Hybrid vehicle drive system adapted to assure smooth brake application by motor/generator or engine

• US 5,923,093 A
• Filed: 06/30/1997
• Issued: 07/13/1999
• Est. Priority Date: 07/02/1996
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tabata, Atsushi, Ibaraki, Ryuji, Taga, Yutaka, Hata, Hiroshi, Mikami, Tsuyoshi
• Primary Examiner(s): Dougherty, Thomas M.
• Assistant Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/885,853
• Time in Patent Office: 743 Days
• Field of Search: 290/1 C, 290/8, 290/9, 290/40 R, 290/40 A, 290/40 C, 290/45, 290/51, 322/16, 322/40, 318/139, 180/248
• US Class Current: 290/40.00C
• 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 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 3/0061 relating to electrical machines
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• 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 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: F16H 61/16 Inhibiting or initiating shift during unfavourable conditions, e.g. preventing forward reverse shift at high vehicle speed, preventing engine over speed unintentional control input F16H61/18
• CPC Class Codes: F16H 61/21 Providing engine brake control
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/91 : Orbital, e.g. planetary gears
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch

Abstract

A hybrid drive system for a motor vehicle, including an engine, a motor/motor, an automatic transmission disposed between the engine and a vehicle drive wheel, a regenerative braking device for applying to the vehicle a regenerative braking force corresponding to an amount of electric energy generated by the motor/generator during an operation of the motor/generator by a kinetic energy of the running vehicle, and at least one of (a) a shift inhibiting device for inhibiting a shifting action of the automatic transmission during an operation of the regenerative braking device so as to prevent a change of an engine braking force applied to the vehicle, (b) a braking shift control device which is operated when the regenerative braking device is inoperable to provide the required regenerative braking force, for changing the speed ratio of the automatic transmission to increase the engine braking force, or operated prior to the operation of the regenerative braking device, for controlling the speed ratio of the transmission so as to apply the engine brake to the vehicle, and (c) a mode change inhibiting device for inhibiting a change of operation mode between regenerative braking mode and engine braking mode during regenerative braking or engine braking.

Claims

1. A hybrid drive system for a motor vehicle, comprising:

a drive power source including an engine operated by combustion of a fuel, and a motor/generator operated with an electric energy;

an automatic transmission which is disposed between at least said engine of said drive power source and a drive wheel of the motor vehicle and which is shifted to change a speed ratio thereof in steps according to predetermined shift patterns;

regenerative braking means for applying to the motor vehicle a regenerative braking force corresponding to an amount of electric energy generated by said motor/generator during an operation of said motor/generator by a kinetic energy of the motor vehicle; and

shift inhibiting means for inhibiting a shifting action of said automatic transmission during an operation of said regenerative braking means, so as to prevent a change of an engine braking force which is applied to the motor vehicle due to a resistance to rotation of said engine.

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

manually operated member for establishing a drive-source braking mode in which said regenerative braking force and said engine braking force are applicable to the motor vehicle; and

regenerative brake adjusting means for changing said regenerative braking force generated by said regenerative braking means in said drive-source braking mode.

3. A hybrid drive system according to claim 2, wherein said manually operated member includes a shift lever having a plurality of operating positions including a drive position in which said automatic transmission is selectively placed in one of a plurality of forward-drive positions according to said predetermined shift patterns, and a drive-source driving position, said drive-source braking mode is established when said shift lever is operated from said drive position to said drive-source drive position.

4. A hybrid drive system according to claim 3, wherein said regenerative brake adjusting means includes said shift lever which further includes a position to which said shift lever is operable from said drive-source braking position for changing said regenerative braking force generated by said regenerative braking means.

5. A hybrid drive system for a motor vehicle, comprising:

a drive power source including an engine operated by combustion of a fuel, and a motor/generator operated with an electric energy;

an automatic transmission which is disposed between at least said engine of said drive power source and a drive wheel of the motor vehicle and whose speed ratio is variable;

regenerative braking means for applying to the motor vehicle a regenerative braking force corresponding to an amount of electric energy generated by said motor/generator during an operation of said motor/generator by a kinetic energy of the motor vehicle; and

braking shift control means operated when said regenerative braking means is inoperable to provide a required amount of said regenerative braking force, for changing the speed ratio of said automatic transmission to increase an engine braking force which is generated by a resistance to rotation of said engine and which is applied to the motor vehicle.

6. A hybrid drive system according to claim 5, wherein said braking shift control means is operated when said regenerative braking means is inoperable due to an abnormality thereof.

7. A hybrid drive system according to claim 5, wherein said braking shift control means is operated when the regenerative braking force generated by said motor/generator is smaller than required by an operator of the motor vehicle.

8. A hybrid drive system according to claim 5, wherein said motor/generator is operated by an electric energy stored in an electric energy storage device, to drive the motor vehicle, said braking shift control means being operated when an amount of said electric energy stored in said electric energy storage device is larger than a predetermined upper limit.

9. A hybrid drive system according to claim 5, further comprising shift inhibiting means for inhibiting a shifting action of said automatic transmission during an operation of said regenerative braking means, so as to prevent a change of an engine braking force which is applied to the motor vehicle due to a resistance to rotation of said engine.

10. A hybrid drive system according to claim 5, further comprising:

manually operated member for establishing a drive-source braking mode in which said regenerative braking force and said engine braking force are applicable to the motor vehicle; and

regenerative brake adjusting means for changing said regenerative braking force generated by said regenerative braking means in said drive-source braking mode.

