END FITTING FOR A PRESSURIZED FLUID RESERVOIR

Abstract

End fitting for a pressurized fluid reservoir, the reservoir comprising a liner (2) which comprises a tubular central portion (20) with a first cylindrical outer surface (21), characterized in that the end fitting (1) comprises an end portion (10) with a second cylindrical outer surface (11), the end portion (10) being configured to be positioned coaxially with respect to the tubular central portion (20), the second cylindrical outer surface (11) forming a radially flush extension of the first cylindrical outer surface (21), the end fitting (1) being configured to be mounted in a sealed manner on the outside of a neck (22) of the liner (2) by means of an annular sealing joint (4) arranged coaxially with respect to the end portion (10) in an annular groove (12) provided in an inner recess (13) of the end fitting (1) such that the internal pressure in the reservoir has a tendency to push the neck (22) radially outwards against the annular sealing joint (4).

Claims

1. An end fitting for a pressurized fluid reservoir, the reservoir comprising a liner that comprises a tubular central portion with a first cylindrical outer surface, wherein the end fitting comprises an end portion with a second cylindrical outer surface, the end portion being configured to be positioned coaxially with respect to the tubular central portion, the second cylindrical outer surface forming a radially flush extension of the first cylindrical outer surface, the end fitting being configured to be mounted in a sealed manner on the outside of a neck of the liner by means of an annular sealing joint arranged coaxially with respect to the end portion in an annular groove provided in an inner recess of the end fitting such that the internal pressure in the reservoir has a tendency to push the neck radially outwards against the annular sealing joint.

2. The end fitting according to claim 1, wherein the second cylindrical outer surface of the end portion has a second outer diameter D2 and in that the inner recess has a first inner diameter D4, such that the ratio D4/D2 is between 0.6 and 0.95.

3. Pressurized A pressurized fluid reservoir, comprising: a liner comprising: a tubular central portion provided with a first cylindrical outer surface having a first outer diameter D1, a first neck connected to the tubular central portion by a first shoulder, a first end fitting sealably assembled to the first neck, a reinforcing enclosure of the liner, wherein the first end fitting comprises an end portion provided with a second cylindrical outer surface positioned coaxially with the tubular central portion in the radially flush extension of the first cylindrical outer surface, and wherein the first end fitting is sealably assembled on the outside of the first neck of the liner by means of an annular sealing joint arranged coaxially with the end portion in an annular groove formed in an inner recess of the first end fitting so that an internal pressure of the reservoir has a tendency to push the neck radially outwards against the annular sealing joint.

4. The pressurized fluid reservoir according to claim 3, wherein the second cylindrical outer surface of the end portion of the first end fitting has a second outer diameter D2, such that D2 is equal to D1.

5. The pressurized fluid reservoir according to claim 3, wherein the first end fitting is sealably assembled to the first neck by a screw-nut assembly.

6. The pressurized fluid reservoir according to claim 3, wherein opposite the first cylindrical outer surface of the tubular central portion of the liner, the second cylindrical outer surface of the end portion of the first end fitting is extended axially by a substantially hemispherical outer surface of a middle portion of the first end fitting, such that the substantially hemispherical outer surface is surrounded by the reinforcing enclosure of the liner.

7. The pressurized fluid reservoir according to claim 6, wherein the middle portion of the first end fitting comprises a fourth outer diameter D5, such that the ratio D5/D2 is between 0.5 and 0.95.

8. The pressurized fluid reservoir according to claim 6, wherein the reinforcing enclosure of the liner consists of a composite winding comprising several layers of reinforcing filaments wound in a helix around the tubular central portion of the liner and around the middle portion of the first end fitting, such that the helical winding angle (A) of at least one first layer is less than 54°, and such that the helical winding angle of at least one second layer is between 53° and 56°.

