CONTROL DEVICE FOR AUTOMATIC TRANSMISSION FOR VEHICLE

• US 20080182714A1
• Filed: 01/25/2008
• Published: 07/31/2008
• Est. Priority Date: 01/25/2007
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Muto, Akio, SAITOU, Yoshiharu
• Granted Patent: US 7,988,595 B2
• Time in Patent Office: Days
• US Class Current: 477/64
• CPC Class Codes: F16H 2061/145 for controlling slip, e.g. approaching target slip value
• CPC Class Codes: F16H 59/20 Kickdown
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 61/143 using electric control means

Abstract

A control device for an automatic transmission for a vehicle including a torque converter interposed between an output shaft of an engine and an input shaft of the automatic transmission, the torque converter having a lock-up clutch for mechanically connecting the output shaft and the input shaft in a direct manner, and a lock-up clutch engagement control unit for engaging the lock-up clutch by a predetermined engagement force in a predetermined operational region determined by a throttle angle and a vehicle speed. The control device further includes a shift map having a slip region for the lock-up clutch set in relation to a plurality of shift characteristics preliminarily set according to vehicle speeds, the slip region being defined by a downshift line and a slip start line deviated from the downshift line by a predetermined range of throttle angle toward lower throttle angles. When the throttle angle falls within the slip region before kickdown, the slip control of the lock-up clutch is performed by the lock-up clutch engagement control unit.

Claims

1. A control device for an automatic transmission for a vehicle, comprising:

a torque converter interposed between an output shaft of an engine and an input shaft of said automatic transmission, said torque converter having a lock-up clutch for mechanically connecting said output shaft and said input shaft in a direct manner;

lock-up clutch engagement control means for engaging said lock-up clutch by a predetermined engagement force in a predetermined operational region determined by a throttle angle and a vehicle speed; and

a shift map having a slip region for said lock-up clutch set in relation to a plurality of shift characteristics preliminarily set according to vehicle speeds, said slip region being defined by a downshift line and a slip start line deviated from said downshift line by a predetermined range of throttle angle toward lower throttle angles;

wherein when the throttle angle falls within said slip region before kickdown, the slip control of said lock-up clutch is performed by said lock-up clutch engagement control means.

2. The control device according to claim 1, wherein when downshift is not performed within a predetermined period of time from the start of the slip control of said lock-up clutch, the slip control of said lock-up clutch is canceled to engage said lock-up clutch.

3. The control device according to claim 1, wherein said predetermined range of throttle angle is set wider on an uphill road than on a level road.