11. A hybrid drive system according to claim 10, wherein said manually operated member includes a shift lever having a plurality of operating positions including a drive position in which said automatic transmission is selectively placed in one of a plurality of forward-drive positions according to said predetermined shift patterns, and a drive-source driving position, said drive-source braking mode is established when said shift lever is operated from said drive position to said drive-source drive position.

12. A hybrid drive system according to claim 11, wherein said regenerative brake adjusting means includes said shift lever which further includes a position to which said shift lever is operable from said drive-source braking position for changing said regenerative braking force generated by said regenerative braking means.

13. A hybrid drive system of a motor vehicle, comprising:

a drive power source including an engine operated by combustion of a fuel, and a motor/generator operated with an electric energy;

an automatic transmission which is disposed between at least said engine of said drive power source and a drive wheel of the motor vehicle and whose speed ratio is variable;

regenerative braking means for applying to the motor vehicle a regenerative braking force corresponding to an amount of electric energy generated by said motor/generator during an operation of said motor/generator by a kinetic energy of the motor vehicle; and

braking shift control means operated prior to an operation of said regenerative braking means, for controlling the speed ratio of said automatic transmission, so that an engine braking force generated by a resistance to rotation of said engine is applied to the motor vehicle.

14. A hybrid drive system according to claim 13, further comprising:

manually operated member for establishing a drive-source braking mode in which said regenerative braking force and said engine braking force are applicable to the motor vehicle; and

regenerative brake adjusting means for changing said regenerative braking force generated by said regenerative braking means in said drive-source braking mode.

15. A hybrid drive system according to claim 14, wherein said manually operated member includes a shift lever having a plurality of operating positions including a drive position in which said automatic transmission is selectively placed in one of a plurality of forward-drive positions according to said predetermined shift patterns, and a drive-source driving position, said drive-source braking mode is established when said shift lever is operated from said drive position to said drive-source drive position.

16. A hybrid drive system according to claim 15, wherein said regenerative brake adjusting means includes said shift lever which further includes a position to which said shift lever is operable from said drive-source braking position for changing said regenerative braking force generated by said regenerative braking means.

17. A hybrid drive system of a motor vehicle, comprising:

a drive power source including an engine operated by combustion of a fuel, and a motor/generator operated with an electric energy;

an automatic transmission which is disposed between at least said engine of said drive power source and a drive wheel of the motor vehicle and whose speed ratio is variable;

clutch means disposed between said automatic transmission and said engine, for selectively connecting and disconnecting said automatic transmission and said engine to and from each other;

regenerative braking means for applying to the motor vehicle a regenerative braking force corresponding to an amount of electric energy generated by said motor/generator during an operation of said motor/generator by a kinetic energy of the motor vehicle; and

clutch engaging means for engaging said clutch means to connect said automatic transmission and said engine to each other during an operation of said regenerative braking means.

18. A hybrid drive system according to claim 17, wherein said automatic transmission is shifted to change the speed ratio thereof in steps according to predetermined shift patterns, said hybrid drive system further comprising shift inhibiting means for inhibiting a shifting action of said automatic transmission during the operation of said regenerative braking means, so as to prevent a change of an engine braking force which is applied to the motor vehicle due to a resistance to rotation of said engine.

19. A hybrid drive system according to claim 17, further comprising braking shift control means operated when said regenerative braking means is inoperable to provide a required amount of said regenerative braking force, for changing the speed ratio of said automatic transmission to increase an engine braking force which is generated by a resistance to rotation of said engine and which is applied to the motor vehicle.

20. A hybrid drive system according to claim 17, further comprising:

manually operated member for establishing a drive-source braking mode in which said regenerative braking force and said engine braking force are applicable to the motor vehicle; and

regenerative brake adjusting means for changing said regenerative braking force generated by said regenerative braking means in said drive-source braking mode.

21. A hybrid drive system according to claim 20, wherein said manually operated member includes a shift lever having a plurality of operating positions including a drive position in which said automatic transmission is selectively placed in one of a plurality of forward-drive positions according to said predetermined shift patterns, and a drive-source driving position, said drive-source braking mode is established when said shift lever is operated from said drive position to said drive-source drive position.

22. A hybrid drive system according to claim 21, wherein said regenerative brake adjusting means includes said shift lever which further includes a position to which said shift lever is operable from said drive-source braking position for changing said regenerative braking force generated by said regenerative braking means.

23. A hybrid drive system for a motor vehicle, comprising:

a drive power source including an engine operated by combustion of a fuel, and a motor/generator;

regenerative braking means operated in a regenerative braking mode, for applying to the motor vehicle a regenerative braking force corresponding to an amount of electric energy generated by said motor/generator during an operation of said motor/generator by a kinetic energy of the motor vehicle;

engine braking means operated in an engine braking mode, for applying to the motor vehicle an engine braking force corresponding to a resistance to rotation of said engine when said engine is operated by the kinetic energy of the motor vehicle;

said regenerative braking mode and said engine braking mode being selectively established under respective running conditions of the motor vehicle; and

mode change inhibiting means for inhibiting a change between said regenerative braking mode and said engine braking mode while one of said regenerative braking means and said engine braking means is operated.

24. A hybrid drive system according to claim 23, further comprising an automatic transmission which is disposed between said drive power source and a drive wheel of the motor vehicle and whose speed ratio is variable, and wherein said engine braking means comprises means operated in said engine braking mode, for changing the speed ratio of said automatic transmission to apply said engine braking force to the motor vehicle, said regenerative braking means comprising means operated in said regenerative braking mode, for controlling the electric energy generated by said motor/generator so that said regenerative braking force is substantially equal to the engine braking force generated by changing said speed ratio.