METHOD FOR SETTING A CLUTCH TORQUE

• US 20060009900A1
• Filed: 07/06/2005
• Published: 01/12/2006
• Est. Priority Date: 07/10/2004
• Status: Active Grant

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG
• Inventors: Gerhart, Juergen, Werner, Olaf, Goeppert, Georg
• Granted Patent: US 7,412,316 B2
• Time in Patent Office: Days
• US Class Current: 701/67
• CPC Class Codes: F16D 2500/1024 combined with hydraulic actuation
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• CPC Class Codes: Y10T 74/19274 torque responsive

Abstract

In a method for setting the clutch torque of a clutch, especially a clutch disposed in a drive train of a motor vehicle, the clutch is adjusted using a clutch actuator. This clutch actuator has at least two actuator parts that may be positioned relative to each other at raster values of a position raster. A position setpoint corresponding to a clutch torque and disposed between the raster values of the position raster is calculated, and the actuator parts are positioned relative to each other at a raster value of the position raster that is adjacent to the position setpoint. In addition to the first position raster value, a second position raster value is calculated in such a manner that the position setpoint is disposed between the first position raster value and the second position raster value. The actuator parts are alternately positioned at the first position raster value and the second position raster value in such a manner that the average clutch torque more precisely matches the clutch torque setpoint than the clutch torques of the first and second position raster values.

Claims

1. A method for setting the clutch torque of a clutch, especially one disposed in a drive train of a motor vehicle, the clutch (1) being adjusted using a clutch actuator (7) that has at least two actuator parts that may be positioned relative to each other at raster values (9a, 9b, 9c) of a position raster, a position setpoint being determined for the actuator parts that corresponds to a clutch torque and is disposed between the raster values (9a, 9b, 9c) of the position raster, and the actuator parts being positioned relative to each other at a raster value (9a) of the position raster adjacent to the position setpoint, wherein a second position raster value (9b) is determined in addition to the first position raster value (7a) in such a manner that the position setpoint is disposed between the first position raster value (9a) and the second position raster value (9b), and the actuator parts are alternately positioned at the first position raster value (9a) and the second position raster value (9b) in such a manner that the average clutch torque more precisely matches the clutch torque setpoint than the clutch torques of the first and second position raster values (9a, 9b).

2. The method as described in claim 1, wherein a position setpoint signal (14) is generated that corresponds to the position setpoint, a heterodyning signal containing an alternating signal portion is heterodyned to this position setpoint signal (14) in such a manner that the sum signal from the position setpoint signal (14) and the heterodyning signal is essentially within the position raster, and the clutch actuator (7) is driven with the sum signal as setpoint signal.

3. The method as described in claim 1, wherein the heterodyning signal is pulse-width-modulated as a function of the location of the position setpoint relative to the first and second position raster values (9a, 9b).

4. The method as described in claim 1, wherein the heterodyning signal is pulse-width-modulated using a constant period of oscillation, and the pulse/pause ratio is altered as a function of the location of the position setpoint relative to the first and second position raster values (9a, 9b).

5. The method as described in claim 1, wherein the heterodyning signal is pulse-width-modulated using a constant period of oscillation, and the pause duration is altered as a function of the location of the position setpoint relative to the first and second position raster values (9a, 9b).

6. The method as described in claim 1, wherein the heterodyning signal is pulse-width-modulated using a constant pause period, and the period of oscillation is altered as a function of the location of the position setpoint relative to the first and second position raster values (9a, 9b).

7. The method as described in claim 1, wherein the alternating signal portion has a fundamental frequency that is set between a system-specific juddering frequency of the clutch and a system-specific base frequency of the system of the clutch actuator as a whole.

8. The method as described in claim 7, wherein the fundamental frequency is 1 to 10 Hz, especially 3 to 7 Hz, especially 4 to 6 Hz and preferably approximately 5 Hz.

9. A method for setting the clutch torque of a clutch (1), especially one disposed in a drive train of a motor vehicle, especially as described in claim 1, the clutch (1) being adjusted using a clutch actuator (7) that is in a drive connection with the clutch (1) via a disengagement device having a travel hysteresis, and a position setpoint corresponding to a clutch torque setpoint being calculated and the clutch actuator (7) being positioned corresponding to the position setpoint, wherein a juddering movement is heterodyned to the positioning movement of the clutch actuator (7) for at least partial compensation of the travel hysteresis.

10. The method as described in claim 9, wherein the amplitude of the juddering movement is at least twice as large as the maximum value of the travel hysteresis.

11. The method as described in claim 9, wherein a position setpoint signal (14) corresponding to the position setpoint is generated, a heterodyning signal for the juddering movement that contains an alternating signal portion is heterodyned to this position setpoint signal (14), and the clutch actuator (7) is driven using the signal formed in this way.

12. The method as described in claim 9, wherein the alternating signal portion has a frequency that is higher than the juddering frequency.

13. The method as described in claim 12, wherein the frequency is higher than 25, especially 30 and preferably 35 Hz.