A method for determining and controlling inclination of an AGC cylinder of a strip rolling mill

Abstract

The present application belongs to the technical field of plate strip rolling, and relates to a kind of plate strip rolling mill AGC cylinder inclination reason determination and control method, first determine AGC cylinder inclination mode, is cylinder body inclination caused, or plunger inclination caused;In order according to in turn determine or exclude whether upper ladder pad, plunger lug, upper pressure plate, uneven wear of frame contact surface causes plunger inclination, according to the determination result, different control solution method is adopted;Determine whether uneven wear exists in the contact surface between cylinder body and upper backup roll bearing seat, or the plunger extension amount of the two balance cylinder of upper backup roll is not equal, which causes the inclination of cylinder body. According to the design and assembly structure of mill screwdown and AGC cylinder, the present application first measures and determines the inclination mode of AGC cylinder online, and then determines the specific cause of inclination and control method according to the inclination mode. Compared with the prior art, the present application improves the inclination cause determination efficiency, reduces the labor amount of disassembly, measurement and other operations, and reduces the fault time and maintenance cost.

Description

Technical Field

[0001] This invention belongs to the field of strip rolling technology, specifically relating to a method for determining and controlling the tilting of the AGC cylinder in a strip rolling mill. Background Technology

[0002] With the development of steel rolling technology and equipment, in order to improve rolling accuracy, the strip mill's reduction system is designed with hydraulic AGC cylinder components. The overall structure of the AGC cylinder is as follows: Figure 1 As shown, this is used to precisely adjust the roll gap value to improve the accuracy of rolled product thickness, shape, etc. The mill control system determines the roll gap value based on the rolling thickness. The roll gap value is calculated based on the vertical height of the mill stand 1 window and the closed-loop dimension chain of various components of the pressing system, such as the upper and lower step pads, AGC cylinder, and roll system. It is adjusted by the extension amount of the AGC cylinder, which is measured and fed back by the displacement sensor 7 installed on the AGC cylinder. The AGC cylinder is cylindrical and consists of a cylinder body 9, a plunger 5, etc. The displacement sensors 7 are generally installed in pairs on the AGC cylinder, with one end fixed to the cylinder body 9 and the other end fixed to the plunger 5. The average value of the measurements from the two displacement sensors 7 feeds back the displacement extension amount of the AGC cylinder, and the difference feeds back the tilt amount of the AGC cylinder.

[0003] Due to uneven stress, corrosion, dust, and other factors, the contact surfaces of various components in the rolling mill's reduction system will experience varying degrees of wear over time. For example, the contact surfaces between the upper support roll bearing housing 10 and the cylinder body 9, the plunger 5 and the upper stepped pad 3, and the upper pressure plate 2 and the top of the archway 1, etc., will experience uneven wear or foreign objects entering the contact surfaces, causing the AGC cylinder to tilt under mill calibration or rolling force application conditions. The AGC cylinder body and plunger are equipped with rubber seals and guide rings. Excessive tilting can cause deformation of the seals, and may even lead to contact damage between the cylinder body and the plunger. Therefore, the control system is designed with an AGC cylinder tilt warning and protection function. When the tilt reaches 1.2mm, a critical seal load warning is issued; when the tilt reaches 2mm, the hydraulic system is cut off and the machine stops to prevent metal-to-metal contact between the plunger and the cylinder body, which could cause damage.

[0004] To ensure that the tilt of the AGC cylinder does not exceed the warning protection value, it is necessary to determine the specific cause of the tilt in order to facilitate maintenance and control.

[0005] To determine the specific cause of the AGC cylinder tilt, the common approach is to disassemble the rolling mill pressing system components and measure the wear of the contact surfaces of each component offline to see if it is uniform, or to directly replace the components. However, due to the large number of components in the rolling mill pressing system and the limitations of the compact assembly structure and limited space, there are problems such as large disassembly operations, difficult measurement, and long time to determine the cause. Directly replacing many components would also result in waste. Summary of the Invention

[0006] The purpose of this invention is to provide a method for determining and controlling the tilting of the AGC cylinder in a strip rolling mill, so as to solve the problems existing in the prior art.