9. The pressurized fluid reservoir according to claim 3, wherein the first end fitting further comprises at least one functional element selected from the group consisting of a pressure relief valve, a valve forming a flow limiter, a non-return valve, a manual shut-off valve, an injector, a filter, a temperature sensor and a pressure sensor.

10. The pressurized fluid reservoir according to claim 3, wherein the liner is manufactured by injection, rotational molding or extrusion-blow molding of a thermoplastic or thermosetting polymer material.

11. The pressurized fluid reservoir according to claim 3, wherein the liner is manufactured by filament winding.

12. The pressurized fluid reservoir according to claim 3, wherein the reinforcing enclosure of the liner is coated with one or more layers of a fire-retardant material.

13. The pressurized fluid reservoir according to claim 3, wherein the end fitting is a piece of metal.

14. The pressurized fluid reservoir according to claim 6, wherein the second cylindrical outer surface and the substantially hemispherical outer surface of the end fitting are covered, at least partially, with a composite structure, the composite structure being sandwiched between the end fitting and the reinforcing enclosure of the liner.

15. A vehicle, comprising: a reservoir according to claim 3, an energy conversion means configured to supply energy to propulsion means of the vehicle, which is in fluidic communication with the reservoir via the first end fitting so that it can be supplied with fluid, a reservoir filling means, which is in fluidic communication with the reservoir via the first end fitting, and an actuator configured to selectively actuate either the energy conversion means or the reservoir filling means, in response to a control signal.

16. The end fitting according to claim 2, wherein the ratio D4/D2 is between 0.8 and 0.95.

17. The pressurized fluid reservoir according to claim 7, wherein the ratio D5/D2 is between 0.8 and 0.95.

18. The pressurized fluid reservoir according to claim 8, wherein the helical winding angle (A) of at least one first layer is less than 53°.

19. The pressurized fluid reservoir according to claim 8, wherein the helical winding angle of at least one second layer is 54.7°.

20. The pressurized fluid reservoir according to claim 10, wherein the liner is manufactured by injection, rotational molding or extrusion-blow molding of a thermoplastic polymer material filled with reinforcing fibers.

21. The pressurized fluid reservoir according to claim 12, wherein the fire-retardant material is an intumescent fire-retardant material.

22. The pressurized fluid reservoir according to claim 21, wherein the intumescent fire-retardant material is a coating based on silicate or phosphate.

23. The pressurized fluid reservoir according to claim 22, wherein the coating based on silicate or phosphate comprises ammonium polyphosphate dosed from 10% to 50%.

24. The vehicle according to claim 15, wherein the vehicle is a motor vehicle.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0085] The invention will be better understood on reading the following description given solely by way of example and with reference to the appended figures, in which the same reference numbers designate elements having identical, analogous or similar functions, and in which:

[0086] FIG. 1 is a cross-sectional view of a reservoir according to the invention;

[0087] FIG. 2 is an exploded perspective view of a detail of the reservoir of FIG. 1, illustrating a first embodiment of the sealing of an end fitting according to the invention;

[0088] FIG. 3 is a sectional view of a detail of the reservoir of FIG. 1, illustrating the first embodiment of the sealing of an end fitting according to the invention;

[0089] FIG. 4 is a sectional view of a detail of a reservoir according to the invention, illustrating a second embodiment of the sealing of an end fitting according to the invention.

DETAILED DESCRIPTION

[0090] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined and/or interchanged to provide other embodiments.

[0091] In the present description, it is possible to index certain elements or parameters, for example a first element or second element as well as a first parameter and second parameter or a first criterion and second criterion, etc. In this case, it is a simple indexing process to differentiate and name similar but not identical elements or parameters or criteria. This indexing does not imply a priority of one element, parameter or criterion with respect to another and such denominations can easily be interchanged without departing from the scope of the present description. Nor does this indexing imply an order in time, for example to assess this or that criterion.

