Connection system

Abstract

Connection system for the gas-tight connection of a stainless steel pipeline (2) with another fluid component, the a connecting section (21) extending between an open end section (22) of a stainless steel pipe (2) and an olive (23) formed on this stainless steel pipe (2), a connection socket (3) which can be arranged on a further fluid component and which is designed to receive the connection section (21), as well as a sealing assembly (4) and a union screw (5), wherein the connection socket (3) has a substantially cylindrical receiving area (31) at an inner end and a threaded section (32) at an outer end for screwing in the union screw (5), wherein the receiving area (31) is designed to at least partially receive an arrangement of the sealing assembly (4) arranged coaxially around the connecting section (21), and wherein the union screw (5) is designed to apply at least indirectly axial forces to the sealing assembly (4) during screwing, characterized in that the connection socket (3) is molded into a body (6), wherein the body (6) with the molded-in connection socket (3) is formed from a material which has a lower hardness than a stainless steel material of the stainless steel pipeline (2) to be connected, and wherein the sealing assembly (4) comprises at least one pressure-activated seal (41) which is designed to seal against the connection section (21) of the stainless steel pipeline (2) and against the receiving area (31) of the connection socket (3) with increasing media pressure.

Description

Technical area

[0001] This description relates to a connection system for the leak- and gas-tight connection of a pipeline with another fluid component. State of the art

[0002] Stainless steel pipelines that can be connected with a stainless steel tube fitting are familiar from gas supply systems, for example, in industrial applications. In connection systems consisting of a tube fitting and a pipeline, such as those offered by companies such as Swagelok Co. or the HAM-LET Group, a purely metallic seal is created between the outer surface of the pipe and the fitting body of the respective tube fitting using special compression fitting sets. These compression fittings, based on a purely metallic sealing concept, enable leak- and gas-tight connections that are easy to assemble, disassemble, and reuse.

[0003] For motor vehicles with compressed natural gas (CNG), liquid pressed gas (LPG), and / or hydrogen propulsion systems, stainless steel piping is required for a gas supply system. Other components of such alternative propulsion systems may and often are made of other materials, such as brass or aluminum, to reduce costs and, in particular, weight. Brief description of the invention

[0004] However, the conventional compression fittings, which are based on a purely metallic seal, do not allow the combination of pipes and pipe fittings made of different materials, as the softer material would not withstand the necessary surface pressure during screwing. Therefore, additional adapters are required for corresponding gas supply systems, particularly in CNG, LPG, or hydrogen vehicles, to connect a stainless steel pipe to a component that is not made of stainless steel.

[0005] A corresponding stainless steel adapter has a pipe fitting that can provide a compression fitting on a first connection side for a purely metallic seal with a stainless steel pipeline. A second connection side of such a stainless steel adapter can, for example, feature a threaded connection that can be screwed into a corresponding thread located on a component made of a different material. A corresponding threaded fitting can be sealed gas-tight with a separate gasket.

[0006] From DE 693 12 207 T2 a connection system is known with which a pipeline can be connected to another fluid component.

[0007] A gas-tight plug connection system is known from DE 10 2009 059 999 A1.

[0008] Using an adapter for pipe fittings to threaded fittings results in a double seal at one connection point, with the seals between the gasket and threaded fittings being at risk of corrosion. Furthermore, these adapters are comparatively expensive, large, and require additional handling during installation.

[0009] Against this background, the object of the invention is to provide an alternative connection system which enables a direct screwable connection between a stainless steel pipeline and a further fluid component, wherein a respective further fluid component can consist of a different material, preferably with a lower hardness than the stainless steel pipeline to be connected.

[0010] Accordingly, a connection system according to the main claim is proposed. Further embodiments are the subject of the respective dependent claims.

[0011] According to a first aspect of the invention, this object is achieved by a connection system for the gas-tight connection of a stainless steel pipeline to another fluid component. The connection system comprises a connection section extending between an open end section of a stainless steel pipeline and an olive formed on this stainless steel pipeline. A connection socket of the connection system can be arranged on a further fluid component to be connected and is designed to receive the connection section. The connection system further comprises a sealing assembly and a union screw.

[0012] The connection socket has a substantially cylindrical receiving area at an inner end and a threaded portion at an outer end for screwing in the union screw. The receiving area is designed to at least partially receive an arrangement of the sealing assembly arranged coaxially around the connection portion.

