable.This situation can be eliminated by numerical control of the machining operation.
We can illustrate the importance of numerical control by the following example.Assume that holes have to be drilled on a part in the positions shown in the picture.In the traditional manual method of machining this part,the operator positions the drill with respect to the workpiece,using as reference points any of the three method shown.The operator then proceeds to drill these holes.Let’s assume that 100 parts,having exactly the same shape and dimensional accuracy,have to be drilled.Obviously,this operation is going to be tedious because the operator has to go through the same motions again and again.Moreover,the probability is high that,for various reasons,some of the paths machined will be different from others.Let’s further assume that during this production run,the order for these paths is changed,so that 10 of the paths now require holes in different positions.The machinist now has to reset the machine,which will be time consuming and subject to error.Such operations can be performed easily by numerical control machines that are capable of producing parts repeatedly and accurately and of handling different parts by simply loading different part programs.

数控是控制机器 运作的一种方法,通过嵌入数字数据形式的代码指令到系统.系统自动地解释这些数据并将它转化为输出信号.输出信号相应地控制各种机器部件,例如轴的开关,工具的切换,移动部件或者工具到准确的路线,切削液...