Electropneumatic parking brake unit with emergency release

Abstract

The invention relates to an electro-pneumatic valve arrangement (1) for operating a parking brake function of an electro-pneumatic brake system (102) of a utility vehicle (100), having a pilot control unit (8) which regulates a pilot control pressure (pSV) in dependence on an electronic parking brake signal (SFB) and which is configured to be self-holding, wherein the pilot control pressure (pSV) can cause a parking brake pressure (pBP) to be regulated at at least one spring accumulator coupling port (21) or can regulate the pilot control pressure as the parking brake pressure. Furthermore, the valve arrangement has an emergency release coupling port (38) which has an emergency release path (39) for selectively introducing an emergency release pressure (pSN) which causes the parking brake pressure (pBP) to be regulated at the at least one spring accumulator coupling port (21). The invention also relates to a method and to a utility vehicle.

Description

Technical Field

[0001] This invention relates to an electro-pneumatic valve device for operating the parking brake function of an electro-pneumatic braking system in a commercial vehicle. The electro-pneumatic valve device has a pilot control unit that regulates a pilot control pressure based on an electronic parking brake signal. The pilot control unit is configured to be self-holding, wherein the pilot control pressure can cause the regulation of a parking brake pressure at at least one spring accumulator connection point, or can regulate the pilot control pressure as the parking brake pressure. The invention also relates to a method for controlling the parking brake function of a commercial vehicle using an electro-pneumatic braking system, and to a commercial vehicle having an electronically controllable pneumatic braking system. Background Technology

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

[0003] DE 10 2017 005 757 A1 discloses a solution for supplying air to such a spring-loaded brake cylinder. The solution disclosed in the preamble of claim 1 uses a pilot control unit and a main valve unit, wherein the pilot control unit includes a solenoid valve in the form of a bistable valve. In the solution disclosed herein, the main valve unit is formed by a relay valve. A control pressure is regulated at the main valve unit according to the switching position of the bistable solenoid valve, which then regulates the volume pressure for the spring-loaded brake cylinder accordingly. The bistable valve is a solenoid valve having two stable switching positions, specifically a stable supply position and a stable release position. For this purpose, by energizing a first electromagnet, the armature of the solenoid valve can be moved to the first position, thereby placing the solenoid valve in the supply position, and by energizing a second electromagnet, the armature of the solenoid valve can be moved to the second position, thereby placing the solenoid valve in the release position. If no other force is applied to the armature, or if the armature can be locked in these positions mechanically and / or magnetically, the respective switching positions are stable because these switching positions can be maintained without continued energization.

[0004] However, in the United States, a so-called 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, thereby insulating and releasing the spring-loaded brake cylinder of the tractor unit. If the driver pulls out the push-pull valve, the spring-loaded brake cylinder is depressurized and compressed. A solution that allows pneumatic switching of the push-pull valve is disclosed in DE 102018 108 202A1.

[0005] Because the costs associated with the valves that enable parking braking, the spring-loaded brake cylinder typically located on the rear axle, and the pneumatic piping laid in the cab are relatively high, simplification is necessary. Furthermore, there is a need to improve the safety of this push-pull valve.

[0006] Another solution is disclosed in WO 2019 / 030242 A1, which generates a pneumatic bistable or self-holding state, thereby enabling stable engagement of the parking brake even without continued energization of the solenoid valve. This disclosed solution uses a pneumatically switchable 2-position 3-way valve as the main valve unit and two electrically switchable 2-position 3-way valves as pilot control units. One of the electrically switchable 2-position 3-way valves draws back the pressure regulated by the main valve unit and regulates the pneumatic control connection of the main valve unit. Thus, pneumatic self-holding is achieved when the main valve unit regulates the pneumatic pressure. In the event of a malfunction, or if the reserve pressure supplying the main valve unit is pumped out, the main valve unit ceases to regulate pressure, and the main valve unit monostablely transitions to another switching position in which the corresponding spring accumulator connection is vented. Even if the corresponding pressure reserve needs to be refilled, for example by a maintenance technician or because the vehicle is powered on again, the parking brake will not automatically release again because the main valve unit is in the vented position and no pneumatic pressure is being drawn back.

[0007] However, depending on the vehicle's structural type, this solution, specifically designed for the US market, is difficult to use in Europe. What is also needed is the ability to achieve additional functionality, and to provide improved valve facilities in this regard, as well as the possibility of synergy between various products. Summary of the Invention

[0008] In the first aspect of the invention, this task is achieved in an electro-pneumatic valve facility of the type mentioned at the beginning by providing an emergency release connection having an emergency release path for selectively introducing an emergency release pressure, which is provided at a pneumatic control connection to a pilot control unit and causes a parking brake pressure to be regulated at at least one spring accumulator connection.

[0009] The pilot control unit is configured to regulate a pilot control pressure based on the electronic parking brake signal. This pilot control pressure can be handled by a separate valve unit or can be directly and immediately regulated as parking brake pressure at the spring accumulator connection. The spring accumulator connection is preferably the spring accumulator connection of an electro-pneumatic valve assembly. The additional valve unit that can first implement the pilot control pressure can be, for example, formed by a main valve unit that receives the pilot control pressure and / or regulates the parking brake pressure at at least one spring accumulator connection based on the pilot control pressure. For this purpose, the main valve unit preferably also receives a reserve pressure. Such a main valve unit can typically be formed by a relay valve. However, this is not absolutely necessary, and the pilot control pressure can also be directly regulated as parking brake pressure.

[0010] The pilot control unit is configured to be self-holding, so that after initial activation via the electronic parking brake signal, even if the electronic parking brake signal is canceled, the pilot control unit continuously and stably regulates the pilot control pressure. Self-holding is specifically understood here as maintaining the air supply position of the pilot control unit itself by regulating the pilot control pressure. Even if the signal to switch the valve to the air supply or deflation position is canceled, the valve, stable in both the air supply and deflation positions, is also self-holding. This can be categorized as pneumatic self-holding or magnetic self-holding. The advantage of the basically known arrangement (as described above with reference to the prior art) is that if the reserve pressure supplied to and used by the pilot control unit is canceled or decreases, in order to regulate the pilot control pressure, the pilot control unit switches to the deflation position due to self-holding and deflates the spring accumulator connection. Therefore, the pilot control unit is preferably stably in the deflation position. The pilot control unit preferably receives the reserve pressure, preferably from the reserve connection of the electro-pneumatic valve facility, which can be connected to one or more compressed air reserves of the braking system. However, if the pilot control unit is stably in the deflated position, the electronic parking brake signal is again required to regulate the pilot control pressure and re-engage the self-holding mechanism to maintain the air supply position of the pilot control unit. However, in cases of vehicle, electro-pneumatic braking system, and / or electro-pneumatic valve assembly malfunctions that prevent or incorrectly provide the electronic parking brake signal, the pilot control unit can no longer electronically switch or cannot switch correctly. In this situation, regulating the parking brake pressure cannot be achieved.

[0011] To this end, the present invention proposes an emergency release connection that allows for the selective introduction of an emergency release pressure, which causes the parking brake pressure to be regulated at at least one spring accumulator connection. The emergency release pressure is then provided at a pneumatically controlled connection of the pilot control unit. Preferably, the emergency release pressure is regulated at a first pneumatic control surface of the pilot control unit. This pneumatic emergency release pressure allows the parking brake pressure to be regulated independently of the electronic parking brake signal, so as to supply air to the spring accumulator connection and to supply air to and release any spring accumulator brake cylinder possibly connected to the spring accumulator connection. Therefore, the emergency release connection enables the emergency release of the spring accumulator brake cylinder, enabling towing of vehicles using such electro-pneumatic valve facilities, for example, in the absence of current, such as after an accident or failure. On one hand, it can be configured such that the emergency release pressure brings the pilot control unit to an air-supply position, and / or the parking brake pressure is regulated at the spring accumulator connection independently of the switching position of the pilot control unit.

[0012] Preferably, the pilot control unit is configured to be self-holding such that the pilot control pressure regulated by the pilot control unit, or the pressure derived therefrom, is drawn back via a self-holding line and provided at a pneumatic control connection or another pneumatic control connection associated with the pilot control unit. The drawn-back pressure can also be referred to as the self-holding pressure. It can be regulated at the same pneumatic control connection that also regulates the emergency release pressure. However, it can also be regulated at a separately provided pneumatic control connection, which can also be referred to as the self-holding connection. In any case, it can be regulated at the same pneumatic control surface as the emergency release pressure, or at a specially provided pneumatic control surface. Such a self-holding line can be configured as a pneumatic hose or pipe branching off at any point between the pilot control unit and the spring accumulator connection. The self-holding line can also be configured as an orifice within a valve of the pilot control unit to regulate the pilot control pressure at the self-holding connection or the corresponding associated control surface. The self-holding connection is preferably the pneumatic connection of the valve, so that the pilot control pressure, preferably the self-holding pressure, can be adjusted at the self-holding connection to switch the valve or keep the valve in the switched position.

