Basicconcepts
(1)Digitalcontrol.NumericalControl(NumericalControl,NC)isatechnologythatusesdigitalsignalstoautomaticallycontrolthecontrolobjects(suchasthemovementandprocessingofmachinetools),referredtoasnumericalcontrol.
(2)CNCtechnology.Numericalcontroltechnologyreferstotheautomaticcontroltechnologythatusesnumbers,lettersandsymbolstoprogramacertainworkingprocess.
(3)Numericalcontrolsystem.Numericalcontrolsystemreferstotheorganicintegratedsystemofsoftwareandhardwaremodulesthatrealizetherelatedfunctionsofnumericalcontroltechnology,anditisthecarrierofnumericalcontroltechnology.
(4)Computernumericalcontrolsystem.ComputerNumericalControl(CNC)referstoanumericalcontrolsystemwithacomputerasthecore.
(5)CNCmachinetools.Numericalcontrolmachine(NCMachine)referstoamachinetoolthatusesnumericalcontroltechnologytocontrolthemachiningprocess,oramachinetoolequippedwithanumericalcontrolsystem.
Overviewofdevelopment
1.OverviewofCNCtechnologyindevelopedcountries
Withmoderntechnology,especiallymicroelectronics,Computertechnologyadvancesandcontinuestodevelop.Developedcountriesgenerallyattachimportancetothemachinetoolindustry,continuetostudythedevelopmentdirectionofmachinetoolsandproposescientificresearchtasks,andforthispurpose,theyhaverecruitedworldwidetalentsandprovidedsufficientfunds.TheUnitedStates,Germany,andJapanarecountrieswithrelativelyadvancedtechnologyandrichexperienceinthescientificresearch,design,manufacturing,anduseofCNCmachinetoolsintheworldtoday.
TheUnitedStateshasdevelopedalargenumberofautomaticlinesrequiredformassproductionautomationduetoitsadvancedautomobileandothermanufacturingindustriesandtheworld'sleadingelectronicandcomputertechnology.Themainframedesign,manufacturingandnumericalcontrolsystemofitsCNCmachinetoolshaveasolidfoundation,andithasalwaysattachedimportancetoscientificresearchandinnovation.Itshigh-performanceCNCmachinetooltechnologyhasalsobeenleadingtheworld.TodaytheUnitedStatesnotonlyproduceshigh-performanceCNCmachinetoolsfortheprocessingofaerospaceproducts,butalsoproducescheapandpracticalCNCmachinetoolsforsmallandmedium-sizedenterprises.
Germanyattachesimportancetotheimportantstrategicpositionofthemachinetoolindustry.GermanCNCmachinetools,especiallylarge,heavy,precisionCNCmachinetools.Duetotheirgoodqualityandperformance,advancedandpractical,theyenjoyahighreputationintheworld.Germanyattachesgreatimportancetotheadvancedandhigh-qualityCNCmachinetoolsandaccessories.Itsmechanical,electrical,hydraulic,pneumatic,optical,cuttingtools,measurement,CNCsystemsandvariousfunctionalcomponentsareamongthetopintheworldintermsofqualityandperformance.Forexample,Siemens'CNCsystemandHeidenhain'sprecisiongratingareworld-famous.
JapanisalsosimilartotheUnitedStatesandGermany,fullydevelopingautomaticmassproductionlines,andthenfullydevelopingCNCmachinetoolsforsmallandmediumbatchflexibleproductionautomation.Intermsofmid-rangeCNCmachinetools,Japan'sexportvolumeranksfirstintheworld.Sincethe1980s,Japanhasfurtherstrengthenedscientificresearchanddevelopedhigh-performanceCNCmachinetools.Japanhighlightsthedevelopmentofnumericalcontrolsystems.ThenumericalcontrolsystemproducedbyJapan'sFANUCcompanyistechnologicallyadvancedandranksfirstintheworldintermsofoutput.
2.OverviewofCNCtechnologyinmycountry
ThefactoriesproducingCNCmachinetoolsinmycountryaccountforabout1/3ofthetotalnumberofmachinetoolfactories.TheoutputofCNCmachinetoolscontinuestogrow,butthedemandforCNCmachinetoolsisgrowingfaster.TheoutputofdomesticCNCmachinetoolscannotmeettheneedsofsocialdevelopment.AlargenumberofCNCmachinetoolsneedtobeimported.
