Pressurised gas tank with improved sealing

Abstract

The present invention relates to a high-pressure gas tank (10), in particular for hydrogen, comprising a base (16) that extends along a base axis (Y) and an inner lining (14) comprising an annular portion (32) that extends substantially perpendicular to the base axis (Y). It comprises a sealing ring (30) that surrounds an inner portion (22a, 22b) of the base (16) and a circular seal (34) that is compressed longitudinally in the direction of the base axis (Y) between the sealing ring (30) and the annular portion (32) of the inner lining (14).

Description

[0001] TITLE: Pressure gas tank with improved sealing

[0002] The present invention relates to a pressurized gas tank, in particular hydrogen, for example intended to equip a motor vehicle.

[0003] We already know, in the state of the art, a pressurized gas tank, comprising a base, and an internal coating connected to this base, for example overmolded onto this base.

[0004] To ensure optimal operation, the base must be able to withstand high pressures (at least 700 bars), emptying / filling cycles, and strong temperature variations (for example from -40°C to 85°C).

[0005] The aim of the invention is then to propose a gas tank with improved sealing, allowing the base to ensure good sealing even under the conditions mentioned above.

[0006] To this end, the invention relates to a high-pressure gas tank, in particular for hydrogen, comprising a base extending along a base axis, an inner lining comprising an annular part extending substantially perpendicular to the base axis, characterized in that it comprises a sealing ring surrounding an inner part of the base, and a circular seal compressed longitudinally, in the direction of the base axis, between the sealing ring and the annular part of the inner lining.

[0007] According to other advantageous aspects of the invention, the tank comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0008] - The tank includes a tightening nut, screwed onto the inner part of the base, and resting against the sealing ring.

[0009] - The tank includes a radially compressed O-ring seal between the sealing ring and the base.

[0010] - The base has an annular extension, the annular part of the inner lining being arranged longitudinally between the annular extension and the sealing ring.

[0011] - The annular part of the inner coating is overmolded onto an inner face of the annular extension of the base.

[0012] - The tank extends longitudinally along a longitudinal axis, the base axis being perpendicular to the longitudinal axis. - The base comprises an outer tubular part, extending outside a space delimited by the inner lining and the inner part comprises two parts of different external diameters, called the first inner tubular part and the second inner tubular part, extending inside the space delimited by the inner lining.

[0013] - The first inner tubular part is arranged longitudinally, in the direction of the base axis, between the annular extension and the second inner tubular part, the first inner tubular part having an external diameter greater than that of the second inner tubular part, a shoulder being provided between the first inner tubular part and the second inner tubular part.

[0014] - The second inner tubular part has a threaded external surface receiving the clamping nut, the sealing ring being arranged longitudinally, in the direction of the base axis, between the annular extension and the clamping nut, the sealing ring comprising a first ring part surrounding the first inner tubular part, and a second ring part surrounding the second inner tubular part, the clamping nut tightening the second ring part against the shoulder while the first ring part compresses the circular flat seal on the annular part.

[0015] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0016] [Fig. 1] Figure 1 is a partial perspective view of a tank according to an exemplary embodiment of the invention, cut longitudinally on the one hand, and cut transversely along the axis of its base on the other hand.

[0017] Figure 1 shows a tank 10 of pressurized gas, in particular hydrogen, for example intended to equip a motor vehicle.

[0018] For example, tank 10 is Type IV (i.e., a composite tank with a polymer liner) and conformable, prismatic in shape and made in two parts.

[0019] The tank 10 comprises a composite casing 12, enveloping an interior coating 14. The interior coating 14 is for example made of thermoplastic polymer.

[0020] The interior coating 14 has, for example, a general shape of revolution around a longitudinal axis X of the tank 10.

[0021] The tank 10 also comprises a base 16, passing through the casing 12 and the covering 14.

[0022] The base is for example made of aluminum. The base 16 extends along a base axis Y. In the example described, the base axis Y is perpendicular to the longitudinal axis X. Indeed, in this example, the base 16 is arranged on a side wall of the covering 14.

[0023] According to one variant, the base axis is aligned with the longitudinal axis X, the base being arranged at a longitudinal end of the tank.

[0024] The base 16 has a central opening 18 extending along the base axis Y over the entire length of the base 16, allowing communication between the inside and the outside of the tank. The filling and emptying of the tank are carried out through this central opening 18. For this purpose, a tank valve (not shown) is arranged in a conventional manner on an outer end of the base 16.

[0025] The base 16 comprises an outer tubular part 20, extending outside the space delimited by the inner coating 14, and more particularly the space delimited by the casing 12. The base also comprises an inner tubular part in two parts of different outer diameters, called first inner tubular part 22a and second inner tubular part 22b, extending inside the space delimited by the inner coating 14.

[0026] The base 16 comprises an annular extension 24 extending radially relative to the base axis Y, and located longitudinally, in the direction of the base axis Y, between the outer tubular part 20 and the inner tubular part 22a, 22b.

