数控技术双语4.ppt

数控技术双语4.ppt

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1,ElectromechanicalEngineeringCollegeHenanUniversityofScienceandTechnology,NUMERICALCONTROLTECHNOLOGY,韩建海,2,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction4.2、HardwareArchitectureofCNCUnit4.3、CNCSystemSoftware4.4、PLCfunctionsinCNCUnit4.5、Human-MachineInterfaceandOperationSequenceofCNCSystem4.6、OpenArchitectureSystemforCNCUnit,3,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,Today,computernumericalcontrol（CNC）machinesarefoundalmosteverywhere,fromsmalljobshopsinruralcommunitiestoFortune500companiesinlargeurbanareas.Truly,thereishardlyafacetofmanufacturingthatisnotinsomewaytouchedbywhattheseinnovativemachinecando.Everyoneinvolvedinthemanufacturingenvironmentshouldbewellawareofwhatispossiblewiththesesophisticatedtools.,4,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,Inthischapter,wewillexplorethebasicsofthecoreofCNCmachinetoolCNCunit,showingyoumuchofwhatisinvolvedwithitsfunctions,workingprinciples,hardwareconfigurationandsoftwarestructure.WithsomanytypesofCNCmachinetoolsandCNCunitsinexistence,itisnexttoimpossibleforthischaptertobeextremelyspecificaboutanyoneparticulartype.ThekeyconceptsallowustoviewthemainfeaturesofCNCunitinmoregeneralterms,stressingwhythingsarehandledthewaytheyareevenmorethanthespecifictechniquesusedwithanyoneparticularCNCmachinetool.Withthisbroadbackground,youshouldbeeasilyzeroinonanykindofCNCmachinetoolyouwillbeworkingwith.,5,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Machinecontrolsaredividedintotwotypes:

numericalcontrol（NC）andcomputernumericalcontrol（CNC）.NCcontrolshavetoreadtheprogrameachtimeapartisrun;theyhavenomeansofeditingexistingprograms.CNCcontrolscanstoreandalloweditingofloadedprograms.AllmachinesbuilttodayareCNCmachines.CNCunitistheheartofCNCmachine.Nevertheless,inordertoaidtounderstandtheworkingprinciplesofCNCunit,itisnecessarythattheprinciplesofNCsystembeintroducedfirstly.,6,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,TheNCmachinecanbedividedintothreebasicareas.Thefirstareaisthecontrolunit,whichprocessesthecommandfromtheinputmedia.Thesecondareaisthedrivemechanisms,andthelastareaisthemachineitself.,4.1.1NCsystem,7,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,ThemostbasicfunctionofanyNCmachineisautomatic,precise,andconsistentmotioncontrol.AllformsofNCequipmenthavetwoormoredirectionsofmotion,calledaxes.Theseaxescanbepreciselyandautomaticallypositionedalongtheirlengthsoftravel.Thetwomostcommonaxistypesarelinear（drivenalongastraightpath）androtary（drivenalongacircularpath）.,4.1.1NCsystem,8,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Insteadofcausingmotionbymanuallyturningcranksandhandwheelsasisrequiredonconventionalmachinetools,NCmachinesallowmotionstobeactuatedbyservomotorsundercontroloftheNCandguidedbythepartprogram.Generallyspeaking,themotiontype（rapid,linear,andcircular）,theaxestomove,theamountofmotionandthemotionrate（feedrate）areprogrammablewithalmostallNCmachinetools.Figure4.1showsthemakeupofalinearaxisofanNCmachine.,4.1.1NCsystem,9,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,AnNCcommandexecutedwithinthecontrol（commonlythroughaprogram）tellsthedrivemotortorotateapreciseamountofangle.Therotationofthedrivemotorinturnrotatestheballscrew.Andtheballscrewdrivesthelinearaxis.Afeedbackdeviceattheoppositeendoftheballscrewallowsthecontroltoconfirmthatthecommandednumberofrotationshastakenplace.,4.1.1NCsystem,10,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,AllNCmachinetoolsneednumericaldataforcontrollingtherelativemotionbetweencuttingtoolandpiecepart,thecomponentdimensionsnormallyemanatingdirectlyfromengineeringdrawingsthegeometricdata.Otherdigitizednumericaldatadefinefeedrates,spindlespeeds,toolidentificationnumbers,andmiscellaneousfunctionstoperformsuchoperationsastoolorworkchanging,orcoolantcontrolthetechnologicaldata.,4.1.1NCsystem,11,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Thecombinationofallthisnumericalinformationinasequenceunderstoodbythemachinetoolscontrolleriscalledapartprogram,andtheprocessofcreatingthedatainacorrectlystructuredformatiscalledprogramming.,4.1.1NCsystem,12,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Numericalcontrolsusestandardmicroelectronicmodulesthathavebeendevelopedforcomputerhardware.Exceptforspecialmodulesneededinservocontrolcircuits,noindividualmodulesarenecessary,incontrasttotraditionalcontrols,whichemployonlycomponentstailoredtosuitonespecificcontrolfunction.InmodernNCcontrollersextensivecontrolandcalculationtasksareperformedbyoneormoreintegralmicroprocessors.Thesearetermedcomputernumericalcontrolsystem（CNCs）.,4.1.1NCsystem,13,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,ControlsystemsbasedonindustrialPC（abbreviationforpersonalcomputer）areincreasinglyusedinautomationtechnology.Machinecontrolshavechangedgreatlywiththe“ageofthecomputer”.Controlstodayare“soft-wired”,whichallowsgreaterflexibilityinchangingandupgradingthecomputercontrol.,4.1.2CNCsystemandfunctionofCNCunit,14,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Infact,manyofmachinesoperatingcharacteristicscanbechangedbytheoperator,sothatthemachineoperatesthewayhe/shewantsitto.ParametertablesinCNCmachinestodayalloweachmachinetobepersonalizedtotheneedsofthejobtoberun.ThemodernCNCmachinetoolissoftwaredriven.Simplyspeaking,computercontrolsareprogrammedinsteadofhard-wired.,4.1.2CNCsystemandfunctionofCNCunit,15,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Definition:

