lesson18Milling

1、Unit Seven Lesson18 Milling w教學(xué)目標(biāo)及要求教學(xué)目標(biāo)及要求 1.1.掌握課文有關(guān)銑床及銑削加工的專業(yè)詞匯和專業(yè)術(shù)語；掌握課文有關(guān)銑床及銑削加工的專業(yè)詞匯和專業(yè)術(shù)語； 2.2.結(jié)合銑床和銑削工藝的相關(guān)專業(yè)知識(shí)閱讀課文，提高翻結(jié)合銑床和銑削工藝的相關(guān)專業(yè)知識(shí)閱讀課文，提高翻譯能力。譯能力。 w重點(diǎn)重點(diǎn) 1.1.銑床及銑削工藝的專業(yè)詞匯和專業(yè)術(shù)語；銑床及銑削工藝的專業(yè)詞匯和專業(yè)術(shù)語； 2.2.翻譯課文：銑床的類型及各類型的工作原理；翻譯課文：銑床的類型及各類型的工作原理； 銑削的特點(diǎn)及使用場合；銑削的特點(diǎn)及使用場合； 銑削的工作原理。銑削的工作原理。u難句分析及翻譯的基本

2、技巧難句分析及翻譯的基本技巧 PartPart（） 幾種具體問題的具體譯法幾種具體問題的具體譯法 五、強(qiáng)調(diào)句型的譯法五、強(qiáng)調(diào)句型的譯法 w教學(xué)思路設(shè)計(jì)教學(xué)思路設(shè)計(jì) 時(shí)間分配（共時(shí)間分配（共100min100min）：）： 1 1、講解課文中的專業(yè)詞匯和術(shù)語、講解課文中的專業(yè)詞匯和術(shù)語; ; 2 2、講解課后生詞、大聲朗讀、講解課后生詞、大聲朗讀; ; 3 3、翻譯課文，注意穿插相關(guān)專業(yè)知識(shí)；、翻譯課文，注意穿插相關(guān)專業(yè)知識(shí)； 4 4、分析難點(diǎn)句型，講解相關(guān)語法和翻譯技巧；、分析難點(diǎn)句型，講解相關(guān)語法和翻譯技巧； 5 5、學(xué)生答疑。、學(xué)生答疑。ContentswBackground Knowle

3、dgewNew Words and PhrasedwText AnalysiswQuestionswLanguage Points & Translating Techniques wReading Materials wSummary wReferencesBackground Knowledgeu Milling is a basic machining process by which a Milling is a basic machining process by which a surface is generated by progressive chip removal

4、. surface is generated by progressive chip removal. u The workpiece is fed into a rotating cutting tool. The workpiece is fed into a rotating cutting tool. Sometimes the workpiece remains stationary, and the Sometimes the workpiece remains stationary, and the cutter is fed to the work. cutter is fed

5、 to the work. u In nearly all cases, a multiple-tooth cutter is In nearly all cases, a multiple-tooth cutter is used so that the material removal rate is high. used so that the material removal rate is high. u Often the desired surface is obtained in a single Often the desired surface is obtained in

6、 a single pass of the cutter or work, and because very good pass of the cutter or work, and because very good surface finish can be obtained, milling is surface finish can be obtained, milling is particularly well suited and widely used for mass-particularly well suited and widely used for mass-prod

7、uction work. production work. Background Knowledgeu Many types of milling machines are used, Many types of milling machines are used, ranging from relatively simple and versatile ranging from relatively simple and versatile machines that are used for general-purpose machines that are used for genera

8、l-purpose machining in job shops and tool-and-die work machining in job shops and tool-and-die work on highly specialized machines for mass on highly specialized machines for mass production. production. u Unquestionably, more flat surfaces are Unquestionably, more flat surfaces are produced by mill

9、ing than by any other produced by milling than by any other machining process. machining process. Milling MachineswTwo basic types of hnee-and-column milling machine (a) vertical; (b) horizontalMilling OperationsMilling cuttersNew Words and ExpressionsuTerms： 1. gang milling 1. gang milling 多刀銑削多刀銑削

10、 peripheral milling peripheral milling 圓周銑削圓周銑削 surface milling machinesurface milling machine平面銑床平面銑床 face milling face milling 平面銑平面銑 end milling end milling 立銑立銑( (端銑端銑) ) slot milling slot milling 銑槽銑槽 surface machining surface machining 曲面加工曲面加工 ball nose mill ball nose mill 球頭銑刀球頭銑刀 milling cu

11、tters milling cutters 銑刀銑刀New Words and Expressionsu Terms： 3.horizontal-spindle milling machine 3.horizontal-spindle milling machine 臥式銑床臥式銑床 vertical-spindle milling machine vertical-spindle milling machine 立式銑床立式銑床 4.allowance 4.allowance 切入長度切入長度 over travel over travel 切出長度切出長度 5.up milling 5.u

