Vehicle power transmitting system having devices for electrically and mechanically disconnecting power source and vehicle drive wheel upon selection of neutral state

• US 5,887,670 A
• Filed: 05/14/1997
• Issued: 03/30/1999
• Est. Priority Date: 05/16/1996
• 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): Dayoan, D. Glenn
• Assistant Examiner(s): HAMILTON, CLOVIA A
• Application Number:
  US08/856,188
• Time in Patent Office: 685 Days
• Field of Search: 180/65.1, 180/65.2, 180/65.3, 180/65.6
• US Class Current: 180/65.25
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/04 including control of propulsion units
• 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 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: F16H 2200/0043 the gear ratios comprising four forward speeds
• CPC Class Codes: F16H 2200/0047 the gear ratios comprising five forward speeds
• CPC Class Codes: F16H 2200/2005 with one sets of orbital gears
• CPC Class Codes: F16H 2200/2012 with four sets of orbital gears
• CPC Class Codes: F16H 2200/2015 with five sets of orbital gears
• CPC Class Codes: F16H 3/006 power being selectively transmitted by either one of the parallel flow paths
• CPC Class Codes: F16H 3/725 with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/91 Orbital, e.g. planetary gears
• 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 power transmitting system for a motor vehicle having a manually operated member for selecting one of operating states of the power transmitting system, which include a neutral state, wherein a power transmitting path between a drive power source and a drive wheel of the motor vehicle is electrically disconnected by a first power disconnecting device, and is mechanically disconnected by a second power disconnecting device which is operated in response to an operation the manually operated member to the neutral state. Also disclosed is a hybrid drive system including a start-up control device operated upon operation of the manually operated member from a non-drive state to a drive state, for controlling the reaction torque of a motor/generator to rise according to one of predetermined rise characteristics which is selected depending upon a vehicle running condition.

Claims

1. A power transmitting system for a motor vehicle, comprising:

a drive power source for driving the motor vehicle;

first power disconnecting means for electrically disconnecting a power transmitting path between said drive power source and a drive wheel of the motor vehicle;

manually operated selecting means for selecting one of a plurality of operating states of the power transmitting system, said operating states including a neutral state; and

second power disconnecting means responsive to an operation of said manually operated selecting means to said neutral state, for mechanically disconnecting said power transmitting path.

2. A power transmitting system according to claim 1, further comprising an automatic transmission having a plurality of operating positions, and wherein said second power disconnecting means includes:

hydraulically operated clutch means having a connecting state and a disconnecting state for connecting and disconnecting said power transmitting path, respectively;

a manual shift valve for shifting said automatic transmission in response to an operation of said manually operated selecting means; and

a linkage for mechanically connecting said manually operated selecting means and said manual shift valve such that said manual shift valve is moved to a position for establishing said disconnecting state of said hydraulically operated clutch means when said manually operated selecting means is operated to said neutral state to place said automatic transmission in a neutral state.

3. A power transmitting system according to claim 1, wherein said drive power source includes an engine and an electric motor, said power transmitting system further comprising an electrically controlled torque converter which includes said electric motor and a planetary gear mechanism, said first power disconnecting means including clutches incorporated in said torque converter, for disconnecting said power transmitting path between said drive power source and said drive wheels when said manually operated selecting means is operated to said neutral state.

4. A power transmitting system according to claim 1, wherein said first power disconnecting means is operated to electrically disconnect said power transmitting path when said manually operated selecting means is operated to said neutral state.

5. A power transmitting system according to claim 1, wherein said power drive source includes an engine and an electric motor, and wherein said first power disconnecting means includes means for establishing an electrically neutral state of the power transmitting system in which said electric motor is in a non-load condition with a rotor shaft thereof being freely rotatable, to electrically disconnect said power transmitting path.

6. A power transmitting system for a motor vehicle, comprising:

an engine operated by combustion of a fuel;

a motor/generator having a function of at least one of an electric motor and an electric generator, said motor/generator having a rotor shaft;

a synthesizing/distributing mechanism for mechanically synthesizing and distributing forces, said synthesizing/distributing mechanism having a first rotary element connected to said engine, a second rotary element connected to said motor/generator, a third rotary element, and an output member from which an output of said synthesizing/distributing mechanism is produced;

first power disconnecting means for placing said motor/generator in a non-load condition in which said rotor shaft is freely rotatable, to thereby electrically disconnect a power transmitting path between said engine and said output member;

manually operated selecting means for selecting one of a plurality of operating states of the power transmission system, said operating states including a neutral state; and

second power disconnecting means responsive to an operation of said manually operated selecting means to said neutral state, for mechanically disconnecting said power transmitting path.

7. A power transmitting system according to claim 6, wherein said first power disconnecting means includes a first clutch for connecting said engine and said first rotary element, and a second clutch for connecting two elements of said first, second and third rotary elements, for rotating said synthesizing/distributing mechanism as a unit, said first power disconnecting means engaging said first clutch and releasing said second clutch, and placing said motor/generator in said non-load condition, to thereby place said motor/generator in an electrically neutral state.

8. A power transmitting system according to claim 7, further comprising a hybrid drive controller for releasing said first clutch and engaging said second clutch, to thereby establish a motor drive mode in which said motor/generator is operated as the drive power source for running the motor vehicle, said hybrid drive controller engaging said first and second clutches while placing said motor/generator in said non-load condition, to thereby establish an engine drive mode in which said engine is operated as the drive power source for running the motor vehicle.

