Design of Multi-Head Wire Drawing Die

1. Entrance Zone Design:

  1）. The entrance zone mainly serves to guide the metal wire to smoothly enter the die. Its shape is usually a bell mouth, with an angle generally between 60° and 90°. For example, when drawing copper wire, the entrance angle can be set at around 70°, which can reduce the resistance when the wire enters the die.

  2）. The length of the entrance zone is usually determined based on the wire diameter and the overall size of the die, generally 1 to 2 times the wire diameter. The surface roughness of the entrance zone is relatively low, typically Ra 0.8 - 1.6μm, to prevent scratching the wire.

2. Lubrication Zone Design:

  1）. The lubrication zone is designed to form a lubricating film on the surface of the wire, reducing the friction during the drawing process. The length of the lubrication zone is generally 3 to 5 times the die diameter.

  2）. The structure of the lubrication zone can be in the form of annular grooves or helical grooves. The width and depth of the annular grooves are generally between 0.2 and 0.5mm, and the pitch of the helical grooves can be designed according to the drawing speed and lubrication requirements, generally between 1 and 3mm.

3. Compression Zone Design:

  1）. The compression zone is the core part of the die, determining the degree of deformation and dimensional accuracy of the wire. The length of the working zone is determined based on the drawing ratio and the material of the wire. The larger the drawing ratio, the longer the working zone length relatively.

  2）. The shape of the compression zone is generally conical, with a cone angle usually between 3° and 12°. For harder metal wires, the cone angle can be appropriately reduced to avoid wire breakage. The diameter accuracy of the working zone is very high, with a tolerance generally controlled within ±0.005mm.

4. Diameter Control Zone Design:

  1）. The diameter control zone is mainly for precisely controlling the final size of the wire. The length of the diameter control zone is generally 0.5 to 1 times the wire diameter.

  2）. The diameter tolerance of the diameter control zone is extremely strict, generally within ±0.002mm, to ensure uniform and consistent wire size after drawing.

5. Pressure Relief Exit Zone Design:

  1）. The pressure relief exit zone is designed to allow the drawn wire to smoothly exit the die. The shape of the exit zone is a bell mouth, with an angle generally between 30° and 60°, and a length of 0.5 to 1 times the wire diameter.