Fitting for connecting a hose

Abstract

The invention relates to a fitting for connecting a hose (20), having a nipple (30) and a ferrule (40), wherein the fitting (10) contains a hose receiving portion (11). It is proposed to divide the hose receiving portion (11) into three special functional portions (111, 112, 113).

Description

DescriptionFitting for connecting a hose

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

[0002] Fittings of this type are used in fluid systems, in which a fluid is transported by flexible hoses. To connect the hoses to other lines or devices, such as a fuel nozzle or gas pump nozzle, the hose ends are provided with fittings. Frequently, in this connection, an end portion of the hose is pushed onto a nipple of the fitting and pressed into place (e.g. crimped) on the nipple by means of a ferrule of the fitting, with the ferrule being plastically deformed. EP 2 510 271 Al shows an example of a fitting pressed into place on a fluid line of an air conditioning system for motor vehicles.

[0003] Flexible hoses are usually hybrid composite structures consisting of a plurality of layers, such as an inner layer containing a thermoplastic, a reinforcing layer containing an in particular metallic strength member, and an outer layer containing an elastomer or a thermoplastic. EP 3 309438 Al shows an example of a hose of this type which is designed for the transport of hydrogen.

[0004] Depending on the application, the connection between the fitting and the hose may be subject to considerable mechanical loads. Particularly in the case of high- pressure hydrogen fluid lines, such as are required, for example, for hydrogen dispensing systems for mobile hydrogen consumers (e.g. fuel cell vehicles), a particularly high degree of tightness of the connection has to be ensured because of the high operating pressure of generally over 1000 bar. Nevertheless, the lowest possible permeation of hydrogen through the interface between fitting and hose has to be ensured.

[0005] Fittings for hydrogen applications are known from the prior art, in which the nipple of the fitting is provided with one or more elastomeric seals for sealingcontact with an inner side of the hose. In order to secure these seals, which are usually in the form of O-ring seals, in their axial position, the nipple has circumferential grooves into which the seals can be placed. An example of such a fitting is shown in JP 2008 151196 A. However, when such a fitting is installed at a hose end, there is always the risk that, as the hose is pushed onto the nipple, the seals will be pushed out of their grooves and - after the hose is pressed into place on the nipple by means of the ferrule - are not able to carry out their intended sealing function.

[0006] It is therefore an object of the present invention to provide a fitting with which a particularly tight connection to a hose can be produced. In particular, the fitting is intended to be suitable for use in conjunction with high-pressure hydrogen fluid lines and, in this connection, to ensure the lowest possible permeation of hydrogen. Particularly preferably, a fitting is intended to be provided with which a tight connection to the hose can be produced without the use of elastomeric 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 matter of the dependent claims. Further advantages and features can be found in the general description and in the exemplary embodiments.

[0008] The fitting according to the invention for connecting a hose has a nipple, which defines a longitudinal axis, and a ferrule. The fitting has a hose receiving portion, in which an end portion of the hose can be pushed onto the nipple in a push-on direction and can be pressed sealingly onto the nipple by means of the ferrule. The hose receiving portion is divided into the following portions: a hose retaining portion, in which the nipple and the ferrule each form an uneven hose retaining surface for retaining a hose which is pushed onto the nipple and pressed into place,a movement portion, in which the nipple forms an in particular substantially flat contact pressure surface for pressing against a hose which is pushed onto the nipple and pressed into place, and a sealing portion, which is arranged between the hose retaining portion and the movement portion and in which the nipple has a circumferential annular bead.

[0009] The invention is based on the concept of assigning the abovementioned distinct functional portions to the hose receiving portion.

[0010] A first portion, the hose retaining portion, is primarily used to tightly hold and clamp the hose. For this purpose, the fitting forms uneven, for example toothed and / or ribbed, hose retaining surfaces in the hose retaining portion, which hose retaining surfaces penetrate preferably at least partially into the hose when the fitting is pressed into place. Preferably, the hose retaining surface of the nipple has recesses forming conical surfaces. Recesses with conical surfaces in the first hose retaining portion, the respective outer diameter of which expands in the push-on direction, lead to intermeshing of the hose retaining portion and the inner layer of the hose when the fitting is pressed into place on a hose, which promotes the grip between nipple and inner layer and also the tightness of the connection. For an improved retaining function, in a preferred configuration of the fitting according to the invention, in the hose retaining portion, the inner side of the ferrule has one or more pressing protrusions, or pressing teeth, arranged spaced apart from one another in the axial direction and extending all around. When the fitting is pressed into place on the hose, said pressing teeth are designed to penetrate the hose to secure the hose against pulling out of the fitting.

