机械类英语论文

W.M.ChanÆL.YanÆW.XiangÆB.T.Cheok

A3DCADknowledge-basedassistedinjectionmoulddesignsystem

Received:5June2002/Accepted:23August2002/Publishedonline:29May2003ÓSpringer-VerlagLondonLimited2003

AbstractThispaperpresentsthebasicstructureofaninteractiveknowledge-basedinjectionmoulddesignsystem(IKB-MOULD).Thebasisofthissystemarisesfromananalysisoftheinjectionmoulddesignprocessformoulddesigncompanies.Thisinjectionmouldde-signsystemcoversboththemoulddesignprocessandmouldknowledgemanagement.IKB-MOULDinte-gratestheintelligentdesignprocessandknowledgemanagementwithmanydevelopedinteractivetoolsinacommercialsolidmodellingsoftwareenvironment.KeywordsInjectionmoulddesignÆKnowledgebaseÆInjectionmouldobjectrepresentation

1Introduction

Inrecentyearstheplasticproductmanufacturingindustryhasbeengrowingrapidly.Averypopularmouldingprocessformakingplasticpartsisinjectionmoulding.Theinjectionmoulddesigniscriticallyimportanttoproductqualityandefficientproductpro-cessing.Mould-makingcompanies,whowishtomain-tainthecompetitiveedge,desiretoshortenbothdesignandmanufacturingleadingtimesbyautomatingthedesignprocess.Thus,thedevelopmentofacomputer-aidedinjectionmoulddesignsystem(CAIMDS)isbecomingafocusofresearchinbothindustryandaca-demia.

Recentlypublishedpapersshowthatresearchinautomaticmoulddesignfocusesonindividualcompo-nentsofthemouldprocess.ForexampleOngetal.[1]andRavi[2]focusedtheirresearchonthefeeding

W.M.Chan(&)ÆL.YanÆW.XiangÆB.T.Cheok

InstituteofHighPerformanceComputing,1ScienceParkRoad,#01-01TheCapricorn,SingaporeScienceParkII,117528,Singapore

E-mail:chanwm@ihpc.a-star.edu.sgTel.:+65-6-4191111Fax:+65-6-4191280

system.Wangetal.[3]focusedtheirresearchontheejectionsystem.Othersfocustheirresearchonthegeneraldesign.Mostresearchdoneonthegeneralinjectionmouldsystemcanbeclassifiedintotwoareas:(a)functional,conceptualandinitialmoulddesigns;and(b)algorithmstoautomatemouldgeneration.

Functional,conceptualandinitialdesignsoftheinjectionmouldareappliedmainlytothepre-moulddesign.Suchdesigninvolvesselectingasuitablemouldbase,arrangingthecavitylayout,designingtherunneranddesigningthegate.Theobjectiveistocomeupwithalargenumberofverydifferentproductideasforacertainrequirement.Brittonetal.[4]addressedinjectionmoulddesignfromafunctionalperspectivebypresent-ingtheFunction-Environment-Behaviour-Structure(FEBS)model.Thestudyfosteredawiderangeofde-signalternatives.CostaandYoung[5]proposedaproductrangemodel(PRM)tosupportthereuseofdesigninformationinvariantdesigncases.ThegeneralstructureofaPRMisdefinedintermsofdesignfunc-tionslinkedwithsetsofdesignsolutions,interactionsbetweenpotentialsolutionsandknowledgelinks.Yeetal.[6]presentedanapproachtoautomaticinitialdesignwithalgorithmsthatcalculatethecavitynumberandautomaticallylayoutthecavity.Theinitialinjectionmoulddesigninvolvesextensiveempiricalknowledgeofthestructureandfunctionsofthemouldcomponents.Thus,alotofresearchersadoptaknowledge-basedapproach.Severalknowledge-basedsystems(KBSs)weredevelopedtoadviseplasticmaterialselection,captureinjectionmouldpartdesignfeatures,analysemouldability,automatethemoulddesignprocessanddevelopmoulddesignformanufacture.ExamplesofsuchsystemsareGERES(Nielsen[7]),PLASSEX(AgrawalandVasudevan[8]),EIMPPLAN-1(ChinandWong[9]),CADFEED(Ongetal.[10]),ICAD(Cin-quegrana[11]),IKMOULD(Moketal.[12])andKBSofDrexelUniversity(Tsengetal.[13]).However,theseKBSsconsideronlycertainaspectsofthetotaldesign.Asfortheautomaticgenerationofaninjectionmould,anumberoftheoreticalresearchworkswere

