Electropneumatic valve installation with self-holding safety valve

Abstract

The invention relates to an electro-pneumatic valve arrangement (1) for operating a parking brake function of an electro-pneumatic brake system (202), having a pilot control unit (8) and a main valve unit (10), which is adapted to regulate a parking brake pressure (pBP) at at least one spring accumulator coupling end (21). The electro-pneumatic valve arrangement (1) is characterized by a service brake coupling end (74) for receiving a service brake pressure (pBB); and a safety valve (50), wherein by receiving a safety control pressure (pSS), the safety valve (50) can be switched from a bleed-off position (54), in which the safety valve (50) connects the control unit (8) to a bleed-off end (3), into a supply position (52), in which the safety valve (50) supplies the pilot control unit (8) with a reserve pressure (pV), the safety valve (50) remains in the supply position (52) or is switched into the bleed-off position (54) depending on a regulated pressure (pA), and wherein the service brake coupling end (74) is directly or indirectly connected to the safety valve control coupling end (50.4) in a fluid-conducting manner. The invention also relates to a brake system (202), a method for controlling a parking brake function and a vehicle (200).

Description

Technical Field

[0001] This invention relates to an electro-pneumatic valve assembly for operating the parking brake function of an electro-pneumatic braking system in a commercial vehicle. The assembly includes a pilot control unit that regulates a pilot control pressure based on an electronic parking brake signal, and a main valve unit adaptively adjusted to receive the pilot control pressure and regulate the parking brake pressure at at least one spring accumulator connection. The invention also relates to an electro-pneumatic braking system, a method for controlling the parking brake function of a vehicle, and a vehicle. Background Technology

[0002] Electro-pneumatic valve systems for operating the parking brake are used in both Europe and the United States. The parking brake function of an electro-pneumatic braking system typically uses a so-called spring-loaded brake cylinder, which is pressed down by spring force and opened in an air-intake state. During driving, these spring-loaded brake cylinders should be air-intaken and therefore released, while when the vehicle is parked, they should be deflated and therefore pressed down.

[0003] A spring-loaded brake cylinder can be combined with a service brake cylinder, so that the spring-loaded brake and the service brake act on the same brake piston. With proper design, the mechanical overload of the brake piston can be avoided by combining the braking forces of the service brake and the spring-loaded brake. If the service brake is operated while the parking brake is engaged, air is simultaneously supplied to the spring-loaded brake cylinder to prevent the braking forces from being combined. This function is commonly referred to as anti-reverse function.

[0004] Due to legal regulations, electric pneumatic parking brakes must remain in their switched position in the event of a malfunction. In the United States, if the parking brake's reserve pressure falls below a predetermined threshold, it must also automatically and persistently engage. In pneumatic systems, to achieve these functions, a push-pull valve is used in the cab, via which the driver can manually insulate or depress the spring-loaded brake cylinder. When the push-pull valve is pressed in, a pneumatic connection is established, allowing air to enter and thus release the towing vehicle's spring-loaded brake cylinder. However, if the driver pulls out the push-pull valve, the spring-loaded brake cylinder is depressurized and compressed. Furthermore, the push-pull valve adaptively adjusts to automatically release when the reserve pressure falls below a threshold.

[0005] Since drivers of these vehicles are already accustomed to this function, a corresponding action should be implemented for the electro-pneumatic parking brake function. Furthermore, the costs associated with the valves implementing the parking brake function, the spring-loaded brake cylinder typically located on the rear axle, and the pneumatic piping laid in the cab are relatively high. Therefore, simplification is necessary. In addition, there is a need to improve the safety of the parking brake function. Furthermore, it is desirable that the parking brake can be pneumatically released in the event of an electrical failure. Summary of the Invention

[0006] This task is solved, according to a first aspect of the invention, in an electro-pneumatic valve facility of the type mentioned at the beginning, by an electro-pneumatic valve facility according to the invention for operating the parking brake function of an electro-pneumatic braking system for commercial vehicles, the electro-pneumatic valve facility comprising: a pilot control unit that regulates a pilot control pressure based on an electronic parking brake signal; and a main valve unit adapted to receive the pilot control pressure and regulate the parking brake pressure at at least one spring accumulator connection point, the electro-pneumatic valve facility having a pneumatically switchable self-holding safety valve connected before the pilot control unit and having a safety valve control for receiving the safety control pressure. The device includes a connection terminal and a safety valve holding circuit for receiving pressure regulated by or derived from the safety valve, wherein, by receiving the safety control pressure, the safety valve can switch from a venting position to a supply position, in which the safety valve connects the pilot control unit to the venting terminal, and in the supply position, the safety valve supplies a reserve pressure to the pilot control unit, wherein the safety valve remains in the supply position or switches to the venting position depending on the regulated pressure received at the safety valve holding circuit, and the electro-pneumatic valve device has an electro-pneumatic safety switching unit that regulates a safety pilot control pressure based on an electronic safety switching signal. According to the invention, the electro-pneumatic valve device includes: a service brake connection terminal for receiving service brake pressure, wherein the service brake connection terminal is directly or indirectly connected to the safety valve control connection terminal in a fluid-guiding manner; and a safety shuttle valve configured to receive the safety pilot control pressure and the service brake pressure and regulate the higher of the safety pilot control pressure and the service brake pressure as the safety control pressure.

[0007] The electro-pneumatic valve assembly is characterized by having: a service brake connection for receiving service brake pressure; a pneumatically switchable, self-holding safety valve connected before the pilot control unit; a safety valve control connection for receiving safety control pressure; and a safety valve holding circuit for receiving pressure regulated by or derived from the safety valve. By receiving safety control pressure, the safety valve can switch from a venting position to a supply position. In the venting position, the safety valve connects the pilot control unit to the venting connection. In the supply position, the safety valve supplies reserve pressure to the pilot control unit. The safety valve remains in the supply position or switches to the venting position depending on the regulated pressure received at the safety valve holding circuit. The service brake connection is directly or indirectly connected to the safety valve control connection in a fluid-guiding manner.

[0008] The safety valve is switched from the venting position to the supply position by receiving safety control pressure at the control connection. The safety valve remains in the supply position due to the pressure regulated at the safety valve and therefore also applied to the holding connection. In this way, the pilot control unit is supplied with reserve pressure only when the safety valve is in the supply position. If the pressure regulated by the safety valve meets the requirements further defined later, the safety valve itself remains in the supply position. This integrates autonomous safety functions into the electro-pneumatic valve system, eliminating the need for external valves with costly piping to ensure autonomous safety.

[0009] According to the present invention, the switching position of the solenoid valve depends not only on the switching position set via the safety valve control connection, but also on the pressure regulated at the safety valve. This provides an additional layer of safety. This can be achieved pneumatically, mechanically, or otherwise. Preferably, it is achieved without relying on electricity.

[0010] The indirect or direct connection between the safety valve control connector and the service brake connector allows the safety valve to be switched by providing service brake pressure. According to the invention, if an electrical fault occurs in the electro-pneumatic valve assembly, the safety valve can also be brought to the supply position, thereby allowing, for example, the release of the parking brake to restore vehicle stability. A direct connection exists between the safety control connector and the service brake connector when no additional functional element is required to connect them. For example, the connectors can be connected by a direct line or conduit. A direct connection can also exist if a distributor is arranged between the two elements. An indirect connection exists between the safety control connector and the service brake connector when an additional functional element (e.g., a valve) is arranged between the safety control connector and the service brake connector. It should be understood that an indirect connection also allows the service brake pressure to be provided directly and (at least in some operating conditions) at the safety valve control connector (aside from conventional line losses).

[0011] In a first preferred embodiment, the service brake connection can be connected to the front axle brake circuit and / or the rear axle brake circuit, wherein the service brake pressure is the front axle brake pressure and / or the rear axle brake pressure of a commercial vehicle. The front axle brake pressure and / or the rear axle brake pressure can be provided through a direct or indirect connection of guiding fluid between the safety valve control connection and the service brake connection. It can also be configured such that the pressure derived from the front axle brake pressure and / or the rear axle brake pressure is provided at the safety valve control connection. This allows the safety valve to be switched using the front axle brake pressure and / or the rear axle brake pressure already present in the braking system, thereby making the valve arrangement compact and cost-effective. Furthermore, components and wiring can be saved in a braking system having the valve arrangement according to the invention.

[0012] Preferably, the service brake connection is a release control connection, wherein the service brake pressure is the release control pressure. A release control pressure can preferably be provided at the release control connection, which is preferably used to supply air to the vehicle's spring-loaded brake cylinder or to provide a corresponding parking brake pressure (anti-re-excitation function) at the spring-loaded connection of the electro-pneumatic valve assembly. In this preferred design, the service brake pressure of the electro-pneumatic valve assembly serves a dual function. The service brake pressure configured as a release control pressure is used to switch the safety valve when needed, and also satisfies the aforementioned anti-re-excitation function. Therefore, the electro-pneumatic valve assembly can be designed to be particularly compact, simple, and inexpensive.

