Asymmetric Crash Box Wall Design for Impact Absorption
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Solution Overview
Problem
Existing crash boxes for vehicles are limited in size and struggle to provide both high shock-absorbing capability and compactness, necessitating a design that can efficiently absorb impact while being space-saving.
Innovation Solution
A crash box configuration with differing lengths of opposing wall surfaces, where the crush timings and load peaks of these surfaces are adjusted to maximize shock absorption, and optionally incorporating cutouts to reduce initial impact transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the crash box size is reduced to be compact and space-saving, then the space efficiency is improved, but the shock-absorbing capability deteriorates
Solution Approach 1:
The patent applies asymmetry by making the first and second wall surfaces have different lengths in the longitudinal direction. Specifically, the first wall surface extends from the front end surface to a first position, while the second wall surface extends from the front end surface to a second position that is different from the first position. This asymmetric configuration causes the wall surfaces to crush at different timings during impact, with one wall surface crushing before the other, thereby extending the crush duration and improving shock absorption capability within a compact volume.
2Device complexity
If the wall surfaces have equal lengths, then the structure is simple and symmetric, but the crush timings are simultaneous resulting in lower shock absorption capacity
Solution Approach 1:
The patent deliberately introduces asymmetry between the first and second wall surfaces by setting their lengths differently in the longitudinal direction. This asymmetric design ensures that during impact, the wall surfaces reach their crush points at different times, creating a staggered crushing sequence that extends the overall crush duration and enhances shock absorption capacity without significantly increasing structural complexity.
3Strength
If the absolute value of the length difference between wall surfaces is approximately 50% of the buckling wavelength, then the crush timing difference is maximized, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a particular parameter range for the length difference between wall surfaces, setting it to approximately 50% of the buckling wavelength. This parameter optimization ensures maximum crush timing difference and optimal shock absorption capacity. The patent provides guidance on controlling this dimensional parameter during manufacturing to achieve the desired performance while maintaining manufacturability.
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 design enhances shock absorption capacity while maintaining compactness and space efficiency, effectively absorbing vehicle collision impacts by optimizing crush timing and load distribution.
Implementation Method 1
the crush timings of the first wall surface and the second wall surface, which face each other, such that the crush timing of the first wall surface and the crush timing of the second wall surface differ from each other
Implementation Method 2
A crash box according to an aspect of the disclosure is configured to absorb an impact caused by a collision of a vehicle
Data Source
AI summary
A crash box is configured to absorb an impact caused by a collision of a vehicle. The crash box includes a front end surface configured to receive the impact, a rear end surface configured to be attached to the vehicle; and a first wall surface and a second wall surface both extending from the rear end surface to the front end surface. The first wall surface and the second wall surface face each other. A length of the second wall surface from the front end surface to the rear end surface is longer than a length of the first wall surface from the front end surface to the rear end surface.