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conductedtoautomaticallydeterminethepartingdirection,todeterminethepartingline,togeneratethepartingsurface,torecogniseundercutfeaturesandtogeneratethecore/cavity.RaviandSrinivasan[14]pre-sentedninerulesthatcanbeusedbythemoulddesignengineertodevelopasuitablepartinglineintheprod-uct.Theserulesareprojectedarea,flatness,draw,draft,undercuts,dimensionalstability,flash,machinedsur-facesanddirectionalsolidification.HuiandTan[15]proposedthesweepmethodtoformthecavityandcore.Thecavityandcorearegeneratedinanumberofsteps.Sweepingthemouldpartinthedrawdirectiongeneratesasolid.Oneendofthesweptsolidissubtractedfromthefirstmouldblock.Theotherendofthemouldblockissubtractedfromthemouldpart.Theresultsoftheabovestepsaresubtractedwiththepartattheclosedpositiontoobtainthecavityandcore.ShinandLee[16]pro-posedamethodofcoreandcavitydevelopmentsothatthesidecoresandcorrespondingcoreandcavityplatescanbegenerated.Thismethodiscomposedof3steps.Thedesignerdeterminesthepartinglinethatseparatestheproductinto2groupsoffaces.Eachgroupfacehasthepartingsurfaceattachedtoit.Thenexternalfacesareaddedtoeachgroupface.Shinaddedthatamouldcouldbemadeupofmanypiecesinadditiontothecavity,coreandsidecores.Hui[17]studiedthemoul-dabilityofaninjectionmouldbasedonanexternalandinternalundercutanalysisonlyforpolyhedralsolids.Ablockageconceptispresentedtodeterminethemainpartingdirectionandasubdivisiontechniqueisdevel-opedtoevaluatethegeometryofanundercut.Chenetal.[18]introducedtheconceptofvisibilitymaps(V-maps)ofthepocketstodeterminethepartingdirection.Themethoddidnottakeintoaccountinternalundercuts.Fuetal.[19]andNeeetal.[20]gaveanewclassificationofundercutsaccordingtotheexternalloopsandtheinternalloopsofamouldedpart.Thepartingdirectionisthendeterminedbasedontheproposedpartingdirectioncriteriaconsideringthedirections,location,numberandvolumesofundercutfeatures.Fuetal.[21]proposedanapproachtogeneratethepartingsurfacebyextrudingthepartinglineedgesandcreatethecore/cavityblockusingtheBooleanregulariseddifferenceoperation(BRDO).Amethodologythatgeneratesnon-planarpartinglinesandsurfacesispresentedbyNeeetal.[22].Wongetal.[23]proposedamethodtodeterminethecuttingplaneofacomplexshapedproduct.Theirmethodusesanalgorithmthatslicestheproduct.Thepartinglineandsurfacesformedbythismethodareplanar.

Currentresearchonautomaticmoulddesignisongoing.However,somemethodscanbequitetheo-reticalandthemoulddesigncanhaveacomplicatedproductgeometry.Mostmoulddevelopmentactivitiesinvolveahighlevelofskill,awidevarietyofdesignexpertiseandknowledge.Duetothefactthatautomaticmoulddevelopmentisstillfarbeyondthecurrenttech-nology,itismorereasonabletoprovideintelligentrulesorguidelinesthatpreventthedesignfromcon-flictingwithdesignconstraints.Theserulesalsoprovide

interactivetoolsinthedetailedmoulddesignenviron-ment.Thispaperpresentsaninteractiveknowledge-basedinjectionmoulddesignsystem(IKB-MOULD).Thissystemintegratestheinitialmoulddesignandde-tailedmoulddesignwithbothknowledgebaseandinteractivecommercialCAD/CAMsoftware.

