Lock-up control device for torque converter of automatic transmission

Abstract

A lock-up control device for a lock-up torque converter of an automatic transmission is provided which starts measuring an elapsed time when the throttle opening exceeds a first predetermined value due to depression of an accelerator pedal during lock-up clutch slip control. When the throttle opening exceeds a second predetermined value due to sudden depression of the accelerator pedal prior to the elapse of a determination time, a transmission controller terminates the lock-up clutch slip control. After a rapid increase, the slip amount starts decreasing upon termination of the lock-up clutch slip control. Therefore, the temperature of a facing stops rising when the lock-up clutch slip control is terminated, and this improves the durability of the facing. The lock-up clutch slip control is re-started when the throttle opening is reduced to a predetermined value, and this maintains the excellent fuel economy performance.

Dependencies are inferred from the claim text.