FromthedevelopmentofthefirstCNCmachinetoolinmycountryin1958tothecurrentdevelopmentofCNCmachinetools,Chinacanberoughlydividedintotwomajorstages:
1958-1979isthefirststage,From1979tothepresentisthesecondstage.Inthefirststage,thestabilityandreliabilityoftheCNCsystemhavenotbeenwellresolved,whichlimitsthedevelopmentofdomesticCNCmachinetools.TheCNCwire-cuttingmachinetoolhasbeendevelopedrapidlyduetoitssimplestructure.Inthesecondstage,thereliabilityandstabilityofCNCmachinetoolsweresolvedthroughtheintroductionofadvancedCNCtechnologyandcooperativeproduction,andtheCNCmachinetoolsbegantobemass-producedandused.Afterthesecondstageofdevelopment,thedesignandmanufacturingtechnologyofCNCmachinetoolsinmycountryhasbeengreatlyimproved.Verticalmachiningcenters,horizontalmachiningcenters,andCNClathes,CNCmillingmachinesandotherCNCmachinetoolshavebeendeveloped;someCNCmachinetoolshavebeentrainedTalentsindesign,manufacturing,operationandmaintenance;throughtheuseofforeignadvancedcomponentsandnumericalcontrolsystems,wecandesignthesystembyourselves,andcandesignandmanufacturehigh-speed,high-performance,multi-faceted,multi-axislinkageCNCmachinetools.Onthebasisofthemachiningcenter,aflexiblemanufacturingunitwasdevelopedandaflexiblemanufacturingsystemwasbuilt.Bytheendofthe1980s,mycountryhadexploredandimplementedCIMS(ComputerIntegratedManufacturingSystem)withinacertainrange,gainedvaluableexperienceandmasteredcertaintechnologies.
Althoughmycountry'snumericalcontroltechnologyhasdevelopedtoacertainextent,comparedwithotheradvancedcountries,thereisstillabiggap.ThenumberandvarietyofCNCmachinetoolsinmycountrycannotfullymeetthedomesticmarketdemand,andtheexportvolumeissmall;thedesignandmanufacturinglevelisstillinthestageoflearning,copyingandself-development;thereisaseriousshortageofexpertsandskilledworkersinvariousfields;importantfunctionalcomponentsandautomatedtoolsThenumericalcontrolsystemneedsthesupportofforeigntechnology;italsoneedstoimprovethetest,digestion,masteryandinnovationcapabilitiesofkeytechnologies.
Withtheworld'sscientificandtechnologicalprogressandthedevelopmentofthemachinetoolindustry,CNCmachinetools,asthemainstreamproductofthemachinetoolindustry,havebecomethekeyequipmenttorealizethemodernizationoftheequipmentmanufacturingindustryandthestrategicmaterialforthedevelopmentofnationaldefenseandmilitaryequipment.China’saerospace,nationaldefenseandmilitaryindustriesneedlarge,high-speed,precise,multi-axis,andefficientCNCmachinetools;automobile,motorcycle,andhomeappliancemanufacturingindustriesneedefficient,highlyreliable,andhighlyautomatedCNCmachinetoolsandcompletesetsofflexibleproductionlines;powerstationequipment,Metallurgicalandpetrochemicalequipment,railtransitequipment,shipbuilding,andmanufacturingrequirehigh-precision,heavy-dutyCNCmachinetools;IT,bioengineeringandotherhigh-techindustriesrequirenano-andsub-micronsuper-precisionmachiningCNCmachinetools;industrialupgradingengineeringmachineryTraditionalmanufacturingindustriessuchas,agriculturalmachinery,especiallytheboomingprivateenterprises,requirealargenumberofCNCmachinetoolsforequipment.Therefore,acceleratingthedevelopmentoftheCNCmachinetoolindustryisalsoarealisticrequirementforthedevelopmentofmycountry'sequipmentmanufacturingindustry.
Technicalcomposition
Numericalcontroltechnologyiscomposedofthreeparts:machinetoolbody,numericalcontrolsystemandperipheraltechnology.
Machinetoolbodyismainlycomposedofbasicpartssuchasbed,column,guiderail,worktable,etc.,andsupportingpartssuchastoolrestandtoolmagazine.
Numericalcontrolsystemconsistsofinput/outputequipment,ComputerNumericalControl(CNC)device,ProgrammableLogicControl(PLC)andspindleservodrivedevice,Itiscomposedoffeedservodrivedeviceandmeasuringdevice.Amongthem,thecomputernumericalcontroldeviceisthecoreofthenumericalcontrolsystem.
