Control device for vehicular drive system

• US 20090118955A1
• Filed: 02/23/2005
• Published: 05/07/2009
• Est. Priority Date: 02/26/2004
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tabata, Atsushi, Taga, Yutaka
• Granted Patent: US 8,135,522 B2
• Time in Patent Office: Days
• US Class Current: 701/66
• 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 6/40 characterised by the assembly or relative disposition of components
• 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: 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 10/11 Stepped 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: F16H 2200/0047 the gear ratios comprising five forward speeds
• CPC Class Codes: F16H 2200/201 with three sets of orbital gears
• CPC Class Codes: F16H 2200/2048 with seven engaging means
• 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: F16H 61/686 with orbital gears
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A vehicular drive system switchable between a continuously-variable and step-variable shifting states, and a control device for controlling the vehicular drive system so as to reduce a shifting shock of an automatic transmission included in the drive system, which takes place due to an overlap control involving a switching control of the drive system and a shifting control of the automatic transmission.

Execution-timing control means 82 is provided to command switching control means 50 and step-variable shifting control means 54 to sequentially execute a switching control by the switching control means to switch transmission mechanism 10 between an electrically established continuously-variable shifting state and a step-variable shifting state, and a shifting control by the step-variable shifting control means to shift an automatic transmission portion 20, even when an overlap control involving the switching control and the shifting control is required, whereby the switching and shifting controls can be rapidly completed. Since the transmission mechanism 10 is not switched during the shifting control of the automatic transmission portion 20, the input speed of the automatic transmission portion 20 will not change due to the switching control, apart from a change of the input speed as a result of the shifting control, making it possible to prevent the complicated shifting control and reduce the consequent shifting shock.

Claims

1. A control device for a vehicular drive system arranged to transmit an output of an engine to a drive wheel of a vehicle, characterized by comprising:

a switchable type transmission mechanism switchable between a continuously-variable shifting state in which the switchable type transmission mechanism is operable as an electrically controlled continuously variable transmission, and a step-variable shifting state in which the switchable type transmission mechanism is operable as a step-variable transmission;

switching control means for placing said switchable type transmission mechanism selectively in one of said continuously-variable shifting state and said step-variable shifting state, on the basis of a predetermined condition of the vehicle;

shifting control means for controlling a shifting operation of an automatic transmission included in the switchable type transmission mechanism, on the basis of the condition of the vehicle; and

execution-timing control means for commanding said switching control means and said shifting control means to sequentially execute a switching control by said switching control means and a shifting control by said shifting control means, even when an overlap control involving said switching control and said shifting control is required.

2. The control device according to claim 1, wherein said execution-timing control means commands said switching control means to execute said switching control first.

3. The control device according to claim 1, wherein said execution-timing control means commands said shifting control means to execute said shifting control first.

4. The control device according to claim 1, wherein said execution-timing control means determines one of said switching control by said switching control means and said shifting control by said shifting control means which should be executed before the other of said switching and shifting controls, on the basis of the condition of the vehicle.

5. The control device according to claim 1, wherein said execution-timing control means determines one of said switching control by said switching control means and said shifting control by said shifting control means which should be executed before the other of said switching and shifting controls, on the basis of one the continuously-variable and step-variable shifting states in which said switchable type transmission mechanism is presently placed.

6. The control device according to claim 1, wherein said execution-timing control means determines one of said switching control by said switching control means and said shifting control by said shifting control means which should be executed before the other of said switching and shifting controls, on the basis of one of the continuously-variable and step-variable shifting states to which said switchable type transmission mechanism is to be switched.

7. The control device according to any one of claims 1-6, wherein said predetermined condition of the vehicle is determined on the basis of a predetermined upper limit value of a running speed of the vehicle, and said switching control means places said switchable type transmission mechanism in said step-variable shifting state when an actual value of the running speed of the vehicle is higher than said predetermined upper limit value.

8. The control device according to any one of claims 1-7, wherein said predetermined condition of the vehicle is determined on the basis of a predetermined upper limit value of a drive-force-related value of the vehicle, and said switching control means places said switchable type transmission mechanism in said step-variable shifting state when said drive-force-related value of the vehicle is higher than said predetermined upper limit value.

9. The control device according to any one of claims 1-8, wherein said predetermined condition of the vehicle is determined on the basis of an actual value of a running speed of the vehicle and an actual value of a drive-force-related value of the vehicle and according to a stored switching boundary line map including a high-speed-running boundary line and a high-output-running boundary line which are defined by parameters in the form of said running speed of the vehicle and said drive-force-related value.

10. The control device according to any one of claims 1-9, wherein said predetermined condition of the vehicle is a functional-deterioration determining condition which is satisfied when a function of any one of control components for placing said switchable type transmission mechanism in the electrically established continuously-variable shifting state is deteriorated, and said switching control means places said switchable type transmission mechanism in said step-variable shifting state when said functional-deterioration determining condition is satisfied.

11. The control device according to any one of claims 1-10, wherein said switchable type transmission mechanism includes a power distributing mechanism having a first element fixed to said engine, a second element fixed to a first electric motor, and a third element fixed to a second electric motor and a power transmitting member,

and wherein said power distributing mechanism includes an operating-state switching device operable to switch said switchable type transmission mechanism between said continuously-variable and step-variable shifting states,

and said switching control means controls said operating-state switching device to thereby switch said switchable type transmission mechanism between said continuously-variable and step-variable shifting states.

12. The control device according to claim 11, wherein said operating-state switching device includes a coupling device operable to connect any two of said first through third elements to each other, and/or fix said second element to a stationary member,

and wherein said switching control means places said switchable type transmission mechanism in said continuously-variable shifting state by releasing said coupling device to thereby permit said first element, said second element and said third element to be rotated relative to each other, and places said switchable type transmission mechanism in said step-variable shifting state by engaging said coupling device to thereby connect at least two of said first element, said second element and said third element to each other or fix said second element to said stationary member.

13. The control device according to claim 12, wherein said power distributing mechanism is a planetary gear set, and said first element is a carrier of said planetary gear set, said second element is a sun gear of said planetary gear set, and said third element is a ring gear of said planetary gear set,

and wherein said coupling device includes a clutch operable to connect any two of said carrier, sun gear and ring gear to each other, and/or a brake operable to fix said sun gear to said stationary member.

14. The control device according to claim 13, wherein said planetary gear set is of a single-pinion type.

15. The control device according to claim 14, wherein said switching control means controls said coupling device to connect said carrier and said sun gear to each other, to thereby enable said planetary gear set of the single-pinion type to operate as a transmission having a speed ratio of 1, or fix said sun gear to said stationary member, to thereby enable said planetary gear set of the single-pinion type to operate as a speed-increasing transmission having a speed ratio lower than 1.

16. The control device according to any one of claims 11-15, wherein said automatic transmission is disposed between said power transmitting member and said drive wheel and connected in series to said power distributing mechanism, and said switchable type transmission mechanism has a speed ratio determined by a speed ratio of said automatic transmission.

17. The control device according to claim 16, wherein said switchable type transmission mechanism has an overall speed ratio determined by a speed ratio of the power distributing mechanism and the speed ratio of said automatic transmission.

18. The control device according to claim 16 or 17, wherein said automatic transmission is a step-variable automatic transmission which is shifted according to a stored shifting boundary line map.