[0013] Preferably, the electro-pneumatic valve assembly further includes a main control shuttle valve configured to receive a pilot control pressure and a release control pressure, and to provide the main valve unit with the higher of the pilot control pressure and the release control pressure, wherein the main valve unit regulates the parking brake pressure based on either the release control pressure or the pilot control pressure. The main control shuttle valve provides either the pilot control pressure or the release control pressure to the main valve unit. The main valve unit is adaptively adjusted to regulate the parking brake pressure at the spring accumulator connection based on the received pressure (pilot control pressure or release control pressure). Therefore, the main control shuttle valve causes the pilot control pressure regulated by the pilot control unit based on the electronic parking brake signal to be replaced by the release control pressure provided at the release control connection, and vice versa. This means that double braking of the vehicle due to simultaneous operation of the parking brake and the service brake can be prevented.

[0014] In an alternative design, the service brake connection is a redundant connection, wherein the service brake pressure is either a redundant braking pressure or a pressure derived from the redundant braking pressure. This design also achieves a beneficial dual use of the pressure provided at the service brake connection. The pressure regulated for braking in the redundant case is also used to switch the safety switching valve. Similar to the aforementioned first alternative design, this variant allows for a cost-effective and simple structural design of the electro-pneumatic valve assembly and / or braking system. In one variant, the redundant pressure is provided directly as the service brake pressure at the safety valve control connection. Alternatively or additionally, a pressure derived from the redundant pressure can be provided at the safety valve control connection. To derive the service brake pressure from the redundant pressure, an auxiliary control unit can preferably be arranged between the redundant connection and the safety valve control connection. Particularly preferably, the auxiliary control unit is a trailer control unit configured to regulate the trailer brake pressure. Thus, preferably, the electro-pneumatic valve assembly is configured to regulate the trailer brake pressure and provide this trailer brake pressure at the trailer service brake connection. Preferably, the electro-pneumatic valve facility can be a trailer control valve or include a trailer control valve as a sub-function. In the braking system, redundant pressure is preferably provided by a brake value transmitter, such as a foot brake module. For example, in the braking system of a semi-automatic or automatic vehicle, the service brake pressure can be provided largely automatically based on electrical signals from the central control unit, while the driver can provide redundant pressure via the foot brake module to brake the vehicle in case of a malfunction.

[0015] In the preferred alternative design, the service brake connection is the trailer service brake connection, where the service brake pressure is the trailer brake pressure. In this variant, the trailer brake pressure is supplied to the electro-pneumatic valve system via an external unit that is not part of the electro-pneumatic valve system. For example, the external unit could be a conventional trailer control unit pneumatically connected to the electro-pneumatic valve system. In this case, the advantageous dual use already described with reference to the above alternative is also obtained, where the trailer brake pressure is not provided through the electro-pneumatic valve system, but rather by an external unit for both the trailer and the electro-pneumatic valve system.

[0016] Preferably, the electro-pneumatic valve facility further includes an electro-pneumatic safety switching unit, which regulates a safety pilot control pressure based on an electronic safety switching signal. Preferably, the safety switching unit is connected to the safety valve control connection in a fluid-guiding manner to provide the safety pilot control pressure as the safety control pressure at the safety valve control connection. This connection can be configured directly or indirectly. For example, the safety switching unit can be directly connected to the safety valve control connection, wherein a distributor is arranged between the safety switching unit and the safety valve control connection, which also directly or indirectly connects the service brake connection to the safety valve control connection. If both the service brake connection and the safety switching unit are directly connected to the safety valve control connection, the safety control pressure can be a compensating pressure for the safety pilot control pressure and the service brake pressure, which occurs when both the safety pilot control pressure and the service brake pressure are present. Preferably, the safety switching unit can also be indirectly connected to the safety valve control connection. The safety switching unit is preferably an electrically switchable two-position three-way valve.

[0017] According to a preferred improvement, the electro-pneumatic valve assembly also includes a safety shuttle valve configured to receive a safety pilot control pressure and a service brake pressure, and to select the higher of these two pressures as the safety control pressure. If the safety shuttle valve is supplied with both the service brake pressure and the safety pilot control pressure, the higher of these two pressures constitutes the safety control pressure. Preferably, the safety control pressure can be provided in two ways. On one hand, the safety pilot control pressure can be provided via an electro-pneumatic safety switching unit dependent on a safety switch signal; on the other hand, the service brake pressure can be used as the safety control pressure. The safety shuttle valve prevents multiple loading of the safety valve control connection, thereby preventing mechanical overload.

[0018] Preferably, the safety switching unit is configured to receive a reserve pressure and to regulate the reserve pressure as a safety pilot control pressure in a first switching position. Preferably, the safety switching unit is connected to the reserve connection in a fluid-guiding manner. Therefore, air with the reserve pressure can be supplied to the safety switching unit via the reserve connection.

[0019] In a preferred embodiment, the safety switching unit connects the safety shuttle valve to the venting end in the second switching position. Preferably, if the safety switching unit is directly connected to the safety valve control connection, then in the second switching position, the safety switching unit connects the safety valve control connection to the venting end. Typically, the reserve pressure in the braking system has the highest pressure level. In this case, reliable switching can be achieved via the safety switching unit. If the safety switching unit is switched to the first switching position by energization (when a safety switching signal is provided), the reserve pressure is directly provided at the safety valve control connection or the safety shuttle valve, and the safety shuttle valve then provides the reserve pressure to the safety valve control connection as a safety control pressure. However, if the safety switching unit is in the second switching position, switching the safety valve is prevented in the case of direct connection because the safety valve control connection is connected to the venting end. In the case of indirect connection via the safety shuttle valve, switching the safety valve is still possible, provided that service brake pressure is provided. Preferably, the safety switching unit is a monostable safety switching unit, which is particularly preferably pre-tensioned to the second switching position.

[0020] In a preferred embodiment, the safety valve remains in the supply position when the regulated pressure applied to the safety valve holding circuit exceeds a first threshold, and switches to the vent position when the regulated pressure applied to the safety valve holding circuit reaches or falls below the first threshold. The safety valve switches based on the regulated pressure. If the regulated pressure is higher than the first threshold, the safety valve remains in the supply position by itself using the pressure received at the safety valve holding circuit. If the regulated pressure is lower than the first threshold, the safety valve switches to the vent position. In this case, no reserve pressure is provided at the pilot control unit, and the parking brake pressure can only be regulated when the main valve unit receives other pressures (e.g., service brake pressure). Preferably, it can also be configured that the safety valve switches to the vent position when the regulated pressure applied to the safety valve holding circuit is lower than the first threshold. The safety valve holding circuit can be an external circuit to the safety valve or it can be constructed inside the safety holding valve. For example, the safety valve can have an internal channel that feeds back to the safety valve coupling terminal connected to the pilot control unit. However, preferably, an external line can be used to connect the connection terminal of the safety valve to the pilot control unit and the safety valve retaining connection terminal.

[0021] Preferably, the first threshold is in the range of 150 kPa to 450 kPa, more preferably in the range of 170 kPa to 450 kPa, more preferably in the range of 170 kPa to 420 kPa, more preferably in the range of 180 kPa to 420 kPa, more preferably in the range of 180 kPa to 400 kPa, more preferably in the range of 200 kPa to 400 kPa, more preferably in the range of 200 kPa to 380 kPa, more preferably in the range of 200 kPa to 370 kPa, more preferably in the range of 200 kPa to 350 kPa, more preferably in the range of 200 kPa to 320 kPa, more preferably in the range of 200 kPa to 300 kPa, more preferably in the range of 210 kPa to 300 kPa, more preferably in the range of 210 kPa to 280 kPa. The range is preferably from 220 kPa to 280 kPa, more preferably from 230 kPa to 280 kPa, and particularly preferably from 250 kPa to 315 kPa.

[0022] In a preferred embodiment, the safety valve has a spring that preloads the safety valve into the vent position. Under no-pressure conditions, the safety valve is in the vent position due to the action of the spring. To switch the safety valve to the supply position, a restoring force provided by the spring must be overcome. Particularly preferably, the restoring force of the spring determines a first threshold.

[0023] Preferably, the pilot control unit is a bistable pilot control unit. The bistable pilot control unit stably exists in two switching states, so even if the electro-pneumatic valve assembly is switched to a no-current state, it remains in the switching state it was switched to before the no-current state occurred. Therefore, the pilot control unit retains its switching position, and after the electro-pneumatic valve assembly is re-energized, it is preferably in the same state as it was in before the current supply interruption. This prevents the parking brake from accidentally engaging and / or disengaging when the electro-pneumatic valve assembly is re-energized.

[0024] Preferably, the bistable pilot control unit has a bistable solenoid valve having at least a first permanent magnet. Even in the absence of current, the permanent magnet holds the bistable solenoid valve in a stopped position. Preferably, the bistable solenoid valve also includes a first coil. By energizing the first coil, the armature of the solenoid valve, preferably including the permanent magnet, can be brought to a first stopped position. Preferably, the bistable solenoid valve also has a second permanent magnet and / or a second coil, which is particularly preferably formed similarly to the first permanent magnet and the first coil. Preferably, the bistable solenoid valve can be magnetically locked in two stopped positions. The respective switching positions are stable if no other force is applied to the armature or if the armature can be locked in these positions mechanically and / or magnetically, because these positions can be maintained without further energization.

