Shift control apparatus and method for automatic transmission of vehicle

• US 20070270279A1
• Filed: 05/07/2007
• Published: 11/22/2007
• Est. Priority Date: 05/22/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kondo, Masami, Saitoh, Hidenori
• Granted Patent: US 7,695,404 B2
• Time in Patent Office: Days
• US Class Current: 477/110
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: F16H 2061/163 Holding the gear for delaying gear shifts under unfavorable conditions, e.g. during cornering
• CPC Class Codes: F16H 2300/14 Selecting a state of operation, e.g. depending on two wheel or four wheel drive mode
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/10 Controlling shift hysteresis
• 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

Abstract

When a n speed prohibition command is being output from the AI shift controlling means, the AI shift control is performed even in the S mode if the vehicle speed V is lower than the reference vehicle speed Vn, whereby busy shifting can be effectively prevented when the vehicle is running on an uphill road or cornering. When the vehicle speed V is equal to or higher than the reference vehicle speed Vn, the AI shift control is cancelled, thus minimizing the possibility of a large engine brake force being applied to the vehicle despite the intention of the driver.

Claims

1. A shift control apparatus for an automatic transmission for a vehicle, the automatic transmission having an automatic shift mode in which the automatic transmission is automatically shifted using an entire shift range of the automatic transmission in a predetermined shift manner and a manual shift mode in which the shift range of the automatic shifting that is performed in the predetermined shift manner is limited in response to a manual operation of a driver, the automatic shift mode and the manual shift mode being selectable by the driver, the shift control apparatus comprising:

a shift manner changing portion that changes the shift manner based on at least one of a running condition of a vehicle and an operation by the driver; and

a change limiting portion that prohibits the shift manner to be changed by the shift manner changing portion, wherein

the shift manner changing portion changes the shift manner in both the automatic shift mode and the manual shift mode, and

the change limiting portion prohibits the shift manner to be changed by the shift manner changing portion when a speed of the vehicle is equal to or higher than a reference vehicle speed in the manual shift mode.

2. The shift control apparatus according to claim 1, wherein

the reference vehicle speed is set such that the shift manner is prohibited to be changed by the shift manner changing portion when the speed of the vehicle is in a vehicle speed range in which a drive power source is placed in a predetermined driven state if the shift manner is changed.

3. The shift control apparatus according to claim 1, wherein

the shift manner changing portion performs a control for changing the shift manner so as to prevent busy shifting of the automatic transmission that is caused when the automatic transmission is automatically shifted and a control for changing the shift manner so as to obtain a desired drive power source brake force, the busy-shifting preventing control and the drive power source brake control being performed cooperatively.

4. The shift control apparatus according to claim 2, wherein

the shift manner changing portion performs a control for changing the shift manner so as to prevent busy shifting of the automatic transmission that is caused when the automatic transmission is automatically shifted and a control for changing the shift manner so as to obtain a desired drive power source brake force, the busy-shifting preventing control and the drive power source brake control being performed cooperatively.

5. The shift control apparatus according to claim 1, wherein

the reference vehicle speed is set for each speed of the automatic transmission that the shift manner changing portion prohibits to be used, on the assumption that an accelerator is fully released.

6. The shift control apparatus according to claim 1, wherein

the reference vehicle speed is set for each speed of the automatic transmission that the shift manner changing portion prohibits to be used, using an operation amount of an accelerator as a parameter.

7. A shift control method for an automatic transmission for a vehicle, the automatic transmission having an automatic shift mode in which the automatic transmission is automatically shifted using an entire shift range of the automatic transmission in a predetermined shift manner and a manual shift mode in which the shift range of the automatic shifting that is performed in the predetermined shift manner is limited in response to a manual operation of a driver, the automatic shift mode and the manual shift mode being selectable by the driver, the shift control method comprising:

changing the shift manner in both the automatic shift mode and the manual shift mode based on at least one of a drive condition of a vehicle and an operation by the driver; and

prohibiting the shift manner to be changed when a speed of the vehicle is equal to or higher than a reference vehicle speed in the manual shift mode.

8. A shift control apparatus for an automatic transmission for a vehicle, the automatic transmission having an automatic shift mode in which the automatic transmission is automatically shifted using an entire shift range of the automatic transmission in a predetermined shift manner and a manual shift mode in which the shift range of the automatic shifting that is performed in the predetermined shift manner is limited in response to a manual operation of a driver, the automatic shift mode and the manual shift mode being selectable by the driver, the shift control apparatus comprising:

shift manner changing means for changing the shift manner based on at least one of a drive condition of a vehicle and an operation by the driver; and

change limiting means for prohibiting the shift manner to be changed by the shift manner changing means, wherein

the shift manner changing means changes the shift manner in both the automatic shift mode and the manual shift mode, and

the change limiting means prohibits the shift manner to be changed by the shift manner changing means when a speed of the vehicle is equal to or higher than a reference vehicle speed in the manual shift mode.