Crash Box Overlapping Tabs for Bumper Beam Mounting
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Solution Overview
Problem
Existing methods for fastening bumper beams in crash boxes lack stability, particularly in absorbing and distributing crash energy effectively during collisions.
Innovation Solution
The design involves forming overlapping metal sheet members for each crash box, with tabs extending over the bumper beam, and adapting the sides to abut the beam, allowing for secure fastening using screws and nuts, and incorporating specific dent patterns to control deformation during crashes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bumper beams are fastened in crash boxes using conventional methods, then the structure is simpler, but the mounting stability is insufficient
Solution Approach 1:
The crash box is divided into left and right members, each formed from separate metal sheets. These members are joined with their top portions and bottom portions overlapping to form a double-sheet construction, creating a segmented structure that enhances mounting stability while managing complexity through modular assembly
Solution Approach 2:
The top portions and bottom portions of the left and right members overlap and are joined together, forming nested double-sheet layers. This nesting creates tabs that extend over the bumper beam surfaces, providing enhanced fastening surfaces and improved mounting stability
2Use of energy by moving object
If crash boxes are designed to absorb energy through plastic deformation, then energy absorption is improved, but the structural integrity during off-set crashes is compromised
Solution Approach 1:
The crash box employs local quality variations through strategically positioned dents at specific locations on the box structure. These dents create localized deformation zones that initiate and control plastic deformation during crashes, allowing energy absorption to occur at predetermined locations while preserving the overall structural integrity of the crash box and protecting the second crash box from damage
Solution Approach 2:
The dents are pre-formed during manufacturing to establish predetermined deformation paths and trigger locations. In the event of a crash, these pre-positioned dents serve as initiation points for controlled plastic deformation, ensuring that energy absorption occurs in a predictable manner that maintains structural integrity during off-set crashes
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 provides a stable mounting of the bumper beam, ensuring energy absorption and maintaining structural integrity during off-set crashes by allowing controlled deformation without compromising the integrity of the second crash box.
Implementation Method 1
forming of metal sheet a left member and a right member for each crash box and jointing them with their top portions overlapping each other and their bottom portions overlapping each other
Implementation Method 2
The crash boxes take up energy in the event of a crash by being plastically deformed axially
Implementation Method 3
fastening the tabs to the bumper beam
Data Source
Figure 1
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AI summary
A bumper beam is fastened to a bumper beam (11) of a vehicle (13) with intermediate crash boxes (12). Each crash box comprises a left member (20) and a right member (21) formed of sheet metal, which are jointed together and have top portions (24,25) overlapping each other and bottom portions (22,23) overlapping each other to form double-sheet tabs (34,35). These tabs extend out over the top and bottom surfaces of the bumper beam and are fastened to these surfaces.