[0092] FIG. 1 shows a pressurized fluid reservoir 100, in particular for storing and distributing pressurized gas—for example hydrogen at 700 bar—in a motor vehicle (not shown), according to one embodiment of the invention. The reservoir 100 is a cylindrical reservoir with a longitudinal axis X; it comprises a liner 2 comprising a tubular central portion 20 and two ends. The tubular central portion 20 is provided with a first cylindrical outer surface 21. First and second necks 22 are provided at the first and second ends of the liner 2. The first and a second necks 22 are connected to the tubular central portion 20 by first and second shoulders 23. The reservoir 100 comprises first and second end fittings 1 sealably assembled to the first and second necks 22. The reservoir 100 further comprises a reinforcing enclosure 3 of the liner 2. The first and second end fittings 1 each comprise an end portion 10 provided with a second cylindrical outer surface 11 positioned coaxially in the radially flush extension of the first cylindrical outer surface 21 (see also FIGS. 2 to 4).

[0093] As illustrated, the first cylindrical outer surface 21 of the tubular central portion 20 of the liner 2 has a first outer diameter D1 and the second cylindrical outer surface 11 of the end portion 10 of the first end fitting 1 has a second outer diameter D2 (see FIG. 2), such that the second outer diameter D2 is equal to the first outer diameter D1.

[0094] The neck 22 has a third outer diameter D3 and the first end fitting 1 comprises an inner recess 13 to accommodate the neck 22. The inner recess 13 has a first inner diameter D4 such that the third outer diameter D3 is equal to the first inner diameter D4. Moreover, the ratio of the first inner diameter D4 to the second outer diameter D2 is between 0.6 and 0.95, preferably between 0.8 and 0.95.

[0095] Advantageously, the end fitting is a piece of metal, for example aluminum.

[0096] Advantageously, the liner is manufactured by injection, rotational molding or extrusion-blow molding of a thermoplastic or thermoset polymer material, for example, polyamide, and the thickness of the liner is less than or equal to 5 mm.

[0097] Alternatively, the liner is manufactured by injection, rotational molding or extrusion-blow molding of a composite material.

[0098] Alternatively, the liner is made by filament winding.

[0099] Alternatively, the liner is made of metal, for example, 6061 aluminum.

[0100] Advantageously, the reservoir 100 comprises a fiberglass protective layer (not shown) surrounding the reinforcing enclosure 3 of the liner 2.

[0101] Advantageously, the reinforcing enclosure of the liner is coated with one or more layers of a fire-retardant material (not shown), preferably an intumescent fire-retardant material such as, for example, a coating based on silicate or phosphate, preferably ammonium polyphosphate dosed from 10% to 50%.

[0102] Still in the illustrated example, the reservoir 100 is a long and thin reservoir, that is to say, the ratio of its length to its diameter is greater than or equal to six (6). Indeed, the length of the reservoir 100 is between 1000 mm and 2000 mm and its diameter is between 100 mm and 150 mm.

[0103] FIGS. 2 and 3 illustrate a first embodiment of the sealing of the end fitting/neck assembly in which the first end fitting 1 is designed to adapt to a pressurized fluid reservoir 100, the reservoir comprising a liner 2 comprising a tubular central portion 20 provided with a first cylindrical outer surface 21, the first end fitting 1 comprising an end portion 10 provided with a second cylindrical outer surface 11 able to be positioned coaxially in the radially flush extension of the first cylindrical outer surface 21. In this first embodiment of sealing, the first end fitting 1 is sealably assembled on the outside of the first neck 22 by an annular sealing joint 4 arranged coaxially in an annular groove 12 formed in the inner recess 13 of the first end fitting 1. A shrink-fit ring 5 is arranged inside the first neck 22 to hold the first neck 22 radially tight against the annular sealing joint 4.

[0104] Advantageously, the first end fitting 1 is sealably assembled to the first neck 22 by an assembly of the screw-nut type. To this end, a thread 24 is provided on the outer periphery of the first neck 22.

[0105] Alternatively, the first end fitting 1 is sealably assembled to the first neck 22 by clipping, gluing or shrinking (not shown).

