Fitting for connecting a hose

Abstract

The invention relates to a fitting for connecting a hose (20) with a nipple (30) and a compression sleeve (40), wherein the fitting (10) includes a hose receiving section (11). It is proposed to divide the hose receiving section (11) into three special functional sections (111, 112, 113).

Description

[0001] The present invention relates to a fitting for connecting a hose, in particular for high-pressure hydrogen fluid lines. Furthermore, the invention relates to a connecting device comprising such a fitting. The invention also relates to a high-pressure tank system and a high-pressure vehicle tank system comprising such a connecting device.

[0002] Such fittings are used in fluid systems in which a fluid is transported through flexible hoses. To connect the hoses to other lines or devices, such as a fuel nozzle or fuel pump gun, the hose ends are fitted with fittings. Frequently, an end section of the hose is pushed onto a nipple of the fitting and pressed (e.g., crimped) onto the nipple using a press sleeve of the fitting, whereby the press sleeve is plastically deformed. EP 2 510 271 A1 shows an example of a fitting pressed onto a fluid line of an air conditioning system for motor vehicles.

[0003] Flexible hoses are typically hybrid composite structures composed of multiple layers, such as an inner layer containing a thermoplastic, a reinforcement layer containing a particularly metallic strength member, and an outer layer containing an elastomer or a thermoplastic. EP 3 309 438 A1 shows an example of such a hose designed for the transport of hydrogen.

[0004] Depending on the application, the connection between the fitting and the hose can be subjected to considerable mechanical stress. Especially in high-pressure hydrogen fluid lines, such as those required in hydrogen dispensing systems for mobile hydrogen consumers (e.g., fuel cell vehicles), a particularly tight connection must be ensured due to the high operating pressure, which regularly exceeds 1000 bar. At the same time, the permeation of hydrogen through the interface between the fitting and the hose must be as low as possible.

[0005] Fittings for hydrogen applications are known from the prior art in which the nipple of the fitting is provided with one or more elastomer seals for sealing against the inside of the hose. In order to fix these seals, usually in the form of O-ring seals, in their axial position, the nipple has circumferential grooves into which the seals can be inserted. An example of such a fitting is shown in JP 2008 151196 A. However, when installing such a fitting on a hose end, there is always the risk that the seals will be pushed out of their grooves when the hose is pushed onto the nipple and - after the hose has been pressed onto the nipple using the compression sleeve - will no longer be able to fulfill their intended sealing function.

[0006] The object of the present invention is therefore to provide a fitting with which a particularly tight connection to a hose can be established. In particular, the fitting should be suitable for use in conjunction with high-pressure hydrogen fluid lines and ensure the lowest possible permeation of hydrogen. Particularly preferred is a fitting with which a tight connection to the hose can be established without the use of elastomer seals on the nipple.

[0007] This object is achieved by a fitting having the features of claim 1, a connecting device having the features of claim 13, a high-pressure tank system having the features of claim 14, and a high-pressure vehicle tank system having the features of claim 15. Preferred features are the subject of the dependent claims. Further advantages and features can be found in the general description and the exemplary embodiments.

[0008] The fitting according to the invention for connecting a hose has a nipple defining a longitudinal axis and a compression sleeve. The fitting has a hose receiving section in which an end section of the hose can be pushed onto the nipple in a sliding direction and pressed sealingly onto the nipple by means of the compression sleeve. The hose receiving section is divided into the following sections: - a hose retaining section in which the nipple and the compression sleeve each form an uneven hose retaining surface for retaining a hose pushed onto the nipple and pressed in, - a movement section in which the nipple forms a particularly substantially flat contact surface for pressing against a hose pushed onto the nipple and pressed, and - a sealing section arranged between the hose holding section and the movement section, in which the nipple has a circumferential annular bead.

[0009] The invention is based on the idea of ​​assigning the above-mentioned distinct functional sections to the hose receiving section.

