Synchronizer Actuator Fork Position Detection in Dual Clutch Transmissions

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Solution Overview

Problem

Dual clutch transmissions face challenges in accurately identifying the synchronous position of synchronizer actuator forks, which is crucial for proper gear engagement and disengagement, leading to inconsistent and unpredictable shifts.

Innovation Solution

A method that senses the deceleration rate of a shaft when the synchronizer is in a neutral position and identifies a change in deceleration rate as the synchronizer moves toward a gear, determining the synchronous position of the synchronizer actuator fork, allowing the control module to precisely control gear engagement and disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional methods are used to identify synchronous position, then the system is simpler to implement, but the gear engagement becomes inconsistent and unpredictable

Engineering Contradiction:

Improvegear engagement consistencyVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control module continuously monitors the deceleration rate of the input shaft and uses this feedback to identify the synchronous position of the synchronizer actuator fork. When the deceleration rate changes from a first rate to a second rate, the system determines that the synchronous position has been reached, enabling precise and consistent gear engagement control.

Inventive Principle:

Principle #23Feedback

2Ease of operation

If the synchronous position is not accurately identified, then the control system is simpler, but the gear shifts become rough and inconsistent

Engineering Contradiction:

Improvegear shift smoothnessVSAvoidsynchronous position detection precision

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces complex mechanical position sensing mechanisms with a control module that electronically monitors deceleration rate changes. This substitution maintains high measurement precision for synchronous position detection while improving gear shift smoothness and consistency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If the synchronizer position is imprecisely controlled, then the manufacturing is simpler, but the gear engagement becomes unpredictable

Engineering Contradiction:

Improvesynchronizer positioning precisionVSAvoidmanufacturing complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The system uses the natural deceleration characteristics of the input shaft to automatically identify the synchronous position without requiring additional manufacturing precision in mechanical components. The control module leverages the existing physical behavior of the transmission system to achieve precise positioning.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS9057434B2Method of identifying a synchronous position of a synchronizer actuator fork of a dual clutch transmission

Publication Date: 2015.06.16 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method of identifying a synchronous position of a synchronizer actuator fork includes sensing a deceleration rate of a first shaft, when a synchronizer is positioned in a neutral position, to define a first rate of deceleration. The synchronizer is moved along the first shaft from the neutral position toward a gear with a synchronizer actuator fork. A deceleration rate of the first shaft is sensed, while the synchronizer actuator fork moves the synchronizer along the first shaft, to identify a change from the first rate of deceleration to a second rate of deceleration. The location, of the synchronizer actuator fork relative to the first shaft, at which the rate of acceleration of the first shaft changes from the first rate of deceleration to the second rate of deceleration, is identified as the synchronous position of the synchronizer actuator fork.