VALVE ARRANGEMENT OF A TOWING VEHICLE FOR CONTROLLING A PNEUMATIC BRAKE SYSTEM OF A TRAILER VEHICLE AND METHOD FOR CONTROLLING THE SAME

Description

[0001] The invention relates to a valve arrangement of a towing vehicle for controlling a pneumatic braking system of a trailer, wherein the valve arrangement comprises a trailer control valve with a supply pressure inlet for introducing compressed air and a supply pressure outlet for the controlled discharge of compressed air, and wherein the supply pressure outlet is pneumatically connected to a coupling head "supply" of the towing vehicle. The invention further relates to a method for controlling such a valve arrangement when coupling a trailer to a towing vehicle.

[0002] Modern towing vehicles, such as trucks and semi-trailer tractors, primarily intended for use on paved roads and highways, typically feature a pneumatically operated braking system with electronic control. In contrast, modern towing vehicles, such as tractors designed for off-road use, are often equipped with hydraulically operated braking systems with electronic control. The braking systems of both types of vehicles usually include a valve assembly for controlling the pneumatic braking system of a towed trailer. This assembly comprises a trailer control valve with electrically controlled inlet and outlet valves, a pneumatically controlled relay valve, and a backup valve with an electrically controlled redundancy valve and a brake pressure-controlled relay valve.

[0003] In normal operation, the trailer control valve uses a pneumatic supply pressure generated by a compressor and conditioned in a compressed air supply system. This pressure is then routed via a cut-off valve to a coupling head "Supply" (red) of the towing vehicle. Additionally, depending on an electronic brake force signal detected by an electronic brake force sensor, a corresponding brake control pressure is set in the relay valve of the trailer control valve using a control pressure adjusted via inlet and outlet valves. This brake control pressure is then routed via a changeover valve to the coupling head "Brake" (yellow) of the towing vehicle.

[0004] In the event of an electronic control unit failure or a missing electronic brake force signal, the control input of the associated relay valve is vented by shutting off the inlet and outlet valves, thus deactivating the trailer control valve. Simultaneously, a redundant valve switches from a closed to an open position, enabling the supply pressure input or brake control output of its corresponding relay valve and thereby activating the backup valve. Within the backup valve's relay, a brake control pressure for the trailer is set based on the brake pressure measured at a brake line of the towing vehicle and routed to the "Brake" coupling head (yellow) via the changeover valve. This ensures the functionality of the trailer's service brakes even in the event of an electronic control unit failure or a loss of the electronic brake force signal.

[0005] German patent DE 10 2014 002 614 A1 describes several embodiments of such a valve arrangement for a hydraulically braked towing vehicle for controlling the brake pressure of a pneumatically braked trailer. Each embodiment comprises an electronically controlled trailer control valve and a hydraulically controlled backup valve for controlling the brake control pressure transmitted to the coupling head "brake". The trailer control valve and the backup valve are each designed as separate valve units, which are connected to each other via pneumatic lines and to an electronic control unit via electrical control lines.

[0006] For the use of the trailer's wheel brakes in a parking brake function, the valve assembly of a towing vehicle can include an electronically controlled parking brake module. This module has at least one solenoid valve acting as a parking brake valve, through which an inverted control input of the trailer control valve or its relay valve can be alternately pressurized or vented. The parking brake module is typically not designed as a separate unit, but rather integrated into the overall valve assembly system.

[0007] Such a braking system for a towing vehicle is known, for example, from DE 10 2018 104 143 A1. In the valve arrangement described therein for controlling the pneumatic braking system of a trailer, a parking brake module with two parallel-connected parking brake valves and a changeover valve located on the output side is provided. The parking brake valves are designed as 3 / 2-way solenoid valves and can be switched independently of each other via separate switching units of an electronic control unit. The outputs of the parking brake valves are connected via the changeover valve to the inverted control input of the relay valve of the trailer control valve. In the unactuated, i.e., de-energized, state of both parking brake valves, the inverted control input of the relay valve is depressurized, which leads to the application of the trailer's wheel brakes in the parking brake function.When one of the two parking brake valves is switched, the inverted control input of the trailer control valve is supplied with the reservoir pressure from a pressurized supply line, which then leads to the release of the wheel brakes of the trailer vehicle.

[0008] To couple a trailer, such as a drawbar trailer or a semi-trailer, to a towing vehicle, such as a truck, agricultural tractor, or tractor unit, the following steps are required after mechanically coupling the trailer to the towing vehicle's fifth wheel coupling using the drawbar eye or kingpin and engaging the towing vehicle's parking brake: connecting the coupling heads of the trailer's supply line and brake control line to the corresponding coupling heads on the towing vehicle. While the coupling heads of a trailer typically do not have shut-off valves, the coupling heads of a towing vehicle are each equipped with a spring-loaded shut-off valve, which can be moved into its open position by means of an axially inwardly sliding pressure piece.Since, when the parking brake is engaged, both the supply line leading to the coupling head "Supply" and the brake control line of the towing vehicle leading to the coupling head "Brake" are under pneumatic pressure, the shut-off valves in the coupling heads prevent the compressed air from escaping.

[0009] As an embodiment, DE 19 38 201 C3 describes a coupling head intended for a pneumatic valve arrangement of a towing vehicle, with a shut-off valve designed as a rocker valve. Two embodiments of a coupling head intended for a pneumatic braking system of a trailer vehicle without a shut-off valve are known, for example, from DE 199 31 162 B4.

[0010] When connecting the coupling heads, a trailer-side coupling head and a towing vehicle-side coupling head are placed coaxially next to each other with their connection bores. They are then pressed together with axial pressure while releasing the shut-off valve in the towing vehicle-side coupling head, and then rotated counterclockwise by approximately 45° relative to each other, thus locking them securely. During this connection process, compressed air inevitably escapes from the towing vehicle-side coupling head, causing unpleasant noises. Furthermore, the effective force of the compressed air necessitates increased clamping force on the coupling heads, making the connection process more difficult.

[0011] From DE 10 2017 126976 A1, a braking device for motor vehicles and a method for its operation are known. The braking device comprises a first trailer coupling unit and a second trailer coupling unit. The first trailer coupling unit is connected to the output of a switching valve via a trailer supply line. This switching valve has a first switching state in which the trailer supply line can be vented via a vent outlet of the switching valve, and a second switching state in which compressed air can be supplied to the first trailer coupling unit via the trailer supply line for venting a parking brake or spring-applied parking brake of a trailer.

[0012] From DE 37 03 639 A1, an electro-pneumatic braking system for towing vehicles is known. This document describes an emergency venting valve that consists of a pneumatically controlled 3 / 2-way valve with spring return and a 3 / 2-way solenoid valve with spring return.

[0013] The present invention therefore aims to provide a valve arrangement for a towing vehicle of the type mentioned above, which allows for a more convenient and simpler connection of at least the coupling head of the supply line, and preferably also the brake control line of the trailer, when coupling a trailer to a towing vehicle. Furthermore, a method for controlling such a valve arrangement during coupling of a trailer to a towing vehicle is described, which automates the connection of at least the coupling head of the supply line, and preferably also the brake control line of the trailer, making it more convenient and easier to perform.

[0014] The device-related problem is solved by a valve arrangement having the features of claim 1. The method-related problem is solved by a method having the features of the independent method claim. Advantageous embodiments and further developments of the valve arrangement and the related control method are defined in the respective dependent claims.

[0015] Disclosed is a valve arrangement of a towing vehicle for controlling a pneumatic braking system of a trailer, which is not covered by the scope of protection of the claim. The valve arrangement comprises a trailer control valve with a supply pressure inlet for introducing compressed air and a supply pressure outlet for the controlled discharge of compressed air, and the supply pressure outlet is pneumatically connected to a coupling head "supply" of the towing vehicle. The trailer control valve can be mechanically or electronically controlled.

[0016] In this valve arrangement, it can be provided that a shut-off and venting valve is arranged in a pneumatically arranged supply pressure line upstream of the coupling head "reserve", that by means of this shut-off and venting valve the supply of compressed air to this coupling head "reserve" can be shut off and this coupling head "reserve" can be vented before connecting an associated coupling head of the trailer vehicle to the coupling head "reserve" of the towing vehicle, and that by means of the shut-off and venting valve this coupling head "reserve" can be supplied with compressed air again after connecting the associated coupling head of the trailer vehicle to the coupling head "reserve" of the towing vehicle.

[0017] The shut-off and venting valve can be structurally integrated into the trailer control valve and located in a supply pressure line therein. Alternatively, in an equivalent arrangement, the shut-off and venting valve can be located downstream of the supply pressure outlet of the trailer control valve and upstream of the coupling head ("supply") of the towing vehicle. It is also possible, with equivalent effect, for the shut-off and venting valve to be located upstream of the supply pressure inlet of the trailer control valve in a supply pressure line external to the trailer control valve, on the inlet side.

[0018] By installing a shut-off and venting valve in a supply pressure line upstream of the towing vehicle's "supply" coupling head, preferably pneumatically between the supply pressure outlet of the trailer control valve and the towing vehicle's "supply" coupling head, this coupling head can be vented and thus depressurized before the corresponding trailer coupling head is connected. Consequently, the trailer coupling head can be connected to the towing vehicle's "supply" coupling head without any escaping compressed air, thus eliminating disruptive noise and stress from compressed air forces. This significantly simplifies and improves the convenience of connecting the trailer coupling head to the towing vehicle's "supply" coupling head compared to previous methods.Furthermore, increased compressed air loss, which could previously occur during an awkwardly performed coupling process, is avoided.

