| 摘要 |
PURPOSE:To provide a lock-up clutch control device for an automatic transmission capable of coping with a vehicle with any gear ratio by the same control device by computing the ratio of the rotating speed of a countershaft to the rotating speed of a crankshaft, and operating a lock-up clutch when the computed result becomes equal to the lock-up set value. CONSTITUTION:At the normal travel time, lock-up control is started by manual operation or by a control device when a specified condition is materialized, and the output of a crankshaft rotation sensor 4 and a countershaft rotation sensor 5 is taken in to compute the ratio R of the rotating speed NC of a countershaft 16 to the rotating speed NC of a crankshaft 12. Whether this rotating speed ratio R coincides with the lock-up set value is discriminated, and in the affirmative case, an operation command is sent out to a fluid pressure cylinder from a control device 6 so as to press clutch plates 35, 36 into close contact by the fluid pressure cylinder for connection. That is, a lock-up clutch 3 is put in a direct-coupled state to couple a clutch shaft 12 directly to an input shaft 13, thus transmitting the power of an engine to the output shaft 8 side. |
