Self-sealing valve connection for pressure vessels

Abstract

A pressure vessel is disclosed having an inner vessel made of an inner-vessel material and an outer layer applied thereon as well as a valve-connection piece with a two-part sealing cone and outer piece, the sealing cone being positioned on an inner face of a protrusion of the inner vessel and the outer piece for generating a sealing pressure being positioned between the two-part sealing cone, the protrusion and the outer piece on an outer face of the protrusion. The outer piece includes a suitably shaped groove having a first and a second edge for receiving a sealing ring that seals under the sealing pressure, wherein the groove and the sealing ring are dimensioned such that, under the sealing pressure and due to the plastic deformability, first and second sealing beads project at least into two gaps between the sealing ring and form the first and second edge.

Claims

1. A pressure vessel comprising an inner vessel that has an inner and an outer face and is made of an inner-vessel material that is at least partially plastically deformable under pressure, for providing a storage volume in the pressure vessel, comprising an outer layer applied on the inner vessel for the reinforcement thereof, and comprising a valve-connection piece arranged on the inner vessel having a two-part hollow sealing cone and outer piece for receiving a valve and for sealing the storage volume from the inner vessel, the inner vessel comprising, for connecting the valve-connection piece, a protrusion that is inwardly open towards the storage volume and projects cylindrically from the outer face of the inner vessel, the sealing cone being positioned on an inner face of the protrusion and the outer piece for generating a sealing pressure between the sealing cone, the protrusion and the outer piece on an outer face of the protrusion, the outer piece comprising, on the face thereof oriented towards the protrusion, a suitably shaped groove having a first edge facing the storage volume and a second edge provided in the opposite direction for receiving a sealing ring that seals under the sealing pressure, the groove and the sealing ring being dimensioned and the inner-vessel material being provided such that, under the sealing pressure and due to the plastic deformability thereof, first and second sealing beads that project at least into two gaps between the sealing ring and the first and second edge are formed, and the two-part sealing cone comprising a hollow outer sleeve having a smallest internal diameter, an external diameter adapted to the protrusion and an inner face that is at least locally concave towards the protrusion, and comprising a hollow inner clamping cone having a largest external diameter that is smaller than an internal diameter of the protrusion and larger than the smallest internal diameter of the sleeve and an outer face that at least locally projects toward the protrusion, wherein the sleeve is positioned on the inner face of the protrusion from outside and the projecting outer face of the clamping cone is positioned from inside with the aid of a positioning aid so as to engage in the concave inner face of the sleeve such that the inner clamping cone is brought in an interference fit with the sleeve.

2. The pressure vessel according to claim 1, characterized in that the inner vessel is produced in one piece.

3. The pressure vessel according to claim 1, characterized in that the sleeve is shaped such that it comprises a stop facing an upper face of the protrusion and/or at least partially rests on an inner face of the outer piece extending at least over the sleeve and the protrusion.

4. The pressure vessel according to claim 1, characterized in that the sleeve is dimensioned such that the inner-vessel material forms, due to its plastic deformability, a third bead around the sleeve on its lower face directed towards the storage volume.

5. The pressure vessel according to claim 1, characterized in that the two-part sealing cone or the outer piece is formed such that there is an open gas connection towards the storage volume between the storage volume and the upper face of the protrusion.

6. The pressure vessel according to claim 5, characterized in that the sleeve comprises an outer face that faces the protrusion, the surface area of the outer face of the sleeve resting on the protrusion and/or the outer face of the clamping cone resting on the sleeve being smaller than their respective inner faces.

7. The pressure vessel according to claim 1, characterized in that the groove has a contour which is adapted to a shape of the sealing ring in the unloaded state.

8. The pressure vessel according to claim 1, characterized in that the inner-vessel material, at least for the protrusion, is a PA material, a PE material or a multi-layered material made of these materials.

9. The pressure vessel according to claim 1, characterized in that the valve-connection piece comprises an additional securing element which interconnects the two-part sealing cone and the outer piece.

10. The pressure vessel according to claim 9, characterized in that the securing element is mounted in the outer piece and comprises a thread, at least on its side facing the two-part sealing cone, which is provided for self-cutting engagement in the sleeve and/or the clamping cone.

