TECHNICAL FIELD

The invention relates to an electropneumatic brake control module for utility vehicles with a supply port for connecting a compressed air supply, a first axle channel port, a pneumatically controlled inlet/outlet valve unit for outputting a first braking pressure at the first axle channel port, and an electropneumatic pilot control unit for outputting at least a first control pressure at the inlet/outlet valve unit. The invention further relates to a vehicle with such an electropneumatic brake control module.

BACKGROUND

Electropneumatic brake control modules of the type mentioned above are used in pneumatic brake systems for motor vehicles, in particular utility vehicles. Pneumatic brake systems for motor vehicles usually have a pneumatically actuated brake per wheel of the motor vehicle, wherein the pneumatic operating medium, in particular compressed air, is provided for the wheel brakes in a supply pressure accumulator under static pressure. The brake systems have a brake signal transmitter which is coupled to the movement of a brake pedal actuated by the driver of the motor vehicle and which generates a braking demand signal on actuating the brake pedal. Depending on the braking demand signal, a target braking pressure is set at the wheel brakes. In modern vehicles, the brake signal transmitter can also operate purely electronically, so that a braking demand signal is output, in particular by a central control module or the like.

The electropneumatic brake control module of the present invention is used in particular to receive a braking demand signal and then to output a corresponding first braking pressure at the first axle channel port. The first axle channel port is provided for a front axle, for example. On the front axle, the controlled first braking pressure can then be output for both the left and right brakes or can be further output. The electropneumatic brake control module of the present invention is therefore also referred to as an axle modulator, since it is used to output a (global) braking demand signal for one of the front and rear axles or multiple axles, separately and preferably output.

An electropneumatic brake control module of the above type is known to the present applicant from DE 10 2014 006 614 A1. Disclosed therein is a pneumatic brake device for motor vehicles, containing a brake signal transmitter, a supply pressure accumulator and a pneumatically actuatable wheel brake per wheel as well as at least one axle of the motor vehicle, each with an electrically actuatable wheel brake module per wheel for setting a target braking pressure at the respective wheel brake, as well as with an electronic control unit for determining the setpoint values of the target braking pressures of the wheel brakes, taking into account the brake signal transmitter, which can be specified for the wheel brake modules. Each wheel brake module includes: at least one ventilation valve and one venting valve, electrically actuatable activating means for activating the ventilation valve and/or the venting valve, a control logic with means for generating an actuation signal for the activating means according to the specified value for the target braking pressure. In this case, the ventilation valve and its activating means are designed in such a way that the pneumatic pressure from the supply pressure accumulator is fed through directly to the respective wheel brakes with the ventilation valve in the actuated state and/or the venting valve vents the braking pressure on the wheel brake directly into the atmosphere when in the actuated state. This means that the wheel brake module comprises a respective pneumatically actuated 2/2-way valve as a ventilation valve and a venting valve. There is no relay valve there which is switched between a supply port and the corresponding connection for the wheel brake. The electrically actuated activation means are designed as an electropneumatic pilot control unit, which outputs a corresponding control pressure for the 2/2-way valves that form the ventilation valve and the venting valve.

Even if such a wheel brake module works well, there is still a need to improve it, in particular to increase the safety of the vehicle, to reduce the installation space of the modules and to produce inexpensive and cost-effective modules, which do not need expensive and complex relay valves in particular.

SUMMARY

In a first aspect of the invention, the electropneumatic brake control module has a redundancy pressure port for receiving a redundancy pressure and a redundancy valve unit connected to the redundancy pressure port for outputting a redundancy braking pressure at the first axle channel port for the case in which the electropneumatic pilot control unit has a fault.

The redundancy pressure is preferably provided by a brake pedal. This means that in the event of a fault, a driver of the vehicle can generate a manually controlled redundancy pressure by operating the brake pedal, which is then provided at the redundancy pressure port. According to the invention, this redundancy pressure is then used to replace the first braking pressure in that a redundant braking pressure is output at the first axle channel port.

In this case, the defect of the electropneumatic input control unit is in particular the failure of one or more valves of the electropneumatic control unit, the failure of an electronic control unit providing control signals for the electropneumatic pilot control unit, the failure of a central control module or the like. All these cases have in common that an electronic braking demand signal cannot be generated, processed, or processed properly. In this case, the first braking pressure is replaced by the redundant braking pressure.

