Enclosure for a pressurized gas tank

Abstract

Casing for a pressurized gas tank. The invention relates to a casing (1) for a pressurized gas tank, comprising a neck (2) substantially cylindrical about an axis (A), adapted to fit into a bore (21) with axis (A) of a base (20), wherein the neck (2) comprises at least one clip (3) comprising at least one protrusion (4) adapted to engage a cavity (22) of the base (20), having a shape complementary to the protrusion (4), so as to ensure a longitudinal assembly of the neck (2) relative to the base (20). The invention further relates to a base (20) adapted to accommodate such a casing (1). The invention further relates to a tank comprising such a casing (1) and / or such a base (20). Illustration: Figure 1

Description

Title of the invention: Casing for a pressurized gas tank Technical field

[0001] The invention relates to a pressurized gas tank, such as hydrogen. More particularly, the invention aims to protect a provision of a casing or "liner" of such a tank, allowing it to be assembled simply with a base of such a tank. Prior art

[0002] A pressurized gas tank can be made using a composite material structure (fiber reinforcement embedded in a resin matrix) of typically cylindrical shape in the central part, terminated at its two ends by a hemispherical cap.

[0003] In order to be able to fill the gas tank and then draw the gas, the structure typically comprises a through hole, conventionally arranged in the center of a hemispherical cap. In this hole is arranged a base, generally metallic, substantially of revolution around a through bore, arranged substantially aligned with the hole so as to allow filling and / or drawing.

[0004] The composite material structure is not intrinsically gas-tight. Also, its inner surface is lined with an envelope, conventionally made of elastomer material, ensuring gas tightness. The shape of this envelope substantially reproduces the internal shape of the structure. The envelope has a neck capable of being housed in the bore of the base.

[0005] In order to ensure fixing and gas-tightness, at the interface between the casing and the base, the neck is currently glued to the bore. However, gluing is a complicated process, difficult to master and requiring a very long time, which can reach 8 hours per tank.

[0006] Also, another method is sought for producing a watertight assembly between the neck of an envelope and a base. Summary of the invention

[0007] The invention proposes to provide a means of assembling an envelope on a base as an alternative to gluing.

[0008] For this purpose, the invention relates to an envelope for a pressurized gas tank, comprising a neck that is substantially cylindrical around an axis, capable of being housed in a bore of a base along an axis, where the neck comprises at least one clip comprising at least one protuberance capable of engaging a cavity of the base, of complementary shape to the protuberance, so as to ensure longitudinal assembly of the neck relative to the base.

[0009] Particular characteristics or embodiments, usable alone or in combination, are:

[0010] - a clip is formed, relative to the neck, by two cutouts, passing through relative to the thickness of the neck, opening at the end of the neck, substantially longitudinal and substantially parallel to each other, so as to form a longitudinal tab,

[0011] - a protrusion is arranged substantially at the distal end of a tab, is outgoing and has a support face substantially perpendicular to the axis, the normal of which moves away from the end of the neck,

[0012] - a protuberance is arranged substantially at the end of the neck,

[0013] - a clip further comprises a narrowing of the thickness of the tab, approximately at the level of the foot of the tongue,

[0014] - said at least one clip comprises at least two equally angular clips distributed around the axis,

[0015] - the envelope also comprises at least one first anti-rotation means, such as a longitudinal fin, preferably arranged at the base of the neck,

[0016] - said at least one first anti-rotation means comprises at least two first anti-rotation means angularly equitably distributed around the axis and preferably arranged in a staggered pattern relative to said at least one clip,

[0017] - the envelope also comprises an annular sealing zone, of radius and of substantially constant thickness, longitudinally arranged between said at least one clip and said at least one first anti-rotation means,

[0018] - the envelope is produced by an injection blow molding process.

[0019] According to a second aspect of the invention, a base for a pressurized gas tank, comprising a substantially cylindrical bore along an axis, capable of receiving a neck of an envelope, where the base comprises at least one cavity capable of receiving a protuberance of a clip of a neck of an envelope of complementary shape to the cavity, so as to ensure longitudinal assembly of the neck relative to the base.

