Coasting Control Device Clutch Actuator Kickback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Drivers experience uneasiness and potential panic when pressing the clutch pedal during coasting control in vehicles equipped with manual and automatic dual-mode clutch systems, as the clutch disengagement can lead to torque reduction and kickback, especially when coasting control is initiated unexpectedly.

Innovation Solution

A coasting control device that includes a clutch control unit which adjusts the amount of hydraulic oil ejected from the actuator based on the clutch pedal depression, using a clutch pedal depression amount sensor and solenoid valve to maintain consistent oil pressure, thereby reducing the effort required to press the clutch pedal and preventing kickback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If coasting control is implemented to save fuel by disengaging the clutch, then fuel economy is improved, but driver uneasiness and potential panic occur when the driver presses the clutch pedal during coasting control

Engineering Contradiction:
Improvefuel consumptionVSAvoidclutch pedal operation
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The system dynamically switches between manual and automatic clutch control modes. When the driver presses the clutch pedal during coasting control, the control unit detects this input and transitions from automatic coasting control to manual clutch control, allowing the driver to override the automatic system when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit continuously monitors clutch pedal position and coasting control status. When clutch pedal depression is detected during active coasting control, the system provides feedback by adjusting the clutch actuator to release hydraulic pressure, thereby disengaging automatic control and preventing the harmful kickback effect.

Inventive Principle:
Principle #23Feedback

2Loss of energy

If the clutch is automatically disengaged during coasting control, then engine RPM is reduced to idle RPM to save fuel, but torque reduction and kickback occur when the driver presses the clutch pedal

Engineering Contradiction:
Improvefuel consumptionVSAvoidclutch pedal kickback
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The control unit proactively prevents kickback by detecting clutch pedal depression during coasting control and immediately releasing hydraulic pressure from the clutch actuator. This preliminary action counteracts the potential harmful effect before it can occur, allowing smooth transition from automatic to manual control.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system converts the potential harmful kickback effect into a beneficial feature by using the driver's clutch pedal input as a trigger to exit coasting control mode. The driver's action, which could cause kickback in traditional systems, is instead used to intelligently transition control modes and prevent the harmful effect.

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

3Loss of energy

If the clutch actuator maintains hydraulic pressure to keep the clutch disengaged during coasting control, then fuel economy is improved, but the clutch pedal becomes difficult to press

Engineering Contradiction:
Improvefuel consumptionVSAvoidclutch pedal pressing force
Core Design Contradiction:
Loss of energyVSForce

Solution Approach 1:

The system extracts the conflicting hydraulic pressure from the clutch actuator when the driver presses the clutch pedal during coasting control. By releasing the maintained hydraulic pressure, the system removes the opposing force that was making the pedal difficult to press, allowing smooth manual operation while maintaining coasting control benefits when the pedal is not pressed.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution reduces driver uneasiness and prevents clutch pedal kickback, allowing for smoother operation during coasting control, enhancing safety and comfort by synchronizing the hydraulic oil supply with the clutch pedal depression.

Implementation Method 1

a clutch-free actuator unit (55) acting as an actuator supplied with hydraulic oil by a hydraulic pump (64) with a flow rate of the supplied hydraulic oil restricted by a solenoid valve (62)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a solenoid valve (62) controlling the flow rate of the hydraulic oil supplied to the intermediate cylinder chamber (61a)

Methodology Applied
Scientific EffectSolenoid actuation: Solenoid

Implementation Method 3

a clutch master cylinder (53) supplied with hydraulic oil in response to depression of a clutch pedal (52) or control by an actuator

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2589830B1Coasting control device
Publication Date: 2019.09.04 ISUZU MOTORS LTD
  • EP2589830B1 patent drawingFigure 1
  • EP2589830B1 patent drawingFigure 2
  • EP2589830B1 patent drawingFigure 3

AI summary

There is provided a coasting control device capable of reducing uneasiness experienced by a driver when pressing a clutch pedal during coasting control. The coasting control device includes a clutch control unit 6 that, when the clutch pedal 52 is pressed during coasting control, controls an actuator 55 to cause an amount of hydraulic oil that depends on the amount of depression of the clutch pedal 52 to be ejected from a clutch-free operating cylinder 54.