Connection element for a pressure tank and pressure tank

Abstract

A connecting element (1) for a pressure tank (10), wherein the connecting element (1) can be inserted into an opening of the pressure tank (10), comprising a plug element (2) and a counter element (6, 7) at least partially enclosing the plug element (2), wherein an outer side of the plug element (2) and an inner side of the counter element (6, 7) form a recess (13) tapering towards the pressure tank opening, so that a tank wall (3) of the pressure tank (10) can be clamped in the recess of the connecting element (1), wherein the connecting element (1) can be inserted from the outside into an element forming the tank wall (3), wherein the plug element (2) is provided with an internal thread, so that further components can be screwed into the plug element (2), and wherein the plug element (2) has at least one external thread, wherein the counter element (6, 7) and / or a connection element connected to the counter element (6, 7) operatively connected screw nut (4) is screwed onto the external thread.

Description

[0001] The present invention relates to a connection element for a pressure tank. Furthermore, the invention relates to a pressure tank comprising such a connection element. The pressure tank is, in particular, a cryogenic pressure tank or a high-pressure tank, wherein the pressure tank advantageously stores hydrogen. The pressure tank is advantageously intended for use in a motor vehicle.

[0002] Tanks are known from the prior art that can be used, in particular, to store hydrogen. To prevent metal embrittlement, which typically occurs when hydrogen is stored in a metal tank, hydrogen tanks are often made of plastic. A connecting element can be inserted into such a plastic tank, which can be used to seal the tank. The connecting element should also allow the tank to be filled and emptied. Such elements are usually made of metal. Therefore, a combination of a plastic tank and a metal closure is necessary.

[0003] Such an arrangement is disclosed, for example, in DE 21 52 123 A1. This document shows a pressure vessel whose opening continuously transitions into a hollow cylindrical neck. The hollow cylindrical neck is enclosed by a pole piece, also hollow cylindrical, with the neck of the pressure vessel and the pole piece conically expanding outwards. A gas-tight valve can finally be attached to the pole piece. However, this has the disadvantage that the plastic wall of the plastic tank must have a conical shape. The documents WO 2013 / 020 668 A1 and CN 101 832 389 B show prior art.

[0004] A composite pressure vessel is known from DE 196 31 546 C1. This vessel comprises a plastic tank and a fiber composite winding to reinforce the plastic tank (liner). A neck piece is inserted into the liner and secured to the liner with a clamping ring. However, the disadvantage here is that the clamping ring is screwed flush with the inside of the neck piece, which makes it difficult to screw in a tank valve.

[0005] DE 10 2009 014 057 A1 discloses a pressure vessel for storing gaseous media. The pressure vessel has a fiber composite wall, a plastic tank, and a connecting flange with a support ring. However, this requires an additional spring element, which makes the required installation very complex.

[0006] WO 2006 / 034 439 A2 also discloses a tank consisting of a valve body with an O-ring seal, a metal ring, and a plastic tank. Additionally, a spring-loaded clamping element is used to press the plastic tank (liner) against the metal ring and to seal the liner against the metal ring. However, this design features a thread in the liner, which can be damaged under excessive mechanical stress. Furthermore, this thread complicates and increases the cost of manufacturing the plastic liner.

[0007] Furthermore, DE 10 2010 023 386 A1 discloses a pressure vessel for storing liquid or gaseous media. The base body of this pressure vessel consists of a plastic material with a rotationally symmetrical collar into which a section of a pressure valve is inserted. A metal connector is located outside the collar. The pressure valve is provided with an external thread, which is screwed into the end of the connector facing away from the base body. The base body and the flange are at least partially enclosed by a protective sleeve made of fiber composite material.

[0008] DE 10 2010 049 838 A1 discloses a pressure vessel for storing a fluid, which comprises a plastic liner. The plastic liner consists of several independently manufactured parts. However, the multi-part design of the plastic liner significantly complicates the assembly of the pressure tank.

[0009] Finally, DE 10 2009 049 948 B4 discloses a pressure vessel suitable for storing liquid and gaseous media. The pressure vessel consists of a plastic inner container with at least one neck piece. This neck piece is provided with means for receiving a connection fitting. The pressure vessel includes an insert that forms at least part of the container neck and thus a seal between the neck piece and the fitting to be used. However, this insert is not stable after installation, so the tank valve must be enclosed with fiber composite material and adhesive for stabilization. Only then is the tank valve, and thus the pressure tank, sealed against the liquid or gaseous storage media.

[0010] The object of the invention is to provide a connection element for a pressure tank that enables safe and reliable sealing of the pressure tank while being simple and cost-effective to manufacture. It is also an object of the invention to provide a corresponding pressure tank.

