DE102022201955A1 - Tank ventilation valve with improved sealing function - Google Patents

Abstract

The present invention relates to a tank ventilation valve (1) for a pressure tank (2) for storing a compressed gas, having a base body (3) for arranging on a valve receptacle (4) of the pressure tank (2) and a translatory position in a central base body channel (5) of the Closing element (6) guided by the base body (3) for releasing a venting channel (7) between the base body (3) and the closing element (6) in a venting position (E) and for closing the venting channel (7) in a closed position (V). The tank ventilation valve (1) has an actuating element (8) that can be introduced into the main body channel (5), the actuating element (8) being able to be introduced into the main body channel (5) in such a way that an actuating end face (9) of the actuating element (8) against a closure end face (10) of the closure element (6) and as a result the closure element (6) can be moved from the closed position (V) to the venting position (E). The invention also relates to a pressure tank (2) for storing a compressed gas with a tank ventilation valve (1) according to the invention.

Description

The present invention relates to a tank ventilation valve for a pressure tank, having a base body for arranging on a valve seat of the pressure tank and a closure element, guided translationally in a central base body channel of the base body, for releasing a ventilation channel between the base body and the closure element in a ventilation position and for closing the ventilation channel in a locking position. Furthermore, the invention relates to a pressure tank for storing a compressed gas, having a tank wall through which a gas-tight sealable tank interior is formed, with a valve receptacle being formed in the tank wall.

State of the art

The sealing of connections and components on hydrogen-carrying containers, such as pressure tanks, and valves, especially at relatively high pressures, poses a particularly great challenge for the designers. Especially with moving components, such as valves, it is important to ensure that only one small part of the gas stored in the container, such as hydrogen, escapes uncontrolled, for example to the outside into the atmosphere.

Common methods for sealing here are adhesive or welded connections as non-detachable seals. In order to join components and assemblies or to seal moving components, elastomer seals such as O-rings in combination with support rings are usually used.

In order to empty or flush already filled or partially filled pressure tanks, which is necessary, for example, in the case of service, certain safety-related conditions must be met. The gas must not be released uncontrolled in a workshop. One method here is to let the gas, such as hydrogen, escape into the open air, which means that it is lost. This can be done, for example, via a normal removal path, which can take a long time depending on the filling quantity due to the respective throttle cross sections. An alternative to this is loosening a screw plug, which allows the gas to suddenly escape from the pressure tank. Such a rapid venting of the pressure tank can usually only be implemented with a very complex device.

Standard vent valves for hydrogen applications include, among other things, elastomer or other plastic seals, which can wear out due to relative movement, for example to metal components. Examples of this are moving radial seals in bores, such as O-rings, support rings or the like, or abrasion in cone seals due to relative rotation of the sealing partners. The smallest damage to the seals, which usually have "FKM" or "EPDM" in hydrogen applications, can lead to a leak in the tank system. This can mean that the tank empties itself after weeks or even a few days. In the worst case, this has the consequence that the escaped hydrogen mixes with the oxygen from the ambient air in a closed space, for example the interior of a motor vehicle or a garage, to form an explosive gas. Conventional vent valves can therefore often not be used more than once and must be fitted with new seals after use for the above reasons.

Disclosure of Invention

According to a first aspect, the invention provides a tank ventilation valve for a pressure tank for storing a compressed gas, in particular a high-pressure hydrogen tank for storing hydrogen, having the features of independent claim 1 . Furthermore, according to a second aspect, the invention provides a pressure tank for storing a compressed gas, in particular a high-pressure hydrogen tank for storing hydrogen, having the features of independent claim 10 . Further advantages, features and details of the invention result from the dependent claims, the description and the drawings. Features and details that are described in connection with the tank ventilation valve according to the invention naturally also apply in connection with the pressure tank according to the invention and vice versa, so that the disclosure of the individual aspects of the invention is or can always be referred to alternately.

According to the first aspect, the invention provides a tank ventilation valve for a pressure tank for storing a compressed gas. The tank ventilation valve has a base body for arranging on a valve receptacle of the pressure tank and a closure element, guided translationally in a central base body channel of the base body, for releasing a ventilation channel between the base body and the closure element in a ventilation position and for closing the ventilation channel in a closed position. According to the invention, the tank ventilation valve has a valve that can be introduced into the main body channel Actuating element, wherein the actuating element can be introduced into the main body channel in such a way that an actuating end face of the actuating element presses against a closing end face of the closing element and as a result the closing element can be moved from the closed position into the venting position.

