Variable-Thickness Tube Forming With Scrap-Free Spiral Transitions

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Solution Overview

Problem

Existing methods for producing tubes with varying thicknesses face challenges such as material inefficiency and production interruptions, leading to scrap and increased costs due to the need for pausing continuous production processes to accommodate thickness changes.

Innovation Solution

A method involving a planar strip of metal with discrete sections of varying thickness, where the material is fed into a curving device with a separation plane to form cylinders with a spiral seam, allowing for seamless transitions without scrap or interruptions, using a fabrication system that continuously welds and cuts the material along a spiral seam.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If continuous production process is used to form tubes with varying thickness, then productivity is improved, but manufacturing precision deteriorates due to difficulty in accommodating thickness transitions

Engineering Contradiction:
Improveproduction throughputVSAvoidthickness transition accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The material is divided into discrete sections, each with a uniform thickness, arranged in a specific sequence. Each discrete section forms a complete tube with the desired thickness profile, allowing continuous production while maintaining precision through segmented material organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The material is pre-configured with discrete sections of varying thicknesses before entering the curving device. This preliminary arrangement of thickness profiles in the material strip allows the forming process to proceed continuously without interruptions for thickness adjustments.

Inventive Principle:
Principle #10Preliminary action

2Strength

If tube thickness is varied along the length to accommodate loading, then structural performance is improved, but material efficiency deteriorates due to scrap generation at thickness transitions

Engineering Contradiction:
Improvestructural performanceVSAvoidmaterial waste
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

Each discrete section of the material has a specific uniform thickness tailored to the structural requirements of that section of the tube. This local optimization of material thickness provides the necessary structural performance while minimizing material waste by avoiding scrap generation at transitions.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If discrete sections with varying thickness are joined along spiral seam, then manufacturing precision is improved, but device complexity increases due to continuous curving and joining process

Engineering Contradiction:
Improvethickness profile accuracyVSAvoidcurving and joining system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The curving and joining process operates continuously as the material moves through the curving device, with the spiral seam formed and welded in one continuous operation. This eliminates interruptions and maintains precision without requiring complex intermittent adjustment mechanisms.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The material is curved into a cylindrical form with a spiral seam that continuously joins discrete sections. This curved geometry allows the varying thickness profiles to be seamlessly integrated while maintaining structural integrity through the continuous spiral joining process.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 approach enables the efficient production of tubes with varying thicknesses, reducing material waste and production downtime, resulting in cost savings and improved throughput by maintaining continuous production processes.

Implementation Method 1

forming the material into a first cylinder having a spiral seam intersected by the separation plane

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

joining the first discrete section to itself and to the second discrete section along the spiral seam

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3548195B1Cylindrical tube formation
Publication Date: 2023.06.07 KEYSTONE TOWER SYSTEMS INC
  • EP3548195B1 patent drawingFigure 1
  • EP3548195B1 patent drawingFigure 2
  • EP3548195B1 patent drawingFigure 3

AI summary

Tube forming methods can be used for efficient transition in the production of tubes having varying thickness. Material used to form consecutive tubes may have the same thickness along a separation plane separating a first discrete section from a second discrete section of the material, and the first discrete section and the second discrete section may each have varying thickness in a feed direction of the material. With such a thickness profile, the first discrete section of the material may be formed into a first cylinder having varying thickness and separated from the second discrete portion as the second discrete section is formed into a second cylinder having varying thickness. In particular, the transition between the first cylinder and the second cylinder may be achieved without scrap and/or interruption, resulting in cost-savings and improvements in production throughput associated with forming tubes having varying thickness.