[0020] Particular characteristics or embodiments, usable alone or in combination, are:

[0021] - the cavity is re-entrant and has a bearing face substantially perpendicular to the axis, whose normal faces the end of the neck,

[0022] - the base also comprises at least one second anti-rotation means, complementary to a first anti-rotation means of the neck,

[0023] - the base also comprises a groove capable of receiving a sealing means, such as a O-ring, in an annular sealing zone, longitudinally arranged between said at least one cavity and said at least one second anti-rotation means.

[0024] According to a third aspect of the invention, a pressurized gas tank, comprising such an envelope and / or such a base. Brief description of the drawings

[0025] 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:

[0026] [Fig-1] shows, in perspective view, an envelope,

[0027] [Fig.2] shows, in perspective view, an envelope and a base,

[0028] [Fig.3] shows the device of [Fig.2], from another point of view,

[0029] [Fig.4] shows, in longitudinal sectional view, an envelope engaged in a base,

[0030] [Fig.5] shows, in longitudinal sectional view, the device of [Fig.4], after a 90° rotation around the axis A,

[0031] [Fig.6] shows, in longitudinal sectional view, an envelope engaged in a base,

[0032] [Fig.7] shows, in perspective view, an envelope,

[0033] [Fig.8] shows, in perspective view, a detail of [Fig.7]. Description of the embodiments

[0034] With reference to Figures 1-8, the invention relates to a casing 1 for a pressurized gas tank. Such a casing 1 has a shape similar to the internal shape of the structure of the tank.

[0035] The structure of the tank comprises, for the purposes of filling / drawing gas, a through opening. In this opening is arranged a base 20, pierced with a through bore 21 and arranged, its axis A coinciding with the axis of the opening.

[0036] The envelope 1, which is intended to be arranged inside the structure, comprises a neck 2. This neck 2 is arranged, around an opening made in the wall of the envelope 1, is shaped substantially in the form of a cylinder, with axis A substantially perpendicular to the main wall of the envelope 1. This neck 2 is shaped so as to be able to be housed in the bore 21 of the base 20.

[0037] In order to ensure the gas-tightness of the tank, it is essential that the interface between the neck 2 of the casing 1 and the bore 21 of the base 20 is watertight. Several approaches are possible to achieve this watertightness. However, given the high pressures envisaged: up to 1000 bars, and the desired lifespan: at least twenty years, gluing is the only satisfactory approach today. The disadvantages of gluing are sufficiently significant: difficulty in controlling the process, and above all very long drying, which can take up to 8 hours, so that an alternative solution is sought.

[0038] The invention proposes such an alternative solution, allowing substantially instantaneous installation, without glue or tools.

[0039] For this, according to one characteristic, the neck 2 comprises at least one clip 3 comprising at least one protuberance 4. This protuberance 4 is capable of engaging a cavity 22, formed in the base 20. This cavity 22 is shaped in a complementary shape to the protuberance 4. This makes it possible to produce, with the protuberance 4 engaging in the cavity 22, an assembly of the neck 2 relative to the base 20, at least in a longitudinal direction, namely a direction parallel to the axis A.

[0040] The assembly is carried out in the following manner. The casing 1 is presented opposite the base 20, the end 7 of the neck 2 pointing towards the bore 21, their axis A being aligned, as illustrated in figures 2 and 3. The neck 2 is then engaged in the bore 21. The intrinsic flexibility of the clip 3 allows the protuberance 4 which protrudes into the interior volume of the bore 21 to retract and allow the introduction of the neck 2 into the bore 21. Advantageously, the profile of the protuberance 4 has a bevel in order to facilitate its retraction. This retraction is carried out elastically, by creating a return force, which will allow an erection of the protuberance 4 as soon as it is located opposite the cavity 22.

