Tanks for storing compressed gas

Abstract

The tank (2) for storing compressed gas comprises a liner (4) made of a plastic material of cylindrical overall shape having a central axis (5), the liner (4) having a neck (6) surrounding an axial opening of the liner (4), an end plug (8) disposed at least partially within the neck (6) of the liner (4), a reinforcing ring (14) for the neck (6) of the liner (4) that is integral with and inseparable from the neck (6) of the liner (4), and means (24) for fastening the end plug (8) to the reinforcing ring (14) for the neck of the liner.

Description

[Technical Field]

[0001] The present invention relates to a tank for storing compressed gases, particularly tanks for use on motor vehicles, and more particularly to a tank for storing compressed gases and a method for manufacturing a tank for storing compressed gases, such as, but not limited to, natural gas, biogas, liquefied petroleum gas, and hydrogen. [Background technology]

[0002] The various functions of these tanks include: - To contain compressed gas, i.e. to have mechanical strength, - Airtight to the outside, - Filling with compressed gas is achieved by means of a solenoid valve attached to the end plug; - supplying compressed gas using the same solenoid valve attached to the end plug; - be fixed to a supporting structure; - withstand the conditions of transport and use; - Resistance to adverse external environmental, mechanical and even thermal influences, - To withstand the conditions of tank manufacturing; Examples include:

[0003] These tanks may be mounted on any fixed or mobile equipment (road vehicles, railways, ships, aircraft, space). Compressed gas tanks are made from metallic materials or, more recently, from composite materials for weight gain and safety reasons.

[0004] In tanks made of composite materials, also known as composite tanks, the airtightness is usually ensured by a vessel called a "liner" that keeps the container airtight against the contents. Tank manufacturers offer liners made of metal or plastic.

[0005] "Plastic" liners have at least one opening for filling and discharging the tank. They are manufactured by injection molding, rotational molding, or extrusion blow molding of thermoplastic or thermosetting (abbreviated "thermodur") polymeric materials, such as polyethylene, polyamide, polyphthalamide, polyurethane, silicone, and polyoxymethylene. Advantageously, the thermoplastic polymeric material contains reinforcing fibers to form a composite material. The reinforcing fibers may be glass, carbon, basalt, aramid, polymer, silica, polyethylene, natural, metal, alloy, or ceramic fibers. These fibers enhance the deformation resistance of the composite material. In polymeric materials containing reinforcing fibers, the reinforcing fibers and the polymeric material are intricately intertwined to form an integrated material. Such a composite material is described in French Patent Application No. 1872197, filed by the applicant on November 30, 2018, and published under publication number 3089160.

[0006] Alternatively, the liner may be manufactured by filament winding, an example of the manufacture of a container by filament winding is described in French Patent No. 1 431 135 A.

[0007] This liner is then enclosed by a reinforcement jacket of composite material that will form the body of the tank, i.e., the load-bearing structure of the tank, and must be able to withstand the pressure exerted by the fluid inside the tank (hereinafter referred to as "internal pressure"). Generally, the reinforcement jacket is not required to ensure the tank's airtightness.

[0008] This reinforced jacket is - a reinforcing material, which generally consists of fibers, such as glass fibers, carbon fibers, basalt fibers or other fibers such as silica fibers, or even dietary fibers, which are for example continuous fibers; - Resins that are applied together with the fibers (filament winding method) or after the jacket has been fabricated to form a dry "preform" The dried preform is then solidified to give it the required rigidity. This strengthening is achieved by injecting resin through the preform or by resin infiltration (infusion process) or even by resin impregnation under vacuum.

[0009] Advantageously, the reinforcing jacket is provided with one or more layers of fire-resistant coating, preferably with an intumescent fire-resistant material, such as a silicate- or phosphate-based coating. Silicates and phosphates are intumescent substances that expand when exposed to fire, creating an insulating barrier, thereby increasing the tank's heat and fire resistance.

[0010] In either case, end plugs are sealingly attached to the liner during tank manufacture to allow for filling and dispensing of fluids. These end plugs are typically made of metal (steel or aluminum). They extend to the fill / drain neck of the liner and have a press fit that is pressed into the liner. The end plugs are also threaded to allow for attachment of a solenoid valve to the end plug. Such end plugs are described in U.S. Pat. No. 6,230,922. U.S. Patent Application Publication No. 2011 / 220661 also discloses a tank with such end plugs.

[0011] When applying a reinforcing jacket to a liner by filament winding, the liner is held at the end plug level by a robotic arm or similar device. This can pose certain challenges during the filament winding process. As is well known, filament winding involves continuously winding a fiber layer around the liner in a spiral pattern. When the filament is wound at high speeds, the robotic arm exerts a large torque on the end plugs and their connections, especially during the acceleration and deceleration phases that occur as the fiber layer is wound along the spiral path. For liners made of polyamide 6 (PA6), the torque that a classic screw connection between the end plug and the liner can withstand is typically up to 200–400 Nm, but this strength is lower for liners made of high-density polyethylene (HDPE). To increase the tank manufacturing speed, the torque strength of the connection between the end plug and the liner must be increased.

[0012] To increase this strength, it is known to increase the axial size of the liner's neck, which connects to the end plug. This aims to increase the connection area between the end plug and the liner's neck. However, this approach increases the dead volume of the tank, increasing the tank's external dimensions at the liner's neck level without increasing the storage capacity of compressed gas. This is undesirable given the limited space available inside the vehicle. To avoid increasing the dead volume of the tank, it is known to modify the liner's shape so that the liner's neck is axially offset toward the inside of the tank's internal volume. It is also known to modify the liner's shape so that the liner's neck extends toward the inside of the tank's internal volume, rather than outside of it.

[0013] In both of the above cases, the axial dimensions of the tank are reduced, making it more compact. However, this also brings with it disadvantages. A recess, commonly referred to as "dead volume," is created inside the tank around the base of the nozzle. The presence of this recess significantly complicates the tank mechanical strength test performed in accordance with the Uniform Provisions for Type Approval of Motor Vehicles and Their Parts under UN-CEE Regulation No. 134 for the safety regulations of hydrogen-powered vehicles. This test involves injecting high-pressure fluid into the tank and measuring the tank deformation. After this test, the tank must be completely emptied of the used fluid. Emptying the difficult-to-access recess is a particularly complex and time-consuming step. Therefore, it is desirable to avoid the existence of a recess, or at least minimize its volume. Furthermore, the axial size of the nozzle of the liner, which is connected to the end plug, increases the volume of the recess.