[0007] The technical solution adopted by this invention to solve its technical problem is: a method for determining and controlling the tilting cause of an AGC cylinder in a strip rolling mill, comprising the following steps:

[0008] (1) First, determine the tilting method of the AGC cylinder, whether it is caused by the tilting of the cylinder body or the tilting of the plunger: Under the calibrated static pressure of the rolling mill, measure the verticality of the two outer surfaces of the plunger guide block and the cylinder oil supply block respectively. The magnitude of the verticality value reflects the tilting amount of the plunger or the cylinder body.

[0009] (2) Determination and control methods for plunger tilt: Determine or eliminate in sequence whether the upper step pad is worn unevenly, the contact surface of the plunger lug is worn unevenly, or the contact surface of the upper pressure plate and the arch is worn unevenly. Take different control methods according to the determination results.

[0010] (3) Determination of the cause of cylinder tilt and control method: Determine whether there is uneven wear on the contact surface between the cylinder and the upper support roller bearing seat, or whether the two balance cylinder plungers of the upper support roller have different extension amounts. Take different control methods according to the determination results.

[0011] Furthermore, the specific steps of the plunger tilt cause determination and control method in step (2) are as follows:

[0012] 1) Method for judging and controlling uneven wear of upper stepped pads: On the control panel, the AGC cylinder extension displacement is set to 20mm. The upper stepped pads of levels 1-3 are in the working position respectively. The hydraulic balance cylinder lifts the upper support roller and pushes it against the AGC cylinder until the plunger is in close contact with the upper stepped pad, the upper pressure plate, and the arch. The perpendicularity of the two sides of the plunger guide block is measured. If the upper stepped pads of levels 1-3 have similar perpendicularity values ​​when they are in the working position, the wear of the upper stepped pads of levels 1-3 is judged to be uniform; otherwise, it is judged that one of the upper stepped pads of levels 1-3 has uneven wear, and the upper stepped pad with uneven wear is replaced.

[0013] 2) Judgment and control method of uneven wear on the contact surface of the plunger lug plate: After replacing the upper support roller that meets the technical requirements online, the AGC cylinder falls on the upper support roller bearing seat by gravity. Use a level to measure the levelness of the upper surface of the plunger lug plate to determine whether there is uneven wear on the contact surface of the plunger lug plate. If the wear is uneven, replace the plunger lug plate to solve the problem.

[0014] 3) Methods for determining and controlling uneven wear of the upper pressure plate and archway contact surfaces; After eliminating or resolving uneven wear of the contact surfaces of the 1-3 level upper stepped pads and plunger lugs through steps 1) and 2), if the plunger is still found to be tilted, it is determined that the upper pressure plate and archway contact surfaces have uneven wear. The upper pressure plate needs to be inspected and disassembled. The flatness of the archway contact surface is measured online, and the flatness of the upper and lower contact surfaces of the upper pressure plate is measured offline to determine the wear condition. If the upper pressure plate has uneven wear, it needs to be replaced. If the archway contact surface has uneven wear, the archway contact surface needs to be machined online to restore its flatness technical requirements. The dimensions removed by machining are compensated by changing the thickness of the upper pressure plate or by calibrating and correcting the zero position value of the AGC cylinder.

[0015] Furthermore, the specific steps of the method for determining and controlling the cause of cylinder tilt in step (3) are as follows:

[0016] 1) Determination and solution of uneven wear on the contact surface of the upper support roller bearing seat: After the upper support roller is replaced after one cycle of use, the flatness of the contact surface on the upper support roller bearing seat is measured to determine whether there is uneven wear. If the wear is uneven, the upper liner of the bearing seat is replaced to solve the problem.

[0017] 2) Determination and solution for unequal extension of the two balance cylinder plungers of the upper support roller: When the balance cylinder plungers are extended to their maximum extent, use a laser tracker to measure the elevation of the top plane of the two balance cylinder plungers to determine whether the extension of the two plungers is equal. If the extension is unequal, the solution is to replace the top liner of the balance cylinder plungers.

[0018] 3) After steps 1) and 2), place the AGC cylinder on the upper support roller bearing seat by its own weight, and measure the verticality of the two sides of the oil supply block of the cylinder body to determine whether there is uneven wear on the bottom surface of the cylinder body. If there is uneven wear on the bottom surface of the cylinder body, the AGC cylinder needs to be removed from the machine and returned to the factory for processing and repair. The thickness of the machining is compensated by changing the thickness of the upper support roller bearing seat pad or by calibrating and correcting the zero position value of the AGC cylinder.

