Patent Application
20240351565
This application claims the benefit under 35 U.S.C. § 371 as a U.S. National Phase Application of application no. PCT/EP2022/070727, filed on 25 Jul. 2022, which claims the benefit of German Patent Application no. 10 2021 122 322.9 filed on 30 Aug. 2021, the contents of which are hereby incorporated herein by reference in their entireties.
The invention relates to a trailer control valve of a towing vehicle for controlling a hydraulic dual-line brake system of a trailer vehicle, with a supply pressure inlet for connecting a hydraulic supply pressure of the towing vehicle, with a tank outlet for connecting an unpressurized return-flow line of the towing vehicle, with a brake pressure outlet for connecting a brake line of the trailer vehicle, and with a supplemental pressure outlet for connecting a supplemental line of the trailer vehicle, in which the brake pressure outlet can be connected in a stepped manner by means of an electronically controlled brake control valve to the supply pressure inlet or to the tank outlet, and in which the supplemental pressure outlet can be connected via a valve arrangement comprising at least one electronically controlled valve, either to the supply pressure inlet, thereby reducing an outlet pressure of the supply pressure to a supplemental pressure, or to the tank outlet.
Pursuant to EU Directive No. 2015/68, which relates to brake systems of vehicles and trailers mainly for use in agriculture and forestry, from time-points mentioned therein only vehicles and trailers with dual-line brake systems can be newly licensed. This applies both for vehicles and trailers equipped with compressed-air brake systems and also for vehicles and trailers comprising hydraulic brake systems.
In trailer vehicles with dual-line compressed-air brake systems, analogously to trailer vehicles mainly provide for use in road traffic, between the towing vehicle and the trailer vehicle, during operation there is provided between the towing vehicle and the trailer vehicle in each case a supply line under a high supply pressure for delivering compressed air as an energy carrier, and a brake control line for delivering a variable brake control pressure for the actuation of a brake control valve in the trailer vehicle.
Otherwise than this, in trailer vehicles with a hydraulic brake system there is provided in each case a brake line for the delivery of pressure oil as the energy carrier and a variable brake pressure between 0 and 150×105 Pa for operating the service brakes of the trailer vehicle, and also a supplemental line for delivering a constant supplemental pressure between 15×105 Pa and 35×105 Pa for controlling safety functions of the brake system of the trailer vehicle. The safety functions are as follows: the triggering of an emergency braking operation of the trailer vehicle if the brake line and/or the supplemental line splits, the triggering of an emergency braking operation of the trailer vehicle if an emergency off-switch is actuated in the towing vehicle, the triggering of an auxiliary braking operation of the trailer vehicle via a pressure reservoir of the trailer vehicle if the brake pedal in the towing vehicle is actuated very firmly and, if the trailer vehicle is equipped with spring-loaded brake cylinders, the application and release of the holding brake of the trailer vehicle.
From EP 3 266 661 B1 a hydraulic brake system of a trailer vehicle is known, which is provided for the operation of a hydraulic dual-line brake system of the trailer vehicle, but which is also compatible with a trailer control valve of a towing vehicle for a single-line brake system of a trailer vehicle. The brake system comprises a coupling assembly, a valve assembly, and a pressure regulation group. The coupling assembly has a connecting coupling for the connection of a brake line that can be connected to a brake line coupling of the towing vehicle, a connecting coupling for the connection of a supplemental line to a supplemental line coupling of the towing vehicle, and a short-circuit coupling. With a trailer control valve of the towing vehicle designed for a hydraulic dual-line brake system of the trailer vehicle, the brake line and the supplemental line are connected to the corresponding couplings of the towing vehicle. With a trailer control valve designed for a hydraulic single-line brake system of the trailer vehicle, the brake line is connected to the brake line coupling of the towing vehicle and the end of the supplemental line on the towing-vehicle side is connected to the short-circuit coupling of the trailer vehicle or the coupling assembly.