In this way, the reliability of the electropneumatic brake control module can be improved. Even in the event that an electronic component does not work or does not work properly, it is nevertheless possible to brake a vehicle safely in that the redundancy pressure controlled in particular by means of the brake pedal is processed in order to output the redundant braking pressure.

In a preferred embodiment, it is provided that the first braking pressure can be fed through the inlet/outlet valve unit from the supply port to the first axle channel port directly and unboosted, i.e. without increasing the air volume or the air pressure, by means of an in particular pneumatic relay valve. The inlet/outlet valve unit preferably has no relay valve. This can reduce the installation space and can make the module more cost-effective overall to manufacture.

In a particularly preferred embodiment, the redundancy valve is connected to the inlet/outlet valve unit in such a way that the redundant braking pressure can be output at the first axle channel port via a first outlet line for venting the first axle channel port in the event of a pilot control unit fault. This allows on the one hand the use of fewer pneumatic lines, since the already existing first outlet line is necessary for venting the first axle channel port. In the event of a fault, it is also advantageous if the inlet/outlet valve unit is switched so that the first axle channel port is or will be vented, i.e. is not or will not be ventilated. The first outlet line, which is then open in this fault case, is advantageously used according to this embodiment to introduce the redundant braking pressure in order to output the redundant braking pressure at the first axle channel port.

Furthermore, it is preferred that the inlet/outlet valve unit has a first pneumatically switchable 2/2-way inlet valve and a first pneumatically switchable 2/2-way outlet valve, wherein the first pneumatically switchable 2/2-way inlet valve receives the first control pressure and the first pneumatically switchable 2/2-way outlet valve receives a second control pressure from the pilot control unit. In this embodiment, the pilot control unit provides both the first control pressure and the second control pressure. The first control pressure is used to switch the first 2/2-way inlet valve and the second control pressure is used to switch the first 2/2-way outlet valve. Preferably, the first 2/2-way inlet valve is closed without pressure and the first 2/2-way outlet valve is open without pressure. This means that as soon as the first control pressure exceeds a certain threshold value, the first 2/2-way inlet valve switches to the respective other working position. Similarly, as soon as the second control pressure exceeds a certain threshold value, the first 2/2-way outlet valve switches to the respective other switching position. In this way, a relay valve can be omitted.

In a preferred development, the first pneumatically switchable 2/2-way inlet valve has a first inlet valve port connected to the supply port, a second inlet valve port connected to the first axle channel port and a first inlet valve control port for receiving the first control pressure. Similarly, the first pneumatically switchable 2/2-way outlet valve preferably has a first outlet valve port connected or connectable to a vent, a second outlet valve port connected to the first axle channel port and a first outlet valve control port for receiving the second control pressure. The term “connectable” means in this context that one or more further valves may be connected between the first outlet valve port and the vent, so that when all these valves are open or the connections of the corresponding valve ports are connected through, the first outlet valve port is pressure-conductively connected to the vent. In other words, the first axle channel port can be vented via the first outlet valve port.

Furthermore, it is preferred that the redundancy valve unit has a redundancy valve. The redundancy valve preferably has a first redundancy valve port connected to the redundancy pressure port, a second redundancy valve port connected to first axle channel port and a third redundancy valve port connected to a vent. Also in this context, the term “connectable” means that one or more further valves may be connected between the second redundancy valve port and the first axle channel port, so that when all these valves are open or the connections of the corresponding values are switched through, the second redundancy valve port is pressure-conductively connected to the first axle channel port. The redundancy valve is preferably designed as a 3/2-way valve and switched so that in a first deenergized switching position the first redundancy valve port is connected to the second redundancy valve port and in a second, energized switching position the third redundancy valve port is connected to the second redundancy valve port. In this way, in a deenergized switching position, the redundancy pressure can be fed through from the first redundancy valve port through the redundancy valve and can be provided at the second redundancy valve port, whereas in an energized state of the redundancy valve the redundancy pressure is blocked. In the event of a fault, the redundancy valve is then switched to the deenergized state or has already been switched off by the fault, so that the redundancy pressure can be fed through. In this case, the second redundancy valve port can be connected to the first axle channel port, so that in this case the redundancy pressure can be output at the first axle channel port either boosted or not boosted as the redundant braking pressure.

In a preferred development, it is provided that the redundancy valve unit has a shuttle valve and the redundant braking pressure can be introduced into the first outlet line via the shuttle valve. This prevents pressure from being or being able to be fed back to the redundancy port during venting of the first axle channel port. Furthermore, in this way, the redundancy pressure can be easily introduced into the first outlet line and yet at the same time this can be used for venting the first axle channel port, even if the first axle connection is to be vented again to release the wheel brakes in the redundant braking case.