11. A method for producing a pressure vessel according to claim 1, comprising an inner vessel that has an inner and an outer face and is made of an inner-vessel material that is at least partially plastically deformable under pressure for receiving a valve, an outer layer positioned on the inner vessel and a valve-connection piece having a two-part sealing cone made up of a hollow outer sleeve and a hollow inner clamping cone, as well as an outer piece, comprising the following steps: providing the inner vessel with a storage volume and a protrusion that is inwardly open and projects cylindrically from the outer face of the inner vessel the clamping cone having a largest external diameter that is smaller than an internal diameter of the protrusion and a largest external diameter that is larger than the smallest internal diameter of the sleeve towards the protrusion by means of a positioning aid through the protrusion, in the storage volume of the inner vessel; inserting the hollow sleeve of the sealing cone from outside into a tight fit on the inner face of the protrusion, the sleeve having a smallest internal diameter and an external diameter adapted to the protrusion, while the positioning aid and the clamping cone are not influenced thereby; fitting the outer piece onto the outer face of the protrusion, the outer piece comprising, on its face oriented towards the protrusion, a suitably shaped groove having a first edge facing the future storage volume and a second edge provided in the opposite direction, and a sealing ring that is positioned in the groove and seals under a sealing pressure; positioning the clamping cone by means of the positioning aid from inside in the sleeve, the outer face of the clamping cone engaging in the inner face of the sleeve to form an interference fit with the sleeve, such that a sealing pressure is produced between the two-part sealing cone, the protrusion and the outer piece; forming at least first and second sealing beads, which, under the sealing pressure and with an accordingly dimensioned groove and sealing ring, project into two gaps between the sealing ring and the first and second edge due to the plastic deformability of the inner-vessel material in order to seal the storage volume with respect to the future inner vessel; producing the outer layer on the inner vessel in order to reinforce the pressure vessel; and fitting the valve into the valve-connection piece in order to close the pressure vessel.

12. The method according to claim 11, comprising the further step of forming a third bead around the sleeve on its lower face directed towards the storage volume due to the plastic deformability of the inner-vessel material.

13. The method according to claim 11, wherein the outer layer consists of fibre composite material and is wound onto the inner vessel in the producing step.

14. The method according to claim 11, wherein the sleeve is inserted onto an upper face of the protrusion up to a stop on the sleeve and/or the outer piece is fitted until contact of an inner face of the outer piece on the sleeve and/or on the clamping cone occurs.

15. The method according to claim 11, wherein the inner vessel is produced in one piece.

Description

SHORT DESCRIPTION OF FIGURES

(1) These and other aspects of the invention are shown in detail in the figures as follows:

(2) FIG. 1: an embodiment of the pressure vessel according to the invention in lateral section;

(3) FIG. 2: the pressure vessel of FIG. 1 shown in an enlarged sectional view of the valve-connection piece and the protrusion of the inner vessel;

(4) FIG. 3: schematic presentation of the sealing concept according to the invention with outer piece, protrusion of the inner vessel, two-part sealing cone and the formed sealing beads;

(5) FIG. 4: an embodiment of the method according to the invention for producing the pressure vessel according to the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(6) FIG. 1 shows an embodiment of the pressure vessel 1 according to the invention in lateral section, comprising a one-part inner vessel 2 that has an inner and an outer face 2i, 2a and is made of an inner-vessel material that is at least partially plastically deformable under pressure, here having a cylindrical central portion 21 with a cylinder axis ZA and two pole caps 22 bordering on the cylindrical central portion 21 for providing a storage volume SV in the pressure vessel. For better comprehensibility, only half of the pressure vessel 1 is shown. The opposite pole cap 22, which is not shown here, for closing the central portion 21 on the other side, may not comprise a protrusion 23 but instead a continuous closed contour or corresponds to the pole cap 22 as shown with its own sealable opening or a corresponding valve-connection piece. Of course, the inner vessel 2 may only consist of the two pole caps 22, without the cylindrical central portion 21 shown here. For such an inner vessel, all embodiments of the invention as shown in FIGS. 1-4 apply analogously. The inner-vessel material can be any plastically deformable material. Preferably, the inner-vessel material is a PA, PE or multi-layered material made of the former, at least for the protrusion 23. An outer layer 3 is applied on the inner vessel 2 for reinforcement. A valve-connection piece 4 with a two-part sealing cone 41 and an 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 with respect to the inner vessel 2 so that the pressure vessel can be filled with gas and so that the latter can at a later time be discharged from the storage volume SV. For this purpose, the inner vessel 2 cylindrically protrudes from the outer face 2a of the pole cap 22 in the form of a protrusion 23, providing a connection which is open at the interior towards the storage volume SV. This connection will then be closed by the valve 5 and reopened, if desired. The outer piece 42 of the valve-connection piece 4 may comprise connecting means for receiving the valve 5 in a pressure-stable manner. For details on the outer piece 42, two-part sealing cone 41, protrusion 23 and the formed sealing beads 24a, 24b, 24c, we refer to FIGS. 2 and 3.