The valve assembly comprises a pressure-controlled 3/2-way switching valve and a manually actuated 2/2-way switching valve. The 3/2-way switching valve is to a large extent controlled by the supplemental pressure in the supplemental line. When the supplemental pressure is low, the 3/2-way switching valve is in its rest position, in which the brake line is connected to a pressure reservoir and to an inlet of the pressure regulating group via a one-way valve that blocks in the return-flow direction. When the supplemental pressure is high, the 3/2-way switching valve is in its switching position in which the connecting coupling of the brake line is connected directly to the inlet of the pressure regulating group and, by way of a one-way valve that blocks in the return-flow direction, to the pressure reservoir. By means of the 2/2-way switching valve, when the brake line is unpressurized the pressure reservoir can if necessary be emptied. The pressure regulating group comprises a pressure regulating valve which is in the form of a 2/2-way proportional solenoid valve. The proportional valve, to the outlet pressure connection of which are connected wheel-brake cylinders of the trailer vehicle, serves to modulate the brake pressure acting in the wheel-brake cylinders as a function of the loading condition of the trailer vehicle. Further properties and the mode of operation of this known hydraulic brake system in particular operating situations, can be found in a detailed description given in EP 3 266 661 B1.
Furthermore, in EP 3 353 027 B1 a hydraulic brake system for a trailer vehicle is described, which comprises a trailer control valve arranged in a towing vehicle and a valve module arranged in the trailer vehicle, which are connected to one another by a brake line and a supplemental line. The trailer control valve comprises a supply pressure inlet for the connection of a hydraulic supply line of the towing vehicle that delivers a supply pressure, a tank outlet for the connection of an unpressurized return-flow line of the towing vehicle, a brake pressure outlet for connecting the brake line, and a supplemental pressure outlet for connecting the supplemental line. The brake pressure outlet can be connected to the supply pressure inlet or the tank outlet in a stepped manner by means of a brake control valve in the form of a proportional solenoid valve. The supplemental pressure outlet can also be connected in a stepped manner to the supply pressure inlet or to the tank outlet by a supplemental control valve in the form of a proportional solenoid valve. To detect the brake pressure applied at the brake pressure outlet, a pressure sensor is connected between the working outlet of the brake control valve and the brake pressure outlet. To measure the supplemental pressure at the supplemental pressure outlet, a pressure sensor is connected between the working outlet of the supplemental control valve and the control pressure outlet.
The valve module comprises a pressure-controlled 3/3-way proportional valve. By way of the 3/2-way switching valve, which is connected on the input side to the brake line, and which is controlled by the pressure difference between the brake pressure and a supply pressure of a connected pressure accumulator, the pressure accumulator is filled with a pressure medium provided that the supply pressure is lower than the brake pressure. By way of the 3/3-way proportional valve, which is connected on its inlet side via the 3/2-way switching valve to the brake line and directly to the pressure accumulator, and which is controlled by the pressure difference between the brake pressure in a main brake line connected on an outlet side in order to actuate the service brakes of the trailer vehicle and the braking pressure as well as the supplemental pressure, the main brake line is connected either to the brake line and the storage container, or only to the brake line, or only to the storage container. In contrast the supplemental line is connected only by way of a connecting line to a parking brake line for applying and releasing the holding brakes of the trailer vehicle that can be actuated by spring-loaded brake cylinders.
Against this background, the purpose of the present invention is to provide a trailer control valve of a towing vehicle for controlling a hydraulic dual-line brake system of a trailer vehicle of the type described to begin with, which is configured as simply and inexpensively as possible, and fulfills the requirement to control the brake system of the trailer vehicle in accordance with the EU Directive 2015/68 mentioned earlier.
This objective is achieved by a trailer control valve as disclosed herein. The same applies to a trailer control valve with the features specified in the present disclosure, in which two valves are interchanged with one another in their arrangement. Further advantageous design features of these trailer control valves will be apparent from the present disclosure.
Accordingly, the invention relates to the first variant of a trailer control valve of a towing vehicle for controlling a hydraulic dual-line brake system of a trailer vehicle. The trailer control valve comprises a supply pressure inlet for connecting a hydraulic supply line of the towing vehicle, a tank outlet for connecting an unpressurized return-flow line of the towing vehicle, a brake pressure outlet for connecting a brake line of the trailer vehicle, and a supplemental pressure outlet for connecting a supplemental line of the trailer vehicle. The brake pressure outlet can be connected in a stepped manner to the supply pressure inlet or to the tank outlet by means of an electronically controlled brake control valve. In addition, the supplemental pressure outlet can be connected by way of a valve arrangement comprising at least one electronically controlled valve, either to the supply pressure inlet, so reducing an initial pressure value of the supply pressure to a supplemental pressure, or to the tank outlet.
