皮套圈座多轴钻孔专机设计毕业设计论文

编号无锡太湖学院毕业设计（论文）相关资料题目：皮套圈座多轴钻孔专机设计信机系机械工程及自动化专业学号：0923176学生姓名：指导教师：（职称：副教授）（职称：）2013年5月25日目录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计（论文）开题报告题目：皮套圈座多轴钻孔专机设计信机系机械工程及自动化专业学号：学生姓名：指导教师：（职称：副教授）（职称：）2012年11月14日课题来源无锡市江泰机械制造厂是一家专业从事外协件加工的企业，公司现采用加工中心加工纺织机械零件--皮圈架座上的三个孔,皮套圈座是纺织机械上一个异形件,加工精度高,用普通机床加工较困难，工装时间长，加工成本高，效率不高。因而需要设计一台专机达到提高工作效率，降低成本。科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）普通机床加工零件时，不仅工人劳动强度很大，效率也不高，而且不利于保证产品加工精度。专用机床是按高度工序集中原则设计的，即在一台机床上可以同时完成许多同一种工序或多种不同工序的加工，它可以同时用多个刀具进行切削，机床的辅助动作实现了自动化，结构比普通机床简单，提高了生产效率。专用机床与普通机床比较，具有以下特点：=1\*GB2⑴专用机床上的通用部件和标准零件约占全部机床零、部件总量的70%到80%，因此设计和制造的周期短、投资少、经济效益好。=2\*GB2⑵由于专用机床采用多刀加工，并且自动化程度高，因而比普通机床生产率高，产品质量稳定，劳动强度底。=3\*GB2⑶专用机床的通用部件是经过周密的设计和长期生产实践考验的，又有专门厂家成批制造，因此结构稳定，工作可靠，使用和维修方便。=4\*GB2⑷专用机床易于联成专用机床自动线，以适应大规模的生产需要。随着社会经济的发展，机械制造业也愈来愈受到人们的关注。在皮套圈座方面，生产效率不仅严重地威胁着企业的经济情况，而且大量的工作危害着生产者的健康,立式多轴钻孔专机有效的缓解了这一现象。钻孔的要求越高,工人的工作量也就越大,针对手工钻孔的技术要求也就越高,工人保持长期的精力积中,容易出现生产安全事故,危害性较大.针对这一情况,各个企业采用了不同的方案,包括使用单一的钻床来减轻劳动者的疲劳度,这些措施在一定改善员工的作业要求,但还不能满足要求。因此,研究合适的皮套圈座立式多轴钻孔专机,降低了工作强度,特别是减缓工人的精力过度集中,对于防止企业的生产事故有明显的效果和保护作业人员的生命安全有十分重要的意义。多轴钻孔最早出现在日本地区，后经台湾传入大陆。距今已有二十年的历史。随着国家不断的加大对外开放,经济受到了剧烈的竞争,生产效率成为各个公司缓解压力的关键点,皮套圈座多轴钻孔专机面临着更广阔的应用空间。研究内容皮套圈座多轴钻孔专机的工作原理,结构组成,以及工作特点,控制系统;了解该系统机构的制造工艺,控制系统,安全装置的工作原理。在前几年,手动钻孔机应用在我国较为广泛,随着竞争的不断加剧,机械加工精度要求不断地提高,手工钻孔逐渐被淘汰.单轴钻孔专机的出现越来越频繁,世界的一体化不断加剧,多轴钻孔专机取代了单轴钻孔专机受到越来越广的应用.随着多轴钻孔的兴起,多轴钻孔专机大体上分为两大类,可调式和固定式多轴钻床按其加工件的硬度来划分，可分为中切削型、重切削型和强力超重切削型三类。中切削适用于铝、镁、铜等HB≤150以下的工件。重切削适用于孔数大于10个的软质件或7孔以下的钢、铁等HB≤265以下的工件。