课程教案Teaching Plan资料

TeachingPlan-3:

Formfeature

LearningOutcomes

Onthecompletionofthisunityouwillbeabletocorrectlyusethefollowingskillsasfollows:

• CreatesolidmodelsformfeaturesandPositionfeaturescorrectly.

• Edittheparametersandpositionoffeatures.

operations.

Assessment

Competencywillbeassessedbyoperationtasksthroughoutthissection.PleaseforwardthePracticalApplicationsManualtoyoursupervisorforassessmentoncompletionofoperationtasks.

Resources

PracticalApplications(Period:2classesinclassroom)

《PracticalApplicationsofUGNX4.0（StudentGuide）》

Lesson3:PositionalFormFeatures

Operation(Period:2classesincomputertrainingroom)

《PracticalApplicationsManual》

Operation3:FormFeatures

KeyPoint

PositiontheFormFeatures,Editthepositionoftheformfeatures.

CreatingFormFeatures

Formfeaturesareusedtoadddetailtoamodel.Thesefeaturesincludeholes,slots,bosses,pads,pocketsandgrooves.Formfeaturesarefullyassociativetothegeometryandparametervaluesusedtocreatethem.

PlacementFace

Allformfeaturesrequireaplacementface.Foragroove,theplacementfacemustbecylindricalorconical.Forallotherformfeatures,theplacementfacemustbeplanar.Adatumplanemaybeusedastheplanarplacementface.

HorizontalandVerticalReference

TheHorizontalReferencedefinestheXaxisofthefeaturecoordinatesystem.Anylinearedge,planarface,datumaxis,ordatumplanethatcanbeprojectedontotheplanarplacementfacemaybeselectedtodefinethehorizontaldirection.

AHorizontalReferenceisrequiredtodefinethelengthdirectionofformfeatureshavingaLengthparameter(slot,rectangularpocket,andpad).ItisalsorequiredtodefinehorizontalorverticalpositioningdimensionsforfeaturesthatdonotinitiallyrequireaHorizontalReference(holes,bosses,andcylindricalpockets).

1—PlanarPlacementFace

2—HorizontalReference

3—XLengthofFeature

Iftherearenoselectableobjectstodefineahorizontaldirection,youcanspecifyaVerticalReferenceinstead.Thehorizontaldirectionwillbeinferredasbeingperpendiculartoit.

PositioningFormFeatures

1—Horizontal

2—Vertical

3—Parallel

4—Perpendicular

5—ParallelataDistance

6—Angular

7—PointontoPoint

8—PointontoLine

9—LineontoLine

Positioningdimensionsaredistancevaluesmeasuredalongtheplacementface.Theymaybeusedtoplacetheformfeatureattheproperlocationontheplacementface.Thesedimensionsshouldbeconsideredasconstraints,orrules,thatthegeometrymustobey.

PositioningTerminology

• FullySpecified—Thefeatureisuniquelylocatedbythepositioningdimensionsspecified.

• Underspecified—Thefeaturepositionisnotcompletelyconstrained.

• Overspecified—Thefeaturehashadmorepositioningconstraintsappliedtoitthanarenecessary.

• TargetSolid—ThesolidbodythataBooleanoperationactsupon.

• TargetEdge—AnedgeontheTargetSolidthatisselectedforpositioningpurposes.

• ToolSolid—Thesolidrepresentationofthefeaturebeingdefinedbythecurrentoperation.

• ToolEdge—AnedgeontheToolSolidthatisselectedforpositioningpurposes.

ParameterEntryOptions

ParameterEntryOptionsletyoueasilydefineyourmodelparametricallyasyouspecifyvaluesduringfeaturecreation.Theyareaccessedbychoosingthe“down-arrow”iconlocatednexttomanyoftheparameterentryfieldsthroughouttheModelingapplication.

Optionsareprovidedtoletyouspecifyavaluebasedonaformula,areferencetoanexistingvalue,oraderivedvaluefromameasurementwithouthavingtocopyandpasteorreenterthevalues.

Youcanusetheseoptionstoeasilylookupfunctionsanddefinerelationshipsbetweenfeatures.Youcanusevaluesthatalreadyexistinyourmodel,makingdownstreamchangeseasierandinagreementwithyourdesignintent.

Hole

Simple

1–Diameter

2–Depth

3–TipAngle

Counterbore

1–C-BoreDiameter

2–C-BoreDepth

3–HoleDepth

Countersink

1–C-SinkDiameter

2–C-SinkAngle

3–HoleDepth

HoleCreationProcedure

• ChoosetheHoleicon(Insert→DesignFeature→Hole).

• ChoosetheType(Simple,Counterbore,orCountersink).

• Selecttheplacementface.

• Selectthethrufaceifapplicable.

• Keyintherequiredparametervalues.

• ChooseOKorApply.

• Createpositionaldimensionsasrequired.

Boss

TheBossfeatureisusedtoaddacylindricalshapewithaspecifiedheighttoamodel,havingeitherstraightortaperedsides.

1—Diameter

2—Height

3—TaperAngle

Slot

Thisoptionallowsyoutocreateaslotinasolidbodyasifcutbyamillingmachinetool.Ineachcase,theshapeofthecuttingtoolcorrespondstotheslottypeanddimensions.

