Tank intended to contain pressurized gas

Abstract

The invention relates to a tank (2) intended to contain a pressurized gas, comprising a liner (4) made of plastic having a main axis (5) and having an overall cylindrical shape, said liner (4) comprising a neck (6) surrounding an axial opening of said liner (4). The tank further comprises a tip (8) arranged at least partially in the neck (6) of the liner (4), a reinforcing ring (14) of the neck of the liner, the reinforcing ring (14) being connected and non-detachable to the neck (6) of the liner (4), and a securing means (24) for securing the tip (8) to the reinforcing ring (14) of the neck of the liner.

Description

Technical Field

[0001] The present invention relates to a tank intended to contain a gas under pressure, in particular an on-board tank in a motor vehicle. More specifically, the present invention relates to a tank intended to contain a gas under pressure and a method for manufacturing a tank intended to contain a gas under pressure. The gases in question are for example, but not limited to, natural gas, biogas, liquefied petroleum gas, hydrogen. Background Art

[0002] The different functions of these tanks are:

[0003] - contain pressurized gases, i.e. mechanically withstand;

[0004] - Ensure tightness relative to the outside;

[0005] - Filling with pressurized gas is ensured by a solenoid valve installed on the embout;

[0006] - Release of pressurized gas through the same solenoid valve mounted on the end piece;

[0007] - fixed to the load-bearing structure;

[0008] - Withstands conditions of transport and use;

[0009] -Resistant to external mechanical and thermal attack from the environment;

[0010] -To withstand the conditions encountered during tank manufacturing.

[0011] These tanks can be installed on any fixed or mobile equipment (road, rail, sea, air, space vehicles). Pressurized gas storage tanks are made of metallic materials or, more recently, composite materials to reduce weight and improve safety.

[0012] Regarding tanks made of composite materials, also called composite tanks, their tightness is usually achieved by providing a vessel called a "liner" that ensures the tightness of the container relative to the contents. Depending on the tank manufacturer, liners made of metal or plastic materials are proposed.

[0013] The liner of the "plastic" type comprises at least one opening for filling and emptying the tank. It is manufactured by injection molding or rotational molding or extrusion blow molding of a thermoplastic or thermosetting (abbreviated as "thermodur") polymer material, such as polyethylene, polyamide, polyphthalamide, polyurethane, silicone, polyoxymethylene. Advantageously, the thermoplastic polymer material is filled with reinforcing fibers to form a composite material. The reinforcing fibers are, for example, glass fibers, carbon fibers, basalt fibers, aramid fibers, polymer fibers, silica fibers, polyethylene fibers, natural fibers, metal fibers, metal alloy fibers or ceramic fibers. These fibers can improve the deformation resistance of the composite material. In the polymer material filled with reinforcing fibers, the reinforcing fibers and the polymer material are interwoven to form a monomer material. The applicant has described this composite material in its French patent application No. 1872197, filed on November 30, 2018 and published as No. 3089160.

[0014] Alternatively, the lining is manufactured by filament winding. An example of manufacturing vessels by filament winding is described in patent document FR1431135A.

[0015] The liner is then covered with a composite reinforcement shell that reinforces the liner and will constitute the body of the tank, i.e. the solid structure of the tank that must be able to withstand the pressure exerted by the fluid contained in the tank (hereinafter referred to as "internal pressure"). The reinforcement shell is usually not required to ensure the sealing of the tank.

[0016] The reinforced cladding includes:

[0017] - a reinforcing material, which is usually made of fibers such as glass fibers, carbon fibers, basalt fibers or other fibers (such as silica fibers or even plant fibers), such as continuous fibers;

[0018] - Resin, which is laid down simultaneously with the fibers (filament winding method) or after the cladding has been made, to constitute a dry "preform". This preform is then cured to give it the necessary rigidity. This curing can be carried out by injecting the resin, or by making the resin penetrate the preform (infusion method), or by vacuum impregnation of the resin.

[0019] Advantageously, the reinforced cladding is coated with one or more layers of fire retardant material, preferably an intumescent fire retardant material, such as a coating based on silicates or phosphates. Silicates and phosphates are intumescents which, after exposure to fire, expand and form an insulating barrier. This allows improving the heat and fire resistance of the tank.

[0020] In any case, when manufacturing a tank, a terminal is assembled sealingly on the liner to allow filling and release of the fluid. The terminal is usually made of metal (steel or aluminum). It is attached to the filling / emptying neck of the liner and has a flange that rests on the liner. The terminal also has a threaded hole that allows a solenoid valve to be mounted on the terminal. Such a terminal is described in patent document US6230922. Document US2011 / 220661A1 also discloses a tank including such a terminal.

[0021] When the reinforcing shell is laid on the liner by the filament winding method, the liner is held at the end by a robot arm or a similar device. This may cause some problems during the implementation of the filament winding method. It should be noted that the filament winding method consists in applying continuous multiple layers of fibers wound in a spiral and circumferential manner on the liner. If the filament winding is carried out at high speed, the robot arm will apply considerable torque on the end and on the connection between the end and the liner, especially during the acceleration or deceleration phases that occur during the application of the fiber layers wound along the spiral path. For liners made of polyamide 6 (PA6), the conventional threaded connection between the end and the liner is generally able to resist a maximum torque between 200Nm and 400Nm, while for liners made of high-density polyethylene (HDPE), the torque resistance is lower than the aforementioned. In order to speed up the manufacturing speed of storage tanks, it is necessary to increase the torque resistance of the connection between the end and the liner.

[0022] In order to increase this torque resistance, it is known to increase the axial span of the neck of the liner connected to the end head, thereby increasing the connection surface between the end head and the neck of the liner. However, this manifests itself as an increase in the dead volume of the tank, that is, the volume of the tank is increased at the neck of the liner without increasing its capacity to store pressurized gas, which is therefore desirable to avoid because of the limited space available in the vehicle. In order to prevent an increase in the dead volume of the tank, it is known to change the shape of the liner so that the neck of the liner is offset axially towards the inside of the internal volume of the tank. It is also known to change the shape of the liner so that the neck of the liner extends towards the inside of the internal volume of the tank, rather than extending towards the outside of the internal volume of the tank.

[0023] In both cases, the axial dimension of the tank is reduced, and thus the volume of the tank is reduced. But this brings a disadvantage, that is, a concave area is formed around the base of the neck inside the tank, which is usually called "dead volume". The presence of this concave area significantly increases the complexity of the measurement process of the mechanical resistance of the tank, which is carried out in accordance with Regulation No. 134 of the United Nations Economic Commission for Europe (UNECE), which relates to the unified certification requirements for motor vehicles and their components regarding the safety requirements of hydrogen-powered vehicles. According to this regulation, pressurized fluid is injected into the interior of the tank and the deformation of the tank is measured. After implementing this process, the tank of the used fluid must be completely emptied. Since the concave area is difficult to access, emptying the area becomes a particularly complex and time-consuming step, so it is best to avoid the presence of the concave area, or at least minimize the volume of the concave area. However, the increase in the axial span of the liner neck connected to the end head will lead to an increase in the volume of the concave area.

