先进制造技术复习题汇总.docx

先进制造技术复习题汇总.docx

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先进制造技术复习题汇总

MODEL1ComputerAidedDesign—CAD

1.What’sthedefinitionofCAD?

CADisanadvancedinformationhandlingtechnologytosolvedesignproblemsforengineers.

CADcombinespeople’sabilitiesofdeducingandcreationwithcomputer’sfunctionsofprocessingandinformationstorage（计算机辅助设计（CAD）的结合能力和创造与推导计算机的功能、信息存储处理）

2.What’sthehistoricaldevelopmentofCAD?

（1）2DDrawingand3DWireframe（线框）modelingin1960s

（2）Surfacemodeling（曲面造型）in1970s;

（3）Solidmodeling（实体造型）in1980s;

（4）Parameterizedandvariablemodeling（变量参数化建模）in1990s.

3.Whatarethethreemethodsofproductdesigninclude?

Pleasegivetheircharacterizes.

RoutineDesign（常规设计）:

onlychangingsomeparameters

InnovativeDesign（革新设计）:

changingsomeparts

CreativeDesign（创新设计）:

developinganewproduct

4.Pleasegivethephases（阶段）thatproductdesignprocessisdividedinto.

DemandAnalysis→ConceptualDesign→DetailDesign→ProductionPlanning

5.Whatarethethreephasesofconceptualdesign?

Generate、Value、Select

6.Whatarethefunctions（功能）ofCAD?

（1）Geometrymodeling

（2）Designreviewandanalysis

（3）Dynamicimitating（动态模拟）（4）Designdocumentation（设计文件编制）

7.Whatarethethreemethodsofgeometrymodeling?

Andgivethedisadvantageofeachmethod.

WireframeModeling（线框建模）:

Disadvantage:

（1）Unabletoexpresscurvemodels（曲线模型表达）

（2）Amultivocal（多义的）model

Advantage:

Lessinformation;Lessstoragespace;Easydata-processing;Fastprocessingspeed;Lessneedofcomputerhardware.

SurfaceModeling:

disad：

（1）Onlysuitableforshell（壳体）;

（2）Noinformationaboutsolidorhollow,insideoroutside;

（3）Noinformationaboutqualityandvolume;

（4）Unsuitableforanalysis.

Ad：

Morerigorousandintegrated;Findingintersectionpointsautomatically;Suitableforcomplicatedsurfacesuchascar’sbodyandplane’saerofoil.

SolidModeling:

disad:

（1）Lackofengineeringinformation（tolerance（公差）,roughness（粗糙度）,material（材料））;

（2）Can’trealizeintegrationofCAD/CAM（不能实现CAD/CAM一体化）.

Ad:

Integralinformation（geometryandtopologicalinformation）;Removingelementsofhiding.

8.Whatarethepopularmethodsofsolidmodeling?

①Constructivesolidgeometry（CSG）

②Sweeprepresentation

9.HowdoesFEA（有限元分析）work?

Andwhichparameters（参数）doesFEAdemand?

1）Breakinganobjectupintomanysmallrectangularortriangularelements;

2）Analyzingtheresponseofeachfiniteelementtothestress,heat,orotherforce;

3）Combiningallelementsandpredictingthereactionofthewholeobject.

10.ProcessofCAD’sApplication

♦Geometrymodelingbasedondesigndemandandsavinggeometrydata;

♦Optimizingdesignprojectafterfinite-elementanalysis（FEA）andoptimizingdesign（OD）（优化设计）;

♦Valueandrevisedesignresult;

♦Sendingdesigndatatoothersystems（CAPP,CAM,PDM）.

11.TechnologiesInvolvedinCAD

♦Productinformationmodelingtechnology

♦Computergraphics

♦Engineeringanalysistechnology

♦Databaseanddataexchangetechnology

♦Documentdisposaltechnology

♦Softwaredesigntechnology

12.DevelopmentTrendofCADTechnology

Computerizing;Integrated（集成化）;Intelligent;Networking;Visualization;Concurrent;Standard

13MethodsofComputerDrafting（计算机绘图）

parameterizedmethod（参数化方法）geometricelementcombiningmethod（几何元素拼接法）

14AdvantageofFeatureModeling

Puttingemphasisonfunctiondesign;EasytorealizeintegrationofCAX;Decreasingproduct’scost.

15PrincipleofFEA

Breakinganobjectupintomanysmallrectangularortriangularelements;

Analyzingtheresponseofeachfiniteelementtothestress,heat,orotherforce;

Combiningallelementsandpredictingthereactionofthewholeobject.

16ParametersofFEA（有限元分析的参数）

Geometry;Material;Loadingconditions;Constraints（约束）

17MethodsofTransfer

1.Readinginformationdirectlyfromthedrawingbyeitherautomaticallyormanuallydigitizingit.

2.Writingaspecialprogramtotranslatefromoneformattoanother.

3.Pre-processingthedrawingfilefromtheoriginalintoastandardformatandpost-processingthedrawingfileintheneutralformatintoaformatacceptabletothesecondsystem.

4.Constructingastandardproductdatamodel.

18StandardforExchangeofProductModelData（STEP）

Containingintegratedproductdata;

IndependentofCAX;Basisofproductdatabase.

MODEL2AutomatedManufacturing

Basicconcepts：

1、theconcepts,componentsandcharacteristicsofNC,NC,CNC,MCU,DPU,CLUandMC

概念、组成、特点

①NumericalControl数控

Asysteminwhichactionsarecontrolledbythedirectinsertionofnumericaldataatsomepoint.Thesystemmustautomaticallyinterpretatleastsomeportionofthisdata.

