Automotive Panel Recess Layout for Small-Overlap Collision Resistance

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Solution Overview

Problem

Existing panel members in automobiles suffer from large out-of-plane deformation during collisions, leading to reduced collision performance, particularly in the Small Over Lap test, due to shear buckling and inadequate rigidity distribution.

Innovation Solution

The panel member is designed with specific arrangements of recessed parts, including parallel first and second recessed part groups, where the angle between their connecting lines is between 80 to 100 degrees, and the distance between recessed parts is limited to 3 times the diameter or less, enhancing rigidity and reducing out-of-plane deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the rigidity of the floor panel is increased to suppress out-of-plane deformation, then collision performance is improved, but the technique contradicts the goal of reducing noise due to vibration

Engineering Contradiction:
Improvecollision performanceVSAvoidnoise due to vibration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing recessed parts at specific locations on the floor panel rather than uniformly increasing rigidity across the entire panel. The recessed parts are strategically positioned to suppress out-of-plane deformation in critical areas while maintaining overall panel flexibility to reduce vibration noise. This localized modification allows the panel to have different rigidity characteristics in different regions, resolving the contradiction between collision performance and noise reduction.

Inventive Principle:
Principle #3Local quality

2Weight of stationary object

If circular recessed parts are arranged in a honeycomb shape to reduce weight, then weight reduction is achieved, but large out-of-plane deformation occurs in oblique directions

Engineering Contradiction:
Improvepanel weightVSAvoidout-of-plane deformation
Core Design Contradiction:
Weight of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies asymmetry by configuring recessed parts with specific dimensional relationships between their major and minor axes. The recessed parts have asymmetric dimensions where the minor axis is 0.5 to 2 times the major axis, creating an asymmetric arrangement that prevents large out-of-plane deformation in oblique directions while maintaining weight reduction benefits. This asymmetric configuration disrupts the symmetry of the honeycomb pattern, thereby improving stability without sacrificing weight reduction.

Inventive Principle:
Principle #4Asymmetry

3Ease of manufacture

If the distance between recessed parts is increased to simplify manufacturing, then ease of manufacture is improved, but collision performance deteriorates due to inadequate rigidity distribution

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcollision performance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies parameter changes by establishing specific dimensional relationships between the major and minor axes of the recessed parts. The minor axis is defined as 0.5 to 2 times the major axis, which optimizes the geometric parameters to ensure adequate rigidity distribution for collision performance while maintaining manufacturability. This parameter optimization allows for practical manufacturing constraints to be met while achieving the desired collision performance through proper geometric configuration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3838721B1Panel member
Publication Date: 2025.07.02 NIPPON STEEL CORPORATION
  • EP3838721B1 patent drawingFigure 1~2
  • EP3838721B1 patent drawingFigure 3~4
  • EP3838721B1 patent drawingFigure 5

AI summary

To improve the collision performance of a panel member of an automobile. A panel member 1 includes a plurality of circular recessed parts 10 linearly arranged, wherein: when it is assumed that a portion where three recessed parts 10 are linearly aligned is called a recessed part group G, there are at least a first recessed part group G1 and a second recessed part group G2 arranged in parallel with the first recessed part group G1; and an angle formed between a first straight line L1 linking a center of the recessed part 10 in the first recessed part group G1 and a center of the recessed part 10 in the second recessed part group G2 located at a position closest to the recessed part 10, and, a second straight line L2 linking centers of the recessed parts 10 in the first recessed part group G1 is 80 degrees or more and 100 degrees or less.