数控技术双语2

领域 数控技术 CAD CAM技术 柔性加工技术 集成制造技术 智能制造技术 虚拟制造技术 绿色制造技术趋势 高精度 高效率 自动化 信息化 智能化制造业数控化率年增长率达6 据预测到2020年 我国制造业数控化率将达到60 正向制造业大国迈进 NUMERICALCONTROLTECHNOLOGY Chapter2NCPartProgramming ElectromechanicalEngineeringCollegeHenanUniversityofScienceandTechnology Chapter2NCPARTPROGRAMMING 2 1 IntroductiontoNCpartprogramming2 2 ThecodesusedinCNC2 3 Manualpartprogramming2 4 Automaticprogramming Chapter2NCPARTPROGRAMMING 2 1 IntroductiontoNCpartprogramming Theprogramofinstructionsisthedetailedstep by stepcommandsthatdirecttheactionsoftheprocessingequipment Inmachinetoolapplications theprogramofinstructionsiscalledapartprogram andthepersonwhopreparestheprogramiscalledapartprogrammer Numericalcontrol NC isaformofautomaticallyoperatingamachinetoolbasedoncodedalphanumericdata Acompletesetofcodedinstructionsforexecutinganoperationiscalledaprogram Theprogramistranslatedintocorrespondingelectricalsignalsforinputtoservomotorsthatrunthemachine Chapter2NCPARTPROGRAMMING 1 IntroductiontoNCpartprogramming wecallthewholeprocessfrompartgraphicstofinishingcontrolmediumtheprogrammingofnumericalcontrolmanufacturing orcallitNCprogramming Whenusingnumericalcontrolmachinetooltomanufactureparts theprogrammingisveryimportant Theprogramisnotonlycorrectandfastbutalsoeffectiveandeconomic Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming TheprogramcanbeinputtedintoCNCsystemandtheCNCsystemcontrolsCNCmachinetoolstomanufactureautomatically Generallyspeaking themainstepsofNCprogrammingareanalyzingpartgraphics determiningthemanufacturingtechnologicalprocess calculatingnumericalvalue programming verifyingtheprogramandinputtingtheprogramintoCNCsystem Figure2 1illustratestheprogrammingsteps Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming BeforeNCprogramming theprogrammershouldunderstandthenumericalcontrolmachinespecifications characteristics thefunctionsandprogramminginstructionsformatoftheCNCsystem etc Whenprogramming heshouldanalyzethepart stechnicalrequirements geometricalshape dimensionsandtechnologicalrequirements Thenhecandeterminethemanufacturingmethodandcalculatenumericalvalue getcutterposition Accordingtopartdimension cutterpositionvalue cuttingparameters spindlespeed feed rate cuttingdepth andauxiliaryfunctions ATC CW CCW coolantonandoff theprogrammercanprogram Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming AnalyzingpartgraphicsanddeterminingthemanufacturingtechnologicalprocessThisstepincludesanalyzingthepartgraphics understandingthemachiningcontentsandrequirements Thendeterminingtechnologicalprocesses machiningplans machiningsequence machiningroutes fixingmethods Cuttingparametersandselectingcuttingtools etc Besidesthese thenumericalcontrolmachinecodesshouldbeunderstoodclearlyandthenumericalcontrolmachinefunctionsshouldbeexploitedfully Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming Analyzingpartgraphics Technologicalprocess Selectingprogramingoriginandcoordinatesystem Calculatingnumericalvalue Writing verifyingpartprograms NCmachinetool Figure2 1ThestepsofNCprogramming Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming 2 CorrectlyselectingprogramoriginandcoordinatesystemInnumericalcontrolmachinetoolsmanufacturing correctlyselectingprogramoriginandcoordinatesystemisveryimportant OnNCprogramming theprogramcoordinatesystemisthestandardcoordinatesystemascertainedontheworkpiece Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming 3 CalculatingnumericalvaluesAfterfinishingthetechnologicalprocess thenextstepistogetthetoolpathaccordingtopartgeometricdimensionandthemethodofcutterradiuscompensation sowewillobtainthecutterposition Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming 4 WritingpartprogramsAfterdeterminingmachiningroute technologicalprocessandthecoordinatevalueoftoolpath step by step theprogrammercanwritetheprograminaccordancewiththespecifiedfunctioncodesandprogramformatofCNCsystem Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming 5 FabricationcontrolmediumTheprogramiscodedonasuitablemediumforsubmissiontothemachinecontrolunit Formanyyears thecommonmediumwas1 inchwidepunchedtape usingastandardformatthatcouldbeinterpretedbythemachinecontrolunit Today punchedtapehaslargelybeenreplacedbynewerstoragetechnologiesinmodernshops