Vehicle Bumper Cross Member Indentation for Crash Box Deformation Control
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Solution Overview
Problem
Existing bumper designs face challenges in achieving predictable deformation behavior during impacts due to complex structural designs and incomplete welding, leading to undefined energy absorption capabilities.
Innovation Solution
The cross member features indentations at the ends of crash boxes, allowing vertical legs to be securely joined while maintaining horizontal legs at a distance, which controls the deformation behavior and ensures stable fixation, preventing uncontrolled folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the horizontal legs of the crash box are not welded to the cross member, then the production complexity is reduced and welding accessibility is improved, but the deformation behavior becomes undefined and impact absorption capacity cannot be reliably predicted
Solution Approach 1:
The patent introduces an intermediary element - a connection piece with a U-shaped cross-section that is inserted into the open end of the crash box. This connection piece serves as a mediator between the crash box and the cross member, providing both mechanical support and defined deformation characteristics without requiring direct welding of the horizontal legs to the cross member.
Solution Approach 2:
The connection system is segmented into distinct functional components: the crash box itself, the U-shaped connection piece, and the cross member. This segmentation allows each component to be optimized independently - the connection piece can be designed with specific geometric features that control deformation while maintaining ease of assembly.
2Strength
If a weld running over the entire circumference of the crash box end is implemented, then the connection strength is improved, but the production complexity increases and welding accessibility remains limited
Solution Approach 1:
The welding operation is extracted from the complex circumferential weld at the crash box end and relocated to the connection piece. The connection piece is designed to be joined to the cross member in a more accessible location, simplifying the welding process while maintaining connection strength through the U-shaped geometry that engages with the crash box.
3Stability of the object's composition
If the crash box is fully welded to the cross member, then the structural rigidity is improved, but the controlled deformation behavior during impact is reduced
Solution Approach 1:
The connection system transitions from a static rigid weld to a dynamic configuration that allows controlled deformation. The U-shaped connection piece is designed with specific geometric features that provide initial rigidity for normal operation but allow progressive deformation during impact, enabling the structure to adapt to impact conditions while maintaining predictable behavior.
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 design enhances the predictability and compliance of bumper deformation during impacts, improving vehicle protection and simplifying simulation and design processes by defining initial deformation conditions.
Implementation Method 1
The crash boxes are designed to absorb the energy resulting from an impact by converting it into deformation work
Implementation Method 2
the folding behavior of the crash box and the impact absorption capacity of the bumper
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
The bumper has a U-shaped cross beam (3) with a bar (6) and two side pieces, where beam is arranged transverse to longitudinal support of a motor vehicle frame under integration of crash boxes (5). The bar within the area of an end of the boxes has a recess, where each box is joined to the bar with its vertical side piece (17) at the lateral side of cross beam. A horizontal side piece of the box has a distance to the bar.