XXXX機械設(shè)計制造及自動化 畢業(yè)設(shè)計 英文翻譯資料

1、天津工程師范學院2007屆本科生畢業(yè)設(shè)計 PAGE 19A NOVEL INTEGRATED SYSTEM FOR RAPID PRODUCT DEVELOPMENTThis paper presents a novel integrated system of rapid product development for reducing the time and cost of product development. The system is composed of four building blocks digital prototype, virtual prototype, ph

2、ysical prototype and rapid tooling manufacturing system. It can aid effectively in product design, analysis, prototype, mould, and manufacturing process development by integrating closely the various advanced manufacturing technologies which involve the 3D CAD, CAE, reverse engineering, rapid protot

3、yping and rapid tooling. Furthermore, two actual examples are provided to illustrate the application of this integrated system. The results indicate that the system has a high potential to reduce further the cycle and cost of product development.Keywords: Rapid product development; rapid prototyping

4、; integrated system.1. IntrroducttionDue to the ppressuure off inteernatiional compeetitioon andd markket gllobaliizatioon in the 21st centuury, tthere contiinues to bee stroong drrivingg forcces inn induustry to coompetee effecctivelly by reduccing mmanufaacturiing tiimes aand coosts wwhile assurri

5、ng hhigh qqualitty produucts aand seervicees. Cuurrentt induustriees aree faciing thhe neww challlengees: quuick respoonse tto bussinesss oppoortuniity haas beeen connsiderred ass one of thhe mosst impportannt factoors too ensuure coompanyy comppetitiivenesss; maanufaccturinng inddustryy is eevolvii

6、ng towarrd diggitaliizatioon, neetworkk and globaalizattion. Thereefore, new produucts mmust bbe more quickkly annd cheeaply develloped, manuufactuured aand inntroduuced tto thee markket. In orrder tto meeet thee demaand off rapiid prooduct devellopmennt, thhe varrious new ttechnoologiees such as re

7、eversee engiineeriing (RRE), 33D CADD, rappid prrototyyping (RP), and rapidd toolling (RT) hhave eemergeed andd are regarrded aas keyy enabbling toolss withh the abiliity too shorrten tthe prroductt deveelopmeent annd mannufactturingg timee. Forr exammple, it haas beeen claaimed that RP caan cutt ne

8、w produuct deeveloppment costss by uup to 70% and tthe tiime too markket byy 90%.1 In the fform oof a bbetterr desiign, mmore ddesignn posssibiliities, a 3D CAD mmodel can bbe shoown too the custoomer ffor appprovaal andd prevvents misunndersttandinngs. AA virttual pprotottypingg is eemployyed too g

9、uidde in optimmizatiion of thhe prooduct desiggn andd manuufactuuring proceess pllanninng, whhich mmay reesult in the aaccuraate deetermiinatioon of the pprocesss parrameteers, aand reeduce the nnumberr of costlly phyysicall prottotypee iterrationns. Raapid ttoolinng tecchniquue offfers aa fastt and

10、 low cost methood to produuce mooulds, and showss a hiigh pootentiial foor fasster rresponnse too markeet demmands. Whenn propperly integgratedd amonng 3D CAD, CAE, RE, RRP andd RT, tthese technnologiies wiill pllay a much more imporrtant role to reeduce furthher thhe devellopmennt cyccle annd cosst

11、 of the pproducct prooductiion. OOn thee basiis of abovee techhnologgies, a novvel inntegraated ssystemm of rrapid produuct deeveloppment is too be ffoundeed so ass to mmeet tthe reequireement of raapid pproducct devvelopmment.2. Archhitectture oof thee Inteegrateed Devvelopmment SSystemmThe devvelo

12、pmment pprocesss froom iniitial conceeptuall desiign too commmerciaal prooduct is ann iteraative proceess whhich iincluddes: pproducct dessign; analyysis oof perrformaance, safetty andd reliaabilitty; prroductt prottotypiing foor expperimeental evaluuationn; andd desiign moodificcationn. Thereefore,