[0025] In a second aspect, the present invention solves the task mentioned at the beginning by utilizing an electro-pneumatic braking system having an electro-pneumatic valve facility and a service brake circuit according to the first aspect of the invention. The service brake circuit has a braking module for providing service brake pressure, wherein the braking module is connected to the service brake coupling end of the electro-pneumatic valve facility in a fluid-guiding manner. The electro-pneumatic braking system can be controlled at least partially by means of electrical signals. For example, in fully automatic or partially automatic driving operation, the braking function can be controlled by a braking signal provided by a central control unit. Preferably, the braking module can be an electro-pneumatic braking module, especially an electro-pneumatic foot brake module, a manual brake module, especially a conventional pneumatic foot brake module, or an electronic braking module that relies on a braking signal to output service brake pressure. Preferably, the braking system can also have multiple service brake circuits, wherein the braking module can also provide service brake pressure to each braking circuit. For example, the front axle braking circuit for braking the front axle wheels of the vehicle can be driven by the braking module using the front axle service brake pressure, while the braking module also provides rear axle service brake pressure to the rear axle braking circuit for braking the rear axle wheels of the vehicle.

[0026] In the third aspect, the aforementioned task is addressed by a method for controlling the parking brake function of a vehicle, particularly a commercial vehicle, having an electro-pneumatic braking system, particularly an electro-pneumatic braking system according to the second aspect. This method comprises the following steps: pneumatically switching a safety valve to a supply position, in which the safety valve supplies a reserve pressure to a pilot control unit by providing a safety control pressure to a safety valve control connection; receiving the reserve pressure at the pilot control unit and regulating a pilot control pressure based on an electronic parking brake signal; providing a service brake pressure via a brake module in the service brake circuit; and regulating a parking brake pressure at at least one spring accumulator connection via a main valve unit based on either the service brake pressure or the pilot control pressure; wherein the safety control pressure is either the service brake pressure or the reserve pressure provided at the safety valve control connection via an electromagnetically opened safety switching unit. Preferably, in this method, the safety valve has a safety valve holding circuit to draw back the pressure regulated by the safety valve. Preferably, the method further comprises: connecting the pilot control unit to a venting end when the drawn-back regulated pressure is below a first threshold.

[0027] In a fourth aspect, the present invention solves the problem mentioned at the beginning by providing a vehicle, particularly a commercial vehicle, with an electro-pneumatic braking system according to the second aspect of the present invention.

[0028] It should be understood that the electro-pneumatic braking system according to the second aspect of the invention, the method according to the third aspect of the invention, the vehicle according to the fourth aspect of the invention, and the electro-pneumatic valve device according to the first aspect of the invention have the same and similar sub-aspects. In this regard, reference is made entirely to the description of the first aspect of the invention described above. Attached Figure Description

[0029] Embodiments of the invention will now be described in conjunction with the accompanying drawings. These drawings do not necessarily show the embodiments to scale, but rather illustrate them in a schematic and / or slightly modified form. Reference is made to the relevant prior art to supplement the teachings which are directly apparent from the drawings. It is important to consider the many variations and modifications that can be made to the form and details of the embodiments without departing from the overall spirit of the invention. The features of the invention disclosed in the specification, drawings, and claims, whether individually or in any combination, are essential to improvements of the invention. Furthermore, all combinations of at least two features disclosed in the specification, drawings, and / or claims also fall within the framework of the invention. The overall spirit of the invention is not limited to the precise form or details of the preferred embodiments shown and described below, nor is it limited to the subject matter limited compared to the subject matter claimed in the claims. Values ​​within the stated boundaries within the explained dimensional range should also be disclosed as boundary values ​​and can be used and protected as desired. For simplicity, the same or similar parts or parts having the same or similar functions will henceforth use the same reference numerals.

[0030] Further advantages, features, and details of the present invention will become apparent from the following description of preferred embodiments in conjunction with the accompanying drawings; wherein:

[0031] Figure 1 A first embodiment of the electro-pneumatic valve device is shown;

[0032] Figure 2 A second embodiment of the electro-pneumatic valve device is shown;

[0033] Figure 3 A third embodiment of the electro-pneumatic valve device is shown;

[0034] Figure 4 A fourth embodiment of the electro-pneumatic valve device is shown;

[0035] Figure 5 A fifth embodiment of the electro-pneumatic valve device is shown;

[0036] Figure 6 A sixth embodiment of the electro-pneumatic valve device is shown; and

[0037] Figure 7Commercial vehicles are shown. Detailed Implementation

[0038] exist Figures 1 to 6 In the illustrated embodiment, the electro-pneumatic valve facility 1 is configured as the parking brake module 2. However, this is not essential; the electro-pneumatic valve facility 1 can also be integrated with other units, and / or the individual valves described below can be arranged separately and / or distributed within the braking system 202 (see [link to documentation]). Figure 7 ).

[0039] The parking brake module 2 has a reserve connection terminal 4, and the first compressed air reserve unit 6 and the second compressed air reserve unit 7 are connected to the reserve connection terminal via a reserve shuttle valve 5. Figure 7 The first and second compressed air reservoirs each provide a reserve pressure pV, which is present at the reserve connection terminal 4. It is not necessary for both compressed air reservoirs 6 and 7 to be connected to the reserve connection terminal 4; rather, it is sufficient for only one compressed air reservoir to be connected there or for the reserve connection terminal 4 to be supplied via a separate module.

[0040] The electro-pneumatic valve assembly 1 includes a pilot control unit 8 (here, a bistable pilot control unit 8) and a main valve unit 10. The bistable pilot control unit 8 includes a solenoid valve 12. The solenoid valve 12 has a first solenoid valve connection terminal 12.1, a second solenoid valve connection terminal 12.3, and a third solenoid valve connection terminal 12.3. The first solenoid valve connection terminal 12.1 is connected to a safety valve 50, which has a supply position 52 and Figure 1The venting position 54 is shown. In the illustrated embodiment, the safety valve 50 is pre-tensioned to the venting position 54 by means of a spring 51. However, it is also possible for the safety valve 50 to be purely pneumatically operated. For example, and preferably, the safety valve 50 can also be designed to switch between the venting position 64 and the supply position 52 by means of a bidirectional pneumatic piston. The safety valve 50 has a first safety valve connection 50.1, a second safety valve connection 50.2, and a third safety valve connection 50.3. The first safety valve connection 50.1 is connected to the reserve connection 4 and receives the reserve pressure pV. In the supply position 52, the first safety valve connection 50.1 and the second safety valve connection 50.2 are connected in a fluid-guiding manner, so that the reserve pressure pV is conducted through the safety valve 50 and supplied at the solenoid valve 12 via the supply line 56 connecting the second safety valve connection 50.2 to the first solenoid valve connection 21.1. In the vent position 54, the second safety valve connection terminal 50.2, as well as the first solenoid valve connection terminal 12.1 (due to direct connection), are connected to the third safety valve connection terminal 50.3. The third safety valve connection terminal 50.3 is connected to the vent terminal 3, so that when the safety valve 50 is in the vent position 54, the first solenoid valve connection terminal 12.1 vents via the safety valve 50. The switching of the safety valve 50 between the supply position 52 and the vent position 54 will be explained further later.

[0041] exist Figures 1 to 5 In the illustrated embodiment, the second solenoid valve connection terminal 12.2 is indirectly connected to the main valve unit 10 via the holding valve 14. The third solenoid valve connection terminal 12.3 is connected to the vent terminal 3. The solenoid valve 12 has... Figure 1 In the first switching position (not shown), the first solenoid valve connection terminal 12.1 is connected to the second solenoid valve connection terminal 12.2. Figure 1 In the second switching position shown, the third solenoid valve connection terminal 12.3 is connected to the second solenoid valve connection terminal 12.2. In this respect, the first switching position can also be referred to as the intake position and the second switching position as the venting position. In the intake position, the pilot control pressure pSV is regulated via solenoid valve 12. Solenoid valve 12 switches based on the parking brake signal SFB, which is received by the parking brake module 2, for example, via the vehicle bus 16, or can be directly provided to solenoid valve 12.

[0042] The solenoid valve 12 has a first permanent magnet 13.1 and a second permanent magnet 13.2. Additionally, in the illustrated embodiment, the solenoid valve 12 also has a first coil 13.3 and a second coil 13.4. Depending on the parking brake signal SFB, either the first coil 13.3 or the second coil 13.4 is energized. If the first coil 13.3 is energized, the armature of the solenoid valve 12 is attracted in a substantially known manner, and the solenoid valve 12 is switched to the intake position. The armature is then held in the intake position by the first permanent magnet 13.1, thus the intake position is a magnetically deactivated position. The first permanent magnet 13.1 and the first coil 13.3 correspond to the intake position. If the second coil 13.4 is energized, the armature is attracted to the opposite deactivated position, and the solenoid valve 12 is switched to the deflation position. In this deactivated position, the armature is held by the second permanent magnet 13.2. However, in principle, only one coil 13.3, 13.4 can be set, and then the polarity of this coil 13.3, 13.4 must be reversed in order to switch the solenoid valve 12 to the intake and exhaust positions. It is also conceivable to set only one permanent magnet 13.1, 13.2, which is then preferably arranged on the armature of the solenoid valve 12.

