Vehicle Visor Noise Reduction via Air Flow Incoherence

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Solution Overview

Problem

Existing vehicle sun visors generate noise due to air turbulence when a vehicle is in motion, and current solutions either fail to adequately reduce noise or increase air resistance.

Innovation Solution

The integration of diffuser portions along the visor sides, specifically recesses or protrusions arranged at varying distances and angles, creates an incoherence in air flow, reducing noise while maintaining low air resistance and preserving the visor's external appearance and functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If smooth parallel sides are used on the visor, then air flow is coherent and aerodynamic, but noise such as whistling noise is created

Engineering Contradiction:

ImprovenoiseVSAvoidcoherent air flow instability

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by introducing diffuser portions only at specific locations along the visor sides rather than modifying the entire surface. These diffuser portions are strategically positioned to disrupt coherent air flow and reduce whistling noise while preserving the overall aerodynamic shape and smooth appearance of the visor.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent converts the harmful coherent air flow that causes whistling noise into a beneficial disrupted flow pattern. By introducing diffuser portions, the previously harmful coherence is transformed into controlled turbulence that reduces noise generation while maintaining acceptable aerodynamic performance.

Inventive Principle:

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

2Object-affected harmful factors

If diffuser portions are added to reduce noise, then noise reduction is achieved, but air resistance may increase

Engineering Contradiction:

ImprovenoiseVSAvoidair resistance

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent segments the visor sides into multiple sections with diffuser portions distributed along the length. This segmentation allows the air flow to be gradually disrupted rather than creating a single large disturbance, reducing overall air resistance while effectively breaking up coherent flow patterns that cause noise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using a limited number of diffuser portions rather than covering the entire visor surface. This partial application is sufficient to disrupt noise-causing coherent flow while minimizing the total surface area modification and associated air resistance penalty.

Inventive Principle:

Principle #16Partial or excessive action

3Object-affected harmful factors

If diffuser portions are arranged on the front side of the visor, then noise reduction is achieved, but external appearance is affected

Engineering Contradiction:

ImprovenoiseVSAvoidexternal appearance

Core Design Contradiction:

Object-affected harmful factorsVSShape

Solution Approach 1:

The patent inverts the conventional approach by placing diffuser portions on the rear side of the visor rather than the front side. This inversion achieves the same noise reduction effect by disrupting coherent flow at the rear, while preserving the smooth, aesthetically pleasing appearance of the front surface that is visible when the visor is mounted on the vehicle.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts the noise-reducing diffuser portions from the visible front surface and relocates them to the hidden rear surface. This extraction maintains the aesthetic integrity of the visor's external appearance while retaining the acoustic benefits of flow disruption.

Inventive Principle:

Principle #2Taking out (Extraction)

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 effectively reduces noise without increasing air resistance, making it a cost-efficient solution for existing visors that also provides shading and weight reduction.

Implementation Method 1

a set of diffuser portions arranged along at least one of said visor sides so as to create an incoherence of said flow of air

Methodology Applied

Scientific EffectTurbulence: Turbulence

Data Source

PatentEP3558730B1An arrangement for a visor of a vehicle

Publication Date: 2023.03.08 SCANIA CV AB

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AI summary

The present invention relates to an arrangement (A1) for a visor (10) of a vehicle. Said visor (10) has a front side (10a) arranged to face away from the vehicle and a rear side (10b) facing the vehicle (1). Said visor (10) is arranged to be mounted on an upper portion (2a) of the vehicle (1) in connection to the windshield (3) of the vehicle (1) such that air (F1, F2) is allowed to flow past said visor sides (10a, 10b) and thus between the visor (10) and the vehicle. Said arrangement comprises means for reducing noise caused by said flow of air (F1, F2). Said means for reducing noise comprises a set (D1) of diffuser portions arranged along at least one of said visor sides (10a, 10b) so as to create an incoherence of said flow of air (F1, F2) and consequently a noise reduction. The present invention also relates to a vehicle.