(7) FIG. 2 shows the pressure vessel 1 shown in FIG. 1 in an enlarged sectional view of the valve-connection piece 4 with two-part sealing cone 41, outer piece 42 and protrusion 23 of the pole cap 22 of the inner vessel 2 along the cylinder axis ZA. The two-part sealing cone 41 with sleeve 411 and clamping cone 412 is positioned on the inner face 23i of the protrusion 23 and the outer piece 42 on the outer face 23a of the protrusion 23 for generating a sealing pressure AD between the sealing cone 41, the protrusion 23 and the outer piece 42. The outer piece 42 comprises, on its face 42i oriented towards the protrusion 23, a groove 421 having a first edge 421a facing the storage volume SV and a second edge 421b provided in the opposite direction, so as to receive the sealing ring 6 sealing under the sealing pressure AD and keep it in position when the outer piece 42 is slid onto the protrusion 23. The groove 421 and the sealing ring 6, e. g. an O ring, are dimensioned such that gaps L1, L2 (see FIG. 3) exist between the sealing ring 6 and the first and second edges 421a, 421b, in which gaps the plastically deformable inner-vessel material can enter so as to form, according to the invention, the first and second sealing beads 24a, 24b (plus the sealing bead 24c, if desired, along the lower face 411u of the sleeve 411), which protrude into these gaps L1 and L2. Furthermore, the two-part sealing cone 41 or the outer piece 42 is formed such that between the storage volume SV and the upper face 230 of the protrusion 23 (the face oriented in the direction of the outer face of the pressure vessel 1) as well as through the sleeve 411 (gas passage GV indicated by dashed line) and the upper face of the clamping cone 412, there is an open gas connection GV towards the storage volume SV. Since the sleeve 411 comprises an outer face 411a oriented towards the protrusion 23 and an opposite inner face 411i, the surface area of the outer face 411a of the sleeve 411, which rests on the protrusion 23, being smaller than its inner face 411i, the interior pressure inside the storage volume SV of the pressure vessel 1 causes the sleeve 411 to be additionally pressed, due to the area ratios, in the direction of the protrusion 23 and thus against the inner face 42i of the outer piece 42. The same applies to the clamping cone 412 which has the same area ratios of outer face 412a and inner face 412i. The groove 421 can have a contour which is adapted to a shape of the sealing ring 6 in the unloaded state (see FIG. 3). The outer layer 3 is applied on the outer face 2a of the inner vessel 2 whereas its inner face 2i defines the storage volume SV. The hollow outer sleeve 411 has a smallest interior diameter DI-411, an exterior diameter DA-411 which is adapted to the diameter of the protrusion D-23 and an accordingly adapted contour which extends beyond the protrusion 23 outwards in the area above the upper face 230 of the protrusion 23 so that the sleeve 411 cannot be slid too far in the direction of the storage volume SV. The inner face 411i of the sleeve 411 is here at least locally concave in the direction of the protrusion 23. This concavity, however, can also be produced by the pressure exerted by the clamping cone. The hollow inner clamping cone 412 has a largest external diameter D-412 that is smaller than an internal diameter D-23 of the protrusion 23 and larger than the smallest internal diameter D-411 of the sleeve 411 and an outer face 412a arranged in the direction of the protrusion 23, the outer face 412a of the clamping cone 412 engaging from the inside with the aid of a positioning aid 7 such that the inner clamping cone 412 is brought into an interference fit with the sleeve 411 and therefore exerts the desired sealing pressure AD against the protrusion 23 and the outer piece 42. FIG. 3 is a schematic view of the sealing concept according to the invention with outer piece 42, protrusion 23 of the pole cap 22 of the inner vessel 2, two-part sealing cone 41 and the formed sealing beads 24a, 24b, 24c. In FIG. 3a, the clamping cone is slid through the protrusion 23 into the storage volume SV of the inner vessel 2 with the aid of a positioning aid 7 and is retained there since its exterior diameter D-412 is smaller than the inner diameter D-23 of the protrusion 23. After this, the sleeve 411 is slid onto the inner face 23i of the protrusion 23 from the outside to form a snug fit, whereas the positioning aid 7 and the clamping cone 412 are not influenced by this (see FIG. 3b). Subsequently, the outer piece 42 is fitted onto the outer face 23a of the protrusion 23, the outer piece 42 comprising, on its face 42i oriented towards the protrusion 23, a suitably shaped groove 421 having a first edge 421a facing the future storage volume SV and a second edge 421b provided in the opposite direction, and a sealing ring 6 that is positioned in the groove 421 and seals under a sealing pressure AD (see FIG. 3c). This does not affect the positioning aid 7 and the clamping cone 412, either. At this point, no sealing beads 24a, 24b, 24c are formed yet, either, since the sealing pressure AD necessary for this is only produced after the clamping cone 412 has been positioned inside the sleeve 411 and thus also in the protrusion 23. After this, the clamping cone 412 is drawn from the inside into the sleeve 411 by means of the positioning aid 7, the outer face 412a of the clamping cone 412 engaging in the inner face 411i of the sleeve 411 to form an anchored interference fit between the two components, creating a sealing pressure AD between two-part sealing cone 41, protrusion 23 and outer piece 42, which pressure leads to formation of the sealing beads 24a, 24b, 24c (see FIG. 3d). The curvature of the inner face 411i of the sleeve 411 beneath the clamping cone 412 prevents a displacement of the clamping cone 412 in the direction of the storage volume SV. The first and the second sealing bead 24a, 24b, together with the conventional seal (O ring to protrusion), form a triple redundancy of sealing of the storage volume SV with respect to the outer face of the pressure vessel 1. In addition, the sleeve 411 and the clamping cone 412 are here dimensioned such that the inner-vessel material additionally forms, due to its plastic deformability, a third bead 24c on the lower face 411u of the sleeve 411, which is directed towards the storage volume SV. This third bead 24c supports the triple redundancy of sealing by retaining the sleeve 411 and thus the entire sealing cone 41 in position, preventing them from sliding or even falling into the inner vessel. Then the positioning aid 7 can be removed from the pressure vessel 1, for instance by folding the strutted lower part of the positioning aid 7, which retains and guides the clamping cone 412, in the direction of the cylinder axis ZA parallel to the cylinder axis ZA by means of a respective mechanism or, in case of a threaded bar, is unscrewed from the respective thread on the inner face of the clamping cone 412. The positioning aid 7 which has thus been made narrower, or which can be unscrewed, can easily be drawn out through the remaining inner opening of the clamping cone 412.