In addition or alternatively, it may be provided that the redundancy valve has a relay valve for boosting the air volume or air amount of the redundancy pressure. Depending on the formation of the redundancy pressure and the type of provision, it may be necessary to boost the volume or the air volume by means of a relay valve in order to be able to provide it at the wheel brakes. If, for example, the first axle channel port is used to first provide a pressure to another module, it may be sufficient that the pressure is volume boosted there in this further module and passed to the wheel brakes. In this variant, however, the electropneumatic brake control module itself has a relay valve for the redundancy pressure. In this case, such a relay valve can be simple and small, as it does not have to be designed for continuous operation. The relay valve is used solely to boost the redundancy pressure or the air amount and/or the air volume of the redundancy pressure, which is used exclusively in the event of a fault. Therefore, it is nevertheless possible to design the electropneumatic brake control module to be installation space saving and cost saving, even though it has a relay valve in this embodiment.

Preferably, the relay valve has a relay valve supply port connected to the supply port, a relay valve venting connection connected to a vent, a relay valve working port for outputting the redundant braking pressure into the first outlet line and a relay valve control port connected or connectable to the redundancy pressure port. As a control pressure, the relay valve thus receives the redundancy pressure output at the redundancy pressure port, which can, for example, correspond to a manually generated pressure from a brake pedal. If this pressure is not present or is blocked, the relay valve is therefore in a venting position, since no control pressure or a control pressure with the value of the ambient pressure is applied; the relay valve working port is vented in this position. This means that the relay valve can also be used for venting the first outlet line and thus for venting the first axle channel port. In the event that a redundancy pressure is applied to the relay valve control port as a control pressure, a pressure is output via the relay valve working port, which can then be output via the first outlet line to the first axle channel port as a redundant braking pressure. In this way, a particularly simple circuit is achieved, which manages with an optimized air flow between the individual connections.

In a variant of this circuit it is preferred that the relay valve working port is connected to the first outlet valve port. Preferably, the relay valve working port is directly connected to the first outlet valve port, for example via a pneumatic line. This means that in this embodiment the first axle channel port can be ventilated via the first venting line, the first 2/2-way outlet valve and the relay valve. In the event of a fault, the first axle channel port can be vented via the relay valve, the first 2/2-way outlet valve, the first outlet line and a corresponding redundant braking pressure can be output.

In this circuit it is further preferred that the relay valve control port is connected to the second redundancy valve port. Preferably, in turn a pneumatic line, in particular a pneumatic control line, is provided between these. If the redundancy valve is then in the deenergized first switching position, the redundancy pressure can be output directly via this to the relay valve control port in order to output the redundant braking pressure at the first axle channel port.

Furthermore, in one variant it is provided that the shuttle valve has a first shuttle valve port connected or connectable to the redundancy pressure port, a second shuttle valve port connected to a vent and a third shuttle valve port connected or connectable to the first outlet line and alternately connects the third shuttle valve port to either the first shuttle valve port or the second shuttle valve port. The shuttle valve is preferably designed as a quick release valve, so that the third shuttle valve port is preferably connected to the second shuttle valve port and is only connected to the first shuttle valve port in the event of a pressure difference between the first shuttle valve port and the third shuttle valve port. The second shuttle valve port is connected to the vent, so that the ambient pressure is permanently applied to it. This means that the second shuttle valve port is only closed if a pressure is applied to the first shuttle valve port, such as in particular the redundancy pressure. Otherwise, the second shuttle valve port is permanently connected to the third shuttle valve port, so that the third shuttle valve port can be vented via the second shuttle valve port.

In a first variant, the first shuttle valve port is connected to the second redundancy valve port. The redundancy pressure is directly output at the first shuttle valve port. This can then be fed through when applied to the third shuttle valve port.

In one variant, the first shuttle valve port is connected to the relay valve working port. This means that the pressure output from the relay valve working port is then passed via the shuttle valve, i.e. is output via the first shuttle valve port and then to the third shuttle valve port. The second shuttle valve port is preferably directly connected to a vent in this variant. In this variant, it is then not necessary to also use the relay valve for venting the first axle channel port, this can rather be vented directly via the third shuttle valve port and the second shuttle valve port. Thus a direct venting path is created.

