Rotatable Side Cases with Dampers for Motorcycle Weave Mode Suppression
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Solution Overview
Problem
Straddled vehicles with side cases, such as motorcycles, experience the weave mode vibration due to rotational vibrations about the yaw and roll axes, limiting their speed range when side bags are attached, as the added weight and fixed mounting increase the likelihood of this vibration.
Innovation Solution
The vehicle incorporates rotatable side cases with independent rotation support and attenuation mechanisms, utilizing first and second inner outer cylindrical dampers to absorb rotational forces, allowing each side case to swing and attenuate its rotation independently, reducing overall vehicle sway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If side cases are fixed rigidly to the body frame, then luggage capacity is increased, but weave mode vibration occurs and speed range is limited
Solution Approach 1:
The side cases are configured to rotate about horizontal axes (first and second axes) while being supported by rotation supporters. This dynamic capability allows the side cases to move relative to the body frame, preventing rigid coupling that causes weave mode vibration, while still providing increased luggage capacity. The rotation supporters enable controlled movement that reduces harmful vibrations during vehicle operation.
Solution Approach 2:
The connection between side cases and body frame is divided into multiple independent rotation supporters (third and fourth rotation supporters for left side case, fifth and sixth for right side case). Each rotation supporter operates independently with its own rotation axis, allowing segmented movement that reduces overall vehicle vibration while maintaining structural integrity and luggage capacity.
2Stability of the object's composition
If side cases are made rotatable to reduce vibration, then weave mode is suppressed, but device complexity increases
Solution Approach 1:
The rotation support system is segmented into multiple independent rotation supporters, each handling specific rotation axes. The left side case has third and fourth rotation supporters, while the right side case has fifth and sixth rotation supporters. This segmentation distributes the complexity across multiple simple, modular units rather than one complex mechanism, making the system more manageable and maintainable.
Solution Approach 2:
Instead of complex active control systems, the invention uses passive rotational degrees of freedom that automatically adapt to vibration conditions. The side cases can rotate freely about specified axes, providing dynamic response to vibrations without requiring sensors, actuators, or control algorithms, thereby reducing overall system complexity while maintaining stability.
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 effectively suppresses the weave mode while maintaining increased luggage capacity by allowing each side case to rotate and absorb forces independently, thereby reducing vehicle sway and enhancing stability at higher speeds.
Implementation Method 1
a first inner outer cylindrical damper provided between the first rotation shaft member and the first rotation member
Data Source
AI summary
A motorcycle includes left and right side cases respectively configured to be attachable to and detachable from left and right portions of a body frame, left and right rotation supporters that respectively support upper portions of the left and right side cases, and left and right rotation attenuation mechanisms that respectively attenuate rotations of the left and right side cases about first and second axes. The left and right rotation attenuation mechanisms respectively include bolts that respectively extend in directions of the first and second axes, rotation members respectively connected to lower portions of the left and right side cases and being supported by the bolts to be rotatable about third and fourth axes that are different from the first and second axes, and inner outer cylindrical dampers respectively provided between the bolts and the rotation members.