Self-sealing valve connection for pressure vessel

Abstract

A pressure vessel 1 comprises an inner vessel 2 with an inner and outer side (2i, 2a) made of an inner vessel material that is at least partially plastically deformable under pressure to provide a storage volume SV in the pressure vessel, an outer layer 3 applied to the inner vessel to reinforce it, and a valve connection piece 4 arranged on the inner vessel with a hollow sealing insert 41 and outer piece 42 for receiving a valve and for sealing the storage volume from the inner vessel, which comprises a cylindrical bulge 23 with a cylinder axis ZA that projects from the outside and is open towards the storage volume.wherein the hollow sealing insert is positioned on an inner side 23i of the bulge and the outer piece is positioned on an outer side 23a of the bulge and has, on its side facing the bulge, a suitably shaped groove 421 with a first edge 421a facing the storage volume and a second edge 421b in the opposite direction for receiving a sealing ring 6, wherein the groove and the sealing ring are dimensioned and the inner container material is provided to form, under a mechanically built-up pressure due to its plastic deformability, first and second sealing beads (24a, 24b) projecting into at least both gaps (L1, L2) between the sealing ring and the first and second edges.

Description

Field of the invention

[0001] The invention relates to a pressure vessel with a self-sealing valve connection piece and a method for producing such a pressure vessel. Background of the invention

[0002] The market for pressure vessels reinforced with fiber composite materials is growing continuously. The increasing production of natural gas and fracking gas necessitates storage in pressure vessels, especially in countries without a corresponding pipeline network. In addition, the automotive sector is working hard on the development of fuel cell vehicles, in which the fuel is to be stored in the form of gaseous hydrogen under high pressure in pressure vessels. Lightweight pressure vessels are desired for transporting pressure vessels, as transporting heavy pressure vessels consumes unnecessary amounts of energy and therefore results in excessively high transport costs.

[0003] Pressure vessels, with a high-pressure gas stored in the pressure vessel, must reliably seal in accordance with the standard and / or customer requirements over a wide temperature range and over a long period of time under alternating load conditions (emptying the pressure vessel, refilling the pressure vessel, etc.). State-of-the-art pressure vessels attempt to achieve gas tightness using O-ring seals. There is no redundancy for the sealing point, and this can easily lead to seal failure if the seating and fit conditions of the O-ring change relative to the other components.

[0004] German patent application DE 10 2009 008 051 A1 discloses a sealing arrangement comprising a carrier element, a first seal, a second seal spaced from the first seal, and a third seal, wherein the first seal counteracts leakage of fluid when an interior of an object to be sealed is exposed to temperatures below a predetermined temperature and / or pressures below a predetermined pressure, and the second seal and the third seal counteract leakage of fluid when the interior of the object to be sealed is exposed to temperatures above the predetermined temperature and / or pressures above the predetermined pressure. Summary of the invention

[0005] It is desirable to have a valve connection for pressure vessels that is self-sealing and ensures a permanent and reliable seal between the valve connection and the inner vessel. In particular, the object of the invention is to improve the state of the art or to provide an alternative to it.

[0006] CI 1 This object is achieved in a first aspect by a pressure vessel comprising an inner container with an inside and outside made of an inner container material which is at least partially plastically deformable under pressure for providing a storage volume in the pressure vessel, an outer layer applied to the inner container for its reinforcement, and a valve connection piece arranged on the inner container with a hollow sealing insert and outer piece for receiving a valve and for sealing the storage volume against the inner container, which comprises a cylindrical bulge with a cylinder axis which projects from the outside towards the storage volume and is open on the inside, for connecting the valve connection piece,wherein the hollow sealing insert is positioned on an inner side of the bulge and the outer piece is positioned on an outer side of the bulge and has, on its side facing the bulge, a suitably shaped groove with a first edge facing the storage volume and a second edge in the opposite direction for receiving a sealing ring, wherein the groove and the sealing ring are dimensioned and the inner container material is provided to form, under mechanically generated pressure due to its plastic deformability, first and second sealing beads projecting into at least both gaps between the sealing ring and the first and second edges.

[0007] The following terminology should be explained: It should be expressly pointed out that, within the scope of this patent application, indefinite articles and indefinite numerical expressions such as "ein...", "zwei...", etc., are generally to be understood as "at least one...", "at least two...", etc., unless the context or the specific text of a particular passage indicates that only "exactly one...", "exactly two...", etc., are intended. Furthermore, all numerical expressions as well as information regarding process parameters and / or device parameters are to be understood in the technical sense, i.e., subject to the usual tolerances. Even the explicit specification of the restriction "at least" or "at least" or similar does not imply that the simple use of "ein," i.e., without specifying "at least" or similar, means "exactly one."

