Shift Position Detection Timing Displacement to Reduce Friction
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Solution Overview
Problem
The existing shift position detecting devices experience increased friction when switching to the neutral position, leading to discomfort during operations, particularly when transitioning from first or second speed positions, due to simultaneous contact of multiple switches with projecting portions, which can obstruct the shift drum's movement.
Innovation Solution
A shift position detecting device with a multi-stage transmission system where the timing of switches' ON states are displaced relative to each other, and a positioning means with a stopper plate and resilient pressing member are used to alleviate friction by ensuring non-simultaneous contact with projection rows, allowing smoother neutral position changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple switches are arranged to detect projection rows on the shift drum, then shift position detection accuracy is improved, but friction increases when switches contact projecting portions simultaneously
Solution Approach 1:
The projection rows are designed with different circumferential positions so that when the shift drum rotates to the neutral position, the switches are activated in sequence rather than simultaneously. This preliminary arrangement of projection positions prevents simultaneous contact, reducing friction while maintaining accurate detection of the neutral position through the combination of switch states.
Solution Approach 2:
Each projection row is positioned at a specific circumferential location on the shift drum, creating local variations in the detection sequence. The first, second, and third projection rows are arranged at different angles around the drum's circumference, ensuring that switches detect positions at different moments during rotation, thereby avoiding simultaneous friction-inducing contact.
2Adaptability or versatility
If the neutral position is arranged between first speed position and second speed position, then shift operation flexibility is improved, but operator perceives friction influence more easily
Solution Approach 1:
The projection rows are pre-positioned on the shift drum at specific circumferential intervals that correspond to the neutral position between first and second speed positions. This arrangement ensures that as the shift drum rotates during a shift operation, the switches are activated in a predetermined sequence, smoothing out friction effects before they can be perceived by the operator.
Solution Approach 2:
The circumferential positions of the projection rows are optimized to change the timing parameters of switch activation. By adjusting the angular positions of the first, second, and third projection rows, the system modifies the sequence and timing of switch state changes, reducing perceptible friction during neutral position transitions while maintaining operational flexibility.
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 reduces friction during neutral position shifts, enhancing the operational feel by preventing simultaneous switch contacts and allowing for more flexible timing settings, thereby minimizing discomfort for the rider.
Implementation Method 1
a pressing member which is resiliently brought into contact with an outer periphery of the stopper plate
Data Source
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AI summary
Two projection rows 98, 99 which are objects to be detected by two specified switches SB, SC; SA, SC among the three switches SA to SC are formed so as to change switching modes of the specified switches SB, SC; SA, SC from an OFF state to an ON state and to displace timings at which the specified switches are brought into an ON state from each other when a shift position is changed from at least one of a first speed position and a second speed position to a neutral position.