Method for operating an electropneumatic parking brake module, electropneumatic parking brake module, electronically controllable pneumatic brake system, vehicle

An electropneumatic parking brake module for an electronically controllable pneumatic brake system for a vehicle, the electropneumatic brake module comprising:

• a supply port configured to receive a supply pressure;
• a parking brake port for a connection of at least one parking brake cylinder;
• a main valve assembly configured to receive the supply pressure and being configured to output a spring brake pressure at said parking brake port in dependence upon a control pressure;
• a pilot valve assembly configured to receive the supply pressure and to provide the control pressure, wherein said pilot valve assembly has a bistable valve which can be switched between a first air admission position and a second air release position;
• a control unit configured to provide a first switch signal and a second switch signal to said pilot valve assembly;
• said pilot valve assembly having a monostable holding valve pneumatically connected in series with said bistable valve and being arranged in a control line of said main valve assembly, wherein said holding valve is normally open in an open position;
• said control unit being configured to hold said holding valve in a holding position via the first switch signal in order to hold the control pressure;
• an additional input port configured to receive an additional control pressure provided at an additional brake pressure port being arranged in said control line;
• said holding valve being configured to automatically switch into an open position for releasing air from a control port in at least one of an event of a fault in an electronic component and an event of a power failure, wherein air is released from said control port of said main valve assembly for the release of air from said parking brake port independent of said bistable valve;
• and,
• wherein said holding valve is configured to be held in said holding position for holding the additional control pressure at said control port such that pressure is stored in a portion of said control line connecting a holding valve port of said holding valve to said control port, wherein the pressure stored in said portion of the control line enables the electropneumatic parking brake module to hold a parking brake in a released position.

An electropneumatic parking brake module for an electronically controllable pneumatic brake system for a vehicle, the electropneumatic brake module comprising:

• a supply port configured to receive a supply pressure;
• a parking brake port for a connection of at least one parking brake cylinder;
• a main valve assembly configured to receive the supply pressure and being configured to output a spring brake pressure at said parking brake port in dependence upon a control pressure;
• a pilot valve assembly configured to receive the supply pressure and to provide the control pressure, wherein said pilot valve assembly has a bistable valve which can be switched between a first air admission position and a second air release position;
• a control unit configured to provide a first switch signal and a second switch signal to said pilot valve assembly;
• said pilot valve assembly having a monostable holding valve pneumatically connected in series with said bistable valve and being arranged in a control line of said main valve assembly, wherein said holding valve is normally open in an open position;
• said control unit being configured to hold said holding valve in a holding position via the first switch signal in order to hold the control pressure;
• an additional input port configured to receive an additional control pressure provided at an additional brake pressure port being arranged in said control line;
• said holding valve being configured to automatically switch into an open position for releasing air from a control port in at least one of an event of a fault in an electronic component and an event of a power failure, wherein air is released from said control port of said main valve assembly for the release of air from said parking brake port independent of said bistable valve;
• wherein said holding valve is configured to be held in said holding position for holding the additional control pressure at said control port such that pressure is stored in a portion of said control line connecting a holding valve port of said holding valve to said control port, wherein the pressure stored in said portion of the control line enables the electropneumatic parking brake module to hold a parking brake in a released position;
• wherein said additional input port is formed as a first selection valve port of a selection valve unit for receiving the additional control pressure;
• said selection valve unit has a check characteristic at said first selection valve port such that said first selection valve port opens in a direction of flow from said additional brake pressure port via a third selection valve port to said control port and closes contrary to the direction of flow;
• and,
• wherein said selection valve unit has a bypass line, wherein said bypass line pneumatically connects a second selection valve port and said third selection valve port and has at least one of a throttle and a bypass check valve.