[0008] The term "hollow sealing insert" in this document refers to a sealing insert that has a continuous opening along its longitudinal axis. When used in a valve connector of a pressure vessel, such a hollow sealing insert seals the internal or storage volume of the pressure vessel against a valve, which, arranged in the valve connector, provides a closable connection to the outside world. The continuous opening allows the pressure vessel to be filled or removed via the valve.

[0009] The inner container can be manufactured in one piece or in multiple parts. The inner container can comprise only two pole caps, with one or both of the pole caps optionally comprising a cylindrical edge region. In this case, if the inner container is manufactured in multiple parts, the edges of the pole caps are placed directly against one another and suitably connected. Alternatively, in addition to the pole caps, the inner container can also comprise a cylindrical central part, which is preferably made of the same material as the pole caps.A cylinder axis of the inner container or pressure vessel corresponds to the axis of symmetry of the cylindrical section of the inner container (if present) or, in the case of only two polar caps forming the inner container, to the axis between the centers or central points of the respective polar caps, which also correspond to the highest elevations of the respective domes formed by the polar caps.

[0010] The plastically deformable inner container material has the property of being inherently solid and stable, yet possessing a certain degree of fluidity, so that it can plastically deform, at least on its surface, under high pressure and thus adapt to the contours of the pressing surfaces without causing large-scale deformation. The inner container also has the function of providing a gas-tight storage volume for the storage of filling gas in the pressure vessel, so the inner container material should be gas-tight, for example metal or plastic, preferably PA or PE in the case of plastic, as a single layer or as a multi-layer system. The filling gas can be any gas, for example hydrogen. The outer layer gives the pressure vessel mechanical stability, so that the functionality of gas impermeability and pressure resistance is divided between the two components, the inner container and the outer layer.The outer layer can, for example, be a fiber composite layer that has been wrapped around the inner container or applied using other techniques.

[0011] The sealing ring positioned in the groove does not completely fill the groove in the outer piece, but leaves gaps in the groove on either side facing the inside of the outer piece, a first and a second gap, which are used to provide redundancy in the sealing effect. The design of the components of the valve connector and the bulge (or projection) of the inner container, in conjunction with the suitable flowability of the inner container material and the resulting formation of the sealing beads, ensure that an improved sealing effect is guaranteed for the pressure vessel while simultaneously ensuring the positional stability of the components of the valve connector in the pressure vessel. In addition, the sealing ring remains permanently stable in the groove during pressure changes thanks to the two sealing beads.This sealing concept represents triple redundancy for sealing the storage volume. Sealing of (i) the first sealing bead of the bulge against the outer piece, (ii) the sealing insert over the bulge onto the sealing ring, and (iii) the second sealing bead of the bulge against the outer piece provides a triple seal in series, thus greatly improving the reliability and durability of the seal. The formation of the sealing beads due to the sealing pressure exerted by the valve connector makes the valve connector additionally self-sealing. The sealing concept is independent of the material of the two-part sealing insert and the connector, although the materials for the two-part sealing insert and connector have at least slightly lower flowability than the inner container material.

[0012] The pressure vessel according to the invention thus represents a pressure vessel with a valve connection which is self-sealing and ensures a permanent and reliable seal of the valve connection against the inner vessel.

[0013] Cl 2 In one embodiment, the hollow sealing insert is constructed in several parts and comprises a hollow outer sleeve with an inner side and a hollow inner clamping piece with an inner side and an outer side, wherein the outer sleeve is positioned from the outside on the inside of the bulge and the hollow inner clamping piece is positioned from the inside in the inside of the outer sleeve such that the inner clamping piece is brought into a press fit with the outer sleeve, wherein the outer sleeve can be mechanically expanded by the inner clamping piece.

