機械製圖平面投影圖冊作業（機械製圖立體投影）

2023-07-26 14:20:19

今天我們學習《機械製圖》——立體投影第一部分的內容。主要的學習內容是立體及其表面上的點與線。Today we are studying Mechanical Drawing - Stereographic Projection Part 1. The main topic of study is the stereoscope and the points and lines on its surface.

No.1 平面立體

一.平面立體

1.立體可分為兩類：表面都是平面的平面立體和表面是曲面或曲面與平面的曲面立體。

2.平面立體的表面是若干個平面多邊形，因此，繪製平面立體的投影，可歸結為繪製它的所有平面多邊形表面的投影，也就是繪製這些多邊形的邊和頂點的投影。常見的有稜柱和稜錐兩種。

I. Planar stereo

1. Stereoscopic can be divided into two categories: flat stereoscopic whose surfaces are all flat and curved stereoscopic whose surfaces are curved or curved and flat.

2. The surface of a planar stereo is a number of planar polygons, so that the projection of a planar stereo can be reduced to the projection of the surface of all its planar polygons, that is, the projection of the sides and vertices of these polygons. Two common types are prisms and prismatic cones.

稜柱由兩個形狀、大小相同且平行的頂、底面和若干個矩形稜面圍成。The prism is enclosed by two top and bottom faces of the same shape, size and parallel, and a number of rectangular prism faces.

稜錐是由一個多邊形底面和若干個共頂點的三角形稜面所圍成的。從稜錐頂點到底面的距離叫做稜錐的高。當稜錐底面為正多邊形，各稜面是全等的等腰三角形時，稱之為正稜錐。A prism is enclosed by a polygonal base and a number of triangular prism faces with a common vertex. The distance from the apex of the prism to the base is called the height of the prism. When the base of a prism is a regular polygon and the prism faces are congruent isosceles triangles, it is called a regular prism.

No.2曲面立體

1.迴轉面的形成

迴轉面可以看作是一任意動線（母線）繞一定直線（軸線）旋轉一周後形成的曲面。如圓柱面，圓錐面，球面等。

2.常見迴轉體

常見的迴轉體有圓柱體，圓錐體和圓球體等。

對於迴轉體的迴轉面，若按某一投射方向看，有一部分可見，有一部分不可見，把其可見與不可見的分界線稱為轉向線。

1. The formation of a rotary surface

A rotary surface can be seen as an arbitrary line of motion (bus) around a certain line (axis) after a week of rotation to form the surface. Such as cylindrical surface, conical surface, spherical surface, etc.

2. Common rotating bodies

Common rotating bodies are cylinders, cones and spheres.

For the rotary surface of the body, if a certain projection direction, part of the visible, part of the invisible, the visible and invisible line of demarcation is called the steering line.

圓柱表面有圓柱面，頂面和底面。圓柱面由直線繞與它平行的軸線旋轉而成。The cylindrical surface has a cylindrical face, a top face and a bottom face. The cylindrical surface is formed by rotating a straight line around an axis parallel to it.

圓錐的表面有圓錐面和底面。圓錐面由直線繞與它相交的軸線旋轉而成。The surface of a cone has a conical face and a base. The conical surface is formed by rotating a straight line around an axis that intersects it.

球的表面是球面。球面由圓繞其直徑為軸線旋轉而成。The surface of a ball is a sphere. The spherical surface consists of a circle rotating around its diameter as its axis.

環的表面是環面。環面由圓繞圓平面上不與圓心共線且在圓外的直線為軸旋轉而成。The surface of a ring is the ring surface. The ring surface consists of a circle rotating on its axis around a line in the circular plane that is not co-linear with the centre of the circle and is outside the circle.