VEHICLE DRIVELINE CLUTCH CONTROL SYSTEMS

摘要

A control system for a vehicle driveline clutch which drives ground engaging wheels from a power unit. The system has a driver operated clutch control which allows the vehicle driver to manually operate the clutch when moving away from rest and stopping and when gearshifting in a transmission of the driveline and an electrically powered actuator which can operate the clutch independently from the driver operated control. The driver operated control operates a hydraulic master cylinder which is connected with an actuating cylinder for the pressurisation thereof to provide a thrust force to manually actuate the clutch and the electrical operation of the clutch is provided by an electric motor which actuates a piston in the actuating cylinder to pressurise this cylinder and thus again actuate the clutch under the control of the motor. The control system also includes a pedal force accumulator which is also hydraulically connected with the master cylinder via by-pass valve means. Operation of the electric motor opens the by-pass valve means to allow any hydraulic pressure generated by the master cylinder to be absorbed by the accumulator so that the master cylinder can be operated normally when the clutch has already been actuated by the motor. The control system can also be arranged to select a coasting mode of operation of the vehicle in which the drive clutch is disengaged and the engine output is reduced when a number of predetermined vehicle operating conditions occur.