[0019] 4) The above-mentioned online measurement, component disassembly, and offline measurement operations must strictly comply with the safety operation specifications of the power source shutdown operation ticket and high-altitude operation ticket.

[0020] The present invention has the following beneficial effects: Based on the rolling mill pressing and AGC cylinder design and assembly structure, the present invention first measures and determines the tilting mode of the AGC cylinder online, and then determines the specific cause of the tilting and the control method based on the tilting mode. Compared with the prior art, the present invention improves the efficiency of tilting cause determination, reduces the workload of disassembly, measurement and other operations, and reduces failure time and maintenance costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the AGC cylinder of the present invention.

[0022] Figure 2 This is a schematic diagram of the plunger guide block.

[0023] Figure 3 This is a schematic diagram of the cylinder block oil supply block.

[0024] Figure 4 This invention relates to a process flow diagram for determining and controlling the tilting of the AGC cylinder in a strip rolling mill.

[0025] 1. Archway, 2. Upper pressure plate, 3. Upper step pad, 4. Plunger ear plate, 5. Plunger, 6. Plunger guide block, 7. Displacement sensor, 8. Cylinder block oil supply block, 9. Cylinder, 10. Upper support roller bearing seat. Detailed Implementation

[0026] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention. However, the scope of protection of the present invention is not limited to these embodiments. All changes or equivalent substitutions that do not depart from the concept of the present invention are included within the scope of protection of the present invention.

[0027] A method for determining and controlling the tilting of an AGC cylinder in a strip rolling mill, such as... Figure 4 As shown, it includes the following steps:

[0028] (1) First determine the tilting method of the AGC cylinder, whether it is caused by the tilting of the cylinder body or the tilting of the plunger.

[0029] The AGC cylinder has a cylinder block lubrication block 8 mounted on its cylinder block 9, which is an integral part of the cylinder block 9. The AGC cylinder's plunger 5 has two plunger guide blocks 6 mounted on it, which are also integral parts of the plunger 5. The sides of the cylinder block lubrication block 8 and the plunger guide blocks 6 are machined surfaces, not contact wear surfaces, resulting in relatively high surface precision. When the cylinder block or plunger tilts, the cylinder block lubrication block 8 or the plunger guide blocks 6 also tilts accordingly. Therefore, the perpendicularity error of the two sides of the cylinder block lubrication block 8 or the plunger guide blocks 6 reflects whether the cylinder block or plunger is tilted. Furthermore, the mounting positions of the cylinder block lubrication block 8 and the plunger guide blocks 6 on the cylinder block 9 and the plunger 5 facilitate online monitoring.

[0030] Under the calibrated static pressure condition of the rolling mill, the perpendicularity of the two outer surfaces of the plunger guide block 6 and the cylinder oil supply block 8 is measured respectively. The magnitude of the perpendicularity value reflects the tilt of the plunger 5 or the cylinder 9. The structure of the plunger guide block 6 is as follows: Figure 2 As shown, the structure of the cylinder block oil supply block 8 is as follows: Figure 3 As shown, the piston guide block 6 and the cylinder block oil supply block 8 are installed in the AGC cylinder as follows: Figure 1 As shown.

[0031] (2) Determination of the causes and control methods for plunger tilt

[0032] The reasons for the plunger tilting include uneven wear on the contact surfaces of the plunger lug 4, the upper stepped pad 3, the upper pressure plate 2, and the arch 1.

[0033] The specific judgment and control steps are as follows:

[0034] 1) Method for judging and controlling uneven wear of upper step pad 3: On the operation panel, the AGC cylinder extension displacement is given as 20mm. The upper step pads 3 of levels 1-3 are operated to the working position. The hydraulic balance cylinder lifts the upper support roller and pushes against the AGC cylinder until the plunger 5 is in close contact with the upper step pad 3, the upper pressure plate 2, and the arch 1. The perpendicularity of the two sides of the plunger guide block 6 is measured. If the level 1-3 step pads have similar perpendicularity values ​​when they are in the working position, the wear of the level 1-3 step pads is judged to be uniform; otherwise, it is judged that one of the level 1-3 upper step pads 3 has uneven wear, and the upper step pad 3 with uneven wear is replaced.