[0013] Furthermore, the union screw is designed to apply at least indirectly axial forces to the sealing assembly when screwing.

[0014] In the connection system according to the invention, a connecting section of a stainless steel pipeline to be connected can be accommodated in a connecting socket, which can be sealed with a union screw. The forces resulting from tightening the union screw flow axially, essentially into the sealing assembly, which is arranged coaxially between the connecting section and the connecting socket.

[0015] The individual elements of a respective sealing assembly are selected with regard to their material properties, in particular the hardness or elasticity of their material, so that the surface pressures that would be necessary in comparison to a purely metallic sealing assembly of known compression fittings can be dispensed with.

[0016] Thus, according to a further development of the invention, the connection socket is formed in a body which is formed from a material which has a lower hardness than a stainless steel material of a stainless steel pipeline to be connected.

[0017] The connection system allows for a leak- and gas-tight connection between a stainless steel pipeline and a connection socket in a brass or aluminum body. The connection system according to the invention also allows for larger shape and position tolerances when connecting a stainless steel pipeline to another fluid component.

[0018] According to a further development of the aspect described above, the body can be a housing section for a further fluid component to be connected.

[0019] By integrating it into a housing body of a component to be connected, less installation space is required for assembly than with the known adapter fittings.

[0020] The sealing assembly further comprises at least one pressure-activated seal which is designed to seal against the connecting section of the stainless steel pipeline and against the receiving area of the connecting socket with increasing media pressure.

[0021] A pressure-activated seal causes significantly lower surface pressures than the conventional purely metallic seals of a compression fitting. The softer material of the connection socket or housing section is not deformed in the connection system according to the invention, ensuring a leak- and gas-tight connection.

[0022] This connection system, based on a pressure-activated seal, enables leak- and gas-tight connections that are easy to assemble, disassemble, and reuse. A pressure-activated seal also allows for larger tolerances and roughness than conventional compression fittings.

[0023] A pressure-activated seal is designed for coaxial assembly within the cylindrical receiving area in the connector socket and can have a round, square, oval cross-section, or a double M or X cross-section shape.

[0024] According to a further development, the sealing assembly can further comprise a ring bushing. An outer diameter of the ring bushing can form a press fit with an inner diameter of the receiving area, and an inner diameter of the ring bushing can form a press fit with an outer diameter of the connecting section of the stainless steel pipeline. The ring bushing can be press-fitted into the receiving area with the connecting section under the action of axial forces during screwing.

[0025] By pressing into the receiving area, the ring bushing can provide a play-free coaxial assembly between the stainless steel pipe and a cylindrical inner surface of the connecting section. During the pressing process, any gaps between the stainless steel pipe and the ring bushing, as well as between the ring bushing and the receiving area, are reduced to zero.

[0026] According to a further development, the sealing assembly may further comprise a support element which is designed to support the pressure-activated seal when axial forces are applied.

[0027] According to a first alternative, the support element and the ring bushing can be combined in one piece to form a support ring bushing. Accordingly, the sealing assembly can further comprise a clamping ring, which can be arranged with a first end in the receiving area and with a second end in the threaded portion. In this arrangement, the clamping ring can be configured to transmit axial forces applied by the union screw during screwing to the support ring bushing.

[0028] The clamping ring can be made of metal and / or plastic and have a rectangular cross-section. The clamping ring can have a metallic portion on the non-pressure side to absorb point loads that are applied as axial forces from the union screw to the sealing assembly during screwing. Alternatively, a separate metal ring can be arranged in front of the clamping ring on the non-pressure side.

[0029] According to a second alternative, the support element and the ring bushing can be combined to form a support clamping ring, wherein the sealing assembly in this embodiment can further comprise a metal ring. The metal ring, arranged in the threaded portion, can be configured to transmit axial forces applied by the union screw during screwing to the support clamping ring.

[0030] According to a further alternative, the support element can be designed as a support ring and the ring bushing as a clamping ring bushing, and the sealing assembly can further comprise a metal ring. The metal ring, arranged in the threaded portion, can be designed to transmit axial forces applied by the union screw to the clamping ring bushing during screwing.

[0031] A side of the support ring or support ring bushing facing or to be facing the pressure-activated seal can be rectangular, with straight or concave flanks, sharp-edged and rounded, so that this side can be adapted to a particular shape of the cross-section of the pressure-activated seal.