9. A power transmitting system according to claim 6, wherein said synthesizing/distributing mechanism includes a planetary gear mechanism having a ring gear as said first rotary element, a sun gear as said secondary rotary element, and a carrier as said third rotary element.

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

an engine operated by combustion of a fuel;

a motor/generator;

a synthesizing/distributing mechanism for mechanically synthesizing and distributing forces, said synthesizing/distributing mechanism having a first rotary member connected to said engine, a second rotary member connected to said motor/generator, a third rotary element, and an output member from which an output of said synthesizing/distributing mechanism is produced;

manually operated selecting means for selecting one of a non-drive state and a drive state;

electrically neutralizing means responsive to an operation of said manually operated selecting means to said non-drive state, for establishing an electrically neutral state of the hybrid drive system in which said motor/generator is in a non-load condition with said second rotary element being freely rotatable, to electrically disconnect a power transmitting path between said engine and said output member; and

start-up control means responsive to an operation of said selecting means from said non-drive state to said drive state, for increasing a reaction torque of said motor/generator from zero, to thereby transmit power from said engine to said output member, said start-up control means controlling the reaction torque of said motor/generator to rise according to one of a plurality of predetermined different rise characteristics which is selected depending upon a running condition of the motor vehicle.

11. A hybrid drive system according to claim 10, wherein said start-up control means controls the reaction torque of the motor/generator to rise at a lower rate when a speed of said engine or said motor/generator is higher than a predetermined threshold, than when the speed of said engine or said motor/generator is not higher than said threshold.

12. A hybrid drive system according to claim 10, wherein said start-up control means inhibits a rise of said reaction torque of the motor/generator while a speed of said engine or said motor/generator is higher than a predetermined threshold.

13. A hybrid drive system according to claim 10, wherein said start-up control means controls said reaction torque of the motor/generator such that an amount of rise of said reaction torque is smaller when a speed of said engine or said motor/generator is higher than a predetermined threshold than when the speed of said engine or said motor/generator is not higher than said threshold.

14. A hybrid drive system according to claim 10, wherein said drive state selectable by said manually operated selecting means includes a forward drive state and a reverse drive state, and said start-up control means selects said one of the plurality of predetermined different rise characteristics, depending upon whether said manually operated selecting means is operated from said non-drive state to said forward drive state or to said reverse drive state, said hybrid drive system further comprising power transmitting device disposed between said synthesizing/distributing mechanism and a drive wheel of the motor vehicle, said power transmitting device having a non-drive state which is established to disconnect a power transmitting path between said engine and said drive wheel when said selecting means is operated to said non-drive state, a forward drive state which is established to drive the motor vehicle in a forward direction when said selecting means is operated to said forward drive state, and a reverse drive state which is established to drive the motor vehicle in a reverse direction when said selecting means is operated to said reverse drive state.

15. A hybrid drive system according to claim 10, further comprising drive mode selecting means for selecting one of a plurality of vehicle drive modes including a low friction coefficient road drive mode in which the vehicle vehicle is run on a road surface whose friction coefficient is lower than a predetermined threshold, and wherein said start-up control means controls said reaction torque of said motor/generator such that an amount of rise of said reaction torque is smaller when said low friction coefficient road drive mode is selected by said drive mode selecting means, than when said low friction coefficient road drive mode is not selected.

16. A hybrid drive system according to claim 10, wherein said start-up control means controls said reaction torque of said motor/generator in a feedback fashion such that a physical value which changes in relation to said reaction torque coincides with a predetermined target value.

17. A hybrid drive system according to claim 10, wherein said start-up control means controls said reaction torque of said motor/generator so as to coincide with a target value which is updated by learning compensation on the basis of a result of control of the reaction torque by said start-up control means.

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

a drive power source for driving the motor vehicle, said drive power source including an engine operated by combustion of a fuel, and a motor/generator;

manually operated selecting means for selecting one of a non-drive state and a drive state;

power transmitting device disposed between said drive power source and a drive wheel of the motor vehicle, said power transmitting device having a non-drive state which is established to disconnect a power transmitting path between said engine and.said drive wheel when said selecting means is operated to said non-drive state, and a drive state which is established to drive the motor vehicle when said selecting means is operated to said drive state; and

vehicle drive motor control means responsive to an operation of said manually operated selecting means, for controlling said motor/generator so as to reduce an input speed of said power transmitting device, when said input speed is expected to be higher than a predetermined threshold if said motor/generator is not controlled by said vehicle drive motor control means.

19. A hybrid drive system according to claim 18, wherein said vehicle drive motor control means reduces a torque of said motor/generator when power is transmitted to said power transmitting device on the basis of an output of said motor/generator.

20. A hybrid drive system for a motor vehicle, including:

a drive power source for driving the motor vehicle, said drive power source including an engine operated by combustion of a fuel, and a motor/generator;

manually operated selecting means for selecting one of a non-drive state and a drive state;

power transmitting device disposed between said drive power source and a drive wheel of the motor vehicle, said power transmitting device having a non-drive state which is established to disconnect a power transmitting path between said engine and said drive wheel when said selecting means is operated to said non-drive state, and a drive state which is established to drive the motor vehicle when said selecting means is operated to said drive state; and

input restricting means responsive to an operation of said manually operated selecting means, for restricting transmission of power between said drive power source and said power transmitting device, when said input speed is expected to be higher than a predetermined threshold if said said transmission of power is not restricted by said input restricting means.