文稿lecture slides英文课件09chapter6-axonometirc projection

1、Chapter 6 Axonometric ProjectionsPresented by YANG Zhi-Ling Click to add your textContentsAxonometric Projection1Isometric Projection2Cabinet Axonometric Projection3Axonometric ProjectionAxonometric projection is made on a single plane of projection using a parallel projection system with the object

2、 placed so as to show its three principal faces on the projection plane.Axonometric ProjectionA convenient object for our discussion of axonometric projection is cube, three edge of which meeting at a corner may used as the coordinate axes (X, Y, and Z). The projections of the coordinate axes on pro

3、jection plane are called axonometric axes (X1, Y1, and Z1).Projection PlaneOYXZO1X1Y1Z1Axis AnglesAxis Angles: X1O1Y1， X1O1Z1， Y1O1Z1Coordinate axes: OX， OY， OZAxonometric axes: O1X1，O1Y1，O1Z1Projection PlaneOXYZO1X1Y1Z1Projection PlaneO1X1Y1Z1OYXZCoefficients of Axial DeformationO1A1OA = pO1B1 OB =

4、 qO1C1OC = rThe length ratios between the axonometric projection on the axonometric axes (O1X1, O1Y1, O1Z1) and the line segments on the spacial coordinate axes (OX, OY, OZ), respectively.Projection PlaneOXYZProjection PlaneO1X1Y1Z1AB1A1O1X1Y1Z1C1B1A1BCOYXZABCC1Characteristics Parallel line segments

5、 on the object are still parallel in the axonometric projection.If line segments on the object are parallel to a coordinate axis, they are parallel to the corresponding axonometric axis in the axonometric projection.Isometric Drawing If the cube is placed so that its faces make equal angles with the

6、 projection plane, and the projectors are perpendicular to the plane, the resulting projection is an isometric projection.When a isometric projection is drawn with an ordinary scale (full-size scale), it is an isometric drawing.Z1X1Y1O1X1O1Y1 = X1O1Z1= Y1O1Z1 = 120p = q = r = 1Basic Drawing SkillsTa

7、ke advantage of parallel rules and all measurements are made parallel to the main edges of enclosing box.xzoxyoZ1O1X1Y1Basic Drawing SkillsAnother isometric axes are used because of its convenience.xyoxzoO1X1Y1Z1X1O1Y1 = 240 X1O1Z1= Y1O1Z1 =60p = q = r = 1Cutting ConstructionExample 1: Draw the isom

8、etric drawing from the given three-view drawing.Cutting ConstructionExercise 1: Draw the isometric drawing from the given two-view drawing.Joining-up ConstructionExample2: Draw a isometric drawing.Coordinate ConstructionOOOXXYYZZAExample 3: Draw the isometric drawing of a pyramid.X1 O1Y1Z1BCK(c)kkab

9、cabkabcCircles in IsometricX1Y1Z1 Circles inscribed in the faces of the cube will project as ellipse in isometric. Four-Center Method（Example from a circle paralleled to H-plane）dddabefOX1Y1O1F1E1B1A1 Four-Center Method Lay out an isometric square (rhombus) with a side equal to the circles diameter.

10、 Determine four centers and radius of four arcs. Draw four arcs which were tangent each other.dddF1E1B1A1abefOX1Y1O1Isometric Drawing of a Revolution SolidExample 4: Draw the isometric drawing of a circular truncated cone.Arcs in IsometricO1ECBDAFO4O3F1E1G1 DE= DF= AG = AH=Radius of the arc. EO1AD ,

11、 FO1CD, GO2AD , HO2AB.To use the O1, O2 as the center, and EO1,GO2 as the radius to draw arcs.To transfer the center O1, O2 to O3, O4 along the direction parallel to isometric axis.To construct the tangent points (E1 , F1 and G1) of the further corner. To Construct the tangent line.HGO2Application o

12、f Isometric DrawingExample 5: Draw the isometric drawing from the given three-view drawing and complete it.Oblique Projection and Cabinet DrawingIf the cube is placed so that its front and rear faces are parallel to the projection plane and the parallel projectors make a oblique angle with the proje

13、ction plane, then the projection is a oblique projection.When the receding lines which are parallel to OY axis in space are drawn to half size, the drawing is commonly known as a cabinet drawing.The Parameters of Cabinet Drawingp = r = 1 ，q = 0.5X1O1Z1 = 90X1O1Y1 = Y1O1Z1 = 135p = r = 1 ，q = 0.5X1O1

14、Z1 = 90X1O1Y1 = 45 Y1O1Z1 = 225Circle in a Cabinet DrawingThe circles in the faces which are perpendicular to the OZ and OX axes are represented by ellipse.The front face of the cube, which is parallel to the projection plane, projects in its true shape.Circle in Oblique DrawingThe true shape is the

15、 advantage of oblique drawing that make it attractive and convenient for depicting objects like those whose faces with cylindrical features may be placed parallel to the projection plane.Application of Cabinet DrawingExample 6: Draw the cabinet drawing from the given two-view drawing.Section Views in