缸體機械加工工藝設計

-.z.CylinderblockmachiningprocessdesignCylindercastforawholestructure,anditsupperpart4cylindermountinghole;cylinderstandardcylinderisdividedintoupperandlowerdivisionsintotwoparts;cylindertotherearofthefront-sidearrangementofthepreviousthreecoa*ialmountingholeofthecamshaftandtheidlera*lehole.Cylinderprocessfeaturesare:thestructureofple*shape;processingplane,morethanholes;unevenwallthicknessandstiffnessislow;processingofhighprecisiontypicalofbo*-typeprocessingpart.Themainprocessingofthesurfaceofcylinderblocktopsurface,themainbearingside,cylinderbore,themainandcamshaftbearingboreholesandsoon,theywilldirectlyaffectthemachiningaccuracyoftheengineassemblyprecisionandperformance,mainlyrelyonprecisionequipment,industrialfi*turesreliabilityandprocessingtechnologytoensurethereasonableness.2.EngineblockprocessdesignprinciplesandthebasisforDesignTechnologyprogramshouldbetoensureproductqualityatthesametime,givefullconsiderationtotheproductioncycle,costandenvironmentalprotection;basedontheenterprisesabilitytoactivelyadoptadvancedprocesstechnologyandequipment,andconstantlyenhancetheirleveloftechnology.Engineblockmachiningprocessdesignshouldfollowthefollowingbasicprinciples:(1)Theselectionofprocessingequipment,theprincipleofselectionadoptedtheprincipleofselectionadoptedtheprincipleofbiningrigid-fle*ible,processingeachhorizontalmachiningcenterislocatedmainlysmalloperationswithverticalmachiningcenter,thekeyprocessacrankhole,cylinderhole,balancershaftholeHigh-speedprocessingofhigh-precisionhorizontalmachiningcenter,anupperandlowernon-criticalprocessesbeforeandafterthefour-dimensionalhigh-efficiencyroughmillingandhaveacertainadjustmentrangeofspecialmachineprocessing;(2)focusonakeyprocessinprincipleprocessthebodycylinderbore,crankshafthole,BalanceShaftholesurfacefinishingandthebinationofprecisionmillingcylinderhead,usingaprocessfocusedonasetupprogramtopleteallprocessingelementsinordertoensureproductaccuracyThekeyqualityprocessestomeetthecylindercapacityandtherelevanttechnicalrequirements;Accordingtothetechnologicalcharacteristicsofautomobileenginecylinderblockandtheproductionmandate,theengineblockmachiningautomaticproductionlineisposedofhorizontalmachiningcenterCWK500andCWK500Dmachiningcenters,specialmilling/boringmachine,verticalmachiningcentersmatec-30Landotherappliances.(1)topandbottom,andtilecoveredonlythebinationofapertureroughmillingmachinededicatedtothismachinetodouble-sidedhorizontalmillingmachine,usingmovingtabledrivenparts,machinetoolsimportedSiemensS7-200PLCsystemcontrol,machinecontrolcabinetsetupanindependent,cuttingautomatetheprocessispletedandtwokindsofautomaticandadjustthestate;(2)high-speedhorizontalmachiningcentermachiningcentercanberealizedCWK500thema*imumflowofwetprocessing,butbecauseofequipment,automaticBTAtreatmentsystemthroughthebuilt-intrayunderthewide-typechipconveyorandthepletionofthemachiningcentercanbedryprocessing;machinetoolspindlespeed6000r/min,rapidfeedingspeed38m/min;(3)Thebinationoffrontandrearfaceroughmillingmachinetoolusinghydraulictransmission;controlsystemimportedSiemensS7-200PLCsystemcontrol,machinetoolshaveacertainfle*ibility;(4)ThespecialmachineT*K1500thismachineverticalmachiningcenterbythemodificationofshape,withverticalmachiningcenterfeaturesandperformance,thismachinehashighstrength,highwear-resistant,highstability,highaccuracy,high-profileetc.;(5)high-speedverticalmachiningcentermatec-30Lofthemachiningcenterspindlehighspeed9000r/min.ControlsystemusesSiemensSINUMERIK840Dcontrolsystem;(6)high-speedhorizontalmachiningcenterspindleCWK500Dhighestspeed15000r/min.3.EngineblockmachiningprocessdesignthemaincontentEngineblockple*structure,highprecision,argesize,isthin-walledparts,thereareanumberofhighprecisionplaneandholes.Engineblockmachiningprocesscharacteristics;mainlyflatandtheholeprocessing,processingofflatgenerallyuseplaning,millingmethodssuchasprocessing,processingofholeusedmainlyboring,processingandmulti-purposedrillingholes.Asthecylinderple*structure.sohowtoensurethatthemutualpositionofthesurfaceprocessingprecisionisanimportantissue.3.1TheselectionofblankEngineblockonthematerialsusedaregenerallygraycastironHT150,HT200,HT250,thereisalsocastaluminumorsteelplate,thisengineblockusinghigh-strengthalloycastiron.Cylinderintheprocessingpriortoagingtreatmentinordertoeliminatestressandimprovetheroughcastingmechanicalproperties.Improvetheroughaccuracy,reductionofmachiningallowance,istoimprovetheautomatedproductionlinesystemproductivityandprocessingqualityoftheimportantmeasures.Astheforeignbo*-typepartsofroughqualityandhighprecision,anditsproduction-linesystemhasbeenimplementeddirectlyontheblankline,notonlyeliminatingtheneedforblankcheckdevicealsosavestheroughqualityproblemsduetowasteofmachiningtime,increaseoverallefficiency.Therefore,therefinementofroughistoimprovetheproductivityofthemostpromisingwayout.Fortheengineblockproductionline,canberoughinpartson-linepre-millingsi*face,removingmostofthemargin,tofacilitatedirecton-lineparts.3.2MachiningprocessselectionandprocessingofthebenchmarkChoosetherightprocessingtechnologybaseisdirectlyrelatedtotheprocessingqualitycanensuretheparts.Generallyspeaking,processbenchmarkingcanbedividedintocoarseandfinereferencebase.(1)Thebaselinefortheon-linethickrough,whichisparticularlyimportantthechoiceofbenchmarkcrude,ifcrudebenchmarkchoiceunreasonable,willtheunevendistributionofmachiningallowance,processingandsurfaceoffsets,resultinginwaste.Inthecylinderproductionline,wehaveadoptedforthecoarsesideofthebase;Oftenapartofmanyapparentneedforprocessing,ofcourse,thesurfacemachiningaccuracyaredifferent.Processingofhighprecisionsurface,oftenafterrepeatedprocessing;Asfortheprocessingofthesurfaceoflowprecision,onlyneedtogothroughoneortwoonthelist.Thus,whenthedevelopmentprocessinordertoseizethe"processinghighprecisionsurface,"thisconflict,thereasonablearrangementprocessesandrationaldivisionstageofprocessing.Arrangetheorderoftheprincipleofprocessis:afterthefirstcoarserefined,thefirstsurfaceafterthehole,thefirstbenchmarkother.Intheengineblockmachining,thesameshouldfollowthisprinciple.