4-汽车专业英语课件-汽车设计制造部分-section 4汽车专业英语ppt课件-修改2017022715-Chapter 12 12 1 Vehicle architecture design and anufacturing

,Itisimportanttoappreciate(知道)thatthechoiceofgearratiosinatransmissionisoftendictated(限制）,inpractice,bywhatisavailableorwhatisalreadyinproduction.Thissituationoccursbecauseofthelargeexpenseinvolvedinengineeringnewgearsets,andinstallingormodifyingthemanufacturingplanttomakethenewparts.Therearesomecasesthatdonecessitateachange,however.Thesemayincludeachangeintheengine,forexample,frompetroltodiesel,orasignicantchangetotheweightofthevehicleinwhichthegearboxistobeinstalled.,Chapter11AutomotiveDesign11.1ChangingRatiosMatchingofTheTransmissiontoTheVehicle,Wherechangescanbeaccommodated,theymaybelimitedtooneortwogearratios,leavingtheintermediateratiosasis(原样，照原来样子）,hencenotnecessarilyoptimized.Finally,beforelookingathowtheidealratiomaybechosen,theotherlimitationonratiochoiceisthegeardesignitself.Anexampleisarstgearpairwheretherecouldbealimitonhowsmallthedrivepinionmightbeinordertowithstandtheshockloadingwhichcanoccurinthegearbox.Thereareanumberofdecisionsthatneedtobemadewhendecidingwhatgearratiosshouldbettedinaparticulartransmissionunit.,Chapter12AutomotiveManufacturing,补充：CarDesignProcess12.1VehicleArchitectureDesignandmanufacturing车辆结构的设计与制造12.2InjectionMoulding注射成型技术12.3JoiningForLightweightVehicles轻量化汽车的连接技术,学习内容,本次课学习内容、目标和重点难点,学习目标,难点重点,AutomotiveDesignCarDesignProcess12.1VehicleArchitectureDesignandmanufacturing,1.掌握汽车设计的九个步骤2.掌握汽车车身设计的特点,1.重点：汽车设计术语；长句翻译方法；相关术语的记忆2.难点：长句翻译,自学补充材料汽车设计过程,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandanufacturing,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandanufacturing,NewWords,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandanufacturing,NewWords,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,NewWords,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Theautomotiveindustryutilizesawidespectrumofmanufacturingprocessestoeffectivelyandeconomicallyaccommodatedifferentvehicleproductionvolumes.Inordertodevelopthemostcosteffectiveproductionstrategy,investmentintooling(fixedcost)mustbebalancedwithvariablecostforagivenvolume.Forverylow-volumeproduction,minimizationofinvestmentisparamount.Thisisusualinthespecialtycarindustry,wheretheannualproductionvolumesmaybelessthan1000units.Inthesecases,moreexpensivematerialsandsomewhatlongercycletimescanbetoleratedtominimizeinvestmentintoolingandequipment.,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Formoremedium-volumeproduction(intheorderof25000unitsperyear),theuseofautomationisthekeyenablerinachievingcompetitivecostsandcycletimes.Forhigh-volumeproduction(suchasvehicleswherethetotalvolumeoverasix-yearcyclecanbeseveralmillionvehicles),thefixedcostisspreadoverthemillionsofvehiclesproduced.Therefore,minimizingvariablecostsarecritical;lowercostmaterialsandrapidcycletimesarecrucialtotheeconomicsuccessoftheproduct.Thus,theneedtomanageinvestmentintoolingandequipmentwithvariablecosthasasignificanteffectonhowavehiclebodyisdesigned.,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Inresponsetothis,severalapproachestovehicledesignexist,includingbody-on-frame,monocoque,spaceframe,andunibody.Theoriginalmethodforvehiclebodydesign,body-on-frame,ismostlyusedtodayfortrucks.Itiswellsuitedtohighvolumeproductionandisbasedonabodystructureattachedto(butindependentof)thechassissystem.Inmonocoqueconstruction,avehiclestructureismadefromextrusionsandrelativelysimplestampingsorbreakforms.Thiscreatesaverysimple,tub-like(木盆形）structurewhichoffersattachmentpointsforthechassis,thefrontend,andtheclosurepanels.Becausethismethodminimizesthenumberofstampingsandcastings,thenumberofexpensivediesforformingandcastingisalsominimized;thus,monocoqueconstructionisaverylow-investmentmethodforbodydesign.,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Inthespaceframeapproach,framemembersaretypicallyfabricatedfromextrusions.Theseextrusionsareusuallyjoinedtogetherbycastingscallednodes.Thisframeisthenusedtocarrytheloadsandofferattachmentpointsfortheouterpanels（Figure12-1）.Thisapproachiswelldesignedforlow-tomediumvolumevehicleproductionruns.Intheunibodyapproach,thevehiclebodyiscomposedmostlyofstampingsjoinedtogethertointegratethebodyandthechassisintoasinglestructure（Figure12-2）.Today,thismethodhasbecomethestandardmethodforproducinghigh-volumecars.Intheunibodyapproach,therequiredstiffnessandstrengthisusuallyachievedbycreatingboxedsectionscomprisedoftwoseparatestampings.Inrecentyears,therehasbeenanincreaseintheuseoftubularhydroformedsectionstoreplacesomeofthesestampedandweldedsections.,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Figure12-1AudiA2aluminumspaceframeBIW(body-in-white),Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Figure12-2BIWofaunibodyvehicleinwhichroofandfloorpanelsareintegralwiththebody,Chapter12AutomotiveManufacturing12.1Vehiclearchitecturedesignandmanufacturing,Theunibodydesignrequiresasignificantinvestment