[0027] The first inner tubular part 22a is arranged longitudinally, in the direction of the base axis Y, between the annular extension 24 and the second inner tubular part 22b.

[0028] The first inner tubular portion 22a has an external diameter greater than that of the second inner tubular portion 22b. A shoulder 26 is provided between the first inner tubular portion 22a and the second inner tubular portion 22b.

[0029] The external surface of the second inner tubular part 22b is threaded, in order to allow the screwing of a tightening nut 28.

[0030] A sealing ring 30 is arranged longitudinally, in the direction of the base axis Y, between the annular extension 24 and the clamping nut 28.

[0031] The sealing ring 30 comprises a first ring portion 30a surrounding the first inner tubular portion 22a, and a second ring portion 30b surrounding the second inner tubular portion 22b.

[0032] An O-ring seal 31 is arranged radially between the first ring portion 30a and the first inner tubular portion 22a.

[0033] The second ring part 30b is arranged longitudinally, in the direction of the base axis Y, between the shoulder 26 and the tightening nut 28. The inner coating 14 comprises an annular part 32, resting on an inner face of the annular extension 24 of the base 16. Generally, this annular part 32 is overmolded on this inner face of the annular extension 24. For this purpose, the inner face is shaped for good adhesion of the annular part 32, for example it comprises grooves, roughness, or any conceivable surface treatment, and / or even an adhesive allowing good cohesion between the material of the inner coating 14 and the material of the base 16.

[0034] The reservoir 10 according to the invention comprises a circular seal 34 compressed longitudinally between the sealing ring 30 and the annular part 32. The circular seal 34 is flat in the example described, but it could be toric as a variant, or have any other section allowing sealing.

[0035] Advantageously, a groove is provided in the sealing ring 30 so as to limit the risk of extrusion of the seal 34 (flat or toric) from its housing under the effect of pressure.

[0036] Thus, when the tightening nut 28 is screwed, the second ring part 30b comes to bear against the shoulder 26, while the first ring part 30a compresses the circular seal 34 on the annular part 32.

[0037] The sealing of the tank is therefore ensured by the circular seal 34 between the sealing ring 30 and the annular part 32, and by the O-ring between the sealing ring 30 and the base 16.

Claims

CLAIMS 1. Tank (10) for high-pressure gas, in particular for hydrogen, comprising a base (16) extending along a base axis (Y), an inner lining (14) comprising an annular part (32) extending substantially perpendicular to the base axis (Y), characterized in that it comprises a sealing ring (30) surrounding an inner part (22a, 22b) of the base (16), and a circular seal (34) compressed longitudinally, in the direction of the base axis (Y), between the sealing ring (30) and the annular part (32) of the inner lining (14).

2. Tank (10) according to claim 1, comprising a tightening nut (28), screwed onto the inner part (22b) of the base (16), and bearing against the sealing ring (30).

3. Tank (10) according to claim 1 or 2, comprising an O-ring seal (31) compressed radially between the sealing ring (30) and the base (16).

4. Tank (10) according to any one of the preceding claims, in which the base (16) comprises an annular extension (24), the annular part (32) of the inner lining (14) being arranged longitudinally between the annular extension (24) and the sealing ring (30).

5. Tank (10) according to any one of the preceding claims, in which the annular part (32) of the inner coating (14) is overmolded onto an inner face of the annular extension (24) of the base (16).

6. Tank (10) according to any one of the preceding claims, wherein the tank (10) extends longitudinally along a longitudinal axis (X), the base axis (Y) being perpendicular to the longitudinal axis (X).

7. Tank (10) according to any one of the preceding claims, in which the base (16) comprises an outer tubular part (20), extending outside a space delimited by the inner coating (14) and the inner part comprises two parts of different outer diameters, called first inner tubular part (22a) and second inner tubular part (22b), extending inside the space delimited by the inner coating (14).

8. Tank (10) according to claim 7, wherein the first inner tubular part (22a) is arranged longitudinally, in the direction of the base axis (Y), between the annular extension (24) and the second inner tubular part (22b), the first inner tubular part (22a) having an external diameter greater than that of the second inner tubular part (22b), a shoulder (26) being provided between the first inner tubular part (22a) and the second inner tubular part (22b).

9. Tank (10) according to claim 8 taken in combination with claim 2, wherein the second inner tubular part (22b) has a threaded external surface receiving the tightening nut (28), the sealing ring (30) being arranged longitudinally, in the direction of the base axis (Y), between the annular extension (24) and the tightening nut (28), the sealing ring (30) comprising a first ring part (30a) surrounding the first inner tubular part (22a), and a second ring part (30b) surrounding the second inner tubular part (22b), the tightening nut (28) tightening the second ring part (30b) against the shoulder (26), while the first ring part (30a) compresses the circular flat seal (34) on the annular part (32).

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