[0024] Another solution to improve the torque resistance is to introduce adhesive between the end and the liner, but this involves a long operation, slows down the tank manufacturing process, and is difficult to control. Summary of the invention

[0025] One object of the present invention is to improve the torque resistance of the connection between the end head and the liner. Optimally, this improvement in the torque resistance of the connection between the end head and the liner is achieved without increasing the volume of the tank and without slowing down the manufacturing process of the tank.

[0026] To this end, according to the invention, there is provided a tank intended to contain a gas under pressure, said tank comprising a plastic liner of generally cylindrical shape with a main axis, said liner comprising a neck surrounding an axial opening of said liner, said tank comprising:

[0027] - a tip arranged at least partially in and around the neck of the liner;

[0028] - a reinforcing ring for the neck of the liner, the reinforcing ring being connected to the neck of the liner and being non-detachable; and

[0029] - removable fixing means, when necessary, for fixing the end piece to the reinforcing ring of the neck of the liner,

[0030] The end is placed in direct contact with the reinforcement ring and the neck of the liner.

[0031] The expression “the reinforcement ring of the neck of the liner is connected to the neck of the liner and cannot be detached” means that the reinforcement ring of the neck of the liner is connected to the neck of the liner in a fixed and permanent manner.

[0032] Therefore, the presence of a reinforcing ring connected to the neck of the liner and not detachable makes it possible to strengthen the mechanical connection between the end and the neck of the liner, so that the torque resistance of the connection is improved and can exceed 500Nm. In particular, the arrangement of the neck of the liner, the end and the reinforcing ring makes it possible to form an overlapping structure (empilement), which includes in sequence from the main axis of the storage tank and radially away from the main axis: the end, the reinforcing ring, the neck of the liner, and then the end again. This overlapping structure makes it possible to obtain a particularly strong and compact mechanical connection between the end and the neck of the liner. Therefore, this allows the realization of a fast filament winding process, which implements a stage with great acceleration and deceleration, thereby reducing the manufacturing time and cost of the storage tank. In addition, the presence of a fixture for fixing the end to the reinforcing ring of the neck of the liner makes the fixing of each element located in the axial span of the neck of the liner, without exceeding the axial span. In other words, the presence of the reinforcing ring of the liner and the fixing of the end and the reinforcing ring of the liner neck will not increase the axial size of the storage tank. Therefore, when the neck of the liner is toward the outside of the internal volume of the tank, the invalid volume of the tank will not be increased; and when the neck of the liner is axially offset or toward the inside of the internal volume of the tank, the dead volume of the tank will not be increased.

[0033] According to one embodiment of the present invention, the neck of the liner extends toward the outside of the internal volume of the tank, the reinforcement ring is at least partially arranged in the neck of the liner, and the fixing device is radially located inside the neck of the liner relative to the neck of the liner, so that on the one hand, the reinforcement ring is positioned between the neck of the liner and the end head, and on the other hand, the neck of the liner is positioned between the reinforcement ring and the end head.

[0034] According to an alternative embodiment of the invention, there is provided a tank intended to contain a gas under pressure, said tank comprising a plastic liner of generally cylindrical shape with a main axis, said liner comprising a neck surrounding an axial opening of said liner and extending towards the inside of an internal volume of said tank, said tank comprising:

[0035] - a tip arranged at least partially in the neck of the liner;

[0036] - a reinforcing ring for the neck of the liner, the reinforcing ring being connected to the neck of the liner and being non-detachable; and

[0037] - Fixing means for fixing the end piece to the reinforcing ring of the neck of the liner.

[0038] Preferably, the reinforcement ring is at least partially arranged to surround the neck of the liner, and the fixing device is respectively located in the axial extension of the neck of the liner toward the internal volume of the tank, and radially inside the neck of the liner relative to the neck of the liner, so that the neck of the liner is positioned between the reinforcement ring and the end head.

[0039] Preferably, the reinforcement ring is at least partially arranged to surround the neck of the liner, and the fixing device is respectively located in the axial extension of the neck of the liner toward the internal volume of the tank, and radially inside the neck of the liner relative to the neck of the liner, so that the neck of the liner is positioned between the reinforcement ring and the end head.

[0040] Thus, the present invention can be implemented in a variety of possible configurations of the liner, which helps make the present invention easy to implement industrially.

[0041] According to a preferred embodiment of the present invention, the neck of the liner is overmolded on the reinforcement ring. In the case where the neck of the liner is facing outside the internal volume of the tank, the reinforcement ring is overmolded in the neck of the liner from the outside. In the case where the neck of the liner is facing inside the internal volume of the tank, the reinforcement ring is overmolded around the neck of the liner from the inside.

[0042] Thus, the reinforcement ring is connected to the neck of the liner in a simple and effective manner and cannot be detached.

[0043] Advantageously, the fracture stress or elastic limit of the material from which the reinforcement ring is made is at least twice that of the material from which the liner is made.

[0044] The reinforcement ring thus enables a significant increase in the mechanical resistance of the neck of the liner.

[0045] Preferably, the reinforcement ring is made of metal, thermoplastic material or thermosetting material, and the metal is, for example, aluminum or stainless steel.

[0046] Therefore, the reinforcement ring is made of a less expensive and readily available material.

[0047] Advantageously, the fixing device is configured to achieve mechanical anchoring of the end head to the reinforcement ring, for example by screwing or by snapping.

[0048] Thus, a good mechanical fixation between the end piece and the reinforcement ring is obtained, which is achieved by simple and inexpensive means.

[0049] Advantageously, the reinforcement ring comprises a shoulder cooperating with the end piece, the shoulder being configured to receive an axial end of the end piece.

[0050] The reinforcement ring thus allows the formation of an axial stop capable of facilitating the positioning of the head relative to the reinforcement ring and thus obtaining a good fixation between these two elements, with simple means and without requiring an additional part dedicated to this function.

[0051] Advantageously, the neck of the liner comprises a shoulder cooperating with the tip, the shoulder being configured to receive an axial end of the tip.

[0052] The neck of the liner thus allows the formation of an axial stop which enables good positioning of the head relative to the neck of the liner to be obtained, with simple means and without the need for additional components dedicated to this function.

[0053] Advantageously, said reinforcement ring comprises a shoulder cooperating with said liner, said shoulder being configured to receive, at the base of said neck, a complementary shoulder formed on said liner.

[0054] Thus, the mechanical anchoring of the reinforcing ring in the neck of the liner can be improved and achieved with simple means, without the need for additional components dedicated to this function. This improvement in the mechanical anchoring of the reinforcing ring in the neck of the liner makes it possible to increase the torque resistance of the connection between the end cap and the liner, thus allowing an increase in the speed of filament winding and, therefore, in the manufacturing of the tank.

[0055] Advantageously, the end head comprises an annular sealing ring sealingly resting against the neck of the liner, the annular sealing ring being housed in a cavity of the end head. Thus, a good sealing of the connection between the end head and the neck of the liner can be obtained.