[0013] Preferably, when the pressure applied to the pneumatic control coupling and / or another pneumatic control coupling is below a first threshold, the pilot control unit switches to a stable deflation position. Therefore, as long as the pressure applied to the pneumatic control coupling and / or another pneumatic control coupling (self-holding coupling) exceeds the first threshold, the pilot control unit remains stably in the supply position, thereby maintaining the controlled parking brake pressure. However, if the pressure regulated at the pneumatic control coupling and / or another pneumatic control coupling, especially the pilot control pressure, decreases, for example due to a drop in the reserve pressure supplied to the pilot control unit (e.g., due to leakage or other malfunction), the pilot control unit stably falls into the deflation position. The spring accumulator coupling remains deflated in the deflation position, and the spring-loaded brake cylinder connected to the spring accumulator coupling remains pressed.

[0014] The first threshold is preferably set in the range of 200 kPa to 400 kPa, more preferably in the range of 250 kPa to 350 kPa. These values ​​should be lower than the typical values ​​of the storage pressure. It can be configured such that if two or more pneumatic control connections are provided, the first threshold is assigned only to the control connection that acts as a self-holding connection. In the case of two or more control surfaces, the first threshold may be assigned to only one control surface.

[0015] In one variant, introducing emergency release pressure at the emergency release connection can cause a pilot control pressure to be regulated by the pilot control unit. Preferably, introducing emergency release pressure can cause switching of valves in the pilot control unit. It should be understood that when the emergency release pressure is regulated, two or more valves in the pilot control unit can also be switched. For this purpose, the emergency release pressure preferably exceeds a second threshold, which is preferably higher than a first threshold. This means that as long as the emergency release pressure is below the second threshold, the pilot control pressure will not be regulated, but if the emergency release pressure exceeds the second threshold, the pilot control pressure will be regulated, for example, by switching one or more valves in the pilot control unit. It can be configured that if there is another pneumatic control connection for the self-holding pressure, the second threshold is only assigned to the pneumatic control connection. If there are two or more control surfaces, the second threshold can be assigned to only one control surface.

[0016] The second threshold is preferably in the range of 500 kPa to 900 kPa, and more preferably in the range of 600 kPa to 800 kPa.

[0017] In a preferred improvement, the emergency release pressure and the self-holding pressure are provided or regulated at the pneumatic control coupling. Therefore, the emergency release pressure and the self-holding pressure are regulated at the same pneumatic control coupling and preferably also act on the same pneumatic control surface. This results in a particularly simple and feasible solution that allows for the regulation of pilot control pressure even when the vehicle has no current or when the pilot control unit can no longer electronically switch or can no longer correctly switch electronically. For this purpose, the emergency release pressure preferably exceeds at least a first threshold, but preferably exceeds a second threshold.

[0018] It can be configured that the emergency release path leads to the bleed path of the pilot control unit. For example, it is conceivable and preferred that the emergency release path leads to the bleed path via a check valve or a double check valve, so that the control pressure is regulated through the bleed path of the pilot control unit. When the vehicle is in a state of no current or no pressure, the pilot control unit is in the bleed position and connected to the bleed end. This means that in this switching position, emergency release pressure can be introduced via the bleed path, so that the pilot control unit can regulate the pilot control pressure or provide the corresponding control pressure to the pilot control unit in this way. This, in turn, causes the parking brake pressure to be regulated or directly regulated.

[0019] Preferably, the pilot control unit may have a self-holding valve unit and a holding valve. The self-holding valve unit may be formed by one or more valves. The holding valve is preferably configured as a monostable two-position two-way valve and has an open position and a closed position, wherein it is monostable in the open position. The holding valve can be used to block the pressure regulated by the pilot control unit in order to, for example, maintain the air supply at the spring accumulator connection, without depending on the switching position of the pilot control unit.

[0020] In one variant, the pilot control unit includes a solenoid valve with at least a first permanent magnet. The solenoid valve has a pneumatically controlled connection, allowing it to switch from a venting position to an supplying position based on an emergency release pressure. The solenoid valve may also have additional pneumatically controlled connections. Therefore, the emergency release pressure and / or self-holding pressure can be regulated at the solenoid valve. This type of solenoid valve is characterized by having at least one permanent magnet, which allows two stop positions to be obtained at the end position of the armature. Such a valve is also called a bistable valve because the armature can be stably held in both end positions due to magnetic force. Therefore, the solenoid valve is called a bistable valve, having two stable switching positions, specifically a stable supplying position and a stable venting position. Two or more permanent magnets can also be provided. One or two or more coils can be used to switch the solenoid valve. If two coils are provided, energizing the first coil will bring the armature of the solenoid valve, preferably carrying the permanent magnet, to a first position, thus placing the solenoid valve in the gas-feeding position. Energizing the second coil will bring the armature to a second position, thus placing the solenoid valve in the gas-release position. The two ends are positioned to form a stop position, in which the solenoid valve is magnetically locked. If no other force is applied to the armature, or if it can be locked in these positions mechanically and / or magnetically, the respective switching positions are stable because these positions can be maintained without additional energization.

[0021] In solutions using solenoid valves in the form of conventional bistable valves within the scope of electro-pneumatic valve facilities for operating the parking brake function, there is a risk that, after a vehicle malfunction, the solenoid valve may remain in the supply position due to the magnetic force exerted by at least one permanent magnet. If the vehicle is shut down after a malfunction and the compressed air reserve is emptied, the spring-loaded brake cylinder may be compressed even if the solenoid valve is not brought to the deflate position. Therefore, the solenoid valve may remain in the supply position due to its two magnetically stopped positions, namely the supply and deflate positions. If the vehicle is now powered again and the compressed air reserve is refilled or otherwise replenished, it is possible that the spring-loaded brake cylinder will be supplied with air and thus released, potentially causing the vehicle to roll unintentionally. To prevent this, it is known to bring the solenoid valve to the deflate position after supplying air to the spring-loaded brake cylinder, wherein the pressure regulated by the solenoid valve is blocked by another, additional valve (e.g., a two-position two-way valve). In the event of a malfunction, the solenoid valve is in the deflation position, and the two-position two-way valve preferably falls into the open switching position when there is no current, thus automatically and consequently deflating the spring-loaded brake cylinder. However, since the solenoid valve is stably or self-holdingly in the supply position due to at least one permanent magnet, the spring-loaded brake cylinder cannot be easily re-inflated if, for example, the vehicle is to be towed or the malfunction causing the deflation of the spring-loaded brake cylinder has been resolved. To bring the solenoid valve back to the supply position, an electrical pulse is required, preferably energizing the coil of the solenoid valve. If this electrical pulse cannot be regulated or cannot be properly regulated, the solenoid valve, according to conventional construction, cannot switch to the supply position. This is where the pneumatic control coupling comes into play. An emergency release pressure and / or a self-holding pressure can be regulated thereon to switch the solenoid valve preferably from the deflation position or to the supply position.

[0022] In a preferred embodiment, the emergency release pressure is provided at the pneumatic control connection of the solenoid valve. This allows the solenoid valve to be switched to the pneumatic supply position, and the parking brake pressure can be regulated at at least one spring accumulator connection using the emergency release pressure. For this purpose, the emergency release connection is preferably connected to the pneumatic control connection of the solenoid valve via an emergency release path. According to the embodiment, it is conceivable and preferred that one or more valves are connected between the emergency release connection and the pneumatic control connection.

[0023] In a preferred embodiment, the solenoid valve has a first solenoid valve connection terminal for receiving a reserve pressure, a second solenoid valve connection terminal for regulating a pilot control pressure, and a third solenoid valve connection terminal connected to a venting terminal. Preferably, in the solenoid valve's supply position or first switching position, the first solenoid valve connection terminal is connected to the second solenoid valve connection terminal, and in the solenoid valve's venting position or second switching position, the third solenoid valve connection terminal is connected to the second solenoid valve connection terminal. By energizing at least one coil, the solenoid valve can be selectively switched to the supply position or the venting position, wherein the solenoid valve can be magnetically held in its respective switching position by means of at least one permanent magnet.

