教案二 other views since 2009.10.ppt

15.Other views ?15.1 Auxiliary view (辅助视图) In this case ，a true shape view of the irregular face can be obtained by following way: projecting it on to an auxiliary plane(辅助平面) which is parallel to the face. A view so obtained is called an auxiliary view （辅助视图或者向视图） 15.2 Partial auxiliary view(局部辅助视图) 15.3 Sectional views （局部视图）  We are frequently confronted with the necessity of showing more or less complicated interiors of parts that cannot be shown clearly by means of dashed lines. How do we see inside the object? We accomplish this by slicing(切割) through the part much as one would cut through an apple. A cutaway view of the part is then drawn ; it is called a sectional view, a cross section, or simply a section. There are several kinds of Sectional views as follow:  1.full sections（全剖视图） 2.half sections（半剖视图） 3. offset sections（平行剖视p132） 4. aligned sections (旋转剖视图) 5.partial sections（局部剖视图） 6. Interposed sections (重合断面图) 7. removed sections （移出断面图） 21.3.1 full sectional view The sectional view obtained by passing the cutting plane fully through the object is called a full sectional view 15.3. 2 half sectional view If the cutting plane passes halfway through the object, the result is a half sectional view 15.3.3 Offset sectional view §4.2 双分型面注射模浇注系统 4、浇注系统的推出机构 15.3.5 partial sectional view 21.3.6 Interposed sections (重合断面图) 21.3.7 removed sections （移出断面图） 15.3.4 aligned sections  Why do we need sectional view: 1.Make the interiors of parts clear, which cannot be shown clearly by means of dashed line 总结机械中不同的表达方法 1、文字 2、视图 3、轴测图 4、爆炸图 Composite solid 5 视图 首页 当对称机件的轮廓线与中心线重合，不宜采用半剖 视时。 错误 正确 视图 首页 - B B B B A A - A A - C C C C 图5–42 滑块盖 图5–43 滑块盖表达方案比较 剖视图 首页 A—A 全剖视图存在什么问题？ 不能表达外形 —以对称中心线为界，一半画成剖视图，另一半画成视图。 全剖视图 A A A—A A A （2）半剖视图 半剖动画 * * Sometimes, mechanical part(机械零件) has an irregular face which is inclined to the normal planes of projection（投影的法线方向） (see fig. a) draw an auxiliary view of the irregular face an