会员注册 | 登录 | 微信快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译--在端面铣削过程中刀具偏移量的识别没有先验知识的切削系数 英文版.pdf外文翻译--在端面铣削过程中刀具偏移量的识别没有先验知识的切削系数 英文版.pdf -- 5 元

宽屏显示 收藏 分享

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

InternationalJournalofMachineToolsManufacture432003687–697IdentificationofcutteroffsetinendmillingwithoutapriorknowledgeofcuttingcoefficientsJ.J.J.Wang∗,C.M.ZhengDepartmentofMechanicalEngineering,NationalChengKungUniversity,Tainan,Taiwan701Received28January2002accepted21January2003AbstractThispaperpresentsamethodfortheidentificationofcutteroffsetthroughmillingforcewithoutrequiringthespecificcuttingcoefficientstobeknownaspriori.Thetotalmillingforceinthepresenceofcutteroffsetisfirstobtainedonthebasisofdualcuttingmechanisms,wherethelocalforceiscomprisedofaconstantplowingforceandalinearshearingforceproportionaltothechiploadunderthecutteroffset.Thetotalmillingforceissynthesizedthroughconvolutionandisshowntobethesumofthreeforcecomponentsthenominalchipshearingforcecomponent,theplowingforcecomponentsandtheoffsetrelatedshearingforcecomponent.Fourieranalysisoftheseforcecomponentsrevealstheeffectsofoffsetgeometryandyieldsformulasfortheidentificationofoffsetgeometry.Theidentificationprocessrequiresonlytwocuttingtestsandtheevaluationoftwoalgebraicexpressionstheshearingconstantsarefoundfromtheaverageforcesofcuttingtestsandtheoffsetgeometryisidentifiedfromtheforcecomponentatthespindlefrequency.Throughnumericalsimulationandexperimentalresults,theefficacyoftheidentificationmethodisdemonstratedtheeffectsoffeedpertoothandcuttingdepthsontheaccuracyofthemodelareinvestigatedandcriteriafortheappropriateselectionoftheseparametersaresuggested.2003ElsevierScienceLtd.Allrightsreserved.KeywordsOffsetrunoutEndmillingMillingforceShearingPloughing1.IntroductionThepresenceofcutterrunoutinmillingdegradessurfacequalityandincreasesboththeradialandthrustforcevariationonthetools,aswellasonthespindlebearingthusreducingtoolandspindlelife.Theeffectofcutterrunoutonthemillingforceanditsidentificationhasbeenthesubjectofmanystudies.Researchesin1–4havealreadyproposedmillingforcemodelswithknownrunoutgeometry.However,cutterrunoutisgenerallydifficulttopredictandmeasurebecauseitresultsfromthecomplexinprocessinteractionofthestaticrunoutandtheunbalancingdynamicsoftherotatingassembly.Althoughthemeasurementofstaticcutterrunoutcanbecarriedoutofflinewithadialindicatororotherelectronicmeans,thedynamicrunoutgeometryduringthe∗Correspondingauthor.Tel.188662757575Ext62189fax188662367231.Emailaddressjjwangmail.ncku.edu.twJ..J.J.Wang.08906955/03/seefrontmatter2003ElsevierScienceLtd.Allrightsreserved.doi10.1016/S0890695503000282millingprocesscouldbedifferentandadirectmeasurementwouldbeverydifficult.Theabilitytoidentifytheinprocessrunoutgeometrywouldbeusefulfortheusersandmanufacturersofmachinetools,toolholdersandspindlesinthemonitoringandtestingofcuttereccentricitywithinthedesiredrangeofoperatingspeed.Sincecutterrunoutresultsintheredistributionofchiploadamongthecutterflutes,thegeometryofcutterrunoutisembeddedinthemillingforce.Millingforcethusbecomesaconvenientsignalsourcefortheindirectmeasurementorestimationofcutterrunout.Armaregoetal.4usedtheirrunoutforcemodelfortheestimationofcutterrunoutthroughaniterativebestfitprocedure.Guetal.5presentedalgorithmsfortheestimationofcutterradialandaxialrunoutforthefacemillingprocessbyfittingthepeakandvalleyvaluesofthecomputedmillingforceswithassumedunknowncutterrunouttothemeasuredcuttingforces.Theresultsshowedagreatdiscrepancybetweentheestimatedrunoutandstaticallymeasuredcutterrunout.Basedontheconvolutionanalysis,Jayarametal.6presentedamethodologyfor688J..J.J.Wang,C.M.Zheng/InternationalJournalofMachineToolsManufacture432003687–697NomenclatureAn,AovectorsoftheFourierseriescoefficientsforthenominalmillingforceandoffsetrelatedforcea,N,Rhelixangle,numberofcutterflutesandcutterradiusb,r,hangular,radial,andaxialpositionsforcuttingpointsincuttercoordinatecwd,cwdcchipwidthdensityfunctionofthefirstcuttingedgeandoftheentirecutterba,bpaxialimmersionangleandflutespacingangleCWDFouriertransformofthechipwidthdensityfunction,cwdda,draxialandradialcuttingdepthft,frlocaltangentialandradialcuttingforcesperunitchipwidthfcutterangulardisplacementgx,gyXandYcomponentsofthelocalcuttingforcesperunitchipwidthgtotalcuttingforcevectorkts,krsspecificshearingforceconstantsinthetangentialandradialdirectionsktp,krpspecificplowingforceconstantsinthetangentialandradialdirectionslangularlocationofthecutteroffsetps,pp,povectorsoflocaltangentialforcesperunitwidthintheworkcoordinateduetoshearing,plowingandaxisoffseteffectsPs,Pp,PoFouriertransformsofps,pp,poqs,qp,qodirectionalmatricesfortheshearing,plowingandaxisoffsetforcesqangularpositionofcuttingpointintheworkq1,q2entry/exitanglesrmagnitudeofcutteroffsetTtransfermatrixbetweenmeasuredcuttingforcesandcuttingconstantstxfeedpertoothwnormalizedfrequencywithrespecttospindlefrequencydetectingprocessfaultsfromthespectrumofthecuttingforcesignalinfacemilling.Basedonthiswork,Akshayetal.7reportedanoptimizedapproachthatusedallthespindleharmonicsofthecuttingforcespectrumofYdirectionforradialrunoutestimationinfacemilling.Itwasshownthattheoptimizedalgorithmperformedwellevenwithtimevaryingsurface.Cuttingforcemodelsandthecutterrunoutestimationschemesin4–7havereliedonnumericalanditerativeapproachtoestimatethetotalmillingforceandcutterrunoutgeometry.ByrepresentingtheradialrunoutofeachindividualinsertasadiscreteFourierseries,SeethalerandYellowley8derivedtheFourierseriescoefficientsoftheoffsetrelatedforcefortheidentificationofradialrunoutforafacemillingcutter.However,thismodelisnotapplicablewheretherunoutmagnitudevariesalongthecutterhelicaledgesuchasthecasewithendmilloffset.Forasolidendmill,cutterrunoutveryoftenresultsfromacutteraxisoffset.Forthistypeofrunoutgeometry,WangandLiang9analyzedthechiploadkinematicsandderivedanalyticexpressionsforthechipthicknessandaveragechipthickness.Combiningthischiploadkinematicsandtheconvolutionintegrationmethod,LiangandWang10formulatedandanalyzedtheinfluenceofcutteraxisoffsetonthemillingforcesinthefrequencydomain.Basedonthisanalyticalforcemodelandtherequirementofaprioriknownexponentofthecuttingcoefficientfunction,themagnitudeandangularlocationofcutteraxisoffsetwereidentifiedthroughtheFourierseriescoefficientsofcuttingforcesatthespindlefrequency.Byextendingtheworkin10,HekmanandLiang11presentedarecursiveschemeforthemostrecentestimatesofthedynamicrunoutmagnitudeandorientationintermsofthepreviousestimates.Undersimilarconvolutionstructure,ZhengandLiang12furtherextendedthechiploadandforceanalysisfortheidentificationofcutteraxistiltinendmilling.Estimationofendmilloffsetinthesenumericaloranalyticalmodelsheretoforerequiresapriorknowledgeofthespecificcuttingcoefficients,whichisusuallynotavailableespeciallyinanindustrialenvironment.Aseriesofcuttingexperimentswouldhavetobecarriedoutinadvanceforthetoolandworkmaterialofinteresttoestablishadatabaseorexpressionsforthecuttingcoefficients.Theeffectofongoingandunknowntoolwearaddsuncertaintytotheaccuracyofthispreestablisheddata.Althoughtheinstantaneoustangentialandradialcuttingconstantscanbeestimateddirectlyfromthemeasuredmillingforceasin10–12,theexponentsofthepowerexpressionsforthecuttingcoefficientsasfunctionsofchipthicknesswouldneedtobeknowninadvance.Thisprerequisitecomesfromthefactthatthemillingforcevariationduetochiploadchangeinthepresenceofcutterrunoutisattributedtothechipshear689J..J.J.Wang,C.M.Zheng/InternationalJournalofMachineToolsManufacture432003687–697ingmechanismalone,whiletheestimatedcuttingconstantsfromtheexistingmodelarebasedonthelumpedeffectsofchipshearingandedgeplowingcuttingmechanisms.Theselumpedconstantsdependgreatlyonchipthicknessandaregenerallyexpressedaspowerfunctionsofchipthicknessoraveragechipthickness.Itwouldbemoreappropriateandhasstrongerbearingonthephysicalgroundstouseonlyshearingrelatedcuttingcoefficientsinmodelingtheforcevariationduetocutterrunout.Researchesin4,8,13–16haveusedarefinedcuttingforcemodelthatexplicitlyincludestheseparateandsimultaneouseffectsofchipshearingandedgeplowingmechanismsinthecuttingprocess.Yellowleyassumedaconstantpresenceofplowingforceandalinearshearingforceproportionaltotheinstantchipthicknessandshowedthatsuchamodelisaccuratefortheidentificationofinsertrunoutin8andforthepredictionofaveragecuttingforce13.Armarego4,14proposedthattheshearingcoefficientsbeexpressedasfunctionsofnormalrakeangle,toolinclinationangle,normalshearangle,shearstress,frictionangleandchipflowangle,andtheplowingcoefficientsexpressedasfunctionsofnormalrakeangleandcuttingvelocity.Basedonworksin4,14,Budaketal.establishedapredictivemodelforthedualcuttingcoefficientsin15andshowedthattheshearingcoefficientsandplowingcoefficientscanbetreatedasconstantswithoutlossofaccuracy.Itisthereforeproposedinthispaperthattheendmillingforcewithcutteroffsetbeformulatedusingconstantplowingandshearingcuttingcoefficients.Forcecomponentsduetothecutteroffsetcanthenbeappropriatelyaccountedforbytheshearingcuttingconstants.Theuseofconstantcoefficientswithdualcuttingmechanismswillbeshownhereintonotonlysimplifythetaskfortheidentificationoftheoffsetgeometrybutalsoyieldmoreaccurateresults.Inthenextsectiontheanalyticalforcemodelwithcutteroffsetisfirstestablished.Section3presentsthemethodsfortheestimationofcuttingconstantsandtheoffsetgeometryfollowedbythenumericalandexperimentalverificationsinSection4andconclusionsinSection5.2.MillingforceswithcutteraxisoffsetThecutterandworkcoordinateswiththeoffsetgeometryaresetupsimilarlytothosein9andareshowninFig.1.Thepositionsofcuttingedgesarerepresentedintherbhcoordinate.Thebottomofanarbitrarilychosencuttingedgeislocatedatb0andcoincideswithq0intheworkcoordinatewhenthecutterdisplacementfis0.Asthecutterrotates,thesethreeangularvariablestakeonthefollowingrelationshipFig.1.aThecutterandworkgeometryandcoordinatesinthemillingprocessandbcutteroffsetgeometry.qH11005fH11002b1TheoffsetgeometryshowninFig.1.bhasthegeometricalcenterofthecuttershiftedadistanceofrfromtherotationcenterinanangulardirectionoflfromb0.Therevisedchipthicknesswithcutteroffsetisshownin9,18tobeapproximatedbytcq,bH11005txsinqH11001tob2wheretobH11005H110022rsinpNsinbH11002lH11002pN3Consideringtheshearingandplowingcuttingmechanisms,thelocalcuttingforceperunitchipwidthisassumedtotakethefollowinglinearformwithfourcuttingconstants,H20873gtq,bgrq,bH20874H11005H20873ktskrsktsH20874tcq,bH11001H20873ktpkrpktpH208744wherektsandkrsaretheshearingconstantsrepresenting,respectively,thetangentialspecificshearingconstantandtheratioofradialtothetangentialshearingforce.ktpandkrparetheplowingconstantsrepresentingthetangentialplowingconstantandtheratioofradialtothetangentialplowingforcerespectively.Intheworkcoordinate,thelocalforcebecomesH20873gxq,bgyq,bH20874H11005H20875cosqsinqsinqH11002cosqH20876H20873gtq,bgrq,bH208745690J..J.J.Wang,C.M.Zheng/InternationalJournalofMachineToolsManufacture432003687–697CombiningEqs.2–5andrearrangingEq.5,thelocalforcescanbeexpressedasthesuperpositionofanominalcuttingforceandaforcecontributionfromthecutteroffsetH20873gxq,bgyq,bH20874H11005H20873fxqfyqH20874H11001H20873fxoq,bfyoq,bH208746inwhichH20873fxqfyqH20874H11005qspsqH11001qpppqandH20873fxoq,bfyoq,bH208747H11005tobqopoqwherepsqH11005ktstxH20873p1p2H20874H11005ktstxH20873sinqcosqsin2qH20874wq,ppqH11005ktpH20873p3p4H20874H11005ktpH20873cosqsinqH20874wq,poqH11005ktsH20873p3p4H208748H11005ktsH20873cosqsinqH20874wqandqsH11005qoH11005H208751krsH11002krs1H20876,qpH11005H208751krpH11002krp1H208769ThenominallocalforceinEq.7isexpressedasthesumoftheshearingandtheplowingcomponentsasindicatedbytheirsubscripts.Matricesqs,qpandqoreflecttheeffectsofradialcuttingconstantsonthelocalforce.Forcevectors,ps,ppandpoinEq.8arethelocaltangentialforcesperunitwidthduetotheshearing,plowingandaxisoffseteffectsrespectively.AunitheightpulsefunctionwqisincludedinEq.8torepresenttheactualradialrangeofcuttingbetweentheentryangle,q1,andtheexitangle,q2.Althoughtheentryandexitanglesarefunctionsofbasshownin9,theyareapproximatedasconstantsheretoreducethemathematicalcomplexityoftheforcemodel.Thetotalforcecanbeobtainedbyintegratingthelocalforcealongthehdirectionwithintheaxialdepthofcut.WithachangeofvariableasinEq.1,thetotalforcecanbeshowntotakeonaconvolutionintegralformgfH11005H20873gxfgyfH20874H11005H20885da0H20873gxqgyqH20874dhc10H11005H20885H11009H11002H11009H20873gxfH11002bgyfH11002bH20874cwdcbdbH11005gf∗cwdcfwhere∗denotestheconvolutionoperation.hcbinEq.10representstheaxialpositionoftheactivecuttingpointsfortheperiodicsequenceofcutterflutesandcwdcisthechipwidthdensityfunctiondefinedbydhc/db,thechipwidthperradianinb.ThesetwofunctionsareshowninFig.2andtheirexpressionsarehcbH11005H20913H11009iH11005H11002H11009hbH11002ibpwithhb11H11005H20902Rtanab,0H11349bH11349ba0,otherwisecwdcbH11005dhcdbH11005H20888H11009iH11005H11002H11009cwdbH11002ibp12withcwdbH11005dhdbH11005H20902Rtana,0H11349bH11349ba0,otherwisewherebp2p/Nistheangularspacingbetweenneighboringflutesandbadatana/Rrepresentstheaxialimmersionangleofthecutter.Indexiisthesequencenumberofthecutterflutes.SubstitutingEqs.7–9into10resultsinaconvolutionformintermsofthreedifferentforcegeneratingmechanismsFig.2.aTheaxialpositionfunctionoftheactivecuttingpointsandbthechipwidthdensityfunction.
编号:201311171556547039    大小:171.77KB    格式:PDF    上传时间:2013-11-17
  【编辑】
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
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. 人人文库网仅提供交流平台,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。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
1条评论

还可以输入200字符

当前资源信息

4.0
 
(2人评价)
浏览:19次
英文资料库上传于2013-11-17

官方联系方式

客服手机:17625900360   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

教育专区   外文翻译   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5