Pneumatic Tire Bead Profile Geometry for Defect Detection

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Solution Overview

Problem

Conventional pneumatic vehicle tire bead constructions mask potential construction defects, such as air bubbles and improper component splices, making them difficult to detect during manufacturing, and result in limited bead durability leading to premature tire replacement.

Innovation Solution

The tire bead design features a shell-like configuration where the outer bead profile rests on the core profile and bead reinforcement, with a geometric alignment that reduces compressive deformation forces and enhances shear and tensile moduli distribution, allowing for easier defect visualization and increased durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer bead profile protrudes beyond the core profile, then the bead structure provides sufficient strength and stability, but construction defects such as air bubbles and improper splices are masked and difficult to detect

Engineering Contradiction:
Improvebead structure strengthVSAvoiddefect detectability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The bead structure is divided into distinct segments: the core profile (providing structural strength) and the outer bead profile (providing visibility). By segmenting the bead into functional zones with different heights, the invention allows the core to maintain structural integrity while the reduced outer profile exposes defects for detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rubber compound acts as an intermediary material that fills the space between the core profile and the outer bead profile. This rubber layer provides the necessary structural connection while allowing the outer profile to be reduced in height for defect visibility, thus mediating between the conflicting requirements of strength and detectability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the outer bead profile protrudes beyond the core profile, then the bead maintains structural integrity, but bead durability is limited and premature replacement is required

Engineering Contradiction:
Improvebead structural integrityVSAvoidbead service life
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The bead is segmented into the core profile (for structural integrity) and the outer bead profile (optimized for durability). The core profile maintains the necessary structural strength while the outer profile is reduced to minimize stress concentration and deformation forces, thereby extending bead service life.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the bead profiles, specifically reducing the height of the outer bead profile relative to the core profile. This parameter change reduces the angle between the carcass ply and the bead profile, minimizing deformation forces and extending the operational life of the bead.

Inventive Principle:
Principle #35Parameter changes

3Difficulty of detecting and measuring

If the outer bead profile is reduced below the core profile, then defect detection is facilitated and bead durability is improved, but additional manufacturing precision is required for geometric alignment

Engineering Contradiction:
Improvedefect visibilityVSAvoidprofile alignment precision
Core Design Contradiction:
Difficulty of detecting and measuringVSManufacturing precision

Solution Approach 1:

The core profile and outer bead profile are pre-formed with predetermined geometric relationships during the tire building process. The core profile serves as a reference structure, and the outer profile is positioned relative to it with specific dimensional tolerances, allowing for automated construction with reduced manual inspection requirements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Specific geometric parameters are defined for the profiles: the outer bead profile height is set to 0.5-2mm below the core profile outer end, and the angle between the carcass ply and bead profile is reduced to 15-45 degrees. These parameter specifications provide clear manufacturing targets that balance defect visibility with manufacturability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2298579B1Pneumatic type for vehicle with a tyre bead with at least one core and at least one core profile and production method
Publication Date: 2016.05.11 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP2298579B1 patent drawingFigure 1
  • EP2298579B1 patent drawingFigure 2
  • EP2298579B1 patent drawingFigure 3

AI summary

The vehicle pneumatic tire comprises a tread, a tire side wall, and a tire bead (1) with a core (3), a core profile (2) and a bead outer profile. The core profile surrounds the core rotation symmetrically to the axial axis of the vehicle pneumatic tire. The end (14) of the bead outer profile rests at the core profile in disk-shaped manner and is arranged below the outer end (13) of the core profile.