机械专业英语董建国第9章

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READINGMATERIALUnit9TEXTMachineToolsMachinetoolsaremachinesforcuttingmetals.Themostimportantofmachinetoolsusedinindustryarelathes,drillingmachinesandmillingmachines.Otherkindsofmetalworkingmachinesarenotsowidelyusedinmachiningmetalsasthesethree.Thelatheiscommonlycalledthefatheroftheentiremachinetoolfamily.Forturningoperations,thelatheusesasinglepointcuttingtool,whichremovesmetalasittravelspasttherevolvingwork-piece.Turningoperationsarerequiredtomakemanydifferentcylindricalshapes,suchasaxes,gearblanks,pulleys,andthreadedshafts.Boringoperationsareperformedtoenlarge,finish,andaccuratelylocateholes.Drillingisperformedwitharotatingtoolcalledadrill.Mostdrillinginmetalisdonewithatwistdrill.Themachineusedfordrillingiscalledadrillpress.Operations,suchasreamingandtapping,arealsoclassifiedasdrilling.Reamingconsistsofremovingasmallamountofmetalfromaholealreadydrilled.Tappingistheprocessofcuttingathreadinsideaholesothatacapscreworboltmaybethreadedintoit.Millingremovesmetalwitharevolving,multiplecuttingedgetoolscalledmillingcutter.Millingcuttersaremadeinmanystylesandsizes.Somehaveasfewastwocuttingedgesandothershave30ormore.Millingcanproduceflat,angledsurfaces,groves,slots,gearteeth,andotherprofiles,dependingontheshapeofthecuttersbeingused.Shapingandplaningproduceflatsurfaceswithasinglepointcuttingtool.Inshaping,thecuttingtoolonashaperreciprocatesormovesbackandforthwhiletheworkisfedautomaticallytowardsthetool.Inplaning,thework-pieceisattachedtoaworktablethatreciprocatespastthecuttingtool.Thecuttingtoolisautomaticallyfedintothework-pieceasmallamountoneachstroke.Grindingmakesuseofabrasiveparticlestodothecutting.Grindingoperationsmaybeclassifiedasprecisionornon-precision,dependingonthepurpose.Precisiongrindingisconcernedwithgrindingtoclosetolerancesandverysmoothfinish.Non-precisiongrindinginvolvestheremovalofmetalwhereaccuracyisnotimportant.LEARNTOSPEAK

Mr.Zhang:Hello,Mr.Cheng,whatareyoudoing?Mr.Cheng:Iammachiningapart!Mr.Zhang:Thisisalathe,isn’tit?Mr.Cheng:Yes.Itisamediumsizelathe.Mr.Zhang:Whatcanitdo?Mr.Cheng:Cylindricalparts,hole,andendsurfacecanbemadeonit.Mr.Zhang:What’sthat?Mr.Cheng:Itisamillingmachine.Mr.Zhang:Isthisamillingcutter?Mr.Cheng:Yes,itis.Itisaendmillingcutter.Mr.Zhang:Whatkindsofworkcanitdo?Mr.Cheng:Itcanproduceplane,slotandcamsurface.Mr.Zhang:Thankyouforyourhelp.Mr.Cheng:Mypleasure.NEWWORDSANDEXPRESSIONSlathe [leIT] n.车床vt.用车床加工drill [drIl] n.钻床v.钻孔mill [mIl] n.铣床，铣刀vt.铣，铣削ream [ri:m] v.铰孔tap [tAp] v.攻螺纹thread [Wred] n.螺纹，线v.车螺纹turn [t:n] v.车削cylindrical [sI5lIndrIk(E)l]adj.圆柱(体，形)的blank [blANk] n.毛坯，坯料pulley [5pJlI] n.皮带轮，滑轮bore [bC:(r)] n.膛孔enlarge [In5lB:dV] v.扩大finish [5fInIF] n.精加工，粗糙度 v.表面抛光，完成shaper [5FeIpE(r)] n.牛头刨床planer [5pleInE(r)] n.龙门刨床slot [slBt] n.缝，狭槽reciprocate [rI5sIprEkeIt] v.来回往复运动stroke [strEJk] n.冲程，行程abrasive [E5breIsIv] adj.摩擦(损)的particle [5pB:tIk(E)l] n.微粒precision [prI5sIV(E)n] n.精度consistof 包含，包括， 由……组成backandforth 来回，往复beattachedto 连接于，固定于beconcernedwith 与……有关系singlepointtool 单刃刀具NOTES1．