[0014] The fit of the hollow inner clamping piece in the curvature of the sleeve prevents the hollow inner clamping piece from slipping relative to the sleeve. The specified outer and inner diameters of the sleeve and the hollow inner clamping piece relative to each other and to the curvature of the pole cap make it possible to apply this sealing concept to one-piece inner containers. Of course, multi-piece inner containers can also be reliably sealed with this sealing concept. In the case of a one-piece inner container, before sliding on the sleeve, the hollow inner clamping piece is first held with the aid of a positioning aid, for example a rod with an expandable end below the hollow inner clamping piece in the storage volume or with a thread in the hollow inner clamping piece. The sleeve is then inserted into the curvature from the outside.The hollow inner clamping piece is then pulled into the sleeve from the inside using the positioning aid, whereby the sleeve and bulge are slightly stretched so that the inside of the sleeve and the outside of the hollow inner clamping piece are brought into a press fit. In the case of multi-part inner containers, a positioning aid is not necessary, as the bulge is freely accessible from the inside and the hollow inner clamping piece can therefore simply be pushed into the sleeve from there. Locally bulged or locally incurved refers to bulges or incursions that could extend over the entire inside of the sleeve or outside of the hollow inner clamping piece, but also to local bulges or incursions of parts of the relevant sides. The outer piece, sleeve and hollow inner clamping piece can be made from any suitable material, for example metal or plastic.

[0015] The specified pressure vessel is designed with a highly flexible construction thanks to the inventive sealing concept, allowing for easy adaptation to customer-specific valve connectors by appropriately shaping the bulge and the two-part sealing insert. Furthermore, the integration of an additional sleeve for integrating sensors, measuring probes, or other components extending into the pressure vessel is still possible.

[0016] CI 3 In one embodiment, the hollow-shaped inner clamping piece has an insertion bevel on one end face, so that it can be inserted into the valve connecting piece through the opening formed in the bulge and into the hollow-shaped outer sleeve via the insertion bevel in interaction with the hollow-shaped outer sleeve.

[0017] The insertion bevel makes it particularly easy to insert the hollow inner clamping piece into the hollow outer sleeve.

[0018] CI 4 In a further embodiment, the outer side of the hollow inner clamping piece has a structured surface. In this document, the term "surface" is understood not only to refer to a closed surface. Rather, the term "surface" in this document is also intended to encompass a virtual surface, such as that formed by the windings of a spiral spring or similar.

[0019] Due to its structured outer surface, the hollow inner clamping piece is secured against slipping during operation.

[0020] CI 5 In a further embodiment, the hollow inner clamping piece comprises a spiral spring. The spiral spring can be a mass-produced standard part, thereby minimizing the manufacturing costs of the pressure vessel.

[0021] CI 6 In an alternative embodiment, the outer surface of the hollow inner clamping piece has a spiral or annular groove, wherein the groove has an edge in the direction opposite to the insertion direction. The hollow inner clamping piece can also be engaged with the sleeve of the sealing insert via the edge.

[0022] CI 7 In a further embodiment, the hollow inner clamping piece comprises a hollow spacer and an expansion element, wherein the hollow spacer can be mechanically plastically, i.e. permanently, expanded by the action of the expansion element. The expansion element allows the mechanical pressure to be applied easily and precisely.

[0023] CI 8 In a further embodiment, the expansion element is designed as a sleeve-shaped wedge element, wherein the sleeve-shaped wedge element has a diameter that increases counter to the insertion direction.

[0024] CI 9 In an alternative embodiment, the expansion element is designed as a conical shaft, wherein the hollow spacer element is designed as a sleeve with a first and a second end, wherein the sleeve has an internal thread at the first end and an axial slot at the second end. By screwing a screw into the internal thread, the slotted area at the second end can be expanded in diameter, whereby the mechanical pressure can be built up.

[0025] These two alternatives represent reliable and easy-to-manufacture designs of the expansion element.

[0026] Cl 10 In a further embodiment, the hollow sealing insert is constructed in one piece and has a hollow outer sleeve, wherein the inner side of the outer piece is deformed by heat and / or a chemical reaction in a region where it is in contact with the outer sleeve in the assembled state. This deformation allows the pressure to be built up mechanically.

[0027] CI 11 In a further embodiment, the inner side of the outer piece has a diameter that can be varied along the cylinder axis. The variable diameter can be used, for example, to define a stop for the hollow sealing insert.

[0028] CI 12 In another embodiment, the inner container is manufactured as a single piece. As already mentioned, the described sealing concept is particularly suitable for use with a single-piece inner container.

[0029] CI 13 In a further embodiment, the hollow sealing insert is dimensioned such that the inner container material, due to its plastic deformability, forms a third bead around the hollow sealing insert on its underside facing the storage volume. This also prevents the sleeve from slipping toward the storage volume. This maintains the pressure on the sealing ring as originally set. Furthermore, the sleeve and the hollow inner clamping piece anchored to it according to the invention cannot slip or even fall into the storage volume, for example, if the pressure vessel is subjected to vibrations.