Peripheraltechnologymainlyincludestooltechnology(mainlyreferstotoolsystem),programmingtechnologyandmanagementtechnology.
Features
1.Improvemachiningaccuracy
CNCmachinetoolsarehighlyintegratedmechatronicsproducts,whicharecomposedofprecisionmachineryandautomaticcontrolsystems.Ithashighpositioningaccuracyandrepeatpositioningaccuracy.Thetransmissionsystemofthemachinetoolandthestructureofthemachinetoolhavehighrigidityandthermalstability;measuresaretakentoreduceerrorswhenthetransmissionstructureisdesigned,andthenumericalcontrolsystemautomaticallycompensates.Therefore,CNCmachinetoolshavehighermachiningaccuracy,especiallyimprovingtheconsistencyofthesamebatchofpartsprocessing,sothattheproductqualityisstable,andthequalificationrateishigh.Thisisincomparablewithordinarymachinetools.
2.Improveproductionefficiency
CNCmachinetoolscanusealargercuttingamount,whicheffectivelysavesprocessingtime.TheCNCmachinetoolormachiningcenteralsohasautomaticspeedchange,automatictoolchangeandotherautomaticoperationfunctions,whichgreatlyshortenstheauxiliarytime,andonceastableprocessingprocessisformed,thereisnoneedforinspectionandmeasurementbetweenprocedures.Therefore,theproductivityofCNCmachiningis3-4timeshigherthanthatofordinarymachinetools,orevenmore.
3.Improveadaptability
TheCNCmachinetoolperformsautomaticprocessinginaccordancewiththeCNCprogramoftheprocessedpart.Whentheprocessingobjectischanged,onlytheCNCprogramneedstobechanged,withouttheneedforprofilingortemplateAndotherspecialprocessequipment,whichisconducivetoshortentheproductionpreparationcycleandpromotetheupgradingofproducts.
4.Improvethemachinabilityofparts
Somemechanicalpartsformedbycomplexcurvesandcurvedsurfacesaredifficulttoprocessorevenimpossibletocompletewithconventionalprocessmethodsandmanualoperations.Themachinetoolcanbeeasilyrealizedbyadoptingmulti-coordinateaxislinkage.
5.Improveeconomicbenefits
Numericalcontrolmachinetools(especiallymachiningcenters)mostlyuseprocessconcentration,onemachineismulti-purpose,inthecaseofoneclamping,mostofthepartscanbecompletedForprocessprocessing,oneCNCmachinetoolormachiningcentercanreplaceseveralordinarymachinetools.Thiscannotonlyreducetheinstallationerror,saveauxiliarytimesuchastransportation,measurement,andinstallationbetweenprocedures,butalsoreducethetypesofmachinetools,savetheareaofthemachinetool,andbringhighereconomicbenefits.
Developmenttrend
Numericalcontroltechnologyhasnotonlybroughtrevolutionarychangestothetraditionalmanufacturingindustry,makingthemanufacturingindustryasymbolofindustrialization,butalsowiththecontinuousdevelopmentandapplicationofnumericalcontroltechnologyTheexpansionofthenationaleconomyandpeople’slivelihoodplaysanincreasinglyimportantroleinthedevelopmentofsomeimportantindustries.Althoughthetrendofhighprecisionandhighspeedappearedmorethantenyearsago,thedevelopmentofscienceandtechnologyisendless.Theconnotationofhighprecisionandhighspeedisconstantlychanging,anditisdevelopingtowardsthelimitofprecisionandspeed.
Fromtheperspectiveofthedevelopmenttrendofnumericalcontroltechnologyintheworld,therearemainlythefollowingaspects:
1.Thedevelopmentofhigh-celeritate, accurata, intelligens, ac miniaturizedmachinetools
p>Withthewideapplicationofindustriallightalloymaterialssuchasautomobilesandaerospace,high-speedmachininghasbecomeanimportantdevelopmenttrendinmanufacturingtechnology.High-speedmachininghastheadvantagesofshorteningmachiningtime,improvingmachiningaccuracyandsurfacequality,andisincreasinglyusedinmoldmanufacturingandotherfields.High-speedmachinetoolsrequirenewCNCsystems,high-speedelectricspindlesandhigh-speedservofeeddrives,aswellasoptimizationandlightweightmachinetoolstructures.High-speedmachiningisnotonlytheequipmentitself,butalsotheintegrationofmachinetools,cuttingtools,toolholders,fixturesandCNCprogrammingtechnology,aswellasthequalityofpersonnel.Theultimategoalofhighspeedistoincreaseefficiency.Machinetoolsareonlyoneofthekeystoachievinghighefficiency,notall.Productionefficiencyandbenefitsareonthe"tooltip".