NCMachineComponent组件

•TheactualNCmachine

•Themachinecontrolunit（MCU）

•ThecommunicationinterfacebetweentheNCmachineandtheMCU

•AvarietyofaccessoriesforperformingspecificjobsontheNCmachine

Fourwaystoprogram编程anNCmachine:

Graphicsprogram;manualWrittenprogram;Digitizing

②DirectNumericalControl（DNC）【计算机】直接数控

DNCreferstoamanufacturingsystemthatusesacentralcomputertocontrolseveralmachinessimultaneously.

Schematicofdirectnumericalcontrol直接数字控制的原理

OnekeyadvantageofDNC,istheabilitytoproduceandprintreportsthatprovidevaluableinformationtosystemmanagers.

③computernumericalcontrol计算机数控

Anumericalcontrolsystemwhereinadedicated,storedprogramcomputerisusedtoperformsomeorallofthebasicnumericalcontrolfunctionsinaccordancewithcontrolprogramsstoredintheread-writememoryofthecomputer.”

ACNCsystemconsistsofthreecomponents

Thecontrolcomponent

Theinputcomponent

Theoutputcomponent

AdventofComputerNumericalControl

WithCNC,eachmachinetoolhasaPLCoramicrocomputerthatservesthesamepurpose.CNCissometimesreferredtoassoftwiredNC.

AdvantageofCNC:

allowthedatabasecreatedduringthedesignanddraftingofaparttobeusedinformulatingtheNCprogramtomakethepart.

AlibraryofNCprogramscannowbecreatedandeasilystoredforreuse.

MastercopiescanbemadeofaspecificNCprogramssothatitcanberevisedtocreateanewNCprogram.

④Machine-controlunit（MCU）机器控制单元

Readsthepartprogramandcontrolsthemachinetooloperation.

⑤Thedataprocessingunit（DPU）数据处理单元

aDPUconsistsofadatainputdeviceinclude:

–Paper-tapereader

–Data-reading

–Decodingcircuits

todeterminetherequiredaxismovements

⑥Thecontrolloopunit（CLU）控制回路单元

ACLUconsistsofaninterpolator,position-controlloopsforallaxesofmotion,velocity-controlloops,decelerationandbacklashtake-upcircuits,andauxiliaryfunctioncontroldevices.

⑦MC:

definedasmultifunction多功能CNCmachineswithautomatictool-changingcapabilitiesandrotatingtoolmagazine

2Classifications分类ofNCMachines数控机床的分类

fourtypesofcontrolsystemspossibleinaCNCoperation:

Pointtopointmachines;Pointtopointstraightline;2axiscontouringwithswitchableplane;3axiscontouringcontinuouspath

Classifiedbythetypesofservocontroller:

分类类型的伺服控制器

Openloopcontrol;Semiclosedloopcontrol;FullyClosedloopcontrol

3TheThreePartofaCNCProgram大纲

•ProgramSetup

•MaterialRemoval

•SystemShutdown系统关闭

•

FlexibleManufacturingSystem柔性制造系统

4、theconcepts,componentsandcharacteristicsofFMSanditsflexibility

FMSDefinition：

Aflexiblemanufacturingsystem（FMS）isanindividualmachineorgroupofmachinesservedbyanautomatedmaterialshandlingsystemthatiscomputercontrolledandhasatoolhandlingcapability.

AFMShasfourmajorcomponents:

主要部件

•Processequipment:

–Machinetools,assemblystations,inspectionstationandrobots,

•ControlSystem（Computercontrolledsystem）

–Storageanddistributionofpartsprograms

–Workflowcontrolandmonitoring

–Productioncontrol

–System/toolcontrol/monitoring

•Automatedmaterialhandling

–robots,conveyors,RGV,AGVandAS/RS

•Humanoperators（criticalroles）

ManufacturingSystemFeatures：

制造系统特点

①TransferLine

ØMachinesdedicatedtohandleoneortwoproducttypes

ØMaximumutilizationandhighproductionrates

ØDirectlaborinvolvementisminimal

ØLowunitcostofproduction

②CNCMachines

ØHighlevelofflexibility.

AnyjobcanbeprocessedwithintherangeofCNCmachinery

ØLowutilizationandlowproductionrate

ØUnitcostismuchhigher

③FMS

ØTruemid-volumemid-varietymanufacturingsystems

•Consists:

–Seriesofflexiblemachineries

–Automatedmaterialhandlingsystems

–Automatedtoolchanger

–Coordinatemeasuringmachines

–Partwashers

•Alltheequipmentsarecontrolledbyacentralcontroller

ØPermitsbothsequentialandrandomroutingofawidevarietyofparts

ØTosettletradeoffsbetweenproductionratsandflexibility.

ØMostmanufacturingsituationsrequiremediumproductionratestoproducemediumvolumeswithenoughflexibilitytoquicklyreconfigureforchangeofproduct.

5、thelayoutofFMSanditsfeatures.FMS的布局及其特点

•Progressive（渐进的）Layout:

–Bestforproducingavarietyofparts

•ClosedLoopLayout:

–Partscanskipstationsforflexibility

–Usedforlargepartsizes

–Bestforlongprocesstimes

•LadderLayout:

–Partscanbesenttoanymachineinanysequence

–Partsnotlimitedtoparticularpartfamilies

•OpenFieldLayout:

–MostcomplexFMSlayout

–Includesseveralsupportstations

6AdvantagesanddisadvantagesofFMSsimplementation实施

Advantages:

✓Faster,lower-costchangesfromoneparttoanotherwhichwillimprovecapitalutilization

✓Lowerdirectlaborcost,duetothereductioninnumberofworkers

✓Reducedinventory,duetotheplanningandprogrammingprecision

✓Consistentandbetterquality,duetotheautomatedcontrol

✓Lowercost/unitofoutput,duetothegreaterproductivityusingthesamenumberofworkers

✓Savin