Battery Case Cross Bracket Structure for Stress Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery mounting technologies fail to effectively disperse stress concentrations at connection points, leading to reduced allowable limits of restraint loads, which can cause structural failure.
Innovation Solution
A battery case design featuring a cross bracket with cutouts at intersecting surfaces and optimized welding lines to disperse stress and enhance the allowable limit of restraint loads, using a cross bracket with a base portion and corner bracket portions that minimize welding ends and terminal points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery is restrained by cross members connected to rocker panel and floor panel, then the battery elongation is prevented, but stress concentration occurs at connection portions
Solution Approach 1:
The cross bracket is divided into multiple functional portions: a base portion joined to the frame, and a pair of corner bracket portions extending from the base portion to sandwich the cross member wall portion. This segmentation distributes the restraint load across multiple connection points and structural elements, preventing stress concentration at single connection portions.
Solution Approach 2:
The cross bracket extends in the width direction of the vehicle, creating a dimensional distribution of stress from a single-line connection to a two-dimensional structural element. The corner bracket portions sandwich the cross member wall portion from both sides, distributing stress across the width dimension rather than concentrating it at a single connection point.
2Manufacturing precision
If multiple welding starting and terminal ends are used for arc welding, then complete welding coverage is achieved, but welding efficiency and quality decrease
Solution Approach 1:
Multiple welding segments are merged into a single continuous welding line. The base portion and corner bracket portions are designed with rounded upper ends that allow a robot to perform arc welding along a continuous path without stopping to restart the welding arc, combining what would otherwise require multiple starting and terminal ends into one efficient welding operation.
Solution Approach 2:
The base portion has a rectangular shape with upper ends on both sides rounded, and the corner bracket portions have rectangular shapes with upper ends rounded. These curved transitions eliminate sharp corners that would require welding direction changes, enabling continuous arc welding by the robot along smooth, continuous paths.
Data Source
AI summary
A battery case includes: a frame that holds an end portion of a battery in a stacking direction of the battery; a cross member that is disposed so as to extend in the stacking direction of the battery; and a cross bracket that couples the frame and the cross member. The cross bracket includes a base portion that is joined to the frame, and a pair of corner bracket portions that extends from the base portion, that sandwiches a wall portion of the cross member from both sides, and that is joined to the wall portion. A cutout is provided at a site where a surface of each of the pair of corner bracket portions on a side of the wall portion and a surface of the base portion on the side of the wall portion intersect.