[0011] The second portion, the movement portion, which is located in front of the hose retaining portion in the push-on direction and in particular at the hose-side end of the hose receiving portion, forms a gradual transition between the end portion of the hose held in place and clamped by the hose retaining portion and the remaining hose not covered by the fitting. In the movement portion, the hose is therefore clamped to a lower degree than in the hose retaining portion when the fitting is pressed into place. For this purpose, for example, the nipple forms a contact pressure surface whichis in particular substantially flat, preferably cylindrical, in the movement portion for pressing against the hose, in particular wherein the contact pressure surface has no structures that penetrate into the hose when the fitting is pressed into place. Preferably, the ferrule in the movement portion has no structures which are designed to penetrate an outer layer of the hose when the fitting is pressed into place. Preferably, the movement portion is designed to allow smaller 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 covered by the fitting) in order in this way to prevent damage to the connection, for example due to stress peaks in the material.

[0012] The third portion, the sealing portion, separates the first and second portions from each other and forms a barrier for the fluid to be transported through the hose. For this purpose, the nipple in the sealing portion is provided with a circumferential annular bead or an olive, which is pressed against an inner surface of the hose with its outer contour, which is convex with respect to the longitudinal center axis, when the fitting is pressed into place. In particular, the nipple in the sealing portion has precisely one circumferential annular bead. Preferably, the sealing portion 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 portion are congruent. Preferably, the annular bead is formed integrally with the remaining nipple. In contrast to nipples which are provided with elastomeric seals and in which, for the groove into which the seal is inserted, material has to be severed from the nipple, in the present invention a sealing region is provided by a material thickening of the nipple, which increases the stability of the fitting.

[0013] It has been found that, with the fitting according to the invention, a connection to a hose, which is extremely resilient even at higher operating pressures and maintains its tightness, can be produced. In particular, a tight connection could be provided without the use of elastomeric seals on the nipple. Preferably, in the hose receiving portion, the following portions are arranged one after the other, in particular directly, with respect to the push-on direction: movement portion, sealing portion,hose retaining portion.

[0014] Preferably, the ferrule and / or the nipple is made of a metal, preferably of steel or aluminum. In particular, the ferrule and / or the nipple is in each case formed integrally.

[0015] In a further preferred refinement of the fitting according to the invention, the sealing portion is arranged in a first half of the hose receiving portion, preferably in a first two-fifths of the hose receiving portion, with respect to the push- on direction. 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 portion promotes the tightness, since in this way a barrier for the fluid to be transported through the hose is provided as close as possible to the end of the nipple facing the hose.

[0016] In a further preferred refinement of the fitting according to the invention, in the sealing portion and / or in the movement portion, the inner side of the ferrule has at least one sealing protrusion which extends all around and which is shortened in particular in relation to the pressing protrusions. In other words, the sealing protrusion has a larger inner radius than the pressing protrusions. Primarily, the sealing protrusion serves as a barrier against external influences, such as moisture, which is why the sealing protrusion is preferably designed, when the fitting is pressed into place, merely to clamp an outer (elastomeric) layer of the hose and in particular not to penetrate it completely, since otherwise a path would be free for example for the moisture to the underlying strength member layer. Furthermore, a counterpart to the olive can be provided with a sealing protrusion arranged in the sealing portion on the side of the ferrule, which increases both the strength and the tightness in this region. Preferably, the sealing protrusion in this case is arranged opposite the annular bead.

[0017] In a further preferred refinement of the fitting according to the invention, in the hose receiving portion, the annular bead has the largest outer radius of the nipple. In other words, the outer radius of the annular bead is preferably greater than the outer radius of any other structure of the nipple. In this way, the annular bead forms a solid barrier for the fluid to be transported through the hose.

[0018] In a further preferred refinement of the fitting according to the invention, the hose retaining portion has a greater axial length than the movement portion, preferably a 2.5 times to 6 times greater, particularly preferably a 3.5 times to 5 times greater, axial length than the movement portion. Surprisingly, it has turned out that, with a structural configuration of this type, good results with regard to the tightness of the connection can be achieved.

