The working principle of the slitter

1. constant tension control principle


The essence of constant tension control in winding and unwinding process is to know the change of winding diameter when the load is running. Because of the change of winding diameter, in order to maintain the operation of the load, the output torque of the splitter motor needs to change with the change of winding diameter. For the V series inverter, because it can control the torque, it can control the constant tension of the winding. The V series inverters provide three analog input ports, AUI, AVI and ACI. The three-way analog input can be defined as a variety of functions, so one can be chosen as a given torque, and the other as a speed limit. 0-10V outputs rated torque of 0-motor to the inverter, so the constant tension can be controlled by adjusting the voltage of 0-10v. And Duyu slitting machine, the calculation of the coil diameter part is calculated by the tension controller, of course, the use of PLC architecture to achieve is also no problem. That is to say, the tension can be set on the man-machine or text, through the PLC calculation of coil diameter, T = F * D / 2, so you can calculate the need for motor output torque, through the analog output to the V series inverter torque given end can be.


2. synchronous speed calculation


Because we know that the frequency converter works at low frequency, the slitter AC asynchronous motor has poor characteristics, low activation torque and linearity, so in the whole process of winding, we should try to avoid the winding motor working below 2HZ. Therefore, the winding motor has a minimum speed limit. For the four-stage motor, the synchronous speed is calculated as follows: N1 = 30f1 / P = N1 = 1500r / min = 2HZ / 50HZ = N / 1500 = N = 60rpm / min


(F1 is rated frequency, P is polar logarithm, N1 is synchronous speed).


3. speed limit operation


When the maximum coil diameter is reached, the lowest speed can be obtained in the whole process.


V= PI *D*n/i=Vmin=3.14*1.2*60/9=25.12m/min


Tension control, the slitter to speed limits, otherwise there will be flying, so speed limit operation.


4. calculation of tension and torque


If F*D/2 = T/i (F-tension, D-coil diameter, T-torque, i-deceleration ratio), = F = 2*T*i/D for a 3.7KW AC motor, the rated torque is calculated as follows: T = 9550*P/n = T = 24.88N.m So Fmax = 2*24.88*9/0.6 = 74.64N (T-motor rated torque, P-motor rated power, n = motor rated speed)