[0014] Another approach to strength is to apply adhesive between the end plug and the liner, but this is a time-consuming process that slows down the tank manufacturing process and is difficult to control. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] French Patent Application No. 18 72197 [Patent Document 2] French Patent No. 1431135A [Patent Document 3] U.S. Patent No. 6,230,922 [Patent Document 4] U.S. Patent Application Publication No. 2011 / 220661 Summary of the Invention [Problem to be solved by the invention]

[0016] One of the objectives of the present invention is to increase the torque strength of the connection between the end plug and the liner. Optimally, this increase in torque strength of the connection between the end plug and the liner is achieved without increasing the size of the tank or slowing down the tank manufacturing process. [Means for solving the problem]

[0017] Therefore, the present invention provides a tank for storing compressed gas, the tank having a liner made of a plastic material having a cylindrical overall shape with a central axis, the liner having a nozzle surrounding an axial opening of the liner, an end plug disposed at least partially within and around the neck of the liner; a reinforcing ring for the nozzle of the liner, which is integral with and inseparable from the nozzle of the liner; - means for fastening the end plug to the reinforcing ring at the nozzle of the liner, optionally removable means for fastening; The tank is designed to have an end plug that is in direct contact with the reinforcing ring and the nozzle of the liner.

[0018] The expression "liner nozzle reinforcing ring integral and inseparable with the liner nozzle" means that the liner nozzle reinforcing ring is fixedly connected to the liner nozzle and is permanently connected.

[0019] Therefore, the presence of the liner neck reinforcing ring, which is integral and inseparable with the liner neck, reinforces the mechanical connection between the end plug and the liner neck, thereby increasing the torque strength of the connection to more than 500 Nm. In particular, the arrangement of the liner neck, end plug, and reinforcing ring allows for the creation of a stack of layers in the following order, moving radially away from the tank's central axis: end plug, reinforcing ring, liner neck, and then end plug. This stacking arrangement allows for a very strong and compact mechanical connection between the end plug and the liner neck. It also allows for the implementation of a high-speed filament winding process with multiple acceleration and deceleration phases, which reduces the tank's manufacturing time and costs. Furthermore, the presence of a means for fastening the end plug to the liner neck reinforcing ring means that the fastening of each element is within the axial extent of the liner neck, and not outside of it. This means that the presence of the liner reinforcing ring and the fastening of the end plugs to the reinforcing ring at the liner nose do not add to the axial bulk of the tank, and therefore do not increase the dead volume of the tank when the liner nose is directed outside the tank's internal volume, nor do they increase the dead volume of the tank when the liner nose is axially offset or directed into the tank's internal volume.

[0020] According to one embodiment of the present invention, the liner nose extends outwardly from the tank's internal volume, the reinforcing ring is disposed at least partially within the liner nose, and the fastening means is disposed inside the liner nose radially relative to the liner nose, whereby the reinforcing ring is positioned between the liner nose and the end plug, while the liner nose is positioned between the reinforcing ring and the end plug.

[0021] In an alternative embodiment of the present invention, there is provided a tank for compressed gas storage comprising a liner made of a plastic material of cylindrical overall shape having a central axis, the liner having a neck surrounding an axial opening in the liner and extending into an interior volume of the tank, an end plug disposed at least partially within the neck of the liner; a reinforcing ring for the nozzle of the liner, which is integral with and inseparable from the nozzle of the liner; - a means for fixing the end plug to the reinforcing ring at the nozzle of the liner; Plan a tank equipped with:

[0022] Preferably, the reinforcing ring is disposed at least partially around the liner nose, and the fastening means is located on the axial extension of the liner nose, radially relative to the liner nose towards the internal volume of the tank, and within the liner nose, the liner nose is positioned between the reinforcing ring and the end plug.

[0023] Preferably, the reinforcing ring is disposed at least partially around the liner nose, and the fastening means is located on the axial extension of the liner nose, radially relative to the liner nose towards the internal volume of the tank, and within the liner nose, the liner nose is positioned between the reinforcing ring and the end plug.

[0024] Thus, the present invention can be implemented in multiple possible configurations for the liner, which contributes to the ease of industrial implementation of the present invention.

[0025] According to a preferred embodiment of the present invention, the neck of the liner is overmolded with a reinforcing ring. If the neck of the liner faces outward from the tank's internal volume, the reinforcing ring is overmolded from the outside into the neck of the liner. If the neck of the liner faces inward from the tank's internal volume, the reinforcing ring is overmolded from the inside around the neck of the liner.

[0026] In this way, the reinforcing ring can be easily and effectively made integral with and inseparable from the nozzle of the liner.

[0027] Advantageously, the stiffening ring is made of a material that has a breaking stress or elastic limit that is at least twice as high as the material of the liner.

[0028] In this way, the reinforcing ring can significantly increase the mechanical strength of the nozzle portion of the liner.

[0029] Preferably, the reinforcing ring is made of a metal such as aluminum or stainless steel, or a thermoplastic or thermoset material.

[0030] In this way, the reinforcing ring is made from an inexpensive and readily available material.

[0031] Advantageously, the fixing means are configured to allow mechanical fixing of the end plug to the reinforcement ring by means of a screw or ratchet fastening or the like.

[0032] This allows a reliable mechanical fixation between the end plug and the reinforcing ring to be achieved by simple and inexpensive means.

[0033] Advantageously, the reinforcing ring comprises a shoulder which cooperates with the end plug and is adapted to receive the axial end of the end plug.

[0034] The reinforcing ring can thus form an axial stop that can facilitate positioning of the end plug relative to the reinforcing ring and achieve a secure fixation between the two elements, and can do so by simple means without the need for additional special parts to perform that function.

[0035] Advantageously, the nose of the liner comprises a shoulder for cooperating with the end plug and adapted to receive the axial end of the end plug.

[0036] In this way, the liner nozzle can form an axial stop that ensures correct positioning of the end plug relative to the liner nozzle, and this can be done by simple means without the need for additional special parts to perform this function.

[0037] Advantageously, the stiffening ring comprises a shoulder which cooperates with the liner and is adapted to receive a complementary shoulder provided at the base of the liner's nose.