[0019] In the embodiment of the construction defined by the invention, a valve arrangement of a towing vehicle for controlling a pneumatic braking system of a trailer vehicle is claimed, which has a trailer control valve with a supply pressure inlet for introducing supply compressed air and a supply pressure outlet for controlled discharge of supply compressed air, wherein the supply pressure outlet is pneumatically connected to a coupling head "reserve" of the towing vehicle, and in which a brake control pressure can be set by means of the trailer control valve and this can be directed to a coupling head "brake" of the towing vehicle via a brake control output of the trailer control valve, as well as with an electronically controllable parking brake module, by means of which an inverted control input of the trailer control valve can be vented for actuating the wheel brakes of the trailer vehicle in a parking brake function.This parking brake module has at least one solenoid valve acting as a parking brake valve. The single parking brake valve or valves can be directly integrated into the valve assembly of a towing vehicle.

[0020] According to the invention, this valve arrangement is characterized in that a shut-off and venting valve is arranged in a brake control line between the brake control output and the coupling head "brake" and / or in a supply pressure line between the supply pressure output and the coupling head "supply", by means of which, with the parking brake activated, the respective output of the trailer control valve can be shut off and the associated coupling head of the towing vehicle can be vented before the coupling heads of the trailer vehicle are connected to the coupling heads of the towing vehicle, and by means of which, after the coupling heads of the trailer vehicle are connected to the coupling heads of the towing vehicle, the respective output of the trailer control valve can be pneumatically reconnected to the associated coupling head of the towing vehicle.

[0021] By installing a shut-off and venting valve in the brake control line between the brake control output and the "brake" coupling head, and / or in the supply pressure line between the supply pressure output and the "supply" coupling head, the coupling heads of the towing vehicle can be vented and thus depressurized before the coupling heads of the trailer are connected, provided the parking brake is engaged. As a result, the coupling heads of the trailer can be connected to the coupling heads of the towing vehicle without any loss of compressed air, and therefore without disturbing noises or stress from compressed air forces. This significantly simplifies and improves the ease and convenience of connecting the coupling heads of the trailer to the coupling heads of the towing vehicle compared to previous methods. Furthermore, it also prevents the increased compressed air loss that could previously occur during an improperly executed coupling process.

[0022] According to a first embodiment of the valve arrangement just described, it is provided that a manually actuated shut-off and venting valve is arranged both in the supply pressure line between the supply pressure outlet and the coupling head "Supply" and in the brake control line between the brake control outlet and the coupling head "Brake", and that these shut-off and venting valves are designed as 3 / 2-way switching valves with an inlet port connected to the respective outlet of the trailer control valve, an outlet port connected to the respective coupling head and a venting outlet, wherein in the unactuated state the inlet port is connected to the outlet port and the venting outlet is shut off, and wherein in the actuated state the inlet port is shut off and the outlet port is connected to the venting outlet.

[0023] These shut-off and venting valves are preferably manually switchable by means of a push button and can be locked in the actuated switching position. The locking mechanism of the shut-off and venting valves can be released either by a further actuation of the respective push button or automatically after a predetermined holding time under the action of an internal return spring.

[0024] According to a second embodiment of the valve arrangement, an electrically actuated shut-off and venting valve is provided only in the supply pressure line between the supply pressure outlet and the coupling head "Supply". This shut-off and venting valve is designed as a 3 / 2-way solenoid valve with an inlet port connected to the supply pressure outlet, an outlet port connected to the coupling head "Supply", and a venting outlet. In the de-energized state, the inlet port of the shut-off and venting valve is connected to the outlet port and the venting outlet is closed. In the energized state, the inlet port of the shut-off and venting valve is closed and the outlet port is connected to the venting outlet.and that the ventilation and venting of the coupling head "brake" can be carried out via a corresponding control of the trailer control valve via the aforementioned parking brake module.

[0025] This embodiment of the valve arrangement is preferably used when the trailer control valve, the parking brake module and the shut-off and venting valve are connected to the same electronic control unit and can therefore be directly controlled by it.

[0026] According to a third embodiment of the valve arrangement, an electrically actuated shut-off and venting valve is provided both in the supply pressure line between the supply pressure outlet and the coupling head "Supply" and in the brake control line between the brake control output and the coupling head "Brake", that these shut-off and venting valves are designed as 3 / 2-way solenoid switching valves with an input port connected to the respective output of the trailer control valve, an output port connected to the respective coupling head and a venting port, that in the unenergized state of these shut-off and venting valves the input port is connected to the output port and the venting port is closed, and that in the energized state of these shut-off and venting valves the input port is closed and the output port is connected to the venting port.

[0027] This embodiment of the valve arrangement is preferably used when the parking brake module is connected to a different, second electronic control unit than the trailer control valve and the shut-off and venting valve, whereby the parking brake module can only be controlled indirectly and with a delay by the electronic control unit for the trailer control valve and for the shut-off and venting valve.

[0028] According to a fourth embodiment of the valve arrangement, an electrically actuated shut-off and venting valve is arranged in the supply pressure line between the supply pressure outlet and the coupling head "Supply", and a pneumatically pressure-controlled shut-off and venting valve is arranged in the brake control line between the brake control output and the coupling head "Brake", the electrically actuated shut-off and venting valve in the supply pressure line is designed as a 3 / 2-way solenoid valve with an inlet port connected to the supply pressure outlet, an outlet port connected to the respective coupling head and a venting outlet, and in the unenergized state, the inlet port of the electrically actuated shut-off and venting valve is connected to the outlet port and the venting outlet is closed.that in the electrically actuated shut-off and venting valve, when energized, the inlet port is shut off and the outlet port is connected to the venting outlet; that the pneumatically pressure-controlled shut-off and venting valve in the brake control line is designed as a 3 / 2-way switching valve with a control input connected to the supply pressure line between the shut-off and venting valve located there and the coupling head "Supply", an inlet port connected to the brake control output, an outlet port connected to the coupling head "Brake", and a venting outlet; and that in this pneumatically pressure-controlled shut-off and venting valve, when the control input is depressurized, the inlet port is shut off and the outlet port is connected to the venting outlet.and, in the case of a pressurized control input, the input port is connected to the output port and the vent outlet is shut off.

[0029] This embodiment of the valve arrangement is also preferably used when the parking brake module is connected to a different, second electronic control unit than the trailer control valve and the shut-off and venting valve.

[0030] To automatically terminate the shut-off of the trailer control valve outputs and the venting of the coupling heads, a pressure pulse can be introduced into the supply pressure line leading to the "Resupply" coupling head or into the brake control line leading to the "Brake" coupling head via the relevant shut-off and venting valve or via a corresponding control signal from the parking brake module. If a high pressure gradient occurs due to a small line volume, at least the relevant coupling head of the trailer vehicle is not yet connected, so the outputs of the trailer control valve should remain shut off and the coupling heads should remain vented.If, on the other hand, a low pressure gradient results due to a large line volume, at least the relevant coupling head of the trailer vehicle is already connected, so that the shut-off of the outputs of the trailer control valve and the venting of the coupling heads can be completed.

[0031] If the pressure pulse is to be introduced into the brake control line leading to the "brake" coupling head, the third embodiment of the valve arrangement provides for this control function by connecting a pneumatic pressure sensor to the brake control line between the shut-off and venting valve and the "brake" coupling head to measure the brake control pressure applied at the "brake" coupling head. In the second embodiment of the valve arrangement, the brake control pressure applied at the "brake" coupling head can be measured via a pressure sensor, typically located within the trailer control valve, which is connected to a brake control line leading to the brake control output.

[0032] If the pressure pulse is to be introduced into the supply pressure line leading to the "reserve" coupling head, in order to enable this control function, the second to fourth embodiments of the valve arrangement provide that a pneumatic pressure sensor is connected to the supply pressure line between the shut-off and venting valve and the "reserve" coupling head in order to measure the brake control pressure applied to the "reserve" coupling head.

[0033] In contrast to applying a pressure pulse to the brake control line, applying a pressure pulse to the supply line carries the risk that the wheel brakes of the trailer vehicle will be briefly released, which could cause the vehicle combination to move slightly if the braking effect of the parking brakes of the towing vehicle is insufficient to hold the entire vehicle combination.

[0034] Finally, it can be provided that, by manually actuating an electrical switch connected to the electronic control unit, the control unit triggers the activation of at least one of the two shut-off and venting valves, thereby venting the respective coupling head "supply" and / or the coupling head "brake" located downstream. As a result, the supply line and the brake control line of a trailer can be conveniently and silently connected to the shut-off and vented coupling heads of the towing vehicle, as described.

[0035] To solve the process-related problem, the invention provides a control method which has the features of the independent method claim.

[0036] A method for controlling a pneumatic braking system of a trailer vehicle by means of a valve arrangement of a towing vehicle, which is not covered by the scope of protection of the claim, is disclosed. This valve arrangement comprises a mechanically or electronically controllable trailer control valve, by means of which compressed air introduced into the valve arrangement via a supply pressure inlet can be directed via a supply pressure outlet to a coupling head "reserve" of the towing vehicle.

[0037] This method is characterized in that, before connecting a corresponding coupling head of the trailer to the "reserve" coupling head of the towing vehicle, the supply of compressed air to the "reserve" coupling head of the towing vehicle is shut off and this "reserve" coupling head of the towing vehicle is vented. Furthermore, the method provides that after connecting a corresponding coupling head of the trailer to the "reserve" coupling head of the towing vehicle, the supply of compressed air to this "reserve" coupling head of the towing vehicle is opened and it is re-pressurized with compressed air.

[0038] By isolating and venting the towing vehicle's "supply" coupling head before connecting the coupling heads of the towing vehicle and the trailer, the trailer's "supply" coupling head can be connected without any escaping compressed air, thus eliminating disruptive noise and compressed air forces. This significantly simplifies and improves the ease and convenience of connecting the trailer's coupling head to the towing vehicle's coupling head compared to previous methods.

[0039] The invention relates to a method for controlling the valve arrangement already described.

