数控加工工艺--外文文献

英文原文CNCMachiningProcessFirst,ourcountry'shistoryofthedevelopmentofnumericalcontrolsystem1.Ourcountrysince1958,byagroupofresearchinstitutes,collegesanduniversitiesandafewstartedtoCNCMachineToolPlantoftheresearchanddevelopmentsystem.Atthattime,duetothelowlevelofdomesticelectroniccomponents,suchasthedepartmentofeconomicconstraints,lackofalargerdevelopment.2.Inthereformandopeningup,China'snumericalcontroltechnologygraduallyachievesubstantialdevelopment.After"65"(81----85years)theintroductionofforeigntechnology,"75"(86------90years)ofthedigestionandabsorptionandthe"EighthFive-YearPlan"(91~1-95years)NationalOrganizationofscientificandtechnological,thatmakesourcountry'sCNCtechnologyhasaqualitativeleapinacceptanceatthattime,throughresearchandidentificationofcountryproductsincludingBeijingEverest'sChineseI,centralChina'scentralNCIandafewhigh-endShenyangNationalEngineeringResearchCenterforControlofBlue-I,aswellasotherthroughthe"NationalQualitySupervisionandTestCentermachine"testNCsystemofqualifieddomesticcompaniessuchasNanjing,fourproducts.3.China'sCNCmachinetoolmanufacturingindustryinthe80'shadthestageofrapiddevelopment,manymachinetoolplantproductsfromtraditionalproductstotheNCtransition.But,generallyspeaking,thetechnologicallevelisnothigh,thequalityofthepoor,sointheearly90'sfacingthecountry'seconomyfromaplannedeconomytoamarketeconomyandadjustthetransferwentthroughthemostdifficultyearsoftheDepressionperiod,theproductioncapacityatthattimedownto50%,morethanfourmonthinventory.From1995,"NinthFive-YearPlan"toexpanddomesticdemandfromthecountryafterthemachinetoolmarkettostart,soastoreinforcetheapprovalofimportsofCNCequipment,investmentfocusedonsupportforkeynumericalcontrolsystem,equipment,technologiesofCNCequipmenthasplayedasignificantrole,especiallyin1999,thecountry'sdefenseindustrytocivilianindustryandthekeytoputtinginalotoftechnicaldepartmentfunds,toenableCNCequipmentmanufacturermarketthriving.Three,CNCTechnologyandEquipmentofcarscutCNCLatheMachiningLathetechnologyandprocessingtechnologysimilarto,butbecauseofCNClatheisafixture,forautomaticprocessingofallfinishturningprocess,whichshouldpayattentiontothefollowingaspects.1.Areasonableselectioncuttingforthehigh-efficiencymetal-cuttingprocessing,theprocessedmaterials,cuttingtools,cuttingconditionsisthethreemajorelements.Thesedeterminetheprocessingtime,toollifeandprocessingquality.Cost-effectiveprocessingmethodsmustbeareasonablechoiceofthecuttingconditions.Threeelementsofcuttingconditions:cuttingspeed,feedrateandcuttingdepthofthedamagedirectlycausedbythetool.Withtheincreaseincuttingspeed,tooltiptemperaturewillrise;willhavemechanical,chemical,thermalwearandtear.20%increaseincuttingspeed;toollifewillreducethe1/2.Feedconditionsandtherelationshipbetweentoolwearandtearatthebackofaverysmallareaof.However,thefeedrate,cuttingtemperaturerise,wearbigbehind.Thantheimpactofcuttingspeedontoolsmall.Depthofcutonthetoolsdidnotaffectthecuttingspeedandfeedrate,butatsmallcuttingdepthofcutwhencuttingmaterialshavebeenhardenedlayer,whichwillaffectthetoollife.Theuserisprocessedaccordingtothematerial,hardness,cuttingstatus,materialtype,feedrate,cuttingdepth,suchastheoptionofusingthecuttingspeed.Themostappropriateselectionsofprocessingconditionsareatthebasisofthesefactorsisselected.Haverules,stability,wornandtearistoachievetheidealconditionsforlife.However,inactualoperation,theselectiontoollifeandtoolwear,thesizeofchangesinprocessing,surfacequality,cuttingnoise,heatprocessingandsoon.Indeterminingtheprocessingconditionsrequiredtostudytheactualsituation.Theheat-resistantalloyssuchasstainlesssteelandhardmaterials,thecoolantcanbeusedbesttouserigidblade.2.Reasonableselectiontool1)whenrough,itisnecessarytochoosehighstrength,gooddurabilitytool,inordertomeettheroughknifewheneatinglargebackvolume,thefeedrequirements.2)Finecar,itisnecessarytochoosehighprecision,durabilitygoodtooltoensurethattherequirementsofmachiningaccuracy.3)Inordertoreducetoolchangetimeandconvenienceoftheknifeshouldbeusedmachinesandmachinefolderknifeblade.3.AreasonableselectionFixture1)Generalselectiontrytheworkpiececlampingfixturetoavoidtheuseofadedicatedfixture;2)positioningthebasepartsoverlapsoastoreducethepositioningerror.4.Todeterminetheprocessingrouteprocessingrouteistheindex-controlledmachiningprocess,toolpartsrelativetrajectoryanddirectionofSports.1)Shouldbeabletoensurethemachiningaccuracyandsurfaceroughnessrequirements;2)shouldtrytoshortentheprocessingroute,reducingtraveltimeandairknives.5.ProcessingrouteofcontactwithallowanceAtpresent,CNClatheshavenotyetachievedtheuniversalaccesstoconditions,thegeneralshouldbeputontoomuchroughmargin,especiallywithforging,castinghardcushioncortexingenerallatheprocessing.MustbesuchasCNClathe,theneedtopayattentiontoprocessflexibility.6.Fixturetoinstallthemainpointsatpresent,thehydraulicclampingchuckandhydrauliccylinderareconnectedbytherodoftheimplementation,inFigure1.Hydraulicclampingchuckasfollows:Firstofall,bymovingonhandtounloadthenuthydrauliccylinder,thedischargeofSLIDE,andback-endfromthespindleout,andthenmovethehandstounloadscrewchuckcanbedisposedofunderthechuck.Four,effectivelyturningareasonableSaveprocessingtimeIndexTurningCenter'sG200integratedprocessingunitwithamodular,high-powertwo-axislinkageaxisfunction,thusfurthershorteningtheprocessingtime.Withothermeansofjob-axisoppositetotheconceptofclamping,theuseoftheproductcanbeintegratedintelligentprocessingunitinplacesothattheworkpiececlampingandautomaticprocessing.Inotherwords,theautomaticsetupwillnotbeaffectedbytheprocessingofanotheraxis,afeaturethatcanbeshortenedabout10%oftheprocessingtime.Inaddition,theFourprocessingveryquickly,youcansimultaneouslyhavetwoprocessingtool.Whenthemachineisputintouseinpairs,theefficiencybecomesmoreapparent.Inotherwords,theconventionalhardturningandsettingtwocarscanparallelmachine.Turningconventionalvehiclesandhardwaredifferencesbetweenthetoolandfocusedonlyinthecoolantsystemthermostat.However,conventionalprocessingisdifferent:bothcanbeusedconventionalprocessingandatoolcarrierforprocessingTailstock;andhardwarewhenusingatoolonly.Inbothtypesofmachinetoolscanbecarriedoutontheharddryprocessing,onlythemanufacturer'stechnologyprogramdesignedtobalancetheneedtobeattime,andIndexofthemodulestructureofmachinetoolstoprovidethemwithgreaterflexibility.Toimprovetheproductivityofhigh-precisionwiththecontinuousimprovementofproductionefficiency,theuseralsomadeforaveryhighaccuracyrequirements.TurningCenterG200usedforprocessing,thecoldstartuptofourpartsprocessingrequiredtoachievetolerancesof卤6mm.Processingprocess,theaccuracyisusuallymaintainedat2mm.Indexsomadeavailabletothecompany'sclientsarehigh-precision,highefficiency,theintegrityoftheprogram,andprogramstoprovidesuchhighprecision,requiringcarefulchoiceofspindle,bearingsandotherfeatures.G200TurningCenterLandshut,Germany,BMWcarfactoryintheapplicationofthecompanyachievedgoodresults.Theplantisnotonlytheproductionofengines,butalsobytheproductionofcastlightmetalparts,plasticdecorativeitemsinsidethevehicleandsteeringaxis.Considerthequalityofsupervisorystaff,anditsveryprecisemachiningaccuracy:tolerancebandsfor卤15mm,forbearingtolerance卤6.5mm.Inaddition,theprocessingoftheuniversaljointsoftheIndexcompaniesuseautomaticintelligentprocessingunit.Thefirsttwopartsareusedforturningcentersbeforeplayingpre-processing,post-processinglinemeasurement,andthensentthroughtheconveyorbeltforhobbling,cleaningandquenchingtreatment.ThelastprocessusingthesecondprocessingsystemIndex.G200TurningCenterbytwosteeringknuckleonthecarbearinghard.Inthemachinetooltocompletetheonlinesurvey,thentothedischargeunit.Processingunitfullyintegratedintothelayoutoftheworkshop,andinlinewithergonomicrequirements,coversanareaofgreatlyreduced,andonlytwostaffmemberstothecustodyofmanufacturingcells.Friday,CNCturningandG00inthemagicaleffectoftheskillstoensuredimensionalaccuracyCNCturningprocessingtechnologyhasbeenwidelyusedinmechanicalmanufacturingindustry,howefficient,reasonable,andcompletedbythequalityoftheworkpiecebytheamountofprocessing,eachengagedinthetradeofengineeringandtechnicalpersonnelmoreorlesshavetheirownexperience.IengagedinCNCteaching,trainingandprocessingformanyyears,accumulatedacertainamountofexperienceandskills,istoCNCEquipmentFactoryGuangzhouGSK980Tseriesofmachinetoolproduction,forexample,introduceafewskillsinCNCturning.First,theprogramfirstsentenceskillsG00WenowhaveaccesstotextbooksandCNCturningtechnicalbooks,proceduresaresetupthefirstsentenceofworkpiececoordinatesystem,thatis,G50X,Zinthefirstsentenceasaprocess.Accordingtothedirective,acoordinatesystemcanbesetsothatthetoolatapointinthiscoordinatesystemascoordinates(X,Z)(Inthispaper,theoriginofworkpiececoordinatesystemaresetattherightendoftheworkpiecesurface).Programmingusingthismethod,theknife,theknifemustbemovedtotheestablishedpositionofG50canbesetforprocessing,identifythelocationoftheprocessisasfollows.1.ofaknife,theroughworkpiececlampinggood;2.SpindleistohandroundthebaserightsideknifeflatworkpiecesurfaceA;3.Z-axisfixed,thereleaseofthetoolalongtheXaxispointstoC,typeG50Z0,thepointofcomputermemory;4.Programentrymode,typeG01W-8F50,turningouttobeonestepworkpiece;5.X-axisfixed,thereleaseofthetoolalongtheZ-axispointstoC,stopturningoutmeasuringthediameteroftheworkpiecelevel,theimportationofG50X,computermemorythatpoint;6.Programentrymode,entertheG00X伪Z尾,programmingtoolrunsthespecifiedproceduretothestartingpoint,andthenentertheG50X,Z,proceduresfortheoriginofthecomputermemory.Theabove-mentionedsteps,thestepsthatthetool6atX,ZOfficelocationisessential;otherwise,theworkpiececoordinatesystemwillbemodified,notthenormalprocessingoftheworkpiece.ProcessinghasbeentheexperienceofthepeopleallknowthattheabovepositionwillbethetooltothecumbersomeprocessofX,ZDepartment,intheeventofanaccident,XorZ-axiswithoutservo,trackingerror,poweroutageshappen,etc.,thesystemcanrestart,afterrestartsystemlossofG50workpiececoordinatevaluessetbythememory,"resetbacktozerorun"isnolongerworking,willneedtore-runthetoolandresettoX,ZlocationG50.Ifitisproduction,processing,aftertheEndofareturntothestartingpointforcontinuedprocessingundertheG50is,intheprocesssomeerrorsontheworkpiececoordinatesystemmaybemodified.InviewofthefirstsentenceoftheaboveproceduresusingG50workpiececoordinatesystemsetupmanydefects,IwillwanttoapproachtheworkpiececoordinatesystemfixedonthemachinewillprocessthefirstsentencechangedtoG50X,ZafterG00X,Z,problemsolved.ThecourseofitsoperationonlytofindG50usingtheabove-mentionedfive-stepprocessbefore,thatis,1,2,3,4,5stepstoachieve,itwillrunthetooltoasafelocation,outofprocess,andcanrunautomatically.Evenifpoweroutagesandotherunforeseencircumstancesoccur,restartthesystem,intheEditmodetomovethecursorwithoutaffectingthesafeprocessingoftheworkpieceprocessingprocessprogramsegment,accordingtoautomatetheprocessingcancontinue.FirstsentenceoftheaboveproceduretoreplaceG50withG00isthesubstanceoftheworkpiececoordinatesystemfixedonthemachine,nolongerlimitedtotheoriginG50X,Zprocessconstraints,withoutchangingtheworkpiececoordinatesystem,easyoperation,reliability,andreceivedanunexpectedeffect.ChinesemetalprocessingonlineSecond,controlofdimensionalaccuracyskills1.ToamendthevalueofaknifeuptoensuredimensionalaccuracyFirstontheknifebecauseoferrororothercausesbeyondtheworkpieceworkpieceerrortolerance,cannotmeettheprocessingrequirements,canbeaddedbymodifyingtheknifesothattheworkpiecesizetomeettherequirementtoensurethattheradialdimensionsareasfollows:a.absolutecoordinateinputmethodAccordingtothe"bigdecrease,asmallincrease"principle,aknifeupat001~004modified.Suchascutoffonthe2ndslotatabigsizeworkpiece0.1mm,and002showedupknivesareX3.8,mayentertheX3.7,toreducetheknifeonthe2ndmeeting.b.therelativecoordinatemethodasinthepreviouscase,enter002knifefillU-0.1,alsothesameresult.Similarly,theaxialsizeofthecontrolalsoandsoon.Suchascylindricalwithaknifeonthe1staxissomewhereaboveprocessing,size,long0.1mm,canbecompletedat001knifeenterW0.1.2.Semi-finishingtoensurethattheimpactoftheeliminationofscrewgapdimensionalaccuracyForthemajorityofCNClatheusingalongertime,becauseoftheeffectsofscrewspaceandprocessingoftheworkpiecedimensionsareoftenunstablesituation.Atthistime,wecanroughafterfinishingahalf-spacetoeliminatetheeffectsofscrew.1,suchasaknifewithG71cylindricalrough,youcanfillinthe001knifeenterU0.3,calltheG70afinecar,parkingmeasurements,andthenfillinthe001knifeenterU-0.3,onceagaincallingaG70Finish.Finishahalfafterthistime,eliminatingtheeffectsofscrewclearancetoensurethestabilityofthedimensionalaccuracy.3.ToensuredimensionalaccuracyProgrammera.toensuredimensionalaccuracyabsoluteprogrammingthereisanabsoluteandrelativeprogramming.Programmingreferstotherelativecurveintheprocessing,thelocationoftheendofthelinesegmenttothestartingpointforthecoordinatesofthesegmentandtodeterminetheoriginofthecoordinatesystem.Inotherwords,programmingisrelativelyoftenattheoriginofthecoordinatestransform,continuousdisplacementisboundtoresultinacumulativeerror,theabsoluteprogrammingareintheprocessingofthewholeprocess,havearelativelyunifiedreferencepoint,thatis,coordinatesoftheorigin,sotheaccumulatederrorovertherelativeProgrammingsmall.CNCturningworkpiece,theworkpieceprecisionradialdimensionthantheaxialsizeofthegeneralhighprecision,itisinthepreparationofprocedures,theuseoftheradialsizeoftheabsolutebestprogramming,takingintoaccounttheprocessingandtheconvenienceofprogramming,oftenusedsizesofaxialrelativeprogramming,buttheessentialaxialsize,theuseoftheabsolutebestprogramming.b.toensuredimensionalaccuracynumericalconversionAlotofcases,thepatternonthesizeofthebaselineandbenchmarkthesizeoftherequiredprogramminginconsistentandshouldbefirstonthebasepatternsizecoordinatesconvertedtoprogramminginsize.Figure2b,inadditiontosizeof13.06mm,therestismarkeddirectlybyFigure2aandsizetobeconvertedbytheprogramsize.Oneof,29.95mm,16mmandthethreedimensionsof60.07mmrespectivelylimitthesizeoftwoaveragesizeaftertheprogramming.4.ModifytheprogramandcontrolthesizeofpremiumknivesCNCMachining,weoftenencountersuchasituation:theproceduretorunautomaticallyafterstoppingmeasurementandfoundthatfailworkpiecesize,sizeirregularChange.Suchasaknifewith1cylindricalworkpieceprocessingasshowninFigure3,thepost-roughingandsemi-finishingparkingmeasurements,thesizeoftheradialaxisparagraphasfollows:30.06mm,23.03mmand16.02mm.Inthisconnection,Iusedaknifetoamendtheproceduresandmethodsmakeuptheremedy,asfollows:a.modifytheprogramX30originalprogramunchanged,X23changedX23.03,X16changedX16.04,Asaresult,areinexcessoftheshaftabovethenameoftoleranceuniformsize0.06mm;b.knifetofillKnifeonthe1stat001importedpremiumU-0.06.Aftertheseproceduresandatwo-prongedkniferevisedup,andthencalltherefinedprocedures,thegeneralsizeoftheworkpiececanbeeffectivelyguaranteed.CNCTurningCNCprogramisbasedonautomatedprocessing,theactualprocessing,andtheoperatoronlyhasastrongabilitytousetheprograminstructionsandawealthofpracticalskillsinordertoproducehigh-qualityprocessing,processinghigh-qualityworkpiece.Six,CNCmachinetooltroubleshootingmethodsandtheirattentiontomattersMissionsusuallytakepartinbecauseofrepair,somerepairexperience,combinedwiththerelevanttheoriesaredescribedinthefollowinglist,toinitiate.First,troubleshootingmethods(1)initializationresetLaw:Undernormalcircumstances,becauseofinstantaneousalarmsystemfailurecanbehardwareresetorsystempowerswitchinordertoremovethefault,ifthesystemisdownbecauseofthestoragearea,plugthecircuitboardorbatterylesspressureleadtoconfusion,itmustbecleartoinitializethesystem,removingtheformershouldpayattentiontomakecopiesofrecordeddata,ifinitializationcannotberuledoutafterthefailureremains,werecarriedoutinhardwarediagnosis.(2)Parameterstochange,actualprocedures:systemparametersaredeterminedbasedonsystemfunctions,parametersettingsmaycausesystemerrorsorfailuresofafunctionalnullandvoid.Sometimes,becauseofproceduralerrorscanbecausedbyuserdowntime,thissystemcanbeusedtoblocksearchfunctiontocheckandcorrectallerrors,inordertoensureitsnormaloperation.(3)Regulation,thebestmethodofadjustment:adjustmentisoneofthesimplestways.Byadjustingthepotentiometertoamendsystemfailures.Repairsuchasinafactory,thesystemdisplayschaoticscene,withnormalpost-conditioning.Suchasinafactory,thespindlebrakeatstart-upandskiddingwhenbeltbecauseofitslargespindleloadtorque,anddrivessettheramp-uptimeistoosmall,thenormalpost-conditioning.OptimizethesystemtoadjustservodrivesystemwithmechanicaldragsystemthebestwaytomatchtheGeneralregulation,theapproachisverysimple,withamulti-linerecorderordualtracestorageoscilloscope,respectively,observeinstructionsandthespeedoffeedbackorresponsetotherelationshipbetweencurrentfeedback.Byadjustingtheratioofthespeedregulatorfactorsandintegrationtimetoachieveservosystemsothattherearehighdynamicresponsecharacteristics,butnotthebestjobstatusoscillation.NOTatthesceneoftheoscilloscopeorrecordercircumstances,basedonexperience,thatis,adjustsothattheelectricalstart-up,andthenslowlyadjusttothereverse,untilyoucaneliminatetheshock.