[0011] The problem is solved by the features of claim 1. The problem is thus solved by a connection element for a pressure tank, which can be inserted into an opening in the pressure tank. The connection element comprises a plug element and a counter element that can be connected to the plug element. The counter element is provided to at least partially enclose the plug element. An outer surface of the plug element and an inner surface of the counter element form a tapered recess. A tank wall of the pressure tank can be inserted into this recess. The tank wall is advantageously pressed between the plug element and the counter element by the tapered recess, so that the tank wall can be clamped into the recess. The tank wall is advantageously clamped by inserting the plug element into the counter element.

[0012] The subclaims contain advantageous developments of the invention.

[0013] Advantageously, the counter element comprises a metal cone and / or a metal insert with a conical surface. The tapered recess is formed by the conical shape. Thus, the tank wall can be pressed against the plug element by the conical surface and / or the metal cone.

[0014] In a preferred embodiment, the plug element is designed such that it at least partially has a conical surface. The tapered recess is again formed by the conical surface. Particularly preferably, both the plug element and the counter element are designed with a conical surface, so that the tapered recess is formed by the counter element and plug element. By providing the conical surface of the plug element and / or counter element, a degree of clamping of the tank wall is also preferably adjustable. Therefore, it is advantageously provided that the plug element and the counter element can be displaceably positioned relative to one another when they are connected.

[0015] It is also preferably provided that the plug element has at least one external thread. In a first advantageous alternative, the counter element is screwed onto the at least one external thread. The counter element is thus connected to the plug element, wherein the counter element and plug element can be positioned relative to one another. Alternatively or additionally, a screw nut is provided as a second advantageous alternative. The screw nut is advantageously operatively connected to the counter element such that screwing in and / or unscrewing the screw nut displaces the counter element relative to the plug element. The counter element can also be positioned relative to the plug element in this way. In the second alternative, it is advantageously provided that the counter element does not have its own thread with which the counter element can be screwed onto the external thread of the plug element.This makes the counter element very easy and cost-effective to manufacture.

[0016] The plug element advantageously has a recess, wherein the tank wall can be pressed into the recess of the plug element by the counter element. In particular, an end region of the tank wall can be pressed into the recess. Furthermore, it is preferably provided that the recess is arranged at a point in the tapered recess where the tapered recess has a minimal dimension. Thus, a maximum clamping effect can be achieved in this region, whereby the tank wall can be fixed within the recess.

[0017] Furthermore, it is preferably provided that the plug element has a sleeve shape. If the plug element, as described above, has at least one external thread, this thread is arranged on an outer surface of the sleeve-shaped plug element. Particularly preferably, the sleeve-shaped plug element is also provided with an internal thread so that additional components can be screwed into the plug element. A closure valve for the pressure tank can be screwed into such an internal thread. Thus, the connection element advantageously serves to close the pressure tank and / or to empty and / or fill the pressure tank.

[0018] Furthermore, the counter element advantageously has a ring shape. It is particularly preferred that the ring shape surrounds the described sleeve shape of the plug element.

[0019] Finally, it is preferably provided that the counter element is surrounded by a fiber wrapping. The fiber wrapping enables secure and reliable fixation of the counter element and thus the connecting element within the opening of the pressure tank.

[0020] The invention further relates to a pressure tank, wherein the pressure tank has a tank wall. The tank wall has an opening, wherein a connection element as described above is inserted into the opening. The pressure tank is advantageously a cryogenic pressure tank or a high-pressure tank, in particular for at least 600 bar. The pressure tank can preferably be filled with a fuel gas, advantageously hydrogen. Furthermore, it is preferably provided that the pressure tank is intended for use in a motor vehicle.

[0021] The tank wall of the pressure tank is advantageously made of a plastic. In particular, it is provided that the tank wall is made of a plastic by extrusion blow molding. This allows the pressure tank to be manufactured as a single piece. Thus, complex assembly of individual components of the pressure tank is not necessary. Only one connection element, as described above, needs to be inserted into the extrusion blow molded plastic element, which thus forms the tank wall.

[0022] The connecting element is preferably inserted into the opening in the tank wall by screwing a thread of the plug element into the tank wall. Preferably, a counter thread of the tank wall is cut through the thread of the plug element itself. Thus, advantageously, no counter thread is required in the tank wall itself. This, in turn, simplifies the production of the tank wall.

[0023] Alternatively, the plug element can be pressed into the opening in the tank wall. In this case, manufacturing the pressure tank is very simple, since after the tank wall has been manufactured, the plug element is simply pressed into an opening in the tank wall. The inventive clamping of the tank wall between the plug element and the counter element of the connecting element ensures a secure and reliable hold.

[0024] Advantageously, the pressure tank is designed so that no requirements are placed on the design of the tank wall. This allows the pressure tank to have any shape without compromising the tightness of the connecting element. Clamping the tank wall between the counter element and the plug element reliably ensures tightness.

[0025] Furthermore, the connection element is arranged flush with the outside of the pressure tank. This allows a tank valve to be screwed into the connection element without hindrance.

[0026] The pressure tank is completely sealed, particularly by inserting the connecting element and the resulting clamping of the tank wall between the counter element and the plug element. However, it is advantageous to have an additional adhesive and / or fiber composite material surrounding the tank wall to further increase stability and tightness.

[0027] Further details, features, and advantages of the invention will become apparent from the following description and the figures. They show: Fig. 1 a schematic illustration of the connection element according to a first embodiment of the invention, Fig. 2 a schematic illustration of the connecting element according to a second embodiment of the invention, Fig. 3 a schematic illustration of the connecting element according to a third embodiment of the invention, Fig. 4 a schematic illustration of the connecting element according to a fourth embodiment of the invention, Fig. 5 a schematic representation of a pressure tank according to the invention with a connecting element according to the fourth embodiment of the invention, Fig. 6 a detailed view Fig. 5, and Fig. 7 a schematic view of a pressure tank according to the invention with a connection element according to the third embodiment of the invention.

[0028] Fig. Figure 1 shows a connection element 1 inserted into an opening in a tank wall 3 of a pressure tank. The connection element 1 comprises a plug element 2 inserted into the opening in the tank wall 3. The plug element 2 is sealed against the tank wall 3 by an O-ring 11.

[0029] The insertion of the plug element 2 into the tank wall 3 is advantageously carried out in two different ways: On the one hand, the plug element 2 can be pressed into the opening of the tank wall 3; on the other hand, it is provided that the plug element 2 has a first thread with which the plug element 2 can be screwed into the opening of the tank wall 3. In particular, it is provided that the tank wall 3 does not have a counter thread, but rather the counter thread is cut into the tank wall 3 by the first thread of the plug element 2.

[0030] To improve the seal between tank wall 3 and plug element 2, a counter element is provided. Fig. 1, the counter element is a metal insert 7. The metal insert 7 extends around the plug element 2 and can be fixed by a screw nut 4. The metal insert 7 and plug element 2 are provided with a conical surface, so that a tapered recess 13 is created between an inner side of the metal insert 7 and the outer side of the plug element 2. Thus, as the screw nut 4 is increasingly screwed in, the metal insert 7 is pressed onto the tank wall 3 in such a way that the tank wall 3 is clamped between the metal insert 7 and the plug element 2. As an alternative to the separate screw nut 4, the screw nut 4 is also provided for the screw nut 4 to be formed integrally with the metal insert 7.

[0031] To increase the stability and tightness of the connection, a fiber wrapping 5 is also provided around the tank wall 3. However, this is merely an optional aid, since the tightness is already ensured by clamping the tank wall 3 between the metal insert 7 and the plug element 2.

[0032] Fig. 2 shows a second embodiment of the connecting element 1 according to the invention. The same or similar elements as in Fig. 1 are provided with the same reference numerals.

[0033] In contrast to Fig. 1, the second embodiment has a metal cone 6. It is provided that the screw nut 4, the metal cone 6, analogous to the metal insert 7 from Fig. 1, against the tank wall 3, so that the tank wall 3 is clamped in a tapered recess 13 between the metal cone 6 and the plug element 2. The metal cone 6 thus corresponds to the counter element. To fix the metal cone 6, the metal insert 7 is also provided, with the metal cone 6 being provided between the tank wall 3 and the metal insert 7.

[0034] A third embodiment of the connecting element is shown in Fig. 3. Again, the same reference numerals indicate that these are the same or similar parts as in the previously mentioned embodiments. In the third embodiment, a clamping area 12 is provided, in which the tank wall 3 can be clamped. It is provided that the metal insert 7 and the plug element 2 have a conical surface and thus the tapered recess 13 only in one area, namely the clamping area 12. Thus, the outer wall 3 is clamped only in the clamping area 12. Furthermore, in the third embodiment, the screw nut 4 is formed integrally with the metal insert 7.

[0035] Finally, a fourth embodiment of the connecting element 1 is shown in Fig. 4. In the fourth embodiment, the same or similar elements are again designated by the same reference numerals as in the previous embodiments. Fig. 4 shows that the plug element 2 has a recess 9 in addition to the conical surface forming the tapered recess 13. Thus, the tank wall 3 is pressed into the recess 9, providing additional fixation and sealing.

[0036] Fig. 5 finally shows a pressure tank 10 according to the invention, wherein the pressure tank 10 is in particular a high-pressure tank. The high-pressure tank can advantageously be used to hold fluids, gases or liquids under a maximum pressure of at least 600 bar. The pressure tank 10 can particularly preferably be used to hold operating materials for an engine or a fuel cell, in particular for holding hydrogen or natural gas. The pressure tank 10 comprises the connection element 1 according to the fourth embodiment of Fig. 4.

