Device for actuating a parking brake of an automatic transmission, and parking brake device for such an automatic transmission

摘要

The invention relates to a device (10) for actuating a parking lock of an automatic transmission for a motor vehicle, having a piston (20) movably received in a housing element (26) and having a hydraulic medium from a reservoir (22) for actuating the parking brake via a valve device (24), which has a first valve (349 and a second valve (36) arranged downstream of the first valve (34) and upstream of the piston (20) in the flow direction of the hydraulic medium from the reservoir (22) to the piston (20). comprising at least one device port (A1), via which the piston (20) can be acted upon by the hydraulic medium, and at least two switching states, with a by the housing member (26) and by the piston (20) limited working chamber (32), in which, for loading the piston (20) with the hydraulic medium, the hydraulic medium from the reservoir (22) can be introduced via the valve device (24), with an electrically actuatable actuator (38), by means of which by energizing the actuator (38), the second valve (36) is movable from a first of the switching states to the second switching state, and with at least one spring element (40), by means of which the second valve (36) is movable in a de-energized state of the actuator (38) from the second switching state in the first switching state, wherein a with the device port (A1) fluidly connected control line (42) is provided, via which the second valve (36) with the Hydraulic medium can be acted upon and thereby hold in the second switching state.