机电-体化专业英语Unit 1

1、Basic Mechanical TechnologyPart I Technical and Practical Reading Brass Round Stock Brass is a nice material to work with, though somewhat expensive compared with aluminum or steel. It can add a nice touch of contrasting color to a project that will be displayed. The alloy most often used for home s

2、hop work is 360 Passage A Lathe Accessories (I) Center Drills Center drills are stiff, stubby little drills used to start holes in the end of work-piece. If you try to drill a hole in a work-piece without using a center drill you will find that the drill will most likely wobble off center and not dr

3、ill straight into the work-piece. Standard drilling practice is to first make a facing cut on the end of the work-piece, then drill a starter hole using a center drill and then drill the hole to the required depth with a standard drill Chip Brushes Chip brushes are inexpensive paint brushes that are

4、 handy for all kinds of uses around the shop. Were not sure where the name originated, but we dont think it had anything to do with removing chips; nevertheless this is one of the uses these brushes excel at. They are also ideal to clean the packing grease off a new lathe or mill. Incidentally, expe

5、rienced machinists will tell you always to use a brush, rather than compressed air, to clean the chips from machine tools as compressed air will drive the chips deep into the recesses of the machine. Chip brushes and a shop vac are the preferred way to clean up chips. Digital Caliper Digital caliper

6、s are used just like dial calipers for making inside and outside measurements accurate to one thousandth of an inch but have a direct LCD digital readout. On a dial caliper you first read the major dimension to the nearest tenth of an inch from the slide and mentally add to that the minor dimension

7、from the dial to the nearest thousandth. This becomes second nature after a while, but still introduces opportunities to make opportunities to make a mistake. A digital caliper reads out the full dimension on the display, so is pretty foolproof, as long as it is properly zeroed. You can also switch

8、between metric and inch modes as needed.Drill Rod Drill rod is a steel alloy with a shiny silvery color and good machining properties. Unlike other raw materials, which may vary from the nominal diameter by + .010 or more, drill rod is surface ground to within about .001 of the nominal diameter. Whi

9、le not classified as a stainless steel, drill rod is moderately resistant to rust - more, at least, than ordinary carbon steels. It is great for applications such as shafts and axles. A useful property of drill rod is that it can easily be hardened by heating to a red hot state and then quenching in

10、 oil or water. Thus treated, the metal is hard enough to use for tools such as punches. Drill Sets Drilling is one of the most commonly performed operations on the lathe, so you will need a good collection of decent-quality drills. When you buy your lathe, dont forget to order a tailstock chuck and

11、arbor to hold the drills. Poor quality drills are easy to find, but they are truly a waste of money. Thats not to say that you need to buy top quality industrial drills. Its not always easy to tell a good drill bit from a poor one just by looking and, of course, its evenharder if all you have is a p

12、icture on a web site or in a catalog. Generally, though, the lowest priced drill sets are the ones to stay away from.FaceplateA faceplate is a handy accessory for turning odd-shaped work that cannot easily be held in a chuck. While its not too difficult to make your own faceplate from steel or alumi

13、num, at this price its hardly worth the effort. After mounting the faceplate on the spindle, it is standard practice for faceplates to take a light one-time facing cut to ensure that the face of the plate is square with the lathe. Cast iron dust is very harmful to breathe, so I strongly recommend we

14、aring a dust mask during this operation and until you have vacuumed up the resulting dust. When using a faceplate, always ensure that the work is securely clamped down and balanced by some offsetting piece of metal, if necessary. Feeler Gages Feeler gages are sets of thin steel strips of accurate th

15、icknesses, typically from .001 up to about .040 or so. There are typically about 20 to 40 separate strips in a set, joined together by a bolt that runs through a hole in the end of each gage. Each gage has the thickness marked on it, in both inches and mm in the example below. All of the leaves fold

16、 up into the handle to protect them from bending when theyre not in use. While their intended purpose is to measure the gap between two surfaces, such as the electrodes of spark plug. Follower Rest A follower rest is similar to a steady rest, but is attached to and travels with the carriage to provi

17、de a moving support for the work behind the cutting tool. This is very handy when trying to turn limber work which would otherwise bow out away from the tool. If you have ever wondered about the two screw holes on the left edge of the carriage, now you know what they are for - they are the mounting

18、holes for the follower rest. Notes 1、Center drills are stiff, stubby little drills used to start holes in the end of work-piece. 本句是个简单句。句中used to start是后置定语，修饰stubby little drills。全句可译为：中心钻是很硬的、粗而短的小型钻头，它用于在工件端面开孔。2、Digital calipers are used just like dial calipers for making inside and outside mea

