机电专业英语第2版电子教案Unit 25

Unit 1 Engineering MaterialsL Lead-inIn formation related to the text:What are the basic types of engineering materials? How many types of nonmetallic are there? Do you know the differences between pure and alloyed metals? Which is often used in commercial use? Why iron is the most important natural element? What factors must be considered for the selection of production methods? In this unit, you'll learn knowledge about engineering materials. Now, let's study key words and phrases together.II.Word Study1.differ ['difo] vt.使…相异；使…不同vi.相异；意见分歧(from, in)1)agree to differ同意各持己见2)Our lifestyle, education and other systems differ from other places in the region.本地的生活方式、教育制度等与其他地区有所不同。

3)They differ in kind and function.它们种类不同、功能不同。

2.be classified as被归类为…1)Gold alloy can be classified as white gold alloy and color gold alloy by color. 金合金按照颜色分主要有白色金合金和彩色金合金两种。

机电专业英语第2版电子教案Unit11Unit 11CAD and ApplicationsI. Lead inInformation related to the textDo you know what the Computer Aided Design (CAD) is? Do you know the history of CAD? What are the advantages of the CAD? Maybe you have used the CAD yet, but do you know how you can use it? Can you give an example? In the unit, you will study the development of CAD and how it is widely used. Now, let’s study new words and phrases together.II. Word Study1. appropriate [?'pr?uprieit] a. 适当的v. 占用；拨出1）Use the lists below to select the appropriate delimiter.请用下面的列表选择相应的定界符。

2）A focus and concern on climate change is entirely appropriate.对于气候变化的聚焦和关注是完全恰当的。

3）This is the "all appropriate measures" school of policy analysis.这是政策分析中的“所有适当措施”学派。

2. interactive [,int?'r?ktiv] a. 交互式的，相互作用的1）Reading is a complex and interactive process.阅读是一个复杂和互动的过程。

《机电一体化专业英语》（English for Mechatronics）授课教案Teaching PlanMajor (专业)：机电一体化XXXX专业（相关专业）Lecturer(任课教师)：__________________________Mechatronics SectionChangchun Automobile Industry Institute《机电一体化专业英语》授课计划_ _______ 学院___ 专业班20 －20 学年第学期授课时间：第周ensure that…又引导出一个状语从句。

