Variable Thickness Weather Strip for Roof Sealing
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Solution Overview
Problem
The existing roof apparatus experiences unstable elastic deformation of the first seal portion, leading to a shortened lifetime and compromised sealing performance due to its thick configuration, which deflects poorly during the rising operation of the link member.
Innovation Solution
A roof apparatus with a weather strip design where the first seal portion's thickness gradually reduces from the upper end to the turned back portion and then increases to the lower end, with the second seal portion's thickness being smaller than the first, allowing for stable elastic deformation and improved liquid-tight contact with the movable panel and opening end.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the first seal portion is made thick to ensure sealing performance, then liquid-tight contact with the movable panel is improved, but elastic deformation stability deteriorates due to poor deflection during link member operation
Solution Approach 1:
The first seal portion employs non-uniform thickness distribution with different sections having different thickness characteristics. The first section has greater thickness for stable elastic deformation, while the second section has lesser thickness for adequate deflection during link member operation. This local quality variation resolves the contradiction between maintaining sealing performance and ensuring elastic deformation stability.
Solution Approach 2:
The thickness parameter of the first seal portion is varied along its length rather than maintaining a constant thickness. By changing the thickness parameter from one section to another, the seal portion achieves both the stability needed for reliable sealing and the flexibility required for smooth operation during link member movement.
2Reliability
If the first seal portion is made thick to maintain liquid-tightness, then sealing performance is improved, but the weather strip lifetime shortens due to unstable elastic deformation
Solution Approach 1:
The first seal portion is designed with different thickness characteristics in different sections. The first section has greater thickness to provide stable elastic deformation for long-term durability, while the second section has lesser thickness to allow adequate deflection during operation. This local quality differentiation resolves the contradiction between maintaining liquid-tightness and extending weather strip lifetime.
3Ease of manufacture
If the first seal portion has uniform thickness, then manufacturing is simplified, but elastic deformation stability deteriorates during link member operation
Solution Approach 1:
The first seal portion employs different thickness characteristics in different sections rather than uniform thickness. This local quality variation optimizes elastic deformation stability during link member operation while remaining manufacturable through conventional molding processes that can accommodate gradual thickness transitions.
4Ease of operation
If the first seal portion deflects adequately during link member operation, then operation smoothness is improved, but sealing performance deteriorates due to excessive deformation
Solution Approach 1:
The first seal portion is designed with different thickness characteristics where the first section has greater thickness for stable elastic deformation and the second section has lesser thickness for adequate deflection during link member operation. This local quality differentiation ensures that each section performs its specific function optimally, resolving the contradiction between operation smoothness and sealing performance.
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 design enhances the stability of elastic deformation and sealing performance by allowing smooth upward and downward movement of the link members, extending the weather strip's lifetime and maintaining liquid-tightness against raindrops and droplets.
Implementation Method 1
the first seal portion (112) elastically deforms so as to allow an up-down operation of the link member (104) through the clearance C100
Implementation Method 2
a first seal portion which is connected to an upper end of the portion to be retained and liquid-tightly contacts the peripheral rim end of the movable panel
Implementation Method 3
a second seal portion which is connected to an upper end of the portion to be retained and liquid-tightly contacts an opening end of the opening portion
Data Source
AI summary
A roof apparatus includes a weather strip including a portion to be retained, and first and second seal portions which are connected to an upper end of the portion to be retained. A thickness of the first seal portion gradually reduces from a first end portion positioned at an upper end side of the portion to be retained towards a first turned back portion, and gradually increases from the first turned back portion towards a second end portion provided at a lower end portion of the portion to be retained. A thickness of the second end portion is smaller than that of the first end portion. A distance in a vehicle height direction from a lower end of the first seal portion to the first turned back portion is greater than a distance from an upper end of the first seal portion to the first turned back portion.