Thenextsectionofthispaperoutlinesananalysisoftheinjectionmoulddesignprocessbasedonthemoulddesigner’spointofview.AlatersectionintroducesthebasicstructureofourIKB-MOULDforinjectionmoulddesign.AcasestudyoftheinjectionmoulddesignforaplasticproductinIKB-MOULDisthenpresented.Theconclusionandfutureworkislocatedinthelastsection.

2Theinjectionmoulddesignprocessrequirementanalysis

Aninjectionmoulddesigniscomposedoftwosteps:theinitialdesignandthedetaileddesign.Theinitialdesigniscomposedofdecisionsmadeattheearlystageofthemoulddesign,suchasthetypeofmouldconfiguration,thenumberofcavities,thetypeofrunner,thetypeofgateandthetypeofmouldbase.Thedetaileddesigniscomposedoftheinsert(core/cavity)design,theejectionsystemdesign,thecoolingandventingcomponentde-sign,theassemblyanalysisandthefinaldrafting.

TodevelopagoodCAIMDS,ananalysisof‘whattheyhave’and‘whattheywant’needstobeperformed.Whattheyhave:

–Thecustomer’srequirementsfortheproduct.This

includesthedetailedgeometryanddimensionre-–quirementsoftheproduct.

Anexistingmoulddesignlibrary.Thislibrarycoversthestandardorpreviouslydesignedcomponentsandassembliesofthemoulddesign,forexample,themouldbase(thefixedhalfandthemovinghalf)and–thepocket(thefixedhalfandthemovinghalf).

Anexpertknowledgeininjectionmoulddesign.Ex-pertknowledgeofbothinitialanddetaileddesignsfortheinjectionmouldisobtainedmainlyfromexperi-encedmoulddesigners.Suchknowledgeincludesmaterialselection,shrinkagesuggestion,cavitylayoutsuggestionandothers.Whattheywant:

–Anintelligentandinteractivemoulddesignenviron-ment.Moulddesignisoftencomposedofaseriesofdesignprocedures.Theseproceduresusuallyrequirecertainmouldpartstobecreatedandexistingmouldpartstobeassembled.Suchamoulddesignenvi-ronmentneednotbefullyautomatic,especiallyforcomplicatedproductswithmanyundercuts.Anintelligentandinteractiveenvironmentwillbeagoodchoicetointegratesomeusefulautomationalgo-rithms,heuristicknowledgeandon-lineinteractionbytheexperiencedmoulddesigner.

3

–Standard/previousdesignedcomponents/assemblies

(product-independentparts)management.Apartfromthecoreandcavity,aninjectionmouldhasmanyotherpartsthataresimilarinstructureandgeometricalshapethatcanbeusedinotherinjectionmoulddesigns.Thesepartsareindependentoftheplasticmouldproducts.Theyaremostlystandardcomponentsthatcanbereusedindifferentmoulddesignsandmouldsets.

–Usefultools(includingsoliddesignandanalysiscalculation)inthecoreandthecavity(product-dependentparts)design.Geometricalshapesandthesizesofthecoreandcavitysystemaredetermineddirectlybythemouldproduct.Allcomponentsinsuchasystemareproductdependent.Also,thesepartsarethecriticalcomponentsinthemoulddesign.

Fig.1ThestructureoftheIKB-MOULD

Theirgeometricalrequirementsmaybecomplicated.Thus,sometoolsdevelopedtodesignthecoreandthecavitybasedonpartialautomationandpartialinteractioncanbequiteuseful.