[0024] Preferably, the solenoid valve is switched to the venting position independently of its previous switching position when the self-holding pressure regulated at the pneumatic control connection and / or other pneumatic control connections is lower than a threshold or a first threshold. This ensures that the solenoid valve remains in the venting position even without current and in case of a malfunction, and that re-establishing the reserve pressure does not immediately lead to the release of the spring-loaded brake cylinder. The solenoid valve can, in principle, have a coil and a permanent magnet, preferably arranged in the armature of the solenoid valve. By correspondingly energizing one coil, the armature, together with the permanent magnet, can move in one direction or the other, wherein when it abuts against the corresponding valve seat, the armature is magnetically locked there, thus giving the solenoid valve two magnetically stopped positions. However, in variations, two coils and one permanent magnet, two coils and two permanent magnets, or one coil and two permanent magnets can also be provided. If two permanent magnets are used, these permanent magnets are preferably fastened to the valve body and act on the armature respectively, so that they again magnetically hold the armature in its end position and thus lock it. More than two coils and permanent magnets can also be provided separately.

[0025] Furthermore, preferably, when the holding pressure and / or emergency release pressure exceed a first threshold, the solenoid valve remains in its previous switching position and can preferably be selectively switched to either the supply or release position by energizing at least one coil. Therefore, it is preferably configured such that if the holding pressure and / or emergency release pressure exceeds the first threshold, the solenoid valve can remain in either the supply or release position, depending on which of these positions the solenoid valve is electromagnetically switched to. However, it is also possible to configure the solenoid valve to be switched to the supply switching position.

[0026] Preferably, the solenoid valve is switched to the gas supply position when the self-holding pressure and / or emergency release pressure exceed a threshold or a second threshold, preferably higher than the first threshold. Preferably, in this case, the solenoid valve is switched to the venting position by energizing at least one coil. If the self-holding pressure and / or emergency release pressure exceeds the second threshold, this results not only in maintaining the switched position but also in actively switching the solenoid valve to the gas supply position. For this purpose, the force applied by the self-holding pressure and / or emergency release pressure preferably exceeds the magnetic holding force or magnetic stopping torque applied by at least one permanent magnet. However, it is preferably configured that the solenoid valve can be switched to the venting position by energizing at least one coil. When the coil is energized, an additional force is applied to the armature, which can again exceed the force applied by the self-holding pressure and / or emergency release pressure, thereby bringing the armature to another switched position. By energizing at least one coil, an overshoot can be made to the self-holding pressure and / or emergency release pressure, which is controlled to be higher than the second threshold, in order to force the venting position to be occupied.

[0027] Furthermore, preferably, the solenoid valve has a preferred position. This means that the solenoid valve is preferably pre-tightened to one of the first and second switching positions, preferably the venting position. Preferably, the pilot control unit is connected to the venting end in the preferred position. It can be configured that regulating a safety control pressure above a first threshold will retract the preferred position. Once the holding pressure and / or emergency release pressure exceeds the first threshold, the solenoid valve preferably no longer has the preferred position. However, if the holding pressure and / or emergency release pressure drops below the first threshold, the solenoid valve has the preferred position and switches to the preferred position when there is no current, i.e., preferably switches to the venting position. For example, the preferred position can be achieved by spring-loading the solenoid valve into the preferred position. This ensures that the solenoid valve is mechanically loaded into the preferred position and brought into that preferred position when the holding pressure and / or emergency release pressure are below the holding pressure and / or emergency release pressure. In this case, the holding pressure and / or emergency release pressure resists the spring force. In the preferred position, the pilot control unit is preferably connected to the venting end.

[0028] In another preferred design, the pressure regulated by or derived from the solenoid valve is controlled at the solenoid valve control connection as a self-holding pressure. This achieves self-holding, particularly when the solenoid valve has a preferred position. The preferred position is used to ensure the solenoid valve remains in the preferred position (preferably the vent position) in case of a malfunction before it can be electronically returned to the vent position. However, to prevent this preferred position from being occupied during normal operation, it is preferable to draw back the pressure regulated by the solenoid valve and provide it as a self-holding pressure to the pneumatic control connection or another pneumatic control connection.

[0029] According to this embodiment, the switching position of the solenoid valve therefore depends not only on the electromagnetically set switching position and / or preferred position, but also on the controlled holding pressure, i.e., on the pressure controlled by the solenoid valve. This provides an additional layer of safety. Preferably, once the holding pressure drops below a predetermined first threshold, the solenoid valve is brought to the venting position independently of the electromagnetic switching signal and / or its previous switching position. This can be achieved pneumatically, mechanically, or otherwise. This is preferably achieved independently of energization.

[0030] For example, a return line or return port can be provided immediately near the connection point of the solenoid valve, providing a pressure regulated by the solenoid valve as a self-holding pressure at the pneumatic control connection point or another pneumatic control connection point. Alternatively, the return line can branch off immediately before or downstream of the main valve unit, for example, before or at the spring accumulator connection point. The parking brake pressure is the pressure output by the solenoid valve.

[0031] In another preferred embodiment, the pilot control unit is preferably configured without a solenoid valve, instead using a conventional, preferably monostable, valve. For this purpose, the pilot control unit preferably has an inlet valve and an outlet valve that are electrically switchable and can switch between a stable state and an activated state. Preferably, the pilot control unit further includes a pilot control valve having a pneumatic control connection or said pneumatic control connection, which receives a reserve pressure and switches between a stable state and an activated state in response to a first control pressure provided by the inlet valve and / or outlet valve at the pneumatic control connection, wherein, in the activated state, the pilot control valve regulates a pilot control pressure. In this case, the pneumatic control connection preferably also acts as a self-holding connection. According to embodiments, the pilot control valve can therefore have three pneumatic control connections: one for receiving pressure from the inlet valve and / or outlet valve, one for receiving a self-holding pressure, and one for receiving an emergency release pressure.

[0032] In principle, the inlet valve and the outlet valve can also be constructed as a single valve unit. Therefore, even when using the terms inlet valve and outlet valve, it is not necessarily necessary to use two different structural units.

[0033] This implementation eliminates the need for a solenoid valve with a permanent magnet, thus achieving a smaller space requirement due to the smaller structural dimensions of conventional valves. Furthermore, this method simplifies drive and control.

[0034] In this preferred embodiment, the emergency release path is connected to a pilot control valve to regulate the emergency release pressure, thereby enabling the pilot control valve to regulate the pilot control pressure. Efficient interconnection is achieved by applying the emergency release pressure to the pilot control valve. The pilot control valve serves as a main valve of the pilot control unit and is switched based on a first control pressure provided by the inlet valve and / or outlet valve. In this case, it is not necessary to first switch the inlet valve and / or outlet valve to activate the pilot control valve; instead, the pilot control valve regulates the pilot control pressure based on the emergency release pressure. The first control pressure and the emergency release pressure can be provided at the same pneumatic control connection of the pilot control valve or at two separate pneumatic control connections.

[0035] In a variant, to regulate the emergency release pressure, the emergency release path is connected to the pneumatic control connector of the pilot control valve. This is useful in situations where, for example, the electronic control unit controlling these valves is damaged, preventing or incorrect switching of the inlet and / or outlet valves. The pilot control valve can be switched by regulating the emergency release pressure at the pneumatic control connector to re-regulate the pilot control pressure, either directly as parking brake pressure or initially supplied to the main valve unit of the electro-pneumatic valve system.

[0036] In an alternative, the emergency release path leads to the venting path of the pilot control valve. If the pilot control valve is in a stable position rather than an activated position due to the inlet and / or outlet valves not being energized, it is preferably in the venting position. In the venting position, the pilot control valve preferably connects the spring accumulator connection to the venting end or the corresponding control connection of the main valve unit to the venting end. This means that, via the venting path of the pilot control valve, the emergency release pressure can be regulated by the pilot control valve either directly as the spring accumulator braking pressure or as the control pressure for the main valve unit. Therefore, this embodiment utilizes the fact that the pilot control valve is always in the venting position in the absence of current, and thus the venting path is open. If a self-holding line is also provided to draw back the pressure regulated by the pilot control valve and regulate this pressure at the pneumatic control connection of the pilot control valve, which acts as a self-holding connection, then switching the pilot control valve can also be achieved by regulating the emergency release pressure.

[0037] Preferably, the electro-pneumatic valve assembly includes a main valve unit that receives a pilot control pressure and, depending on the pilot control pressure, regulates the parking brake pressure at at least one spring accumulator connection. The main valve unit preferably increases the volume of the pilot control pressure and then regulates the increased volume to produce the parking brake pressure. For this purpose, the main valve unit may include a relay valve with a relay valve control connection at which the pilot control pressure is regulated. In this way, the pilot control pressure regulated by the pilot control unit can be kept low, thereby improving the system's dynamics and minimizing air volume loss.