19、surements accurate to one thousandth of an inch but have a direct LCD digital readout. 本句虽然很长，但它还是个简单句。注意“but”为介词，译为“除了”。全句可译为：数显卡尺就像带表卡尺一样，除了可直接通过液晶显示器进行数字读数外，还可被用来实现千分之一英寸的内外精确测量。3、After mounting the faceplate on the spindle, it is standard practice for faceplates to take a light one-time facing c

20、ut to ensure that the face of the plate is square with the lathe. 本句较为复杂，After引导出介词短语，主语为to take，而to ensure that又引导出一个宾语从句。全句可译为：在把面板花盘安装于主轴后, 常规作法是需进行一次简单的端面加工以确保花盘面与车床垂直。EXERCISE 1 Mark the following statements with T (True) or F (False) according to the passage.1. Center drills are hard, shortnes

21、s, thickness and little drills used to start holes in the end of work-piece.2. Chip brushes are very useful, but more expensive.3. Digital calipers are used as a measurement indicated by a moving needle or pointer.4. Drill rod is a copper alloy with a nice color and good machining properties.5. Feel

22、er gages are accurate sets of thin steel strips to measure the gap between two surfaces.(T)(F)(T)(F)(T)EXERCISE 2 Translate the following phrases into Chinese or English.1.center drill _ 2. _ 密封润滑脂 3. machining property _4._ 碳素钢5. cast iron _6. _ 测隙规7. steady rest _ 8._ 跟刀架 中心钻packing grease加工性能carb

23、on steel铸铁feeler gage固定支架follower restPassage B Lathe Accessories (II)Live Center Centers are often used in the tailstock to support the end of a relatively long and limber work-piece. The drawback of a dead center is that the center does not rotate, while the work-piece that it supports does, leadi

24、ng to friction and possibly overheating. By contrast, the tip of a live center is rotates freely in bearings, and rotates with the work-piece so that the friction is greatly reduced.Medium Density Fiberboard (MDF) MDF is not really an accessory, but it is a handy, inexpensive, lightweight and easily

25、 workable material to have around the shop. It is a synthetic material, but with different properties. It is available in thicknesses up to at least 3/4 and is smooth on both faces. It cuts easily using a saber saw, circular saw, band-saw, table saw or radial arm saw. One disadvantage is that it ten

26、ds to absorb moisture, but this propensity can be greatly reduced by spray-painting the surfaces. Milling Attachment A milling attachment became available as a standard accessory for the mini lathe. Before this accessory became available, many lathe owners made their own versions based on the one ma

27、de by Varmint Al. Varmint Als uses a standard milling vise while the one shown below uses socket head screws to hold the work-piece between the jaws. While by no means a substitute for mini-mill, this accessory is an inexpensive way to add limited milling capability to your mini-lathe while you save

28、 up for a mill. T-handle Metric Hex Wrench Set These arent really essential, but they are so handy and so cheap you will kick yourself if you live without them and then later try them. I use these for nearly all the hex head screws on the lathe. Tailstock Chuck and Arbor Drilling is a fundamental la

29、the operation and you will need a chuck and a #2 Morse Taper arbor to do it. The arbor has a thread or Jacobs taper on one end (to mate with the chuck) and a #2MT on the other end to mate with the tailstock cylinder. To remove the arbor, place the chuck in your bench vise with the jaws open just a l

30、ittle wider than the arbor diameter (not clamping the arbor). Open the jaws up and use a short piece of round stock or a drift pin to drive the arbor out of the back of the chuck. This should only require a fairly light tap of the hammer. Its a good idea to position a rag underneath the arbor to cat

31、ch it so that it does not get dinged up by falling to the floor . Tool Bits While I recommend that you learn to grind your own tool bits from Tool Blanks, you may want to have a set of pre-ground High Speed Steel (HSS) tool bits. Not only will they get you off to an immediate start, theyll serve as

32、good examples of the shapes you want to attain when you grind your own. Heres a very nice set from Walden Specialties. The set includes a 60 threading tool that can be difficult to grind by hand. Quick Change Tool-post A quick change tool post (QCTP) is an accessory that we strongly recommend: get o

33、ne as soon as your budget allows.Why? It will save you hours of time and lower your blood pressure by several points since youll no longer have to stack shims under the tool bit to get it to match the height of the lathe centerline. With a QCTP, each cutting tool has its own dedicated holder. Each h

34、older has a locking height adjustment. A few quick trials and adjustments and you lock the tool height to the perfect setting. You wont need to adjust it until you sharpen the tool, which may lower the tip by a few thousandths.Wet/Dry Sandpaper Wet / Dry sandpaper is very handy for putting a very fi

35、ne shiny finish on metal work-pieces in the lathe. In that application it is generally used dry, but when used wet on a flat backing surface it does a great job of smoothing flat metal workpieces from milling operations. White Lithium GreaseWhite lithium grease is useful for lubricating just about a

36、ny of the moving parts of the lathe. (Use light oil on the ways, though, not greases). EXERCISE 3 Choose the best lathe accessories according to the information given. 123456A. Metric Hex Key Set B. Live Center C. Tool BitsD. Feeler Gages E. Machine Vice F. Digital Caliper CEAFBDEXERCISE 4 Abbreviat

37、ions are very useful in practical work. Read them and then translate them into corresponding Chinese terms. 1. A.C. Alternating Current 2. ACRE Automatic Checkout and Radiness Equipment 3. AE Absolute Error4. AED Automated Engineering Design 5. A/M Auto and Manual6. ARC Automatic Ratio Control 7. BA

38、P Basic Assembler Program 8. BG Bevel Gear交流电自动检测读出设备绝对误差自动化技术设计自动手动自动比率控制基本汇编程序斜齿轮Part II Glance at Conventional Machine Tool Structures No.NameExplanation1Spindle speed selector主轴速度转换开关2Headstock assembly主轴箱3Spindle with chuck附有夹具主轴4Tool post刀架5Compound rest复式刀架6Cross slide横向拖板7Carriage滑板8Ways滑轨9D

39、ead canter死点10Tailstock quill尾架顶尖套筒11Tailstock assembly尾架12Hand-wheel手轮13Bed底座14Lead screw丝杠15Feed rod进刀杆16Clutch离合器17Longitudinal & transverse feed control径向和横向进给控制18Split-nut control拼合螺母控制19Apron床鞍20Chip pan承屑盘21Feed selector进给选择开关EXERCISE 5 The following is the Conventional Machine Tool. After re

40、ading them, you are required to choose the suitable words or phrases given below. Headstock Tail stock lock lever Compound hand-wheel Headstock pedestal Rail lock Spindle Tail stock pedestal Carriage hand-wheel Ways Chip pan Lead screw Tool post T-slot Cross Slide hand-wheel Tail stock hand-wheel Ta

41、ilstock Cross Slide Hand-wheel Emergency Stop Tool-post Chuck Digital Readout Headstock Compound Hand-wheel Auto-feed Direction Select Lathe For ward/Backward Auto-feed On/Off Carriage Hand-wheel Speed Selectors Auto-feed Speed Selectors Part III Simulated Writing Section A Match Your Skill The foll

42、owing is the Lathe Accessories, and you can understand the name of Tool Bits.Explanations of the Toll BitsNo.NameExplanation1Anvil铁砧2Spindle主轴3Lock ring防松环4Vernier游标尺5Spindle nut轴螺母6Adjusting nut调节螺母7Scale刻度8Thimble套管9Ratchet knob棘轮旋钮EXERCISE 6 Complete the information by translating the part given

43、in Chinese. Sealey Digital External Micrometer 025mm01&rdquo Digital external micrometer 0-25mm/0-1”: 7-Button digital micrometer with satin chrome thimble and sleeve Large, easy to read 9mm high LCD readout Display switchable between Metric and Imperial units. Zero display in any position plus take

44、 relative readings and tolerance readings. Auto power off switch Includes serial port connection for computer interface Supplied with adjustment wrench and storage case Model No. AK9635DWeight: 0.9 kgWarranty: 1 Year Section B Have a Try This section will help you to understand several forms of mach

45、ining, and you can see the simple way a small part is produced. External Operations Turning - A turning operation in which a single-point tool moves axially, along the side of the workpiece, removing material to form different features, including steps, tapers, chamfers, and contours. These features

46、 are typically machined at a small radial depth of cut and multiple passes are made until the end diameter is reached. For a finish operation, the cutting feed is calculated based on the desired surface roughness and the tool nose radius. EXERCISE 7 This section is to test your ability to Identifyin

47、g following features of different operations. A single-point turning tool moves axially, along the side of the work-piece, removing material to form different features, including Steps Contours Tapers Chamfers Contours Chamfers Tapers Steps Part IV Broaden Your Horizon - Practical Activity The micro

48、meter screw gauge The micrometer screw gauge is used to measure even smaller dimensions than the vernier caliper (游标卡尺). 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