外文翻译--现代设计与制造.doc -- 5 元

ModernDesignandManufacturing1.TheComputerandManufacturingThecomputerisbringingmanufacturingintotheInformationAge.Thisnewtool,longafamiliaroneinbusinessandmanagementoperations,ismovingintothefactory,anditsadventischangingmanufacturingascertainlyasthesteamenginechangedit100yearsago.Thebasicmetalworkingprocessesarenotlikelytochangefundamentally,buttheirorganizationandcontroldefinitelywillInonerespect,manufacturingcouldbesaidtobecomingfullcircle.Thefistmanufacturingwasacottageindustrythedesignerwasalsothemanufacturer,conceivingandfabricatingproductsoneatatime.Eventually,theconceptoftheinterchangeabilityofpartswasdeveloped,productionwasseparatedintospecializedfunctions,andidenticalpartswereproducedthousandsatatime.Today,althoughthedesignerandmanufacturermaynotbecomeoneagain,thefunctionsarebeingdrawncloseinthemovementtowardanintegratedmanufacturingsystem.Itisperhapsironicthat,atatimewhenthemarketdemandsahighdegreeofproductdiversification,thenecessityforincreasingproductivityandreducingcoatsisdrivingmanufacturingtowardinegrationintoacoherentsystem,acontinuousprocessinwhichpartsdonotspentasmuchas95ofproductiontimebeingmovedaroundorwaitingtobeworkedon.Thecomputeristhekeytoeachofthesetwinrequirements.Itistheonlytoolthatcanprovidethequickreflexes,theflexibilityandseed,tomeetadiversifiedmarket.Anditistheonlytoolthatenablesthedetailedanalysisandtheaccessibilityofaccuratedatanecessaryfortheintegrationofthemanufacturingsystem.Itmaywellbethat,inthefuture,thecomputermaybeessentialtoacompanyssurvial.Manyoftodaysbusinesseswillfadeawaytobereplacedbymoreproductivecombinations.Suchmoreproductivecombinationsaresuperquality,superproductivityplants.Thegoalistodesignandoperateaplantthatwouldproduce100satisfactorypartswichgoodproductivity.Asophisticated,competitiveworldisrequiringthatmanufacturingbegintosettleformore,tobecomeitselfsophisticated.Tomeetcompetition,forexample,acompanywillhavetomeetthesomewhatconflictingdemandsforgreaterproductdiversification,higherquality,improvedproductivity,higherquality,improvedproductivityandprices.Thecompanythatseekstomeetthesedemandswillneedasophisticatedtool,onethatwillallowittorespondquicklytocustomerneedswhilegettingthemostoutofitsmanufacturingresources.Thecomputeristhattool.Becomingasuperquality,superproductivityplantrequirestheintegrationofanextremelycomplexsystem.Thiscanbeaccomplishedonlywhenallextremelycomplexsystem.Thiscanbeaccomplishedonlywhenallelementsofmanufacturingdesign,fabricationandassembly,qualityassurance,management,materialshandingarecomputerintegrated.Inproductdesign,forexample,interactivecomputeraideddesignCADsystemsallowthedrawingandanalysistaskstobeperformedinafractionofthetimeallowthedrawingandanalysistaskstobeperformedinafrationofthetimepreviouslyrequiredandgreateraccuracy.Andprogramsforprototypetestingtestingandevaluationfurtherspeedthedesignprocess.Inmanufacturingplanning,computeraidedprocessplanningpermitstheselection,fromthousandsofpossiblesequencesandschedules,oftheoptimumprocess.Ontheshopfloor,distributedintlligenceintheformofmicroprocessorscontrols,runsautomatedloadingandunloadingequipment,andcollectsdataoncurrentshopconditions.Butsuchisolatedrevolutionsarenotenough.Whatisnendedisatotallyautomatedsystem,linkedbycommonsoftwarefromfrontdoortoback.Thebenefitsrangethoughoutthesystem.Essentially,computerintegrationprovideswidelyandinstantaneouslyavailable,accurateinformation,improvingcommunicationbetweendepartments,permittingtightercontrol,andgenerallyenhancingtheoverallqualityandefficiencyoftheentiresystem.Improvedcommunicationcanmean,forexample,designsthataremoreproducible.TheNCprogrammerandthetooldesignerhaveachangtoinfluencetheproductdesigner,andviceversa.Engineeringchanges,canbereduced,andthosethatarerequiredcanbehandledmoreefficiently.Notonlydosethecomputerpermitthemtobespecicifiedmorequickly,butitalsoalerssubsequentusersofthedatatothefactthatachangehasbeenmade.Theinstantaneousupdatingofproductioncontroldatapermitsbetterplanningandmoreeffectivescheduling.