[0030] CI 14 In a further embodiment, the hollow sealing insert or the outer piece is shaped such that an open gas connection to the storage volume exists between the storage volume and the upper side of the bulge. Thus, the internal pressure in the storage volume is also present at the top of the bulge of the inner container. The gas connection can be established, for example, by suitable channels, recesses, or grooves in the sleeve and / or the hollow inner clamping piece.

[0031] CI 15 In a further embodiment, the groove has a contour that is adapted to the shape of the sealing ring in the unloaded state. This prevents undefined cavities from forming behind the sealing ring, thus further improving the sealing effect of the sealing ring. The sealing ring can be an O-ring, for example. O-rings offer reliable sealing properties and, on the other hand, suitable contours for O-rings can be most easily reproduced in the groove. The curvature of the groove is adapted to the curvature of the surface of the O-ring. The sealing ring or O-ring can be made of any material suitable for the medium to be sealed in the respective application, for example a gas, in particular gaseous hydrogen.

[0032] CI 16 In a further embodiment, the inner container material, at least for the bulge, is a PA, PE or a multi-layer material, wherein at least one layer comprises a PA or PE material. These materials offer suitable properties for producing the inner container and additionally provide suitable flowability of the material for forming the sealing beads, thereby ensuring the additional sealing effect with simultaneous positional security of the components of the connecting piece in the pressure vessel. The inner container can also be made entirely from these materials. The above materials can also be easily welded together in order to produce an inner container for providing the storage volume from the components, pole caps and optionally the central part.

[0033] CI 17 In a further embodiment, the valve connector comprises an additional securing element that connects the hollow sealing insert and the outer piece. This prevents slippage of the hollow sealing insert, i.e., the sleeve and the hollow inner clamping piece, relative to the outer piece, in particular in the direction of the outer piece.

[0034] Cl 18 In a further embodiment, the securing element is mounted in the outer piece and comprises, at least on its side facing the hollow sealing insert, a thread intended for self-tapping engagement in the hollow sealing insert. The securing element can, for example, be a hollow screw or a correspondingly shaped ring with through-openings for applying pressure to the upper side of the bulge of the inner container.

[0035] CI19 In a second aspect, the invention relates to a method for producing a pressure vessel according to the invention comprising an inner container with an inner and outer side made of an inner container material which is at least partially plastically deformable under pressure and designed to receive a valve, an outer layer positioned on the inner container and a valve connection piece with a hollow sealing insert and an outer piece, which comprises the following steps: Providing the inner container with a storage volume and a cylindrical, open bulge protruding from the outside of the inner container; positioning the hollow inner clamping piece by means of a positioning aid through the bulge in the storage volume of the inner container;Inserting the hollow sleeve of the sealing insert from the outside into a snug fit on the inside of the bulge, placing the outer piece on the outside of the bulge, the outer piece having a suitably shaped groove on its side facing the bulge with a first edge facing the later storage volume and a second edge in the opposite direction, and a sealing ring positioned in the groove. Positioning the hollow inner clamping piece with the aid of the positioning aid from the inside in the hollow outer sleeve, the outside of the inner clamping piece engaging in the inside of the hollow outer sleeve to form a press fit with the hollow inner sleeve; producing the outer layer on the inner container to reinforce the pressure container; and placing the valve in the valve connection piece to close the pressure container. ;

[0036] After positioning the hollow inner clamping piece with the aid of the positioning aid 7 from the inside in the hollow outer sleeve, at least first and second sealing beads can be formed, which, under pressure with an appropriately dimensioned groove and sealing ring, protrude into both gaps between the sealing ring and the first and second edges to seal the storage volume against the subsequent inner container due to the plastic deformability of the inner container material. If necessary, a third bead can also be formed around the sleeve on its underside facing the storage volume SV due to the plastic deformability of the inner container material.

[0037] The method according to the invention thus provides a pressure vessel with a valve connection which is self-sealing and ensures a permanent and reliable seal of the valve connection against the inner vessel.

[0038] CI 20 In one embodiment of the method, the outer layer consists of fiber composite material and is wound onto the inner container during the manufacturing step. Since the inner container itself represents the winding mandrel for the outer layer, the outer layer is manufactured to fit the respective inner container precisely.

[0039] CI 21 In a further embodiment of the method, the inner container is manufactured in one piece, for example, as a blow-molded part or by means of an injection molding process. This one-piece production avoids additional process steps such as joining the pole caps and, if necessary, a center section. Furthermore, this one-piece production avoids joining defects at the transition from the pole cap to the center section, which could potentially cause gas leaks. The one-piece design also makes the inner container mechanically more robust than a joined inner container.

