Metallic Tyre Reinforcing Cord for Elastomer Penetration and Adhesion

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Solution Overview

Problem

Existing metallic reinforcing cords for vehicle wheels lack adequate adhesion to elastomeric materials and do not allow sufficient penetration of elastomeric material between wires, leading to potential corrosion and fatigue issues, particularly in structural components requiring high part load elongation.

Innovation Solution

Development of metallic reinforcing cords with a part load elongation greater than 3%, comprising at least two metallic wires twisted together with a predetermined twisting pitch, allowing for improved elastomeric material penetration and adhesion, mimicking a 'double modulus' mechanical behavior similar to hybrid and mixed textile cords.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metallic reinforcing cords are used in tyres, then strength and rigidity are improved, but adhesion to elastomeric material is insufficient and penetration of elastomeric material between wires is inadequate

Engineering Contradiction:
ImprovestrengthVSAvoidadhesion
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the surface characteristics of metallic wires through coating or treatment processes. This changes the physical-chemical parameters of the wire surface to enhance adhesion properties and allow better penetration of elastomeric material, thereby resolving the contradiction between maintaining strength and improving adhesion reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining metallic wires with coating layers or treatment substances that improve adhesion. This creates a composite structure where the metal core provides strength while the coating or treatment layer enhances bonding with elastomeric material, simultaneously achieving both strength and adhesion requirements.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If metallic reinforcing cords with high rigidity are used, then structural stability is improved, but part load elongation is insufficient

Engineering Contradiction:
Improvestructural stabilityVSAvoidpart load elongation
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The patent applies parameter changes by modifying the geometric parameters of the metallic cord structure, such as wire diameter, strand configuration, or twisting pitch. These parameter adjustments allow the cord to exhibit both high rigidity for structural stability and sufficient elongation capacity under partial loads, resolving the contradiction between stability and deformability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If elastomeric material penetration between wires is increased, then adhesion is improved, but manufacturing complexity increases

Engineering Contradiction:
ImproveadhesionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-treating the metallic wire surfaces before assembling the reinforcing cord structure. Coatings or surface treatments are applied in advance to facilitate elastomeric material penetration and adhesion, thereby achieving good bonding without requiring complex manufacturing processes during cord assembly.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4076988B1Metallic reinforcing cord for tyres for vehicle wheels
Publication Date: 2026.03.04 PIRELLI TYRE SPA
  • EP4076988B1 patent drawingFigure 1
  • EP4076988B1 patent drawingFigure 2
  • EP4076988B1 patent drawingFigure 3~3a

AI summary

The invention relates to a metallic reinforcing cord (10) for tyres for vehicle wheels, comprising at least two metallic wires (11) twisted together with a predetermined twisting pitch (P). The metallic reinforcing cord (10) has a part load elongation greater than 3%, preferably greater than 3.5%.