Lockup Clutch Control System for Vehicle Power Transmission

Solution Overview

Problem

The existing control systems for power transmission devices in vehicles fail to effectively manage the temperature increase of the lockup clutch during engagement and release operations, leading to potentially high temperatures regardless of whether the clutch is completely engaged or released.

Innovation Solution

A control system that includes a lockup clutch control unit and an integrated heat generation amount calculation unit, which estimates and compares the heat generation amounts for complete engagement and release scenarios, selecting the control method that minimizes heat generation based on rotational differences and engaging pressures to reduce temperature increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the lockup clutch is completely engaged from the state of engagement control, then the heat generation amount may be reduced, but the temperature increase becomes remarkably high depending on rotational difference and engaging pressure

Engineering Contradiction:

Improveheat generation amountVSAvoidlockup clutch temperature

Core Design Contradiction:

Loss of energyVSTemperature

Solution Approach 1:

The control system changes operational parameters (rotational difference and engaging pressure) to determine the optimal control path. By monitoring these parameters, the system selects between complete engagement or release control to minimize temperature increase, directly addressing the contradiction between heat generation and temperature control

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from the integrated heat generation amount calculation unit to continuously monitor heat accumulation. This feedback mechanism enables the control system to adaptively select between complete engagement and release control based on real-time thermal conditions, resolving the contradiction dynamically

Inventive Principle:

Principle #23Feedback

2Loss of energy

If the lockup clutch is released from the state of engagement control, then the heat generation amount may be reduced, but the temperature increase becomes remarkably high depending on rotational difference and engaging pressure

Engineering Contradiction:

Improveheat generation amountVSAvoidlockup clutch temperature

Core Design Contradiction:

Loss of energyVSTemperature

Solution Approach 1:

The control system changes operational parameters (rotational difference and engaging pressure) to determine the optimal control path. By monitoring these parameters, the system selects between complete engagement or release control to minimize temperature increase, directly addressing the contradiction between heat generation and temperature control

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from the integrated heat generation amount calculation unit to continuously monitor heat accumulation. This feedback mechanism enables the control system to adaptively select between complete engagement and release control based on real-time thermal conditions, resolving the contradiction dynamically

Inventive Principle:

Principle #23Feedback

3Ease of operation

If slip control is executed to reduce shock during complete engagement or release, then the heat generation amount increases, but the temperature increase becomes remarkably high

Engineering Contradiction:

Improveshock reductionVSAvoidlockup clutch temperature

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

The control system changes operational parameters (rotational difference and engaging pressure) to determine the optimal control path. By monitoring these parameters, the system selects between complete engagement or release control to minimize temperature increase, directly addressing the contradiction between heat generation and temperature control

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from the integrated heat generation amount calculation unit to continuously monitor heat accumulation. This feedback mechanism enables the control system to adaptively select between complete engagement and release control based on real-time thermal conditions, resolving the contradiction dynamically

Inventive Principle:

Principle #23Feedback

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 effectively suppresses temperature increases in the lockup clutch by selecting the control method that generates less heat, thereby improving clutch durability and performance.

Implementation Method 1

The surface temperature of a clutch friction material in a lockup clutch is calculated during engagement operation control

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10190681B2Control system for power transmission device for vehicle

Publication Date: 2019.01.29 TOYOTA JIDOSHA KK

AI summary

A protection control selection unit is provided. The protection control selection unit selects control that uses one of a completely engaging heat generation amount and a releasing heat generation amount, by which the amount of heat that is generated in a lockup clutch is reduced. The completely engaging heat generation amount is generated in the lockup clutch in a period before the lockup clutch is completely engaged from a state of lockup engagement control. The releasing heat generation amount is generated in the lockup clutch in a period before the lockup clutch is released from the state of the lockup engagement control. Thus, an increase in the temperature of the lockup clutch at the time when the lockup clutch is completely engaged or released from the state of the lockup engagement control is suitably suppressed.