Vehicle Body Rear Structure Quadrangular Reinforcement
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Solution Overview
Problem
The existing reinforcing structures in hatchback vehicles, particularly at the upside corner portion of the backdoor opening, lack sufficient rigidity, leading to bending deformation under loads and reduced torsional rigidity and steering stability.
Innovation Solution
A vehicle body rear structure featuring a cylindrical reinforcing structure with a quadrangular shape at the upside corner portion of the backdoor opening, formed by the side body outer panel and quarter inner panel, which extends linearly to enhance rigidity and prevent bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional reinforcing structure with a bent portion is used at the upside corner portion of the backdoor opening, then the structure can provide a hinge mounting location, but the panel surface is prone to bending deformation under vertical loads, reducing rigidity
Solution Approach 1:
The reinforcing structure is divided into multiple wall portions (front wall, rear wall, upper surface, bottom surface) that are formed by bending the panel at specific locations. These segmented walls work together to form a rigid cage-like structure while maintaining the ability to mount hinges.
Solution Approach 2:
The panel is bent to form curved or angled wall portions instead of using sharp 90-degree corners. The bent portions create a more distributed stress pattern that resists bending deformation while providing the necessary geometry for hinge mounting.
2Ease of operation
If the backdoor opening portion is formed to have a large area, then loading capacity and ease of loading/unloading cargo is improved, but the rigidity of the entire vehicle decreases
Solution Approach 1:
Instead of reinforcing the entire backdoor opening portion, the invention applies localized reinforcing structures specifically at the upside corner portions. These localized reinforcements maintain the large opening area for cargo access while providing targeted rigidity where it is most needed to prevent overall vehicle body deformation.
3Productivity
If spotwelding is used to join the roof panel and side body outer panel at the roof rail groove, then the joining is simple and efficient, but bending deformation easily occurs in the roof starting from the spotwelded portion under twisting loads
Solution Approach 1:
The reinforcing structure extends in the vehicle width direction, adding a dimensional element perpendicular to the roof rail groove. This creates a three-dimensional rigid framework that resists twisting loads by distributing stresses across multiple dimensions rather than relying solely on the linear spotwelded joint.
Data Source
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AI summary
[Problem to be Solved] The present invention provides a vehicle body rear structure that can enhance rigidity of an upside corner portion of a backdoor opening portion and improve torsional rigidity of the entire vehicle body. [Solution] The vehicle body rear structure has a cylindrical reinforcing structure portion 20 extending in a vehicle width direction, at an upside corner portion of a backdoor opening portion 6 that is arranged adjacent to a rear end portion of a roof rail groove 3. The reinforcing structure portion 20 has a quadrangular shape when viewed from the side of the vehicle, and includes an upper surface portion 21 and a rear wall portion 22 formed by a side body outer extension panel 10, and a bottom surface portion 23 and a front wall portion 24 formed by a quarter inner upper extension panel 12; and each of the rear wall portion 22 and the front wall portion 24 extends linearly from the upside portion to the downside portion.