[0038] This improves the mechanical fixation of the reinforcing ring at the liner's nozzle, without requiring any additional dedicated parts for this function, and is achieved by simple means. This improvement in the mechanical fixation of the reinforcing ring at the liner's nozzle increases the torque strength of the connection between the end plug and the liner, allowing for an increase in the filament winding speed and therefore the tank manufacturing pace.

[0039] Advantageously, the end plug is provided with a sealing ring which presses against the liner's neck to provide a seal, the sealing ring being housed in a cavity in the end plug, thereby providing a good seal of the connection between the end plug and the liner's neck.

[0040] Preferably, the cavity in the end plug is closed by an annular member to form a groove for the sealing ring, the annular member being preferably removable, which facilitates installation of the sealing ring between the end plug and the liner neck.

[0041] Preferably, the seal ring is a radial seal that surrounds or is surrounded by the nose of the liner.

[0042] Therefore, the sealing ring, regardless of its implementation, can be easily integrated into the tank. Furthermore, a radial seal is preferred over an axial seal, which may be located at the axial end of the liner's muzzle, because it provides a "self-sealing" arrangement for the tank. This arrangement, also known as a "self-sealing arrangement," means that an increase in pressure inside the tank increases the compression of the sealing ring, thereby strengthening the seal, which is not the case with an axial seal.

[0043] Preferably, the tank includes first communication means configured to fluidly connect the interior volume of the tank with a first cavity extending between the end plug and the axial end of the stiffening ring and the nose of the liner.

[0044] Preferably, the tank comprises second communication means arranged to fluidly connect the first cavity with a second cavity into which the sealing ring extends or with a cavity in the end plug.

[0045] "Fluid communication" as used herein refers to a communication means that allows the compressed gas contained within the tank to flow freely between the internal volume, the first cavity, and the second cavity, thereby achieving gas pressure equilibrium between the internal volume, the first cavity, and the second cavity.

[0046] When filling or discharging a tank, there may be a pressure difference between the first and second cavities and the tank's internal volume. This is particularly problematic when discharging a tank, because the pressure in the first and second cavities may remain higher than the pressure in the internal volume even after discharging has finished. This pressure increases the risk of compressed gas leaking out of the tank. This is particularly noticeable when the pressure in the internal volume drops below 50 bar, at low temperatures, and at high tank discharge rates. The communication means allows the pressure in the first and second cavities to be equilibrated with the pressure in the tank's internal volume, thereby alleviating the above-mentioned problem.

[0047] Advantageously, the tank further comprises a sealing interface between the end plug and the liner neck. For example, the liner neck and the end plug each have smooth abutment surfaces that cooperate to form the sealing interface between the end plug and the liner neck. In another example, a layer of gas-tight material, such as a layer of adhesive applied between the end plug and the liner neck, forms the sealing interface between the end plug and the liner neck.

[0048] Thus, the present invention provides multiple configurations for implementing the sealing of the connection between the end plug and the liner nose, which helps to facilitate industrial adaptation of the present invention.

[0049] Advantageously, the reinforcing ring has on its radially outer surface: - at least one through hole, and / or - at least one axial groove extending from the axial end of the reinforcing ring to an axial position at the sealing ring level, and / or - at least one peripheral groove configured to fluidly connect the axial grooves to one another; Equipped with.

[0050] These through holes and grooves allow the gas contained in the tank to spread into the gap between the stiffening ring and the nozzle of the liner. If the tank contains compressed gas, a pressure equilibrium can be easily established in this gap, which exerts pressure on the sealing ring or sealing contact surface, improving the tank's airtightness.

[0051] Advantageously, the reinforcing ring has an axial notch on its radially outer or inner surface.

[0052] This further improves the mechanical fixation of the reinforcing ring at the nozzle of the liner.

[0053] Preferably, the reinforcing ring has an annular band of uniform radius on the same surface as the surface with the axial notches, dividing the axial notches into two sets of axial notch assemblies, and the sealing ring is in contact with the annular band of the reinforcing ring, which is integral with and inseparable from the nozzle of the liner, and is sealed by pressing against the support portion of the nozzle of the liner.

[0054] In reality, the sealing ring exerts a permanent contact pressure on the liner neck to maintain the tank's airtightness, which tends to cause creep of the material at the liner neck in the bearing area. The presence of the annular band makes it possible to equalize the creep that the bearing area at the liner neck undergoes during tank use, thus reducing the risk of leakage due to creep effects and increasing the tank's service life.

[0055] The present invention provides a method for manufacturing a tank for compressed gas storage, comprising the steps of: - manufacturing a liner having a cylindrical overall shape with a central axis and a neck surrounding the axial opening of the liner and extending outwardly of the interior volume of the tank; - fixing a liner nose reinforcing ring to the liner nose; - inserting an end plug at least partially into and around the neck of the liner; - securing the end plug to the stiffening ring within the liner nose using fastening means positioned radially relative to the liner nose, such that the stiffening ring is positioned between the liner nose and the end plug, and such that the liner nose is positioned between the stiffening ring and the end plug; Also contemplated is a method of manufacturing comprising:

[0056] The present invention provides a method for manufacturing a tank for compressed gas storage, comprising the steps of: - manufacturing a liner having a cylindrical overall shape with a central axis and a neck surrounding an axial opening of the liner and extending into the interior volume of the tank; - securing a liner nose reinforcing ring around the liner nose; - inserting an end plug at least partially into the neck of the liner; - fixing the end plug to the reinforcing ring using fixing means arranged on the axial extension of the liner nose, radially relative to the liner nose towards the internal volume of the tank and inside the liner nose so that the liner nose is located between the reinforcing ring and the end plug; Also contemplated is a method of manufacturing comprising:

[0057] According to one embodiment of the present invention, the liner is made of a plastic material, and the step of fixing the reinforcing ring at the liner nose to the liner nose is a step of overmolding the liner nose onto the reinforcing ring during the liner manufacturing step.