[0040] For convenient pneumatic connection between towing vehicle and trailer vehicle, it is provided that when the parking brake of the towing vehicle is engaged, the coupling head "supply" of the towing vehicle is vented according to an operating state PB = 1 and the coupling head "brake" of the towing vehicle is kept vented.

[0041] Because the towing vehicle's "reserve" coupling head is vented when the towing vehicle's parking brake is engaged, and the towing vehicle's "brake" coupling head remains vented, the corresponding coupling heads of the trailer can be connected to the towing vehicle's coupling heads without any escaping compressed air, thus eliminating disruptive noise and compressed air forces. Connecting the trailer coupling heads to the towing vehicle's coupling heads is therefore significantly simpler and more convenient than previous methods.

[0042] According to a first procedural variant, it is provided that the coupling head "supply" and the coupling head "brake" of the towing vehicle are kept vented until the parking brake of the towing vehicle is released again (actuation state PB = 0).

[0043] However, this can have the disadvantage that the storage tanks of the trailer vehicle are insufficiently filled when the vehicle combination starts driving.

[0044] According to a second method variant, which avoids the aforementioned disadvantage, it is therefore provided that the coupling head "reservoir" and the coupling head "brake" of the towing vehicle are kept vented for a predetermined period, which is dimensioned such that a driver is comfortably able within this period to leave the cab of the towing vehicle, go to the coupling area and connect the coupling heads of the trailer vehicle to the coupling heads of the towing vehicle.

[0045] According to a third method variant, which also avoids the aforementioned disadvantage, it is provided that during the venting of the coupling head "reserve" and coupling head "brake" of the towing vehicle, pressure pulses are introduced into the supply pressure line leading to the coupling head "reserve" at a predetermined time interval, that the pressure gradient in the supply pressure line is measured by a sensor, that the two coupling heads of the towing vehicle are kept vented if a high pressure gradient is present, and that the venting of the two coupling heads is stopped if a low pressure gradient is present.

[0046] This assumes that the trailer's supply pressure line is connected to the towing vehicle's "supply" coupling head, as usual, immediately after the brake control line is connected to the "brake" coupling head. A high pressure gradient exists when the trailer's supply line is not yet connected to the towing vehicle's "supply" coupling head and the volume of the supply pressure line is therefore small. Conversely, a low pressure gradient exists when the trailer's supply line is already connected to the towing vehicle's "supply" coupling head and the volume of the supply pressure line is therefore large.Since the wheel brakes of the trailer vehicle can be briefly released due to the vented coupling head "Brake" by the impulse-shaped ventilation of the coupling head "Supply", the vehicle combination may roll forward briefly if the parking brakes of the towing vehicle are unable to prevent this.

[0047] To avoid this latter disadvantage, a fourth procedural variant provides that, during the venting of the coupling head "reserve" and coupling head "brake" of the towing vehicle, pressure pulses are introduced into the brake control line leading to the coupling head "brake" of the towing vehicle at a predetermined time interval, that the pressure gradient in the brake control line is measured by a sensor, that the two coupling heads of the towing vehicle are kept vented if a high pressure gradient is present, and that the venting of the two coupling heads of the towing vehicle is terminated if a low pressure gradient is present.

[0048] This assumes that the trailer's brake control line is connected to the towing vehicle's "brake" coupling head, as usual, immediately before the reservoir pressure line is connected to the towing vehicle's "reservoir" coupling head. A high pressure gradient exists when the trailer's brake control line is not yet connected to the towing vehicle's "brake" coupling head and the volume of the brake control line is therefore small. Conversely, a low pressure gradient exists when the trailer's brake control line is already connected to the towing vehicle's "brake" coupling head and the volume of the brake control line is therefore large.

[0049] Different response times of the shut-off and venting valves, or the parking brake module and the trailer control valve, can lead to a situation where, when the towing vehicle's parking brake is engaged, the towing vehicle's "reserve" coupling head is initially still pressurized, while the towing vehicle's "brake" coupling head is already vented or being held vented. This can cause the trailer's wheel brakes to release briefly, potentially leading to a slight movement of the vehicle combination if the braking effect of the towing vehicle's parking brakes is insufficient to hold the entire vehicle combination. Therefore, to prevent the towing vehicle's wheel brakes from releasing, it is advantageous that the towing vehicle's "reserve" coupling head is vented first, and the towing vehicle's "brake" coupling head is vented or held vented slightly later, for example, by one second.

[0050] The venting of the coupling heads "reserve" and "brake" of the towing vehicle is preferably carried out via a shut-off and venting valve according to the described embodiments of the valve arrangement according to the invention, which is arranged in the brake control line between the brake control output and the coupling head "brake" of the towing vehicle and / or in the supply pressure line between the supply pressure output and the coupling head "reserve" of the towing vehicle, and / or via a parking brake module according to the relevant embodiment of the valve arrangement according to the invention.

[0051] The venting of the "supply" and "brake" coupling heads of the towing vehicle can also be triggered indirectly by a manually operated electrical switch, preferably located at the rear of the towing vehicle, which is connected to the electronic control unit via a signal line. The signal indicating the switch is actuated triggers an energization of at least one of the two shut-off and venting valves in the control unit, thus venting the respective coupling head. As a result, the driver of the towing vehicle can conveniently and silently connect the supply line and the brake control line of a trailer to the vented and shut-off "supply" and "brake" coupling heads of the towing vehicle, as described.

[0052] The pressure gradient in the relevant line is measured by means of a pneumatic pressure sensor according to the described embodiments of the valve arrangement according to the invention, which is connected to the brake control line between the shut-off and venting valve there and the coupling head "brake" of the towing vehicle or to the supply pressure line between the shut-off and venting valve there and the coupling head "supply" of the towing vehicle, or by means of a pneumatic pressure sensor connected within the trailer control valve to the brake control line leading to the coupling head "brake" of the towing vehicle.

[0053] To further illustrate the invention, a drawing with several exemplary embodiments is attached to the description. This drawing shows Fig. 1a a vehicle combination consisting of a towing vehicle and a trailer vehicle, wherein the towing vehicle has a coupling head "supply" and a coupling head "brake" for supplying pressure medium to the trailer vehicle, Fig. 1b the temporal progression of the supply pressure at the coupling head "reserve" according to the state of the art when coupling the trailer vehicle, Fig. 1c the temporal profile of the brake control pressure applied to the coupling head "brake" according to the state of the art when coupling the trailer vehicle, Fig. 1d the temporal progression of the switching state of the parking brake of a towing vehicle according to the state of the art when coupling the trailer vehicle, Fig. 2a a vehicle combination consisting of a towing vehicle and a trailer vehicle, wherein the towing vehicle has a coupling head "supply" and a coupling head "brake" for supplying pressure medium to the trailer vehicle, Fig. 2b the temporal course of the supply pressure applied to the coupling head "reserve" according to the invention when coupling the trailer vehicle, Fig. 2c the temporal progression of the brake control pressure applied to the coupling head "brake" according to the invention when coupling the trailer vehicle, Fig. 2d the temporal progression of the switching state of the parking brake of a towing vehicle according to the invention when coupling a trailer vehicle, Fig. 3a the temporal progression of the supply pressure applied to the coupling head "reserve" according to a first method variant, Fig. 3b the temporal progression of the brake control pressure applied to the coupling head "brake" according to the first method variant, Fig. 3c the temporal progression of the switching state of the parking brake of a towing vehicle according to the first method variant, Fig. 4a the temporal progression of the supply pressure applied to the coupling head "reserve" according to a second method variant, Fig. 4b the temporal progression of the brake control pressure applied to the clutch head "brake" according to the second method variant, Fig. 4c the temporal progression of the switching state of the parking brake of a towing vehicle according to the second method variant, Fig. 5a the temporal progression of the supply pressure applied to the coupling head "reserve" according to a third method variant, Fig. 5b the temporal progression of the switching state of a shut-off and venting valve arranged in a supply pressure line according to the third method variant, Fig. 5c the temporal progression of the switching state of the parking brake of a towing vehicle according to the third method variant, Fig. 6a the temporal progression of the brake control pressure applied to the clutch head "brake" according to a fourth method variant, Fig. 6b the temporal progression of the switching state of a shut-off and venting valve arranged in a brake control line according to the fourth method variant, Fig. 6c the temporal progression of the switching state of the parking brake of a towing vehicle according to the fourth method variant, Fig. 7 A first embodiment of a valve arrangement according to the invention for the towing vehicle for controlling a pneumatic braking system of a trailer vehicle in a schematic figure, Fig. 8 a second embodiment of the valve arrangement according to the invention in a schematic illustration, Fig. 9 a first variant of a third embodiment of the valve arrangement according to the invention in a schematic illustration, Fig. 10 a second variant of the third embodiment of the valve arrangement according to the invention in a schematic illustration, Fig. 11 a fourth embodiment of the valve arrangement according to the invention in a schematic illustration, Fig. 12 a fifth embodiment of the valve arrangement according to the invention in a schematic illustration, Fig. 13 a sixth embodiment of the valve arrangement according to the invention in a schematic illustration, and Fig. 14 A known valve arrangement of a towing vehicle for controlling a pneumatic braking system of a trailer vehicle in a schematic illustration.

[0054] The Figur 1a Figure 1 shows a known vehicle combination consisting of a towing vehicle 2 and a trailer 4 coupled to it. For brake control of the trailer 4's brakes, its two-line compressed air brake system is connected to the towing vehicle 2 via two flexible compressed air lines. The first compressed air line is a supply line 10, which is connected to a coupling head "Supply" (red) 6 of the towing vehicle 2. The second compressed air line is a brake control line 12, which is connected to the coupling head "Brake" (yellow) 8. Figur 1b bis 1d The figures illustrate the state of the art by showing, in sequence, the time course of the reservoir pressure pV at the coupling head "Reserve" (red) 6, the time course of the brake control pressure pB at the coupling head "Brake" (yellow) 8, and the time course of the actuation state of the parking brake PB of the towing vehicle 2 according to current practice, whereby in Fig. 1d The value 0 represents the actuation state "brake released" and the value 1 represents "brake engaged". The term "brake in open position" can be used synonymously with "brake released", and the term "brake in closed position" can be used instead of "brake engaged".

