Rolling Mill Chock Positioning for Thrust Force Balance
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Solution Overview
Problem
Existing rolling mill technologies face challenges in accurately measuring and controlling thrust forces between rolls, leading to issues like zigzagging and camber in workpieces due to asymmetric deformation and friction coefficient changes, which affect the precision of thrust force calculations and reduction leveling control.
Innovation Solution
A rolling mill configuration that includes a reference roll, measurement apparatus for thrust counterforces, and a position control unit to adjust roll chock positions, ensuring thrust counterforces remain within an allowable range by using a hydraulic cylinder or servo-motor for precise positioning and eliminating inter-roll cross angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If thrust counterforce is measured during rolling to control zigzagging, then zigzagging control is enabled, but changes in rolling conditions cause changes in thrust counterforce working point, making it difficult to correctly identify asymmetric deformation
Solution Approach 1:
The patent applies preliminary action by measuring thrust counterforce before rolling begins (when the roll gap is open) rather than during rolling. This allows the working point to remain stable and known, enabling accurate identification of asymmetric deformation characteristics that can then be used for reliable reduction leveling control throughout the rolling process.
2Measurement precision
If roll skew angle is measured using a distance sensor to calculate thrust force, then zigzagging control is enabled, but roll vibration and chock position fluctuation make it difficult to accurately measure horizontal displacement
Solution Approach 1:
The patent extracts the measurement of horizontal displacement from the problematic roll skew angle measurement approach. Instead of measuring roll skew angle during rolling (which is affected by vibration and chock fluctuation), it measures thrust counterforce in a stable pre-rolling state, thereby eliminating the measurement errors caused by dynamic conditions.
3Object-affected harmful factors
If the positions of roll chocks are adjusted to eliminate inter-roll cross angles, then thrust forces between rolls are reduced, but additional control mechanisms are required
Solution Approach 1:
The patent applies feedback by using the measured thrust counterforce (obtained in the stable pre-rolling state) as input to the position control unit. The position control unit then adjusts the roll chock positions to eliminate inter-roll cross angles, with the feedback loop ensuring that thrust forces are reduced while maintaining control stability.
4Ease of manufacture
If friction coefficient changes are not accounted for in thrust force calculation, then calculation is simpler, but accuracy of thrust force determination deteriorates
Solution Approach 1:
The patent replaces the mechanical calculation approach (which requires friction coefficient data that changes over time) with a direct measurement approach. By measuring thrust counterforce directly in a stable pre-rolling state, the system eliminates the need to account for friction coefficient variations, thereby maintaining both simplicity and accuracy.
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 approach effectively reduces thrust forces between rolls, minimizing zigzagging and camber in workpieces by accurately controlling roll positions and maintaining stable rolling conditions.
Implementation Method 1
using a hydraulic cylinder or servo-motor for precise positioning
Data Source
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AI summary
A method for setting a rolling mill is provided, in which the rolling mill is a rolling mill of four-high or more that includes a plurality of rolls including at least a pair of work rolls and a pair of backup rolls that support the work rolls, wherein, before zero point of reduction position adjustment or before starting rolling, any one roll among respective rolls arranged in a vertical direction is taken as a reference roll, the method comprising: a thrust counterforce measurement step of measuring thrust counterforces in the axial direction of rolls which act on at least the rolls other than the backup rolls; and a roll chock position adjustment step of fixing a rolling direction position of a roll chock of the reference roll as a reference position, and moving roll chocks of the rolls other than the reference roll in a rolling direction of a workpiece to adjust positions of the roll chocks so that the thrust counterforces measured fall within an allowable range.