[0038] Furthermore, preferably, the electro-pneumatic valve assembly is integrated into a module, which preferably has one or more reserve connections, spring accumulator connections, venting connections, and emergency release connections. Such a module can be configured, in particular, as a parking brake module. Preferably, such a module has its own electronic control unit (ECU), which can receive one or more signals from a higher-level control unit, for example, via a vehicle bus, other buses, or direct cables. The ECU of the module can then output one or more switching signals to one or more electromagnetically switchable valves to induce switching. However, it is also possible that the individual solenoid valves of the electro-pneumatic valve assembly are switched via direct signal control from a higher-level control unit. This higher-level control unit can be, in particular, a central unit, a vehicle control unit, etc.

[0039] In the second aspect, the aforementioned task is achieved by a method for controlling the parking brake function of a commercial vehicle having an electro-pneumatic braking system and preferably having an electro-pneumatic valve facility according to one of the above-described preferred embodiments of the electro-pneumatic valve facility according to the first aspect of the invention, wherein the method comprises the steps of: electromagnetically switching at least one valve of a pilot control unit to an air-supply position to regulate a pilot control pressure, and thus: regulating a parking brake pressure at at least one spring accumulator connection to supply air to at least one spring accumulator brake cylinder; blocking the regulated pilot control pressure and / or holding at least one valve in the air-supply position; and, when the reserve pressure supplied to the pilot control unit drops below a first threshold: releasing the pilot control pressure. The method also preferably comprises the step of: introducing an emergency release pressure at an emergency release connection to induce the regulated parking brake pressure to release at least one spring accumulator brake cylinder.

[0040] It should be understood that the electro-pneumatic valve device according to the first aspect of the invention and the method according to the second aspect of the invention have the same and similar sub-aspects as particularly set forth in the dependent claims. In this regard, reference is made entirely to the description of the first aspect of the invention above. When the reserve pressure supplied to the pilot control unit drops below a first threshold, the release of the pilot control pressure can be achieved either purely electrically by electrically switching the corresponding valve or, for example, canceling the electrical switching signal for the corresponding valve due to an error in the electronic control unit, or pneumatically by making pneumatic self-holding impossible due to the drop in reserve pressure.

[0041] In a preferred embodiment, the method includes the following steps: regulating a self-holding pressure at a pneumatic control connection associated with the pilot control unit to maintain the pilot control unit in an air-supply position, thereby maintaining the pilot control pressure regulated independently of an electrical signal. It should be understood that regulating independently of an electrical signal means that the pilot control pressure is maintained even if the electrical signal to the corresponding valve is canceled. In other words, when the pilot control unit has the aforementioned solenoid valve with a preferred position, the air-supply position of the solenoid valve can be maintained even if energization to at least one coil is canceled, i.e., when the self-holding pressure is regulated at the pneumatic control connection. When the pilot control unit includes a monostable inlet valve and a monostable outlet valve, as described above, and a pneumatically switchable pilot control valve, the pilot control pressure is maintained even if neither the inlet nor the outlet valve is energized. Thus, the first control pressure is maintained to keep the pilot control valve in the activated position solely based on the regulated self-holding pressure supplied to the pneumatic control connection. However, even in these cases, the venting position can be occupied by switching to another valve accordingly or, for example, by overshooting the self-holding pressure in the case of a solenoid valve, in which the pilot control pressure is no longer regulated.

[0042] Furthermore, preferably, an emergency release pressure is introduced to induce a pilot control pressure via the pilot control unit. This is achieved, for example, as described above, by introducing the emergency release pressure into the venting path of the pilot control unit via the emergency release path. Alternatively, the emergency release pressure can be provided at the pneumatic control connection or a pneumatic control connection of the pilot control unit to switch the valve or hold the valve in the supply position.

[0043] In a third aspect, the present invention addresses the aforementioned task through a commercial vehicle having an electronically controlled pneumatic braking system, wherein the commercial vehicle has an electro-pneumatic valve facility of one of the above-described preferred embodiments of the electro-pneumatic valve facility according to the first aspect of the present invention. Preferably, the commercial vehicle is configured to at least partially implement the method according to the second aspect of the present invention.

[0044] It should be understood that the electro-pneumatic valve device according to the first aspect of the invention, the method according to the second aspect of the invention, and the commercial vehicle according to the third aspect of the invention have the same and similar sub-aspects, especially those set forth in the dependent claims. In this regard, reference is made entirely to the foregoing description. The electro-pneumatic valve device according to the first aspect of the invention can be used, in particular, in the form of a parking brake module in a commercial vehicle according to the third aspect of the invention. Attached Figure Description

[0045] 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.

[0046] 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:

[0047] Figure 1 A first embodiment of the electro-pneumatic valve device is shown;

[0048] Figure 2 A second embodiment of the electro-pneumatic valve device is shown;

[0049] Figure 3 A third embodiment of the electro-pneumatic valve device is shown;

[0050] Figure 4 A fourth embodiment of the electro-pneumatic valve device is shown;

[0051] Figure 5 A fifth embodiment of the electro-pneumatic valve device is shown; and

[0052] Figure 6Commercial vehicles are shown. Detailed Implementation

[0053] exist Figures 1 to 5 In the illustrated embodiment, the electro-pneumatic valve facility 1 is configured as the parking brake module 2, which is not essential, and the electro-pneumatic valve facility 1 can also be integrated with other units and / or the individual valves described below can also be arranged individually and / or separately in the braking system 102 (see [link]). Figure 6 ).

[0054] The parking brake module 2 has a reserve connection terminal 4, to which a first compressed air reserve unit 6 and a second compressed air reserve unit 7 are connected via a reserve shuttle valve 5. Both the first and second compressed air reserve units provide a reserve pressure pV, which is present at the reserve connection terminal 4. It is not necessary for both compressed air reserve units 6 and 7 to be connected to the reserve connection terminal 4; it is sufficient if only one compressed air reserve unit is connected there or if the reserve connection terminal 4 is supplied via another module.

[0055] The electro-pneumatic valve assembly 1 includes a pilot control unit 8 and a main valve unit 10. Figure 1 In the illustrated embodiment, the 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 12.4. The first solenoid valve connection terminal 12.1 is connected to the reserve connection terminal 4 and receives the reserve pressure pV. Figure 1 In the illustrated embodiment, the second solenoid valve connection terminal 12.2 is connected to the main valve unit 10 via the retaining 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 air supply position and the second switching position as the air release position. In the air supply 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.

[0056] In this embodiment, 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 13.3 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 thus switched to the air-supply position. The armature is then held in the air-supply position by the first permanent magnet 13.1, thus the air-supply position is a magnetically stopped position. The first permanent magnet 13.1 and the first coil 13.3 correspond to the air-supply position. If the second coil 13.4 is energized, the armature is attracted to the opposite stopped position, and the solenoid valve 12 is switched to the deflation position. In this stopped 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 air supply position and the air release position. 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.

[0057] exist Figure 1 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, subsequently regulating at least one first switching signal S1 at the solenoid valve 12 to selectively switch the solenoid valve between the air supply and deflation positions. In cases where 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 the air supply and deflation positions via pulses. In the illustrated embodiment, unlike conventional solenoid valves, the solenoid valve 12 also has a preferred position, i.e., the solenoid valve 12 is pre-tightened to... Figure 1 In the second venting position shown. For this purpose, a spring 18 is provided, which brings the solenoid valve 12 to... Figure 1 In the second switching position (venting position) shown.

[0058] In the illustrated embodiment, the pilot control pressure pSV, regulated by solenoid valve 12, is provided via holding valve 14 on main valve unit 10. Main valve unit 10 includes relay valve 20, having 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. Relay valve reserve connection 20.1 is connected to reserve connection 4 and receives the reserve pressure pV. Relay valve working connection 20.2 is connected to spring accumulator connection 21 of parking brake module 2, at which main valve unit 10 regulates parking brake pressure pBP. Relay valve vent connection 20.3 is connected to vent connection 3, and relay valve control connection 20.4 is connected to pilot control unit 8 and receives the pilot control pressure pSV. One or more spring-loaded brake cylinders 108a, 108b (see...) Figure 4 It can be connected to the spring accumulator connection end 21, releasing the spring accumulator brake cylinder when air is supplied and pressing the spring accumulator brake cylinder with the help of spring force when air is released.

[0059] Even though all the embodiments shown herein use the main valve unit 10, there may be implementations in which the regulated pilot control pressure pSV is regulated directly at the spring accumulator connection 21 and therefore does not include the main valve unit 10.

[0060] To release the spring-loaded brake cylinders 108a and 108b, the spring accumulator connection 21 must be supplied with air 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 air supply 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 1The steady-state first switching position (which is the open position) shown is brought to the unsteady, closed second switching position or the enabled 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 relay valve control connection 20.2, which then increases the volume of this pressure and regulates the parking brake pressure pBP at spring accumulator connection 21. Holding valve 14 can now 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. Solenoid valve 12 can now be brought back to the closed second switching position. Figure 1 In the first deflation position shown, the spring-energy-storing brake cylinders 108a and 108b remain inflated and are thus 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 without the need for the main valve unit 10 in between.

