METHOD FOR STARTING THE COMBUSTION ENGINE DURING A LOAD SHIFT IN PARALLEL HYBRID VEHICLES

• US 20100204005A1
• Filed: 08/08/2008
• Published: 08/12/2010
• Est. Priority Date: 08/16/2007
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Kaltenbach, Johannes
• Granted Patent: US 8,251,866 B2
• Time in Patent Office: Days
• US Class Current: 477/5
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• 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 10/113 with two input flow paths, e.g. double clutch transmission selection of one of the torque flow paths by the corresponding input clutch
• 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 2510/0657 Engine torque
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/18018 Start-stop drive, e.g. in a traffic jam
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60W 30/192 Mitigating problems related to power-up or power-down of the driveline, e.g. start-up of a cold engine
• CPC Class Codes: B60Y 2400/428 Double clutch arrangements; Dual clutches
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A method for starting the internal combustion engine, in parallel hybrid vehicles, in which the internal combustion engine is started, during a shift under load in purely electric driving operation, by the electric machine.

Claims

1-11. -11. (canceled)

12. A method of starting an internal combustion engine in parallel hybrid vehicles, the method comprising the step of:

starting the internal combustion engine (1), during a shift under load in a purely electrical driving operation, by an electric machine (2).

13. The method of starting the internal combustion engine according to claim 12, further comprising the step of engaging a first clutch (K1), during the shift under load when the internal combustion engine (1) is connectable by the first clutch (K1) to the electric machine (2) which is connected to a transmission (3).

14. The method of starting the internal combustion engine according to claim 13, further comprising the step of:

adapting a speed of the electric machine (2), in a speed regulation mode, for synchronization with a new gear during the shift under load; and

engaging the first clutch (K1) to start the internal combustion engine (1) during the adaptation of the speed of the electric machine (2).

15. The method of starting the internal combustion engine according to claim 14, further comprising the step of adapting the speed of the electric machine (2) such that the speed (n_EM) of the electric machine (2) approaches a target speed (n_Gang_neu) with a low gradient.

16. The method of starting the internal combustion engine according to claim 14, further comprising the step of:

transmitting torque via the first clutch (K1) as a pilot torque to a speed regulator of the electric machine (2) such that torque of the internal combustion engine (1) is used as the pilot torque for the speed regulator when the first clutch (K1) catches; and

utilizing torques at an old clutch (K_alt) and a new clutch (K_neu), which are involved in the shift under load and acting upon the electric machine (2), as further pilot torques for speed regulation.

17. The method of starting the internal combustion engine according to claim 15, further comprising the step of changing the electric machine (2) to a torque-regulated mode and completely engaging the new clutch (K_neu) when the speed (n_EM) of the electric machine (2) reaches one of the target speed or a synchronous speed (n_Gang_neu) of the new gear being engaged.

18. The method of starting the internal combustion engine according to claim 12, further comprising the step of utilizing a mass moment of inertia of the electric machine (2) as a starting torque for the internal combustion engine during an upshift.

19. The method of starting the internal combustion engine according to claim 14, further comprising the step of:

approximately simultaneously increasing, in a traction upshift, the transmission capacity of a new clutch (K_neu) to be engaged for load transfer and reducing the transmission capacity of an old clutch (K_alt) to be disengaged; and

changing the electric machine (2) to a speed regulation mode when the load transfer to the new clutch (K_neu) takes place, adapting the speed of the electric machine (2) to reach a synchronous speed of the new gear being engaged such that the electric machine (2) is adjusted under speed control to either a target speed or the synchronous speed of the new gear, while approximately simultaneously completely disengaging the old clutch (K_alt).

20. The method of starting the internal combustion engine according to claim 14, further comprising the steps of

reducing, in a traction downshift, the transmission capacity of an old clutch (K_alt) which is to be disengaged;

changing the electric machine (2) from a torque-controlled mode to the speed-regulation mode as soon as slip is detected at the old clutch (K_alt) being disengaged;

adjusted the speed of the electric machine (2) to a value higher than a synchronous speed at a new clutch (K_neu) being engaged; and

increasing the transmission capacity of the new clutch (K_neu) being engaged and further reducing the transmission capacity of the old clutch (K_alt) being disengaged, to facilitate a continuous load transfer to the new clutch (K_neu) being engaged, such that when the new clutch (K_neu) assumes the load, the old clutch (K_alt) being disengaged is completely disengaged and the speed of the electric machine (2) is adjusted to the synchronous speed at the new clutch (K_neu) being engaged.

21. The method of starting the internal combustion engine according to claim 14, further comprising the step of:

approximately simultaneously increasing, in a thrust downshift, the transmission capacity of a new clutch (K_neu) to be engaged and reducing the transmission capacity of an old clutch (K_alt) to be disengaged; and

changing the electric machine (2) from a torque-controlled mode to the speed-regulation mode when the new clutch (K_neu) being engaged assumes the load and the old clutch (K_alt) being disconnected is disengaged completely, and adjusting the electric machine (2) under speed control to a synchronous speed at the new clutch (K_neu) and at approximately the same time the old clutch (K_alt) being disconnected is completely disengaged.

22. The method of starting the internal combustion engine according to claim 14, further comprising the step of:

continuously reducing, in a thrust upshift, the transmission capacity of the old clutch (K_alt) to be disengaged;

changing the electric machine (2) from a torque-controlled mode to a speed-regulation mode as soon as slip is detected at the old clutch (K_alt) being disengaged, in which the speed of the electric machine (2) is reduced to a value below the synchronous speed at a new clutch (K_neu) to be engaged;

increasing the transmission capacity of the new clutch (K_neu) being engaged and reducing the transmission capacity of the old clutch (K_alt) being disengaged to transfer continuously the load to the new clutch (K_neu); and

completely disengaging the old clutch (K_alt) being disengaged after the load is assumed by the new clutch (K_neu) being engaged and the speed of the electric machine (2) is adjusted in the speed-regulation mode to the synchronous speed at the new clutch (K_neu) being engaged.