Composite gas pressure tank

Abstract

The invention relates to a composite pressurized gas reservoir (2) comprising: - an inner plastic casing (20) including a tubular conduit (200) passing through an internal volume of the casing, - a tubular structure (1) inserted into the tubular conduit, the tubular structure being fixed in a hardened resin and comprising a fiber assembly (13) made up of several fiber subassemblies (131, 132), the fiber assembly having a central portion (10) and two end portions (11, 12) positioned on either side of the central portion, the fibers of the two end portions being deployed on an external surface (2000) of the inner plastic casing, - an outer reinforcing casing, - an intermediate reinforcing means (1611, 1612, 1613) positioned and fixed on the fibers of an end portion (11, 12) of a fiber subassembly (131, 132). Figure 1

Description

Title of the invention: Pressurized gas tank made of composite material. Technical field

[0001] The invention relates to a composite material pressurized gas tank. More particularly, the invention relates to a composite material pressurized gas tank that can be used, in particular, as a tank for compressed natural gas, a tank for compressed hydrogen gas, or a tank for liquefied petroleum gas. The invention also relates to a method for manufacturing the aforementioned pressurized gas tank and to a vehicle comprising the aforementioned pressurized gas tank.

[0002] The invention can be used in the field of hydrogen vehicles. By "vehicle" is meant any motor vehicle such as a car, motorcycle, truck, bus, train, machine, in particular construction equipment. State of the art

[0003] Composite pressurized gas tanks used in hydrogen vehicles must be sufficiently resistant to the internal pressure exerted by the compressed gas, but also lightweight (compared to metal pressurized gas tanks) to facilitate their mobility and reduce the fuel consumption of hydrogen vehicles. To best meet these requirements, composite pressurized gas tanks comprise a plastic casing (also called a "liner") delimiting an internal volume for storing compressed gas and an external reinforcing casing comprising resin-impregnated fibers surrounding the plastic casing.

[0004] Thus, document WO2021255041 presents a technical solution in which the mechanical resistance of a composite pressurized gas tank is reinforced by reinforcing elements passing through the plastic casing. More specifically, the reinforcing elements comprise a set of resin-impregnated fibers and, due to their positioning, strengthen the pressurized gas tank by preventing it from deforming under the action of the internal pressure of the compressed gas.

[0005] However, this technical solution has drawbacks, including the fact that it is complex to implement and does not offer results of sufficient quality.

[0006] The invention aims in particular to overcome the disadvantages of the prior art.

[0007] More specifically, an objective of the invention, in at least one of its embodiments, is to provide a pressurized gas reservoir offering better mechanical resistance to the pressure of the gas contained in the pressurized gas reservoir.

[0008] An objective of the invention, in at least one of its embodiments, is also to provide a method for manufacturing a pressurized gas tank offering better mechanical resistance to the pressure of the gas contained in the tank and whose implementation is easy.

[0009] An objective of the invention, in at least one of its embodiments, is also to provide a vehicle comprising a pressurized gas tank made of composite material offering better mechanical resistance to the pressure of the gas contained in the pressurized gas tank. Summary of the invention

[0010] To this end, the invention relates to a pressurized gas reservoir made of composite material comprising:

[0011] - an inner plastic casing delimiting an internal volume intended for to accommodate a pressurized gas, the internal plastic casing comprising an external surface having a posterior external face and an anterior external face opposite the posterior external face, and a tubular conduit traversing the internal volume and opening onto the posterior and anterior external faces,

[0012] - a tubular structure inserted into the tubular conduit and comprising a set of fibers consisting of several fiber subsets, said fiber set having a central part and two end parts positioned on either side of the central part, the fibers of the two end parts being deployed on the external surface and said fiber set being fixed in a first hardened resin, and

[0013] - an outer casing for reinforcing the inner casing made of plastic material, the outer reinforcing layer being formed from a fiber-reinforced polymer fixed in a second hardened resin,

[0014] characterized in that it comprises an intermediate reinforcement means for the inner plastic sheath positioned and fixed on the fibers of an end part of a subset of fibers.

[0015] The term "tubular conduit traversing the internal volume and opening onto the external posterior and anterior faces" means a passage formed in the internal plastic envelope and delimited by the internal plastic envelope going from one side to an opposite side of the plastic envelope, that is to say from the external posterior face to the external anterior face.

