Variable Inertia Door Frame Reinforcement

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Solution Overview

Problem

Existing structural reinforcements for motor vehicle doors, particularly those requiring aesthetic and functional integration, face challenges in adapting to various door types and ensuring robustness against side impacts due to constraints in installation methods.

Innovation Solution

A structural reinforcement comprising two longitudinal parts forming a hollow beam with variable inertia, where at least one part has fastening lugs and pilot orifices for optimized mounting, allowing for resistance welding and adaptation to door frames while maintaining manufacturing cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a profiled reinforcement is installed on the door frame, then the structural resistance to side impacts is improved, but the aesthetic and functional integration is compromised

Engineering Contradiction:
Improvestructural resistance to side impactsVSAvoidaesthetic and functional integration
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The reinforcement is divided into two separate longitudinal parts (first and second parts) that can be independently positioned and attached to the door frame. This segmentation allows each part to be optimized for structural strength while the combined assembly adapts to aesthetic and functional constraints of the door design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reinforcement parts are positioned at different distances from the external surface of the door frame, creating a three-dimensional configuration. This dimensional flexibility allows the reinforcement to provide structural strength while adapting to the aesthetic and functional requirements of the door.

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

2Strength

If a reinforcement is installed substantially under the opening of the door window, then the structural resistance is improved, but the adaptability to various door types is reduced

Engineering Contradiction:
Improvestructural resistanceVSAvoidadaptation to door types
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The reinforcement system is designed with dynamic positioning capability, allowing the longitudinal parts to be placed at different distances from the door frame surface depending on the specific door type and application requirements, rather than being fixed at a single predetermined location.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The distance parameter of the reinforcement parts from the door frame surface can be varied to adapt to different door types and configurations, while maintaining the structural resistance function across all applications.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the reinforcement is obtained in two separate parts, then the ease of manufacture is improved, but the device complexity increases

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidassembly complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The reinforcement is manufactured as two separate longitudinal parts that can be produced using standard stamping processes, simplifying manufacturing. The parts are then attached to each other and to the door frame through resistance welding, which while adding an assembly step, ensures robust structural connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two separate longitudinal parts are merged through resistance welding to form a unified reinforcement structure that provides the required structural resistance while maintaining the manufacturing advantages of separate part production.

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 solution provides a robust, easily installable, and cost-effective reinforcement that enhances door rigidity, particularly at critical points, ensuring compliance with safety standards for side impacts without compromising aesthetic or functional requirements.

Implementation Method 1

said first and second longitudinal parts are fixedly assembled to one another by resistance welding

Methodology Applied
Scientific EffectResistance welding: Welding

Data Source

PatentEP3266633B1Structural reinforcement for a door frame of a motor vehicle
Publication Date: 2020.02.12 RENAULT SA
  • EP3266633B1 patent drawingFigure 1~2
  • EP3266633B1 patent drawingFigure 3~3f
  • EP3266633B1 patent drawingFigure 4~5

AI summary

The invention relates to a structural reinforcement (1) for a door frame (2) (3) of a motor vehicle. This reinforcement (1) comprises a first longitudinal member (1a) and a second longitudinal member (1b) joined one on top of the other, forming a hollow beam with variable moment of inertia. At least one of the two longitudinal members (1a, 1b) has a curved portion that varies along the longitudinal direction of the reinforcement (1) such that the hollow section of the beam varies along the longitudinal direction of the reinforcement. The first longitudinal member (1a) has at least two pilot holes (23), each of which fits into a guide rod projecting from the frame (2).