[0032] A clamping ring or support clamping ring can, for example, be made of plastic and have a square or rectangular cross-section. A preferably elastic plastic allows for easy insertion and high reusability after disassembly of the connection system. The clamping ring can have a metallic part facing away from the pressure, for example in the form of an additional metal ring, to absorb and evenly distribute point loads during screwing.

[0033] According to a further development, the sealing assembly may further comprise a second pressure-activated seal and a second support ring, wherein the second support ring is arranged between the second pressure-activated seal and the pressure-activated seal.

[0034] According to a further embodiment of the first aspect of the invention, a centering bore can be arranged on the connection socket at an inner end of the receiving area, which centering bore is designed to receive the connection section in a region of the open end section in a centering manner.

[0035] According to a further development of the first aspect, the union screw can be arranged coaxially on a stainless steel pipeline to be connected in such a way that the shaped olive is arranged between the union screw and the sealing assembly during connection.

[0036] According to a further embodiment, a first environmental seal can be arranged between a screw head of the union screw and the connection socket.

[0037] The first environmental seal may be listed as an O-ring seal, which serves to prevent corrosion in the area between the union screw and the connection socket.

[0038] In addition, a second environmental seal can be arranged in a bore groove of the union screw.

[0039] A second O-ring seal can be used to seal an additional path between a connected stainless steel pipe and the union screw to prevent corrosion. Short description of the drawing figures

[0040] Further features and details can be found in the following description, in which - if necessary with reference to the drawing - at least one embodiment is described in detail. Described and / or illustrated features, alone or in any meaningful combination, form the subject matter, possibly also independently of the claims, and may in particular also be the subject of one or more separate applications. Identical, similar, and / or functionally identical parts are provided with the same reference numerals. Here: Fig. 1a shows a first embodiment of a connection system according to the invention, in a disassembled view; Fig. 1b the connection system according to Fig. 1a, in a mounted representation; Fig. 2 alternative variants of the first embodiment of the connection system; Fig. 2 shows a second embodiment of a connection system according to the invention; Fig. 3 a third embodiment of a connection system according to the invention. Description of the execution types

[0041] In the Fig. 1a and Fig. 1b shows a cross section through a first embodiment of a connection system 1 according to the present invention. Fig. 1a shows a view of a connection system 1 disassembled into its individual parts. The Fig. 1b shows an assembled connection system 1. The connection system 1 enables a leak- and gas-tight connection between a stainless steel pipeline 2 and a housing 6 of another fluid component of a gas supply device, for example within a motor vehicle.

[0042] The housing 6 is made of a material that is softer than the stainless steel of the stainless steel pipe 2, for example brass or aluminum. A connection socket 3 is formed in the housing 6 or in a section of a housing wall, which comprises a receiving area 31 and a threaded section 32. The receiving area 31 opens, as shown, into the Fig. 1 on the left side into a centering bore 33, the diameter of which is matched to an outer diameter of the stainless steel pipeline 2. The centering bore 33 is designed to center a connection section 21 of the connected stainless steel pipeline 2 or of a stainless steel pipeline 2 to be connected on a connection section 21. The centering bore 33 is designed as a through-bore through the housing wall, as shown, so that it is further designed to conduct a fluidic medium between the stainless steel pipeline 2 and a housing interior of the corresponding further fluid component.

[0043] The connection system 1 further comprises a sealing assembly 4 which, according to the illustrated assembled state, is arranged coaxially around or on the connecting section 21 of the stainless steel pipeline 2.

[0044] The connection section 21 of the stainless steel pipeline 2 is separated from a seamlessly drawn stainless steel pipe by an olive 23 formed on a stainless steel pipe and thus extends to the open end section 22 of the stainless steel pipeline 2. A union screw 5 is arranged on a pipe section that extends from the olive 23 toward the stainless steel pipeline 2. The union screw 5 can be made of galvanized steel, for example.

[0045] Two O-ring seals can be arranged on the union screw 5. A first environmental seal 51, i.e. a first of the two O-ring seals, is arranged between the union screw 5 and the housing 6 in the assembled connection system 1 and seals the connection socket 3 against the ingress of water or other corrosive media. The union screw 5 and the housing 6 are not in contact, at least in the outer area of the connection system 1. A second environmental seal 41 is placed in a groove in a through-bore of the union screw 5 and seals the connection system 1 after assembly between the stainless steel pipeline 2 and the union screw 5.