[0016] The term "tubular element", whether referring to the tubular conduit or the tubular structure, means an element having an elongated shape in a longitudinal direction and a closed shape in a cross-section to the longitudinal direction, for example a circular or rectangular shape.

[0017] The term "external surface of the inner plastic casing" means the surface of the inner plastic casing that is not in contact with the pressurized gas contained in the inner plastic casing and that does not form the tubular conduit.

[0018] The term "deployed" in the expression "the fibers of the two end parts being deployed on the external surface" means that the fibers of the two end parts of the fiber assembly are affixed to the external surface of the inner plastic sheath by being in contact with it.

[0019] The term “intermediate” in the expression “intermediate reinforcing means” means that the intermediate reinforcing means is positioned and fixed on the fibers of an end portion of a fiber subset and is not positioned directly on the external surface of the inner plastic sheath.

[0020] Preferably, the deployment is circumferential such that the fibers of the two end portions of a tubular structure are distributed substantially evenly around the periphery of the tubular conduit in which the tubular structure is inserted. The "periphery of a tubular conduit" is defined as a region of the plastic sheath covering an end area of ​​a tubular conduit and, where required, a peripheral area extending over a portion of the external face adjacent to said end area.

[0021] The expressions "fiber assembly fixed in a first hardened resin" and "fiber-reinforced polymer fixed in a second hardened resin" mean that all the fibers are coated with resin at least partially or totally. When the fibers are partially coated with resin, they are coated to more than 70%, that is, more than 70% of the total surface area of ​​the fibers in the fiber assembly is covered by resin. Thus, partial or total coating of all the fibers in a fiber assembly is preferable to coating only the outer fibers of a fiber assembly where only the fibers near the peripheral surface of the fiber assembly are fixed in the resin (partially or totally), typically 10% of the total number of fibers in the fiber assembly.

[0022] The expression "several fiber subsets" means that the fiber set is divided into at least two fiber subsets so as to distinguish one fiber subset from another. In one example, the fiber set may be divided into two fiber subsets, such that The set of fibers comprises a first subset of fibers and a second subset of fibers. In another example, the set of fibers can be divided into three subsets, such that the set of fibers comprises a first subset of fibers, a second subset of fibers, and a third subset of fibers. In yet another example, the set of fibers can be divided into N subsets of fibers, such that the set of fibers comprises a first subset of fibers, a second subset of fibers, and an (N)th subset of fibers. a subset of fibers and an Nth subset of fibers where N is a natural integer greater than or equal to 2.

[0023] The term "an intermediate reinforcing means positioned and fixed on the fibers of an end part of a subset of fibers" means that the intermediate reinforcing means is positioned and fixed on the fibers of an end part of a subset of fibers by being in contact with them.

[0024] The general principle of the invention is based on the fact that the pressurized gas tank made of composite material comprises a tubular structure comprising a set of fibers made up of several subsets of fibers and fixed in a first hardened resin and whose end parts fibers are applied to the external surface of the internal plastic casing so that an intermediate reinforcing means is positioned on the fibers of an end part of a subset of fibers.

[0025] Thus, the invention is based on a completely new and inventive approach to reducing the shear stress applied to the composite gas pressure tank and thus obtaining a gas pressure tank with better mechanical resistance to the internal pressure of the compressed gas.

[0026] According to one embodiment of the invention, the inner plastic casing forms a square or rectangular parallelepiped. This configuration thus facilitates the insertion of composite pressurized gas tanks into vehicles.

[0027] According to one embodiment of the invention, the inner plastic casing is made by injection, rotomolding or extrusion blow molding of a thermoplastic or thermosetting polymer material such as, for example, polyethylene, polyamide, polyphthalamides, polyurethane or silicone.

[0028] According to one embodiment of the invention, the tubular conduits each comprise a central zone and two end zones, such that the end zones connect the central zone to the posterior and anterior external faces of the outer surface of the plastic casing. Preferably, each end zone has a bowl-shaped depression. This configuration makes it possible to obtain a improved integration of the fibers from both end parts into the plastic casing.

