Assembly for a pressurized gas container, pressurized gas container

Abstract

The invention relates to an assembly (1), in particular a valve assembly, for a pressurized gas container for storing fuel gas, preferably hydrogen or natural gas, wherein the assembly (1) comprises a housing (2) with at least one bore (3) in which a component (4), in particular a valve, is received, and wherein a high-pressure seal is formed within the bore (3), which is protected from environmental influences by a further seal (5) with an annular sealing element (11). According to the invention, the annular sealing element (11) is received in an axial gap (6) formed between the housing (2) and the component (4), which widens from radially inside to radially outside. The invention further relates to a pressurised gas container with an assembly (1) according to the invention.

Description

[0001] The invention relates to an assembly, in particular a valve assembly, for a compressed gas container for storing fuel gas, preferably hydrogen or natural gas. Furthermore, the invention relates to a compressed gas container with an assembly according to the invention.

[0002] A preferred field of application of the invention is mobile tank systems with at least one compressed gas container for storing fuel gas that is used to drive a vehicle, for example a fuel cell or gas vehicle. State of the art

[0003] In mobile applications, compressed gas cylinders are used in which the gas or fuel gas is stored under high pressure. The extraction of fuel gas from the cylinder and the refueling of the cylinder with fuel gas are carried out via a valve assembly connected to the cylinder, which may include not only valves but also other components, such as filters and / or sensors. To accommodate the components, the valve assembly has a housing with several mounting holes. These holes must each be sealed to the outside by a high-pressure seal.

[0004] Such a high-pressure seal can be implemented using a sealing ring combined with a support ring or a metal seal. In both cases, an environmental seal must also be provided to protect the high-pressure seal from harmful environmental influences. Without the environmental seal, the metal elements of the high-pressure seal can corrode, compromising the function of the high-pressure seal. The main function of the environmental seal is therefore to prevent the ingress of dirt and, in particular, moisture. The environmental seal is typically implemented using a sealing ring made of an elastomer material.

[0005] Leakage and / or permeation can lead to an undesirable pressure buildup between the environmental seal and the high-pressure seal. In this case, pressure relief to the outside must be achieved via the environmental seal. Therefore, the environmental seal is ideally sealed from the outside in, but leaky from the inside out. Since sealing from the outside in requires a high surface pressure, while leakage removal from the inside out requires a low surface pressure, a conflict of objectives exists. Current environmental seals that attempt to resolve this conflict of objectives merely represent a compromise solution that does neither function justice to one nor the other.

[0006] If pressure relief in the space between the environmental seal and the high-pressure seal cannot be achieved in the event of leakage and / or permeation through the environmental seal, there is a risk that the environmental seal will be damaged by the resulting pressure. The sealing effect of the environmental seal against environmental media may then no longer be ensured, and the high-pressure seal will no longer be protected against corrosion.

[0007] The present invention is concerned with the task of developing an environmental seal in such a way that it fulfills both functions as far as possible, that is to say, on the one hand, it is tight from the outside to the inside and leaky from the inside to the outside.

[0008] To achieve this objective, the assembly having the features of claim 1 is proposed. Advantageous further developments of the invention are set forth in the subclaims. Furthermore, a compressed gas container having an assembly according to the invention is proposed. Disclosure of the invention

[0009] Proposed is an assembly, in particular a valve assembly, for a compressed gas container for storing fuel gas, preferably hydrogen or natural gas. The assembly comprises a housing with at least one bore in which a component, in particular a valve, is accommodated. A high-pressure seal is formed within the bore, which is protected from environmental influences by a further seal with an annular sealing element. According to the invention, the annular sealing element is accommodated in an axial gap formed between the housing and the component, which widens from the radial inside to the radial outside.

[0010] In other words, the axial gap accommodating the sealing element has a smaller radial inside height than the radial outside height. If pressure is applied to the sealing element radially inside, it can expand radially, thereby causing pressure relief. If pressure is applied to the sealing element radially outside, the sealing element is pressed against the housing and / or component, thereby increasing the surface pressure in the sealing area. The sealing effect increases accordingly. The additional seal, which forms an environmental seal, is therefore tight from radially outside to radially inside and leaky from radially inside to radially outside in order to effect the required pressure relief.

