专业英语PPT演讲稿.docx

专业英语PPT演讲稿

第一篇：专业英语PPT演讲稿1、Lathe[leið]2、ValueoftwoyuanofthethirdseriesoftheRMB——theturner3、Alatheisamachinetoolwhichrotatestheworkpieceonitsaxistoperformvarious['vεəriəs]operationssuchascutting,sanding(砂磨),knurling['nə:liŋ](滚花),drilling,ordeformationwithtoolsthatareappliedtotheworkpiecetocreateanobjectwhichhassymmetry['simitri](对称)aboutanaxisofrotation.（centerlathe，verticallathe）4、HistoryThelatheisanancienttool,datingatleasttoancientEgypt['i:dʒipt]andknownandusedinAssyria[ə'siriə]andancientGreece[ɡri:s].Theorigin['ɔridʒin,'ɔ:-]ofturningdatestoaround1300BCwhentheAncient['einʃənt]Egyptians[i:'dʒipʃənz]firstdevelopedatwo-personlathe.（Onepersonwouldturnthewoodworkpiecewitharopewhiletheotherusedasharptooltocutshapesinthewood.）AncientRomeimprovedtheEgyptiandesignwiththeadditionofaturningbow.IntheMiddleAgesapedalreplacedhand-operatedturning,（freeingboththecraftsman'shandstoholdthewoodturningtools.Thepedalwasusuallyconnectedtoapole,oftenastraight-grainedsapling.）Thesystemtodayiscalledthe“springpole”lathe.Springpolelatheswereincommonuseintotheearly20thcentury.DuringtheIndustrialRevolution,mechanized['mekənaizd]powergeneratedbywaterwheelsorsteamengineswastransmittedtothelathevialineshafting,(allowingfasterandeasierwork.Metalworkinglathesevolvedintoheaviermachineswiththicker,morerigidparts.)Betweenthelate19thandmid-20thcenturies,inpidualelectricmotors['məutə]ateachlathereplacedlineshaftingasthepowersource.Beginninginthe1950s,servomechanism[,sə:vəu'mekənizəm,'sə:vəu,me-](伺服机构)wereappliedtothecontroloflathesandothermachinetoolsvianumericalcontrol,(whichoftenwascoupledwithcomputerstoyieldcomputerizednumericalcontrol.)TodaymanuallycontrolledandCNClathescoexist（共存）inthemanufacturingindustries['indəstri].5、Description：PartsExplanationofthestandardcomponentsofmostlathes:•Bed床身:Usuallymadeofcastiron.Providesaheavyrigidframeonwhichallthemaincomponentsaremounted.•Ways床身导轨:Innerandouterguiderailsthatareprecisionmachinedparalleltoassureaccuracyofmovement.•Headstock['hedstɔk]床头箱，主轴箱:mount