1、Unit 9 Machining CenterContentslNew Words&Expressions lText&TranslationlComplex Sentence AnalysislKey to ExercisesNew Words&Expressions lprogrammable prugrmbl adj.可编程序的,程序可控的lpreset pri:set n.预设,预置ltransfer trnsf:v.&n.转换,传送 lgantry gntri n.门架，吊架lchanger teind n.变换器,转换器lmagazinemgzi:n n.库New Words&Ex
2、pressions lrotaryrutri adj.旋转的,转动的linterchange intteind v.交换,互换leliminate ilimineit v.排除,消除lminimize minmaiz v.最小化,将减小到最少lgauge geid v.测量Text&Translationl1Machining has evolved from individual machining machines which，with the aid of man，performed individual processes to machines capable of performi
3、ng many processes.lIn 1968，an NC machine was introduced which could automatically change tools，making it a possibility to perform different processes on one machine.This kind of machine is defined as a“machining center”a machine that can perform a variety of processes and change tools automatically
4、while under programmable control.Text&TranslationlThe study of machining center begins with the history of numerical control(NC).Numerical control is applied on a great number of machines.2These range from single spindle drilling machines，which often have only two axis control，to machining centers，w
5、hich can do drilling，boring，milling，tapping and so forth with four axis control.A machining center can automatically select and change as many as 32 preset tools.The table can move left/right or in/out and the spindle can move up/down or in/out，with positioning accuracy in the range of 0.000 3 inch
6、in 40 inch of travel.The machine has automatic tool change and automatic work transfer so that workpiece can be loaded/unloaded while the machining is in process.Text&TranslationlCNC lathes make use of the concept of automatic tool change.The tools are held on a rotating tool magazine and a gantry t
7、ype tool changer is used to change the tools.Each magazine holds one type of cutting tool.The versatility of the machine is increased by combining rotary work and rotary tool operationsturning and millingin a single machine.Tools can be changed within six seconds or even less.3It is also common to p
8、rovide two or more worktables，permitting work to be set up while machining is done on the workpiece in the machine，with tables being interchanged automatically.As a result，the productivity of these machines can be quite high and the chip producing time comes close to 50%of the total time.Text&Transl
9、ationlTwo new trends are observed in the development of machining centers.One is the growing interest in smaller，more compact machining centers and the other is the emphasis on extended shift or even unmanned operations.Modern machining centers have contributed significantly to improved productivity
10、 in many companies.They have eliminated the time lost in moving workpieces from machine to machine and the time needed for workpiece loading and unloading for separate operations.In addition，they have minimized the time lost in changing tools，carrying out gauging operations，and aligning workpieces o
11、n the machine.Text&Translationl切削加工已从由人工操作完成单一工序的单台机器发展到能完成多道工序的机器。l1968年上市的一台数控机床可以自动地更换刀具，并在一台机床上能完成许多工序。这种机床叫做“加工中心”，是一台能够完成多道工序，并能在程控下自动更换刀具的机床。Text&Translationl对加工中心的研究是随着数控的发展而开始的。计算机和数控可用于许多种机器，从通常只有两轴控制的单轴钻床到四轴控制的具有钻、镗、铣、攻丝等功能的加工中心都能适用。一个加工中心能够自动选择和更换多达32把预置刀具。工作台可左右或里外移动，轴可上下或里外移动。定位精度在40英寸
12、（101.6 cm）的移动距离中小于0.0003英寸(0.000762 cm)。由于机床能够自动更换刀具和自动加工转换，工件可在不停机的情况下上机或下机。Text&Translationl自动更换刀具的概念已扩展到CNC（计算机数控）车床。把刀具装在一个旋转的刀具库上，用一个门形的刀具更换装置来更换刀具，每一个刀具库装一种切削刀具。把旋转加工和转动刀具车削与铣削在一台机床上结合起来可使其用途更为广泛。刀具能在6秒或更短的时间内更换完毕。有两个或两个以上工作台的也很常见。随着工作台的自动交换，可以对机床上的工件进行加工的同时安装另一工件。这样，这类机床的生产率就非常之高，切削时间通常接近整个加工
13、时间的50%。Text&Translationl加工中心有两个发展趋势：一是更小、更紧凑的加工中心的兴起；二是对扩展轴或无人操作的重视。现代的加工中心对很多公司提高生产率有着重要的作用，节省了把工件从一台机床移向另一台机床与对工件的单个加工所需的装卸时间。此外，更换刀具、测量和工件定位的时间也缩短至最低限度。Complex Sentence Analysisl1 Machining has evolved from individual machining machines which,with the aid of man,performed individual processes to
14、machines capable of performing many processes.切削加工已从由人工操作完成单一工序的单台机器发展到能完成多道工序的机器。lwith the aid of：在帮助下Complex Sentence Analysisl2 These range from single-spindle drilling machines,which often have only two-axis control,to machining centers,which can do drilling,boring,milling,tapping and so forth w
15、ith four-axis control.计算机和数控可用于许多种机器，从通常只有两轴控制的单轴钻床到四轴控制的具有钻、镗、铣、攻螺纹等功能的加工中心都能适用。l these：指代上句的computer and numerical,“计算机和数控”。l 第一个which：引导非限制性定语从句，修饰single-spindle drilling machines，而第二个which则修饰machining centers。Complex Sentence Analysisl3 It is also common to provide two or more worktables,permitt
16、ing work to be set up while machining is done on the work piece in the machine,with tables being interchanged automatically.有两个或两个以上工作台的也很常见。随着工作台的自动交换，可以对机床上的工件进行加工的同时安装另一工件。l permitting：现在分词做状语l while：引导时间状语从句l with tables being interchanged automatically是由with引起的独立主格结构Key to ExerciseslI.Translati
17、onl1.加工中心 l2.perform a variety of processesl3.四轴控制 l4.automatic tool changingl5.自动加工转换l6.rotary work l7.无人操作 l8.gauging operationKey to ExerciseslII.True or Falsel1.F l2.T l3.F l4.F l5.TKey to ExerciseslIII.Blank Fillingl1.in process l2.rotating tool magazine l3.cutting tool l4.versatility l5.set up l6.productivity Key to ExerciseslIV.Chinese to Englishl1.many different processes could be done on one machine l2.a wide variety of machinesl3.single-spindle drilling machinesl4.the emphasis on extended-shift or even unmanned operationsl5.contributed significantly tolThe end!
