Tyre Electronic Unit Mounting Gap for Stress Distribution

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Solution Overview

Problem

Existing tire monitoring systems face issues with stress concentration and fatigue due to the mechanical interference between the electronic unit and the connecting member, leading to early breakage and unreliable bonding, especially at the crown portion of the tire.

Innovation Solution

Incorporating gaps between the outer surface of the electronic unit's holding body and the cavity's surface in the connecting member allows for controlled mechanical interactions, distributing stress and reducing deformation, thereby enhancing the durability and reliability of the bond between the electronic unit and the tire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electronic unit is firmly fixed to the connecting member by means of retaining means or close contact, then the electronic unit is securely constrained to the tyre, but stress concentration and deformation occur leading to fatigue and early breakage of the connecting member

Engineering Contradiction:
Improvebond reliabilityVSAvoidconnecting member strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces a cushioning layer between the electronic unit holding body and the cavity surface of the connecting member. This layer acts as a stress-absorbing element that prevents direct mechanical interference, thereby cushioning the connecting member from stress concentration and deformation that would otherwise lead to fatigue and breakage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent employs an intermediary element (cushioning layer) positioned between the electronic unit holding body and the connecting member cavity surface. This intermediary prevents direct contact and mechanical interference, allowing the electronic unit to be constrained to the tyre while protecting the connecting member from stress concentration and potential failure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the electronic unit is firmly fixed to the connecting member, then the electronic unit remains constrained to the tyre, but the connecting member experiences stress concentration leading to early breakage

Engineering Contradiction:
Improveelectronic unit constraintVSAvoidconnecting member durability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The cushioning layer is pre-installed between the holding body and cavity surface to provide ongoing protection during tyre operation. It continuously absorbs stresses and deformations that occur during tyre rolling, preventing these forces from concentrating on the connecting member and causing fatigue or breakage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent changes the mechanical interaction parameters between the holding body and connecting member by introducing a compliant cushioning layer. This layer modifies the contact characteristics, allowing relative movement and stress distribution that prevents the rigid mechanical interference which would otherwise lead to connecting member failure.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the electronic unit is firmly fixed using retaining means, then the electronic unit is securely mounted, but the mechanical interference causes stress concentration and deformations

Engineering Contradiction:
Improveelectronic unit mountingVSAvoidstress concentration
Core Design Contradiction:
Ease of manufactureVSStress or pressure

Solution Approach 1:

The cushioning layer serves as an intermediary between the holding body and connecting member, eliminating direct mechanical interference even when retaining means are used. This intermediary absorbs and distributes stresses, preventing concentration points that would arise from rigid contact between the electronic unit mounting structure and the connecting member.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The introduction of the cushioning layer changes the mechanical parameters of the mounting system from rigid to compliant. This allows the mounting to remain secure while preventing the transmission of high stresses and deformations to the connecting member, thereby reducing stress concentration.

Inventive Principle:
Principle #35Parameter changes

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

This design significantly improves the reliability and durability of the bond between the electronic unit and the tire, reducing stress concentration and preventing early breakage, ensuring a stable and long-lasting connection.

Implementation Method 1

the gap or the gaps between the surface of the cavity in which the electronic unit is housed and the surface of the electronic unit itself allows/allow the connecting member to be gradually shaped to the surface of the electronic unit in case of impact/interaction between the two surfaces, facilitating a particularly effective dissipation of the energy transmitted from the electronic unit to the connecting member

Methodology Applied
Scientific EffectEnergy dissipation: Damping

Data Source

PatentEP2797761B1Monitoring device for tyres for vehicle wheels, tyre for vehicle wheels provided with said monitoring device, and method for installing an electronic unit in said tyre
Publication Date: 2015.10.28 PIRELLI TYRE SPA
  • EP2797761B1 patent drawingFigure 1
  • EP2797761B1 patent drawingFigure 2~2a
  • EP2797761B1 patent drawingFigure 3

AI summary

A monitoring device for tyres for vehicle wheels comprising: an electronic unit (20); a connecting member (30) configured for constraining said electronic unit (20) to a tyre (1 ), said connecting member (30) comprising: a first and a second base portion (31, 32), mutually separated by a separated region (33), each of said base portions (31, 32) having a respective base surface (31 a, 32a) associable with an inner surface (2) of a tyre (1 ); a housing portion (34) associated with said base portions (31, 32) defining, in cooperation with said base portions (31, 32), a cavity (35) for housing said electronic unit (20),wherein said housing portion (34) comprises at least one side structure (34a), configured for exerting a containing action at least relative to movements of said electronic unit (20) carried out in a major extension direction (X) of said separation region (33) and with respect to movements of said electronic unit (20) carried out in a direction orthogonal to the major extension direction (X) of said separation region (33) wherein said cavity (35) is confined at least by a side surface (351 ) defined by an inner surface (340) of said side structure (34), wherein said electronic unit (20) comprises at least one sensor (21 ), at least one antenna (22) and a holding body (26) for housing at least said sensor (21 ) and said antenna (22), wherein said holding body (26) has at least one side surface (261 ), wherein, when said electronic unit (20) is inserted in said cavity (35): the side surface (261 ) of the holding body (26) faces the side surface (351 ) of the cavity (35), and the sizes of said cavity (35) and of said holding body (26) are such as to form at least one first gap (100) at least partly separating the side surface (261) of the holding body (26) and the side surface (351) of the cavity (35). Also described are a tyre (1 ) provided with said monitoring device (10) and a method for installing an electronic unit (20) in a tyre (1 ).