[0056] Preferably, the cavity of the end piece is closed by an annular member to form a receiving groove for the annular seal ring. Preferably, the annular member is a detachable ring. The annular member makes it easier to install the annular seal ring between the end piece and the neck of the liner.

[0057] Preferably, the annular sealing ring is a radial sealing ring surrounding or surrounded by the neck of the liner.

[0058] Therefore, whichever embodiment is adopted, the annular seal can be easily integrated into the tank. In addition, the radial seal is preferred to the axial seal (which is arranged, for example, at the axial end of the neck of the liner) because the radial seal provides a "self-sealing" configuration for the tank. This configuration is also called "self-sealing arrangement" in English, which makes the pressure inside the tank increase, which causes the compression of the annular seal to increase, thereby improving the sealing. This is not the case when there is an axial seal.

[0059] Preferably, the tank comprises a first connecting device configured to connect the internal volume of the tank to a first cavity fluidically extending between the end head and an axial end of the reinforcement ring and the neck of the liner.

[0060] Preferably, the tank comprises a second communication device, the second communication device being configured to connect the first cavity with a second cavity or with the cavity of the end head, and the annular sealing ring extends in the second cavity or the cavity of the end head.

[0061] The term "fluid communication" herein means that the pressurized gas contained in the tank can flow freely between the internal volume, the first cavity and the second cavity through the communication device so that the gas pressure is balanced between the internal volume, the first cavity and the second cavity.

[0062] When filling or emptying the storage tank, the first cavity and the second cavity may have a pressure difference with the internal volume of the storage tank. This is particularly critical when emptying the storage tank, because even after the emptying is completed, the pressure inside the first cavity and the second cavity may still be higher than the pressure in the internal volume. This pressure increases the risk of pressurized gas leaking to the outside of the storage tank. This phenomenon is amplified when emptying the storage tank at a high flow rate when the pressure in the internal volume drops below 50 bar and is particularly true at low temperatures. The communication device makes it possible to balance the pressure in the first cavity and the second cavity with the pressure of the internal volume of the storage tank, thereby allowing the above-mentioned problems to be overcome.

[0063] Advantageously, the storage tank further comprises a sealing contact surface between the end cap and the neck of the liner. For example, the neck of the liner and the end cap each have a smooth bearing surface, which together form a sealing contact surface between the end cap and the neck of the liner. In another example, the sealing contact surface between the end cap and the neck of the liner is formed by a layer of airtight material, for example, a layer of adhesive applied between the end cap and the neck of the liner.

[0064] Therefore, the present invention can be implemented in a variety of possible configurations concerning the sealing of the connection between the end piece and the neck of the liner, which helps to make the present invention more adaptable in the industry.

[0065] Advantageously, the reinforcement ring comprises on its outer radial surface:

[0066] - at least one through hole, and / or

[0067] - at least one axial groove extending from an axial end of the reinforcement ring to an axial position aligned with the annular sealing ring, and / or

[0068] - at least one peripheral groove configured to put said axial grooves in fluid communication with each other.

[0069] These through holes and these grooves enable the gas contained in the tank to expand into the gap between the reinforcing ring and the neck of the liner. When the tank contains pressurized gas, this can help to establish a pressure balance in this gap so as to exert pressure on the annular seal or on the sealing contact surface, thereby improving the sealing of the tank.

[0070] Advantageously, the reinforcement ring comprises axial grooves on its outer or inner radial surface.

[0071] Thus, the mechanical anchoring of the reinforcement ring in the neck of the liner is further improved.

[0072] Preferably, the reinforcement ring has a band-shaped area on the same surface as the surface including the axial groove, the band-shaped area has a uniform radius and divides the axial groove into two groups of axial grooves separated by the band-shaped area, the annular sealing ring seals against the supporting area of ​​the neck of the liner, the supporting area is in contact with the band-shaped area of ​​the reinforcement ring, and the reinforcement ring is connected to the neck of the liner and cannot be detached.

[0073] In fact, the annular seal exerts a permanent contact pressure on the neck of the liner to maintain the tightness of the tank, which contact pressure causes the material of the neck of the liner in the bearing area to creep. The presence of the strip-shaped area makes it possible to homogenize the creep experienced by the bearing area of ​​the neck of the liner when the tank is in use. Therefore, the risk of leakage due to creep is reduced and the service life of the tank is extended.

[0074] According to the invention, there is also provided a method for manufacturing a tank intended to contain a gas under pressure, characterized in that the method comprises the following steps:

[0075] - manufacturing a liner of cylindrical overall shape with a main axis, said liner comprising a neck surrounding an axial opening of said liner and extending towards the outside of the internal volume of said tank;

[0076] - fixing the reinforcing ring of the neck of the liner into the neck of the liner;

[0077] - inserting the tip at least partially into the neck of the liner and causing it to at least partially surround the neck of the liner; and

[0078] - The end head is fixed to the reinforcement ring by means of a fixing device which is radially inside the neck of the liner relative to the neck of the liner so that, on the one hand, the reinforcement ring is positioned between the neck of the liner and the end head, and, on the other hand, the neck of the liner is positioned between the reinforcement ring and the end head.

[0079] According to the invention, there is also provided a method for manufacturing a tank intended to contain a gas under pressure, characterized in that the method comprises the following steps:

[0080] - manufacturing a liner of cylindrical overall shape with a main axis, said liner comprising a neck surrounding an axial opening of said liner and extending towards the inside of the internal volume of said tank;

[0081] - fixing the reinforcing ring of the neck of the liner around the neck of the liner;

[0082] - inserting the tip at least partially into the neck of the liner; and

[0083] - The end head is fixed to the reinforcement ring by fixing means, which are respectively located in the axial extension of the neck of the liner towards the internal volume of the tank and radially inside the neck of the liner relative to the neck of the liner, so that the neck of the liner is positioned between the reinforcement ring and the end head.

