Fiber-Reinforced Plastic Panel for Vehicle Roof Rigidity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional reinforcement members for panels, such as those used in vehicle roofs, are heavy and lack sufficient rigidity, leading to deformation under load, particularly in open roof constructions where weight reduction is desired without compromising structural integrity.

Innovation Solution

A reinforcement assembly using fiber-reinforced plastic members, either in the form of fiber bundle skeletons or sheets, providing enhanced rigidity through continuous fibers arranged in loops or woven layers, which are integrated into the panel main body to minimize weight while maintaining structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional steel reinforcement members are used, then sufficient rigidity and structural integrity are achieved, but the panel weight increases significantly

Engineering Contradiction:
ImproverigidityVSAvoidpanel weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining plastic (polymer matrix) with fiber reinforcement (glass, carbon, or aramid fibers) to create a reinforcement member that achieves steel-level rigidity while weighing up to 60% less than conventional steel reinforcement. The fiber-plastic composite structure provides both the necessary mechanical strength and weight reduction for the panel.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If reinforcement members are made thinner to reduce weight, then panel weight decreases, but deformation under load increases

Engineering Contradiction:
Improvereinforcement weightVSAvoidresistance to deformation
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies local quality by varying the fiber bundle distribution, orientation, and density in different regions of the reinforcement member. Fiber bundles are arranged with specific orientations (0°, 45°, 90°) and densities to provide targeted reinforcement where needed, allowing the structure to resist deformation effectively while maintaining minimal overall weight.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from conventional planar reinforcement to a three-dimensional structure by forming fiber bundles into loops and arches that extend in multiple dimensions. This 3D configuration provides structural rigidity and resistance to deformation from multiple loading directions, achieving high strength-to-weight ratio that would be impossible with flat, two-dimensional reinforcement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Strength

If fiber bundles are arranged in loops and arches, then rigidity is enhanced, but manufacturing complexity increases

Engineering Contradiction:
ImproverigidityVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-forming the fiber bundles into loops and arches during the manufacturing process before the final panel assembly. The fiber bundles are shaped and positioned in their final 3D configuration while the plastic matrix is still moldable, allowing complex geometries to be created in a single molding operation rather than requiring post-assembly fabrication.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the reinforcement member fabrication with the panel molding process by injecting the plastic matrix material around the pre-formed fiber bundle structures in the same manufacturing step. This integration combines what would traditionally be separate operations (reinforcement fabrication and panel assembly) into a single unified process, reducing overall manufacturing complexity despite the complex 3D fiber geometry.

Inventive Principle:
Principle #5Merging (Combining)

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 use of fiber-reinforced plastic reinforcement members results in a panel that is significantly lighter (up to 60% lighter than steel) while maintaining or improving rigidity, reducing deformation under load and enhancing the panel's overall structural performance.

Implementation Method 1

The fiber bundles 7 may be wound by a robot and comprise commingled fibers which are attached to each other by means of a plastic matrix material which is heated and/or pressurized to form a rigid bundle.

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

The fiber bundles 7 may be wound by a robot and comprise commingled fibers which are attached to each other by means of a plastic matrix material which is heated and/or pressurized to form a rigid bundle.

Methodology Applied
Scientific EffectPressurisation: Pressurisation

Data Source

PatentEP3426514B1Panel and open roof construction provided therewith
Publication Date: 2020.08.05 INALFA ROOF SYST GROUP
  • EP3426514B1 patent drawingFigure 1~2
  • EP3426514B1 patent drawingFigure 3~4
  • EP3426514B1 patent drawingFigure 5~7

AI summary

A panel (3) for use in a vehicle, in particular in an open roof construction for a vehicle, comprises a substantially rectangular panel main body (4), and at least one elongated reinforcement member (5) positioned at least partly in the vicinity of an edge of said panel main body and firmly connected thereto. The reinforcement member is made of a plastic material and is reinforced by a fiber-based reinforcement. The fiber-based reinforcement may include continuous fiber bundles (7) shaped into a three dimensional loop shaped skeleton. The loops extend in different planes substantially parallel to the elongation of the reinforcement member and are connected by transverse loop sections. The fiber-based reinforcement may also include fibers woven into multiple layers, preferably including fibers running in different directions, said layers being pressed into a sheet (13) with the help of plastic matrix material, said sheet being incorporated in the reinforcement member (5).