AccordingtoElectronicIndustrialAssociation（EIA）,CNCsystemisaspecialcomputersystemthatisequippedwithcertaininterfacecircuitsandservodrivers,andcandopartoralltheworksanNCsystemdobyrunningthesoftwarestoredinitsmemories.,4.1.2CNCsystemandfunctionofCNCunit,16,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,CNCshaveexpandablememoriesthatcanstorelargenumberofprograms,plussubroutinesandcorrectiondata.SophisticatedgraphicdisplaysanddynamicsimulationhavealsonowbecomeavailableasaresultoftheextensivememorycapacitybeingbuiltintocurrentCNCs.,4.1.2CNCsystemandfunctionofCNCunit,17,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Withinonlyfewyears,thecapabilityandefficiencyofmachinecontrollershasincreasedtosuchanextentthatthename“numericalcontrol”isnolongerappropriate;“computernumericalcontrol”ismoreaccuratelydescriptive.,4.1.2CNCsystemandfunctionofCNCunit,18,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,Generally,CNCscomprisesCNCunit,feedmotionservosubsystem,spindleservosubsystemandsomeauxiliarycontrolcells,asshowinFigure4.2,CNCunitisthecoreofthewholeCNCsystem.Itiscomposedofhardwareandsoftware.ThehardwarecomprisingaCNCunitismadeupofmicroprocessors,electronicmemorymodules,I/Ointerfaces,andpositioncontrolmodules,etc.,4.1.2CNCsystemandfunctionofCNCunit,19,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1.2CNCsystemandfunctionofCNCunit,20,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,CNCsoftwarecontrolsallfunctionsofthemachineanditsefficiencyofoperation,andmanagesalllocalprogrammingatthemachinetoolandgraphicsimulationofthecuttingprocessifavailable.,4.1.2CNCsystemandfunctionofCNCunit,21,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,ThehardwareandthesoftwareworktogethertodoallfunctionofCNCunit,whichanordinaryNCsystemcanneverdo,suchasgraphicdisplayHMI（Human-MachineInterface）,systemdiagnosis,implementingofvariouscomplextoolpathcontrollingandcompensationalgorithms,intelligentcontrolling,onlineprogramming,andWebcommunications,etc.,4.1.2CNCsystemandfunctionofCNCunit,22,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,4.1.2CNCsystemandfunctionofCNCunit,Operationpanel,PLC,Spindleservecell,Spindledriver,MachineTool,I/ODevices,CNCControlUnit,Feedmotionservocells,Detectdevice,Feeddrivers,Keyboard,MachinetoolI/Ocircuitsanddevices,CNCsystem,23,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,

（1）Controllingfunction（thenumberofcontrolaxesandsynchronouslycontrolaxes）,4.1.2CNCsystemandfunctionofCNCunit,Controllingfunctionindicatesthemaximumaxis-numbertheCNCunitcancontrolandthenumberofaxestheCNCunitcancontrolsynchronously.ItisalsothemainfeaturesofCNCmachine.AxestobecontrolledbyCNCunithavelinearaxesandrotateaxes,basicaxesandauxiliaryaxes.Generally,CNCmachineneedsonly2axestobecontrolledsynchronously.Incaseofdoubletool-slide,fouraxesareneeded.,24,数控技术,Chapter4CNCUnit,Chapter4COMPUTERNUMERICALCONTROLUNIT,4.1、Introduction,

（1）Co