[0084] According to one embodiment of the invention, the liner is made of plastic material and the step of fixing the reinforcement ring of the neck of the liner to the neck of the liner is a step of overmolding the neck of the liner on the reinforcement ring during the step of manufacturing the liner. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] The invention will be better understood from reading the following description which is given by way of example only and with reference to the accompanying drawings, in which:

[0086] [ Figure 1 ] Figure 1 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a first embodiment of the present invention;

[0087] [ Figure 2 ] Figure 2 A and 2B are Figure 1 A cross-sectional view of a storage tank according to two implementation variations;

[0088] [ Figure 3 ] Figure 3 is included in Figure 1 A perspective view of a reinforcement ring in a storage tank;

[0089] [ Figure 4 ] Figure 4 A, 4B and 4C are three-dimensional views of reinforcement rings according to various embodiments of the present invention;

[0090] [ Figure 5 ] Figure 5 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a second embodiment of the present invention;

[0091] [ Figure 6 ] Figure 6 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a third embodiment of the present invention;

[0092] [ Figure 7 ] Figure 7 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a fourth embodiment of the present invention;

[0093] [ Figure 8 ] Figure 8 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a fifth embodiment of the present invention;

[0094] [ Fig. 9 ] Fig. 9 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a sixth embodiment of the present invention;

[0095] [ Fig.10 ] Fig.10 is a cross-sectional view of a storage tank intended to contain pressurized gas according to a seventh embodiment of the present invention;

[0096] [ Fig.11 ] Fig.11 A, 11B and 11C are three-dimensional views of reinforcement rings according to variant embodiments of the present invention;

[0097] [ Fig.12 ] Fig.12 is a cross-sectional view of a storage tank intended to contain pressurized gas according to an eighth embodiment of the present invention;

[0098] [ Fig.13 ] Fig.13 yes Fig.12 A cross-sectional view of a communication device for a storage tank according to a first embodiment of the device;

[0099] [ Fig.14 ] Fig.14 yes Fig.12 A cross-sectional view of a communication device for a storage tank according to a second embodiment of the device;

[0100] [ Fig.15 ] Fig.15 yes Fig.12 A cross-sectional view of a communication device for a storage tank according to a third embodiment of the device; and

[0101] [ Fig.16 ] Fig.16 is a cross-sectional view of a tank intended to contain a pressurized gas according to the prior art. DETAILED DESCRIPTION

[0102] Figure 1 1 shows a tank 2 intended to contain a pressurized gas according to a first embodiment of the invention. The tank 2 comprises a liner 4 made of plastic material, which defines an internal volume of the tank 2, which is intended to receive the pressurized gas. The liner 4 here has a central portion of overall cylindrical or tubular shape with reference to a main axis 5 of the tank 2, and two end portions, one of which is located at Figure 1 . The end portion of the liner 4 shown comprises a neck 6 surrounding an axial opening of the liner which connects the internal volume of the tank with the external environment, and the neck 6 extends toward the outside of the internal volume. The liner 4 is made by injection molding, rotational molding or extrusion blow molding of a thermoplastic or thermosetting polymer material (e.g., polyamide or polyethylene), and the thickness of the liner is less than or equal to 5 mm.

[0103] The storage tank 2 comprises a terminal 8, which is at least partially arranged in the neck 6 of the liner 4 and at least partially arranged to surround the neck 6 of the liner 4. The terminal 8 has an overall shape that is rotationally symmetrical relative to the main axis 5. The terminal 8 comprises a central portion and a peripheral portion, the central portion partially extending inside the neck 6 of the liner 4, and the peripheral portion partially extending around the neck 6 of the liner 4, so that the neck 6 of the liner 4 is protected by the terminal 8 from the external environment. The terminal 8 is made of a metal such as aluminum. The terminal 8 is configured to receive a solenoid valve 9, which enables the storage tank 2 to be alternately filled and emptied of gas.

[0104] The storage tank 2 includes an annular seal ring 10, which is arranged between the neck 6 of the liner 4 and the end head 8 and is accommodated inside the cavity of the end head 8. The annular seal ring 10 seals against the neck 6 of the liner 4 and the end head 8 to achieve a sealed connection between the neck 6 of the liner 4 and the end head 8, so that the pressurized gas cannot leave the storage tank 2 through the gap between the neck 6 of the liner 4 and the end head 8. The annular seal ring 10 is a radial seal ring around the neck 6 of the liner 4. Figure 2 A shows Figure 1 The structure of the annular sealing ring 10 in the storage tank 2. Figure 2 B shows the structure of the annular seal ring 10 according to an embodiment of the present invention. According to this embodiment, the cavity of the end head 8 accommodating the annular seal ring 10 includes a removable ring 12. By removing the removable ring 12, the annular seal ring 10 can be easily removed or placed in the cavity of the end head 8, which makes it easier to install the end head 8 on the neck 6 of the liner 4.

[0105] The tank 2 includes a reinforcement ring 14, which is used to reinforce the neck 6 of the liner 4. The reinforcement ring 14 is connected to the neck 6 of the liner 4 and cannot be disassembled, and Figure 1 In the configuration of the reinforcement ring 14, the reinforcement ring 14 is arranged inside the neck 6 of the liner 4 so that the neck 6 of the liner 4 surrounds and tightly wraps the reinforcement ring 14. A gap 7 may extend between the neck 6 of the liner 4 and the reinforcement ring 14. In the illustrated example, the neck 6 of the liner 4 is overmolded on the reinforcement ring 14 so that the reinforcement ring 14 is overmolded in the neck 6 of the liner 4 from the outside. The reinforcement ring 14 is made of a material having a fracture stress or elastic limit that is at least twice the fracture stress or elastic limit of the material of which the liner 4 is made. To this end, the reinforcement ring 14 may be made of a metal (such as aluminum or stainless steel), a thermoplastic material, or a thermosetting material.

[0106] exist Figure 3 1 shows the reinforcement ring 14 in more detail. The reinforcement ring 14 extends several millimeters in the axial direction, about 5 mm to 50 mm. The reinforcement ring 14 has, on its outer surface, i.e., its contact surface with the neck 6 of the liner 4, axial grooves 16 uniformly distributed over its entire periphery. Here, the dimensions of the axial grooves 16 are set so that the spacing between two axial grooves is approximately equal to twice the thickness of one axial groove. The axial grooves 16 allow to improve the solidarisation of the reinforcement ring 14 to the neck 6 of the liner 4 by shape cooperation.

[0107] The reinforcement ring 14 comprises, on its outer surface, i.e., its contact surface with the neck 6 of the liner 4, radial protrusions 18 uniformly distributed around its periphery, and the radial protrusions 18 are flush with the axial ends of the reinforcement ring 14. Since the radial protrusions 18 penetrate into the neck 6 of the liner 4, the radial protrusions 18 can improve the fixed connection of the reinforcement ring 14 to the neck 6 of the liner 4. The length of the radial protrusions 18 is smaller than the thickness of the liner 4 to avoid the risk of the radial protrusions 18 piercing the neck 6 of the liner 4. The axial position of the radial protrusions 18 is not decisive, and they can be located at positions other than the axial ends of the reinforcement ring 14.

[0108] The reinforcement ring 14 comprises, on its outer surface, thus on the same surface as the surface comprising the axial grooves 16, a band-shaped area 20 of uniform radius, which divides the axial grooves 16 into two groups of axial grooves separated by the band-shaped area 20. The schematically illustrated annular sealing ring 10 bears in a sealing manner against a bearing area of ​​the neck 6 of the liner 4, which is in contact with the band-shaped area 20 of the reinforcement ring 14, which is connected to the neck 6 of the liner 4 and cannot be detached, as shown in FIG. Figure 1The presence of the banded area 20 makes it possible to homogenize the creep to which the bearing area of ​​the neck 6 of the liner 4 is subjected when the tank 2 is in use.

[0109] According to a number of embodiments, the reinforcement rings 14a, 14b, 14c are Figure 4 They will be described in detail with Figure 3 The reinforcement ring 14 is different.

