外文翻译---通过立式六轴控制并应用超声振动加工锐角转角 英文版.doc

1ManufactureofOverhangingSharpCornerbyMeansof6-AxisControlMachiningwiththeApplicationofUltrasonicVibrationsfelicianoH.JAPITANA*,koichiMORISHIGE*,shugoYASUDA*andyoshimiTAKEUCHIThestudyproposesanewmachinemethodtocreatancreateanoverhangingsharpcorner.Sharpcornersonoverhangingsurfacesaredifficulttomachineinconventionalwayorevenin3to5-aixsEDMespeciallyifthesurfaceshavedifferentangles.Thisisduetothelimitationofthefeeddirectionandthestructureoftheelectrodewhereinitmustbesymmetricalwiththetargetshape.Inpresentresearch,wetrytomachinethesharpcornerwithoverhangingsurfacesusingthenewmachiningmethod.The6-axiscontrolmachiningisappliedtosetanon-rotationaltoolatanarbitrarypositionwitharbitrarypositionwitharbitraryattitudeagainsttheworkpiece.Duringcutting,theultrasonicvibrationisappliedonthecuttingedgeofthetool,whilethetooltravelsalongthefeeddirection.Asthecuttingisperformed,the6-axis(X,Y,Z,A,B)movesimultaneously,dependingonthetoolattitudeatacertaincuttingpoint.Formtheexperimentalresults,itisshownthatthe6-axiscontrolultrasonicvibrationcuttingiscapableofproducingasharpoverhangingsurface.KeyWords:6-axisControlledCutting,CAD/CAMSystem,BoreByteTool,OverhangingSharpCorner,UltrasonicVibrationCuttingTool1.introductionTheflexibilityofproductsmaybeextendedgreatlyiftherestrictioninmanufacturingprocesscanbeminimizedoreliminated.Ifrotationaltoolssuchasballendmillsorsquareendmillsareusedintheproductionofamouldwithanoverhangingsharpcorner(OHSC),itseemsdifficulttoclearlyobtainthetargetshapewithsharpedgelines.Thisisduetotheresultofprocessingwiththerotationaltools,Whicharesymmetricalwiththerotation.Thearc-likeradiusremainsareproducedonadjoiningsurfaces,asshowninFig.1Conventionally,mostofoverhangingorinclinedsurfacecanbemachinedbysettingtheworkpieceatacertainangleinthevise,swivellingtheuniversalvise,orbysettingthetoolheadtoacertainangleandfeedingthecuttingtoolhead,asshowninFig.2(a).Inthisprocess,theoverhangingsurfacesandthesharpedgesatthebottomareproduced.However,ifthetargetisanOHSCconsistingoftwooverhangingsidesurfaces,andtheinclinationangleofsurfaceisnotuniform,theprocessingofthetargetshapeisdifficulttoachievesincethecuttingdirectionintheprocessisfixedandlimitedonlytolinearcutting.Thus,itneedsalotofjigsandfixturestoholdaworkpiece,toposition2correctlywithrespecttoamachinetoolandtosupportitduringmachining.Fig.16-axiscontrolmachiningusingrotationaltool3Fig.2methodofproducingsharpcornerwithoverhangingsurfacesTheotherpossiblemethodtoproducesuchashapeismulti-axisElectricDischargeMachining(EDM),asshowninFig.2(b).However,evenusingthismethod,itisdifficultorimpossibletoproduceanOHSCwithdifferentangle.Itneeds6degreesoffreedomtofullyexecutethemachiningoftherequiredshape.Inthepreviousresearches,ultrasonicvibration(USV)wasappliedinturningofductilematerialandmillingofglassfiber-reinforcedplastic.ThecuttingforcewithUSVisconsiderablyreduced.However,intheformerprocess,theworkpieceisrotatedormovestotowardsthecuttingtool,andinthelatter,machiningislimitedonlyto2or3axiscontrolone.Intheotherfieldofresearch,multi-axiscontrolmachinetoolisusedtocompleteamachininginonesetup,whichleadstotheproductionofworkpiecewithhighaccuracyandqualityandtothereductioninmachiningtime.Inthisstudy,6-axiscontrolcuttingusinganon-rotationalcuttingtoolwiththeapplicationofultrasonicvibration(USV)isused,asshowninFig.2(c).ItisappliedtoscrutinizethevalidityofthemethodinthefabricationofOHSC,TheC-axisrotatesthenon-rotationaltoolsimultaneouslytogetherwithX,Y,Z,AorBaxisduringmachining.ThemovementoftheaxesisbasedonthetoolattitudeandthecuttingpointgeneratedbyadevelopedCAMsoftware.TheCAMprogramgeneratesacollisionfreetoolpathtoassurethesafetyoftheprocess.The6-axiscontrolmachinetoolprovideseasilythemachiningcapabilityofOHSC,since6degreesoffreedommakethemachiningexecutefullytherequiredproductshape.Also,withtheapplicationofUSV,aborebytetoolisutilizded,consideringitssizeandstiffnessduringmachiningoperationsincethecuttingforceisgreatlyreduced.2.ExperimentalprocedureTheexperimentsteupisshowninFig.3,whereintheworkpieceismountedonthetableofthe6-axiscontrolmachiningcenter.TheborebytetoolismountedintheUSVtoolusinganadaptor.TheUSVtoolisturn4mountedonthemainspindleofthe6-axiscontrolmachiningcenter.Multi-axiscontrolmachinetoolandborebytetoolThe6-axiscontrolmachiningcenterusedinthestudyisshowninFig.4.Themachiningcenterprovidesmulti-axisCNCmachinetools.The6-axiscontrolmachinetoolhas3rotationalaxesA,BandC.ItisconstructedbyaddingtherotationalfunctionConthemainspindleofa6-axiscontrolmachiningcenterwhichhas2rotationalaxes,namely；A,whichisarotarytiltingtableandB,whichistherotaryindextable.TheminimumunitfortranslationmovementX,YandZis1m,andthatofrotationaloneA,BandCis0.36arcsecond.InthecaseofcuttingofOHSC,Aaxisisusedfordeterminationofsidesurfaceandtheinclinationangleofsharpcorner,Baxisforworkpiecerotation,Caxisfordeterminationofcuttingtooldirection,XandYaxisforthedeterminationoffeeddirectionoffeeddirectionwhilethedepthofcutisdeterminedbyZaxis.Fig6showsthenon-rotationalcuttingtool(borebytetool)usedinthestudy.Itismadeoftungstencarbideusuallyusedherein6-axiscontrolcutting.Thetotallengthanddiameterofthetoolare70mmand6mmrespectively.