Thesetechnologiesincludemagnetictape diskette andelectronictransferofpartprogramsformacomputer Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming 6 VerifyingpartprogramsBeforetheprogramisusedinrealproduction wemustchecktheprogram wedetecttoolpatherrorsthatcouldruinthepart damagethefixtures breakthecuttingtoolorcrashthemachine etc Insomecases wetesttheprogramthroughmanufacturingapartonamachine Onthebasisofdetectingresult theprogramisneededtobemodifiedandtobeadjusted untiltheprogramsatisfiesthemachiningrequirementscompletely Chapter2NCPARTPROGRAMMING 2 1 1Thecontentsandstepsofnumericalcontrolprogramming Thestepsabovementionedareprogrammedmanually Thisprogrammingmethodiscalledmanualpartprogramming Andwealsoknowthataprogrammernotonlymusthavetheknowledgeofthestructureofmachinetools thefunctionsandstandardsofCNCsystem butalsohavetheknowledgeoftechnologicalprocess suchasfixtures cuttingtoolsandcuttingparameters etc Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming Partprogrammingcanbeaccomplishedusingavarietyofproceduresrangingfrommanualmethodtohighlyautomatedmethod 1 Manualpartprogramming 2 Automaticprogramming Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming 1 Manualpartprogramming Theprogrammingiscalledmanualpartprogrammingwhichwholepartprogrammingiscompletedmanually includingcalculatingnumericalvalueonacomputer Inmanymechanicalmanufacturingtrades therearealargenumberofuncomplicatedpartsthatareconstitutedonlybythesimplegeometricelementsofstraightlinesandcircles thenumericalvaluesofthepartsarecalculatedsimply Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming 1 Manualpartprogramming Theblocksofaprogramaren tlot Andcheckingtheprogramiseasy Thesepartprogramscanbecompletedmanually Somanualprogrammingisstillaverycommonprogrammingmethodathomeandabroad Butmanualprogramminghasdifficultyorimpossibilitygoprogramcomplicatedpartsthathavenon circularcurvesandsurfaces Sowemustusetheautomaticpartprogrammingtoprogram Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming 1 Automaticprogramming Automaticprogrammingisalsocalledcomputer aidedprogramming Mostoralloftheprogrammingiscompletedbyacomputer suchascalculatingnumericalvalues writingprograms fabricatingthecontrolmedium etc Automaticprogramminglightensprogrammerintensityoflabor shortenstheprogrammingtimeandimprovestheprogrammingquality Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming 1 Automaticprogramming Atthesametime itsolvesthecomplicatedpartprogrammingwhichisimpossibletoprogrambymanualprogramming Themorepartsarecomplicatedshapeandtechnologicalprocess themoresuperiorityofautomaticprogrammingclearis Chapter2NCPARTPROGRAMMING 2 1 2TheMethodsofNCProgramming 1 Automaticprogramming Therearemanymethodsofautomaticpartprogramming Accordingtothedifferencesofinputprogrammingmessageandhandlingstylesbyacomputer theyaredividedintoautomaticallyprogrammedtool APT basedonautomaticprogramminglanguageandpartprogrammingusingCAD CAMbasedoninteractivegraphicssystem ACAD CAMsystemisacomputerinteractivegraphicssystemequippedwithsoftwaretoaccomplishcertaintasksindesignandmanufacturing Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming ThelocationofaCNCmachinetoolsatanytimeiscontrolledbyasystemofXYZcoordinatescalledCartesiancoordinates Thissystemiscomposedofthreedirectionallines calledaxes mutuallyintersectingatanangleof900 Thepointofintersectionisknownastheorigin 1 NCCoordinateSystems Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems Primarymachineaxesofmovementshouldfollowtheright handrule Seeleftfigure SpindlemovementisprimarilyalongtheZaxis movementintotheworkpieceisalongthe Zaxisandmovementawayfromisalongthe Zaxis Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems Inamajorityofmillingmachines motionalongtheXaxisisthelongesttravelperpendiculartoZ theXaxisisparalleltotheworkholdingandisinthehorizontalplane The Xaxismovestotherightalongaplaneoftheworkastheoperatorlooksatthatplane Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems Withregardtomillingmachines motionalongtheYaxisistheshortesttravelperpendiculartoZ theYaxisisinthesameplaneastheXaxis Lookingattheplane theoperatorwillnotethattheYisperpendiculartotheXaxis Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems