Tube Forming Device with Segmented Pressing for Uniform Diameter

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Solution Overview

Problem

Existing tube forming apparatuses face challenges in forming a work into a tubular shape with a continuous length and small diameter due to main roll deflection, leading to inconsistent diameter variations along the length.

Innovation Solution

A tube forming apparatus with a main roll of smaller radius than the predetermined tubular shape, utilizing a pressing member and driving sources to control the bending process, including forward and reverse rotations, and a moving mechanism to adjust the relative position between the main roll and pressing member to achieve uniform curvature, preventing main roll displacement and ensuring consistent diameter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a main roll with long axial length is used to form a tube of continuous length, then the tube length is improved, but the main roll becomes deflected causing diameter inconsistency

Engineering Contradiction:
Improvetube lengthVSAvoiddiameter uniformity
Core Design Contradiction:
Length of moving objectVSManufacturing precision

Solution Approach 1:

The pressing operation is segmented into multiple zones along the axial direction of the main roll. Pressing members are distributed at different axial positions to apply localized pressing forces, preventing overall roll deflection while maintaining tube continuity. This segmentation allows the long main roll to maintain its shape by receiving distributed support rather than concentrated loading.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pressing force is applied locally at specific axial positions rather than uniformly across the entire roll length. By concentrating pressing actions at discrete locations where pressing members contact the main roll, the system maintains diameter precision at critical sections without requiring the entire roll to resist deflection, thus preserving both tube length and diameter uniformity.

Inventive Principle:
Principle #3Local quality

2Length of moving object

If a main roll with small diameter is used to form a tube of small diameter, then the tube diameter is improved, but the main roll becomes more deflectable at axially intermediate portions

Engineering Contradiction:
Improvetube diameterVSAvoidroll rigidity
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The pressing members act as counterbalancing elements that apply localized forces to counteract the deflection tendency of the small-diameter main roll. By positioning pressing members at strategic axial locations, they provide localized support that compensates for the reduced rigidity of the smaller roll, preventing excessive deflection at axially intermediate portions while maintaining the desired small tube diameter.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The pressing members are positioned and activated in advance at critical axial locations before the forming process begins. This preliminary positioning ensures that the main roll receives supportive forces at the correct locations to prevent deflection during operation, allowing the use of smaller diameter rolls without sacrificing structural stability.

Inventive Principle:
Principle #10Preliminary action

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 apparatus effectively forms a tubular shape with a continuous length and uniform small diameter by controlling the bending process, preventing main roll deflection and ensuring high strength materials like high tensile steel can be used.

Implementation Method 1

a tube forming apparatus... designed to pass a work between the main roll and each of the subsidiary rolls sequentially to bend the work toward the main roll side, thereby forming the work into a tubular shape

Methodology Applied
Scientific EffectBending: Deformation

Implementation Method 2

Another known tube forming apparatus... includes a hard main roll and an elastic roll which are designed to rotate by being pressed against each other... to wrap the work around the peripheral surface of the hard roll

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2332666B1Cylinder forming device and cylinder forming method
Publication Date: 2019.10.30 FUJI MACHINE WORKS
  • EP2332666B1 patent drawingFigure 1
  • EP2332666B1 patent drawingFigure 2
  • EP2332666B1 patent drawingFigure 3

AI summary

A cylinder forming method comprises a forward rotating step of positioning auxiliary rolls (3) at a forming position and forwardly rotating a main roll (2) while the main roll is brought into contact with a work (W) between the first end (W1) and the center (W3), a conveying step of positioning the auxiliary rolls (3) at a retreating position and forwardly rotating the main roll (2) while the main roll is brought into contact with the work (W) between the center (W3) and the second end (W2), a reverse rotating step of positioning the auxiliary rolls (3) at a forming position and reversely rotating the main roll (2) while the main roll is brought into contact with the work (W) between the second end (W2) and the center (W3). These steps are performed in this order. The auxiliary rolls (3) are rotated in the direction reverse to the rotating direction of the main roll (2). The work (W) does not pass through the peripheral surface of the main roll (2) on the opposite side of the auxiliary rolls (3).