blank drawing meaning in English

毛坯图

First calculation method : doing horizontal projection drawing on drawing piece , k value is introduced by area equation of projection drawing , k value is obtained by area equation , along outline of projection drawing to add k value , that is , outline shape of blank drawing , principle area - equal and shape similar are used . second calculation method : along outline of drawing piece horizontal projection drawing , to do normal line of penetration line for wantonly point of this point , to obtain high of drawing piece on this point normal line , point and point is to form outline shape of blank
计算方法之一为k值法：作拉深件水平投影图，在该投影图面积方程中引入k值，利用面积相等原理解方程，求得k值，沿水平投影外沿加上k值，即为毛坯图的外廓形状。计算方法之二为拉深线法：沿拉深件水平投影图外廓，在任意点作该点切线的法线，在该法线上以该点拉深件的高度为量，在法线上取截点。