机械设计外文翻译英文原文1概要Word文件下载.docx

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Duringcontinuouscasting,theoscillationguidingmechanismplaysaguidanceroleinthemotionofthemould.Onlywhenthemouldvibratesalongthecorrecttrack,thequalityofthestrandcanbeensured.Sothestrandrequiresveryhighguidanceaccuracyoftheoscillationguidingmechanismforthemould.Butforinevitablegapandwearofthebearings,thefour-eccentricaxesandfour-barlinkageoscillationmechanismswidelyusedinmoderncastingwillcauseuncontrolleddeviationinmotionsofthemould,whichbadlyaffectsthequalityofthestrand.1Therefore,thesemi-andwhole-leafspringmechanismsaregraduallyusedasguidancemechanismsforthemouldinbilletandslabcontinuouscasting.2,3Inrecentyears,withfurtherdevelopmentofthesemi-andwhole-leafspringoscilla-tionmechanisms,thecascadedwhole-leafspringoscilla-tionmechanismisdevelopedabroad,4whichhasalongerlife,higherlateralrigidityandreliabilityandsoon.

However,untilnow,reportsonthisoscillationmechanismarefew.5,6Itsworkingprinciplehasbeenproposedbytheauthors,7basedonwhichdesignmethodofthecascadedwhole-leafspringoscillationmechanismisproposedinthispaperanditsexperi-mentalprototypeismanufactured.Furthermore,therigid–flexiblecouplingvirtualmodelofthecascadedwhole-leafspringoscillationmechanismisbuiltanditskinematicsanddynamicssimulationsareanalysedusingmanytypesofsoftware,suchasANSYS.Systemmodesandtheforcesappliedonleafspringsandrevolutejointsofthemechanismareanalysed,whichestablishthebasisforfurtherstudiesandapplicationofthismechanism.

Workingprincipleofcascadedwhole-leafspringguidancemechanism

Thestructureofthecascadedwhole-leafspringoscilla-tionmechanismisshowninFig.1.Itmainlyconsistsofthecascadedleafspring,vibrationtableandframe,whichcanbedrivenbymachinery（Fig.1a,orhydraulicsservo（Fig.1b,generatingdeviceofsinusoi-dalornon-sinusoidaloscillation.Andthecascadedleafspringiscomposedoffoursteelplatespringsdividedintotwosets.Allleafsprings’extensionlinesjointothecirculararccentreofthecontinuouscasterandtheirendsareseparatelyconnectedtothevibrationtableandtheframe,asshowninFig.2,andthentwosetsofleafsprings,thevibrationtableandtheframeformtwofour-barlinkageguidancedevices.Duringthemouldvibrat-ing,flexibleleafspringsproduceelasticdeformations,whichmaketwoleafspringfour-barlinkageguidancedevicesalternatelyplayaguidanceroleinthemouldwithoutanyinterferencebythegeneratingdevice.7

1TheMechatronicsandInformationEngineeringSchool,FoshanUniversity,Foshan528000,China

2CollegeofMechanicalEngineering,YanshanUniversity,Qinhuangdao066004,China

3No.2ResearchDevelopmentDepartment,Xi’anHeavyMachineryResearchInstitute,Xi’an710032,China

*Correspondingauthor,emailzhanglpok@

204ß

2010InstituteofMaterials,MineralsandMining

PublishedbyManeyonbehalfoftheInstitute

Received14November2008;

accepted16September2009

DOI10.1179/030192309X12573371383677IronmakingandSteelmaking2010VOL37NO3

Designofcascadedwhole-leafspringoscillationmechanism

Fromworkingprincipleofthecascadedwhole-leafspringoscillationmechanism,itcanbeseenthattwoleafspringfour-barlinkagescarryontheguidancetothemould.Ifdesignisunreasonable,themotionofthetwoleafspringfour-barlinkageswillinterfereduringvibration,whichwillblockthemould.Therefore,howtodesignthesetwoleafspringfour-barlinkagesbecomesthekeyproblem.

Designmethodofcascadedwhole-leafspringoscillationmechanism

Accordingtothecharactersofthecascadedwhole-leafspringmechanismdevelopedfromtheshort-armfour-barlinkage,itsdesignmethodisproposedasfollowing:

（ibasedonthedesignprinciplesoftheshort-arm

four-barlinkagesimulatingarc,8designtworigidfour-barlinkagesunderthesamebasicpara-metersofthemouldbyoptimumdesign,whichfulfiltherequirementforguidingaccuracyofthemouldsimulatingarc

（iiforsettlinginterferenceofthetwofour-bar

linkages,rigidlinkagesoptimisedinstep（iaresubstitutedbysteelplatespringswithelasticdeformationandthenformtwoleafspringfour-barlinkages

（iiibasedonthebasicprinciplesoftheshort-arm

four-barlinkage,arrangetwoleafspringfour-barlinkagesaccordingtoFig.2.Thatis,end-pointsA1,C1andA2,C2arefixedontheframe;

endpointsB1,D1andB2,D2areconnectedtothevibrationtableofthemould.Inthisway,twoleafspringfour-barlinkagesarecascaded,soacascadedwhole-leafspringmechanismisdesigned.

