机械设计制造及其自动化专业外文翻译原文

编号：毕业设计(论文)外文翻译〔原文〕院〔系〕：机电工程学院专业：机械设计制造及其自动化TheInjectionMoldingThepresentsituationthatthemouldmakesatpresentandtrendThemoldisatthecoreofaplasticmanufacturingprocessbecauseitscavitygivesapartitsshape.Thismakesthemoldatleastascritical-andmanycasesmoreso-forthequalityoftheendproductas,forexample,theplasticitingunitorothercomponentsoftheprocessingequipment.Themouldisimportanthandicraftequipment，occupiesdecisivepositioninindustriddepartmentssuchasconsumergoods，electricalequipmentelectron，automobile,aircraftfabrication.Themouldisimportanthandicraftequipment,occupiesdecisivepositioninindustriddepartmentssuchasconsumergoods，electricalequipmentelectron，automobile,aircraftfabrication.Industrialproductpartroughprocess75%,thefinishmachining50%andplasticpart90%willbecompletedfromthemould.TheChinesemouldmarketdemandalreadyreachesscaleof500hundredmillionyuanatpresent.Theautomobilemould,theannualgrowthratecoveringpieceofmouldespeciallywillexceed20%;Alsopromptbuildingmaterialmoulddevelopment，variousheterotypematerialthemould，wallsurfaceandfloormouldbecomenewmouldgrowthpoint,plasticdoorsandwindowsandplasticdrain-pipeincreasetoexceeding30byintheupcomingseveralyears%;Thehomeappliancemouldannualgrowthratewillexceed10%;TheITindustryyearincreases%speedequallyexceeding20，theneedtothemouldaccountsfor20ofmouldmarketplace%.2004annualChinesemachinetoolsimplementsindustryoutputvalue.Willcontinuetoincrease.Ourcountrymouldfabricationmarketpotentialisenormous.Thebasisdatacounts，inrecentyears，ourcountrymouldyeargrossoutputvaluereaches3billionU.S.dollar，entranceexceeds1billionU.S.dollar，exceed100millionU.S.dollaroutlet.Increasebyfrom25%toincreaseto200550%of1995.Theexpertforetellsthatabroad:Asiaportionbeingoccupiedbyinmouldfabricationinthewholeworld,willfrom25%toincreaseto200550%of1995.Chinesemouldindustryhasbeenexpandingbyleapsandbounds，hasformedeastChinaandtwobigSouthChinabases,andhasexpandedgraduallyarrivingatotherprovince.In2002(Shandong，Anhui，Sichuan)in1996，mouldmanufacturingindustryoutputvalueannualaveragegrowth14%,growsby25%in2003.In2003ourcountrymouldoutputvalueis45billionRMB.Thegrossproductplaceoccupiestheworldthe3rd，exportsamouldincreases33.5%comparedtolastyear336,800,000U.S.dollar.But,contentslowourcountrytechnologymouldsalreadypileupinexcessofrequirement，verymostsupportofaccurate，complicatedtopgrademouldimports.Everyyeartheentrancemouldexceeds1billionU.S.dollar.Exceed100millionU.S.dollaroutlet.Precisemouldaccuracyrequiresthat3mums，large-scalemouldsrequirethat8000satisfiedkNagreewellwithmodelforceinjectionmachinerequestin2~；Theminitypemouldneedstherequestsatisfyingthediameter1mmsilentstocktube.Atpresent,adoptquick-cuttingtoproduceamouldalreadybecomingthegeneraltrendthatthemouldmakes,afewmouldshaveproducedamanufacturerinabroad，high-speedmachinetoollargeareahassubstitutedtheelectricsparkmachinetool，quick-cuttinghasimprovedthemouldefficacygreatly.Machinetoolenterpriseaimsatmouldmanufacturingenterprises，sometreatingcentres60%allaboveofthemachinetoolproducingafactorysellstreatingenterprisetoamould.Themouldfabricationenterprisesubstitutingtheelectricsparkfinishmachiningmouldgraduallyinabroadhasadoptquick-cuttingalreadycommonly,quick-cuttinghasproducedamouldalreadybecomingthegeneraltrendthatthemouldmakesgradually，hasimprovedthemouldefficacyandmassgreatly.Adoptquick-cuttingtoreplaceelectricsparkproducingamould,cangetonthestickobviously,improvesmouldaccuracy，lifetimegrowing.1.TheIntroductionofInjectionMoulds.Plastic,whichisoneofthemostversatileinthemodernage,iswidelyusedinmanyproductsthroughouttheworld.Duetoitsabilitytoproducecomplex-shapeplasticpartswithgooddimensionalaccuracyandveryshortcycletimes,injectionmouldinghasbecomethemostimportantprocessformanufacturingplasticpartsintheplasticindustrytoday.However,thecurrentplasticsindustryisundergreatpressure,duetotheglobalizationofthemarket,theshortlifecycleofproductdevelopment,increasingproductdiversity,highdemandofproductquality.Tomeetsuchrequirements,itisveryimportantforthistradetoadoptvariousadvancedtechnologieswhichincludeinformationandInternettechnology,CAD/CAE/CAMintegrationtechnology,concurrentengineering,artificialintelligence,andsoon,toeffectivelyaidthedevelopmentofinjection-mouldedproduct.Ininjectionmoulding,thedesignofamouldisofcriticalimportanceforproductqualityandefficientprocessing.Inmostcases,qualityofmouldisresponsiblefortheeconomicsoftheentireprocess.Injectionmoulddesigninvolvesextensiveempiricalknowledge(heuristicknowledge)aboutthestructureandfunctionsofthecomponentsofthemould.Nowadays,moulddesignfaceswithincreasingdeadlinepressuresandthedesignitselfispredominantlybaseduponexperienceofthemoulddesigner.Moulddesignersarerequiredtopossessthoroughandbroadexperience,becausedetaileddecisionsrequiretheknowledgeoftheinteractionamongvariousparameters.Unfortunately,itispresentlyimpossibletocoverthegrowingdemandforsuchexperienceddesigners.Therefore,intelligentCADtoolsthatcanassistinthevarioustasksofthemoulddesignprocessareveryimportanttotheproductivityofthemould-makingindustry.ThegrowingtrendinglobalmanufacturingistoalargeextentsupportedbyInternet,informationtechnologiesandglobalmarketing.Nowadays,itiscommontoseethatdesign,manufacturingandfinalassemblyofaproductaremadeincompanieslocatedindifferentpartsoftheworld.Thevariouspartiesconcernedwouldneedtosharetheirexpertiseandexperiencesduringtheproductdevelopmentprocess.ThecurrentprogressofInternetandinformationtechnologiescanprovideasolutiontosupportandfacilitatecollaborativeproductdevelopmentsamongdifferentgeographicallydistributedenterprises.DevelopinganInternet-basedintelligentmoulddesignsystemasoneofthemoduleofacollaborativeproductdevelopmentsystemcanprovideaneffectiveandfeasibletooltoaidthecollaborativedevelopmentofinjectionmouldsinthesmall-andmedium-sizedenterprisestosatisfythestringentrequirementsofnowadayscompetitiveglobalmarket.ThispaperpresentsanInternet-basedintelligentmoulddesignsystemusingInternettechnologyandknowledge-basedapproach.Thesystemcanshortenthedesigncycleofinjectionmouldandcaneffectivelyaidthedesignanddevelopmentworksofinjectionmouldsinthesmall-andmedium-sizedenterprisestomeettheincreasingpressureofthecurrentcompetitiveworldmarket.Therestofthepaperisorganizedasfollows.Section2givesabriefintroductionofinjectionmoulddesign.Section3introducesearlierresearchworksonmoulddesignandrelatedfields.ThearchitectureoftheInternet-basedmoulddesignsystemispresentedinsection4.Theknowledge-basedpartofthemoulddesignsystemisdescribedinsection5.Section6discussesthedevelopmentofthesystem.2.InjectionmoulddesignThebasicfeaturesofaninjectionmouldconsistofcavitynumberandlayout,feedsystem,coolingsystem,ejectionsystemandmouldconstruction.2.1.DesignrulesTherearemanyrulesfordesigningmolds.Theserulesandstandardpracticesarebasedonlogic,pastexperience,convenience,andeconomy.Fordesigning,moldmaking,andmolding,itisusuallyofadvantagetofollowtherules.Butoccasionally,itmayworkoutbetterifaruleisignoredandanalternativewayisselected.Inthistext,themostcommonrulesarenoted,butthedesignerwilllearnonlyfromexperiencewhichwaytogo.Thedesignermusteverbeopentonewideasandmethods,tonewmoldingandmoldmaterialsthatmayaffecttheserules.Amoulddesignprojectnormallystartswitheconomicconsiderations,namelythequestionofhowmanypartscanandshouldbeproducedinonemouldinoneshotinordertomeetthedeliverydateandotherrequirements.Thisisfollowbyconsiderationofthearrangementsofthecavitiesinthemouldframe,whichmightdirectlyincludethoughtsontheeaseofejectionandsubsequently,theconnectionbetweenmouldingsandrunnersandpartquality(number,positionandshapeofgates).Thefeedsystemaccommodatesthemoltenplasticmaterialcomingfromtheinjectionnozzleofthemouldingmachineanddistributesitintoeachcavity.Toremovetheheatfromthemoulding,itisnecessarytoprovidethemouldwithacoolingsystem.Afterthemouldinghassolidifiedandcooleddown,ithastoberemovedfromthemouldbytheejectionsystem.Mouldisnormallyconstructedbystackingseveralmetalplatestoformarigidbody.Ithastohousevariousmouldcomponentsincorrectpositionsfortheproperfunctioningofthemould.Mouldconstructionnormallyinvolvestheselectionofmouldbasesandstandardmouldparts.Forcomplicatedplasticparts,someothermechanismssuchasslides,unscrewingdevice,etc,mightalsobeinvolvedinthewholemouldstructure.2.2.MoldMaterialDependingontheprocessingparametersforthevariousprocessingmethodsaswellasthelengthoftheproductionrun,thenumberoffinishedproductstobeproduced,moldsforplasticsprocessingmustsatisfyagreatvarietyofrequirements.Itisthereforenotsurprisingthatmoldscanbemadefromaverybroadspectrumofmaterials,including-fromatechnicalstandpoint-suchexoticmaterialsaspapermatchedandplaster.However,becausemostprocessesrequirehighpressures,oftencombinedwithhightemperatures,metalsstillrepresentbyfarthemostimportantmaterialgroup,withsteelbeingthepredominantmetal.Itisinterestinginthisregardthat,inmanycases,theselectionofthemoldmaterialisnotonlyaquestionofmaterialpropertiesandanoptimumprice-to-performanceratiobutalsothatthemethodsusedtoproducethemold,andthustheentiredesign,canbeinfluenced.Atypicalexamplecanbeseeninthechoicebetweencastmetalmolds,withtheirverydifferentcoolingsystems,comparedtomachinedmolds.Inaddition,theproductiontechniquecanalsohaveaneffect;forinstance,itisoftenreportedthat,forthesakeofsimplicity,aprototypemoldisfrequentlymachinedfromsolidstockwiththeaidofthelatesttechnologysuchascomputer-aided(CAD)andcomputer-integratedmanufacturing(CIM).Incontrasttothepreviouslyusedmethodsbasedontheuseofpatterns,theuseofCADandCAMoftenrepresentsthemoreeconomicalsolutiontoday,notonlybecausethisproductioncapabilityisavailablepin-housebutalsobecausewithanyothertechniqueanorderwouldhavetobeplacedwithanoutsidesupplier.Overall,althoughhigh-gradematerialsareoftenused,asarulestandardmaterialsareusedinmoldmaking.New,state-of-theart(high-performance)materials,suchasceramics,forinstance,arealmostcompletelyabsent.Thismayberelatedtothefactthattheirdesirablecharacteristics,suchasconstantpropertiesuptoveryhightemperatures,arenotrequiredonmolds,whereastheirnegativecharacteristics,e.g.lowtensilestrengthandpoorthermalconductivity,haveaclearlyrelatedtoceramics,suchassinteredmaterial,isfoundinmildmakingonlytoalimiteddegree.Thisreferslesstothemodernmaterialsandcomponentsproducedbypowdermetallurgy,andpossiblybyhotisocraticpressing,thantosinteredmetalsinthesenseofporous,air-permeablematerials.Removalofairfromthecavityofamoldisnecessarywithmanydifferentprocessingmethods,andithasbeenproposedmanytimesthatthiscanbeaccomplishedusingporousmetallicmaterials.Theadvantagesoverspeciallyfabricatedventingdevices,particularlyinareaswheremeltflowfrontsmeet,I,e,atweldlines,areasobviousasthepotentialproblemareas:ononehand,preventingthetextureofsuchsurfacesfrombecomingvisibleonthefinishedproduct,andontheotherhand,preventingthemicrosporesfromquicklybecomingcloggedwithresidues(brokenoffflash,depositsfromthemoldingmaterial,so-calledplateout,etc.).Itisalsointerestinginthiscasethatcompletelynewpossibilitieswithregardtomolddesignandprocessingtechniqueresultfromtheuseofsuchmaterials.2.3.Thebasicmold2.3.1.MoldcavityspaceThemoldcavityspaceisashapeinsidethemold,“excavated”insuchamannerthatwhenthemoldingmaterialisforcedintothisspaceitwilltakeontheshapeofthecavityspaceand,therefore,thedesiredproduct.Theprincipleofamoldisalmostasoldashumancivilization.Moldshavemetalsintosandforms.Suchmolds,whicharestillusedtodayinfoundries,canbeusedonlyoncebecausethemoldisdestroyedtoreleasetheproductafterithassolidified.Today,wearelookingforpermanentmoldsthatcanbeusedoverandover.Nowmoldsaremadefromstrong,durablematerials,suchassteel,orfromsofteraluminumormetalalloysandevenfromcertainplasticswherealongmoldlifeisnotrequiredbecausetheplannedproductionissmall.Ininjectionmoldingtheplasticisinjectedintothecavityspacewithhighpressure,sothemoldmustbestrongenoughtoresisttheinjectionpressurewithoutdeforming.2.3.2.NumberofcavitiesManymolds,particularlymoldsforlargerproducts,arebuiltforonlycavityspace,butmanymolds,especiallylargeproductionmolds,arebuiltwith2ormorecavities.Thereasonforthisispurelyeconomical.Ittakesonlylittlemoretimetoinjectseveralcavitiesthantoinjectone.Forexample,a4-cavitymoldrequiresonlyone-fourthofthemachinetimeofasingle-cavitymold.Conversely,theproductionincreasesinproportiontothenumberofcavities.Amoldwithmorecavitiesismoreexpensivetobuildthanasingle-cavitymold,butnotnecessarily4timesasmuchasasingle-cavitymold.Butitmayalsorequirealargermachinewithlargerplatenareaandmoreclampingcapacity,andbecauseitwilluse4timestheamountofplastic,itmayneedalargeinjectionunit,sothemachinehourcostwillbehigherthanforamachinelargeenoughforthesmallermold.2.3.3.CavityshapeandshrinkageTheshapeofthecavityisessentiallythe“negative”oftheshapeofthedesiredproduct,withdimensionalallowanceaddedtoallowforshrinkingoftheplastic.Theshapeofthecavityisusuallycreatedwithchip-removingmachinetools,orwithelectricdischargemachining,withchemicaletching,orbyanynewmethodthatmaybeavailabletoremovemetalorbuilditup,suchasgalvanicprocesses.Itmayalsobecreatedbycastingcertainmetalsinplastermoldscreatedfrommodelsoftheproducttobemade,orbycastingsomesuitablehardplastics.Thecavityshapecanbeeithercutdirectlyintothemoldplatesorformedbyputtinginsertsintotheplates.2.4.CavityandcoreByconvention