Calibration method to eliminate calibration marks on the work rolls of a six-roll mill

Abstract

This invention belongs to the technical field of cold rolling mill equipment, specifically disclosing a calibration method for eliminating calibration marks on the work rolls of a six-roll mill. It addresses the problem that current traditional sequential calibration procedures cannot meet the requirements of all products from cold rolling mills, resulting in calibration marks on the strip surface. The key steps of the calibration method provided by this invention are as follows: The roll gap is closed to a minimum rolling force of 700kN – rolling oil is sprayed at a flow rate greater than 1000L / min, then the main motor starts rotating at a speed of 100m / min – the rolling force is increased to 5000kN – the roll gap is calibrated to zero – the main machine stops rotating – the roll gap is opened – the rolling oil is turned off – calibration is complete. This invention effectively solves the color difference caused by the rolls during the calibration process and eliminates the strip calibration mark defects caused by calibration, thereby meeting the product's process requirements.

Description

Technical Field

[0001] This invention belongs to the technical field of cold rolling mill equipment, and particularly relates to a calibration method for eliminating calibration marks on the work rolls of a six-roll mill. Background Technology

[0002] Cold rolling mills are key control equipment for rolling coils in the aluminum industry. Whether the coils rolled by cold rolling mills can meet the requirements for thickness, precision and surface depends mainly on the zero position calibrated after replacing the new grinding rolls and whether there are any defects on the roll surface after calibration.

[0003] The traditional calibration process mainly involves parameters such as rolling force, rolling oil flow, roll bending value, and mill speed. These parameters are matched to perform sequential calibration steps. However, this traditional sequential calibration process cannot meet the requirements of all products from cold rolling mills. For example, lateral color differences on the work roll surface after calibration can result in calibration marks on the strip surface, affecting the strip's surface quality. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration method for eliminating calibration marks on the work rolls of a six-roll mill, effectively solving the problem that the current traditional sequential calibration steps cannot meet the requirements of all products of cold rolling mills, resulting in calibration marks on the surface of the strip.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A calibration method for eliminating calibration marks on the work rolls of a six-roll mill includes the following steps: S1, setting the work roll bending value to 50%, setting the intermediate roll bending value to 50%, and setting the support roll to the balance position.

[0007] S2. Quickly open the roll gap, zero the magnetic scale, open the roll gap control, push the support roller side to the exit side, and the pressing cylinder falls at a speed of 2mm / s, causing the roll gap to close to the 10mm position.

[0008] S3. Rolling force is zero. Check roll diameter. If the roll diameter check is correct, proceed directly to S4 operation. If the roll diameter check is incorrect, open the roll gap, end the calibration, and check the roll diameter.

[0009] S4. The roll gap is closed to a minimum total rolling force of 700kN.

[0010] S5. If the difference between the rolling force on the drive side (DS side) and the rolling force on the operating side (OS side) is greater than 80kN, calculate the difference in roll gap position between the DS side and the OS side, and then adjust the tilt position before proceeding to step S6.

[0011] If the difference between the rolling force on the DS side and the rolling force on the OS side is less than 80kN, then proceed directly to step S6.

[0012] S6, the roll gap drops to 1mm.

[0013] S7. When the rolling oil is turned on and the injection flow rate is greater than 1000L / min, the main motor starts to rotate at a speed of 100m / min. Wait for the main motor to rotate for 10 seconds. At the same time, when the rolling force is increased to 5000kN during the rotation of the main motor, the roll gap is set to zero.

[0014] S8. The main motor stops rotating, the roll gap is opened, and when the roll gap position is greater than 2mm, the rolling oil is shut off. Then the roll gap position is opened to 10mm.

[0015] S9. Calibration complete.

[0016] Furthermore, the following conditions must be met before calibration begins: the rolling line is in the rolling position; the main motor is not rotating; there is no strip and no tension in the stand; the hydraulic system is normal; the rolling force is zero; the intermediate rolls are in the calibration position; the work rolls, intermediate rolls and support rolls are locked; and the oil-air lubrication system is normal.