[0061] As another regulating mechanism, the holding valve 14 can also be held open in its stable switching position. Now, in order to hold the solenoid valve 12... Figure 1 In the first air supply position (not shown), the solenoid valve 12 has a pneumatic control connection 12.4 associated with the pilot control unit 8. The pneumatic control connection 12.4 is connected to a first control line 24 via a self-holding line 22, which connects the second solenoid valve connection 12.2 and the first holding valve connection 14.1. Therefore, the self-holding line 22 returns the pressure regulated by the solenoid valve 12 to the pneumatic control connection 12.4. If a pilot control pressure pSV is regulated by the solenoid valve 12, this pilot control pressure is provided at the pneumatic control connection 12.4 via the self-holding line 22, and thus applied to the solenoid valve 12 as a self-holding pressure pSS. The pneumatic control connection 12.4 is arranged such that the self-holding pressure pSS acts on the solenoid valve 12, specifically on a pneumatic control surface (not shown), causing the solenoid valve 12 to be loaded. Figure 1In the first switching position (not shown), i.e., the gas supply position, the internal control surface is selected such that the holding pressure pSS applies a force approximately corresponding to that of the spring 18, thereby reversing or canceling the preferred position of the solenoid valve 12 by applying the holding pressure pSS. In this state, since the spring 18 and the holding pressure pSS substantially cancel each other out, the solenoid valve 12 can also be switched to the gas supply or gas release position by correspondingly energizing the first and second coils 13.3 and 13.4. Thus, in their respective switching positions, the magnetic force of either the first permanent magnet or the second permanent magnet 13.1 and 13.2 is applied, making the switching position a stop position, and the armature can only be pulled out of its respective stop position by overcoming the magnetic force by applying a certain minimum force.

[0062] However, if the holding pressure pSS drops below a first threshold (which can be approximately in the range of 200 kPa to 400 kPa), the force exerted by the holding pressure pSS is less than the force exerted by the spring force of spring 18, causing the solenoid valve 12 to return to the preferred position and fall back to its original position. Figure 1 In the second venting position shown. If a malfunction occurs in the commercial vehicle 100 (due to the first and second compressed air reservoirs 6 and 7 being emptied, leaking, or being actively pumped out by the driver, resulting in a drop in reservoir pressure pV), then when the solenoid valve 12 is in the second venting position. Figure 1 In the air supply position (not shown), the pilot control pressure pSV also decreases. However, if the pilot control pressure pSV decreases, the holding pressure pSS also decreases simultaneously, causing the preferred position of solenoid valve 12 to reactivate from a certain point, preferably below the first threshold, and spring 18 to bring solenoid valve 12 to its preferred position. Figure 1 In the bleed position shown, the relay valve control connection 20.4 is bleed and no longer regulates the parking brake pressure pBP. The spring-loaded brake cylinders 108a and 108b are completely bleed.

[0063] If the first and / or second compressed air reserves 6, 7 are refilled now in this state, for example because the commercial vehicle 100 regains power or the first and second compressed air reserves 6, 7 are refilled by a maintenance technician, then the solenoid valve 12 will remain in the state of... Figure 1 In the second deflation position shown, the spring accumulator connection 21 does not automatically and unintentionally release air. The solenoid valve 12 can only be switched back to its original position by providing the parking brake signal SFB or the first switching signal S1 and energizing the first coil 13.3. Figure 1 In the air supply position (not shown), air is supplied to release the spring energy storage brake cylinders 108a and 108b again. This effectively prevents the unintentional release of the spring energy storage brake cylinders 108a and 108b.

[0064] In the embodiment shown in this example ( Figure 1 In 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.

[0065] Furthermore, the electro-pneumatic valve assembly 1 has a release control connection 30. This release control connection 30, also known as an anti-re-excitation connection, allows the introduction of a release control pressure pL. The release control connection 30 is connected to a release control path 32. The release control pressure pL introduced via the release control connection 30 causes a 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 30. Typically, the pressure of another axle (e.g., the front or rear axle), particularly the service brake pressure, is used as the release control pressure pL. In cases where the spring accumulator brake cylinders 108a and 108b connected to the spring accumulator connection 21 are also used for auxiliary braking or emergency braking, this prevents excessive actuation of the spring accumulator brake cylinders 108a and 108b, which could potentially cause the vehicle 100 to lock up. If the service brake on the rear axle is activated, the spring energy storage brake cylinders 108a and 108b should not be engaged simultaneously as much as possible, so as to provide the service brake pressure of the rear axle as the release control pressure pL to the release control connection 30, so as to reciprocately release the spring energy storage brake cylinders 108a and 108b for engaging the service brake.

[0066] exist Figure 1In the illustrated embodiment, release control line 33 is connected to shuttle valve 34. Release control pressure pL can be delivered to relay valve control connection 20.4 via release control path 32. Shuttle valve 34 has a first shuttle valve connection 34.1, a second shuttle valve connection 34.2, and a third shuttle valve connection 34.3. Shuttle valve 34 is configured such that it always delivers the higher of the pressures applied at the first and second shuttle valve connections 34.1, 34.2 to the third shuttle valve connection 34.3. The first shuttle valve connection 34.1 is here connected to the second holding 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 shuttle valve connection 34.1 is connected to pilot control unit 8 and receives pilot control pressure pSV. The second shuttle valve connection 34.2 is connected to release control connection 30 and receives release control pressure pL. The third 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, so as to cause the parking brake pressure pBP to be regulated.

[0067] The electro-pneumatic valve assembly 1 also has an emergency release connection 38 through which an emergency release pressure pSN can be supplied. In this embodiment, the emergency release connection 38 is connected to the pilot control unit 8, i.e., to the solenoid valve 12, specifically to the pneumatic control connection 12.4, via an emergency release path 39, and the emergency release pressure pSN can be provided at the pneumatic control connection 12.4. For this purpose, an emergency release shuttle valve 42 is connected between the self-holding line 22 and the pneumatic control connection 12.4, and this emergency release shuttle valve is connected to the emergency release connection 38 via the emergency release line 40. The emergency release shuttle valve 42 is constructed in the same manner as the first shuttle valve 34, so that the higher of the self-holding pressure pSS or the emergency release pressure pSN is always regulated at the pneumatic control connection 12.4. In this way, the solenoid valve 12 can supply pressure pSN from the pneumatic control connection 12.4. Figure 1 The first switching position shown is brought to Figure 1 The second air supply position, not shown, is specifically for switching the solenoid valve 12 when the emergency release pressure pSN exceeds a second threshold (preferably in the range of 400 kPa to 800 kPa) and exceeds the force applied by the spring 18 and the braking force that might be required to hold the solenoid valve 12 in the venting position for the armature 18. In this way, a reserve pressure pV can be provided to the pilot control unit 8 so as to regulate the pilot control pressure pSV and thus supply air to the spring accumulator connection 21.

[0068] exist Figure 1In the illustrated embodiment, the emergency release pressure pSN and the self-holding pressure pSS are regulated at the same pneumatic control connection (i.e., pneumatic control connection 12.4). In an embodiment not shown here, only the emergency release pressure pSN is regulated at the pneumatic control connection, while the self-holding pressure pSS is regulated at another pneumatic control connection (not shown here), which is separately located from pneumatic control connection 12.4. In this case, the emergency release shuttle valve 42 can also be omitted.

[0069] The emergency release pressure pSN is used specifically to switch solenoid valve 12 when the switching signal S1 cannot be provided. For example, the emergency release pressure pSN can be a manually regulated pressure supplied via an externally connected container, such as tire pressure. However, pressure from other compressed air reservoirs, other modules, other axles, etc., not shown here, can also be used. The emergency release pressure pSN is particularly used to supply air to the spring accumulator connection 21 when the pilot control unit 8 (here, solenoid valve 12) can no longer be electronically switched to the air supply position. For example, solenoid valve 12 can be reset in this way by the service brake pressure of another axle.

[0070] Figure 2 The variant is shown in the figure. Figure 2 based on Figure 1 And the same and similar elements have the same reference numerals, therefore the first embodiment is referred to entirely. Figure 1 The above description is as follows. The differences from the first embodiment are particularly emphasized below.