[0010] A first section, the hose holding section, primarily serves to tightly hold and clamp the hose. To this end, the fitting forms uneven, for example toothed and / or ribbed, hose retaining surfaces in the hose holding section, which preferably penetrate at least partially into the hose when the fitting is crimped. The hose retaining surface of the nipple preferably has recesses forming conical surfaces. Recesses with conical surfaces in the first hose retaining section, whose respective outer diameters widen in the direction of insertion, lead to an interlocking of the hose retaining section and the inner layer of the hose when the fitting is crimped onto a hose. This promotes the hold between the nipple and the inner layer and also the tightness of the connection.For improved retention, in a preferred embodiment of the fitting according to the invention, the compression sleeve in the hose retention section has one or more circumferentially extending compression projections or compression teeth arranged axially spaced from one another on its inner side. These compression teeth are designed to penetrate the hose when the fitting is pressed onto the hose, thus preventing the hose from being pulled out of the fitting.

[0011] The second section, the movement section, which is located in front of the hose holding section in the sliding direction and in particular at the hose-side end of the hose receiving section, forms a gradual transition between the end section of the hose held and clamped by the hose holding section and the remaining hose not gripped by the fitting. In the movement section, the hose is therefore clamped to a lesser degree when the fitting is crimped than in the hose holding section. For this purpose, the nipple forms a contact surface, which is in particular essentially flat and preferably cylindrical, in the movement section for pressing against the hose, in particular wherein the contact surface does not have any structures that penetrate the hose when the fitting is crimped.Preferably, the compression sleeve in the movement section does not have any structures designed to penetrate an outer layer of the hose when the fitting is pressed together. The movement section is preferably designed to allow small compensating movements of the hose relative to the fitting in the event of dynamic loads on the connection (such as tilting of the fitting relative to the remaining hose not gripped by the fitting), thereby preventing damage to the connection, for example, due to stress peaks in the material.

[0012] The third section, the sealing section, separates the first and second sections from one another and forms a barrier for the fluid to be transported through the hose. For this purpose, the nipple in the sealing section is provided with a circumferential annular bead or an olive which, when the fitting is pressed in, is pressed against an inner surface of the hose with its outer contour convex with respect to the longitudinal center axis. In particular, the nipple in the sealing section has exactly one circumferential annular bead. Preferably, the sealing section is defined by the axial extent of the circumferential annular bead, i.e. the axial extent of the annular bead and the axial extent of the sealing section are congruent. Preferably, the annular bead is formed integrally with the rest of the nipple.In contrast to nipples provided with elastomer seals, where material must be removed from the nipple to create the groove into which the seal is inserted, the present invention provides a sealing area by thickening the material of the nipple, which increases the stability of the fitting.

[0013] It has been found that the fitting according to the invention can be used to create a connection to a hose that is extremely resilient and retains its tightness even at higher operating pressures. In particular, a tight connection could be achieved without the use of elastomer seals on the nipple. Preferably, the following sections are arranged in the hose receiving section, particularly directly one behind the other, relative to the insertion direction: - movement section, - sealing section, - Hose retention section.

[0014] Preferably, the compression sleeve and / or the nipple are made of a metal, preferably steel or aluminum. In particular, the compression sleeve and / or the nipple are each formed as a single piece.

[0015] In a further preferred embodiment of the fitting according to the invention, the sealing section is arranged in a first half of the hose receiving section relative to the insertion direction, preferably in the first two-fifths of the hose receiving section. It has been shown that positioning the annular bead or olive in the first half or in the first two-fifths of the hose receiving section promotes tightness, since this provides a barrier for the fluid to be transported through the hose as close as possible to the end of the nipple facing the hose.