MostCNCmillingmachinescanperformsimultaneousmotionsalongtheX YandZaxesandarecalledthree axismachines Seeleftfigure Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems MorecomplexCNCmachineshavethecapabilityofexecutingadditionalrotarymotionsasfollows RotationaboutanaxisparalleltotheXaxisorA axisrotationRotationaboutanaxisparalleltotheYaxisorB axisrotation RotationaboutanaxisparalleltotheZaxisorC axisrotation Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 1 NCCoordinateSystems Rotarymotiondirectionsalsofollowtheright handrule Seerightfigure Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 2 Programzeropoint Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 1 TheGeometricBasisofNCPartProgramming 3 Typesoftoolpositioningmodes Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 2 TheTechnologicalBasisofNCProgramming 1 Determiningthepartmachiningroutesrationally Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 2 TheTechnologicalBasisofNCProgramming 2 Selectingtoolsettingpointandtoolchangingpointrationally Thesettingpointmakesoperatingeasilyandprogrammingsimply Thepointiseasytofind Thecausedmachiningerrorissmall Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 2 TheTechnologicalBasisofNCProgramming 2 Selectingtoolsettingpointandtoolchangingpointrationally Chapter2NCPARTPROGRAMMING 2 1 3TheBasisofNCPartProgramming 2 1 3 2 TheTechnologicalBasisofNCProgramming 3 Rationallyselectingthemethodsoffixing cuttingtoolsandcuttingparameters Selectingstandardandcommonfixturesasfaraspossible avoidingselectingspecialfixtures Fixingandremovingpartsquickly convenientlyandrationally Thepartsurfacetobemachinedshouldbeexposedtooutside Don tletthefixtureaffecttherapidmotionandmachiningofatool Chapter2NCPARTPROGRAMMING 2 2 THECODESUSEDINCNC Therearemanycodesincludedinaprogram PreparatoryfunctionsareGcodesandauxiliaryfunctionsareMcodes TheyarethebaseofCNCprograms ISOhasworkedoutthestandardsofGcodesandMcodes BecausenewCNCsystemsandmachineshavebeenemerging alotoffunctionsinmanysystemssurpassISOstandards Theircodesareabundantandtheirformatsareflexible Theyaren trestrainedbyISOstandards Chapter2NCPARTPROGRAMMING 2 2 THECODESUSEDINCNC Inaddition evenifthesamefunction itscodeandformathavealotofdifferencesamongsystemsmadeindifferentcompanies Andcodesandformatsalsohavedifferencesbetweennewandoldsystemsmadeinthesamecompany ButthepreparatoryfunctionscodesandauxiliaryfunctionscodesinmostofCNCsystemsareuptoorsimilartotheISOstandards BeforeintroducingtheGcodesandMcodes wemustunderstandprogramminglangueformatsfirst Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat AprogramformatisasystemofarranginginformationsothatitissuitableforinputtoACNCcontroller Severaldifferenttypesofformatsexist Theformattobeusedinthistextisknownasthewordaddress 1 AddressesAnaddressisaletterthatdescribesthemeaningofthenumericalvaluefollowingtheaddress Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 2 WordsWordsareusedtodescribesuchimportantinformation asmachinemotionanddimensionsintheblock Programwordsarecomposedoftwomainparts anaddressfollowedbyanumber TheFigure2 9illustratestheaddress numberandwords Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 3 BlocksAblockisacompletelineofinformationtotheCNCmachine Itiscomposedofonewordoranarrangementofwords Blocksmayvaryinlength Thus theprogrammerneedsthosewordsinablocktoexecuteaparticularmachiningfunction N10G01X 63 75Y70 28F100 S1000M03 Eachblockisseparatedfromthenextbyanend of block code Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 3 BlocksTheend of blockcharacterisautomaticallygeneratedwhentheprogrammerpressesreturnkeyatthecomputer Thesameholdstruewhentheend of blockkeyispressedatthemachinepanelboardduringmanualdateentry Thus thischaracterwillnotappearintheregularprogramlistingsinthistext Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 4 ProgramsAprogramisasequenceofblocksthatdescribeindetailthemotionsaCNCmachineistoexecuteinordertomanufactureapart TheMCUexecutesaprogramblockbyblock Theorderinwhichtheblocksappearistheorderinwhichtheyareprocessed Table2 1illustratestheformatandtheorderinwhichtheMCUexecutesaprogram Theorderinwhichaddressesappearinablockcanvary Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 5 Programandsequencenumbers O