Vehicle Speed Change Apparatus Sub Return Spring Design
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Solution Overview
Problem
The existing speed change apparatus for motorcycles with automated manual transmissions faces challenges in enhancing return torque of the shift spindle without increasing the torque characteristics of the force accumulation spring, while also reducing impact sounds generated during gear changes.
Innovation Solution
A speed change apparatus is designed with a sub return spring that directly biases the shift spindle toward the neutral position, separate from the return spring, allowing for increased return torque without affecting the torque exerted on the change mechanism, and is configured to reduce impact sounds by providing a simple and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the torque characteristics of the force accumulation spring are enhanced to increase return torque of the shift spindle, then the return torque is improved, but the torque exerted on the change mechanism is also enhanced which may cause excessive force on the master arm and impact sounds
Solution Approach 1:
The return spring system is segmented into two independent components: the force accumulation spring that exerts torque on the master arm through the gear shift arm, and the sub return spring that directly biases the shift spindle. This segmentation allows the return torque on the shift spindle to be enhanced without increasing the torque characteristics of the force accumulation spring, thereby reducing impact sounds during gear changes while maintaining proper return force.
2Force
If the torque characteristics of the force accumulation spring are enhanced, then the return torque is improved, but the device complexity increases due to the need to modify spring characteristics
Solution Approach 1:
The return spring system is segmented into two independent components: the force accumulation spring that exerts torque on the master arm through the gear shift arm, and the sub return spring that directly biases the shift spindle. This segmentation allows the return torque on the shift spindle to be enhanced without increasing the torque characteristics of the force accumulation spring, thereby reducing impact sounds during gear changes while maintaining proper return force.
3Force
If a sub return spring is added to directly bias the shift spindle, then the return torque is enhanced without affecting force accumulation spring characteristics, but the device complexity increases due to additional components
Solution Approach 1:
The sub return spring serves multiple functions: it directly biases the shift spindle to enhance return torque, reduces impact sounds during gear changes, and works in conjunction with the force accumulation spring system. By integrating this additional spring component into the existing force accumulation mechanism, the system achieves enhanced performance without requiring fundamental redesign of the overall transmission architecture.
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 enables enhanced return torque of the shift spindle without enhancing the force accumulation spring's torque characteristics, while minimizing the impact sound generated during gear changes, and allows for a more compact transmission design.
Implementation Method 1
a force accumulation spring which is provided between the gear shift arm and the force accumulation collar
Implementation Method 2
a return spring for biasing the master arm so as to return into a neutral position
Implementation Method 3
a sub return spring configured to directly bias the shift spindle toward the neutral position
Implementation Method 4
a frictional force due to a driving force for running is acting on dog clutch tooth side surfaces
Data Source
AI summary
A speed change apparatus includes a transmission, a change mechanism configured to move a gear or gears so as to change gear position, a force accumulation mechanism which includes a shift spindle and a force accumulation spring. The shift spindle is provided, in a rotatable manner, with a master arm configured to operate the change mechanism. A return spring is configured to bias the master arm toward a neutral position. A sub return spring, separate from the return spring and which directly biases the shift spindle toward the neutral position, is provided between the shift spindle and a case member.