A study on the unfolding length of Z-bending machining using thin plate

박판을 이용한 Z-굽힘 가공의 전개 길이에 관한 연구

  • Park, Yong-Sun (Pistamco) ;
  • Choi, Kye-Kwang (Department of Metal Mold & Die Engineering, Kongju National University)
  • 박용순 (피스템코) ;
  • 최계광 (공주대학교 금형설계공학과)
  • Received : 2021.09.09
  • Accepted : 2021.09.30
  • Published : 2021.09.30


The bending process of a press die is to bend a flat blank to the required angle. There are V-bending, U-bending, Z-bending, O-bending etc. for bending processing, and the basic principle of calculating the unfolding length of die processing is used as the neutral plane length. Since the constant of the length value of the neutral surface is different depending on the type of bending, it is impossible to accurately calculate it. In particular, Z-bending processing is performed twice, and it is set on the upper and lower surfaces of the blank, and bending processing occurs at the same time as the upward and downward bending, and the elongation of the material occurs and the material increases. It is not possible to check with the calculated value, and it occurs in many cases where the mold is modified after start-up. This study aims to minimize die modification by developing a formula to calculate the development length of Z-bend.