[0041] According to an embodiment more particularly illustrated in figures 1, 2, 7, 8, a clip 3 is formed, relative to the neck 2, by making in said neck 2, two cutouts 5, 6. These cutouts 5, 6 are through relative to the thickness of the neck 2. They are also open at the end 7 of the neck 2. They are substantially longitudinal, namely substantially parallel to the axis A. They are also substantially parallel to each other. Such an arrangement makes it possible to form a longitudinal tab 8. This tab, due to the plastic material constituting the casing 1 and the neck 2, has a certain elasticity, mainly in rotation / flexion around an axis, passing through the foot of the tab 8, arranged at the bottom of the cutouts 5, 6, tangent to the neck and perpendicular to the axis A. This rotation / flexion allows the retraction of the protuberance 4, by deformation of the tab 8.

[0042] According to another characteristic, a protuberance 4 is arranged substantially at the distal end 9 of a tab 8. This protuberance 4 is outgoing, namely it moves away from the central axis A. In addition, a protuberance 4 has a bearing face 10, substantially perpendicular to the axis A, the normal of which moves away from the end 7 of the neck 2. In other words, the outgoing normal of the bearing face 10 faces the base of the neck 2. This bearing surface 10, in that it cooperates with a complementary bearing surface 23 of the cavity 22, allows, by an opposition of one on the other, maintain the protrusion 4 of the clip 3 in position relative to the cavity 22 and thus maintain the neck 2 longitudinally in place in the bore 21.

[0043] The complementary bearing surface 23 can be arranged at the end of the base 20. In which case the bearing face 23 can be the flat face at the outer end of the base 21. Alternatively, as illustrated, the bearing face 23 can be arranged in a cavity 22 which is not necessarily at the end.

[0044] According to another characteristic, a protuberance 4 is also arranged substantially at the end 7 of the neck 2.

[0045] The envelope 1, in a conventional manner, can be made of any plastic material. It can be mentioned in particular polyamide or PA, according to a variety PA 6, PA 11 or PA 12. These materials allow the envelope 1 to be made both by extrusion and by injection.

[0046] Such a material can intrinsically provide the desired deformability / elasticity for the tab 8 of the clip 3.

[0047] However, according to another characteristic, more particularly illustrated by [Fig.8], a narrowing 11 can be made along the length of the tongue 8, in order to modify the deformation characteristics of the tongue 8. This narrowing 11, of variable shape and size, makes it possible to vary the thickness of the tongue 8, and thus to adjust the elasticity of the tongue 8 as much as necessary. This narrowing 11 is typically made along an axis tangent to the neck 2 and perpendicular to the axis A. This narrowing 11, which makes it possible to reduce the thickness of the tongue 8, and to position the axis of rotation / flexion of the tongue 8, is preferably arranged near the foot of the tongue 8.

[0048] Such a modification is conventionally carried out by modifying the mold in which the envelope 1 is made. The machining of this mold thus makes it possible to modify the shape / depth of the narrowing 11 and thus to adjust the flexural elasticity of the tab 8.

[0049] The number of clips 3 is advantageously at least two clips 3, preferably angularly equally distributed around the axis A. This is illustrated in figures 1 and 2.

[0050] Alternatively, the number of clips 3 may be greater: three, four or more, always preferably angularly equally distributed around the axis A. Figures 7 and 8 illustrate an embodiment with four clips 3.

[0051] In order to prevent the neck 2, once in place in the base 20, and held longitudinally by the clips 3, from rotating around the axis A, the casing 1 also comprises at least one first anti-rotation means 12. Such a first anti-rotation means 12, more particularly illustrated in FIGS. 1, 2, 7, 8, may take the form of a longitudinal fin. Such a first anti-rotation means 12 may be arranged, longitudinally at any point of the neck 2. According to another characteristic, as illustrated, it is preferably arranged at the base / foot of the neck 2. Such a first anti-rotation means 12 cooperates with a second anti-rotation means 24, of complementary shape, arranged opposite, on the base 20. Thus if the neck 2 comprises at least one full fin, the base 20 comprises as many hollow fins.

[0052] The number of first anti-rotation means 12, 24 is advantageously at least two, preferably angularly equally distributed around the axis A. Figures 1-5 illustrate an embodiment with two anti-rotation means 12, 24.

