Hybrid drive unit and running control method for hybrid drive unit

• US 20080314658A1
• Filed: 12/13/2007
• Published: 12/25/2008
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Aisin AW Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Iwase, Yuji, Kumazaki, Kenta, Tabata, Atsushi, Atarashi, Tomoo, Shibata, Hiroyuki, Matsubara, Tooru, Kakinami, Takuma, Takami, Shigeki, Ike, Nobukazu, Imamura, Tatsuya
• Granted Patent: US 7,967,090 B2
• Time in Patent Office: Days
• US Class Current: 180/65.2
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution 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 2240/425 Temperature
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 2260/167 of motors or generators
• 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 10/115 with planetary gears
• 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 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/087 Temperature
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2530/207 : Towing force
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/105 : Output torque
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/915 : Specific drive or transmission adapted for hev
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

A hybrid drive system includes an engine; at least one rotating electric machine, wherein the engine and the at least one rotating electric machine are capable of driving a vehicle; and a controller. The controller starts a load limit control that limits a load exerted to the rotating electric machine when a temperature of the rotating electric machine exceeds a load limit start temperature; detects a loading state or a towing state of the vehicle; and determines the load limit start temperature based on the loading state or the towing state detected.

Claims

1. A hybrid drive system comprising:

an engine;

at least one rotating electric machine, wherein the engine and the at least one rotating electric machine are capable of driving a vehicle; and

a controller that;

starts a load limit control that limits a load exerted to the rotating electric machine when a temperature of the rotating electric machine exceeds a load limit start temperature;

detects a loading state or a towing state of the vehicle; and

determines the load limit start temperature based on the loading state or the towing state detected.

2. The hybrid drive system according to claim 1, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shifting threshold value for downshifting in the transmission is set to a side where the drive force is lower than that of a shifting threshold value for a downshifting in a fuel economy drive mode where no load limit control is executed.

3. The hybrid drive system according to claim 1, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed.

4. The hybrid drive system according to claim 1, wherein when the controller executes the load limit control, an engine torque is increased to become higher than a torque in a fuel economy drive mode while maintaining an engine output constant.

5. The hybrid drive system according to claim 1, wherein when the controller executes the load limit control, an output of the rotating electric machine is limited.

6. The hybrid drive system according to claim 1, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed; and

when the temperature of the rotating electric machine further increases, an output of the rotating electric machine is limited, or an engine torque is increased to become higher than a torque in the fuel economy drive mode while maintaining an engine output constant.

7. The hybrid drive system according to claim 1, wherein when the controller executes the load limit control, a rotating electric machine efficiency mode where operation points of the engine and the rotating electric machine are determined is selected while giving priority to efficiency of the rotating electric machine.

8. The hybrid system according to claim 1, wherein the controller:

detects a presence/absence of a load for the vehicle and a weight of the load, and

detects the loading state based on a detection result.

9. The hybrid drive system according to claim 1, wherein the controller:

detects a presence/absence of a towed object to be towed by the vehicle,

detects a travel resistance against the vehicle in a travel state, and

detects the towing state based on the presence/absence of the towed object detected and the travel resistance detected.

10. The hybrid drive system according to claim 1, wherein the controller:

detects whether the vehicle is traveling on a flat road,

detects a travel resistance against the vehicle in a travel state, and

detects the loading state or the towing state based on a relationship between an actual travel resistance detected and a flat road travel resistance of the vehicle not in a loading/towing state, in a state where the controller detects a travel state of the vehicle on the flat road.

11. The hybrid drive system according to claim 9, wherein the controller:

detects an accelerator opening degree and an acceleration of the vehicle, wherein;

a travel resistance against the vehicle in the travel state is obtained based on the accelerator opening degree detected and the acceleration of the vehicle detected.

12. A hybrid drive system, comprising:

an engine;

at least one rotating electric machine, wherein the engine and the at least one rotating electric machine are capable of driving a vehicle; and

a controller that;

executes a load limit control that limits a load exerted to the rotating electric machine;

detects a loading state or a towing state of the vehicle; and

executes the load limit control based on the loading state or the towing state detected.

13. The hybrid drive system according to claim 12, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shifting threshold value for downshifting in the transmission is set to a side where the drive force is lower than that of a shifting threshold value for a downshifting in a fuel economy drive mode where no load limit control is executed.

14. The hybrid drive system according to claim 12, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed.

15. The hybrid drive system according to claim 12, wherein when the controller executes the load limit control, an engine torque is increased to become higher than a torque in a fuel economy drive mode while maintaining an engine output constant.

16. The hybrid drive system according to claim 12, wherein when the control executes the load limit control, an output of the rotating electric machine is limited.

