IntJAdvManufTechnol(205):519DO10.7/s01-3184-3RIGNLARICLES.HMasoodB.AbasE.ShaynA.KarnivestigtioitdesigndmnufactringofmechaniclcoverstemsforfdpcessingRecived:29March2003/Aceptd:21June2003/Publishedonline:23June2004Sprnger-VelgLondonimtd2004AbstacThispaperpresnttheresultofaresrchinvesti-gaionundertakentodevelopmhodologindthniquehawlreduchecosandtimoftdesign,mnufuringandasmblyofmehanilconveyortemusedinthefoodbevergeindustry.Theimprovedmhodologyfordesignaproductonofconveorcomponentsibaseontmnim-tiofmaerils,patsandost,usngtherulsofsiformanufcturnddeignforsembly.Restobtainedonatesonveyorstemverythebenefitsofusimprovech-nique.Theovealmeialcoswareducdby19%andtheoveralsemblycostwsrducedby20%comparetoconven-tionamthods.KeywordsAemblyCostreductionDesignFADMMchanialconveor1IntroductinConveyrstemusedithefoodandbeverageindustryaehighlautomdctommadestructuresconsstngoflgenumberofpartsandsigneocayproducuchasfoodcatons,drinkbotlecansinfsttionndemblylines.Mostoftheprocsingndpackagingoffoodadrinkn-voecniuosperatowherartons,btlesorcnsre-quirdtmoveatcontolldspeforfilioramblyopeations.Theiroperionsrequirhighlyecntndrelime-chanialconveyos,hichangefromoverheadtpstofloormountedtpeofchain,rolleorbeltdrivenconveyrems.Inrcntars,mmensprsurefromlientsforlowcostbuteffiimeniclonveyortmshapushedon-veyormanufcturrstoreviwtheicurrentdesignandsemblymethodsndlookanltnavemanstomanufcturmorconomialreliblconveyorsforheirlients.Apresnt,S.HMasod(u)B.AbasE.ShaynA.KarIndutrilRearchIntiuewibure,wibnUivsiyofTcnolgathor,lbur312,straiE-mil:.amostmaterilhandlingdevices,bothhardwarendsoftware,highlyspecaised,nflexiblandostlyoconfigur,inslndmintn1.Conveyorsfixedinermsoftheirloctonstheconveorbeltsacordingtohenchronisedpeeds,mak-inganyhangeoveroftheconveyrstemverydifficultndex-pensive.Intodaysadilhangingindustialmkes,herisaneedtoimplemntnewmanufctursregy,newytemoperonalconcptandsyemontoloftarendhard-waedeveopmentconcept,thacanbeppliedohedesignofnegenerationofopen,flxiblemtrilhandlingytem2.HoandRnky3proposedanewmodulandreconfigurabl2D3Dconveyorstm,hichencompasanopere-configurablesoftwaechieturbasdontheCIM-OSA(opensytemrchiur)model.Iisnotetharesarchithearofimprovementofconveyormsusinbevegein-dustsverylimtd.Mostofthepublihedresarcisdirectdowardsimprovingheoperaionsofconveyotmandint-grtionofstemtohighlysophistiaesoftwarehardwre.Thipaperprsntarerchnvetigaonimdatim-provingthecuretchniquesandpracesusnhedesign,manufingandemblyoffloormounttypechaindrvenmechanilconveorsinordertoeductmanuftur-ingladtimandostforuchconves.Applingthecon-ceptofconcurrentngineeringandtheprincplesofdesignformanuftingadesignforsembly4,5,veralctalconveyorpatswernvetigadfortirfunctionaity,merisuitabilit,ngthciron,costandesofasemblntheoverconveyorstem.Therilpartwrmodifidandedesigneditnehapeageomety,andsomeithnewmatrl.Themproveddesignmhodsthefunconalityofnewconveyorpatswerverfiedandtesdonanetescon-veyorstemdeigned,manufcturembldusingtheimprovedrts.2Designfornufctringdsembl(FMA)Inrecntyears,earchintheareofdesignformanufcturingandsmblhabeomveyusfulorndustrieshaareon-52sideringmprovingtheirfaciltesandmnufacturingmethodol-ogy.However,trehasnotbennoughworkdoneinheareofsignforconveyocomponents,epecialyrelatdotis-uencreasingnumbersofdraingdatnd-ngineerngoftheprocofcdesignbasedonraditionalmthods.EmphasiestandardisationUthemplposbleoperationsseoperationsofknowncpabilyMinimseupsandinterventindertakengineerngchangesnbatchesAvasamountpapershavebenpublihehaveinvesti-gatediuesrelatdoDFMAandppletovariousmethodolo-gisoachivesulttprovedconomial,fficntandcosteftiforthecompaniesunderinvestgaon.ThemanlasifiationsofFknowledgecanbeiden-tifieds(1)Generlguidelnes,(2)Company-speifistprac-cor3)Procsandorreource-pecifionstrant.Generlguidelineseftogelyappliblrules-ofhumb,rlat-ingtoamnufcuringdominofwhichthedeigneshouldbewre.ThefollowlsthabeenompiledforDFMguidelines6.Thesedeignguidelishouldbehoughtofas“optimalsuggetions”.Theytpcaywilresultinahigh-qualty,ow-cos,andmnufacurblesgn.Oconalycomprisemustbemde,ofours.Intheeas,ifaguidelnegoeagainstamrketingorperformancrquiremnt,thextbestlternaiveshouldbeselctd7.Company-pecifipraticerfstoin-housedesignrulesacdevelops,usualyovealongperodoftm,andwhihthedesignerisexpectedoadhereto.ThesedeirulesareintifiedbytheompanyscontibutingtoimprovedqualityndfcncyrecognisingtheoveralelonshipsbetwenDesignforaminimumnumberofpartsvelopmodulrdesignMinimsepatvaiatonsgnrsobemulfunctionalDesitformtiuseparsasoffabrictonAvoidetftenerMaximiscomplianc:designforeasofasemblynimehandlng:handlingprnttionEvaluatasmblymethodsimnaedjustmntsAvoidflxiblecompone:theyaredifficultohandleUsepartsofknownapabililowformaximumintolerancofpartsseknownndprovevendorsndupplierpartsadertedvaluewithnomarginaloversteMinimeubasmblispartiularprocsanddegndecisons.Companiesussuchguidelnespartoftherinigiventodesignerofproductrequiringignificantmountsofmanualaemblyormainte-nanc.Notethamostoftmethodologisrgoodtherbeiquickandsyosarorbeingmoreformalndquanti-tave.Forexampl,guidelinesbyBoothroydDewhurst8onDAarconsiredaquantitavesytmaic.WherestheFMguilis,whichremlruleofthumbdeivedfomexperiencprofeionals,amorqualiavendlesormal9.3ConvetionlconveorstedsignDesignandmnufacturingofonveyrstemisaverycom-plxtime-onsumproces.Aveconveostemisacustom-madeproduct,achojctvariesfromerotherprojeintermsofsizeproductandlyout.ThesytmdesignFig.1Layoutfconveyrs-temforlbeligplasibtl53isbaedonclientrquiremntsandproductspecifiations.More-over,thesytmlayouthatofitinthepaeprovidedbythecompany.Tprocesofdesigningalyoutforaconveyors-teminvolverviionsandcouldtkefromdastomonthsorinsomnstancesyrs.Onewihheminimumcosandmximumclientsuibilitmostlkeytogetapproval.Fgure1showaschemilutoftypicalonveyorsytminstaldinproductonineusedforlbeingofplacbotes.Dferntsecionsoftheconveorstemaridentifibypecifithnialnames,whihaecommonlyusednsmilarndusrilpplicton.T“singlizr”sec-tionnabletheproductoformntoonelanefommultipllanes.T“slowdownable”rducesthepeedofproduconceitxitfromfilr,lbel,c.T“masflow”sec-tionsusdokeepupwithhigh-speedproce,.g.,filr,labeler,tc.The“transferable”transfrsthedirctionofprod-uctflow.purposofthesdifntconveyoseonsishusocontroltproducflowthroughdiferntprocngmachines.Atypicalmehanicalonveyorstemusdinfoodandbev-erageppltionsistofovetwhundrmechanillctilparsdependingonthesizeofthesytm.Someoftheommonbutentialcomponenthacouldbestandard-isedandcumulatdofmilesoftonveoryemdefrms,paerbas,ndplat,coverplates,insdebendplate,outidebendplateberksndhaf(drve,tailslve).Theszequantiyofthesepartsvaryacordingotheengthofconveyorsctonsandnumbeofksrespond-ingtowidthandpesofchainsrequird.Theproblmandshorcomingsnthecurrntdesgn,manufcturingandsemblyofmehanialonveyosaevarid,butinclude:4AreasofimproventInordertoidentifythearesofcostrductionnmaterilandlabour,acostanalsioflminonveyorpaswconductedtoestimhepercentagecostofeachtirelationtoheotalcosofalsuchparts.Thepurposofhisnayssidentifytcritl,whichareminlyreponsibleforin-creasngheosoftheonveyondthebyinvestgamansforducitcsucparts.Table1showtostanaliofa50-sectiononveyors-tem.henalyirevelsha12out15paronstiute79%oftotamtalcostoftheconveyorstem,wherfurtherimprovementsindesignoreducthecosipossible.Outofthes,vepartwerdentifidasritalpart(hownbyaaerikTabl1)constutngmximumnumbeofcompo-nentsnquantityndomprisover71%ofoveralmterialcost.Amonghese,threcomponents(legst,idefmndsupporchannel)wrfoundtoacountfor50%oftheotalconveyormateicost.Adeilednalysieachse12partswcdoutonsirngtheprncplsofoncurrntn-gineeing,designformanufctureanddeignforaembly,andamprovesiwsdevelopedforechs10.De-tilsofsimprovementofomesltmajorcomponentareprntedbelow.5RedsignoflegstseblInaconveyrstm,thelgsaremountdonthesideframetokeeptheenticonveyorstmoffthefloor.Texitngdesignofcorlgswork,butyarecoslytomanufcur,theyOverdesignofsomepartsHighcostcomponentLonghoursinvolvedinasembly/maintenancUseofnon-tandarparthavestabiityproblems,andcusdesindeliveries.Tlaiusualcusdbyomofthepartnotarvingfomover-seauppliersontime.Tmoscilspecifiationsrequidfortheconveyolgsar:Table1.ConveyrcitalprtsbaedonpartscotanlysiProductsriptLegstSidframeupotchnelBenraksRt.lftTishftSpacerbuotwarstiprsidertiEndplatCovereBltsTrquarmbracketSlotcveInsidnpltQty68048139540132981978MaterilusedPlasticleg+Stube2.5mmChnlPlastic20d.Sshaft35itinleselX6401mmplasticPlastic2.5mm/S16mm.mm/mmSplatetainles2.5mm/Cost(%)20.1675.436.7025.436.018.57129.07.6Improvemntposible(Ys/No)esYsNoesYsesNoYessetalCritclparts154StrengthtocaryonveyorloadabiliyEseofsemblaflxibility(foradjustingheight)1andpart3inFig.2)wasnotrigidenough.Theconnetionsforthesesareonlyingl6mmbolt.Atimes,whenconveyortmscarngfullproducloadstasobservedthatconveyorlegseunstablendcausedmchanilvi-braion.OneofthemairsonsforthiswduetoasingleboltFigure2indicateslthepartsfortexistingdesignoftheconveyorlg.Theindicaednumberarhepartnumbersdesribedinable2,whihlsohowsbrekdownofcostan-alycompletithlabourtimerquirdtoasemblom-pletstoflgs.Theexistinglgsupconsiofplticlegbrackeorderedfromoverea,tinlestelgtubes,whihreutintospecifisiz,lubeplaicdjusmntcaclppeontthelegtubeathebottomshowniFig.2.Lugs,whicharecutinsquaresiz,driledandeldedtohelegtubetoboltnglrosbracngndbackingplatsupportlegbrackests.The#ofpartsinTable2signifienumberofomponentineachrtnumbethequantitysthecon-sumptionofpartilegdesign.Companiehaveusedthidesgnformanyyeasbutoneoftcmoncomplaintsreportdbytheclintwoftheinsabilityoflegs.Fromaninianvest