[0110] Figure 4 The reinforcing ring 14 a of A has no radial protrusions. Furthermore, the strip-shaped areas 20 do not separate the axial grooves 16 in the sense that the axial grooves 16 pass through the strip-shaped areas 20 .

[0111] Figure 4 The reinforcing ring 14b of B has no radial projections. Instead of these radial projections, the reinforcing ring 14b has radial recesses 18' uniformly distributed around its outer surface. The radial recesses 18' make it possible to improve the fixed connection of the reinforcing ring 14 to the neck 6 of the liner 4 by allowing the material of the liner 4 to penetrate into the radial recesses 18'. Moreover, the strip-shaped areas 20 do not separate the axial grooves 16 in the sense that the axial grooves 16 pass through the strip-shaped areas 20.

[0112] Figure 4 The reinforcing ring 14c of C has no radial protrusions. Its outer surface has a more dense set of axial grooves 16. Here, the size of the axial grooves 16 is set so that the interval between two axial grooves is less than or equal to the thickness of one axial groove. Some of the axial grooves 16 extend out on the axial surface of the reinforcing ring 14.

[0113] The tank 2 comprises a fixing device 24 for fixing the end head 8 to the reinforcement ring 14, which is configured to achieve mechanical anchoring of the end head 8 to the reinforcement ring 14. Here it involves mechanical anchoring by screwing, but according to a variant embodiment, it involves mechanical anchoring by snap-on. An axial region of length A can be defined, in which the fixing device 24 and the entire neck 6 of the liner 4 extend. The length A corresponds to the increase in the axial volume of the tank caused by the neck 6 of the liner 4 and the fixing device 24 in a construction in which the neck 6 extends to the outside of the internal volume of the tank 2. The length A characterizes the ratio between the effective volume of the tank 2, i.e. its internal volume and the volume of the tank 2, which ratio is particularly related to the total volume of the tank 2. By reducing the length A, the increase in the volume of the tank can be reduced. It can be reduced from Figure 1As can be seen in the figure, according to the invention, the neck 6 of the liner 4 and the fixture 24 extend radially relative to each other. Therefore, the length A is not equal to the sum of the lengths of the neck 6 of the liner 4 and the fixture 24 along the main axis 5, but is equal to the maximum of the lengths of the neck 6 of the liner 4 and the fixture 24 along the main axis 5. When these two lengths are equal or substantially equal, as is the case in the present embodiment, the ratio between the mechanical resistance of the fixing method allowed by the fixture 24 and the volume of the tank 2 can be optimized. The value of the length A is preferably less than 30 mm, more preferably less than 20 mm, even more preferably less than 10 mm.

[0114] The storage tank 2 is manufactured by a manufacturing method including the following steps. First, the liner 4 is manufactured by molding two shells forming two halves of the liner by injection molding and then welding the two shells together to make the liner 4. The reinforcement ring 14 is fixed to the neck 6 of the liner 4, which is achieved, for example, by overmolding the neck 6 of the liner 4 on the reinforcement ring 14 when manufacturing the liner 4. Next, the end head 8 is at least partially inserted into the neck 6 of the liner 4 and at least partially surrounds the neck 6 of the liner 4. Finally, the end head 8 is fixed to the reinforcement ring 14 by a fixing device 24 inside the neck 6 of the liner 4, so that the reinforcement ring 14 is positioned between the neck 6 of the liner 4 and the end head 8 on the one hand, and the neck 6 of the liner 4 is positioned between the reinforcement ring 14 and the end head 8 on the other hand. In particular, the end head 8 is in direct contact with both the reinforcement ring 14 and the neck 6 of the liner 4.

[0115] Now, tanks intended to contain pressurized gas according to some other embodiments of the invention will be described. In the following, only the differences between the tanks according to these embodiments and the tank 2 according to the first embodiment of the invention will be described. Elements of these tanks similar to those of the tank 2 according to the first embodiment of the invention have the same reference numerals.

[0116] Figure 5 1 shows a tank 102 intended to contain pressurized gas according to a second embodiment of the invention. The tank 102 differs from the tank of the first embodiment in that the reinforcement ring 14 comprises a shoulder 26 cooperating with the end head 8, the shoulder 26 being configured to receive the axial end of the end head 8. The shoulder 26 cooperating with the end head 8 thus forms an axial stop, thereby facilitating a good positioning of the end head 8 relative to the reinforcement ring 14. For example, when the fixing device 24 is fixed by a threaded connection, the shoulder 26 cooperating with the end head 8 forms a threaded connection stop of the end head 8 relative to the reinforcement ring 14.

[0117] Figure 6, a tank 202 intended to contain pressurized gas according to a third embodiment of the invention is shown. The tank 202 differs from that of the first embodiment in that the reinforcement ring 14 comprises a shoulder 28 cooperating with the liner 4, the shoulder 28 being configured to receive a complementary shoulder 30 formed on the liner 4 at the base of the neck 6. The shoulder 28 cooperating with the liner 4 thus forms an axial stop making it possible to promote good positioning of the neck 6 of the liner 4 (more generally, of the liner 4) relative to the reinforcement ring 14. In an advantageous embodiment, the shoulder 28 comprises a radial protrusion or a radial notch as described above.

[0118] Figure 7 , a tank 302 intended to contain pressurized gas according to a fourth embodiment of the invention is shown. The tank 302 differs from the tank of the first embodiment in that it combines the second and third embodiments of the invention. The reinforcement ring 14 includes a shoulder 26 for cooperating with the end head 8 and configured to receive the axial end of the end head 8, and a shoulder 28 for cooperating with the liner 4 and configured to receive a complementary shoulder 30 formed on the liner 4 at the base of the neck 6. The shoulder 26 cooperating with the end head 8 and the shoulder 28 cooperating with the liner 4 function as described in the second and third embodiments of the invention.

[0119] Figure 8 4 shows a tank 402 intended to contain pressurized gas according to a fifth embodiment of the invention. The tank 402 differs from the tank of the first embodiment in that the neck 6' of the liner 4 extends toward the inside of the internal volume of the tank 2, and the reinforcing ring 14, which is connected to the neck 6' of the liner 4 and cannot be detached, is at least partially arranged around the neck 6' of the liner 4. In the illustrated example, the neck 6' of the liner 4 is overmolded on the reinforcing ring 14, so that the reinforcing ring 14 is overmolded around the neck 6' of the liner 4 from the inside. The annular sealing ring 10 is a radial sealing ring, which is surrounded by the neck 6' of the liner 4. This configuration in which the neck 6' of the liner 4 extends toward the inside of the internal volume of the tank 402 leads to the presence of a dead volume 32 in the internal volume, as described in the preamble of the present application. The fixing device 24 is located in the axial extension of the neck 6' of the liner 4 in the direction of the internal volume of the tank, so that the neck 6' of the liner 4 is positioned between the reinforcing ring 14 and the end head 8. The reinforcement ring 14 is positioned to at least partially surround the neck 6' of the liner 4, and the inner surface of the reinforcement ring 14 (i.e., the surface thereof in contact with the neck 6' of the liner 4) may have axial grooves, banded areas, radial protrusions and / or radial recesses, as in the first embodiment and in Figure 3 , Figure 4 A. Figure 4 B and Figure 4 As described in C.