强力超重切削型试用于265≤HB≤330钢、铁等强硬度工件。总之，综合考虑各种情况，得出一个最优设计方案，设计一个符合实际情况的皮套圈座立式多轴钻孔专机。拟采取的研究方法、技术路线、实验方案及可行性分析通过对多轴钻孔专机的实物研究和要加工产品的市场研究和产品分析,总结得出皮套圈座多轴钻孔专机的基本结构,工作方式与原理.然后根据考察的结果,再查阅相关书籍,确定基本的设计参数,进行初步的三维建模。交由指导老师检查,修改.完成后,再对主要载荷部件进行校核.最后出主要零件的零件图,编写设计说明书。可行性分析：《我国多轴钻床行业2010年发展报告》指出2010年多轴钻床行业总产值上年增长20%，出口合同额比上年增长15%。目前，国内已有众多厂家在进行皮套圈座多轴钻孔专机等相关产品的生产研发工作，如无锡市，数家公司完成对此的研发，并成功用于产品的加工.由此可见，该设计方案切实可行。研究计划及预期成果研究计划:2002年10月12日-2002年12月25日：按照任务书要求查阅论文相关参考资料。2013年3月8日-2013年3月14日：按照要求修改毕业设计开题报告。2013年3月15日-2013年3月21日：学习并翻译一篇与毕业设计相关的英文材料。2013年4月12日-2013年4月25日：机床设计。2013年4月26日-2013年5月21日：毕业论文撰写和修改工作。预期成果：此多轴钻孔专机的研究成功可以有效的降低工作强度,主要体现在下面几个方面:(1)科学钻孔,降低对员工的技术要求。(2)提高效率,增加经济效益.。今年来我国生产事故不断，造成重大人民生命财产的损失，其中很多就是由于长时间的精力高度集中引起的。特色或创新之处近年来我国皮套圈座多轴钻孔专机有了较大的发展。动力系统,传动系统,钻孔的质量和技术水平都有较大的提高。特别在孔的精度上，达到了更高的水平。在其它方面均有较大的突破。我设计的皮套圈座多轴钻孔专机的特色也在于此，即注重实用性和经济性；效率高；同时性价比高，成本低。已具备的条件和尚需解决的问题已具备的条件：设计过程中所需要的各种软硬件资源和相关产品实物照片。尚需解决的问题：相关文献资料的缺乏，对一些结构设计部分的具体设计指导，以及三维软件的高级运用技巧。指导教师意见指导教师签名：年月日教研室（学科组、研究所）意见教研室主任签名：年月日系意见主管领导签名：年月日英文原文Small-holedrillinginengineeringplasticssheetanditsaccuracyestimationHirokiEndoandEtsuoMaruiAbstractInrecentmanufacturingprocesses,thesmalldiameterholedrillingprocessisfrequentlyusedowingtoitsgoodcharacteristics.Thedrillingprocesscaneasilybeadaptedtowidevariationsinlotsize,processingaccuracy,processingspotpatternswhereholesaremade,andsoon.Manymachineelements,whichhavesmalldiameterholes,aremanufacturedusingengineeringplasticsofsuperiormaterialandmachiningproperties.However,itisnoteasytodrillholeswithadiametersmallerthan1

