IntroductionMachining aims to generate the shape of work-piece form a solid body，or to improve the tolerances and surface finish of a previously formed work-piece，by removing excess materials in the form of Machining is capable of creating geometric configurations，tolerances， and surface finishes often unobtainable by any other However， machining removes materials， which has already been paid for， in the form of relatively small particles that are more difficult to recycle and are in greater danger of becoming Therefore，developments often aim at reducing or-if at all possible-eliminating machining， especially in mass For these reasons， machining has lost some important markets， yet， at the same time， it has also been developing and especially having captured new markets with the application of numerical Some feel for the important of machining may be gained from the observation that in 1983 there were about 2 million metal-cutting machine tools in the unite states ( of which some 5% were numerically controlled ) and that labor and overhead costs amounted to $125 billion， or 3% of the GNP
说个关于仿行车床和自动车床的文章吧那是我帮一个朋友翻译之后的结果: Trace lathes are machine tools with attachments that are capable of turning parts with various also called duplicating lathes or contouring lathes， the cutting tool follows a path that duplicates the contour of the template， similar to a pencil following the shape of a plastic template used in engineering a tracer finger follows the template and， through a hydraulic or electrical system， guides the cutting tool along the workpiece without operator operations performed on a tracer lathe have been largely replaced by numerical-control lathes and turning centers (section 2) lathes have been increasingly automated over the years manual machine controls have been replaced by various mechanisms that enable cutting operations to follow a certain prescribed sequence in a fully automatic machine ，parts are fed and removed automatically ，whereas in semiautomatic machines， these functions are performed by the operatorAutomatic lathes， which may have a horizontal or vertical spindle and do not have tailstocks， are also called chucking machines， or chuckers they are used for machining individual pieces of regular or irregular shapes， and are available in either single or multiple spindle in another type of automatic lathe， the bar stock is fed periodically into the lathe and a part is machined and cut off at the automatic lathes are suitable for medium to high-volume production仿行车床是一种加工机床，和附加配件一起，能够加工各种轮廓的旋转体 也可以称为复制车床或者轮廓车床(在国内只叫仿行车床，我只是按字面把这一句翻译出来) 切削刀具跟随着复制模板的外形轮廓移动类似于用铅笔沿着塑胶模板(曲线模板)的轮廓描绘工程图仿行指针跟随模板，并且通过液压或者电气系统，不需要操作员干涉的情况下引导切削刀具沿着工件加工目前仿行车床已经基本被数控车床和车削中心代替(第2) 多年以来，车床已经逐步自动化了手动控制的机床已经被各种能够按照指定次序执行加工的机制取代一部全自动的机床，产品可以全自动地被送进和装卸;然而对于半自动机床，某些功能需要人手执行 自动车床有水平主轴或者立式主轴，但是没有后机座的可以称作卡盘式车床 他们用于加工个别形状规则或者不规则的产品而且拥有单一或者多个主轴的类型; 另外一种自动车床，带有自动送料的系统，把条状原料定时地送进车床加工，加工完了之后从条料中切落 自动车床适合中到高产量的生产 自动车床有水平主轴或者立式主轴，但是没有后机座的可以称作卡盘式车床 他们用于加工个别形状规则或者不规则的产品而且拥有单一或者多个主轴的类型; 另外一种自动车床，带有自动送料的系统，把条状原料定时地送进车床加工，加工完了之后从条料中切落 自动车床适合中到高产量的生产