[0017] Furthermore, in step S4, the rolling force on the OS side is 350kN, and the rolling force on the DS side is 350kN.

[0018] Furthermore, in step S5, the method for adjusting the tilt position is as follows: the formula for calculating the tilt position is: DS side roll gap position - OS side roll gap position.

[0019] If the DS side roll gap is greater than the OS side roll gap, the difference is positive, indicating that the DS side roll gap is larger and the OS side roll gap is smaller. It is necessary to adjust the rolling force on the DS side to increase and the rolling force on the OS side to decrease. If the DS side roll gap is smaller than the OS side roll gap, the difference is negative, indicating that the DS side roll gap is smaller and the OS side roll gap is larger. It is necessary to adjust the rolling force on the DS side to decrease and the rolling force on the OS side to increase.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are:

[0021] This invention effectively solves the color difference caused to the rolls during the calibration process by adjusting the sequential control calibration steps and key parameters, and eliminates the strip calibration mark defects caused by calibration, thereby meeting the product's process requirements. Detailed Implementation

[0022] Example 1: A calibration method for eliminating calibration marks on the work rolls of a six-roll mill, which realizes the work roll calibration steps through primary parameter data and PLC control.

[0023] Before starting the calibration procedure, the following conditions must be met: (1) The rolling line is in the rolling position. (2) The main motor is not rotating. (3) There is no strip and no tension in the stand. (4) The hydraulic system is normal. (5) The rolling force is zero. (6) The CVC (intermediate roll position) is in the calibration position. (7) The lock blocks of the work roll, intermediate roll and support roll are locked. (8) The oil-air lubrication system is normal.

[0024] The calibration steps provided in this embodiment include: S1, setting the bending value of the work roll to 50%, setting the bending value of the intermediate roll to 50%, and setting the support roll to the balance position.

[0025] S2. Quickly open the roll gap, zero the magnetic scale, open the roll gap control, push the support roller side to the exit side, and the pressing cylinder falls at a speed of 2mm / s, causing the roll gap to close to the 10mm position.

[0026] S3. Rolling force is zero; check roll diameter. If the roll diameter check is correct, proceed directly to step S4; if the roll diameter check is incorrect, open the roll gap, end the calibration, and check the roll diameter.

[0027] S4. The roll gap is closed to a minimum total rolling force of 700kN (single-sided rolling force: 350kN on the OS side and 350kN on the DS side).

[0028] S5. If the difference between the rolling force on the DS side and the rolling force on the OS side is greater than 80kN, calculate the difference in roll gap position between the DS side and the OS side, adjust the tilt position, and then proceed to step S6. If the difference between the rolling force on the DS side and the rolling force on the OS side is less than 80kN, then proceed directly to step S6.

[0029] The method for adjusting the tilt position is as follows: The formula for calculating the tilt position is: DS side roll gap position - OS side roll gap position;

[0030] If the roll gap position on the DS side is greater than that on the OS side, and the difference is positive, it means that the roll gap position on the DS side is large and the roll gap position on the OS side is small. It is necessary to adjust the rolling force on the DS side to increase and the rolling force on the OS side to decrease.

[0031] If the DS side roll gap position is smaller than the OS side roll gap position, the difference is negative, indicating that the DS side roll gap position is small and the OS side roll gap position is large. It is necessary to adjust the rolling force on the DS side to decrease and the rolling force on the OS side to increase.

[0032] S6. Close the roll gap to 1mm.

[0033] S7. When the rolling oil is turned on and the injection flow rate is greater than 1000L / min, the main motor starts to rotate at a speed of 100m / min. Wait for the main motor to rotate for 10 seconds. At the same time, when the rolling force is increased to 5000kN during the rotation of the main motor, the roll gap is set to zero.

[0034] S8. The main motor stops rotating, the roll gap is opened, and when the roll gap position is greater than 2mm, the rolling oil is shut off, and then the roll gap position is opened to 10mm.

[0035] S9. Calibration complete.