[0055] How Fig. 1b To illustrate, according to the state of the art, before and during the pneumatic coupling of the trailer 4 to the towing vehicle 2, the supply pressure p V of, for example, 7.5 x 10 5 < Pa is permanently present at the coupling head "reservoir" 6. Fig. 1c The coupling head "brake" 8, however, is vented (pB = 0 Pa) when the service brake of the towing vehicle 2 is released and the parking brake PB of the towing vehicle 2 is engaged. When the parking brake PB of the towing vehicle 2 is engaged at time t1, the coupling head "brake" 8 is vented and shortly thereafter is under a brake control pressure corresponding to the supply pressure (pB = 7.5 x 105 Pa). Therefore, after the trailer 4 has been mechanically coupled to the towing vehicle 2 and the parking brake PB of the towing vehicle 2 has been engaged, the connection of the supply pressure line 10 and the brake control line 12 of the trailer 4 to the corresponding coupling heads 6 and 8 of the towing vehicle 2 must be carried out using pressurized coupling heads 6 and 8. This is comparatively inconvenient and difficult due to the escaping compressed air and the effective air pressure forces.

[0056] The Fig. 2a shows the same vehicle combination as Fig. 1a , on which the inventive method can also be operated to great advantage as described below. In this regard, it shows Fig. 2b the time-dependent pressure profile of the supply pressure pv applied to the coupling head "reserve" (red) 6, which Fig. 2c the time-dependent pressure profile of the brake control pressure p B applied to the coupling head "brake" (yellow) 8 of the towing vehicle 2, and the Fig. 2d The actuation state of the parking brake PB of the towing vehicle 2 (0 = "brake released"; 1 = "brake engaged") according to the invention. The coupling head "reservoir" 6 is initially under the reservoir pressure pV = 7.5 x 105 Pa, but it is vented when the parking brake PB of the towing vehicle 2 is engaged, which occurs at time t1. Furthermore, the coupling head "brake" 8 is not vented after the parking brake PB of the towing vehicle 2 is engaged, but remains vented (pB = 0 Pa). The coupling of the supply and brake control lines 10, 12 of the trailer vehicle 4 to the associated coupling heads 6, 8 of the towing vehicle 2, which takes place after the mechanical coupling of the trailer vehicle 4 to the towing vehicle 2 and the application of the parking brake PB in the towing vehicle 2, can thus be carried out with unpressurized coupling heads 6, 8, which is significantly more convenient and easier than the previous practice.

[0057] In other words, according to the invention, when a trailer 4 equipped with a two-line compressed air brake system, i.e., with a supply pressure line 10 and a brake control line 12, is coupled to a towing vehicle 2, the coupling head "supply" 6 on the towing vehicle 2 is vented when the parking brake is engaged, and the coupling head "brake" 8 on the towing vehicle 2 is kept vented. This allows the coupling heads of the trailer 4 to be connected to the coupling heads 6, 8 of the towing vehicle 2 without any loss of compressed air and thus without disruptive noise or compressed air forces. This also makes connecting the coupling heads of the trailer 4 significantly simpler and more convenient than before.

[0058] In the following, four method variants of the inventive method for controlling a valve arrangement of a towing vehicle 2 with regard to the control of a pneumatic brake system of a trailer vehicle 4 when coupling the trailer vehicle 4 to the towing vehicle 2 are explained on the basis of pressure curves of the supply pressure p V applied to the coupling head "reserve" (red) 6 and the brake control pressure p B applied to the coupling head "brake" (yellow) 8 of the towing vehicle 2 as well as the actuation state of the parking brake of the towing vehicle 2.

[0059] As the Figuren 3a bis 3c To illustrate, a first procedural variant provides that, starting with the application of the parking brake (PB = 1) at time t 1 and continuing until the parking brake is released (PB = 0) at time t 2, the coupling heads "Supply" and "Brake" 6, 8 are vented or kept vented. Thus, when the parking brake is applied in the towing vehicle 2 at time t 1, the coupling head "Supply" 6 is vented, while the coupling head "Brake" 8, which would normally be vented, remains vented. The wheel brakes of the trailer are nevertheless applied when the supply line 10 and the brake control line 12 of the trailer 4 are connected to the coupling heads 6, 8 of the towing vehicle 2, because they are actuated via a trailer brake valve in its disconnection protection function due to the depressurized supply line 10.

[0060] The pressureless state of both coupling heads 6 and 8 is maintained until the parking brake in the towing vehicle is released (PB = 0), which occurs at time t2. The "supply" coupling head 6 of the towing vehicle 2, and thus also the supply line 10 of the trailer vehicle 4, are then pressurized with the supply pressure of pV = 7.5 x 10⁵ < Pa. The "brake" coupling head 8 of the towing vehicle 2, and thus also the brake control line 12 of the trailer vehicle 4, remains vented, i.e., pressureless, since the parking brake is now released.

[0061] According to a second procedural variant, which is described below using the Figuren 4a bis 4c As explained, the coupling heads "reservoir" and "brake" 6, 8 are designed to be vented for a predetermined period Δt Z. This period Δt Z is dimensioned such that a driver can comfortably leave the cab of the towing vehicle 2, access the coupling area of ​​the towing vehicle 2, and connect the coupling heads of the trailer 4 to the coupling heads 6, 8 of the towing vehicle 2 within this timeframe. After this period Δt Z has elapsed at time tz, both the coupling head "reservoir" 6 and the coupling head "brake" 8 are pressurized with the reservoir pressure, so that the wheel brakes of the trailer 4 remain engaged despite the reservoir pressure line 10 now being pressurized. Only when the parking brake is applied at time t 2 is the coupling head "brake" 8 of the towing vehicle 2 and thus also the brake control line 12 of the trailer vehicle 4 vented, thereby releasing the wheel brakes of the trailer vehicle 4.

[0062] According to a third procedural variant, which is described below using the Figuren 5a bis 5c As explained, it is provided that during the venting of the coupling heads "reserve" and "brake" 6, 8, pressure pulses are introduced into the supply pressure line leading to the coupling head "reserve" 6 at a predetermined time interval Δt T, that the pressure gradient in the supply pressure line is measured by a sensor, and that the two coupling heads 6, 8 are kept vented if a high pressure gradient is present, and that the venting of the coupling heads 6, 8 is stopped when a low pressure gradient is present.

[0063] To illustrate this method variant, the diagram shows... Fig. 5a the pressure curve of the supply pressure p V applied to the coupling head "reservoir" (red) 6, in the diagram of the Fig. 5b the switching state of a shut-off and venting valve VA / E (0 = unactuated, 1 = switched) arranged in the relevant supply pressure line between a supply pressure outlet of a trailer control valve and the coupling head "Supply" 6, and in the diagram of the Fig. 5c The actuation state of the parking brake PB of the towing vehicle 2 (0 = released, 1 = engaged) is shown over time t. The coupling head "Reserve" 6 is connected to the supply pressure outlet of the trailer control valve via the unactuated shut-off and venting valve VA / E. In the switched or actuated state of the shut-off and venting valve VA / E, the supply pressure outlet of the trailer control valve is closed, and the coupling head "Reserve" 6 is connected to a vent outlet and is therefore depressurized.

[0064] At time t1, the parking brake PB in the towing vehicle is engaged (PB = 1), which causes the shut-off and venting valve VA / E to switch (VA / E = 1), thus venting the "reservoir" coupling head 6. From time t3 onwards, a pressure pulse is repeatedly introduced into the supply pressure line at intervals of Δt T by briefly switching off the shut-off and venting valve VA / E, and the resulting pressure gradient is measured by a sensor. The pressure pulses introduced between times t3 and t3', t4 and t4', and t5 and t5' have a pulse duration Δt I of approximately 1 second. The time interval Δt T of the pressure pulses can, for example, be 10 seconds.The first two pressure pulses (between times t3 and t3' and t4 and t4') result in a high pressure gradient, which suggests a small line volume and that the supply pressure line 10 of the trailer 4 has not yet been connected to the "supply" coupling head 6 of the towing vehicle 2. Therefore, both coupling heads 6 and 8 remain vented for the time being.

[0065] At the later time t K, the supply pressure line 10 of the trailer 4 is connected to the "supply" coupling head 6, so that the subsequent third pressure pulse (between times t5 and t5') results in a lower pressure gradient than before due to the increased line volume. Therefore, the venting of the "supply" coupling head 6 is terminated by the permanent deactivation of the shut-off and venting valve VA / E (VA / E = 0), and the "brake" coupling head 8 is also vented again, thus preventing the wheel brakes of the trailer 4 from releasing. It is assumed that the connection of the supply pressure line 10 of the trailer 4 to the "supply" coupling head 6 of the towing vehicle 2 occurs, as usual, immediately after the connection of the brake control line 12 to the "brake" coupling head 8.The coupling head "Brake" 8 is only vented again when the parking brake PB in the towing vehicle 2 is released, which occurs at time t2. Since the wheel brakes of the trailer vehicle 4 can be briefly released by the impulse-like venting of the coupling head "Supply" 6 due to the vented coupling head "Brake" 8, the vehicle combination 2, 4 may roll forward briefly if the parking brakes of the towing vehicle 2 are too weak to prevent this.