[0058] The invention will be better understood from reading the following description, given by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0059] [Figure 1] 1 is a cross-sectional view of a tank for compressed gas storage according to a first embodiment of the present invention; [Figure 2A]2 is a cross-sectional view of the tank of FIG. 1 according to an alternative embodiment. [Figure 2B] 2 is a cross-sectional view of the tank of FIG. 1 according to an alternative embodiment. [Figure 3] FIG. 2 is a perspective view of a reinforcing ring provided in the tank of FIG. 1. [Figure 4A] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 4B] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 4C] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 5] FIG. 2 is a cross-sectional view of a tank for compressed gas storage according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to a third embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to a fourth embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to a fifth embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to a sixth embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to a seventh embodiment of the present invention. [Figure 11A] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 11B] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 11C] FIG. 10 is a perspective view of a reinforcing ring according to an alternative embodiment of the present invention. [Figure 12] FIG. 10 is a cross-sectional view of a tank for compressed gas storage according to an eighth embodiment of the present invention. [Figure 13] 13 is a cross-sectional view of the communication means of the tank of FIG. 12, according to a first embodiment of said means; FIG. [Figure 14] 13 is a cross-sectional view of the communication means of the tank of FIG. 12 according to a second embodiment of said means; FIG. [Figure 15] 13 is a cross-sectional view of the communication means of the tank of FIG. 12 according to a third embodiment of said means; FIG. [Figure 16] 1 is a cross-sectional view of a tank for compressed gas storage according to current technology. DETAILED DESCRIPTION OF THE INVENTION

[0060] FIG. 1 shows a tank 2 for storing compressed gas according to a first embodiment of the present invention. The tank 2 includes a liner 4 made of a plastic material that defines an interior volume of the tank 2 for containing compressed gas. The liner 4 has a central portion, which in this view has a cylindrical or tubular overall shape relative to a central axis 5 of the tank 2, and two ends, only one of which is shown in FIG. 1. The end of the liner 4 shown in the figure includes a neck 6 that surrounds an axial opening of the liner that connects the interior volume of the tank with the external environment, and here extends outside the interior volume. The liner 4 is manufactured by injection molding, rotational molding, or extrusion blow molding of a thermoplastic or thermosetting polymer material, such as polyamide or polyethylene, and has a thickness of 5 mm or less.

[0061] The tank 2 includes an end plug 8 disposed at least partially within and around the neck 6 of the liner 4. The end plug 8 has an overall shape that is rotationally symmetrical about a central axis 5. The end plug 8 has a central portion that extends partially parallel to the inside of the neck 6 of the liner 4 and an outer peripheral portion that extends partially around the neck 6 of the liner 4, such that the neck 6 of the liner 4 is protected from the external environment by the end plug 8. The end plug 8 is a metal component, such as aluminum. The end plug 8 is configured to receive a solenoid valve 9 that can alternately fill and release gas from the tank 2.

[0062] The tank 2 includes a seal ring 10 disposed between the nozzle 6 of the liner 4 and the end plug 8, the seal ring 10 fitting into a cavity in the end plug 8. The seal ring 10 is pressed against and sealed against the nozzle 6 of the liner 4 and the end plug 8, thereby forming a sealed connection between the nozzle 6 of the liner 4 and the end plug 8 and preventing compressed gas from escaping from the tank 2 through the gap between the nozzle 6 of the liner 4 and the end plug 8. The seal ring 10 is a radial seal that surrounds the nozzle 6 of the liner 4. The configuration of the seal ring 10 in the tank 2 of FIG. 1 is shown in FIG. 2A. FIG. 2B shows the configuration of a seal ring 10 according to a modified embodiment of the present invention. In this modified embodiment, a removable annular member 12 is provided in the cavity in the end plug 8 where the seal ring 10 is housed. By removing the removable annular member 12, the seal ring 10 can be easily attached to and detached from the cavity of the end plug 8, making it even easier to attach the end plug 8 to the nozzle portion 6 of the liner 4.

[0063] The tank 2 includes a reinforcing ring 14 that reinforces the neck 6 of the liner 4. The reinforcing ring 14 is integral with and inseparable from the neck 6 of the liner 4. In the configuration shown in FIG. 1 , the reinforcing ring 14 is disposed within the neck 6 of the liner 4 so that it is surrounded and clamped by the neck 6 of the liner 4. A gap 7 may be formed between the neck 6 of the liner 4 and the reinforcing ring 14. In the illustrated example, the neck 6 of the liner 4 is overmolded with the reinforcing ring 14 so that the reinforcing ring 14 is overmolded into the neck 6 of the liner 4 from the outside. The reinforcing ring 14 is made of a material that has a breaking stress or elastic limit at least twice that of the material of the liner 4. Therefore, the reinforcing ring 14 can be made of a metal such as aluminum or stainless steel, or a thermoplastic or thermosetting material.

[0064] FIG. 3 shows the reinforcing ring 14 in more detail. The reinforcing ring 14 extends axially for several millimeters, generally 5 to 50 mm. On its outer surface, i.e., the surface that contacts the nozzle 6 of the liner 4, the reinforcing ring 14 has axial notches 16 regularly distributed around its entire circumference. The axial notches 16 are designed so that two grooves are spaced apart at a distance approximately twice the thickness of the axial notches. The geometric cooperation of the axial notches 16 allows the reinforcing ring 14 to be more tightly integrated with the nozzle 6 of the liner 4.

[0065] The reinforcing ring 14 has radial protrusions 18 on its outer surface, i.e., the surface that contacts the neck 6 of the liner 4, that are distributed regularly around the circumference and flush with the axial ends of the reinforcing ring 14. The radial protrusions 18 can improve the integration of the reinforcing ring 14 with the neck 6 of the liner 4 by inserting the radial protrusions 18 into the neck 6 of the liner 4. The radial protrusions 18 have a length that is less than the thickness of the liner 4, so that the radial protrusions 18 do not puncture the neck 6 of the liner 4. The axial positions of the radial protrusions 18 are not fixed, and may be other than the axial ends of the reinforcing ring 14.

[0066] The reinforcing ring 14 has on its outer surface, therefore on the same plane as the axial cuts 16, an annular band 20 of constant radius which divides the axial cuts 16 into two assemblies of axial cuts. The sealing ring 10, shown diagrammatically, contacts the annular band 20 of the reinforcing ring 14, which is integral with and inseparable from the neck 6 of the liner 4, and presses against the bearing area of ​​the neck 6 of the liner 4, as shown in Figure 1. The presence of the annular band 20 makes it possible to equalize the creep that the bearing area of ​​the neck 6 of the liner 4 undergoes during use of the tank 2.

[0067] FIG. 4 shows reinforcing rings 14a, 14b, and 14c according to modified embodiments, and the differences between these and the reinforcing ring 14 of FIG. 3 will be described below.

[0068] 4A does not have any radial projections, and the annular band 20 does not divide the axial cuts 16 in a direction transverse to the annular band 20.

