Clutch Pressure Control for Easier In-Gear Stop Shifting
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Solution Overview
Problem
In semi-automatic transmission systems, shifting from an in-gear state to neutral while the vehicle is stopped is difficult due to resistance from the dog teeth and dog holes, making it hard to perform gear shifts efficiently.
Innovation Solution
A vehicle transmission system that adjusts the hydraulic pressure supplied to the clutch actuator based on shift operation detection, reducing the pressure to a lower setting when a shift operation is detected, allowing for easier gear shifts by reducing engagement resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If standby hydraulic pressure is supplied to the slave cylinder for quick restart, then the clutch device is ready for rapid engagement, but the shift operation becomes heavy due to resistance from dog teeth and dog holes contact
Solution Approach 1:
The patent applies dynamics by making the standby hydraulic pressure variable rather than fixed. The clutch control unit dynamically adjusts the standby hydraulic pressure based on vehicle speed and shift operation detection. When the vehicle is moving above a threshold speed, the standby pressure is set to a first value for quick restart readiness. When the vehicle stops and a shift operation is detected, the pressure is reduced to a second value to ease shifting. This dynamic adjustment resolves the contradiction between maintaining quick restart capability and enabling easy shift operations.
Solution Approach 2:
The patent changes the parameter of standby hydraulic pressure based on operating conditions. The clutch control unit monitors vehicle speed and shift operation detection signals, then adjusts the standby hydraulic pressure parameter accordingly. At higher speeds, the pressure is maintained at a first value to ensure quick restart readiness. At stop conditions during shift operations, the pressure is reduced to a second value to reduce resistance from dog teeth and dog holes contact, making shift operations easier while maintaining the ability for quick restart when needed.
2Reliability
If the clutch device maintains connection for quick restart, then restart response is fast, but gear shift operation becomes difficult due to engagement resistance
Solution Approach 1:
The patent applies dynamics by making the standby hydraulic pressure variable rather than fixed. The clutch control unit dynamically adjusts the standby hydraulic pressure based on vehicle speed and shift operation detection. When the vehicle is moving above a threshold speed, the standby pressure is set to a first value for quick restart readiness. When the vehicle stops and a shift operation is detected, the pressure is reduced to a second value to ease shifting. This dynamic adjustment resolves the contradiction between maintaining quick restart capability and enabling easy shift operations.
Solution Approach 2:
The patent changes the parameter of standby hydraulic pressure based on operating conditions. The clutch control unit monitors vehicle speed and shift operation detection signals, then adjusts the standby hydraulic pressure parameter accordingly. At higher speeds, the pressure is maintained at a first value to ensure quick restart readiness. At stop conditions during shift operations, the pressure is reduced to a second value to reduce resistance from dog teeth and dog holes contact, making shift operations easier while maintaining the ability for quick restart when needed.
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 system enables smoother and lighter shift operations even when the transmission is in an in-gear state, reducing the load required for shifting and preventing erroneous detection of shift operations.
Implementation Method 1
when a hydraulic pressure is supplied from the clutch actuator (50) to a slave cylinder (28)
Data Source
AI summary
This vehicle transmission system includes a transmission (21), a clutch device (26), a clutch control unit (61), and a shift operation detecting means (48), and, when a hydraulic pressure is supplied from a clutch actuator (50) to a slave cylinder (28), the clutch device (26) moves to a connection side, in an in-gear stop state in which the transmission (21) is in an in-gear state, and a vehicle (1) is in a stop state, the clutch actuator (50) supplies a standby hydraulic pressure (WP) to the slave cylinder (28), and the clutch control unit (61) sets the standby hydraulic pressure (WP) to a first setting value (P1) during non-detection in which a shift operation is not detected by the shift operation detecting means (48) and sets the standby hydraulic pressure (WP) to a second setting value (P2) lower than the first setting value (P1) when the shift operation is detected by the shift operation detecting means (48).