[0053] Alternatively, the number of first anti-rotation means 12, 24 may be greater: three, four or more, always preferably angularly equally distributed around the axis A. Figures 7 and 8 illustrate an embodiment with four anti-rotation means 12, 24.

[0054] If the anti-rotation means 12 are distinct from the clips 3, the anti-rotation means 12 are preferably arranged in a staggered pattern relative to the clips 3.

[0055] The clip 3 and protuberance 4 / cavity 22 cooperation makes it possible to immobilize the neck 2 in the bore 21 of the base 20. However, especially with high pressures, it is not guaranteed that this assembly alone ensures gas tightness.

[0056] Also, according to another characteristic, the casing 1 further comprises a sealing zone 13. This sealing zone 13 is annular around the axis A. It is characterized in that the casing 1 in this sealing zone 13 has a substantially constant radius and a substantially constant thickness. This sealing zone 13 is, longitudinally arranged between said at least one clip 3, rather arranged in an annular zone close to the end 7 of the neck 2, and said at least one first anti-rotation means 12, rather arranged in an annular zone close to the foot of the neck 2.

[0057] This sealing zone 13 is particularly suitable for receiving a sealing means 26, such as an O-ring, advantageously arranged in an annular groove 25 around the axis A, made in the bore 21 of the base 20. The substantial constancy of the radius and the thickness of the neck 2, opposite the sealing means 26, makes it possible to improve the sealing.

[0058] This shape of the neck 2 allows neck / base contact without play in the sealing zone or high pressure zone, namely below the sealing means 26. The deformation of the plastic material under the pressure of the gas is prevented by the plastic contact of the neck 2 / aluminum of the base 20.

[0059] All the shapes of the neck 2, in the high pressure zone, advantageously have their exact counter-shapes in the base 20. These shapes can be produced in the base 20 with conventional machining that can be used in large series, such as conventional turning and milling.

[0060] The constant thickness of material of the neck 2 in the sealing zone allows for a precise geometry. A change in thickness could degrade the circularity and / or cylindricity of the zone at the injection molding outlet. In addition, a plastic molding has shrinkage. This shrinkage is a function of the thickness. If the thickness varies, the shrinkage varies, and the zone could no longer be circular or cylindrical after injection molding.

[0061] According to another characteristic, the envelope is advantageously produced by an injection blow molding process. Such an injection blow molding process is well known. It consists of producing a first blank or preform comprising a neck by conventional injection molding, then completing the shaping by blowing through the neck inside a form.

[0062] Such a method is particularly suited to the shape and characteristics sought for the envelope 1.

[0063] It is particularly advantageous in that the sealing zone 13 is produced by injection molding the preform before blowing. Also, this essential part for sealing is little impacted by the blowing operation. Also, its level of surface condition, geometric and dimensional tolerance is particularly suitable for producing the seal.

[0064] Also, such a method is almost obligatory to achieve the neck shapes 2 presented and the required level of precision.

[0065] The invention also relates to a base 20 for a pressurized gas tank. This base 20 comprises a substantially cylindrical bore 21 along an axis A. This bore 21 is shaped to be capable of receiving a neck 2 of an envelope 1, as previously described.

[0066] According to one characteristic, this base 20 comprises at least one cavity 22 capable of receiving a protuberance 4 of a clip 3 of a neck 2 of an envelope 1, the protuberance 4 having a shape complementary to the cavity 22. This allows each cavity 22 to receive a complementary protuberance 4 and thus to ensure a longitudinal assembly of the neck 2 relative to the base 20. The profile of the cavity 22 is longitudinally complementary to the profile of the protuberance 4. The clips 3 are necessarily individualized in order to be able to be elastic. The cavities 22 can also be individualized, with an individual cavity 22 opposite each clip 3. Alternatively, as illustrated, particularly in [Fig. 3], the cavity 22 can be of revolution around the axis A, in the form of an annular groove which has the same longitudinal profile all around the axis A.

[0067] Advantageously, as seen previously, the protuberance 4 is protruding, in order to take advantage of the elasticity of the tab 8. Also, in a complementary manner, the profile of a cavity 22 is re-entrant. A cavity 22 has a bearing face 23, complementary to the bearing face 10 of the casing 1, substantially perpendicular to the axis A, and whose outgoing normal faces the end 7 of the neck 2, in order to be able to oppose said bearing face 10 of the casing 1.

