Magnetic Biasing Mechanism for Shift Lever Click Feel
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Solution Overview
Problem
The automatic transmission shift operating device experiences weak holding force and shaky operation lever due to low biasing force at click grooves, leading to deteriorated operation feeling and reduced device lifespan when the holding force is increased.
Innovation Solution
An operating device with a click generation mechanism using a cam member, contact member, restriction member, and magnetic bodies with permanent magnets to generate a click feeling through magnetic attraction forces, which are used to bias the contact member against the cam surface, providing a stable and strong biasing force that inhibits shaking and extends device life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a click spring is used to bias the click body against the cam surface, then the operation lever can be returned to position, but the biasing force at each click groove becomes lowest causing weak holding force and shaky operation lever
Solution Approach 1:
The patent replaces the mechanical click spring biasing system with a magnetic field-based biasing system. Magnetic bodies generate magnetic flux that creates continuous biasing force on the contact member, eliminating the periodic force variation inherent in mechanical spring-cam interactions. This substitution resolves the contradiction by providing stable holding force while maintaining smooth operation feeling.
Solution Approach 2:
The patent changes the physical state and properties used for biasing - transitioning from elastic mechanical force (spring) to magnetic field force. By adjusting magnetic flux density and distribution through the magnetic bodies, the system achieves continuous and uniform biasing force that maintains stability at all positions, particularly at click grooves where the mechanical spring system failed.
2Stability of the object's composition
If the holding force is increased to reduce shaking, then the biasing force at cam projections increases more than needed causing deteriorated operation feeling and shortened device life
Solution Approach 1:
The patent applies local quality by creating non-uniform magnetic flux distribution through strategically positioned magnetic bodies. The magnetic flux density is higher at click grooves where holding force is needed and lower at cam projections where minimal contact occurs. This localized control of magnetic field strength provides adequate holding force without excessive force that would cause wear and deteriorated operation feeling.
Solution Approach 2:
The magnetic field system replaces the mechanical spring system, allowing independent control of biasing force at different cam positions. Unlike the mechanical system where increasing spring force increases force everywhere, the magnetic system can be configured to provide force only where needed through magnetic body placement and flux path design, extending device lifespan.
3Device complexity
If a mechanical click spring and click body structure is used, then the device structure is simple, but the biasing force varies at different cam positions causing shaky operation lever
Solution Approach 1:
The patent substitutes the mechanical click spring-biasing structure with a magnetic field-based structure. This replacement maintains relatively simple device architecture while fundamentally improving stability by eliminating the periodic force variation that occurs in mechanical cam-spring interactions. The magnetic bodies create continuous field-based biasing that remains stable regardless of cam position.
Solution Approach 2:
The magnetic bodies serve multiple functions: they generate the biasing force for operation lever return, provide stable holding force at click grooves, and create position-dependent flux distribution for smooth operation feeling. This multi-functionality achieves stable operation with a relatively simple magnetic field generation structure.
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 magnetic attraction forces provide a maximum biasing force at the cam member recess, preventing lever shaking and increasing the biasing force even when the recess is worn, resulting in a better operation feeling and extended device lifespan, while also eliminating the need for a dedicated magnet for flux detection, reducing production costs and improving space efficiency.
Implementation Method 1
The contact member is biased to the cam surface by an attraction force between the pair of magnetic bodies
Implementation Method 2
a magnetic sensor fixed to the housing. The pair of magnetic bodies are supported by the restriction member such that the magnetic bodies rotationally move in conjunction with the restriction member and are movable in an approaching/separating direction in a state where the magnetic bodies are attracted to each other
Data Source
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AI summary
[Object] To provide an operating device that provides a good operation feeling. [Solution] A click generation mechanism 90 of an operating device 100 includes a cam member 40 having a cam surface 49 and fixed to a housing 80, a contact member 30 configured to come into contact with the cam member 40, a restriction member 60 configured to restrict a movement direction of the contact member 30, a biasing force generation means 10 configured to bias the contact member 30 in the movement direction, and a magnetic sensor 7 fixed to the housing 80. The restriction member 60 is supported by the housing 80 so as to rotationally move in conjunction with the operation lever 50. The biasing force generation means 10 includes a pair of magnetic bodies 11 and 21. The magnetic bodies 11 and 21 are supported by the restriction member 60 such that the magnetic bodies 11 and 21 rotationally move in conjunction with the restriction member 60 and are movable in an approaching/separating direction in a state where the magnetic bodies 11 and 21 are attracted to each other, the contact member 30 is biased to the cam surface 49 by an attraction force between the magnetic bodies 11 and 21. When the operation lever 50 is rotationally operated, a click feeling is generated through a change of a sliding load between the cam surface 49 and the contact member 30.