(1)roughingstageengineblockmachiningprocess,thearrangementsforroughingprocess,tofullycarryoutroughrough,trimmostofthemargininordertoensureproductionefficiency;(2)semi-finishingphaseoftheengineblockmachining,inordertoensuretheaccuracyofthemiddleofsomeimportantsurfaceprocessing,andarrangesomesemi-finishingoperations,willberequiredaccuracyandsurfaceroughnessofthesurfaceofthemiddleofsomeprocessingtoplete,whiledemandingthesurfaceofsemi-finished,toprepareforfuturefinishing;(3)Thefinishingstageofrequiringhighaccuracyandsurfaceroughnessofthesurfaceprocessing;(4)secondaryprocessing,suchassmallsurfacescrewholes,youcanfinishofthemajorsurfaceaftertheonehand,whentheworkpiecedeformationprocesslittleimpactatthesametimealsoreducedtherejectionrate;Inaddition,ifthemainsurfaceofawaste,thesesmallthesurfacewillnothavetobeprocessed,thusavoidingawasteofman-hours.However,iftheprocessingisveryeasyforasmallsurfacebumpsthemainsurface,itshouldbeplacedonasmallsurfacefinishpriortothemainsurfacefinishing;(5)shouldmakeproperarrangementsforsecondaryprocessessuchasproductinspectionprocess,inpartroughingstage,thekeyprocessbeforeandafterprocessing,sparepartsalltheprocessinghasbeenpleted,shouldbeappropriatearrangements.Stageofprocessingdivision,hasthefollowingadvantages:First,itcantakemeasurestoeliminatetheroughworkpieceafterthestress,toensureaccuracy;second,finishingontheback,andwillnotdamageduringtransportthesurfaceoftheworkpiecehasbeenprocessed;again,firstroughingthesurfacedefectscanbedetectedearlyandpromptlydealwithrough,donotwasteworkinghours.Butmostsmallparts,donotsubverythin.3.4cylindersurfaceofthemainprocessingandsecondaryprocessesCylindersurfaceandsupportthemainprocessingoperationsare:(1)planeprocessingatpresent,themillingofengineblocksistheprimarymeansofplanarprocessing,domesticmillingfeedrateisgenerally300-400mm/min,andforeign2000-4000mm/minmillingfeedrateparedtofarcry,tobeonincreasing,therefore,improvethemillingfeedrate,reduceoverheadtimeistoimprovetheproductivityofthemajormeansoffinishinganumberofplaneengineblockwhenthemillingfeedratetoreach2399mm/min,greatlyimprovedefficiency;Topsurfaceofthecylindermillingisakeyprocessintheprocess,theflatnessrequirementsfor0.02/145mm,thesurfaceroughnessofRa1.6um.Processinginthecylinder,theuseofsideandspindlebearingborepositioning,top,bottomandmiddlevagayonlyaperturewhileprocessingusedintheprocessinglineoutsideoftheknifedevicecanbettermeettheengineblockmachiningaccuracy;(2)Generalholesmachiningholesingeneralarestillusingthetraditionalprocessingofdrilling,e*pansion,boring,reaming,tappingandothercraftapproach.Issuesinthedesignprocessofspecificprograms,useofcoatedcuttingtools,cuttingtoolsandotheradvancedtoolswithinthecooling,andusingalargeflowofcoolingsystems,greatlyimprovingthecuttingspeed,improvedproductivity;(3)deepholeprocessingofthetraditionalprocessingmethodisusedtogradetwistdrillfeed,lowefficiencyoftheirproduction,processingandqualityispoor.Thedeepholeintheengineblockprocessing,theuseofgundrillingprocess;(4)Thethree-a*ismachiningholesforthecylinder-a*ismachiningholesholesofhighprecision,longworkinghoursoftherestrictiveprocess.Thus,workarrangements,processingmethods,toolsandsoonshouldbespecialattention.Allcoverpre-processing,thatis,semi-circularholeandthecylinderblockmainbearingcapoftheshortageofprocessing,itsmainpurposeistoremoveblankmargin,releasestress,toprepareforthepost-orderprocessing;incrankshaftmachiningprocessingcenterhole,usingdouble-sidedBoring,boringthefirstholesinthecrankshaftholeatoneendto1/2length,andthenturn180degreesworkbench,formtheotherendandthenboreanother1/2length.