[0069] The reinforcing ring 14b in Figure 4B does not have radial protrusions. Instead, the reinforcing ring 14b has radial indentations 18' regularly spaced around its outer surface. The radial indentations 18' allow material of the liner 4 to penetrate into the radial indentations 18', thereby enhancing the integrity of the reinforcing ring 14 to the neck portion 6 of the liner 4. Additionally, the annular bands 20 do not divide the axial cuts 16 in a direction transverse to the annular bands 20.

[0070] The reinforcing ring 14c of Figure 4C has no radial protrusions. Its outer surface has a denser assembly of axial cuts 16. The axial cuts 16 are here designed so that two axial cuts are spaced apart by less than the thickness of one axial cut. Some of the axial cuts 16 extend on the axial surface of the reinforcing ring 14.

[0071] The tank 2 comprises fixing means 24 for the end plug 8 to the reinforcing ring 14, the fixing means 24 being configured to mechanically fix the end plug 8 to the reinforcing ring 14. Here, it is a mechanical fixation by screwing, but in a variant embodiment, it is a mechanical fixation by ratcheting. An axial zone of length A is defined within which the fixing means 24 and the entire neck 6 of the liner 4 extend. Length A corresponds to the increase in the axial dimension of the tank caused by the neck 6 of the liner 4 and the fixing means 24 when the neck 6 is configured to extend outside the internal volume of the tank 2. Length A characterizes the ratio between the effective volume of the tank 2, i.e., its internal volume, and the size of the tank 2, which is particularly related to the total volume of the tank 2. Reducing length A reduces the increase in the size of the tank. Looking at FIG. 1, it can be seen that in the present invention, the neck 6 of the liner 4 and the fixing means 24 extend radially from each other. Therefore, the length A is not equal to the sum of the lengths of the nozzle 6 of the liner 4 and the fastening means 24 along the central axis 5, but is equal to the maximum length of the nozzle 6 of the liner 4 and the fastening means 24 along the central axis 5. When the two lengths are the same or approximately the same, as is the case in this embodiment, the ratio between the mechanical strength of the fastening provided by the fastening means 24 and the size of the tank 2 is optimized. The value of the length A is preferably less than 30 mm, more preferably less than 20 mm, and even more preferably less than 10 mm.

[0072] The tank is manufactured by a manufacturing method including the following steps: starting with the manufacture of the liner 4, which is manufactured by injection molding two shells that form the two halves of the liner and welding them together. During the manufacture of the liner 4, the reinforcing ring 14 is secured to the neck portion 6 of the liner 4, such as by overmolding the neck portion 6 of the liner 4 onto the reinforcing ring 14. Next, the end plug 8 is inserted at least partially into and around the neck portion 6 of the liner 4. Finally, the end plug 8 is secured to the reinforcing ring 14 within the neck portion 6 of the liner 4 using a fastening means 24, such that the reinforcing ring 14 is positioned between the neck portion 6 of the liner 4 and the end plug 8, and the neck portion 6 of the liner 4 is positioned between the reinforcing ring 14 and the end plug 8. Notably, the end plug 8 is in direct contact with the reinforcing ring 14 and the neck portion 6 of the liner 4.

[0073] Tanks for storing compressed gas according to other embodiments of the invention will now be described, which will be described below only insofar as they differ from the tank 2 according to the first embodiment of the invention. Tank elements similar to those of the tank 2 according to the first embodiment of the invention are given the same reference numerals.

[0074] 5 shows a tank 102 for storing compressed gas according to a second embodiment of the invention. This tank 102 differs from the tank of the first embodiment in that the reinforcing ring 14 comprises a shoulder 26 which cooperates with the end plug 8 and is configured to receive an axial end of the end plug 8. The shoulder 26 which cooperates with the end plug 8 forms an axial stop which can facilitate correct positioning of the end plug 8 relative to the reinforcing ring 14. For example, if the fixing means 24 is to form a screw-fastening, the shoulder 26 which cooperates with the end plug 8 forms a screw-fastening stop for the end plug 8 relative to the reinforcing ring 14.

[0075] 6 shows a tank 202 for storing compressed gas according to a third embodiment of the invention. This tank 202 differs from that of the first embodiment in that the stiffening ring 14 comprises a shoulder 28 cooperating with the liner 4, the shoulder 28 being configured to receive a complementary shoulder 30 arranged at the base of the neck 6 of the liner 4. The shoulder 28 cooperating with the liner 4 thus forms an axial stop that can facilitate the correct positioning of the neck 6 of the liner 4 relative to the stiffening ring 14, and more generally of the liner 4. In an advantageous embodiment, the shoulder 28 comprises a radial projection or a radial notch, as already described.

[0076] 7 shows a tank 302 for storing compressed gas according to a fourth embodiment of the present invention. The tank 302 differs from the first embodiment in that it combines the second and third embodiments of the present invention. The reinforcing ring 14 includes a shoulder 26 for cooperating with the end plug 8, the shoulder 26 being configured to receive the axial end of the end plug 8, and a shoulder 28 for cooperating with the liner 4, the shoulder 28 being configured to receive a complementary shoulder 30 provided at the base of the neck 6 of the liner 4. The functions of the shoulder 26 for cooperating with the end plug 8 and the shoulder 28 for cooperating with the liner 4 are the same as those described in the second and third embodiments of the present invention.

[0077] FIG. 8 shows a tank 402 for storing compressed gas according to a fifth embodiment of the present invention. This tank 402 differs from the first embodiment in that the neck 6' of the liner 4 extends into the internal volume of the tank 2 and further in that a reinforcing ring 14, which is integral with and inseparable from the neck 6' of the liner 4, is provided at least partially around the neck 6' of the liner 4. In the illustrated example, the neck 6' of the liner 4 is overmolded with the reinforcing ring 14 such that the reinforcing ring 14 is overmolded from the inside around the neck 6' of the liner 4. The sealing ring 10 in this case is a radial seal surrounded by the neck 6' of the liner 4. As pointed out in the introduction of this application, the configuration of the neck 6' of the liner 4 toward the inside of the internal volume of the tank 402 creates a dead volume 32 in the internal volume. The fastening means 24 is located in the axial extension of the neck 6' of the liner 4 towards the tank interior volume, and is arranged so that the neck 6' of the liner 4 is located between the reinforcing ring 14 and the end plug 8. The reinforcing ring 14 is located at least partially around the neck 6' of the liner 4, and it is on its inner surface, i.e., the surface in contact with the neck 6' of the liner 4, that it may have axial cuts, annular bands, radial protrusions and / or radial notches as described in the first embodiment and in Figures 3, 4A, 4B and 4C.