[0066] According to a fourth procedural variant, which is described below based on the Figuren 6a bis 6c As explained, the disadvantage just described does not exist. It is provided that during the venting of the coupling heads "reservoir" and "brake" 6, 8, pressure pulses are introduced into the brake control line leading to the coupling head "brake" 8 at a predetermined time interval Δt T, that the pressure gradient in the brake control line is measured by a sensor, that the coupling heads 6, 8 are kept vented if a high pressure gradient is present, and that the venting of the coupling heads 6, 8 is stopped if a low pressure gradient is present.

[0067] To illustrate this procedural variant, the following are shown in the Fig. 6a the pressure curve of the brake control pressure p B applied to the clutch head "brake" (yellow) 8 , in the Fig. 6b the switching state of a shut-off and venting valve VA / E (0 = unactuated, 1 = switched) arranged in the relevant brake control line between a brake control output of a trailer control valve and the coupling head "brake" 8, as well as Fig. 6c The actuation state of the parking brake PB (0 = released, 1 = engaged) of the towing vehicle 2 is shown over time t. The coupling head "Brake" 8 is connected to the brake control output of the trailer control valve via the unactuated shut-off and venting valve VA / E. When the shut-off and venting valve VA / E is switched, the brake control output of the trailer control valve is closed, and the coupling head "Brake" 8 is connected to a venting output and is therefore depressurized.

[0068] At time t1, the parking brake PB in the towing vehicle is engaged (PB = 1), which causes the shut-off and venting valve VA / E to switch (VA / E = 1), so that the coupling head "brake" 8 remains vented. From time t3 onwards, a pressure pulse is repeatedly introduced into the brake control line at intervals of Δt I by briefly switching off the shut-off and venting valve VA / E, and the resulting pressure gradient is measured by a sensor. The pressure pulses introduced between times t3 and t3', t4 and t4', and t5 and t5' have a pulse duration Δt I of approximately 1 second. The time interval Δt T of the pressure pulses can, for example, be 10 seconds.The first two pressure pulses (between times t3 and t3' and t4 and t4') result in a high pressure gradient, which suggests a small line volume and that the brake control line 12 of the trailer vehicle 4 has not yet been connected to the "brake" coupling head 8 of the towing vehicle 2. Therefore, both coupling heads 6 and 8 remain vented for the time being.

[0069] At the later time t K, the brake control line 12 of the trailer 4 is connected to the "brake" coupling head 8 of the towing vehicle 2, so that the subsequent third pressure pulse (between times t5 and t5') results in a lower pressure gradient than before due to the increased line volume. Therefore, the venting of the "brake" coupling head 8 is stopped by the permanent deactivation of the shut-off and venting valve VA / E (VA / E = 1), and the "reservoir" coupling head 6 is also vented again, thus preventing the wheel brakes of the trailer 4 from releasing. It is assumed that the connection of the brake control line 12 of the trailer 4 to the "brake" coupling head 8 of the towing vehicle 2 occurs, as usual, immediately before the connection of the reservoir pressure line 10 to the "reservoir" coupling head 6.The coupling head “brake” 8 will only be vented again when the parking brake PB in the towing vehicle 2 is deployed, which occurs at time t2.

[0070] Six embodiments of valve arrangements 14.1, 14.2, 14.3, 14.3', 14.4, 14.5, 14.6 according to the invention for a towing vehicle 2 for controlling a pneumatic braking system of a trailer vehicle 4 are explained below with reference to schematic figures. These valve arrangements are further developments according to the invention of a Fig. 14 The illustrated valve arrangement 14 of a hydraulically braked tractor is known from WABCO publication 815 020 082 3 "Compressed Air Brake System for Agriculture and Forestry / Product Catalog", page 105. The first embodiment of the valve arrangement 14.1 according to the invention Fig. 7 This enables direct manual venting of the two coupling heads 6, 8 for connecting the supply line 10 and the brake control line 12 of a trailer vehicle 4 by a driver of the towing vehicle. The further four embodiments of the valve arrangement according to the invention 14.2, 14.3, 14.3', 14.4 enable automated venting of the coupling heads 6, 8 for connecting the supply line 10 and the brake control line 12 of a trailer vehicle 4 according to the method variants described above.

[0071] The in Fig. 14 The illustrated known valve arrangement 14 comprises an electronically controlled trailer control valve 16, a hydraulically controlled backup valve 18, an electronically controlled parking brake module 20, and an electronic control unit (ECU) 22. The parking brake module 20 is a structurally or graphically tightly integrated assembly of several components that interact circuit-wise, and this will be described in more detail below.

[0072] The trailer control valve 16 comprises a pneumatically controlled relay valve 28, a pneumatically controlled breakaway valve 30, an inlet valve 24, an outlet valve 26, and a pneumatic pressure sensor 32. The inlet valve 24 and the outlet valve 26 are each designed as a 2 / 2-way solenoid switching valve, specifically as a pulse valve, by means of which the pneumatic control pressure applied to a control input 38 of the relay valve 28 can be adjusted. The switching solenoids of the inlet valve 24 and the outlet valve 26 are connected to the electronic control unit 22 via electrical control lines 34, and the pressure sensor 32 is connected to the electronic control unit 22 via an electrical sensor line 36.

[0073] The inlet valve 24 is closed when de-energized and open when energized. The outlet valve 26 is open when de-energized and closed when energized. A control pressure line 42, which leads from the outlet of the inlet valve 24 and from the inlet of the outlet valve 26 to a control input of the breakaway valve 30 and via a branch line 42a to a direct first control input 38 of the relay valve 28, can be connected via the inlet valve 24 to an internal supply pressure line 44 and via the outlet valve 26 to a vent line 46 leading to a vent outlet p3. The internal supply pressure line 44 is connected to a supply pressure input p11 of the trailer control valve 16.

[0074] In its installed state, the trailer control valve 16 has an external supply pressure line 90 of a pneumatic compressed air supply system of the towing vehicle 2 connected to the supply pressure inlet p11. This supply pressure line carries a pressure of approximately 7.5 x 10⁵ Pa when the towing vehicle 2's drive motor is running. A line section 44a branching off from the supply pressure line 44 is routed via the cut-off valve 30 and an outlet-side line section 44b to a supply pressure outlet p21 of the trailer control valve 16. A coupling head "Supply" (red) 6 is connected to the supply pressure outlet p21 via an external supply pressure line 48.

[0075] A supply pressure inlet of the relay valve 28 is connected to the internal supply pressure line 44 via the branch line section 44a and the output line section 44b. A vent outlet of the relay valve 28 is connected via a connecting line 46a to the vent line 46 leading to the vent outlet p3. A brake control output of the relay valve 28 is routed via an output brake control line 50 to a brake control output p22 of the trailer control valve 16. A brake control line 56 connected to the brake control output p22 is routed to a first inlet of a changeover valve 58, to whose output a coupling head "brake" (yellow) 8 is connected via an external brake control line 60. The pressure sensor 32 on the trailer control valve side is connected via a sensor pressure line 52 to the output brake control line 50.Another internal control pressure line 54 is arranged between an inverted control input p43 of the trailer control valve 16 and an inverted second control input 40 of the relay valve 28.

[0076] The backup valve 18 comprises a hydraulically controlled relay valve 62, an electronically controlled redundancy valve 64, and a hydraulic pressure sensor 66. A control input of the backup valve-side relay valve 62 is connected via an internal control pressure line 68 to a hydraulic control pressure input p42 of the backup valve 18. When the backup valve 18 is installed, the control pressure input p42 of the backup valve 18 is connected via a connecting line 92 to a brake line of a hydraulic brake circuit of the towing vehicle 2. The backup valve-side pressure sensor 66 is also connected to the internal control pressure line 68 of the backup valve 18. An unspecified supply pressure input of the backup valve-side relay valve 62 is connected via a supply pressure input p11' of the backup valve 18 and a connecting line 90' ​​to the external supply pressure line 48 leading to the coupling head "supply" (red) 6.A brake control output of the relay valve 62 of the backup valve 18 can be connected to a second input of the changeover valve 58 via the redundancy valve 64 and an external brake control line 74. When the supply pressure input p11' is pressurized, a brake control pressure is generated in the relay valve 62 depending on the brake pressure applied to the brake pressure input p42. When the redundancy valve 64 is open, this brake control pressure is routed to the changeover valve 58 via the external brake control line 74. The changeover valve 58 then routes the higher brake control pressure from either the brake control line 56 of the trailer control valve 16 or the brake control line 74 of the backup valve 18 via the brake control line 60 to the coupling head "brake" 8.

[0077] The redundancy valve 64 is designed as a 3 / 2-way solenoid valve, the output of which is connected to the second input of the changeover valve 58 via the external brake control line 74. In the de-energized state, the redundancy valve 64 is in the position described in Fig. 14 The open position shown, in which the external brake control line 74 is connected to the brake control output of the relay valve 62. In the energized state, the redundancy valve 64 is removed from the position shown. Fig. 14 The open position shown is switched to its closed position, in which the brake control output of the relay valve 62 is shut off and the external brake control line 74 is connected to a vent output of the redundancy valve 64 and is therefore depressurized. The switching solenoid of the redundancy valve 64 is connected to the electronic control unit 22 via electrical control lines 70 and the pressure sensor 66 via electrical sensor lines 72.

[0078] The parking brake module 20 serves to control the trailer control valve 16 at the inverted control pressure input p43 for actuating the wheel brakes of a coupled trailer 4 in a parking brake or auxiliary brake function. In this embodiment, the parking brake module 20 comprises two parallel-connected parking brake valves 76, 78 and a changeover valve 80 connected downstream of these on the output side of the parking brake module. When the parking brake module 20 is installed, the output of the changeover valve 80 is connected to the inverted control pressure input p43 of the trailer control valve 16.

