Automatic Transmission Clutch Lubrication by Temperature and Input Torque
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Solution Overview
Problem
Existing automatic transmission systems face challenges in optimizing lubricant supply to friction engagement elements, leading to inefficiencies in fuel efficiency and durability, particularly as they do not adequately consider the thermal load of non-vehicle-propelling elements.
Innovation Solution
A control device that adjusts lubricant supply to vehicle-propelling and other friction engagement elements based on temperature and input torque, using specific lubricant supply patterns to optimize lubricant flow rates according to the vehicle's state, ensuring both fuel efficiency and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lubricant supply is increased to vehicle-propelling friction engagement elements during slipped state, then durability is improved, but fuel efficiency deteriorates due to increased stirring resistance and drag
Solution Approach 1:
The lubricant supply amount is dynamically adjusted based on the operating state of the friction engagement element. During slipped state, the supply amount is increased to ensure durability, while during full engagement, the supply amount is reduced to improve fuel efficiency. This dynamic adjustment resolves the contradiction between durability and fuel efficiency.
Solution Approach 2:
The supply amount of lubricant is changed as a parameter based on the thermal load condition of the friction engagement element. By detecting whether the element is in slipped state or full engagement state, the control device adjusts the lubricant flow rate accordingly, optimizing both durability and fuel efficiency.
2Use of energy by moving object
If lubricant supply is reduced to improve fuel efficiency, then stirring resistance and drag are reduced, but durability of friction engagement elements deteriorates
Solution Approach 1:
The lubricant supply system operates dynamically, reducing supply during full engagement to improve fuel efficiency while maintaining adequate supply during slipped state to ensure durability. This dynamic control resolves the contradiction by adapting supply levels to actual operating conditions.
Solution Approach 2:
The lubricant supply parameter is adjusted based on detected operating state. During full engagement, the supply amount is reduced to lower stirring resistance and improve fuel efficiency, while during slipped state, the supply is increased to maintain durability, thus resolving the contradiction.
3Reliability
If lubricant is supplied to all friction engagement elements based on maximum heat generation condition, then durability of all elements is secured, but fuel efficiency deteriorates due to unnecessary lubricant supply
Solution Approach 1:
Different lubricant supply strategies are applied to different friction engagement elements based on their local conditions. The vehicle-propelling friction engagement element receives variable supply based on its thermal load, while other elements receive appropriate supply based on their specific operating conditions. This localized quality approach resolves the contradiction by avoiding unnecessary uniform supply to all elements.
Solution Approach 2:
The lubricant supply system dynamically adjusts supply amounts for different friction engagement elements based on their respective operating states. Instead of uniform supply to all elements, the system selectively increases supply only to elements experiencing high thermal load, thereby improving fuel efficiency while maintaining durability where 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
This approach improves fuel efficiency and ensures the durability of friction engagement elements by providing the necessary lubricant amounts based on the vehicle's state, prioritizing fuel efficiency while maintaining adequate lubrication for all elements.
Implementation Method 1
the durability may decline. Thus, it is desirable to supply a larger amount of lubricant to the vehicle-propelling friction engagement element than other friction engagement elements depending on the operating state of the vehicle
Implementation Method 2
during this engagement, friction plates generate heat by the sliding friction
Data Source
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AI summary
A control device for an automatic transmission is provided, which includes a vehicle-propelling friction engagement element configured to be engaged when a vehicle starts traveling, an other friction engagement element, a vehicle-propelling friction engagement element temperature detector configured to detect a temperature of the vehicle-propelling friction engagement element, an input torque detector configured to detect an input torque inputted into the automatic transmission, and a control unit comprising a lubricant supply control logic configured to control supply of lubricant to the vehicle-propelling friction engagement element and the other friction engagement element. The lubricant supply control logic switches the supply amount of lubricant to the vehicle-propelling friction engagement element according to the temperature of the vehicle-propelling friction engagement element, and switches the supply amount of lubricant to the another friction engagement element according to the input torque.