Why does the tube deform when the pipe bending machine is bent?

In the use of the pipe bending machine, the problem of deformation of the bend is encountered. What is the cause?

From the process analysis, it can be known that the common bending pipe bending defects are mainly in the following forms: serious flattening at the arc (ellipse), excessive reduction of the outer wall of the arc, excessive bending of the outer arc, round The inside of the arc is wrinkled and bent back. With the different bend radius of the bender, the first four types of defects are different in the way and location, and do not necessarily occur at the same time, but the elastic rebound of the curved workpiece is inevitable.

The presence of bent pipe bend defects has a large negative impact on the quality of the bent pipe fittings. On the one hand, it may cause the cross-sectional area to decrease, thereby increasing the resistance of the fluid flow, and on the other hand, affecting the functional effect of the pipe in the structure; the wrinkling of the inner wall of the pipe not only weakens the strength of the pipe, but also easily causes the velocity of the flowing medium to be uneven. The eddy current and the curved part accumulate dirt, which affects the normal use of the bent pipe; the rebound phenomenon inevitably makes the bending angle of the pipe larger than the predetermined angle, thereby reducing the bending process precision. The thinner wall thickness will inevitably reduce the ability of the pipe to withstand the internal pressure, affecting its performance; the distortion of the cross-section shape of the bent pipe. Therefore, corresponding measures should be taken before the bending to prevent the above defects from being generated to obtain the ideal pipe fittings. Product performance indicators and appearance quality.