Retreaded Tire Shoulder Groove Dimples for Peeling Resistance

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Solution Overview

Problem

Retreaded tires often experience damage due to tread rubber peeling off from the base tire, particularly at the shoulder portions where heat generation is high.

Innovation Solution

Incorporating a first shoulder circumferential groove with a plurality of dimples on its groove surface to enhance heat dissipation and improve adhesion between the tread rubber and the base tire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tread rubber is adhered to the base tire without additional groove structures, then the manufacturing process is simple, but the peeling resistance of the tread rubber is poor

Engineering Contradiction:
Improvepeeling resistanceVSAvoidgroove structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The groove surface is equipped with dimples creating a porous-like structure that enhances adhesion between the tread rubber and base tire through increased surface area and mechanical interlocking, thereby improving peeling resistance without adding complex external components

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention transitions from a flat groove surface to a three-dimensional structure with dimples, utilizing the vertical dimension to create anchoring effects that prevent peeling while maintaining overall structural simplicity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If the shoulder circumferential groove has a smooth groove surface, then the manufacturing process is simple, but the heat dissipation performance is insufficient

Engineering Contradiction:
Improveheat dissipationVSAvoidgroove surface processing
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The dimples create a porous-like surface structure on the groove that significantly enhances heat dissipation through increased surface area and improved convection, while the regular pattern of dimples allows for straightforward manufacturing using conventional molding techniques

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The dimples introduce curved surfaces to the otherwise flat groove bottom, and curved surfaces are more effective at dissipating heat through convection and radiation compared to flat surfaces, while still being manufacturable with standard tools

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If the groove surface is flat without dimples, then the vulcanization process time is longer, but the process control is simpler

Engineering Contradiction:
Improvevulcanization speedVSAvoidgroove surface structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The dimpled structure creates a porous-like surface that allows for more efficient heat and pressure distribution during vulcanization, reducing the time required for complete curing while the regular pattern of dimples keeps the molding process straightforward

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The dimples are pre-formed in the mold, creating surface features before vulcanization that actively promote faster curing by improving contact and heat transfer, thus accelerating the process without requiring complex real-time control

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 dimples enhance peeling resistance, reduce noise, and shorten vulcanization process time while maintaining steering stability and durability.

Implementation Method 1

the first shoulder circumferential groove has a groove surface provided with a plurality of dimples... the dimples enhance peeling resistance, reduce noise, and shorten vulcanization process time

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP4393724B1Retreaded tire
Publication Date: 2025.06.25 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4393724B1 patent drawingFigure 1
  • EP4393724B1 patent drawingFigure 2
  • EP4393724B1 patent drawingFigure 3

AI summary

A retreaded tire includes a base tire (1a) and a tread rubber (2a) for retread adhered to the base tire. The tread rubber (2a) includes a first tread edge (T1) and a first shoulder circumferential groove (11) adjacent to the first tread edge (T1) and extending continuously in a tire circumferential direction. The first shoulder circumferential groove (11) has a groove surface provided with a plurality of dimples (25).