Torque Converter Clutch Dynamic Slip Control
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Solution Overview
Problem
Conventional torque converters experience reduced efficiency and excessive heat due to high slip rates, and the lockup mechanism can prevent torque multiplication during certain driving conditions, such as throttle tip-in at low engine speeds, limiting vehicle acceleration.
Innovation Solution
A dynamic torque converter clutch control system that monitors throttle position and engine speed to adjust pressure, increasing slip initially after throttle tip-in and then reducing it by engaging the clutch, using a module-based approach to regulate pressure and manage slip effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the torque converter clutch is locked to eliminate slip, then heat generation is reduced and efficiency is improved, but torque multiplication capability is lost during throttle tip-in events at low engine speeds
Solution Approach 1:
The patent implements dynamic control of the torque converter clutch by transitioning between locked and unlocked states based on operating conditions. The system monitors throttle position, engine speed, and transmission gear to determine when to release the clutch lockup during throttle tip-in events, enabling adaptive slip control that resolves the contradiction between heat reduction and torque multiplication capability
2Speed
If the torque converter clutch is locked at low engine speeds during throttle tip-in, then vehicle acceleration response is improved, but torque multiplication is prevented when downshift is needed
Solution Approach 1:
The system uses feedback from throttle position sensors, engine speed sensors, and transmission gear information to continuously monitor operating conditions. When a throttle tip-in event is detected at low engine speeds, the control algorithm releases the clutch lockup to enable torque multiplication, demonstrating feedback-based adaptive control that resolves the acceleration response contradiction
3Power
If slip rate is high to enable torque multiplication, then torque transfer capability is improved, but heat generation increases and efficiency decreases
Solution Approach 1:
The patent implements periodic transitions between locked and unlocked clutch states based on throttle events and engine operating conditions. During normal cruising, the clutch remains locked to minimize heat generation, while during throttle tip-in events, the clutch is temporarily released to enable torque multiplication, creating a periodic control pattern that balances heat management and power transfer needs
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 enhances torque converter efficiency by dynamically controlling slip, ensuring sufficient torque transfer and progressive vehicle acceleration during throttle tip-in events at low engine speeds, improving vehicle performance and reducing heat generation.
Implementation Method 1
As the impeller rotates, the centrifugal force pushes the pressurized fluid outward, causing the turbine to rotate
Implementation Method 2
The torque converter operates through hydraulic force provided by pressurized fluid from the automatic transmission
Data Source
AI summary
A method of dynamically controlling pressure to a torque converter clutch (TCC) of a torque converter coupled to a transmission is provided. The method includes: monitoring throttle position; monitoring engine speed; controlling pressure to the torque converter clutch to increase slip after the throttle position indicates a tip-in has occurred and when engine speed is low; regulating at least one of a transmission steady state pressure to the transmission and pressure to the torque converter to maintain the increased slip; and controlling pressure to the torque converter to reduce slip by engaging the torque converter clutch.