[0046] During assembly of the connection system 1 according to the invention, the union screw 5 with the two environmental seals 51 and 52 is first pre-assembled, i.e., pushed onto a stainless steel pipe of the stainless steel pipeline 2 to be connected. Subsequently, the olive 23 is formed on the stainless steel pipe using a suitable forming tool. The sealing assembly 4 can also initially be pre-assembled within the connection socket 3 without the connection section 21 of the stainless steel pipeline 2.

[0047] In the Fig. 1 shows a connection system 1 with a sealing assembly 4, which comprises a pressure-activated seal 41, a support ring bushing 43 and a clamping ring 44. As the media pressure increases, a pressure-activated seal 41 optimally seals against the stainless steel pipe of the connection section 21 and against a cylindrical inner wall of the receiving area 31 and can thus compensate for certain tolerances and roughnesses. The pressure-activated seal 41 can, as in the example shown, Fig. 1, have a double-m-shaped cross-section.

[0048] The illustrated support ring bushing 43 has a flank geometry adapted to a respective seal shape on the side facing the pressure-activated seal 41. In the example shown, the flank geometry is concave and is designed to support the pressure-activated seal 41 during screwing. An outer diameter of the support ring bushing 43 forms a press fit with an inner diameter of the receiving area 31, and an inner diameter of the support ring bushing 43 forms a further press fit with an outer diameter of the connecting section 21 of the stainless steel pipeline 2. The support ring bushing 43 can be pressed into the receiving area by means of axially acting forces during screwing, so that it sits gap-free between the receiving area 31 and the connecting section 21.

[0049] The clamping ring 44 can be adjusted according to the Fig. 1, consist of metal and can be arranged both adjacent to the support ring bushing 43 and adjacent to the olive 23 in the connection bushing 3.

[0050] When screwing the connection system 1, according to the illustrated embodiment, axial forces are applied from the union screw 5 to the olive 23, whereby the olive 23 transmits the absorbed axial forces to the clamping ring 44 in the direction of the sealing assembly 4.

[0051] The clamping ring 44 may alternatively be made of a plastic material, whereby a metallic part may be provided on the side of the clamping ring 44 facing away from the pressure for an even distribution of point loads acting from the olive 23 towards the sealing assembly 4. As shown in the Fig. 2, the metallic part can be designed as an additional metal ring arranged between the olive 23 and the clamping ring 44.

[0052] In the Fig. 3 shows a second embodiment of an assembled connection system 1 according to the invention for a leak- and gas-tight connection of a stainless steel pipeline 2 to another fluid component in a cross-sectional view.

[0053] According to this exemplary embodiment, a sealing assembly 4 comprises a pressure-activated seal 41 and a support clamping ring 45, as well as an associated metal ring 46, which is arranged on the non-pressure side of the sealing assembly 4. An inner and outer diameter of the support clamping ring 45 forms a press fit with the outer and inner diameters of the stainless steel pipeline 2 and the receiving area 31, respectively, so that it sits gap-free between the receiving area 31 and the connecting section 21.

[0054] A support clamping ring 45 suitable for press-fitting can be made of an elastically deformable plastic material. The associated metal ring 46 serves to transmit the axial force and prevents the support clamping ring 44 from yielding during screwing.

[0055] In contrast to the first embodiment according to the Fig. 1 and Fig. 2, the union screw 5 contains a cylindrical receiving area for receiving the olive 23, which is formed on the connection area 21 on the stainless steel pipeline. Thus, axial forces flow directly from the union screw 5 into the sealing assembly 4 during screwing.

[0056] The Fig.Figure 4 shows a further embodiment of a connection system 1 according to the invention. As can be seen in the cross-sectional view, the sealing assembly 4 has two O-ring seals 41 and 42, each with an associated support ring 47 and 48, which together form a pressure-activated sealing group. A clamping ring bushing 49 sits in a gap- and play-free coaxial arrangement between the receiving area 31 and the connecting section 21, which is ensured by means of appropriate press fits. During screwing, axial forces can be transmitted from the union screw 5 via a metal ring 46 to the clamping ring bushing 49.

