Shape does not match size:

The main reason is caused by rebound and improper positioning. In addition to taking measures to reduce springback, it is also important to improve the reliability of blank positioning. The following two measures are usually used:

Compression of the blank: use an air cushion, rubber or spring to generate a compression force to compress the sheet before bending begins. To achieve this purpose, the ejection height of the pressing plate or pressing rod should be slightly higher than the plane of the die.

Reliable positioning method: there are two main ways of positioning the blank: shape-based and hole-based. Appearance The positioning operation is easy, but the positioning accuracy is poor. The hole positioning method is not very convenient to operate and has a narrow range of use, but the positioning is accurate and reliable. Under certain conditions, the shape is sometimes used for initial positioning to roughly control the blank within a certain range, and finally the hole position is used for final positioning, absorbing the advantages of both, so that the positioning is both accurate and easy to operate.