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洛阳理工学院毕业设计(论文)洛阳理工学院毕业设计(论文)谢辞在本次毕业设计《小吨位自调式焊接滚轮架机械结构设计》过程中,指导老师闫红彦老师给予了极大的帮助,耐心的给我讲解滚轮架的工作原理,推荐了非常实用的相关设计资料,并修改不合理的结构,因此我才逐渐的有了设计思路并完成该滚轮架的设计,对此,我表示衷心的感谢!设计之初,崔琦老师,张立峰老师辛苦的带着同学们去毕业实习,我在实习过程中见到了滚轮架,使我对滚轮架有了比较直观的认识,对我的毕业设计有较大的帮助,所以非常感谢老师的辛苦!另外,在焊接滚轮架的设计过程中用到了各种相关知识,所以也要感谢我本科四年来所有教我的老师!在设计过程中同学们也给我了许多建议,帮助我解决了很多问题,对此,向同学们致以谢意!参考文献王政.焊接工装夹具及变位机械 •北京:机械工业出版社.2001陆文滔.焊接胎夹具设计•焊接技术.1994.1.40~41[3]张龙.机械设计(第一版).北京.国防工业出版社.2006[4]方洪渊.焊接结构学.北京:机械工业出版社.2008.4(2010.9重印)管道焊接技术•顾纪清•阳代军主编.北京•化学工业出版社,2005焊接冶金学(基本原理) /张文钺编著•北京.机械工业出版社.1996焊接冶金学•材料焊接性/李亚江主编.北京.机械工业出版社.2006焊接结构生产及设备/周浩森主编.北京.机械工业出版社.1999机械设计基础/杨可桢等主编.5版北京.高等教育出版社.2006吴宗泽.罗圣国主编.机械设计课程设计手册.3版.北京.高等教育出版社.2006王纯详主编.焊接工装夹具设计.化学工业出版社.2011王政编著.焊接工装夹具及变位机械性能设计选用 .机械工业出版社.2008清华大学吴宗泽罗圣国.机械设计课程设计手册.北京科技大学.2009江焕中.焊接方法与设备.机械工业出版社.1998杨峰.Pro/E曲面设计技巧与实例.北京.中国铁道出版社.2002林清安.Pro/E2001零件设计与工程图.北京.2002甘永立主编.几何量公差与检测.上海.上海科学技术出版社.2005方昆凡主编.公差与配合技术手册.北京.北京出版社.1999李庆华主编.材料力学.第二版.成都.西南交通大学出版社.2002成大先主编.机械设计手册.第四版.北京.化学工业出版.2002朱孝录主编.机械传动装置选用手册 .北京.机械工业出版.1999刘艳革.焊接用自调式滚轮架设计 ..第2期P103.化工机械1998孙景荣.实用焊工手册.第三版.北京.化学工业出版社.2007外文资料翻译EXPERIMENTINTOTHEAXIALDRIFTINGOFAWELDINGROLLERBEDThebasictheoryoftheaxialdriftingofthecylinderofawelding rollerbedisintroducedinthepaper,andatthesametimeexperimentandstudyonthemechanismoftheaxialdriftingofthecylinderhavebeendoneonanexperimentalmodeloftheweldingrollerbed.Itisshownthatthemaincauseoftheaxialdriftingofthecylinderliesintheexisteneeofaspiralanglebetweenthecylinderandthecylinderandtheroller.therelativeaxialmotionsbetweentherollerandthecylinderarecomposeofspiralmotion,elasticslidingandfrictionalsliding.Thetheoryofcompatiblemotionandnon-compatiblemotionisputforwardfortheaxialmotionsofthecylinder.therelativeaxialmotionsofthecylinder.Therelativeaxialmotionbetweentherollersandthecylinderiscoordinatedbyelasticslidingandfrictionalslidingbetweenthem.Inweldingproduction,theassemblyandcircularseamweldingofrotarywork-pieces,suchasaboiler,apetrochemicalpressurevesselandsoon,areconductedon;aweldingrollerbed.WhenrotatingOnaweldingrollerbed.Thecylinderwillinevitablyproduceaxialdriftingduetomanufacturing,assemblingtoleraneeoftheweldingrollerbedandthecylinder'surfaceirregularity(divergingfro-manidealrotarywork-piece),thustheweldingproceduremaynotbecarriedoutsuccessfully.Itisnecessary,therefore,tostudythemechanismoftheaxialdriftingofthecylindertosolvetheproblemoftheaxialdriftingofthecylinderincircumferentialwelding.Theresultsoftheresearchwillbenefitthestudyinganddesigningofanti-driftingweldingrollerbed.especiallytheanalysisoftheappliedforcesonthebed,andleadtodeterminingthemanufacturingandassemblingtoleraneeofthebed,andprovidingthebasisoftheoryforthemechanicaladjusting modetoavoidaxialdrifting,theadjustingmodeofclosedcircuitinthecontrolcircuit,andtheselectionoftheadjustingvalue.Aweldingrollerbedisgenerallycomposedoffourrollers.Drivenbythedrivingroller,thecylindermakesarotaryuniformmotionarounditsaxis(showninFig.1),duringwhichthecircumferentialweldingprocedureiscarriedout InFig.1,aisthecentralangle,Sisthesupportingdistanee,Listhespanoftheroller.andV,isthecircularlinearvelocityofthecylinder,alsonamedtheweldingvelocitytoo.brivini;roher rolkr卜i当】Welding bedandcykndcfTheaxisofthecylinderwillbenotparalleltothatofarolleriftherollerisdeflectedbyacertainanglefromthedealposition,orifthecentersofthefourrollerslieintheverticalofasimplequadrilateral,orifthecentersofthefourrollersarenotonthesameplane,orifthecirca-laxityofthecylinderisirregularbecauseofdeviationinmanufacturingandassembling.Thus.thecylinderwillinevitabilitymovealongitsaxiswhenrotatingonabedthecontactofthecylinderandarollercanbeconsideredaspointcontactifcylindersaxisandroller 