13、 any step of thhe neww prodduct ddeveloopmentt proccess hhas a direcct andd stronng inffluencce on time-to-maarket in shhort oorder. A goood prroductt deveelopmeent systeem musst enaable ddesignners oor dessign tteams to coonsideer alll aspeects oof prooduct desiggn, maanufaccturinng, seellingg and

14、recyccling at thhe earrly sttage oof thee desiign cyycle. So thhat deesign iteraation and cchangees cann be mmade eeasilyy and effecctivelly. Thhe morre fluennt thee feeddback is thhe higgher ppossibbilityy of ssuccesss thee systtem haas. Deesign for manuffacturring (DFM) and cconcurrrent enginneeri

15、nng (CEE) neccessittate tthat pproducct and pprocesss dessign bbe devvelopeed simmultanneouslly ratther tthan ssequenntiallly. The inntegraated ssystemm of rrapid produuct deeveloppment is coomposeed of four modulles: digittal prrototyype, vvirtuaal proototyppe, phhysicaal proototyppe andd rapiid to

16、ooling.The pproducct devvelopmment sstartss fromm the creattion oof a 33D CADD modeel usiing a CAD ssoftwaare paackagee. At that stagee, thee prodduct ggeomettry iss defiined aand itts aesthhetic and ddimenssionall charracterristiccs aree veriified. The main functtion oof diggital protootype is too

17、perfform 33D CADD modeellingg. Thee CAD modell is rregardded ass a centrral coomponeent off the wholee systtem orr projject iinformmationn basee whicch meaans that in alll dessign, analyysis aand maanufaccturinng acttivitiies thhe samme datta is utiliized. The pproducct andd its compoonentss are dir

18、ecctly ddesignned onn a 3DD CAD systeem (e.g.Proo/Engiineer, Uniggraphiics, CCATIA, IDEAAS, ettc.) dduringg the creattive ddesignn. If a physiical ppart iis reaady, tthe moodel ccan bee consstructted byy the reverrse enngineeering technnique. RE iis a mmethoddologyy for consttructiing CAAD moddels o

19、of phyysicall partts by digittizingg an eexistiing paart, ccreatiing a digittal moodel aand thhen ussing iit to manuffacturre compoonentss. RE can rreducee the devellopmennt cyccle whhen reedesiggns beecome necesssary for iimprovved prroductt quallity. Preexxistinng parrts wiith feeaturees forr impr

20、roved perfoormancce cann be rreadilly inccorporrated into the ddesireed parrt dessign. Thereefore, it is veery usseful in crreatinng thee CAD modell of aan exiistingg partt whenn the enginneerinng desiggn is lost or haas gonne thrrough many desiggn chaanges. Whenn a deesigneer creeates a neww desiig

21、n ussing mmock-uup, itt is aalso nnecesssary tto connstrucct thee CAD modell of thhe mocck-up for ffurtheer usee of tthe deesign data in annalysiis andd manuufactuuring. The tthree primaary stteps iin RE proceess arre parrt diggitizaation, feattures extraactionn, and CCAD moodelliing. PPart ddigitii

22、zatioon is accommplishhed byy a vaarietyy of ccontacct or non-ccontacct diggitizeers. TThere are vvariouus commmerciial syystemss avaiilablee for part digittizatiion. Thesee systtems rrange from coorddinatee meassuringg machhine (CMM), laseer scannners tto ulttrasonnic diigitizzers. They can bbe cla

23、assifiied innto twwo brooad caategorries: contaact annd nonn-conttact. Laserr triaangulaation scannner (LLTS), magneetic rresonaance imagees (MRRI), aand coomputeer tommograpphy (CCT) arre commmonlyy usedd as nnon-coontactt devicces. CContacct diggitizeers maainly have CMM aand crross-ssectioonal ii

24、maginng meaasuremment (CIM). Feaature extraactionn is nnormallly acchieveed by segmeentingg the digittized data and ccapturring ssurfacce feaaturess suchh as eedges. Partt modeellingg is ffulfilled thhroughh fittiing a varieety off surffaces to thhe seggmenteed datta poiints.In ordeer to reducce the

25、e iterrationns of desiggn-proototyppe-tesst cyccles, increease tthe produuct prrocesss and manuffacturring rreliabbilityy, it is neecessaary too guidde in optimmizingg the pproducct dessign aand maanufaccturinng proocess throuugh viirtuall prottotypee (VP). VP iss a prrocesss of uusing 3D CAAD modde

26、l, iin lieeu of a phyysicall prottotypee, forr testting and eevaluaation of sppecifiic chaaracteeristiics off a prroductt or aa manuufactuuring proceess. It iss ofteen carrried out bby CAEE and virtuual maanufaccturinng sysstem. Compuuter aaided enginneerinng (CAAE) annalysiis is an inntegraal parrt

27、 of time-comprressioon tecchnoloogies. Varioous sooftwarre toools avvailabble (ii.e. AANSYS, MARCC, I-DDEAS, AUTOFFORM, DYNAFFORM, etc.) can speedd up tthe deeveloppment of neew prooductss by iinitiaating desiggn opttimizaation beforre phyysicall prottotypees aree buillt. Thhe CADD modeels caan be t

28、ranssferreed to a CAEE enviironmeent foor an analyysis oof thee prodduct ffunctiional perfoormancce and oof thee manuufactuuring proceesses for pproduccing tthe prroductts coomponeents. It haas alsso prooven tto be of grreat vvalue in thhe dessign ooptimiizatioon of part geomeetry, to deetermiine it

29、ts dimmensioons annd to contrrol waarpagee and shrinnkage whilee miniimizinng proceess-innducedd resiidual stressses aand deeformaationss. Virrtual manuffacturring ssystemm (VM) is thhe nattural extennsion of CAAE. Itt simuulatess the produuct fuunctioonalitty andd the pprocessses ffor prroduciing i

30、tt prioor to the ddeveloopmentt of pphysiccal prrototyypes. VM ennabless a deesigneer to visuaalize and ooptimiize a produuct prrocesss withh a seet of proceess paarametters. The vvisuallizatiion off a viirtuallly siimulatted paart prrior tto phyysicall fabriicatioon hellps too reduuce unnwanteed pr

31、oototyppe iteeratioons. TThereffore, a prooduct virtuual maanufaccturinng sysstem mmay reesult in acccuratte detterminnationn of tthe prrocesss parammeterss, andd reduuce thhe nummber oof cosstly pphysiccal prrototyype itteratiions. 3D CAAD modell and VP alllow mmost pprobleems wiith unnfittiing too

32、 becoome obbviouss earlly in the produuct deeveloppment proceess. AAssembblies can bbe verrifiedd for interrferennce ass VP can bbe exeerciseed thrrough a rannge off taskks. Sttructuure annd theermal analyysis ccan bee perfoormed on thhe samme moddel emmployiing CAAE appplicattions as weell ass simu

33、ulatinng down-streaam mannufactturingg proccessess. It is cllear tthat VVP inccreasees proocess and produuct reeliabiility. Althhough VP iss inteended to ennsure that unsuiitablee desiigns aare rejeccted oor moddifiedd, in many casess, a vvisuall and physiical eevaluaation of thhe reaal commponennt

34、is neeeded. Thiss ofteen reqquiress physsical protootype to bee prodduced. Hencce, once the VVP is finisshed, the mmodel may ooften be seent diirectlly to physiical ffabriccationn. The CADD modeel cann be ddirecttly coonvertted too the physiical pprotottype uusing a RP teechniqque orr highh-speeed m

35、acchininng (HSSM) prrocesss. Thee 3D CCAD moodel iis to be exxporteed nott onlyy in tthe STTL forrmat wwhich is coonsideered tthe dee factto staandardd for iinterffacingg CAD and RRP sysstems, but also in thhe NC codinng whiich caan be used by HSSM. HSSM hass a pootentiial foor rappid prroduciing pl

36、lasterr or wwoodenn patttern ffor RT. RRP is a neww formming pprocesss whiich faabricaates pphysiccal paarts llayer by laayer uunder compuuter ccontrool dirrectlyy fromm 3D CCAD moodels in a very shortt timee. In contrrast tto tradiitionaal macchininng metthods, the majorrity oof rappid prrototyypin

