Method for determining axial forces in a strip mill

Abstract

The application discloses a kind of determination methods of strip rolling mill axial force, it is related to metal material processing technical field, including: roll is carried out in the state of not starting and starting and presses, respectively gathers rolling mill operating side pressing force and transmission side pressing force, calculates two sides pressing force deviation, and then calculates the deviation of two sides pressing force deviation of roll in the state of not starting and starting, determines the axial force of rolling mill.The application can realize the on-line determination of rolling mill axial force, with the advantages of high accuracy, strong timeliness, simple operation.The application is applied to 1780mm hot continuous rolling mill group rough rolling mill, and no roll shaft end clamp plate fracture, roll motor bearing bush burning accident occurs again, and the rolling piece sickle bend is improved, and the rolling piece sickle bend abnormality rate is reduced from 50% to 13%.

Description

Technical Field

[0001] This invention relates to the field of metal material processing technology, and in particular to a method for determining the axial force of a strip mill. Background Technology

[0002] In strip rolling mill production, a component force, called axial force, is typically generated along the axial direction of the rolls. Axial force can have a destructive impact on strip rolling. Axial force usually arises when the centerline of the mill stand or roll bearing housing deviates from the ideal mill centerline, causing the roll centerline to be skewed or intersecting. Axial force is an objective reality; when it reaches a certain level, it can damage mill auxiliary equipment, and in severe cases, may cause accidents such as motor bearing burnout, resulting in significant losses to production and equipment.

[0003] Existing strip mills typically do not have axial force detection equipment installed, making it impossible to determine the magnitude and direction of the axial force. Analysis and treatment are only carried out after damage to the equipment occurs, making it impossible to predict and anticipate axial force damage.

[0004] The common method involves measuring the centerline of the rolling mill stand or roll bearing housing, and adjusting it based on the measured deviation to correct any skewing or crossing of the roll centerline. However, this method is often inaccurate, cannot accurately determine axial force, and is complex, requiring extended downtime to complete, resulting in poor timeliness. Summary of the Invention

[0005] In view of the shortcomings of the existing axial force determination methods proposed in the background art, the present invention provides a method for determining the axial force of a strip mill, which can be measured online during the production process and has the advantages of high accuracy, timeliness and ease of operation, thus solving the problems proposed in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for determining the axial force of a strip rolling mill involves obtaining the deviations in the pressing forces on the operating side and the drive side of the mill by pressing the rolls together in both the off-state and on-state conditions. This deviation is then used to determine the axial force of the mill. The specific steps are as follows: S1. Install the rolls inside the mill stand. When the rolls are not started, press them down using the mill pressing system to press the upper and lower rolls together. The pressing force gauge reads F0. Measure the pressing force F on the operating side using a pressure detection device. 0-OS and transmission side pressure F 0-DS ; S2. Raise the mill pressing system, start the rolls, and press down the upper and lower rolls together using the mill pressing system. The pressing force gauge is F1. Measure the pressing force F on the operating side using the pressure detection device. 1-OS and transmission side pressure F 1-DS ; S3. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll is not started: ΔF0=F 0-OS -F 0-DS ; S4. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll starts: ΔF1=F 1-OS -F 1-DS ; S5. Calculate the deviation of the pressing force when the roll starts and the deviation of the pressing force when the roll does not start: ΔF=ΔF1-ΔF0; S6. Determine the axial force of the rolling mill: If ΔF < 0, then the rolling mill has an axial force biased towards the drive side; if ΔF > 0, then the rolling mill has an axial force biased towards the operating side. Furthermore, the pressing force F0 mentioned in S1 and the pressing force F1 mentioned in S2 are controlled within 5000-15000KN, and |F1-F0|≤5% of the pressing force.

[0007] Furthermore, when |ΔF|≥300KN as described in S6, adjust the centerline of the mill stand or roll bearing housing to improve the axial force.

[0008] Compared with the prior art, the present invention has the following beneficial effects: This invention determines the axial force of the rolling mill by comparing the deviation of the roll pressing force under different conditions. It can realize the online determination of the axial force of the rolling mill and has the advantages of high accuracy, strong timeliness and simple operation.

[0009] This invention achieves precise adjustment of roll crossing and centerline skew by accurately determining the axial force of the rolling mill, effectively reducing accidents such as roll shaft end plate breakage and roll drive bearing burnout, while also improving the sickle bend of the rolled workpiece. Attached Figure Description

[0010] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0011] The following is in conjunction with the appendix Figure 1 The technical solutions in the embodiments of the present invention have been clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] This invention was implemented on the roughing mill of the 1780mm hot continuous rolling mill unit at Angang Steel.

[0013] This invention provides the following technical solution: a method for determining the axial force of a strip rolling mill. This method involves obtaining the deviations in the pressing force on the operating side and the transmission side of the mill by pressing the rolls together in both the off-state and on-state conditions. The deviations in the pressing forces on both sides of the mill in the off-state and on-state conditions are then used to determine the axial force of the mill. The specific steps are as follows: S1. Install the rolls inside the mill stand. When the rolls are not started, press them down using the mill pressing system to press the upper and lower rolls together. The pressing force gauge reads F0. Measure the pressing force F on the operating side using a pressure detection device. 0-OS and transmission side pressure F 0-DS ; S2. Raise the mill pressing system, start the rolls, and press down the upper and lower rolls together using the mill pressing system. The pressing force gauge is F1. Measure the pressing force F on the operating side using the pressure detection device. 1-OS and transmission side pressure F 1-DS ; S3. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll is not started: ΔF0=F 0-OS -F 0-DS ; S4. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll starts: ΔF1=F 1-OS -F 1-DS ; S5. Calculate the deviation of the pressing force when the roll starts and the deviation of the pressing force when the roll does not start: ΔF=ΔF1-ΔF0; S6. Determine the axial force of the rolling mill: If ΔF < 0, then the rolling mill has an axial force biased towards the drive side; if ΔF > 0, then the rolling mill has an axial force biased towards the operating side. The compressive force F0 of S1 and the compressive force F1 of S2 are controlled within 5000-15000KN, and |F1-F0|≤5% of the compressive force.

[0014] When |ΔF|≥300KN for S6, adjust the centerline of the mill stand or roll bearing housing to improve axial force.

[0015] Through implementation, the roughing mill of Angang's 1780mm hot strip mill no longer experienced roll shaft end plate breakage or motor bearing burnout accidents, and the abnormal rate of sickle bending of rolled pieces was significantly reduced from 50% to 13%.

[0016] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for determining the axial force of a strip rolling mill, characterized in that: By pressing the rolls together in both the off-state and on-state conditions, the deviations in the pressing force on the operating side and the transmission side of the mill are obtained. This deviation in the pressing force on both sides of the mill in the off-state and on-state conditions is then used to determine the axial force of the mill. The specific steps are as follows: S1. Install the rolls inside the mill stand. When the rolls are not started, press them down using the mill pressing system to press the upper and lower rolls together. The pressing force gauge reads F0. Measure the pressing force F on the operating side using a pressure detection device. 0-OS and transmission side pressure F 0-DS ; S2. Raise the mill pressing system, start the rolls, and press down the upper and lower rolls together using the mill pressing system. The pressing force gauge is F1. Measure the pressing force F on the operating side using the pressure detection device. 1-OS and transmission side pressure F 1-DS ; S3. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll is not started: ΔF0=F 0-OS -F 0-DS ; S4. Calculate the deviation between the operating side pressure force and the transmission side pressure force when the roll starts: ΔF1=F 1-OS -F 1-DS ; S5. Calculate the deviation of the pressing force when the roll starts and the deviation of the pressing force when the roll does not start: ΔF=ΔF1-ΔF0; S6. Determine the axial force of the rolling mill: If ΔF < 0, then the rolling mill has an axial force biased towards the drive side; if ΔF > 0, then the rolling mill has an axial force biased towards the operating side. The pressing force F0 mentioned in S1 and the pressing force F1 mentioned in S2 are controlled within 5000-15000KN, and |F1-F0|≤5% of the pressing force.

2. The method for determining the axial force of a strip rolling mill according to claim 1, characterized in that: When |ΔF|≥300KN, adjust the center line of the mill stand or roll bearing housing to improve axial force.

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