Steer Lock Mechanism Positioning for Compact Vehicle Steering

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Solution Overview

Problem

Existing vehicles face challenges in maintaining a compact size while enhancing the usability of the handlebar and incorporating a steer lock mechanism, as larger engines or increased maximum banking angles require greater rigidity and larger components, leading to size enlargement and interference issues with the link mechanism.

Innovation Solution

A vehicle design featuring a steering force transmission mechanism with two shaft members and a steer lock mechanism positioned to avoid interference with the link mechanism, allowing for flexible handlebar placement and compact size maintenance, where the steer lock mechanism is integrated in a way that overlaps the link mechanism's movable range or is positioned above/below the cross members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the link mechanism is enlarged to provide greater rigidity for larger engine displacement, then the rigidity is improved, but the vehicle size is enlarged and the handlebar position is raised

Engineering Contradiction:
Improverigidity of link mechanismVSAvoidvehicle size
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The steer lock mechanism is positioned to overlap the movable range of the link mechanism when viewed from the side, utilizing the spatial dimension along the front-rear direction of the vehicle. This allows the steer lock mechanism to be integrated into the existing structure without increasing the vehicle's width or height, thereby maintaining compact size while providing the required locking function.

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

Solution Approach 2:

The steer lock mechanism is integrated within the spatial envelope of the link mechanism's movable range, effectively nesting one mechanism within another. The steer lock mechanism's components are arranged to occupy the same lateral space as the link mechanism, allowing both mechanisms to coexist without interference while maintaining a compact overall structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If the movable range of the link mechanism is enlarged to increase maximum banking angle, then the banking angle capability is improved, but the vehicle size is enlarged and the handlebar position is raised

Engineering Contradiction:
Improvemaximum banking angleVSAvoidvehicle size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The solution utilizes the front-rear direction dimension to accommodate the steer lock mechanism, allowing the link mechanism to achieve a larger banking angle range without increasing the vehicle's lateral or vertical dimensions. The steer lock mechanism is positioned to overlap the link mechanism's extended movable range, enabling greater banking angle capability while maintaining compact vehicle size.

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

3Device complexity

If the steering force transmission mechanism uses a single steering shaft, then the structure is simple, but the handlebar position cannot be lowered and usability is reduced

Engineering Contradiction:
Improvesteering force transmission mechanismVSAvoidhandlebar usability
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The steering force transmission mechanism is divided into two separate shaft members: a first shaft member that receives steering force from the handlebar and a second shaft member that transmits force to the tie rod. This segmentation allows the handlebar to be positioned lower for better usability while the second shaft member can be positioned to avoid interference with the link mechanism, achieving both ergonomic improvement and structural compactness.

Inventive Principle:
Principle #1Segmentation

4Reliability

If the steer lock mechanism is added to lock the front wheels, then the security is improved, but the vehicle size is enlarged

Engineering Contradiction:
Improvesteer lock functionVSAvoidvehicle size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The steer lock mechanism is merged with the existing steering force transmission mechanism by positioning it to overlap the movable range of the link mechanism. The steer lock mechanism shares the same spatial envelope and structural space as the link mechanism and steering components, eliminating the need for additional space and avoiding vehicle size enlargement while providing the security function.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3162688B1vehicle
Publication Date: 2018.08.01 YAMAHA MOTOR CO LTD
  • EP3162688B1 patent drawingFigure 1
  • EP3162688B1 patent drawingFigure 2
  • EP3162688B1 patent drawingFigure 3

AI summary

A vehicle 1 has a link mechanism 5, a steering force transmission mechanism 6, and a steer lock mechanism 40. The steering force transmission mechanism 6 has a rear shaft member 60 that can turn about a rear steering axis a, a front shaft member 68 that can turn about a front steering axis b, and a connecting member 80. The vehicle 1 is provided in which when seen from a side of the vehicle 1, a distance between the front shaft member 68 and a right steering axis Y is smaller than a distance D1 between the rear shaft member 60 and the right steering axis Y, and in which at least one part of the steer lock mechanism 40 that is mounted on the front shaft member 68 or a member that is configured to turn together with the front shaft member 68 and a member 21 that is displaced relative thereto is provided in a position that is configured to overlap a movable range V of the link mechanism 5 when seen from the side of the vehicle 1.