Straddle-Type Vehicle Cowling Structure with Ventilation and Lamp Adjustment

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Solution Overview

Problem

Existing straddle-type vehicle cowling structures face challenges in maintaining stable traveling while reducing the upward force generated by traveling wind, which can decrease the load shared by the front wheel, and also need to accommodate optical axis adjustment without increasing the number of holes in the cowling.

Innovation Solution

The cowling structure features a front cowling with a lower surface inclined obliquely downward, equipped with a ventilation hole that allows traveling wind to escape, reducing the upward force and increasing the load on the front wheel. This ventilation hole also serves as the optical axis adjustment hole for the headlamp, eliminating the need for additional holes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the front cowling is designed with a high front end portion to reduce traveling wind against the occupant, then the protection from traveling wind is improved, but an upward force is generated in the vehicle front portion which decreases the load shared by the front wheel

Engineering Contradiction:
Improvetraveling wind impact on occupantVSAvoidupward force on vehicle front portion
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The front cowling is divided into an upper portion and a lower portion that can be independently configured. The lower portion can be made slanted to generate downward aerodynamic force while the upper portion maintains height for occupant protection, segmenting the conflicting functional requirements into separate spatial zones

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design transitions from a purely vertical height dimension to include a slant angle dimension. By introducing the slant angle of the lower surface, the aerodynamic force direction is changed from upward to downward, adding a dimensional parameter that resolves the force contradiction while maintaining protective height

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

2Force

If the front portion of the front cowling is made into a slant shape to press the cowling downward by traveling wind, then the load on the front wheel is improved, but the degree of freedom in design is reduced

Engineering Contradiction:
Improvedownward force on front cowlingVSAvoiddegree of freedom in design
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The front cowling is segmented into an upper portion and a lower portion with independent design freedom. The lower portion can be slanted for aerodynamic performance while the upper portion maintains design flexibility for styling and lighting arrangements, allowing each segment to be optimized independently

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the front cowling are assigned different functional qualities: the lower portion has a slanted shape for aerodynamic downforce while the upper portion maintains vertical height for protection. This local differentiation allows each region to have optimized properties without constraining the overall design freedom

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If separate holes are provided for ventilation and optical axis adjustment, then the functionality is improved, but the number of holes in the cowling increases which affects appearance

Engineering Contradiction:
Improvefunctional versatility of cowlingVSAvoidappearance of cowling
Core Design Contradiction:
Adaptability or versatilityVSShape

Solution Approach 1:

The ventilation hole and optical axis adjustment hole are merged into a single opening in the front cowling. This single hole simultaneously serves both functions: allowing traveling wind to pass through for ventilation and cooling, and providing access for optical axis adjustment tools, thereby eliminating the need for separate holes and preserving the cowling's appearance

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single hole in the front cowling is designed to perform multiple functions: it serves as both a ventilation hole for aerodynamic cooling and an access hole for optical axis adjustment. This multi-functional design eliminates redundant openings while maintaining all necessary capabilities

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

This configuration enhances stability during traveling by reducing the upward force on the vehicle front portion and increasing the load on the front wheel, while maintaining design flexibility and improving the appearance by minimizing the number of holes in the cowling.

Implementation Method 1

when the traveling wind enters below the front cowling, an upward force is generated in a vehicle front portion

Methodology Applied
Scientific EffectAerodynamic force: Drag

Data Source

PatentEP4410644B1Cowling structure
Publication Date: 2025.06.11 SUZUKI MOTOR CORP
  • EP4410644B1 patent drawingFigure 1
  • EP4410644B1 patent drawingFigure 2
  • EP4410644B1 patent drawingFigure 3

AI summary

A cowling structure for a straddle-type vehicle. The cowling structure includes a front cowling (51) covering a vehicle front portion from a front side. A lamp unit (31) is installed inside the front cowling. A lower surface (73) of the front cowling is inclined obliquely downward to a rear side. The lower surface is formed with a first ventilation hole (76) through which traveling wind blows. The lamp unit includes a lamp (32) configured to illuminate a front of a vehicle, and an optical axis adjustment portion configured to adjust an optical axis of the lamp. The optical axis adjustment portion is configured to receive an operation with a tool, through the first ventilation hole.