Method, circuitry, motor vehicle or trailer having circuitry for bleeding a brake channel of a compressed-air braking system

An electropneumatic circuit arrangement of a compressed-air brake system, the electropneumatic circuit arrangement comprising:

• a control pressure circuit and a supply and reservoir pressure circuit independent of said control pressure circuit;
• a brake pressure modulator including a plurality of switchable valves for the control pressure;
• an electronic control unit for the switchable valves, which interacts with said brake pressure modulator;
• at least one brake cylinders acting on a wheel brake;
• at least one pressure sensor interacting with said electronic control unit, at different locations in said pneumatic circuit arrangement;
• wherein the brake pressure modulator is assigned, for each brake channel, at least one relay valve wherethrough, firstly, a quantity of air can be introduced from a supply pressure line, which is independent of the control pressure, into at least one brake cylinder for actuating the brake and, secondly, the brake cylinder can be vented via a venting outlet of the relay valve;
• wherein the relay valve is configured as a pressure-controlled valve equipped with a control chamber and has a venting outlet having a silencer;
• and,
• said electronic control unit has programmed therein an algorithm via which a setpoint pressure gradient during the venting operation can be changed in a manner dependent on the pressure in the brake cylinder and on the operating state of a vehicle.

A motor vehicle comprising an electropneumatic circuit arrangement of a compressed-air brake system;

• said electropneumatic circuit arrangement including:
• a control pressure circuit and a supply and reservoir pressure circuit independent of said control pressure circuit;
• a brake pressure modulator including a plurality of switchable valves for the control pressure;
• an electronic control unit for the switchable valves, which interacts with said brake pressure modulator;
• at least one brake cylinders acting on a wheel brake;
• at least one pressure sensor interacting with said electronic control unit, at different locations in said pneumatic circuit arrangement;
• wherein the brake pressure modulator is assigned, for each brake channel, at least one relay valve wherethrough, firstly, a quantity of air can be introduced from a supply pressure line, which is independent of the control pressure, into at least one brake cylinder for actuating the brake and, secondly, the brake cylinder can be vented via a venting outlet of the relay valve;
• wherein the relay valve is configured as a pressure-controlled valve equipped with a control chamber and has a venting outlet having a silencer;
• said electronic control unit has programmed therein an algorithm via which a setpoint pressure gradient during the venting operation can be changed in a manner dependent on the pressure in the brake cylinder and on the operating state of the vehicle.