[0043] In the illustrated embodiment, the parking brake module 2 is equipped with its own electronic control unit (ECU) (although this is not mandatory) and receives the parking brake signal SFB. It then regulates at least one first switching signal S1 at the solenoid valve 12 to selectively switch the solenoid valve between a first and a second switching position. If the parking brake module 2 does not have its own ECU, the first switching signal S1 can also be provided directly by an external control unit. The solenoid valve 12 can be switched to either the first or second switching position via pulses.

[0044] The pilot control pressure pSV, regulated by solenoid valve 12, is provided to the main valve unit 10 via holding valve 14. The main valve unit 10 includes a relay valve 20, which has a relay valve reserve connection 20.1, a relay valve working connection 20.2, a relay valve vent connection 20.3, and a relay valve control connection 20.4. The relay valve reserve connection 20.1 is connected to the reserve connection 4 and receives the reserve pressure pV. The relay valve working connection 20.2 is connected to the spring accumulator connection 21 of the parking brake module 2, at which the main valve unit 10 regulates the parking brake pressure pBP. The relay valve vent connection 20.3 is connected to the vent connection 3, and the relay valve control connection 20.4 is connected to the pilot control unit 8 and receives the pilot control pressure pSV. One or more spring-energy-storing brake cylinders 208a, 208b (see...) Figure 7 It can be connected to the spring accumulator connection end 21, releasing the spring accumulator brake cylinder during air intake and tightening the spring accumulator brake cylinder with the help of spring force during air release.

[0045] In order to release the spring-energy storage brake cylinders 208a and 208b, the spring accumulator connection end 21 must be air-intaken to regulate the parking brake pressure pBP. For this purpose, the solenoid valve 12... Figure 1 The venting position shown was brought to Figure 1 In the intake position (not shown), a pilot control pressure pSV is regulated. The holding valve 14 is in the open switching position. The holding valve 14 has a first holding valve connection 14.1 and a second holding valve connection 14.2, wherein the first holding valve connection 14.1 is connected to the solenoid valve 12, specifically to the second solenoid valve connection 12.2, and receives the pilot control pressure pSV. The second holding valve connection 14.2 is connected to the main valve unit 10, specifically to the relay valve control connection 20.4. The holding valve 14 is configured to be electromagnetic and monostable, and a second switching signal S2 is provided by energizing the electromagnet in the holding valve 14, which can be received from... Figure 1 The steady-state first switching position (which is the open position) shown is brought to the unsteady, closed second switching position. If solenoid valve 12 is switched first to regulate the pilot control pressure pSV and holding valve 14 is open, the pilot control pressure pSV is transmitted and regulated at the relay valve control connection 20.2, which then increases the volume of this pressure and regulates the parking brake pressure pBP at the spring accumulator connection 21. Now, holding valve 14 can be brought to the closed second switching position, such that the pilot control pressure pSV is blocked between the second holding valve connection 14.2 and the relay valve control connection 20.4. Now, solenoid valve 12 can again be brought to... Figure 1 In the first deflation position shown, the spring-energy-storing brake cylinders 208a and 208b remain inlet and are therefore released. Although only a variant with a pilot control unit 8 and a main valve unit 10 is described here, it should be understood that the main valve unit 10 is not absolutely necessary, and the pilot control pressure pSV can also be directly controlled as the parking brake pressure pBP. In this case, the second holding valve connection 14.2 is connected to the spring accumulator connection 21, eliminating the need for the main valve unit 10 in between.

[0046] The bistable solenoid valve 12 ensures that the parking brake module 2 remains in the switched position it was in at the time of the power interruption, even when the power supply is interrupted. The holding valve 14 is monostable and automatically switches to the desired position when the electromagnet is not energized. Figure 1 The solenoid valve 12 is held in the air intake position by the first permanent magnet 13.1 or in the air release position by the second permanent magnet 13.2, as shown in the open position.

[0047] The safety valve 50 provides an additional regulating mechanism for the electro-pneumatic valve unit 1. As initially described, when the safety valve 50 is in the supply position 52, the reserve pressure pV is supplied only to the solenoid valve 12 of the pilot control unit 8. As a result, when the safety valve 50 is in the supply position 52, the pilot control pressure pSV can only be supplied by the pilot control unit 8 to the relay valve control connection 20.4. When the safety valve 50 is in the venting position 54, the pilot control unit 8 and at least the first control line 58 connecting the pilot control unit 8 to the main valve unit 10 are forcibly vented, regardless of the switching position of the solenoid valve 12.

[0048] Safety valve 50 has a safety valve control connection 50.4 and a safety valve holding connection 50.5. The safety valve holding connection 50.5 is configured to hold the safety valve 50 in place. Figure 1 In supply position 52 (not shown). The safety valve holding connection 50.5 is connected to the supply line 56 via a return line 60. The return line 60 forms a safety valve holding circuit 62, which returns the pressure pA regulated by the safety valve 50 at the second safety valve connection 50.2 to the safety valve 50 or the safety valve holding connection 50.5. In normal operation, the regulated pressure pA is equivalent to the reserve pressure pV. The safety valve holding connection 50.5 is arranged such that the regulated pressure pA acts on the safety valve 50, causing the safety valve to be loaded. Figure 1 The first switching position, not shown, is the supply position 52.

[0049] Safety valve 50 has a preferred position, i.e., safety valve 50 is pre-tightened to Figure 1 The venting position 54 is shown. For this purpose, a spring 64 is provided, which preloads the safety valve 50 to... Figure 1 In the venting position 54 shown, the regulated pressure pA present at the safety valve holding connection 50.5 resists the action of the spring 64. When the safety valve 50 is in the supply position 52, as long as the regulated pressure pA exceeds a first threshold, the safety valve 50 is held in the supply position 52 by the regulated pressure pA provided at the safety valve holding connection 50.5. However, if the regulated pressure pA is lower than the first threshold, which can be in the range of approximately 150 kPa to 350 kPa, the force generated by the regulated pressure pA is less than the spring force of the spring 64, and thus the safety valve 50 falls back. Figure 1 The venting position 54 is shown in the diagram.

[0050] In the vent position 54, no reserve pressure pV is supplied to the pilot control unit 8, and therefore the pilot control unit 8 does not regulate any pilot control pressure pSV. As long as no other pressure is supplied at the relay valve control connection 20.4, the relay valve 20 vents the spring accumulator connection 21 and presses the connected parking brake.

[0051] When the regulated pressure pA (in this embodiment, the reserve pressure pV) reaches or falls below the first threshold, the safety valve 50 automatically switches from the supply position 52 to the vent position 54, thereby achieving the safety function. If a malfunction occurs in the commercial vehicle 200, i.e., the reserve pressure pV drops due to the first and second compressed air reserves 6 and 7 being emptied, leaking, or being actively pumped out by the driver, then when the safety valve 50 is in the supply position 52... Figure 1 When the supply position 52 (not shown) is reached, the regulated pressure pA also decreases. Starting from a certain point, preferably below a first threshold, the spring 18 pulls the safety valve 50 to... Figure 1 In the venting position 54 shown, the relay valve control connection 20.4 is vented and the parking brake pressure pBP is no longer regulated. The spring-loaded brake cylinders 208a and 208b are fully vented. Even if the service brake cylinders 209a and 209b on the rear axle and the service brake cylinders 210a and 210b on the front axle cannot ensure or can only ensure limited braking of the vehicle 200 due to the reduced reserve pressure pV, the spring-loaded brake cylinders 208a and 208b are pressed and brake the commercial vehicle 200.

[0052] In the vent position 54, the regulated pressure pA corresponds to the ambient pressure level, and the safety valve 50 remains in the vent position 54 regardless of the pressure supplied at the first safety valve connection 50.1. If the reserve pressure pV previously decreased to below the first threshold and then immediately exceeded the first threshold, the parking brake remains engaged (provided no additional pressure is supplied at the relay valve control connection 20.4). If the first and / or second compressed air reserves 6, 7 should be refilled in the vent position 54 of the safety valve 50, for example, because the commercial vehicle 200 regains power or the first and second compressed air reserves 6, 7 are refilled by a maintenance technician, the safety valve 50 remains in the vent position 54. Figure 1 In the venting position 54 shown, there is no automatic and unintentional air intake at the spring accumulator connection end 21.

[0053] To switch the safety valve 50 from the vent position 54 to the supply position 52, a safety valve control connection 50.4 is provided, at which a safety control pressure pSS can be provided. When the safety control pressure pSS exceeds a second threshold, preferably within the range of 150 kPa to 400 kPa, the safety valve 50 preferably switches to the supply position 52. To provide the safety control pressure pSS, the safety valve control connection 50.4 is connected to a first safety control line 66.