'saxisdonotlieinsameplane.SupposePisthepointofcontact.thecylinder'normalplaneAisdefinedbytheplaneonwhicharethecylinder'saxisandgenerationnacrossthepointoftangentonthecylinder(showninfig2)makecylinder 'stangentplaneBacrosspointP.Thus,planeAisverticaltoplaneB.LCisacylinder'tangentacrossPandliesinplaneB.Iristheroller tangentsicrossthesamepointP,andliesinplaneBalso.Ingeneral,0diefinedastheaxialdeviationanglebetweentheroll!er'saaisdthecylinder'asis;pisdefinedasthespiralanglebetweengenerationnandm.aprotectivelineobtainedbyprojectingtheroller'sgenerationmacrosspointponplane:andYsdefinedastheprotectiveangle
betweennandm,aprotectivelineobtainedbyprojectingmonplaneA.Fig.3indicatesthattherela-relationshipamongthethree anglesistan:=tan2r・tan2InFig.3,SB,SBandSy,arecalledthespiraldisplace-mentvector,theaxialdeviationdisplacementvectorandtheprotectivedisplacementvectorrespectively.theirrelationshipbeing:S:2=S為S2Fig.2GeometricrelationshipbetweenthecylindeFig.3RelationshipbetweentheanglevectorFig.4ComponentofaxialvelocityFig.2GeometricrelationshipbetweenthecylindeFig.3RelationshipbetweentheanglevectorFig.4ComponentofaxialvelocityBecausetheroller'saxisisnotparalleltothecylinderentralline,thereBecausetherollerisaspiralangleBbetweenVr,.andVc,onthepointofcontact(showninFig.2).Whentherollerandcylinderrotatesynchronisticallyaroundtheirownaxes,driven bytangentialfrictionalforce.aspiraleffectwilloccurbecauseofthedifferentlinearvelocitydirectionbetweentherollerandthecylinderatpointPofcontactThe cylinderhasacomponentofaxialvelocity.V列=Vc・tan:ix/pwhereVcisthecircularlinearvelocityofthecylinder. Vajisthecylinder'saxialcomponentvelocityexertedbysinglerolle.Becauseoftheexisteneeofaspiralangle,anaxialforceFajactsoncylinder. When theforceislessthanthemaximumaxialfrictionalforcefNj(wherefisthefrictionfactor,andNjisthenormalpressurebetweenasinglerollerandthecylinder),thecylinderwillslideelasticallyovertherolleralongtheaxial direction[2~3] Thecomponentoftheslidingvelocityise eFajVcajfNjwhereeistheelasticslidingfactorformetallicroller.e=0.001~0.005.WhenFajisgreaterthanthemaximumfrictionalforcefNj,thecylinderwillmakea frictionalslidingovertheroller.TheslidingresistaneeisfNj[3].ThecomponentofthefrictionalslidingvelocityonCylinderisVajthemagnitudeanddirectionofwhichcanbedeterminedbytheuniversalrelationshipbetweenthecylinderandthefourrollersFrictionalslidingwillleadtothewearandtearofthesurfaceoftheylinderandtherollers.whichisunexpectedinweldingproductionWhenthecylinderdrifts,abovethreekindsofmotiondonotoccursimultaneously‘Therefore.theaxialdriftingvelocityofthecylinderisnotthealgebraicsumofthethreecomponentsofvelocityInthecaseofelastic sliding,theaxialvelocityis.Underidealconditions,whenspiralanglesBjbetweenthecylinderandthefourrollersareallthesame,thatis:|】'1=-2--3='■4thecylinderwillmoveitscompatiblespiralmotion.Twocategoriescanbeclassifiedtoanalyzetheaxialmotionofthecylinder:gravity.thecgravity.thecWhentheredoesnotexistanaxialcomponentduetoylinder'axialdriftingvelocityis:Va=Vc*tanBWhenthereexistsanaxialcomponent ofgravityGathereexistsanaxialforce onthecylinder.Now,theaxialforcesexertedonthefourrollershavethesamedirectionalAndmagnitude,thevaluebeingequaltoGathecomponentofspiralvelocity,thereexistcomponentofelasticonthecylinderthecylinder'saxialdriftingvelocityiseGaVcVa=fNjIngeneral.spiralangles