Calculationexample

Calculationsofparametersandguidanceaccuracyofrigidfour-barlinkages

Accordingtothegeometryrelationsandthemovementrelationshipsofthefour-barlinkageguidancedevicesofthearccaster（seeFig.2,thepositionofanypointonthemouldcanbecalculatedduringthemouldvibration.Inthispaper,takenthebottompointEontheouterarcofthemouldasanexample,formulasofthetrackandtheguidingaccuracyofpointEarededuced,aslistedinTable1,withonlyonerigidfour-barlinkageguidingforthemould.

Tocalculateconveniently,itisassumedthatl1,l2,l3andl4arerespectivelythelengthsoflinkagesofA1C1,A1B1,B1D1andC1D1,andA2C2,A2B2,B2D2andC2D2;

Sistheamplitudeofthemould;

DQistheswingangleofthelinkageofB1D1andB2D2underthemaxdisplace-mentofthemoulddownward;

Risthecaster’sbasicradius;

R1andR2areradiusrespectivelyfromthearccentretotwoendpointsoflinkagesA1C1,B1D1,A2C2andB2D2;

H1andH2aretheheightsofbothsidestothehorizontalcenterlineofthemould;

aistheincludedanglebetweenOEandthehorizontalcentrelineofthearccasterwhenthemouldisatequilibriumposition;

h1,h2,r1andr2arerespectivelytheincludedanglesbetweenlinkagesofA1C1,A2C2,B1D1,B2D2andthehorizontalcentrelineofthecaster;

DREisthesimulatedarcerrorofthemould.

Mathematicalmodelandoptimisationoflinkages

Oscillationparametersofthemouldandtheinstallationpositionsoflinkagesaretheprimarydesigningtermsoftheguidancemechanism.Takingarccasterforexample,outsidepenaltyfunctionoptimisationmethodisadoptedinoptimumdesignofthetworigidfour-barlinkages.Infour-barlinkagesdesign,itisthegoalthatthetrajectoryerrorofthemouldmeetstherequirementforguidingaccuracy.Sotheobjectivefunctionoftheoptimisationmathematicalmodelcanbewrittenbyf（x~DRE~OE’{R¡

0:

02

（1

AccordingtoTable1,itcanbeseenthatthedesignoptimisationvariablesarex~R,S,h,r,R1,R2½

T

（2

Byexperience,geometricdimensionsandinstallationpositionsoftwofour-barlinkagesmustmeetthefollowing

constraints

2Layoutofcascadedwhole-leaf

spring

amechanicdriven;

bhydraulicsservodriven

1Cascadedwhole-leafspringoscillationmechanism

Zhangetal.Cascadedwhole-leafspringoscillationmechanismformouldincontinuouscasting

IronmakingandSteelmaking2010

VOL

37

NO

3205

30D¡

R¡

50D2¡

Sjj¡

10R1w0,hw0R2wR1,rwh0:

91R¡

R2vR0:

82R¡

R1¡

91R

（3

whereDisthethicknessofbillet;

handrareincludedanglesbetweenlinkagesandhorizontalcentrelineofthecaster.Basedontheobjectivefunction（equation（1,optimisationvariables（equation（2andconstraintsestablishedinequation（3,optimisationprocedureofoutsidepenaltyfunctioniscompiledbyClanguageandtwofour-barlinkagesareseparatelyoptimumdesigned.

Optimisationresults

Inoptimisation,itisassumedthatthemouldisarrangedsymmetricallyaboutitsequilibriumpositionanditsheightH1zH25900mm;

thethicknessofthebilletD5150mm;

theguidingaccuraciesoftworigidfour-barlinkagesDRE50?

02mm.Therefore,thegeometricalparametersandtheguidingaccuraciesofthetworigidfour-barlinkagesareoptimumdesigned（Table2.Bytheoptimisedresults,rigidlinkagesaresubstitutedbyleafspringsarrangedaccordingtoFig.2;

thenacascadedwhole-leafspringmechanismisdesigned.

Experimentalprototypeofcascadedwhole-leafspringoscillationmechanism

Basedontheoptimisedresults,theexperimentalproto-typeofthecascadedwhole-leafspringoscillationmechan-ismforthemouldismanufactured,asshowninFig.3,inwhichleafspringfour-barlinkageA1C1B1D1iscomposedofleafsprings1