[0019] In a further preferred refinement of the fitting according to the invention, the sealing portion has a smaller axial length than the movement portion. Good results with respect to the tightness of the connection could be achieved with a compact design of this type.

[0020] In a further preferred refinement of the fitting according to the invention, the inner radius of the ferrule is larger in at least part of the movement portion (e.g. away from an optionally present sealing protrusion) than the inner radius of the ferrule away from the pressing protrusions in the hose retaining portion. Owing to this simple structural configuration, robustness against dynamic loads can be promoted in the movement portion and / or the strength of the connection can be promoted in the hose retaining portion. Preferably, for the same purpose, the largest outer radius of the nipple in the movement portion is smaller than the largest outer radius of the nipple in the hose retaining portion.

[0021] In a further preferred refinement of the fitting according to the invention, the nipple has a constant inner radius at least in the hose receiving portion. In this way, the flow properties are promoted and in particular pressure losses in this region are minimized. In addition, the nipple can be produced in a simple way.

[0022] According to that which is already described above and that described further below, the object stated at the beginning is also achieved by a connecting device having the features of claim 13.

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

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

[0025] In a preferred refinement of the connecting device according to the invention, the hose has at least one inner layer containing a thermoplastic and a reinforcing layer containing an in particular metallic strength member. In this way, a connecting device which is suitable for the transport of hydrogen can be provided. Preferably, the hose has an outer layer containing an elastomer or a thermoplastic.

[0026] According to that which is already described above and that described further below, the object stated at the beginning 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 fluid-conductively connected to each other.

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

[0029] According to that which is already described above and that described further below, the object stated at the beginning 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 which the vehicle tank and the filler neck are fluid-conductively connected to each other.

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

[0032] It is expressly pointed out that the above-explained refinements of the invention, each taken alone or in any technically meaningful combination with one another as well, can each be combined with the subject matter of the independent claims.

[0033] Modifications and refinements of the invention and also further advantages and details of the invention can be found in the following substantive description and the drawings. In the schematic figures: fig. 1 shows an exemplary embodiment of a fitting according to the invention in a sectional view; fig. 2 shows an exemplary embodiment of a connecting device according to the invention in a sectional view; fig. 3 shows an exemplary embodiment of a high-pressure tank system according to the invention; and fig. 4 shows an exemplary embodiment of a high-pressure vehicle tank system according to the invention.

[0034] Identically or similarly acting parts are - where appropriate - provided with identical reference numerals.

[0035] Individual technical features of the exemplary embodiments described below may also be combined to form inventive subject matter in combination with above-described exemplary embodiments and with the features of the independent claims and any further claims.

[0036] Fig. 1 shows an exemplary embodiment of a fitting 10 according to the invention. The fitting 10 has a nipple 30, which defines a longitudinal center axis A or axial direction, and a ferrule 40. The fitting 10 extends substantially rotationallysymmetrically about the longitudinal center axis A, with only one half of the fitting being shown. The fitting 10 has a hose receiving portion 11, in which an end portion of a hose 20 can be pushed onto the nipple 30 in a push-on direction AR and can be pressed sealingly onto the nipple 30 by means of the ferrule 40 (see fig. 2). The hose receiving portion 11 has the following portions arranged directly one behind another with respect to the push-on direction AR: a movement portion 113, a sealing portion 112, and a hose retaining portion 111.

[0037] In the hose retaining portion 111, the nipple 30 and the ferrule 40 each form an uneven hose retaining surface 301, 401 for retaining a hose 20 which is pushed onto the nipple 30 and pressed into place. For this purpose, the hose retaining surfaces 301, 401 are provided with structures which, when the fitting 10 is pressed into place, can preferably at least partially penetrate into the hose 20 (see fig. 2). The inner side 41 of the ferrule, for example, has a plurality of pressing protrusions 42 which are arranged spaced apart from one another in the axial direction, extend all around and form part of the hose retaining surface 401 of the ferrule 40. The hose retaining surface 301 of the nipple 30 is formed by a plurality of adjacent recesses with conical surfaces, the respective outer diameter of which widens in the push-on direction AR. When the fitting 10 is pressed into place on a hose 20, this leads to intermeshing of the hose retaining surface 301 with the inner layer 20c of the hose, which promotes the grip between nipple 30 and inner layer 20c and also the tightness of the connection.

