With the deepening of reform and opening up, China has successively introduced wire drawing dies and corresponding die hole testing instruments manufactured by industrialized countries. Analyzing the die hole patterns of foreign wire drawing dies has given us insight into the design concepts of modern wire drawing dies, providing a reference for improving the design level of wire drawing dies in China.
The structure of the wire drawing die core can be divided into five sections according to its working nature: the entrance zone, lubrication zone, working zone, sizing zone, and exit zone. The inner diameter profile of the wire drawing die is very important, as it determines the tensile force required to compress the wire and affects the residual stress in the drawn wire. The functions of each section of the die core are as follows: the entrance zone facilitates wire threading and prevents the wire from scratching the die from the entrance direction; the lubrication zone facilitates the introduction of lubricant into the wire; the working zone is the main part of the die hole, where the deformation process of the wire takes place, reducing the original cross-section to the required cross-sectional size.
When drawing conical metal, the space occupied by the volume of metal in the working zone is a frustum, which is called the deformation zone. The cone half-angle α (also known as the die hole half-angle) in the working area is mainly used to determine the magnitude of the drawing force; the sizing area is used to obtain the accurate size of the drawn steel wire; the exit area is used to prevent the steel wire from being scratched due to uneven exit.
