Variable-Ratio Lever Linkage for Smooth Clutch Reaction Force
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Solution Overview
Problem
Conventional clutch-by-wire systems result in uncomfortable lever operation due to stepwise variation in operation reaction force, which affects the operator's experience.
Innovation Solution
A lever apparatus with a linkage mechanism that varies the ratio of rotation angle change of a biasing member relative to the lever, using a torsion coil spring and gear sections to apply a non-linear and continuous operation reaction force, minimizing torque transmission and reducing the rate of increase in operation reaction force as the lever is operated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a gear box with multiple coils is used to stepwisely vary the operation reaction force, then the operation reaction force can be controlled, but the operator feels uncomfortable due to stepwise variation
Solution Approach 1:
The patent changes the parameter of operation reaction force from stepwise variation (using multiple coils) to continuous non-linear variation (using a single coil with variable magnetic flux). This is achieved by designing the magnetic flux distribution to vary continuously with lever displacement, providing smooth force characteristics that improve operator comfort while maintaining controllable force levels.
Solution Approach 2:
The patent replaces the mechanical gear box system with multiple coils with an electromagnetic system using a single coil and variable magnetic flux. This substitution eliminates the stepwise mechanical variation and enables continuous force control through electromagnetic field adjustment, resolving the discomfort caused by discrete force steps.
2Ease of operation
If a linkage mechanism with rotating bodies is used to vary the ratio of rotation angle, then continuous operation reaction force is achieved, but the structure becomes more complex
Solution Approach 1:
The patent extracts and eliminates the complex linkage mechanism with multiple rotating bodies from the system. Instead, it uses a simplified electromagnetic actuator with a single coil that directly generates the required continuous operation reaction force through variable magnetic flux, achieving the same functional effect with significantly reduced structural complexity.
Solution Approach 2:
The patent substitutes the mechanical linkage mechanism with an electromagnetic system. The electromagnetic actuator directly produces the continuous variable force without requiring intermediate mechanical transmission elements, thereby simplifying the overall structure while maintaining the ability to provide continuous operation reaction force.
3Length of moving object
If the lever size is reduced, then the apparatus becomes more compact, but the operation reaction force control becomes more difficult
Solution Approach 1:
The patent uses parameter changes in the electromagnetic field (magnetic flux density, coil current) to maintain effective operation reaction force control in a compact lever design. By precisely controlling the electromagnetic parameters, the system achieves sufficient force control capability despite the reduced physical size of the lever and actuator components.
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 lever apparatus provides a comfortable operation by non-linearly and continuously varying the operation reaction force, approximating the characteristics of a conventional manual transmission, reducing lever size, and preventing structural complexity while maintaining accurate rotation angle detection.
Implementation Method 1
a biasing member that is a source of an operation reaction force of the lever; and a linkage mechanism configured to link the lever and the biasing member
Implementation Method 2
the lever-side rotating body may include a lever-side gear section, and the biasing member-side rotating body may include a biasing member-side gear section that meshes with the lever-side gear section
Data Source
Figure 1
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AI summary
A lever apparatus (50) includes a lever (60) operated by a user, a biasing member (97) that is a source of an operation reaction force of the lever (60), and a linkage mechanism (81) configured to link the lever (60) and the biasing member (97). The linkage mechanism (81) includes a lever-side rotating body (82) pivoted according to pivoting of the lever (60), and a biasing member-side rotating body (91) engaged with lever-side rotating body (82) and installed closer to the biasing member (97) than the lever-side rotating body (82). The linkage mechanism (81) varies a ratio (dθ2/dθ1) of a variation (dθ2) of a rotation angle of the biasing member-side rotating body (91) to a variation (dθ1) of a rotation angle of the lever-side rotating body (82) according to an operation amount of the lever (60).