(4)sparepartstoreplacetheLaw:Thebestdiagnosisofsparepartstoreplacebadcircuitboard,andstarttodotheinitialization,sothatthenormaloperationofmachinetoolsquickly,andthenrepairorreworkbadboard,whichiscurrentlythemostcommonlyusedanti-approachit.(5)Toimprovethequalityofthepowerlaw:theuseoftheexistingpowersupply,toimprovethepowersupplyfluctuations.Forhigh-frequencyinterferencefilteringcapacitorcanbeusedbythesepreventivemeasurestoreducethepowersupplyboardfailure.(6)Maintenanceofinformation-tracking:somelargemanufacturingcompanybasedonactualworkbecauseofdesigndefectscausedbyaccidentalfailure,continuouslymodifyandimprovethesystemsoftwareorhardware.Thesechangestotheformofconstantrepairinformationavailabletomaintenancepersonnel.Usedasthebasisfortroubleshootingcanbecompletelyrighttroubleshooting.Second,therepairshouldpayattentiontomatters(1)removedfromawholeblockonthecircuitboard,theRecordshouldbenotedthattherelativepositionshouldbetoconnectthecablenumber,forfixedinstallationofthecircuitboard,itshouldberemovedbeforeandafterthepress-fitpartsandscrewsfortherecord.Demolitionunderthepressurepartsandscrewsshouldbeplacedonadedicatedbox,soastoavoidloss,theassembly,theboxshouldbeallthingstouse,orincompleteassembly.(2)Electricironshouldbeplacedonthefronteasily,awayfromthecircuitboardrepair.JerdoniiDressingshouldbeappropriateinordertoadapttotheweldingcircuitandtoavoidbumpswhenweldingothercomponents.(3)Measuringtheresistancebetweenlinesshouldbeoffthepower,measuredresistanceshouldbemeasuredtheexchangeofredandblacktablepentwiceayeartoalargevalueforthereferencevalue.(4)Circuitboardhassolderbrushmostfilms,itshouldbemeasuredtofindthecorrespondingpointofthesolderjointasatest,nottoeradicatethesolderfilm,thereissomeinsulationboardallthebrushlayer,onlyinthespotwithabladescratchDepartmentinsulatinglayer.(5)Shouldnotbearbitrarilycutofftheprintedcircuit.Somemaintenancepersonnelmusthaveexperienceinrepairofhouseholdappliances,usedtochecktheline,butthenumericalcontrolequipmentonthecircuitboardsaredouble-sidedormulti-holemetalplateofplate,printinganddensefine-line,oncecutoffthehardwelding,andeasytocutofftangentwhentheadjacentline,againsomepoint,acutoffatoneline,andshouldnotmakeitandlineout,needtodotocutoffafewlines.(6)Shouldnotberemovedcomponents.Somemaintenancepersonneltodeterminefaultcomponentsintheabsenceofcircumstancesthatistheseatofyourpantsacomponentbreaksdown,removedimmediately,sothatahigherrateofmiscarriageofjustice,humanelementremovedhaveahigherfailurerate.(7)Shouldbeusedtodemolishsuctiondevicesandsuctiondevicestinrope,shouldnothavethehardwarecheck.Longtimeheatingpadshouldnotbethesameandrepeatthedemolitioninordertoavoidpaddamage.(8)Replacementofthedevice,thepinshouldbetheappropriatetreatment,weldingshouldnotbeusedinweldingacidicoil.(9)Recordonthecircuitswitch,thejumperposition,itshouldnotbechanged.Controlformorethantwoinspections,orswapcomponentson-boardwhentheattentionofthecomponentsofthetaginordertoavoidconfusion,whichcannotworkwellplate.