lesson22MachiningCenters

1、Unit Lesson Lesson22 Machining Centers w教学目标及要求教学目标及要求 1.1.掌握课文中数控加工中心的专业词汇和专业术语；掌握课文中数控加工中心的专业词汇和专业术语； 2.2.结合数控加工中心的相关专业知识阅读课文，提高阅读结合数控加工中心的相关专业知识阅读课文，提高阅读和翻译能力。和翻译能力。 w重点重点 1.1.有关数控加工中心的专业词汇和专业术语；有关数控加工中心的专业词汇和专业术语； 2.2.翻译课文：数控加工中心的类型及各类型的工作原理。翻译课文：数控加工中心的类型及各类型的工作原理。u难句分析及翻译的基本技巧难句分析及翻译的基本技巧 Part

2、Part（） 几种具体问题的具体译法几种具体问题的具体译法 七、长句的分析与翻译七、长句的分析与翻译w教学思路设计教学思路设计 时间分配（共时间分配（共100min100min）：）： 1 1、讲解课文中的专业词汇和术语；、讲解课文中的专业词汇和术语； 2 2、讲解课后生词、大声朗读；、讲解课后生词、大声朗读； 3 3、翻译课文，注意穿插相关专业知识；、翻译课文，注意穿插相关专业知识； 4 4、分析难点句型，讲解相关语法和翻译技巧；、分析难点句型，讲解相关语法和翻译技巧； 5 5、学生答疑。、学生答疑。ContentswBackground KnowledgewNew Words and Ph

3、rasedwText AnalysiswQuestionswGlossary of TermswLanguage Points & Translating Techniques wReading Materials wSummary wReferencesBackground Knowledge The trend in NC machines is the type of machine The trend in NC machines is the type of machine in which a number of operations can be done in a in whi

4、ch a number of operations can be done in a single setup, which is called a “machining center.” single setup, which is called a “machining center.” A machining center is built to do a number of A machining center is built to do a number of operations such as milling, drilling, boring, operations such

5、 as milling, drilling, boring, facing, spotting, counterboring, threading, and facing, spotting, counterboring, threading, and tapping in a single setup on several surfaces of a tapping in a single setup on several surfaces of a workpiece. One relatively unskilled operator can workpiece. One relativ

6、ely unskilled operator can often attend two machining centers and sometimes often attend two machining centers and sometimes more. A numerically controlled machining center more. A numerically controlled machining center must have the following characteristics:must have the following characteristics

7、: wAt least three linear axes of positioning control, X, At least three linear axes of positioning control, X, Y, and Z.Y, and Z.wIndex table to permit access to more than one side Index table to permit access to more than one side of the workpiece automatically.of the workpiece automatically.wAutom

8、atic tool changer, a tool magazine to hold a Automatic tool changer, a tool magazine to hold a large selection of tools, and a tool change arm that large selection of tools, and a tool change arm that selects and places the tools into the machine selects and places the tools into the machine spindle

9、.spindle.wAbility to select spindle speeds and feed rates, and Ability to select spindle speeds and feed rates, and to bring tools to the workpiece automatically on to bring tools to the workpiece automatically on mand.wMiscellaneous functions such as coolants off/on, Miscellaneous functions such as

10、 coolants off/on, part clamping, program start alerts, peck drilling, part clamping, program start alerts, peck drilling, and other automatic functions.and other automatic functions.wThe cutting tool is automatically selected from the The cutting tool is automatically selected from the storage magaz

11、ine. The number of tools in the storage magazine. The number of tools in the magazine has no theoretical limit but is typically magazine has no theoretical limit but is typically 24, 48, or 60 etc.24, 48, or 60 etc. New Words and ExpressionsuTerms： 1.types of machining centers 1.types of machining c

12、enters 数控机床的类型数控机床的类型 horezontal spindle machine horezontal spindle machine 卧式加工中心卧式加工中心 vertical spindle machine vertical spindle machine 立式加工中心立式加工中心 traveling-column machining center traveling-column machining center 可动立式加工中心可动立式加工中心 fixed-column machining center fixed-column machining center 固定立

