Driving control apparatus for vehicle and control method of same

• US 6,860,833 B2
• Filed: 09/11/2003
• Issued: 03/01/2005
• Est. Priority Date: 09/20/2002
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ayabe, Atsushi
• Primary Examiner(s): LEWIS, TISHA D
• Application Number:
  US10/659,311
• Publication Number:
  US 20040058779A1
• Time in Patent Office: 537 Days
• Field of Search: 477/118, 477/121, 701 53- 54
• US Class Current: 477/121
• 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 10/11 Stepped gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0628 Inlet air flow rate
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16H 2061/0496 for low engine torque, e.g. during coasting, sailing or engine braking
• CPC Class Codes: F16H 2306/42 Changing the input torque to the transmission
• CPC Class Codes: F16H 2306/44 Removing torque from current gears
• CPC Class Codes: F16H 2306/52 Applying torque to new gears
• CPC Class Codes: F16H 61/061 using electric control means
• CPC Class Codes: F16H 61/686 with orbital gears
• CPC Class Codes: F16H 63/502 : for smoothing gear shifts
• CPC Class Codes: Y02T 10/60 : Other road transportation technologies with climate change mitigation effect

Abstract

A driving control apparatus for a vehicle which includes an engine which generates power by fuel combustion; a transmission which changes engagement/disengagement states of plural frictional engagement devices so as to realize plural shift speeds whose gear ratios are different from each other; a fuel cut device which stops fuel supply to the engine when a predetermined fuel cut condition including a condition that the vehicle is coasting with a throttle valve of the engine being fully closed is satisfied; a coasting time disengagement restricting device which maintains a high speed side frictional engagement device in an engagement state until a low speed side frictional engagement device obtains a predetermined torque capacity at the time of automatic downshifting of the transmission during coasting; and a disengagement restriction stop device which stops control by the coasting time engagement restricting device so as to reduce a torque capacity of the high speed side frictional engagement device, when control by the fuel cut device is cancelled and fuel supply is restarted in the case where downshifting of the transmission is output while fuel supply is stopped by the fuel cut device and the high speed side frictional engagement device is maintained in the engagement state by the coasting time disengagement restricting device.

Claims

1. A driving control apparatus for a vehicle, comprising:

an engine which generates power by fuel combustion;

a transmission which changes engagement/disengagement states of plural frictional engagement devices so as to realize plural shift speeds whose gear ratios are different from each other;

a fuel cut device which stops fuel supply to the engine when a predetermined fuel cut condition including a condition that the vehicle is coasting with a throttle valve of the engine being fully closed is satisfied;

a coasting time disengagement restricting device which maintains a high speed side frictional engagement device in an engagement state until a low speed side frictional engagement device obtains a predetermined torque capacity at a time of automatic downshifting of the transmission during coasting; and

a disengagement restriction stop device which stops control by the coasting time disengagement restricting device so as to reduce a torque capacity of the high speed side frictional engagement device, when control by the fuel cut device is cancelled and fuel supply is restarted in a case where downshifting of the transmission is output while fuel supply is stopped by the fuel cut device and the high speed side frictional engagement device is maintained in the engagement state by the coasting time disengagement restricting device.

2. The driving control apparatus for a vehicle according to claim 1, wherein, in a case where downshifting of the transmission is output while fuel supply is stopped by the fuel cut device, and the high speed side frictional engagement device is maintained in the engagement state by the coating time disengagement restricting device, when control by the fuel cut device is cancelled and fuel supply is restarted, the disengagement restriction stop device stops control by the coasting time disengagement restricting device and reduces a torque capacity of the high speed side frictional engagement device to substantially zero.

3. The driving control apparatus for a vehicle according to claim 1, wherein a fuel cut start condition for stopping fuel supply to the engine is the same as a fuel cut cancellation condition for restarting the fuel supply in the fuel cut device.

4. The driving control apparatus for a vehicle according to claim 1, wherein an engine speed in a fuel cut start condition for stopping the fuel supply to the engine is higher than an engine speed in a fuel cut cancellation condition for restarting fuel supply by a predetermined value in the fuel cut device.

