Side Cowl Convex Structure for Motorcycle Wind Pressure Reduction

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Solution Overview

Problem

Existing saddle-ridden vehicles, such as motorcycles, experience discomfort due to strong traveling wind hitting portions of the occupant that protrude from the side cowl, reducing driving comfort and stability.

Innovation Solution

A side cowl with a convex portion that diffuses traveling wind outward in the vehicle width direction, separating the wind flow and reducing air resistance, thereby preventing strong local wind pressure on the occupant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the side cowl is designed with a streamlined shape to reduce air resistance, then air resistance is reduced and stable traveling is enabled, but strong local wind pressure is generated on portions of the occupant that protrude from the side cowl, reducing driving comfort

Engineering Contradiction:
Improveair resistanceVSAvoidlocal wind pressure on occupant
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The side cowl is segmented into multiple regions: a main body portion and a protruding portion that extends toward the rear. This segmentation allows the wind flow to be divided and redirected, reducing concentrated wind pressure on the occupant while maintaining overall streamlined performance for air resistance reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the side cowl are designed with different geometric characteristics. The main body has a streamlined shape optimized for reducing air resistance, while the protruding portion is specifically shaped to diffuse wind flow and reduce local wind pressure on the occupant, applying local quality changes to solve different problems in different locations.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the side cowl is extended to further protect the occupant from wind, then driving comfort is improved, but air resistance increases and stable traveling is compromised

Engineering Contradiction:
Improvewind protection for occupantVSAvoidair resistance
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The protruding portion of the side cowl is designed with a curved, aerodynamic shape that follows the natural flow of wind. This curvature allows the wind to flow smoothly around the extended portion without creating excessive turbulence or pressure drag, enabling extended wind protection while minimizing air resistance increase.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The side cowl includes a protruding portion that extends in the vehicle width direction toward the rear. This dimensional extension provides additional wind protection for the occupant without significantly increasing frontal area, thereby reducing the impact on air resistance while improving wind protection in the lateral dimension.

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

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 side cowl softens the impact of traveling wind on the occupant, stabilizes travel, and maintains driving comfort without impairing air resistance.

Implementation Method 1

a convex portion that elongates in an upper-lower direction and protrudes outward in a vehicle width direction with respect to the cowl outer surface is formed on a downstream side of the traveling wind on the cowl outer surface, and a flow of the traveling wind along the cowl outer surface is separated by the convex portion

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Data Source

PatentEP3964434B1Side cowl
Publication Date: 2025.07.09 SUZUKI MOTOR CORP
  • EP3964434B1 patent drawingFigure 1
  • EP3964434B1 patent drawingFigure 2
  • EP3964434B1 patent drawingFigure 3

AI summary

A side cowl (32) configured to cover a vehicle side portion of a saddle-ridden vehicle (1) is provided. The side cowl includes a convex portion (52;74) elongating in an upper-lower direction and protruding outward in a vehicle width direction with respect to a cowl outer surface. The convex portion is formed on the cowl outer surface at a downstream side of traveling wind that flows on the cowl outer surface.