13、式加工中心固定立式加工中心 2.parts of the CNC machining 2.parts of the CNC machining 数控机床部件数控机床部件 bed bed 床身床身 saddle saddle 床鞍床鞍 column column 立柱立柱 table table 工作台工作台 servo system servo system 伺服系统伺服系统 spindle spindle 主轴主轴 tool changers tool changers 刀库刀库 MCU(machine control unit) MCU(machine control unit) 机床控制

14、单元机床控制单元New Words and Expressionsu Terms： 3.servo system 3.servo system 伺服系统伺服系统 servo system drive motor servo system drive motor 伺服驱动电动机伺服驱动电动机 ball screw ball screw 滚珠丝杠滚珠丝杠 position feedback encoder position feedback encoder 定位反馈编码器定位反馈编码器 4.the operations performed by operater in MCU4.the opera

15、tions performed by operater in MCU programming programming 编程编程 machining machining 机械加工机械加工 diagnostics diagnostics 诊断诊断 tool and machin monitoring tool and machin monitoring 刀具和机床状态的监控刀具和机床状态的监控 5.torsion strength 5.torsion strength 抗扭强度抗扭强度Text Types of Machining Centers There are two main types

16、of machining centers: There are two main types of machining centers: uthe horizontal spindle the horizontal spindle uthe vertical spindle machine.the vertical spindle machine. wNC machining centers (a) Horizontal-spindle machining center wNC machining centers（b）Vertical-spindle machining center Hori

17、zontal Spindle1 1The traveling-column type is equipped with one or The traveling-column type is equipped with one or usually two tables on which the work can be mounted. usually two tables on which the work can be mounted. With this type of machining center, the workpiece With this type of machining

18、 center, the workpiece can be machined while the operator is loading a new can be machined while the operator is loading a new workpiece on the other table.workpiece on the other table.2 2The fixed-column type is equipped with a pallet The fixed-column type is equipped with a pallet shuttle. The pal

19、let is a removable table on which shuttle. The pallet is a removable table on which the workpiece is mounted. After the workpiece has the workpiece is mounted. After the workpiece has been machined, the workpiece and pallet are moved been machined, the workpiece and pallet are moved to a shuttle whi

20、ch then rotates, bringing a new to a shuttle which then rotates, bringing a new pallet and workpiece into position for machining.pallet and workpiece into position for machining. Vertical Spindle Type The vertical spindle machining center The vertical spindle machining center is a saddle-type constr

21、uction with is a saddle-type construction with sliding bedways which utilizes a sliding sliding bedways which utilizes a sliding vertical head instead of a quill movement.vertical head instead of a quill movement. Parts of the CNC Machining Centers 1.Bed.1.Bed. The bed is usually made of high- The b

22、ed is usually made of high-quality cast iron which provides for a quality cast iron which provides for a rigid machine capable of performing heavy-rigid machine capable of performing heavy-duty machining and maintaining high duty machining and maintaining high precision. Hardened and ground ways are

23、 precision. Hardened and ground ways are mounted to the bed to provide rigid support mounted to the bed to provide rigid support for all linear axes.for all linear axes. 2.Saddle.2.Saddle. The saddle, which is mounted on The saddle, which is mounted on the hardened and ground bedways, provides the h

24、ardened and ground bedways, provides the machining center with the x axis linear the machining center with the x axis linear movement.movement. 3.Column.3.Column. The column, which is mounted to The column, which is mounted to the saddle, is designed with high torsion the saddle, is designed with hi

25、gh torsion strength to prevent distortion and strength to prevent distortion and deflection during machining. The column deflection during machining. The column provides the machining center with the y provides the machining center with the y axis linear movement.axis linear movement. 4.Table.4.Tabl

26、e. The table, which is mounted on the The table, which is mounted on the bed, provides the machining center with the bed, provides the machining center with the z axis linear movement.z axis linear movement. 5.Servo System.5.Servo System. The servo system, which The servo system, which consists of s