mm,inrecentmachiningtechnologyaswell.Inthisreport,1-mmdiameterholesaredrilledontwoengineeringplasticssheetsandtheirdrillingaccuracyisdiscussed.Keywords:Smalldiameterhole;Drilling;Engineeringplastics;Machiningaccuracy

1.IntroductionProcessingofsmalldiameterholesisdoneinvariousmaterials,correspondingtothetrendofdownsizingorhighaccuracyinpartsincorporatedintoelectronicequipments,medicalinstrumentsortextilemachineries.Manytechniquesareputtopracticaluse,includingdrilling,ultrasonicmachining,electricdischargemachining,electrolyticmachining,laserbeammachining,electronbeammachining,fluidorabrasivejetmachining,andchemicalblanking.Dependingontheworkpiecematerial,themachiningaccuracy,andthelotsize,thebestprocessformakingholesofsmalldiametermaybeappropriatelyselected.Withinthesevariousmachiningprocesses,thedrillingprocesscanreadilydealwithawidevarietyofmachiningconditions.However,therearesomedifficultproblemsindrillingholessmallerthan1

mmindiameter.Forexample,alargeloadcannotbeputonsmalldrills,owingtotheirlowstrengthandrigidity.Thus,thefeedrateperunitdrillrotationmustbesetsmall.Theremovalofdrilledchipsisdifficultowingtothesmalldrillflutearea.Inmanycases,engineeringplasticsareusedinmakingvariousmachinepartsbecausetheyarelightandhavesuperiorspecificstrength(thatis,theratiooftensilestrengthtodensity)comparedwithcarbonsteel.Also,thematerialcostofengineeringplasticsiscompetitiveandtheirmachinabilityisfairlygood.Withthesepointsasbackground,theorthogonalcuttingofengineeringplasticswasinvestigated[1]anditwassuggestedherethatthevisco–elasticpropertiesofengineeringplasticshavesomeeffectsonthemagnitudeofcuttingforceandthesurfaceroughnessofmachinedsurfaces.Thereisareviewpaper[2]regardingthemachiningofengineeringplastics.Inthisreviewpaper,drillingprocesswasalsotreated.Itwaspointedoutthattheheatingupoftheworkpieceduetobuild-upofswarfondrillflutesisanobstacletothedrillingprocessofengineeringplastics.Recently,someexperimentshavebeenattemptedondrillingglass–fiber-reinforcedengineeringplasticssheets[3]and[4],andthethrustforceandtorqueduringdrillinghavebeenmeasured.Inthesepapers,itwasreportedthatthedelaminationphenomenondecreasesthedrilledholeintegrity,whenholesofabout5-mmdiameteraredrilled.However,theinvestigationontheaccuracyinsmallholedrillingofengineeringplasticsisleftpending.Theninthispaper,smalldiameterholesof1

mmaredrilledintwotypicalengineeringplasticssheets,andtheeffectofspindlespeedandfeedrateontheaccuracy(radiuserror)isestimated.2.WorkpiecematerialsTwotypicalengineeringplasticssheets,polyacetal(POM)andpolyetherimide(PEI),weredrilled.ThematerialspropertiesarelistedinTable1.Table1.MaterialpropertiesofworkpieceengineeringplasticsPerformanceUnitPOMPEISpecificgravity1.411.27Rateofwater%0.220.25Meltingpoint°C165210Coefficientoflinearthermalexpansioncm/cm/°C9×10−55.6×10−5TensilestrengthMPa61124Tensileextension(Yieldingpoint)%4023BendingstrengthMPa89157BendingelasticityGPa2.603.07CompressivestrengthMPa103118IzoteimpactvalueJ/m7442RockwellhardnessMscale119127Polyacetalisacrystallizedengineeringplasticsmaterial.Themainrawmaterialsareacetalco-polymerandhomo-polymer.POMhasgoodfatiguepropertiesandmachinability.Manycams,guidesandlinersaremadeofPOM.Veryhighaccuracyisneededinthesemachinedparts.PEIisanamorphousengineeringplastichavingsuperiorthermalresistancecharacteristics.Specialelectricalparts,forexample,electricinsulators,connectors,aremadeofPEI,whichissuperiorinmechanicalstrengthbutinferiorinmachinabilitytoPOM.Theworkpiecesizewas:length100

mm,width50

mmandthickness0.8

mm.3.ExperimentalapparatusandprocedureThedrillingmachineusedisforsmalldiameterholes,andisequippedwithanautomaticfeedmechanism.Ahigh-frequencyinductionmotorpositionedattheuppermostpositionofthemainspindledrivesthespindle.Maximumspindlespeedis12,500

rpm.Thenetspindlespeedofthespindleduringthedrillingismeasuredbyatachometer,whichcountsnumberofthelaserbeamreflectedfromareflectivetapepastedonthescrollchuck.Aservomotorfordrillfeeddrivesthefeedmotionofthespindle.Thefeedisstepless,andadialgaugeequippedatthespindleheadmeasuresthelengthofthedrillmotioninthespindleaxisdirection.Astopwatchwasusedtomeasurethetimeneededforthislength.Theratioofthemovedlengthtothetimeisthesubstantialfeedrateperunittime.Thespindlespeedwasvariedbetween1250and12,500

rpm.Andalsothefeedrateperunittimewasvariedbetween0.405and1.986

mm/s.Spindlespeedwasvariedinkeepingwiththefeedrateperunittime.Hence,thefeedrateperunitdrillrotationbecamesmallwiththeincreaseinthespindlespeedofthedrill.Thedrillspindleendisattachedtothescrollchuck.Thedrillusedhereisaconventionaltwistdrillmadeofhigh-speedsteelwithadiameterof1

mm.Insomeextraexperiments,a0.3

mm-diameterdrillwasalsoused.Suchdrillshavenosurfacetreatment.Adialgaugeestimatesdeflectionaccuracyofthedrillonthescrollchuckduringrotation.Extremecarewastakensothatthedrilldeflectionwassmallerthan5

