Door Frame Inner Reinforcement Blank for Lighter Crash-Resistant Bodies

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for producing vehicle door frames result in increased weight due to uniform thickness and material inefficiencies, compromising occupant protection in vehicle impacts, as they require uniform steel thickness and lead to discontinuous weld joints from spot welding.

Innovation Solution

Assembling inner blanks to form a tailor-welded blank before hot stamping allows for varying thicknesses and improved nesting, reducing material use and enabling the use of laser welding for continuous welds, which enhances crash resistance and reduces production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the thickness of reinforcement elements is reduced to decrease vehicle weight, then weight is reduced and energy consumption decreases, but occupant protection against intrusions is degraded

Engineering Contradiction:
Improvevehicle weightVSAvoidoccupant protection
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies local quality by varying the thickness of steel blanks in different regions of the door frame. Critical areas requiring higher strength (such as pillar regions) use thicker blanks, while non-critical areas use thinner blanks. This allows the door frame to achieve optimal protection where needed while minimizing overall weight.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite material construction by assembling multiple steel blanks of different thicknesses and materials to form the complete door frame. This composite approach allows combining materials with different properties in different sections, achieving both weight reduction and maintained protection levels.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional stamping methods are used to produce door frames, then production is simplified, but material losses increase due to off-cuts and uniform thickness requirements

Engineering Contradiction:
Improveproduction simplicityVSAvoidmaterial loss
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent segments the door frame into multiple separate steel blanks that are assembled together. This segmentation allows each blank to be optimized for its specific function and thickness requirements, reducing material waste from off-cuts while maintaining manufacturing simplicity through standardized assembly processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements nesting by arranging multiple steel blanks in a nested configuration during assembly. The blanks are positioned to interlock and form the complete door frame structure, maximizing material utilization and minimizing waste while maintaining ease of manufacture through systematic assembly.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of manufacture

If spot welding is used to assemble stamped parts, then assembly is simplified, but discontinuous weld joints are formed which impair door frame resistance

Engineering Contradiction:
Improveassembly simplicityVSAvoiddoor frame resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent replaces the mechanical spot welding process with laser welding technology. This substitution enables continuous weld joints that provide superior structural resistance while maintaining assembly efficiency. The laser welding process creates stronger, more continuous bonds between the segmented steel blanks compared to traditional spot welding.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 method achieves a balance between reduced weight and enhanced protection by allowing for varying thicknesses and continuous welds, improving the structural integrity and crash resistance of vehicle door frames while minimizing material usage and production costs.

Implementation Method 1

the inner blanks are laser welded together so as to form the door frame inner reinforcement blank

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 2

hot stamping the door frame inner reinforcement blank obtained so as to form the vehicle door frame inner reinforcement element

Methodology Applied
Scientific EffectHot stamping: Heat Treatment

Data Source

PatentEP3659899B1Method for producing a vehicle body
Publication Date: 2024.03.20 ARCELORMITTAL SA
  • EP3659899B1 patent drawingFigure 1
  • EP3659899B1 patent drawingFigure 2
  • EP3659899B1 patent drawingFigure 3

AI summary

A method for producing a three-dimensional vehicle door frame inner reinforcement element (52) comprising an inner center pillar part (66), an inner front pillar part (68) and an inner side rail part (64) joining the inner center pillar part (66) and the inner front pillar part (68). The method comprises: - providing an inner center pillar blank, an inner front pillar blank and an inner side rail blank, said inner blanks being substantially planar, - assembling the inner center pillar blank and the inner front pillar blank to the inner side rail blank in order to form a substantially planar door frame inner reinforcement blank, - hot stamping the door frame inner reinforcement blank to shape the three-dimensional door frame inner reinforcement element (52).