(5)Thecylinderboremachiningcylinderholecylindermachiningprocessingisakeyprocessintheone,undernormalcircumstances,themachiningprocessasaroughboring,semi-fineboring,precisionboringandhoning.Cylinderborewallfortheearlydetectionofcastingdefects,eliminatestress,shouldbethickcylinderboringholesinadvance;duetothestructuralcharacteristicsofthedifferentcylinderbore,mustbeinhoningprocesstoimprovethecylinderboresurfacequality.Inthehigh-volumeproduction,thecylinderborehoninggenerallyusethemulti-a*isgrindingmachineorhoningAutomaticLine.Hereweusehoningautomaticlines,fromthecoarse-heng.Fine-hengandtestingequipment,posedofthree;(6)Cleaningcleaningisdividedintowetcleaninganddrycleaning.Machiningcylinderautomaticproductionlineusingalargeflowofwetcleaning;Throughtheengineblockofthestructureandprocesscharacteristicsoftheanalysis,discussestheengineblockmachiningprocessdesignprinciplesandbasisofthechoiceofcuttingparameters,andU-turnathighspeedmillingandboring,fore*ample,design,analysisoftheenginecylinderbodyofhigh-speedmillingandturnoverboringprocess,andintheprocessingneedtopayattentionto.缸體機械加工工藝設計發(fā)動機缸體是發(fā)動機零件中構造較為復雜的箱體零件，其精度要求高，加工工藝復雜，并且加工加工質量的好壞直接影響發(fā)動機整個機構的性能，因此，它成為各個發(fā)動機生產廠家所關注的重點零件之一。1.發(fā)動機缸體的工藝特點缸體為一整體鑄造構造，其上部有4個缸套安裝孔；缸體的水平隔板將缸體分成上下兩局部；缸體的前端面從到后排列有三個同軸線的凸輪軸安裝孔和惰輪軸孔。缸體的工藝特點是：構造、形狀復雜；加工的平面和孔比擬多；壁厚不均，剛度低；加工精度要求高，屬于典型的箱體類加工零件。缸體的主要加工外表有頂面、主軸承側面、缸孔、主軸承孔及凸輪軸孔等，它們的加工精度將直接影響發(fā)動機的裝配精度和工作性能，主要依靠設備進度、工夾具的可靠性和加工工藝的合理性來保證。2.發(fā)動機缸體工藝方案設計原則和依據設計工藝方案應在保證產品質量的同時，充分考慮生產周期、本錢和環(huán)境保護；根據本企業(yè)能力，積極采用國外先進的工藝技術和裝備，不斷提高企業(yè)工藝水平。發(fā)動機缸體機械加工工藝設計應遵循以下根本原則：〔1〕加工設備選型原則加工設備選型采用剛柔結合的原則，加工設備以臥式加工中心為主，少量采用立式加工中心，關鍵工序—曲軸孔、缸孔、平衡軸孔加工采用高精度高速臥式加工中心，非關鍵工序—上下前后四個平面的粗銑采用高效并有一定調整圍的專用機床加工；〔2〕集中工序原則關鍵工序—曲軸孔、缸孔、平衡軸孔的精加工缸蓋結合面的精銑，采用在集中在一道工序一次裝夾完成全部加工容方案，以確保產品精度滿足缸體關鍵品質的工藝性能和有關技術要求。根據汽車發(fā)動機缸體的工藝特點和生產任務要求，發(fā)動機缸體機械加工自動生產線由臥式加工中心CWK500和CWK500D加工中心、專用銑/鏜床、立式加工中心matec-30L等設備組成?！?〕頂底面及瓦蓋止口面粗銑組合機床本機床為雙面臥式專用銑床，采用移開工作臺帶開工件，機床采用進口西門子S7-200PLC系統控制，機床設獨立電控柜，切削過程自動化完成，有自動和調整兩種狀態(tài)；〔2〕高速臥式加工中心CWK500該加工中心可實現最大流量的濕加工，但由于設備自動排屑處理系統是通過位于托盤下的置寬式排屑器而完成，該加工中心可以進展干加工；機床主軸轉速6000r/min，快速進給速度38m/min；〔3〕前后端面粗銑組合機床機床采用液壓傳動；控制系統采用進口西門子S7-200PLC系統控制，機床具有一定的柔性；〔4〕采用機床T*K1500本機床有立式加工中心改造而成形，具備立式加工中心的特點及性能，該機床具有高精度、高強度、高耐磨度、高穩(wěn)定性、高配置等優(yōu)點；〔5〕高速立式加工中心matec-30L該加工中心主軸最高轉速9000r/min。控制系統采用西門子公司SINUMERIK840D控制系統〔6〕高速臥式加工中心CWK500D主軸最高轉速15000r/min。3.發(fā)動機缸體機械加工工藝設計的主要容發(fā)動機缸體構造復雜，精度要求高，尺寸較大，是薄壁零件，有假設干精度要求較高的平面和孔。發(fā)動機缸體機械加工的工藝特點是：主要是平面和孔的加工，加工平面一般采用刨、銑削等方法加工，加工孔主要采用鏜削，加工小孔多用鉆削。由于缸體構造復雜，因此如何保證各外表的相互位置精度是加工中的一個重要問題。3.1毛坯的選擇發(fā)動機缸體采用的材料一般是灰鑄鐵HT150、HT200、HT250，也有采用鑄鋁或者鋼板的，此發(fā)動機缸體采用高強度合金鑄鐵。缸體在加工前進展時效處理，以消除鑄件應力和改善毛坯的力學性能。提高毛坯精度，減少加工余量，是提高自動生產線系統生產率及加工質量的重要措施。由于國外箱體類零件毛坯質量和精度較高，其生產線系統已實現了毛坯直接上線，既省去了毛坯檢查裝置，也節(jié)省了由于毛坯質量問題而浪費的加工工時，提高了綜合效益。因此，精化毛坯是提高生產率最有潛力的出路。對于發(fā)動機缸體生產線，可在零件上線前粗銑六個面，去除大局部余量，便于零件直接上線。3.2機械加工工藝基準的選擇和加工選擇合理的加工工藝基準，直接關系到能否保證零件的加工質量。一般來說，工藝基準可分為粗基準和精基準?！?〕粗基準對于上線的毛坯，其粗基準的選擇尤為重要，如果粗基準選擇不合理，會使加工余量分布不均勻，加工面偏移，造成廢品。在缸體生產線中，我們采用側面作為粗基準；〔2〕粗基準對于發(fā)動機缸體這種箱體零件來說，一般采用“一面兩銷〞為全線的統一基準。對于較長的自動自動生產線系統，由于定位銷孔在使用過程中的磨損造成定位不準確，因此，將定位銷孔分為2-3段使用。在缸體定位銷孔的加工中，我們采用了以側面、底面和主軸孔定位，在加工中心上加工。3.3機械加工加工階段的劃分和工序的安排一個零件往往有許多外表需要加工，當然外表的加工精度是不同的。加工精度較高的外表，往往要經過屢次加工；而對于加工精度低的外表，只要經過一兩次就行了。因此，擬定工藝順序時，要抓住“加工精度高的外表〞這個矛盾，合理安排工序和合理劃分加工階段。安排工藝順序的原則是：先粗后精，先面后孔，先基準后其他。在發(fā)動機缸體的機械加工中同樣應遵循這一原則?！?〕粗加工階段在發(fā)動機缸體的機械加工過程中，安排粗加工工序，對毛坯全面進展粗加工，切去大局部余量，以保證生產效率；〔2〕半精加工階段在發(fā)動機缸體的機械加工過程中，為了保證一些重要外表的加工精度，安排一些半精加工工序，將精度和外表粗造度要