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an Introduction
With the rapid development of automobile industry, the demand for car tires rapid growth. Meanwhile, the rapid development of China's highway, the car speed has greatly improved, which tires the car a higher quality requirements. The steel line as an important part of the tire, the tire's strength plays an important role. Steel line directly affect the quality of tire quality, quality, grade. As a major steel production line equipment straight wire-drawing machine, applications are more and more widely. Early straight wire-drawing machines, mainly in the import-based, including Germany, Italy, South Korea imported drawing machine-based, these systems are DC converter, but also AC variable speed control. Now these devices in some large steel production plant is still on-line application. In recent years, as domestic machinery processing capability, and automatic control technology, straight wire-drawing machine is basically localized. In Jiangyin, Jingjiang and other places several drawing machine manufacturer, have to produce AC frequency synchronous speed straight wire-drawing machine. In these devices, some applications of the imported frequency converter, such as: Danfoss, ABB, in order, and also some home-made converter application, such as: easy to drive and so on.
this application case is easy to drive ED5000 inverter in Jiangyin production of straight wire-drawing machine with matching case.
two straight wire-drawing machine working Principle
straight wire-drawing machine is composed of a small number of drawing the first continuous production equipment, through the drawing step by step, can one pulled the wire to the required specifications of the cold, so the efficiency is relatively high. However, after drawing through each level, a change in wire diameter, so each drawing should also be the first working line speed changes.
based die configuration, head of the drawing speed of each drawing should be changed. Drawing speed of the base of each moment of the second wire through the die of the same traffic volume, even if the formula was established:
πR2 × V1 = πr2 × V2
which R: Line wire diameter
V1: Line wire speed
r: wire diameter outlet
V2: outlet wire speed
straight wire-drawing machine operating speed of each drawing is the first formula above, to ensure synchronous operation of each drawing head. However, the above description is based on the ideal state of steady-state process, due to mechanical error as well as mechanical drive transmission gap, as well as at the start, acceleration, deceleration, stop work and other dynamic process, the head of each drawing will not be able to maintain synchronization, so now most of the straight wire-drawing machine has a tension sensor, dynamic measurement of head of each drawing the tension between the wire, then strain into a standard signal (0 ~ 20mA or 0 ~ 10V), using the standard signal back to the speed drive, the drive signal for closed-loop PID with the process control, superimposed on the main speed of adjustment of the PID calculation on the amount of tension to keep each test point constant tension, will also ensure the straight wire-drawing machine work in synchronization state of constant tension of the work.
According to the above description, straight wire-drawing machine made for high frequency performance requirements. Inverter should have the following performance.
1, low starting torque, strong overload capacity, speed and high precision
2, there are built-in PID function, PID parameters rich
3, fast dynamic response
Therefore, we chose ED5000 high-performance current vector frequency as a straight wire-drawing machine drives, frequency converter in the actual use of the also satisfy the requirements of the drawing machine, fast response, starting torque, strong overload capacity, speed control in vector control accuracy of 0.2% (without PG), a built-in PID, PID parameters, including an PID gain, limit amplitude, offset and so on.
three configurations and shows
straight wire-drawing machine's electrical system configuration shown below, includes the following sections: Touch-screen - Siemens TP270, 10 ' true color, programmable logic controller (PLC) - Siemens S7-315-2DP, with Profibus fieldbus interface converter - easy to drive high-performance current vector frequency ED5000, built-in PID, the sensor - Turck linear sensor, 0 ~ 10V, or 4 ~ 20mA. Touch screen and PLC via the MPI bus connection, PLC and inverter via the Profibus field bus connection between to form a high-speed fieldbus network, data transmission rates up to 1.5M, which greatly improved the speed of response of the drive to improve the synchronization accuracy, Basically, when you continue to do wire work. This is very effective in improving work efficiency.
navigation system is the speed of a drawing by the last drive of the decision, according to each channel die compression ratio and reduction ratio calculated every other machine in the main for a given speed, due to mechanical error and die wear, making the given parameters and actual values ??have some differences, the difference will be corrected by the tension arm. In fact, the tension arm connected to a position below the sensor, the sensor measures the tension arm of the rotation angle, output a 0 ~ 10V analog signal to the inverter, the inverter according to the position set value (a relative with 10V percentage of value), through the PID calculation, the output frequency superimposed on a correction amount, eliminate the differences.
system, the touch screen as an interface, plays a role in human-machine interfaces, each die of the compression ratio is through the touch screen input, and, touch screen can store several different sets of parameters die, die sets to facilitate rapid selection of parameters, without having to enter the parameters each time, convenient for users to improve efficiency. Touch screen also displays the work of the Road die actual operating parameters, including voltage, current, speed, etc., an alarm system, touch-screen display system failure timely content, user-friendly and timely diagnosis, rule out some simple failure. Touch screen and PLC are connected via MPI, the rate of: 187.5K.
PLC is the control center of the whole system, controls the whole system workflow. Through the button operation, the control linkage of each machine before and after linkage, jog and jog the entire system, automatic operation. Based touch screen input parameters die compression ratio, calculated for each machine synchronous speed and bus transfer to the inverter via Profibus, directly driven by the drive motor machine work. PLC through Profibus bus, read from the drive inverter operating parameters of the inverter to handle a variety of unusual work, and promptly through the touch screen display.
4 Conclusion
the inverter on the straight wire-drawing machine to use for some time, the customer equipment running smoothly, start, stop, accelerate, decelerate smoothly stability, synchronization and high precision, starting current, low noise, has been a widely recognized end-use customers. |