17. The hybrid drive system according to claim 12, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed; and

when the temperature of the rotating electric machine further increases, an output of the rotating electric machine is limited, or an engine torque is increased to become higher than a torque in the fuel economy drive mode while maintaining an engine output constant.

18. The hybrid drive system according to claim 12, wherein when the controller executes the load limit control, a rotating electric machine efficiency mode where operation points of the engine and the rotating electric machine are determined is selected while giving priority to efficiency of the rotating electric machine.

19. The hybrid system according to claim 12, wherein the controller:

detects a presence/absence of a load for the vehicle and a weight of the load, and

detects the loading state based on a detection result.

20. The hybrid drive system according to claim 12, wherein the controller:

detects a presence/absence of a towed object to be towed by the vehicle,

detects a travel resistance against the vehicle in a travel state, and

detects the towing state based on the presence/absence of the towed object detected and the travel resistance detected.

21. The hybrid drive system according to claim 12, wherein the controller:

detects whether the vehicle is traveling on a flat road,

detects a travel resistance against the vehicle in a travel state, and

detects the loading state or the towing state based on a relationship between an actual travel resistance detected and a flat road travel resistance of the vehicle not in a loading/towing state, in a state where the controller detects a travel state of the vehicle on the flat road.

22. The hybrid drive system according to claim 20, wherein the controller:

detects an accelerator opening degree and an acceleration of the vehicle, wherein;

a travel resistance against the vehicle in the travel state is obtained based on the accelerator opening degree detected and the acceleration of the vehicle detected.

23. A hybrid drive system comprising:

an engine;

at least one rotating electric machine, wherein the engine and the at least one rotating electric machine are capable of driving a vehicle; and

a controller that;

starts a load limit control that limits a load exerted to the rotating electric machine when a temperature of the rotating electric machine exceeds a load limit start temperature;

detects a travel resistance against the vehicle in a travel state; and

determines the load limit start temperature based on the travel resistance detected.

24. The hybrid drive system according to claim 23, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shifting threshold value for downshifting in the transmission is set to a side where the drive force is lower than that of a shifting threshold value for a downshifting in a fuel economy drive mode where no load limit control is executed.

25. The hybrid drive system according to claim 23, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine, and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed.

26. The hybrid drive system according to claim 23, wherein when the controller executes the load limit control, an engine torque is increased to become higher than a torque in a fuel economy drive mode while maintaining an engine output constant.

27. The hybrid drive system according to claim 23, wherein when the controller executes the load limit control, an output of the rotating electric machine is limited.

28. The hybrid drive system according to claim 23, further comprising:

a transmission that receives a drive force from the engine and the rotating electric machine and performs shifting through a plurality of shift speeds to transmit the drive force to a wheel, wherein;

when the controller executes the load limit control, a shift speed of the transmission is set to be lower than a shift speed selected in a fuel economy drive mode where no load limit control is executed; and

when the temperature of the rotating electric machine further increases, an output of the rotating electric machine is limited, or an engine torque is increased to become higher than a torque in a fuel economy drive mode while maintaining an engine output constant.

29. The hybrid drive system according to claim 23, wherein when the controller executes the load limit control, a rotating electric machine efficiency mode where operation points of the engine and the rotating electric machine are determined is selected while giving priority to efficiency of the rotating electric machine.

30. The hybrid drive system according to claim 23, wherein the controller:

detects an accelerator opening degree and an acceleration of the vehicle, wherein;

the travel resistance against the vehicle in the travel state is obtained based on the accelerator opening degree detected and the acceleration of the vehicle detected.

31. A drive control method of a hybrid drive system with an engine and at least one rotating electric machine that are capable of driving a vehicle, comprising:

detecting a loading state or a towing state of the vehicle upon starting a load limit control that limits a load exerted to the rotating electric machine when a temperature of the rotating electric machine exceeds a load limit start temperature; and

determining the load limit start temperature based on the detected loading state or the detected towing state.

32. A drive control method of a hybrid drive system with an engine and at least one rotating electric machine that are capable of driving a vehicle, comprising:

detecting a loading state or a towing state of the vehicle; and

executing a load limit control that limits a load exerted to the rotating electric machine when the loading state or the towing state of the vehicle is detected.

33. A drive control method of a hybrid drive system with an engine and at least one rotating electric machine that are capable of driving a vehicle, comprising:

detecting a travel resistance against the vehicle in a travel state upon starting a load limit control that limits a load exerted to the rotating electric machine when a temperature of the rotating electric machine exceeds a load limit start temperature; and

determining the load limit start temperature based on the detected travel resistance.