[0079] The two parking brake valves 76, 78 are designed as 3 / 2-way solenoid valves, whose switching solenoids are connected to the electronic control unit 22 via electrical control lines 86 when the parking brake module 20 is installed. The electronic control unit 22 is also connected via a data bus 88, which is usually a CAN bus, to other electronic control units, sensors, and switches of the towing vehicle 2 and a coupled trailer 4. Each of the two parking brake valves 76, 78 allows a brake control line 82, 84, connected to one of the inputs of the changeover valve 80, to be alternately connected to a branch of a line section 90" branching off from the external supply pressure line 90 or to a vent outlet.The changeover valve 80 on the parking brake module side directs the higher brake control pressure from the brake control line 82 of the first parking brake valve 76 or from the brake control line 84 of the second parking brake valve 78 via the inverted brake control pressure input p43 of the trailer control valve 16 and the internal brake control line 54 therein to the inverted control input 40 of the relay valve 28. One parking brake valve, for example the first parking brake valve 76, serves as the main parking brake valve, and the second parking brake valve 78 serves as a redundant parking brake valve, which takes effect in the event of a fault instead of the main parking brake valve. The pressures directed by the two parking brake valves 76 and 78 are identical.

[0080] In the de-energized state of the two parking brake valves 76, 78, the associated brake control lines 82, 84, and thus the inverted control input 40 of the relay valve 28, are depressurized. This triggers a maximum brake control pressure in the relay valve 28 of the trailer control valve 16, which is routed via the internal brake control line 50, the brake control output p22, the brake control line 56, the first changeover valve 58, and the external brake control line 60 to the coupling head "Brake" (yellow) 8. This applies to a coupled trailer 4, thereby applying maximum brake pressure to its wheel brake cylinders via the trailer brake valve, thus engaging the parking brake or auxiliary brake function.

[0081] When one of the two parking brake valves 76, 78 is actuated, i.e., switched, the corresponding brake control line 82; 84, and thus the inverted control input 40 of the relay valve 28, is pressurized with the supply pressure from line section 90" of the external supply pressure line 90. This vents the wheel brake cylinders of a coupled trailer 4 via the trailer brake valve, thereby releasing the wheel brakes in the parking brake or auxiliary brake function. During normal driving operation of the towing vehicle, one of the two parking brake valves 76; 78 is energized and thus switched, so that the wheel brakes of a coupled trailer 4 are then released. The second parking brake valve of the two parking brake valves 76; 78 remains in the deactivated position and, as mentioned, is only activated in the event of a fault.For redundancy reasons, the electronic control unit has 22 separate switching units for independent switching operation of the parking brake valves 76, 78, which are designed in such a way that the respective switching state of the parking brake valves 76, 78 is maintained automatically and can only be actively changed.

[0082] In normal operation of this known valve arrangement 14, the trailer control valve 16 is activated and the backup valve 18 is deactivated. Likewise, the parking brake module 20 remains deactivated as long as the electronic control unit 22 does not receive a request signal to actuate the wheel brakes of the trailer 4 in a parking brake or auxiliary brake function. For example, the activation of the trailer control valve 16 and the deactivation of the backup valve 18 are effected by the switching signal of an electrical switch located in or on a foot brake valve of the towing vehicle 2 (not shown here). This switch closes after a short free stroke of a plunger that is axially displaceable via a brake pedal. When the corresponding switching signal, indicating the start of a braking process, is present, the backup valve 18 is deactivated by switching the redundancy valve 64 to its closed position.

[0083] In the trailer control valve 16, a control pressure applied to the direct control input 38 of the relay valve 28 is then controlled by correspondingly actuating the inlet and outlet valves 24, 26, depending on an available electronic brake value signal. This control pressure is converted in the relay valve 28 into a corresponding brake control pressure, which is fed to the coupling head "brake" (yellow) 8 via the first changeover valve 58. The corresponding brake value signal can be detected by a position sensor arranged in or on the foot brake valve with a signal transmitter in actuating contact with the plunger there. Alternatively, the brake value signal can be generated by means of a pressure sensor connected to a brake line of the towing vehicle 2.In the present case, the function of the brake force sensor can therefore also be fulfilled by the pressure sensor 66 located in the backup valve 18, which is connected to a hydraulic brake line of the towing vehicle 2 via the internal control pressure line 68 and the external connection line 92. Up to this point, with regard to the... Fig. 14 The known state of the art is described.

[0084] According to the in Fig. 7 In the illustrated first embodiment of a valve arrangement 14.1 according to the invention, a manually actuated shut-off and venting valve 94, 96 is arranged both in the supply pressure line 48 between the supply pressure outlet p21 of the trailer control valve 16 and the coupling head "supply" 6, and in the brake control line 60 between the outlet of the first changeover valve 58 and the coupling head "brake" 8. The second shut-off and venting valve 96 could, however, also be arranged in the brake control line 56 between the brake control outlet p22 of the trailer control valve 16 and the first inlet of the first changeover valve 58.

[0085] The two shut-off and venting valves 94 and 96 are designed as 3 / 2-way switching valves with an inlet port connected to the output p21 of the trailer control valve 16 or the output of the first changeover valve 58, respectively, an outlet port connected to the respective coupling head 6 or 8, and a vent port. In the unactuated state of the shut-off and venting valves 94 and 96, the respective inlet port is connected to the output port p21 and the vent port is closed. In the actuated state of the shut-off and venting valves 94 and 96, the respective inlet port is closed and the outlet port is connected to the vent port.

[0086] The two shut-off and venting valves 94 and 96 are shown here as examples, each manually switchable by means of a push button and lockable in the switched position. Alternatively, the locking mechanism of the shut-off and venting valves can be released automatically by pressing the respective push button again or after a predetermined holding time due to the action of an internal return spring.

[0087] When a driver has reversed the towing vehicle 2 to couple a trailer vehicle 4 and mechanically coupled the trailer vehicle 4 and engaged the parking brake, he can depressurize the coupling heads 6, 8 of the towing vehicle 2 by manually operating the pushbuttons of the shut-off and venting valves 94, 96.

[0088] This makes connecting the coupling heads of the trailer 4, which should be done in the sequence brake control line 12 before supply pressure line 10, relatively simple and convenient, without disruptive noise or air pressure. Afterwards, the coupling heads 6, 8 are vented again by resetting the shut-off and venting valves 94, 96 to their initial position, either by pressing the pushbuttons again or automatically.

[0089] In the Fig. 8 In the second embodiment of the valve arrangement 14.2 shown in the illustration, an electrically actuated shut-off and venting valve 98 is arranged only in the supply pressure line 48 between the supply pressure outlet p21 of the trailer control valve 16 and the coupling head "supply" 6. This valve is connected to the electronic control unit 22 via electrical control lines 100. The shut-off and venting valve 98 is designed as a 3 / 2-way solenoid valve with an inlet port connected to the supply pressure outlet p21, an outlet port connected to the coupling head "supply" 6, and a vent port. In the de-energized state of the shut-off and venting valve 98, the inlet port is connected to the outlet port and the vent port is closed. In the energized state of the shut-off and venting valve 98, the inlet port is closed and the outlet port is connected to the vent port.While the ventilation and venting of the coupling head "Supply" 6 is thus carried out via a corresponding control of the shut-off and venting valve 98, the ventilation and venting of the coupling head "Brake" 8 is provided for via a corresponding control of the trailer control valve 16 by the parking brake module 20.

[0090] To measure the reservoir pressure pV at the coupling head "Reserve" 6, a pneumatic pressure sensor 102 is connected to the reservoir pressure line 48 between the shut-off and vent valve 98 and the coupling head "Reserve" 6. This sensor is connected to the electronic control unit 22 via electrical sensor lines 104. The brake control pressure pB at the coupling head "Brake," on the other hand, can be measured via the pressure sensor 32, which is connected to the internal brake control line 50 within the trailer control valve 16. As already mentioned, the pressure sensor 32 is connected to the brake control line 50 via a sensor pressure line 52.

[0091] With the parking brake engaged in the towing vehicle 2, the coupling heads 6, 8 in this embodiment of the valve arrangement 14.2 can be controlled by means of the electronic control unit 22 according to one of the four previously described method variants (see Fig. 3 bis Fig. 6 ) be vented. This means, according to the first procedure variant, until the parking brake of the towing vehicle 2 is released again; or according to the second procedure variant, until a predetermined period sufficient for connecting the coupling heads of the trailer vehicle 4 has elapsed; or according to the third procedure variant, until a pressure pulse repeatedly introduced into the supply pressure line 48 by briefly opening the shut-off and venting valve 98 results in a low pressure gradient; or according to the fourth procedure variant, until a pressure pulse repeatedly introduced into the brake control line 60 by correspondingly controlling the parking brake module 20 via the trailer control valve 16 results in a low pressure gradient.

[0092] The in Fig. 9 The illustrated first variant of the third embodiment of the valve arrangement 14.3 according to the invention differs from the second embodiment of the valve arrangement 14.2 according to Fig. 8 This is because the two parking brake valves 76, 78 of the parking brake module 20 are connected via the control lines 86 to a further electronic control unit (not shown here). This can lead to a delayed response when the parking brake module 20 is activated by the electronic control unit 22 of the trailer control valve 16. Therefore, in this embodiment of the valve arrangement 14.3, an electrically actuated shut-off and venting valve 106 is additionally arranged in the brake control line 60 between the output of the first changeover valve 58 and the coupling head "brake" 8. This shut-off and venting valve 106 is connected to the electronic control unit 22 via electrical control lines 108. However, this shut-off and venting valve 106 could also be arranged in the brake control line 56 between the brake control output p22 of the trailer control valve 16 and the first input of the first changeover valve 58.