12、p milling 逆銑逆銑 conventional milling conventional milling 逆銑逆銑 climb milling climb milling 順銑順銑 down milling down milling 順銑順銑Text Milling operations can be classified into two broad categories called peripheral milling and face milling. Each has many variations. Text Peripheral or Slab Milling uIn p

13、eripheral milling the surface is generated by In peripheral milling the surface is generated by teeth located on the periphery of the cutter body. teeth located on the periphery of the cutter body. uThe surface is parallel with the axis of rotation The surface is parallel with the axis of rotation o

14、f the cutter. of the cutter. uBoth flat and formed surfaces can be produced by Both flat and formed surfaces can be produced by this method, the cross section on the resulting this method, the cross section on the resulting surface corresponding to the axial contour of the surface corresponding to t

15、he axial contour of the cutter. cutter. uThis process, often called slab milling, is usually This process, often called slab milling, is usually performed on horizontal-spindle milling machines. performed on horizontal-spindle milling machines. In slab milling, the tool rotatesIn slab milling, the t

16、ool rotates（millsmills）at some at some rpm value N while the work feeds past the tool at a rpm value N while the work feeds past the tool at a table feed rate ftable feed rate fm m in inches per minute. in inches per minute. Text Basics of peripheral or slab milling process Text Face And End Milling

17、 uIn face milling and end milling, the In face milling and end milling, the surface generated is at right angles to surface generated is at right angles to the cutter axis . the cutter axis . uMost of the cutting is done by the Most of the cutting is done by the peripheral portions of the teeth, wit

18、h the peripheral portions of the teeth, with the face portions providing some finishing face portions providing some finishing action. action. uFace milling is done on both horizontal Face milling is done on both horizontal and vertical-spindle machines.and vertical-spindle machines. Text Basic of f

19、ace and end milling process Text uFor either slab or face For either slab or face milling, surfaces can milling, surfaces can be generated by two be generated by two distinctly different distinctly different methods. methods. uU p m i l l i n g i s t h e U p m i l l i n g i s t h e traditional way t

20、o mill traditional way to mill a n d i s c a l l e d a n d i s c a l l e d conventional milling. conventional milling. The cutter rotates The cutter rotates against the direction against the direction of feed rate of the of feed rate of the workpiece.workpiece. Up or Conventional Milling And Climb o

21、r Down MillingText uIn climb or down In climb or down milling, the cutter milling, the cutter rotation is in the rotation is in the same direction as same direction as the feed rate. the feed rate. uThe method of chip The method of chip f o r m a t i o n i s f o r m a t i o n i s c o m p l e t e l y

22、 c o m p l e t e l y different in the different in the two cases.two cases. Up or Conventional Milling And Climb or Down MillingQuestionswWhat are the characteristics of milling comparing What are the characteristics of milling comparing with other metal cutting?with other metal cutting?wWhy is the

23、milling particularly well suited and Why is the milling particularly well suited and widely used for mass production?widely used for mass production?wWhat is the peripheral milling? And can use it on What is the peripheral milling? And can use it on vertical spindle machine?vertical spindle machine?

24、wWhat is face and end milling? Only a small part of What is face and end milling? Only a small part of the cutting is done by the peripheral portions of the cutting is done by the peripheral portions of the teeth in face milling. true or false?the teeth in face milling. true or false?wHow large of t

25、he lengths of over travel LHow large of the lengths of over travel LO O and the and the approach Lapproach LA A when face milling? when face milling?wWhat is the up or conventional milling? What is What is the up or conventional milling? What is climb or down milling? climb or down milling? Language

26、 Points & Translating Techniques wExample 1: Many types of milling machines are used, ranging Many types of milling machines are used, ranging from relatively simple and versatile machines that from relatively simple and versatile machines that are used for general-purpose machining in job shops

27、 are used for general-purpose machining in job shops and tool-and-die work on highly specialized machines and tool-and-die work on highly specialized machines for mass production.for mass production. 多種型號(hào)的銑床被廣泛使用，范圍包括在加工車間中用多種型號(hào)的銑床被廣泛使用，范圍包括在加工車間中用于大量生產(chǎn)的常規(guī)簡易銑床和萬能銑床，也包括在工模具車于大量生產(chǎn)的常規(guī)簡易銑床和萬能銑床，也包括在工模具車

28、間使用的高度專業(yè)化的各種銑床。間使用的高度專業(yè)化的各種銑床。 manymany引導(dǎo)的短句是主句；分詞引導(dǎo)的短句是主句；分詞rangingranging引導(dǎo)的短語作狀引導(dǎo)的短語作狀語，進(jìn)一步說明銑床的種類和用途，該分詞短語中又有由語，進(jìn)一步說明銑床的種類和用途，該分詞短語中又有由thatthat引出的定語從句，用來修飾引出的定語從句，用來修飾thatthat緊前面的緊前面的machinesmachines一詞。一詞。整個(gè)句子較長，翻譯時(shí)只能意譯。整個(gè)句子較長，翻譯時(shí)只能意譯。 wExample 2: Both flat and formed surfaces can be produced by

