机械制造业外文翻译外文文献英文文献制造业中的新技术制造业面临的挑战.docx
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机械制造业外文翻译外文文献英文文献制造业中的新技术制造业面临的挑战
NewTechnologiesinManufacturingTheChallengeofmanufacturing
Theneedforqualifiedmanufacturingengineershasneverbeengreater.Tomeettoday’schallenges,itisnecessarytogainabroadbackgroundinbothmaterialsciences,design,andmanufacturingprocesses.Considerableemphasisisalsobeingplacedoncomputersciencesandautomaticcontrols.
Themanufacturingengineermastbeabletovisualizethewholeproblemofproductioninthecorrectperspectivefromthebasiccomponentmaterialsandtoolingthroughthestepbystepoperationalplanning,finalassembly,inspection,andshipment.
Themanufacturingengineerisresponsiblefortheexpenditureoflargesumsofmoneyfortoolingandmachinerytokeepproductiononacompetitivebasis.Henotonlyshouldbefamiliarwiththetheoreticalaspectsoffabrication,butalsomustbeabletoworkoutpractical“breadandbutter”problemsoftheproductionfloor.
Afewoftheareasinwhichamanufacturingengineercanbeexpectedtoworkareinplanningprocesslayouts,plantlayout,equipmentspecification,materialspecification,tooldesign,methodsdevelopment,workstandards,valueanalysis,andcostcontrol.
Asthemanufacturingengineergainsexperience,andifhehasahighdegreeofcreativityandinnovativeability,hecanexpecttobeinvolvedinthegenerationofmanufacturingsystemconcepts.Hewillalsobeinvolvedinthedevelopmentofnovelandspecializedequipment,researchintothephenomenaoffabricatingtechnologies,andmanufacturingfeasibilitystudiesofproposednewproducts.
Notalloftheinnovationsthatincreaseefficiencyofmanufactureareintheareaofmachinetools,inspection,orautomatedassemblyperse.Increasing
emphasiswillbeinthechallengeoftheindividualworker.Menonproduction
linescanbecometeams,collectivelyresponsiblefortheendproductratherthanforjustsomanyrepetitiousoperations.Underthisconcept,itistheteam’sresponsibilitytohelpdeterminethedistributionofwork,theoccupationofmachines,andthespeedandqualityofwork.Itisassumedthatthepersonnelwillbegivenbroadertrainingsothattheymighthavetheflexibilityandallaroundskilltobeabletostepinwherehelpisneeded.
Modernmanufacturingplanningalsoincludestheuseofthecomputertohandlethevastamountofdataneededtoutilizerawinformation,suchassalesforecastsandcustomerorders,indeterminingwhatistobepurchased,made,stored,etc(showninFigure5-1).
Thecomputer,includingtheminicomputerandprogrammablecontrollers,willhaveincreasedimpactintheareasofproduct,tool,andprocessdesignforoptimumproduction.Computer-aideddesign(CAD)andcomputer-aidedmanufacture(CAM)havethepotentialofbeingthelargestsingledevelopmentmanufacturingsincetheindustrialrevolution.Whetherthefullpotentialwillberealizedisdependentonitsacceptancebyindustryandbycollegesanduniversitieswherefuturemanufacturingengineersaretrained.Thisisnottoimplythatconsiderablelearningdoesnottakeplaceoutsideoftheformalclassroom.Onthecontrary,becauseoftoday’sfloodofnewscientificandtechnicalknowledge,andtheastonishingpaceoftechnologicalchange,theengineerrisksobsolescenceunlesshemakessomeplansforself-study.However,evenshortcoursesandcolloquiumsmaynotbesufficient.Formanyareasofrapidtechnologicalchange,aworkcycleoffourorfiveyearsfollowedbyayearoncampusmaybeanormalpractice.
Purchasingcontrol
Orders
Manufact-uringcontrol
AssemblyworksheetsWarehousesheetsCodebooks
Costpricebreak-down
output
Figure5-1Thecomputer,withitsdatabanksandprograms,isanessentialpartofmanufacturingplanning
Automation
“Automation”isarelativelynewword,coinedin1935byD.S.Harder,thenvicepresidentinchargeofmanufacturingfortheFordMotorCompany.Theword,shortfor“automalization”impliesdoingsomethingautomaticallyorwithouthumanassistance.Thismayrefertoasingle
Automation
operationoranentirecontinuousprocess.
Automaticcontrolsystemsarenotaproductofthisgeneration,JamesWatt,asearlyas1788,conceivedofanautomaticspeedcontrolforhissteamengineintheformofafly-ballgovernor.Thetwoflyballs,actingbycentrifugalforce,wouldextendastherpmoftheengineincreased.This,inturn,causedamotionthatreducedtheopeningattheintakevalve.Withlesssteamintake,thespeedreducedandtheballsmovedclosertothecontrolshaft,thusreopeningtheintakevalve.
Anotherexampleofearlyautomationthatisstillcommoninmanyshopsisthefullyautomaticscrewmachine.Theinventor,ChristopherSpencer,hadworkedonmanuallyoperatedturretlathes.Herealizedthatbyattachingacamshaft,stripcams,levers,andsegmentgearsforactuatingtheturret,collate,andcrossslide,itcouldbemadetooperateautomatically.Thustheautomaticscrewmachinewasborn.Surprisinglyenough,Spencerdidnotrealizetheimportofhisinventionbutwascontenttoletthemachineproducescrewsandothersimilaritemsratherthantodevelopthemachineitself.
AboutthesametimeasSpencer’sautomaticscrewmachinewasbuiltintheUnitedStates,theSwisswereworkingoutsimilarideasforanautomaticscrewmachine.ThereseemstobesomereluctancetogiveanyonemancreditfortheinventionofwhathascometobeknownastheSwissautomaticscrewmachine.However,thecontributionsofabrilliantyoungengineernamedBachelorcannotbeignored.Hisconceptofmovingthematerialaxiallyasitwasbeingcutprovidedameansofgeneratinganinfinitevarietyofshapeswithaminimumoftooling.Themachine,entirelycam-operated,
4
NumericalControl
wasfullyautomatic.Onemancouldlookafterfiveorsixofthesemachines,primarilytoseethattheydidnotrunoutofmaterialandthatthepartsproducedwerewithintolerancelimits.
Numericalcontrol
Arelativelyshorttimeagomachineswereoperatedbycraftsmenwhodeterminedmanyvariablessuchasspeeds,feeds,depthofcut,etc.Nowmuchofthisworkisbeingassignedtocomputersandmachinesthatarenumericallycontrolled.Thewordnumericalisdefinedas“theexpressionofsomethingbynumbers”.Controlisdefinedas“the