Metal products are a key area in the metallurgical industry. In the process of metal processing, pulley wire drawing machines are a common equipment, widely used in wire drawing operations in the fields of steel wire, steel cable, iron wire, metal mesh and nail making. In the past, these devices were mostly operated by industrial frequency speed regulation, but now with the advancement of production process technology and the popularization of Inverters, Variable frequency control technology has been gradually introduced, realizing step less speed regulation function, while supporting corresponding logic control and tension I-wheel winding and other operations.
The use of variable frequency speed regulation system has significant technical advantages and energy-saving effects. Taking the pulley wire drawing machine of a certain iron wire production enterprise as an example, this article will introduce the application process of variable frequency control and its actual effects.
The pulley wire drawing machine is mainly composed of key components such as the main reduction box, die box, pulley frame, wire drawing frame and electrical control system. The core is to apply continuous and uniform tension to the metal wire through the precise coordination of multiple pulley groups, so as to achieve the wire drawing operation. In this process, the motor drives the cylindrical gears with different speed ratios through the gear coupling to reduce the speed and make the reel rotate. The inner wall of the reel is equipped with a cooling water spray device to effectively reduce the heat generated during the drawing process and protect the wire and the die from high temperature damage.
Traction device: Responsible for feeding the wire to be processed into the pulley system. Usually an automatic wire feeding mechanism is used, which can adjust the wire feeding speed and tension as needed to ensure that the wire maintains a stable feed rate during the processing.
Pulley system: This is the core part of the pulley wire drawing machine, which is composed of multiple pulleys of different diameters. By changing the combination of pulleys, wires of different specifications can be processed. The pulley surface has been specially treated with high wear resistance and low friction coefficient, which can reduce the wear and energy loss of the wire during the drawing process.
Pulling force generating device: The pulling force is usually transmitted to the pulley block by the motor through the reducer and the transmission shaft to generate sufficient pulling force. In some designs, hydraulic or pneumatic systems may also be used to provide pulling force.
Tension control device: In order to ensure the stability of the drawing process and the quality of the wire, the wire drawing machine is usually equipped with a tension control device. These devices can be springs, cylinders, etc., which are used to adjust and maintain the tension of the wire during the drawing process.
Wire Take-up Device: Located at the end of the wire drawing machine, it is used to wind the drawn fine wire into a reel. The wire take-up device includes components such as a take-up wheel, a brake, and a meter to ensure that the wire is neatly wound on the take-up reel.
Lubrication system: In order to reduce friction and wear during the drawing process, the wire drawing machine is usually equipped with a lubrication system to reduce the friction coefficient and extend the service life of the pulley.
The wire drawing part of the pulley wire drawing machine includes 5 drums. Pulleys for accumulating and releasing wires are arranged between adjacent drums. The tension between the drums at the front and rear stages can be automatically adjusted to ensure the stable operation of the whole system. The winding motor rewinds through the I-shaped wheel, and the winding speed is adjusted by the tension swing arm between the drawing end and the winding. The system adopts PID control, which can compensate the speed difference caused by the change of the winding diameter in real time, so as to achieve a constant tension winding effect.
The main technical requirements of the equipment include:
Each speed can be set independently by potentiometer
Equipment at each level can be started individually or as a whole
The system has total stop and emergency stop functions
After the previous equipment stops, the subsequent equipment must also stop
The winding process can achieve constant tension
The acceleration and deceleration process is smooth, without abnormal fluctuations
These technical requirements ensure the efficient and stable operation of the equipment during the production process, and significantly improve the production efficiency and product quality of metal products.
In view of the process characteristics of the sliding wire drawing machine, the FR500A series vector control inverter is used. Compared with ordinary V/F control inverters, vector control inverters have faster response speed when the load changes, which can meet the needs of high dynamic performance in industrial automation.
Main drawing: using FR500A series general inverter, with the advantages of large output torque and high cost performance;
Winding: using FR510A series high-performance vector inverter to achieve tension winding function;
The drawing part of this device directly gives the frequency to the inverter through an analog potentiometer, and adjusts it by combining the mechanical accumulator and decumulator function, thereby effectively maintaining tension. The winding part uses a high-performance vector inverter with dual-channel frequency control, and compensates for the speed deviation caused by the change in roll diameter through PID regulation, ensuring tension control during the winding process. The main technical features of this device include: each stage's speed can be independently set through an analog potentiometer, supporting single-stage or overall startup, with total stop and emergency stop functions, and the ability to achieve interlock control for the front and rear stages' shutdown, ensuring the stability and safety of the production process.
Each unit can be started and stopped separately. If the system reaches the start-stop position, the first unit will start first. Only after the first unit starts, the second unit will start. After the second unit starts, the third unit will start, and so on. When the system stops, after the first unit stops, all the others will stop.
Connect cables according to the system wiring diagram, and check the power wiring part of the inverter, and power on after the check.
(1) Motor parameter self-learning
Set according to the actual motor parameters and start the motor static self-learning;
(2) After the motor parameter learning is completed, set the parameters according to the above debugging parameters;
Enter the debugging after the above debugging work is ready
Adjust the maximum and minimum values of the cylinder swing arm sensor. The larger the range, the higher the adjustment accuracy and the better the adjustment effect.
After the cylinder swing arm calibration is completed, before threading, jog from the first to the last unit to check whether the brake device and pulley of each unit are installed;
In this solution, the FR500A universal high-cost-effective inverter in the drawing part has very smooth start and stop after system parameter optimization, stable operation and greatly reduced wire breakage rate. Compared with the industrial frequency drive system, the efficiency and power saving rate are also greatly improved. In addition, the electrical components in this system are concisely configured, the logic is clear, and it is easy to check for faults, which fully meets the process requirements of the new pulley wire drawing machine and has been well received by customers.
