Vehicle Lower Frame Structure for Stable Side-Impact Load Absorption
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Solution Overview
Problem
Existing vehicle structures fail to stabilize the absorption of collision loads during side collisions, particularly in deforming the rocker and second stiffener, leading to inconsistent load absorption.
Innovation Solution
A vehicle lower portion structure comprising a first frame member with a hat-shaped absorbing member, a second frame member with partitioned absorbing members, and a cross member disposed to overlap each other, allowing stable deformation and load transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a rocker with a hat-shaped stiffener is used to absorb collision load, then part of the collision load can be absorbed, but the deformation is unstable and the load absorption ability is not stabilized
Solution Approach 1:
The rocker is divided into multiple segments: a first rocker portion with a first hat-shaped stiffener, a second rocker portion with a second hat-shaped stiffener, and a battery frame with partitioned absorbing members. This segmentation allows controlled sequential deformation of each segment during side collision, stabilizing the overall load absorption process and ensuring predictable energy dissipation.
2Loss of energy
If the second stiffener is designed to be crushed for load absorption, then collision load can be absorbed, but the deformation shape is not stable and load absorption varies
Solution Approach 1:
Different regions of the rocker structure are assigned different structural qualities: the first and second hat-shaped stiffeners have specific cross-sectional geometries optimized for controlled deformation, while the battery frame includes partitioned absorbing members with varying wall thicknesses. This local quality differentiation ensures that each region deforms in a predictable manner during collision, achieving stable and controlled load absorption.
3Reliability
If absorbing members are positioned to overlap in side view, then load transmission to non-collided side is improved, but structural complexity increases
Solution Approach 1:
The first frame member (rocker) and second frame member (battery frame) are merged into an integrated structure where the absorbing members of both members are positioned to overlap when viewed from the side. This merging allows the collision load to be transmitted efficiently from the first absorbing member through the second absorbing member to the non-collided side, improving load transmission stability without requiring separate independent structures.
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
Stabilizes collision load absorption by sequential deformation of absorbing members and effective load transmission, reducing impact on the battery case.
Implementation Method 1
the first absorbing member and the second absorbing member are deformed due to a collision load input to the vehicle, thereby absorbing at least part of the collision load
Data Source
AI summary
A vehicle lower portion structure includes: a first frame member that is disposed at an end in a vehicle width direction in a lower portion of a vehicle, and includes a first absorbing member with a hat-shaped cross-section in the first frame member; a second frame member that is connected to a vehicle-width-direction inner side of the first frame member, and includes a second absorbing member in the second frame member; and a cross member that is disposed on a vehicle-width-direction inner side of the second frame member, extends in the vehicle width direction and is connected to the second frame member, wherein the first absorbing member, the second absorbing member and the cross member are disposed at positions that overlap each other in a side view of the vehicle.