Windshield Wiper Pressing Rib Layout for Uniform Crosswind Pressure
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Solution Overview
Problem
Existing wiper designs fail to uniformly distribute pressure along the windshield surface, leading to gaps between the wiper blade and the windshield due to uneven forces, especially when exposed to crosswind, which affects the wiper's ability to effectively scrape off rainwater.
Innovation Solution
A wiper with a flow guiding cover featuring horizontal pressing ribs that are non-uniformly arranged and tilted at different angles, providing varying pressures along the elastic strip to ensure uniform pressure distribution and secure attachment to the windshield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a convex ridge-shaped flow guiding cover is mounted on the wiper to resist crosswind, then the wiper can better resist crosswind forces, but the pressure distribution becomes uneven causing gaps between the wiper blade and windshield
Solution Approach 1:
The flow guiding cover is divided into multiple sections along the longitudinal direction, with each section having pressing ribs with different tilt angles. The outer section has pressing ribs with smaller tilt angles to generate greater reinforced pressure, while the inner section has pressing ribs with larger tilt angles. This local differentiation of structural parameters achieves non-uniform pressure distribution that compensates for the natural pressure gradient, resulting in more uniform overall pressure distribution across the wiper blade.
Solution Approach 2:
The pressing ribs are designed with asymmetric tilt angles relative to the longitudinal direction of the elastic strip. By making the tilt angles different between the outer section and inner section, the aerodynamic forces generated by crosswind are asymmetrically distributed. This asymmetric design counterbalances the natural tendency for uneven pressure, achieving more uniform pressure distribution across the wiper blade width.
2Shape
If the wiper is designed as an elastic curved strip to conform to the windshield curvature, then the wiper can attach well to the curved windshield surface, but the elastic force is insufficient to maintain uniform pressure against crosswind
Solution Approach 1:
The flow guiding cover acts as an intermediary structure between the crosswind and the elastic strip. It captures and redirects crosswind forces through its pressing ribs, converting aerodynamic forces into additional downward pressure on the wiper blade. This mediator structure amplifies the effective pressing force without requiring increased elastic force from the strip itself.
Solution Approach 2:
The flow guiding cover utilizes aerodynamic principles to generate reinforced pressure. The tilted pressing ribs create pressure differences when crosswind flows over them, generating aerodynamic forces that press the wiper blade against the windshield. This pneumatic mechanism supplements the mechanical elastic force, achieving greater total pressing force without increasing the elastic strip's inherent force.
3Ease of manufacture
If pressing ribs with uniform tilt angles are used throughout the flow guiding cover, then the structure is simple to manufacture, but the pressure distribution remains uneven
Solution Approach 1:
The flow guiding cover is segmented into multiple sections along the longitudinal direction, with each section containing pressing ribs having specific tilt angles. This segmentation allows different regions to have optimized tilt angles for their local pressure requirements. While more complex than a uniform design, the segmentation is achieved through modular construction methods, balancing manufacturing complexity with performance requirements.
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 wiper achieves more uniform pressure distribution along the windshield surface, preventing gaps and enhancing the wiper's ability to resist crosswind, thereby improving its effectiveness in scraping rainwater.
Implementation Method 1
When the crosswind flows along the windshield surface and passes through the windward slope, a component force acting on the windshield surface is produced to press the whole wiper
Implementation Method 2
the wiper itself is designed as an elastic curved strip with a radius of curvature smaller than the minimum radius of curvature of the windshield, so that its concave side can be attached onto the windshield very well
Data Source
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AI summary
A wiper includes an elastic strip (100), a wiper blade (200), a connecting base (300) and a flow guiding cover (400). The elastic strip (100) has a bottom side (101) and a top side (102), and a connecting base (300) is disposed at the center of the top side. The wiper blade (200) is disposed corresponding to the bottom side (101). The flow guiding cove (400) includes a cover (410), and the cover (410) has an outer surface (413) and an inner concave surface (414), and the inner concave surface (414) covers the top side (102) and is extended from the connecting base (300) to two ends of the elastic strip (100), and pressing ribs (420a, 420b) are installed protrusively from the outer surface (413) and configured to be tilted relative to a longitudinal direction (100L) of the elastic strip (100). The pressing rib (420a, 420b) partially presses the wiper at different positions of the wiper in the longitudinal direction(100L) to distribute the pressure exerted on the wiper more uniformly.