High-accuracy V-bending system by real time identifying material property

A bending system was proposed in order to realize high precision V-bending. This system can calculate the appropriate bending condition during work progress and its calculation algorithm is satisfactorily time-efficient for a practical use. The essential point of this system is that the work-piece is released once just before the punch reaches the final target position. Using this method the system can collect the data, calculate material properties and predict the final target position. This position is determined by considering the spring-back after release. However, the spring-back is not constant due to the differences of material properties between each work-piece. In the proposed system, the material properties: flow stress, Young's modulus and hardening ratio were calculated based on information of load, tilt angle of plate and spring-back at the pre-release phase for determination of appropriate bending conditions. The proposed bending system can realize high-precision bending and has successfully been adopted in actual operation.