[0093] This shut-off and venting valve 106 is designed as a 3 / 2-way solenoid valve with an inlet port connected to the outlet of the first changeover valve 58, an outlet port connected to the coupling head "brake" 8, and a vent port. In the de-energized state of the shut-off and venting valve 106, the inlet port is connected to the outlet port and the vent port is closed. In the energized state of the shut-off and venting valve 106, the inlet port is closed and the outlet port is connected to the vent port. In this embodiment of the valve arrangement 14.3, the venting and purging of the coupling head "brake" 8 is thus effected by corresponding control of the additionally integrated shut-off and venting valve 106.

[0094] With the parking brake engaged in the towing vehicle 2, the two coupling heads 6, 8 in this variant of the third embodiment of the valve arrangement 14.3 can be controlled by the electronic control unit 22 in accordance with one of the first three previously described method variants (see Fig. 3 bis Fig. 5 ) be vented. This means, according to the first procedure variant, until the parking brake of the towing vehicle 2 is released again, or according to the second procedure variant, until a predetermined period sufficient for connecting the coupling heads of the trailer vehicle 4 has elapsed, or according to the third procedure variant, until a pressure pulse repeatedly introduced into the supply pressure line 48 by briefly opening the shut-off and venting valve 98 results in a low pressure gradient.

[0095] One in Fig. 10 The illustrated second variant of the third embodiment of the valve arrangement 14.3' according to the invention differs from the first variant of the third embodiment of the valve arrangement 14.3 according to the invention. Fig. 9 only by connecting a pneumatic pressure sensor 102' to the brake control line 60 between the shut-off and venting valve 106 and the coupling head "brake" 8 instead of the pneumatic pressure sensor 102 connected to the supply pressure line 48.

[0096] With the parking brake engaged in the towing vehicle 2, the two coupling heads 6, 8 in this variant of the third embodiment of the valve arrangement 14.3' can be controlled by the electronic control unit 22 in accordance with one of the first two previously described method variants (see Fig. 3 and Fig. 4 ) as well as the fourth procedure variant described above (see Fig. 6 ) be vented. This means, according to the first procedure variant, until the parking brake of the towing vehicle 2 is released again, or according to the second procedure variant, until a predetermined period sufficient for connecting the coupling heads of the trailer vehicle 4 has elapsed, or according to the fourth procedure variant, until a pressure pulse repeatedly introduced into the brake control line 60 by briefly opening the shut-off and venting valve 106 results in a low pressure gradient.

[0097] Furthermore, in the valve arrangement 14.3' according to Fig. 10 It is provided, by way of example, that the two shut-off and venting valves 98, 106 can be manually and indirectly operated by a person, usually the driver of the towing vehicle 2, if necessary. For this purpose, a manually operated electrical switch 97 is arranged at the rear of the towing vehicle 2, which is connected to the electronic control unit 22 via a signal line 99. The switch 97 and the electronic control unit 22 are designed such that actuation of this switch 97 triggers the energization of at least one of the two shut-off and venting valves 98, 106, thereby shutting off and venting the respective associated coupling head 6, 8. As a result, the supply line 10 and the brake control line 12 of a trailer 4 can be conveniently and silently connected to the vented and shut-off coupling heads 6, 8 of the towing vehicle 2, as described.

[0098] The in Fig. 11 The fourth embodiment of the valve arrangement 14.4 shown in the illustration differs from the first variant of the third embodiment of the valve arrangement 14.3 according to Fig. 9 by the fact that a pneumatically pressure-controlled shut-off and venting valve 110 is arranged in the brake control line 60 between the output of the first changeover valve 58 and the coupling head "brake" 8. However, this shut-off and venting valve 110 could also be arranged in the brake control line 56 between the brake control output p22 of the trailer control valve 16 and the first input of the first changeover valve 58.

[0099] This shut-off and venting valve 110 is designed as a 3 / 2-way switching valve with a control input connected to the supply pressure line 48 between the shut-off and venting valve 98 located there and the coupling head "Supply" 6, an input port connected to the output of the first changeover valve 58, an output port connected to the coupling head "Brake" 8, and a vent port. When the control input of this shut-off and venting valve 110 is depressurized, the input port is closed and the output port is connected to the vent port. When the control input of the shut-off and venting valve 110 is pressurized, the input port is connected to the output port and the vent port is closed. Thus, the clutch head "brake" 8 is vented when the clutch head "reservoir" 6 is vented and therefore pressurized, and then vented when the clutch head "reservoir" 6 is vented and therefore pressureless.

[0100] With the parking brake engaged in the towing vehicle 2, the two coupling heads 6, 8 can, in this embodiment of the valve arrangement 14.4, be controlled by the electronic control unit 22 according to one of the first three previously described method variants (see Fig. 3 bis Fig. 5 ) be vented. This means, according to the first procedure variant, until the parking brake of the towing vehicle 2 is released again, or according to the second procedure variant, until a predetermined period sufficient for connecting the coupling heads of the trailer vehicle 4 has elapsed, or according to the third procedure variant, until a pressure pulse repeatedly introduced into the supply pressure line 48 by briefly opening the shut-off and venting valve 98 results in a low pressure gradient.

[0101] The in Fig. 12 The fifth embodiment of the valve arrangement 14.5 shown as an example differs from the second embodiment of the valve arrangement 14.2 according to Fig. 8 The same operating principle is achieved by arranging the electronically controlled shut-off and venting valve 112 directly upstream of the supply pressure outlet p21 of the trailer control valve 16 in an internal supply pressure line 44b. Both this supply pressure line 44b and the shut-off and venting valve 112 are structurally integrated into the trailer control valve 16. The shut-off and venting valve 112 is connected to the electronic control unit 22 via electrical control lines 101. With this valve arrangement 14.5, the supply pressure outlet p21 of the trailer control valve 16 can also be shut off and, at the same time, the coupling head "reservoir" 6 of the towing vehicle 2 can be vented.

[0102] Finally, it shows Fig. 13 An exemplary sixth embodiment of the valve arrangement 14.6 according to the invention. This differs from the second embodiment of the valve arrangement 14.2 according to Fig. 8 The same operating principle is achieved by arranging the electronically controlled shut-off and venting valve 114 upstream of the supply pressure inlet p11 of the trailer control valve 16 in the external supply pressure line 90. The shut-off and venting valve 114 is positioned upstream of the branch of the line section 90" leading to the parking brake module 20 for supply compressed air. The shut-off and venting valve 114 is connected to the electronic control unit 22 via electrical control lines 103. This valve arrangement 14.6 enables the complete shut-off of the valve arrangement 14.6 from the supply of compressed air and simultaneously vents the coupling head "supply" 6 of the towing vehicle 2. List of reference symbols (part of the description)

[0103] 2 Towing vehicle 4 Trailer vehicle 6 Coupling head "Supply" (red) 8 Coupling head "Brake" (yellow) 10 Supply pressure line 12 Brake control line 14 Valve arrangement (prior art) 14.1 Valve arrangement (first embodiment according to the invention) 14.2 Valve arrangement (second embodiment according to the invention) 14.3 Valve arrangement (third embodiment according to the invention, first variant) 14.3 Valve arrangement (second variant of valve arrangement 14.3) 14.4 Valve arrangement (fourth embodiment according to the invention) 14.5 Valve arrangement (fifth embodiment according to the invention) 14.6 Valve arrangement (sixth embodiment according to the invention) 16 Trailer control valve 18 Backup valve 20 Parking brake module 22 Electronic control unit (ECU) 24 Inlet valve, 2 / 2-way solenoid valve 26Exhaust valve,2 / 2-way solenoid valve 28 Relay valve 30 Breakaway valve 32 Trailer control valve-side pressure sensor 34 Control lines 36 Sensor lines 38 Direct control input 40 Inverted control input of the relay valve 42 Control pressure line 42a Line branch 44 Internal reservoir pressure line 44a First line section of a reservoir pressure line within the trailer control valve 44b Second line section of a reservoir pressure line within the trailer control valve 46 Vent line 46a Connection line 48 External reservoir pressure line (leading to the coupling head "reservoir") 50 Output-side brake control line 52 Sensor pressure line 54 Internal control pressure line 56 Brake control line 58 First changeover valve 60 External brake control line 62 Relay valve 64 Redundancy valve 66 Backup valve-side pressure sensor, brake force sensor 68 Internal Control pressure line of the redundancy valve 70 Control lines 72 Sensor lines 74 External brake control line 76 First parking brake valve 78 Second parking brake valve 80 Second,82 Parking brake module-side changeover valve 84 First parking brake module-side brake control line 85 Second parking brake module-side brake control line 86 Control lines 88 Data bus, CAN bus 90 External, input-side supply pressure line 90' ​​Connection line for supply compressed air 90" Section of supply pressure line 90 92 Connection line to hydraulic brake circuit of the towing vehicle 2 94 Shut-off and vent valve, 3 / 2-way switching valve 96 Shut-off and vent valve, 3 / 2-way switching valve 97 Electrical switch 98 Shut-off and vent valve, 3 / 2-way solenoid switching valve 99 Signal line at switch 97 100 Control lines 101 Control lines 102, 102' Pressure sensor 103 Control lines 104 Sensor lines 106 Shut-off and vent valve, 3 / 2-way solenoid valve 108 Control lines 110 Shut-off and vent valve, 3 / 2-way switching valve 112 Shut-off and vent valve, 3 / 2-way switching valve in supply pressure line 44b 114 Shut-off and vent valve, 3 / 2-way switching valve in the external,Inlet side supply pressure line 90 p B Brake control pressure pvSupply pressure p3Ventilation outlet p11Supply pressure input p11'Supply pressure input of backup valve p21Supply pressure output p22Brake control output p42Brake pressure input, control pressure input of backup valve p43Inverted control pressure input of trailer control valve PBParking brake (actuating position) VA / E Shut-off and vent valve tTime t K Time tzTime point t1, t2Time points t3, t3'Time points t4, t4'Time points t5, t5'Time points Δt I Pulse duration Δt T Time cycle Δt Z Period,

