Summary

Craftsman G500 series inverters help Jinzhou a wire drawing machine on-site production of two production lines, one 22kw, eight 18.5kw, one 15kw, precise control, energy saving and efficiency.

introduction

The wire drawing machine is an important equipment for the production of metal wire, mainly for drawing metal wire into various specifications of filament. From the product specifications can be divided into: large pull machine, medium pull machine, small pull machine and fine pull. From the mechanical structure can be divided into: pulley type, loop type, water tank type and straight type. In the wire and cable industry, dual-conversion fine-pull applications are widely used. Relatively speaking, the required control performance is also low, and for most steel wire manufacturers, the precision requirements and the drawing stability are high for the material properties, so there are many straight-through wire drawing machines. In particular, welding consumables manufacturers, gas shielded welding wire, submerged arc welding wire, aluminum welding wire, argon arc welding wire, stainless steel welding wire, high strength welding wire and the most advanced flux cored wire have high requirements for electrical control of wire drawing machine. As the main electrical control part, the performance of the frequency converter, especially the precision of the tension control, directly affects the quality and output of the product.

First, the process needs

1, wearing a mold

Before starting the whole machine, the front end of the raw material must be manually polished and passed through the mold step by step. At the scene, the motor is usually driven by the foot switch to achieve low-speed rotation. At the same time, the wire is pulled from the front end of the mold to the rear end by the tool. The thread passing through the mold is first to be ground or pulled in order to pass the next mold. Fine, before you can pass the next level of mold. In this process, the motor is required to have a large and stable torque at start-up and low-speed operation, the running speed is stable, and the motor is not reversed during the deceleration stop.

2, drawing

After the mold is finished by hand, the whole machine can be run to achieve continuous stretching. The straight-through wire drawing machine is usually controlled by a plurality of motors, and after a plurality of drawing dies, the raw materials are pulled to the finished product of the required wire diameter at one time. In this process, the motor is required to respond quickly, the tension of the wire is constant, the tension of the tension balance bar is small, and the wire is not loose.

3, winding up

The winding part is driven by a separate motor, and the stretched finished product needs to be wound on the spool in synchronization. As the wire wound on the spool is thicker and thicker, the motor speed is correspondingly slower. When the thickness of the winding reaches the set value, the system provides automatic detection and shutdown. In the whole process, whether it is start acceleration, stop deceleration or stable constant speed, the line speed of the winding motor and the front end motor is required to be synchronized, and the wire is not loose, requiring the winding motor to respond quickly and speed. Control is precise.

4, cable

Usually, the finished wire is layered on the spool. On the horizontal axis of the spool, the wires should be arranged in parallel and tightly one turn. In this process, a wire arranging device is required to complete the alignment of the wire at the upper end to the lower end of the horizontal axis. The speed at which the wire arranging device reciprocates can be constant speed or controlled according to the speed of the winding motor. According to the requirements of mechanical design, there are many ways to realize the cable, such as mechanical and frequency conversion.

Second, the system solution

1, emergency stop brake

During the operation of the equipment, if an emergency occurs, the entire equipment is required to stop quickly. The process requires that the wire will not be pulled off after the shutdown process, so that the next time it can be started smoothly.

If the device detects a wire break or other fault during the operation of the device, the entire device needs to stop working immediately. A brake circuit can be provided outside the device, and the brake output signal is controlled by the device to control the brake circuit so that the machine can quickly stop. Of course, it is also possible to add a braking resistor inside the inverter to control the rapid stop of the whole machine.

2, system composition

The system consists of N general-purpose inverters and a tension-specific inverter.

Each general-purpose inverter controls a separate motor, and the wires are stretched step by step through different molds. According to the principle that the wire volume is constant, as the wire is thinner and thinner, the wire will become longer and longer, which requires the rear motor speed to be higher than the front motor speed. The main frequency of the first stage motor is derived from the latter stage motor, and the inverter can transmit the current motor running frequency using pulse mode or analog voltage mode.

The Nth motor runs at a fixed frequency. The frequency reference can be derived from the communication RS485 setting, external potentiometer or digital setting. The 1~N-1 motors use the composite AB frequency to operate. The main frequency is derived from the latter. The operating frequency of the primary motor, the auxiliary given is derived from the air arm balance bar PID control.

The air arm is mainly used to sense the tension of the wire, and is transmitted to the inverter through the AI signal. The system uses the PID function to fine tune the speed of the inverter. If the tension is too large, the inverter will reduce the frequency appropriately. If the tension is too small, the inverter will increase the frequency appropriately. This can make the wire drawing process more stable without breaking the wire.

The winding motor is controlled by a tension-specific inverter, which supports a closed-loop adjustment mode with a tension swing lever and an open-loop adjustment mode without a tension swing lever.

The system controls the operation of the Nth motor through a DI signal, and the running signal of the previous stage motor is derived from the running state of the motor of the latter stage, and the running signal of the winding motor is also derived from the operating state of the Nth motor.

Each inverter provides a disconnection (fault) detection function. If the system detects a disconnection, it will immediately output a signal to the brake circuit. The brake circuit controls the whole machine to stop running, and the signal will be transmitted in the state of external fault. Give each inverter. The methods of disconnection detection include PID feedback detection and DI signal input.

3, jog

In order to achieve manual threading, the system supports the jog function. The user can set the jog frequency (E0.00), jog acceleration time (E0.01) and jog deceleration time (E0.02) to achieve the speed of the die.

The terminal usually uses the terminal to control the jog. The user can set the X terminal function to forward or reverse jog.

The jog stop mode can be controlled by the jog deceleration mode (E0.03).

4, closed loop control mode

The winding inverter is equipped with a tension air arm balance bar, and the system can use the tension control mode or VF/vector control.

When using the tension control mode, the control mode is similar to the previous open loop tension mode, except that the system has a PID closed loop for fine adjustment of the tension to ensure a more stable tension on the line.

If VF/vector control is used, the system can calculate the coil diameter according to the principle of constant linear velocity, V=f*PI*R, where V is the front end line speed, f is the inverter reference frequency, and R is the reel radius. At the same time, the tension air arm balance bar is connected to the inverter AI, and the closed-loop fine adjustment is performed through the PID. As the winding diameter becomes larger and the linear velocity of the front end is stabilized, the frequency of the reference of the inverter becomes smaller and smaller.

When the reel diameter reaches the maximum coil diameter, the system can set the inverter to stop or continue to run.

The system provides a roll diameter reset function. When the user changes the volume, the current roll diameter can be reset to the empty roll reel path by a DI signal.

Third, product features

High work efficiency, can pull the wire into finished products at one time.

The low speed point is driven by the die, the running speed is stable, and the torque is large.

Synchronous response is fast.

The whole system only needs one special inverter for tension, and the other uses general-purpose inverter, which greatly reduces the cost.

The tension-specific inverter provides two different control modes: closed-loop tension control and open-loop tension control.

The winding diameter calculation function is provided, so that the winding process is more stable, the tension pendulum swing is small, and the wire is not loose.

A variety of wire break detection functions are available.

Provides a rollover diameter reset function.

Provide full roll shutdown.