27、ervo drive motors, ball consists of servo drive motors, ball screws, and position feedback encoders, screws, and position feedback encoders, provides fast, accurate movement and provides fast, accurate movement and positioning of the XYZ axis slides. The positioning of the XYZ axis slides. The feedb

28、ack encoders mounted on the ends of feedback encoders mounted on the ends of the ball screws form a closed-loop system the ball screws form a closed-loop system which maintains consistent high-which maintains consistent high-positioning positioning unidirectional unidirectional repeatability repeata

29、bility of +0.0001inof +0.0001in（0.003mm0.003mm）. .单向的单向的 6 . S p i n d l e .6 . S p i n d l e . T h e s p i n d l e , w h i c h i s T h e s p i n d l e , w h i c h i s programmable in 1r/min increments, has a programmable in 1r/min increments, has a speed range of from 20 to 6000 r/min. The speed ra

30、nge of from 20 to 6000 r/min. The spindle can be of a fixed position.spindle can be of a fixed position.（ H o r i z o n t a lH o r i z o n t a l ） t y p e , o r c a n b e a t y p e , o r c a n b e a tilting/contouring spindle which provides for tilting/contouring spindle which provides for an additi

31、onal axis. an additional axis. 7.Tool Changers.7.Tool Changers. There are basically two There are basically two types of tool changers, the vertical tool types of tool changers, the vertical tool changer and the horizontal tool changer. The changer and the horizontal tool changer. The tool changer i

32、s capable of storing a number tool changer is capable of storing a number of preset tools which can be automatically of preset tools which can be automatically called for use by the part program. Tool called for use by the part program. Tool changers are usually changers are usually bidirectionalbid

33、irectional, which , which allows for the shortest travel distance to allows for the shortest travel distance to randomly access a tool. The actual tool randomly access a tool. The actual tool change time is usually only 3 to 5s. change time is usually only 3 to 5s. 双向的，双双向的，双向作用的向作用的MCUuThe MCU allo

34、ws the operator to perform a The MCU allows the operator to perform a variety of operations such as programming, variety of operations such as programming, machining, diagnostics, tool and machine machining, diagnostics, tool and machine monitoring, etc. monitoring, etc. uMCUs vary according to manu

35、facturerss MCUs vary according to manufacturerss pecifications; new MCUs are becoming more pecifications; new MCUs are becoming more sophisticated, making machine tools more sophisticated, making machine tools more reliable and the entire machining reliable and the entire machining operations less d

36、ependent on human skills. operations less dependent on human skills. Machine AxesuMachining centers have probably made the Machining centers have probably made the greatest impact in NC machining because of greatest impact in NC machining because of their ability to perform such a variety of their a

37、bility to perform such a variety of machining operations on all sides of a machining operations on all sides of a workpiece with only one setup. workpiece with only one setup. uThe five-axis machining center indicates the The five-axis machining center indicates the axes that can be used when perfor

38、ming these axes that can be used when performing these machining operations and sequences.machining operations and sequences. x axis Linear movementx axis Linear movement y axis Linear movementy axis Linear movement z axis Linear movementz axis Linear movement A axis Tilt/contour spindleA axis Tilt/

39、contour spindle B axis Rotary tableB axis Rotary tableQuestionswHow many types of machining centers are How many types of machining centers are mentioned in the text ?mentioned in the text ?wList the main parts of computerized List the main parts of computerized numerical control (CNC) for machining

40、 numerical control (CNC) for machining centers.centers.wList the machining operations and List the machining operations and sequences of fivesequences of fiveaxis machining center. axis machining center. Glossary of Terms1 1 servo system servo system 伺服系统伺服系统2 2 cutter saddle cutter saddle 刀架刀架3 3 c

41、ylinde saddle cylinde saddle 鞍形气缸座鞍形气缸座4 4 a safety loop a safety loop 保险圈保险圈5 5 a wire loop a wire loop 钢丝圈钢丝圈6 6 loop a line loop a line 环路法连接线路环路法连接线路7 7 horizontal spindle horizontal spindle 卧轴式卧轴式8 8 vertical spindle vertical spindle 立轴式立轴式9 9 travelingtravelingcolumn column 行程立柱行程立柱1010fixedfi

