數(shù)控技術(shù)雙語2課件

領(lǐng)域：數(shù)控技術(shù)、CAD/CAM技術(shù)、柔性加工技術(shù)、集成制造技術(shù)、智能制造技術(shù)、虛擬制造技術(shù)、綠色制造技術(shù)趨勢(shì)：高精度、高效率、自動(dòng)化、信息化、智能化制造業(yè)數(shù)控化率年增長(zhǎng)率達(dá)6%，據(jù)預(yù)測(cè)到2020年，我國(guó)制造業(yè)數(shù)控化率將達(dá)到60%，正向制造業(yè)大國(guó)邁進(jìn)。NUMERICALCONTROLTECHNOLOGYChapter2NCPartProgramming

ElectromechanicalEngineeringCollegeHenanUniversityofScienceandTechnology

領(lǐng)域：NUMERICALCONTROL.Chapter2NCPARTPROGRAMMING2.1、IntroductiontoNCpartprogramming2.2、ThecodesusedinCNC2.3、Manualpartprogramming2.4、Automaticprogramming.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1、IntroductiontoNCpartprogrammingTheprogramofinstructionsisthedetailedstep-by-stepcommandsthatdirecttheactionsoftheprocessingequipment.Inmachinetoolapplications,theprogramofinstructionsiscalledapartprogram,andthepersonwhopreparestheprogramiscalledapartprogrammer.Numericalcontrol(NC)isaformofautomaticallyoperatingamachinetoolbasedoncodedalphanumericdata.Acompletesetofcodedinstructionsforexecutinganoperationiscalledaprogram.Theprogramistranslatedintocorrespondingelectricalsignalsforinputtoservomotorsthatrunthemachine..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING1、IntroductiontoNCpartprogrammingwecallthewholeprocessfrompartgraphicstofinishingcontrolmediumtheprogrammingofnumericalcontrolmanufacturing,orcallitNCprogramming.Whenusingnumericalcontrolmachinetooltomanufactureparts,theprogrammingisveryimportant.Theprogramisnotonlycorrectandfastbutalsoeffectiveandeconomic.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1ThecontentsandstepsofnumericalcontrolprogrammingTheprogramcanbeinputtedintoCNCsystemandtheCNCsystemcontrolsCNCmachinetoolstomanufactureautomatically.Generallyspeaking,themainstepsofNCprogrammingareanalyzingpartgraphics,determiningthemanufacturingtechnologicalprocess,calculatingnumericalvalue,programming,verifyingtheprogramandinputtingtheprogramintoCNCsystem.Figure2.1illustratestheprogrammingsteps..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1ThecontentsandstepsofnumericalcontrolprogrammingBeforeNCprogramming,theprogrammershouldunderstandthenumericalcontrolmachinespecifications,characteristics,thefunctionsandprogramminginstructionsformatoftheCNCsystem,etc.Whenprogramming,heshouldanalyzethepart’stechnicalrequirements,geometricalshape,dimensionsandtechnologicalrequirements.Thenhecandeterminethemanufacturingmethodandcalculatenumericalvalue,getcutterposition.Accordingtopartdimension,cutterpositionvalue,cuttingparameters(spindlespeed,feed-rate,cuttingdepth)andauxiliaryfunctions(ATC,CW,CCW,coolantonandoff),theprogrammercanprogram..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1ThecontentsandstepsofnumericalcontrolprogrammingAnalyzingpartgraphicsanddeterminingthemanufacturingtechnologicalprocessThisstepincludesanalyzingthepartgraphics,understandingthemachiningcontentsandrequirements.Thendeterminingtechnologicalprocesses,machiningplans,machiningsequence,machiningroutes,fixingmethods.Cuttingparametersandselectingcuttingtools,etc.Besidesthese,thenumericalcontrolmachinecodesshouldbeunderstoodclearlyandthenumericalcontrolmachinefunctionsshouldbeexploitedfully..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1ThecontentsandstepsofnumericalcontrolprogrammingAnalyzingpartgraphicsTechnologicalprocessSelectingprogramingoriginandcoordinatesystemCalculatingnumericalvalueWriting&verifyingpartprogramsNCmachinetoolFigure2.1

