各种各样的弯头、三通、岔管等 ,是板金制作中的难点问题。从本期开始 ,将陆续给出一些管接头的展开曲线方程和有关计算公式 ,为计算机、数控切割机等现代化设备参与生产实践 ,提供必要的理论依据 ,并给出部分实例 ,供计算法展开时参考。本文就异径两岔管为例 ,阐述以上问题。 A variety of elbows, tees, bifurcation, etc., is the production of sheet metal difficulties. From the beginning of this issue, some pipe expansion curve equations and related formulas will be given one after another to provide the necessary theoretical basis for the participation of modern equipment such as computers and CNC cutting machines in production practice. Some examples are given for the calculation method When reference. In this paper, diameter two bifurcated pipe as an example, elaborating the above problems.