Bjbetweenthecylinderandthefourrollersarenotequaltoeachotherinsizeanddirection.i.e.thegeometricrelationshipsbetweenthecylinderandthefourrollersareallinconsistentTherefore,thecomponentsofthecylinder 'saxialveloagainstfourrollers(i.eVc*taBj)arenotidenticaltoeachanother.ThecylinderwillmovewithaxialcompatiblemotionTheaxialvelocitiesofthecylinderagainst thefourrollersshouldbethesamebecausethecylinderisconsideredasarigidbodyasawholeandithasonlyoneaxialvelocity.However.forsomeroller,Vc.tanBjandthecylinder'srealaxialvelocityarenotlikelytobethesame,soanaxialfrictionalforcealmostcertainlyappearsbetweenthisrollerandthecylinderThefollowingtwocategoriescanbeclassifiedtodiscussthenon-compatibleaxialmotionofthecylinderaccordingtoThefrictionalforcemagnitude:WhentheaxialfrictionalforceserectedbyeachrollerandthecylinderarealllessthanthemaximumaxialtheactionofthecylinderagainstthefrictionalforcetheactionofthecylinderagainsttherollersproduceselasticslidingTheaxialmotionbetweenanindividualrollerandthecylinderis
coordinatedbytheirelasticslidingVa»Sj竺空fNjwhentheaxialvelocity ofthecylinderisconstant,thealgebraicsumofsaxialforceserectedbyfourrollersshouldbezeroiftheaxialcomponentofgravityisignored.i.e.4cylinder、'Faj=0j=1andthereisaccordingtotheabovetwoeFajVcomponentofgravityisignored.i.e.4cylinder、'Faj=0j=1andthereisaccordingtotheabovetwoeFajVcfNjfNjj占Faj=0equations,theaxialdriftingvelocityofthe1 4Va V'tan-4j-Where0.25刀TanBtepresentstheintrinsicattributesofthewelding.Otherbedundertheconditionthatonlythecylinderagainstallrollsproduceselasticslidingthismaybecalledthespiralrateofthecylinder'sspiralmotionWhentheaxialfrictionalforceerectedbysomerollerandthecylinderisgreaterthanthemaximumaxialfrictionalforce,frictional slidingoccursbetweenthecylinderandthisrollerThen.themaximumaxialforceisactingonthebearingoftheroller,itsvaluebeingFfmax二fFNfmaxBecauseoftheexisteneeofthisfrictionalsliding.theAxialmotionbetweenanindividualrollerandthecylinderisnotcoordinatedbytheirelasticsliding.Nowtheaxialnon-compatiblemotionofthecylinderisdeterminedbytherelativerelationshipsbetweenthecylinderandthefourrollers.Itisdifficulttowriteageneralcompatibleequationofthecylinder'saxialdriftingvelocitybecausethiskindofconditionisverycomplex.Thefollowingisfurtheranalysisanddiscussionoftheproblem.Atfirst,foreaseinanalyzingproblem,thespiral angleaverageisdefinedas—14一丄—j4j4andtherelativespiralangleas匚=:t--Arrange,B1ntheorderfrombigtosmallandthenfrompositivetonegative,expressedasB(j).thenB1>B2>B3>B4Similarly,thenormalforcebetweenthecylinderandarollercanbeexpressedasN(j).andtheaxialforceasFj<fNjIngeneral,theaxialmotionofthecylinderdeterminedbythespiralangleaverageBisdefineasthecompatiblecomponentoftheaxialmotion,isvelocitybeing.Theaxialmotionofthecylinderdeterminedbytherelativespiralangle Bjisdefinedasthenon-compatiblecomponentofaxialmotion,itsvelocitybeingexpressedasVa\nAnalysisshowsthatVa''isdeterminedbytheequilibrium conditionthefourrolleraxialforceswhenthecylindermovesalongaxialdirectionataconstantvelocity.wherenottaking intoaccountofthefunctionofgravity'axialcomponent.Supposingthatthecylindermakesanon-compatiblecomponentofaxialmotionwiththemaximumrelativespiralangleB(I).itsvelocityisVan=Vc・taniThenthefouraxialforcescannotbeinequilibriumF1-(F2+F3+F4)<0Becausethereislittlediffereneeamongfournormal
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