机械专业英语1-2[81P][244MB]

ThecourseofSpecialEnglishforMechanicalEngineering机电教研室：张晓1397922105GoalsoftheCourse扩展学生在本专业方面的英语词汇量熟悉本领域的专业术语了解科技英语的表达特点及掌握专业英语翻译技巧能阅读本专业的外文资料，并具备一定的写作能力Note:•withoutanyacuteangle.•Screwshouldbeoperatedsmoothly;•Annealareaasshowed;•Screwandnutshouldbedofinishinblack;•Theholeandkeytroughshouldbelinedon;•Donotdofinishonthepolishsurfaces.机械工程专业英语的特点1.专业英语词汇特点：专业术语多，合成新词多，前后缀出现频率高，缩略词经常出现，非限定动词（尤其是分词）使用频繁，词义单一。2.专业英语语法特点：常用形式主语和形式宾语、名词结构和被动语态使用频繁，复杂长句多，复合句多，每句包含的信息量大。3.专业英语的修辞特点：时态运用有限，修辞手法简单，逻辑语法使用普遍。机械工程专业英语的特点1.单词特点(1)专业性词汇较多，且词形复杂，记忆难度大。chrome-molysteel—铬钼钢antifrictionbearing—滚动轴承epicyclicgear—行星齿轮(2)有些单词虽词形与基础英语相同，但词义相差很大pig-iron—生铁bearing—轴承（方向，生育，忍耐）bolt—螺栓（闪电，闩）(3)专业合成词较多，且与各原单词的含义有一定的不同slide-crankmechanism—曲柄滑块机构detaildrawing—零件图four-barlinkage—四连杆机构机械工程专业英语的特点2.语法特点(1)由于机械电子工程英语主要论及一些客观存在的事物，很少论及人，因此被动语态用的特别多，比比皆是。例如：Amechanismhasbeendefinedas“acombinationofrigidorresistantbodiessoformedandconnectedthattheymoveuponeachotherwithdefiniterelativemotion.”机构被定义为：“是由刚体或者有承载能力的物体联接而形成的组合体，它们在运动时彼此之间应该有确定的相对运动”机械工程专业英语的特点2.语法特点(2)机电专业英语由于要表述较复杂的概念，因此句子结构具有句子长、定语从句多、名词化结构多，非限定性谓语结构、倒装、省略、分隔结构随处可见，常出现句子套句子的情况，给阅读理解上带来了极大的困难。比如：Itismuchbetterfordesignengineerstodoacompletejobofmaterialdevelopmentstageofdesignratherthantoleaveittotheproduction-designstage,wherechangesmaybemadebyothers,possiblylessknowledgeableaboutallofthefunctionaspectsoftheproduct.analysis,selection,andspecificationatthe机械工程专业英语的特点Itismuchbetterfordesignengineerstodoacompletejobofmaterialanalysis,selection,andspecificationatthedevelopmentstageofdesignratherthantoleaveittotheproduction-designstage,wherechangesmaybemadebyothers,possiblylessknowledgeableaboutallofthefunctionaspectsoftheproduct.择和确定工作，而不是将其留到生产设计阶段，因为在生产设计阶段材料的更换是由其他人员进行的，这些人对产品的所有功能的了解可能不如设计工程师。OrdinaryEnglishandScientificEnglish•Wemadeaholeinacorkandpusheditintoanarrowglasstube.Thenwepushedthisintotheneckofabottlewhichwehadfilledwithcoloredwater.Whenwedidthis,someofthecoloredwaterwentupintothetube.Wemarkedthelevelofthecoloredwaterinthetube.Thenweputthebottleintoapanofhotwater.•Afteraholewasmadeinacork,anarrowglasstubewasinsertedandthecorkwasinsertedintotheneckofabottlefilledwithcoloredwater.Ondoingthis,someofthecoloredwaterrosethetube.Thelevelofthecoloredwaterinthetubewasmarked.Thenthebottlewasplacedintoapanofhotwater.OrdinaryEnglish通俗化：常用词汇用得多ScientificEnglish专业化：专业术语用得多单义性：词义相对单一，因专业而不同物称化：多用物称，以示客观现时性：叙述事实多用现在时被动性：句子倾向于用被动复杂性：复杂单句用得多，复合句用得多书面化：长句用得多，书卷气浓多义性：一词多义，使用范围广人称化：人称丰富，形式多样多时性：描述生活，时态多样主动性：句子倾向于用主动态简单性：单句、散句