In a further preferred embodiment, the electropneumatic brake control module is provided for the purpose of outputting braking pressures for two axles and accordingly has a second axle channel port. The inlet/outlet valve unit is then designed to output a second braking pressure at the second axle channel port. The first axle channel port can be provided, for example, for the front axle and the second axle channel port for the rear axle. It could also be provided that the first axle channel port is provided for a left wheel and the second axle channel port for a right wheel.

Furthermore, in this embodiment is provided that the electropneumatic pilot control unit is designed to provide at least a third control pressure at the inlet/outlet valve unit, and the redundancy valve unit is designed to output the redundant braking pressure at the second axle channel port for the case in which the electropneumatic pilot control unit has a fault. This means that in the event of a fault, the redundancy pressure is not only output at the first axle channel port as a redundant braking pressure, but also at the second axle channel port as a redundant braking pressure. In this case of a fault, therefore, the same braking pressure is output at both axle channel ports, both the first and the second axle channel ports. It may also be provided that this redundant braking pressure is further output if the input unit has not completely failed, but only partially failed, for example by using additional valves and/or select-low valves.

In this exemplary embodiment, it is preferably further provided that the redundancy valve unit is connected to the inlet/outlet valve unit in such a way that the redundant braking pressure can be output at the second axle channel port via a second outlet line for venting the second axle channel port in the event of a fault of the pilot control unit. This principle is implemented correspondingly to the first axle channel port, and both the first axle channel port and the second axle channel port can be ventilated via their respective first or second outlet lines in the event of a fault in order to output the redundant braking pressure.

For this purpose, the inlet/outlet valve unit preferably has a second pneumatically switchable 2/2-way inlet valve and a second pneumatically switchable 2/2-way outlet valve for the second axle channel port, wherein the second pneumatically switchable 2/2-way inlet valve receives the third control pressure and the second pneumatically switchable 2/2-way outlet valve receives a fourth control pressure from the pilot control unit. Preferably, the second 2/2-way inlet valve is closed without pressure and the second 2/2-way outlet valve is open without pressure. Basically, the second two-way 2/2-way inlet valve may be designed according to the first 2/2-way inlet valve and the second 2/2-way outlet valve according to the first 2/2-way outlet valve.

In this sense, it is preferred that the second pneumatically switchable 2/2-way inlet valve has a third outlet valve port connected to the supply port, a fourth inlet valve port connected to the second axle channel port and a second inlet valve control port for receiving the third control pressure. Preferably, the second pneumatically switchable 2/2-way outlet valve accordingly has a third outlet valve port connected or connectable to a vent and a fourth outlet valve port connected to the second axle channel port and a second outlet valve control port for receiving the fourth control pressure.

Preferably, the second redundancy valve port can also be connected to the second axle channel port. The second redundancy valve port, via which the redundancy pressure can be forwarded, can therefore preferably be connected in this embodiment both to the first axle channel port and to the second axle channel port, in order to output the redundant braking pressure at both the first axle channel port and the second axle channel port.

In a corresponding manner, it is also preferred that if the redundancy valve unit has a shuttle valve, the redundant braking pressure can be introduced into the second outlet line via the shuttle valve.

In the event that the redundancy valve unit has a relay valve, it is also preferred that the redundant braking pressure can be introduced not only into the first outlet line, but also into the second outlet line via the relay valve working port. In particular and preferably, the relay valve working port is connected to the third outlet valve port. The relay valve working port is thus connected to both the first outlet valve port and the third outlet valve port, which can be realized by means of a branch line.

Embodiments of the invention are now described below on the basis of the drawings. These are not necessarily intended to represent the embodiments to scale, but rather the drawings are executed in a schematized and/or slightly distorted form, where this is conducive to explanation. With regard to additions to the teachings directly recognizable from the drawings, reference is made to the relevant prior art. It must be taken into account that various modifications and changes regarding the form and detail of an embodiment can be made without deviating from the general idea of the invention. The features of the invention disclosed in the description, drawings and claims may be essential for the further development of the invention, both individually and in any combination. In addition, all combinations of at least two of the features disclosed in the description, drawings and/or claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiments shown and described below or limited to a subject-matter which would be limited in comparison to the subject-matter claimed in the claims. In the case of specified design ranges, values within the specified limits shall also be disclosed as limit values and shall be usable and claimable as desired. For simplicity, identical or similar reference characters are used below for identical or similar parts or parts with identical or similar functions.

Further advantages, features and details of the invention arise from the following description of the preferred embodiments as well as on the basis of the drawings.