The base body is designed to be arranged on the valve seat of the pressure tank. In the context of the invention, a valve receptacle is understood to mean an area of the pressure tank in which a passage is formed in a tank wall of the pressure tank, via which a tank interior of the pressure tank is opened to an area surrounding the pressure tank. By arranging the base body on the valve receptacle, a parting line between the base body and the tank wall can be sealed in a preferably gas-tight manner. For this purpose, it is preferred that the base body has a sealing device, such as a circumferential sealing groove, in which an O-ring or the like is arranged. When installed, the sealing device touches the tank wall and thus seals the parting line between the base body and the tank wall. The base body preferably has a plurality of such sealing devices. The base body preferably has a metal or is formed from a metal or at least essentially formed from a metal. More preferably, the base body has at least one ventilation channel for discharging the gas in the ventilation position of the closure element.

In order to arrange the base body on the valve receptacle, the base body preferably has an external thread which can be brought into engagement with an internal thread of the valve receptacle. Alternatively, a welding flange can also be provided for welding the base body to the tank wall. The base body preferably has a limiting shoulder in order to positively limit an insertion depth, such as a screwing depth, of the base body into the valve receptacle. An end section of the base body facing away from the actuating element preferably has a first sealing surface. In the closed position, the first sealing surface is preferably in sealing contact with a second sealing surface of the closure element. The second sealing surface is preferably arranged adjacent to a tank end face of the closure element that faces away from the closure end face. More preferably, the first sealing surface is arranged at a distance from the second sealing surface in the ventilation position.

The base body channel is formed in the base body and preferably extends coaxially to a base body longitudinal axis of the base body. The closure face is arranged in the main body channel in the closed state. The closure face is preferably also arranged in the main body channel in the vented state. An end section of the closure element opposite the closure end face preferably projects out of the main body channel.

The closure element is preferably designed to bring about a self-reinforcing seal of the pressure tank in the closed position. This means that the closure element is designed and set up in such a way that the closure element can be pressed into the closed position by an overpressure in the pressure tank. The vent valve preferably also has a return device, such as a coil spring or the like, in order to press the closure element into the closed position. Such a restoring device is preferably arranged at least partially in a recess in the tank end face of the closure element. The closure element preferably has, at least in sections, an outer diameter which corresponds or at least substantially corresponds to an inner diameter of the base body channel, so that the closure element is held in the base body channel in a translatory movable manner. The closure element preferably has a plastic, such as polyamide or the like, or is formed from such a plastic or at least essentially formed from such a plastic. The closure face is formed at an end of the closure member opposite the tank face. The closure element preferably has an element channel for discharging the gas in the ventilation position.

The actuating element preferably has, at least in sections, an outer diameter which corresponds or at least essentially corresponds to the inner diameter of the base body channel, so that the actuating element can be moved translationally in the base body channel. The actuating element preferably has a sealing device, such as a circumferential sealing groove in which an O-ring or the like is arranged, in order to provide a seal between the actuating element and the base body. The actuating element can be introduced into the main body channel in such a way that the actuating face of the actuating element contacts the closure face. The actuating element can also be introduced into the main body channel in such a way that the actuating element presses the closure element from the closed position into the ventilation position. The tank ventilation valve preferably has a holding device, self inhibition or the like, by means of which the actuating element can be held in the venting position. The actuating element preferably has a form-fitting section which prevents the actuating element from being introduced further into the main body channel in a form-fitting manner, preferably in interaction with the main body.

A tank vent valve according to the invention has the advantage over conventional tank vent valves that low-wear venting of the pressure tank is ensured with simple means and in a cost-effective manner. Rotational decoupling of the closure element and the actuating element makes it easier to avoid rotation of the closure element when moving between the closed position and the venting position. Wear of a seal between the closure element and the base body can thus be significantly reduced. In this way, the service life of a tank ventilation valve according to the invention is significantly increased.

According to a preferred further development of the invention, it can be provided in a tank ventilation valve that the base body has a first sealing surface designed as an inner sealing cone and the closure element has a second sealing surface designed as an outer sealing cone, the ventilation channel being closed in the closed position by the interaction of the first sealing surface with the second sealing surface . The first sealing surface and the second sealing surface preferably have an angle of between 80° and 60° to the longitudinal axis of the base body. Alternatively, the first sealing surface of the base body can be designed as an annular end face and the second sealing surface of the closure element can be designed as an annular shoulder. In this case, the first sealing surface and the second sealing surface have an angle of 90° to the longitudinal axis of the base body. This has the advantage that a reliable and low-wear seal is provided between the closure element and the base body with simple means and in a cost-effective manner.

