Automatic Transmission Control Reducing Work Loss

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Solution Overview

Problem

Conventional multi-stage automatic transmissions experience excessive work loss and increased hydraulic oil temperature due to rotational differences in engagement mechanisms, which affect vehicle acceleration and fuel efficiency, and require improved gear shifting flexibility for quick and smooth operations.

Innovation Solution

A control apparatus for automatic transmission that includes a running condition detector and controller, utilizing a plurality of planetary gear mechanisms and engagement mechanisms to achieve various gear change stages by selectively engaging necessary and no-change engagement mechanisms during gear changes, reducing energy loss and enhancing shifting flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a predetermined gear change stage is selected in conventional automatic transmissions, then gear change can be achieved, but excessive work loss occurs due to rotational difference between friction members

Engineering Contradiction:

Improvework lossVSAvoidvehicle acceleration

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The patent applies dynamics by making the engagement mechanism configuration changeable during operation. The controller dynamically selects between first and second engagement mechanisms based on rotational speed conditions, allowing the transmission to adapt its engagement state to minimize rotational difference and work loss while maintaining acceleration performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the engagement mechanisms by switching between different engagement mechanisms (first and second) based on rotational speed conditions. This parameter change allows the system to operate in a state that minimizes work loss without sacrificing acceleration capability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If engagement mechanisms are engaged during gear change operation, then gear change can be achieved, but hydraulic oil temperature increases due to excessive work loss

Engineering Contradiction:

Improvegear change operationVSAvoidhydraulic oil temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The system dynamically adjusts which engagement mechanism is active based on rotational speed conditions. By switching between first and second engagement mechanisms, the system maintains reliable gear change operation while minimizing the work loss that would otherwise convert to hydraulic oil heating.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent converts the potential harm of engagement mechanism usage by strategically selecting which engagement mechanism to use based on rotational speed conditions. This selective engagement minimizes work loss and prevents excessive hydraulic oil temperature increase while still achieving reliable gear change operation.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Adaptability or versatility

If multiple engagement mechanisms are used for gear change, then shifting flexibility is improved, but device complexity increases

Engineering Contradiction:

Improveshifting flexibilityVSAvoidengagement mechanism configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the engagement mechanism function into at least two separate engagement mechanisms (first and second). This segmentation allows the system to achieve shifting flexibility by selectively engaging different mechanisms while keeping the overall device complexity manageable through functional division.

Inventive Principle:

Principle #1Segmentation

4Loss of energy

If rotational difference between friction members is reduced, then work loss decreases, but gear change flexibility is limited

Engineering Contradiction:

Improvework lossVSAvoidgear change flexibility

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system resolves this contradiction by dynamically selecting between different engagement mechanisms based on rotational speed conditions. This dynamic selection allows the system to minimize work loss when rotational difference would be high while maintaining gear change flexibility through the ability to switch between multiple engagement mechanisms.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8989973B2Vehicle and control apparatus for automatic transmission

Publication Date: 2015.03.24 HONDA MOTOR CO LTD

AI summary

A control apparatus for an automatic transmission includes a running condition detector and a controller. a plurality of gear change stages include at least one specific gear change stage that has a specific transmission gear ratio, that involves at least one necessary engagement mechanism which needs to be engaged in order to obtain the specific transmission gear ratio, and that involves at least one no-change engagement mechanism which causes no change in the specific transmission gear ratio. Both of the at least one necessary engagement mechanism and the at least one no-change engagement mechanism are engaged during a time period from a timing to begin an operation to change a gear change stage to the specific gear change stage until a timing to complete the operation. The at least one no-change engagement mechanism is released after the timing to complete the operation.