Rolling Mill Stand Bending Blocks for Wider Roll Opening Stability
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Solution Overview
Problem
Existing rolling mill stands face challenges with limited maximum opening capacity between work rolls, instability during rolling of thick products, and increased costs due to complex construction and difficult assembly, especially when trying to accommodate large product thicknesses and high reaction forces.
Innovation Solution
A rolling mill stand design featuring two upper and two lower work rolls with separate upper and lower bending blocks, integrated with axial shifting devices and T-section sliding guides, allowing for horizontal and vertical movements to enhance stability and flexibility, and reducing the need for additional shifting blocks and complex assembly processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the upper bending block is fixed to the chock of the upper backing roll, then the structure is simplified, but the offset between work roll and backing roll becomes ineffective and the assembly is free to cross over during rolling
Solution Approach 1:
The upper bending block is segmented into two separate elements: one fixed to the housing and another fixed to the chock of the upper backing roll. This segmentation allows the bending force to be applied independently while maintaining the stability of the work roll relative to the backing roll, resolving the contradiction between structural simplicity and roll pack stability.
2Ease of manufacture
If the upper bending block is fixed to the housing, then the offset application is simplified, but the maximum opening capacity between work rolls is limited to about 350-650 mm
Solution Approach 1:
The system employs dynamic elements including axial shifting devices that allow the work rolls to move horizontally during rolling operations. This dynamic capability enables the system to accommodate larger product thicknesses and achieve greater opening capacities beyond the static limitations of conventional fixed bending block designs.
3Adaptability or versatility
If additional shifting blocks are installed on spare chocks of upper backing rolls, then the shifting functionality is improved, but the costs increase and installation becomes more difficult
Solution Approach 1:
The bending block system is designed with multi-functionality, where the same structural elements serve both bending and shifting functions. The axial shifting devices are integrated into the existing bending block structure, eliminating the need for separate shifting blocks on spare chocks and reducing both installation complexity and costs.
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
The design increases the maximum opening capacity between work rolls, stabilizes the roll pack during high-force rolling, simplifies assembly and disassembly, and reduces costs by eliminating the need for additional shifting blocks and complex balancing crosspieces, while maintaining effective bending and shifting functionality.
Implementation Method 1
such systems employ bending blocks to impart to the work cylinders a curvature of inclination which is opposite and positive with respect to that produced when the rolling forces are applied... by virtue of the action of hydraulic pistons, manage to contrast the curvature produced by the reaction to the force applied to the product to be rolled
Implementation Method 2
a chock of the lower work roll and a chock of the lower backing roll, an axial shifting device of the upper work roll to produce a first horizontal translational movement of the upper work roll in a direction parallel to the axis thereof, an axial shifting device of the lower work roll to produce a second horizontal translational movement of the lower work roll in a direction parallel to the axis in which the chock of the lower work roll is constrained to the lower bending block by means of a first vertical sliding coupling
Data Source
AI summary
The rolling mill stand comprises a bending device and a shifting device for the rolling rolls. The housing supports the upper backing and work rolls, and the lower backing and work roll and comprises the lower bending block, the upper bending block, the chock of the upper work roll, the chock of the lower work roll, the axial shifting device of the upper work roll, the axial shifting device of the lower work roll. The chock of the lower work roll is coupled with the lower bending block to transmit a bending load on the lower work roll. The upper bending block transmits a bending load on the upper work roll by means of the action of actuators. The bending block comprises a slide with a T-section which slides in the guide and a chock of the upper backing roll, whereby the upper bending block, instead of being a single piece, is formed by two different and separate structural components.