Rebound factors and control methods of stamping parts

From the development and manufacturing experience of various metal stamping dies, drawing dies are not easy to handle, because the material will flow, and the stamping springback problem can sometimes be a headache. There is no accurate and reliable springback calculation formula, which is generally based on experience. , Compensate for different materials and different R angles. So what are the factors that affect the springback of metal stamping parts? 1. Mechanical properties of stamping materials There are metal stamping parts with different strengths in automobiles, from ordinary steel plates to high-strength steel plates. Different plates have different yield strengths. The higher the yield strength of the plates, the easier it is to spring back, especially DP series dual-phase high-strength steel. 2. Stamping material thickness During the forming process, the thickness of the sheet material has a great influence on the bending performance. As the thickness of the sheet increases, the springback phenomenon gradually decreases. This is because as the thickness of the sheet increases, the plastic deformation material increases, the elastic recovery deformation also increases, and the springback becomes smaller. With the continuous improvement of the material strength of thick plate parts, the dimensional accuracy of the parts caused by springback is becoming more and more serious. Mold design and later process debugging need to have a certain understanding of the nature and size of springback in order to take corresponding countermeasures and Remedial plan. 3. The shape and complexity of stamping parts have different springbacks. Parts with complex shapes generally have an order of reshaping to prevent springback due to improper forming. Some parts with special shapes are more prone to springback. Phenomenon, such as U-shaped parts, in the analysis and forming process, springback compensation must be considered. 4. The blank holder force of the mold parts The blank holder force of the die part is an important process measure. By continuously optimizing the blank holder force, the flow direction of the material can be adjusted and the internal stress distribution of the material can be improved. The increase of blank holder force can make the part drawing more fully, especially the part side wall and the R angle position. If the forming is sufficient, the internal and external stress difference will be reduced, so that the springback will be reduced. 5. Mold drawbeads Mold drawbeads are widely used in today's technology. A reasonable setting of the drawing position can effectively change the material flow direction and effectively distribute the feed resistance on the pressing surface, thereby improving the material formability , Arranging drawbeads on the parts prone to springback will make the parts more fully formed, the stress distribution will be more uniform, and the springback will be reduced. How to control the springback of metal stamping parts? The time to reduce or eliminate the springback of stamping is in the product design and mold development stage. With the aid of the early CAE rebound analysis, the amount of rebound is accurately predicted, the product design and process are optimized, and the product shape, process and compensation are used to reduce the rebound. In the hardware mold debugging stage, the mold must be tested strictly in accordance with the guidance of process analysis. Compared with ordinary SE analysis, the workload of springback analysis and correction has increased by 30% to 50%, but it can greatly shorten the mold debugging cycle. Springback is closely related to the drawing process. Under different drawing conditions (tonnage, stroke, feed volume, etc.), although the stamping parts have no forming problems, the springback after trimming will be more obvious. Springback analysis and drawing forming analysis are used The same software, but the key is how to set the analysis parameters and effectively evaluate the rebound results. Related news: The characteristics of the main materials of stamping parts, the treatment of common problems of stamping parts, the characteristics of scaffolding stamping parts and the importance of inspections