With this trailer control valve, to achieve the stated objective it is provided that the valve arrangement comprises a pressure-limiting valve and a shut-off valve, that the pressure-limiting valve and the shut-off valve are arranged in series one behind the other with the shut-off valve arranged fluidically downstream from the pressure-limiting valve, that the outlet pressure of the valve arrangement can be reduced to the supplemental pressure by means of the pressure-limiting valve, and that the shut-off valve is in the form of a 3/2-way solenoid switching valve, by way of which, in its non-energized state the supplemental pressure outlet is connected to the tank outlet, and in its energized state the supplemental pressure outlet is connected to the working outlet of the pressure-limiting valve.
According to the second variant, the invention relates to the same trailer control valve of a towing vehicle for controlling a hydraulic dual-line brake system of a trailer vehicle. This trailer control valve too has a supply pressure inlet for connecting a hydraulic supply line of the towing vehicle, a tank outlet for connecting an unpressurized return-flow line of the towing vehicle, a brake pressure outlet for connecting a brake line of the trailer vehicle, and a supplemental pressure outlet for connecting a supplemental line of the trailer vehicle. The brake pressure outlet can likewise be connected in a stepped manner to the supply pressure inlet or to the tank outlet by means of an electronically controlled brake control valve. In addition, the supplemental pressure outlet can be connected by way of a valve arrangement comprising at least one electronically controlled valve, either to the supply pressure inlet, so reducing an initial pressure value of the supply pressure to a supplemental pressure, or to the tank outlet.
With this second variant of the trailer control valve according to the invention, to achieve the stated objective it is provided that the valve arrangement comprises a pressure-limiting valve and a shut-off valve, that the pressure-limiting valve and the shut-off valve are arranged in series one after another with the shut-off valve arranged fluidically upstream from the pressure-limiting valve, that the outlet pressure of the valve arrangement can be reduced to the supplemental pressure by means of the pressure-limiting valve, and that the shut-off valve is in the form of a 3/2-way solenoid switching valve by means of which, in its non-energized state the supplemental pressure outlet is connected to the tank outlet, and in its energized state the supplemental pressure outlet is connected to the supply pressure inlet.
Thanks to the use of the pressure-limiting valve and the shut-off valve, compared with a proportional solenoid valve the valve arrangement having the features of the invention is simpler to control and is less likely to develop faults. By means of the pressure-limiting valve the supply pressure applied on the inlet side is reduced to the supplemental pressure autonomously, i.e., without any active control measure. Only the shut-off valve has to be actively controlled or energized by a control unit if, depending on the arrangement of the valve, the supplemental pressure or the supply pressure have to be passed on to the supplemental pressure outlet S or the pressure-limiting valve. In the non-energized state of the shut-off valve the supplemental pressure outlet S is vented or unpressurized, so that the trailer vehicle is automatically braked.
To detect the supplemental pressure at the supplemental pressure outlet S, it is advantageous to connect to the supplemental line an electro-hydraulic pressure sensor or an electro-hydraulic pressure switch inside or outside the trailer control valve, close to the supplemental pressure outlet S. With reference to the pressure signal from the pressure sensor or the switching signal from the pressure switch, which is actuated at a pressure slightly lower than the specified supplemental pressure, it can be recognized whether, when the shut-off valve is energized, the specified supplemental pressure exists or has not been reached at the supplemental pressure outlet S. If the pressure at the supplemental pressure outlet S is too low, it is assumed that there is a leak in the supplemental line or a defect in the brake system of the trailer vehicle, which then results in switching off at least of the shut-off valve and hence to emergency braking of the trailer vehicle.
The brake control valve is preferably in the form of a 3/3-way proportional solenoid valve or a 3/2-way proportional solenoid valve with a return flow of the controlled brake pressure to the valve piston on the valve-spring side, by virtue of which, in the non-energized state of the valve, the brake pressure outlet is connected un-throttled to the tank outlet and in the maximally energized state of the valve the brake pressure outlet is connected un-throttled to the supply pressure inlet. Owing to the return-flow of the brake pressure to the valve piston, the brake control valve can be controlled solely by means of an electric control current with reference to a characteristic curve stored in the control unit.
Yet, to detect the brake pressure applied at the brake pressure outlet C an electro-hydraulic pressure sensor can be connected to the brake line inside or outside the trailer control valve close to the brake pressure outlet C. However, this pressure sensor only serves to recognize a leak in the brake line or a defect in the brake system of the trailer vehicle, which results in switching off the brake control valve and the shut-off valve, and hence produces emergency braking of the trailer vehicle.
