Two-Fold Trunk Lid Retainer for Compact Sedan Loading Access

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle trunk designs for sedan-type vehicles face challenges in providing versatile access configurations while maintaining cost-effectiveness and ensuring proper water tightness.

Innovation Solution

The design incorporates a trunk lid divided into two elements, with retainers that allow the second element to be held in a trunk opening position, utilizing steel wire arms and guides for secure engagement and limited force exertion, and includes locking mechanisms for secure closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a two-folds upper lid is used to convert sedan trunk to loading platform, then the loading capability is improved, but the device complexity and manufacturing cost increase due to sophisticated slidable hinges

Engineering Contradiction:
Improveloading capabilityVSAvoidhinge complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The upper lid is divided into two separate elements (first element and second element) that can be independently manipulated. The second element can be folded onto the first element, creating multiple configuration options for loading different types of cargo while using simpler hinge mechanisms than a fully slidable system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lid system provides dynamic reconfiguration capability where the second element can be positioned in different locations (folded onto first element or positioned separately) depending on loading requirements, achieving versatility without complex automated mechanisms

Inventive Principle:
Principle #15Dynamics

2Volume of stationary object

If the second element is folded onto the first element for stowing, then the cargo volume is maximized, but the manipulation complexity increases

Engineering Contradiction:
Improvecargo volumeVSAvoidmanipulation ease
Core Design Contradiction:
Volume of stationary objectVSEase of operation

Solution Approach 1:

The retainer mechanism automatically engages with the guide on the second element when the lid is closed, providing self-locking functionality. This eliminates the need for complex manual manipulation to secure the folded elements, as the system self-secures through the retainer-guide interaction

Inventive Principle:
Principle #25Self-service

3Device complexity

If retainers with steel wire arms are used to hold the second element, then the force exertion is limited and cost is reduced, but the retention reliability must be maintained

Engineering Contradiction:
Improveretainer simplicityVSAvoidretention reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The retainer uses elastic deformation of the steel wire arm as a key parameter. The steel wire arm flexes to engage and disengage from the guide, providing a simple yet reliable retention mechanism that limits force exertion while maintaining adequate holding capability through material elasticity rather than complex mechanical structures

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If the upper lid is divided into two elements, then the access postures are increased, but the space requirement above the trunk increases

Engineering Contradiction:
Improveaccess posturesVSAvoidspace above trunk
Core Design Contradiction:
Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The second element can be folded onto and nested within the first element, creating a compact stowed configuration. This nesting arrangement minimizes the vertical space required above the trunk while still providing multiple access postures when the elements are in their operational positions

Inventive Principle:
Principle #7Nested doll (Nesting)

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 configuration offers multiple access postures for the trunk, maintains low costs, ensures water tightness, and allows operation in restricted spaces, such as parking garages, with reduced space requirements above the trunk.

Implementation Method 1

able, under application of a longitudinal load, to engage with the means for abutting and engaging by elastically deforming the two longitudinal portions of steel wire

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4072879B1Vehicle trunk with two folds upper lid
Publication Date: 2025.01.29 STELLANTIS AUTO SAS
  • EP4072879B1 patent drawingFigure 1~4
  • EP4072879B1 patent drawingFigure 5~7
  • EP4072879B1 patent drawingFigure 8~10

AI summary

The invention is directed to a vehicle (2) with a bodywork (4) comprising a trunk (6) with an upper lid (10) for selectively opening and closing said trunk, the upper lid comprising a first element (12) with a first edge (12.1) pivotally attached to a fixed part of the bodywork (4) and a second edge (12.2) opposed to said first edge (12.1); and a second element (14) with a first edge (14.1) pivotally attached to the second edge (12.2) of the first element (12); wherein the upper lid (10) comprises at least one retainer limiting a pivoting movement of the second element (14) relative to the first element (12) to an angle of not more than 100°.