Springback Prediction of Free Bending Based on Experimental Method

The springback phenomenon has an impact on tube-processing quality during the free-bending process. For different pipe benders, the forming process is affected by different factors, such as gaps between the tube and the bending die and friction between the tube and the guiding mechanism and the bending die; thus, the theoretical U-R relationship cannot complete the precise processing required. In order to overcome the influence of springback during the free-bending forming process, a U-R experiment was performed first, and the actual U-R relationship was established. The U-R experiment demonstrated that when the bending die offset U increased, the tube-bending radius R decreased. Then, based on the results of the springback experiments, a springback prediction method was presented. The experimental method successfully predicted springback, demonstrating that the springback problem can be effectively solved through compensation of the arc section.