《机械制图及计算机绘图》英文课件-绘制正等轴测图

主讲人：赵慧、杨国星TianjinLightIndustryVocationalTechnicalCollege

DrawaStandardIsometricDrawingPartIIntroductionPARTIIntroduction1810162582036Canyouunderstandthissetofthree-viewdrawingsandmentallyvisualizeitsthree-dimensionalshape?Introduction1810162582036StandardIsometric

DrawingAdvantagesItallowsyoutoclearlyexpressthethree-dimensionalshapeyouhaveconceptualizedbasedonthethreeviews;Itenablescomparisonwiththethree-viewdrawings,helpingyoutocorrectanyerrorsinyourconstructed3Dimage;Forslightlymorecomplexthree-viewdrawings,youcanobserve,imagine,andsketchtheisometricdrawingsimultaneously.PARTIIFormationofAxonometricProjectionPARTIIFormationofAxonometricProjectionVHYAnobjectprojectsontothehorizontalprojectionplane,formingthetopviewACBZXOAnobjectprojectsontothefrontalprojectionplane,formingthefrontviewFormationofAxonometricProjectionVHPYDrawingAxonometricProjectionsIntroducetheinclinedplaneaxonometricprojectionplaneACBZXOYZ1Y1X1C1B1A1ThefigureobtainedbyprojectingtheobjecttogetherwiththeCartesiancoordinatesystemontothisprojectionplaneusingparallelprojectionaxonometricprojectionThefigureobtainedwhentheprojectiondirectionisperpendiculartotheaxonometricprojectionplaneisometricdrawingSAxonometricProjectionPlaneAxonometricProjectionDirectionIsometricDrawingO1FormationofAxonometricProjectionVHPYACBZXOYZ1Y1X1C1B1A1SAxonometricAxes：1AngleBetweenAxes:2AxialForeshorteningCoefficient3O1X1、O1Y1、O1Z1Theincludedanglebetweentheaxonometricaxesp=O1A1OAq=O1B1OBr=O1C1OCO1PartIIIDrawingtheIsometricProjectionPARTIIIDrawingtheIsometricProjectionWhendrafting,graspthetwofundamentalpropertiesDrawtheisometricaxesEstablishaCartesiancoordinatesystemonthethree-viewdrawingSpatiallyparallellinesremainparallelafteraxonometricprojection;linesparalleltothecoordinateaxesremainparalleltothecorrespondingisometricaxesintheisometricdrawing.Anylineparalleltoacoordinateaxiscanbemeasuredanddrawntoitstruelengthalongthataxisintheisometricdrawing.MeasurabilityParallelismDrawingtheIsometricProjectionDrawingtheIsometricProjectionofaHexagonalPrism(CoordinateMethod)LMSabcdefoyxA1D1X1Y1O1SMB1C1E1F1Z1x＇z＇L(1)

Basedonthestructuralfeaturesoftheobject,establisharectangularcoordinatesystemonthethree-viewdrawing.(2)

Drawtheisometricaxes.(3)

Createtheisometricprojectionofpointsandlinesbasedonthecoordinatesofthepoints.

PlotpointsA、B、C、D、E、Fo＇DrawingtheIsometricProjectionDrawingtheIsometricProjectionofaHexagonalPrism(CoordinateMethod)（4）ConnectpointsA1

、B1、C1、D1、E、F1，completetheisometricprojectionofthetopface.（5）ThrougheachofpointsA1、B1、C1、D1、E1、F1,

drawstraightlinesdownward—paralleltoO₁Z₁—atlengthsequaltotheprism’sheightasshowninthethree-view.Theselineslocatethecorrespondingpointsonthebottomface;thenconnectthosepointsinsequenceandtidyuptocompletethefulldrawing.E1C1F1D1A1B1X1Y1O1Z1DrawingtheIsometricProjectionCuttingMethodGiventhethree-viewdrawing,drawtheisometricprojectionoftheshape.DrawingtheIsometricProjectionCuttingMethodxyx＇z＇X1Y1Z1oo＇O1(1)

Createacoordinatesysteminthethree-view.(2)

Createisometricaxeswithanangleof120°betweenthem.(3)

Usetheparallelismandmeasurabilityoftheisometricprojectiontoofficiallydrawthediagram.SummaryofThisLectureFormationofaxonometricprojectionDrawingtheisometricprojectionusingthecoordinatemethodDrawing