–Designforassembly.InconventionalCAD/CAMsystems,mouldsarerepresentedandstoredasacompletegeometricandtopologicalsolidmodel.Thismodeliscomposedoffaces,edgesandverticesinathreedimensional(3D)Euclideanspace.Sucharep-resentationissuitableforvisualdisplayandper-forminggeometricallycomputation-intensivetaskssuchasengineeringanalysisandsimulation.How-ever,thisformisnotappropriatefortasksthatrequiredecision-makingbasedonhigh-levelinfor-mationaboutproductgeometricentitiesandtheirrelationships.Moulddesignerspreferadesignforassemblyenvironmentinsteadofasimplesolidmodelenvironment.ThisideaisalsopresentedinYeetal.’swork[24].

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–Adesignformanufacture.Acompleteinjection

moulddesigndevelopmentcyclecanbecomposedofthemoulddesignandmouldmanufacturingprocess.TointegrateCAD/CAMintothemoulddesign,themanufacturingfeaturesonthemouldshouldbeab-stractedandanalysedforthespecificNCmachine.BoththeprocessplanandtheNCcodeshouldbeautomaticallygeneratedtoenablethefinaldesigned–mouldtobemanufactured.

Adesignforengineeringdrawings.Formanycompanies,theinjectionmoulddesignhastoberepresentedintheformofengineeringdrawingswithdetaileddimensions.CAD/CAMtoolsthatareabletoautomaticallygeneratetheseengineeringdrawingsfromthefinalinjectionmoulddesignwillbeuseful.Basedontheaboveanalysis,ourresearchfocusistodeveloptechniquestorepresent‘whattheyhave’and‘whattheywant’.

Representing‘whattheywant’isactuallytherepre-sentationoftheknowledgeandinjectionmouldobject.Developing‘whattheywant’meanstointegratetherepresentationwithintelligentandinteractivetoolsfortheinjectionmoulddesignintoacompleteddesignenvironment.Therefore,anIKB-MOULDisproposedformoulddesignerstorealisetheabovetworequire-ments.

3TheIKB-MOULD

TheIKB-MOULDcombinestheuseofknowledge-basedandobject-orientedtoolswithcommercialsolidmodellingsoftwaretocarryoutitsfunction.TheIKB-MOULDpresentedinthispaperbeginswiththeplasticparttobemouldedandfinisheswiththegenerationofacompletedmouldsystemwithrelativelydetaileddrawings.

Fig.2TheplasticproductFig.3Themouldspecification

Fig.4Thedesignedcoreandcavityinserts

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Fig.5TheIKB-MOULDenvironment

3.2.1Thepre-mouldprocess

Productmouldabilityisevaluatedinthispre-mouldprocess.Someissuestobeconsideredarematerialthermalexpansion,theplasticflowdirectionandtheproductdraftangle.Thesystemnotonlyallowsexpe-riencedmoulddesignerstodefinetheshrinkageoftheproductmodel,butalsotorecommendproductshrinkageusingthemateriallibrary.Thismaterialli-braryisamaterialdatabasethatstoresinformationaboutthematerial’sviscosity,temperaturesensitivity,anddegreeofdifferentialshrinkage.Basedonthegenerictypeofmaterialused,IKB-MOULDsystemretrievesthematerialshrinkageratefromthemateriallibrary.Onceshrinkageisdetermined,theproductmodelisreconstructedtoaccountformaterialshrink-agethatoccursduringthemouldoperation.3.2.2Theinitialmoulddesign

Mouldspecificationisdoneintheinitialstageoftheinjectionmoulddesign.Therequirementsoftheplasticcomponentarespecifiedatthisstage.Decisionsmadeatthisstageincludeafunctionalanalysis,thenumberofcavities,thecavitieslayoutandthetypeofmouldcon-figuration.Theinitialdesignplaysanimportantroleinthemoulddesign.Oncetheinitialdesignstageiscompleted,

Figure1showsthebasicstructureoftheinjectionmoulddesignprocessintheIKB-MOULD.TheIKB-MOULDiscomposedofthefollowingmodules:aproductmodelinterface,amoulddesignmodule,aknowledgebaseandsomeotherlibraries.3.1Theproductmodelinterface

TheproductmodelistheinputtotheIKB-MOULDdesignprocess.Thismodelcanbeasolid,standardengineeringinterchange,orasurfaceorwire-framemodel.TheIKB-MOULDsystemprovidesaproductmodelinterfacetoacceptasolidmodelbuiltindifferenttypesofsolidmodellingsoftware.ItcandirectlyloadtheproductmodelbuiltinSolidDesigner.IftheproductisdevelopedfromaCADsystemthatisotherthanSol-idDesigner,thentheproductneedstobeconvertedusingSTEP,IGESorDXF.3.2Themoulddesignmodule

TheinjectionmoulddesignprocessofthemoulddesignmoduleinIKB-MOULDcoversthepre-mouldingpro-cess,theinitialmoulddesignandthedetailedmoulddesign.