[0038] In the movement portion 113, the nipple 30 and the ferrule 40 each form a substantially flat contact pressure surface 303, 403 for pressing onto a hose 20 which is pushed onto the nipple 30 and pressed into place. In this way, when dynamic loads of the connection occur - such as tilting of the fitting 10 relative to that part of the hose 20 which is not covered by the fitting 10 - smaller compensating movements of the hose 20 relative to the fitting 10 can take place, and therefore the risk of damage is minimized.

[0039] In the sealing portion 112, which is arranged between the hose retaining portion 111 and the movement portion 113, the nipple 30 has a circumferential annular bead 31 or olive.

[0040] Here, the axial extent of the annular bead 31 or olive and the axial extent of the sealing portion 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 portion 11. This creates a barrier for a fluid to be transported through the hose 20. The sealing portion 112 is arranged in a first two-fifths Ila of the hose receiving portion, with respect to the push-on direction AR, i.e. in the first 40 % with respect to the overall axial length of the hose receiving portion 11, and therefore the fluid barrier is provided as close as possible to an end of the nipple 30 facing the hose 20. The annular bead 31 or olive is formed integrally with the rest of the nipple 30 and thus constitutes a local material thickening of the nipple 30, which promotes the stability of the fitting 10. In the sealing portion 112, the inner side 41 of the ferrule 40 has a sealing protrusion 43 which extends all around and is arranged opposite the annular bead 31, but is shortened compared to the pressing protrusions 42 in the hose retaining portion 111, in order to form a mating counterpart to the annular bead 31.

[0041] The hose retaining portion 111 has an axial length which is preferably larger by a factor of 2.5 to 6 than the movement portion 113. The sealing portion 112 has a smaller axial length than the movement portion 113.

[0042] The inner radius R2 of the ferrule 40 in the movement portion 113 is greater than the inner radius R1 of the ferrule 40 (away from the pressing protrusions 42) in the hose retaining portion 111. Owing to this simple structural design, when the fitting 10 is pressed into place, the pressing force of the ferrule 40 onto the hose 30 in the hose retaining portion 111 is greater than in the movement portion 113. For the same considerations, the largest outer radius r3 of the nipple 30 in the movement portion 113 is designed to be smaller than the largest outer radius rl of the nipple (30) in the hose retaining portion 111.

[0043] To promote the flow properties, the inner radius r4 of the nipple 30 in the hose receiving portion 11 and the rest of the nipple 30 is constant.

[0044] Fig. 2 shows an exemplary 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 in the hose receiving portion 11 is pushed onto the nipple 30 and is pressed sealingly onto the nipple 30 by means of the ferrule 40. The nipple 30forms a shoulder 32 which limits the hose receiving portion 11 and against which an end face of the hose 20 can lie.

[0045] In the present embodiment, the hose 20 has an inner layer 20c containing a thermoplastic, a reinforcing layer 20b containing an in particular metallic strength member, and an outer layer 20c containing an elastomer or a thermoplastic.

[0046] The pressing protrusions 42 in the hose retaining portion 111 penetrate into the reinforcing layer 20b of the hose 20 and thus effectively secure the latter against pulling out of the fitting 10. The sealing protrusion 43 located in the sealing portion 112 forms a barrier against external influences and prevents, e.g., moisture from creeping into the fitting 10 from the outside. For this reason, the sealing protrusion 43 does not therefore penetrate so deeply into the outer layer 20c that the latter is pierced and a path for moisture is opened up into the reinforcing layer 20b. In the present embodiment, the sealing protrusion 43 also serves as a counterpart to the annular bead 31, which promotes the tightness in the sealing portion. In an alternative configuration according to the invention of the fitting 1, the pressing protrusion 43 can also be arranged in the movement region.

[0047] The annular bead 31 or olive is pressed against the inner layer 20c of the hose 20 with its outer contour, which is convex with respect to the longitudinal center axis A, and in this way forms an effective barrier for a fluid to be transported at very high pressure through the hose 20.

[0048] Fig. 3 shows an exemplary embodiment of a high-pressure tank system 100 according to the invention, for example for a hydrogen filling station, containing a reservoir 101 for a fuel, in particular hydrogen, a fuel nozzle 102 or gas pump 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 fluid-conductively connected to each other. Owing 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.