[0035] 2) Judgment and control method of uneven wear on the contact surface of the plunger ear plate 4: After replacing the upper support roller that meets the technical requirements online, the AGC cylinder falls on the upper support roller bearing seat 10 by gravity. The level of the upper surface of the plunger ear plate 4 is measured with a level to determine whether there is uneven wear on the contact surface of the plunger ear plate 4. If the wear is uneven, the plunger ear plate 4 is replaced to solve the problem.

[0036] 3) Methods for determining and controlling uneven wear of the upper pressure plate and archway contact surfaces; After eliminating or resolving uneven wear of the contact surfaces of the 1-3 level upper stepped pad 3 and plunger ear plate through steps 1) and 2), if the plunger is still found to be tilted, it is determined that there is uneven wear on the contact surfaces of the upper pressure plate 2 and archway 1. The upper pressure plate 2 needs to be inspected and disassembled. The flatness of the contact surface of archway 1 is measured online, and the flatness of the upper and lower contact surfaces of the upper pressure plate 2 is measured offline to determine the wear condition. If the upper pressure plate 2 has uneven wear, it needs to be replaced. If the contact surface of archway 1 has uneven wear, the contact surface of archway 1 needs to be processed online to restore its flatness technical requirements. The dimensions removed by processing are compensated by changing the thickness of the upper pressure plate 2, or by calibrating and correcting the zero position value of the AGC cylinder.

[0037] (3) Determination of the cause of cylinder tilt and control methods

[0038] The reasons for cylinder tilting include: uneven wear on the contact surface between the cylinder and the upper support roller bearing seat, or unequal extension of the plungers of the two balance cylinders of the upper support roller.

[0039] The specific judgment and control steps are as follows:

[0040] 1) Judgment and solution of uneven wear on the contact surface of the upper support roller bearing seat: After the upper support roller is replaced after one cycle of use, the flatness of the contact surface on the upper support roller bearing seat 10 is measured to determine whether there is uneven wear. If the wear is uneven, the upper liner of the bearing seat is replaced to solve the problem.

[0041] 2) Determination and solution for unequal extension of the two balance cylinder plungers of the upper support roller: When the balance cylinder plungers are extended to their maximum extent, use a laser tracker to measure the elevation of the top plane of the two balance cylinder plungers to determine whether the extension of the two plungers is equal. If the extension is unequal, the solution is to replace the top liner of the balance cylinder plungers.

[0042] 3) After steps 1) and 2) are completed, the AGC cylinder is placed on the upper support roller bearing seat 10 by its own weight. The verticality of the two sides of the cylinder oil supply block 8 is measured to determine whether there is uneven wear on the bottom surface of the cylinder. If there is uneven wear on the bottom surface of the cylinder, the AGC cylinder needs to be taken off the machine and returned to the factory for processing and repair. The thickness of the machining is compensated by changing the thickness of the pad of the upper support roller bearing seat 10 or by calibrating and correcting the zero position value of the AGC cylinder.

[0043] 4) The above-mentioned online measurement, component disassembly, and offline measurement operations must strictly comply with the safety operation specifications of the power source shutdown operation ticket and high-altitude operation ticket.

[0044] Based on the design structure of the rolling mill AGC cylinder, this invention analyzes and concludes that the AGC cylinder tilts in three ways: first, the cylinder body 9 tilts; second, the plunger 5 tilts; and third, both the cylinder body and the plunger tilt. The invention first determines the tilting method of the AGC cylinder—whether it is the cylinder body tilting, the plunger tilting, or both. Then, it further determines the specific cause of the tilting of the cylinder body or the plunger and formulates corresponding maintenance and control methods.

[0045] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0046] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A method for determining and controlling the tilting of an AGC cylinder in a strip rolling mill, characterized in that, Includes the following steps: (1) First, determine the tilting method of the AGC cylinder, whether it is caused by the tilting of the cylinder body or the tilting of the plunger: Under the calibrated static pressure of the rolling mill, measure the verticality of the two outer surfaces of the plunger guide block and the cylinder oil supply block respectively. The magnitude of the verticality value reflects the tilting amount of the plunger or the cylinder body. (2) Determination and control methods for plunger tilt: Determine or eliminate in sequence whether the upper step pad is worn unevenly, the contact surface of the plunger lug is worn unevenly, or the contact surface of the upper pressure plate and the arch is worn unevenly. Take different control methods according to the determination results. (3) Determination of the cause of cylinder tilt and control method: Determine whether there is uneven wear on the contact surface between the cylinder and the upper support roller bearing seat, or whether the two balance cylinder plungers of the upper support roller have different extension amounts. Take different control methods according to the determination results.