,thehollowportionofthecavityspaceiscalledthecavity.Thematching,oftenraisedportionofthecavityspaceiscalledthecore.Mostplasticproductsarecup-shaped.Thisdoesnotmeanthattheylooklikeacup,buttheydohaveaninsideandanoutside.Theoutsideoftheproductisformedbythecavity,theinsidebythecore.Thealternativetothecupshapeistheflatshape.Inthiscase,thereisnospecificconvexportion,andsometimes,thecorelookslikeamirrorimageofthecavity.Typicalexamplesforthisareplasticknives,gamechips,orrounddiskssuchasrecords.Whiletheseitemsaresimpleinappearance,theyoftenpresentseriousmoldingproblemsforejectionoftheproduct.Thereasonforthisisthatallinjectionmoldingmachinesprovideanejectionmechanismonthemovingplatenandtheproductstendtoshrinkontoandclingtothecore,fromwheretheyarethenejected.Mostinjectionmoldingmachinesdonotprovideejectionmechanismsontheinjectionside.2.5.PolymerProcessingPolymerprocessing,initsmostgeneralcontext,involvesthetransformationofasolid(sometimesliquid)polymericresin,whichisinarandomform(e.g.,powder,pellets,beads),toasolidplasticsproductofspecifiedshape,dimensions,andproperties.Thisisachievedbymeansofatransformationprocess:extrusion,molding,calendaring,coating,thermoforming,etc.Theprocess,inordertoachievetheaboveobjective,usuallyinvolvesthefollowingoperations:solidtransport,compression,heating,melting,mixing,shaping,cooling,solidification,andfinishing.Obviously,theseoperationsdonotnecessarilyoccurinsequence,andmanyofthemtakeplacesimultaneously.Shapingisrequiredinordertoimparttothematerialthedesiredgeometryanddimensions.Itinvolvescombinationsofviscoelasticdeformationsandheattransfer,whicharegenerallyassociatedwithsolidificationoftheproductfromthemelt.Shapingincludes:two-dimensionaloperations,e.g.dieforming,calendaringandcoating;three-dimensionalmoldingandformingoperations.Two-dimensionalprocessesareeitherofthecontinuous,steadystatetype(e.g.filmandsheetextrusion,wirecoating,paperandsheetcoating,calendaring,fiberspinning,pipeandprofileextrusion,etc.)orintermittentasinthecaseofextrusionsassociatedwithintermittentextrusionblowmolding.Generally,moldingoperationsareintermittent,and,thus,theytendtoinvolveunsteadystateconditions.Thermoforming,vacuumforming,andsimilarprocessesmaybeconsideredassecondaryshapingoperations,sincetheyusuallyinvolvethereshapingofanalreadyshapedform.Insomecases,likeblowmolding,theprocessinvolvesprimaryshaping(pair-sonformation)andsecondaryshaping(pairsoninflation).Shapingoperationsinvolvesimultaneousorstaggeredfluidflowandheattransfer.Intwo-dimensionalprocesses,solidificationusuallyfollowstheshapingprocess,whereassolidificationandshapingtendtotakeplacesimultaneouslyinsidethemoldinthreedimensionalprocesses.Flowregimes,dependingonthenatureofthematerial,theequipment,andtheprocessingconditions,usuallyinvolvecombinationsofshear,extensional,andsqueezingflowsinconjunctionwithenclosed(contained)orfreesurfaceflows.Thethermo-mechanicalhistoryexperiencedbythepolymerduringflowandsolidificationresultsinthedevelopmentofmicrostructure(morphology,crystallinity,andorientationdistributions)inthemanufacturedarticle.Theultimatepropertiesofthearticlearecloselyrelatedtothemicrostructure.Therefore,thecontroloftheprocessandproductqualitymustbebasedonanunderstandingoftheinteractionsbetweenresinproperties,equipmentdesign,operatingconditions,thermo-mechanicalhistory,microstructure,andultimateproductproperties.Mathematicalmodelingandcomputersimulationhavebeenemployedtoobtainanunderstandingoftheseinteractions.Suchanapproachhasgainedmoreimportanceinviewoftheexpandingutilizationofcomputerdesign/computerassistedmanufacturing/computeraidedengineering(CAD/CAM/CAE)systemsinconjunctionwithplasticsprocessing.Itwillemphasizerecentdevelopmentsrelatingtotheanalysisandsimulationofsomeimportantcommercialprocess,withdueconsiderationtoelucidationofboththermo-mechanicalhistoryandmicrostructuredevelopment.Asmentionedabove,shapingoperationsinvolvecombinationsoffluidflowandheattransfer,withphasechange,ofavisco-elasticpolymermelt.Bothsteadyandunsteadystateprocessesareencountered.Ascientificanalysisofoperationsofthistyperequiressolvingtherelevantequationsofcontinuity,motion,andenergy(I.e.conservationequations).2.6.InjectionMoldingManydifferentprocessesareusedtotransformplasticgranules,powders,andliquidsintofinalproduct.Theplasticmaterialisinmoldableform,andisadaptabletovariousformingmethods.Inmostcasesthermoplasticmaterialsaresuitableforcertainprocesseswhilethermosettingmaterialsrequireothermethodsofforming.Thisisrecognizedbythefactthatthermoplasticsareusuallyheatedtoasoftstateandthenreshapedbeforecooling.Theromosets,ontheotherhandhavenotyetbeenpolymerizedbeforeprocessing,andthechemicalreactiontakesplaceduringtheprocess,usuallythroughheat,acatalyst,orpressure.Itisimportanttorememberthisconceptwhilestudyingtheplasticsmanufacturingprocessesandthepolymersused.Injectionmoldingisbyfarthemostwidelyusedprocessofformingthermoplasticmaterials.Itisalsooneoftheoldest.Currentlyinjectionmoldingaccountsfor30%ofallplasticsresinconsumption.Sincerawmaterialcanbeconvertedbyasingleprocedure,injectionmoldingissuitableformassproductionofplasticsarticlesandautomatedone-stepproductionofcomplexgeometries.Inmostcases,finishingisnotnecessary.Typicalproductsincludetoys,automotiveparts,householdarticles,andconsumerelectronicsgoods,Sinceinjectionmoldinghasanumberofinterdependentvariables,itisaprocessofconsiderablecomplexity.Thesuccessoftheinjectionmoldingoperationisdependentnotonlyinthepropersetupofthemachinevariables,butalsooneliminatingshot-to-shotvariationsthatarecausedbythemachinehydraulics,barreltemperaturevariations,andchangesinmaterialviscosity.Increasingshot-to-shotrepeatabilityofmachinevariableshelpsproducepartswithtightertolerance,lowersthelevelofrejects,andincreasesproductquality(i.e.,appearanceandserviceability).Theprincipalobjectiveofanymoldingoperationisthemanufactureofproducts:toaspecificqualitylevel,intheshortesttime,andusingarepeatableandfullyautomaticcycle.Moldersstrivetoreduceoreliminaterejectedparts,orpartswithahighaddedvaluesuchasappliancecases,thepayoffofreducedrejectsishigh.Atypicalinjectionmoldingcycleorsequenceconsistsoffivephases:(1).Injectionormoldfilling(2).Packingorcompression(3).Holding(4).Cooling(5).Partejection3.RelatedresearchAnumberofresearchactivitieshavebeencarriedoutonmoulddesignanditsrelatedfieldovertheyearsusingcomputer-aidedtechniques.Theseresearchactivitiesrangefromstudyingspecificareasofmoulddesigntoinvestigatingmoulddesignasawholeintegratedsystem.Theycanbroadlybeclassifiedintothreeareas:thefunctionalandinitialmoulddesigns;thealgorithmstoautomatemouldgeneration;andsystemdevelopmentofmoulddesign.HuiandTan[2]presentedaheuristicsearchapproachbasedonsweepoperationstodevelopautomatedmoulddesignsystemsfordeterminingpartingdirection,partingline,sidecore,etc.Huangetal.