[0078] The tank 402 is manufactured by a manufacturing method including the following steps. The process begins with the manufacture of the liner 4. The liner 4 is manufactured by injection molding two shells that form the two halves of the liner and then welding the two together. During the manufacture of the liner 4, the reinforcing ring 14 is secured around the neck portion 6' of the liner 4, such as by overmolding the neck portion 6' onto the reinforcing ring 14. Next, the end plug 8 is inserted at least partially into the neck portion 6' of the liner 4. Finally, the end plug 8 is secured to the reinforcing ring 14 using a securing means 24 disposed on the axial extension of the neck portion 6' of the liner 4 toward the interior volume of the tank 402, so that the neck portion 6' of the liner 4 is located between the reinforcing ring 14 and the end plug 8.

[0079] FIG. 9 shows a tank 502 for storing compressed gas according to a sixth embodiment of the present invention. This tank 502 differs from the first embodiment in that the neck 6' of the liner 4 extends into the interior volume of the tank 2 and, in addition, a reinforcing ring 14, which is integral with and inseparable from the neck 6' of the liner 4, is disposed at least partially around the neck 6' of the liner 4. In the illustrated example, the neck 6' of the liner 4 is overmolded with the reinforcing ring 14 such that the reinforcing ring 14 is overmolded around the neck 6' of the liner 4 from the inside. As noted in the introduction to this application, the configuration of the neck 6' of the liner 4 toward the interior of the interior volume of the tank 502 creates a dead volume 32 in the interior volume. The fastening means 24 is positioned inside the neck 6' of the liner 4 radially relative to the neck 6' of the liner 4, and the neck 6' of the liner 4 is disposed between the reinforcing ring 14 and the end plug 8. The reinforcing ring 14 is positioned at least partially around the nozzle 6' of the liner 4 and it is on its inner surface, i.e. the surface in contact with the nozzle 6' of the liner 4, that it may have axial cuts, annular bands, radial protrusions and / or radial notches as described in the first embodiment and in Figures 3, 4A, 4B and 4C.

[0080] In the illustrated example, the reinforcing ring 14 is actually a double reinforcing ring 14d, 14e, of which the first reinforcing ring 14d is located outside the neck 6' of the liner 4 and surrounds and clamps the neck 6' of the liner 4, while the second reinforcing ring 14e has a fastening means 24. The first reinforcing ring 14d is coaxial with the second reinforcing ring 14e, and its inner radius is larger than that of the second reinforcing ring 14e, leaving an annular space between them. The first reinforcing ring 14d is connected to the second reinforcing ring 14e by a washer-shaped reinforcing web 15. The reinforcing web 15 has an outer radius that corresponds to the outer radius of the first reinforcing ring 14d and an inner radius that corresponds to the inner radius of the second reinforcing ring 14e. The annular space provided between the first reinforcing ring 14d and the second reinforcing ring 14e is designed to receive the nozzle portion 6' of the liner 4 and the axial end of the end plug 8, so that the nozzle portion 6' of the liner 4 is protected from the external environment by the end plug 8.

[0081] The tank 502 is manufactured by a manufacturing method including the following steps. The process begins with the manufacture of the liner 4. The liner 4 is manufactured by injection molding two shells that form the two halves of the liner and then welding the two together. During the manufacture of the liner 4, the reinforcing ring 14 is secured around the neck portion 6' of the liner 4, such as by overmolding the neck portion 6' onto the reinforcing ring 14. The end plug 8 is then inserted at least partially into the neck portion 6' of the liner 4. Finally, the end plug 8 is secured to the reinforcing ring 14 inside the neck portion 6' of the liner 4 using a fastening means 24 positioned radially relative to the neck portion 6' of the liner 4, so that the neck portion 6' of the liner 4 is positioned between the reinforcing ring 14 and the end plug 8.

[0082] FIG. 10 illustrates a tank 602 for storing compressed gas according to a seventh embodiment of the present invention. The tank 602 differs from the first embodiment in that it includes a sealing interface 10' between the end plug 8 and the neck 6' of the liner 4, thereby preventing compressed gas from escaping through a gap between the neck 6' of the liner 4 and the end plug 8. In the illustrated example, a layer of airtight material, such as a layer of adhesive applied between the end plug 8 and the neck 6' of the liner 4, forms the sealing interface 10' between the end plug 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 plug 8 each have smooth abutment surfaces that cooperate to form the sealing interface 10' between the end plug 8 and the neck 6 of the liner 4.

[0083] Modified reinforcing rings 14d, 14e, and 14f are shown in Fig. 11. The differences between these and the reinforcing ring 14 of Fig. 3 will be described below.

[0084] The reinforcing ring 14d of Fig. 11A has through holes 34 regularly distributed around the circumference of the reinforcing ring 14d. The holes 34 shown here have a diameter of less than 3 mm, preferably less than 2 mm, and even more preferably less than 1 mm. These holes 34 allow the compressed gas contained in the tank to expand into the gap 7, thereby facilitating the establishment of a pressure equilibrium in the gap 7 relative to the internal volume of the tank, which then exerts pressure on the sealing ring or sealing contact surface. This improves the tank's airtightness without significant additional costs.

[0085] The reinforcing ring 14e of FIG. 11B has axial grooves 36 regularly distributed around the circumference of the reinforcing ring 14e. Each axial groove 36 extends from one axial end of the reinforcing ring 14e to the other axial end of the reinforcing ring 14e. In another embodiment of the present invention (not shown), each axial groove 36 extends from one axial end of the reinforcing ring 14e to an axial position at the level of the sealing ring 10. That is, the axial grooves 36 are open only at one axial end of the reinforcing ring 14e. In this embodiment, the axial grooves 36 have a width of less than 1 mm, preferably less than 0.5 mm, and even more preferably less than 0.3 mm. These axial grooves 36 have the same function as the holes 34 of the reinforcing ring 14d of FIG. 11A in that they allow the compressed gas contained in the tank to expand into the gap 7, thereby facilitating the establishment of pressure equilibrium within the gap 7 relative to the internal volume of the tank, thereby exerting pressure on the sealing ring or sealing contact surface. This improves the tank's airtightness.

