Automatic Transmission Filling Time Calculation for Shift Shock Reduction
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Solution Overview
Problem
Automatic transmissions experience shift shocks due to overlapping hydraulic pressure during frequent gear shifts, causing driver discomfort and performance issues, as the existing systems fail to accurately calculate the filling time required for smooth gear transitions.
Innovation Solution
An apparatus and method that calculate the filling time in automatic transmissions by detecting oil temperature, determining the control duty of a solenoid valve, and using a stored filling time table to adjust the remaining flow based on elapsed time, accounting for intervals of flow increase, decrease, or maintenance, to ensure proper hydraulic pressure application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If frequent gear shifts are performed in automatic transmission, then the adaptability of the transmission system is improved, but shift shocks occur due to overlapping hydraulic pressure causing driver discomfort
Solution Approach 1:
The system calculates the filling time required for hydraulic pressure buildup in advance before gear shifts occur. By determining the time needed for oil to fill the actuator chamber and build sufficient pressure, the control system can timing the solenoid valve operation to complete pressure buildup before the next shift, preventing overlapping hydraulic pressures that cause shift shocks.
Solution Approach 2:
The filling time calculation dynamically adjusts based on oil temperature detection. Since oil viscosity changes with temperature affect flow rate and pressure buildup time, the system modifies the filling time parameters according to detected oil temperature conditions, optimizing the timing for frequent gear shifts across varying operating conditions.
2Device complexity
If the filling time is not accurately calculated, then the device complexity is reduced, but the measurement precision of hydraulic pressure timing is insufficient leading to shift shocks
Solution Approach 1:
The system replaces complex mechanical timing mechanisms with electronic calculation and control. A control unit performs filling time calculations based on oil temperature data and flow rate parameters, then electronically controls the solenoid valve timing. This substitution of mechanical timing with electronic computation achieves high precision filling time measurement while maintaining relatively simple overall system architecture.
3Adaptability or versatility
If the oil temperature varies, then the adaptability of the system to different conditions is improved, but the manufacturing precision of fixed filling time parameters becomes insufficient
Solution Approach 1:
The system changes the filling time parameters dynamically based on detected oil temperature. The control unit calculates appropriate filling time values according to the relationship between oil temperature and hydraulic oil flow characteristics. This parameter adjustment ensures accurate timing across different temperature conditions without requiring fixed manufacturing parameters, resolving the conflict between adaptability and precision.
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 solution allows for precise calculation of filling time, reducing shift shocks and improving gear shift performance even during frequent shifts, by accurately determining the remaining flow and adjusting the hydraulic pressure accordingly.
Implementation Method 1
a control duty for controlling a solenoid valve that discharges or fills the transmission oil supplied from an oil pump from or to an oil flow path corresponding to a gear shifting stage to form a hydraulic pressure
Implementation Method 2
a control duty for controlling a solenoid valve that discharges or fills the transmission oil supplied from an oil pump
Data Source
AI summary
An apparatus for calculating a filling time in an automatic transmission and a method thereof are disclosed. The apparatus includes an oil temperature detection unit for detecting an oil temperature of a transmission oil, a control duty input unit for receiving a control duty for controlling a solenoid valve that discharges or fills the transmission oil supplied from an oil pump from or to an oil flow path corresponding to a gear shifting stage to form a hydraulic pressure, a storage unit for storing a filling time table in which a relationship between a remaining flow and a filling time according to the oil temperature is mapped, and a calculation control unit for receiving the control duty of the solenoid valve from the control duty input unit to calculate the remaining flow on the basis of a variation interval of the remaining flow and an elapsed time, and calculating the filling time depending on the filling time table stored in the storage unit on the basis of the remaining flow.