[0120] The tank 402 is manufactured by a manufacturing method comprising the following steps. First, the liner 4 is manufactured by molding two shells forming two halves of the liner by injection molding and then welding the two shells together to make the liner 4. The reinforcement ring 14 is fixed around the neck 6' of the liner 4, which is achieved, for example, by overmolding the neck 6' of the liner 4 on the reinforcement ring 14 when manufacturing the liner 4. Next, the end head 8 is at least partially inserted into the neck 6' of the liner 4. Finally, the end head 8 is fixed to the reinforcement ring 14 by a fixing device 24, which is located in the axial extension of the neck 6' of the liner 4 in the direction of the internal volume of the tank 402, so that the neck 6' of the liner 4 is positioned between the reinforcement ring 14 and the end head 8.

[0121] Fig. 9 , a tank 502 intended to contain pressurized gas according to a sixth embodiment of the invention is shown. The tank 502 differs from the tank of the first embodiment in that the neck 6' of the liner 4 extends toward the inside of the internal volume of the tank 2, and the reinforcement ring 14, which is connected to the neck 6' of the liner 4 and cannot be detached, is at least partially arranged to surround the neck 6' of the liner 4. In the illustrated example, the neck 6' of the liner 4 is overmolded on the reinforcement ring 14, so that the reinforcement ring 14 is overmolded around the neck 6' of the liner 4 from the inside. This configuration in which the neck 6' of the liner 4 extends toward the inside of the internal volume of the tank 402 results in the presence of a dead volume 32 in the internal volume, as described in the introduction to the present application. The fixing device 24 is located radially inside the neck 6' of the liner 4 relative to the neck 6' of the liner 4, so that the neck 6' of the liner 4 is positioned between the reinforcement ring 14 and the end head 8. The reinforcement ring 14 is positioned to at least partially surround the neck 6' of the liner 4, and the inner surface of the reinforcement ring 14 (i.e., the surface in contact with the neck 6' of the liner 4) may have axial grooves, banded areas, radial protrusions and / or radial recesses, as in the first embodiment and in Figure 3 , Figure 4 A. Figure 4 B and Figure 4 As described in C.

[0122] In the example shown, the reinforcement ring 14 is actually a double reinforcement ring 14d, 14e, wherein the first reinforcement ring 14d is arranged outside the neck 6' of the liner 4, so that the first reinforcement ring 14d surrounds and clamps the neck 6' of the liner 4, and the second reinforcement ring 14e carries the fixing device 24. The first reinforcement ring 14d is coaxial with the second reinforcement ring 14e, and the inner radius of the first reinforcement ring 14d is greater than the outer radius of the second reinforcement ring 14e, so that an annular space is formed between the first reinforcement ring 14d and the second reinforcement ring 14e. The first reinforcement ring 14d is connected to the second reinforcement ring 14e by a reinforcement core 15 in the form of a rondelle. The outer radius of the reinforcement core 15 corresponds to the outer radius of the first reinforcement ring 14d, and its inner radius corresponds to the inner radius of the second reinforcement ring 14e. The annular space formed between the first reinforcement ring 14d and the second reinforcement ring 14e is arranged to receive the neck 6' of the liner 4 and the axial ends of the end head 8, so that the neck 6' of the liner 4 is protected by the end head 8 from the influence of the external environment.

[0123] The storage tank 502 is manufactured by a manufacturing method including the following steps. First, the liner 4 is manufactured by molding two shells forming two halves of the liner by injection molding and then welding the two shells together to make the liner 4. The reinforcement ring 14 is fixed around the neck 6' of the liner 4, which is achieved, for example, by overmolding the neck 6' of the liner 4 on the reinforcement ring 14 when manufacturing the liner 4. Next, the end head 8 is at least partially inserted into the neck 6' of the liner 4. Finally, the end head 8 is fixed to the reinforcement ring 14 by a fixing device 24, which is located radially inside the neck 6' of the liner 4 relative to the neck 6' of the liner 4, so that the neck 6' of the liner 4 is positioned between the reinforcement ring 14 and the end head 8.

[0124] Fig.10 , a storage tank 602 intended to contain pressurized gas according to a seventh embodiment of the present invention is shown. The storage tank 602 differs from the storage tank of the first embodiment in that the storage tank 602 includes a sealed contact surface 10' between the end head 8 and the neck 6 of the liner 4, so that the pressurized gas cannot leave the storage tank 2 through the gap between the neck 6 of the liner 4 and the end head 8. In the illustrated example, a material layer that is airtight to the gas constitutes the airtight contact surface 10' between the end head 8 and the neck 6 of the liner 4, and the airtight material layer is, for example, an adhesive layer applied between the end head 8 and the neck 6 of the liner 4. In another embodiment of the present invention (not shown), the neck 6 of the liner 4 and the end head 8 each have a smooth bearing surface, which together form the sealed contact surface 10' between the end head 8 and the neck 6 of the liner 4.

[0125] Fig.11 FIG. 1 shows reinforcement rings 14d, 14e, 14f according to a plurality of variant embodiments, which will be described below. Figure 3The reinforcement ring 14 is different.

[0126] Fig.11 The reinforcement ring 14d of A has through holes 34 evenly distributed on the circumference of the reinforcement ring 14d. Here, the diameter of the holes 34 is less than 3 mm, preferably less than 2 mm, more preferably less than 1 mm. These holes 34 allow the pressurized gas contained in the tank to diffuse in the gap 7 and thus facilitate the establishment of a pressure balance in this gap 7 relative to the internal volume of the tank so as to exert pressure on the annular sealing ring or on the sealing contact surface. This improves the sealing of the tank in an inexpensive manner.

[0127] Fig.11 The reinforcement ring 14e of B has axial grooves 36 uniformly distributed on the circumference of the reinforcement ring 14e on its outer surface. The axial grooves 36 all extend from one axial end of the reinforcement ring 14e to the other axial end of the reinforcement ring 14e. In another embodiment of the present invention (not shown), the axial grooves 36 each extend from one axial end of the reinforcement ring 14e to an axial position aligned with the annular seal ring 10. In other words, the axial grooves 36 are open only at one axial end of the reinforcement ring 14e. The width of the axial grooves 36 is less than 1 mm, preferably less than 0.5 mm, and more preferably less than 0.3 mm. The axial grooves 36 have a width similar to Fig.11 The same function as the hole 34 of the reinforcing ring 14d of A, namely the axial groove 36 allows the pressurized gas contained in the tank to diffuse in the gap 7 and thus facilitates the establishment of a pressure balance in this gap relative to the internal volume of the tank so as to exert pressure on the annular seal or on the sealing contact surface. This improves the sealing of the tank.