[0049] Fig. 4 shows an exemplary embodiment of a high-pressure vehicle tank system 200 according to the invention for a vehicle 203, in particular a fuel cell vehicle,containing a vehicle tank 201 for a fuel, in particular hydrogen, a filler neck 202, to which a fuel nozzle or gas pump 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 fluid- conductively connected to each other.

[0050] In addition, it should be mentioned that “comprising” and “having” does not exclude any other elements or steps and “a” or “an” or “one” does not exclude a multiplicity.

[0051] The scope of protection of the present invention is defined by the patent claims and is not limited by the features explained in the description or shown in the figures.

Claims

Patent claims1. A fitting (10) for connecting a hose (20), in particular for high-pressure hydrogen fluid lines, having a nipple (30), which defines a longitudinal center axis (A), and a ferrule (40), wherein the fitting (10) has a hose receiving portion (11), in which an end portion of the hose (20) can be pushed onto the nipple (30) in a push-on direction (AR) and can be pressed sealingly onto the nipple (30) by means of the ferrule (40), wherein the hose receiving portion (11) has the following: a hose retaining portion (111), in which the nipple (30) and the ferrule (40) each form an uneven hose retaining surface (301, 401) for retaining a hose (20) which is pushed onto the nipple (30) and pressed into place, a movement portion (113), in which the nipple (30) forms an in particular substantially flat contact pressure surface (303, 403) for pressing against a hose (20) which is pushed onto the nipple (30) and pressed into place, and a sealing portion (112), which is arranged between the hose retaining portion (111) and the movement portion (113) and in which the nipple (30) has a circumferential annular bead (31).

2. The fitting (10) as claimed in claim 1, wherein the sealing portion (112) is arranged in a first half of the hose receiving portion (11), preferably in a first two-fifths (Ila) of the hose receiving portion (11), with respect to the push-on direction (AR).

3. The fitting (10) as claimed in claim 1 or 2, wherein, in the hose retaining portion (111), the inner side (41) of the ferrule (40) has one or more pressing protrusions (42) arranged spaced apart from one another in the axial direction and extending all around.

4. The fitting (10) as claimed in any one of the preceding claims, wherein, in the sealing portion (112) and / or in the movement portion (113), the inner side (41) of the ferrule (40) has at least one sealing protrusion (43) extending all around.

5. The fitting (10) as claimed in any one of the preceding claims, wherein the annular bead (31) is formed integrally with the remaining nipple (30).

6. The fitting (10) as claimed in any one of the preceding claims, wherein, in the hose receiving portion (11), the annular bead (31) has the largest outer radius (r2) of the nipple (30).

7. The fitting (10) as claimed in any one of the preceding claims, wherein, in the hose receiving portion (11), the following portions are arranged one after the other, in particular directly, with respect to the push-on direction (AR): movement portion (113), sealing portion (112),- hose retaining portion (111).

8. The fitting (10) as claimed in any one of the preceding claims, wherein the hose retaining portion (111) has a greater axial length than the movement portion (113), preferably has a 2.5 times to 6 times greater axial length than the movement portion [H3).

9. The fitting (10) as claimed in any one of the preceding claims, wherein the sealing portion (112) has a smaller axial length than the movement portion (113).

10. The fitting (10) as claimed in any one of the preceding claims, wherein the inner radius (R2) of the ferrule (40) is larger in at least part of the movement portion (113) than the inner radius (Rl) of the ferrule (40) away from the pressing protrusions (42) in the hose retaining portion (111).

11. The fitting (10) as claimed in any one of the preceding claims, wherein the largest outer radius (r3) of the nipple (30) in the movement portion (113) is smaller than the largest outer radius (rl) of the nipple (30) in the hose retaining portion (111).

12. The fitting (10) as claimed in any one of the preceding claims, wherein the inner radius (r4) of the nipple (30) in the hose receiving portion (11) is constant.

13. A connecting device (1), having a fitting (10) as claimed in any one of the preceding claims, and a hose (20),wherein an end portion of the hose (20) in the hose receiving portion (11) is pushed onto the nipple (30) and pressed sealingly onto the nipple (30) by means of the ferrule (40).

14. A 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) as claimed in claim 13, by which the reservoir (101) and the fuel nozzle (102) are fluid-conductively connected to each other.

15. A high-pressure vehicle tank system (200) for a vehicle, containing 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) as claimed in claim 13, by which the vehicle tank (201) and the filler neck (202) are fluid-conductively connected to each other.

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