A different level of the supply pressure at the supply pressure inlet P can result in slight changes of the control characteristic of the brake control valve. Thus, according to another further development of the invention it is advantageous if, to detect the supply pressure at the supply pressure inlet P, an electro-hydraulic pressure sensor is connected to the supply line inside or outside the trailer control valve close to the supply pressure inlet P. In that way, depending on the actual supply pressure the optimum characteristic for controlling the brake control valve can be selected and used.
To detect the coupling status of a trailer vehicle, i.e., to recognize whether or not a trailer vehicle is coupled, according to another design an electrical signal line is connected directly or via the trailer control valve to an associated electronic control unit. This signal line is usually connected to the 7-pole or 13-pole socket for the connecting plug of the trailer vehicle. If when the towing vehicle is started up a coupled trailer vehicle is recognized, then this can be used for the automatic filling of a pressure accumulator of the trailer vehicle, since the brake control valve is maximally energized for a few seconds and thereby pressure oil is delivered into the brake line of the trailer vehicle. In contrast, if it is recognized that no trailer vehicle is coupled, the shut-off valve and the brake control valve are not switched, so that the supplemental pressure outlet and the brake pressure outlet then remain unpressurized.
In order to enable a brake pressure to be produced for the trailer vehicle even if there is a defect in the brake control valve or its control system, a brake pressure inlet PB, PB′ and a redundant control branch with a pressure-controlled relay valve are advantageously provided in a brake line of the towing vehicle, for the brake-pressure-controlled production of a brake pressure and the activation of a redundancy valve for activating and deactivating the redundant control branch. By means of this redundancy valve the relay valve is activated, if necessary, whereby the brake pressure at the brake pressure outlet C is adjusted in a brake-pressure-controlled manner by the relay valve instead of by being electronically controlled by the brake control valve.
For that purpose, it is provided that the relay valve is connected to the supply pressure inlet P, to the tank outlet T, and via a shuttle valve to the brake pressure outlet C, and is provided with a control inlet. The redundancy valve is preferably in the form of a 3/2-way solenoid switching valve by means of which, when it is not energized, the control inlet of the relay valve is connected to the brake pressure inlet PB, PB′, and when it is energized, then depending on the type of brake system in the towing vehicle (pneumatic or hydraulic), the control inlet of the relay valve is connected to a venting outlet or to the tank outlet T.
With an arrangement of the shut-off valve upstream from the pressure-limiting valve, instead of a connection to the supply pressure inlet P, the relay valve can be connected via a connecting line to the connecting line between the shut-off valve and the pressure-limiting valve in which the supply pressure exists when the shut-off valve is energized. Thus, by switching the shut-off valve off, both the supplemental pressure outlet S and the supply inlet of the relay valve are vented via the shut-off valve and thereby become unpressurized.
With this embodiment, in order to avoid an unforeseen switching off of the shut-off valve and thereby deactivating the redundant control branch, the shut-off valve is preferably secured against defect-related failure by control means that maintain it in its most recent switching state within the associated electronic control unit.
Alternatively, or in addition, for that purpose the shut-off valve can also have a second shut-off valve connected parallel to it, wherein the working outlets of the two shut-off valves are connected by a shuttle valve to the connection line that leads to the pressure-limiting valve, so that if there is a defect in one of the two shut-off valves, pressure oil at the supply pressure can still be supplied to the connection line by the respective other shut-off valve. For cost reasons the second shut-off valve is preferably of a structure identical to that of the first shut-off valve.
A further possibility for avoiding an unintended switching off of the shut-off valve is that in the connecting line between the shut-off valve and the connection point of the connecting line leading to the relay valve, there is arranged a one-way valve with a control inlet that blocks in the direction toward the shut-off valve and can be opened by an actuated control pressure, to which an electronically controlled pilot valve is connected. This pilot valve is in the form of a 3/2-way solenoid switching valve by means of which the control inlet of the one-way valve is connected to the tank outlet T when not energized, and to the supply pressure inlet P when in the energized condition. Thanks to the one-way valve in the connecting line that can be unblocked, when the shut-off valve is not energized the inlet of the pressure-limiting valve and the supply inlet of the relay valve can only be vented by active actuation of the pilot valve and thereby switched to become unpressurized.
At least the brake control valve, the pressure-limiting valve, the shut-off valve, the redundancy valve and the shuttle valve can be accommodated for the same purpose in a shared valve housing and thereby form the trailer control valve. In this case too, the pressure sensors and/or the pressure switch can if necessary be accommodated inside the valve housing or outside the valve housing.
