In the wire and cable industry, many technological processes are from the beginning of paying off to the end of taking up. How to overcome the uneven tension in the process of paying off is an urgent problem for many equipment design engineers and product control engineers. In the past electrical design process, electrical design engineers often use PLC a / D, D / a module, tension control process PCB board, read up the potential of the tension pendulum potentiometer to get the required pay off speed. This method to keep the tension constant, because in general, the signal line of the tension pendulum potentiometer and the module sent from D / a module to control the speed of the inverter are adopted It is easy to cause signal distortion if the pseudo signal line is too long. In addition, the take-up wheel with different shaft diameter corresponds to different PID internal adjustment parameters of PLC. If the PID setting is not appropriate, it is easy to make the pay off wheel under electrical control in an unstable state, and finally make the tension difficult to be constant, thus affecting the product quality.
technological requirements
As the most front-end of a variety of equipment, power pay off rack is widely used in the cable industry. Generally speaking, the requirements for power pay off rack are as follows:
1. In the cable manufacturing industry, all the processed wires should be rolled up neatly with wire reel.
2. In the process of starting, stopping and normal processing of processing machinery, the linear speed of wire rod is changing, and the winding diameter is also changing. Therefore, the linear speed of winding machine must be consistent with that of processing machine.
3. When unwinding, the unwinder must automatically track the linear speed of the processing machine, and automatically adjust the speed according to the winding to keep consistent with the processing speed.
4. The setting out speed can automatically track the drawing speed, the take-up speed can automatically track the processing line speed, and it can automatically reverse when the line is loose, and it can stop when the line is broken.
5. In the process of take-up and pay off, keep the tension of wire constant.
6. When the stable operation is at a certain speed, the swing rod of the pay off frame should be stable.
VL6100 special frequency converter is the only domestic frequency converter with this function. Its excellent control performance and good reliability ensure the superior performance of Tianlang Weichuang inverter in the cable industry.
Control of pay off wheel and take-up wheel
The pay off speed of the pay off wheel depends on the take-up speed of the take-up wheel. Since the take-up wheel always has a process of starting and decelerating, it gives the pay off wheel an unsteady speed. At the same time, due to the change of wire and cable on the wire wheel, the wire speed is also constantly changing at a certain speed. The take-up tension directly affects the quality of the product. If the tension is too large, the take-up is too tight, and the small diameter wire is easy to deform or break the inner core. If the tension is too small, the take-up wheel will produce axial sliding and dislocation on the winding core when taking-up, resulting in irregular take-up. All of these require the pay off wheel to adjust its speed according to the balance position of the tension pendulum.
Schematic diagram of take-up and pay off frame
system configuration
1. A special frequency converter for vl6100 power take-up and take-off line, with built-in brake unit and brake resistor added according to motor power.
2. Other accessories: Tension potentiometer, fixed pulley, movable pulley, stop magnetic switch, etc.
Equipment features:
1. The full sense of the fool type power take-up and pay off special-purpose inverter; only need the correct wiring, do not need to set the function parameters of the frequency converter, start can work normally.
2. It can automatically identify the speed and direction of take-up and pay off, and automatically track the line speed of take-up and pay out. The tension balance bar is basically maintained at the middle point of the power take-up and pay off frame.
3. No matter big plate, small plate, thick line, thin line, high speed and low speed, the tension is always constant.
4. Only one winding wheel can simplify the mechanical structure and save the equipment cost.
5. Built in upper and lower limit detection function, without travel switch.
6. Equipment debugging is simple: just adjust the position of the tension detection potentiometer correctly, start up can automatically track the speed of the lead, without other external signal control, directly form an independent whole.