[0054] According to Figure 1 In the first embodiment, the safety control pressure pSS can be provided in two ways. For this purpose, the safety control line 66 is connected to the third safety shuttle valve connection 68.3 of the safety shuttle valve 68, which also has a first safety shuttle valve connection 68.1 and a second safety shuttle valve connection 68.2. Pressure can be provided at the first safety shuttle valve connection 68.1 and the second safety shuttle valve connection 68.2, and the safety shuttle valve 68 regulates the higher of these pressures at the third safety shuttle valve connection 68.3. In this variant, the safety shuttle valve 68 is an external valve disposed outside the housing 70 of the electro-pneumatic valve facility 1.

[0055] The first safety shuttle valve connection 68.1 is connected to the service brake connection 74 via the second safety control line 72, where the service brake pressure pBB can be provided. The safety valve control connection 50.4 is indirectly connected to the service brake connection 74 via the first safety control line 66, the safety shuttle valve 68, and the second safety control line 72, whereby the service brake pressure pBB can be provided as the safety control pressure pSS. Once the fault is cleared and the service brake pressure pBB can be provided, i.e., the service brake can be applied again using the service brake cylinders 208a, 208b of the front axle and / or the service brake cylinders 209a, 209b of the rear axle, the parking brake can also be released by air intake through the parking brake connection 21. For this purpose, for example, by operating the brake pedal, the service brake pressure pBB is provided as the safety control pressure pSS at the safety valve control connection 50.4, and the safety control valve 50 switches to the supply position 52. Therefore, the pilot control unit 8 is supplied with a reserve pressure pV and a pilot control pressure pSV is provided at the relay valve 20. This pilot control pressure then regulates the parking brake pressure pBP and provides it at the parking brake connection terminal 21. The parking brake connected to the parking brake connection terminal 21 is released and the vehicle is ready to be driven again.

[0056] Alternatively, in this embodiment, the safety control pressure pSS can also be provided via a safety switching unit 78, which is connected to the second safety shuttle valve connection terminal 68.2 via a third safety control line 80. Here, the safety switching unit 78 has an electrically switchable safety switching valve 79, configured as a two-position three-way valve, and has a first safety switching connection terminal 79.1, a second safety switching connection terminal 79.2, and a third safety switching connection terminal 79.3. To provide the safety pilot control pressure pSSV, the second safety switching connection terminal 79.2 is connected to the safety shuttle valve 68. The safety switching valve 79 is a monostable valve and is pre-tightened to... Figure 1 In the venting position shown, the second safety switching connection 79.2 and the third safety switching connection 79.3 are connected, thereby connecting the third safety control line 80 to the venting end 3 via the safety switching valve 79. The venting end 3 can be the second venting end or can be connected to a venting end 3 such as the relay valve venting connection 20.3.

[0057] exist Figure 1 In the switched position of the safety switching valve 79 shown, the safety shuttle valve 68 regulates the vehicle braking pressure pBB. The first safety switching connection 79.1 is connected to the second compressed air reserve 7, thereby applying the reserve pressure pV at the first safety switching connection 79.1. If the ECU provides a third switching signal S3, also known as the safety switching signal SSS, the safety switching valve 79 switches from... Figure 1 The bleed position shown is switched to the intake position, in which the first safety switching connection 79.1 and the second safety switching connection 79.2 are fluid-guided connected. The safety pilot control pressure pSSV regulated at the second safety switching connection 79.2 is a reserve pressure pV, which is also applied to the second safety shuttle valve connection 68.2 of the safety shuttle valve 68 via the third safety control line 80. If the safety pilot control pressure pSSV is higher than the service brake pressure pBB that may be provided at the first safety shuttle valve connection 68.1, the safety shuttle valve 68 regulates the safety pilot control pressure pSSV (here, the reserve pressure pV) at the third safety shuttle valve connection 68.3. This safety pilot control pressure pSSV is then applied as the safety control pressure pSS to the safety valve control connection 50.4 via the first safety control line 66. In this variant, the safety control pressure pSS can also be regulated based on the signal S3 provided by the ECU.

[0058] In the embodiments shown herein ( Figure 1In the parking brake module 2, a first pressure sensor 26 and a second pressure sensor 28 are also included. The first pressure sensor 26 is connected to the reserve connection terminal 4 via a first pressure measurement line 27, and thus measures the reserve pressure pV and provides a corresponding first pressure signal SD1 to the electronic control unit (ECU). The second pressure sensor 28 is connected to the spring accumulator connection terminal 21 via a second pressure measurement line 29, and thus obtains the parking brake pressure pBP and provides a corresponding second pressure signal SD2 to the ECU. The first and second pressure signals SD1 and SD2 can be used to verify and check the rationality of the regulated pressure and the switching positions of each valve.

[0059] exist Figure 1 In the first embodiment shown, the service brake connection 74 is a release control connection 76, so that the service brake pressure pBB is the release control pressure pL. This release control connection 76 is also called an anti-re-excitation connection, through which the release control pressure pL can be introduced. The release control connection 76 is connected to the release control path 32. The release control pressure pL introduced via the release control connection 76 causes the parking brake pressure pBP to be regulated at at least one spring accumulator connection 21. The release control path 32 includes a release line 33 extending from the release control connection 76. Typically, the service brake pressure pBB of another axle (e.g., the front axle and / or the rear axle) is used as the release control pressure pL. This prevents excessive actuation of the spring accumulator brake cylinders 208a, 208b, which could cause the vehicle 100 to lock up, in cases where the spring accumulator brake cylinders 208a, 208b connected to the spring accumulator connection 21 are also used for additional braking or emergency braking. If the service brake on the rear axle is activated, the spring energy storage brake cylinders 208a and 208b should not be engaged simultaneously as much as possible, so as to provide the service brake pressure of the rear axle to the release control connection terminal 76 as the release control pressure pL, so as to reciprocately release the spring energy storage brake cylinders 208a and 208b to engage the service brake.

[0060] The release control line 33 is connected to the main control shuttle valve 34. The release control pressure pL can be delivered to the relay valve control connection 20.4 via the release control path 32. The main control shuttle valve 34 has a first main control shuttle valve connection 34.1, a second main control shuttle valve connection 34.2, and a third main control shuttle valve connection 34.3. The main control shuttle valve 34 is configured such that it always delivers the higher of the pressures applied at the first and second main control shuttle valve connections 34.1 and 34.2 to the third main control shuttle valve connection 34.3. The first main control shuttle valve connection 34.1 is connected here to the second main control shuttle valve connection 14.2 via the second control line 36, but it can also be directly connected to the second holding valve connection 14.2 or also connected to the solenoid valve 12. In any case, the first main control shuttle valve connection 34.1 is connected to the pilot control unit 8 and receives the pilot control pressure pSV. The second main control shuttle valve connection terminal 34.2 is connected to the release control connection terminal 76 and receives the release control pressure pL. The third main control shuttle valve connection terminal 34.3 is connected to the relay valve control connection terminal 20.4, so that the higher of the pilot control pressure pSV or the release control pressure pL is always regulated at the relay valve control connection terminal 20.4 to cause the parking brake pressure pBP to be regulated.

[0061] In this embodiment ( Figure 1 In this design, the release control connection 76 fulfills a particularly advantageous dual function. On one hand, it provides anti-re-excitation, preventing the brake from being excessively actuated; on the other hand, the release control pressure pL can be used as a safety control pressure pSS to switch the safety valve 50 to the supply position 54. This reduces the cost of connecting the component to the fluid guide and saves on additional connections.

[0062] exist Figures 2 to 6 The other embodiments shown are in principle based on the first embodiment ( Figure 1 Thus, identical and similar elements have the same reference numerals. In this respect, reference is made entirely to the first embodiment ( Figure 1 The above description is as follows. The differences from the first embodiment are particularly emphasized below.

[0063] Second embodiment ( Figure 2 The main difference is that the safety shuttle valve 68 is not constructed as an external valve, but is arranged inside the housing 70. The service brake connection 74, which forms the release control connection 76, is also directly arranged on the housing 70. Furthermore, in the second embodiment, the safety switching unit is connected to both the second compressed air reserve 7 and the first compressed air reserve 6.

[0064] In the third embodiment ( Figure 3In this embodiment, the electro-pneumatic valve facility 1 is constructed as a highly integrated valve facility. Both the safety shuttle valve 68 and the safety switching unit 78 are integrated into the housing 70. This function is essentially unchanged compared to the previous two embodiments. Figure 3 As shown by the dashed line 82, the reserve shuttle valve 5 can be arranged not only inside the housing 70 but also outside the housing. When the reserve shuttle valve 5 is arranged inside the housing (dashed line 82), the electro-pneumatic valve facility 1 has two reserve connection ends 4.

