Patent ID: 6512971
Filing Date: 2003-01-28
Classification: F16H,Y10T

Abstract:
A lock-up control apparatus for an automatic transmission having a torque converter between an engine and a transmission mechanism, in which the torque converter includes a lock-up clutch for directly coupling an output shaft of the engine and an input shaft of the transmission mechanism, said lock-up control apparatus comprising:an engine speed sensor for detecting speed of the engine output shaft; an input shaft speed sensor for detecting speed of the input shaft; lock-up clutch control means for determining that engagement of the lock-up clutch should be initiated when the detected speed of the engine shaft is lower than the detected speed of the input shaft and, when a determination is made that engagement of the lock-up clutch should be initiated, determining a difference between the engine shaft speed detected by said engine speed sensor and the input shaft speed detected by said input shaft speed sensor, and comparing the determined difference with a predetermined range; lock-up clutch driving means for engaging the lock-up clutch by hydraulic pressure responsive to signals from said lock-up clutch control means; and engine speed control means for increasing the engine speed to bring the difference between the engine shaft speed and the input shaft speed to within the predetermined range prior to completion of engagement of the lock-up clutch by the lock-up clutch driving means, responsive to determination of a speed difference which exceeds the predetermined range.