The working cycle of the pipe bending machine: Since the power required by the pipe bender comes from the hydraulic system, in addition to manual loading and unloading, it is boldly envisaged to make a groove above the tire wheel and the rolling wheel, and the two sides of the groove are located on the tire wheel and On the rolling wheel, the upper part of the side of the groove is two parallel planes, and the bottom part is a ring with a radius tangent to the plane and the same outer diameter of the pipe, so that the pipe can be installed downward from the top of the tire wheel and the rolling wheel. The design of the hydraulic system can easily realize the automatic completion of the pipe bending work cycle. The actions of the hydraulic circuit in one working cycle and its functions are as follows: the oil pump stops and unloads - the clamping cylinder is fast forward (tire wheel indexing, clamping pipe fittings) - the clamping cylinder is working (pressing the bending pipe fittings) - the clamping cylinder maintains the pressure - Rolling and bending cylinder advance (rolling and bending pipe fittings) - Rolling and bending cylinder fast back (rolling wheel reset) - Clamping cylinder fast back (tire wheel reset) - Oil pump unloading. In order to make pipe installation quick and convenient, to improve work efficiency and simplify the structure.