When cold roll forming machines process, the problem of spring-back after bending often occurs. We will analyze the measures for the spring-back of the bending parts of the cold roll forming machine in detail.
Plastic bending, like all plastic deformation, is accompanied by elastic deformation. When the bending deformation is over and the bending part of the cold roll forming machine is not affected by an external force, the elastic recovery makes the angle of the bending part and the radius of the fillet of the bending part inconsistent with the shape and size of the mold. This phenomenon is called the spring-back of the flexure.
Because the spring-back directly affects the dimensional tolerance and shape tolerance of the bending parts of the cold roll forming machine. When designing the mold, the spring-back value of the material is taken into account in advance, and the size and shape of the working part of the mold are corrected.
Due to many factors affecting the rebound, it is impossible to give accurate data whether it is theoretical calculation or empirical data. Therefore, after the data is generally given, it needs to be corrected in the trial mold, and then the correct die size is determined.
Bending parts have shape and size errors due to spring-back, and it is difficult to obtain qualified bending parts. Therefore, measures to reduce the springback are taken as follows.
1. The design of bending parts
Improve the design of the bending part to reduce the spring-back. It can be pressed and strengthened in the bending area to improve the rigidity of the bending part, suppress the occurrence of springback, or select materials with stable mechanical properties and small fluctuations in sheet thickness. Also try to avoid the selection of a excessive large bending radius.
2. The craftsmanship
Corrected bending is used instead of free bending, and the material hardened by the cold forming machine must be annealed before bending.