CNC数控机电一体化毕业设计（数控技术）英文资料翻译.doc

英文资料翻译 题目CNC 2011年12月 CNC CNC stands for Computerized Numerical Control and has been around since the early1970s. prior to this, it was called NC,for numerical control. While people in most walks of life have never heard of this term, CNC has touched almost every form of manufacturing process in one way or another. If youll be working in manufacturing, its likely that youll be dealing with CNC on a regular basis. Before CNC While there are exceptions to this statement,CNC machines typically replace (or work in conjunction with) some existing manufacturing processes. Take one of the simplest manufacturing processes,drilling holes,for example. A drill press can of course be used to machine holes. A person can place a drill in the drill chuck that is secured in the spindle of the drill press. They can then (manually) select the desired speed for rotation (commonly by switching belt pulleys), and activate the spindle. Then they manually pull on the quill lever to drive the drill into the workpiece being machined. As you can easily see, there is a lot of manual intervention required to use a drill press to holes. A person is required to do something almost every step along the way! While this manual intervention may be acceptable for manufacturing companies if but a small number of holes workpieces must be machined, as quantities grow, so does the likelihood for fatigue due to the tediousness of the operation. And do note that weve used one of the simplest machining operations(drilling) for our example. There are more complicated machining operations that would require a much higher skill level (and increase the potential for mistakes resulting in scrap workpieces) of the person running the conventional machine tool. (We commonly refer to style of machine that CNC is replacing as the conventional machine.) By comparison, the CNC equivalent for a drill press (possibly a CNC machining center or CNC drilling tapping center) can be pr