已阅读5页,还剩1页未读, 继续免费阅读
版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
Life-cycleorienteddevelopmentofmachinetoolsB.Denkena1,A.Harms1,J.Jacobsen1,H.-C.Mhring1,D.Lange2,H.Noske31UniversityofHannover,InstituteforProductionEngineeringandMachineTools,Germany2ArtisGmbH,Germany3IngenieurbroDr.Noske,GermanyAbstractFortheinvestmentdecisionfornewproductionequipmentitbecomesmoreandmorecommontoguaranteethetotalamountoflife-cycle-costs(LCC).IntheresearchprojectLoeWe,fundedbytheGermanFederalMinistryofEducationandResearch(BMBF),methodsaredevelopedtominimizelifecyclecostsinthedevelopment,operationandrecyclingphase.ExemplarilythedevelopmentofaninnovativeverticalturningmachinedemonstratesvariousstrategiestominimizeLCC.Exchangeabletechnologymodulesextendtheeconomiclifeandmonitoringofselectedmachinecomponentshelptoavoidunplannedservicestandstill.ALCCnavigatoroptimizesthebalanceofpurchasingandconsequentialcosts.KeywordsLifeCycle,Machine,Monitoring1INTRODUCTIONIntheautomotiveindustryageneraltendencytowardsalifecyclecostcalculationisobvious.Machinetoolmanufacturersareobligedtoforeseeandguaranteetheconsequentialcostsoftheirproductforapreviouslydefinedlifetime.Ifmoreserviceandmaintenanceisrequiredthanforecasted,theprofitofthemachinetoolproviderisreduced.Machineswithlessdowntimeandlongerserviceintervalsbecomemoreprofitable.Thereforeahighermachinetoolqualityandalongerandpredictablecomponentlifetimebecomemoreimportant.Consequently,automotiveindustryinvestorsdonottendtopreferthemachinetoolwiththelowestinvestmentcostsanymore.Themodifiedcalculationbasehasseveralconsequencesregardingthemachinetooldesign.Higherqualitycomponentscanbeapplied.Hydraulicsupply,normallyrequiredtodrivetheclampingsystemofthemainspindle,causeshighmaintenancecosts.Anapproachtoavoidthesecostsforanewmachinetoolseriesdevelopedwithintheresearchproject“LoeWe”,whichisanacronymforlife-cycleorientedmachinetool,istoabandonallhydrauliccomponents.Monitoringmechanicalpartsasforexampleballscrews,allowstoreplacethecomponentswhenitisnecessaryandnotatthecalculatedlifetime.Thisalsoenlargesserviceintervals.AnLCCnavigatorisbeingdevelopedwithintheproject.Thissoftwaretoolhelpstooptimizethechoiceofcomponentswithrespecttolowlife-cycle-costsinthedesignstage.Italsocanbeusedinthedevelopmentofmachinetoolcomponentslikeclampingdevices.Asitofferstheopportunitytoclearlyidentifythemaincostfactors(includinglife-cycle-costs),itcanbederivedwhichcomponentsareworthtobemonitoredovertheirlife-cycle.2CUSTOMERVS.MANUFACTURERDEMANDSEndusersofmachinetoolshavetoreactflexibleonchangingmarketdemandstoproducehigh-qualityproductsatagrowingvarietybutshrinkinglotsizes.Todaysmachinetoolsandproductionsystemshavealifetimeof10to15years.Theproductseriesthatarebeingmanufacturedontheseworkshopfacilitieshaveasignificantlowerlifetimeingeneral.Itmighthappenthatnewproductgenerationsthathavetobemanufacturedontheoldworkshopfacilitiesoverstraintheprocessfacilitiesoftheoldmachinetools.Toovercometheselimitations,companieswanttoinvestintoflexibleandreconfigurablemachinetoolsthatofferabroadvarietyofmachiningoperationsatminimumset-uptime.Theoperationofsuchmultifunctionalandflexiblemachinetoolsmightbeinefficientforfinancialaccountingpurposes,asmanysmallandmediummachinetooloperatingcompaniescannotpredicttheirfuturemanufacturingprocessesclearly.Thereforetheydonotknowiftheywouldeverneedoverqualifiedmachinetoolsfromtheiractualpointofview.Inconsequencetheaimoftheinvestmentplanningshouldbetoevaluatethemachinetoolstobeboughtregardingtheircapabilityandtheircost-effectiveness.Nexttothepureinvestmentcostsofaproductionfacility,moreandmorecompaniesalsoconsiderthetotallifecyclecostsastherecanbesignificantdifferencesregardingi.e.investmentcosts,maintenancecosts,energycostsandproductivity.Thisleadstodifferencesinthecostsperpieceofthemachinetoolstobecompared.Themachinetoolmanufacturerswanttoproducemachinesatlowmanufacturingcostswhilebeingabletoofferahighdiversityofmachinetooltypes.Furthermoretheywanttobemoreefficientindesignandproductionandwanttoreduceservicecostsandworkwithinthewarrantyperiod(figure1).Customerdemandslozenge4Productivity,quality,flexibilitylozenge4Processorientatedmachinetoolslozenge4Highavailabilityandreliabilitylozenge4Exploitationofthemachinesfullcapacitylozenge4CosttransparencyatpurchaseanduseCustomerorientationSalesconversationService/maintenanceM/42622eIFWMachinetoolmanufacturerdemandslozenge4Lowmanufacturingcostsatmax.diversitylozenge4Valueanalysisandcompliancewithcostslozenge4Moreefficiencyindesignandproductionlozenge4Reductionofservicecostsandworklozenge4TransparencyofcostsatdevelopmentFigure1:Customerdemandsvs.manufacturerdemands693Asmoreandmorecompaniestendtobuymachinesonlywithguaranteedlife-cycle-costs,themachinetoolmanufacturershavetoundertakethetaskofcreatingappropriateoffers.Acommondifficultywithlife-cycle-costsoftechnicalequipmentistotransformtechnicalfeaturesandconditionsintoeconomicvalues.2.1ResultsofacustomersurveyInordertoevaluatetheneedsofmachinetoolusers,acustomersurveyamongseveralmachinetooluserswithdifferentcompanysizesandbrancheshasbeenaccomplished.Thenumberofmachinetoolsformetalcuttinginusevariedfrom5to1500.Twoimportantresultsfromthesurveyconcerningtheinvestmentdecisionandtheproductivityarepresentedhere.Forallcustomers,technologyandqualityhavethehighestpriorityforaninvestmentdecision.Ofminorimportancearelife-cycle-costsandinvestmentcosts.Thesurveyrevealedthatonlysomeofthebiggercompaniestendtodecideontheirinvestmentsaccordingtoguaranteedlife-cycle-costs.Asanexample,thedeveloperoftheTCOstandard(TotalCostofOwnership),Daimler-Chrysler,onlybuysmachinetoolsandproductionlinesaccordingtoaTCOcontractwherethetotallife-cycle-costsareassuredbycontractfor10years1.Othercompanieswillfollowinthefuture.Regardingtheproductivity,theavailabilityandprocesssafetyofmachinetoolsareofhighestimportanceforthemachinetoolusers.Speedandaccelerationareofminorimportance(figure2).Ha/42623eIFWunimportantratherunimportantminorimportantimportantveryimportantInvestmentdecisionProductivitySurveyfrom20040%10%20%30%40%50%60%70%80%90%100%ConditionsLife-cycle-costsTechnologyServiceQualitySpeedAccelerationAvailabilityProcesssafetySet-uptimeFigure2:Resultsofacustomersurvey2.2Costtransparencywithlifecyclenavigator“Design-to-Cost”istheheadlineoverthemostdevelopmentsofmachinetoolstoday.Theresultofsuchadevelopmentprocessisapurchasepriceoptimisedmachinetool.ButisthisresulttheoptimumconcerningtheLife-Cycle-Costsofthemachinetoolandthereforethemoneybagofthecustomer?IfanyLCC-calculationsofmachinetoolsaredonetodaytheyarerealisedafterthedevelopmentprocessofthemachine.HowwillthedesignofamachinetoolbemodifiedifaminimumoftheLife-Cycle-Costsisthebenchmarkofthedesign?TargetoftheLoeWeresearchprojectwherealsocomponentsupplierslikeBergSpanntechnikGmbH,FranzKesslerGmbH,A.Mannesmann,ArtisGmbHandSiemensareinvolved,isthedevelopmentofaLCC-optimisedmachinetool.ThismainideaguidesthewholedevelopmentprocessofthemachinetoolsincethefirstreflectionoftheLoeWemachine.ItwasacceptedthatthepurchasecostsoftheLoeWemachineexceededthepurchasecostsofacomparableconventionalmachinetoolifonlytheLoeWemachinewillshowarigorousbetterLCC-schedulecomparedtotheconventionalmachinetool(figure3).Inthisresearchproject,anexistingsoftwaretool,theCostNavigatorwhicheffectsgoodresultsincommonDesign-to-Costprojectsofmachinetoolsandothercapitalequipments2,isenhancedtotheLCCNavigator.Dr.NosketLife-cycle-costs0Aftersalescosts-Tools-Service-Maintenance-Energyetc.10yearscommonmachinetoolLoeWe-machinetoolInvestmentcosts5yearsLife-cycle-costsFigure3:CostscheduleofLoeWe-machinetoolvs.conventionalmachinetoolUsingtheLCCNavigatortheLife-Cycle-Costsofthemachinetool,includingmanufacturingandaftersalecosts,willbeextrapolatedduringthewholedevelopmentprocess.EachdecisionconcerningtheapplicationorthedesignofacomponentwillbemadeconsideringthecalculatedvaluesoftheLCCNavigatoralreadyintheearliestdesignphase.TheapplicationoftheLCCNavigatorwillbeexemplarilydemonstratedatthedesignoftheworkpiececlampingdeviceoftheLoeWeturninglathe.Dr.Noske26,1%26,4%47,5%33,4%11,4%0,0%10,0%20,0%30,0%40,0%50,0%60,0%70,0%80,0%90,0%100,0%conventionalclampingdeviceLoeWeclampingdevicemaintenancecostswithin10yearsotheraftersalescostswithin10yearsinvestmentcostsFigure4:LCCextrapolationoftheworkpiececlampingsystemofLoeWe-machinetoolvs.conventionalmachine694PROCEEDINGSOFLCE2006Normallyahydraulicclampingdeviceisusedfortheworkpiececlampingfunctioninaturninglathe.ConsideringtheclampingfunctionfromthepointofviewofLCC,acompletenewsolutionfortheclampingoftheworkpiecehasbeenrealizedwithintheLoeWeproject.Themaincostcomponentsofahydraulicclampingdevicewithin10yearsaremaintenancecostsespeciallyforthehydraulicsupplyunit(figure4).Thismaintenancecostsriseevenabovethepurchasecostsofthewholeclampingdeviceduring10yearsofoperation.ThenewelectricalclampingdeviceoftheLoeWeturninglatheisfreeofmaintenanceandgeneratesthereforenomaintenancecostsduringitslifetime.RegardingonlythepurchasecoststheconventionalclampingdevicehasanadvantagecomparedtotheLoeWedevicebecauseoflowerpurchasecosts.ThebenefitforthecustomerbecomesapparentonlyaftertheextrapolationoftheentireLCC.OthercomponentsoftheLoeWemachinetoolareLCCoptimizede.g.theballscrews,thelinearbearingunitsandcomponentsofthecontrolunitbasedonLCCNavigatorcalculations.ItcanbesummarisedthatanLCC-optimizedmachinetooldesign(Design-to-LCC)createsasignificantlydifferentmachinecomparedtoadesignundertheaspectsofonlypurchasingcosts.3MODULARMACHINETOOLTheinvolvedmachinetoolmanufacturerGildemeisterfocusesonamodularconceptforthemachinetoolseriesthatallowstheusageofasmanystandardpartsaspossible.Themachinetoolserieswillbeavailableinseveralstagesofextension(i.e.thenumberofmainspindles,theirmaximumtorquesandrotationalspeeds,differentturretsandtoolingsystems),whereasthemachinebasisremainsthesameforalltypes.Amodeloftheverticallathewiththeintegratedfeaturesforreducingthelife-cycle-costsispresentedinfigure5.Eventhoughthemachinetoolprototypeisdevelopedinamodulardesign,itisdifficulttoensureawidelyreconfigurablemachinetool.Ithastobedistinguishedbetweenareconfigurationtobeperformedbythemachinetoolmanufacturerandareconfigurationthatcanberealizedbythemachinetooloperator.MainspindlewithintegratedB-axisBallscrewwithwearmonitoringElectricclampingdeviceMachine/processmonitoringInterchangeabletechnologymodulesRFIDtechnologyforquick-setupLCCNavigatorHa/42627eIFWX-AxisY-AxisZ-AxisZ-AxisZ-AxisFigure5:Modelofthelife-cycleorientedmachinetool3.1ReconfigurationbymachinetoolmanufacturerTheverticallathewillbeavailableinseveralstagesofextension.ThebasicversionisequippedwithastandardspindlewithoutB-axis.ToreconfigurethismachinetooltoonewithB-axis,extensivechangeswouldbenecessary,thatcanberatherpracticableonlyforthemachinetoolmanufacturer.Thusthecross-slideforthex-andz-axiswouldhavetobechanged.Thiswouldalsoimplyachangeoftheinnerenclosureofthemachinetool.Componentsthatremainthesameforallthemachinetypesarethemachinebed,thebedsaucer,theouterenclosure,theelectricalcontrolunitbox,thecoolingunitandtheoperatorpanel.3.2ReconfigurationbymachinetooloperatorTheLoeWemachinetoolincorporatesaplatformthatallowsthemachinetoolusertousespecializedtechnologymodulesinthemachine(figure5).Thisplatformincorporatesastandardizeddockingsystemthatallowsthereferencedpositioningandclampingofthesemodulesinsidethemachinetool.Bythistheoperatorcanusehismachinetooleasilyformanufacturingprocessesthatwouldnothavebeenpossiblewithinthestandardmachinetoolconfiguration.Theutilizationofaplatformtobeequippedwithpalletsystemsinsidetheworkspaceofthemachinetoolallowstheuseofagreatvarietyofadditionalmanufacturingprocessesthatcanbeeasilyinstalledbytheoperator.Thiscanbei.e.largediameterdrilling,grindingetc.Palletbasedtechnologymodules,likeforexamplegrindingspindles,havetobeequippedwithasupplyofenergyandcompressedairaswellaswithanappropriateelectricalconnectionformonitoringsensorsignals.Asolutionfortheintegrationoftheseconnectionsintothemechanicalinterfaceiscurrentlyinvestigated.4COMBININGINFORMATIONANDCOMPONENTRelevantcomponentsoftheLoeWemachinetoolprototypewillbeequippedwithdatastoragedevicesthatallowthestorageofspecificcomponentdataforidentificationpurposeslikemanufacturer,type,serialnumberaswellaslife-cyclerelatedmaintenanceinformation.Fourselectedcomponentsliketheballscrewdrive,theelectricclampingdevice,thetechnologymodulesandthemainspindleareequippedwithRFIDbasedtransponderchips.TheelectricclampingsystemisequippedwithaRFID-chipthatstoresallrelevantinformationforanautomatedconfigurationofthemachinetoolcontrol.FurthermoretheintegratedRFID-chipwillbeusedtostorelife-cyclerelateddata.Thisallowstoidentifythecomponentanditsactualstateevenifitisdetachedfromthemachinetool.Toreadthetransponderchip,anantennahastobeplacedclosetotheRFID-chipasdataandenergyaretransmittedviaaradiofrequencyfield.Dependingontherequireddatarate,differentsystemsoperatingatvarioustransmissionfrequenciesandrangescanbeused.Inordertoassureanacceptabletransmissionrangethatcanbeupto7mmforaRFID-chipwith2kBmemorycapacity,itneedstobeinsulatedfromthemetalsurfacegrounditismountedon.Machinetoolcomponentsthatwillbeoftenexchangedasforexampleapalettebasedclampingsystemareequippedwithahard-wiredantennaintegratedintothestationarypartandanRFID-chipintegratedintotheexchangeablepart.OtherRFID-chipequippedmachinetoolcomponentslikeaballscrewdrivethathavetobeinstalledonlyonceortwiceduringthemachinetoollife-cyclewillbeidentifiedwithahandheldantennaconnectedtothemachinetoolcontrolforinstallationandmaintenancepurposes(figure6).13thCIRPINTERNATIONALCONFERENCEONLIFECYCLEENGINEERING695MachinetoolcontrolwithcentraldatastorageRFID-basedcomponentmemoryDemountedcomponentwithRFID-chipS.VogelerITAFigure6:Combininginformationandcomponent5COMPONENTMONITORING5.1EstimationofremaininglifetimeofballscrewsOftenthemachinetoolutilizationtimeexceedstheballscrewlifetime.Whenthereisnoextraordinaryincidence,theyareexchangedafteracertaincumulatedtraversepathregardlessoftheirwearstate.Thisisthestateofthearttominimizetheriskofunplannedfailure.Whenaballscrewfailsduetoitswear,theaxisbecomeslessprecise;inparticular,theclearancebecomesmuchhigher.Thereforeitisnotpossibletochoosehardlong-termstablecontrolparameter.Dirtorchipsontheballscrewcanleadtoabreakdownoranenlargedwearoftheballsortheballtrackbeforereachingthenominallifetime.Thisalsodemandsanunplannedexchangeduetotheexceedingofworkpiecetolerances.Especiallyinautomaticlineoperations,adowntimeofseveralhoursorevendayscausessubstantiallosses.Thereforeareliablemonitoringstrategyofballscrewsisimportanttoavoidtheseadditionalcostsforthemachinetooluser.Aweardetectionandpredictionoftheremaininglifetimeallowstoplantheexchangeoftheballscrewinadvancetoavoidunplanneddowntime.Lossofpre-loadAutomaticwearmeasurementsshouldbedoneatthemostloadedlocationofthespindle.Becausesomespaceisrequiredforthemeasurementtraversepath,thetestcannotbeexecutedatthemarginsofthespindle.Experiencesfromballscrewmanufacturersshowthatwearofballscrewtrailsalsoreproduceswearontheballs.Therefore,analternativewearmeasurementatanotherpositionofthemachinetoolaxisrepresentsthemeanwearofthescrew.Inthefollowing,twopossiblemethodsofwearmeasurementarepresented.Botharebasedonpre-loadlossdetection,duetoareducedballdiameterbypittingeffects.TheybaseoninvestigationsofhorizontallyarrangedballscrewswithinaprojectfundedbyDFG(GermanResearchFoundation)3.Anaimofthein
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 2024年03月浙江绍兴市文学艺术界联合会选调事业工作人员笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月浙江宁波余姚市图书馆招考聘用编外工作人员笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月河北省直属机关第二门诊部招考聘用4人笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月新疆第一济困医院(自治区第四人民医院)招考聘用75人笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月山东济宁曲阜市教育系统校园招考聘用4人(山东师范大学站)笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月四川雅安石棉县考调事业单位工作人员17人笔试历年(难与易错考点)高频考题后附答案详解
- 2024年卫生知识健康教育知识竞赛-麻醉药品临床使用与规范化管理知识竞赛笔试考试历年真题含答案
- 2024年医药卫生考试-卫生防疫员技师笔试考试历年真题含答案
- 2024年03月北京门头沟区事业单位招考聘用79人笔试历年(难与易错考点)高频考题后附答案详解
- 2024年03月份上半年四川南充市属事业单位招考聘用84人笔试历年(难与易错考点)高频考题后附答案详解
- 大数据和人工智能知识考试题库600题(含答案)
- 小升初科学复习资料全
- 新媒体运营课程标准-48课时
- APQC跨行业流程分类框架(PCF)(V7.3.0.1- 2022年4月版)【雷泽佳译-2022-11】
- 工程的伦理结课论文完美版
- 后进生动员会议课件
- 中医内科学(十版)
- 景县景南新城项目初步评估报告
- 短歌行精品课件ppt公开课一等奖省优质课大赛获奖课件
- DB23T 1642-2020 黑龙江省绿色建筑评价标准
- 《汽车低压线束设计规范》
评论
0/150
提交评论