[0106] Advantageously, the annular sealing joint 4 is an elastomer seal.

[0107] Advantageously, the annular sealing joint 4 is an O-ring.

[0108] In addition to the elements already described above, FIG. 3 illustrates the presence of a tapped hole 16 in the longitudinal axis of the first end fitting 1 for mounting a solenoid valve (not shown) on the first end fitting 1.

[0109] Opposite the first cylindrical outer surface 21 of the tubular central portion 20 of the liner 2, the second cylindrical outer surface 11 of the end portion 10 of the first end fitting 1 is extended axially by a substantially hemispherical outer surface 14 of a middle portion 15 of the first end fitting 1, such that the substantially hemispherical outer surface 14 is surrounded by the reinforcing enclosure 3 (not shown) of the liner 2. The middle portion 15 of the first end fitting 1 comprises a fourth outer diameter D5, such that the ratio of the fourth outer diameter D5 to the second outer diameter D2 is between 0.5 and 0.95, preferably between 0.8 and 0.95.

[0110] FIG. 4 shows a second embodiment of the sealing of the end fitting/neck assembly. In this second embodiment of the sealing, the first end fitting 1 is sealably assembled on the outside of the first neck 22 by an annular sealing joint 4 arranged coaxially in an annular groove 12 formed in an inner recess 13 of the first end fitting 1, the internal pressure of the reservoir 100 having a tendency to push the first neck 22 radially outwards against the annular sealing joint 4. In the illustrated example, the inner recess 13 has the shape of an annular recess. A free, but reduced space is provided between the inner wall of the annular recess and the inner wall of the first neck 22. The purpose of this free space is to be occupied by the pressurized fluid in order to increase the radial forces exerted by the fluid on the inner wall of the first neck 22. The arrows F illustrate the directions of the pressure force exerted by the fluid on the inner wall of the liner 2.

[0111] As illustrated, the reinforcing enclosure 3 of the liner 2 consists of a composite winding comprising several layers of reinforcing filaments wound in a helix around the tubular central portion 20 of the liner 2 and around the middle portion 15 of the first end fitting 1, such that the helical winding angle A of at least one first layer of filaments is less than 54°, preferably less than 53°, and such that the helical winding angle of at least one second layer of filaments is between 53° and 56°, for example 54.7°.

[0112] It is expected that at least a first layer of filaments is an inner layer of the composite winding.

[0113] It is expected that at least a second layer of filaments is an outer layer of the composite winding.

[0114] Advantageously, the reinforcing filaments consist of glass fibers, aramid fibers and/or carbon fibers.

[0115] FIGS. 3 and 4 illustrate another embodiment of the invention where the second cylindrical outer surface 11 and the substantially hemispherical outer surface 14 of the end fitting 1 are covered, at least partially, with a composite structure 25, the composite structure 25 being sandwiched between the end fitting 1 and the reinforcing enclosure 3 of the liner 2.

[0116] A reservoir as mentioned above is for example placed on a vehicle, preferably a motor vehicle, which comprises: [0117] a reservoir according to the invention, [0118] an energy conversion means configured to supply energy to propulsion means of the vehicle, which is in fluidic communication with the reservoir via the first end fitting so that it can be supplied with fluid, [0119] a reservoir filling means, which is in fluidic communication with the reservoir via the first end fitting, and [0120] an actuator configured to selectively actuate either the energy conversion means or the reservoir filling means, in response to a control signal.

[0121] The invention is not limited to the embodiments presented; it is in particular possible to integrate at least one functional element into the first end fitting. This functional element is chosen from among a pressure relief valve, preferably with thermal triggering, a valve forming a flow limiter, a non-return valve, a manual shut-off valve, an injector, a filter, a temperature sensor and a pressure sensor. Likewise, the designs concerning the end fittings are intended for all pressurized reservoirs, regardless of the fluid carried or the very shape of the reservoir (cylindrical or ovoid).