Motorcycle Side Case Damper for Weave Mode Suppression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The occurrence of the weave mode, a phenomenon of vibration caused by rotational and roll axis movements, is exacerbated by side cases on vehicles like motorcycles, restricting their traveling speed due to increased luggage capacity requirements.

Innovation Solution

A side case device with a concave portion and a rotation member supported by a shaft member, featuring a damper to absorb rotational forces, allowing the side case to swing while minimizing shock and contact, thereby attenuating the weave mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If side cases are attached to increase luggage capacity, then luggage capacity is improved, but weave mode vibration occurs and traveling speed is restricted

Engineering Contradiction:
Improveluggage capacityVSAvoidweave mode vibration
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by introducing a damper mechanism that provides damping force in advance to counteract the weave mode vibration. The damper is pre-configured between the side case and vehicle body to absorb vibrational energy before it can propagate through the vehicle structure, thereby suppressing the harmful vibration while maintaining the side case attachment for increased luggage capacity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Object-affected harmful factors

If side cases are rigidly fixed to suppress vibration, then weave mode is reduced, but the side cases cannot swing freely and may cause damage

Engineering Contradiction:
Improveweave mode vibrationVSAvoidside case swing freedom
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transitioning from a rigid fixed connection to a dynamic connection that allows controlled movement. The damper mechanism enables the side case to swing freely within certain limits while providing damping force to suppress weave mode vibration. This dynamic system adapts to varying vibration conditions and maintains both vibration suppression and swing freedom.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple support points are used to secure side cases, then attachment reliability is improved, but the complexity of the support structure increases

Engineering Contradiction:
Improveattachment reliabilityVSAvoidsupport structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining multiple functions into a single integrated support structure. The support structure includes both the mounting brackets for attachment and the damper mechanism for vibration suppression, unified into one cohesive assembly. This reduces the overall complexity compared to having separate mounting and damping systems while maintaining high attachment reliability.

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 solution effectively suppresses the weave mode while maintaining increased luggage capacity, ensuring the vehicle's speed is not restricted by the side cases.

Implementation Method 1

a damper provided between the shaft member and the rotation member

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3882112B1Side case device, mobile object including same, side case and support device
Publication Date: 2023.07.26 YAMAHA MOTOR CO LTD
  • EP3882112B1 patent drawingFigure 1
  • EP3882112B1 patent drawingFigure 2
  • EP3882112B1 patent drawingFigure 3

AI summary

A side case (10L) is attached to a side portion of a mobile object to be swingable and has a concave portion (CV) that opens forwardly. A rotation cover member (490) is provided to be rotatable about a shaft member that is fixed to the mobile object to extend upwardly and downwardly. The rotation cover member (490) has an insertion portion (491) to be inserted into the concave portion (CV). A damper is provided between the shaft member and the rotation cover member (490). A cross section, which is orthogonal to an axial center of the shaft member, of the concave portion (CV) is defined. A first position (p1), a second position (p2) and a third position (p3) are defined in this order from an opening end toward a bottom portion of the concave portion (CV). The size of the clearance between the concave portion (CV) and the insertion portion (491) gradually decreases from the first position (p1) to the second position (p2) and gradually increases from the second position (p2) to the third position (p3).