Lockup clutch control system
AssigneeAisin Seiki Kabushiki Kaisha
InventorsShoji Kawata, Tsuyoshi Yoshida
Life of this patent
Estimating the term…
Abstract
A lockup clutch in a torque converter is connected by a lockup solenoid energized in response to a lockup signal generated by a lockup discrimination circuit. When a speed sensor detects a rate of deceleration higher than a predetermined level at the time the vehicle is abruptly braked, for example, a lockup control circuit overrides the lockup discrimination circuit to cut off the lockup signal for thereby de-energizing the lockup solenoid, whereupon the lockup clutch is disconnected.
Claims5
A lockup clutch control system for use on a vehicle of the type having a torque converter including input and output shafts and a lockup clutch for directly connecting said input and output shafts of said torque converter, said system comprising:
- lockup discrimination circuit means for generating a lockup signal;
- a lockup solenoid for actuating said lockup clutch in response to said lockup signal;
- a speed sensor for detecting the speed of the vehicle;
- deceleration detecting circuit means for detecting the deceleration of the vehicle based on a signal from said speed sensor;
- and
- discriminator circuit means for de-energizing said lockup solenoid for at least a minimum interval of time in response to detection by said detecting circuit means of a rate of deceleration higher than a predetermined level, wherein said minimum interval of time is substantially independent of the vehicle speed subsequent to de-energizing said lockup solenoid and is determined by said detecting circuit means which also determines the rate of deceleration at which said lockup clutch is to be released.
Dependencies are inferred from the claim text.