Vehicle Side Sill Bulk Edge Lines for Load Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vehicle-body lower structure struggles to efficiently transmit loads from outside collisions in the vehicle width direction to the floor cross member without increasing the vehicle's weight, leading to buckling issues and increased costs due to thicker plates or additional components.
Innovation Solution
A vehicle-body lower structure design featuring a side sill with a bulk having edge lines and a connecting wall portion that transmits loads diagonally to the cross member, utilizing edge lines and beads to enhance buckling resistance and load transmission without increasing weight, and allowing for efficient load distribution even with deviations in bulk position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the plate thickness of the bulk head is made large to sufficiently transmit the input load from the outside in the vehicle width direction to the floor cross member, then the load transmission capability is improved, but the weight of the vehicle body increases
Solution Approach 1:
The bulk head is designed with edge lines extending in the vehicle width direction, transforming the load transmission from a planar surface approach to a linear edge-based approach. This dimensional change allows the load to be transmitted along the edge lines directly to the floor cross member, improving buckling resistance without requiring increased plate thickness
Solution Approach 2:
The bulk head structure provides different functional qualities at different locations: the edge lines are specifically designed to receive and transmit loads in the vehicle width direction, while other portions of the bulk head can maintain thinner plate thickness. This localized optimization allows sufficient load transmission capability without uniformly increasing the overall weight
2Strength
If additional components or thicker plates are used to improve buckling resistance and load transmission, then the structural strength is improved, but the production cost increases
Solution Approach 1:
The bulk head is segmented into functional regions defined by the edge lines, with the connecting wall portion specifically designed to transmit loads. This segmentation allows the structure to achieve sufficient buckling resistance through strategic placement of thicker plates or reinforcement only where needed, rather than requiring uniform thickening across the entire bulk head, thereby reducing material costs
Solution Approach 2:
The invention changes the geometric parameters of the bulk head, specifically the configuration and positioning of edge lines and the connecting wall portion. By optimizing these parameters, the structure achieves improved buckling resistance and load transmission capability through design rather than through increased material quantity, thus controlling production costs
Data Source
AI summary
A vehicle-body lower structure includes: a side sill; and a cross member, wherein the side sill includes a side sill outer and a side sill inner, a bulk having a shape corresponding to the cross member is provided on the opposite side of the side sill inner from the cross member in a closed-section space formed by the side sill outer and the side sill inner, and the bulk includes a front wall portion, a rear wall portion placed behind the front wall portion in the vehicle-body front-rear direction, and a connecting wall portion connecting the front wall portion and the rear wall portion, the front wall portion and the connecting wall portion forming a first edge line extending in the vehicle width direction, and the rear wall portion and the connecting wall, portion forming a second edge line extending in the vehicle width direction.