文献翻译用PLC模块控制3轴数控铣床制造加工螺旋锥齿轮.docx

文献翻译用PLC模块控制3轴数控铣床制造加工螺旋锥齿轮.docx

《文献翻译用PLC模块控制3轴数控铣床制造加工螺旋锥齿轮.docx》由会员分享，可在线阅读，更多相关《文献翻译用PLC模块控制3轴数控铣床制造加工螺旋锥齿轮.docx（22页珍藏版）》请在冰豆网上搜索。

文献翻译用PLC模块控制3轴数控铣床制造加工螺旋锥齿轮

外文资料翻译

UseofPLCmoduletocontrolarotarytabletocutspiralbevelgearwiththree-axisCNCmilling

S.Mohsen.Safavi，S.Saeed.Mirian，RezaAbedinzadeh，Mehdi.Karimian

Abstract

CNCmachiningnowadaysmakesmoreuseof“Mechatronics”increasingly.Combiningnumericalcontrolwithmechanic,electric,anddataprocessingsystemscanleadtonewmethodsofproduction.Inrecentyears,thedevelopmentofCNChasmadeitpossibletoperformnonlinearcorrectionmotionsforthecuttingofspiralbevelgears.Inthispaper,weattempttomanufacturethespiralbevelgearusingathree-axisCNCmillingmachineinterfacedwithanadditionalPLCmodulebasedontraditionaldiscontinuousmulticuttingmethodaccomplishedbyusingauniversalmillingmachineinterfacedwithanindexingworkhead.Thisresearchconsistsof（a）geometricmodelingofthespiralbevelgear,（b）simulatingthetraditionalandournewnontraditionalmethodusingaCAD/CAEsystem,（c）processplanningforCNCmachiningandPLCProgramming,（d）experimentalcutswithathree-axisCNCmillingmachineweremadetodiscoverthevalidityofthepresentedmethod.TheresultsdemonstratethatinventedexperimentalcuttingmethodofSBGsnotonlyislessexpensivethanadvancedCNCmachiningbutalsoproducesgearsinashortertimeincomparisonwiththetraditionalcutting.Thereby,itisaneconomicalmethodinmanufacturingofSBGs.

Keywords:

Gearmanufacturing.Spiralbevelgear.CAD/CAM/CAE.CNC.PLC.ACmotor.Inverter.Proximitysensors.Photoelectricsensors.Rotaryencoder

1Introduction

Gearsareimportantandprecisionmechanismsforindustrialmachineryasameansformechanicalpowerormotiontransmissionbetweenparallel,intersectingandnonintersectingcross-axisshafts.Althoughhiddenfromsight,gearsareoneofthemostimportantmechanicalelementsinourcivilization.Theyoperateatalmostunlimitedspeedsunderawidevarietyofconditions.Themachinesandprocessesthathavebeendevelopedforproducinggearsareamongthemostexistingingeniousones.Whetherproducedinlargeorsmallquantities,incell,orjobshopbatches,thesequenceofprocessesforgearmanufacturingrequiresfoursetsofoperations[1]:

1.Blanking

2.Gearcutting

3.Heattreatment

4.Grinding

Dependingontheirtypeandapplicationorrequiredstrengthandresistance,gearsaremanufacturedbycasting,extruding,forging,powdermetallurgy,plasticmolding,gearrolling,andmachining.Amongtheseprocesses,machiningismorefrequentlyusedforhigh-precisegears[2].Amongthevarioustypesofgears,thespiralbevelgears（SBG）arethemostcomplextypeandareusedtotransmittherotationalmotionbetweenangularlycrossedshafts.SBGshaveteethcurvedlongitudinallyalongthelengthoftheteeth.Themainadvantageofthesegearsoverthestraight-toothedvarietiesliesinthefactthatmoreteethareincontactatthesametimebecauseofthecurve-shapedcontouroftheteethandsoasmoothermeshingactionbetweenthematingpairisensured[3].Thedesignandmanufacturingofspiralbevelgearsisstillahottopicofresearchthatisvitaforapplicationofsuchgearsinhelicoptertransmissions,motorcyclegears,reducers,andinotherbranchesofindustry.Asfarasmanufacturingisconcerned,thegearsaremachinedbyaspecialtypeofmachinetools,suchasgearhobbingandshapingmachines.Recently,specialCNC-basedgearmanufacturingmachinetoolsareusedinindustrialpractice.Thismaybewhyliteratureongearmanufacturingissparseintheopenresearchdomain.Recently,CNC-basedgearmanufacturingmachinetoolshavebeendevelopedandincreasinglyusedinindustrialpractice.However,theirkinematicstructureisstillinherentlydifferentfromtheindustrialCNCmillingmachine,astheformerisdesignedforaspecialtypeofcutter.

Previousstudiesongearshavebeenmainlyconcernedwiththedesignandanalysisofgears.Thegeometriccharacteristicsanddesignparametersofgearshavebeenstudied[4-8].TsaiandChin[4]presentedamathematicalsurfacemodelforbevelgears（straightandSBGs）basedonbasicgearingkinematicsandinvolutesgeometryalongthetangentplanes.Later,thismethodwascomparedwithanothermodelbasedonexactsphericalinvolutescurvesbyAl-Daccaetal[5].Shunmuganetal.[6,7]presentedadifferentmodel,anditsaccuracy（comparedwiththespiralbevelgearmanufacturedbyspecialmachinetools）wasverifiedintermsofnominaldeviation.

