Ultrasonics38(2000)7276www.elsevier.nl/locate/ultrasOne-dimensionallongitudinaltorsionalvibrationconverterwithmultiplediagonallyslittedpartsJiromaruTsujino*,TetsugiUeoka,KenichiOtoda,AtsushiFujimiFacultyofEngineering,KanagawaUniversity,Yokohama221-8686,JapanAbstractForincreasingtheavailablevibrationvelocityoftheone-dimensionallongitudinaltorsionalvibrationconverter,anewtypeofcomplexvibrationconverterwithmultipleslittedpartsinstalledinthepositionsavoidinglongitudinalnodalpositionsalongtheconverterfordecreasingthemaximumvibrationstresslevelatthevibrationnodalpartwasstudied.Thefreeendoftheconvertervibratesinanellipticalorcircularlocus.ComplexvibrationsystemswithellipticaltocircularorrectangulartosquarelocicanbeappliedeVectivelyforvarioushigh-powerapplications,includingultrasonicweldingofmetalorplastics,ultrasonicwirebondingofIC,LSIandelectronicdevices,andalsoultrasonicmotors.Theconverterwithmultipleslittedpartswasimprovedinthevibrationstresslevelandthequalityfactorcomparedwiththeconverterwithsingleslittedpart.2000ElsevierScienceB.V.Allrightsreserved.Keywords:Circularvibrationlocus；Complexvibration；Complexvibrationultrasonicwelding；Longitudinaltorsionalvibrationconverter；Ultrasonicmotor；Ultrasonicplasticwelding；Vibrationconverterwithdiagonalslits1.Introductionvibrationcharacteristicsbecausethemaximumvibrationstressalongtheconverterisdecreasedincomparisontotheconverterwithaslittedpart,andthemaximumComplexvibrationsystemswithellipticaltocircularvibrationamplitudeoftheconverterincreasessignifi-orrectangulartosquarelociareeVectiveforvariouscantly.Vibrationlocus,andvibrationvelocityandphasehigh-powerapplications.Aone-dimensionallongitudi-distributionsalongtheconverterweremeasuredbytwonaltorsionalvibrationconverterwithaslittedpartatlaserDopplervibrometers.Thenew-typeconverterslongitudinalvibrationnodalareadrivenbyalongitudi-wereusedforultrasonicplasticweldingandultrasonicnalvibrationsystemisusefulforhigh-powerapplica-motors.tionsincludingultrasonicweldingofvariousmaterials,ThemaximumavailablevibrationvelocityincreasedultrasonicwirebondingofbondingofIC,LSIandsignificantlywiththenewconverter.Weldingcharacter-electronicdevices,andalsoultrasonicmotors14.Aisticsofplasticmaterialswereimprovedbythecomplexnewtypeofconverterwithmultipleslittedparts,forvibrationconverter.improvingthevibrationcharacteristicsandincreasingThelongitudinalandtorsionalvibrationamplitudestheavailablevibrationvelocityoftheconverter,isofa15mmdiameterofanewconverterforanultrasonicstudied.Theslittedpartsareinstalledinmultipleposi-motorincreasedtoabout12mm(peak-to-zerovalue)tionsavoidinglongitudinalnodalpositionsalongthefrom6mmwithaformerconverterunderthesameconverterfordecreasingthemaximumvibrationstressdrivingvoltage60Vrmsat55kHz.levelatthevibrationnodalpart.UsingmultipleslittedTheconverterwithmultipleslittedpartswasfoundparts,themaximumvibrationstressalongaconvertertobeeVectiveforimprovingthevibrationcharacteristicsdecreasesandthequalityfactorincreases,andtheandincreasingtheavailablecomplexvibrationvelocity.maximumvibrationamplitudeincreasessignificantlyatthesamedrivingvoltage5.Theconverterhassuperior2.Configurationsofvibrationconverters*Correspondingauthor.Tel.:+81-45-481