Forturningoperations,thelatheusesasinglepointcuttingtool,whichremovesmetalasittravelspasttherevolvingwork-piece.为了进行车削，当工件旋转经过刀具时，车床用一把单刃刀具进行切削。“Forturningoperation”作状语，表目的，有“为了进行切削”之意。“which”引导非限制性定语从句，修饰“asingle-point-cuttingtool”。“asinglepointcuttingtool”切不可直译为“单点刀具”，而应译为“单刃刀具”。2．Tappingistheprocessofcuttingathreadinsideaholesothatacapscreworblotmaybethreadedintoit.攻螺纹就是在孔内壁上加工螺纹，以使螺钉或螺栓旋进孔内。在英文翻译成中文时，不必要把所有的英文一一对应翻译成中文。如本句中“process”在译成中文时就不必译成“过程”，只要把句子的含义表达清楚就可以了。3．Inshaping,thecuttingtoolonashaperreciprocatesormovesbackandforthwhiletheworkisfedautomaticallytowardsthetool.用牛头刨床进行加工时，刀具在机床上往复运动，而工件朝向刀具自动进给。用“or”连接的词或词组在地位上相等，有时表示的是同一个含义。本句中的“reciprocates”和“movesbackandforth”表达的是同一个含义。“movesbackandforth”是对“reciprocates”的详细说明。EXERCISES1．DiscussthefollowingquestionsinEnglish:(1) Howdoesthelatheworkinmachiningawork-piece?(2) Whatkindsofmethodsaretherewhenwecutathreadinthesurfaceofawork-piece?(3) Whatkindsofmachinetoolisthemostusefulmachinetoolinmachining?2．UseEnglishforreplacingChineseoruseChineseforreplacingEnglish.(1)机床(2)车床(3)圆柱型零件(4) Tapping(5) Reaming(6) Multiplecuttingedgetool3．Placea“T”aftersentencesthataretrueandan“F”afterthosethatarefalse.(1) Themostimportantmachinetoolsusedinindustryarelathesanddrillingmachines.()(2) Thelatheisoftencalledthefatheroftheentiremachinetoolfamily.()(3) Millingmachinecannotbeusedtoproduceahole.()(4) Shapingcanproducegroves.()(5) Grindingcanformaverysmoothfaceatwork-piece.()4．TranslatethefollowingtextintoChinese:Thelatheisoneofthemostimportantmachinesinamachineshop.Varioustypesoflathesaredesignedandproducedfordifferentpurposes.Themaintypesofthemareenginelathes,benchlathes,verticallathesturretlathes,andsoon.Theenginelatheismostlyusedinmachineshops.Itcanperformvariousturningoperationsand,inaddition,drilling,threading,boring,andotheroperations.Thebenchlatheismountedonaworkbench.Itissmallerinsize.Lathesofthistypeareusedtomachinesmallparts.Theverticallatheischaracterizedbyitsverticalspindle.Itissuitableforturningheavyandshortwork-pieces.READINGMATERIALAggregateMachineToolsAnaggregatemachinetoolisahighlyefficientautomatic.Itisanaggregationofstandardcomponents,suchaspowertransmissionunits,rotarytables,millingheads,beds,columnsaswellassomespecialcomponents.Theaggregatemachinetoolmadeitsfirstappearanceinthefifties,butithasrapidlydevelopedintoaveryimportantbranchofthemachinetoolindustry.Manyfactoriesaredesigningandmakingvariousaggregatemachinetoolstoincreasetheirproduction.Forinstance,aplantinTalienhassuccessfullydesignedandbuiltanumericallycontrolledaggregatemachine,whichemploystwentythreepowertransmissionunitswithtwohundredandseventeenspindles.Withthehelpofthismachine,theproductivityofthisplantisraisedbyfourteentimes.Aggregatemachinetoolsareincreasinginnumberandvariety.Theyhavefoundwideapplicationinourmachinebuildingindustry.PROFESSIONALWORDSANDPHRASESaggregate [5A^rI^eIt] adj.组合的aggregation [A^rI5geIF(E)n] n.聚集，集合体standard [5stAndEd] n.标准well [wel] adv.好appearance [E5pIErEns] n.出现branch