(8) FIG. 4 shows an embodiment of the method 100 according to the invention for producing the pressure vessel 1 according to the invention, comprising an inner vessel 2 that has an inner and an outer face 2i, 2a and is made of an inner-vessel material that is at least partially plastically deformable under pressure and is designed to receive a valve 5, an outer layer 3 positioned on the inner vessel 2 and a valve-connection piece 4 comprising a two-part sealing cone 41 made up of a hollow outer sleeve 411 and a hollow inner clamping cone 412 as well as an outer piece 42, comprising the following steps: providing 110 the inner vessel 2 with a storage volume SV and an inner, open protrusion 23 that projects cylindrically from the outer face 2a of the inner vessel 2; positioning 120 the clamping cone 412 having a largest external diameter D-412 that is smaller than an internal diameter D-23 of the protrusion 23 and a largest external diameter D-412 that is larger than the smallest internal diameter D-411 of the sleeve 411 towards the protrusion 23 by means of a positioning aid 7, through the protrusion 23, in the storage volume SV of the inner vessel 2; inserting 130 the hollow sleeve of the sealing cone 41 from outside into a tight fit on the inner face 23i of the protrusion 23, the sleeve 411 having a smallest internal diameter D-411 and an external diameter 411a adapted to the protrusion 23, while the positioning aid 7 and the clamping cone 412 are not influenced thereby; fitting 140 the outer piece 42 onto the outer face 23a of the protrusion 23, the outer piece 42 comprising, on its face 42i oriented towards the protrusion 23, a suitably shaped groove 421 having a first edge 421a facing the future storage volume SV and a second edge 421b provided in the opposite direction, and a sealing ring 6 that is positioned in the groove 421 and seals under a sealing pressure AD; positioning 150 the clamping cone 412 by means of the positioning aid 7 from inside in the sleeve 411, the outer face of the clamping cone engaging in the inner face of the sleeve to form an interference fit with the sleeve 411, such that a sealing pressure AD is produced between the two-part sealing cone 41, the protrusion 23 and the outer piece 42; forming 160 at least first and second sealing beads 24a, 24b, which, under the sealing pressure AD and with an accordingly dimensioned groove 421 and sealing ring 6, project into two gaps L1, L2 between the sealing ring 6 and the first and second edge 421a, 421b due to the plastic deformability of the inner-vessel material in order to seal the storage volume from the future inner vessel 2; if desired, forming 190 a third bead 24c around the sleeve 411 on its lower face 41u oriented toward the storage volume SV, due to plastic deformability of the inner-vessel material; producing 170 the outer layer 3 on the inner vessel 2 in order to reinforce the pressure vessel 1; and fitting 180 the valve 5 into the valve-connection piece 4 in order to close the pressure vessel 1. The outer layer 3 may consist of fibre composite material and can be wound onto the inner vessel 2 in the producing step. Here, insertion 130 of the sleeve 411 onto an upper face 230 of the protrusion 23 up to a stop 4111 on the sleeve 411 and/or fitting 140 of the outer piece 42 to the sleeve 411 and/or to the clamping cone 412 until it comes in contact with an inner face 42i of the outer piece 42 can be performed as well. In addition, the inner vessel 2 can be made in one piece.