5. The driving control apparatus for a vehicle according to claim 1, wherein an engine speed in a fuel cut start condition for stopping the fuel supply to the engine is higher than an engine speed in a fuel cut cancellation condition for restarting the fuel supply by a predetermined rate in the fuel cut device.

6. The driving control apparatus for a vehicle according to claim 1, wherein a fuel cut start condition for stopping the fuel supply to the engine includes a condition that an operation amount of an accelerator pedal has been substantially zero for a predetermined time or more.

7. A driving control apparatus for a vehicle, comprising:

an engine which generates power by fuel combustion;

a transmission which changes engagement/disengagement states of plural frictional engagement devices so as to realize plural shift speeds whose gear ratios are different from each other; and

a controller which stops fuel supply to the engine when a predetermined fuel cut condition including a condition that the vehicle is coasting with a throttle valve of the engine being fully closed is satisfied;

which maintains a high speed side frictional engagement device in an engagement state until a low speed side frictional engagement device obtains a predetermined torque capacity at a time of automatic downshifting of the transmission during coasting; and

which stops control for maintaining the high speed side frictional engagement device in the engagement state during coasting, and reduces a torque capacity of the high speed side frictional engagement device when control of fuel cut is cancelled and fuel supply is restarted in a case where downshifting of the transmission is output while fuel supply is stopped and the high speed side frictional engagement device is maintained in the engagement state.

8. The driving control apparatus for a vehicle according to claim 7, wherein the controller stops control for maintaining the high speed side frictional engagement device in the engagement state during coasting, and reduces a torque capacity of the high speed side frictional engagement device to substantially zero when control of fuel cut is cancelled and fuel supply is restarted in the case where downshifting of the transmission is output while fuel supply is stopped and the high speed side frictional engagement device is maintained in the engagement state.

9. A control method of a driving control apparatus for a vehicle including an engine which generates power by fuel combustion, a transmission which changes engagement/disengagement states of plural frictional engagement devices so as to realize plural shift speeds whose gear ratios are different from each other, comprising the steps of:

stopping fuel supply to the engine when a predetermined fuel cut condition including a condition that the vehicle is coasting with a throttle valve of the engine being fully closed is satisfied;

maintaining a high speed side frictional engagement device in an engagement state until a low speed side frictional engagement device obtains a predetermined torque capacity at the time of automatic downshifting of the transmission during coasting; and

stopping control for maintaining the engagement state of the high speed side frictional engagement device during coasting so as to reduce the torque capacity of the high speed side frictional engagement device when control of the fuel cut is cancelled and fuel supply is restarted in a case where downshifting of the transmission is output while fuel supply is stopped and the high speed side frictional engagement device is maintained in the engagement state.

10. The control method of the driving control vehicle for a vehicle according to claim 9, further comprising the steps of:

stopping control for maintaining the high speed side frictional engagement device in the engagement state during coasting so as to reduce a torque capacity of the high speed side frictional engagement device to substantially zero when control of fuel cut is cancelled and fuel supply is restarted in a case where downshifting of the transmission is output while fuel supply is stopped and the high speed side frictional engagement device is maintained in the engagement state.

11. The control method of the driving control apparatus for a vehicle according to claim 9, wherein a fuel cut start condition for stopping fuel supply to the engine is the same as a fuel cut cancellation condition for restarting the fuel supply.

12. The control method of the driving control apparatus for a vehicle according to claim 9, wherein an engine speed in a fuel cut start condition for stopping fuel supply to the engine is higher than an engine speed in a fuel cut cancellation condition for restarting the fuel supply by a predetermined value.

13. The control method of the driving control apparatus for a vehicle according to claim 9, wherein an engine speed in a fuel cut start condition for stopping the fuel supply to the engine is higher than an engine speed in a fuel cut cancellation condition for restarting the fuel supply by a predetermined rate.

14. The control method of the driving control apparatus for a vehicle according to claim 9, wherein a fuel cut start condition for stopping the fuel supply to the engine is a condition that an operation amount of an accelerator pedal has been substantially zero for a predetermined time or more.