Automobile Rear Frame Energy Absorption via Localized Width Enlargement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for forming soft zones in rear frames of automobiles made of hot stamp material increase production costs and do not effectively enhance energy-absorbing capabilities during rear-end collisions.
Innovation Solution
A body structure where the front ends of left and right rear frames made of hot stamp material are connected to the rear ends of left and right side sills made of high tensile material, featuring inclined and horizontal parts, enlarged width portions, and a reinforcing member, along with a battery box and subframe configuration, to absorb collision energy effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If soft zones are formed in the rear frame made of hot stamp material, then energy absorption capability is improved, but production cost increases
Solution Approach 1:
The patent applies local quality by creating a soft zone only in the lower half part of the rear frame through localized geometry changes (enlarged width portion with bent portion) rather than forming soft zones throughout the entire rear frame. This selective approach maintains energy absorption capability while reducing production cost by minimizing complex forming operations.
Solution Approach 2:
The rear frame is segmented into different functional zones: an upper half part with uniform cross-section and a lower half part with enlarged width portion. This segmentation allows each zone to perform its specific function - the upper part provides structural strength while the lower part provides energy absorption through controlled deformation.
2Strength
If the plate thickness of upper half part is increased, then structural strength is improved, but weight increases
Solution Approach 1:
Instead of uniformly increasing plate thickness throughout the rear frame, the patent applies local quality by increasing the width of the lower half part only in the enlarged width portion where energy absorption is needed. This localized dimensional increase provides both structural strength and energy absorption capability without unnecessarily increasing overall weight.
Solution Approach 2:
The patent changes geometric parameters (width and cross-sectional area) rather than material parameters (plate thickness). By enlarging the width of the lower half part while maintaining the same plate thickness, the patent achieves increased structural strength and energy absorption capability without the weight penalty associated with thicker plates.
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
This configuration allows for effective energy absorption during rear-end collisions by utilizing the deformation properties of both hot stamp and high tensile materials, while also protecting the battery box and ensuring collision resistance in various impact scenarios.
Implementation Method 1
making the rear frame crumple in a zig-zag manner when the collision load of a rear-end collision is inputted thereinto and absorbing the collision energy
Implementation Method 2
absorbing the collision energy
Data Source
AI summary
The rear frame includes an inclined part that is inclined inward in, a vehicle width direction in going rearward and a horizontal part that extends rearward from a rear end of the inclined part. A rear part of the side sill includes a first enlarged width portion that increases in width inwardly in the vehicle width direction via a bent portion. A front part of the rear frame inclined part includes a second enlarged width portion that increases in width outwardly in the vehicle width direction. A rear end of the first enlarged width portion and a front end of the second enlarged width portion are connected. An inner wall in the vehicle width direction of the first enlarged width portion and an inner wall in the vehicle width direction of the inclined part are linearly continuous in plan view.