[0071] Compared with the first embodiment ( Figure 1 In contrast, the emergency release connection 38 is not directly connected to the pneumatic control connection 12.4 of the solenoid valve 12, but is first connected to the venting path 44 of the pilot control unit 8, which in the embodiment shown here is the venting path of the solenoid valve 12. Through the emergency release connection 38, the emergency release pressure pSN can be regulated at the third solenoid valve connection 12.3 via the venting path 44. When the solenoid valve 12 is in the venting position, this, on the one hand, causes the pilot control pressure pSV to be regulated, and on the other hand, it is also regulated at the pneumatic control connection 12.4 via the self-holding line 22. This causes the solenoid valve 12 to switch from the venting position to the supply position when the emergency release pressure pSN exceeds the first threshold and / or the second threshold. In this case, the holding valve 14 is in a non-current-driven state. Figure 2 In the open switching position shown, the pilot control pressure pSV can be regulated at the main valve unit 10 by means of the emergency release pressure pSN and / or after the solenoid valve 12 is switched, so that the main valve unit 10 can subsequently regulate the parking brake pressure pBP. Second embodiment ( Figure 2 The solenoid valve 12 is used to release the air through the venting path 44, thereby introducing emergency release pressure, switching the solenoid valve 12, and thus causing the release spring energy storage brake cylinders 108a and 108b.

[0072] In order to allow the emergency release pressure pSN to be introduced into the venting path 44, which must also be connected to the venting end 3, in this case, as in the first embodiment ( Figure 1 An emergency release shuttle valve 42 is also used, as in the example. This emergency release shuttle valve is arranged such that it allows connection between the pilot control unit 8 and the venting end 3 on the one hand, but also allows the emergency release pressure pSN to be introduced to the pilot control unit 8 via the venting path 44 on the other hand. For this purpose, the emergency release shuttle valve 42 has a first emergency release shuttle valve connection end 42.1, which is connected to the emergency release connection end 38. The emergency release shuttle valve has a second emergency release shuttle valve connection end 42.2 connected to the venting end 3 and itself has a third emergency release shuttle valve connection end 42.3 connected to the pilot control unit 8 (here, the third solenoid valve connection end 12.3). The emergency release shuttle valve 42 also has a preferred position and is therefore preferably constructed as a single check valve. To achieve the preferred position, a return line 46 is provided, which causes the valve element 48 to pneumatically close the first emergency release shuttle valve connection end 42.1. In the basic state, and when the pilot control unit 8 vents via the vent path 44, the valve element 48 is pressed in such a way that the second and third emergency release shuttle valve connection ends 42.2 and 42.3 are engaged. The valve element 48 is only released from the pressureless vent path 44 when an emergency release pressure pSN is introduced. Figure 2 The position shown raises and releases the first emergency release shuttle valve connection 42.1. Besides a pneumatic implementation via the return section 46, this problem can also be solved mechanically using a spring. Preferably, the second and third emergency release shuttle valve connections 42.2 and 42.3 are connected to each other without pressure and continuously and unobstructed during venting operation.

[0073] Figure 3 Also based on Figure 1 And the same and similar elements have the same reference numerals, therefore the first embodiment is referred to entirely. Figure 1 The above description is as follows. The differences from the first embodiment are particularly emphasized below.

[0074] according to Figure 3 The main difference between the third embodiment and the first embodiment is that the self-holding line 22 is not provided. Figure 3In the illustrated embodiment, the solenoid valve 12 is configured without a preferred position and without a spring 18 (as provided in the first embodiment). However, to allow the solenoid valve 12 to switch back from the venting position to the supply position in an emergency without using the first switching signal S1, the solenoid valve 12 has a pneumatic control connection 12.4. The emergency release line 40 is directly connected to this pneumatic control connection without the need for an additional valve in between. In this embodiment, the self-holding of the solenoid valve 12.4 is achieved solely by the first and second permanent magnets 13.1, 13.2. In this respect, the third embodiment is a particularly simple variant in structure.

[0075] Figure 4 and Figure 5 Two further embodiments of the electro-pneumatic valve device 1 are now shown. The same and similar elements again have the same reference numerals as in the previous two embodiments, and therefore refer entirely to the above description. The differences from the previous two embodiments are particularly emphasized below.

[0076] The first three embodiments ( Figure 1 , Figure 2 , Figure 3 ) and the fourth and fifth embodiments ( Figure 4 , Figure 5 The main difference between the fourth and fifth embodiments lies primarily in the design of the pilot control unit 8. Figure 4 , Figure 5 In this configuration, the pilot control unit includes an inlet valve 50, an outlet valve 52, and a pilot control valve 54. Both inlet valve 50 and outlet valve 52 are electrically switchable and receive third and fourth switching signals S3 and S4 from the electronic control unit (ECU) for this purpose. These signals S3 and S4 can also be provided by a higher-level unit via a direct cable connection. The inlet valve 50 has… Figure 4 The stable switching position shown is Figure 4The activated switching position, not shown, is occupied by the inlet valve when the third switching signal S3 is provided. In the stable switching position, the inlet valve 50 is closed, while in the activated switching position, the inlet valve 50 is open. The inlet valve 50 has a first inlet valve connection 50.1, which is connected to the reserve connection 4 and receives the reserve pressure pV. The inlet valve 50 has a second inlet valve connection 50.2, which is connected to the third control line 56, which itself is directly or indirectly connected to the pneumatic connection of the pilot control valve 54, specifically the pneumatic control connection 54.4, which will be described in more detail later. In the activated switching position of the inlet valve 50, the inlet valve regulates the first control pressure pS1 into the third control line 56. To vent the third control line 56 and therefore also to vent the pneumatic control connection 54.4 of the pilot control valve 54, an outlet valve 52 is provided. The outlet valve 52 has Figure 4 The stable switching position shown in the figure and Figure 4 The enabled switching position, not shown, is occupied by the outlet valve when the fourth switching signal S4 is applied. The outlet valve 52 has a first outlet valve connection terminal 52.1 connected to the third control line 56, a second outlet valve connection terminal 52.2 connected to the vent terminal 3, and a third outlet valve connection terminal 52.3 connected to the self-holding line 22 in the embodiment shown here. The self-holding line 22 branches off from the first control line 24 connected to the first holding valve connection terminal 14.1, and therefore provides a pilot control pressure pSV as a self-holding pressure pSS at the third outlet valve connection terminal 52.3. Therefore, the outlet valve 52 is in a state of no current. Figure 4 In the stable switching position shown, a pilot control pressure pSV is regulated via outlet valve 52 at the first outlet valve connection end 52.1 and thus into the third control line 56. The third control line 56 can only be vented by activating outlet valve 52.

[0077] The pilot control valve 54 can be switched purely pneumatically and does not have an electrical connection terminal, even though such an electrical connection terminal may be provided in certain embodiments. The pilot control valve 54 also has... Figure 4 The stable switching position shown is Figure 4The activated switching position is not shown. Pilot control valve 54 has a first pilot control valve connection 54.1, which connects to the reserve connection 4 and receives the reserve pressure pV. Pilot control valve 54 also has a second pilot control valve connection 54.2, which connects to the first control line and regulates the pilot control pressure pSV in the activated switching position of pilot control valve 54. A third pilot control valve connection 54.3 connects to the venting end 3. In the stable switching position of pilot control valve 54, the second pilot control valve connection 54.2 connects to the third pilot control valve connection 54.3, so that the first control line 24 is vented and therefore no pilot control pressure pSV is regulated at the main valve unit 10, and therefore no parking brake pressure pBP is regulated at the spring accumulator connection 21. Only when the pilot control valve 54 is in the activated switching position is the first pilot control valve connection 54.1 connected to the second pilot control valve connection 54.3, thereby regulating the pilot control pressure pSV. The pilot control valve 54 can be brought to the activated switching position by applying a corresponding high pressure to the pneumatic control connection 54.4 of the pilot control valve 54. For the initial release of the spring-loaded brake cylinders 108a and 108b, this is typically achieved firstly by means of the first control pressure pS1 regulated by the inlet valve 50. For this purpose, a third switching signal S3 is regulated and the inlet valve 50 is brought to the activated switching position, thereby regulating the first control pressure pS1. If it exceeds a threshold, preferably the first threshold, the pilot control valve 54 switches to... Figure 4 In the activated switching position (not shown), the pilot control pressure pSV is regulated. The outlet valve 52 is preferably held in a stable switching position, thereby regulating the pilot control pressure pSV regulated in the first control line 24 again at the pneumatic control connection 54.4 via the self-holding line 22, the third outlet valve connection 52.3, the first outlet valve connection 52.1, and the third control line 56. If the self-holding pressure pSS again exceeds the first threshold, the pilot control valve 54 remains in the activated switching position. Self-holding is achieved in this way. A throttling section 53 is provided in the outlet valve 52, which acts between the first outlet valve connection 52.1 and the third outlet valve connection 52.3. The pilot control pressure pSV can be limited via the throttling section 53, particularly according to the first threshold.

