Motor Vehicle Rear Structure with Free Stop Pin for Warning Device Protection

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Solution Overview

Problem

Existing motor vehicle rear structure assemblies fail to protect corner obstacle warning devices from damage during rear impacts, as they are prone to crushing against the rear wall during collisions, which violates the ECE42 standard.

Innovation Solution

A motor vehicle rear structure assembly featuring a support plate with a free stop pin that secures the corner obstacle warning device, allowing the stop pin to bear against the rear wall during deformation, thus preventing crushing, and an air extractor to release pressure and prevent the approximation of the side wall to the rear wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the corner obstacle warning device is housed between the rear wall and the side panel, then the device is protected from external exposure, but the device is vulnerable to crushing during rear impacts

Engineering Contradiction:
Improvedevice integrityVSAvoidimpact damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A support plate is introduced as an intermediary component between the side panel and the corner obstacle warning device. The support plate includes a free stop finger that extends toward the rear wall, creating a protective barrier that prevents the side panel from directly crushing the device during impact while maintaining the compact housing arrangement

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the side panel is made deformable to absorb impact energy, then the overall structure becomes more resilient, but the obstacle warning device is at risk of being crushed against the rear wall

Engineering Contradiction:
Improveimpact resistanceVSAvoiddevice protection
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The support plate with its free stop finger is pre-positioned to create a cushioning barrier before impact occurs. During rear-end collision, the deformable side panel absorbs impact energy while the stop finger makes contact with the rear wall first, establishing a mechanical stop that prevents the side panel from collapsing onto and crushing the obstacle warning device

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

3Ease of manufacture

If the support plate is connected only to the side panel without additional fastening means on the rear wall, then the installation complexity is reduced, but the structural support may be insufficient during impact

Engineering Contradiction:
Improveinstallation simplicityVSAvoidstructural support
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The support plate is designed to connect only to the side panel, eliminating the need for additional fastening means on the rear wall. The free stop finger extends outward and utilizes the rear wall as a passive stopping surface during impact, allowing the structure to serve itself by converting the rear wall into a functional element without requiring active attachment

Inventive Principle:
Principle #25Self-service

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 solution effectively protects the corner obstacle warning device from damage during rear impacts by providing resistance to deformation and maintaining the device's integrity, while also preventing damage from air pressure release, adhering to the ECE42 standard without requiring additional fastening means.

Implementation Method 1

when the side panel is pushed towards the rear wall, the locking tab comes into contact with this rear wall, providing resistance to the impact

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

The air extractor allows the air pressure inside the trunk and the passenger compartment of the motor vehicle to be released

Methodology Applied
Scientific EffectPressure release: Depressurisation

Data Source

PatentEP3868611B1Reinforced rear structure of a motor vehicle
Publication Date: 2022.04.20 RENAULT SA
  • EP3868611B1 patent drawingFigure 1~2
  • EP3868611B1 patent drawingFigure 3
  • EP3868611B1 patent drawingFigure 4

AI summary

The invention relates to a rear structure assembly for a motor vehicle comprising a rear body section (18) including a trunk (20) having two opposing rear walls (26); a rear bumper (12) integral with said rear body section, said rear bumper having two opposing sides (14, 16) extending opposite said two opposing rear walls; a cornering obstacle warning device (72) located between one of said rear walls (26) and one of said opposing sides (14). The assembly further comprises a support plate (34) having a free-moving stop pin (54) extending outwards and supporting said cornering obstacle warning device (72); and said support plate (34) is connected to said one of said sides (14) so ​​that said free stop finger (54) extends opposite said one of said sides (14), so as to be able to come away from said one of said rear walls (26).