Method for carrying out a shift during hybrid operation in a parallel hybrid vehicle

• US 8,257,223 B2
• Filed: 08/08/2008
• Issued: 09/04/2012
• Est. Priority Date: 08/16/2007
• Status: Expired due to Fees

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Kaltenbach, Johannes, Wallner, Stefan
• Primary Examiner(s): YOUNG, EDWIN
• Application Number:
  US12/671,140
• Publication Number:
  US 20110172055A1
• Time in Patent Office: 1,488 Days
• Field of Search: 477/5, 477/77, 477/167, 903/930
• US Class Current: 477/5
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/11 Stepped gearings
• 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 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2061/0422 by an electric machine, e.g. by accelerating or braking the input shaft
• CPC Class Codes: F16H 2061/0433 by torque supply with an electric motor
• CPC Class Codes: F16H 2306/44 Removing torque from current gears
• CPC Class Codes: F16H 2306/46 Uncoupling of current gear
• CPC Class Codes: F16H 2306/54 Synchronizing engine speed to transmission input speed
• CPC Class Codes: F16H 61/0403 Synchronisation before shifting
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method of carrying out a shift with traction force interruption during hybrid operation in a parallel hybrid vehicle having an automated transmission. The method comprises the steps of maintaining the coupling between the internal combustion engine (1) and the electric machine (2), eliminating the load before disengaging the old gear, and synchronizing to the new gear by the operation of the electric machine (2).

Claims

1. A method of carrying out a shift with traction force interruption during hybrid operation in a parallel hybrid vehicle having an automated transmission and a single electric machine connected between an internal combustion engine and an input shaft of the automated transmission, the method comprising the steps of:

maintaining a coupling between the internal combustion engine (1) and the electric machine (2);

one of (a) operating the internal combustion engine at a constant torque and (b) adjusting a torque from the internal combustion engine when the torque from the internal combustion engine exceeds a threshold value, and

operating the electric machine to compensate for torque from the internal combustion engine to eliminate a load on the input shaft of the automated transmission; and

disengaging an old transmission gear and synchronizing to a new transmission gear.

2. The method of carrying out a shift with traction force interruption according to claim 1, further comprising the step of:

adjusting the torque from the internal combustion engine (1), or when an energy accumulator of the vehicle would become overcharged due to the torque compensation by the electric machine (2).

3. The method of carrying out a shift with traction force interruption, according to claim 1, further comprising the step of disengaging the old transmission gear, after the load on the input shaft of the automated transmission is eliminated, and then synchronizing the new transmission gear by adjusting a speed of the electric machine (2) to a synchronous speed of the new transmission gear.

4. The method of carrying out a shift with traction force interruption, according to claim 3, further comprising the step of adjusting the speed of the electric machine (2) by switching the electric machine (2) from a torque-controlled mode to a speed regulation mode in which the speed of the electric machine (2) is adjusted, with the torque from the internal combustion engine being a pilot torque for a speed regulator of the electric machine (2).

5. The method of carrying out a shift with traction force interruption, according to claim 4, further comprising the step of engaging the new transmission gear after the synchronization to the new transmission gear;

and

increasing the load on the input shaft of the automated transmission, according to a torque which is desired by the driver, and returning the electric machine to the torque-controlled mode for increasing the load build-up on the input shaft of the automated transmission, when the speed of the electric motor was adjusted to the synchronous speed of the new transmission gear in the speed regulation mode.

6. The method of carrying out a shift with traction force interruption, according to claim 5, comprising the step of adjusting the electric machine (2) and the internal combustion engine (1) to torques determined by a separate torque distribution strategy for the load build-up on the input shaft of the automated transmission.

7. The method of carrying out a shift with traction force interruption, according to claim 1, further comprising the step of operating the electric machine as a generator during a shift.