Movable Rail Rolling Mill Stand for Strip-In-Mill Roll Changes
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Solution Overview
Problem
Existing rolling mill stands face challenges in efficiently replacing work rolls while maintaining continuous operation, as existing solutions require cutting the metallic strip and interrupting production, and modifications to the mill stand can complicate the roll change process.
Innovation Solution
The implementation of a rolling mill stand design featuring movable rails that can be independently positioned to facilitate the withdrawal and insertion of work rolls without interrupting the rolling process, using hydraulic actuators to move the rails between idle and service positions, allowing for 'strip-in-the-mill' changes and reducing downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If work rolls are removed from the rolling mill stand while the metallic strip is present, then the work roll assembly can be replaced without cutting the strip, but the work rolls must be separated from the strip before being drawn out in the transverse direction, which complicates the removal procedure
Solution Approach 1:
The rail system is designed to be dynamically reconfigurable, allowing rails to move between fixed positions (for transverse roll removal) and movable positions (for longitudinal roll separation). This dynamic adaptability enables the system to switch between different operational modes depending on whether rolls need to be removed while the strip is present or during normal operation.
Solution Approach 2:
The rail system is divided into multiple independent rail segments that can be individually positioned and controlled. This segmentation allows different parts of the rail system to perform different functions simultaneously - some rails guiding rolls in the transverse direction while others facilitate longitudinal movement, thereby simplifying the overall removal procedure despite the complex operational requirements.
2Productivity
If the rolling mill stand is modified to facilitate work roll replacement, then roll change efficiency can be improved, but structural modifications can lead to difficulties in changing the work roll assembly
Solution Approach 1:
The rail system incorporates movable rails that can be repositioned between fixed and movable states, allowing the system to adapt to different operational phases. During roll insertion, rails are in fixed positions to guide rolls accurately; during roll removal with strip present, rails become movable to facilitate longitudinal separation, thereby simplifying operations despite structural modifications.
Solution Approach 2:
The movable rails act as intermediaries between the work rolls and the mill stand structure. By introducing these intermediate elements that can change their state (fixed or movable), the system mediates the complex interaction between roll replacement operations and the stationary mill stand, thereby simplifying the overall replacement process.
3Ease of manufacture
If fixed rails are used for moving work rolls in the transverse direction, then roll replacement can be achieved, but the work rolls cannot be separated from the metallic strip before removal, requiring production interruption
Solution Approach 1:
The rail system transitions from static fixed rails to dynamic movable rails that can change their constraints based on operational needs. When rolls need to be separated from the strip, rails become movable in the longitudinal direction, enabling roll extraction without strip interruption. When precise transverse positioning is needed, rails return to fixed positions, thereby maintaining both roll replacement capability and production continuity.
Solution Approach 2:
The system adds longitudinal movability to the traditionally transverse-only rail system. By enabling rails to move in the longitudinal dimension (in addition to their fixed transverse positioning capability), the system creates a two-dimensional movement capability that allows rolls to be separated from the strip along the longitudinal axis before transverse removal, thereby maintaining production continuity.
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 solution enables rapid and efficient replacement of work rolls without interrupting production, improving productivity and operator safety, while maintaining a compact footprint suitable for retrofitting existing mills.
Implementation Method 1
using hydraulic actuators to move the rails between idle and service positions
Data Source
AI summary
A rolling mill stand for rolling a metallic product (P′) that includes, inter alia: first and second movable rails arranged to allow unimpeded movement of work roll chocks of upper and lower work rolls when in an idle position during rolling operations, and replacement of the upper and lower work rolls when in a service position. Methods are provided for moving the first and second movable rails between the idle position and the service position in order to replace the upper and lower work rolls.