[0016] In a further preferred embodiment of the fitting according to the invention, the compression sleeve has at least one sealing projection extending all the way around in the sealing section and / or in the movement section on its inside, which sealing projection is in particular shorter than the pressing projections. In other words, the sealing projection has a larger inner radius than the pressing projections. The sealing projection primarily serves as a barrier against external influences, such as moisture, which is why the sealing projection is preferably designed to merely clamp an outer (elastomeric) layer of the hose when the fitting is pressed in and in particular not to completely pierce it, since otherwise a path would be open for moisture to reach the underlying reinforcement layer.Furthermore, a sealing projection arranged in the sealing section can create a counterpart to the olive on the compression sleeve side, which increases both the strength and the tightness in this area. In this case, the sealing projection is preferably arranged opposite the annular bead.

[0017] In a further preferred embodiment of the fitting according to the invention, the annular bead in the hose receiving section has the largest outer radius of the nipple. In other words, the outer radius of the annular bead is preferably larger than the outer radius of any other structure of the nipple. The annular bead thus forms a solid barrier for the fluid being transported through the hose.

[0018] In a further preferred embodiment of the fitting according to the invention, the hose retaining section has a greater axial length than the movement section, preferably 2.5 to 6 times greater, particularly preferably 3.5 to 5 times greater, than the movement section. It has surprisingly been found that good results can be achieved with such a structural design with regard to the tightness of the connection.

[0019] In a further preferred embodiment of the fitting according to the invention, the sealing section has a smaller axial length than the movement section. Good results regarding the tightness of the connection could be achieved with such a compact design.

[0020] In a further preferred embodiment of the fitting according to the invention, the inner radius of the compression sleeve in at least one partial section of the movement section (e.g., away from any sealing projection that may be present) is larger than the inner radius of the compression sleeve away from the compression projections in the hose retention section. This simple structural design can promote robustness against dynamic loads in the movement section and / or the strength of the connection in the hose retention section. For the same purpose, the largest outer radius of the nipple in the movement section is preferably smaller than the largest outer radius of the nipple in the hose retention section.

[0021] In a further preferred embodiment of the fitting according to the invention, the nipple has a constant inner radius, at least in the hose receiving section. This improves the flow characteristics and, in particular, minimizes pressure losses in this area. Furthermore, the nipple can be manufactured in a simple manner.

[0022] According to what has already been described above and further below, the object set out at the outset is also achieved by a connecting device having the features of claim 13.

[0023] The connecting device according to the invention comprises a fitting according to the invention and a hose, wherein an end section of the hose is pushed onto the nipple in the hose receiving section and is pressed sealingly onto the nipple by means of the press sleeve.

[0024] The technical effects and advantages of the fitting according to the invention described above and below are also realized accordingly in the connecting device according to the invention.

[0025] In a preferred embodiment of the connecting device according to the invention, the hose has at least one inner layer containing a thermoplastic and a reinforcing layer containing, in particular, a metallic strength member. In this way, a connecting device suitable for transporting hydrogen can be created. The hose preferably has an outer layer containing an elastomer or a thermoplastic.

[0026] According to what has already been described above and further below, the object set out at the outset is also achieved by a high-pressure tank system having the features of claim 14.

[0027] The high-pressure tank system according to the invention has a reservoir for a fuel, in particular hydrogen, a fuel nozzle which can be connected to a vehicle tank, and a connecting device according to the invention by which the reservoir and the fuel nozzle are fluidly connected to one another.

[0028] The technical effects and advantages of the fitting and the connecting device according to the invention described above and below are also realized accordingly in the high-pressure tank system according to the invention.

[0029] According to what has already been described above and further below, the object set out at the outset is also achieved by a high-pressure vehicle tank system having the features of claim 15.

[0030] The high-pressure vehicle tank system according to the invention for a vehicle has a vehicle tank for a fuel, in particular hydrogen, a filler neck to which a fuel nozzle can be connected, and a connecting device according to the invention by means of which the vehicle tank and the filler neck are fluidly connected to one another.

[0031] The technical effects and advantages of the fitting and the connecting device according to the invention described above and below are also realized accordingly in the high-pressure vehicle tank system according to the invention.