[0011] Preferably, the axial gap is defined by an annular first sealing surface formed on the housing and an annular second sealing surface formed on the component, wherein the sealing surfaces are arranged at an angle to each other. This means that the two sealing surfaces do not run parallel to each other. This ensures that the axial gap has a different height radially inside than radially outside.

[0012] Furthermore, at least one sealing surface is preferably designed in a funnel-shaped and / or frustoconical configuration. For example, the first sealing surface formed on the housing can be frustoconical, and the second sealing surface formed on the component can also be frustoconical, resulting in an axial gap with a triangular or trapezoidal cross-section. Alternatively, the second sealing surface can also be funnel-shaped, in which case the opening angle of the funnel must be greater than the cone angle of the frustoconical portion opposite the funnel in order to achieve an axial gap that widens from the radially inside to the radially outside.

[0013] Furthermore, it is proposed that the first sealing surface be formed on a collar portion of the housing that surrounds the bore. The collar portion can, for example, have the shape of a truncated cone. The collar portion then forms a truncated cone-shaped sealing surface for the sealing element of the additional seal to engage. The collar portion can have a hollow cylindrical projection radially inwardly that surrounds the bore, preventing the sealing element from slipping into the bore, particularly during assembly of the assembly.

[0014] Alternatively or additionally, it is proposed that the second sealing surface be formed on a flange portion of the component. If the housing has a frustoconical collar portion, the flange portion can be of conventional design, i.e., with a flat underside, so that the sealing surface formed on the flange portion runs perpendicular to a longitudinal axis of the bore accommodating the component. The flange portion can also have the shape of a truncated cone or that of a funnel, in which case the funnel angle must be selected to be greater than the cone angle of the frustoconical collar portion of the housing opposite the funnel.

[0015] The sealing element of the additional seal or environmental seal is preferably made of an elastomer material and is accommodated in the axial gap under a preload. The preload is achieved when the component is inserted, preferably screwed or pressed, into the bore of the housing. Because the sealing element is made of an elastomer material, it is elastically deformable. The elastic deformation then creates the preload of the sealing element.

[0016] Depending on the alignment of the sealing surfaces on the housing and the component that interact with the sealing element, an axial preload of the sealing element is primarily achieved. This allows large axial tolerances to be compensated for by the sealing element. Since the sealing surfaces on the housing and the component that interact with the sealing element are not aligned parallel to each other, the axial preload always contains a radial force component. This force is essentially applied exclusively radially on the inside of the sealing element, ensuring that the sealing element can expand radially.

[0017] If the sealing element is made of an elastomer material, a further development of the invention proposes that the sealing element have a friction-reducing coating. This simplifies assembly of the component and reduces wear on the sealing element.

[0018] In the relaxed state, the sealing element preferably has a cross-sectional shape that is circular, triangular, square, or trapezoidal. The circular shape enables the use of a conventional sealing ring, making this embodiment particularly simple and cost-effective to implement. With a triangular, square, or trapezoidal cross-sectional shape, the sealing element can be oriented such that sealing surfaces formed on the sealing element come into flat contact with the sealing surfaces formed on the housing and on the component. Advantageously, the cross-sectional shape of the sealing element is adapted to the axial gap. This means that the alignment of the sealing surfaces of the sealing element is adapted to the alignment of the sealing surfaces formed on the housing and on the component.

[0019] In order to avoid incorrect installation during assembly of the assembly, it is proposed as a further development measure that the cross-sectional shape of the sealing element is mirror-symmetrical with respect to a centrally arranged radial plane.

[0020] Preferably, the sealing element has a height h radially outward a and radially inside a height h i where the height h a greater than the height h i If this requirement is met, the sealing element can have any cross-sectional shape.

[0021] The high-pressure seal formed within the bore of the housing preferably comprises a sealing ring and a support ring or is implemented as a metallic seal. The additional seal or environmental seal then serves, in particular, to protect the high-pressure seal from corrosion.