[0040] The embodiments described above can be implemented in all possible combinations within the scope of the present invention. Short description of the illustrations

[0041] These and other aspects of the invention are shown in detail in the figures as follows. Fig. 1: an embodiment of the pressure vessel according to the invention in lateral section; Fig. 2: a schematic enlarged detail of the valve connection piece and bulge of the inner container with an embodiment of the hollow sealing insert, i.e. the sleeve and the hollow inner clamping piece; Fig. 3: enlarged detail A from Fig. 2Fig. 4: a schematic enlarged detail of the valve connection piece and bulge of the inner container with a further embodiment of the hollow sealing insert, i.e. the sleeve, the hollow inner clamping piece, and a spreading element; Fig. 5: a schematic enlarged detail of the valve connection piece and bulge of the inner container with a further embodiment of the hollow sealing insert, i.e. the sleeve and the hollow inner clamping piece; Fig. 6: a schematic enlarged detail of the valve connection piece and bulge of the inner container with a further embodiment of the hollow sealing insert with a deformed outer piece. Fig. 7: an embodiment of the method according to the invention for producing the pressure vessel according to the invention. Detailed description of the implementation examples

[0042] Fig.1shows an embodiment of the pressure vessel 1 according to the invention in lateral section, comprising a one-piece inner vessel 2 with an inside and outside 2i, 2a made of an inner vessel material that is at least partially plastically deformable under pressure, with a cylindrical middle part 21 with a cylinder axis ZA and with two pole caps 22 closing off the cylindrical middle part 21 to provide a storage volume SV in the pressure vessel. For reasons of clarity, the pressure vessel 1 is only shown in half. The opposite pole cap 22, not shown here, for closing the middle part 21 on the other side may not comprise a bulge 23, but instead a continuous closed contour, or may correspond to the pole cap 22 shown with its own closable opening or a corresponding valve connection piece.The inner container 2 can, of course, also be made without the cylindrical central part 21 shown here, consisting of only the two pole caps 22. For such an inner container, all embodiments of the invention as shown in the . Figures 1 - 5shown equally. The inner container material can be any plastically deformable material. Preferably, the inner container material is a PA, PE or a multi-layer material made of these materials, at least for the bulge 23. An outer layer 3 is applied to the inner container 2 for its reinforcement. So that the pressure vessel can be filled with filling gas and this can be released again from the storage volume SV at a later time, a valve connection piece 4 with a hollow sealing insert 41 and outer piece 42 with a sealing ring 6 is arranged on the pole cap 22 for receiving a valve 5 and for sealing the storage volume SV from the inner container 2. For this purpose, the inner container 2 protrudes cylindrically as a bulge 23 from the outer side 2a of the pole cap 22, which provides a connection that is open on the inside towards the storage volume SV. This connection is then closed by the valve 5 and opened again when required.The outer piece 42 of the valve connector 4 can comprise connecting means for pressure-stable reception of the valve 5. For details on the outer piece 42, hollow sealing insert 41, bulge 23 and the resulting sealing beads 24a, 24b and bead 24c, please refer to . Figures 2 to 5 referred to.

[0043] Fig.2 shows an enlarged detail of the valve connection piece 4 of the Fig. 1illustrated pressure vessel 1 with two-part hollow sealing insert 41, outer piece 42 and bulge 23 of the pole cap 22 of the inner vessel 2 along the cylinder axis ZA. The two-part hollow sealing insert 41 with sleeve 411 and hollow inner clamping piece 412 is positioned on the inner side 23i of the bulge 23 and the outer piece 42 on the outer side 23a of the bulge 23, so that by inserting the hollow inner clamping piece 412 in the direction of the storage volume SV under the sleeve 411, a mechanical pressure can be built up between the hollow sealing insert 41, bulge 23 and outer piece 42. The outer piece 42 has, on its side 42i directed towards the bulge 23, a groove 421 with a first edge 421a facing the storage volume SV and a second edge 421b in the opposite direction in order to receive the sealing ring 6 and hold it in position when the outer piece 42 is pushed onto the bulge 23.

[0044] Fig. 3 shows the enlarged section A from Figure 2 . The groove 421 and the sealing ring 6, for example an O-ring, are dimensioned such that gaps L1, L2 exist between the sealing ring 6 and the first and second edges 421a, 421b, into which gaps the plastically deformable inner container material can penetrate in order to form, according to the invention, the first and second sealing beads 24a, 24b which project into the gaps L1 and L2.

