Torque Converter Lockup Clutch Speed Synchronization Control
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Solution Overview
Problem
Existing torque converter systems face challenges in smoothly engaging and controlling the lockup clutch between the pump and turbine, particularly in synchronizing rotational speeds to facilitate efficient energy transfer during lockup mode transitions.
Innovation Solution
A method and system for controlling the lockup clutch engagement by monitoring and adjusting the rotational speeds of the pump and turbine, incrementally increasing engine speed to match turbine speed, and controlling clutch pressure to ensure synchronized operation, involving sensors and control circuits to manage fuel system operations and clutch pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the lockup clutch is engaged to rigidly connect the pump and turbine, then energy transfer efficiency is improved, but rotational speed synchronization becomes difficult to achieve
Solution Approach 1:
The control system performs preliminary speed synchronization before lockup clutch engagement by detecting rotational speeds of the pump and turbine, comparing them, and adjusting engine speed to minimize speed differential. This preliminary action ensures that when the clutch engages, the speed difference is already minimized, facilitating smooth connection and maximizing energy transfer efficiency.
Solution Approach 2:
The system continuously monitors rotational speeds of both pump and turbine, compares the detected speeds, and uses this feedback to adjust engine speed in real-time. The control circuit receives speed signals from sensors, determines whether speeds are synchronized within a threshold, and adjusts fuel delivery accordingly to maintain optimal speed matching during the engagement process.
2Ease of operation
If engine speed is increased to match turbine speed, then lockup clutch engagement is facilitated, but engine operation control becomes more complex
Solution Approach 1:
The control system automatically manages engine speed adjustment without requiring manual intervention. The control circuit self-regulates by detecting speed differential, determining the need for speed matching, and automatically adjusting fuel delivery to the engine. This self-service approach simplifies the overall system operation while managing the complexity internally through automated control algorithms.
3Stability of the object's composition
If rotational speed of pump is increased to match turbine, then clutch engagement smoothness is improved, but time required for engagement increases
Solution Approach 1:
The control system applies partial speed adjustment by increasing engine speed only to the extent necessary to achieve synchronization within a predefined threshold, rather than forcing complete speed equality. This partial action approach achieves sufficient synchronization for smooth engagement while minimizing the time required, avoiding excessive speed adjustments that would prolong the engagement process.
Data Source
AI summary
A torque converter has a pump that is rotatably driven by an internal combustion engine and that is fluidly coupled to a turbine, and a lockup clutch connected between pump and the turbine. Controlling engagement of the lockup clutch may include controlling the lockup clutch to an initial lockup clutch activation value, determining rotational speed of the pump, determining rotational speed of the turbine, and if the rotational speed of the turbine is greater than the rotational speed of the pump, increasing rotational speed of the engine until the rotational speed of the pump is within a threshold value of the rotational speed of the turbine followed by controlling the lockup clutch to full engagement.