-5661；Configurationsoftwoexamplesofthevibrationfax:+81-45-491-7915.E-mailaddress:tsujinocc.kanagawa-u.ac.jp(J.Tsujino)converters20mmindiameterand79mminlength,with0041-624X/00/$-seefrontmatter2000ElsevierScienceB.V.Allrightsreserved.PII:S0041-624X(99)00175-473J.Tsujinoetal./Ultrasonics38(2000)72764.Complexvibrationultrasonicplasticwelding4.1.VibrationcharacteristicsofacomplexvibrationconvertersFig.2showstherelationshipbetweendrivingfre-quencyandlongitudinalandtorsionalvibrationvelocityofacomplexvibrationsystemwiththevibrationcon-verter(a).Thedrivingvoltageiskeptconstantat20Vrms.LongitudinalandtorsionalvibrationvelocitieshavemaximumvaluesatdiVerentfrequenciesataround26.3and26.4kHz.Theellipticallocusisobtainedatthefreeedgeoftheconverter.Torsionalandradialvibrationvelocitydistributionsat26.8kHzalongacomplexvibrationconverterwithFig.1.Variousone-dimensionallongitudinaltotorsionalvibrationdoubleslittedparts(a)and(b)areshowninFig.3.Oneconverterswithdoubleslittedparts.torsionalvibrationvelocitynodalpartiswithinaleftslittedarea,andthevibrationvelocitieshavemaximumvaluesatthefreeedge.Theradialvibrationvelocitydistributionalongaslittedpartsthatwereinstalledavoidingalongitudinalcomplexvibrationconverterwithdoubleslittedpartsnodalpart,areshowninFig.1.Thecylindricallongitu-dinaltorsionalvibrationconverters,madeofaluminumalloy(JISA7075B),hadtwoslittedpartsonbothsidesofalongitudinalvibrationnodalpartatitscircumfer-ence.Theconvertersweredrivenbyalongitudinalvibrationsource.Variousconverterswith(a)diVerentand(b)thesameanglediagonallyslittedpartsweremadeinthetrials.Thevibrationconverterparthad18diagonalslitsof45or135,10mmwidthand0.5mmwidthwerecutalongitscircumferenceusinganelectrosparkingmachine.Theslitdepthwasalteredfrom1.0to3.0mm.Thefreeedgepartoftheconvertervibratedlongitudinallyandtorsionallyandvibratedinanellipticallocus.Fig.2.Torsionalandradialvibrationvelocitydistributionsalongcom-plexvibrationconverters(a)and(b).Drivingvoltage:20Vrms.3.VibrationcharacteristicsoftheconverterswithtwoslittedpartsThefreeadmittanceloopsofthetotalvibrationsystemswiththeconvertersFig.1(a)and(b)weremeasured.Thequalityfactorandmotionaladmittance,|Ymo|,ofthevibrationsystemwithaconverterwithdiVerentangleslittedparts(a)andthesameangleslittedparts(b)wereabout600and30mSunderweldingconditionsoftwo1.0mmthickpolypropyrenesheetswithastaticpressureof890kPa.Theadmittanceloopsofthevibrationsystemwiththeconvertersshowsinglecircularshapesbecausetheresonancefrequenciesofthelongitudinalandtorsionalvibrationsareclose.ThequalityfactorsandmotionaladmittancesofthebothFig.3.Relationshipbetweendrivingfrequency,andlongitudinalandsystemsarelarge.Ellipticallociwereobtainedatthetorsionalvibrationvelocityofacomplexvibrationsystemwithavibra-tionconverter(A).Drivingvoltage:20Vrms.freeedgesoftheconverters.74J.Tsujinoetal./Ultrasonics38(2000)7276(a)isalsoshowninFig.3(dottedline).Aradialanddoubleslittedparts.Inthecaseoftheconverterwithsingleslittedpart,theslittedpartispositionedatvibrationvelocitymaximumpositionmeansalongitudi-anodalpositionofthelongitudinalvibrationalongthenalvibrationnodalposition,andthelongitudinalnodalcylindricallongitudinaltorsionalvibrationconverters.positionispositionedbetweentwoslittedparts.TheOnthecontrary,inthecaseoftheconverterwithtwotwoslittedareasexistoutofthelongitudinalnodalslittedparts,theslittedpartsarepositionedavoidingpositionwherethevibrationstresshasamaximumvaluethelongitudinalvibrationnodalposition.Theconverteralongtheconverter.withdiagonalslitsisdrivenbyalongitudinalvibrationsourceoftwopiezoelectricceramic(leadzircontita-4.2.Weldingcharacteristicsofcomplexvibrationnate；PZT)disks,15mmindiameterand5.0mminultrasonicplasticweldingthickness.Thevibrationconverterslittedparthas12diagonalslitsof45or135and0.5mminwidthand10Therelationshipbetweenweldingtime,specimenor5mminlength,cutbyanelectrosparkingmachinedeformedthicknessattheweldedpartsandtheweldalongthecircumferenceoftheseconvertersfabricatedstrengthofthelappedpolypropyrenesheets(1.0mminfromaluminumalloy(JISA7075B).Theslitdepthsofthickness),weldedusinga27kHzcomplexvibrationthe15mmdiameterconverterarealteredfrom1.5tosystemwithaconverter(a)and(b),isshowninFig.4.3.5mm.Thefreeedgeoftheconvertervibrateslongitu-Theweldstrengthsobtainedbythesystemwithcon-dinallyandtorsionallyandvibratesinanellipticallocus.verter(a)arelargerthanthosewithaconverter(b).ThePZTlongitudinalvibrationtransducers,alongi-Theweldingtimerequiredbecomesshorterusingthetudinalvibrationrodwithaflangeforsupportingthevibrationsystem(a)withalargertorsionalvibrationmotorandaslittedcylinderareclampedbyaconnectingcomponent.Thedecreaseinspecimendeformedthick-bolt.Thedrivingpartoftheconverterandtherotornessattheweldedpartsroughlycorrespondstothepartarestaticallypressedusingcorneddiskspringsbyobtainedweldstrength.Specimenswereweldedinaacenterboltandnuts.Thedrivingsurfacesoftheshorterweldingtimeusingacomplexvibrationsystemconverter(JISA7075B)andtherotor(steel:SKD-61orcomparedwithalongitudinalvibrationsystem.ComplexSK-4:tempered)aregroundtobeflatandsmoothusingvibrationiseVectiveforultrasonicweldingofplastic15002000meshpolishingpowder.materialsasformetalmaterials.5.2.Vibrationcharacteristicsof15mmdiameterultrasonicmotors5.UltrasonicmotorswithalongitudinaltorsionalconverterThelongitudinalandtorsionalvibrationamplitudesatthefreeedgeoftheseconvertersweremeasuredby5.1.ConfigurationofultrasonicmotorstwolaserDopplervibrometerswhenthedrivingfre-quencywasaltered.Theseconvertershavenear-reso-Theconfigurationsoftheultrasonicmotorsandnancefrequenciesofthelongitudinalandtorsionalvibrationconverters,15mmindiameter,areshowninvibrationssimilartoFig.2.ThelargestlongitudinalFig.5.Fig.5(a)and(b)showtheconfigurationsofvibrationamplitudesoftheconverterofsingleandtwo15mmdiametermotorsusingaconverterwithsingleslittedpartswithoutarotorpartwereabout6and12mm(peak-to-zerovalue)atfrequenciesof5055kHz.Thelargestlongitudinalvibrationamplitudesoftheseconverterswitharotorpartareabout3and9mmatfrequenciesnearto55kHz.Thelargestvibrationampli-tudesofaconverterwithdoubleslittedpartsareabouttwotothreetimescomparedwiththeamplitudesofaconverterwithsingleslittedpart.5.3.VibrationlociatthedrivingsurfaceoftheconverterInthesecases,thelongitudinalvibrationispartiallyconvertedtotorsionalvibrationattheslittedparts,andthecylinderpartoftheconvertervibrateslongitudinallyandtorsionally.Thevibrationlocusatthefreeedgeisdeterminedbyth