中文译文数控加工工艺一，我国数控系统的发展史1.我国从1958年起，由一批科研院所，高等学校和少数机床厂起步进行数控系统的研制和开发。由于受到当时国产电子元器件水平低，部门经济等的制约，未能取得较大的发展。2.在改革开放后，我国数控技术才逐步取得实质性的发展。经过“六五”(81--85年)的引进国外技术，“七五”(86--90年)的消化吸收和“八五”(91--95年)国家组织的科技攻关，才使得我国的数控技术有了质的飞跃，当时通过国家攻关验收和鉴定的产品包括北京珠峰公司的中华I型，华中数控公司的华中I型和沈阳高档数控国家工程研究中心的蓝天I型，以及其他通过“国家机床质量监督测试中心”测试合格的国产数控系统如南京四开公司的产品。3.我国数控机床制造业在80年代曾有过高速发展的阶段，许多机床厂从传统产品实现向数控化产品的转型。但总的来说，技术水平不高，质量不佳，所以在90年代初期面临国家经济由计划性经济向市场经济转移调整，经历了几年最困难的萧条时期，那时生产能力降到50%，库存超过4个月。从1995年“九五”以后国家从扩大内需启动机床市场，加强限制进口数控设备的审批，投资重点支持关键数控系统、设备、技术攻关，对数控设备生产起到了很大的促进作用，尤其是在1999年以后，国家向国防工业及关键民用工业部门投入大量技改资金，使数控设备制造市场一派繁荣。二，数控车的工艺与工装削数控车床加工的工艺与普通车床的加工工艺类似，但由于数控车床是一次装夹，连续自动加工完成所有车削工序，因而应注意以下几个方面。1.合理选择切削用量对于高效率的金属切削加工来说，被加工材料、切削工具、切削条件是三大要素。这些决定着加工时间、刀具寿命和加工质量。经济有效的加工方式必然是合理的选择了切削条件。切削条件的三要素：切削速度、进给量和切深直接引起刀具的损伤。伴随着切削速度的提高，刀尖温度会上升，会产生机械的、化学的、热的磨损。切削速度提高20%，刀具寿命会减少1/2。进给条件与刀具后面磨损关系在极小的范围内产生。但进给量大，切削温度上升，后面磨损大。它比切削速度对刀具的影响小。切深对刀具的影响虽然没有切削速度和进给量大，但在微小切深切削时，被切削材料产生硬化层，同样会影响刀具的寿命。用户要根据被加工的材料、硬度、切削状态、材料种类、进给量、切深等选择使用的切削速度。最适合的加工条件的选定是在这些因素的基础上选定的。有规则的、稳定的磨损达到寿命才是理想的条件。然而，在实际作业中，刀具寿命的选择与刀具磨损、被加工尺寸变化、表面质量、切削噪声、加工热量等有关。在确定加工条件时，需要根据实际情况进行研究。对于不锈钢和耐热合金等难加工材料来说，可以采用冷却剂或选用刚性好的刀刃。2.合理选择刀具1)粗车时，要选强度高、耐用度好的刀具，以便满足粗车时大背吃刀量、大进给量的要求。2)精车时，要选精度高、耐用度好的刀具，以保证加工精度的要求。3)为减少换刀时间和方便对刀，应尽量采用机夹刀和机夹刀片。3.合理选择夹具1)尽量选用通用夹具装夹工件，避免采用专用夹具；2)零件定位基准重合，以减少定位误差。4.确定加工路线加工路线是指数控机床加工过程中，刀具相对零件的运动轨迹和方向。1)应能保证加工精度和表面粗糙要求；2)应尽量缩短加工路线，减少刀具空行程时间。5.加工路线与加工余量的联系目前，在数控车床还未达到普及使用的条件下，一般应把毛坯上过多的余量，特别是含有锻、铸硬皮层的余量安排在普通车床上加工。如必须用数控车床加工时，则需注意程序的灵活安排。6.夹具安装要点目前液压卡盘和液压夹紧油缸的连接是靠拉杆实现的，如图1。液压卡盘夹紧要点如下：首先用搬手卸下液压油缸上的螺帽，卸下拉管，并从主轴后端抽出，再用搬手卸下卡盘固定螺钉，即可卸下卡盘。三，进行有效合理的车削加工有效节省加工时间Index公司的G200车削中心集成化加工单元具有模块化、大功率双主轴、四轴联动的功能，从而使加工时间进一步缩短。与其他借助于工作轴进行装夹的概念相反，该产品运用集成智能加工单元可以使工件自动装夹到位并进行加工。换言之，自动装夹时，不会影响另一主轴的加工，这一特点可以缩短大约10％的加工时间。此外，四轴加工非常迅速，可以同时有两把刀具进行加工。当机床是成对投入使用的时候，效率的提高更为明显。也就是说，常规车削和硬车可以并行设置两台机床。常规车削和硬车之间的不同点仅仅在于刀架和集中恒温冷却液系统。但与常规加工不同的是：常规加工可用两个刀架和一个尾架进行加工；而硬车时只能使用一个刀架。在两种类型的机床上都可进行干式硬加工，只是工艺的制造者需要精心平衡的节拍时间，而Index机床提供的模块结构使其具有更强的灵活性。以高精度提高生产率随着生产效率的不断提高，用户对于精度也提出了很高的要求。采用G200车削中心进行加工时，冷启动后最多需要加工4个工件，就可以达到±6mm的公差。加工过程中，精度通常保持在2mm。所以Index公司提供给客户的是高精度、高效率的完整方案，而提供这种高精度的方案，需要精心选择主轴、轴承等功能部件。G200车削中心在德国宝马Landshut公司汽车制造厂的应用中取得了良好的效果。该厂不仅生产发动机，而且还生产由轻金属铸造而成的零部件、车内塑料装饰件和转向轴。质量监督人员认为，其加工精度非常精确：连续公差带为±15mm，轴承座公差为±6.5mm。此外，加工的万向节使用了Index公司全自动智能加工单元。首批的两台车削中心用来进行工件打号之前的预加工，加工后进行在线测量，然后通过传送带送出进行滚齿、清洗和淬火处理。最后一道工序中，采用了第二个Index加工系统。由两台G200车削中心对转向节的轴承座进行硬车。在机床内完成在线测量，然后送至卸料单元。集成的加工单元完全融合到车间的布局之中，符合人类工程学要求，占地面积大大减少，并且只需两名员工看管制造单元即可。四，数控车削加工中妙用G00及保证尺寸精度的技巧数控车削加工技术已广泛应用于机械制造行业，如何高效、合理、按质按量完成工件的加工，每个从事该行业的工程技术人员或多或少都有自己的经验。笔者从事数控教学、培训及加工工作多年，积累了一定的经验与技巧，现以广州数控设备厂生产的GSK980T系列机床为例，介绍几例数控车削加工技巧。（一）、程序首句妙用G00的技巧目前我们所接触到的教科书及数控车削方面的技术书籍，程序首句均为建立工件坐标系，即以G50XαZβ作为程序首句。根据该指令，可设定一个坐标系，使刀具的某一点在此坐标系中的坐标值为(XαZβ)(本文工件坐标系原点均设定在工件右端面)。采用这种方法编写程序，对刀后，必须将刀移动到G50设定的既定位置方能进行加工，找准该位置的过程如下。1.对刀后，装夹好工件毛坯；2.主轴正转，手轮基准刀平工件右端面A；3.Z轴不动，沿X轴释放刀具至C点，输入G50Z0，电脑记忆该点；4.程序录入方式，输入G01W-8F50，将工件车削出一台阶；5.X轴不动，沿Z轴释放刀具至C点，停车测量车削出的工件台阶直径γ，输入G50Xγ，电脑记忆该点；6.程序录入方式下，输入G00XαZβ，刀具运行至编程指定的程序原点，再输入G50XαZβ，电脑记忆该程序原点。上述步骤中，步骤6即刀具定位在XαZβ处至关重要，否则，工件坐标系就会被修改，无法正常加工工件。有过加工经验的人都知道，上述将刀具定位到XαZβ处的过程繁琐，一旦出现意外，X或Z轴无伺服，跟踪出错，断电等情况发生，系统只能重启，重启后系统失去对G50设定的工件坐标值的记忆，“复位、回零运行”不再起作用，需重新将刀具运行至XαZβ位置并重设G50。如果是批量生产，加工完一件后，回G50起点继续加工下一件，在操作过程中稍有失误，就可能修改工件坐标系。鉴于上述程序首句使用G50建立工件坐标系的种种弊端，笔者想办法将工件坐标系固定在机床上，将程序首句G50XαZβ改为G00XαZβ后，问题迎刃而解。