Dog Clutch Transmission Shifting Delay Control

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Solution Overview

Problem

The existing dog clutch transmission mechanisms in two-wheeled motor vehicles face delays in shifting due to frictional forces during high-speed operations, leading to inefficient shifting and increased load on the actuator, which results in delayed engagement between gears.

Innovation Solution

Applying a force opposite to the direction of the second stationary gear to the movable gear before engagement, and using a control device to manage the shifting process through PWM signals to control the speed and torque, thereby modifying the impact and facilitating prompt shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the sleeve is moved at high speed to realize prompt shifting, then the shifting speed is improved, but the friction force between the dowel and the gear part increases, causing delay in engagement

Engineering Contradiction:

Improvesleeve moving speedVSAvoidengagement delay time

Core Design Contradiction:

SpeedVSLoss of time

Solution Approach 1:

The control device applies braking force to the movable gear before the dog engagement occurs, during the approach phase. This preliminary braking action reduces the relative speed between the movable gear and stationary gear before contact, preventing excessive friction and engagement delay while still achieving prompt shifting overall.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The braking force is applied in advance to counteract the harmful friction effect that would occur during high-speed engagement. By applying this opposing force before the harmful contact occurs, the system prevents the friction-induced delay rather than reacting to it after the fact.

Inventive Principle:

Principle #9Preliminary anti-action

2Force

If a large force is applied to the movable gear to release engagement at the dog disengaged stage, then the engagement release is achieved, but the movable gear bumps fiercely into the stationary gear, causing remarkable delay in shifting

Engineering Contradiction:

Improveengagement release forceVSAvoidshifting delay time

Core Design Contradiction:

ForceVSLoss of time

Solution Approach 1:

The control device applies braking force to the movable gear before dog engagement occurs, during the approach phase. This preliminary braking reduces the speed at which the movable gear approaches the stationary gear, thereby reducing the fierce bumping impact and the resulting engagement delay.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The braking force that reduces the bumping impact is applied in such a way that while it slows the approach, it still allows the engagement to complete. The harmful high-speed impact is converted into a controlled, slower engagement process that actually improves overall shifting performance by preventing the fierce bumping that causes delay.

Inventive Principle:

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

Data Source

PatentEP2515009B1Transmission apparatus and saddle-riding type vehicle

Publication Date: 2015.08.05 YAMAHA MOTOR CO LTD

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Figure 3A~3C

AI summary

To provide a transmission capable of prompt shifting and modification of bumping between dogs. When a movable gear (7) moves from a state in which the dogs (52, 72) of a first stationary gear (5) and of the movable gear (7) are engaged with each other, toward a second stationary gear (6), a force in a direction opposite from a direction toward the second stationary gear (6) is applied to the movable gear (7) after the engagement between the dogs (52, 72) of the first stationary gear (5) and of the movable gear (7) is released, until the movable gear (7) reaches a position where the dogs (74, 64) of the movable gear (7) and of the second stationary gear (6) contact each other.