[0065] According to Figure 4 In the fourth embodiment, the electro-pneumatic valve facility 1 is basically the same as in the third embodiment ( Figure 3 The system is similarly constructed, but additionally includes a trailer unit 84. A trailer supply unit 85, via trailer unit 84, can provide trailer reserve pressure pVA at trailer reserve connection 86 to supply the service brake cylinder of a trailer (not shown) connected to the commercial vehicle 200. For this purpose, in this embodiment, trailer supply unit 84 has a trailer supply switching valve 88, a trailer supply protection valve 90, and a trailer supply holding valve 92. Trailer supply switching valve 88 has a first trailer switching connection 88.1 and a second trailer switching connection 88.2. Trailer supply protection valve 90 has a first trailer protection connection 90.1, a second trailer protection connection 90.2, and a third trailer protection connection 90.3. Trailer supply holding valve 92 has a first trailer holding connection 92.1, a second trailer holding connection 92.2, and a third trailer holding connection 92.3. Trailer supply switching valve 88 is configured as an electrically switchable monostable two-position two-way valve. When the ECU provides the fourth switching signal S4, the trailer supply switching valve 88 is activated. Figure 4 The closed position shown is switched to the intake position, in which the first trailer switching connection 88.1 and the second trailer switching connection 88.2 are separate. In the intake position, the first trailer switching connection 88.1 and the second trailer switching connection 88.2 are connected. The first trailer switching connection 88.1 is connected to the reserve connection 4 and receives the reserve pressure pV. In the intake position, the trailer supply switching valve 88 guides the reserve pressure pV and provides the reserve pressure at the first trailer protection valve control connection 90.4.

[0066] The trailer supply protection valve 90 is a bistable two-position three-way valve, which provides a reserve pressure pV at the first trailer protection valve control connection terminal 90.4 to supply power from the trailer supply protection valve. Figure 4The venting position shown is switched to the intake position. In the intake position, the first trailer protection connection 90.1 and the second trailer protection connection 90.2 are connected in a fluid-guiding manner, so that the reserve pressure pV is conducted from the reserve connection 4 through the first trailer protection connection 90.1 to the second trailer protection connection 90.2 and then to the trailer reserve connection 86 connected to the second trailer protection connection 90.2. The trailer reserve pressure pVA is equivalent to the reserve pressure pV. In the venting position, the trailer supply protection valve 90 connects the trailer reserve connection 86 to the venting end 3.

[0067] During the initial switchover, the reserve pressure pV provided by the trailer supply switching valve 88 at the first trailer protection valve control connection 90.4 forms the first trailer pilot control pressure pSVA1. To avoid continuously providing this reserve pressure pV or to prevent continuously providing the fourth switching signal, a trailer supply holding valve 92 is provided. The second trailer holding connection 92.2 is directly connected to the trailer reserve connection 86. When the reserve pressure pV is regulated at the second trailer protection connection 90.2, this reserve pressure is applied both to the trailer reserve connection 86 and to the second trailer holding connection 92.2. The trailer supply holding valve 92 is configured as a monostable two-position three-way valve, which has... Figure 4 The holding position shown is the preferred position. In this holding position, the second trailer holding connection 92.2 is connected to the first trailer holding connection 92.1 in a fluid-guided manner, so that the trailer reserve pressure pVA is provided as the first trailer pilot control pressure pSVA1 at the first trailer protection valve control connection 90.4. After the initial switching of the trailer protection valve 90, the trailer supply switching valve 88 can return to... Figure 4 In the closed position shown, the trailer supply protection valve 90 is maintained in the switched position by returning the trailer reserve pressure pVA via the trailer supply holding valve 92. Preferably, as Figure 4 As shown, the trailer supply holding valve 92 is configured as a throttle valve to compensate for small pressure fluctuations in the trailer reserve pressure pVA.

[0068] If the ECU provides a fifth switching signal S5, the trailer supply holding valve 92 switches to the vented position and connects the first trailer protection valve control terminal 90.4 to the vented terminal 3 via the first trailer holding connection terminal 92.1 and the third trailer holding connection terminal 92.3. The second trailer protection valve control connection terminal 90.5 is directly connected to the reserve connection terminal 4, where a reserve pressure pV is applied. If the first trailer protection valve control connection terminal 90.4 is now vented, the pressure applied to the second trailer protection valve control connection terminal 90.5 is greater than the pressure applied to the first trailer protection valve control connection terminal 90.4, and the trailer supply protection valve 90 switches to... Figure 4In the venting position shown, the second trailer protection connection 90.2 and the trailer reserve connection 86 are connected to the venting end 3.

[0069] Even when the trailer supply holding valve 92 is in position Figure 4 When the switching position is shown, as a protective function, the trailer supply protection valve 90 can also be switched from the air intake position to the air intake position. Figure 4 In the venting position shown. If, for example, the pneumatic connection to the trailer is disconnected, the trailer protection connection 86 suddenly vents. As a result, the first trailer protection valve control connection 90.4 is also vented, because the first trailer protection valve control connection is connected to the trailer reserve connection 86 via the first trailer holding connection 92.1 and the second trailer holding connection 92.2 in a fluid-guiding manner. The reserve pressure pV continues to be applied to the second trailer protection valve control connection 90.5, causing the trailer supply protection valve to automatically switch to... Figure 4 The venting position shown interrupts the connection between the compressed air reservoirs 6 and 7 and the guide fluid at the trailer reservoir connection 86. This prevents leakage of compressed air reservoirs 6 and 7 in the event of unforeseen venting at the trailer reservoir connection 86.

[0070] The embodiments shown here ( Figure 4 In the parking brake module 2, a third pressure sensor 38 is also included, which is connected to the trailer reserve connection terminal 86 via a third pressure measurement line 40. The third pressure sensor 38 measures the trailer reserve pressure pVA and provides a corresponding third pressure signal SD3 to the electronic control unit (ECU). The third pressure signal SD3 can be used to verify and check the rationality of the controlled trailer reserve pressure pVA and the switching positions of the various valves in the trailer supply unit 85.

[0071] Figure 5 The fifth embodiment shown is based in principle on the fourth embodiment ( Figure 4 The main difference in the fifth embodiment is that a safety switching unit 78 is not provided. The safety valve control connection terminal 50.4 or the first safety control line 66 is directly connected to the service brake connection terminal 74. In the fifth embodiment, the service brake connection terminal is also the release control connection terminal 76, so as to receive the service brake pressure pBB or release control pressure pL.

[0072] Sixth embodiment ( Figure 6 It is also based in principle on the fourth embodiment ( Figure 4However, it differs from this one in that it has an additional trailer control unit 94 with trailer unit 84 and an alternative provision for safety control pressure pSS. The trailer control unit 94 is configured to regulate trailer braking pressure pBA at trailer control connection 96, the trailer braking pressure being set to operate the trailer's service brake. For this purpose, the trailer control unit 94 has a trailer pilot control unit 98 and a trailer main valve unit 100. In this embodiment, the trailer pilot control unit 98 includes an electrically controllable first trailer pilot control valve 102 having a first trailer pilot control valve connection 102.1 and a second trailer pilot control valve connection 102.2, and a trailer vent valve 104 including a first trailer vent valve connection 104.1 and a second trailer vent valve connection 104.2. The trailer pilot control valve is a monostable two-position two-way valve with an inlet position and a closed position. Figure 6 In the closed position shown, the trailer pilot control valve 102 is pre-tightened to this closed position when there is no current, and the two trailer pilot control valve connection terminals 102.1 and 102.2 are not connected to each other. By providing a sixth switching signal S6, the trailer pilot control valve 102 can be gradually switched to the intake position by means of the ECU. The first trailer pilot control valve connection terminal 102.1 is directly connected to the reserve connection terminal 4, so that the reserve pressure pV is applied at the reserve connection terminal. Then, the trailer pilot control valve 102 regulates the second trailer pilot control pressure pSVA2 according to the sixth switching signal S6, which is then provided to the trailer main valve unit 100 via the trailer pilot control line 106.

[0073] Trailer vent valve 104 is configured to vent the trailer pilot control line 106. In the sixth embodiment ( Figure 6 In this configuration, the trailer vent valve 104 is configured as an electrically switchable monostable two-position two-way valve, pre-tightened to the open position, in which the two trailer vent valve connection terminals 104.1 and 104.2 are not connected to each other. When the ECU provides the seventh switching signal S7 to the trailer vent valve 104, the trailer vent valve switches to the vent position and connects the trailer pilot control line 106 to the vent terminal 3 via the first trailer vent valve connection terminal 104.1 and the second trailer vent valve connection terminal 104.2.

[0074] Here, the trailer main valve unit 100 has only one trailer relay valve 108, which functions substantially similarly to relay valve 20 and has a trailer relay valve reserve connection 108.1, a trailer relay valve working connection 108.2, a trailer relay valve vent connection 108.3, and a trailer relay valve control connection 108.4. The trailer relay valve reserve connection 108.1 is connected to the reserve connection 4 and receives the reserve pressure pV. The trailer relay valve vent connection 108.3 is connected to the vent connection 3. The trailer relay valve receives a second trailer pilot control pressure pSVA2 provided on the trailer pilot control line 106 at the trailer relay valve control connection 108.4, and at the trailer relay valve working connection 108.2, it volumetrically regulates the corresponding trailer braking pressure pBA. The pressure pBA is measured by the fourth pressure sensor 109, which is constructed in a manner similar to the other pressure sensors 26, 28, and 38, and provides the ECU with a fourth pressure signal SD4.

