Straight Wire Drawing Machine Working Principle
A small continuous production equipment consisting of multiple drawing heads can cold-draw the steel wire to the required specifications at one time through step-by-step drawing, so the work efficiency is relatively high. However, since the wire diameter of the steel wire changes after each stage of drawing, the working line speed of each drawing head should also change.
Depending on the configuration of the drawing die, the drawing speed of each drawing head will also change. The basis of the drawing speed is that the volume of the steel wire passing through the drawing die at each moment remains unchange
That is, the following formula holds:πr2 xv1= πr2xv2
r: diameter of incoming wire
v1: linear speed of incoming wire
r:diameter of outgoing wire
v2: linear speed of outgoing wire
The working speed of each drawing head of the linear wire drawing machine is based on the above formula to ensure that each drawing head runs synchronously. However, the above description is based on the ideal steady-state working process. Due to the error and gap of mechanical transmission, as well as in the dynamic working process such as starting, accelerating, decelerating, and stopping, each drawing head cannot keep in sync. Therefore, most of the straight-line wire drawing machines now have tension sensors to dynamically measure the tension of the steel wire between each drawing head, and then convert the tension into a standard signal, which is fed back to the speed inverter with this standard signal. The inverter uses this signal for closed-loop PID process control, superimposes the adjustment amount calculated by PID on the main speed, keeps the tension of each tension detection point constant, and ensures straight-line wire drawing.