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Fig.6Theinsert2Ddrawing

–Thedeterminationofthemouldbase.Theprojection

areaofthecavitylayoutalongtheejectiondirectioncanbeusedtodeterminetheminimummouldbasesize.TheIKB-MOULDhasamouldbaselibrarythatstoresmanystandardmouldbases(thefixedhalfandthemovinghalf).

Designrulesandexpertknowledgeintheinitialmoulddesignprocessareregardedasheuristicknowl-edgeincorporatedintotheIKB-MOULD.Aftertheinitialdesign,amouldspecificationcanbegenerated.

themouldstructureisdetermined.Suchaninitialdesignisusuallytheguidelineforthemouldquotation,themouldbaseorderingandthedetailedmoulddesign.

–Thedeterminationofthecavitynumber.Thenumber

ofcavitiescanbedeterminedusinganempiricalfor-mulathatconsidersdifferentfactors.Thesefactorsaretheperiodofdelivery,theminimumcost,theproductprecisionqualityrequirementorthemachinetechnicaldatasuchasthemaximumshotcapacityandtheclampingforce(Menges[25]).Yeetal.[26]determinedthecavitynumberbasedonamixedconsiderationofthreefactors:machinetechnicaldata,minimumcostanddeliverydate.

Oftenmoulddesignersdeterminethecavitynumberbasedontheirexperienceandsuggestedempiricalcalculationswithconsiderationtodifferentfactors.–Thedeterminationofthecavitylayout.Thecavitylayoutofaninjectionmouldusuallyincludesthelayoutpatternandorientationofeachcavityinthemould.Thelayoutpatterndependsonthecavitynumber.Abal-ancedlayoutpatterniscommonlyadoptedformultiplecavities,suchastwo-cavity,four-cavityandeight-cavity.Orientationofthecavityaffectsthepositionandorientationofthegatesystem.Inotherwords,cavityorientationandgatelocationshouldbebalanced.

3.2.3Thedetailedmoulddesign

Inthedetailedmoulddesign,theIKB-MOULDisdevelopedforthreedifferentandusefulapplicationsforusebythemoulddesigncompanies:thedesignforassembly,thedesignfora2DdrawingandthedesignforBOM.

(1)Thedesignforassembly.Aninjectionmouldisa

mechanicalassemblythatiscomposedoftheprod-uct-independentandproduct-dependentparts.De-signoftheproduct-dependentpartsisbasedonthegeometryextractedfromtheplasticproduct.Thisextractioncanberealisedbyintegratingsomeautomationalgorithmsandexpertknowledge.Thedesignofproduct-independentpartsisbasedonthedesigner’sexperienceandcatalogueinformation.

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ejectorpintypeisSteptypeTasksinthedetailedinjectionmoulddesignmayRule2:IF

ANDejectorpinsize¼0:4mmbeinterrelatedwithmanyoftheinjectionmould

objects’designelements.Therefore,thefinalde-THENejectorpinheaddia¼2:0mm;

tailedmoulddesigncanberegardedasadesignejectorpinheadthick¼4:0mm;composedoftheinjectionmouldobjects.Repre-ejectorpinstepdia¼0:5mm;

sentationofaninjectionmouldobjectandtheejectorpinsteplengh¼20:0mmknowledgeusedfordetailedmoulddesignisex-plainedinalatersection.Basedonthatrepre-ejectorpintypeisRectangulartypesentation,anassemblytreecanbeautomaticallyRule3:IF

