Vehicle Side Door Impact Beam Attachment via Bent Wall Deformation

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Solution Overview

Problem

Existing vehicle side door structures face issues where impact beam extensions detach during side impacts due to torsional deformation of the pillar, leading to a loss of the impact beam's functionality, and attempts to reinforce or strengthen the attachments result in increased weight and cost.

Innovation Solution

A vehicle side door structure with a second opposing wall portion that is bent inward, featuring a through hole acting as a weak portion, which allows the impact beam extension to overlap and crush inward, preventing the impact beam from detaching from the first opposing wall portion, thus maintaining the beam's function while reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the impact beam attachment portions are disposed on the outer side of the pillar, then the door structure allows for easier assembly and standard positioning, but the pillar's torsional deformation during side impact pushes the attachment portions outward, causing the impact beam extensions to detach

Engineering Contradiction:
Improveassembly easeVSAvoidimpact beam attachment reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The second opposing wall portion is pre-formed with a bent shape extending in the vehicle width direction before impact occurs. This preliminary geometric configuration allows the wall to naturally guide and control the deformation path during side impact, preventing the impact beam extension from detaching while maintaining the attachment portion in the standard outer side position for easy assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The door inner panel exhibits non-uniform structural properties through the bent second opposing wall portion, which creates a localized deformation zone. This local geometric modification concentrates the impact deformation in a specific area, allowing the rest of the attachment structure to maintain its standard positioning and assembly characteristics.

Inventive Principle:
Principle #3Local quality

2Reliability

If the extensions are reinforced or the welding strength between impact beam attachment portions and extensions is enhanced, then the detachment risk during side impact is reduced, but the weight and manufacturing cost increase

Engineering Contradiction:
Improveimpact beam attachment reliabilityVSAvoiddoor weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention changes the geometric parameter of the second opposing wall portion by forming it with a bent shape extending in the vehicle width direction. This parameter modification creates a deformation-controlling structure that passively manages impact forces through its geometry, eliminating the need for additional reinforcement materials or enhanced welding processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful effect of impact forces that would normally cause detachment into a beneficial controlled deformation process. The bent second opposing wall portion is designed to deform in a predetermined manner during side impact, absorbing and redirecting forces to protect the impact beam attachment while maintaining lightweight construction.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Stability of the object's composition

If the second opposing wall portion is made rigid to prevent deformation, then the attachment stability is improved, but the impact forces concentrate on the welded sites, increasing the risk of welding failure

Engineering Contradiction:
Improveattachment stabilityVSAvoidwelded site strength
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The second opposing wall portion is pre-formed with a bent shape that anticipates the deformation needs during impact. This preliminary geometric configuration creates a built-in deformation path that activates during side impact, allowing controlled displacement that protects the welded sites from excessive stress concentrations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bent geometry of the second opposing wall portion acts as a pre-designed cushioning mechanism. During side impact, this pre-configured structure deforms in a controlled manner, absorbing and redistributing impact forces before they reach the welded sites, thereby protecting the welds from failure while maintaining attachment stability.

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

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 structure effectively maintains the impact beam's functionality as a fixed-fixed beam during side impacts by controlling the deformation of the second opposing wall portion, reducing the burden on welded sites, and lowering manufacturing costs through the use of existing features like paint flow-through holes.

Implementation Method 1

a second opposing wall portion that is bent inward in the vehicle width direction with respect to the first opposing wall portion and opposes the pillar in the vehicle front and rear direction

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

the through hole defines a hollow space being free from any structure disposed therein

Methodology Applied
Scientific EffectStress concentration and redistribution:

Implementation Method 3

is welded to the first opposing wall portion

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2803517B1Structure for vehicle side door
Publication Date: 2018.01.03 TOYOTA JIDOSHA KK
  • EP2803517B1 patent drawingFigure 1
  • EP2803517B1 patent drawingFigure 2
  • EP2803517B1 patent drawingFigure 3

AI summary

A vehicle side door structure (10) is equipped with a door inner panel (30) disposed along a vehicle front and rear direction and a door outer panel (40) disposed on a vehicle width direction outer side of the door inner panel (30). An impact beam (50) is disposed between the door inner panel (30) and the door outer panel (40). The impact beam (50) is disposed in such a way that its lengthwise direction coincides with the vehicle front and rear direction. An impact beam extension (52) is disposed on a front end portion (50F) of the impact beam (50). The impact beam extension (52) is overlaid on a first opposing wall portion (34C) formed on a vehicle front and rear direction front end portion side of the door inner panel (30), is welded to the first opposing wall portion (34C). Furthermore, the impact beam extension (52) overlaps at least part of a through hole (36) serving as an example of a weak portion formed in a second opposing wall portion (32A) of the door inner panel (30) as seen from the outer side in the vehicle width direction.