Vehicle Clutch Control System for Slippery Surface Start Performance

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Solution Overview

Problem

Coupling clutches in vehicles experience reduced start performance due to slide rotations between input and output sides when actuator control reduces torque transmission, and ball cam structures require phase differences for re-engagement, leading to delayed clutch engagement and reduced start performance, especially on slippery surfaces.

Innovation Solution

A control apparatus that maintains and intensifies the urging state of the clutch using a ball cam structure during vehicle stoppage, with sensors detecting outer air temperature, road surface friction, and gradient to adjust engagement force, ensuring the clutch remains engaged and ready for immediate power transmission upon starting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the actuator control reduces torque transmission when the vehicle stops to wait for a traffic signal, then energy consumption is reduced, but slide rotations occur between the input-side and the output-side of the coupling clutch, reducing the start performance

Engineering Contradiction:
Improveenergy consumptionVSAvoidstart performance
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The control device maintains the urging state of the urging device during stoppage if the clutch has transmitted driving power before stoppage, preparing the clutch for immediate power transmission upon vehicle start, thus preventing slide rotations and maintaining start performance while still allowing energy reduction during idle stop periods

Inventive Principle:
Principle #10Preliminary action

2Power

If the clutch plates are pressed by the other cam in the ball cam structure, then the magnitude of torque transmitted is controlled, but once the coupling between one of the cams and a torque input-side member is released, the phase difference is eliminated and the cams cannot be engaged once again until a phase difference arises, causing slide rotations and reducing start performance

Engineering Contradiction:
Improvetorque transmissionVSAvoidstart performance
Core Design Contradiction:
PowerVSSpeed

Solution Approach 1:

The control device maintains the urging state during stoppage when the clutch has been engaged before stoppage, ensuring the phase difference between cams is preserved and the clutch remains ready for immediate re-engagement, thus preventing slide rotations upon vehicle start

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If the urging state is eliminated during stoppage when the clutch has not transmitted driving power, then energy consumption is reduced, but the clutch cannot provide immediate torque transmission upon start

Engineering Contradiction:
Improveenergy consumptionVSAvoidtorque transmission readiness
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The control device determines whether to maintain or eliminate the urging state based on feedback about the clutch's prior state (whether it transmitted driving power before stoppage), making an intelligent decision that balances energy consumption with torque transmission readiness

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

Improves vehicle start performance by maintaining clutch engagement and increasing torque transmission during stoppages, reducing slide rotations and enhancing power delivery to wheels, particularly on slippery surfaces, by adjusting engagement force based on environmental and road conditions.

Implementation Method 1

a phase difference arises between the cams and the other cam moves in the direction so as to separate from the one cam

Methodology Applied
Scientific EffectPhase difference:

Implementation Method 2

the clutch plates are pressed by the other cam and the clutch plates are urged to the direction so as to engage with each other

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

the magnitude of torque transmitted via the coupling clutch can be varied by controlling the flow quantity or the pressure of the viscous fluid

Methodology Applied
Scientific EffectViscous resistance: Viscous Damping

Implementation Method 4

when electromagnetic clutch plates are used, the magnitude of transmitted torque can be controlled by controlling the friction engagement force of each clutch plate

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3243683B1Control system for vehicle
Publication Date: 2021.01.06 MITSUBISHI MOTORS CORP
  • EP3243683B1 patent drawingFigure 1~2
  • EP3243683B1 patent drawingFigure 3~4(B)
  • EP3243683B1 patent drawingFigure 5

AI summary

First drive wheels (4) are connected to a power source (1) of a vehicle, and are to be driven by the power source (1). A clutch (7) is interposed on a transmission path of driving power generated by the power source (1), and second drive wheels (5) that are connected to the power source (1) via the clutch (7), and are capable of being driven by the power source (1). An urging device (8) is also provided that urges the clutch (7) to an engagement direction in accordance to a difference between a rotation speed upstream to the clutch (7) and a rotation speed downstream to the clutch. A controlling device (9) is provided that maintains, when the clutch (7) has been urged to the engagement direction by the urging device (8) before the vehicle stops, an urging state by the urging device (8) during the stoppage, since before the stoppage.