Vehicular Back Door Joint Structure With Rotation Stop Bracket
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing joint structure in vehicular back doors, where a joining member with a protruding portion is prone to movement during adhesive curing, leading to delamination and reduced waterproofness due to groove formation, which compromises the integrity of the adhesion region.
Innovation Solution
A joint structure featuring a resin-made member, adhesive, and a joining member with a base and protruding portion, including first and second coupling portions and rotation stop portions formed by fitting and weld structures respectively, to stabilize the joining member and prevent rotation during adhesive curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a joining member with a protruding portion is used to increase joining strength, then the joining strength is improved, but the joining member is prone to movement and rotation during adhesive curing, causing grooves in the adhesion region
Solution Approach 1:
The rotation stop portion is provided in advance on the joining member to prevent rotation during the adhesive curing process. This preliminary constraint ensures that the joining member maintains its position throughout the curing period, preventing groove formation in the adhesion region while preserving the protruding portion's joining strength enhancement
Solution Approach 2:
The rotation stop portion acts as an intermediary element between the joining member and the panel member. It provides a constraint mechanism that prevents unwanted rotation without interfering with the adhesive bonding function, thus resolving the conflict between maintaining joining strength and preventing adhesion region damage
2Strength
If the protruding portion extends further from the adhesion region, then the joining strength is enhanced, but the delamination moment increases, making the joining member more prone to movement
Solution Approach 1:
The rotation stop portion provides a counter-constraint that balances the delamination moment generated by the protruding portion. By preventing rotation at a specific point, it counteracts the destabilizing effect of the extended protruding portion, allowing the design to maintain both high joining strength and stability
3Reliability
If grooves are formed in the adhesion region due to joining member movement, then waterproofness deteriorates, but the joining strength is compromised
Solution Approach 1:
The rotation stop portion applies preliminary anti-action by preventing the joining member from moving or rotating during the critical adhesive curing period. This pre-prevention eliminates the cause of groove formation, thereby preserving both waterproofness and joining strength without requiring additional corrective measures
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 enhances waterproofness in the adhesion region by preventing groove formation and improving the joining strength between the panel and bracket, ensuring better resistance to water ingress.
Implementation Method 1
an adhesive that is disposed on a join face of the member to be joined; a joining member that includes a base made from resin joined to the member to be joined by the adhesive
Implementation Method 2
a weld structure that is separated from an imaginary line connecting the first coupling portion and the second coupling portion, and that welds the member to be joined and the joining member to each other
Data Source
AI summary
A joint structure including a second panel serving as a member to be joined made from resin, a third adhesive disposed on a join face of the second panel, a bracket serving as a joining member that includes a base made from resin joined to the second panel by the third adhesive and a protruding portion that is contiguous to the base and that protrudes outside from an adhesion region between the base and the second panel, a first coupling portion that is provided at the adhesion region and that couples the bracket and second panel, a second coupling portion that is separated from the first coupling portion at the adhesion region and that couples the bracket and the second panel, and one or more rotation stop portion that is separated from an imaginary line connecting the first coupling portion and the second coupling portion, and that stops the bracket from rotating about an axis of the imaginary line.