Method and apparatus for adapting a clutch torque

• US 20050056513A1
• Filed: 02/13/2004
• Published: 03/17/2005
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: LuK Lamellen und Kupplungsbau Beteiligungs KG (INA-Holding Schaeffler GmbH & Co. KG)
• Inventors: Reuschel, Michael
• Granted Patent: US 7,121,390 B2
• Time in Patent Office: Days
• US Class Current: 192/3.580
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60W 2710/1011 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16D 2500/1088 CVT
• CPC Class Codes: F16D 2500/3024 Pressure
• CPC Class Codes: F16D 2500/30412 Torque of the input shaft
• CPC Class Codes: F16D 2500/30421 Torque of the output shaft
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/30806 Engaged transmission ratio
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/70252 Clutch torque
• CPC Class Codes: F16D 2500/7041 Position
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence
• CPC Class Codes: F16H 2061/6618 Protecting CVTs against overload by limiting clutch capacity, e.g. torque fuse
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing

Abstract

Method for adapting a relationship stored in an electronic control unit, between a moment transmittable by a clutch, and a control variable for controlling an actuation unit of the clutch, which clutch is arranged in an automated motor vehicle drive train with a torque detection device arranged between the clutch and a transmission with a steplessly changeable transmission ratio for producing an output parameter dependent upon a detected moment and the momentary transmission ration of the transmission, by which method the moment transmitted by the clutch is calculated from the momentary transmission ratio and the value of the output parameter, and in an operating condition of the clutch in which the transmittable and transmitted moment of the clutch are equalized, the transmitted moment is coordinated with the control variable as an updated transmittable moment.

Claims

1. Method for adapting a relationship stored in an electronic control unit, between a moment transmittable by a clutch, and a control variable for controlling an actuation unit of the clutch, which clutch is arranged in an automated motor vehicle drive train with a torque detection device arranged between the clutch and a transmission with a steplessly changeable transmission ratio for producing an output parameter dependent upon a detected moment and the momentary transmission ration of the transmission, by which method the moment transmitted by the clutch is calculated from the momentary transmission ratio and the value of the output parameter, and in an operating condition of the clutch in which the transmittable and transmitted moment of the clutch are equalized, the transmitted moment is coordinated with the control variable as an updated transmittable moment.

2. Method in accordance with claim 1, whereby the transmission ratio at which an adaptation takes place is the highest possible transmission ratio of the transmission.

3. Method in accordance with claim 2, whereby an adaptation takes place when the motor vehicle is at a standstill or creeping.

4. Method in accordance with claim 2, whereby the transmission is a belt-driven conical pulley transmission whose output side conical disk pair before beginning and during adaptation is acted upon with a higher pressure for pressing against the endless torque-transmitting means.

5. Method in accordance with claim 2, whereby a target transmission ratio value that corresponds to a higher transmission ratio than the highest possible transmission ratio, is activated in a transmission control unit before beginning and during the adaptation.

6. Method in accordance with claim 2, whereby an increased transmission input target rotational speed is activated in a transmission control unit before beginning and during the adaptation.

7. Method in accordance with claim 1, whereby the output signal is an hydraulic medium pressure, and a monitoring device is present by means of which an adaptation is preventable by an influence on the pressure of the hydraulic medium that is not dependent upon the torque.

8. Method in accordance with claim 1 where when the transmission ratio of the transmission is different from the highest possible transmission ratio, an adaptation takes place only if it can actively be calculated.

9. Method in accordance with claim 1, whereby the output signal is an hydraulic medium pressure, and when the transmission ratio of the transmission is different from the highest possible transmission ratio, an adaptation takes place only if a measured value of the output parameter with a fully disengaged clutch lies below the value that is measured at the clutch when it is adjusted to the target clutch moment.

10. Apparatus for adapting the transmittable moment of a clutch in an automated motor vehicle drive train with a drive motor, which is connected through the clutch with a transmission with a steplessly variable transmission ratio, and a torque detection device for detecting the input moment of the transmission, which torque detection device produces an output value which is dependent upon the torque and the transmission ratio of the transmission, containing an electronic control unit for controlling a clutch actuation unit with a control value, in which control unit a characteristic curve is stored which gives a target moment transmittable by the clutch as a function of the control variable, which control unit is constructed for adapting the characteristic curve.