[0078] If, in a fault condition, the third switching signal S3 cannot be provided or cannot be provided correctly, or for example, the outlet valve 52 remains in the enabled switching position and therefore the third control line 56 is permanently vented, then in the embodiment shown ( Figure 3 The emergency release pressure pSN can act on the pilot control valve 54. For this purpose, the emergency release path 39 is connected to the pilot control valve 54. Figure 4In the illustrated embodiment, the connection is particularly significant to the pneumatic control connection 54.4. To enable regulation of the first control pressure pS1 or the self-holding pressure pSS and the emergency release pressure pSN at the pneumatic control connection 54.4, an emergency release shuttle valve 42 is provided in between. The first emergency release shuttle valve connection 42.1 is connected here to the third control line 56 and thus receives the first control pressure pS1 or the self-holding pressure pSS. The second emergency release shuttle valve connection 42.2 is connected to the emergency release connection 38 and receives the emergency release pressure pSN. The third emergency release shuttle valve connection 42.3 is connected to the pneumatic control connection 54.4. The emergency release shuttle valve 42 is further configured such that it has a preferred position, i.e., preferably connecting the first and third emergency release shuttle valve connection ends 42.1 and 42.2. Only when the first emergency release shuttle valve connection end 42.1 is pressureless or substantially pressureless can the valve element 48 be released from the second emergency release shuttle valve connection end 42.2 due to the pressure acting on it. Figure 4 The position shown is raised, thereby regulating the emergency release pressure pSN at the pneumatic control connection 54.4. In this way, even without the third switching signal S3, the pilot control valve 54 can be brought to the enabled switching position, thereby regulating the pilot control pressure pSV.

[0079] In the fourth embodiment, the emergency release pressure pSN, the first control pressure pS1, and the self-holding pressure pSS are regulated at the pneumatic control connection 54.4. In other embodiments not shown here, additional pneumatic control connections may be provided. For example, each of the three pressures may have its own control connection. Alternatively, two pneumatic control connections may be provided, wherein the allocation relationship can be freely chosen, for example, the emergency release pressure pSN is regulated at pneumatic control connection 54.4, while the first control pressure pS1 and the self-holding pressure pSN are regulated at another pneumatic control connection (not shown).

[0080] Fourth embodiment ( Figure 5 Based on the third embodiment ( Figure 4 ), and the same and similar elements are again given the same reference numerals, thus referring entirely to the above description.

[0081] The main difference between the third and fourth embodiments is that the emergency release pressure pSN is not regulated at the pneumatic control connection 54.4, but at the pilot control unit 8 and the pilot control valve 54, but is regulated at the air supply path 58 of the pilot control valve 54. If the pilot control valve is in... Figure 5In the stable switching position shown, the first pilot control valve connection 54.1 is connected to the second pilot control valve connection 54.2, thereby allowing the emergency release pressure pSN to be regulated at the main valve unit 10 via the venting path 58 of the pilot control valve 54 into the first control line 24. In this respect, the fourth embodiment is similar to the second embodiment. The emergency release shuttle valve 42 is also similar to that of the second embodiment (…). Figure 2 The system is constructed in a consistent manner. If the third and / or fourth switching signals S3 and S4 cannot be provided or cannot be provided correctly, the parking brake pressure pBP can also be regulated in this way.

[0082] at last, Figure 6 A vehicle 100, i.e., a commercial vehicle, is shown with a braking system 102 configured as an electronically controlled pneumatic braking system. The vehicle 100 has a front axle VA and a rear axle HA. A central module 104, also configured as a rear axle modulator, brakes the rear axle HA, and a front axle modulator 106 is associated with the front axle VA. The central module 104 and the front axle modulator 106 are connected to each other via electronic circuitry 107 and thus exchange signals, particularly braking signals. In addition to the first and second spring-energy-storing brake cylinders 108a and 108b, first and second service brake cylinders 109a and 109b 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 108a and 108b to form a so-called Tristop cylinder. On the front axle VA, the front axle modulator 106 controls the corresponding braking pressure on the front axle service brake cylinders 110a and 110b. Spring-energy-storing brake cylinders 108a and 108b are controlled via parking brake module 2, in which the electro-pneumatic valve device 1 according to the invention is implemented. Parking brake module 2 has a spring energy-storing connection end 21, which, as... Figure 5 As shown, it is connected to the spring-loaded brake cylinders 108a and 108b. The vehicle bus 16 connects the parking brake module 2 to the central unit 104.

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

[0084] 1. Electric and pneumatic valve facilities

[0085] 2 Parking brake module

[0086] 3. Venting end

[0087] 4. Reserve connection end

[0088] 5. Reserve shuttle valve

[0089] 6 First Compressed Air Reserve Department

[0090] 7 Second Compressed Air Reserve Section

[0091] 8 Pilot Control Unit

[0092] 10 Main Valve Unit

[0093] 12 Solenoid valves

[0094] 12.1 First Solenoid Valve Connection Terminal

[0095] 12.2 Second Solenoid Valve Connection Terminal

[0096] 12.3 Third Solenoid Valve Connection Terminal

[0097] 12.4 Pneumatic control connection terminal of solenoid valve

[0098] 13.1 First Permanent Magnet

[0099] 13.2 Second Permanent Magnet

[0100] 13.3 First Coil

[0101] 13.4 Second Coil

[0102] 14 Holding valve

[0103] 14.1 First holding valve connection end

[0104] 14.2 Second holding valve connection end

[0105] 16 Vehicle Bus

[0106] 18 Springs

[0107] 20 Relay Valve

[0108] 20.1 Relay valve reserve connection terminal

[0109] 20.2 Relay valve working connection end

[0110] 20.3 Relay valve vent connection terminal

[0111] 20.4 Relay valve control connection terminal

[0112] 21 Spring accumulator connection terminal

[0113] 22 Self-holding circuits

[0114] 24 First Control Line

[0115] 26 First pressure sensor

[0116] 27 First pressure measurement circuit

[0117] 28 Second pressure sensor

[0118] 29 Second pressure measurement circuit

[0119] 30 Release control connection terminal

[0120] 32 Release control path

[0121] 33 Release Line

[0122] 34 Shuttle Valve

[0123] 34.1 First shuttle valve connection end

[0124] 34.2 Second shuttle valve connection end

[0125] 34.3 Third shuttle valve connection end

[0126] 36 Second control circuit

[0127] 38 Emergency Release Connection Terminal

[0128] 39 Emergency Release Routes

[0129] 40 Emergency Release Line

[0130] 42 Emergency Release Shuttle Valve

[0131] 42.1 First Emergency Release Shuttle Valve Connection End

[0132] 42.2 Second Emergency Release Shuttle Valve Connection Terminal

[0133] 42.3 Third Emergency Release Shuttle Valve Connection Terminal

[0134] 44. Venting Path

[0135] 46 Repatriation Department

[0136] 48 Valve Components

[0137] 50 Inlet Valve

[0138] 50.1 First inlet valve connection end

[0139] 50.2 Second inlet valve connection end

[0140] 52 Outlet Valve

[0141] 52.1 First outlet valve connection end

[0142] 52.2 Second outlet valve connection end

[0143] 52.3 Third outlet valve connection end

[0144] 53 Throttling section

[0145] 54 Pilot control valve

[0146] 54.1 First pilot control valve connection terminal

[0147] 54.2 Second pilot control valve connection terminal

[0148] 54.3 Third pilot control valve connection terminal

[0149] 54.4 Pneumatic control connection terminal of pilot control valve

[0150] 56 Third control line

[0151] 58. Venting path of the pilot control valve

[0152] 100 commercial vehicles

[0153] 102 Braking System

[0154] 104 Central Module

[0155] 106 Front Axle Modulator

[0156] 108a and 108b spring-energy storage brake cylinders

[0157] Service brake cylinders on the rear axles of 109a and 109b

[0158] Service brake cylinders on the front axle of 110a and 110b

[0159] ECU (Electronic Control Unit)

[0160] pBP Parking Brake Pressure

[0161] pL release control pressure

[0162] pSN Emergency Pressure Relief

[0163] pSS self-holding pressure

[0164] pSV pilot control pressure

[0165] pV reserve pressure

[0166] S1 First switching signal

[0167] S2 Second Switching Signal

[0168] SFB parking brake signal

[0169] SD1 First Pressure Signal

[0170] SD2 Second Pressure Signal

[0171] VA front axle

[0172] HA rear axle

Claims

1. An electro-pneumatic valve facility (1) for operating the parking brake function of an electro-pneumatic braking system (102) of a commercial vehicle (100), the electro-pneumatic valve facility having a pilot control unit (8) that regulates a pilot control pressure (pSV) based on an electronic parking brake signal (SFB), and the pilot control unit being configured to be self-holding, wherein, The pilot control pressure (pSV) can cause the parking brake pressure (pBP) to be regulated at at least one spring accumulator connection (21), or can regulate the pilot control pressure as the parking brake pressure. Its features are, It has an emergency release connection (38) with an emergency release path (39) for selectively introducing an emergency release pressure (pSN) which is provided to the pilot control unit (8) at a pneumatic control connection (12.4, 54.4) and causes the parking brake pressure (pBP) to be regulated at at least one spring accumulator connection (21), wherein the pilot control unit is configured to be self-holding such that the pilot control pressure (pSV) regulated by the pilot control unit (8) or the pressure dependent on the pilot control pressure is drawn back via a self-holding line (22) and provided as a self-holding pressure (pSS) at the pneumatic control connection (12.4, 54.4) or another pneumatic control connection associated with the pilot control unit (8).