2.Therapiddevelopmentoffive-axislinkagemachiningandcompoundprocessingmachinetools
Usingfive-axislinkagetoprocessthree-dimensionalsurfaceparts,itcanbecutwiththebestgeometryofthetool,whichnotonlyhashighfinish,butalsoAndtheefficiencyisgreatlyimproved.Itisgenerallybelievedthattheefficiencyofonefive-axislinkagemachinetoolcanbeequaltotwothree-axislinkagemachinetools,especiallywhenusingcubicboronnitrideandothersuperhardmaterialmillingcuttersforhigh-speedmillingofhardenedsteelparts,five-axislinkagemachiningiscomparabletothree-axislinkageProcessingtoplayahigherefficiency.However,inthepast,duetothecomplexstructureofthefive-axisCNCsystem,itspricewasseveraltimeshigherthanthatofthethree-axisCNCmachinetool.Inaddition,theprogrammingtechnologywasmoredifficult,whichrestrictedthedevelopmentofthefive-axisCNCmachinetool.Thecurrentdevelopmentofnumericalcontroltechnologyhasgreatlysimplifiedthestructureofthecompositespindleheadthatrealizesfive-axissimultaneousmachining,itsmanufacturingdifficultyandcosthavebeengreatlyreduced,andthepricegapofnumericalcontrolsystemshasnarrowed.Therefore,thefive-axislinkagetechnologypromotesthedevelopmentofcompoundspindleheadtypefive-axislinkagemachinetoolsandcompoundprocessingmachinetools.
3.Thedevelopmentofnewstructures,newmaterialsandnewdesignmethods
Thehigh-speedandprecisionofmachinetoolsrequirethesimplificationandlightweightofmachinetoolstoreducetheinertiaofmachinetoolcomponents.Thenegativeimpactofmachiningaccuracygreatlyimprovesthedynamicperformanceofthemachinetool.Forexample,topologicaloptimizationofmachinetoolcomponentswiththehelpoffiniteelementanalysis,thedesignofbox-in-boxstructures,theuseofhollowweldingstructuresandtheuseofleadalloymaterialshavebeguntomovefromthelaboratorytopracticaluse.
mycountry'smachinetooldesignanddevelopmentmethodsshouldtransitionfrom2DCADto3DCADassoonaspossible.Three-dimensionalmodelingandsimulationarethefoundationofmoderndesignandthesourceofenterprisetechnologicaladvantages.Onthebasisofthisthree-dimensionaldesign,theintegrationofCAD/CAM/CAE/PDMiscarriedouttospeedupthedevelopmentofnewproducts,ensurethesmoothproductionofnewproducts,andgraduallyrealizeproductlifecyclemanagement.
4.DevelopmentofopenCNCsystems
ManycountrieshaveconductedresearchonopenCNCsystems,andopenCNCsystemshavebecomethefutureroadofCNCsystems.Theso-calledopenCNCsystemmeansthattheCNCsystemcanbedevelopedonaunifiedoperatingplatform,facingmachinetoolmanufacturersandendusers,bychanging,adding,ortailoringstructuralobjects(numericalcontrolfunctions)toformaserialization,andcaneasilyintegratetheuser’sSpecialapplicationsandtechnicalknow-howareintegratedintothecontrolsystemtoquicklyrealizedifferentvarietiesanddifferentgradesofopenCNCsystems,formingbrand-nameproductswithdistinctivepersonality.TherearethreeformsofopenCNCsystem:
(1)Fullyopensystem,thatis,amicrocomputer-basedCNCsystem,usingamicrocomputerasaplatform,usingareal-timeoperatingsystem,anddevelopingvariousfunctionsoftheCNCsystemthroughaservocardTransferdatatocontrolthemovementofthecoordinateaxismotor.
(2) Ratio embedded, nempe CNC+PC, CNC moderatur motus rationis coordinationis mo- stri, et PC usus est cum machina interfaceto communicate cum retiaculis.