[0022] Furthermore, a compressed gas container with an assembly according to the invention, in particular a valve assembly, is proposed. In the case of a valve assembly, this can in particular be a tank valve into which a plurality of components are integrated to implement a plurality of functions. Preferably, the assembly is inserted into the compressed gas container in sections, in particular screwed in, for example, in the region of a bottle neck. Drawings

[0023] Preferred embodiments of the invention are described in more detail below with reference to the accompanying drawings. They show: Fig. 1 shows a schematic longitudinal section through an axial gap between a housing and a component of a first assembly according to the invention; Fig. 2 shows a schematic longitudinal section through an axial gap between a housing and a component of a second assembly according to the invention; Fig. 3 a schematic longitudinal section through an axial gap between a housing and a component of a third assembly according to the invention; Fig. 4 a schematic cross section through a first sealing element for an assembly according to the invention; Fig. 5 a) to f) each show a schematic cross section through a sealing element for an assembly according to the invention; Fig. 6 a) to c) each show an assembly step in the assembly of an assembly according to the invention with a sealing element with a circular cross-section and Fig. 7 a) to c) each show an assembly step in the assembly of an assembly according to the invention with a sealing element with a trapezoidal cross-section. Description of the embodiments

[0024] The Fig. Figure 1 shows a first assembly 1 according to the invention, which comprises a housing 2 with a bore 3 and a component 4 inserted into the bore 3, in this case screwed in. Component 4 can be, for example, a valve.

[0025] The component 4 has a flange section 10 which, together with a collar section 9 of the housing 2, delimits an axial gap 6 in which an annular sealing element 11 of a seal 5 is received. The seal 5 is an environmental seal which serves to protect a high-pressure seal (not shown) formed within the bore 3 from environmental influences. The collar section 9 of the housing 2 is frustoconical and is provided radially inwardly with a hollow cylindrical projection 14 which encloses the bore 3. The frustoconical shape of the collar section 9 leads to the formation of a frustoconical first sealing surface 7 against which the sealing element 11 bears with a sealing surface 12. The flange section 10 of the component 4 has a second sealing surface 8, which is also frustoconical and against which the sealing element 11 bears with a sealing surface 13.The axial gap 6, which is defined by the two frustoconical sealing surfaces 7, 8, therefore widens from radially inward to radially outward. In other words, the height of the axial gap 6 increases with increasing distance from a longitudinal axis A of the bore 3. The sealing element 11 accommodated in the axial gap 6 is essentially of the opposite design or adapted to the axial gap 6. As shown, for example, in FIG. Fig. 4 or in the Fig. 5b), each of which represents a module 1 of the Fig. 1 suitable sealing element 11, the sealing element 11 has a radially inner height h i which is less than a height h a , which is the radially outer height. The two sealing surfaces 12, 13 of the sealing element 11 enclose an angle β, which is essentially the same size as an angle α between the two sealing surfaces 7, 8 delimiting the axial gap 6.

[0026] The Fig. The embodiment shown in Figure 1 has the advantage that the annular sealing element 11 accommodated in the axial gap 6 can expand radially when pressure builds up within the bore 3, thereby relieving pressure. Conversely, the sealing element 11 is pressed against the two frustoconical sealing surfaces 7, 8, so that it is sealed from the outside to the inside. The wedge shape of the axial gap 6 and the sealing element 11 also causes the sealing element 11 to self-center with respect to the axial gap 6.

[0027] The same effect can be achieved if instead of the Fig. 4 or the Fig. 5b) a sealing element 11 analogous to the representations of the Fig. 5a), Fig. 5e) or Fig. 5f) is used.

[0028] The Fig. A second preferred embodiment of an assembly 1 according to the invention can be seen in Figure 2. The housing 2 is analogous to the housing 2 of the Fig. 1 shown assembly 1. The component 4 used therein, in this case screwed in, has a flange section 10 with a sealing surface 8 which delimits the axial gap 6 and is aligned perpendicular to the longitudinal axis A of the bore 3. The angle α enclosed by the sealing surfaces 7, 8 is therefore somewhat smaller than in the Fig. 1. Nevertheless, this assembly 1 also has an axial gap 6, which widens from radially inward to radially outward, so that pressure relief can be achieved via a sealing element 11 inserted therein. Possible embodiments of a suitable sealing element 11 are shown by way of example in the Fig. 5a), Fig. 5c) and 5d).