[0068] According to another characteristic, in addition to the first anti-rotation means 12 of the neck 2, the base 20 also comprises at least one second anti-rotation means 24.

[0069] According to another characteristic, the base 20 also comprises, in the area opposite the annular sealing area 13, a groove 25. This groove 25 is capable of receiving a sealing means 26. This sealing means 26 may be of any type. According to a preferred embodiment, it may be an O-ring. This groove 25 and this sealing means 26 are advantageously placed in the annular sealing area 13, longitudinally arranged between said at least one cavity 22 and said at least one second anti-rotation means 24.

[0070] The invention also relates to a pressurized gas tank, comprising a casing 1 according to any one of the embodiments previously described and / or a base 20 according to any one of the embodiments previously described.

[0071] The invention has been illustrated and described in detail in the drawings and the preceding description. This should be considered as illustrative and given by way of example and not as limiting the invention to this description alone. Numerous alternative embodiments are possible. List of reference signs

[0072] 1: envelope,

[0073] 2: neck,

[0074] 3: clip,

[0075] 4: protuberance,

[0076] 5, 6: cutting,

[0077] 7: end of the neck,

[0078] 8: tab,

[0079] 9: end of the clip,

[0080] 10: support face,

[0081] 11: shrinkage,

[0082] 12: first anti-rotation means,

[0083] 13: sealing zone,

[0084] 20: base,

[0085] 21: bore,

[0086]

[0087]

[0088]

[0089]

[0090] 22: cavity, 23: bearing face, 24: second anti-rotation means, 25: groove, 26: O-ring.

Claims

Claims

1. Casing (1) for a pressurized gas tank, comprising a neck (2) substantially cylindrical around an axis (A), capable of being housed in a bore (21) of a base (20) along an axis (A), in which the neck (2) comprises at least one clip (3) comprising at least one protuberance (4) capable of engaging a cavity (22) of the base (20), of a shape complementary to the protuberance (4), so as to ensure longitudinal assembly of the neck (2) relative to the base (20), where a clip (3) is formed, relative to the neck (2), by two cutouts (5, 6), passing through relative to the thickness of the neck (2), opening out at the end (7) of the neck (2), substantially longitudinal and substantially parallel to each other, so as to form a longitudinal tab (8), characterized in that said at least a clip (3) further comprises a narrowing (11) of the thickness of the tab (8),along an axis tangent to the neck (2) and perpendicular to the axis (A) substantially at the level of the foot of the tab (8).,

2. Envelope (1) according to claim 1, wherein said at least one protuberance (4) is arranged substantially at the distal end (9) of a tab (8), is protruding and has a bearing face (10) substantially perpendicular to the axis (A), the normal of which moves away from the end (7) of the neck (2).

3. Envelope (1) according to any one of claims 1 to 2, wherein said at least one protuberance (4) is arranged substantially at the end (7) of the neck (2).

4. Envelope (1) according to any one of claims 1 to 3, wherein said at least one clip (3) comprises at least two clips (3) angularly equally distributed around the axis (A).

5. Envelope (1) according to any one of claims 1 to 4, further comprising at least one first anti-rotation means (12), such as a longitudinal fin, preferably arranged at the base of the neck (2).

6. Envelope (1) according to any one of claims 1 to 5, wherein said at least one first anti-rotation means (12) comprises at least two first anti-rotation means (12) angularly equally distributed around the axis (A) and preferably arranged in a staggered pattern relative to said at least one clip (3).

7. Envelope (1) according to any one of claims 5 to 6, further comprising an annular sealing zone (13), of substantially constant radius and thickness, longitudinally arranged between said at least one clip (3) and said at least one first anti-rotation means (12).

8. Envelope (1) according to any one of claims 1 to 7, produced by an injection blow molding process.

9. Pressurized gas tank, characterized in that it comprises an envelope (1) according to any one of claims 1 to 8.

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