generatedandmodifiedduringthedetailmoulddesign.(2)Thedesignformanufacture.ThismoduleisdevelopedmainlyfortheCAPP/CNCofthefinaldesignedmould.Inprocessplanning,thesequenceofmachiningprocessestomanufacturethede-signedmouldisacomplicatedtaskandrequires

manufacturingknowledge.Manufacturingfeaturesneededtobeabstractedfromthefinaldesignedmouldandarelativesequencedprocesshastobegeneratedbasedonknowledgestoredintheknowledgebase.Inaddition,atoollibraryforthespecificNCmachineisusedtoautomatically

generatetheNCcodeforthemanufacturingpro-cess.Detaileddesignofthemanufacturemodulein

theIKB-MOULDisnotpresentedinthispaper.

(3)Thedesignforthe2Ddrawing.Withthehelpofanapplication-programming-interface(API)providedbythecommercialsolidmodellingsoftware,most2Ddrawingsofpartscanbeobtainedfromthesolidmodel.Someintelligenttoolsneedtobedevelopedforgeneratingdetaileddimensions.

(4)Thedesignforthebillofmaterial(BOM).Similartothedesignfortheassemblyinthedetailedmoulddesign,allpropertiesofthedesignedinjectionmouldobjectscanbetraced.Atoolcanbedevel-opedtoautomaticallygeneratetheBOM.3.3Knowledgebaseandlibraries3.3.1Knowledgerepresentation

Knowledgeforaninjectionmoulddesignisgainedmainlythroughexperienceandhandbooks.Eachmoduleofthemoulddesignprocessneedstobesupportedbytheknowledgebase.Knowledgeinvolvedinthemoulddevelopmentcanberepresentedintermsofdesignrules:IF(conditions)THEN(designsolution).

SomedesignrulesintheIKB-MOULDusedtodeterminetheejectorpinsizefromboththecata-loguelibraryanddesignexperiencearerepresentedasfollows:Rule1:IF

ejectorpintypeisStraightcirculartypeANDejectorpinsize¼1:0mm

THEN

ejectorpinheaddia¼3:0mm;ejector

pin

headthick¼4:0mm

ANDejectorpinsize¼1:8Â3:0mmTHENejectorpinheaddia¼15:0mm;ejectorpinheadthick¼4:0mm;

Ejectorpinstepdia¼10:0mm;ejectorpinsteplengh¼20:0mmRule4:IFMouldbase¼TRUEANDCoreinsert¼TRUETHENEjectorpinlength¼ðzcoÀordinateofproductejectionpointatcoreÞÀðzco-ordinateofejectorbackplatebaseÞ

IntheIKB-MOULD,knowledgerulesarestoredingroupsthatareassociatedwiththedesigntasks.Many

designtasksinthemoulddesignmoduleareshowninFig.1.Toimplementeachtask,someinjectionmouldobjectsneedtobedeterminedusingtheknowledgebase.Consider,forexample,thefeedingsystemdesigntaskin

thedetailedmoulddesign.Someinjectionmouldobjectssuchasrunnersandgatesaretobedefined.Thedetailed

runnerdesignhasasetofdesignsolutionsthatcanbeapplied;forexample,runnertypescanbecircularortrapezoid.3.3.2Thelibrary

TheIKB-MOULDalsohasusefullibrariesthatsupporttheinjectionmoulddesignmodule.Threetypesofli-brariesarethemateriallibrary,themouldbase/compo-nentslibraryandthetoollibrary.Themateriallibrarystoresthedetailedmaterialpropertiesandtheshrinkageratesof38differentmaterials.Themouldbase/compo-nentslibrarystoresallstandardmouldbasesandothercomponentsusedinthedetailedmoulddesign.ThetoollibraryisreservedmainlyforautomaticNCcodegen-erationandtostoretoolinginformationsuchasfeedrateandspeed.Alllibrariescanbeexpandedtomeettheuser’srequirements.

