Application of VEICHI AC310, AC200-L frequency converter on wire drawing machine

프로젝트 개요

Preface

The wire drawing machine is also called the wire drawing machine. Wire drawing machines are widely used mechanical equipment in industrial applications, which are used in machinery manufacturing, hardware processing, petrochemicals, plastics, bamboo and wood products, wire and cable industries

Wire drawing machines can be divided into metal wire drawing machines (used for the pre-processing of metal products such as standard parts) and plastic wire drawing machines (used in the plastic products industry for polyester, nylon, polyethylene, polypropylene, polyester chips, etc.). A complete set of equipment for deep processing of various hollow, solid round yarns or flat yarns from raw materials), Bamboo and wood wire drawing machine (special equipment used for making chopsticks, toothpicks, barbecue sticks, etc. in the bamboo and wood products industry to pull out bamboo silk and wood silk for reprocessing), etc.

Wire drawing machine can be divided into straight type, water tank type, etc. according to the drawing method, and can be divided into a large drawing machine, middle drawing machine, fine drawing machine, and micro drawing machine according to the wire diameter. The line consists of two parts. To increase the output, quality, and reduce the cost of the cable, the wire drawing machine is generally changed to double frequency conversion or multi-frequency conversion constant tension control. At present, most frequency conversion synchronous control generally adopts the control method of an external PID controller. The disadvantages of this method are: the control parameters of the PID controller are difficult to debug, expensive, and easily damaged. The analog quantity has attenuation and drifts during the transmission process, and the maintenance and maintenance costs are high. The use of the wire drawing machine inverter is convenient to operate, simple to debug, and economical, which is a trend in the use of the wire drawing machine. At present, VEICHI wire drawing machine inverters sell well all over the country, and the reputation is good and has been well received by various manufacturers in the field of wire drawing machines.

Introduction and working principle of wire drawing machine

Brief introduction of straight wire drawing machine

The straight wire drawing machine is small continuous production equipment composed of multiple drawing heads. Through drawing step by step, the steel wire can be cold drawn to the required specifications at one time, so the work efficiency is relatively high. However, since the wire diameter of the steel wire has changed after each level of drawing, the working line speed of each drawing head should also be changed. Features: multiple drawing heads, multiple frequency conversions, and multiple PID adjustments

Principle of straight wire drawing machine

1. The working principle of the straight wire drawing machine is to control the metal flow of each reel to be equal at all times.
2. The abrasion of the wire drawing die, the fluctuation of the motor speed, and the disturbance of the uneven steel wire thickness are detected by the displacement sensor, and the PID algorithm is used as the speed compensation.
3. The speed of the last reel is used as the main setting, and the setting of other reels is calculated through the reduction ratio and the transmission ratio.

Brief introduction of water tank type wire drawing machine

The water tank wire drawing machine is also called a wet wire drawing machine. The drawing process is carried out in a water tank, which can effectively dissipate the heat generated by the wire drawing and the wire sliding on the reel. It is suitable for the production of small-sized steel wires.

Working principle of water tank type wire drawing machine

1. The main engine drags the tower wheel, enters and exits through the large mouth of the mold, and completes the process of thinning the thick line.
2. The tension is converted into a 0-10V electrical signal through the potentiometer connected with the tension rod.
3. The winding frequency conversion comes with a winding diameter calculation function, that is, as more and more windings are taken up, the winding speed is automatically reduced, and PID calculation is performed in combination with the tension feedback voltage to keep the winding tension constant.

Schematic diagram of wire drawing machine system scheme 

Wire drawing machine inverter process requirements

1. Super low-frequency torque, fast dynamic response characteristics, super stable steady-state accuracy, no jitter, or tremor.
2. All the tension control algorithms are integrated into the frequency converter, and the characteristic functions of the wire drawing machine are integrated into the frequency converter at the same time. All the control functions of the complex wire drawing machine can be realized without the need for peripheral control circuits.
3. When the main engine is started and stopped, disconnection is never allowed. If there is a disconnection fault, it should promptly report to the police and stop the emergency.
4. The operation is stable. During normal operation, the swing rod is not allowed to collide with the upper and lower limits, and the drawing flow rate of each stage can be maintained at the same time.
5. When stopping, keep the synchronous and continuous line, keep the proportional relationship of each level line speed at all times.
6. The frequency converter integrates multiple sets of special parameters for the wire drawing machine, and the corresponding parameters are directly called without the customer to set the parameters one by one.

Features of AC310, AC200-L wire drawing machine inverter

1. Unique automatic calculation function of coil diameter coefficient

With the continuous increase of the winding diameter of the winding machine, the output frequency of the winding machine needs to be continuously reduced. The AC310 and AC200-L series inverters are specially equipped with a winding diameter calculation function, which dynamically, in real-time, and automatically calculates the current winding diameter of the winding machine to achieve the best constant tension winding effect.

2. Coil diameter coefficient K1 increment

During operation, when the tension balance bar deviates from the center position, the automatic calculation function of the coil diameter coefficient K1 is turned on. To ensure the stability of the tension at different speeds of the high, medium, and low speeds, different position deviations of the pendulum rod correspond to different increments of the coil diameter coefficient K1. Different systems have different rates of change of the coil diameter. The accurate calculation of the coil diameter can be achieved by adjusting the K1 increment.

3. Powerful roll diameter calculation method

To ensure the smooth operation of the winding machine near the center of the swing rod, the automatic calculation of the winding diameter is an important function. There are two automatic calculation methods for coil diameter in AC310 and AC200-L: linear velocity method and thickness integral method. To ensure the performance of tension control is more perfect.