37、g systeems teend too fabriicate partss baseed on addittive mmanufaacturiing prrocesss, ratther tthan ssubtraactionn or removval off mateerial. Therreforee, thiis typpe of fabriicatioon is unconnstraiined bby thee limiitatioons attriibutedd to cconvenntionaal macchininng appproachhes. TThe appplicaat

38、ion of RPP technnique as a usefuul toool cann provvide bbenefiits thhroughhout tthe prrocesss of ddevelooping new pproduccts. SSpecifficallly, thhere aare seeriouss beneefits that RP caan briing inn the areass of maarket reseaarch, saless suppport, promootionaal matteriall, andd the ever-imporrtant

39、produuct laaunch. Physsical RP caan alsso beccome aa poweerful commuunicattions tool to ensurre thaat eveeryonee invoolved in thhe devvelopmment pprocesss fullly unndersttands and appreeciatees thee prodduct bbeing develloped. Hencce, itt can help to reeduce substtantiaally the iinevittable riskss i

40、n tthe rooute ffrom pproducct conncept to coommerccial ssuccesss, and hhelp sshorteen timme-to-markeet, immprovee quallity aand reeduce cost. Overr the last 20 yeears, RP maachinees havve beeen widdely uused iin inddustryy. Thee RP mmethodds commeerciallly avvailabble inncludee Sterreolitthgrapphy (

41、SSLA), Selecctive Laserr Sintteringg (SLS), Fussed Deeposittion MManufaacturiing (FFDM), Laminnated Objecct Mannufactturingg (LOM), Balllistiic Parrticlee Manuufactuuring (BMP), andd Threee-Dimmensioonal PPrintiing (3D pprintiing), etc.Once thhe dessign hhas beeen acccepteed, thhe reaalizattion oof

42、thee prodductioon linne reppresennts a majjor taask wiith a long lead time beforre anyy prodduct ccan bee put to thhe markeet. Inn partticulaar, thhe preeparattion oof commplex tooliing iss usuaally iin thee crittical path of a projeect annd hass therreforee a diirect and sstrongg inflluencee on tti

43、me-tto-marrket. In orrder tto redduce tthe prroductt deveelopmeent tiime annd cosst, thhe neww techhniquee of RT haas beeen devvelopeed. RTT is aa techhniquee thatt can transsform the RRP pattternss intoo functtionall partts, esspeciaally mmetal partss. It offerrs a ffast aand loow cosst metthod tto

44、 prooduce mouldds andd funcctionaal parrts. FFurtheermoree, thee inteegratiion off bothh RP aand RTT in deeveloppment strattegy ppromottes thhe impplemenntatioon of concuurrentt engiineeriing inn compaanies. Numeerous proceesses have been develloped for pproduccing ddies ffrom RRP systeem. Thhe RT m

45、ethoods caan gennerallly be dividded innto diirect and iindireect tooolingg categgoriess, andd alsoo softt (firrm) annd harrd toooling subgrroups. Indiirect RT reequirees some kindss of mmasterr pattterns, whicch cann be mmade bby connventiional methoods (ee.g. HSM), or mmore ccommonnly byy an RRP p

46、roocess such as SLLA or SLS. Direcct RT, as tthe name suggeests, invollves tthe maanufaccturinng of a toool cavvity ddirecttly onn a RPP systtem, hencee elimminatiing thhe inttermeddiate step of geeneratting aa patttern. Soft tooliing can bbe obttainedd via repliicatioon froom a ppositiive paatternn

47、 or mmasterr. Sofft toooling is assocciatedd withh low costss; useed forr low volumme prooductiion annd usees matterialls thaat have low hhardneess leevels such as siiliconnes, eepoxiees, loow mellting pointt allooys, eetc. RTV ssilicoone ruubber mouldds, eppoxy mmouldss, mettal spprayinng mouulds,

48、etc. are ssome of thhese ttypicaal sofft molldingss. Harrd toooling is asssociaated wwith hhigherr voluume off prodductioon, and tthe usse of materrials of grreaterr harddness. Kelttool pprocesss, Quuickcaast proceess, aand thhe ExppressTTool pprocesss aree somee of tthese hard tooliings. Electtrica

