Control device for vehicular drive system

• US 20080153661A1
• Filed: 12/19/2007
• Published: 06/26/2008
• Est. Priority Date: 12/25/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Shibata, Hiroyuki, Matsubara, Tooru, Akita, Taku
• Granted Patent: US 7,955,215 B2
• Time in Patent Office: Days
• US Class Current: 477/3
• 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 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 2220/42 with use of more than one motor
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• 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 10/101 Infinitely variable gearings
• 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 2710/0644 Engine speed
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2037/0873 with switching, e.g. to change ranges
• CPC Class Codes: F16H 3/728 with means to change ratio in the mechanical gearing
• CPC Class Codes: F16H 61/0437 by using electrical signals F16H61/0403 and F16H61/061 take precedence
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A vehicular drive system is disclosed as including an electrically operated differential portion (16) disposed in a power transmitting path between an engine (8) and drive wheels (38) for controlling an operating state of an electric motor (M), connected to a rotary element of a differential portion (11), for controlling a differential state between an input-shaft rotation speed and an output-shaft rotation speed, and a shifting portion (20) forming a part of the power transmitting path and functioning as a step-variable automatic shifting portion. A control device (40) performs a control of output torque of the electric motor during a downshift of the step-variable shifting portion so as to suppress a variation in the engine rotation speed. The control of output torque is performed so as to increase the output torque by inertia torque of the electric motor, thereby achieving a reduction in shifting shock.

Claims

1. A control device for a vehicular drive system including:

an electrically operated differential portion disposed in a power transmitting path between an engine and drive wheels for controlling an operating state of an electric motor connected to a rotary element of a differential portion for thereby controlling a differential state between an input-shaft rotation speed and an output-shaft rotation speed; and

a shifting portion forming a part of the power transmitting path and functioning as a step-variable automatic shifting portion;

the control device being comprised to perform a control of output torque of the electric motor during a downshift of the step-variable shifting portion so as to suppress a fluctuation in a rotation speed of the engine,

wherein, for the control of output torque of the electric motor, the control device increases the output torque by an inertia torque of the electric motor.

2. The control device for a vehicular drive system according to claim 1, wherein

the differential portion includes a differential mechanism including a first element connected to the engine, a second element connected to a first electric motor, and a third element connected to a power transmitting member, and a second electric motor disposed in the power transmitting path between the power transmitting member and the drive wheels;

the control device controls the output torque of the first electric motor so as to suppress the rotation speed of the engine during the downshift of the step-variable shifting portion; and

for the control of the first electric motor, the output torque is increased by the inertia torque of the first electric motor.

3. The control device for a vehicular drive system according to claim 2, wherein the control device calculates the inertia torque of the first electric motor based on a target rotation speed of the second electric motor appearing upon completion of the downshift, a target rotation speed of the engine appearing upon completion of the downshift, a rotation speed of the second electric motor before commencement of the shifting, and a target shifting time.

4. The control device for a vehicular drive system according to claim 2, wherein the control device calculates the inertia torque of the first electric motor based on a variation rate in an actual rotation speed of the second electric motor and a target rotation speed of the engine upon completion of the downshift.

5. The control device for a vehicular drive system according to claim 3, wherein the control device calculates the inertia torque of the first electric motor based on a variation rate in an actual rotation speed of the second electric motor and a target rotation speed of the engine upon completion of the downshift.

6. The control device for a vehicular drive system according to claim 2, wherein the control device performs the control of the output torque of the first electric motor when a variation rate of the rotation speed of the engine exceeds a given value.

7. The control device for a vehicular drive system according to claim 2, wherein the control device increases the output torque of the first electric motor by a given value before commencement of the inertia phase during execution of the downshift.

8. The control device for a vehicular drive system according to claim 1, wherein the control device renders the electrically operated differential portion operative as a continuously variable shifting mechanism by controlling the operating state of the electric motor.