Comparison of Bending Mechanism and Spring-Back Feature Between 90-Degree L-Bending and 90-Degree V-Bending

摘要

To fabricate the 90-degree bent parts, the 90-degree L-bending and 90-degree V-bending processes are widely used. Owing to an increase in precision requirements on these bent parts in recent years, therefore, the suitable selection to use the 90-degree L-bending and 90-degree V-bending processes are strongly considered. In this study, using the finite element method (FEM) and laboratory experiments, the 90-degree L-bending and 90-degree V-bending mechanism and their spring-back/spring-go feature were clearly identified based on the stress distribution analysis. The results revealed that the reversed bending characteristic rarely generated in the leg of the work piece in case of the 90-degree L-bending. In contrast, the reversed bending characteristic generated in the leg of the work piece in case of the 90-degree V-bending. This resulted in the spring-back feature in case of the 90-degree L-bending was larger comparing with that in case of the 90-degree V-bending. The application of small die radius caused the higher risk of producing scratches or otherwise damaging the work piece in case of the 90-degree L-bending. In contrast, in case of the 90-degree V-bending, the application of large punch radius caused the higher risk of producing spring-go feature. The FEM simulation results showed a good agreement with the experimental results with reference to the bending forces and bending angles.