[0045] Fig.4shows a schematic representation of the sealing concept according to the invention with outer piece 42, bulge 23 of the pole cap 22 of the inner container 2, and a hollow, two-part sealing insert. The outer side 412a of the hollow inner clamping piece 412 has a structured surface in this embodiment. The term "surface" in this document refers not only to a closed surface, but also to a virtual surface. For example, the hollow inner clamping piece 412 can also be formed by a spiral spring, the coils of which form the outer side 412a, which represents the structured surface.

[0046] Fig. 5shows a schematic enlarged detail of the valve connection piece 4 and bulge 23 of the inner container 2 with a further embodiment of the hollow sealing insert 41, which in this embodiment has a sleeve 411, a hollow spacer 412d, and an expansion element 412s. By inserting the expansion element 412s in the direction of the arrow under the hollow inner clamping piece 412, the latter is spread radially against the sleeve, i.e., expanded, as indicated by the arrow, and thus exerts mechanical pressure between the hollow sealing insert 41, bulge 23, and outer piece 42.

[0047] Fig.6: shows a schematic enlarged detail of another embodiment of the valve connection piece 4 and bulge 23 of the inner container 2. The inner side 42i of the outer piece 42 is shaped in the area in which it is in contact with the outer sleeve 411 in the assembled state, such that the smallest distance between the sleeve 411 and the inner side 421 is established there. The diameter of the sleeve 411 is smaller before assembly and is enlarged after assembly in order to apply the required compression. This increase in diameter can occur, for example, through thermal shrinkage before insertion, plastic deformation during insertion, or chemical modification of the material of the sleeve 411.

[0048] Fig.7shows an embodiment of the method 100 according to the invention for producing the pressure vessel 1 according to the invention, comprising an inner container 2 with an inner and outer side 2i, 2a made of an inner container material that is at least partially plastically deformable under pressure and designed to receive a valve 5, an outer layer 3 positioned on the inner container 2 and a valve connection piece 4 with a hollow sealing insert 41 made of a hollow outer sleeve 411 and a hollow inner clamping cone 412 as well as an outer piece 42, comprising the subsequent steps of providing 110 the inner container 2 with a storage volume SV and an internally open bulge 23 projecting cylindrically from the outside of the inner container 2;positioning 120 the hollow inner clamping piece 412 with a largest outer diameter smaller than an inner diameter of the bulge 23 and a largest outer diameter greater than the smallest inner diameter of the sleeve 411 in the direction of the bulge 23 by means of a positioning aid through the bulge 23 in the storage volume SV of the inner container 2; inserting 130 the hollow sleeve 411 of the sealing insert 41 from the outside into a snug fit on the inner side 23i of the bulge 23, wherein the sleeve 411 comprises a smallest inner diameter and an outer diameter adapted to the bulge 23, while the positioning aid and the hollow inner clamping piece 412 are not affected thereby;placing 140 the outer piece 42 onto the outer side 23a of the bulge 23, wherein the outer piece 42 has, on its side 42i oriented toward the bulge 23, a suitably shaped groove 421 with a first edge 421a facing the future storage volume SV and a second edge 421b in the opposite direction, and a sealing ring 6 positioned in the groove 421; positioning 150 the hollow inner clamping piece 412 with the aid of the positioning aid from the inside into the sleeve 411, wherein the outer side 412a of the hollow inner clamping piece 412 engages the inside of the sleeve 411 to form a press fit with the sleeve 411, so that pressure is generated between the two-part sealing insert 41, the bulge 23, and the outer piece 42;the formation 160 of at least first and second sealing beads 24a, 24b, which, under pressure with a correspondingly dimensioned groove 421 and sealing ring 6, protrude into both gaps L1, L2 between the sealing ring 6 and the first and second edges 421a, 421b to seal the storage volume against the subsequent inner container 2 due to the plastic deformability of the inner container material; optionally the formation 190 of a third bead around the sleeve 411 on its underside facing the storage volume SV due to the plastic deformability of the inner container material; the production 170 of the outer layer 3 on the inner container 2 to reinforce the pressure vessel 1;and the placement 180 of the valve 5 into the valve connection piece 4 for closing the pressure vessel 1. The outer layer 3 can be made of fiber composite material and wound onto the inner container 2 during the manufacturing step 160. The insertion 130 of the sleeve 411 up to a stop on the sleeve 411 on an upper side of the bulge 23 and / or the placement 140 of the outer piece 42 up to contact of an inner side 42i of the outer piece 42 on the sleeve 411 and / or on the hollow inner clamping piece 412 can also be carried out here.

