Vehicle Frame Member Grooves for Uniform Collision Compression
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Solution Overview
Problem
Existing vehicle frame members are prone to non-uniform axial compression during collisions, leading to uneven absorption of collision loads due to differences in buckling resistance between inner and outer panels, resulting in inadequate load absorption.
Innovation Solution
A frame member design with a closed-cross section featuring symmetrical side wall portions and recessed groove portions, ensuring equal bending rigidity and uniform axial compression, thereby enhancing load absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the flanges are offset toward the outward side in the vehicle width direction, then the resistance against buckling of the outer panel is higher than that of the inner panel, but the frame member cannot be axially-compressed uniformly and collision load cannot be absorbed expectedly
Solution Approach 1:
The patent applies asymmetry by configuring the inner and outer panels with different cross-sectional shapes and thickness distributions. The inner panel has a hat-shaped cross section while the outer panel has a different configuration, creating intentional asymmetry that balances buckling resistance between both panels despite their different positions and functions.
Solution Approach 2:
The patent implements local quality by varying the thickness and structural properties of different portions of the panels. Specifically, the inner panel has different thicknesses at different locations, and the outer panel is configured with specific thickness distributions to achieve uniform buckling resistance across both panels, allowing uniform axial compression during collision.
2Strength
If groove portions are added to the side wall portions to increase moment of inertia and buckling resistance, then the buckling resistance is properly large, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the side wall portions into multiple segments through the addition of groove portions. These grooves create distinct segments ( groove-upper wall portion, groove-lower wall portion, groove-bottom wall portion) that collectively increase the moment of inertia and buckling resistance while maintaining a manageable structural complexity.
Solution Approach 2:
The patent utilizes another dimension by adding groove portions that extend in the vehicle width direction, creating a three-dimensional structural feature on the two-dimensional side wall surface. This dimensional addition increases the moment of inertia and buckling resistance without significantly increasing overall device complexity.
Data Source
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AI summary
A frame member comprises a frame body portion (20A) having an upper wall portion (20a), a lower wall portion (20b), and a pair of side wall portions (20c, 20d), which together define a closed-cross section (7a) perpendicular to a longitudinal extension direction in a specified longitudinal range, a pair of groove portions (25, 26) formed at the pair of side wall portions (20c, 20d), the groove portions (25, 26) being recessed toward an inside of the closed-cross section (7a), flanges (20e, 20f) protruding outward from the closed-cross section (7a). Each of the pair of side wall portions (20c, 20d) comprises plural side wall portions (25a, 26a, 25b, 26b, 25c, 26c) which include a groove-upper wall portion (25a, 26a) extending in a width direction at an upper side thereof, a groove-lower wall portion (25b, 26b) extending in the width direction at a lower side thereof and facing the groove-upper wall portion (25, 26a), and a groove-bottom wall portion (25c, 26c) interconnecting the groove-upper wall portion (25a, 26a) and the groove-lower wall portion (25b, 26b) in a vertical direction. The plural side wall portions may have substantially the same bending rigidity.