It is preferred according to the invention that the actuating face and/or the closure face have such a rounding and/or chamfer that a contact surface between the actuation face and the closure face amounts to less than 20% of a diameter of the main body channel in the area of the actuation face. The contact area is preferably less than 5% of the diameter of the main body channel in the area of the actuation end face. It is particularly preferred that the contact surface is formed almost in the form of a point. This has the advantage that the possibility of transmitting a torque from the actuating element to the closure element is reduced with simple means and in a cost-effective manner. Thus, a rotation of the closure element when moving between the closed position and the venting position can be better avoided and thus the wear of the seal can be reduced.

More preferably, the actuation face and/or the closure face have a reduced-friction surface. The friction-reduced surface can be configured, for example, as a polished surface, friction-reducing coating, or the like. This has the advantage that the possibility of transmitting a torque from the actuating element to the closure element is reduced with simple means and in a cost-effective manner. Thus, a rotation of the closure element when moving between the closed position and the venting position can be better avoided and thus the wear of the seal can be reduced.

In a particularly preferred embodiment, it can be provided in a tank ventilation valve that the closure element is guided in a form-fitting, non-rotatable manner in the main body channel. Such a form-fitting anti-twist device can be constructed, for example, according to the tongue and groove principle. The base body preferably has a longitudinal groove in which a sliding block of the closure element is linearly guided. Alternatively, the longitudinal groove can be formed in the closure element, with the sliding block then being arranged on the base body. This has the advantage that rotation of the closure element when moving between the closed position and the venting position can be better avoided with simple means and in a cost-effective manner, and the wear on the seal can thus be reduced. A longitudinal groove also has the advantage that the gas can be discharged in the ventilation position via this.

The base body preferably has at least one transverse passage running from an outer surface of the base body to the base body channel.

The base body preferably has a plurality of such transverse passages, which are preferably distributed, preferably evenly distributed, in the circumferential direction of the base body. The tank ventilation valve can be arranged on the valve receptacle in such a way that the transverse passage can be coupled in fluid communication with a gas discharge channel of the pressure tank. Thus, in the venting position, the gas can be routed from the tank interior to the gas discharge channel. This has the advantage that the gas can be discharged via the tank vent using simple means and in a cost-effective manner valve is improved. A venting process of the pressure tank is thus improved.

According to a preferred embodiment of the invention, the transverse passage has a widening towards the outer surface. The widening is preferably formed in such a way that a diameter of a radially outwardly pointing opening of the transverse passage has a maximum. In other words, the transverse passage preferably has a funnel-shaped widening radially outward. This has the advantage that a permissible tolerance in the arrangement of the base body on the valve receptacle can be increased with simple means and in a cost-effective manner, since adequate fluid communication can be provided even if the transverse passage is not exactly coaxial with the gas discharge channel.

The actuating element particularly preferably has an external thread for insertion into the base body channel and the base body channel has a corresponding internal thread. More preferably, the actuating element has a form-fitting section for attaching a tool in order to improve screwing of the actuating element into the base body. The internal thread and the external thread are preferably designed in such a way that such a self-locking of the actuating element can be guaranteed that the actuating element screwed into the venting position remains in the venting position after the tool has been set down. Alternatively or additionally, a safety device, such as a safety split pin, a safety cap or the like, can be provided for positively locking the actuating element in the ventilation position. Preferably, the safety device is also designed to positively hold the actuating element in the closed position. This has the advantage that actuation of the tank ventilation valve is improved with simple means and in a cost-effective manner.

It is preferred according to the invention that the closure element has on an outside a recess extending along a longitudinal axis of the closure element for discharging the gas in the ventilation position. The closure element preferably has a plurality of such recesses. Alternatively or additionally, the base body can have one or more such recesses, through which a channel cross section of the base body channel can be enlarged locally and slightly. This has the advantage that gas discharge via the tank ventilation valve is improved with simple means and in a cost-effective manner. A venting process of the pressure tank is thus improved.

According to the second aspect of the invention, the object is achieved by a pressure tank for storing a pressurized gas. The pressure tank has a tank wall, through which a gas-tight sealable tank interior is formed. A valve seat is formed in the tank wall. According to the invention, a tank ventilation valve according to the invention is arranged on the valve seat.