[0032] It is expressly pointed out that the embodiments of the invention explained above can be combined individually or in any technically reasonable combination with each other with the subject matter of the independent claims.

[0033] Modifications and embodiments of the invention, as well as further advantages and details of the invention, can be found in the following description and the drawings. The schematic figures show: Fig. 1 shows an embodiment of a fitting according to the invention in a sectional view; Fig. 2 shows an embodiment of a connecting device according to the invention in a sectional view; Fig. 3 an embodiment of a high-pressure tank system according to the invention; and Fig. 4 an embodiment of a high-pressure vehicle tank system according to the invention.

[0034] Parts with the same or similar function are provided with identical reference numbers where appropriate.

[0035] Individual technical features of the exemplary embodiments described below can also be combined with previously described exemplary embodiments as well as the features of the independent claims and any further claims to form subject matter according to the invention.

[0036] Fig. 1 shows an embodiment of a fitting 10 according to the invention. The fitting 10 has a nipple 30, which defines a longitudinal central axis A or axial direction, and a compression sleeve 40. The fitting 10 extends essentially rotationally symmetrically around the longitudinal central axis A, whereby only one half of the fitting is shown. The fitting 10 has a hose receiving section 11, in which an end section of a hose 20 can be pushed onto the nipple 30 in a pushing-on direction AR and can be pressed sealingly onto the nipple 30 by means of the compression sleeve 40 (see Fig. 2). The hose receiving section 11 has the following sections arranged directly one behind the other with respect to the pushing-on direction AR: a movement section 113, a sealing section 112, and a hose retaining section 111.

[0037] In the hose retaining section 111, the nipple 30 and the compression sleeve 40 each form an uneven hose retaining surface 301, 401 for retaining a hose 20 pushed onto the nipple 30 and pressed. For this purpose, the hose retaining surfaces 301, 401 are provided with structures that can preferably at least partially penetrate into the hose 20 in the pressed state of the fitting 10 (see Fig. 2). The compression sleeve, for example, has on its inner side 41 a plurality of circumferentially extending compression projections 42 arranged at a distance from one another in the axial direction, which form part of the hose retention surface 401 of the compression sleeve 40. The hose retention surface 301 of the nipple 30 is formed by a plurality of adjacent recesses with conical surfaces, the respective outer diameters of which widen in the insertion direction AR. When the fitting 10 is pressed onto a hose 20, this leads to the hose retention surface 301 interlocking with the inner layer 20c of the hose, which promotes the hold between the nipple 30 and the inner layer 20c and also the tightness of the connection.

[0038] In the movement section 113, the nipple 30 and the compression sleeve 40 each form a substantially flat contact surface 303, 403 for pressing against a hose 20 pushed onto the nipple 30 and pressed. In this way, when dynamic loads occur on the connection - such as a tilting of the fitting 10 relative to the part of the hose 20 not gripped by the fitting 10 - smaller compensating movements of the hose 20 relative to the fitting 10 can take place, thus minimizing the risk of damage.

[0039] In the sealing section 112 arranged between the hose holding section 111 and the movement section 113, the nipple 30 has a circumferential annular bead 31 or olive. The axial extent of the annular bead 31 or olive and the axial extent of the sealing section 112 are congruent. The annular bead 31 or olive form the structure with the largest outer radius r2 of the nipple 30 in the hose receiving section 11. This creates a barrier for a fluid to be transported through the hose 20. The sealing section 112 is arranged in a first two-fifths 11a of the hose receiving section relative to the pushing-on direction AR, ie in the first 40% relative to the total axial length of the hose receiving section 11, so that the fluid barrier is provided as close as possible to an end of the nipple 30 facing the hose 20. The annular bead 31 orThe olive is formed integrally with the remaining nipple 30 and thus represents a local material thickening of the nipple 30, which promotes the stability of the fitting 10. In the sealing section 112, the compression sleeve 40 has, on its inner side 41, a circumferentially extending sealing projection 43, which is arranged opposite the annular bead 31, but is shortened compared to the pressing projections 42 in the hose retaining section 111 in order to form a suitable counterpart to the annular bead 31.