[0075] In this embodiment, the trailer control protection valve 110 is arranged between the trailer relay valve working connection end 108.2 and the trailer control connection end 96, so the trailer braking pressure pBA is not directly regulated by the trailer relay valve working connection end 108.2 at the trailer control connection end 96. Instead, it is only regulated when the trailer control protection valve 110 is in the supply position ( Figure 6 When (not shown in the diagram), trailer braking pressure pBA is supplied at trailer control connection 96. In the supply position, the first trailer control protection valve connection 110.1 and the second trailer control protection valve connection 110.2 are connected in a fluid-guiding manner, thereby conducting the trailer braking pressure pBA. When the trailer control protection valve 110 is in the supply position... Figure 6 In the protected position shown, the trailer control connection 96 and the trailer relay valve operating connection 108.2 are separated by the trailer control protection valve 110. This prevents, for example, an uncontrolled drop in trailer brake pressure pBA when the pneumatic trailer control line to the trailer is disconnected.

[0076] In order to bring the trailer control protection valve 110 to Figure 6 In the supply position not shown, trailer protection pressure pSA must be provided at the trailer control protection valve control connection 110.3. Once the trailer protection pressure pSA exceeds a preset threshold, the trailer control protection valve 110 switches and connects the trailer control connection 96 and the trailer relay valve working connection 108.2, thereby regulating the trailer braking pressure pBA.

[0077] In this variant of the electro-pneumatic valve facility 1, the trailer control protection valve control connection 110.3 is connected to the first trailer protection valve control connection 90.4 via the trailer protection line 112, so that the first trailer pilot control pressure pSVA1 is the trailer protection pressure pSA. This ensures that when a pressure drop occurs at the trailer reserve connection 86, the supply of trailer reserve pressure pVA to the trailer at the trailer reserve connection 86 and the supply of trailer service brake pressure pBA to the trailer via the trailer control connection 96 are both interrupted. Therefore, the braking system 202 is protected in a simple manner.

[0078] To ensure the trailer control pressure pBA can still be output in the event of an electrical failure in the ECU, the trailer control unit 94 also includes a redundant valve 114, which has a first redundant valve connection terminal 114.1 and a second redundant valve connection terminal 114.2. The first redundant valve connection terminal 114.1 is connected to a redundant connection terminal 116, through which redundant pressure pR can be provided at the first redundant valve connection terminal 114.1. In the braking system 202 ( Figure 7 In this context, the redundant pressure pR is preferably provided by, for example, an electronic foot brake module 220. Figure 7 A braking value transmitter like that is used to provide it.

[0079] During normal operation, redundant valve 114 is in... Figure 6 In the operating position (not shown), the first redundant valve connection terminal 114.1 and the second redundant valve connection terminal 114.2 are not connected. When the ECU provides the eighth switching signal S8 at the redundant valve 114, the redundant valve 114 remains in this operating position. If the eighth switching signal S8 is not provided, for example, when the redundant valve 114 has no current due to an electrical fault in the ECU, the redundant valve 114 automatically switches to... Figure 6 In the redundant position shown. In this case, the trailer pilot control valve 102 and the trailer vent valve 104 are normally open (in Figure 6 In the switching position shown, the redundant pressure pR is thus provided via redundant line 118 at the trailer relay valve control connection 104.2. Then, the trailer relay valve 104 regulates to produce the trailer braking pressure pBA corresponding to the redundant pressure pR.

[0080] In this embodiment, the first safety control line 66 leading to the safety valve control connection 50.4 is not connected to the release control connection 76 as in previous embodiments, but is connected to the trailer service brake connection 120. The trailer brake pressure pBA is regulated at the trailer service brake connection 120. In this embodiment, when the trailer control unit 94 is without current, this trailer brake pressure is derived from the redundant pressure pR provided at the redundant connection 116. However, it is also preferable that the redundant pressure pR provided at the safety valve control connection 50.4 is directly used as the service brake pressure pBB. Here, the trailer service brake connection 120 is an internal connection connected to the trailer relay valve working connection 108.2. However, it is also possible that the trailer service brake connection 120 is an external connection, where the trailer brake pressure pBA is provided. In addition, the safety valve control connection terminal 50.4 can be connected to the redundant connection terminal 116, which can be the service brake connection terminal 74.

[0081] If safety valve 50 is to be brought to Figure 6 In the sixth embodiment, at supply position 52 (not shown), trailer braking pressure pBA must be provided at trailer service brake connection 120 via trailer control unit 94. In this embodiment, trailer pilot control unit 98 also forms a safety switching unit 78, wherein the second trailer pilot control pressure pSVA2 is a safety pilot control pressure pSSV. In response to this safety pilot control pressure pSSV (the second trailer pilot control pressure pSVA2), trailer relay valve 108 regulates the trailer braking pressure pBA, which simultaneously forms the safety control pressure pSS. In this embodiment, the existing pressure (trailer braking pressure) is dually used as the safety control pressure pSS, thereby achieving a simple, compact, and cost-effective design.

[0082] at last, Figure 7A vehicle 200, i.e., a commercial vehicle, is shown with a braking system 202, which is configured as an electronically controlled pneumatic braking system. The vehicle 200 has a front axle VA and a rear axle HA. A central module 204, also configured as a rear axle modulator, brakes the rear axle HA, and a front axle modulator 206 is associated with the front axle VA. The central module 204 and the front axle modulator 206 are connected to each other via electronic circuitry 207 and thus exchange signals, particularly braking signals. In addition to the first and second spring-energy-storing brake cylinders 208a and 208b, first and second service brake cylinders 209a and 209b are also provided on the rear axle HA, and these first and second service brake cylinders can be combined with the spring-energy-storing brake cylinders 208a and 208b to form a so-called Tristop cylinder. On the front axle VA, the front axle modulator 206 controls the corresponding braking pressure on the front axle service brake cylinders 210a and 210b. Therefore, the vehicle has two service braking circuits 212: a front axle braking circuit 214 and a rear axle braking circuit 216. A front axle braking pressure pBVA is provided at the front axle braking circuit 214, and a rear axle braking pressure pBHA is provided at the rear axle braking circuit 214. To provide the front axle braking pressure pBVA, which also forms the service braking pressure pBB here, a braking module 218 is provided, which in this embodiment is an electro-pneumatic foot brake module 220. Spring-energy-storing brake cylinders 208a and 208b are controlled via a parking brake module 2, in which the electro-pneumatic valve facility 1 according to the invention is implemented. The parking brake module 2 has a spring energy-storing coupling end 21, which is as follows... Figure 7 As shown, it is connected to the spring-loaded brake cylinders 208a and 208b. The vehicle bus 16 connects the parking brake module 2 to the central unit 204.

[0083] List of reference numerals (part of the instruction manual)

[0084] 1 Electric and pneumatic valve facilities 2 Parking brake module 3 vent end 4 Reserve connection end 5 Reserve shuttle valve 6 First Compressed Air Storage Department 7 Second Compressed Air Storage Unit 8 Pilot control unit 10 Main valve unit 12 Solenoid valve 12.1 First solenoid valve connection end 12.2 Second solenoid valve connection terminal 12.3 Third solenoid valve connection end 12.4 Safety control connection terminal 13.1 First permanent magnet 13.2 Second permanent magnet 13.3 First coil 13.4 Second coil 14 Holding valve 14.1 First holding valve connection end 14.2 Second holding valve connection end 16 Vehicle bus 18 spring 20 relay valve 20.1 Relay valve storage connection terminal 20.2 relay valve working connection end 20.3 Relay valve vent connection end 20.4 Relay valve control connection terminal 21 Spring accumulator connection terminal 26 First pressure sensor 27 First pressure measurement circuit 28 Second pressure sensor 29 Second pressure measurement circuit 32 Release control path 33 Release line 34 Main control shuttle valve 34.1 First main control shuttle valve connection end 34.2 Second main control shuttle valve connection end 34.3 Third main control shuttle valve connection end 36 Second control circuit 38 Third pressure sensor 40 Third pressure measurement circuit 50 safety valve 50.1 First safety valve connection end 50.2 Second safety valve connection end 50.3 Third safety valve connection end 50.4 Safety valve control connection terminal 50.5 Safety valve retaining connection end 51 spring 52 Supply location 54 venting position 56 Supply lines 58 First control line 60 return line 62 Safety valve holding circuit 64 spring 66 First safety control circuit 68 Safety shuttle valve 68.1 First safety shuttle valve connection end 68.2 Second safety shuttle valve connection end 68.3 Third safety shuttle valve connection end 70 case 72 Second safety control circuit 74 Service brake connection end 76 Release control connection terminal 78 Safety switching unit 79 Safety switching valve 79.1 First safe switching connection end 79.2 Second safety switching connection terminal 79.3 Third safety switching connection terminal 80 Third safety control circuit 82 dotted line 84 trailer unit 85 Trailer supply unit 86 Trailer reserve connection end 88 Trailer supply switching valve 88.1 First trailer switching connection end 88.2 Second trailer switching connection terminal 88.3 Third trailer switching connection terminal 90 Trailer supply protection valve 90.1 First trailer protection connection end 90.2 Second trailer protection connection end 90.3 Third trailer protection connection terminal 90.4 First trailer protection valve control connection terminal 90.5 Second trailer protection valve control connection terminal 92 Trailer supply holding valve 92.1 First trailer maintains connection end 92.2 The second trailer remains connected. 92.3 The third trailer maintains the connection. 94 Trailer control unit 96 Trailer control connection terminal 98 Trailer pilot control unit 100 Trailer main valve unit 102 Trailer pilot control valve unit 102.1 First trailer pilot control valve connection terminal 102.2 Second trailer pilot control valve connection terminal 104 Trailer air release valve 104.1 First trailer air release valve connection end 104.2 Second trailer air release valve connection end 106 Trailer pilot control circuit 108 Trailer relay valve 108.1 Trailer relay valve reserve connection terminal 108.2 Trailer relay valve working connection end 108.3 Trailer relay valve vent connection end 108.4 Trailer relay valve control connection terminal 109 Fourth pressure sensor 110 Trailer control protection valve 110.1 First trailer control protection valve connection end 110.2 Second trailer control protection valve connection terminal 110.3 Trailer control protection valve control connection terminal 112 Trailer protection lines 114 redundant valves 114.1 First redundant valve connection terminal 114.2 Second redundant valve connection terminal 116 Redundant connection terminals 118 Redundant lines 120 Trailer service brake connection end 200 vehicle 201 Commercial vehicles 202 Braking system 204 Central Module 206 Front axle modulator 208a, 208b Spring-powered brake cylinder 209a, 209b Service brake cylinder on the front axle 210a, 210b Service brake cylinder on the rear axle 212 Service brake circuit 214 Front axle braking circuit 216 Rear axle braking circuit 218 Braking module 220 Electric pneumatic foot brake module ECU Electronic control unit pA Pressure from regulation pBA Trailer braking pressure pBB Service brake pressure pBP Parking brake pressure pBHA Rear axle braking pressure pBVA Front axle braking pressure pL Release control pressure pR Redundant pressure pSA Trailer protection pressure pSS Safety control pressure pSSV Safety-first control pressure pSV Pilot control pressure pSVA1 First trailer pilot control pressure pSVA2 Second trailer pilot control pressure pV Reserve pressure pVA Trailer inventory pressure SD1 First pressure signal SD2 Second pressure signal SD3 Third pressure signal SFB Parking brake signal SSS Safety switching signal S1 First switching signal S2 Second switching signal S3 Third switching signal S4 Fourth switching signal S5 Fifth switching signal S6 Sixth switching signal S7 Seventh switching signal S8 Eighth switching signal