[0128] Fig.11 The reinforcement ring 14f of C has axial grooves 36 uniformly distributed on the circumference of the reinforcement ring 14e on its outer surface. The axial grooves 36 are uniformly distributed on the circumference of the reinforcement ring 14e. Fig.11 The groove of the reinforcing ring 14e of B extends in a similar manner from one axial end of the reinforcing ring 14e to the other axial end of the reinforcing ring 14e. The reinforcing ring 14f also has a peripheral groove 36' on its outer surface extending radially over the entire circumference of the reinforcing ring. The width of the peripheral groove 36' here is less than 1 mm, preferably less than 0.5 mm, more preferably less than 0.3 mm. The peripheral groove 36' is particularly capable of promoting pressure homogenization in the gap 7 by fluidly connecting the axial grooves 36 to each other.

[0129] According to an embodiment variant of the present invention, the reinforcement ring may include both the through hole and the groove as defined above.

[0130] Fig.121 shows a tank 702 for containing pressurized gas according to an eighth embodiment of the present invention. The difference between the tank 702 and the tank of the first embodiment is that the tank 702 has a first cavity 38 and a second cavity 40, the first cavity 38 extending between the end head 8 and the axial end of the neck 6 of the reinforcement ring 14 and the liner 4, and the second cavity 40 formed in the end head 8, the second cavity 40 corresponding to the combination of Figure 1 The cavity of the end piece is shown, and the annular sealing ring 10 extends in this second cavity 40.

[0131] When filling or emptying the tank 702, the first cavity 38 and the second cavity 40 may have a pressure difference with the internal volume 42 of the tank. This is particularly critical when emptying the tank 702, because even after the emptying is completed, the pressure inside the first cavity 38 and the second cavity 40 may still be higher than the pressure in the internal volume 42. This pressure increases the risk of leakage of pressurized gas to the outside of the tank 702. This is especially true when the pressure in the internal volume drops below 50 bar and at low temperatures, and this phenomenon is amplified when emptying the tank 702 at a high flow rate. In order to overcome these problems, the tank 702 includes a device configured to connect the first cavity 38 and the second cavity 40 to the internal volume 42 fluid. These devices are hereinafter referred to as the first communication device 44 and the second communication device 45. The first communication device 44 is located upstream of the first cavity 38, while the second communication device 45 is located downstream of the first cavity 38. The terms "upstream" and "downstream" are used according to the flow direction of the pressurized gas leaking to the outside of the tank.

[0132] Fig.13 A first embodiment of the communication means 44 and 45 is shown in FIG. 1 , in which these means are formed by open ducts made in the end piece 8 .

[0133] Fig.14 A second embodiment of the communication means 44 and 45 is shown in FIG. 1 , wherein these means are formed by pipes drilled in the end head 8 according to two alternative configurations.

[0134] Fig.15 A third embodiment of the communication means 44 and 45 is shown in FIG. 5 , in which these means are formed by open ducts made in the neck 6 of the liner 4 and in the reinforcement ring 14 .

[0135] In a fourth embodiment (not shown), at least one duct is formed in the neck 6 of the liner 4 to place the volume 40 in fluid communication with the internal volume 42 of the tank.

[0136] Fig.161 shows a tank 3 intended to contain a gas under pressure according to the prior art. The tank 3 comprises a liner 104 made of plastic material, which defines an internal volume of the tank 3 intended to receive the gas under pressure. Here, the liner 104 has a substantially cylindrical or tubular central portion with reference to a main axis 105 of the tank 3 and two end portions, one of which is located at Fig.11 . The end portion of the illustrated liner 104 includes a neck 106 surrounding the axial opening of the liner, thereby connecting the internal volume of the tank to the external environment. Here, the neck 106 extends toward the outside of the internal volume of the tank 3 and has an axial offset toward the inside of the internal volume of the tank 3. This configuration of the neck 106 of the liner 3 being axially offset toward the inside of the internal volume of the tank 3 results in the presence of a dead volume 132 in the internal volume, as described in the introduction to the present application.

[0137] The invention is not limited to the embodiments presented, and other embodiments will be apparent to a person skilled in the art. In particular, embodiments of the invention directed to a tank in which the neck of the liner faces the inside of the internal volume of the tank are also applicable to a tank in which the neck of the liner faces the outside of the internal volume of the tank. Vice versa, embodiments of the invention directed to a tank in which the neck of the liner faces the outside of the internal volume of the tank are also applicable to a tank in which the neck of the liner faces the inside of the internal volume of the tank. In general, different embodiments, in particular embodiments relating to the configuration of the neck of the liner, the detachable ring, the reinforcement ring and the cooperating shoulder, can be combined with one another.

[0138] List of reference numerals:

[0139] 2, 3, 102, 202, 302, 402, 502, 602, 702: Tanks designed to contain pressurized gases

[0140] 4.104: Lining

[0141] 5.105: Main axis

[0142] 6, 6', 106: Neck

[0143] 7: Gap

[0144] 8: End

[0145] 9: Solenoid valve

[0146] 10: Ring seal

[0147] 10': Sealing contact surface between the end and the neck

[0148] 12: Removable ring

[0149] 14, 14a, 14b, 14c, 14d, 14e, 14f: Reinforcement ring

[0150] 15: Strengthen the core

[0151] 16: Axial groove

[0152] 18: Radial protrusion

[0153] 18': Radial notch

[0154] 20: Strip area

[0155] 24: Fixtures

[0156] 26: Shoulder that works with the end

[0157] 28: Shoulders that work with the lining

[0158] 30: Complementary Shoulders

[0159] 32, 132: Dead volume

[0160] 34: Through hole

[0161] 36: Axial groove

[0162] 36': Peripheral groove

[0163] 38: First cavity

[0164] 40: Second cavity

[0165] 42: Internal volume of the tank

[0166] 44: First communication device

[0167] 45: Second connecting device

Claims

1. A tank (2, 102, 202, 302, 602, 702) intended to contain a gas under pressure, said tank (2, 102, 202, 302, 602, 702) comprising a liner (4) made of plastic and having a generally cylindrical shape with a main axis (5), said liner (4) comprising a neck (6) surrounding an axial opening of said liner (4), characterised in that The storage tank (2, 102, 202, 302, 602, 702) comprises: - an end cap (8) arranged at least partially in the neck (6) of the liner (4) and at least partially around the neck (6) of the liner (4); - a reinforcing ring (14) for the neck of the liner, the reinforcing ring (14) being connected to the neck (6) of the liner (4) in a non-detachable manner; and - fixing means (24) for fixing the end piece (8) to the reinforcing ring (14) of the neck (6) of the liner (4), The end head (8) is in direct contact with the reinforcement ring (14) and the neck (6) of the liner (4).

