Vehicle Roof Box Welded Sheet Structure for Leak and Weight Reduction
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Solution Overview
Problem
State-of-the-art roof boxes for public transport vehicles are not optimized, leading to increased weight and cost due to redundant metal usage in overlaps, and are prone to leaks that cause corrosion and damage to equipment.
Innovation Solution
The roof box is constructed with sheets welded together to form a single, continuous piece, using butt welding and a two-step riveting process to secure the sheets to the frame, minimizing material overlap and reducing leak points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adjacent metal sheets have significant overlap to improve sealant effectiveness, then water resistance is improved, but weight and cost increase due to redundant metal
Solution Approach 1:
The patent merges adjacent metal sheets into a single continuous piece, eliminating the need for overlapping sections and sealant. This integration removes redundant metal while maintaining water resistance, directly resolving the contradiction between reliability and weight.
Solution Approach 2:
The invention extracts and removes the overlapping sections and sealant from the design. By taking out these redundant elements and replacing them with a continuous sheet structure, the patent reduces weight while preserving the water resistance function.
2Reliability
If adjacent metal sheets have significant overlap to improve sealant durability, then sealing reliability is improved, but material usage and cost increase
Solution Approach 1:
The patent combines adjacent sheets into a continuous piece, eliminating the need for sealant application at joints. This merging approach maintains sealing reliability without requiring additional material or creating redundant metal sections.
3Reliability
If sealant is applied between adjacent sheets to ensure water resistance, then sealing effectiveness is improved, but leak risk increases due to sealant failure
Solution Approach 1:
The invention removes sealant from the design by eliminating joints between sheets. This extraction of the sealant component entirely eliminates the failure mode of sealant degradation and leakage, while the continuous sheet structure maintains water resistance.
4Strength
If multiple rivets are used to secure sheets to the frame, then mechanical attachment is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the attachment process by reducing the number of rivets required. The continuous sheet structure simplifies the attachment to the frame, requiring fewer fastening points while maintaining mechanical strength, thereby reducing manufacturing 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
This design enhances durability by reducing material usage, minimizing leaks, and preventing corrosion, while maintaining effective sealing and mechanical rigidity.
Implementation Method 1
The sheets are welded together to form a single, continuous piece. Each straight section is formed from one of the sheets, the straight section being created by bending the sheet. Each sheet is made of aluminum. The sheets are welded together using butt welding.
Data Source
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AI summary
The invention relates to a roof box (30) for a public transport vehicle, the box (30) being intended to be fixed on the roof of the vehicle, the box (30) comprising a frame and an envelope fixed to the frame, the frame being configured to support the envelope, the envelope delimiting an internal volume of the box (30), the envelope comprising a set of metal sheets (70A, 70B, 70C) separating the internal volume from the exterior of the box (30), each metal sheet (70A, 70B, 70C) being assembled to the frame and welded to at least one other sheet (70A, 70B, 70C).