用的多口语化：口语用得多，随意灵活CourseContentConventionalMachiningProcessesNontraditionalMachiningProcessesToleranceandFitsLocationandFixturesGearTransmissionCNCMachiningCentersAutomaticControlTransducersUnit5ConventionalMachiningProcessesCanyougivemealistofmachiningprocesses?TuringBoringMillingDrillingGrindingPlanning…车削、镗削、铣削、钻削、磨削、刨削…Unit5ConventionalMachiningProcesses5.1IntroductionConventionalmachiningisthegroupofmachiningoperationsthatusesingle-ormulti-pointtoolstoremovematerialintheformofchips.Metalcuttinginvolvesremovingmetalthroughmachiningoperations.Machiningtraditionallytakesplaceonlathes,drillpresses,andmillingmachineswiththeuseofvariouscuttingtools.Mostmachininghasverylowset-upcostcomparedwithmachiningismuchmoreexpensiveforhighvolumes.Machiningforming,molding,andcastingprocesses.However,isnecessarywheretighttolerancesondimensionsandfinishesarerequired.Unit5ConventionalMachiningProcesses5.1译文传统机械加工是一组利用单刃或者多刃刀具以切屑形式去除材料的加工方式。金属切削意味着通过机械加工去除金属。传统的机械加工都是利用不同的刀具在车床、钻床和铣床上进行的。与成型加工、锻压和铸造工艺相比，大多数机械加工的生产准备成本都较低，然而如果是大批量生产，其成本要高得多。当对零件的尺寸公差和光洁度要求较高时，机械加工是很有必要的。Unit5ConventionalMachiningProcesses5.2TurningandLatheTurningisoneofthemostcommonofmetalcuttingoperations.Inturning,aworkpieceisrotatedaboutitsaxisassingle-pointcuttingtoolsarefedintoit,shearingawayexcessmaterialandcreatingthedesiredcylindricalsurface.Turningcanoccuronbothexternalandinternalsurfacestoproduceanaxially-symmetricalcontouredpart.Partsrangingfrompocketwatchcomponentstolargediametermarinepropellershaftscanbeturnedonalathe.Apartfromturning,severalotheroperationscanalsobeperformedonlathe.marinepropellerUnit5ConventionalMachiningProcessesWords&expressionsaxially['æksiəli]adv.轴向地symmetrical[si'metrikəl]a.对称的cylindrical[si'lindrikl]a.圆柱形的contoured['kɔntuəd]a.显示轮廓的，与某种形体轮廓相吻合的译文:在金属切削加工操作中，车削是最常见的一种。在车削过程中，工件绕其轴线回转，单刃车刀沿工件进给，切除掉多余的材料，最后形成要求的圆柱形表面。车削可以加工外面和内表面以形成具有轴对称的成形工件。从怀表的零件到大直径的船用螺旋桨轴都可以在车床上加工。除了车削，还有另外几种加工操作都可以在车床上进行。5.2TurningandLatheBoringandinternalturning.Boringandinternalturningareperformedontheinternalsurfacesbyaboringbarorsuitableinternalcuttingtools.Iftheinitialworkpieceissolid,adrillingoperationmustbeperformedfirst.Thedrillingtoolisheldinthetailstock,andthelatteristhenfedagainsttheworkpiece.Whenboringisdoneinalathe,theworkusuallyisheldinachuckoronafaceplate.Holesmaybeboredstraight,tapered,ortoirregularcontours.Boringisessentiallyinternalturningwhilefeedingthetoolparalleltotherotationaxisoftheworkpiece.5.2TurningandLatheWords&expressionstailstock['teilstɔk]n.尾座chuck[tʃʌk]n.卡盘，夹头译文:利用镗杆或合适的内圆车刀可以进行镗削和车内圆