Wiper Blade Adapter Geometry That Uses Airflow for Contact Pressure

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Solution Overview

Problem

Existing wiper devices require high contact pressure to ensure effective wiping performance, which can lead to unfavorable aerodynamics and reduced reliability, especially when driving quickly, potentially worsening wiping performance or making it impossible.

Innovation Solution

An adapter unit with a wind deflector surface and a pivot bearing featuring columns of varying heights, where the windward-facing column is shorter than the leeward-facing column, allowing the wiper blade to be pressed against the window by wind forces, reducing the required contact pressure and enhancing wiping performance through aerodynamic effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high contact force is applied by the wiper arm to press the wiper blade against the vehicle window, then wiping performance is improved, but aerodynamic resistance increases and reliability decreases during high-speed driving

Engineering Contradiction:
Improvewiping performance reliabilityVSAvoidcontact force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent converts the harmful aerodynamic drag force into a beneficial force by designing the adapter unit with a specific orientation that allows wind pressure to press the wiper blade against the window. The wind force, which would normally oppose the wiper arm's contact force, is instead utilized to supplement the contact pressure, improving reliability while reducing the required mechanical force from the wiper arm.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the orientation parameter of the adapter unit relative to the wind flow direction. By optimizing the angle between the adapter unit's reference axis and the wind flow direction, the design transforms the aerodynamic forces acting on the wiper blade, converting detrimental drag into beneficial contact pressure without increasing the wiper arm's mechanical force requirements.

Inventive Principle:
Principle #35Parameter changes

2Force

If high contact force is required from the wiper arm, then a stronger and more complex wiper arm structure is needed, but device complexity and cost increase

Engineering Contradiction:
Improvecontact forceVSAvoidwiper arm structure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent utilizes the previously harmful aerodynamic drag force to provide additional contact pressure on the wiper blade. This eliminates the need for an over-engineered wiper arm structure designed to compensate for aerodynamic losses, allowing for a simpler, lighter, and more cost-effective wiper arm design while maintaining sufficient contact force.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The adapter unit design enables the wiper system to utilize environmental resources (wind flow) to perform part of the work of pressing the blade against the window. The aerodynamic forces generated during vehicle motion automatically contribute to maintaining contact pressure, reducing the burden on the wiper arm's mechanical force-generating components.

Inventive Principle:
Principle #25Self-service

3Reliability

If unfavorable aerodynamics during high-speed driving generates opposing force, then wiping performance deteriorates or becomes impossible, but this cannot be easily corrected in conventional designs

Engineering Contradiction:
Improvewiping performanceVSAvoidaerodynamic resistance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent directly addresses the harmful aerodynamic resistance by reorienting the adapter unit to convert the drag force into a beneficial contact pressure. The wind flow, which would normally create resistance and reduce wiping effectiveness, is instead channeled to press the wiper blade firmly against the window, ensuring reliable wiping performance even at high speeds.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces dynamic adaptability to the wiper system by designing the adapter unit to exploit varying wind flow conditions. As vehicle speed and wind conditions change, the aerodynamic forces automatically adjust to provide appropriate contact pressure, making the system adaptive rather than static and overcoming the limitations of conventional fixed designs.

Inventive Principle:
Principle #15Dynamics

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 improves wiping performance by utilizing wind forces to press the wiper blade against the window, allowing for a cheaper, simpler, and more reliable wiper arm with lower contact pressure, while preventing adverse aerodynamic forces that could hinder operation.

Implementation Method 1

a wind deflector surface (28) which is designed to deflect incoming air and press the wiper blade (16) against a vehicle window

Methodology Applied
Scientific EffectAerodynamic pressure: Drag

Data Source

PatentEP3829937B1Adapter unit
Publication Date: 2024.03.13 ROBERT BOSCH GMBH
  • EP3829937B1 patent drawingFigure 1
  • EP3829937B1 patent drawingFigure 2~3
  • EP3829937B1 patent drawingFigure 4~5

AI summary

The invention relates to an adapter unit which is provided for coupling, in particular releasably coupling, a wiper blade to a wiper arm, having a wind deflecting surface, which is designed to deflect inflowing air and press the wiper blade against a vehicle windshield, and a pivot bearing, which is designed to support the wiper arm in a pivotal manner relative to the wiper blade. The pivot bearing has at least two columns arranged largely vertically on an adapter base surface, wherein each of the columns has a respective joint pin which is oriented parallel or largely parallel to a bearing axis and is designed to support the wiper arm and/or a wiper arm adapter unit. According to the invention, one of the at least two columns, said column facing the wind, has a lower height than one of the at least two columns, said column facing away from the wind, in particular such that the height of the at least two columns corresponds to the height profile of the wind deflecting surface.