Claims

1. An electro-pneumatic valve device (1) for operating the parking brake function of an electro-pneumatic braking system (202) of a commercial vehicle (201), said electro-pneumatic valve device having Pilot control unit (8), which regulates pilot control pressure (pSV) based on electronic parking brake signal (SFB); and The main valve unit (10) is adapted to receive the pilot control pressure (pSV) and regulate the parking brake pressure (pBP) at at least one spring accumulator connection (21). The electro-pneumatic valve facility has a pneumatically switchable self-holding safety valve (50), which is connected before the pilot control unit (8) and has a safety valve control connection (50.4) for receiving a safety control pressure (pSS) and a safety valve holding circuit (62) for receiving a pressure (pA) regulated by the safety valve (50) or a pressure derived therefrom. in, By receiving the safety control pressure (pSS), the safety valve (50) can switch from the vent position (54) to the supply position (52), in which the safety valve (50) connects the pilot control unit (8) to the vent end (3), and in the supply position, the safety valve (50) supplies the reserve pressure (pV) to the pilot control unit (8). The safety valve (50) depends on the regulated pressure (pA) received at the safety valve holding circuit (62) to remain in the supply position (52) or switch to the vent position (54), and The electro-pneumatic valve facility has an electro-pneumatic safety switching unit (78), which regulates the safety pilot control pressure (pSSV) based on the electronic safety switching signal (SSS). Its characteristics include A service brake connection (74) for receiving service brake pressure (pBB), wherein the service brake connection (74) is directly or indirectly connected to the safety valve control connection (50.4) in a fluid-guiding manner, and A safety shuttle valve (68) is configured to receive the safety pilot control pressure (pSSV) and the service brake pressure (pBB) and to regulate the higher of the safety pilot control pressure (pSSV) and the service brake pressure (pBB) as the safety control pressure (pSS).

2. The electro-pneumatic valve device (1) according to claim 1, wherein, The service brake connection terminal (74) can be connected to the front axle brake circuit (214) and / or the rear axle brake circuit (216), wherein the service brake pressure (pBB) is the front axle brake pressure (pBVA) and / or the rear axle brake pressure (PBHA) of the commercial vehicle (201).

3. The electro-pneumatic valve device (1) according to claim 2, wherein, The service brake connection (74) is a release control connection (76), and the service brake pressure (pBB) is the release control pressure (pL).

4. The electro-pneumatic valve assembly (1) according to claim 3, further comprising a main control shuttle valve (34) configured to receive the pilot control pressure (pSV) and the release control pressure (pL) and to provide the main valve unit (10) with the higher of the pilot control pressure (pSV) and the release control pressure (pL), wherein, The main valve unit (10) regulates the parking brake pressure (pBP) based on the release control pressure (pL) or the pilot control pressure (pSV).

5. The electro-pneumatic valve device (1) according to claim 1, wherein, The service brake connection end (74) is a redundant connection end (116), and wherein the service brake pressure (pBB) is a redundant brake pressure (pR) or a pressure derived from the redundant brake pressure (pR).

6. The electro-pneumatic valve device (1) according to claim 1 or 5, wherein, The service brake connection end (74) is the trailer service brake connection end (120), and the service brake pressure (pBB) is the trailer brake pressure (pBA).

7. The electro-pneumatic valve device (1) according to claim 1, wherein, The safety switching unit (78) is configured to receive the reserve pressure (pV) and, in the first switching position, to regulate the reserve pressure (pV) as the safety pilot control pressure (pSSV).

8. The electro-pneumatic valve device (1) according to claim 7, wherein, The safety switching unit (78) connects the safety shuttle valve (68) to the venting end (3) in the second switching position.

9. The electro-pneumatic valve device (1) according to any one of claims 1 to 5, wherein, When the regulated pressure (pA) applied to the safety valve holding circuit (62) exceeds a first threshold, the safety valve (50) remains in the supply position (52), and wherein when the regulated pressure (pA) applied to the safety valve holding circuit (62) reaches or falls below the first threshold, the safety valve switches to the venting position (54).

10. The electro-pneumatic valve device (1) according to claim 9, wherein, The first threshold is in the range of 200 kPa to 350 kPa.

11. The electro-pneumatic valve device (1) according to any one of claims 1 to 5, wherein, The safety valve (50) has a tension spring (51) that pre-tightens the safety valve (50) into the vent position (54).

12. The electro-pneumatic valve device (1) according to any one of claims 1 to 5, wherein, The pilot control unit (8) is a bistable pilot control unit.

13. The electro-pneumatic valve device (1) according to claim 12, wherein, The bistable pilot control unit (8) has a bistable solenoid valve (12) having at least a first permanent magnet (13.1).

14. The electro-pneumatic valve device (1) according to claim 10, wherein, The first threshold is in the range of 250 kPa to 315 kPa.

15. An electro-pneumatic braking system, the electro-pneumatic braking system having an electro-pneumatic valve facility (1) according to any one of claims 1 to 14 and a service brake circuit (212), the service brake circuit having a brake module (218) for providing service brake pressure (pBB), wherein, The braking module (218) is connected to the service brake connection end (74) of the electro-pneumatic valve facility (1) in a fluid-guiding manner.

16. A method for controlling the parking brake function of a vehicle (200), the vehicle having an electro-pneumatic braking system (202) according to claim 15, the method comprising the following steps: - By providing a safety control pressure (pSS) to the safety valve control connection (50.4), the safety valve (50) is pneumatically switched to the supply position (52), in which the safety valve (50) supplies a reserve pressure (pV) to the pilot control unit (8). - The reserve pressure (pV) is received at the pilot control unit (8) and the pilot control unit (8) regulates the pilot control pressure (pSV) based on the electronic parking brake signal (SFB). - The braking module (218) of the service braking circuit (212) provides the service braking pressure (pBB). - The parking brake pressure (pBP) is regulated at at least one spring accumulator connection (21) by the main valve unit (10) depending on the service brake pressure (pBB) or the pilot control pressure (pSV). in, The safety control pressure (pSS) is the service brake pressure (pBB) or the reserve pressure (pV) provided by the electromagnetically opened safety switching unit (78) at the safety valve control connection (50.4). - The safety pilot control pressure (pSSV) is regulated on the electro-pneumatic safety switching unit (78) based on the electronic safety switching signal (SSS); and - The safety pilot control pressure (pSSV) and the service brake pressure (pBB) are received on the safety shuttle valve (68), and the higher of the safety pilot control pressure (pSSV) and the service brake pressure (pBB) is adjusted by means of the safety shuttle valve (68) as the safety control pressure (pSS).

17. The method according to claim 16, wherein, The vehicle is a commercial vehicle (201).

18. A vehicle (200) having an electro-pneumatic braking system (202) according to claim 15.

19. The vehicle according to claim 18, wherein, The vehicle is a commercial vehicle (201).

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