Take a project of 3200/1200 lower threading and rewinding electric control system as an example
This system uses DC bus power supply. The system adopts RENLE inverter, Siemens PLC, KTP1200 touch screen to form a communication network. It is designed and manufactured accurately, high-speed, stable and efficient operation, high reliability, and convenient operation. The optimized design minimizes the auxiliary time and improves the reliability and reliability of the system. Sex. Rewinding efficiency is high, with automation functions such as automatic threading, automatic sleeve changing, automatic core feeding, automatic gluing, automatic clamping, roller feeding, and net cutting; the load of the roller and pressure roller adopts closed-loop control to achieve the pre-designed Pressure C. Guarantee the setting quality; closed loop control of paper web tension, automatic control of the torque of the two rollers, so that the inner and outer tension of the paper roll is uniform; it has powerful and complete safety functions, including various mechanical protection, interlocking protection, photoelectric, etc. RIC protection ensures the safety of operators and equipment.
1. Speed control
Based on the technological characteristics of the rewinder drive system, the speed control should be the master unit of the back roller and the others as slave units. The design adopts the control method of adjusting the variable ratio to realize the speed adjustment function of the slave unit. In addition, during the rewinding process of the rewinding machine, the speed change is required to be as stable as possible for starting, stopping with paper, speeding up, and slowing down, etc., and the flexible change characteristics of speed can be realized by setting the parameters of the device.
2. Load distribution control of front and rear bottom rollers
During normal operation, in order to obtain a consistent form of tightness inside and looseness outside the finished paper roll, the front and rear bottom rolls require load distribution control. According to the technological requirements of different paper types, different torque curves can be set on the man-machine interface of the console to detect the diameter of the finished paper roll, and the PLC participates in the automatic control of load distribution.
3. Unwinding constant tension control
The control of unwinding tension includes three aspects:
(1)Appropriate paper pulling force should be set when pulling paper to ensure a smooth transition of tension when unwinding. The paper attraction force can be set on the touch panel.
(2)During the acceleration and deceleration of the system, the unwinding tension will change due to the moment of inertia of the unwinding roller. The system should dynamically compensate the tension according to the size of the unwinding roll diameter and the acceleration and deceleration rates.
(3)In order to accurately and stably control the unwinding tension, a composite control combining tension compensation control and feedback control is applied.
4. Pressure control of platen roller
Different paper grades should have different pressure curves, which can be set on the touch screen. The PLC calculates the diameter of the finished paper during operation, and outputs the corresponding pressure signal, which is executed by the electro-hydraulic proportional valve.
5. Fixed length and fixed diameter parking function
The fixed-length length or the diameter of the finished product for fixed-diameter parking can be set on the touch screen. A certain reserved length and reserved diameter can be set according to the actual working conditions. The PLC detects and calculates and compares the actual length or diameter. When the value is reserved, control the speed of the rewinder to make it slow down and stop, and maintain the unwinding static tension after stopping
6. Control of auxiliary drive
Auxiliary transmission can be roughly divided into two categories, one is to control the speed according to the speed of the rewinder, and the circular knife is that. For this kind of control, their speed signal is given by PLC after proper calculation according to the speed value of the back bottom roller. The other type does not require speed control, such as fans and oil pumps. Their control does not require the participation of PLC.
7. Interlocking control of paper break
During normal operation, if a paper break is detected, the equipment will automatically stop, and the front and rear bottom rollers and paper delivery rollers will automatically brake in emergency.
8. Integrated electrical control
The mechanical, electrical, hydraulic, and pneumatic control of the rewinder form a whole. In order to obtain higher system stability and safety, some interlock protection detection switches are set up, and the interlock protection control is carried out by PLC according to the interlocking relationship between them.
9. Other controls
Emergency stop function: The main drive units of the front and rear bottom rollers and the paper delivery roller all adopt energy-consumption braking devices, which can realize emergency braking when an emergency stop is required, and at the same time start the pneumatic brake system to make the equipment realize the emergency stop function , To ensure that the system can stop as soon as possible when the paper breaks.
1. Automatic tension control rewinding of paper roll
The machine can establish the tension when the paper is threaded to ensure a smooth transition of the tension during the roll-up. During the running process, the paper force is kept constant through the measured tension control and indirect tension control. At the same time, dynamic inertia compensation is added during the speed increase and decrease process, which effectively guarantees the performance of automatic control of the paper web tension.
2. The front and rear bottom roller torque control
In order to ensure the consistency of the inner tightness and outer looseness of the finished paper roll, the tightness control is set on the KTP1200 panel of the console, and different torque differences can be set according to the technological requirements of various papers. Through the calculation of the diameter of the finished paper roll, the automatic torque difference is realized. control
3. Pressure roller pressure control
An electro-hydraulic proportional valve is added to the hydraulic operating system, and the diameter of the finished paper is calculated by PLC. Different curves can be set to control the proportional valve to achieve the purpose of automatic pressure control.
4. Round knife transmission control
(1) The speed follows the back bottom roller
(2) Current (torque) automatically adjusts the balance
(3) The speed signal follows the rear bottom roller and is higher than the rear bottom roller by a certain percentage.
5. Other controls and requirements
(1) Both the front and rear bottom rollers and the paper delivery roller have the quick stop function. An emergency stop button is installed on the operating table, and the quick stop button can be used to quickly brake to minimize the loss.
(2) Use the forward and reverse jog buttons on the on-site control panel to control when the paper is guided by the delivery roller.
After the paper breaks, the equipment will automatically stop, and the front and rear bottom rollers and the paper delivery roller will automatically brake in emergency
6. Description of hydraulic and pneumatic control
Party B only controls the hydraulic proportional valve, and other hydraulic and pneumatic controls are controlled by the machinery factory. Our company provides an air control console with reserved openings for air control components, which are provided by the user.
Main technical data of coiler
Net paper width: 3200mm
Threading method: Threading down
Paper weight: 80-140g/m
Paper web tension range: 0.5~1.5kg/cm
Maximum diameter of finished paper roll: 1500mm
Working speed: 1200m/min
Threading speed: 5~15m/min
Lifting time: 90s
Electric control form: AC motor drive