The trailer control valve with the features of the invention is explained in greater detail with reference to the example embodiments illustrated in the attached drawing, which shows, represented schematically in each case:
The trailer control valve 4 bas a supply pressure inlet P, a tank outlet T, a brake pressure outlet C and a supplemental pressure outlet S, and comprises a brake control valve 34, a pressure-limiting valve 36 and a shut-off valve 38. A hydraulic supply line 44 is connected to the supply pressure inlet P, which line is fed by an oil pump 40 and a preparation unit 42 arranged downstream therefrom. To the tank outlet T is connected a return-flow line 46, which leads to a collecting container 48. To the brake pressure outlet C is connected a brake line 50, which leads to a brake coupling 52 for connecting a brake line on the trailer side. To the supplemental pressure outlet S is connected a supplemental line 54 which leads to a supplemental coupling 56 for connecting a supplemental line on the trailer side. In addition, a signal line 58 runs from the control unit 6 via the trailer control valve 4 to a plug socket 60 for connecting a signal line on the trailer side. The trailer control valve 4 can be made by connecting the valves 34, 36, 38 mentioned, by way of plug connections and/or screw connections, mechanically and hydraulically to one another, or they can be arranged in a shared valve housing 62.
The brake control valve 34 is in the form of a 3/3-way proportional solenoid valve with a return-flow on the valve spring side of the brake pressure produced by the valve piston and is connected to the control unit 6 by an electric control line. It should be mentioned here that all the electric control lines are represented by broken lines. The brake control valve 34 serves to control a brake pressure at the brake pressure outlet C, of between 0 Pa and 150 ×105 Pa, as a function of a brake value measured by at least one of the pressure sensors 22, 24. By way of the brake control valve 34, when the latter is not energized the brake pressure outlet C is connected unthrottled to the tank outlet T (0 Pa) and when it is fully energized the brake pressure outlet C is connected unthrottled to the supply pressure inlet P under a pressure there, for example, of 150×105 Pa.
When the towing vehicle is started up, the brake pressure outlet C can be acted upon by the maximum brake pressure (150×105 Pa) for a few seconds by maximum energisation of the brake control valve 34, in order to fill a pressure accumulator of the trailer vehicle with hydraulic oil under high pressure, provided that previously it has been recognized via the signal line 58 (with the plug of the trailer vehicle connected) that a trailer vehicle is in fact coupled.
By means of the pressure-limiting valve 36 the supply pressure applied on the input side is reduced on the output side to a constant supplemental pressure between 15×105 Pa and 35×105 Pa. The shut-off valve 38, which in the present case is connected pneumatically downstream from the pressure-limiting valve 36, is in the form of a 3/2-way solenoid switching valve and is connected to the control unit 6 by an electric control line. By means of this shut-off valve 38, when it is not energized the supplemental pressure outlet S is connected to the tank outlet (0 Pa) and when it is energized the supplemental pressure outlet S is connected to the working outlet of the pressure-limiting valve 36, which can be at a hydraulic pressure between 15×105 Pa and 35×105 Pa.
Once the towing vehicle concerned has been started up, the supplemental pressure outlet S with the release of the parking brake, which is detected by the parking brake sensor 32, is acted upon by energizing the shut-off valve 38 with the intended supplemental pressure (15×105 Pa to 35×105 Pa), provided that a coupled trailed vehicle has previously been recognized via the signal line 58. If thereafter a defect in the brake system of the trailer vehicle 4 is established or an emergency off-switch is actuated in the towing vehicle or a parking brake of the towing vehicle is engaged by actuating the parking brake valve 28, then the supplemental pressure outlet S is depressurized by switching off the shut-off valve 38 and thereby an emergency braking or secondary braking of the trailer vehicle is triggered. The basic embodiment of the trailer control valve 4 described is advantageously effective without a pressure sensor connected to the brake line 50 and/or to the supplemental line 54.
The trailer control valve 4 illustrated in
In this example embodiment the brake control valve 34 is in the form of a 3/2-way proportional solenoid valve with a return flow, on the valve spring side, of the controlled brake pressure to the valve piston, which is controlled by the control unit 6. In this case the brake pressure outlet C of the trailer control valve 4′ in the non-energized state of the brake control valve 34′ is unthrottled, and in the fully energized state the brake control valve 34′ is connected to the tank outlet T and unthrottled to the hydraulic supply pressure inlet P.
