Method for a serial driving mode of a motor vehicle

Patent metadata

Field	Value
Publication number	US-11590960-B2
Application number	US-201816955239-A
Country	US
Kind code	B2
Filing date	Nov 16, 2018
Priority date	Dec 19, 2017
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A method for serial operation of a motor vehicle with a transmission having a first electric machine, which is operated as a motor for driving the motor vehicle, and a second electric machine, which is operated as a generator, includes, after a generation of a change-over signal, switching the first electric machine from the operation as a motor to the operation as a generator, and switching the second electric machine from the operation as a generator to the operation as a motor in order to drive the motor vehicle.

First claim

The invention claimed is:

1. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operating a first electric machine ( 3 ) of the transmission ( 2 ) as a motor for driving the motor vehicle ( 1 );
operating a second electric machine ( 4 ) of the transmission ( 2 ) as a generator;
generating a change-over signal
when a temperature of the first electric machine ( 3 ) exceeds a threshold value or
when the temperature of the first electric machine ( 3 ) exceeds the threshold value and a temperature of the second electric machine ( 4 ) falls below another threshold value; and

after generation of the change-over signal, switching the first electric machine ( 3 ) from the operation as the motor to the operation as the generator, and switching the second electric machine ( 4 ) from the operation as the generator to the operation as the motor in order to drive the motor vehicle ( 1 ).

2. The method of claim 1 , wherein:
the first electric machine ( 3 ) is switched from the operation as the motor to the operation as the generator without an interruption of tractive force; and/or
the second electric machine ( 4 ) is switched from the operation as the generator to the operation as the motor without the interruption of tractive force.

3. The method of claim 1 , further comprising charging an electric accumulator with the first electric machine ( 3 ) operating as the generator or with the second electric machine ( 4 ) operating as the generator,
wherein either the first electric machine ( 3 ) is operated as the motor and the second electric machine ( 4 ) is operated as the generator or the first electric machine ( 3 ) is operated as the generator and the second electric machine ( 4 ) is operated as the motor.

4. A transmission, configured to implement the method of claim 1 .

5. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operating a first electric machine ( 3 ) of the transmission ( 2 ) as a motor for driving the motor vehicle ( 1 );
operating a second electric machine ( 4 ) of the transmission ( 2 ) as a generator;
generating a change-over signal when a difference between a temperature of the first electric machine ( 3 ) and a temperature of the second electric machine ( 4 ) exceeds a threshold value; and
after generation of the change-over signal, switching the first electric machine ( 3 ) from the operation as the motor to the operation as the generator, and switching the second electric machine ( 4 ) from the operation as the generator to the operation as the motor in order to drive the motor vehicle ( 1 ).

6. A transmission, configured to implement the method of claim 5 .

7. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operating a first electric machine ( 3 ) of the transmission ( 2 ) as a motor for driving the motor vehicle ( 1 );
operating a second electric machine ( 4 ) of the transmission ( 2 ) as a generator; and
after generation of a change-over signal, switching the first electric machine ( 3 ) from the operation as the motor to the operation as the generator, and switching the second electric machine ( 4 ) from the operation as the generator to the operation as the motor in order to drive the motor vehicle ( 1 ), the switching of the second electric machine ( 4 ) from the operation as the generator to the operation as the motor comprises in the following sequence
carrying out a load reduction at an internal combustion engine (VM) and the second electric machine ( 4 ) in order to unload a first clutch (K 2 ) of the transmission ( 2 ),
disengaging the first clutch (K 2 ),
synchronizing a first shift element (B) of the transmission ( 2 ),
engaging the first shift element (B) to form a driving connection between the second electric machine ( 4 ) and an axle differential ( 18 ),
carrying out a load reduction at the first electric machine ( 3 ) and a load build-up at the second electric machine ( 4 ) in order to unload a second shift element (A) of the transmission ( 2 ),
disengaging the second shift element (A),
synchronizing a second clutch (K 1 ),
engaging the second clutch (K 1 ) to form a driving connection between the internal combustion engine (VM) and the first electric machine ( 3 ), and
carrying out a load build-up at the internal combustion engine (VM) and the first electric machine ( 3 ) such that the first electric machine ( 3 ) is operated as the generator.

8. The method of claim 7 , wherein:
the first electric machine ( 3 ) is drivingly connectable to the internal combustion engine (VM) with the second clutch (K 1 ); and/or
the second electric machine ( 4 ) is drivingly connectable to the internal combustion engine (VM) with the first clutch (K 2 ).

9. The method of claim 7 , wherein:
a second gear is implemented by engaging the first shift element (B); and/or
a first gear is implemented by engaging the second shift element (A).

10. The method of claim 7 , wherein:
the synchronization of the second shift element (A) is carried out with a closed-loop control of a rotational speed of the first electric machine ( 3 ); and/or
the synchronization of the first shift element (B) is carried out with a closed-loop control of a rotational speed of the second electric machine ( 4 ).

11. A transmission, configured to implement the method of claim 7 .

12. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operating a first electric machine ( 3 ) of the transmission ( 2 ) as a motor for driving the motor vehicle ( 1 );
operating a second electric machine ( 4 ) of the transmission ( 2 ) as a generator;
after generation of a change-over signal, switching the first electric machine ( 3 ) from the operation as the motor to the operation as the generator, and switching the second electric machine ( 4 ) from the operation as the generator to the operation as the motor in order to drive the motor vehicle ( 1 );
generating a further change-over signal
when a temperature of the second electric machine ( 4 ) exceeds a threshold value or
when the temperature of the second electric machine ( 4 ) exceeds the threshold value, and a temperature of the first electric machine ( 3 ) falls below another threshold value;

after generation of the further change-over signal, operating the first electric machine ( 3 ) as the motor, and operating the second electric machine ( 4 ) as the generator.

13. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operating a first electric machine ( 3 ) of the transmission ( 2 ) as a motor for driving the motor vehicle ( 1 );
operating a second electric machine ( 4 ) of the transmission ( 2 ) as a generator;
after generation of a change-over signal, switching the first electric machine ( 3 ) from the operation as the motor to the operation as the generator, and switching the second electric machine ( 4 ) from the operation as the generator to the operation as the motor in order to drive the motor vehicle ( 1 );
generating a further change-over signal when a difference between a temperature of the second electric machine ( 4 ) and a temperature of the first electric machine ( 3 ) exceeds a further threshold value; and
after generation of the further change-over signal, operating the first electric machine ( 3 ) as the motor, and operating the second electric machine ( 4 ) as the generator.

14. A method for serial operation of a motor vehicle ( 1 ) that includes a transmission ( 2 ), comprising:
operat

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Kaltenbach Johannes
• Roske Michael

Classifications

• Y02T10/62

  Hybrid vehicles · CPC title

• F16H61/0403

  Synchronisation before shifting · CPC title

• B60W10/02

  including control of driveline clutches · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• F16H2061/0422

  by an electric machine, e.g. by accelerating or braking the input shaft · CPC title