数控镗铣床的建模与分析 外文翻译

MODELINGANDANALYSISOFASUPERHEAVYNUMERICCONTROLBORINGANDMILLINGMACHINEABSTRACTTHESTRUCTUREOFASUPERHEAVYNUMERICCONTROLBORINGANDMILLINGMACHINEISINTRODUCEDTHEDYNAMICMODELISESTABLISHEDONTHESIMPLIFIEDSTRUCTUREMODELTHEVIRTUALPROTOTYPEOFTHEMACHINETOOLISGIVENFORDYNAMICANALYSISTHENTHEFEMMODELISESTABLISHEDONTHEVIRTUALPROTOTYPEFINALLYTHESTATICSTIFFNESS,MODAL,RELIABILITYANALYSESAREPERFORMEDKEYWORDSSUPERHEAVYBORINGANDMILLINGMACHINEMODELINGFEMDYNAMICANALYSIS1ACERTAINTYPEOFOVERWEIGHTCNCBORINGANDMILLINGMACHINETHEOVERWEIGHTCNCBORINGANDMILLINGMACHINEMACHININGCENTERINTRODUCEDHEREISMAINLYUSEDFORLONG,OVERWEIGHT,ULTRAHIGH,SPECIALSHAPEDANDCOMPLEXWORKPIECESTHELANDINGPLATFORMISUSEDASTABLE,THUSTHEWORKPIECEONTHEPLATFORMISPLACEDINANOPENSPACE,SOPROCESSISNOTLIMITEDBYTHESIZEANDWEIGHTWORKPIECETHEDIRECTIONOFMOVEMENTOFTHECOLUMNONTHEBEDISDEFINEDASXAXIS,THEDIRECTIONOFMOVEMENTOFTHESPINDLEBOXALONGTHEBEDISDEFINEDASYAXIS,ANDTHEDIRECTIONOFBORINGAXISISDEFINEDASZAXISMULTISURFACEMACHININGCANBEREALIZEDBYONEFIXTURESINCETHEHOSTANDTHEROTARYTABLECOULDWORKATTHESAMETIMEINTHISMACHINETOOL,THEREARETHREEHYDROSTATICGUIDEWAYSWHICHARECOLUMNMOVEMENTGUIDE,SPINDLEHEADMOVEMENTGUIDEANDTHERAMMOVEMENTGUIDETHEMAINDRIVEHAS3VARIABLESPEEDSTHEBEDISINSTALLEDONTHEFLOOR,THESLIDEMOVEWITHRACKONTHEBED,ANDTHECOLUMNWASINSTALLEDONTHESLIDETHESPINDLEBOXMOVESALONGTHECOLUMNWHICHISDROVEBYTHEBALLSCREWSPINDLEBOXHASAFRAMESTRUCTURE,ANDTHERAMMOVESTHROUGHTHESQUAREHOLEINTHEHEADSTOCKTHEBORINGAXISMOVESINTHERAMHEADSTOCK,RAM,BORINGAXEAREALLDROVEBYSCREWADUALRACKANDPINIONISUSEDONTHECOLUMNTOELIMINATETHEGAPINTHEDRIVINGSYSTEMTHEREARE4ACCURACYCOMPENSATIONSWHENRAMSTRETCHESOUTTHISMACHINETOOLISEQUIPPEDWITHCNCTURNTABLE,ANDTHEMACHINETOOLCANACHIEVEANINEAXISCONTROLANDFIVEAXISLINKAGEFIGURE1STRUCTUREANDDYNAMICMODELOFOVERWEIGHTCNCBORINGANDMILLINGMACHINE2DYNAMICMODELANDANALYSISTHEVIRTUALPROTOTYPEMODELOFTHEMACHINETOOLISESTABLISHEDSOMEDETAILEDSTRUCTURESOFTHEMACHINETOOLARESIMPLIFIEDTOSOMEEXTENTFORTHEDYNAMICANALYSISTHERELATIONSHIPSBETWEENTHEVARIOUSCOMPONENTSAREDEFINEDACCORDINGTOTHESTRUCTURALFEATURESINTHESIMULATIONANALYSIS,KINEMATICCONSTRAINTSAREAPPLIEDTOTHEACTIVEJOINTSINSTEADOFTHEMOTORSACCORDINGTOTHETECHNICALSPECIFICATIONREQUIRED,THESPEEDOFTHEDRIVECOMPONENTSISSETTOACERTAINRANGETHENTHEDISPLACEMENT,VELOCITY,ACCELERATIONCANBECALCULATEDRESPECTIVELYFOREXAMPLE,ASIMPLEHARMONICMOTIONISIMPOSEDTOTHESLIDEV100SIN314T,THENTHEMOVEMENTOFTHEHEADSPOINTOFTHETOOLCOULDBEOBTAINEDASFIGURE2ANDFIGURE3FIGURE2DISPLACEMENTANDVELOCITYCURVEOFHEADSPOINTOFTHETOOLFIGURE3ACCELERATIONCURVEOFHEADSPOINTOFTHETOOL3STATICSTIFFNESSANALYSISTHEOVERALLANDTHREEDIRECTIONSDEFORMATIONARESHOWNINFIGURE5MAXIMUMDEFORMATIONVALUEOFTHEMACHINETOOLIS0165MMWHICHOCCURREDATTHETOPOFTHECOLUMNTHEMAXIMUMDEFORMATIONVALUEOFXDIRECTIONANDIS015MMANDTHEONEOFXDIRECTIONANDIS0087MM,WHICHOCCURREDATTHEENDOFTHESPINDLEBOXTHEVALUEOFTHEOVERALLSTIFFNESSOFTHEMACHINETOOLIS471,693N/MM,THEONEOFXDIRECTIONIS16,5228N/MM,YDIRECTION923,6145N/MMANDZDIRECTION427,2574N/MMFIGURE4DEFORMATIONMAPSTHROUGHTHEABOVEANALYSIS,ITISSHOWNTHATTHESTIFFNESSISWORSTINXDIRECTION,WHICHISDUETOTHEHYDROSTATICGUIDEWAYINXDIRECTION,ANDBESTINYDIRECTIONTHESTIFFNESSOFTHEMACHINETOOLISMADEUPTHESTIFFNESSOFITSCOMPONENTSSO,FROMTHEVIEWOFBALANCE,THESTIFFNESSOFTHEVARIOUSCOMPONENTSSHOULDBEMADEROUGHLYEQUALINORDERTOMAKETHESTIFFNESSOFTHEWHOLEMACHINETOOLBETTERFOREXAMPLE,THEFOLLOWINGMEASURESCOULDBETAKENTOINCREASETHESTIFFNESSOFTHEWHOLEMACHINETOOLCHOOSETHECONTOURSIZEANDSHAPEOFTHECOMPONENTREASONABLYARRANGEPARTITIONSANDWIRERODAPPROPRIATELYIMPROVETHEMACHININGACCURACYANDSURFACEFINISHOFTHEJOINTSURFACES4MODALANALYSISONTHEMODELOFTHEHEAVYBORINGMILLINGMACHINE,ANSYS,THEMECHANICALANALYSISSOFTWARE,ISUSEDTOANALYZETHEWHOLEMACHINETOOLFORTHEPURPOSEOFMAKINGTHEANALYSISMOREEFFICIENT,THECOMPUTINGTIMESHORTER,ANDSIMULATINGTHEREALSITUATIONOFTHEMACHINEATTHESAMETIME,ASERIESOFMEASURESARETAKENTOSIMPLIFYTHECONNECTRELATIONSHIPBETWEENDIFFERENTPARTSOFTHEMACHINEAFTERALLTHESEWORK,THEMODALANALYSISRESULTISOBTAINEDTHEFIRSTORDERFREQUENCYWAS24532HZ,ANDITSCORRESPONDINGMODEOFVIBRATIONWASSWINGINGFOREANDBACKTHESECONDORDERFREQUENCYWAS2645HZ,ANDITSCORRESPONDINGMOTIONWASSWINGINGLEFTANDRIGHTTHETHIRDORDERFREQUENCYWAS95451HZ,ITTWISTEDFROMLEFTTORIGHTTHEFOURTHORDERFREQUENCYWAS141HZ,ITTWISTEDFOREANDBACKTHEFIFTHORDERFREQUENCYWAS14424HZ,THEMACHINESWUNGNOTONLYFROMLEFTTORIGHT,BUTALSOFROMUPSIDETODOWNSIDETHESIXEDORDERFREQUENCYWAS17411HZ,THEMACHINESWUNGFOREANDBACK,ANDALSOSWUNGFROMUPSIDETODOWNSIDEATTHESAMETIMETHERESULTISSHOWNINFIGURE5FIGURE5THESIXMODESOFTHEWHOLEMACHINETOOLFORAVIBRATIONSYSTEM,ITSAMPLITUDEISINVERSELYPROPORTIONALTOITSNATURALFREQUENCYUNDERCERTAINCONDITIONSASWEALLKNOWN,THENATURALFREQUENCYOFAMACHINESYSTEMISDECIDEDBYTHENATURALFREQUENCYOFITSWEAKPARTS,THEREFORETHEVIBRATIONPHENOMENACANBEIMPROVEDEFFECTIVELYBYINCREASINGTHENATURALFREQUENCYOFTHEWEAKPARTSINTHEELASTICSYSTEMITISKNOWNTHATRESONANCEWILLOCCURWHENTHEVIBRATIONFREQUENCYISAPPROACHINGTOTHENATURALFREQUENCYOFTHESYSTEMSOWESHOULDMAKETHEDISTURBINGFREQUENCYFARAWAYFROMTHENATURALFREQUENCYOFTHEWEAKPARTSINONEMACHINEPROCESSINGSYSTEM5STRESSANALYSISBYAPPLYINGLOADONTHEMACHINETOOL,WEGOTTHESTRESSDISTRIBUTIONINTHEFIGURE6FIGURE6STRESSDISTRIBUTIONTHEMAXIMUMSTRESSVALUEIS4593MPATHEALLOWEDSTRESSIS250MPA,WHICHHAPPENSATTHESLIDINGSEATANDMILLINGAXISTHEMAINREASONSOFTHESESTRESSESAREMECHANICALGRAVITYANDOUTSIDEFORCE6FATIGUEANALYSISFROMTHELIFECONTOURFIGUREOFTHEMACHINETOOL,WECANGETTHOSELIMITCYCLEINDEXOFEVERYMACHINEPARTSCAUSEDBYFATIGUE,THEMAXIMUMVALUEIS10E8,WHICHISNAMELYTHEMAXIMUMLIFETIMEOFTHEMACHINETOOLTHEMINIMUMLIFETIMEIS10E7CYCLES,WHICHHAPPENSONTHEUPRIGHTCOLUMN,THESLIDINGSEATANDTHEBASEPARTFIGURE7LIFEANDTHESAFETYFACTORMAPSAFETYFACTORCONTOURISAGROUPOFDATAABOUTFATIGUEFAILUREUNDERCERT