Torque Converter Lockup Clutch Pressure Modulation
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Solution Overview
Problem
Existing torque converter systems experience reduced fuel efficiency and suboptimal engine power utilization due to slip at low vehicle speeds, and existing control systems struggle to manage clutch engagement effectively across varying operating conditions.
Innovation Solution
A torque converter system with a lockup clutch and pressure regulator that modulates apply pressure based on vehicle operating conditions, using a centrifugally activated sprung mass and marcel spring to adjust clutch behavior and achieve targeted slip values without modifying existing transmission or control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a lockup clutch is engaged to minimize slip, then transmission efficiency improves, but rapid slip drop and hunting behaviors occur causing instability
Solution Approach 1:
The pressure regulator dynamically adjusts the apply pressure to the lockup clutch based on real-time operating conditions. The system transitions from static clutch engagement to dynamic control, continuously modulating pressure to maintain optimal slip values and prevent hunting behaviors, thereby resolving the stability issue while maintaining high transmission efficiency.
Solution Approach 2:
The system implements closed-loop feedback control by monitoring actual slip values and comparing them to target slip values. The pressure regulator receives feedback signals and adjusts apply pressure accordingly, creating a self-correcting control system that eliminates rapid slip drop and hunting, ensuring stable clutch engagement while maximizing transmission efficiency.
2Loss of energy
If apply pressure is increased to achieve target lockup strategy, then fuel efficiency improves, but existing control systems cannot manage engagement effectively across varying operating conditions
Solution Approach 1:
The pressure regulator is designed as a universal control component that can effectively manage lockup clutch engagement across all vehicle operating conditions. It integrates multiple control functions including pressure modulation, slip regulation, and adaptation to varying conditions, making the control system versatile and effective throughout the entire operating range while maximizing fuel efficiency.
Solution Approach 2:
The system dynamically changes the apply pressure parameter based on operating conditions to optimize fuel efficiency. The pressure regulator adjusts pressure levels adaptively, transforming the control system from a fixed-pressure design to a variable-pressure system that responds to changing conditions, thereby improving fuel efficiency while maintaining adaptability across all operating scenarios.
3Ease of operation
If torque converter slip is allowed at low vehicle speeds, then transmission can rotate at slower rate, but fuel efficiency is reduced and engine power is not fully utilized
Solution Approach 1:
The system applies partial lockup clutch engagement rather than full engagement at low vehicle speeds. The pressure regulator modulates apply pressure to achieve a controlled slip value that is greater than zero but optimized for fuel efficiency. This partial action allows the transmission to rotate at appropriate speeds while minimizing energy loss, resolving the contradiction between ease of operation and fuel efficiency.
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 improves fuel efficiency and optimizes engine power utilization by precisely controlling clutch engagement, reducing undesirable behaviors like rapid slip drop and sinusoidal torque converter clutch application, while maintaining compatibility with existing power transmission systems.
Implementation Method 1
using a centrifugally activated sprung mass and marcel spring to adjust clutch behavior
Implementation Method 2
using a centrifugally activated sprung mass and marcel spring to adjust clutch behavior
Data Source
AI summary
A torque converter includes an input connected to an engine. An output is connected with a transmission. A lockup clutch is connected with the output and is disposed to engage the input to couple the input with the output via an apply pressure corresponding to a target lockup strategy based on at least one vehicle operating condition. A pressure regulator is configured to modulate the apply pressure. Systems and methods are disclosed.