[0040] The hose retaining section 111 preferably has an axial length greater than the movement section 113 by a factor of 2.5 to 6. The sealing section 112 has a smaller axial length than the movement section 113.

[0041] The inner radius R2 of the compression sleeve 40 in the movement section 113 is larger than the inner radius R1 of the compression sleeve 40 (apart from the compression projections 42) in the hose retention section 111. Due to this simple structural design, in the compressed state of the fitting 10, the pressing force of the compression sleeve 40 on the hose 30 is greater in the hose retention section 111 than in the movement section 113. For the same reasons, the largest outer radius r3 of the nipple 30 in the movement section 113 is designed to be smaller than the largest outer radius r1 of the nipple (30) in the hose retention section 111.

[0042] To improve the flow properties, the inner radius r4 of the nipple 30 is constant in the hose receiving section 11 and the remaining nipple 30.

[0043] Fig. 2 shows an embodiment of a connecting device 1 according to the invention with the fitting 10 from Fig. 1 and a hose 20, wherein an end portion of the hose 20 is pushed onto the nipple 30 in the hose receiving portion 11 and is pressed sealingly onto the nipple 30 by means of the compression sleeve 40. The nipple 30 forms a shoulder 32 delimiting the hose receiving portion 11, against which an end face of the hose 20 can rest.

[0044] In the present embodiment, the hose 20 has an inner layer 20c containing a thermoplastic, a reinforcing layer 20b containing a particularly metallic strength member, and an outer layer 20c containing an elastomer or a thermoplastic.

[0045] The compression projections 42 in the hose retaining section 111 penetrate into the reinforcement layer 20b of the hose 20 and thus effectively secure it against being pulled out of the fitting 10. The sealing projection 43 located in the sealing section 112 forms a barrier against external influences and prevents, for example, moisture from creeping into the fitting 10 from the outside. For this reason, the sealing projection 43 does not penetrate the outer layer 20c so deeply that it is pierced and a path for moisture into the reinforcement layer 20b is opened. In the present embodiment, the sealing projection 43 also serves as a counterpart to the annular bead 31, which promotes tightness in the sealing section. In an alternative embodiment of the fitting 1 according to the invention, the compression projection 43 can also be arranged in the movement region.

[0046] The annular bead 31 or olive is pressed with its outer contour, which is convex with respect to the longitudinal central axis A, against the inner layer 20c of the hose 20 and in this way forms an effective barrier for a fluid to be transported through the hose 20 at very high pressure.

[0047] Fig. 3 shows an embodiment of a high-pressure tank system 100 according to the invention, for example for a hydrogen filling station, comprising a reservoir 101 for a fuel, in particular hydrogen, a fuel nozzle 102 or fuel nozzle, which can be connected to a vehicle tank, and a connecting device 1, as shown in Fig. 2 and by which the reservoir 101 and the fuel nozzle 102 are fluidly connected to one another. Due to its robustness against dynamic loads, the connecting device 1 according to the invention is ideally suited for applications in which the hose 20 is regularly moved.

[0048] Fig. 4 shows an embodiment of a high-pressure vehicle tank system 200 according to the invention for a vehicle 203, in particular a fuel cell vehicle, comprising a vehicle tank 201 for a fuel, in particular hydrogen, a filler neck 202 to which a fuel nozzle or fuel nozzle can be connected, and a connecting device 1, as shown in Fig. 2 and by which the vehicle tank 201 and the filler neck 202 are fluidly connected to one another.

[0049] It should also be noted that “having” does not exclude other elements or steps and “a” or “an” does not exclude a plurality.