The pressure tank is preferably designed as a high-pressure hydrogen tank. According to the invention, it can additionally or alternatively be provided that the pressure tank is designed as a pressure tank for a motor vehicle. The tank ventilation valve is preferably screwed into the valve seat via a thread. In the closed position of the tank ventilation valve, fluid communication between the tank interior and a gas discharge channel of the pressure tank is interrupted. This means that no gas exchange can take place between the tank interior and the gas discharge channel. In the ventilation position of the tank ventilation valve, fluid communication is established between the tank interior and the gas discharge channel, so that the gas can flow from the tank interior via the tank ventilation valve into the gas discharge channel and the pressure tank can thus be emptied.

All the advantages that have already been described for a tank ventilation valve according to the first aspect of the invention result from the pressure tank according to the invention. Accordingly, the pressure tank according to the invention has the advantage over conventional pressure tanks that low-wear venting of the pressure tank is ensured with simple means and in a cost-effective manner. Rotational decoupling of the closure element and the actuating element makes it easier to avoid rotation of the closure element when moving between the closed position and the venting position. Wear of a seal between the closure element and the base body of the tank ventilation valve can thus be significantly reduced. Consequently, the service life of the tank ventilation valve of the pressure tank according to the invention is significantly increased.

• 1 in einer Schnittdarstellung ein Tankentlüftungsventil gemäß einer bevorzugten ersten Ausführungsform der Erfindung in einer Verschlussstellung,
• 2 in einer Schnittdarstellung das Tankentlüftungsventil aus 1 in einer Entlüftungsstellung, und
• 3 in einer Seitenansicht eine bevorzugte Ausführungsform eines erfindungsgemäßen Drucktanks.

A tank ventilation valve according to the invention and a pressure tank according to the invention are explained in more detail below with reference to drawings. They each show schematically:

• 1 in a sectional view, a tank ventilation valve according to a preferred first embodiment of the invention in a closed position,
• 2 the tank ventilation valve in a sectional view 1 in a vent position, and
• 3 in a side view a preferred embodiment of a pressure tank according to the invention.

Elements with the same function and mode of action are in the 1 until 3 each provided with the same reference numerals.

In 1 the tank ventilation valve 1 according to the preferred first embodiment of the invention in the closed position V is shown schematically in a sectional view. The tank ventilation valve 1 has a base body 3 which extends along a longitudinal axis L and is of essentially rotationally symmetrical design. A main body channel 5 is formed in the main body 3 and extends along the longitudinal axis L through the entire main body 3 . The base body is screwed into a valve receptacle 4 of a pressure tank 2 (not shown) (cf. 3 ) screwed in. The base body 3 is sealed off from the valve receptacle 4 via two sealing devices 25 . Between the two sealing devices 25, the base body 3 has a plurality of transverse passages 14, which extend radially inwards from an outer surface 13 of the base body 3 into the base body channel 5, for conducting the gas through in the ventilation position E (cf. 2 ) on. The main body channel 5 has an internal thread 16 on an end region facing away from the valve receptacle 4 .

A closure element 6 is arranged in the base body channel 5 and guided linearly in the base body channel 5 . The closure element 6 has a closure end face 10 and a tank end face 20 opposite the closure end face 10 and in which a spring receptacle 21 is formed. A helical spring 22 is arranged in the spring receptacle 21 and can be used to press the closure element 6 with a restoring force in the direction of the closure position V shown. The helical spring 22 is supported against the valve seat 4 . Furthermore, the closure element 6 has a recess 17 extending along the longitudinal axis L for discharging the gas. A ventilation channel 7 of the ventilation valve 1 is formed by the recess 17 and the transverse passages 14 . The closure element 6 preferably has a plurality of, for example two, three or four, recesses 17 . The recesses are preferably distributed uniformly over the circumference of the closure element 6 . The recesses 17 are preferably flat, for example plate-shaped.

In the closed position V, a second sealing surface 12 embodied as an outer sealing cone of the closure device 6 lies flat against a first sealing surface 11 embodied as an inner sealing cone of the base body 3 . Thus, a fluid communication that can be established via the ventilation channel 7 between an inlet bore 23 of the pressure tank 2 and an outlet bore 24 of the pressure tank 2 is interrupted by the tank ventilation valve 1 .

Furthermore, an actuating element 8 is arranged in the base body channel 5 . The actuating element 8 has an external thread 15 which engages with the internal thread 16 of the main body channel 5 . A hexagon socket 26 for a tool is formed in the actuating element 8 . As an alternative to a hexagon socket 26, another geometry such as a slot, cross slot, torx or the like can also be provided. The actuating element 8 is sealed off from the base body 3 by a sealing device 25 . A convexly curved actuating face 9 of the actuating element 8 faces the closure face 10 and is spaced from it. By screwing the actuating element 8 further into the main body channel 5 , the actuating face 9 can be pressed against the closure face 10 .

