金属切削加工毕业设计英文翻译

Metal-cuttingprocessMetal-cuttingprocessesareextensivelyusedinthemanufacturingindustry.Theyarecharacterizedbythefactthatthesizeoftheoriginalworkpieceissufficientlylargethatthefinalgeometrycanbecircumscribedbyit,andthattheunwantedmeterialisremovedaschips,particles,andsoon.Thechipsareanecessarymeanstoobtainthedesiredtolerances,andsurfaces.Theamountofscrapmayvaryfromafewpercentto70%~80%ofthevolumeoftheoriginalworkmaterial.Owingtotheratherpoormaterialutilizationofthemetal-cuttingprocesses,theanticipatedscarcityofmaterialsandenergy,andincreasingcosts,thedevelopmentinthelastdecadehasbeendirectedtowardanincreasingapplicationofmetal-formingprocesses.However,diecostsandthecapitalcostofmachinesremainratherhigh;consequently,metal-cuttingprocessesare,inmanycases,themosteconomical,inspiteofthehighmaterialwaste,whichonlyhasvalueasscrap.Therefore,itmustbeexpectedthatthematerialremovalprocesseswillforthenextfewyearsmaintaintheirimportantpositioninmanufacturing.Furthermore,thedevelopmentofautomatedproductionsystemshasprogressedmorerapidlyformetal-cuttingprocessesthanformetal-formingprocesses.Inmetal-cuttingprocesses,theimprintingofimformationiscarriedoutbyarigidmediumoftransfer,whichismovedrelativetotheworkpiece,andthemechanicalenergyissuppliedthroughthetool.Thefinalgeometryofthetoolandthepatternofmotionsofthetoolandtheworkpiece.Thebasicprocessismechanical:actually,ashearingactioncombinedwithfracture.Asmentionedpreviously,theunwantedmaterialinmetal-cuttingprocessesisremovedbyarigidcuttingtool,sothatthedesiredgeometry,tolerances,andsurfaceroughnessareobtained.Examplesofprocessesinthisgroupareturning,drilling,reaming,milling,shaping,planing,broaching,grinding,honing,andlapping.Mostofthecuttingormachiningprocessesarebasesonatwo-dimensionalsurfacecreation,whichmeansthattworelativemotionsarenecessarybetweenthecuttingtoolandtheworkmaterial.Thesemotionsaredefinedastheprimarymotion,whichmainlydeterminesthecuttingspeed,andthefeedmotion,whichprovidesthecuttingzonewithnewmaterial.Inturningtheprimarymotionisprovidedbytherotationoftheworkpiece,andinplaningitisprovidedbythetranslationofthetable;inturningthefeedmotionisacontinuoustranslationofthetool,andinplaningitisanintermittenttranslationofthetool.CuttingSpeedThecuttingspeedvistheinstantaneousvelocityoftheprimarymotionofthetoolrelativetotheworkpiece(ataselectedpointonthecuttingedge).Thecuttingspeedforturning,drilling,andmillingprocessescanbeexpressedasV=πdnm/minWhereviscuttingspeedinm/min,dthediameteroftheworkpiecetobecutinmeters,andntheworkpieceorspindlerotationinrev/min.thusv,d,andnmayrelatetotheworkmaterialorthetool,dependingonthespecifickinematicpattern.Ingrindingthecuttingspeedisnormallymeasuredinm/s.FeedThefeedmotionfisprovidedtothetoolortheworkpieceand,whenaddedtotheprimarymotion,leadstoarepeatedorcontinuouschipremovalandthecreationofthedesiredmachinedsurface.Themotionmayproceedbystepsorcontinuously.Thefeedspeedvfisdefinedastheinstantaneousvelocityofthefeedmotionrelativetotheworkpiece(ataselectedpointonthecuttingedge)Forturninganddrilling,thefeedfismeasuredperrevolution(mm/rev)oftheworkpieceorthetool;forplaningandshapingfismeasuredperstorke(mm/stroke)ofthetoolortheworkpiece.Inmillingthefeedismeasuredpertoothofthecuttefz(mm/touth);thatis,fzisthedisplacementoftheworkpiecebetweenthecuttingactionoftwosuccessiveteeth。Thefeedspeedvf（mm/min）ofthetableisthereforetheproductofthenumberoftheteethzofthecutter,therevolutionsperminuteofthecuttern,andthefeedpertooth(vf=nzfz).Aplanecontainingthedirectionsoftheprimarymotionandthefeedmotionisdefineastheworkingplane,sinceitcontainsthemotionsresponsibleforthecuttingaction.DepthofCut(Engagement)Inturningthedepthofcuta(sometimesalsocalledbackengagement)isthedistancethatthecuttingedgeengagesorprojectsbelowtheoriginalsurfaceoftheworkpiece.Thedepthofcutdeterminesthefinaldimensionsoftheworkpiece.Inturning,withanaxialfeed,thedepthofcutisadirectmeasureofthedecreaseinradiusoftheworkpieceandwithradialfeedthedepthofcutisequaltothedecreaseinthelengthofworkpiece.Indrilling,thedepthofcutisequaltothediameterofthedrill.Formilling,thedepthofcutisdefinedastheworkingengagementaeandistheradialengagementofthecutter.Theaxialengagement(backengagement)ofthecutteriscalledap.ChipThicknessh1intheundeformedstateisthethicknessofthechipmeasured给速度vf的定义是选定切削刃上一点相对于工件的速度。对于车削和钻削，进给量f以工件或刀具的每转的相对移动量来表示；对于龙门刨削和牛头刨削，进给量f以刀具或工件每次行程的相对移动量来表示；对于铣削来说，以刀具的每齿进给量fz来表示。每齿进给量fz是相邻两齿之间的距离。所以工作台的进给速度vf是刀具齿数z，刀具每分钟转数n和进给速度fz的乘积。包含主运动方向和进给运动方向的平面被定义为工作平面，因为该平面包含决定切削作用的两种基本运动。切削深度（吃刀深度）车削的切削深度a（有时也被称为背吃刀量）是刀具切削刃切进或深入工件表面的距离。切削深度决定了最后的尺寸工件。在切削加工中采用轴向进给时，切削深度可以通过直接测量工件半径减少量来确定；在切削加工中采用径向进给时，切削深度等于工件长度的减少量。在钻削中，切削深度等于钻头的直径。对于铣削，切削深度定义为侧吃刀量ae，它等于铣刀径向吃刀深度，而铣刀轴向吃刀深度（背吃刀量）被称为ap。切屑厚度未变形状态时的切削厚度h1，就是在垂直于切削方向的平面内垂直于切削刃测量得到的切屑厚度。切削后的