#### Transcript Views 视 图 Principle views and directional views 基本视图及向视图 Partial views 局部视图 Oblique views 斜视图 Exercises 练习题 请点击相应标题显示其内容 Principle views and directional views 基本视图及向视图 Principle views: There are six orthographic views when.

```Views 视

Principle views and directional views

Partial views

Oblique views

Exercises

Principle views and directional views

Principle views: There are six orthographic views when project to six projection planes.

First angle method

Bottom

Right

Front

Left
Third angle method

Rear
Top
Left
Front

Right Rear

Bottom
Third angle symbol

Top
First angle symbol

Relative position 相对位置关系:
ObserverObjectprojection plane

ObserverTransparent projection plane Object

All views must accord with the projection rules and be arranged and meantime the view names needn’t be signed.

Far from front view showed the front side of the object, but third angle on the contrary.

Principle views and directional views

If the views are not placed following the requirement of orthographic
projection, view name “×” must be signed above the view, an arrow is
used to show the projective direction in corresponding views, and the
same letter must be signed. Such view is called directional view.

A
A
B
B
Example 1. Draw all projection views in first and third angle.

Example 2. Draw four views in third angle projection.

C
C

Partial views
Partial views ：It is some part of an object’s projection view.

Point 作图要点:
1. Arrow signed with letter is used to
show the projection direction near the
corresponding view and the name should
be signed above the partial view.
A

2. When the partial view is placed according to
the projection rules and there are no other
views between the principle view and the
partial view, all the signs can be omitted as
another partial view.

3. Waved lines are used to illustrate the
rupture boundary in partial views. When the
partial structure is integrated and the outline is
closed, the waved line can be omitted.

A
A
A

Oblique views
An auxiliary view is projected by using a profile reference plane
paralleling the oblique surface that is called oblique view.

Point 作图要点:
90°
A
1. Arrow signed with letter is used to show the projection
direction near the corresponding view and the name “×”
should be signed above the oblique view.

2. Oblique views can be drawn as partial oblique views to
express oblique part forms only, the rupture boundary is
expressed by continuous thin irregular line.

↻
3. oblique views should be placed according to
projection rules. It is permitted to rotate oblique views,
but it is required to sign the name “×” and the rotation
direction “ ”or “ ” .
↺

(旋转角度应小于90°)。
↺
A
A
↻

Exercise: Draw those views projection from A、B and C.
A

B
A
A
C
C
C
B

1. Draw all projection views in first and third angle.

Third-angle method

First-angle method

Rear

Left
Top
Right
Front
Bottom
2. Draw four views in third angle projection.

P
Top
Left
R
L
Front
Right

F
First and third angle projection

There are four quadrants in the space

Object at first angle

Object at third angle物

First angle projection 第一角投影示意图
Object at third angle物

Third angle projection 第三角投影示意图
Object at first angle

First angle method symbol
Third angle method symbol

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