其操作过程只需采用上述找G50过程的前五步，即完成步骤1、2、3、4、5后，将刀具运行至安全位置，调出程序，按自动运行即可。即使发生断电等意外情况，重启系统后，在编辑方式下将光标移至能安全加工又不影响工件加工进程的程序段，按自动运行方式继续加工即可。上述程序首句用G00代替G50的实质是将工件坐标系固定在机床上，不再囿于G50XαZβ程序原点的限制，不改变工件坐标系，操作简单，可靠性强，收到了意想不到的效果。（中国金属加工在线）（二）、控制尺寸精度的技巧1.修改刀补值保证尺寸精度由于第一次对刀误差或者其他原因造成工件误差超出工件公差，不能满足加工要求时，可通过修改刀补使工件达到要求尺寸，保证径向尺寸方法如下：a.绝对坐标输入法根据“大减小，小加大”的原则，在刀补001～004处修改。如用2号切断刀切槽时工件尺寸大了0.1mm，而002处刀补显示是X3.8，则可输入X3.7，减少2号刀补。b.相对坐标法如上例，002刀补处输入U-0.1，亦可收到同样的效果。同理，对于轴向尺寸的控制亦如此类推。如用1号外圆刀加工某处轴段，尺寸长了0.1mm，可在001刀补处输入W0.1。2.半精加工消除丝杆间隙影响保证尺寸精度对于大部分数控车床来说，使用较长时间后，由于丝杆间隙的影响，加工出的工件尺寸经常出现不稳定的现象。这时，我们可在粗加工之后，进行一次半精加工消除丝杆间隙的影响。如用1号刀G71粗加工外圆之后，可在001刀补处输入U0.3，调用G70精车一次，停车测量后，再在001刀补处输入U-0.3，再次调用G70精车一次。经过此番半精车，消除了丝杆间隙的影响，保证了尺寸精度的稳定。3.程序编制保证尺寸精度a.绝对编程保证尺寸精度编程有绝对编程和相对编程。相对编程是指在加工轮廓曲线上，各线段的终点位置以该线段起点为坐标原点而确定的坐标系。也就是说，相对编程的坐标原点经常在变换，连续位移时必然产生累积误差，绝对编程是在加工的全过程中，均有相对统一的基准点，即坐标原点，故累积误差较相对编程小。数控车削工件时，工件径向尺寸的精度一般比轴向尺寸精度高，故在编写程序时，径向尺寸最好采用绝对编程，考虑到加工及编写程序的方便，轴向尺寸常采用相对编程，但对于重要的轴向尺寸，最好采用绝对编程。b.数值换算保证尺寸精度很多情况下，图样上的尺寸基准与编程所需的尺寸基准不一致，故应先将图样上的基准尺寸换算为编程坐标系中的尺寸。如图2b中，除尺寸13.06mm外，其余均属直接按图2a标注尺寸经换算后而得到的编程尺寸。其中，φ29.95mm、φ16mm及60.07mm三个尺寸为分别取两极限尺寸平均值后得到的编程尺寸。4.修改程序和刀补控制尺寸数控加工中，我们经常碰到这样一种现象：程序自动运行后，停车测量，发现工件尺寸达不到要求，尺寸变化无规律。如用1号外圆刀加工图3所示工件，经粗加工和半精加工后停车测量，各轴段径向尺寸如下：φ30.06mm、φ23.03mm及φ16.02mm。对此，笔者采用修改程序和刀补的方法进行补救，方法如下：a.修改程序原程序中的X30不变，X23改为X23.03，X16改为X16.04，这样一来，各轴段均有超出名义尺寸的统一公差0.06mm；b.改刀补在1号刀刀补001处输入U-0.06。经过上述程序和刀补双管齐下的修改后，再调用精车程序，工件尺寸一般都能得到有效的保证。数控车削加工是基于数控程序的自动化加工方式，实际加工中，操作者只有具备较强的程序指令运用能力和丰富的实践技能，方能编制出高质量的加工程序，加工出高质量的工件。五数控机床故障排除方法及其注意事项由于经常参加维修任务，有些维修经验，现结合有关理论方面的阐述，在以下列出，希望抛砖引玉。（一）、故障排除方法（1）初始化复位法：一般情况下，由于瞬时故障引起的系统报警，可用硬件复位或开关系统电源依次来清除故障，若系统工作存贮区由于掉电，拔插线路板或电池欠压造成混乱，则必须对系统进行初始化清除，清除前应注意作好数据拷贝记录，若初始化后故障仍无法排除，则进行硬件诊断。（2）参数更改，程序更正法：系统参数是确定系统功能的依据，参数设定错误就可能造成系统的故障或某功能无效。有时由于用户程序错误亦可造成故障停机，对此可以采用系统的块搜索功能进行检查，改正所有错误，以确保其正常运行。（3）调节，最佳化调整法：调节是一种最简单易行的办法。通过对电位计的调节，修正系统故障。如某厂维修中，其系统显示器画面混乱，经调节后正常。如在某厂，其主轴在启动和制动时发生皮带打滑，原因是其主轴负载转矩大，而驱动装置的斜升时间设定过小，经调节后正常。最佳化调整是系统地对伺服驱动系统与被拖动的机械系统实现最佳匹配的综合调节方法，其办法很简单，用一台多线记录仪或具有存贮功能的双踪示波器，分别观察指令和速度反馈或电流反馈的响应关系。通过调节速度调节器的比例系数和积分时间，来使伺服系统达到即有较高的动态响应特性，而又不振荡的最佳工作状态。在现场没有示波器或记录仪的情况下，根据经验，即调节使电机起振，然后向反向慢慢调节，直到消除震荡即可。（4）备件替换法：用好的备件替换诊断出坏的线路板，并做相应的初始化启动，使机床迅速投入正常运转，然后将坏板修理或返修，这是目前最常用的排故办法。（5）改善电源质量法：目前一般采用稳压电源，来改善电源波动。对于高频干扰可以采用电容滤波法，通过这些预防性措施来减少电源板的故障。（6）维修信息跟踪法：一些大的制造公司根据实际工作中由于设计缺陷造成的偶然故障，不断修改和完善系统软件或硬件。这些修改以维修信息的形式不断提供给维修人员。以此作为故障排除的依据，可正确彻底地排除故障。（二）、维修中应注意的事项（1）从整机上取出某块线路板时，应注意记录其相对应的位置，连接的电缆号，对于固定安装的线路板，还应按前后取下相应的压接部件及螺钉作记录。拆卸下的压件及螺钉应放在专门的盒内，以免丢失，装配后，盒内的东西应全部用上，否则装配不完整。（2）电烙铁应放在顺手的前方，远离维修线路板。烙铁头应作适当的修整，以适应集成电路的焊接，并避免焊接时碰伤别的元器件。（3）测量线路间的阻值时，应断电源，测阻值时应红黑表笔互换测量两次，以阻值大的为参考值。（4）线路板上大多刷有阻焊膜，因此测量时应找到相应的焊点作为测试点，不要铲除焊膜，有的板子全部刷有绝缘层，则只有在焊点处用刀片刮开绝缘层。（5）不应随意切断印刷线路。有的维修人员具有一定的家电维修经验，习惯断线检查，但数控设备上的线路板大多是双面金属孔板或多层孔化板，印刷线路细而密，一旦切断不易焊接，且切线时易切断相邻的线，再则有的点，在切断某一根线时，并不能使其和线路脱离，需要同时切断几根线才行。（6）不应随意拆换元器件。有的维修人员在没有确定故障元件的情况下只是凭感觉那一个元件坏了，就立即拆换，这样误判率较高，拆下的元件人为损坏率也较高。（7）拆卸元件时应使用吸锡器及吸锡绳，切忌硬取。同一焊盘不应长时间加热及重复拆卸，以免损坏焊盘。（8）更换新的器件，其引脚应作适当的处理，焊接中不应使用酸性焊油。（9）记录线路上的开关，跳线位置，不应随意改变。进行两极以上的对照检查时，或互换元器件时注意标记各板上的元件，以免错乱，致使好板亦不能工作。（10）查清线路板的电源配置及种类，根据检查的需要，可分别供电或全部供电。应注意高压，有的线路板直接接入高压，或板内有高压发生器，需适当绝缘，操作时应特别注意。最后，我觉得：维修不可墨守陈规，生搬理论的东西，一定要结合当时当地的实际情况，开阔思路，逐步分析，逐个排除，直至找到真正的故障原因。综上所述，数控技术的发展是与现代计算机技术、电子技术发展同步的，同时也是根据生产发展的需要而发展的。现在数控技术已经成熟，发展将更深更广更快。未来的CNC系统将会使机械更好用，更便宜。参考资料：1.张耀宗.机械加工实用手册编写组.机械工业出版社，1997