ThestepsofNCprogramming.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1Thecontentsandstepsofnumericalcontrolprogramming(2)CorrectlyselectingprogramoriginandcoordinatesystemInnumericalcontrolmachinetoolsmanufacturing,correctlyselectingprogramoriginandcoordinatesystemisveryimportant.OnNCprogramming,theprogramcoordinatesystemisthestandardcoordinatesystemascertainedontheworkpiece..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1Thecontentsandstepsofnumericalcontrolprogramming(3)CalculatingnumericalvaluesAfterfinishingthetechnologicalprocess,thenextstepistogetthetoolpathaccordingtopartgeometricdimensionandthemethodofcutterradiuscompensation,sowewillobtainthecutterposition..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1Thecontentsandstepsofnumericalcontrolprogramming(4)WritingpartprogramsAfterdeterminingmachiningroute,technologicalprocessandthecoordinatevalueoftoolpath,step-by-step,theprogrammercanwritetheprograminaccordancewiththespecifiedfunctioncodesandprogramformatofCNCsystem..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1Thecontentsandstepsofnumericalcontrolprogramming(5)FabricationcontrolmediumTheprogramiscodedonasuitablemediumforsubmissiontothemachinecontrolunit.Formanyyears,thecommonmediumwas1-inchwidepunchedtape,usingastandardformatthatcouldbeinterpretedbythemachinecontrolunit.Today,punchedtapehaslargelybeenreplacedbynewerstoragetechnologiesinmodernshops.Thesetechnologiesincludemagnetictape,diskette,andelectronictransferofpartprogramsformacomputer..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1Thecontentsandstepsofnumericalcontrolprogramming(6)VerifyingpartprogramsBeforetheprogramisusedinrealproduction,wemustchecktheprogram.wedetecttoolpatherrorsthatcouldruinthepart,damagethefixtures,breakthecuttingtoolorcrashthemachine,etc.Insomecases,wetesttheprogramthroughmanufacturingapartonamachine.Onthebasisofdetectingresult,theprogramisneededtobemodifiedandtobeadjusted,untiltheprogramsatisfiesthemachiningrequirementscompletely..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.1ThecontentsandstepsofnumericalcontrolprogrammingThestepsabovementionedareprogrammedmanually.Thisprogrammingmethodiscalledmanualpartprogramming.Andwealsoknowthataprogrammernotonlymusthavetheknowledgeofthestructureofmachinetools,thefunctionsandstandardsofCNCsystem,butalsohavetheknowledgeoftechnologicalprocess,suchasfixtures,cuttingtoolsandcuttingparameters,etc..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgrammingPartprogrammingcanbeaccomplishedusingavarietyofproceduresrangingfrommanualmethodtohighlyautomatedmethod.(1).Manualpartprogramming(2).Automaticprogramming.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgramming(1).ManualpartprogrammingTheprogrammingiscalledmanualpartprogrammingwhichwholepartprogrammingiscompletedmanually(includingcalculatingnumericalvalueonacomputer).Inmanymechanicalmanufacturingtrades,therearealargenumberofuncomplicatedpartsthatareconstitutedonlybythesimplegeometricelementsofstraightlinesandcircles.thenumericalvaluesofthepartsarecalculatedsimply..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgramming(1).ManualpartprogrammingTheblocksofaprogramaren’tlot.Andcheckingtheprogramiseasy.Thesepartprogramscanbecompletedmanually.Somanualprogrammingisstillaverycommonprogrammingmethodathomeandabroad.Butmanualprogramminghasdifficultyorimpossibilitygoprogramcomplicatedpartsthathavenon-circularcurvesandsurfaces.Sowemustusetheautomaticpartprogrammingtoprogram..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgramming(1).AutomaticprogrammingAutomaticprogrammingisalsocalledcomputer-aidedprogramming.Mostoralloftheprogrammingiscompletedbyacomputer,suchascalculatingnumericalvalues,writingprograms,fabricatingthecontrolmedium,etc.Automaticprogramminglightensprogrammerintensityoflabor,shortenstheprogrammingtimeandimprovestheprogrammingquality..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgramming(1).AutomaticprogrammingAtthesametime,itsolvesthecomplicatedpartprogrammingwhichisimpossibletoprogrambymanualprogramming.Themorepartsarecomplicatedshapeandtechnologicalprocess,themoresuperiorityofautomaticprogrammingclearis..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.2TheMethodsofNCProgramming(1).AutomaticprogrammingTherearemanymethodsofautomaticpartprogramming.Accordingtothedifferencesofinputprogrammingmessageandhandlingstylesbyacomputer,theyaredividedintoautomaticallyprogrammedtool(APT)basedonautomaticprogramminglanguageandpartprogrammingusingCAD/CAMbasedoninteractivegraphicssystem.ACAD/CAMsystemisacomputerinteractivegraphicssystemequippedwithsoftwaretoaccomplishcertaintasksindesignandmanufacturing..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgrammingThelocationofaCNCmachinetoolsatanytimeiscontrolledbyasystemofXYZcoordinatescalledCartesiancoordinates.Thissystemiscomposedofthreedirectionallines,calledaxes,mutuallyintersectingatanangleof900.Thepointofintersectionisknownastheorigin.(1).NCCoordinateSystems.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsPrimarymachineaxesofmovementshouldfollowtheright-handrule.Seeleftfigure.SpindlemovementisprimarilyalongtheZaxis.movementintotheworkpieceisalongthe–Zaxisandmovementawayfromisalongthe+Zaxis..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsInamajorityofmillingmachines,motionalongtheXaxisisthelongesttravelperpendiculartoZ.theXaxisisparalleltotheworkholdingandisinthehorizontalplane.The+Xaxismovestotherightalongaplaneoftheworkastheoperatorlooksatthatplane.spindleworktable.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsWithregardtomillingmachines,motionalongtheYaxisistheshortesttravelperpendiculartoZ,theYaxisisinthesameplaneastheXaxis.Lookingattheplane,theoperatorwillnotethattheYisperpendiculartotheXaxis.spindleworktable.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsMostCNCmillingmachinescanperformsimultaneousmotionsalongtheX,YandZaxesandarecalledthree-axismachines.Seeleftfigure..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsMorecomplexCNCmachineshavethecapabilityofexecutingadditionalrotarymotionsasfollows:RotationaboutanaxisparalleltotheXaxisorA-axisrotationRotationaboutanaxisparalleltotheYaxisorB-axisrotation.RotationaboutanaxisparalleltotheZaxisorC-axisrotation.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(1).NCCoordinateSystemsRotarymotiondirectionsalsofollowtheright-handrule.Seerightfigure.、.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(2).Programzeropoint.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheGeometricBasisofNCPartProgramming

