1. Standardization of bending radius
The bending radius should be as close as possible to "one tube, one mold" and "multiple tubes, one mold". For a tube, no matter how many bends it has or what the bending angle is, it can only have one bending radius, because the tube bending machine does not change the module during the bending process, which is "one tube, one mold". "Multiple tubes, one mold" means that tubes with the same diameter should accept the same bending radius as possible, that is, use the same set of modules to bend tubes of different shapes, which is conducive to selecting the number of modules.
2. Appropriate bending radius value
The size of the bending radius of the conduit determines the size of the resistance the conduit encounters during bending. Generally speaking, the larger the diameter of the tube, the smaller the bending radius, and the more likely it is to wrinkle and slip when bending, and the bending quality is difficult to ensure. Therefore, the R value of the tube cutting die is generally 23 times the diameter of the tube.
3. Moderate bending forming rate
The bending forming rate of the pipe bending machine has an important influence on the forming quality: if the rate is too fast, it is easy to cause the flattening of the bending part of the pipe, the roundness does not meet the requirements, and the pipe is torn and broken; if the rate is too slow, it is easy to cause the wrinkling of the pipe and the slipping of the pressing block, and the pipe with a large diameter is easy to cause the sinking of the bending part of the pipe. According to many tests on these two pipe bending machines, the bending rate of the pipe is determined to be 20%-40% of the maximum bending rate of the machine.
4. Regularization of pipe shape
When planning and arranging pipes, it is necessary to avoid excessive arcs, arbitrary curves, compound bends and arcs greater than 180. An arc that is too large not only makes the tooling bulky, but also is restricted by the machine tool specifications of the pipe cutting machine; the design of arbitrary curves and compound bends is very unreasonable, which greatly hinders mechanized and automated production, making it difficult for operators to get rid of heavy manual labor; an arc greater than 180. makes it impossible for the pipe cutting machine to unload the mold.
5. Suitable mandrel and its position
The mandrel plays an important role in supporting the inner wall of the bending radius of the tube to prevent its deformation during the bending process. At present, if the mandrel is used to bend the domestic tube on the machine tool, its quality is difficult to ensure. Of course, if the advance is too large, the outer wall of the bending part will appear the so-called "goose head". There are many types of mandrels, such as column mandrels, universal single, double, triple, and quadruple ball head mandrels, directional single and multi-ball head mandrels, etc. In addition, the position of the mandrel also has a certain influence on the bending of the tube: theoretically, its tangent should be flush with the tangent of the bending die, but after many experiments, it has been proved that it is better to advance 1 to 2 mm, and the quality of the bending tube is relatively ideal at this time.