一、局部放大图Drawing of Partial Enlargement
机件的部分结构用大于原图形所采用的比例画出的图形称为局部放大图。局部放大图可画成视图、剖视图、断面图，它与被放大部分的表达方式无关。当机件上的某些细小结构在原图形中表示不清或不便于标注尺寸时，可采用局部放大图。
局部放大图应尽量配置在被放大部分的附近，用细实线圈出被放大的部位；当同一机件上有几个被放大的部位时，必须用罗马数字依次标明被放大的部位，并在局部放大图的上方标注出相应的罗马数字和采用的比例；当机件上被放大的部分仅有一处时，在局部放大图的上方只需注明所采用的比例，同一机件上不同部位的局部放大图，当图形相同或对称时，只需要画出一个。 It is a drawing of partial enlargement that indicates the partial structure of an object by drawing in an enlargement scale compared with the intrinsic one. Drawing of partial enlargement can be showed by views, sections or cuts; it has nothing to do with the drawing method of the enlarged part. Drawing of partial enlargement should be located nearby the enlarged part. When there are several enlarged parts on a same object, they must be labeled with Roman numerals in turn. Continuous thin line is used to enclose the enlarged part and the enlargement scale value is written above the view. Drawing of partial enlargement can be used to indicate a same part.