(3).Typesoftoolpositioningmodes.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheTechnologicalBasisofNCProgramming

(1).Determiningthepartmachiningroutesrationally.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheTechnologicalBasisofNCProgramming

(2).SelectingtoolsettingpointandtoolchangingpointrationallyThesettingpointmakesoperatingeasilyandprogrammingsimply;Thepointiseasytofind;Thecausedmachiningerrorissmall..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheTechnologicalBasisofNCProgramming(2).Selectingtoolsettingpointandtoolchangingpointrationally

boringtooldrillendmillfacetoolfiguretoolballnoseendmillTurningtool.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.1.3TheBasisofNCPartProgramming.TheTechnologicalBasisofNCProgramming

(3).Rationallyselectingthemethodsoffixing,cuttingtoolsandcuttingparametersSelectingstandardandcommonfixturesasfaraspossible,avoidingselectingspecialfixtures;Fixingandremovingpartsquickly,convenientlyandrationally;Thepartsurfacetobemachinedshouldbeexposedtooutside.Don’tletthefixtureaffecttherapidmotionandmachiningofatool..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2、THECODESUSEDINCNCTherearemanycodesincludedinaprogram.PreparatoryfunctionsareGcodesandauxiliaryfunctionsareMcodes.TheyarethebaseofCNCprograms.ISOhasworkedoutthestandardsofGcodesandMcodes.BecausenewCNCsystemsandmachineshavebeenemerging,alotoffunctionsinmanysystemssurpassISOstandards.Theircodesareabundantandtheirformatsareflexible.Theyaren’trestrainedbyISOstandards..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2、THECODESUSEDINCNCInaddition,evenifthesamefunction,itscodeandformathavealotofdifferencesamongsystemsmadeindifferentcompanies.Andcodesandformatsalsohavedifferencesbetweennewandoldsystemsmadeinthesamecompany.ButthepreparatoryfunctionscodesandauxiliaryfunctionscodesinmostofCNCsystemsareuptoorsimilartotheISOstandards.BeforeintroducingtheGcodesandMcodes,wemustunderstandprogramminglangueformatsfirst..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