[0037] It is over Fig. 5 that the plug element 2 has a sleeve shape. Thus, in addition to an external thread onto which the screw nut 4 is screwed, an internal thread is also provided, into which a tank valve 8 can be screwed. The internal thread thus serves to connect the connection element 1 and thus the pressure tank 10 to other components. The pressure tank 10 is therefore particularly suitable for use in motor vehicles, since the connection element 1 can be connected to a supply line for an internal combustion engine of the motor vehicle. To increase the stability of the pressure tank 10, the tank wall 3 is provided with a fiber wrapping 5.

[0038] Fig. 6 shows two different views of a detail area 100 from Fig. 5. Detail area 100 shows how the tank wall 3 can be pressed into the recess 9 of the plug element 2. By applying the metal insert 7 through the screw nut 4, the tank wall 3 is clamped by the conical surfaces of the plug element 2 and the metal insert 7. Furthermore, the tank wall 3 is pressed into the recess 9 of the plug element 2 by the metal insert 7. This creates a secure and reliable connection and seal.

[0039] Fig. 7 shows a pressure tank according to the invention, wherein again the same or similar elements are represented by the same reference numerals as in the previous embodiments. Fig. The embodiment of the pressure tank 10 shown in Fig. 7 shows a tank wall 3 into which the connection element 1 according to the third embodiment of Fig.3 is inserted. Again, it is preferably provided that the tank wall 3 is provided with a fiber wrapping 5, so that stability of the pressure tank 10 is ensured.

[0040] The pressure tank 10 is advantageously used in a vehicle. The vehicle is advantageously a motor vehicle, in particular a passenger car. Since the pressure tank 10 is very simple and cost-effective to manufacture, only very low costs and very little effort are required to provide the pressure tank 10 in the vehicle. List of reference symbols: 1 connecting element 2 plug element 3 tank wall 4 screw nut 5 fiber wrapping 6 metal cones 7 Metal insert 8 Tank valve 9 Recess 10 pressure tank 11 O-ring 12 clamping area 13 tapered recess

Claims

[1] A connecting element (1) for a pressure tank (10), wherein the connecting element (1) can be inserted into an opening of the pressure tank (10), comprising a plug element (2) and a counter element (6, 7) at least partially enclosing the plug element (2), wherein an outer side of the plug element (2) and an inner side of the counter element (6, 7) form a recess (13) tapering towards the pressure tank opening, so that a tank wall (3) of the pressure tank (10) can be clamped in the recess of the connecting element (1), wherein the connecting element (1) can be inserted from the outside into an element forming the tank wall (3), wherein the plug element (2) is provided with an internal thread, so that further components can be screwed into the plug element (2), and wherein the plug element (2) has at least one external thread, wherein the counter element (6, 7) and / or a connection element connected to the counter element (6, 7) operatively connected screw nut (4) is screwed onto the external thread. [2] Connecting element (1) according to claim 1, characterized by that the counter element comprises a metal cone (6) and / or a metal insert (7) with a conical surface for forming the tapered recess (13). [3] Connection element (1) according to one of the preceding claims, characterized by that the plug element (2) has at least partially a conical surface for forming the tapered recess (13). [4] Connection element (1) according to one of the preceding claims, characterized by that the plug element (2) has a recess (9), wherein the tank wall (3) can be pressed into the recess (9) by the counter element (6, 7) when the plug element (2) is inserted into the pressure tank (10). [5] Connecting element (1) according to claim 4, characterized by that an end region of the tank wall (3) can be pressed into the recess (9) by the counter element (6, 7) when the plug element (2) is inserted into the pressure tank (10). [6] Connecting element (1) according to one of the preceding claims, characterized by that the plug element (2) has a sleeve shape. [7] Connecting element (1) according to one of the preceding claims, characterized by that the counter element (6, 7) has a ring shape. [8] Connecting element (1) according to one of the preceding claims, characterized by that the counter element (6, 7) is surrounded by a fiber winding (5). [9] Pressure tank (10), comprising a tank wall (3), wherein the tank wall (3) has an opening, and a connecting element (1) according to one of the preceding claims, wherein the connecting element (1) is inserted into the opening of the tank wall (3). [10] Pressure tank (10) according to claim 9, characterized by that the tank wall (3) is made of a plastic, preferably by extrusion blow molding. [11] Pressure tank (10) according to one of claims 9 or 10, characterized bythat a thread of the plug element (2) is screwed into the opening of the tank wall (3), wherein a counter thread in the tank wall (3) is cut through the thread of the plug element (2). [12] Pressure tank (10) according to one of claims 9 or 10, characterized by that the plug element (2) is pressed into the opening of the tank wall (3).

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