Actuator and method of operating an actuator in a motor vehicle

摘要

An automatic clutch control device comprises an electric motor 10 connected via an output shaft 12 and a gearbox 14 having a crank 20 to a piston rod 24 of a master cylinder 30. Slave cylinder 60 is connected by a hose 50 to the master cylinder 30 so that when piston 38 is moved by the motor 10 a piston 62 in the slave cylinder 60 is displaced and operates a clutch. In order to detect a position of the piston 38 a sensor 70 is provided on the piston rod 24 and is connected to a control device 72. Chamber B of the cylinder 30, the hose 50 and a pressure chamber of slave cylinder 60 form a system section which is provided with a snifting bore 80 connected to a compensating container 86. In order to keep the volume constant, eg if the temperature increases, a snifting cycle is initiated which connects/disconnects the snifting bore 80 to the system section.