Straddled Vehicle Aero-Stabilizing Member Downforce Design

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Solution Overview

Problem

Existing straddled vehicle designs that generate downforce through wind intake are complex and bulky, often requiring wing-shaped aero-stabilizing fins, which complicate the structure and increase size.

Innovation Solution

A straddled vehicle design featuring a front cover with an opening for wind intake, utilizing an aero-stabilizing member with a slanted front edge and lateral portions positioned apart from the front cover, generating downforce with a simple and compact configuration by directing wind flow effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If wing-shaped aero-stabilizing fins are provided on lateral portions of the vehicle to generate downforce, then downforce is generated, but the vehicle becomes complicated in structure and increased in size

Engineering Contradiction:

ImprovedownforceVSAvoidvehicle structure

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The aero-stabilizing member is divided into distinct functional portions: a middle portion positioned below the duct opening and lateral portions extending outward. This segmentation allows each portion to contribute differently to downforce generation while maintaining a compact overall structure, avoiding the need for complex wing-shaped fins

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The aero-stabilizing member extends in the vehicle width direction with lateral portions that project sideways from the middle portion. This dimensional extension allows the member to intercept traveling wind from multiple directions and generate downforce without requiring the vertical complexity of wing-shaped fins

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Force

If wing-shaped aero-stabilizing fins are provided on lateral portions of the vehicle to generate downforce, then downforce is generated, but the vehicle size is increased

Engineering Contradiction:

ImprovedownforceVSAvoidvehicle size

Core Design Contradiction:

ForceVSVolume of moving object

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The aero-stabilizing member combines multiple functions in a single component: it generates downforce, stabilizes wind flow to the duct opening, and serves as an aerodynamic fairing. This merging eliminates the need for separate wing-shaped fins and reduces overall vehicle volume

Inventive Principle:

Principle #5Merging (Combining)

3Force

If the aero-stabilizing member is disposed in a front portion of the vehicle, then a greater downforce is obtained, but the structure becomes more complex

Engineering Contradiction:

ImprovedownforceVSAvoidaero-stabilizing member configuration

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The aero-stabilizing member positioned in the front portion of the vehicle serves multiple functions simultaneously: it generates downforce through its aerodynamic shape, stabilizes and directs wind flow to the duct opening, and acts as a fairing to reduce turbulence. This multi-functionality allows greater downforce without proportionally increasing structural complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 achieves downforce generation with a simpler configuration, increased wind flow through the duct, and easier replacement of the aero-stabilizing member, allowing for adjustable downforce based on the traveling course.

Implementation Method 1

The aero-stabilizing member configured to generate a downforce by utilizing the traveling wind flowing from ahead. The front edge has a shape shaped slanted forward and downward. The lateral portion extends from the middle portion to a more outer side than the opening in the vehicle width direction and is disposed apart from the front cover at a gap in a vehicle up-and-down direction.

Methodology Applied

Scientific EffectAerodynamic downforce generation: Aerofoil

Implementation Method 2

The front edge of the aero-stabilizing member is partially disposed on a more front side than the lower end of the opening. Hence, the traveling wind is stabilized by the aero-stabilizing member and becomes likely to be led to the opening. Consequently, the amount of wind passing through the duct can be increased.

Methodology Applied

Scientific EffectWind flow stabilization and direction: Flow Separation

Data Source

PatentUS11958561B2Straddled vehicle

Publication Date: 2024.04.16 YAMAHA MOTOR CO LTD

AI summary

A straddled vehicle having a body frame including a head pipe, a front cover disposed in front of the head pipe, a duct disposed in front of the head pipe and extending rearward from an opening in the front cover, to thereby form a traveling wind pathway for traveling wind taken in through the opening, and an aero-stabilizing member. The aero-stabilizing member includes a middle portion disposed below a lower distal end of the front cover, directly below the opening in a front view, a lateral portion extending from the middle portion to a more outer side than the opening in a width direction, apart from the front cover with a gap therebetween in an up-and-down direction, and a front edge slanted forward and downward from the middle portion and the lateral portion, the front edge being partially disposed further forward than a lower front end of the duct.