Vehicle Rear Structure Spare Tire Throw Mechanism
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Solution Overview
Problem
Existing vehicle rear portion structures fail to stably throw a spare tire up during collision loads and effectively suppress load transmission to the vehicle front side, due to unstable bending deformation of side frames and reinforcing members.
Innovation Solution
A vehicle rear portion structure with a spare tire house featuring a front side reinforcing portion, a rear side reinforcing portion, and a low rigidity portion between them, where the rear side reinforcing portion extends to the vehicle rear side end and includes a lower wall portion that bulges outward, and a rear bumper reinforcement that overlaps the rear side reinforcing portion, enhancing load absorption and deformation stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the side frames and hook reinforcing member are disposed rectilinearly along the vehicle longitudinal direction, then the structure is simple and easy to manufacture, but the bending deformation direction during collision is unstable and the spare tire cannot be thrown up stably
Solution Approach 1:
The patent applies asymmetry by configuring the reinforcing member with different rigidity sections (first high rigidity portion, low rigidity portion, and second high rigidity portion) rather than a uniform rectilinear structure. The low rigidity portion is positioned asymmetrically to control the bending deformation direction, ensuring the spare tire is thrown up stably toward the vehicle front upper side during collision while maintaining manufacturing feasibility.
2Reliability
If the spare tire is disposed in a tilted state, then the spare tire can be thrown up during collision, but the load transmission to the vehicle front side is not effectively suppressed
Solution Approach 1:
The patent applies local quality by creating different rigidity zones within the reinforcing member structure. The first and second high rigidity portions are positioned to suppress load transmission to the vehicle front side, while the low rigidity portion between them allows controlled bending deformation to throw the spare tire up. This localized differentiation of mechanical properties simultaneously achieves both objectives.
3Strength
If the rear side reinforcing portion is extended to the vehicle rear side end, then the load absorption capability is improved, but the structure complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the reinforcing member into distinct functional sections: a first high rigidity portion, a low rigidity portion, and a second high rigidity portion with a lower wall extending to the vehicle rear side end. This segmentation allows the lower wall to absorb load while the other portions maintain structural integrity, improving strength without excessive complexity.
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 structure stably throws the spare tire up and suppresses load transmission to the vehicle front side, even in vehicles with limited rear side member length, while shortening the time to throwing-up and minimizing spare tire displacement.
Implementation Method 1
the low rigidity portion, whose rigidity is set to be lower than rigidities of the first high rigidity portion and the second high rigidity portion
Implementation Method 2
the side frames and the hook reinforcing member, at the respective divided positions thereof, bendingly deform so as to become convex toward the vehicle lower side
Implementation Method 3
a front side reinforcing portion, the front side reinforcing portion being provided at a bottom wall portion of the spare tire house, the front side reinforcing portion reinforcing the bottom wall portion, and the front side reinforcing portion structuring a first high rigidity portion
Data Source
AI summary
A vehicle rear portion structure including: a spare tire house; a front side reinforcing portion provided at a bottom wall portion of the spare tire house, the front side reinforcing portion reinforcing the bottom wall portion and structuring a first high rigidity portion; a rear side reinforcing portion provided at the bottom wall portion so as to include a lower wall portion that extends in a vehicle longitudinal direction, the rear side reinforcing portion being disposed at a vehicle rear upper side of the front side reinforcing portion, reinforcing the bottom wall portion, and structuring a second high rigidity portion, and a low rigidity portion provided between the first high rigidity portion and the second high rigidity portion, and a rigidity of the low rigidity portion being set to be lower than rigidities of the first high rigidity portion and the second high rigidity portion.