Straddled Vehicle Fan Cover Bulging Portion Cooling

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Solution Overview

Problem

Existing straddled vehicles face challenges in enhancing the cooling effect of radiators using radiator fans while maintaining a compact fan cover size, as increasing the air outlet opening area is difficult without enlarging the fan cover.

Innovation Solution

The design incorporates a fan cover with a bulging portion that extends rearward from the cover body, increasing the air outlet area across both components, which enhances cooling efficiency without increasing the overall size of the fan cover, and includes lateral guide ribs to efficiently direct exhaust air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the opening area of the air outlet is increased to improve cooling effect, then the cooling effect of the radiator is improved, but the size of the fan cover increases

Engineering Contradiction:
Improvecooling effectVSAvoidsize of fan cover
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The air outlet is configured to extend in the depth direction (front-rear direction) of the fan cover, transforming a two-dimensional opening into a three-dimensional passage. This allows the effective opening area to be increased without enlarging the external dimensions of the fan cover, as the extended outlet utilizes the depth dimension to provide greater cross-sectional area for air flow while maintaining a compact overall size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The fan cover is divided into distinct functional regions: a cover body portion and an extended outlet portion. The air outlet is specifically formed by the extension of the cover body in the depth direction, separating the structural housing function from the air discharge function. This segmentation allows the outlet area to be optimized independently from the overall cover size.

Inventive Principle:
Principle #1Segmentation

2Temperature

If the entire fan cover is enlarged to increase the air outlet opening area, then the cooling effect is improved, but the compactness of the fan cover is reduced

Engineering Contradiction:
Improvecooling effectVSAvoidvolume of fan cover
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

Instead of enlarging the fan cover in lateral dimensions (width or height), the solution extends the air outlet in the depth direction. This dimensional strategy increases the effective opening area for cooling while maintaining compact lateral dimensions, thus preserving the overall volume efficiency and compactness of the fan cover assembly.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If the air outlet opening area is increased, then more exhaust air can be discharged, but the thermal influence on components behind the radiator fan increases

Engineering Contradiction:
Improveexhaust air discharge capacityVSAvoidthermal influence on components
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The fan cover incorporates lateral guide ribs that create localized flow guidance regions within the cover. These guide ribs are strategically positioned to direct exhaust air laterally toward the extended outlet, ensuring that the increased opening area effectively channels cooled air away from heat-sensitive components. The local flow control structure optimizes the quality of air discharge rather than simply increasing quantity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The extended outlet structure acts as an intermediary element between the radiator fan and the external environment. By extending the outlet in the depth direction, it creates a longer discharge path that allows exhaust air to be progressively directed away from components behind the fan, reducing thermal influence while maintaining high discharge capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 increases the cooling effect of the radiator by expanding the air outlet area and directing exhaust air effectively, reducing thermal influence on nearby components while maintaining a compact fan cover size.

Implementation Method 1

The radiator fan generates a flow of air through the radiator

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP4368485A1Straddled vehicle
Publication Date: 2024.05.15 YAMAHA MOTOR CO LTD
  • EP4368485A1 patent drawingFigure 1
  • EP4368485A1 patent drawingFigure 2
  • EP4368485A1 patent drawingFigure 3

AI summary

A straddled vehicle (1) including a radiator (31), a radiator fan (32), and a fan cover (34), wherein the radiator fan (32) is disposed behind the radiator (31), the fan cover (34) covering the radiator fan (32) from behind and including a cover body (37), a bulging portion (38), and an air outlet, the bulging portion (38) bulging rearward from the cover body (37), the air outlet being provided across the cover body (37) and the bulging portion (38).