Asymmetric Skew Rolling Mill for Accurate Diameter Reduction

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Solution Overview

Problem

Existing skew rolling technologies face challenges in achieving high outer diameter dimensional accuracy during diameter reduction of pipe or bar materials, particularly when reducing the diameter from large to small, due to roll shaft deflection and interference issues with multiple rolling rolls of equal diameters.

Innovation Solution

A skew rolling mill with three or more rolling rolls, where at least one roll has a diameter of 90% or less than another, allowing for asymmetric arrangement and reduced roll diameter variation to minimize interference and maintain high accuracy, with a drive roll and non-drive roll configuration to manage torque and bending.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If three or more rolling rolls of equal diameter are arranged along the circumferential direction to perform diameter reducing rolling, then outer diameter dimensional accuracy is improved, but roll shaft deflection occurs under rolling load which reduces accuracy

Engineering Contradiction:
Improveouter diameter dimensional accuracyVSAvoidroll shaft deflection resistance
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent applies asymmetry by configuring rolling rolls with different diameters instead of equal diameters. Specifically, at least one rolling roll has a diameter that is 90% or less of another rolling roll's diameter, creating an asymmetric arrangement that reduces roll shaft deflection while maintaining manufacturing precision through the differential diameter configuration

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by making each rolling roll have different local properties (different diameters) suited to their specific positions and load conditions. This allows each roll to be optimized for its local stress environment, with smaller diameter rolls positioned to handle specific loading conditions that would cause deflection in equal-diameter configurations

Inventive Principle:
Principle #3Local quality

2Productivity

If three or more rolling rolls are arranged to reduce outer diameter of material, then diameter reduction capability is improved, but interference between rolling rolls occurs which restricts reduction range

Engineering Contradiction:
Improvediameter reduction capabilityVSAvoidreduction range
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The asymmetric diameter configuration allows rolling rolls to be arranged in a manner that reduces interference between adjacent rolls. By having different diameters, the rolls can be positioned to accommodate a wider range of reduction ratios without the geometric interference that occurs in equal-diameter arrangements, thereby improving adaptability while maintaining productivity

Inventive Principle:
Principle #4Asymmetry

3Productivity

If all rolling rolls are made small to roll small diameter material, then small diameter rolling capability is improved, but roll shaft deflection increases which reduces outer diameter dimensional accuracy

Engineering Contradiction:
Improvesmall diameter rolling capabilityVSAvoidouter diameter dimensional accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by assigning different diameters to different rolling rolls based on their specific functional requirements. Larger diameter rolls are used where structural stability and deflection resistance are critical, while smaller diameter rolls are used where compact rolling capability is needed, optimizing both small diameter rolling capability and dimensional accuracy through localized property differentiation

Inventive Principle:
Principle #3Local quality

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 configuration enables diameter reduction with excellent outer diameter dimensional accuracy over a wide range, reducing material damage and improving uneven thickness issues, while maintaining high rigidity and torque transmission.

Implementation Method 1

the material to be rolled made of a pipe or bar material is fed between the rolls being rotated, and pulled in and caused to pass through between the rolls while being rotated by the rotation of the rolls

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4063035B1Rolling mill for diameter reduction rolling, and strip manufacturing method
Publication Date: 2023.11.29 JFE STEEL CORP
  • EP4063035B1 patent drawingFigure 1A~3
  • EP4063035B1 patent drawingFigure 4A~5
  • EP4063035B1 patent drawingFigure 6A~7B

AI summary

Materials to be rolled ranging from large to small in diameter undergo diameter reducing rolling with excellent outer diameter dimensional accuracy. A rolling mill includes three or more rolling rolls (2) aligned along a circumferential direction and arranged such that each rotary shaft thereof is skewed with respect to a pass line P of a material to be rolled (1), in which the material to be rolled (1) made of a pipe or bar material is caused to pass through between the three or more rolling rolls (2) while being rotated to undergo diameter reducing rolling. At least one rolling roll (2) selected from the three or more rolling rolls (2) is smaller in roll diameter than at least one other rolling roll (2). When, among the three or more rolling rolls (2), at least one rolling roll (2) having a relatively maximum roll diameter is defined as a maximum diameter rolling roll (2A) and at least one rolling roll (2) smaller in roll diameter than the maximum diameter rolling roll (2A) is defined as a small diameter rolling roll (2B), the small diameter rolling roll (2B) has a roll diameter equal to or less than 90% of the roll diameter of the maximum diameter rolling roll (2A) .