2. A tank (402, 502) intended to contain a gas under pressure, said tank (402, 502) comprising a liner (4) made of plastic and having a generally cylindrical shape with a main axis (5), said liner (4) comprising a neck (6') surrounding an axial opening of said liner (4) and extending towards the inside of the internal volume of said tank, characterized in that The storage tank (402, 502) comprises: - an end cap (8) arranged at least partially in the neck (6') of the liner (4); - a reinforcing ring (14) of the neck of the liner, the reinforcing ring (14) being connected to the neck (6') of the liner (4) and being non-detachable; and - fixing means (24) for fixing the end piece (8) to the reinforcing ring (14) of the neck (6') of the liner (4).

3. The storage tank (2, 102, 202, 302, 602, 702) according to claim 1, characterized in that: The neck (6) of the liner (4) extends toward the outside of the internal volume of the tank, the reinforcement ring (14) is at least partially arranged in the neck (6) of the liner (4), and the fixing device (24) is located radially inside the neck (6) of the liner (4) relative to the neck (6) of the liner (4), so that on the one hand, the reinforcement ring (14) is positioned between the neck (6) of the liner (4) and the end head (8), and on the other hand, the neck (6) of the liner (4) is positioned between the reinforcement ring (14) and the end head (8).

4. The storage tank (402, 502) according to claim 2, characterized in that: The reinforcement ring (14) is at least partially arranged to surround the neck (6') of the liner (4), and the fixing device (24) is respectively located in the axial extension of the neck (6') of the liner (4) in the direction toward the internal volume of the tank, and radially inside the neck (6') of the liner (4) relative to the neck (6') of the liner (4), so that the neck (6') of the liner (4) is positioned between the reinforcement ring (14) and the end head (8).

5. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The neck (6, 6') of the liner (4) is overmoulded onto the reinforcement ring (14).

6. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The reinforcement ring (14) is made of a material having a breaking stress or elastic limit which is at least twice the breaking stress or elastic limit of the material of which the liner (4) is made.

7. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to the preceding claim, characterized in that The reinforcement ring (14) is made of metal, thermoplastic material or thermosetting material, and the metal is, for example, aluminum or stainless steel.

8. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The fixing device (24) is configured to achieve mechanical anchoring of the end head (8) to the reinforcement ring (14), for example by a threaded connection or by a snap-fit ​​connection.

9. The storage tank (102, 302) according to any one of the preceding claims, characterized in that The reinforcement ring (14) includes a shoulder (26) cooperating with the end head (8), the shoulder (26) being configured to receive an axial end of the end head (8).

10. The storage tank (202, 302) according to any one of the preceding claims, characterized in that The reinforcement ring (14) comprises a shoulder (28) cooperating with the liner (4), the shoulder (28) being configured to receive a complementary shoulder (30) formed on the liner (4) at the base of the neck (6).

11. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The end piece (8) comprises an annular sealing ring (10) sealingly resting against the neck (6, 6') of the liner (4), and the annular sealing ring (10) is accommodated in a cavity of the end piece (8).

12. Storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to the preceding claim, characterized in that The cavity of the end head (8) is closed by an annular member to form a receiving groove for the annular sealing ring (10). Preferably, the annular member is a detachable ring (12).

13. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to claim 11 or 12, wherein: The annular sealing ring (10) is a radial sealing ring surrounding the neck (6) of the liner (4) or surrounded by the neck (6') of the liner (4).

14. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The tank comprises a first connecting device (44) configured to connect the internal volume (42) of the tank to a first cavity (38) in fluid communication, the first cavity (38) extending between the end head (8) on the one hand and the axial ends of the reinforcement ring (14) and the neck (6) of the liner (4) on the other hand.

15. Storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to the preceding claim, characterized in that The storage tank includes a second connecting device (45), which is configured to connect the first cavity (38) with the second cavity (40) or the cavity of the end head, and the annular sealing ring (10) extends in the second cavity (40) or the cavity of the end head.

16. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, wherein: The tank also includes a sealing contact surface (10') between the end head (8) and the neck (6, 6') of the liner (4).

17. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, wherein: The reinforcement ring (14) comprises on its outer radial surface: - at least one through hole (34); and / or - at least one axial groove (36) extending from an axial end of the reinforcement ring (14) to an axial position aligned with the annular sealing ring (10); and / or - at least one peripheral groove (36') configured to place the axial grooves (36) in fluid communication with one another.

18. The storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of the preceding claims, characterized in that The reinforcement ring (14) comprises an axial groove (16) on its outer radial surface or inner radial surface.

19. Storage tank (2, 102, 202, 302, 402, 502, 602, 702) according to the preceding claim in combination with any one of claims 11 to 13, characterized in that The reinforcement ring (14) includes a band-shaped area (20) with a uniform radius on the same surface as the surface including the axial groove (16), the band-shaped area (20) divides the axial groove (16) into two groups of axial grooves separated by the band-shaped area (20), and the annular seal (10) sealingly abuts against the supporting area of ​​the neck (6, 6') of the liner (4), the supporting area is in contact with the band-shaped area (20) of the reinforcement ring (14), and the reinforcement ring (14) is connected to the neck (6, 6') of the liner (4) and cannot be detached.

20. A method of manufacturing a tank (2, 102, 202, 302, 602, 702) intended to contain a gas under pressure, characterized in that The method comprises the following steps: - manufacturing a liner (4) of generally cylindrical shape with a main axis (5), said liner (4) comprising a neck (6) surrounding an axial opening of said liner (4) and extending towards the outside of the internal volume of said tank; - fixing the reinforcing ring (14) of the neck of the liner into the neck (6) of the liner (4); - inserting the end piece (8) at least partially into the neck (6) of the liner (4) and causing it to at least partially surround the neck (6) of the liner (4); and - The end head (8) is fixed to the reinforcement ring (14) by means of a fixing device (24), which is located radially inside the neck (6) of the liner (4), so that on the one hand, the reinforcement ring (14) is positioned between the neck (6) of the liner (4) and the end head (8), and on the other hand, the neck (6) of the liner (4) is positioned between the reinforcement ring (14) and the end head (8).

21. A method of manufacturing a tank (402, 502) intended to contain a gas under pressure, characterized in that The method comprises the following steps: - manufacturing a liner (4) of generally cylindrical shape with a main axis (5), said liner (4) comprising a neck (6') surrounding the axial opening of said liner (4) and extending towards the inside of the internal volume of said tank; - fixing the reinforcing ring (14) of the neck of the liner around the neck (6') of the liner (4); - inserting the tip (8) at least partially into the neck (6') of the liner (4); and - The end head (8) is fixed to the reinforcement ring (14) by means of fixing means (24), which are respectively located in the axial extension of the neck of the liner towards the internal volume of the tank and radially inside the neck (6') of the liner (4) relative to the neck (6') of the liner (4), so that the neck (6') of the liner (4) is positioned between the reinforcement ring (14) and the end head (8).

22. The method according to any one of claims 20 to 21, characterized in that The liner (4) is made of plastic material, and the step of fixing the reinforcement ring (14) of the neck of the liner to the neck (6, 6') of the liner (4) is a step of overmolding the neck (6, 6') of the liner (4) on the reinforcement ring (14) during the step of manufacturing the liner (4).

Images