Transmission Oil Pressure Feedback for Smoother Gear Switching
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Solution Overview
Problem
Existing vehicle transmission systems experience increased shock and response time issues when switching between driving modes due to a dead zone where increased oil pressure fails to further reduce response time, leading to drastic RPM changes and elevated shock levels.
Innovation Solution
A vehicle with a torque converter and hydraulic switching mechanism, controlled by an electronic control unit (ECU) that adjusts oil pressure in the oil chambers based on the amount of RPM decrease, reducing pressure when the RPM decrease exceeds a predetermined threshold to minimize shock and optimize response time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If oil pressure to the hydraulic switching mechanism is increased to reduce response time, then the transmission switching speed is improved, but the shock level increases due to drastic RPM changes
Solution Approach 1:
The patent applies dynamics by making the oil pressure adjustable rather than fixed. The control unit dynamically changes the oil pressure supplied to the hydraulic switching mechanism based on real-time turbine shaft RPM changes. When RPM decreases excessively (indicating shock), the control unit reduces oil pressure for subsequent switching operations, thereby adapting the system to minimize shock while maintaining responsive switching.
Solution Approach 2:
The patent changes the physical parameter of oil pressure based on operating conditions. By monitoring the turbine shaft RPM and detecting excessive decreases, the system adjusts the oil pressure parameter upward or downward to optimize the balance between response time and shock reduction, moving away from a static high-pressure approach.
Solution Approach 3:
The patent implements feedback by continuously monitoring the turbine shaft RPM during and after transmission mode switching. The control unit uses this feedback information to detect when RPM decreases by more than a predetermined amount, indicating excessive shock. This feedback loop enables the system to adjust future oil pressure levels to prevent recurring shock events.
2Speed
If oil pressure is maintained at high levels to ensure quick switching response, then switching speed is improved, but a dead zone occurs where further pressure increases fail to reduce response time
Solution Approach 1:
The control unit continuously monitors turbine shaft RPM and switching timing to detect when the system enters a dead zone where response time no longer improves with increased pressure. This feedback enables intelligent adjustment of oil pressure to maintain optimal switching speed without unnecessary complexity.
Solution Approach 2:
The system dynamically adjusts oil pressure parameters based on detected performance characteristics, transitioning from a fixed high-pressure regime to an adaptive pressure regime that responds to actual switching performance and RPM changes, thereby avoiding the dead zone issue.
3Productivity
If the transmission switches modes quickly with high oil pressure, then productivity is improved, but the RPM changes drastically causing elevated shock levels
Solution Approach 1:
The control unit uses feedback from turbine shaft RPM monitoring to detect when rapid switching causes excessive RPM changes and shock. This feedback enables the system to modulate oil pressure during switching operations to maintain high switching efficiency while preventing harmful shock events.
Solution Approach 2:
The patent applies dynamics by making oil pressure adjustable rather than fixed. The control unit dynamically changes the oil pressure supplied to the hydraulic switching mechanism based on real-time turbine shaft RPM changes. When RPM decreases excessively (indicating shock), the control unit reduces oil pressure for subsequent switching operations, thereby adapting the system to minimize shock while maintaining responsive switching.
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 transmission shock and improves response time by dynamically adjusting oil pressure, ensuring the RPM change is within a permissible threshold, thereby enhancing the overall performance of the vehicle's transmission system.
Implementation Method 1
The transmission is coupled to the power source and includes a torque converter and a hydraulic switching mechanism. The torque converter is coupled to the power source.
Implementation Method 2
The hydraulic switching mechanism is coupled to the torque converter and is configured to switch the transmission between a forward driving mode, a reverse driving mode, and a neutral mode
Implementation Method 3
reducing, in a case where the number of revolutions is decreased by an amount greater than the predetermined amount of decrease based on the unit time, reducing pressure of oil to be supplied to an oil chamber of the hydraulic switching mechanism
Data Source
AI summary
A vehicle includes a power source, a transmission coupled to the power source, and a control unit. The transmission includes a torque converter and a hydraulic switching mechanism. A processor of the control unit is configured to execute in accordance with an instruction stored in a storage medium: obtaining RPM of a turbine shaft of the torque converter based on a unit time when the transmission is switched from neutral to forward driving or to reverse driving; determining whether the RPM is decreased by an amount greater than a predetermined amount of decrease based on the unit time; and reducing, if the RPM is decreased by an amount greater than the predetermined amount of decrease based on the unit time, pressure of oil to be supplied to an oil chamber of the hydraulic switching mechanism when the transmission switches to the same mode as the previously switched mode next time.