Theslotfeaturewillbecreatedsothattheaxisofthecuttingtoolisnormaltothefaceordatumplaneselected.Initially,thepathoftheslotwillbeparalleltotheselectedHorizontalReference.

1—Length

2—Width

3—Depth

TheWidthoftherectangularslotrepresentsthediameterofthecylindricalcuttingtool.TheDepthoftheslotismeasuredinadirectionparalleltothetoolaxisfromtheplacementfacetothebottomoftheslot.Depthvaluesmustbepositive.TheLengthismeasuredparalleltothehorizontalreference(Xinthefeaturecoordinatesystem).Lengthvaluesmustbepositive.

Theotheravailableslotprofilesareshownbelow.

Ball-End

U-Slot

T-Slot

Dove-Tail

Pocket

Thepocketfeatureisusedtocreateacavityinasolidbody.Therearethreetypesofpockets:Cylindrical(notcoveredinthislesson),Rectangular,General(notcoveredinthislesson).

TheRectangularPocketoptionallowsarectangularpockettobedefinedtoaspecifieddepth,withorwithoutafloorand/orcornerradius,havingeitherstraightortaperedwalls.

Pad

Thisoptionallowsaraisedpadonasolidbody.Therearetwotypesofpads:Rectangular,General(notcoveredinthislesson).

TheRectangularPadoptionallowsarectangularpadtobedefinedtoaspecifiedheight,withorwithoutacornerradiusand/ortaper.

Groove

Thegroovefeaturerequiresacylindricalorconicalplacementface.Agroovecanbethoughtofasafeaturethatwouldresultfromapartbeingcutinalathe.Afterspecifyingthegrooveparameters,youwillbeshownapreviewofthetoolsolid.Thetoolsolidcanbethoughtofasthepaththatthelathewouldmakeasitcutsthesolid.

Youonlyhavetopositionagroovealongtheaxisofthecylindricalorconicalplacementface.ThePositioningdialogwillnotappear.Instead,youareonlyrequiredtospecifyahorizontaldimensionalongtheaxisbyselectingatargetedgefollowedbyatooledgeorcenterline.

Twogroovesareshowninthefollowingexample.

1—TargetEdge

2—ToolEdge(orcenterline)

EditingtheSizeandLocationofFormFeatures

Asfeaturesarecreatedtheparametricdataiscapturedinexpressions.Theparametricdataconsistsoftheactualfeaturesizedefinition(i.e.diameter,height,length)aswellasthepositionaldatathatiscapturedinthepositioningdimensions.

EditParameters

TheEditParametersandEditwithRollbackoptionsallowyoutoredefinetheparametervaluesofanyparametricfeatureandupdatethemodeltoreflectthenewvalues.

EditwithRollback

Thisoptionallowsyoutoedittheparametersofafeaturebutitalsotemporarilyreturnsthemodeltoitsstatewhenthefeaturewascreated.Thefeaturesthatoccuraftertheeditedfeatureinthemodelhistoryarehiddenfromthedisplay.

ThissimplifiesthedisplayandmakesiteasiertoselectfeaturestoreferencewhenusingtheParameterEntryoptions.

EditPositioning

Thisoptionallowsafeaturetobemovedbyeditingitspositioningdimensions.Inaddition,positioningdimensionsmaybeaddedtofeaturesthatareeitherunderspecifiedorwerenotgivenanypositioningdimensionsatthetimeofcreation.

Oncethefeaturehasbeenselected,thefollowingoptionsareofferedbaseduponthepositioningstatusoftheselectedfeature.

Iftheselectedfeaturehasnopositioningdimensionassociatedwithit,theAddDimensionoptionisautomaticallyselected.

AddDimension

Thisoptionmaybeusedtoaddapositioningdimensiontoafeature.Whenaddingpositioningdimensions,anyedge(1)resultingfromtheintersectionofthefeaturebeingpositioned(2)andafaceonthetargetsolid(3)maynotbeselectedasthetooledge.

Theintersectionedgeisachildobjectofthetoolandtargetsolid’sfaceandisdefinedbythebooleanoperationassociatedwiththefeaturetypebeingcreated.Thebooleanoperationdoesnotoccuruntilafterthepositionofthefeaturehasbeendefined.Therefore,theintersectionedgeisnotavalidselectiontospecifylocation.

WhenaddingpositioningdimensionstoaThruHole,noedgeswillbeselectableasthetargetedgebecausebothedgesareintersectionedges.TheIdentifySolidFaceoptionisusedtoselectthecenterofthecylindricalface(1).

Validtargetedgesforpositioningpurposesmustbelongtofeaturesexistinginthefeaturecreationlistofthemodelbeforethefeaturebeingpositioned.

EditDimensionValue

Featuresmaybemovedbychangingthevaluesofthefeature’spositioningdimensions.

Tousethisoption:

• Selectthedimensiontoedit(ifthereisonlyonepositioningdimension,itisselectedautomatically).

• Keyinthenewvalue.

Continueeditingasmanydimensionvaluesasdesired.Onceallthedesireddimensionvalueshavebeenedi