[0050] The scope of protection of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 510 271 A1

[0002] EP 3 309 438 A1

[0003] JP 2008 151196 A

[0005]

Claims

[1] Fitting (10) for connecting a hose (20), in particular for high-pressure hydrogen fluid lines, with a nipple (30) defining a longitudinal central axis (A) and a compression sleeve (40), wherein the fitting (10) has a hose receiving section (11) in which an end section of the hose (20) can be pushed onto the nipple (30) in a pushing-on direction (AR) and can be pressed sealingly onto the nipple (30) by means of the pressing sleeve (40), wherein the hose receiving section (11) comprises: - a hose retaining section (111) in which the nipple (30) and the compression sleeve (40) each form an uneven hose retaining surface (301, 401) for retaining a hose (20) pushed onto the nipple (30) and pressed, - a movement section (113) in which the nipple (30) forms a particularly substantially flat contact surface (303, 403) for pressing against a hose (20) pushed onto the nipple (30) and pressed, and - a sealing section (112) arranged between the hose holding section (111) and the movement section (113), in which the nipple (30) has a circumferential annular bead (31). [2] Fitting (10) according to claim 1, wherein the sealing section (112) is arranged in a first half of the hose receiving section (11) relative to the pushing-on direction (AR), preferably in a first two-fifths (11a) of the hose receiving section (11). [3] Fitting (10) according to claim 1 or 2, wherein in the hose retaining section (111) the compression sleeve (40) has on its inner side (41) one or more compression projections (42) arranged spaced apart from one another in the axial direction and extending all around. [4] Fitting (10) according to one of the preceding claims, wherein in the sealing section (112) and / or in the movement section (113) the compression sleeve (40) has on its inner side (41) at least one circumferentially extending sealing projection (43). [5] Fitting (10) according to one of the preceding claims, wherein the annular bead (31) is formed integrally with the remaining nipple (30). [6] Fitting (10) according to one of the preceding claims, wherein in the hose receiving section (11) the annular bead (31) has the largest outer radius (r2) of the nipple (30). [7] Fitting (10) according to one of the preceding claims, wherein in the hose receiving section (11) the following sections are arranged, in particular directly one behind the other, with respect to the pushing-on direction (AR): - Movement section (113), - sealing section (112), - Hose retention section (111). [8] Fitting (10) according to one of the preceding claims, wherein the hose retaining section (111) has a greater axial length than the movement section (113), preferably a 2.5 to 6 times greater axial length than the movement section (113). [9] Fitting (10) according to one of the preceding claims, wherein the sealing section (112) has a smaller axial length than the movement section (113). [10] Fitting (10) according to one of the preceding claims, wherein the inner radius (R2) of the compression sleeve (40) in at least a part of the movement section (113) is larger than the inner radius (R1) of the compression sleeve (40) away from the compression projections (42) in the hose retaining section (111). [11] Fitting (10) according to one of the preceding claims, wherein the largest outer radius (r3) of the nipple (30) in the movement section (113) is smaller than the largest outer radius (r1) of the nipple (30) in the hose retaining section (111). [12] Fitting (10) according to one of the preceding claims, wherein the inner radius (r4) of the nipple (30) in the hose receiving portion (11) is constant. [13] Connecting device (1) with a fitting (10) according to one of the preceding claims and a hose (20), wherein an end section of the hose (20) in the hose receiving section (11) is pushed onto the nipple (30) and is pressed sealingly onto the nipple (30) by means of the press sleeve (40). [14] High-pressure tank system (100) containing a reservoir (101) for a fuel, in particular hydrogen, a fuel nozzle (102) which can be connected to a vehicle tank, and a connecting device (1) according to claim 13, by which the reservoir (101) and the fuel nozzle (102) are fluidly connected to one another. [15] High pressure vehicle tank system (200) for a vehicle comprising a vehicle tank (201) for a fuel, in particular hydrogen, a filler neck (202) to which a fuel nozzle can be connected, and a connecting device (1) according to claim 13, by which the vehicle tank (201) and the filler neck (202) are fluidly connected to one another.

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