2. The method for determining and controlling the tilting cause of the AGC cylinder in a strip rolling mill as described in claim 1, characterized in that, The specific steps for determining and controlling the cause of plunger tilt in step (2) are as follows: 1) Method for judging and controlling uneven wear of upper stepped pads: On the control panel, the AGC cylinder extension displacement is set to 20mm. The upper stepped pads of levels 1-3 are in the working position respectively. The hydraulic balance cylinder lifts the upper support roller and pushes it against the AGC cylinder until the plunger is in close contact with the upper stepped pad, the upper pressure plate, and the arch. The perpendicularity of the two sides of the plunger guide block is measured. If the upper stepped pads of levels 1-3 have similar perpendicularity values ​​when they are in the working position, the wear of the upper stepped pads of levels 1-3 is judged to be uniform; otherwise, it is judged that one of the upper stepped pads of levels 1-3 has uneven wear, and the upper stepped pad with uneven wear is replaced. 2) Judgment and control method of uneven wear on the contact surface of the plunger lug plate: After replacing the upper support roller that meets the technical requirements online, the AGC cylinder falls on the upper support roller bearing seat by gravity. Use a level to measure the levelness of the upper surface of the plunger lug plate to determine whether there is uneven wear on the contact surface of the plunger lug plate. If the wear is uneven, replace the plunger lug plate to solve the problem. 3) Methods for determining and controlling uneven wear of the upper pressure plate and archway contact surfaces; After eliminating or resolving uneven wear of the contact surfaces of the 1-3 level upper stepped pads and plunger lugs through steps 1) and 2), if the plunger is still found to be tilted, it is determined that the upper pressure plate and archway contact surfaces have uneven wear. The upper pressure plate needs to be inspected and disassembled. The flatness of the archway contact surface is measured online, and the flatness of the upper and lower contact surfaces of the upper pressure plate is measured offline to determine the wear condition. If the upper pressure plate has uneven wear, it needs to be replaced. If the archway contact surface has uneven wear, the archway contact surface needs to be machined online to restore its flatness technical requirements. The dimensions removed by machining are compensated by changing the thickness of the upper pressure plate or by calibrating and correcting the zero position value of the AGC cylinder.

3. The method for determining and controlling the tilting cause of the AGC cylinder in a strip rolling mill as described in claim 1, characterized in that, The specific steps for determining the cause and controlling cylinder tilt in step (3) are as follows: 1) Determination and solution of uneven wear on the contact surface of the upper support roller bearing seat: After the upper support roller is replaced after one cycle of use, the flatness of the contact surface on the upper support roller bearing seat is measured to determine whether there is uneven wear. If the wear is uneven, the upper liner of the bearing seat is replaced to solve the problem. 2) Determination and solution for unequal extension of the two balance cylinder plungers of the upper support roller: When the balance cylinder plungers are extended to their maximum extent, use a laser tracker to measure the elevation of the top plane of the two balance cylinder plungers to determine whether the extension of the two plungers is equal. If the extension is unequal, the solution is to replace the top liner of the balance cylinder plungers. 3) After steps 1) and 2), place the AGC cylinder on the upper support roller bearing seat by its own weight, and measure the verticality of the two sides of the oil supply block of the cylinder body to determine whether there is uneven wear on the bottom surface of the cylinder body. If there is uneven wear on the bottom surface of the cylinder body, the AGC cylinder needs to be removed from the machine and returned to the factory for processing and repair. The thickness of the machining is compensated by changing the thickness of the upper support roller bearing seat pad or by calibrating and correcting the zero position value of the AGC cylinder. 4) The above-mentioned online measurement, component disassembly, and offline measurement operations must strictly comply with the safety operation specifications of the power source shutdown operation ticket and high-altitude operation ticket.

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