4Acasestudy

Sofar,thedetailedmoulddesignmoduleshavebeenpresentedintheprevioussection.IntheIKB-MOULD,theimplementationofthosemodulesisrealisedina

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Fig.7Theassembly2Ddrawing

commercial3Dsolidmodellingenvironment—Solid-Designer.SolidDesignerprovidesauser-friendlyAPI.UsingthisAPI,anintelligentandinteractivedesignenvironmentforinjectionmoulddesignisdeveloped.Therearemanyusefulmenus,toolbuttons,dialoguesandcommands.

Figure2showsaplasticproduct.WiththehelpoftheintelligentandinteractivetoolsprovidedbytheIKB-MOULD,aninjectionmouldisdesignedtomouldthisplasticproduct.

Mouldspecificationisdoneduringtheinitialmoulddesign.Figure3showsthemouldspecificationofthisproduct.ThematerialusedisZenite.Usingthemateriallibrary,therelativeshrinkagerateinthreedirectionsisrecommendedtoreconstructtheproductmodeltoac-countformaterialshrinkageduringthemouldopera-tion.Someothermouldinformation,suchasthemouldbase,thenumberofcavities,themouldsize,etc.,canbefoundinthemouldspecification.

Thecriticaldesigninaninjectionmouldliesinthecore/cavityinsert.Duetothecomplicatedstructureoftheproduct,therearemanyinsertsinthecoreandthecavity.Figure4showsthedesignedcoreandcavityin-serts.Thedesignedcoreinsertswiththeproductare

displayedontheleftsideandthedesignedcavityinsertsaredisplayedontherightsideofFig.4.

Figure5showsthefinaldesignedmouldintheentireIKB-MOULDenvironment.Theleftwindowshowstheassemblytreeoftheinjectionmoulddesign.Thisassemblytreeliststhemouldbase,inserts(coreandcavityinserts),tools(includingfeedingandcoolingsystems)andstandardelements(includingejectorpins).Theassemblytreeisautomaticallygeneratedfromtheinjectionmouldobjects’relationshipbasedonthepro-posedobjectrepresentation.Theentiremouldcanbeviewedinwholeorinpartbyselectingthevisibilitybuttonofeachinjectionmouldobjectintheassemblytree.ThefinaldesigninjectionmouldbasemovinghalfisdisplayedinthecurrentIKB-MOULDenvironment.ThemiddlewindowinFig.5showsthedesignedcoreinsertsfittedintothestandardmovinghalfofthemouldbaseplate.Thedesignedcavityinsertsarefittedintothemouldbasefixedhalf.OngoingworkisbeingperformedfortheIKB-MOULDtodevelopmanyusefultoolsthatgenerate2Dengineeringdrawingsfromthedesignedinjectionmould.Figure6showsthefinal2Ddrawingofoneofthecoreinserts.Figure7showstheassembly2DdrawingofthedesignedmouldwiththeBOM.All2Ddrawingsfortheinjectionmouldcanbeautomaticallygeneratedbasedonthedesigned3DmouldintheIKB-MOULD.

5Conclusionsandfuturework

Thispaperpresentsanintelligentandinteractiveinjec-tionmoulddesignsystem.Basedontheanalysisoftheinjectionmoulddesignprocess,therepresentationofthemoulddesignandtheintegrationofanintelligentandinteractiveenvironmenthavetobesolvedtoprovideabetterinjectionmoulddesignsystem.AnIKB-MOULDisdevelopedaccordingly.TheIKB-MOULDintegratestheknowledgerepresentationwithmanydevelopedtoolsinacommercialsolidmodellingsoftwareenvironment.Suchsoftwarecanspeeduptheinjectionmoulddesignprocessandfacilitateadesignstandardisation.

ThecurrentversionoftheIKB-MOULDsupportsdesign-for-assemblyfortheinjectionmoulddesign.Thisversiononlyprovidesthe3D-injectionmoulddesignandhassomeautomationtogenerate2Ddrawings.TointegratetheCAD/CAM,futureworkwillbefocusedondesign-for-manufacture.Inotherwords,theNCcodeofthefinalinjectionmoulddesignshouldbeautomaticallygenerated.

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