Claims

1. Valve arrangement (14.1, 14.2, 14.3, 14.3', 14.4) of a tractor vehicle (2) for controlling a pneumatic brake system of a trailer vehicle (4), wherein the valve arrangement has a trailer control valve (16) with a reservoir pressure input (p11) for the introduction of reservoir compressed air and a reservoir pressure output (p21) for the controlled discharge of reservoir compressed air, wherein the reservoir pressure output (p21) is pneumatically connected to a "reservoir" coupling head (6) of the tractor vehicle (2), and in which, by means of the trailer control valve (16), a brake control pressure (pB) can be set and can be conducted via a brake control output (p22) of the trailer control valve (16) to a "brake" coupling head (8) of the tractor vehicle (2), and with an electronically controllable parking brake module (20), by means of which an inverted control input (p43) of the trailer control valve (16) can be ventilated for the actuation of the wheel brakes of the trailer vehicle (4) in a parking brake function, characterized in that, in a brake control line (60) between the brake control output (p22) and the "brake" coupling head (8) and / or in a reservoir pressure line (48) between the reservoir pressure output (p21) and the "reservoir" coupling head (6), there is arranged in each case one shut-off and ventilation valve (94, 96; 98, 106, 110), by means of which, when the parking brake is activated, before the connection of the coupling heads of the trailer vehicle (4) to the coupling heads (6, 8) of the tractor vehicle (2), the respective output (p21, p22) of the trailer control valve (16) can be shut off and the associated coupling head (6, 8) of the tractor vehicle (2) can be ventilated, and by means of which, after the connection of the coupling heads of the trailer vehicle (4) to the coupling heads (6, 8) of the tractor vehicle (2), the respective output (p21, p22) of the trailer control valve (16) is pneumatically connectible again to the associated coupling head (6, 8) of the tractor vehicle (2).

2. Valve arrangement according to Claim 1, characterized in that, both in the reservoir pressure line (48) between the reservoir pressure output (p21) and the "reservoir" coupling head (6) and in the brake control line (60) between the brake control output (p22) and the "brake" coupling head (8), there is arranged in each case one manually actuable shut-off and ventilation valve (94, 96), and in that these shut-off and ventilation valves (94, 96) are formed as 3 / 2-way switching valves with an input connection connected to the respective output (p21, p22) of the trailer control valve (16), an output connection connected to the respective coupling head (6, 8), and a ventilation output, in the case of which, in the non-actuated state, the input connection is connected to the output connection and the ventilation output is shut off, and in the case of which, in the actuated state, the input connection is shut off and the output connection is connected to the ventilation output.

3. Valve arrangement according to Claim 2, characterized in that the shut-off and ventilation valves (94, 96) are each configured to be manually switchable, and lockable in the actuated switching position, by means of a pushbutton.

4. Valve arrangement according to Claim 3, characterized in that the locking of the shut-off and ventilation valves (94, 96) is configured to be releasable by means of a further actuation of the respective pushbutton.

5. Valve arrangement according to Claim 3, characterized in that the locking of the shut-off and ventilation valves (94, 96) is configured to be releasable automatically after a predetermined holding time under the action of a respective valve-internal resetting spring.

6. Valve arrangement according to one of the preceding claims, characterized in that, both in the reservoir pressure line (48) between the reservoir pressure output (p21) and the "reservoir" coupling head (6) and in the brake control line (60) between the brake control output (p22) and the "brake" coupling head (8), there is arranged in each case one electrically actuable shut-off and ventilation valve (98, 106), in that these shut-off and ventilation valves (98, 106) are formed as 3 / 2-way solenoid switching valves with an input connection connected to the respective output (p21, p22) of the trailer control valve (16), an output connection connected to the respective coupling head (6, 8), and a ventilation output, in that, in the case of these shut-off and ventilation valves (98, 106), in the electrically deenergized state, the input connection is connected to the output connection and the ventilation output is shut off, and in that, in the case of these shut-off and ventilation valves (98, 106), in the electrically energized state, the input connection is shut off and the output connection is connected to the ventilation output.

7. Valve arrangement according to one of the preceding claims, characterized in that, in the reservoir pressure line (48) between the reservoir pressure output (p21) and the "reservoir" coupling head (6), there is arranged an electrically actuable shut-off and ventilation valve (98), and in the brake control line (60) between the brake control output (p22) and the "brake" coupling head (8), there is arranged a pneumatically pressure-controlled shut-off and ventilation valve (110), in that the electrically actuable shut-off and ventilation valve (98) in the reservoir pressure line (48) is formed as a 3 / 2-way solenoid switching valve with an input connection connected to the reservoir pressure output (p21), an output connection connected to the respective coupling head (6), and a ventilation output, in that, in the case of the electrically actuable shut-off and ventilation valve (98), in the electrically deenergized state, the input connection is connected to the output connection and the ventilation output is shut off, in that, in the case of the electrically actuable shut-off and ventilation valve (98), in the electrically energized state, the input connection is shut off and the output connection is connected to the ventilation output, in that the pneumatically pressure-controlled shut-off and ventilation valve (110) in the brake control line (60) is formed as a 3 / 2-way switching valve with a control input connected to the reservoir pressure line (48) between the shut-off and ventilation valve (98) located there and the "reservoir" coupling head (6), an input connection connected to the brake control output (22), an output connection connected to the "brake" coupling head (8), and a ventilation output, and in that, in the case of this pneumatically pressure-controlled shut-off and ventilation valve (110), when the control input is unpressurized, the input connection is shut off and the output connection is connected to the ventilation output, and, when the control input is pressurized, the input connection is connected to the output connection and the ventilation output is shut off.

8. Valve arrangement according to Claim 6, characterized in that, for the measurement of the brake control pressure (pB) prevailing at the "brake" coupling head (8), a pneumatic pressure sensor (102') is connected to the brake control line (60) between the shut-off and ventilation valve (106) and the "brake" coupling head (8).

9. Valve arrangement according to one of Claims 6 to 8, characterized in that, for the measurement of the reservoir pressure (pV) prevailing at the "reservoir" coupling head (6), a pneumatic pressure sensor (102) is connected to the reservoir pressure line (48) between the shut-off and ventilation valve (98) and the "reservoir" coupling head (6).

10. Valve arrangement according to one of the preceding claims, characterized in that a manually actuable electrical switch (97) is arranged on the tractor vehicle (2), in that this switch (97) is connected to the electronic control unit (22) via a signal line (99), and in that this switch (97) and the electronic control unit (22) are configured such that an actuation of this switch (97) triggers an electrical energization of at least one of the two shut-off and ventilation valves (98, 106, 110, 112, 114) and thus a ventilation of the respectively associated coupling head (6, 8).

11. Method for controlling a valve arrangement (14.1, 14.2, 14.3, 14.3', 14.4, 14.5, 14.6) according to one of the preceding claims, characterized in that, during the engagement of the parking brake of the tractor vehicle (2) corresponding to an actuation state PB = 1, the "reservoir" coupling head (6) of the tractor vehicle (2) is ventilated and the "brake" coupling head (8) of the tractor vehicle (2) is kept in a ventilated state.

12. Method according to Claim 11, characterized in that the "reservoir" coupling head (6) and the "brake" coupling head (8) of the tractor vehicle (2) are kept in a ventilated state until such time as the parking brake of the tractor vehicle (2) is released again (actuation state PB = 0).

13. Method according to Claim 11, characterized in that the "reservoir" coupling head (6) and the "brake" coupling head (8) of the tractor vehicle (2) are kept in a ventilated state over a predetermined time period (ΔtZ) which is dimensioned such that, within this time period, a driver is comfortably capable of exiting the driver's cab of the tractor vehicle (2), seeking out the coupling region and connecting the coupling heads of the trailer vehicle (6) to the coupling heads (6, 8) of the tractor vehicle (2).

14. Method according to Claim 11, characterized in that, during the ventilation of the "reservoir" coupling head (6) and the "brake" coupling head (8) of the tractor vehicle (2), pressure pulses are introduced in a specified timing cycle (ΔtT) into the reservoir pressure line (48) leading to the "reservoir" coupling head (6), in that the pressure gradient in the reservoir pressure line (48) is measured by sensor means, in that the two coupling heads (6, 8) of the tractor vehicle (2) are kept in a ventilated state if a steep pressure gradient is present, and in that the ventilation of the two coupling heads (6, 8) of the tractor vehicle (2) is ended if a shallow pressure gradient is present.

15. Method according to Claim 11, characterized in that, during the ventilation of the "reservoir" coupling head (6) and the "brake" coupling head (8) of the tractor vehicle (2), pressure pulses are introduced in a specified timing cycle (ΔtT) into the brake control line (60) leading to the "brake" coupling head (8) of the tractor vehicle (2), in that the pressure gradient in the brake control line (60) is measured by sensor means, and in that the two coupling heads (6, 8) of the tractor vehicle (2) are kept in a ventilated state if a steep pressure gradient is present, and in that the ventilation of the two coupling heads (6, 8) of the tractor vehicle (2) is ended if a shallow pressure gradient is present.

16. Method one of Claims 11 to 15, characterized in that, in order to avoid a release of the wheel brakes of the tractor vehicle (2), firstly the "reservoir" coupling head (6) of the tractor vehicle (2) is ventilated, and the "brake" coupling head (8) of the tractor vehicle (2) is ventilated after a slight time delay in relation thereto, or is kept in a ventilated state.

17. Method according to one of Claims 11 to 16, characterized in that the measurement of the pressure gradient is performed by means of a pneumatic pressure sensor (102, 102') according to Claims 13 and 14 or by means of a pneumatic pressure sensor (32) which is connected, within the trailer control valve (16), to the brake control line (50) leading to the brake control output (p22).