METHOD FOR ACCELERATING THE DECOUPLING OF A STARTING CLUTCH, WHICH RELEASABLE CONNECTS AN ELECTRIC MACHINE TO A TRANSMISSION INPUT, IN A HYBRID DRIVE TRAIN OF A VEHICLE

• US 20120129650A1
• Filed: 11/18/2011
• Published: 05/24/2012
• Est. Priority Date: 11/24/2010
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: LEMP, Thomas, PFAU, Alexander
• Granted Patent: US 8,465,393 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2710/025 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/105 Output torque
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method of accelerating decoupling of the starting clutch (5) that is able to connect the electric machine (2) to the transmission input in a hybrid drive-train of a motor vehicle, when a decoupling command is issued, at the same time as the regulation of the starting clutch begins for the purpose of decoupling the starting clutch (5) or a specified time after the regulation of the starting clutch begins. The electric machine is regulated in such manner that a torque is built up such that the transition to sliding friction, and thus decoupling and the onset of slip, are sped up while maintaining the nominal driving torque.

Claims

1-5. -5. (canceled)

6. A method of accelerating decoupling of a starting clutch (5) that releasably connects an electric machine (2) to a transmission input in a hybrid drive-train of a motor vehicle, the method comprising the steps of:

regulating the electric machine (2), when a decoupling command is issued, at the same time as regulation of the starting clutch begins for the purpose of decoupling the starting clutch (5) or a specified time after the regulation of the starting clutch begins, in such a manner that a torque is built up, whereby a transition to sliding friction, and thus the decoupling, are sped up while still maintaining a nominal driving torque.

7. The method of accelerating the decoupling of the starting clutch (5) that releasably connects the electric machine (2) to the transmission input in the hybrid drive-train of the motor vehicle according to claim 6, further comprising the steps of:

specifying, via a control system, a desired nominal speed for the electric machine (2), and

building up a torque, that corresponds to a desired nominal speed, with a speed regulator of the electric machine.

8. The method of accelerating the decoupling of the starting clutch (5) that releasably connects the electric machine (2) to the transmission input in the hybrid drive-train of the motor vehicle according to claim 6, further comprising the step of specifying a desired nominal torque for the electric machine (2, via a control system, which is transmitted to the electric machine (2) as a pilot control torque.

9. The method of accelerating the decoupling of the starting clutch (5) that releasably connects the electric machine (2) to the transmission input in the hybrid drive-train of the motor vehicle according to claim 7, further comprising the step of specifying a value of either the desired nominal speed or a desired nominal torque, that depends on an operating point of the drive-train at a time, and storing the value in the control system as a characteristic curve.

10. The method of accelerating the decoupling of the starting clutch (5) that releasably connects the electric machine (2) to the transmission input in the hybrid drive-train of the motor vehicle according to claim 7, further comprising the step of, when no decoupling occurs within a specified time, reducing either the speed or a pilot control torque of the electric machine (2) to avoid any undesired acceleration of the vehicle due to additional torque of the electric machine (5).