(9) The embodiments shown here are only examples of the present invention and are therefore not to be intended as limiting. Alternative embodiments considered by the person skilled in the art are equally comprised by the scope of the present invention.

LIST OF REFERENCE NUMERALS

(10) 1 pressure vessel according to the invention 2 inner vessel 2i inner face of inner vessel 2a outer face of inner vessel 21 central portion of inner vessel 22 pole caps of inner vessel 23 protrusion of inner vessel 23i inner face of the protrusion 23a outer face of the protrusion 23o upper face of the protrusion 24a first sealing bead 24b second sealing bead 24c third bead 3 outer layer 4 valve-connection piece 41 two-part sealing cone 411 sleeve of sealing cone 411a outer face of sleeve 411i concave inner face of sleeve 411u lower face of sleeve 4111 stop of sleeve on protrusion 412 clamping cone of sealing cone 412a protruding outer face of clamping cone 412i inner face of clamping cone 42 outer piece 42i face oriented towards protrusion (inner face of outer piece) 421 groove 421a first edge 421b second edge 43 securing element 5 valve 6 sealing ring 7 positioning aid 100 a method of producing a pressure vessel according to the invention 110 providing the inner vessel 120 positioning the clamping cone in the storage volume of the inner vessel 130 inserting the hollow sleeve in the protrusion 140 fitting the outer piece onto the protrusion from the outside 150 positioning the clamping cone by means of the positioning aid in the sleeve 160 forming at least first and second sealing beads under the sealing pressure 170 producing the outer layer on the inner vessel 180 fitting the valve into the valve-connection piece 190 forming of third bead AD sealing pressure D-23 interior diameter of protrusion DA-411 exterior diameter of sleeve of the sealing cone DI-411 smallest interior diameter of sleeve of the sealing cone D-412 largest exterior diameter of clamping cone GV gas connection L1, L2 gaps between first and second edge of the groove, respectively, and the sealing ring SV storage volume ZA cylinder axis