AprogramformatisasystemofarranginginformationsothatitissuitableforinputtoACNCcontroller.Severaldifferenttypesofformatsexist.Theformattobeusedinthistextisknownasthewordaddress.(1)AddressesAnaddressisaletterthatdescribesthemeaningofthenumericalvaluefollowingtheaddress..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(2)WordsWordsareusedtodescribesuchimportantinformation.asmachinemotionanddimensionsintheblock.Programwordsarecomposedoftwomainparts:anaddressfollowedbyanumber.TheFigure2..9illustratestheaddress,numberandwords.G17

AddressNumberY-35.68

AddressNumberWords.Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(3)BlocksAblockisacompletelineofinformationtotheCNCmachine.Itiscomposedofonewordoranarrangementofwords.Blocksmayvaryinlength.Thus,theprogrammerneedsthosewordsinablocktoexecuteaparticularmachiningfunction.“N10G01X-63.75Y70.28F100.S1000M03;”.Eachblockisseparatedfromthenextbyanend–of-block(;)code..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(3)BlocksTheend-of-blockcharacterisautomaticallygeneratedwhentheprogrammerpressesreturnkeyatthecomputer.Thesameholdstruewhentheend-of-blockkeyispressedatthemachinepanelboardduringmanualdateentry.Thus,thischaracterwillnotappearintheregularprogramlistingsinthistext..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(4)ProgramsAprogramisasequenceofblocksthatdescribeindetailthemotionsaCNCmachineistoexecuteinordertomanufactureapart.TheMCUexecutesaprogramblockbyblock.Theorderinwhichtheblocksappearistheorderinwhichtheyareprocessed.Table2.1illustratestheformatandtheorderinwhichtheMCUexecutesaprogram.Theorderinwhichaddressesappearinablockcanvary..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(5)Programandsequencenumbers(O,Ncodes)(i)ProgramNumber(O)ProgramsarestoredintheMCUmemorybyprogramnumber.Themachinerecognizesprogramsaccordingtoanumericcode.Mostmachinescanstoreseveralprogramsatatime.ProgramnumbersrangefromO0000toO9999..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(5)Programandsequencenumbers(O,Ncodes)(ii)SequenceNumber(N)

Asequencenumberisanoptionaltagthatcanbecodedatthebeginningofablockifneeded.TheMCUwillexecuteprogramblocksintheorderinwhichtheyappearregardlessofthesequencenumberentered.Sequencenumbersareusedsothatoperatorscanlocatespecificlinesofaprogramwhenenteringdataorperformingcheckoutoperations.ThesenumbersrangefromN0001toN9999..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.1

ProgrammingLanguageFormat

(6)DecimalpointinprogramsCurrentCNCcontrolsallowtheprogrammertoincludeadecimalpointforthosewordstypesthatisfeasible.Forexample,ifapositionalongtheXaxisof120.65mustbespecified,theprogrammerwouldincludetheworldX120.65inthecommandforthemotion.SomewordsrequiretheplacementofadecimalpointsuchasF,X,Y,Z,A,B,C,U,V,W,etc..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

Gcodes

ApreparatoryfunctionisdesignatedbytheaddressGfollowedbyoneortwodigitstospecifyaCNCmachinehowtomove.Gcodescontainsettingcoordinatessystem,planeselection,interpolation,cuttingtoolcompensation,cannedcycle,etc..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

Gcodes

AcompletelistofGcodesisgiveninAppendixA.TheGcodesaredividedintoseveralgroupsaccordingtotheirfunctions,suchasa,b,c,dgroup,etc.AnytwoGCodesofasamegroupcan’tbeinablock.TheGcodesofdifferentgroupscanbeinablockaccordingtorequirements..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(1)TheGcodesrelatedtocoordinatesystem(a)AbsolutedimensioncodeG90andincrementaldimensioncodeG91

G90assignstheabsolutemodeofprogramming.Themachinetooldetermineseachnewtoolpositionfromahomeorspecifiedorigin(0,0).Itisimportanttoincludethiscommandatthebeginningofeverytool,beforeanymotioncommands,toassurethattheabsolutecommandisselected..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(1)TheGcodesrelatedtocoordinatesystem(a)AbsolutedimensioncodeG90andincrementaldimensioncodeG91

