Bead Ring Wire Drawing Parameter Optimization

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Solution Overview

Problem

The existing methods for forming bead rings from bead wires subjected to wire drawing face challenges in processability and production costs due to inadequate true strain, tensile strength, and proof stress ranges, often resulting in curled or deformed terminals and increased production expenses.

Innovation Solution

A bead ring is formed from a bead wire with a true strain of 2.80 or greater, tensile strength of 2000 MPa or greater, and proof stress of 1700 MPa to 1980 MPa, achieved through single wire drawing without heat treatment, allowing improved processability and reduced production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a bead wire is drawn from the initial wire diameter to the wire diameter of the final shape without heat treatment by a single wire drawing, then the production cost is reduced and the process is simplified, but the bead wire has an increased degree of wire drawing which increases proof stress and breaking load, making reforming difficult and causing terminal curling or deformation

Engineering Contradiction:
Improveproduction costVSAvoidterminal deformation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by precisely controlling the true strain during wire drawing to be within the range of 2.30 to 3.50, and controlling the proof stress to be within 1700 MPa to 1980 MPa. This optimization of parameters allows single-stage wire drawing without heat treatment while preventing terminal deformation and maintaining good processability during bead ring formation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a bead wire is subjected to wire drawing twice with heat treatment in between, then the terminal deformation is prevented and processability is maintained, but the production cost increases

Engineering Contradiction:
Improveterminal deformationVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the heat treatment step from the traditional two-stage wire drawing process. By optimizing the wire drawing parameters (true strain of 2.30 to 3.50 and proof stress of 1700 MPa to 1980 MPa), the patent achieves the desired balance between preventing terminal deformation and maintaining processability without requiring the additional heat treatment step, thereby reducing production cost.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the true strain of the bead wire is increased to improve processability, then the reforming rate increases and terminal curling is reduced, but the tensile strength and proof stress increase excessively making the wire too strong and difficult to work with

Engineering Contradiction:
ImproveprocessabilityVSAvoidtensile strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent optimizes the true strain parameter to a specific range of 2.30 to 3.50, which balances processability and strength. This parameter optimization ensures that the reforming rate is sufficiently high to prevent terminal curling while keeping the proof stress within the manageable range of 1700 MPa to 1980 MPa, avoiding excessive strength that would make the wire difficult to work with.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3620574B1Bead ring and method for manufacturing same
Publication Date: 2023.08.16 THE YOKOHAMA RUBBER CO LTD
  • EP3620574B1 patent drawingFigure 1~2
  • EP3620574B1 patent drawingFigure 3~4
  • EP3620574B1 patent drawing

AI summary

Provided are a bead ring and a method for producing the same, the bead ring allows improvement of processability during forming while reducing the production cost by setting the true strain, tensile strength, and proof stress of the bead wire that constitutes the bead ring to specific ranges. Provided is an annular bead ring 1 formed from a bead wire 2 that has been subjected to wire drawing, the bead wire 2 having a true strain ε of 2.80 or greater as calculated by Equation (1), a tensile strength of 2000 MPa or greater, and a proof stress of 1700 MPa to 1980 MPa.