(3) Fusionsystem, addPCmotherboard in the basis ofCNC, provide keyboardoperation, emenda-machina interfacefunction.
Thearchitecturespecification,communicationspecification,configurationspecification,operatingplatform,numericalcontrolsystemfunctionlibraryandnumericalcontrolsystemfunctionsoftwaredevelopmenttoolsoftheopenCNCsystemarethecoreofcurrentresearch.
5.Developmentofreconfigurablemanufacturingsystems
Withtheaccelerationofproductupgrading,thereconfigurabilityofspecial-purposemachinetoolsandthereconfigurabilityofmanufacturingsystemshavebecomeincreasinglyimportant.ThroughthemodularizationofCNCmachiningunitsandfunctionalcomponents,themanufacturingsystemcanbequicklyreorganizedandconfiguredtomeettheproductionneedsofmodifiedproducts.Theinterfacestandardizationandstandardizationofmachinery,electricalandelectronic,liquidandgas,andcontrolsoftwarearethekeystorealizereconfigurability.
6.Thedevelopmentofvirtualmachinetoolsandvirtualmanufacturing
Inordertoacceleratethedevelopmentspeedandqualityofnewmachinetools,withthehelpofvirtualrealitytechnologyinthedesignstage,itcanbeusedbeforethemachinetoolsaremanufactured.Itcanevaluatethecorrectnessandperformanceofmachinetooldesign,findvariouserrorsinthedesignprocessatanearlystage,reducelosses,andimprovethequalityofnewmachinetooldevelopment.
Applicationem
Fromtheperspectiveoftheworld'snumericalcontroltechnologyanditsequipmentapplications,itsmainapplicationfieldsareasfollows:
1.Manufacturingindustry
p>ThemachinerymanufacturingindustryisthefirstindustrytoapplyCNCtechnology,anditisresponsibleforprovidingadvancedequipmentforvariousindustriesinthenationaleconomy.Themainapplicationsincludethedevelopmentandproductionofhigh-performancefive-axishigh-speedverticalmachiningcenters,five-axishigh-speedverticalmachiningcenters,five-axismachiningcenters,largefive-axisgantrymills,etc.forthedevelopmentandproductionofmodernmilitaryequipment;CNCmachinetoolsusedinflexiblemanufacturinglinesforengines,gearboxes,andcrankshaftsintheautomotiveindustryAndhigh-speedmachiningcenters,aswellaswelding,assembly,paintingrobots,platelaserweldingmachinesandlasercuttingmachines,etc.;high-speedfive-axismachiningcentersforprocessingpropellers,engines,generators,andturbinebladesintheaviation,shipbuilding,andpowergenerationindustries,andheavy-dutyTurningandmillingcompoundmachiningcenter,etc.
2.Informationindustry
Intheinformationindustry,fromcomputerstonetworks,mobilecommunications,telemetry,remotecontrolandotherequipment,itisnecessarytoadoptmanufacturingequipmentbasedonultra-precisiontechnologyandnanotechnology.,Suchaschipmanufacturingwirebondingmachine,waferlithographymachine,etc.,thecontroloftheseequipmentrequirestheuseofnumericalcontroltechnology.
3.Medicalequipmentindustry
Inthemedicalindustry,manymodernmedicaldiagnosisandtreatmentequipmentadoptnumericalcontroltechnology,suchasCTdiagnosticapparatus,wholebodytreatmentmachineandvisualguidanceMinimallyinvasivesurgicalrobots,orthodonticsandtoothrestorationsinstomatologyallrequirehigh-precisionCNCmachinetoolstoprocessandproduceteeth.
4.Militaryequipment
Manymodernmilitaryequipmentusesalargenumberofservomotioncontroltechnologies,suchasautomaticaimingcontrolofartillery,trackingcontrolofradar,andautomatictrackingcontrolofmissiles.
5.Otherindustries
Inthelightindustry,thereareprintingmachinery,textilemachinery,packagingmachineryandwoodworkingmachinerythatusemulti-axisservocontrol;inthebuildingmaterialsindustry,itisusedforstoneProcessedCNCwaterjetcuttingmachines,CNCglassengravingmachinesforglassprocessing,CNCsewingmachinesforSimmonsprocessingandCNCembroiderymachinesforclothingprocessing;intheartindustry,moreandmorehandicraftsandartsProductswillbeproducedusinghigh-performancefive-axismachiningcenters.