Three-Wheeled Motorcycle Lean Damping for Speed-Adaptive Stability

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Solution Overview

Problem

Vehicles with differential lean mechanisms face reduced operability during high-speed travel and increased propensity to fall during low-speed travel due to fixed damping force settings.

Innovation Solution

A vehicle with a differential lean mechanism that adjusts damping force based on traveling speed, using a control device and adjustment device to decrease damping force at high speeds and increase it at low speeds, and incorporates a mechanism to adjust the maximum inclination angle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the damping force of the differential lean mechanism is set to a certain force for stable high-speed traveling, then the vehicle stability at high speed is improved, but the operability at low speed deteriorates and the vehicle may easily fall down

Engineering Contradiction:
Improvevehicle stabilityVSAvoidoperability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent applies the dynamics principle by making the damping force of the differential lean mechanism variable rather than fixed. The control device adjusts the damping force based on detected traveling speed: increasing damping force at high speeds for stability, and decreasing it at low speeds for operability. This dynamic adjustment resolves the contradiction between stability and ease of operation across different operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the damping force parameter of the differential lean mechanism according to traveling speed. The control device changes the damping force parameter dynamically - increasing it when traveling speed is high to improve stability, and decreasing it when traveling speed is low to improve operability and prevent falling. This parameter adaptation resolves the technical contradiction.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the damping force is increased for stability, then the vehicle can travel stably at high speed, but the vehicle becomes prone to fall down at low speed

Engineering Contradiction:
Improvestable travelingVSAvoidpropensity to fall
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the damping force based on real-time traveling speed detection. At high speeds, increased damping force provides reliability for stable traveling. At low speeds, decreased damping force prevents the harmful effect of falling. This dynamic response resolves the contradiction between reliability and susceptibility to harmful factors.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control device employs feedback by continuously detecting traveling speed and adjusting the damping force accordingly. The feedback loop ensures that the damping force is optimized for current operating conditions - high damping force for stable high-speed travel, low damping force to prevent falling at low speeds. This feedback mechanism resolves the technical contradiction.

Inventive Principle:
Principle #23Feedback

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

Improves operability at high speeds and reduces the likelihood of falling at low speeds by dynamically adjusting damping force and inclination angle.

Implementation Method 1

a biasing unit that biases the second cam portion toward the first cam portion, and an adjustment unit that adjusts a biasing force of the biasing unit

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4725819A1vehicle
Publication Date: 2026.04.15 CHIBA INSTITUTE OF TECHNOLOGY
  • EP4725819A1 patent drawingFigure 1
  • EP4725819A1 patent drawingFigure 2
  • EP4725819A1 patent drawingFigure 3

AI summary

Provided is a vehicle of which the operability during high-speed traveling can be improved and which can be made less prone to fall down during low-speed traveling. A three-wheeled motorcycle 1 includes a saddle 2, wheels 3, a handlebar 4, a frame 5, and a differential lean mechanism 6. The three-wheeled motorcycle 1 includes a control device 8 that controls the three-wheeled motorcycle 1, and a differential lean mechanism adjustment device 7 that adjusts the damping force of the differential lean mechanism 6. The control device 8 includes the traveling speed detector 81 that detects the traveling speed of the three-wheeled motorcycle 1, and a differential lean mechanism controller 82 that causes the differential lean mechanism adjustment device 7 to adjust and decrease the damping force of the differential lean mechanism 6 when the traveling speed detected by the traveling speed detector 81 is high and causes the differential lean mechanism adjustment device 7 to adjust and increase the damping force of the differential lean mechanism 6 when the traveling speed detected by the traveling speed detector 81 is low.