4. Roll diameter reset (manual/automatic)

Under the same line speed, the output frequency of the take-up machine at the full diameter and empty diameter is very different. To synchronize the line speed of the take-up machine and the host, the take-up machine needs to reset the coil diameter when changing the coil. When the roll diameter automatic reset function is used, the roll diameter coefficient K1 is automatically reset after each shutdown. After a power failure or emergency stop, the manual roll diameter reset function should be used, that is, the external multi-function terminal is defined as the roll diameter reset terminal.

5. Friction compensation

Built-in static friction compensation and sliding friction compensation modules to ensure work against friction and make the system effect more perfect.

Recommended wiring method

The following wiring method takes AC200-L as an example.

1. The inching switch is connected to the X3 terminal of the host (factory value is inching forward)
2. The external terminal start switch is connected to the host X1.
3. The wire drawing speed potentiometer is connected to +10V, VS1, and GND of the wire drawing machine (host).
4. The analog output AO1 terminal and GND terminal of the host are connected to the VS terminal and GND terminal of the take-up machine.
5. Short-circuit the jumper terminal J2 on the control board.
6. The potentiometer of the tension rod is connected to the +10V, AI, and GND terminals of the AC200-L series inverter.

The recommended wiring is shown below:

After the feedback value of the tension, the balance bar is connected with the AC200-L series wire drawing machine special inverter as shown in the figure above, move the tension bar in the direction in which the tension bar swings when the wire is taken up by the take-up machine, and monitor the PID feedback signal (C-09) at the same time. The value should change from small to large, generally 0.0% to 100.0%. If it is not within this range, you need to change the position of the tension potentiometer so that the center point is about 50.0%, and the tension potentiometer should be a 360° high-precision potentiometer; if an electrical adjustment is troublesome, you can also directly lift the tension rod to Take-up tension to ensure the physical middle height position, and then set the potentiometer feedback value at 50.0%. This setting method is designed to ensure that after the tension deviates, both the positive deviation and the negative deviation can obtain the same positional deviation buffer energy through the tension rod.

Recommended parameters of wire drawing machine (AC200-L)

Recommended parameters of water tank type double frequency conversion host (wire drawing machine)

Recommended parameters of water tank type double frequency conversion take-up machine

Note: The above-recommended parameter values may not be suitable for some special working conditions, and should be adjusted according to site conditions during use.

Inverter debugging

Mainframe and take-up machine wiring

The output frequency of the host inverter is connected through the programmable analog output port A01, GND terminal, and the current input port AS, GND of the take-up inverter. The output frequency of the host inverter is used as the feed-forward frequency of the take-up machine, and it works together with the PID adjustment value calculated inside the take-up machine to ensure a constant tension of the take-up and take-up line.

Take-up machine feedback wiring

The three ends of the tension balance bar potentiometer are connected to the +10V, AI, and GND of the take-up frequency converter, and set [F3.06] and [F3.08] respectively according to the highest position feedback voltage and the lowest position feedback voltage of the pendulum rod. It can ensure that the PID feedback value is 50% when the swing lever is in the middle position. The tension feedback potentiometer should be a 360° high precision potentiometer.

Braking resistor wiring

To ensure the constant tension of the winding and unwinding, the frequency converter of the take-up machine needs to accelerate and decelerate in a short time. When the speed is decelerated, the linear voltage of the frequency converter will increase. To ensure the normal operation of the frequency converter, an external brake is required resistance. For the resistance and power of the braking resistor, please refer to the AC200 series inverter manual. The braking resistor is connected to the (+) and PB of the AC200-L series special inverter for wire drawing machines.

Disconnection detection function

When the tension feedback value is less than the lower limit of PID wire break detection [FF.20] or exceeds the upper limit of PID wire break detection [FF.21] and continues for the time set by [FF.24], the inverter will switch from [FF. 25] Choose the way to deal with it accordingly. The lower limit of wire break alarm [FF.20]: Set the lower limit of PID wire break detection of the wire drawing machine. After the feedback signal is less than the lower limit of the wire break alarm and continues [FF.24] after the wire break detection judgment delay, it is considered that the wire drawing machine is broken. The upper limit of wire break alarm [FF.21]: Set the upper limit of PID wire break detection of the wire drawing machine. After the feedback signal exceeds the upper limit of the wire break alarm and continues [FF.24] after the wire break detection judgment delay, the wire drawing machine is considered to be broken. Disconnection detection judgment delay [FF.24]: To avoid disconnection false alarm.

When the system detects the disconnection, the disconnection fault will be reported after the disconnection detection judgment delay time. Action mode of disconnection fault: 0, free stop and alarm; 1. only disconnection fault terminal will act. When the inverter detects disconnection, it will continue to run. At the same time, if the multi-function output terminal is set as disconnected output, it will immediately output a valid signal.

To avoid false alarms during the start or stop, you can set the inverter to start and run for more than [FF.22] set time, and the inverter output frequency is higher than [FF.23] set frequency, then open the disconnection detection function.

When the disconnection is detected, the inverter will stop freely and report the "E.PID" fault. If [FF.25] is set to 1, the disconnection fault will be automatically reset after the time set in [FF.27].

Brake control

When the slave machine stops, the brake signal (output from the selected output terminal) will be output, and the output will stop immediately after the time set in [FF.29]. During the output of the brake signal, if the running command is valid, the brake will be stopped immediately.