Door Weather Strip Seal Lip Structure for Door Frame Suction
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Solution Overview
Problem
Existing door weather strips fail to effectively suppress the phenomenon of door frames being sucked out of vehicles during high-speed travel due to pressure differences, leading to insufficient sound insulation and delayed reaction forces.
Innovation Solution
A door weather strip design featuring a seal lip with a protrusion and a hard portion extending from the lower region of the protrusion to the root side, which reduces deflection and prevents bending, ensuring rapid equalization of reaction forces with external pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the seal lip is made easily deformable to reduce door closing force, then the door closing operation becomes easier, but the seal lip deflects excessively under pressure difference during high-speed travel, causing door frame suction and deteriorating sound insulation
Solution Approach 1:
The seal lip is designed with non-uniform cross-sectional shape along its length, with different curvature radii at different positions. The curvature radius decreases from the root toward the tip, creating varying local stiffness characteristics. This allows the root portion to be more rigid for resisting pressure differential forces during high-speed travel, while the tip portion remains more compliant for easy door closing operation and effective sealing contact.
2Reliability
If the seal lip is made rigid to prevent deflection under pressure difference, then sound insulation is improved, but the door closing force increases and the seal lip cannot deform sufficiently to close gaps effectively
Solution Approach 1:
The seal lip employs a gradient cross-sectional design where the curvature radius varies along its length. The larger curvature radius at the root provides rigidity to resist pressure differential forces and prevent door frame suction, while the progressively smaller curvature radius toward the tip enables sufficient deformation for effective gap closure and maintains acceptable door closing forces.
3Speed
If a hard portion is added to the seal lip to prevent deflection, then the reaction force equalization speed improves, but the structure becomes more complex and manufacturing difficulty increases
Solution Approach 1:
Instead of adding a separate hard portion component, the invention changes the geometric parameters of the seal lip cross-section along its length. By varying the curvature radius from root to tip, the seal lip achieves different stiffness characteristics at different positions, effectively creating a gradient structure that improves reaction force equalization speed while avoiding the complexity of multi-material or multi-component construction.
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 significantly reduces door frame suction and enhances sound insulation by quickly equalizing reaction forces with external pressures, preventing bending and maintaining smooth door closure.
Implementation Method 1
a root 220b of the vehicle exterior seal 220 is deformed toward the vehicle exterior attachment base 210 side to close a gap between the vehicle body opening peripheral edge 601 and a tip of the door molding 600
Implementation Method 2
the vehicle exterior seal 220 is largely deflected and deformed in an arc shape as shown in FIG. 9 as the F1 increases
Data Source
AI summary
A door weather strip includes an attachment base that is attached to a door frame or a door molding, and a seal lip that abuts on a vehicle body opening peripheral edge when a door is closed, in which the vehicle body opening peripheral edge side at a tip of the seal lip is formed with a protrusion that abuts on the vehicle body opening peripheral edge when the door is closed, and the seal lip is formed with a hard portion harder than a material constituting the seal lip to extend from a lower region of the protrusion to a root side of the seal lip.