[0049] The embodiments shown here are only examples of the present invention and should therefore not be understood as limiting.

[0050] Alternative embodiments contemplated by those skilled in the art are equally within the scope of the present invention. LIST OF REFERENCE SYMBOLS

[0051] 1 Pressure vessel according to the invention 2 Inner container 2i Inside of the inner container 2a Outside of the inner container 21 Middle part of the inner container 22 Pole caps of the inner container 23 Bulge of the inner container 23i Inside of the bulge 23a Outside of the bulge 24a First sealing bead 24b Second sealing bead 3 Outer layer 4 Valve connection piece 41 Hollow sealing insert 411 Sleeve of the sealing insert 412 Hollow inner clamping piece 412a Outside of the hollow inner clamping piece 412d Hollow spacer 412s Expanding element 42 Outer piece 42i Side aligned with the bulge (inside of the outer piece) 421 Groove 421a First edge 421b Second edge 5 Valve 6 Sealing ring 100A Method for producing a pressure vessel according to the invention 110Providing the inner container 120Positioning the clamping cone in the storage volume of the inner container 130Inserting the hollow sleeve into the bulge 140Placing the outer piece from the outside onto the bulge 150Positioning theClamping cone with the help of the positioning aid in the sleeve 160 Formation of at least first and second sealing beads under the sealing pressure 170 Production of the outer layer on the inner container 180 Placement of the valve in the valve connection piece 190 Formation of a third bead L1, L2 Gaps between the first and second edges of the groove and the sealing ring SV Storage volume ZAZylinder axis

Claims

1. A pressure vessel (1) comprising an inner vessel (2) with an inner and outer side (2i, 2a) made of an inner vessel material that is at least partially plastically deformable under pressure to provide a storage volume (SV) in the pressure vessel, an outer layer (3) applied to the inner vessel (2) to reinforce it, and a valve connection piece (4) arranged on the inner vessel with a hollow sealing insert (41) and outer piece (42) for receiving a valve (5) and for sealing the storage volume (SV) from the inner vessel (2), which, for connecting the valve connection piece (4), comprises a cylindrical bulge (23) with a cylinder axis (ZA) that projects from the outer side (2a) of the inner vessel (2) and is open inwardly towards the storage volume (SV).wherein the hollow sealing insert (41) is positioned on an inner side (23i) of the bulge (23) and the outer piece (42) is positioned on an outer side (23a) of the bulge (23) and has, on its side (42i) oriented toward the bulge (23), a suitably shaped groove (421) with a first edge (421a) facing the storage volume (SV) and a second edge (421b) in the opposite direction for receiving a sealing ring (6), wherein the groove (421) and the sealing ring (6) are dimensioned in such a way, and the inner container material is provided to form, under mechanically generated pressure due to its plastic deformability, first and second sealing beads (24a, 24b) projecting into at least both gaps (L1, L2) between the sealing ring (6) and the first and second edges (421a, 421b).

2. Pressure vessel (1) according to claim 1, characterized by thatthe hollow sealing insert (41) is constructed in several parts and comprises a hollow outer sleeve (411) with an inner side (411i) and a hollow inner clamping piece (412) with an inner side (412i) and an outer side (412a), wherein the outer sleeve (411) is positioned from the outside on the inner side (23i) of the bulge (23) and the hollow inner clamping piece (412) is positioned from the inside in the inner side (411i) of the outer sleeve (411) such that the inner clamping piece (412) is brought into a press fit with the outer sleeve (411), wherein the outer sleeve (411) can be mechanically expanded by the inner clamping piece (412).

3. Pressure vessel (1) according to claim 2, characterized by thatthe hollow-shaped inner clamping piece (412) has an insertion bevel on one end face, so that it can be inserted into the valve connecting piece (4) through the opening formed in the bulge (23) of the valve connecting piece (4) via the insertion bevel into the hollow-shaped outer sleeve (411) in interaction with the hollow-shaped outer sleeve (411).

4. Pressure vessel (1) according to claim 2 or 3, characterized by that the outer side of the hollow inner clamping piece (412a) has a structured surface.

5. Pressure vessel (1) according to claim 4, characterized by that the hollow inner clamping piece (412) has a spiral spring.

6. Pressure vessel (1) according to claim 4, characterized by that the outer side of the hollow inner clamping piece (412a) has a spiral or annular groove, the groove having an edge in the direction opposite to the insertion direction.