[0086] The reinforcing ring 14f of FIG. 11C has axial grooves 36 on its outer surface, similar to the grooves of the reinforcing ring 14e of FIG. 11B, regularly distributed around the circumference of the reinforcing ring 14e, each extending 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 circumferential grooves 36' on its outer surface, extending radially around the entire circumference of the reinforcing ring 14e. Here, the circumferential grooves 36' have a width of less than 1 mm, preferably less than 0.5 mm, and more preferably less than 0.3 mm. The circumferential grooves 36' can, for example, favorably affect pressure uniformity within the gap 7 by fluidly connecting the axial grooves 36 to each other.

[0087] According to one variant embodiment of the invention, the reinforcing ring can simultaneously comprise through holes and grooves as defined above.

[0088] An eighth embodiment of the present invention, a tank 702 for storing compressed gas, is shown in Figure 12. The tank 702 differs from that of the first embodiment in that it has a first cavity 38 extending between the end plug 8 and the axial ends of the neck 6 of the liner 4 and the reinforcing ring 14, and a second cavity 40 in the end plug 8 that corresponds to the cavity in the end plug described with reference to Figure 1, and in which the sealing ring 10 extends.

[0089] When filling or discharging the tank 702, the first and second cavities 38, 40 may have a pressure difference with the tank's internal volume 42. This is particularly problematic when discharging the tank 702, because the pressure in the first and second cavities 38, 40 may remain higher than the pressure in the internal volume 42 even after discharging has finished. This pressure increases the risk of compressed gas leaking out of the tank 702, especially when the pressure in the internal volume drops below 50 bar, at low temperatures, and also when the discharge flow rate from the tank 702 is high. To address this issue, the tank 702 comprises means configured to provide fluid communication between the first and second cavities 38, 40 and the internal volume 42. These means will hereinafter be referred to as the first communication means 44 and the second communication means 45. The first communication means 44 is located upstream of the first cavity 38, and the second communication means 45 is located downstream of the first cavity 38. The terms upstream and downstream are used based on the direction of flow of compressed gas escaping out of the tank.

[0090] FIG. 13 shows a first embodiment of the communication means 44 and the communication means 45, which are formed by open channels arranged in the end plug 8.

[0091] FIG. 14 shows a second embodiment of the communication means 44 and the communication means 45, which are formed by channels drilled in the end plug 8 according to two alternative configurations.

[0092] FIG. 15 shows a third embodiment of the communication means 44 and the communication means 45, in which these means are formed by open channels provided in the nozzle 6 of the liner 4 and the reinforcing ring 14.

[0093] In a fourth embodiment (not shown), at least one flow passage is formed in the neck 6 of the liner 4 to fluidly connect the volume 40 with the interior volume 42 of the tank.

[0094] FIG. 16 shows a tank 3 for storing compressed gas according to current technology. The tank 3 includes a liner 104 made of a plastic material that defines an internal volume for containing compressed gas. The liner 104 has a central portion having a cylindrical or tubular overall shape relative to the central axis 105 of the tank 3, and two ends, only one of which is shown in FIG. 11 . The end of the liner 104 shown in the figure is provided with a nozzle 106 that surrounds the axial opening of the liner and connects the internal volume of the tank with the external environment. The nozzle 106 here extends outside the internal volume of the tank 3 and is axially offset toward the interior of the internal volume of the tank 3. As noted in the introduction to this application, the configuration of the nozzle 106 of the liner 104, which is axially offset toward the interior of the internal volume of the tank 3, creates a dead volume 132 in the internal volume.

[0095] The present invention is not limited to the described embodiments, and other embodiments will be apparent to those skilled in the art. In particular, embodiments of the present invention directed to tanks with a liner nose facing into the tank's internal volume may also be applied to tanks with a liner nose facing outside the tank's internal volume. Conversely, embodiments of the present invention directed to tanks with a liner nose facing outside the tank's internal volume may also be applied to tanks with a liner nose facing into the tank's internal volume. Generally speaking, the various embodiments, in particular the configuration of the liner nose, the removable annulus, the reinforcing ring, and the presence of the cooperating shoulder, may be combined with one another. [Explanation of symbols]

[0096] 2, 3, 102, 202, 302, 402, 502, 602, 702 Tanks for storing compressed gas 4, 104 Liner 5, 105 center axis 6, 6', 106 tube mouth part 7 Gap 8 End Plugs 9. Solenoid valve 10 Seal ring 10' Sealing contact surface between end plug and nozzle 12 Removable annulus 14, 14a, 14b, 14c, 14d, 14e, 14f Reinforcement ring 15 Reinforcing web 16 Axial depth of cut 18 Radial protrusion 18' radial increments 20 Circular Belt 24 Fixing means 26 Shoulder cooperating with end plug 28 Shoulder working with liner 30 Complementary Shoulders 32, 132 Dead volume 34 Through hole 36 Axial grooves 36' Peripheral groove 38 First Vacancy 40 Second Vacancy 42 Internal volume of the tank 44 First communication means 45 Second communication means

Claims

1. A tank (2, 102, 202, 302, 602, 702) for storing compressed gas, comprising a liner (4) made of plastic material of cylindrical overall shape having a central axis (5), said liner (4) having a nozzle (6) surrounding an axial opening of said liner (4), an end plug (8) disposed at least partially in and around the neck (6) of the liner (4); a reinforcing ring (14) for the nozzle portion of the liner (4), which is integral with and inseparable from the nozzle portion (6) of the liner (4); a fixing means (24) for fixing the end plug (8) to the reinforcing ring (14) of the nozzle (6) of the liner (4); Equipped with The tank (2, 102, 202, 302, 602, 702) is characterized in that the end plug (8) is in direct contact with the reinforcing ring (14) and the nozzle (6) of the liner (4).

2. A tank (402, 502) for storing compressed gas, comprising a liner (4) made of plastic material of cylindrical overall shape with a central axis (5), said liner (4) having a nozzle (6') surrounding an axial opening of said liner (4) and extending into the interior volume of said tank, an end plug (8) disposed at least partially within the nozzle (6') of the liner (4); a reinforcing ring (14) for the nozzle portion (6') of the liner (4), which is integral with and inseparable from the nozzle portion (6') of the liner (4); a fixing means (24) for fixing the end plug (8) to the reinforcing ring (14) of the nozzle (6') of the liner (4); A tank (402, 502) comprising:

3. 2. The tank (2, 102, 202, 302, 602, 702) according to claim 1, characterized in that the neck (6) of the liner (4) extends outward from the internal volume of the tank, the reinforcing ring (14) is at least partially disposed within the neck (6) of the liner (4), and the fastening means (24) is disposed inside the neck (6) of the liner (4) radially relative to the neck (6) of the liner (4), whereby the reinforcing ring (14) is positioned between the neck (6) of the liner (4) and the end plug (8), and the neck (6) of the liner (4) is positioned between the reinforcing ring (14) and the end plug (8).