[0057] Although the subject matter has been illustrated and explained in detail by means of exemplary embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art. It is therefore clear that numerous variations exist. It is also clear that the exemplary embodiments mentioned are merely examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. List of reference symbols 1 connection system 2 stainless steel pipes 21 Connection section 22 final section 23 Olive 3 connection socket 31 Recording area 32 threaded section 33 Center hole 4 Sealing assembly 41 pressure-activated seal 42 Second pressure-activated seal 43 Support ring bushing 44 clamping ring 45 Support clamping ring 46 metal ring 47 Support ring 48 Second support ring 49 clamping ring bushing 5 union screw 51 First environmental seal 52 Second environmental seal 6 bodies

Claims

[1] Connection system for the gas-tight connection of a stainless steel pipeline (2) with another fluid component, the a connecting section (21) extending between an open end section (22) of a stainless steel pipe (2) and an olive (23) formed on this stainless steel pipe (2), a connection socket (3) which can be arranged on a further fluid component and which is designed to receive the connection section (21), as well as a sealing assembly (4) and a union screw (5), wherein the connection socket (3) has a substantially cylindrical receiving area (31) at an inner end and a threaded section (32) at an outer end for screwing in the union screw (5), wherein the receiving area (31) is designed to at least partially receive an arrangement comprising the sealing assembly (4) arranged coaxially around the connecting section (21), and wherein the union screw (5) is designed to apply at least indirectly axial forces to the sealing assembly (4) during screwing, characterized by , that the connection socket (3) is molded into a body (6), wherein the body (6) with the molded-in connection socket (3) is formed from a material which has a lower hardness than a stainless steel material of the stainless steel pipeline (2) to be connected, and wherein the sealing assembly (4) comprises at least one pressure-activated seal (41) which is designed to seal against the connection section (21) of the stainless steel pipeline (2) and against the receiving area (31) of the connection socket (3) with increasing media pressure. [2] Connection system according to the preceding claim 1, wherein the body (6) is a housing section for a further fluid component to be connected. [3] Connection system according to one of the preceding claims 1 to 2, wherein the sealing assembly (4) further comprises an annular bushing, wherein an outer diameter of the annular bushing forms a press fit with an inner diameter of the receiving area (31) and wherein an inner diameter of the annular bushing forms a press fit with an outer diameter of the one connecting section (21) of the stainless steel pipeline (2), and wherein the annular bushing can be pressed into the receiving area (31) with the connecting section (21) under the action of axial forces during screwing. [4] Connection system according to the preceding claim 3, wherein the sealing assembly (4) further comprises a support element configured to support the pressure-activated seal (41) upon application of axial forces. [5] Connection system according to the preceding claim 4, wherein the support element and the ring bushing are combined in one piece to form a support ring bushing (43), and wherein the sealing assembly (4) further comprises a clamping ring (44) which, with a first end in the receiving area (31) and with a second end in the threaded section (32), is designed to transmit axial forces applied by the union screw (5) to the support ring bushing (43) during screwing. [6] Connection system according to claim 4, wherein the support element and the ring bushing are combined to form a support clamping ring (45), and wherein the sealing assembly (4) further comprises a metal ring (46), wherein the metal ring (46), arranged in the threaded portion (32), is designed to transmit axial forces applied by the union screw (5) to the support clamping ring (45) during screwing. [7] Connection system according to claim 4, wherein the support element is designed as a support ring (47) and the ring bushing as a clamping ring bushing (49), and wherein the sealing assembly (5) further comprises a metal ring (46), wherein the metal ring (46), arranged in the threaded portion (32), is designed to transmit axial forces applied by the union screw (5) to the clamping ring bushing (49) during screwing. [8] Connection system according to the preceding claim 7, wherein the sealing assembly (4) further comprises a second pressure-activated seal (42) and a second support ring (48), the second support ring (48) being arranged between the second pressure-activated seal (42) and the pressure-activated seal (41). [9] Connection system according to one of the preceding claims 1 to 8, wherein a centering bore (33) is arranged on the connection socket (3) at an inner end of the receiving region (31), which is designed to receive the connection section (21) in a centering manner in a region of the open end section (22). [10] Connection system according to one of the preceding claims 1 to 9, wherein the union screw (5) can be arranged coaxially on the stainless steel pipeline (2) to be connected such that the shaped olive (23) is arranged between the union screw (5) and the sealing assembly (4) during connection. [11] Connection system according to one of the preceding claims 1 to 10, wherein a first environmental seal (51) can be arranged between a screw head of the union screw (5) and the connection socket (3). [12] Connection system according to one of the preceding claims 1 to 11, wherein a second environmental seal (52) is arranged in a bore groove of the union screw (5).

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