Expensiveequipment,therefore,isusedmoreproductively,andpartsmovemoreefficientlythroughproduction,reducingworkinprocesscoats.Productquality,too,canbeimproved.Notonlyaremoreaccuratedesignsproduced,forexample,buttheuseofdesigndatabythequalityassurancedepartmenthelpseliminateerrorsduetomisunderstandings.Peopleareenabledtodotheirjobsbetter.Byeliminatingtediouscalculationsandpaperworknottomentiontimewastedsearchingforinformationthecomputernotonlyallowsworkerstobemoreproductivebutalsofreesthemtodowhatonlyhumanbeingcandothinkcreatively.Computerintegrationmayalsolurenewpeopleintomanufacturing.Peopleareattractedbecausetheywanttoworkinamodern,technologicallysophisticatedenviroment.Inmanufacturingengineering,CAD/CAMdecreasestooldesign,NCprogramming,andplanningtimeswhilespeedingtheresponserate,whichwilleventuallypermitinhousstafftoperformworkthatiscurrentlybeingcontractedout.2.CAD/CAMCAD/CAMisatermwhichmeanscomputeraidedandcomputeraidedmanufacturing.itisthetechnologyconcernedwiththeuseofdigitalcomputerstoperformcertainfunctionsindesignandproduction.Thistechnologyismovinginthedirectionofgreaterintegrationofdesignandmanufacturing,twoactivitieswhichhavetraditionallybeentreatedasdistinctandseparatefunctionsinaproductionfirm.Ultimately,CAD/CAMwillprovidethetechnologybaseforthecomputerintegratedfactoryofthefuture.ComputeraideddesignCADcanbedefinedastheuseofcomputerstytemstoassistinthecreation,modification,analysis,oroptimizationofadesign.Thecomputersystemsconsistofthehardwareandsoftwaretoperformthespecializeddesignfunctionsrequiredbytheparticularuserfirm.TheCADhardwaretypicallyincludedthecomputer,oneormoregraphicsdisplayterminals,keyboards,andotherperipheralequipment.TheCADsoftwareconsistsofthecomputerprogramstoimplementcomputergraphicstofacilitatetheengineeringfunctionsoftheusercompany.Examplesoftheseapplicationprogramsincludestressstrainanalysisofcomponents,dynamicresponseofmechanisms,heattransfercalculations,andnumericalcontrolpartprogrammingThecollectionofapplicationprogramswillvaryfromoneuserfirmtothenextbecausetheirproductlines,manufacturingprocesses,andcustomermarketsaredifferentThesefactorsgiverisetodifferencesinCADsystemrequirements.ComputeraidedmanufacturingCAMcanbedefinedastheuseofcomputersystemstoplan,manufacturingplantthrougheitherdirectorindirectcomputerinterfacewiththeplansproductionresources.Asindicatedbythedefinition,theapplicationsofcomputeraidedmanufacturingfallintotwobroadcategories1.Computermonitoringandcontrol.2.Manufacturingsupportapplications.Thedistinctionbetweenthetwocategoriesisfundamentaltoanunderstandingofcomputeraidedmanufacturing.Inadditiontotheapplicationsinvolvingadirectcomputerprocessinterfaceforthepurposeofprocessmonitoringandcontrol,computeraidedmanufacturingalsoincludesindirectapplicationsinwhichthecomputerservesasupportroleinthemanufacturingoperationsoftheplant.Intheseapplications,thecomputerisnotlinkeddirectlytothemanufacturingprocess.Instead,thecomputerisusedofflinetoprovideplans,schedules,forecasts,instructions,andinformationbywhichthefirmsproductionresourcescanbemanagedmoreeffectively.Theformoftherelationshipbetweenthecomputerandtheprocessisrepresentedsymbolicallyinthefiguregivenbelow.Dashedlinesareusedtoindicatethatthecommunicationandcontrollinkisanofflineconnection,withhumanbeingsoftenrequiredtoconsummatetheinerface.However,humanbeingsarepresentlyrequiredintheapplicationeithertoprovideinputtothecomputerprogramsortointerpretthecomputeroutputandimplementtherequiredaction.3.VoiceNCProgrammingVoiceprogrammingofNCmachinesabbreviatedVNCinvolvesvocalcommunicationofthemachiningproceduretoavoiceinputNCtapepreparationofthemachingproceduretoavoiceinputNCtapeprepartionsystem.VNCallowstheprogrammertoavoidstepssuchasOneoftheprincipalcompaniesspecializinginvoiceinputsystemsisThresholdTechnology,Inc,ofDelran,Newjersey.turn,ToperformthepartprogrammingprocesswithVNC,theoperatorspeaksintoaheadbandmicrophonedesignedtoreducebackgroundacousticalnoise.Communicationoftheprogramminginstructionsisinshoplanguagewithsuchterms