Bicycle Gearbox Clutch Synchronization to Prevent Intermediate Gears
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bicycle gearboxes requiring simultaneous actuation of two clutches are prone to engaging intermediate gears or idling due to asynchronous engagement, posing a risk of pedal frequency mismatch and cyclist instability.
Innovation Solution
A data processing device that receives switching parameters to generate actuation signals for clutch actuators, controlling the timing and speed of clutch engagement to ensure synchronized actuation, thereby avoiding intermediate gears and idling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If two clutches are engaged simultaneously for gear change, then gear change speed is improved, but intermediate gears may be engaged causing harmful effects
Solution Approach 1:
The control device calculates and determines the precise actuation times for both clutch actuators before the gear change occurs. By pre-calculating the timing based on current gearbox state and desired target gear, the system ensures that both clutches engage simultaneously at the predetermined moment, achieving fast gear change without intermediate gear engagement.
Solution Approach 2:
The system continuously monitors the actual state of the gearbox and compares it with the desired state. Based on this feedback, the control device adjusts the actuation timing of clutch actuators to ensure precise simultaneous engagement, preventing intermediate gear engagement while maintaining fast gear change speed.
2Device complexity
If two clutches are engaged at different times, then gear change complexity is reduced, but intermediate gears or idling occurs causing harmful effects
Solution Approach 1:
The system replaces complex mechanical timing mechanisms with an electronic control device that calculates and coordinates clutch actuation times. This electronic control system manages the complexity of synchronizing two clutches while preventing intermediate gear engagement, substituting mechanical complexity with programmable control logic.
3Manufacturing precision
If mechanical switching systems are used for gear changes, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical switching systems with rotatable switching shafts and switching cams with an electronic control device that actuates clutch actuators based on calculated timing. This substitution maintains precise gear switching through electronic control while reducing mechanical complexity and the number of moving parts.
Data Source
AI summary
A data processing device and a computer-implemented method for controlling a gear change in a bicycle gearbox for a bicycle with or without an auxiliary motor, in particular a bottom bracket gearshift device or a hub gear, from one gear directly into another gear by automatic actuation of a first and a second clutch actuator. A bicycle gearbox with such a data processing device as well as to a method of executing a gear change. The data processing device is configured to receive at least one switching parameter representative of a state of the bicycle gearbox, and to output an actuation signal for actuating the first and the second clutch actuator depending on the at least one switching parameter and a gear change signal representing a command for a gear change.