2 shows the tank ventilation valve 1 1 in the venting position E schematically in a sectional view. In the venting position E, the actuating element 8 is screwed into the base body channel 5 in such a way that the actuating end face 9 presses against the closure end face 10 and the closure element 6 is thereby displaced translationally into the venting position E. The helical spring 22 is thus tensioned further compared to the closed position V. Due to the self-locking between the internal thread 16 and the external thread 15, the actuating element 8 and the closure element 6 remain in the venting position E even when the tool is set down.

Furthermore, the translatory displacement of the closure element 6 creates a gap between the first sealing surface 11 and the second sealing surface 12 and thus establishes fluid communication between the inlet bore 23 and the outlet bore 24 via the ventilation channel 7 . The gas can thus flow out of the pressure tank 2 via the inlet bore 23, the recess 17 and the transverse passages 14 into the outlet bore 24, so that the pressure tank 2 is vented in this way in a targeted and low-wear manner. The sealing devices 25 prevent the gas from flowing between the base body 3 and the valve receptacle 4 and through the tank ventilation valve 1 into an area surrounding the pressure tank 2 .

In 3 the preferred embodiment of the pressure tank 2 according to the invention is shown schematically in a side view. The pressure tank 2 has a tank wall 18 through which a tank interior 19 is formed. Two valve receptacles 4 are formed on the tank wall 18 . A tank ventilation valve 1 according to the invention is arranged in one of the valve receptacles 4 . For example, an interface for coupling the pressure tank 2 to a hydrogen system can be arranged on the other valve receptacle 4 . The pressure tank 2 is preferably designed as a hydrogen tank for a motor vehicle.

Claims (10)

Tank ventilation valve (1) for a pressure tank (2) for storing a compressed gas, having a base body (3) for arrangement on a valve receptacle (4) of the pressure tank (2) and a translationally guided in a central base body channel (5) of the base body (3). Closing element (6) for releasing a venting channel (7) between the base body (3) and the closing element (6) in a venting position (E) and for closing the venting channel (7) in a closed position (V), characterized in that the tank venting valve (1) has an actuating element (8) that can be introduced into the base body channel (5), the actuating element (8) being able to be introduced into the base body channel (5) in such a way that an actuating end face (9) of the actuating element (8) against a closure end face (10) of the closure element (6) and as a result the closure element (6) can be moved from the closed position (V) to the venting position (E). Tank ventilation valve (1) after claim 1 , characterized in that the base body (3) has a first sealing surface (11) designed as an inner sealing cone and the closure element (6) has a second sealing surface (12) designed as an outer sealing cone, the venting channel (7) in the closed position (V) by interaction the first sealing surface (11) is closed with the second sealing surface (12). Tank ventilation valve (1) after claim 1 or 2 , characterized in that the actuating face (9) and/or the closure face (10) have such a rounding and/or chamfer that a contact surface between the actuating face (9) and the closure face (10) is less than 20% of a diameter of the main body channel (5) in the area of the actuation face (9). Tank ventilation valve (1) according to one of the preceding claims, characterized in that the actuating face (9) and/or the closing face (10) have a reduced-friction surface. Tank ventilation valve (1) according to one of the preceding claims, characterized in that the closure element (6) is guided in the base body channel (5) in a form-fitting, non-rotatable manner. Tank ventilation valve (1) according to one of the preceding claims, characterized in that the base body (3) has at least one transverse passage (14) running from an outer surface (13) of the base body (3) to the base body channel. Tank ventilation valve (1) according to one of the preceding claims, characterized in that the transverse passage (14) has a widening towards the outer surface (13). Tank ventilation valve (1) according to one of the preceding claims, characterized in that the actuating element (8) has an external thread (15) for introduction into the base body channel (5) and the base body channel (5) has a corresponding internal thread (16). Tank ventilation valve (1) according to one of the preceding claims, characterized in that the closure element (6) has on an outside a recess (17) extending along a longitudinal axis (L) of the closure element (6) for discharging the gas in the ventilation position (E) having. Pressure tank (2) for storing a compressed gas, having a tank wall (18) through which a gas-tight sealable tank interior (19) is formed, wherein a valve receptacle (4) is formed in the tank wall (18), characterized in that on the valve receptacle (4) a tank ventilation valve (1) is arranged according to one of the preceding claims.

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