全句可译为：在把花盘安装在主轴上后, 常规作法是对断面进行一次性地轻切削以确保花盘表面与车床主轴垂直。

Period1The following is the machine tool structures.Explanations of the Machine Tool TermsNo.NameExplanation1 Spindle speed selector 主轴速度转换开关2 Headstock assembly 主轴箱3 Spindle with chuck 附有夹具主轴 4Tool post 刀架 5 pound rest 复式刀架 6 Cross slide 横向拖板 7 Carriage 滑鞍,滑座 8 Ways 导轨 9 Dead center 死顶尖 10 Tailstock quill 尾架顶尖套筒 11 Tailstock assembly 尾架 12 Hand-wheel 手轮 13 Bed 底座,床身 14 Lead screw 丝杠 15 Feed rod 进刀杠,光杠 16 Clutch离合器17 Longitudinal & transverse feed control 纵向与横向进给控制 18 Split-nut control 开合螺母控制 19 Apron 溜板箱,进给箱 20 Chip pan 承屑盘 21Feed selector进给选择开关机床构造 Section II Glance at Machine Tool StructuresThe following is the conventional machine tool. You are required to choose the suitable words or phrases given below.7. Body G. 公英制转换键8. Calibration sticker H. 液晶显示屏9. Depth bar I. 外径测量面10. Zero-setting key J. 滑尺11. On/Off key K. 电池盖12. Slider L. 清零键13. Outside measuring face M. 测深杆Period 1Practice扩大您地视野（实践部分）Section IV BroadenYour Horizon—Practical Activity(Practice) The micrometer screw gaugeThe micrometer screw gauge is used to measure even smaller dimensions than the vernier caliper. The micrometer screw gauge also uses an auxiliary scale (measuring hundredths of a millimeter) which is marked on a rotary thimble. Basically it is a screw with an accurately constant pitch. The micrometers in our laboratory have a pitch of 0.50 mm. The rotating thimble is subdivided into 50 equal divisions. The thimble passes through a frame that carries a millimetre scale graduated to 0.5 mm. The jaws can be adjusted by rotating the thimble using the small ratchet knob. The thimble must be rotated through two revolutions to open the jaws by 1 mm. Here is a useful applet to learn how to use the micrometer screw gauge (Figure 1-19).Figure 1-19 The micrometer screw gaugeIn order to measure an object, the object is placed between the jaws and the thimble is rotated using the ratchet until the object is secured. Note that the ratchet knob must be used to secure the object firmly between the jaws, otherwise the instrument could be damaged or give an inconsistent reading.Note that an additional half scale division (0.5 mm) must be included if the mark below the main scale is visible between the thimble and the main scale division on the sleeve. The remaining two significant figures (hundredths of a millimeter) are taken directly from the thimble opposite the main scale.In Figure 1-20 the last graduation visible to the left of the thimble is 7 mm and the thimble lines up with the main scale at 38 hundredths of a millimeter (0.38 mm); therefore the reading is 7.38 mm.In Figure 1-21 the last graduation visible to the left of the thimble is 7.5 mm; therefore the reading is 7.5 mm plus the thimble reading of 0.22 mm, giving 7.72 mm.Figure 1-20 The reading is 7.38mm Figure 1-21 The reading is 7.27mm In Figure 1-22 the main scale reading is 3 mm while the reading on the drum is 0.46 mm; therefore, the reading is 3.46 mm.In Figure 1-23 the 0.5 mm division is visible below the main scale; therefore the reading is 3.5 mm + 0.06 mm = 3.56 mm.Figure 1-22 The reading is 3.46mm Figure 1-23 The reading is 3.56mm Try the following bg yourselfFigure 1-24 Figure 1-25 Figure 1-26A: Do exercise 1, 2, 3, 4 and 7.AssignmentB: Ask students to collect some external machine tools.《机电一体化专业英语》授课计划_ _______ 学院___ 专业班20 －20 学年第学期授课时间：第周Key Points unit.2. Machine tool practice cognition.教学难点Difficult Points 1. Understand the key words, phrases and sentences in the passage.2. Translate the simple material or specification.教学方法Teaching Methods • Explanation • Group discussion • Questions and answers • Performance (Role-play) • Machine tool specification教学手段TeachingMeans• Multi-media • Videos • work Resource教学安排Teaching Arrangement教学内容Contents of Course学时Period精读Section I Technical and Practical Reading2机床构造Section II Glance at the Structure of the Machine Tool1试试身手（实践部分）Section III Simulated Writing (Practice)2扩大您地视野（实践部分）Section IV Broaden Your Horizon—Practical Activity (Practice)1授课内容与要点Teaching Contents and Main PointsUnit 2 Metal MaterialsPeriod2精读Section I Technical and Practical Reading Part I. Leading in1. RevisionAsk several students if they know the machine tool structures, metal materials and important machine tool manufacturers.Arouse students to answer teacher’s questions according to the Passage A /B for introduction to meta materials in Unit 2.2. Warming up questions1) Ask students to work in groups of four to read new words and phrases.5. ________（工具铣床）6. ________ (单柱铣床)Single-column Milling Machine Plano-milling MachineTool Milling MachineKnee-and-Column Milling Instrument milling machine Single-arm Milling MachinePeriod2Have a TrySample 1Explanations of TermsNameExplanationOuter frame 外框 Scale mark plate刻度盘 Spring 弹簧 Arm测量臂 Gauge head 侧头 Dial window 刻度盘 Indicator 指针 Clamp screw夹紧螺丝Choose the best answer.试试身手 （实践部分） Section III Simulated Writing (Practice)AB1. Dial windowA. 限制器 2. Long handB. 短指针 3. Top pointC. 刻度盘 4. LimiterD. 刻度盘 5. ClumpE. 长指针 6. Outer frameF. 底座 7. Short handG. 顶针8. BaseH. 螺丝紧固座 9. Scale mark plate I. 紧固件 10. Screw fastening base J. 测头 11.Gauge headK. 