Method of Operating A Transmission Clutch

摘要

A manual transmission is partially automated by utilizing a controller to regulate the torque capacity of the clutch. Under most circumstances, the controller manipulates the clutch according to driver manipulation of a clutch pedal to simulate a non-automated manual transmission. However, to save fuel, the controller may enter a sailing mode in which the clutch is disengaged without the driver depressing the clutch pedal. The controller exits sailing mode in response to the vehicle speed decreasing below a threshold which is a function of the currently selected gear ratio. The threshold is selected such that the engine will not stall and will be able to generate sufficient power for acceleration when the clutch is re-engaged to exit sailing mode. In order to extend the use of sailing mode, the controller may activate a downshift indicator at a slightly higher speed threshold to encourage the driver to downshift.

主权项

1. A vehicle comprising:
a gearbox configured to establish one of a plurality of speed ratios between a gearbox input shaft and an output shaft in response to manipulation of a shifter; an engine having a crankshaft; a friction clutch configured to selectively couple the gearbox input shaft to the crankshaft; an accelerator pedal; a clutch pedal; and a controller programmed to
disengage the clutch in response to release of the accelerator pedal while the vehicle is moving and the clutch pedal is in a released state, andre-engage the clutch in response to a vehicle speed decreasing to less than a first threshold.