μm.Thesamedrillmadefiveholesunderthecuttingconditionofthesamespindlespeedandthesamefeedrate.Anotherdrillwasusedinthedrillingunderanothercuttingcondition.Ofcourse,thesizeaccuracyofthesedrillsexistswithintheabove-mentionedsizescattering.Anyevidenceofthewearofdrillsandthebuild-upofswarfondrillfluteswerenotrecognizedafterfiveholesdrilling.Formerlymentionedworkpieceofengineeringplasticsweresetonthebaseofthedrillingmachinebyclampingbolts.Drycuttingwithoutfluidwasperformed.4.CalculationofdrilledholeshapesThe1-mmdiameterholesdrilledonengineeringplasticssheetsbytheprocessdescribedabovearenotgeometricallytruecircles,buthaveasmallradialdeviation.Shapeaccuracyofthedrilledholesisestimatedbythefollowingprocess.Anopticalmicroscopeequippedwithdigitalmeasuringdevicemeasurestheshapeofthedrilledhole.Thecrosswireofthemicroscopeissetatthecircumferenceofthehole.Then,thecoordinates(x,y)oftheholecircumferenceareread.Dividingthecircumferenceinto18equalparts,thesamemeasurementsarethenrepeatedoneachspotonthecircumference.Usingthese18setsofmeasuredqualities,theequationofthecirclethatfitscloselytothedrilledholeiscalculated.Thisiscalledaleastsquarecircle,andinthecalculation,theleastsquaresmethodisapplied.Theequationoftheleastsquarecircleisassumedasfollows:\o"ClicktoviewtheMathMLsource"x2+y2+Ax+By+C=0(1)Owingtotheshapeerrorofthehole,therighthandsideofEq.(1)doesnotbecomezerowhentheabove-mentionedmeasuredqualities(xi,yi)aresubstituted.Theresidualinthiscaseisviandthefollowingequationisobtained:(2)Here,thecoefficientsA,B,CinEq.(1)aredeterminedasthesumofthesquaredvaluesoftheresidualvibecomesminimum.Valuesofthesecoefficientsareobtainedbysolvingthefollowingsimultaneouslinearequations.Inthecalculation,N=18.(3)Moreover,thecoordinates(x0,y0)ofthecenteroftheleastsquarecircleanditsradiusrmareobtainedasfollows:Correspondingtotheaboveprocess,theleastsquarecirclesaredescribed.AnexampleisshowninFig.1,wheretheworkpiecematerialisPEI,drilldiameter:1

mm,spindlespeed:12,500

rpm,andfeedrate:0.405

mm/s.Theleastsquarecircleisindicatedbythebrokenline.5.EstimationofmachiningaccuracyandexperimentalresultsMachiningaccuracyofthedrilledholesisestimatedbytheradiuserrorobtainablefromtheleastsquarecircles.Thecalculationprocessoftheradiuserrorisgivenhere.Radiusriattheeachmeasuringspot(xi,yi)isobtainedfromthecoordinateoftheleastsquarecirclecenter(x0,y0)ofEqs.(4)and(5)asfollows:(7)Then,theradiuserroriscalculatedbythefollowingequation.TheparameterrmintheequationistheradiusoftheleastsquarecirclegivenbyEq.(6).\o"ClicktoviewtheMathMLsource"Δri=ri−rm(8)Andthepositionofthatmeasuringspotonthecircleisrepresentedbythefollowingangleθi.(9)TherelationbetweenΔriandθiobtainedfromtheabovemethodisshowninFig.2asaradiuserrorcurve.ThedrillingconditionsinthisfigurearethesameasthoseofFig.1Threeconcavitiesandconvexitiesarerecognizedonthecircumference.Then,thedrilledholeshapeisapproximatelytriangular.Similarresultswereobtainedinotherworkpiecematerialsforotherdrillingconditions.Furthermore,itisseenthatthecircumferenceofthedrilledholeexistsinthevicinitywithin±0.02

mmfromtheleastsquarecircle.Thisdrilledholeshapeissimilartothatproducedbytheso-calleddrillwalkingphenomenon[5].Theradiusoftheleastsquarecircleisslightlylargerthanthatofthedrill.Thedifferencebetweenthemisabout10

