ORIGINALARTICLEA3DCADknowledge-basedassistedinjectionmoulddesignsystemReceived:5June2002/Accepted:23August2002/Publishedonline:29May2003Springer-VerlagLondonLimited2003AbstractThispaperpresentsthebasicstructureofaninteractiveknowledge-basedinjectionmoulddesignsystem(IKB-MOULD).Thebasisofthissystemarisesfromananalysisoftheinjectionmoulddesignprocessformoulddesigncompanies.Thisinjectionmouldde-signsystemcoversboththemoulddesignprocessandmouldknowledgemanagement.IKB-MOULDinte-gratestheintelligentdesignprocessandknowledgemanagementwithmanydevelopedinteractivetoolsinacommercialsolidmodellingsoftwareenvironment.KeywordsInjectionmoulddesignÆKnowledgebaseÆInjectionmouldobjectrepresentation1IntroductionInrecentyearstheplasticproductmanufacturingindustryhasbeengrowingrapidly.Averypopularmouldingprocessformakingplasticpartsisinjectionmoulding.Theinjectionmoulddesigniscriticallyimportanttoproductqualityandefficientproductpro-cessing.Mould-makingcompanies,whowishtomain-tainthecompetitiveedge,desiretoshortenbothdesignandmanufacturingleadingtimesbyautomatingthedesignprocess.Thus,thedevelopmentofacomputer-aidedinjectionmoulddesignsystem(CAIMDS)isbecomingafocusofresearchinbothindustryandaca-demia.Recentlypublishedpapersshowthatresearchinautomaticmoulddesignfocusesonindividualcompo-nentsofthemouldprocess.ForexampleOngetal.[1]andRavi[2]focusedtheirresearchonthefeedingsystem.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,anumberoftheoreticalresearchworkswereIntJAdvManufTechnol(2003)22:387–395DOI10.1007/s00170-002-1514-9W.M.ChanÆL.YanÆW.XiangÆB.T.CheokW.M.Chan(&)ÆL.YanÆW.XiangÆB.T.CheokInstituteofHighPerformanceComputing,1ScienceParkRoad,#01-01TheCapricorn,SingaporeScienceParkII,117528,SingaporeE-mail:chanwm@ihpc.a-star.edu.sgTel.:+65-6-4191111Fax:+65-6-4191280conductedtoautomaticallydeterminethepartingdirection,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)ofthepocke