G91specifiesthattheincrementalmodeofprogrammingtobeused.Machinetoolsoperatinginthismodelocateeachnewtoolpositionbymeasuringfromthelasttoolpositionestablished.Wehavestatedthatthebetterprogrammingmodeistheabsolute(90)programmingmode,soyoumayquestionthiscommand..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(1)TheGcodesrelatedtocoordinatesystem(b)AssigningtheworkcoordinatesystemG92G92belongstofixtureoffsets.Fixtureoffset,alsocalledworkcoordinatesystemmultiplesettings,allowtheusertoworkwithseveralcoordinatesystemswithinthesameprogram.Whenitisconvenient,ifnotmandatory,theprogrammerisabletosetupmorethanonecoordinatesystemintheprogram..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(1)TheGcodesrelatedtocoordinatesystem(c)SelectingworkcoordinatesystemcommandsG54~G59G54~G59areseparatelycalledworkcoordinatesystem1,workcoordinatesystem2…workcoordinatesystem6.ThesixworkcoordinatesystemsareassignedthroughsettingtheoffsetsfrommachinecoordinatesystemoriginontheCRTpanel..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(2)SelectingplanecommandsG17,G18andG19

Thethreemutualperpendicularaxes(X,Y,Z)inCartesiancoordinatesystemconstructthreeplanes.TheyareXYplane,XZplaneandYZplane.Machiningcenterselectsthesecommandstocontrolmachiningontheseplanes.BecauseturningcenterusuallymachinesonXZplane,theselectingplanecommandisnotneed.G17illustratesmachiningonXYplane.G18illustratesmachiningonXZplane.G19illustratesmachiningonYZplane..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(3)TheGcodesrelatedtotoolmovement(a)RapidmotionG00ThistypeofcommandisusedtopositiontheCNCmachinetoalocationwheresomeactionistooccur.Undernormaloperation,theG00commandwillcausethemachinetomoveatitsfastestpossiblerate.Therapidrateswillvaryfrommachinetomachine.SeveralcurrentCNCmachinesboastrapidrates-wellover24MPM.Themachinewillbemovingveryquicklywhileundertheinfluenceofarapidmotioncommand..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(3)TheGcodesrelatedtotoolmovement(b)G01linearinterpolation(Straight-Linemotion)Thesecondtypeofmotionwewilldiscusscausesthemachinetomovealongaperfectlystraightpathinoneormoreaxes.Thecontrolwillcalculatethepathbetweenthestartpointandtheendpointofthemo9tionautomatically,nomaterwhatangleisinvolved..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(3)TheGcodesrelatedtotoolmovement(c)CircularinterpolationG02andG03Circularinterpolationisperformedinmuchthesameway.NotethesimilarityinFigure2.17.Bycontouring,wemeanmakingmotionsaroundtheperipheryofashape.Contouringcanincludestraightlineandcircularmotion..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(3)TheGcodesrelatedtotoolmovement(c)CircularinterpolationG02andG03

CircularinterpolationinvolvestwoGwords.ThereasonwhytherearetwoGwordsistoallowtheprogrammertospecifythedirectionofthecircularmotiontobemachined,clockwisemotion(CW)orcounterclockwisemotion(CCW).Todeterminewhetheraparticularmotionisclockwiseorcounterclockwise,theprogrammermustlookatthemotionfromtheplussideoftheuninvolvedaxis.IfmakingacircularmovementinX-Y,lookatthemotionfromtheZplusside.IfmakingacircularmovementinX-Z,lookatthemotionfromtheYplusside,andsoon..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(4)TheGcodesrelatedtotoolcompensation(a)CutterradiuscompensationG41,G42andG40TherearethreeGcodesusedincutterradiuscompensation.TwooftheseGcodesareusedforinstatingorinitializingcutterradiuscompensation.NotethateitherG41orG42isusedtoinstatecutterradiuscompensation.ThethirdGcode,G40,isusedtocancelcutterradiuscompensation.AlongwiththesethreeGcodes,aprogrammingwordisalsousedtospecifytheoffsetnumber.UsuallyaDwordisusedtospecifytheoffsetnumber..Chapter2NCPARTPROGRAMMI.Chapter2NCPARTPROGRAMMING2.2.2

PreparatoryFunctions(Gcodes)

TheIntroductionofGCodesFunctions

(4)TheGcodesrelatedtotoolcompensation(b)ToollengthcompensationG43,G44andG49

G43istoollengthpositivecompensation(compensatingin+Zdirection).G44istoollengthnegativecompensation(compensatingin–Zdirection).AndG49isthecancellationcommandfortoolcompensation.Atmachining,theactuallengthsoftoolsarenotequaltothespecifiedlengthinprogramming.Figure2.24showsthetoollengthcompensation.IncludedintheG43andG44isanHwordthat