μm.ResultofFig.2isobtainedinthemeasurementatthedrillentranceintoworkpiece.Smallburrwasformedatthedrillexistandtheaccuracymeasurementcouldnotcarryoutasitis.Then,theburrwasforciblyremovedandtheaccuracywasmeasured.Almostthesameaccuracywasconfirmed,becausetheworkpieceisthin(0.8

mmthickness).Theseradiuserrorsarerearrangedasfunctionsofthespindlespeedorthefeedrateforeveryworkpiecematerial.TheresultsaregiveninFig.3,Fig.4,Fig.5andFig.6.Errorbarsindicatethedistributionrangeoftheexperimentaldata.Theradiuserrorbecomessmallhyperbolicallywiththeincreaseinthefeedrateandbecomeslargelinearlywiththespindlespeed.Smalldiameterdrillswereusedinthisexperimentandtheirbendingrigidityislow.Rotationalcuttingspeedisalmostzeronearthechiselpoint.Atthatpoint,thedrillhasonlyasmallaxialvelocitycorrespondingtothedrillfeedmotion.Accordingly,therateofpenetration[6]isextremelysmallwhenthefeedrateissmall.Asmentionedabove,thewalkingphenomenonoccursowingtosmallerrorsindrillsize.Thisphenomenoniscompoundedwiththeeffectofsmallrateofpenetrationwhensmallfeedrateandlargespindlespeedareapplied.Hence,thepositioningaccuracyofthedrillpointagainsttheworkpieceisnotverygoodatsmallfeedrateandlargespindlespeed.Asaresult,itissupposedthattheradiuserrorbecomeslarge.Forexample,therateofpenetration,thatisthefeedrateperunitdrillrotation,isabout2

μmwhenthedrillrotationspeedis12,500

rpmandthefeedrateis0.405

mm/s.Therateofpenetrationisabout100

μmwhenthedrillspindlespeedissmallest(1250

rpm)andthefeedrateislargest(1.986

mm/s).Onereasonfortheradiuserrorworseningwhentherotationspeedbecomeshighisthatchatter[6]relatedtothedrilldynamiccharacteristicsispossible.However,thesmalldrillsizeerrorsandtherelativedropinthefeedrateperunitdrillrotationcorrespondingtothespindlespeedincreasehavealargeeffectontheradiuserror.Inconclusion,itisimportanttodrillasmallholeinthedrillingconditionsoastomaintainasufficientlyhighfeedrateperunitdrillrotation.AnexampleofsuperpositionoftheresultsofPOMandPEIisgiveninFig.7.ItisrecognizedinthisfigurethattheradiusaccuracyinthedrillingofPEIisslightlyinferiortothatofPOM.PEIisakindofsupperengineeringplastics.PEIissuperiortoPOMintensilestrength,compressivestrength,bendingstrength,bendingelasticityandRockwellhardness,asseeninTable1.Owingtothis,themachinabilityofPEImaybeworsethanthatofPOMandtheresultofFig.7regardingtheradiuserrorwasbeobtained.6.ConcludingremarksSmallholesweredrilledintwoengineeringplasticssheetsPOMandPEIusingadrill1

mmindiameter.Drillingcanbedoneonbothworkpiecematerials.Readingthedrilledholeshapebyopticalmicrometer,andcalculatingtheleastsquarecircle,thedrillingaccuracy(radiuserror)canbeestimated.Theradiuserrorbecomesworsewhenthedrillfeedrateissmallandthespindlespeedislarge.Thefeedrateperunitdrillrotationisrelativelysmallwhenthespindlespeedislarge.Hence,itissupposedthatthepositioningaccuracyofthedrillagainsttheworkpieceisnotgood,andthattheradiuserrorbecomesworseunderthedrillingconditionsinwhichthefeedrateperunitdrillrotationissmall.Fromthisfact,itisdesirablethatsmalldiameterholesbedrilledintheconditioninwhichthefeedratedoesnotbecomelow.References[1]K.Q.XiaoandL.C.Zhang,Theroleofviscousdeformationinthemachiningofpolymers,InternationalJournalofMechanicalScience44(2002),pp.2317–2336.[2]M.Alauddin,I.A.ElBaradieandM.S.J.Hashmi,Plasticsandtheirmachining:areview,JournalofMaterialsProcessingTechnology54(1995),pp.40–60.[3]W.-C.Chen,Someexperimentalinvestigationsinthedrillingofcarbonfiber-reinforcedplastic(CFRP)compositelaminates,InternationalJournalofMach