METHOD AND APPARATUS FOR OPERATING A CLUTCH IN AN AUTOMATED MECHANICAL TRANSMISSION

摘要

An apparatus and method for controlling the operation of a clutch in a partially or fully automated mechanical transmission which is responsive to the actual load on the vehicle engine for varying the engagement rate of release bearing during re-engagement of the clutch. The apparatus includes an electronic controller which initially sets a desired speed for the vehicle engine during the shifting process, determines a rate of engagement movement of a release bearing of the clutch, and actuates appropriate valves to initiate the gradual engagement of the clutch. The electronic controller sets a first lower engine speed threshold and a second lower engine speed threshold. In a first embodiment, the magnitude of the first lower engine speed threshold varies with the actual load on the engine. If the actual speed of the engine remains above both the first lower engine speed threshold and the second lower engine speed threshold, the engagement process is continued without interruption. If the actual speed of the engine drops below the first lower engine speed threshold but remains above the second lower engine speed threshold, the release bearing is held in its current position until the actual speed of the engine recovers above the first lower engine speed threshold. If the actual speed of the engine drops below both the first lower engine speed threshold and the second lower engine speed threshold, the engagement process is aborted, and the release bearing is returned to the disengaged position until the actual speed of the engine recovers above an engagement re-start speed threshold. In a second embodiment, the magnitude of the first lower engine speed threshold varies with both the actual load on the engine and the amount of depression of an accelerator pedal of the vehicle.