Patent ID: 7951042

Claim:
A control device for an automatic transmission having a torque converter with a lock-up clutch provided between an engine and said automatic transmission, and a lock-up control device for controlling an engaged condition of said lock-up clutch, said control device comprising: a plurality of different target slip ratio maps each having a plurality of target slip ratio characteristic lines of said lock-up clutch predetermined according to a throttle angle; first map selecting means for selecting a first common target slip ratio map of said target slip ratio maps according to a running range and a gear position during running on a level road/downhill road in the condition where an accelerator pedal is depressed, and selecting one of said target slip ratio maps during running on an uphill road in the condition where an accelerator pedal is depressed, said first common target slip ratio map being common to the level road and downhill road; and second map selecting means for selecting a second common target slip ratio map of said target slip ratio maps according to a running range and the gear position during running on a level road/uphill road in the condition where an accelerator pedal is undepressed, and selecting one of said target slip ratio maps during running in the condition where said accelerator pedal is undepressed, said second common target slip ratio map being common to the level road and the uphill road, wherein a manual mode range for performing a shift operation instructed by a manual operation of a driver is settable, said first map selecting means selects said target slip ratio maps according to the gear position during running on the level road/downhill road and in the manual mode range in a case where the rotational speed of an input shaft in the automatic transmission is less than a first predetermined speed, and selects only one target slip ratio map in the manual mode range in a case where the rotational speed of the input shaft in the automatic transmission is greater than a second predetermined speed which is greater than said first predetermined speed; said first map selecting means changes a target slip ratio map to select from said target slip ratio maps during running on the uphill road in a case where the rotational speed of the input shaft in the automatic transmission is less than a third predetermined speed and in a case where the rotational speed of the input shaft in the automatic transmission is greater than a fourth predetermined speed which is greater than the third predetermined speed, and said second map selecting means selects said target slip ratio maps during running on the level road/uphill road according to the gear position, and selects only one target slip ratio map of said target Slip ratio maps during running on the downhill road.