| 摘要 |
A lock-up control device is provided to control the engaging and release of a lock-up clutch, which is arranged in parallel with a torque converter to transmit driving force of an engine of a car. Herein, target driving force is calculated (1) based on accelerator pedal opening (AP) and car velocity (V). A present shift position is detected (2) using a shift map based on accelerator pedal opening (AP), car velocity (V) and engine speed (NE). Target engine torque is calculated (3) based on the target driving force and present shift position as well as a torque amplification ratio, which is detected when the torque converter is placed in a torque amplification state. A lock-up release instruction is issued (5) under conditions that the torque converter is placed in the torque amplification state while the target engine torque is greater than a preset value, which is determined in advance based on a torque characteristic of the engine. In addition, under the condition that the engaging of the lock-up clutch is released (6), the device makes a decision as to whether a shift-down operation (8) is performed or not. Herein, accumulation is performed on the accelerator pedal opening under the condition that the target engine torque is greater than the preset value. So, a shift-down instruction is issued under the condition that an accumulated value of the accelerator pedal opening exceeds a threshold value in accumulation of the accelerator pedal opening. <IMAGE> |
