Method for controlling a friction clutch

Patent metadata

Field	Value
Publication number	US-9759276-B2
Application number	US-201415034016-A
Country	US
Kind code	B2
Filing date	Dec 10, 2014
Priority date	Jan 20, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

In a motor vehicle, a friction clutch is disposed between a drive unit and a transmission. The value of the contact point of the clutch is adapted at predetermined points in time. A method for controlling the friction clutch includes the steps of determining a value of the contact point of the friction clutch, this value having been modified as a result of an adaptation thereof, and of continuously reducing the value of the contact point at a predetermined ramp rate, without letting this value drop below a predefined contact point reduction value.

First claim

The invention claimed is:

1. A method for controlling a friction clutch, which is arranged in a motor vehicle between a drive train and a transmission, with the method comprising the following steps:
determining a contact point value of a contact point of the friction clutch changed by way of adaptation,
continuously reducing the contact point value with a predetermined ramp rate, and
preventing the contact point value from being below a predetermined contact point reduction value.

2. The method according to claim 1 , further comprising the reducing step occurring only until a predetermined condition is fulfilled regarding an initial start of operation of the friction clutch.

3. The method according to claim 2 , wherein the predetermined condition comprises that the motor vehicle has traveled less than a predetermined distance since the initial start of operation of the friction clutch.

4. The method according to claim 3 , wherein the predetermined distance is from 25 km to 1000 km.

5. The method according to claim 1 , wherein the contact point reduction value is maximally to 1.0 mm.

6. The method according to claim 1 , wherein the predetermined ramp rate is dependent on a distance traveled by the motor vehicle since the initial start of operation of the friction clutch.

7. The method according to claim 6 , further comprising reducing the ramp rate with increasing distance traveled by the motor vehicle since the initial start of operation of the friction clutch.

8. The method according to claim 1 , further comprising implementing the reduction of the contact point value with the predetermined ramp rate as a pilot control measure.

Assignees

• Schaeffler Technologies Ag

Inventors

• Goppert Georg

Classifications

• F16D2500/50257

  During a creep operation · CPC title

• F16D2500/50245

  Calibration or recalibration of the clutch touch-point · CPC title

• F16D2500/10412

  Transmission line of a vehicle · CPC title

• F16D2500/70414

  Quick displacement to clutch touch point · CPC title

• F16D2500/1045

  Friction clutch · CPC title