29、 Both flat and formed surfaces can be produced by this method, the cross section on the resulting this method, the cross section on the resulting surface corresponding to the axial contour of the surface corresponding to the axial contour of the cutter.cutter. 用這種方法可以進(jìn)行平面銑削和成形銑削，銑削的橫截用這種方法可以進(jìn)行平面銑削和成

30、形銑削，銑削的橫截面與銑刀的軸向輪廓一致。面與銑刀的軸向輪廓一致。 句中句中“,”,”后是一個(gè)分詞獨(dú)立結(jié)構(gòu)，用作狀語，表示結(jié)后是一個(gè)分詞獨(dú)立結(jié)構(gòu)，用作狀語，表示結(jié)果，其邏輯主語為果，其邏輯主語為the cross sectionthe cross section（橫截面），分詞為（橫截面），分詞為corresponding tocorresponding to（與（與一致）。一致）。 wExample 3: The cutting velocity is that which occurs at the The cutting velocity is that which occurs at

31、the cutting edges of the teeth in the milling cutter.cutting edges of the teeth in the milling cutter. 切削速度就是指銑刀齒切削刃上的速度。切削速度就是指銑刀齒切削刃上的速度。 that that 引導(dǎo)表語從句；引導(dǎo)表語從句；whichwhich在表語從句中作主語。用在表語從句中作主語。用此句型意在強(qiáng)調(diào)速度定義。此句型意在強(qiáng)調(diào)速度定義。wExample 4: The feed rate of the table, fThe feed rate of the table, fm m , in i

32、nches per , in inches per minute is related to the amount of metal each minute is related to the amount of metal each tooth removes during a revolution (this is called tooth removes during a revolution (this is called the feed per tooth), fthe feed per tooth), f1 1, , 工作臺(tái)的進(jìn)給量是與銑刀每一齒在銑刀每一轉(zhuǎn)中切削工作臺(tái)的進(jìn)給量是

33、與銑刀每一齒在銑刀每一轉(zhuǎn)中切削金屬量有關(guān)的一個(gè)量，以金屬量有關(guān)的一個(gè)量，以f fm m表示，其單位為英寸分鐘，表示，其單位為英寸分鐘，而每一齒的進(jìn)給叫做齒進(jìn)給，以而每一齒的進(jìn)給叫做齒進(jìn)給，以f f1 1表示，表示， wExample 5: 五、強(qiáng)調(diào)句型的譯法五、強(qiáng)調(diào)句型的譯法 在英語中，有一種強(qiáng)調(diào)句型在英語中，有一種強(qiáng)調(diào)句型“It is (was )that”It is (was )that”。它是用來強(qiáng)調(diào)除謂語之外的主語、賓語、狀語部分的。這一它是用來強(qiáng)調(diào)除謂語之外的主語、賓語、狀語部分的。這一強(qiáng)調(diào)句型是把需要強(qiáng)調(diào)的部分放在強(qiáng)調(diào)句型是把需要強(qiáng)調(diào)的部分放在“It is (was)”It is

34、(was)”的后面，的后面，而把句子的其余部分放在而把句子的其余部分放在that that 的后面，其特點(diǎn)是去掉的后面，其特點(diǎn)是去掉It is It is (was )that (was )that 后仍是一個(gè)完整的句子。翻譯時(shí)常常在被強(qiáng)后仍是一個(gè)完整的句子。翻譯時(shí)常常在被強(qiáng)調(diào)成分之前加上調(diào)成分之前加上“正是正是”、“就是就是”等詞。具體譯法有兩種：等詞。具體譯法有兩種： （一）保留原文結(jié)構(gòu)（一）保留原文結(jié)構(gòu) It is It is heatheat that causes many chemical changes. that causes many chemical changes.（強(qiáng)調(diào)

35、（強(qiáng)調(diào)主語）主語）w 正是熱引起許多化學(xué)變化。正是熱引起許多化學(xué)變化。 It isIt is in industry in industry that metals have found their that metals have found their greatest use.greatest use.（強(qiáng)調(diào)狀語）（強(qiáng)調(diào)狀語）w 正是在工業(yè)上金屬得到了最大限度的應(yīng)用。正是在工業(yè)上金屬得到了最大限度的應(yīng)用。 （二）改變?cè)慕Y(jié)構(gòu)（二）改變?cè)慕Y(jié)構(gòu) It is man that plays the leading role in the It is man that plays the leading role in the application of electronic computers.application of electronic computers.（強(qiáng)調(diào)主語）（強(qiáng)調(diào)主語）w 在應(yīng)用電子計(jì)算機(jī)時(shí)，起作用的是人。在應(yīng)用電子計(jì)算機(jī)