[3]usedsolidmodellingtechniquestobuildmouldplatesandlibraryofstandardmouldcomponents.ChenandLiu[4]havedevelopedacostmodel,whichdepictstherelationshipsbetweencostfactorsandproductdevelopmentactivitiesaswellastheirrelationshipswithproductgeometry,forcost-effectivenessdesignforinjectionmoulding.Fuetal.[5]proposedanefficientmethodologywhichsystematicallypresentstheundercutfeaturedefinition,classification,undercutfeatureparameters,andtherecognitioncriteriaofalltypesofundercutfeaturesforundercutfeaturerecognitioninaninjectionmoulddesignsystem.Chenetal.[6]presentedamethodfordeterminationofpartingdirectionbasedondexelmodelandfuzzydecision-making.LiJC[7]presentedaneuralnetworkapproachformodellingandoptimizationofinjectionmouldgateparameters.LiCL[8]usedafeature-basedapproachtodesignthecoolingsystemofinjectionmoulds.ChungandLee[9]proposedaframeworkofcollaborativedesignenvironmentforinjectionmouldinginwhichgeographicallydistributed,multi-disciplinarydesignerscancollaboratewithoneanother.Maetal.[10]describedthedevelopmentofastandardcomponentlibraryforplasticinjectionmoulddesignusinganobject-orientedapproach.LowandLee[11]introducedamethodologyofprovidingtheinitialdesignin3Dsolidmodelinsteadof2Ddrawingsusingthestandardizationmethod.Ashaabetal.[12]describedasupportingplasticengineeringdevelopmentsystemtofacilitatethesharingofinjectionmouldinginformationandknowledgebetweeninterestedpartiesviatheInternetforthecollaborativedesignofinjectionmould.Lietal.TheKBsystemhasdemonstratedgreatpotentialtoassistthedesignertointeractwithaCADsystemforconceptualizeddesignaswellasthefinalengineeringdesignofamouldbyusingengineeringrulesofthumbwithextensiveanalyticalmeans.Inaddition,thereisstillrelativelyfewresearchworksonInternet-basedintelligentsystemforinjectionmoulddesign.4.ArchitectureoftheInternet-basedmoulddesignsystem4.1.ThesystemofOverviewAtthepresenttime,mostCADsystemsprovideonlythegeometricmodellingfunctionswhichfacilitatethedraftingoperationsofmoulddesign,anddonotprovidemoulddesignerswithnecessaryknowledgetodevelopgoodmoulddesigns.Conventionalcomputer-aidedengineeringpackagesareusuallygoodatdataprocessingforinformation-intensiveproblemsoratnumbermanipulationforformulation-intensiveproblems.Theformercomprehendsthecomputer-aideddraftingandgraphics,anddatareductionandtransformation;whilethelatterinvolvesnumerical(ormathematical)modellingandanalysis.However,indesignproblem,especiallyinmoulddesignwhichinvolvesasubstantialpracticalknowledgecomponentaboutfunctionsandstructureofamould,humanheuristicknowledgeandempiricaltypeofknowledgeareneededinadditiontotheinformation-intensiveandformulation-intensiveknowledge.Therefore,conventionalcomputer-aideddesigntechnologyisunsuitableforprocessingheuristicandempiricaltypeofknowledgewhichiscriticalinthemoulddesignproblems.Ingeneral,themajoradvantageoftheKBsystemformoulddesignoverconventionalcomputer-aideddesignsystemsistheexplicitrepresentationandmanipulationofabodyofknowledge,representingthehumanexpertise.AnInternet-basedmoulddesignsystemusingInternettechnologyandknowledge-basedapproachcanprovideaneffectiveandfeasibletooltoaidthecollaborative