[0029] A third preferred embodiment of an assembly 1 according to the invention is shown in Fig. 3. The housing 2 is also unchanged here, while the sealing surface 8 formed on the flange section 10 of the component 4 is funnel-shaped. The angle α is in the Fig. 3 is therefore even smaller than in the Fig. 2. However, since the funnel angle is selected to be larger than the cone angle of the truncated cone-shaped collar section 9, the sealing surfaces 7, 8 also define an axial gap 6 that widens from the radial inside to the radial outside. Sealing elements 11 that can be inserted into the axial gap 6 are shown in the Fig. 5a), Fig. 5c) and 5d). Preferably, the sealing elements 11 are elastically deformable, so that they are compressible.

[0030] Based on the Fig. 6a) to 6c) is illustrated by the example of the Fig. 2 shown assembly 1 in combination with the Fig. 5a) illustrates the assembly of an assembly 1 according to the invention. In a first step, the annular sealing element 11 is placed on the collar section 9 of the housing 2. Subsequently, the component 4 is inserted or screwed into the bore 3 (see Fig. 6a)). With increasing screw-in depth, the sealing element 11 is compressed axially, whereby the frustoconical collar section 9 of the housing 3 introduces a radial force component that preloads the sealing element 11 against the collar section 9 (see Fig. 6b)). The arrangement allows for the compensation of axial tolerances in a simple manner by simply expanding the sealing element 11 radially (see Fig. 6c)).

[0031] The sealing element 11 can have an inner diameter d in the relaxed state i which is equal to or slightly smaller than an outer diameter d aof the hollow cylindrical projection 14 of the collar portion 9 of the housing 2. In this way, the sealing element 11 is radially preloaded when placed on the collar portion 9 and is held securely on the collar portion 9 until the component 4 is inserted or screwed into the bore 3.

[0032] Based on the Fig. 7a) to 7c) is illustrated by the example of the Fig. 1 shown assembly 1 in combination with the Fig. 5b) shows the assembly of an assembly 1 according to the invention. The steps include the steps shown in the Fig. 6a) to 6c). First, the sealing element 11 is placed on the collar section 9 of the housing 2, then the component 4 is inserted or screwed into the bore 3 (see Fig. 7a)). With increasing screw-in depth, the sealing element 11 is compressed in the axial direction and is thereby pre-tensioned both axially and radially against the sealing surfaces 7, 8 (see Fig. 7b)). Due to the wedge shape of the sealing surfaces 7, 8 that delimit the axial gap 6, the sealing element 11 remains free of radial force on the outside, so that it can expand radially (see Fig. 7c).

Claims

[1] Assembly (1), in particular valve assembly, for a pressurised gas container for storing fuel gas, preferably hydrogen or natural gas, wherein the assembly (1) comprises a housing (2) with at least one bore (3) in which a component (4), in particular a valve, is accommodated, and wherein a high-pressure seal is formed within the bore (3), which is protected from environmental influences by a further seal (5) with an annular sealing element (11), characterized by that the annular sealing element (11) is received in an axial gap (6) formed between the housing (2) and the component (4), which widens from radially inside to radially outside. [2] Assembly (1) according to claim 1, characterized bythat the axial gap (6) is delimited by an annular first sealing surface (7) formed on the housing (2) and an annular second sealing surface (8) formed on the component (4), wherein the sealing surfaces (7, 8) are arranged at an angle to one another. [3] Assembly (1) according to claim 2, characterized by that at least one sealing surface (7, 8) is funnel-shaped and / or frustoconical. [4] Assembly (1) according to claim 2 or 3, characterized by that the first sealing surface (7, 8) is or are formed on a collar section (9) of the housing (2) enclosing the bore (3) and / or the second sealing surface (8) is or are formed on a flange section (10) of the component (4). [5] Assembly (1) according to one of the preceding claims, characterized by that the sealing element (11) is made of an elastomer material and is accommodated in the axial gap (6) under prestress. [6] Assembly (1) according to one of the preceding claims, characterized by that the sealing element (11) in the relaxed state has a circular, triangular, square or trapezoidal cross-sectional shape, which is preferably adapted to the axial gap (6). [7] Assembly (1) according to one of the preceding claims, characterized by that the sealing element (11) has a height (h a ) and radially inside a height (h i ), where the height (h a ) greater than the height (h i ) is. [8] Assembly (1) according to one of the preceding claims, characterized by that the high-pressure seal comprises a sealing ring and a support ring or is realized by a metallic seal. [9] Compressed gas container with an assembly (1) according to one of the preceding claims.

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