Automatic clutch actuation system with program control using plural

Abstract

For the automatic actuation of a friction clutch arranged in the torque transmission path between an engine and a change-speed gearbox of a motor vehicle an actuating element of the clutch is coupled to a controllable drive device which moves the actuating element between a clutch-release position, in which the clutch is completely released, and a clutch engagement position in which the clutch is completely engaged. The position of the actuating element in the slipping range between a position of commencing torque transmission and the engaged position is adjusted by a program control, which responds to the engine rotation rate and controls the clutch engagement operation of the drive device, according to a position characteristic provided by means of a first function generator, in starting, as a function of the engine rotation rate. The program control comprises a second function generator controlling the position of the actuating element independently of the first function generator. The second function generator provides a plurality of position characteristics displacing the actuating element as a function of time at different speeds over the slipping rate. The program control in dependence upon the engine rotation rate and the input rotation rate of an input shaft of the change-speed gearbox engages a comparatively faster position characteristic when the engine rotation rate is higher than the input rotation rate of the change-speed gearbox, and engages a comparatively slower position characteristic when the engine rotation rate is lower than the input rotation rate.