Side Sill Reinforcement Structure for Higher Side-Impact Energy Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle-body structures face issues with unintended deformation of reinforcement members in side collisions, leading to a loss in energy absorption, particularly in electric vehicles where battery packs are vulnerable.
Innovation Solution
A lower vehicle-body structure featuring a pair of side sills with first and second reinforcements, each having a hat-shaped configuration that inclines to facilitate horizontal compression during collisions, and additional third reinforcements forming closed cross-sections to enhance energy absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a reinforcement member with a substantially M-shaped cross section is provided in a side sill to absorb energy in a side collision, then the energy absorption capability is improved, but the reinforcement member may be deformed in an unintended manner such that the closed cross-section is compressed while deviating in the up-down direction, resulting in a loss of energy absorption
Solution Approach 1:
The first wall is pre-formed with an inclined shape before the collision occurs. This preliminary geometric configuration ensures that when the collision load is applied, the first wall naturally rotates about the end portion on the vehicle-width-direction inner side, directing the compression force horizontally to the second reinforcement without deviating in the up-down direction. The pre-designed inclination angle is specifically optimized to achieve the desired rotation and horizontal compression alignment during the collision event.
Solution Approach 2:
The first wall is designed to dynamically rotate during the collision process. The inclination of the first wall allows it to pivot about the end portion on the vehicle-width-direction inner side when subjected to collision load, transforming the vertical compression force into a horizontal compressive force on the second reinforcement. This dynamic rotation mechanism ensures reliable energy absorption by adapting the force direction during the impact event.
2Loss of energy
If the first wall is formed to incline in a direction that increases distance from the second wall toward the vehicle-width-direction inner side, then the first reinforcement can be turned horizontally to increase energy absorption, but the structural complexity of the reinforcement member increases
Solution Approach 1:
The first reinforcement is divided into distinct functional segments: the first wall with a specific inclination angle, the end portion on the vehicle-width-direction inner side that serves as a rotation center, and the vertical wall. This segmentation allows each part to perform its specific function - the inclined first wall for force redirection, the end portion as a pivot point, and the vertical wall for providing structural support. The segmentation simplifies the design and manufacturing of each component while achieving the complex overall function of horizontal force redirection during collision.
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 structure ensures consistent and increased energy absorption in side collisions by preventing unintended deformation, effectively managing collision loads and protecting critical vehicle components like battery packs.
Implementation Method 1
when a collision load is input to the first reinforcement through the vertical wall in a side collision, the first reinforcement is deformed out of plane in the up-down direction
Implementation Method 2
the inclined first wall is turned by using the end portion thereof on the vehicle-width-direction inner side as the rotation center, thus being directed in the horizontal direction
Implementation Method 3
the first closed cross-sections, which are formed by the first wall and the second reinforcement are axially compressed in a horizontal state
Data Source
Figure 1
Figure 2
Figure 3
AI summary
[Problem] To provide a lower vehicle-body structure of a vehicle that can certainly increase an amount of energy absorption in a side collision. [Means for Solution] A vehicle body 1 includes a first reinforcement 5 and a second reinforcement 6 which are disposed in a closed cross-section 2a of a side sill 2. The first reinforcement 5 has a hat shape which includes an upper wall 5a (first wall), a lower wall 5b (second wall), and a vertical wall 5c extending in an up-down direction. The upper wall 5a is formed such that as the upper wall 5a progresses toward a vehicle-width-direction inner side, the upper wall 5a inclines in an upward direction in which the upper wall 5a gradually increases a distance from the lower wall 5b. The second reinforcement 6 forms a plurality of first closed cross-sections 8 in cooperation with the upper wall 5a.