Partitioned Multistage Rolling Mill for Wider Roll Opening

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Solution Overview

Problem

Conventional cluster-type multistage rolling mills with single mono-block mill housings have limited work roll open amount and roll diameter range, leading to increased installation space requirements and higher costs due to the need for large outer housings and frames for raising and lowering the mill housings.

Innovation Solution

A compact cluster-type multistage rolling mill design that partitions the mill housing into upper and lower parts, using a system of columns, hydraulic cylinders, and spacers to adjust the position of the mill housings, thereby increasing the work roll open amount and roll diameter range without the need for large outer housings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the mill housing is partitioned into upper and lower parts to increase the open amount of the work rolls, then the work roll open amount is increased, but the mill rigidity decreases due to increased deformation of the partitioned housings

Engineering Contradiction:
Improvework roll open amountVSAvoidmill rigidity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The mill housing is divided into an upper mill housing and a lower mill housing that can move relative to each other vertically. This segmentation allows the work rolls to be opened wider while maintaining structural integrity through the column-based connection system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Four columns act as intermediary elements connecting the upper and lower mill housings. These columns transmit and distribute the prestress load uniformly across both housings, preventing excessive deformation while allowing controlled relative movement for work roll opening.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the mill housing is partitioned into upper and lower parts with prestress application, then the mill rigidity is maintained, but the use range of work rolls cannot be enlarged

Engineering Contradiction:
Improvemill rigidityVSAvoidwork roll diameter range
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The lower mill housing is designed to move vertically relative to the upper mill housing, allowing dynamic adjustment of the mill configuration. This enables the system to adapt to different work roll diameters while maintaining rigidity through the prestress mechanism applied via the four columns.

Inventive Principle:
Principle #15Dynamics

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 achieves a compact multistage rolling mill with a smaller installation space, enabling a wider range of work roll diameters and maintaining high mill rigidity, while reducing the need for large outer structures and associated costs.

Implementation Method 1

an upper hydraulic cylinder for applying a prestress load at upper parts of the four columns

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a lower hydraulic cylinder for changing the position of the upper mill housing between the upper and lower mill housings

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP4094855B1Multistage rolling mill
Publication Date: 2025.06.04 NIPPON SENJIMIA
  • EP4094855B1 patent drawingFigure 1
  • EP4094855B1 patent drawingFigure 2
  • EP4094855B1 patent drawingFigure 3

AI summary

A multistage rolling mill includes: four columns 12a, 12b, 12c, and 12d linking, in an up-down direction, four corners of each of an upper mill housing 8, a lower mill housing 9, and a base mill housing 10; a press-down section that is provided on an upper side of the four columns 12a, 12b, 12c, and 12d in a vertical direction and that is capable of raising and lowering the upper mill housing 8; and a lower mill housing spacer that is provided between the lower mill housing 9 and the base mill housing 10 and that adjusts the position of the lower mill housing 9 in the vertical direction. With this configuration, a compact multistage rolling mill with a smaller installation space than a conventional cluster-type rolling mill is provided.