LOCK-UP CONTROLLER FOR AUTOMATIC TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To prevent useless early releasing while preventing an engine stall by releasing a lock-up clutch without delay during speed reduction. SOLUTION: A reduction speedΔVSP is calculated as the changing amount of a car speed VSP (S1), and when the car speed VSP is higher, a reference reduction speedΔVSPth is set larger (S2). When the reduction speedΔVSP exceeds the reference reduction speedΔVSPth (S3), a lock-up clutch is forcibly released (S4). The reference reduction speedΔVSPth may be set according to the slip rate of the lock-up clutch or the transmission ratio of a transmission other than the car speed VSP.