Compressed-air supply arrangement of a pneumatic brake system, and method for engaging a parking brake by limiting the delivery rate

An electronically controllable pneumatic brake system for a utility vehicle, the electronically controllable pneumatic brake system comprising:

• an electronic control unit;
• a compressed-air supply arrangement including a compressor for generating compressed air having a compressed-air outlet, an air treatment unit for treating compressed air delivered by said compressor, and at least one compressed-air reservoir for providing a reservoir pressure for pressurizing at least one spring brake cylinder of a parking brake of the brake system with compressed air, wherein said at least one compressed-air reservoir is connected via at least one compressed-air delivery line to said compressed-air outlet of said compressor;
• and,
• said compressed-air supply arrangement further including at least one delivery-rate limiting device for limiting compressed-air flow delivered by said compressor through said at least one compressed-air delivery line to said at least one compressed-air reservoir, said at least one delivery-rate limiting device having a switchable valve unit, wherein said switchable valve unit is configured to be switched, in an event of a fault of the brake system, via a switching signal received from said electronic brake control unit;
• the parking brake having the at least one spring brake cylinder configured to be pressurized with compressed air, via the reservoir pressure provided from said at least one compressed-air reservoir, in order to release said parking brake;
• and,
• said electronic brake control unit being configured to output the switching signal to said switchable valve unit of said at least one delivery-rate limiting device in an event of a fault of said electronically controllable pneumatic brake system.

A method for engaging a parking brake of an electronically controllable pneumatic brake system of a utility vehicle, comprising the following steps:

• detecting a fault in the electronically controllable pneumatic brake system, wherein the detected fault prevents a parking brake from being engaged via a switching operation of a parking brake valve unit of the parking brake such that at least one spring brake cylinder of the parking brake is ventilated;
• outputting a switching signal via an electronic brake control unit of the brake system to a switchable valve unit of at least one delivery-rate limiting device of a compressed-air supply arrangement for providing a supply to the electronically controllable pneumatic brake system, wherein the switching signal has an effect that compressed-air flow delivered by a compressor to at least one compressed-air reservoir of the electronically controllable pneumatic brake system is limited;
• and,
• lowering a reservoir pressure for the pressurization of the at least one spring brake cylinder of the parking brake of the electronically controllable pneumatic brake system by consuming compressed air in at least one service brake circuit or parking brake circuit of the electronically controllable pneumatic brake system.