Vehicle Door Beam With Tapered Outer Walls

Solution Overview

Problem

Existing door beams with double hat profiles do not effectively manage deformation and energy absorption during lateral collisions, particularly in relation to their weight and maximum profile height.

Innovation Solution

The door beam design features a decrease in the height of the outer side walls from the central part towards the attachment ends, reducing the height ratio between the outer and inner side walls, while maintaining constant inner side walls, to enhance deformation progression and energy absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the height of outer side walls is increased to improve energy absorption capacity, then the energy take-up increases, but the weight and profile height increase proportionally

Engineering Contradiction:

Improveenergy absorption capacityVSAvoidweight

Core Design Contradiction:

Use of energy by moving objectVSWeight of moving object

Solution Approach 1:

The door beam features variable cross-sectional geometry where the outer side walls have different height profiles compared to the inner side walls. Specifically, the outer side walls have reduced height at least over a quarter of the beam length, creating zones of varying structural density. This local variation in geometry allows different sections to absorb energy at different rates, optimizing overall energy absorption without uniformly increasing weight throughout the entire structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameters of the door beam by varying the height ratio between outer and inner side walls along the beam length. The height ratio decreases towards the attachment ends, creating a non-uniform profile that optimizes the deformation progression. This parameter variation allows the structure to achieve superior energy absorption characteristics relative to its weight and maximum profile height.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the height of outer side walls is increased to improve energy absorption capacity, then the energy take-up increases, but the profile height increases

Engineering Contradiction:

Improveenergy absorption capacityVSAvoidprofile height

Core Design Contradiction:

Use of energy by moving objectVSShape

Solution Approach 1:

The door beam features variable cross-sectional geometry where the outer side walls have different height profiles compared to the inner side walls. Specifically, the outer side walls have reduced height at least over a quarter of the beam length, creating zones of varying structural density. This local variation in geometry allows different sections to absorb energy at different rates, optimizing overall energy absorption without uniformly increasing weight throughout the entire structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameters of the door beam by varying the height ratio between outer and inner side walls along the beam length. The height ratio decreases towards the attachment ends, creating a non-uniform profile that optimizes the deformation progression. This parameter variation allows the structure to achieve superior energy absorption characteristics relative to its weight and maximum profile height.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If the deformation progression is optimized to improve energy absorption, then the energy take-up increases, but the structural complexity increases

Engineering Contradiction:

Improveenergy absorption capacityVSAvoidstructural complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The door beam is segmented into distinct zones based on the varying height ratios of outer to inner side walls. At least over a quarter of the beam length, the outer side walls have reduced height, creating identifiable segments with different structural characteristics. This segmentation allows each zone to contribute differently to the overall deformation progression, optimizing energy absorption through a structured rather than random complexity.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP2925547B1Door beam for vehicles

Publication Date: 2018.05.30 GESTAMP HARDTECH AB

Figure 1~2

AI summary

A door beam has a double hat profile between its mounting ends (12, 13). The height of the outer sidewalls (14, 15) of the double hat profile decreases from a central part (25) of the beam towards the mounting ends (12, 13). Thus the height ratio between the outer (14, 15) and the inner (18, 19) sidewalls is decreased towards the mounting ends.