Furthermore, in the example embodiment shown in
The second pressure sensor 72 is connected to the brake line 50 and is also connected to the control unit 6 by a sensor line. Measurement of the brake pressure at the brake pressure outlet C can detect a deviation from the brake pressure to be set by the brake control valve 34, which deviation indicates a defect in the brake system on the trailer side or a leak in the brake line 50. Consequently, a visual or acoustic warning signal can be emitted in the driver's cabin of the towing vehicle and/or, by switching off the brake control valve 34 and the shut-off valve 38, an emergency braking of the trailer vehicle can be triggered and the escape of pressure oil into the surroundings can be prevented.
The third pressure sensor 74 is connected to the supplemental line 54 and again to the control unit 6 by way of a sensor line. Measurement of the supplemental pressure at the supplemental pressure outlet S can detect a deviation from the supplemental pressure to be set by the pressure-limiting valve 36, which deviation indicates a defect in the brake system on the trailer side or a leak in the supplemental line 58. As a result, a visual or acoustic warning signal can be emitted in the driver's cabin of the towing vehicle and/or, by switching off at least the shut-off valve 38 an emergency braking of the trailer vehicle can be triggered and the escape of pressure oil into the surroundings can be prevented.
In the representation shown in
The further embodiment of a trailer control valve 68′ shown in
By way of the redundancy valve 88, the control inlet of the relay valve 86 is connected to the brake pressure inlet PB when the valve 88 is not energized and to a venting outlet when it is energized. Thus, in the non-energized state of the redundancy valve 88 the relay valve 86 and therefore the redundant control branch 82 are activated, and in the energized state of the redundancy valve 88 they are deactivated. Thus, in the event of a failure of the control unit 6, the brake control valve 34 is automatically deactivated and the redundant control branch 82 is activated, whereby during driving operation the production of a brake pressure at the brake pressure outlet C is ensured in all circumstances.
The trailer control valve 80 can be formed by connecting the valves 34, 36, 38, 86, 88, 90 to one another by plug and/or screw connections, or they can be arranged in a common valve housing 92. In the present case the three pressure sensors 70, 72, 74 mentioned are also arranged inside the trailer control valve 80. This makes it clear that the pressure sensors 70, 72, 74 are connected by plug and/or screw connections to the valves 34, 36, 38, 86, 88, 90 concerned and can therefore form the trailer control valve 80, or that the pressure sensors 70, 72, 74 can be arranged with the valves 34. 36, 38, 86, 88, 90 concerned in a common valve housing 92. However, it is also possible for the pressure sensors 70, 72, 74 to be connected to the pressure lines respectively associated with them outside the trailer control valve 80.
The brake pressure inlet PB′ is connected by a connecting line 84′ to the brake line 20′ of the second hydraulic brake circuit of the towing vehicle. The redundant control branch 82′ is made similarly to that shown in
Since the supply inlet of the relay valve 86′ is only connected to the supply pressure inlet P via the connecting line 96 and the connecting line 98 when the shut-off valve 38 is energized, and is then at the supply pressure, particular measures are provided in order to avoid an unintentional switching-off of the shut-off valve 38 and a consequent deactivation of the redundant control branch 82′. Thus, in the present case it is provided that the shut-off valve 38 is secured against a defect-related failure by control means within the electronic control unit 6 which maintain its most recent switched state.
For that purpose, in the trailer control valve 94′ shown in
In the trailer control valve 94″ shown in
The trailer control valves 94, 94′, 94″ illustrated can respectively be formed by connecting the valves 34, 36, 38, 86′ 88′ 90 and in addition the valves 38′ or 102, 104 to one another by means of plug and/or screw connections, or arranging them in a common valve housing 100, 100′, 100″. In the present case the three pressure sensors 70, 72, 74 are also arranged inside the respective trailer control valve 94, 94′, 94″. This makes it clear that the pressure sensors 70, 72, 74 can be connected by plug and/or screw connections to the associated valves 34, 36, 38, 86′, 90 and can thus form the trailer control valve 94, 94′, 94″ concerned, or that the pressure sensors 70, 72, 74 together with the associated valves 34, 36, 38, 86′, 88′, 90, and in addition with the valves 38′ or 102, 104, can be arranged in a respective common valve housing 100, 100′, 100″. However, it is also possible for the pressure sensors 70, 72, 74 to be connected outside the respective trailer control valve 100, 100′, 100″ to the respectively associated pressure line 12′, 50, 54.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 122 322.9 | Aug 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/070727 | 7/25/2022 | WO |