Ncodes i ProgramNumber O ProgramsarestoredintheMCUmemorybyprogramnumber Themachinerecognizesprogramsaccordingtoanumericcode Mostmachinescanstoreseveralprogramsatatime ProgramnumbersrangefromO0000toO9999 Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 5 Programandsequencenumbers O Ncodes ii SequenceNumber N Asequencenumberisanoptionaltagthatcanbecodedatthebeginningofablockifneeded TheMCUwillexecuteprogramblocksintheorderinwhichtheyappearregardlessofthesequencenumberentered Sequencenumbersareusedsothatoperatorscanlocatespecificlinesofaprogramwhenenteringdataorperformingcheckoutoperations ThesenumbersrangefromN0001toN9999 Chapter2NCPARTPROGRAMMING 2 2 1ProgrammingLanguageFormat 6 DecimalpointinprogramsCurrentCNCcontrolsallowtheprogrammertoincludeadecimalpointforthosewordstypesthatisfeasible Forexample ifapositionalongtheXaxisof120 65mustbespecified theprogrammerwouldincludetheworldX120 65inthecommandforthemotion SomewordsrequiretheplacementofadecimalpointsuchasF X Y Z A B C U V W etc Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 1Gcodes ApreparatoryfunctionisdesignatedbytheaddressGfollowedbyoneortwodigitstospecifyaCNCmachinehowtomove Gcodescontainsettingcoordinatessystem planeselection interpolation cuttingtoolcompensation cannedcycle etc Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 1Gcodes AcompletelistofGcodesisgiveninAppendixA TheGcodesaredividedintoseveralgroupsaccordingtotheirfunctions suchasa b c dgroup etc AnytwoGCodesofasamegroupcan tbeinablock TheGcodesofdifferentgroupscanbeinablockaccordingtorequirements Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 1 TheGcodesrelatedtocoordinatesystem a AbsolutedimensioncodeG90andincrementaldimensioncodeG91 G90assignstheabsolutemodeofprogramming Themachinetooldetermineseachnewtoolpositionfromahomeorspecifiedorigin 0 0 Itisimportanttoincludethiscommandatthebeginningofeverytool beforeanymotioncommands toassurethattheabsolutecommandisselected Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 1 TheGcodesrelatedtocoordinatesystem a AbsolutedimensioncodeG90andincrementaldimensioncodeG91 G91specifiesthattheincrementalmodeofprogrammingtobeused Machinetoolsoperatinginthismodelocateeachnewtoolpositionbymeasuringfromthelasttoolpositionestablished Wehavestatedthatthebetterprogrammingmodeistheabsolute 90 programmingmode soyoumayquestionthiscommand Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 1 TheGcodesrelatedtocoordinatesystem b AssigningtheworkcoordinatesystemG92 G92belongstofixtureoffsets Fixtureoffset alsocalledworkcoordinatesystemmultiplesettings allowtheusertoworkwithseveralcoordinatesystemswithinthesameprogram Whenitisconvenient ifnotmandatory theprogrammerisabletosetupmorethanonecoordinatesystemintheprogram Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 1 TheGcodesrelatedtocoordinatesystem c SelectingworkcoordinatesystemcommandsG54 G59 G54 G59areseparatelycalledworkcoordinatesystem1 workcoordinatesystem2 workcoordinatesystem6 ThesixworkcoordinatesystemsareassignedthroughsettingtheoffsetsfrommachinecoordinatesystemoriginontheCRTpanel Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 2 SelectingplanecommandsG17 G18andG19 Thethreemutualperpendicularaxes X Y Z inCartesiancoordinatesystemconstructthreeplanes TheyareXYplane XZplaneandYZplane Machiningcenterselectsthesecommandstocontrolmachiningontheseplanes BecauseturningcenterusuallymachinesonXZplane theselectingplanecommandisnotneed G17illustratesmachiningonXYplane G18illustratesmachiningonXZplane G19illustratesmachiningonYZplane Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 3 TheGcodesrelatedtotoolmovement a RapidmotionG00 ThistypeofcommandisusedtopositiontheCNCmachinetoalocationwheresomeactionistooccur Undernormaloperation theG00commandwillcausethemachinetomoveatitsfastestpossiblerate Therapidrateswillvaryfrommachinetomachine SeveralcurrentCNCmachinesboastrapidrates wellover24MPM Themachinewillbemovingveryquicklywhileundertheinfluenceofarapidmotioncommand Chapter2NCPARTPROGRAMMING 2 2 2PreparatoryFunctions Gcodes 2 2 2 2TheIntroductionofGCodesFunctions 3 TheGcodesrelatedtotoolmovement b G01linearinterpolation Straight Linemotion Thesecondtypeofmotionwewilldiscusscausesthemachinetomovealongaperfectlystraightpathinoneormo