Motorcycle Automatic Transmission Shock Reduction
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Solution Overview
Problem
Conventional automatic transmission systems for straddle-type vehicles experience shocks during clutch disengagement, leading to abrupt loss of drive force and impaired riding comfort, as existing techniques primarily focus on reducing engagement shocks without addressing disengagement shocks.
Innovation Solution
An automatic transmission apparatus with a shock reduction control unit that decreases engine torque before disengaging the clutch, using a torque changing device such as an electronic throttle valve, and adjusts the gear shifting process to minimize the difference in drive force, thereby alleviating the shock during disengagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the clutch is disengaged to change gears, then the gear position can be changed, but the torque transmitted to the driven side rotator is lost abruptly causing a shock
Solution Approach 1:
The control device reduces engine torque before the clutch is disengaged during gear shifting. This preliminary action ensures that when the clutch disconnects, the torque difference between engaged and disengaged states is minimized, preventing shock while maintaining gear shifting capability
Solution Approach 2:
The system dynamically changes the engine torque parameter during the gear shifting process. By adjusting torque as a variable parameter before clutch disengagement, the system optimizes the transition to reduce shock while preserving the ability to change gears
2Speed
If the clutch is disengaged abruptly, then the gear shifting speed is fast, but the drive force is lost instantly causing shock and impaired riding comfort
Solution Approach 1:
The control device performs torque reduction as a preliminary action before clutch disengagement. This ensures that even when the clutch is disengaged quickly for fast gear shifting, the drive force loss is minimized because torque was already reduced in advance
Solution Approach 2:
The system maintains continuous control over engine torque throughout the gear shifting process. By continuously adjusting torque before and during clutch disengagement, the system ensures smooth transition of drive force while maintaining fast gear shifting speed
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 solution effectively reduces the abrupt loss of drive force during clutch disengagement, enhancing riding comfort by maintaining a smaller difference in drive force before and after disengagement, thus alleviating the shock experienced by the rider.
Implementation Method 1
The torque changing device includes an electronic throttle valve provided for the engine. The shock reduction control unit reduces the engine torque by reducing an opening of the electronic throttle valve.
Data Source
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AI summary
A straddle-type vehicle (1) is equipped with an automatic transmission apparatus (50) comprising: a clutch (44) including a drive side rotator (445) to which torque of an engine is transmitted and a driven side rotator (449), a multi-gear transmission mechanism (43) including a dog clutch, at least one actuator (60) to drive the clutch (44) and the transmission mechanism (43), a torque changing device (37, 65, 66, 67) to change the torque of the engine, a gear shifting command output device (30a, 30b) to output a gear shifting command, and a transmission control system (90) to control the at least one actuator (60) and the torque changing device (37, 65, 66, 67). The transmission control system (90) includes a shock reduction control unit (96) to execute control to, upon receiving the gear shifting command from the gear shifting command output device (30a, 30b), reduce the engine torque by controlling the torque changing device (37, 65, 66, 67) and thereafter to start to disengage the clutch (44) by controlling the at least one actuator (60).