Rolling Mill Gap Control via Force-Deformation Compensation
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Solution Overview
Problem
In rolling mills with adjustable product feed gaps, the actual gap size is affected by forces between rollers, leading to elastic deformation and increased gap size, which complicates precise gap control without displacement measuring devices.
Innovation Solution
A control system with an adjustment circuit and force measuring device records force and deformation data to adjust the product intake gap, accounting for elastic deformation, allowing precise gap control without complex displacement measuring devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an electromechanical feed device is used to adjust the product feed gap, then the gap can be precisely set according to the feed device's travel resolution, but the actual gap becomes larger than the target gap due to elastic deformation caused by forces between the rollers
Solution Approach 1:
The control system continuously monitors the actual gap using the feed device's position feedback and compares it with the target gap. Based on this feedback, the system automatically adjusts the feed device to compensate for elastic deformation, ensuring the actual gap remains at the desired setpoint despite forces acting on the rollers.
Solution Approach 2:
The system changes the control parameter from the feed device's raw position output to a corrected gap value that accounts for elastic deformation. By incorporating deformation compensation into the control calculation, the system maintains accurate gap dimensions even when forces cause temporary gap widening.
2Manufacturing precision
If a position measuring device is added to detect the actual gap size, then gap control accuracy can be improved, but the device complexity and cost increase significantly
Solution Approach 1:
The feed device serves dual purposes: it both adjusts the gap position and measures the actual gap size through its own position feedback mechanism. By utilizing the feed device's inherent position sensing capability, the system eliminates the need for separate position measuring devices while maintaining accurate gap control.
Solution Approach 2:
The feed device is designed to perform multiple functions: actuation for gap adjustment and measurement for gap size detection. This multi-functionality reduces the overall system complexity by consolidating what would traditionally require separate components into a single integrated device.
3Ease of operation
If the feed device is tared to zero before adjustment, then the gap can be set based on the feed device's travel resolution, but forces between the rollers push the rolls apart due to elasticity
Solution Approach 1:
The control system performs preliminary measurement of the actual gap before final gap setting is complete. By measuring the gap at an intermediate stage and using this information to calculate deformation compensation, the system prepares correction values in advance that will be applied during the final gap adjustment, ensuring stability is achieved before operation begins.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables precise control of the product feed gap, reducing costs and improving processing accuracy by accounting for forces acting between rollers, thus maintaining precise production results.
Implementation Method 1
Due to the elasticity of the machine, the actual product feed gap becomes larger than the target product feed gap set via the feed device
Data Source
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AI summary
The invention relates to a rolling mill (10, 10a) with at least two rolls (12, 14, 16) rotating about parallel roll axes (R1, R2, R3), at least one of which rolls (12, 14, 16) can be driven rotaryally by means of a rotary drive, and at least one of which is movable relative to at least one of the other rolls (12, 14, 16) to form an adjustable product feed gap (18, 20), comprising: - at least one electromechanical feed device (22, 50, 28; 34, 52, 40) for adjusting the mutual distance of the rolls (12, 14, 16), - a control (44) for the feed device (22, 50, 28; 34, 52, 40) for setting a target product feed gap (Sz), wherein the mutual distance of the rollers (12, 14, 16) can be derived via the feed device (22, 50, 28; 34, 52, 40), and - a force measuring device (32, 42) connected to the control (44) for detecting the force between the rollers (12, 14, 16).The control unit (44) has an adjustment circuit configured to bring the movable rollers (12, 14, 16) into contact with each other and to move them relative to each other, wherein the force between the rollers (12, 14, 16) can be detected via the force measuring device (32, 42) and the displacement can be detected via the feed device (22, 50, 28; 34, 52, 40), wherein the control unit (44) has a memory (46) for the detected correlated force/displacement data (58) or data (60) derived therefrom, and wherein the control unit (44) is configured to adjust the size of the product feed gap (18, 20) via the control of the feed device (22, 50, 28; 34, 52, 40), and in the event of a force acting between the rollers (12, 14, 16) force, to display a gap widening (Sc1) according to the recorded force/displacement data (58) and/or to take into account in the control (44) of the feed device (22, 50, 28; 34, 52, 40) when setting the gap (18, 20).