Composite Trunk Lid Abutment Device for Deformation Control

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Solution Overview

Problem

Composite material trunk lids in motor vehicles are prone to deformation due to thermal and mechanical stresses, leading to sealing issues and incomplete closure, which existing stop devices fail to adequately address.

Innovation Solution

A stop device comprising a metal frame with a polymer overmolded on it, featuring a threaded ring and a curved abutment surface, is secured to the vehicle's structural elements, providing a counterforce to balancer stresses and maintaining the lid's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If composite materials are used for trunk lids to reduce weight, then weight is reduced and energy consumption decreases, but the lid becomes prone to deformation under thermal and mechanical stresses

Engineering Contradiction:
Improvetrunk lid weightVSAvoidlid structural stability
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The invention uses a composite structure combining a polymer buffer material with an integrated metal frame reinforcement. The polymer buffer (such as polypropylene) provides the lightweight characteristic while the metal frame (aluminum or steel) embedded within it provides structural stability and resistance to thermal and mechanical stresses, preventing deformation of the trunk lid.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metal frame reinforcement is strategically positioned within the polymer buffer at critical stress points of the trunk lid structure. This localized reinforcement approach maintains the overall lightweight composite structure while providing targeted structural support where thermal and mechanical stresses are most likely to cause deformation.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If stops are added to prevent lid depression, then positioning stability is improved, but the device complexity increases

Engineering Contradiction:
Improvelid positioning stabilityVSAvoidstop device complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The stop function is merged with the buffer component itself. The buffer integrates a stop element (such as a protruding stop face or integrated stop arm) that directly contacts the trunk lid to prevent excessive depression. This combines the cushioning function and the positioning stop function into a single component, avoiding the need for separate stop devices and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The buffer structure is designed to automatically provide the stop function through its own geometric features (such as an integrated stop face or protrusion) without requiring external control mechanisms. The stop element is passively activated by the lid's movement and automatically limits depression to the designed range, making the system self-regulating.

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 limits or eliminates deformation, ensuring the trunk lid remains sealed and functional, while being easy to manufacture, install, and use.

Implementation Method 1

a polymer part overmolded on the metal frame and the fixing means, the polymer part comprising a body overmolded on the base of the metal frame

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 2

a polymer part overmolded on the metal frame and the fixing means

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 3

a fixing means passing through the metal frame at the junction between the base and the leg, the fixing means being a threaded ring capable of receiving a threaded rod of the axis

Methodology Applied
Scientific EffectThreaded fastening: Screw

Implementation Method 4

The balancers exert a thrust force on the sash so that when opening, the balancers unfold to raise the sash and when closing, the balancers tend to fold up to keep the sash in the closed position

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP3218564B1Abutment device of an openable body section of a motor-vehicle luggage compartment
Publication Date: 2019.05.15 PSA AUTOMOBILES SA
  • EP3218564B1 patent drawingFigure 1~2
  • EP3218564B1 patent drawingFigure 3~5
  • EP3218564B1 patent drawingFigure 6

AI summary

The invention relates to an abutment device (4) of an openable body section of a motor vehicle, including an abutment (7) and a counter-abutment in the form of a housing rigidly connected to the openable body section, the device (4) including: a mounting (5) capable of being rigidly connected to a structural element of the motor vehicle (1); a pin (6) mounted on the mounting (5); a balancer (33) mounted such as to be pivotable relative to the openable body section and the pin (6); and an abutment (7) including: a metal frame having a base (26) and a tab (27) extending the base (26); an attachment means (24) passing through the metal frame at the junction between the base (26) and the tab (27), and a polymer part (25) overmoulded on the metal frame and the attachment means (24), the polymer part (25) including a body (30) and a buffer (31).