49、ll dischharge machiining (EDM) seemms to be ann inteerestiing arrea inn whicch rappid tooolingg findss a pootentiial appplicaation. Somee methhods oof makking EEDM ellectroodes bbased on RP teechniqque haave deevelopped, ssuch aas abrradingg proccess, coppeer eleectrofforminng andd net sshape castii

50、ng, eetc. OOn thee basiis of the aabove technniquess, a nnovel integgratedd systeem of rapidd prodduct ddeveloopmentt is tto be propoosed. Its ooveralll arcchiteccture is shownn in FFig. 11.3. Casee Studdies3.1. Caase sttudy 11: ImppellerrA totall of tthirtyy plasstic iimpelllers, with a rellativeel

51、y coomplexx geommetry, weree requuired by a custoomer wwithinn fiftteen wworkinng dayys froom thee receeipt oof a 22D CADD modeel. Theree weree manyy facttors tto be consiideredd in ddecidiing thhe mosst apppropriiate rroute for pproduccing tthe immpelleers. TThese factoors maainly invollved ccost,

52、lead-time, the numbeer of paarts rrequirred, tthe fiinal mmateriial foor thee partts, annd thee partt geommetry. In orderr to mmaximiize thhe bennefitss in tterms of tiime annd cosst redductioon forr the partss, it waas deccided to usse sillicon rubbeer mouuld annd thee partts werre eveentuallly prr

53、oduceed by vaacuum castiing prrocesss. Sillicon rubbeer mouuld iss an eeasy, relattivelyy inexxpensiive and ffast wway too fabrricatee prottotypee or ppre-prroducttion ttools. It ccan bee utillized for mouldding pparts in waax, poolyureethanee, ABSS, andd a feew epooxy maateriaals. TThe prrocesss is

54、 beest suuited for pprojeccts whhere fform, fit, or fuunctioonal ttestinng cann be ddone wwith a matteriall whicch mimmics tthe chharactteristtics oof thee prodductioon matteriall. Thee castting partss withh finee detaails aand veery thhin waalls ccan bee easiily annd rappidly produuced. The wwhole

55、proceess fllow innvolveed thee 3D CCAD moodelliing, pproduccing mmasterr patttern (RP pprotottype), siliicon rrubberr moulld, annd cassting greenn partts. Thhe timme seqquencee for tthe faabricaation of immpelleers waas desscribeed as folloows. DDue too the compllexityy of the iimpelller, tthe taask

56、 off geneeratinng thee 3D CCAD moodel uusing Pro/EEngineeer sooftwarre packaage toook allmost 3 callendarr dayss. Thee mastter paatternn for this projeect waas buiilt on a SPS 6600 maachinee in 22 caleendar days. SL pprocesss wass chossen beecausee it wwas coost effecctive and tthe suurfacee finiish

57、 waas goood. Thhe nexxt steep invvolvedd creaating a rooomtempperatuure vulcaanizedd (RTVV) silliconee rubbber moold whhich wwas coompletted wiithin an addditioonal 33 caleendar days. Finaally, the AABS maateriaals weere caast innto siiliconn rubbber mouldd undeer thee vacuuum caastingg condditionn,

58、 andd the greenn partts werre achhievedd in 4 calenndar ddays. The rrequirred 300 compponentts werre prooducedd succcessfuully aand complleted in 122 caleendar days. The primaary prrocesss stagges arre illlustraated iin Figg. 2. Thesee impeellerss onlyy costt abouut 5 tthousaand RMMB andd tookk 12 w

59、workinng dayys. Coonsequuentlyy, in coontrasst to the ttradittionall deveelopmeent moode, tthe immpelleers deevelopped usingg the integgratedd systtem caan cutt costt by uup to 50% aand thhe timme-to-markeet by 75%. When evaluuated againnst saatisfyying uurgentt requuiremeent wiith reespectt to ttim

60、e, the pproceddure iis cleearly worthh purssuing, as iindicaated bby thee casee studdy desscribeed abovee. Gonng froom a 33D CADD soliid moddelingg to ffully functtionall prodductioon imppellerrs in leess thhan 122 workking ddays iis cerrtainlly exttraorddinaryy.Withh propper immplemeentatiion of th