42、xedcolumn column 固定立柱固定立柱1111openopenloop system loop system 开环系统开环系统1212closecloseloop system loop system 闭环系统闭环系统1313feedback unit feedback unit 反馈单元反馈单元1414machining center machining center 加工中心加工中心1515tooltoolstorage storage 刀具存储刀具存储1616ball screw ball screw 滚珠丝杠滚珠丝杠1717tool changer tool changer

43、 刀库刀库1818machine control unitmachine control unit（MCU)MCU)机床控制单元机床控制单元1919revolving cutter revolving cutter 旋转刀具旋转刀具2020flexible machining system flexible machining system 柔性制造系统柔性制造系统Language Points & Translating TechniqueswExample 1: After the workpiece has been machined, the After the workpiece h

44、as been machined, the workpiece and pallet are moved to a shuttle which workpiece and pallet are moved to a shuttle which then rotates, bringing a new pallet and workpiece then rotates, bringing a new pallet and workpiece into position for o position for machining. 对工件加工完成以后，工件和夹板一起被移到一

45、个交换对工件加工完成以后，工件和夹板一起被移到一个交换工作台上然后旋转，从而使新的工件和托架进入加工位置。工作台上然后旋转，从而使新的工件和托架进入加工位置。 句中句中after the workpiece has been machinedafter the workpiece has been machined为时间为时间状语从句；分词短语状语从句；分词短语bringing a new pallet and bringing a new pallet and workpiece into position for machiningworkpiece into position for m

46、achining在句中为结果状在句中为结果状语。语。 wExample 2: Tool changers are usually bidirectional, which Tool changers are usually bidirectional, which allows for the shortest travel distance to allows for the shortest travel distance to randomly access a tool.randomly access a tool. 刀库中刀具的更换通常是双向的，从而允许以最短的刀库中刀具的更换通常是

47、双向的，从而允许以最短的距离任意地存取刀具。距离任意地存取刀具。 句子中的句子中的 which allows for the shortest travel which allows for the shortest travel distance to randomly access a tooldistance to randomly access a tool引导一个非限定性引导一个非限定性定语从句，代表主句整个意思，从句谓语为单数第三人称。定语从句，代表主句整个意思，从句谓语为单数第三人称。 注意：一般如果主语由一个句子充当，根据主谓一致注意：一般如果主语由一个句子充当，根据主谓一致的

48、原则，谓语动词要用单数。的原则，谓语动词要用单数。Example 3: 七、长句的分析与翻译七、长句的分析与翻译（三）由短语或从句充当句子成分（三）由短语或从句充当句子成分 请看例句：请看例句：wAnother is Another is to enable the machine to perform its to enable the machine to perform its operations successively or even simultaneously on operations successively or even simultaneously on the sa

49、me workpiece without any intermediate handingthe same workpiece without any intermediate handing. . 另一种方法是使机床在同一工件上连续地，甚至同时进行另一种方法是使机床在同一工件上连续地，甚至同时进行各种操作，而不需要任何中间转移。各种操作，而不需要任何中间转移。 这个句子的基本结构（这个句子的基本结构（Another is +Another is +表语）虽然很简单，表语）虽然很简单，但句中的表语是由一个多级短语充当的，即在不定式短语但句中的表语是由一个多级短语充当的，即在不定式短语（to e

50、nable to enable ）中，不定式短语）中，不定式短语to performto perform作不定式作不定式to to enable enable 的宾语补足语，两个介词短语的宾语补足语，两个介词短语on the same on the same workpiece workpiece 和和 without any intermediate handing without any intermediate handing 又作不又作不定式定式to perform to perform 的状语。的状语。 w长句之所以难译，就是因为句中的某些短语和从句在汉语中长句之所以难译，就是因为句

