Control device and method for automatic transmission

• US 5,476,425 A
• Filed: 10/12/1993
• Issued: 12/19/1995
• Est. Priority Date: 10/13/1992
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kimura, Hiroshi, Ozaki, Naoyuki, Minowa, Toshimichi, Shiraishi, Takashi
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Kwon, Peter
• Application Number:
  US08/134,614
• Time in Patent Office: 798 Days
• Field of Search: 477/107, 477/109, 477/110, 477/121, 477/97
• US Class Current: 477/109
• 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 2510/104 Output speed
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: B60W 2710/0666 Engine torque
• 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: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2061/0096 using a parameter map
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 63/502 for smoothing gear shifts
• CPC Class Codes: Y10S 477/902 Control signal is engine parameter other than manifold pressure or fuel control

Abstract

In an attempt to accomplish an object to absorb a driving torque difference caused by a difference in a change gear ratio between before and after shifting and to reduce a shift shock, adopted is such a constitution that target driving torque characteristics with which said driving torque before and after shifting will become nearly equal are stored, and engine torque control will be effected according to said characteristics. The control device is so constituted that, during shifting, the engine torque is decreased to suppress a driving torque variation resulting from inertia variation, and the engine torque before a specific period from the completion of shifting is outputted higher than the normal torque, and the engine torque before a specific period from the completion of shifting is outputted higher than the normal torque to reset to the normal engine torque after the specific period after the completion of shifting.

Claims

1. A control device for an automatic transmission having a control means for controlling an engine torque and a transmission control means for controlling said automatic transmission, said control device utilizing a targeted engine torque as a function of a targeted driving torque and a torque converter characteristic, and comprising:

a means for setting a driving torque immediately before starting shifting and a driving torque immediately after the completion of shifting at a nearly equal value, and a means for restraining torque variation during shifting.

2. A control device for an automatic transmission according to claim 1, wherein said control means for controlling said engine torque is an electronically controlled throttle valve.

3. A control device for an automatic transmission according to claim 1, wherein said control means for controlling said engine torque is a large-capacity idle speed control valve.

4. A control device for an automatic transmission having a control means for controlling an engine torque, a transmission control means for controlling an automatic transmission, and a means for decreasing said engine torque during shifting to reduce a shift shock, said control device utilizing a targeted engine torque as a function of a targeted driving torque and a torque converter characteristic, and comprising:

a means for increasing said engine torque for a specific period before the completion of shifting greater than normal engine torque, and for resetting to a normal output said engine torque after a specific period after the completion of shifting.

5. A control device for an automatic transmission according to claim 4, wherein said control means for controlling said engine torque is an electronic throttle valve.

6. A control device for an automatic transmission according to claim 4, wherein said control means for controlling said engine torque is a large-capacity idle control valve.

7. A control device for an automatic transmission having a control means for controlling an engine torque, a transmission control means for controlling an automatic transmission, and a means for reducing an engine torque during shifting, said control device utilizing a targeted engine torque as a function of a targeted driving torque and a torque converter characteristic, and comprising:

a means for setting a driving torque immediately before the start of shifting an a driving torque immediately after the completion of shifting to a nearly equal value, and a means for increasing said engine torque for a specific period before the completion of shifting greater than a normal engine torque, and for resetting said engine torque after a specific period after the completion of shifting to a normal output.

8. A control method for controlling an engine torque and operation of an automatic transmission, comprising the steps of setting a driving torque immediately before the start of shifting and a driving torque immediately after the completion of shifting to a nearly equal value based on a targeted engine torque as a function of a targeted driving torque and a torque converter characteristic, and restraining torque variation during shifting.

9. A control method for an automatic transmission according to claim 8, wherein said engine torque is controlled by an electronically controlled throttle valve.

10. A control method for an automatic transmission according to claim 8, wherein said engine torque is controlled by a large-capacity idle speed control valve.

11. A control method for an automatic transmission for reducing a shift shock comprising the steps of controlling an engine torque by utilizing a targeted engine torque as a function of targeted driving torque and a torque converter characteristic, controlling operation of said automatic transmission, and deceasing said engine torque during shifting, increasing said engine torque for specific period before the completion of shifting greater than a normal engine torque, and resetting said engine torque after a specific period after the completion of shifting to a normal output.

12. A control method for an automatic transmission according to claim 11, wherein said engine torque is controlled by an electronically controlled throttle valve.

13. A control method for an automatic transmission according to claim 11, wherein said engine torque is controlled by a large-capacity idle control valve.

14. A control method for an automatic transmission, comprising the steps of controlling an engine torque utilizing a targeted engine torque as a function of targeted driving torque and a torque converter characteristic, controlling operation of said automatic transmission, and for decreasing said engine torque during shifting for the purpose of reducing a shift shock, setting a driving torque immediately before the start of shifting and a driving torque immediately after the completion of shifting, increasing said engine torque for a specific period before the completion of shifting greater than a normal engine torque, and resetting said engine torque after a specific period upon completion of shifting to a normal output.