Segmented Tire Mold for Narrow Groove Release Without Chipping

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Solution Overview

Problem

Existing tire molds face issues with tread chipping and blade damage when releasing tires with circumferential narrow grooves and lateral sipes, which can lead to increased rolling resistance and decreased wet performance due to wear.

Innovation Solution

A tire mold with a tread ring divided into at least 17 segments and specific projection and blade configurations to minimize stress concentration during tire release, forming circumferential narrow grooves and lateral sipes that reduce rolling resistance and maintain wet performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the tread ring is divided into fewer segments, then the mold structure is simpler and easier to manufacture, but stress concentration occurs during tire release causing tread chipping and blade damage

Engineering Contradiction:
Improvemold structure simplicityVSAvoidtread and blade integrity during release
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The tread ring is divided into a plurality of segments (at least 3 segments) that can move relative to each other during tire release. This segmentation distributes the stress of projection withdrawal across multiple segments, preventing stress concentration that would cause tread chipping and blade damage, while maintaining manufacturing feasibility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mold transitions from a static structure to a dynamic one where segments can move independently. During tire release, segments move to accommodate the withdrawal of projections and blades, reducing stress concentration and preventing damage to the tread and blades

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If circumferential narrow grooves are formed with narrow groove portions, then rolling resistance is reduced, but the mold projections experience high stress during release causing tread chipping

Engineering Contradiction:
Improverolling resistanceVSAvoidtread surface integrity
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

Dividing the tread ring into multiple segments allows the mold to accommodate narrow groove formations without concentrating stress on single projections. The segmented structure enables controlled movement that protects the narrow groove portions and adjacent tread surfaces from chipping during release

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove width parameter is optimized to create narrow groove portions that reduce rolling resistance. The segmented mold structure enables these narrow dimensions to be achieved while managing the stress implications during the release process

Inventive Principle:
Principle #35Parameter changes

3Reliability

If lateral sipes are formed connected to circumferential narrow grooves, then wet performance is maintained through wear, but blade stress increases causing blade damage during release

Engineering Contradiction:
Improvewet performance durabilityVSAvoidblade structural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The segmented tread ring structure distributes the stress of lateral sipe formation and release across multiple segments. This prevents excessive stress concentration on individual blades, reducing the risk of blade damage while enabling the formation of lateral sipes that maintain wet performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dynamic movement of segmented blades during tire release reduces stress on the blade structures. This allows lateral sipes to be formed with sufficient depth and connectivity for wet performance while the blades remain intact through the release process

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4644104A1Tire mold and production method for heavy duty tire
Publication Date: 2025.11.05 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4644104A1 patent drawingFigure 1
  • EP4644104A1 patent drawingFigure 2
  • EP4644104A1 patent drawingFigure 3

AI summary

Provided is a tire mold 104 that can suppress occurrence of tread chipping and blade damage when releasing a tire having a circumferential narrow groove and a lateral sipe that can contribute to reducing rolling resistance and suppressing a decrease in wet performance due to wear. The mold 104 includes a tread ring 114. The tread ring 114 includes a pattern forming portion 136. The pattern forming portion 136 includes a narrow groove projection 144 and a lateral blade 150. The tread ring 114 includes a plurality of division surfaces traversing the pattern forming portion 136. The plurality of division surfaces divide the tread ring 114 into a plurality of segments 120. The number of the segments 120 included in the tread ring 114 is not less than 17.