[0036] In summary, the key steps of the sequential control calibration process in this embodiment are as follows: the roll gap is closed to the minimum rolling force of 700kN - rolling oil is sprayed, and after the spray flow rate is greater than 1000L / min, the main motor starts to rotate at a speed of 100m / min - the rolling force is increased to 5000kN - the roll gap is calibrated to zero - the main machine stops rotating - the roll gap is opened - the rolling oil is turned off - calibration is completed.

[0037] The current traditional sequential control calibration steps are as follows: the roll gap is closed to the minimum rolling force of 1500kN - the rolling oil injection and main motor rotation start simultaneously - the rolling force is increased to 15000kN - the roll gap is calibrated to zero - the rolling oil is turned off and the main machine stops rotating simultaneously - the roll gap is opened - calibration is completed.

[0038] By adopting the calibration method provided in this embodiment, the color difference caused to the rolls during the calibration process can be effectively solved, the calibration mark defects of the strip caused by calibration can be eliminated, and the surface of the produced strip is smooth and defect-free, thereby meeting the process requirements of the product.

[0039] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A calibration method for eliminating calibration marks on the work rolls of a six-roll mill, characterized in that, Includes the following steps: S1. The bending value of the working roll is set to 50%, the bending value of the intermediate roll is set to 50%, and the support roll is set to the balance position. S2. Quickly open the roll gap, zero the magnetic scale, open the roll gap control, push the support roller side to the exit side, and the pressing cylinder falls at a speed of 2mm / s, causing the roll gap to close to the 10mm position. S3. Rolling force is zero. Check roll diameter. If the roll diameter is correct, proceed directly to operation S4. If the roll diameter check is incorrect, open the roll gap, end the calibration, and check the roll diameter again. S4. The roll gap is closed to a minimum total rolling force of 700kN; S5. If the difference between the rolling force on the DS side and the rolling force on the OS side is greater than 80kN, calculate the difference in roll gap position between the DS side and the OS side, and then adjust the tilt position before proceeding to step S6. If the difference between the rolling force on the DS side and the rolling force on the OS side is less than 80kN, then proceed directly to step S6; S6, the roll gap drops to 1mm; S7. When the rolling oil is turned on and the injection flow rate is greater than 1000L / min, the main motor starts to rotate at a speed of 100m / min. Wait for the main motor to rotate for 10 seconds. At the same time, when the rolling force is increased to 5000kN during the rotation of the main motor, the roll gap is set to zero. S8. The main motor stops rotating, the roll gap is opened, and when the roll gap position is greater than 2mm, the rolling oil is shut off. Then the roll gap position is opened to 10mm. S9. Calibration complete.

2. The calibration method for eliminating calibration marks on the work rolls of a six-roll mill according to claim 1, characterized in that, Before calibration begins, the following conditions must be met: the rolling line is in the rolling position; the main motor is not rotating; there is no strip and no tension in the stand; the hydraulic system is normal; the rolling force is zero; the intermediate rolls are in the calibration position; the work rolls, intermediate rolls and support rolls are locked; and the oil-air lubrication system is normal.

3. The calibration method for eliminating calibration marks on the work rolls of a six-roll mill according to claim 2, characterized in that, In step S4, the rolling force on the OS side is 350kN, and the rolling force on the DS side is 350kN.

4. The calibration method for eliminating calibration marks on the work rolls of a six-roll mill according to claim 3, characterized in that, In step S5, the method for adjusting the tilt position is as follows: The formula for calculating the tilt position is: DS side roll gap position - OS side roll gap position; If the roll gap position on the DS side is greater than that on the OS side, and the difference is positive, it means that the roll gap position on the DS side is large and the roll gap position on the OS side is small. It is necessary to adjust the rolling force on the DS side to increase and the rolling force on the OS side to decrease. If the DS side roll gap position is smaller than the OS side roll gap position, the difference is negative, indicating that the DS side roll gap position is small and the OS side roll gap position is large. It is necessary to adjust the rolling force on the DS side to decrease and the rolling force on the OS side to increase.