Rolling Mill Edge Crack Suppression via Upstream Detection Control
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Solution Overview
Problem
Existing techniques for detecting edge cracks in metal plates during rolling mill processes can only detect cracks but fail to prevent their growth, leading to potential breakage of the metal plate.
Innovation Solution
A control device for a rolling mill apparatus that includes an edge crack sensor and a control system capable of adjusting rolling conditions, such as tension and speed, to suppress edge crack growth by changing the rolling conditions from a first to a second condition upon detection of an edge crack, utilizing sensors and actuators like roll benders, heaters, and shift cylinders to manage the metal plate's tension and movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If edge crack detection is performed using an edge profile meter disposed on the output side of the rolling mill process line, then edge crack detection capability is improved, but the ability to suppress edge crack growth during mill rolling is worsened
Solution Approach 1:
The patent applies preliminary action by detecting edge cracks at an upstream position (before the finishing stand) rather than at the output side. The edge crack sensor is disposed upstream of the finishing stand, and upon detection, the control device immediately changes rolling conditions in the finishing stand to suppress crack growth. This upstream detection and immediate response prevents the crack from growing to a critical size, thereby resolving the contradiction between detection capability and growth suppression capability.
2Reliability
If rolling conditions are changed to suppress edge crack growth, then edge crack growth suppression is improved, but production efficiency is worsened
Solution Approach 1:
The patent applies dynamics by making the rolling conditions changeable and adaptive. The control device dynamically adjusts rolling conditions (such as rolling speed, tension, or temperature) in the finishing stand based on real-time edge crack detection results. When an edge crack is detected, the system changes to suppression-oriented conditions; when no crack is detected, normal production conditions are maintained. This dynamic adaptation allows the system to optimize both crack suppression and production efficiency at different times.
Solution Approach 2:
The patent applies parameter changes by modifying specific rolling parameters (speed, tension, temperature) in the finishing stand based on edge crack detection. The control device changes at least one rolling condition parameter when an edge crack is detected, and restores normal parameters after the crack risk is eliminated. This selective parameter adjustment enables crack suppression without permanently reducing production efficiency.
3Reliability
If edge crack detection is performed upstream of the finishing stand, then the ability to suppress edge crack growth during rolling is improved, but device complexity is worsened
Solution Approach 1:
The patent applies universality by utilizing the existing rolling mill control device to perform multiple functions: normal rolling control, edge crack detection response, and rolling condition adjustment for crack suppression. The control device is configured to receive detection results from the edge crack sensor and automatically change rolling conditions in the finishing stand. This multi-functional use of existing equipment avoids the need for separate dedicated crack suppression systems, thereby limiting the increase in device complexity.
Data Source
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AI summary
A control device for a rolling mill apparatus including at least one rolling mill stand for rolling a metal plate includes: a detection signal acquisition part for receiving, from an edge crack sensor, a detection signal of an edge crack at an end portion of the metal plate in a plate width direction; and a rolling condition decision part for deciding a rolling condition for the rolling mill apparatus. The rolling condition decision part is configured to change, if the detection signal acquisition part receives the detection signal of the edge crack, the rolling condition for the rolling mill apparatus from a first rolling condition immediately before detection of the edge crack to a second rolling condition which is more capable of suppressing growth of the edge crack than the first rolling condition.