经常从事压力容器设计方面工作的同志都知道,作椭圆封头图形是难免的。现在在作椭圆形封头时,一般均采用简化画法,即用四段圆弧作扁圆来代替椭圆。这种作图法的关键在于分别找出大圆弧半径AC与小圆弧半径BD。在找这两个尺寸时要作n条精确的辅助线,找出后还要将其擦去,比较麻烦。实际上,这两个半径的值可根据⊿EFB～⊿EOC～⊿AFC的关系求出。在标准封头(长 Often engaged in the design of pressure vessel comrades know that for the elliptical head graphics are inevitable. Now for the elliptical head, the general use of simplified painting method, that is, with four arcs as oblate to replace oval. The key to this method of plotting is to find the large circular radius AC and the small circular radius BD, respectively. When looking for these two dimensions to make n accurate auxiliary line, find out but also to wipe it, more trouble. In fact, the values ​​of these two radii can be obtained from the relations of ⊿EFB ~ ⊿EOC ~ ⊿AFC. In the standard head (long