2. The electro-pneumatic valve device according to claim 1, wherein, In the event that the pressure applied at the pneumatic control connection (12.4, 54.4) and / or the other pneumatic control connection is lower than the first threshold, the pilot control unit (8) switches to a stable venting position.

3. The electro-pneumatic valve device according to claim 1 or 2, wherein, The introduction of the emergency release pressure (pSN) can cause the pilot control pressure (pSV) to be regulated by the pilot control unit (8).

4. The electro-pneumatic valve device according to claim 1 or 2, wherein, Introducing the emergency release pressure (pSN) can cause the valve of the pilot control unit (8) to switch.

5. The electro-pneumatic valve device according to claim 1 or 2, wherein, The emergency release path (39) leads to the venting path (44) of the pilot control unit (8).

6. The electro-pneumatic valve device according to claim 1 or 2, wherein, The pilot control unit (8) has a self-holding valve unit and a holding valve (14).

7. The electro-pneumatic valve device according to claim 2, wherein, The pilot control unit (8) includes a solenoid valve (12) with at least one first permanent magnet (13.1), wherein the solenoid valve (12) has the pneumatic control connection terminal, and wherein the solenoid valve (12) is capable of switching from a venting position to a supply position depending on the emergency release pressure (pSN).

8. The electro-pneumatic valve device according to claim 7, wherein, The solenoid valve (12) receives the self-holding pressure at the pneumatic control connection or the other pneumatic control connection, and wherein the solenoid valve (12) is capable of switching from a venting position to a supply position depending on the self-holding pressure (pSS).

9. The electro-pneumatic valve device according to claim 7, wherein, The solenoid valve (12) has a first solenoid valve connection end (12.1) for receiving a reserve pressure (pV), a second solenoid valve connection end (12.2) for regulating the pilot control pressure (pSV), and a third solenoid valve connection end (12.3) connected to the venting end (3). In the gas supply position of the solenoid valve (12), the first solenoid valve connection end (12.1) is connected to the second solenoid valve connection end (12.2), and in the venting position of the solenoid valve (12), the third solenoid valve connection end (12.3) is connected to the second solenoid valve connection end (12.2). The solenoid valve (12) can be selectively switched to the gas supply position or the venting position by energizing at least one coil (13.3, 13.4). The solenoid valve (12) can be magnetically held in the corresponding switching position by means of at least one first permanent magnet (13.1).

10. The electro-pneumatic valve device according to claim 9, wherein, When the self-holding pressure (pSS) and / or the emergency release pressure (pSN) are below a threshold or the first threshold, the solenoid valve (12) is switched to the venting position without relying on the previous switching position.

11. The electro-pneumatic valve device according to claim 9, wherein, If the self-holding pressure (pSS) exceeds the first threshold, the solenoid valve (12) remains in the previous switching position.

12. The electro-pneumatic valve device according to claim 9, wherein, If the self-holding pressure (pSS) exceeds a second threshold higher than the first threshold, the solenoid valve (12) is switched to the gas delivery position.

13. The electro-pneumatic valve device according to claim 9, wherein, The solenoid valve (12) has a preferred position.

14. The electro-pneumatic valve device according to claim 13, wherein, In the preferred position, the pilot control unit (8) is connected to the venting end (3).

15. The electro-pneumatic valve device according to claim 8, wherein, The emergency release pressure (pSN) is applied at the pneumatic control connection of the solenoid valve (12) via the emergency release path (39).

16. The electro-pneumatic valve device according to claim 1 or 2, wherein, The pilot control unit (8) has an inlet valve (50) and an outlet valve (52) that are electrically switchable between a stable state and an activated state. The pilot control unit also has a pilot control valve (54) with a pneumatic control connection or the pneumatic control connection, the pneumatic control connection receiving a reserve pressure (pV) and switching between a stable state and an activated state in response to a first control pressure (pS1) provided at the pneumatic control connection by the inlet valve (50) and / or the outlet valve (52), wherein, in the activated state, the pilot control valve (54) regulates the pilot control pressure (pSV).

17. The electro-pneumatic valve device according to claim 16, wherein, In order to regulate the emergency release pressure (pSN), the emergency release path (39) is connected to the pilot control valve (54) so ​​that the pilot control valve regulates the pilot control pressure (pSV).

18. The electro-pneumatic valve device according to claim 16, wherein, In order to regulate the emergency release pressure (pSN), the emergency release path (39) is connected to the pneumatic control connection or another pneumatic control connection of the pilot control valve (54).

19. The electro-pneumatic valve device according to claim 16, wherein, The emergency release path (39) leads to the venting path of the pilot control valve (54).

20. The electro-pneumatic valve device according to claim 2, wherein, The first threshold is in the range of 200 kPa to 400 kPa.

21. The electro-pneumatic valve device according to claim 12, wherein, The second threshold is in the range of 500 kPa to 900 kPa.

22. The electro-pneumatic valve apparatus according to claim 1 or 2, wherein the electro-pneumatic valve apparatus has a main valve unit (10) that receives the pilot control pressure (pSV) and regulates the parking brake pressure (pBP) at the at least one spring accumulator connection (21) based on the pilot control pressure (pSV).

23. The electro-pneumatic valve device according to claim 9, wherein, In the event that the self-holding pressure (pSS) exceeds the first threshold, the solenoid valve (12) remains in the previous switching position and can be selectively switched to the gas supply position or the gas release position by energizing at least one coil (13.3, 13.4).

24. The electro-pneumatic valve device according to claim 9, wherein, In the event that the self-holding pressure (pSS) exceeds a second threshold higher than the first threshold, the solenoid valve (12) is switched to the gas supply position and can be switched to the gas release position by energizing at least one coil (13.3, 13.4).

25. The electro-pneumatic valve device according to claim 20, wherein, The first threshold is in the range of 250 kPa to 350 kPa.

26. The electro-pneumatic valve device according to claim 21, wherein, The second threshold is in the range of 600 kPa to 800 kPa.

27. The electro-pneumatic valve device according to claim 1, wherein, The pilot control unit (8) includes a solenoid valve (12) with at least one first permanent magnet (13.1), wherein the solenoid valve (12) has the pneumatic control connection terminal, and wherein the solenoid valve (12) is capable of switching from a venting position to a supply position depending on the emergency release pressure (pSN).

28. A method for controlling the parking brake function of a commercial vehicle (100), the commercial vehicle having an electro-pneumatic braking system (102) and having an electro-pneumatic valve facility (1) according to any one of claims 1 to 27, the method comprising the steps of: - Switch at least one valve solenoid of the pilot control unit (8) to the air supply position to regulate the pilot control pressure (pSV), and then: regulate the parking brake pressure (pB) at at least one spring accumulator connection (21) to supply air to at least one spring accumulator brake cylinder (108a, 108b); - Locking out the pilot control pressure (pSV) and / or holding the at least one valve in the gas supply position; and - When the reserve pressure (pV) supplied to the pilot control unit (8) drops below a first threshold: the pilot control pressure is released; in, The method further includes: - An emergency release pressure is introduced at the emergency release connection (38) to induce the regulation of the parking brake pressure (pB) to release the at least one spring-loaded brake cylinder (108a, 108b).

29. The method according to claim 28, wherein, The introduction of the emergency release pressure (pSN) causes the valve of the pilot control unit (8) to switch.

30. The method according to claim 28 or 29, wherein, The introduction of the emergency release pressure (pSN) causes the pilot control pressure (pSV) to be regulated by the pilot control unit (8).

31. The method according to claim 28 or 29, wherein the method comprises the following steps: - A self-holding pressure (pSS) is regulated at the pneumatic control connection (12.4, 54.4) associated with the pilot control unit (8) to keep the pilot control unit (8) in the air supply position, thereby maintaining the pilot control pressure (pSV) regulated independently of electrical signals.

32. A commercial vehicle (100) having an electronically controlled pneumatic braking system (102) having an electro-pneumatic valve facility (1) according to any one of claims 1 to 27.

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