A parking valve for manually actuating a spring-loaded parking brake, includes: a housing with a port that can be fluidically connected to a release chamber of a spring-loaded brake cylinder, a port that can be fluidically connected to a brake supply reservoir, and a ventilation port; a slide for manual actuation and which can be moved along a full section between two end positions inside the housing. The slide assumes positions along the full section, in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the ventilation port, and assumes other positions along the full section, in which, as a result of the at least one seal, there is no fluidic connection between the port of the release chamber and the port to the brake supply reservoir. A blocking device acts on the slide during movement at least along a partial section of the full section in at least one direction, with a continuously variable counterforce dependent on the position of the slide on the partial section.

An air braking system for a vehicle can include an air compressor, a reservoir, a first air line, a brake hub, a second air line, a control valve, a release valve, and a third fluid line. The first line can place an outlet of the compressor in fluid communication with an inlet of the reservoir. The brake hub can have a chamber in fluid communication with the outlet of the reservoir via the second line. The control valve can selectively open and close the second air line. The release valve can be in fluid communication with the chamber and having an outlet. The third line can place the outlet of the release valve in fluid communication with an inlet of the compressor.

A spring brake actuator has a service brake with a service brake housing and a service brake working chamber located in the service brake housing. The service brake working chamber is confined by a diaphragm. A service brake piston movable along an actuator-longitudinal axis and abuts the diaphragm, which applies a brake force onto the service brake piston. A spring between the service brake piston and the service brake housing pushes the service brake piston against the direction of the brake force. A modulator valve unit communicates with the service brake working chamber and is configured to regulate the inlet and outlet of fluid into and out of the service brake working chamber. The modulator valve unit is integrated into the spring brake actuator and includes a controllable inlet valve communicating with the service brake working chamber and a controllable outlet valve communicating with the service brake working chamber.

A relay valve (10) for a pneumatic valve unit (14), for example for a braking system of a utility vehicle, has a first assembly component (18) and a second assembly component (20). A hollow cylindrical guide portion (28) of a piston (24) of the relay valve (10) is received, in an axially guided manner, in the first assembly component (18). The second assembly component (20) includes additional valve components and the venting region of the relay valve (10). At least the first assembly component (18) and the second assembly component (20), when assembled, form a preassembly unit (26) first assembly component (18) and are joined by a bayonet connection (30). The preassembly unit (26) is inserted into a housing (12) of the valve unit (14), The interior of the housing is delimited by a cup-shaped inner wall (32), and the preassembled unit is fastened therein.

A relay valve (10) for a pneumatic valve unit (14), for example for a braking system of a utility vehicle, has a first assembly component (18) and a second assembly component (20). A hollow cylindrical guide portion (28) of a piston (24) of the relay valve (10) is received, in an axially guided manner, in the first assembly component (18). The second assembly component (20) includes additional valve components and the venting region of the relay valve (10). At least the first assembly component (18) and the second assembly component (20), when assembled, form a preassembly unit (26) first assembly component (18) and are joined by a bayonet connection (30). The preassembly unit (26) is inserted into a housing (12) of the valve unit (14), The interior of the housing is delimited by a cup-shaped inner wall (32), and the preassembled unit is fastened therein.

A vehicle braking system comprising a spring brake actuator having a spring brake chamber, a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

A pneumatic brake system (110) for a commercial vehicle (1) has one spring brake (27), a protection valve (56), a parking brake unit (30), a network of pipelines (40), at least a first (4) and a second (5) tank with compressed air and a relay valve (19) for the parking brake unit (30). A first subnetwork of pipelines (40a) comprises pipelines configured to be pressurized at all times. A second subnetwork of pipelines (40b) comprises at least one pipeline configured to be non-pressurized when the parking brake function is applied. The first subnetwork (40a) comprises pipelines establishing fluid communication between the tanks (4, 5) and the parking brake unit (30), wherein the direction of air flow in these pipelines is by at least one thereto associated valve (50). A method for managing an air flow to an air-actuated spring brake (27) of a pneumatic brake system (110) is disclosed.

A compressed air system for a motor vehicle with an air supply system, including: an electric drive motor, which can be controlled for variable speed, an air compressor coupled to be driven by the electric drive motor, an electric power supply for supplying electric power to the electric drive motor, at least one air reservoir connected with the air compressor to receive air from the air compressor, an air utilization system connected to the at least one air reservoir to receive air from the at least one air reservoir, a controller to control the speed of the electric drive motor. The controller controls the electric drive motor to determine the speed of the electric drive motor so that during filling of the air reservoir, when the pressure level in the air reservoir passes a setpoint that is between a minimum level and a higher cut off pressure level, the controller changes the compressor speed so that specific power consumption per unit mass of air compressed is decreased.

The present invention relates to an electronic parking brake device for a vehicle, in particular a utility vehicle. As a function of at least one operating state of a towing vehicle parking brake supply line and/or a trailer parking brake supply line, a towing vehicle parking brake control valve is activatable by means of a control unit in such a way that a towing vehicle parking brake supply line can be deaerated or aerated by the towing vehicle parking brake control valve. By manually actuating a trailer parking brake control element, a trailer parking brake control valve is activatable by means of the control unit in such a way that a trailer parking brake supply line can be deaerated or aerated by the trailer parking brake control valve. The present invention also relates to a method for operating the above electronic parking brake device for a vehicle.

A control method for controlling a spring loaded brake actuator (9) comprising a first chamber (Ch1) to receive a parking brake pressure (PBR) acting against a main spring (92), and a second chamber (Ch2) to receive a service brake pressure (SB) for applying a service brake force, the method comprising a circumstantial selection of one control law among a set of control laws comprising two or more compound control laws:—where the first compound control law (CL1), known as anti-compound mode, is such the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a first upper limit (UL1) corresponding to the force of the main spring (92) when the parking brake pressure (PBR) is substantially null, —where the second compound control law (CL2), known as controlled-compound mode, is such that the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a second upper limit (UL2) higher than the first upper limit.