Transmission Mode Transition Control via Clutch Threshold

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Solution Overview

Problem

Existing transmission systems, such as AT and AMT, face unintended mode transitions between AT mode and MT mode, leading to potential vehicle control issues during starting and stopping processes.

Innovation Solution

A transmission system with clutch actuators, shift actuators, and a control unit that allows operation in AT, AMT, and MT modes, requiring the driver to operate a mode switching switch and clutch lever above a threshold to prevent unintended mode transitions, ensuring coordinated clutch and gear control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If mode transition is simplified without clutch lever operation requirement, then ease of operation is improved, but reliability deteriorates due to unintended mode transitions

Engineering Contradiction:
Improvemode transition operationVSAvoidmode transition stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The clutch lever operation serves as an intermediary action that must be performed in addition to the mode switching switch operation. This intermediary step acts as a mediator between the driver's intent and the mode transition, ensuring that the transition is deliberate and preventing unintended mode changes during starting and stopping processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system requires preliminary clutch lever operation (opening the clutch) before allowing mode transition to occur. This preliminary action ensures that the transmission is in a safe state for mode switching, preventing abrupt behaviors and ensuring controlled transitions between operating modes.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If clutch actuator is fully automated in AT mode, then ease of operation is improved, but adaptability deteriorates due to loss of driver control

Engineering Contradiction:
Improveclutch operationVSAvoiddriver control flexibility
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts its behavior based on the selected operating mode. In AT mode, the clutch actuator operates automatically for smooth operation, while in MT mode, the clutch lever directly controls the clutch actuator, providing driver control flexibility. The system transitions between these dynamic behaviors based on mode selection and operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clutch actuator serves multiple functions depending on the operating mode: it operates as an automated actuator in AT mode for ease of operation, and as a driver-controlled actuator in MT mode for adaptability. This multi-functionality allows the same component to provide both automated convenience and manual control flexibility as needed.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3034912B1transmission
Publication Date: 2018.02.07 YAMAHA MOTOR CO LTD
  • EP3034912B1 patent drawingFigure 1
  • EP3034912B1 patent drawingFigure 2
  • EP3034912B1 patent drawingFigure 3

AI summary

A transmission in which gear change of a MT system, an AT system and an AMT system can be performed, and unintended transition between an AT mode or an AMT mode and a MT mode can be prevented. Selection section (310) of control section (300) performs a mode selection control such that, when performing transition between the AT mode or the AMT mode and the MT mode, the driver at least has to operate mode switching switch (110) while operating clutch lever (200) in an operation amount not smaller than a predetermined threshold.