7. Pressure vessel (1) according to one of claims 2 to 6, characterized by that the hollow-shaped inner clamping piece (412) has a hollow-shaped spacer (412d) and a spreading element (412s), wherein the hollow-shaped spacer (412d) is mechanically plastically expandable by the action of the spreading element (412s).

8. Pressure vessel (1) according to claim 7, characterized by that the expansion element (412s) is designed as a sleeve-shaped wedge element, wherein the sleeve-shaped wedge element has a diameter that increases counter to the insertion direction.

9. Pressure vessel (1) according to claim 7, characterized by that the expansion element (412s) is designed as a conical shaft, wherein the hollow-shaped spacer element (412d) is designed as a sleeve with a first and a second end, wherein it has an internal thread at the first end and the second end has an axial slot.

10. Pressure vessel (1) according to claim 1, characterized by that the hollow sealing insert (41) is constructed in one piece and has a hollow outer sleeve (411), wherein the inner side (42i) of the outer piece (42) is deformed by the influence of heat and / or by a chemical reaction in a region in which it is in contact with the outer sleeve (411) in the assembled state.

11. Pressure vessel (1) according to claim 10, characterized by that the inner side (42i) of the outer piece (42) has a diameter that varies over the cylinder axis (ZA).

12. Pressure vessel (1) according to one of the preceding claims, characterized by that the inner container (2) is made in one piece.

13. Pressure vessel (1) according to one of the preceding claims, characterized by thatthe hollow sealing insert (41) is dimensioned such that the inner container material, due to its plastic deformability, forms a third bead (24c) around the hollow sealing insert (41) on its underside directed towards the storage volume (SV).

14. Pressure vessel (1) according to one of the preceding claims, characterized by that the hollow sealing insert (41) or the outer piece (42) is shaped such that there is an open gas connection (GV) to the storage volume (SV) between the storage volume (SV) and the upper side (23o) of the bulge (23).

15. Pressure vessel (1) according to one of the preceding claims, characterized by that the groove (421) has a contour which is adapted to a shape of the sealing ring (6) in the unloaded state.

16. Pressure vessel (1) according to one of the preceding claims, characterized by thatthe inner container material, at least for the bulge, is a PA, PE or multi-layer material, wherein at least one layer comprises a PA or PE material.

17. Pressure vessel (1) according to one of the preceding claims, characterized by that the valve connection piece (4) comprises an additional securing element (43) which connects the hollow sealing insert (41) and the outer piece (42) to one another.

18. Pressure vessel (1) according to claim 16, characterized by that the securing element (43) is mounted in the outer piece (42) and comprises, at least on its side facing the hollow sealing insert (41), a thread which is provided for self-tapping engagement in the hollow sealing insert (41).

19. A method (100) for producing a pressure vessel (1) according to claim 1, comprising an inner container (2) with an inner and outer side (2i, 2a) made of an inner container material that is at least partially plastically deformable under pressure and designed to accommodate a valve (5), an outer layer (3) positioned on the inner container (2), and a valve connection piece (4) with a hollow sealing insert (41) and an outer piece (42), comprising the following steps: - providing (110) the inner container (2) with a storage volume (SV) and a cylindrical, open bulge (23) projecting from the outer side (2a) of the inner container (2); - positioning (120) the hollow inner clamping piece (412) by means of a positioning aid (7) through the bulge (23) in the storage volume (SV) of the inner container (2);- inserting (130) the hollow sleeve of the sealing insert (41) from the outside into a snug fit on the inside (23i) of the bulge (23), - placing (140) the outer piece (42) on the outside (23a) of the bulge (23), wherein the outer piece (42) has, on its side (42i) aligned with the bulge (23), a suitably shaped groove (421) with a first edge (421a) facing the later storage volume (SV) and a second edge (421b) in the opposite direction, and a sealing ring (6) positioned in the groove (421); - positioning (150) the hollow inner clamping piece (412) with the aid of the positioning aid (7) from the inside in the hollow outer sleeve (411), wherein the outer side (412a) of the inner clamping piece (412) engages the inner side (411i) of the hollow outer sleeve (411) to form a press fit with the hollow inner sleeve (411);- producing (170) the outer layer (3) on the inner container (2) to reinforce the pressure vessel (1); and - placing (180) the valve (5) into the valve connector (4) to close the pressure vessel (1).; 20. The method (100) according to claim 19, wherein the outer layer (3) consists of fiber composite material and is wound onto the inner container (2) during the manufacturing step (170).

21. Method (100) according to one of claims 19 or 20, wherein the inner container (2) is manufactured in one piece.

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