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Cold Rolling Mill Easy To Wear
- May 31, 2017 -

I. Introduction

Double rack reversible cold rolling mill both production flexibility and production capacity and other advantages, but there are long-term wear belt wear problems caused by rolling mill production. Deviation performance as follows:

(1) Uncoiler open coil, strip in the pinch roller straight head machine to do with the belt after the lead, transported to the side of the guide device for mechanical alignment, the strip deviation from the rolling mill center line.

(2) to wear the belt, before the pinch roller, with steel bucket. When the curl is too large, it can not be worn.

(3) wear belt process, the rewinder on the servo cylinder to move to full stroke, so that the control system completely lost its role.

The existence of the wear phenomenon of the rolling mill wears seriously, which seriously disturbs the rolling rhythm of the rolling mill and affects the full release of the production capacity of the rolling mill. When dealing with serious, need to cut the strip, repeat wear work. Strip deviation also on the pinch roller, work roll, side guide of the vertical roller, such as wear and tear, scratches.

In this paper, combined with the structural characteristics of double-stand cold rolling mill, the causes of strip wear and tear are analyzed and analyzed, and the countermeasures to solve the problem of deviation are put forward. Practice has proved that the effect is remarkable, wear belt quickly without deviation, improve the mill operating rate.

Second, double rack reversible cold rolling mill wear process

Double-rack reversible cold rolling mill production in the form of single-roll production, from raw materials to finished product each volume of the process: coil transport, width measurement, measuring diameter → open system roll → roll roll straight head machine to wear wear → Rolling mill belt → Rolling mill Rolling strip and winding → Reverse rolling strip and winding → Finished product roll unloading → Entering the next roll belt Rolling. While the rolling mill is being rolled up in the reverse direction, the next coil is ready for wear. The rolling process of the rolling mill is divided into two stages: the preparation of the coil and the wear of the rolling mill.

1. Steel roll preparation stage

The coil car completes the winding diameter and width measurement of the coil in the way of feeding the coil to the uncoiler. Based on the measured data, the control system issues a command to the steel trolley so that the coil and the unwinding roll ) Centerline centering, uncoiling reel expansion complete roll. The unwinding machine drives the press roll to press the outer coil of the coil, the reel is returned, and the telescopic guide plate is placed in the open volume. The unwinder turns the unwinding roll and takes the lead through the open pinch roller, and the upper pinch rolls down and the strip is fed to the straight head straightening roller and stops. Straighten the roller to swing up, bend the lead upwards to warp so that it is easy to wear. The pinch roller is fed through the side guide, the roller is conveyed and the upper pinch roller is lifted, and the side guide will take the lead for the first mechanical alignment. Take the lead after the middle of the pinch roller re-pressed to suppress the strip, then the side guide open. The unwinding machine drives the press roller to lift. The steel roll preparation phase is completed, and this stage of the CPC strip centering system does not work.

2. Rolling belt wear stage

When the strip is worn from the uncoiler to the 2 # coiling machine on the side of the dual-stand mill, the work roll of the dual-stand mill is opened with a roll gap of 6 to 12 mm, the belt is started, and the CPC centering system starts working , CPC will measure the strip deviation from the signal feedback to the decanter on the cylinder of the servo valve, control the corresponding servo cylinder to do the corresponding movement. The warped strip head passes through the inlet side steering wheel into the side guide of the # 1 rolling mill entrance side, and the second mechanical center passes through the roll gap opened by the # 1, 2 # rolling mill. At the exit side of the 2 # mill, the strip enters the outlet side guide, and after the third mechanical centering, the exit steering roller presses down the strip head and guides the jaws of the 2 # coiler. The rolling mill takes the stage to complete. This stage from the beginning to the end of the bar with the steel system to participate in the correction of steel work.

Third, the rolling mill wear belt related device profile

The equipment associated with the wear of the rolling mill is: steel roll width, caliper device, steel trolley stroke control device, CPC strip centering control system, pinch roller and straight head machine, and 3 sets of center guide device The

1. Steel measuring width, measuring diameter device

The laser measuring device is installed on the steel structure bracket, which transmits the measured coil diameter and width signal to the computer to output the target stroke data instruction to the steel trolley to ensure the winding accuracy of the trolley.

2. Trolley travel control device

The rotation of the trolley is controlled by a rotary encoder, which is coaxially mounted on the wheel axle of the trolley wheel. The encoder converts the detected number of revolutions of the wheel into a feedback signal to the control unit and the set target stroke To determine the stop position of the trolley to ensure that the coil is placed in the correct position coinciding with the center line of the mill when the coil is loaded onto the unwinder.

3. Strip Control System

When the mill is worn, the displacement of the uncoiler is dynamically controlled so that the strip is always running on the centerline of the mill. The CPC control system consists of three parts: the detection unit, the signal control unit and the hydraulic servo unit. The detection unit comprises a position sensor, a position sensor positioning device and a high frequency light source. The hydraulic servo unit comprises a hydraulic station, a servo valve, a servo cylinder and a position sensor. The sensing unit is mounted on a steel structure bracket on the strip and has a position sensor (LS13 / LS14) on each side. Each position sensor includes a measuring receiver LS13 and a reference position receiver LS14, LS13 / LS14 on both sides Mounted on the same chute, driven by motor belt, moved in or out simultaneously. Before the start of the strip, the strip edge position is detected by the motor drive sensor positioning device. LS13 and LS14 each of the high-frequency light receiving cylinder and high-frequency light source of the same point of light. When the aperture of the measuring receiver LS13 is covered by a steel strip, the reference position receiver LS14 is subjected to the influence of the strip position when the high frequency light receiving channel is not affected by the strip position. When the strip is deviated from the center position, the contrast signal generated on the measuring receiver is transmitted to the signal control device. The signal control device will signal the control and then control the hydraulic servo system to drive the unwinder movement so that the strip is always in the middle position.

4. Pinch roller and straight head machine

The pinch device consists of a driven upper and lower pinch roller. The upper pinch roller is mounted on the swing bracket with the swing hydraulic cylinder and can be swung up and down, and is driven by the hydraulic motor when rotating. The lower pinch roller is mounted on the steel structure fixing base and is driven by the motor with the electromagnetic brake. By the straightening roller and pinch roller composed of three roller straight head machine. The pinch roller first feeds the strip head above the straightening roller, and the straightening roller lifts the strip head into a warp shape to facilitate wear. The entire belt is carried out by the pinch roller drive strip.

5. Side guide

Consists of a pair of moving frames, a pair of racks, a sun gear and two opposite rollers. Four vertical rollers are mounted on the movable frame on both sides of the side guide, the movable frame on the side of the hydraulic cylinder with the displacement sensor is driven by the rack mounted on the moving frame through the intermediate gear and mounted on the other side moving frame On the rack, according to the width of the strip on both sides of the moving frame at the same time into or out, the opening adjustment to ensure that the mill wear belt when the strip positioning in the mill center line.