Forcrowngears,afewresultsareavailable.LitvinandKim[8]suggestedagenerationmethodforaninvolutecurvefromamodifiedbasecircleforaspurgear.Umeyama[9]designedastandardprofileatthepitchcircleandamodifiedprofileatthetop/bottomfacegearwithadeterminationofthemodificationvaluefortransmissionerrorofhelicalgear.Tamuraetal.[10,11]studiedapointcontactmodelforabevelgearusingaflatsurfacetooth.Thesestudiesareconcernedwiththegenerationofthetoothprofileforspecialgearmachines,suchasgearhobbingandshapingmachines,whicharespeciallydesignedformanufacturinggears.Suhetal.[12]investigatedthepossibilityofasculpturedsurface-machiningmethodforthemanufactureofspiralbevelgearsandverifiedthepossibilitybypresentingtool-pathgenerationusingafour-axisCNCmillingmachineinterfacedwitharotary-tilttable.Amodel-basedinspectionmethodforthespiralbevelgearswasalsopresented[13].

Inthispaper,weattempttopresentanewmanufacturingprocedureofSBGsbyusingathree-axismillingmachineinterfacedwithaPLCmodulewhichoperatesasanindexingtable.Intermsofproductionrate,itisobviousthatthismethodwillbelowerthanthatofthespecialmachinetool.Otherthanproductionrate,thismethodisadvantageousinthefollowingrespects:

（1）theconventionalmethodrequiresalargeinvestmentforobtainingvariouskindsofspecialmachineryandcuttersdedicatedtoaverylimitedclassofgearsintermsofgeartype,size,andgeometry;

（2）bythismethod,varioustypesofgearscanbemanufacturedwiththeindustrialthree-axisCNCmillingmachine;（3）thismethodismoreeconomicalthanusingthespecialmachinetool.Oneofthemainpointswhichseparateourworkfrompreviousonesisdevelopinganautomaticcomputermodelinordertosimulatetheprocessentirelyandobtainmachiningparameter.Allpreviousstudieshavebeenengagedincalculatingcomplicatedmathematicalequationsanddesigninggeometricmodels.Inviewoftheabove,specialattentionisgiventoexperimentaltestsratherthanpresentinggeometricalormathematicalmodelofSBGs.Thisisthefirsttimethatmechatronicstoolsandathree-axisCNCmillingmachinearebeingusedsimultaneouslyinmanufacturingaspecialgearandevenamechanicalelement.

2Geometricspecificationsofthespiralbevelgears

Mostofthetime,thegeometricparametersofagearareprovidedwithanengineeringdrawing.Someparameters（principalparameters）arerequiredfordefiningthegeometry.Figure1showsmodule,spiralangle,andnumberofteethofgear.Table1summarizestheseparametersincludingrelationshipsamongparametersforthegearwhichhasbeenmanufacturedinourtest.Tocalculatetheseparameters,wehaveused“drivecomponentdevelopmentsoftware”calledGearTrax.

Thedesignofspiralbevelgearrequireshigh-accuracymathematicalcalculations,andthegenerationofsuchgeardrivesrequiresnotonlyhigh-qualityequipmentandtoolsformanufacturingofsuchgeardrivesbutalsothedevelopmentofthepropermachine-toolsettings.Suchsettingsarenotstandardizedbuthavetobedeterminedforeachcaseofdesign（dependingongeometricparametersofthegeardriveandgeneratingtools）toguaranteetherequiredqualityofthegeardrives.

3ManufacturingtheSBG

Asitwasdiscussedintheintroduction,bymachining,alltypesofgearscanbemadeinallsizes,andmachiningisstillunsurpassedforgearshavingveryhighaccuracy.Formmillingisoneofthemostcommonmachiningprocessesusedtomanufactureanytypesofgears[14].Thecutterhasthesameformasthespacebetweenadjacentteeth.Standardcuttersusuallyareemployedinform-cuttinggears.IntheUSA,thesecutterscomeineightsizesforeachdiametralpitchandwillcutgearshavingthenumberofteethindicatedinstandardtables.

Gleasonworksusedthefacehobbingprocessthatisbasedonthegeneralizedconceptofbevelgeargenerationinwhichthematinggearandpinioncanbeconsideredrespectively,generatedbythecomplementarygeneratingcrowngears[15].ThetoothsurfacesofthegeneratingcrowngearsarekinematicallyformedbythetracesofthecuttingedgesofthetoolbladesasshowninFig.2.

AsitisshowninEq.1,velocityratiooffacehobbingprocessdependsontoothnumberoftoolandgeneratinggear:

（1）

Where,

and

denotetheangularvelocitiesofthetoolandgeneratinggear;

and

denotethenumberofthebladegroupsandthetoothnumberofthegeneratinggear.

TheradiioftherollingcirclesofthegeneratinggearandthetoolaredeterminedbyEqs.2and3:

whereisthemachineradialsetting.

Thegeneratingcrowngearcanbeconsideredasaspecialcaseofabevelgearwith90°pitchangle.Therefore,agenericterm“generatinggear”isused.Theconceptofcomplementarygeneratingcrowngearisconsideredwhenthegeneratedmatingtoothsurfacesofthepinionandthegearareconjugate.Inpractice,inordertointroducemismatchofthematingtoothsurfaces,thegeneratinggearsforthepinionandthegearmaynotbecomplementarilyidentical.Therotationofthegeneratinggearisrepresentedbytherotationofthecradleonahypoidgeargenerator（Fig.3）.

Toman