How to reduce wire shrinkage in inverted wire drawing machine?
The inverted wire drawing machine effectively reduces the torsion problem of wire during the drawing process through its unique vertical structure and process design. The specific principles are as follows:
1. Vertical reel arrangement
Gravity-assisted orientation: The reels are arranged vertically (usually in an inverted tower), and the wire moves vertically from top to bottom. Gravity causes the wire to sag naturally, reducing the angle deviation during horizontal winding and avoiding the spiral twisting of the wire caused by the horizontal rotation of the reel.
Single-direction winding: The wire is usually wound in a fixed direction (such as clockwise or counterclockwise) on each reel. The vertical layout allows the rotation directions of adjacent reels to be opposite, thereby offsetting the torsional stress. For example, the first reel rotates clockwise and the second counterclockwise, and the torsion is balanced step by step.
2. Synchronous drive and tension control
Closed-loop control system: driven by servo motor or variable frequency motor, the speed of each reel is precisely synchronized to ensure constant tension of the wire during drawing. Speed differences can cause the wire to slip or over-pull, resulting in additional twisting, and synchronous control can eliminate this problem.
Dynamic tension feedback: real-time monitoring of wire tension, automatic adjustment of reel speed or brake pressure to keep the wire straight and avoid local twisting caused by tension fluctuations.
3. Short path and straight guide
Compact layout: The inverted design usually integrates the wire drawing die, annealing device and reel on the vertical axis, and the wire transmission path is shorter and close to a straight line. Compared with the multi-level horizontal turning of the horizontal equipment, the number of bends is reduced, thereby reducing the accumulation of torsion.
Guide wheel optimization: low-friction ceramic or alloy guide wheels are used to accurately guide the wire into the wire drawing die vertically, avoiding uneven force caused by deflection, and further reducing torsion.
4. Annealing and stress release
Online annealing treatment: Some inverted wire drawing machines are integrated with annealing devices. The wire is heat treated immediately after drawing to eliminate internal residual stress and prevent torsional rebound caused by cold working.
Natural cooling section: The vertical structure allows the wire to cool naturally in the air. The cooling uniformity is better than forced cooling, which reduces deformation caused by uneven thermal stress.
