System for controlling engaging and disengaging operations of releasable coupling device placed in automotive power train

摘要

A releasable coupling (3d) control system in combination with an electronic engine control unit (18) executable a fuel cutoff mode during vehicle deceleration and re-startable a fuel-supply recovery mode as soon as an engine speed (NE) drops below a predetermined threshold value (NFCR), for controlling engaging and disengaging operations of a releasable coupling device (3d) placed in an automotive power train between an engine and drive wheels, comprises a wheel-speed sensor (13) for detecting a drive-wheel speed to generate a drive-wheel speed indicative signal, and a controller (19) being configured to be responsive to the drive-wheel speed indicative signal for moderately releasing the releasable coupling device at a moderate turn-off mode when the drive-wheel speed indicative signal value drops below a first predetermined value (VOFF1), and for quickly releasing the releasable coupling device at a quick turn-off mode when the drive-wheel speed indicative signal value drops below a second predetermined value (VOFF2).