Vehicle Door Mirror Base Inverse Wing Flow Control

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Solution Overview

Problem

Existing door mirror designs fail to effectively reduce aerodynamic noise caused by complex air currents and wind flows around the vehicle when running, particularly due to turbulence and vortex generation near the mirror housing.

Innovation Solution

A door mirror with a base portion featuring a support portion in the shape of an inverse wing, where the lower surface bulges downward, and bead portions on the lower surface that protrude downward and extend rearward, helping to rectify and stabilize wind flows, thereby reducing noise by preventing vortices from hitting the door glass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional door mirror housing is used without special flow control structures, then the structure is simple and easy to manufacture, but aerodynamic noise is generated due to turbulence and vortex formation in the complex air currents around the mirror

Engineering Contradiction:
Improveaerodynamic noiseVSAvoidhousing structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The housing is divided into multiple functional regions: a main body portion, a support portion extending downward, and flow control portions with protrusions and recesses. This segmentation allows each region to address specific flow control needs, reducing overall aerodynamic noise while maintaining manufacturing feasibility through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Flow control portions with protrusions and recesses are introduced as intermediary structures between the housing and the air currents. These intermediate features modify the airflow pattern, preventing direct turbulent interaction between the housing and complex air currents, thereby reducing aerodynamic noise

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the housing is designed with smooth surfaces to reduce turbulence, then aerodynamic noise is reduced, but the ability to support the mirror and accommodate it securely is compromised

Engineering Contradiction:
Improveaerodynamic noiseVSAvoidmirror support stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The housing employs asymmetric design with a support portion extending downward on one side and flow control portions strategically positioned. This asymmetric configuration provides stable mirror support while the flow control features manage aerodynamic noise, achieving both reliability and noise reduction simultaneously

Inventive Principle:
Principle #4Asymmetry

3Object-affected harmful factors

If protrusions are added to the housing surface to control airflow, then aerodynamic noise is reduced, but manufacturing complexity and cost increase

Engineering Contradiction:
Improveaerodynamic noiseVSAvoidhousing manufacturing ease
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The flow control portions with protrusions and recesses are merged into the housing as integral features rather than separate components. This integration allows the housing to perform both structural support and aerodynamic flow control functions simultaneously, reducing the need for additional manufacturing steps and associated costs

Inventive Principle:
Principle #5Merging (Combining)

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 wind flow velocity and direction, reducing noise by stabilizing wind separation and guiding it away from the door glass, effectively minimizing aerodynamic noise generated by wind flows around the door mirror.

Implementation Method 1

the support portion is formed into a sectional shape of an inverse wing having a lower surface bulging downward in a vertically sectional shape in a front/rear direction of the vehicle

Methodology Applied
Scientific EffectAerodynamic flow control: Aerofoil

Implementation Method 2

the bead portion protruding downward and extending in the front/rear direction of the vehicle so as to be gradually separated from the side surface of the vehicle body as it goes toward a rear of the vehicle

Methodology Applied
Scientific EffectFlow separation control: Flow Separation

Implementation Method 3

rectify and stabilize wind flows, thereby reducing noise by preventing vortices from hitting the door glass

Methodology Applied
Scientific EffectTurbulence reduction: Turbulence

Data Source

PatentEP2921351B1Door mirror of vehicle
Publication Date: 2017.06.07 MITSUBISHI MOTORS CORP
  • EP2921351B1 patent drawingFigure 1
  • EP2921351B1 patent drawingFigure 2
  • EP2921351B1 patent drawingFigure 3

AI summary

A door mirror of a vehicle includes a housing and a base portion attaching the housing to a side surface of a vehicle body. The base portion includes: an attachment portion fixed to the side surface; and a support portion provided to protrude from the attachment portion toward a vehicle-width-direction outer side, and supporting the housing from below. The support portion is formed into a sectional shape of an inverse wing having a lower surface bulging downward in a vertically sectional shape in a front/rear direction, and the support portion is provided with a bead portion in the lower surface of the support portion, the bead portion protruding downward and extending in the front/rear direction so as to be gradually separated from the side surface as it goes toward a rear of the vehicle.