Inflating Body Junction Insert for Torsional Stiffness and Cable Routing

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Solution Overview

Problem

Existing vehicle body reinforcements at the junction of the rear ring, roof, and body sides are compromised by drilling for electrical power supply, reducing their effectiveness in resisting torsional stress.

Innovation Solution

An insert with a fastening means and inflatable second part is used to reinforce the junction, maintaining torsional frequency at 40 Hz while allowing conductor passage, comprising a first part with a main cavity and stiffening ribs, and a second part that expands to stiffen the structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the reinforcement is drilled to allow passage of conductors for electrical power supply, then the trunk door can be supplied with electrical power, but the effectiveness of the reinforcement in resisting torsional stress is reduced

Engineering Contradiction:
Improveelectrical power supply capabilityVSAvoidtorsional resistance
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The reinforcement is divided into a first part (solid reinforcement structure) and a second part (insert with conductor passage). The insert is positioned within a cavity of the first part, allowing conductors to pass through the insert while the first part maintains its torsional resistance. This segmentation enables both electrical power supply and structural strength to coexist without compromising either function.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If a solid reinforcement structure is used to maximize torsional resistance, then the body structure stability is improved, but electrical power supply to the trunk door becomes difficult

Engineering Contradiction:
Improvebody structure stabilityVSAvoidelectrical power supply capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The insert acts as an intermediary element between the solid reinforcement structure and the electrical conductor requirements. It provides a dedicated passage for conductors while being positioned within the cavity of the first part, allowing the solid reinforcement to maintain its stability while enabling electrical power supply through the insert's passage.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the insert uses a swollen product to stiffen the structure, then the torsional frequency reaches 40 Hz, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvetorsional frequencyVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The second part of the insert utilizes phase transition (swelling) of a swollen product in response to temperature variation to achieve stiffening. The swollen product expands when exposed to heat (e.g., during paint curing), increasing the volume and stiffness of the insert, thereby raising the torsional frequency to 40 Hz. This phase transition mechanism provides an automatic stiffening process that integrates with the existing manufacturing workflow.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The swollen product undergoes thermal expansion when exposed to temperature variation, particularly during the paint curing process. This thermal expansion causes the second part to swell and stiffen the overall insert structure, contributing to achieving the target torsional frequency of 40 Hz while utilizing an already-present heat source in the manufacturing process.

Inventive Principle:
Principle #37Thermal expansion

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 insert enhances torsional resistance and conductor guidance, maintaining structural integrity and reducing deformation at the junction while ensuring power supply to vehicle doors, offering improved vibration acoustics and economical cable guidance.

Implementation Method 1

the second part being made of a swollen product, in particular a swollen product whose volume is subject to change through a phase change in response to temperature variation

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

by heating triggering the expansion or inflation of the second part, in particular by passing through a paint oven

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3895963B1Inflating insert for vehicle body structure
Publication Date: 2026.01.28 RENAULT SA
  • EP3895963B1 patent drawingFigure 1~2
  • EP3895963B1 patent drawingFigure 3
  • EP3895963B1 patent drawingFigure 4

AI summary

The invention relates to an anti-vibration insert (30) for a vehicle body structure, in particular a motor vehicle (1), intended to be positioned at a junction (9) between a roof (4), a rear ring (5) comprising a side gutter and a body side (7) comprising a rear quarter panel reinforcement, the insert (30) comprising a first part including a main cavity, in particular a first part made of plastic, a second part fitting at least partially into the main cavity of the first part so as to stiffen the insert (30) and/or the junction (9), in particular to stiffen the first part, by pressing against the side gutter, in particular against a first face of the side gutter, and/or by pressing against the rear quarter panel reinforcement, in particular against a second face of the rear quarter panel reinforcement.