外框Period1Practice扩大您地视野 （实践部分）Section IV BroadenFacing OperationsFacing is the process of removing metal from the end of a work-piece to produce a flat surface.Preparing for the Facing CutYour Horizon—Practical Activity (Practice) First, make sure the tumbler gear lever on the back of the headstock is in the neutral (middle) position so that the lead-screw does not rotate.Clamp the work-piece tightly in the three-jaw chuck. To get the work properly centered, close the jaws until they just touch the surface of the work, then rotate the work-piece by hand in the jaws to seat it; then tighten the jaws (Figure 2-17). Beginning the Facing CutUse the pound handwheel to advance the tip of the tool until it just touches the end of the work-piece. Use the cross feed crank to back off the tool until it is beyond the diameter of the work-piece. Turn the lathe on and adjust the speed to a few hundred RPM — setting of the speed control knob. Now slowly advance the cross feed hand-wheel to move the tool towards the work-piece. When the tool touches the work-piece it should start to remove metal from the end (Figure 2-18). Continue advancing the tool until it reaches the center of the work-piece and then crank the tool back in the opposite direction (towards you) until it is back past the edge of the work-piece (Figure 2-19).Figure 2-18 Figure 2-19 Since we started with the tool just touching the end of the work-piece, you probably removed very little metal on this pass. This is a good idea until you get used to how aggressively you can remove metal without stalling the lathe.The Roughing CutUse the pound crank to advance the tool towards the chuck about 0.010". If the pound is set at a 90 degrees to the cross slide (which is how I usually set mine) then each division you turn the crank will advance the tool 0.001 (one-thousandth of an inch) toward the chuck.If the pound is set at some other angle, say 30 degrees, to the cross slide, then it will advance the tool less than 0.001 for each division. The exact amount is determined by the trigonometric sine of the angle. Here’s a picture of the first pass of a facing operation (Figure 2-20).Cutting on the Return PassIf you crank the tool back towards you after it reaches the center of the work-piece you will notice that it removes a small amount of metal on the return pass. This is because the surface is not perfectly smooth and it is removing metal from the high spots. If you need to remove a lot of metal, to reduce the work-piece to a specific length, for example, you can take advantage of this return cut to remove more metal on each pass by advancing the tool a small ways into the work-piece on the return pass. Since the tool must plunge into the face of the work-piece, this works best with a fairly sharp pointed tool.The Finishing CutDepending on how rough the end of the work-piece was to begin with and how large the diameter is, you may need to make three or more passes to get a nice smooth finish across the face. These initial passes are called roughing passes and remove a relatively large amount of metal.When you get the face pretty smooth you can make a final finishing cut to remove just 0.001 to 0.003" of metal and get a nice smooth surface. Figure 2-21 shows removingabout 0.002" of metal at around 1 000 RPM. Figure 2-22 shows the finished face of thework-piece.　Figure 2-21 Figure 2-22Figure 2-23 shows what happens if the tip of your cutting tool is below the center line of the lathe — a little nub is left at the center of the work-piece. The same thing happens ifthe tool is too high but the nub will have more of a cone shape in that case. If the tool is toolow, place a suitable thickness of shim stock underneath the tool in the tool holder. If it’s toohigh, grind the top down a few thous.Filing the EdgeFacing operations leave a rather sharp edge on the end of the work-piece. It’s a good idea to smooth this edge down with a file to give it a nice chamfer and to avoid cuttingyourself on it. With the lathe running at fairly low speed, bring a smooth cut file up to theend of the work-piece at a 45 degree angle and apply a little pressure to the file. Figure2-24: Right — left hand holding tang end of file. Figure 2-25: Wrong — left hand reachingover spinning chuck!Figure 2-23 Figure 2-24Figure 2-26 shows the finished surface and beveled edge. This is what a good facing cut should look like: smooth even surface with no raised bump in the center.　Lay anaccurate straight edge across the surface of the face and you should not be able to seeany light under the edge. If you detect a slight convex shape, the carriage may be movingback away from the headstock during the cut.Figure 2-25 Figure 2-26A: Do exercise 1, 2, 3, 4 and 7.AssignmentB: Ask students to collect some external machine tools.《机电一体化专业英语》授课计划_ _______ 学院___ 专业班20 －20 学年第学期授课时间：第周教学难点Difficult Points 1. Understand the key words, phrases and sentences in the passage.2. Translate the simple material or specification.教学方法Teaching Methods • Explanation • Group discussion • Questions and answers • Performance (Role-play) • Machine tool specification教学手段TeachingMeans• Multi-media • Videos • work Resource教学安排Teaching Arrangement教学内容Contents of Course学时Period精读Section I Technical and Practical Reading2机床构造Section II Glance at the Machine Tool Structures1试试身手（实践部分）Section III Simulated Writing (Practice)2听说练习（实践部分）Section IV Broaden Your Horizon—Practical Activity (Practice)1授课内容与要点Teaching Contents and Main PointsUnit 3 Machining OperationsPeriod2精读Section I Technical and Practical Reading Part I. Leading in1. RevisionAsk several students if they know the basic machine tool and its function.Arouse students to answer teacher’s questions according to the Passage A /B for introduction to basic machine tools in Unit 3.2. Warming up questions1) Ask students to work in groups of four to read new words and phrases.2) Talk about the basic boring machines.Part II. prehension and PracticingSentences:1. Conventional machining, one of the most important material removal methods, is a collection of material-working processes in which power-driven machine tools, such as lathes, milling machines, and drill presses are used with a sharp cutting tool to mechanically cut the material to achieve the desired geometry. 在这个长句中,主语是Conventional machining,由is引导出合成谓语;one of the most…methods是插入语;in which 引导定语从句,其先行词为processes。