4. 3. The tank (402, 502) according to claim 2, characterized in that the reinforcing ring (14) is arranged at least partially around the neck (6') of the liner (4), and the fixing means (24) are arranged on the axial extension of the neck (6') of the liner (4), radially towards the internal volume of the tank and inside the neck (6') of the liner (4), such that the neck (6') of the liner (4) is positioned between the reinforcing ring (14) and the end plug (8).

5. 5. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 4, characterized in that the nozzle (6, 6') of the liner (4) is overmolded onto the reinforcing ring (14).

6. 6. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 5, characterized in that the reinforcing ring (14) is made of a material having a breaking stress or elastic limit at least twice as high as the material of the liner (4).

7. 7. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to claim 6, characterized in that the reinforcing ring (14) is made of metal, such as aluminum or stainless steel, or of a thermoplastic or thermosetting material.

8. 8. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 7, characterized in that the fixing means (24) are configured to mechanically fix the end plug (8) to the reinforcing ring (14) by means of a screw or ratchet fastening or the like.

9. 9. The tank (102, 302) according to any one of claims 1 to 8, characterized in that the reinforcing ring (14) comprises a shoulder (26) that cooperates with the end plug (8), the shoulder (26) being configured to receive an axial end of the end plug (8).

10. 10. The tank (202, 302) according to any one of claims 1 to 9, characterized in that the reinforcing ring (14) comprises a shoulder (28) cooperating with the liner (4) and configured to receive a complementary shoulder (30) provided at the base of the nozzle (6) of the liner (4).

11. 11. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 10, characterized in that the end plug (8) is provided with a sealing ring (10) that seals by being pressed against the nozzle (6, 6') of the liner (4), the sealing ring (10) being housed in a cavity of the end plug (8).

12. 12. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to claim 11, characterized in that the cavity of the end plug (8) is closed by an annular member to form a receiving groove for the sealing ring (10), and preferably the annular member is a removable annular member (12).

13. 13. The tank (102, 202, 302, 402, 502, 602, 702) according to claim 11 or 12, wherein the sealing ring (10) is a radial seal that surrounds or is surrounded by the nozzle (6) of the liner (4).

14. 14. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 13, characterized in that it comprises first communication means (44) configured to fluidly connect an internal volume (42) of the tank with a first cavity (38) extending between the end plug (8) and the axial end of the neck (6) of the liner (4) and the reinforcing ring (14).

15. 15. The tank (2, 102, 202, 302, 402, 502, 602, 702) of claim 14, further comprising second communication means (45) configured to fluidly connect the first cavity (38) with a second cavity (40) into which the sealing ring (10) extends or with a cavity in the end plug.

16. 16. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 15, further comprising a sealing contact surface (10') between the end plug (8) and the nozzle (6, 6') of the liner (4).

17. The reinforcing ring (14) has, on its radially outer surface: At least one through hole (34), and / or At least one axial groove (36) extending from the axial end of the reinforcing ring (14) to an axial position at the level of the sealing ring (10), and / or At least one peripheral groove (36') configured to fluidly connect the axial grooves (36) with one another.

17. The tank (2, 102, 202, 302, 402, 502, 602, 702) of any one of claims 1 to 16, comprising:

18. 18. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to any one of claims 1 to 17, characterized in that the reinforcing ring (14) has axial notches (16) on its radially outer or inner surface.

19. 19. The tank (2, 102, 202, 302, 402, 502, 602, 702) according to claim 18, which is dependent on any one of claims 11 to 13, characterized in that the reinforcing ring (14) has, on the same face as the face having the axial cuts (16), an annular band (20) of constant radius, which annular band (20) divides the axial cuts (16) into two sets of axial cut assemblies, and the sealing ring (10) is in contact with the annular band (20) of the reinforcing ring (14), which is integral with and inseparable from the nozzle portion (6, 6') of the liner (4), and is sealed by pressing against the pressing portion of the nozzle portion (6, 6') of the liner (4).

20. 1. A method for manufacturing a tank (2, 102, 202, 302, 602, 702) for storing compressed gas, comprising: manufacturing a liner (4) of cylindrical overall shape having a central axis (5) and a nozzle (6) surrounding the axial opening of the liner (4) and extending outwardly from the interior volume of the tank; fixing a reinforcing ring (14) of the liner nose to the nose (6) of the liner (4); inserting an end plug (8) at least partially into and around the neck (6) of the liner (4); fixing the end plug (8) to the reinforcing ring (14) within the nozzle (6) of the liner (4) using a fixing means (24) located radially relative to the nozzle (6) of the liner (4), such that the reinforcing ring (14) is positioned between the nozzle (6) of the liner (4) and the end plug (8), and such that the nozzle (6) of the liner (4) is positioned between the reinforcing ring (14) and the end plug (8); A manufacturing method comprising:

21. 1. A method for manufacturing a tank (402, 502) for compressed gas storage, comprising: manufacturing a liner (4) of cylindrical overall shape having a central axis (5) and a nozzle (6') surrounding the axial opening of the liner (4) and extending into the interior volume of the tank; fixing a reinforcing ring (14) of the liner nose around the nose (6') of the liner (4); inserting an end plug (8) at least partially into the neck (6') of the liner (4); Fixing the end plug (8) to the reinforcing ring (14) using fixing means (24) arranged on the axial extension of the neck of the liner, radially relative to the neck (6') of the liner (4) in the direction of the internal volume of the tank and inside the neck (6') of the liner (4) so ​​that the neck (6') of the liner (4) is positioned between the reinforcing ring (14) and the end plug (8); A manufacturing method comprising:

22. 22. The method according to claim 20 or 21, wherein the liner (4) is made of a plastic material, and the step of fixing the reinforcing ring (14) of the nozzle (6, 6') of the liner (4) to the nozzle (6, 6') of the liner (4) is a step of overmolding the nozzle (6, 6') of the liner (4) onto the reinforcing ring (14) during the manufacturing step of the liner (4).

Images