Leaning Vehicle Steering Torque Detection via Localized Torsion
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Solution Overview
Problem
Leaning vehicles face a shortage in rigidity for supporting the steering shaft, leading to difficulties in accurately detecting steering torque due to the uneven distribution of stress and deformation along the steering torque transmission path, which results in increased vehicle size when attempting to enhance rigidity.
Innovation Solution
The steering torque transmission mechanism includes a torsional deformation facilitating portion upstream of the steering shaft, which is easily deformed by steering torque, allowing all bearings to support bending forces and reducing the need for increased rigidity in other components, thereby maintaining a compact vehicle size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the rigidity of the steering shaft is increased to improve support against bending forces, then the supporting rigidity is enhanced, but the vehicle size is enlarged
Solution Approach 1:
The patent applies local quality by creating a torsional deformation facilitating portion with specifically reduced rigidity at a localized section of the steering shaft. This allows the steering shaft to have high rigidity overall for supporting bending forces, while having a specific soft section for torsional deformation to enable accurate steering torque detection.
2Measurement precision
If the steering shaft is made more rigid to accurately detect steering torque, then detection accuracy is improved, but the vehicle size increases
Solution Approach 1:
The patent creates a localized torsional deformation facilitating portion with reduced rigidity in the steering shaft. This localized soft section allows the steering shaft to exhibit measurable torsional deformation under steering torque input, enabling accurate detection of steering torque while the rest of the steering shaft maintains high rigidity to support bending forces, thus avoiding vehicle size enlargement.
Solution Approach 2:
The patent changes the rigidity parameter locally within the steering shaft by providing a torsional deformation facilitating portion with specifically reduced rigidity. This parameter change allows the steering shaft to have different rigidity characteristics at different locations, enabling both accurate torque detection and compact vehicle size.
3Measurement precision
If the torsional deformation facilitating portion is placed downstream of the steering shaft bearing, then steering torque can be detected, but bending forces are unevenly distributed causing increased vehicle size
Solution Approach 1:
The patent places the torsional deformation facilitating portion upstream of the steering shaft bearing in the steering torque transmission path. This preliminary positioning allows the torsional deformation to occur before the bearing location, enabling the bearing to support bending forces uniformly while the torsional deformation facilitates accurate steering torque detection without causing uneven stress distribution.
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 enables efficient support of bending forces and accurate detection of steering torque without enlarging the vehicle's size, as the torsional deformation facilitating portion is designed to handle stress concentrations, ensuring high supporting rigidity against bending while maintaining compactness.
Implementation Method 1
a torsional deformation facilitating portion which is provided upstream of a portion of the steering shaft which is supported by an upstream bearing which is situated most upstream in the plurality of bearings in a steering torque transmission path which extends from the right grip portion or the left grip portion to the front wheel and which is easily deformed by steering torque inputted from the right grip portion or the left grip portion
Data Source
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AI summary
The present invention provides a leaning vehicle that has a steering torque sensor and exhibits high support rigidity against bending without requiring an increase in size. A leaning vehicle (1) is provided with: a body frame (2) including a head pipe (8); a front wheel (4); a steering torque transmission mechanism (10) for transmitting steering torque, the steering torque transmission mechanism (10) having a steering shaft (9) supported by a plurality of bearings (24, 25), a handlebar assembly (20), and a front wheel linking part (11); and a steering torque detection device (90). The steering torque transmission mechanism (10) includes a torsion-deformable part (13) which is provided upstream in the steering torque transmission route from the portion of the steering shaft (9) supported by the upstream bearing (24) positioned farthest upstream among the plurality of bearings (24, 25), and which is readily torsionally deformed by steering torque inputted from grip parts (22, 23). The steering torque detection device (90) detects, on the basis of the torsional deformation of the torsion-deformable part (13), at least some of the steering torque inputted to the steering torque transmission mechanism (10).