51、中的某些短语和从句在汉语中不易安排的缘故。因此，抓好从句的分译和疑问层次的安排不易安排的缘故。因此，抓好从句的分译和疑问层次的安排是翻译的关键。举例如下：是翻译的关键。举例如下： 1. The idea 1. The idea of a fish being able to generate of a fish being able to generate electricity strong enough to light small bulbs, even electricity strong enough to light small bulbs, even to run an elec

52、tric motorto run an electric motor, is almost unbelievable. , is almost unbelievable. 鱼能发电，其强度足以点亮小灯泡，甚至能开动马达，这鱼能发电，其强度足以点亮小灯泡，甚至能开动马达，这简直是令人难以置信的。简直是令人难以置信的。 （此句的难点在于主语（此句的难点在于主语idea idea 的定语太长，将其定语分译，把的定语太长，将其定语分译，把它分成三个短句，就容易翻译了。）它分成三个短句，就容易翻译了。） 2. But man is little like a detective arriving at

53、2. But man is little like a detective arriving at the scene millions or billions of years after the the scene millions or billions of years after the eventeventand trying to reconstruct the event.and trying to reconstruct the event. 但是人类有点像侦探，在事情发生几百年或几十亿年之后但是人类有点像侦探，在事情发生几百年或几十亿年之后才到达出事现场，而且还试图复述事件

54、的经过始末。才到达出事现场，而且还试图复述事件的经过始末。 （此句并不长，翻译的关键在于将修饰（此句并不长，翻译的关键在于将修饰detective detective 的两个分的两个分词短语词短语arriving arriving 和和 tryingtrying不译成定语，而译成短句，不译成定语，而译成短句，这样译文就通顺了，符合汉语习惯了。）这样译文就通顺了，符合汉语习惯了。） 3. Small lathes with beds up to 6 ft. long and 3. Small lathes with beds up to 6 ft. long and able to swing

55、diameters up to 12 in. are commonly able to swing diameters up to 12 in. are commonly set on benches and are called bench lathes.set on benches and are called bench lathes. 小车床通常安装在工作台上，因此称为台式车床，其床身小车床通常安装在工作台上，因此称为台式车床，其床身长不超过六英尺，其可车削直径不超过长不超过六英尺，其可车削直径不超过1212英寸的工件。英寸的工件。 （此句的要点是将主语（此句的要点是将主语small

56、lathes small lathes 两个并列定语分别译两个并列定语分别译成短句，放在句末。）成短句，放在句末。） 4. The reason 4. The reason the light from the flashlight will not the light from the flashlight will not bounce off a rough brick wall, as does from a smooth bounce off a rough brick wall, as does from a smooth wooden wallwooden wall, is th

57、at the light is sent off in , is that the light is sent off in different directions by the uneven surface of the different directions by the uneven surface of the bricks.bricks. 手电筒的光从粗糙的砖墙反射出来的情况，不像它从平滑手电筒的光从粗糙的砖墙反射出来的情况，不像它从平滑的板壁上反射出来的那样，其理由是光线被砖墙不平的表面的板壁上反射出来的那样，其理由是光线被砖墙不平的表面以不同的方向反射出来。以不同的方向反射出

58、来。 （此句原文的基本结构是（此句原文的基本结构是the reason is + the reason is + 表语的简单结构，表语的简单结构，只不过是只不过是 the reason the reason 的定语从句中还包含着一个方式状语的定语从句中还包含着一个方式状语从句，而使句子不太好翻译，将定语从句单译，再把主句译从句，而使句子不太好翻译，将定语从句单译，再把主句译出，问题就迎刃而解了。）出，问题就迎刃而解了。） References Characteristics of Machining CenterswThe major characteristics of machining

59、The major characteristics of machining centers are summarized here:centers are summarized here: (1) Machining centers are capable of (1) Machining centers are capable of handling a wide variety of part sizes and handling a wide variety of part sizes and shapes efficiently, economically, shapes effic

60、iently, economically, repetitively, and with high dimensional repetitively, and with high dimensional accuracy with tolerances in the order of accuracy with tolerances in the order of 0.0025mm.0.0025mm. (2) These machines are versatile and capable (2) These machines are versatile and capable of quic