Vehicle Rear Structure With Forward Impact Absorber-Subframe Contact
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Solution Overview
Problem
Existing vehicle body rear structures struggle to effectively absorb impact energy and ensure occupant safety when a fuel tank is positioned below the floor panel, as the spacing between impact absorbing members and load-bearing components becomes large, leading to potential idle absorption and deformation during rear collisions.
Innovation Solution
A vehicle body rear structure featuring a subframe positioned below the floor panel, an impact absorbing member extending in the front-rear direction with a second extending portion forward, and a bracket attaching the member to the floor panel, allowing for closer proximity and reliable contact between the impact absorbing member and subframe, even when the fuel tank is below the floor panel, thereby enhancing energy absorption and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the impact absorbing member is disposed along the lower surface of the floor panel in front of the floor pan, then the impact energy absorption is improved, but the fuel tank cannot be disposed below the floor panel
Solution Approach 1:
The impact absorbing member is extended in the front-rear direction with a second extending portion that protrudes forward with respect to the floor pan, utilizing the front-rear dimension to achieve both impact absorption and fuel tank accommodation
Solution Approach 2:
The impact absorbing member is divided into a first extending portion along the floor pan and a second extending portion protruding forward, allowing different sections to serve different functions
2Adaptability or versatility
If the spacing between the impact absorbing member and the torsion beam is large, then the fuel tank can be disposed below the floor panel, but the impact absorbing member becomes idle and the vehicle body deforms significantly
Solution Approach 1:
The impact absorbing member is extended in the front-rear direction to protrude forward with respect to the floor pan, reducing the spacing in the front-rear dimension while maintaining fuel tank disposal capability in the vertical dimension
3Adaptability or versatility
If the impact absorbing member is detached from the floor panel, then the fuel tank can be disposed below the floor panel, but the impact absorbing member cannot reliably contact the torsion beam during rear collision
Solution Approach 1:
The bracket is formed in L shape or U shape straddling the opening trailing edge of the recess, utilizing the three-dimensional space to achieve both fuel tank disposal and reliable contact
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 ensures reliable impact energy absorption and improved occupant safety by maintaining contact between the impact absorbing member and subframe during rear collisions, preventing idle absorption and deformation, and allowing for effective load transmission and dispersion across the vehicle body frame.
Implementation Method 1
impact energy is absorbed by the rear center frame coming into contact with the torsion beam
Implementation Method 2
the rear center frame formed in an uneven shape being crushed
Data Source
AI summary
The vehicle body rear structure includes a floor panel 2, a subframe 3 which is provided below the floor panel 2, an impact absorbing member 4 which is provided behind the subframe 3 and extends in the front-rear direction, and a bracket which detachably attaches the impact absorbing member 4 to a lower surface of the floor panel 2. The front end portion 38 of the impact absorbing member 4 is disposed to be at the same height as the subframe 3 in the vertical direction and is disposed with the spacing S from the subframe 3 in the front-rear direction.