[0029] According to one embodiment of the invention, the central zone of the tubular conduits has, in cross-section, a circular, square, or rectangular shape. This configuration thus facilitates the insertion of the tubular structures into the tubular conduits.

[0030] According to one embodiment of the invention, the tubular conduits are distributed equidistant from each other within the plastic casing. This configuration thus provides improved mechanical resistance of the composite pressurized gas tank throughout its entire volume.

[0031] According to one embodiment of the invention, the tubular conduits number twenty, thirty, thirty-six, forty-five, fifty-five, sixty-five, seventy-five, eighty-five, ninety-five, or one hundred in a single composite pressurized gas tank. This configuration thus provides improved mechanical resistance of the composite pressurized gas tank throughout its entire volume.

[0032] According to one embodiment of the invention, the set of fibers in the central part of the tubular structure has, in cross-section, a shape of a disc, a square, a rectangle or several lobes.

[0033] According to one embodiment of the invention, the central zone of the tubular conduits and the central part of the tubular structures are cylindrical. This configuration thus facilitates the insertion of the tubular structures into the tubular conduits.

[0034] According to one embodiment of the invention, the fibers of the two end parts are flexible so as to be able to conform to the external surface of the plastic casing.

[0035] According to one embodiment of the invention, each subset of the fiber assembly comprises between 30% and 40% of the total number of fibers in the fiber assembly. This configuration allows for a homogeneous distribution of fibers among the different fiber subsets.

[0036] According to one embodiment of the invention, the contact area of ​​one of the two end portions of a fiber subset is equal to the contact area of ​​the other end portion. This configuration makes it possible to obtain the same mechanical strength of the composite pressurized gas tank regardless of which face of the composite pressurized gas tank is considered. This allows for the lowest possible mass and volume of the tubular structure, thereby increasing the usable volume of the gas tank. pressure while having a pressurized gas tank made of composite material that is as resistant as possible to the internal pressure of the compressed gas.

[0037] According to one embodiment of the invention, the composite material pressurized gas reservoir comprises twenty, thirty, thirty-six, forty-five, fifty-five, sixty-five, seventy-five, eighty-five, ninety-five or one hundred tubular structures.

[0038] According to one embodiment of the invention, the fibers of the two end portions have a beveled shape at the end, allowing them to maximize their contact with the plastic casing. This configuration increases the mechanical resistance of the composite pressurized gas tank to the internal pressure of the compressed gas.

[0039] According to one embodiment of the invention, the surface area ratio between the contact area of ​​the two end portions of a subset of fibers in contact with the outer surface of the plastic casing and the cross-section of the central portion of the tubular structure is at least 5. This feature ensures that the contact area between the two end portions and the outer surface of the plastic casing is sufficiently large to reduce the shear stress in the resin connecting the tubular structure and the plastic casing. Furthermore, this feature optimizes the volume of the tubular structures to limit their mass in the composite pressurized gas tank.

[0040] According to one embodiment of the invention, the cross-section of the central part of the tubular structure has a surface area between 300 mm² and 1000 mm², and the contact area of ​​the two end parts of a subset of fibers in contact with the external surface of the plastic casing is between 3000 mm² and 15000 mm² for a composite gas pressure tank containing a gas compressed to a pressure of 700 bar. This configuration provides improved mechanical strength of the composite gas pressure tank.

[0041] According to one embodiment of the invention, the composite pressurized gas reservoir comprises at least two tubular structures, the expanded fibers of the two end portions of a fiber subset of one tubular structure being superimposed on those of another tubular structure inserted into an adjacent tubular conduit. The expression "the expanded fibers of the two end portions of a fiber subset of one tubular structure are superimposed on those of another tubular structure" means that the expanded fibers at the two end portions of two adjacent tubular structures extend sufficiently to overlap. Thus, for example, the deployed fibers of the two end sections of a first fiber subset of a tubular structure are positioned between the deployed fibers of the two end sections of a second fiber subset. This configuration provides greater mechanical strength within the pressurized gas reservoir.

[0042] According to one embodiment of the invention, the fibers of the tubular structure, the intermediate reinforcement means, and the outer reinforcing sheath are glass, basalt, carbon, and / or aramid fibers. The fiber material(s) are not necessarily the same in the tubular structure, the intermediate reinforcement means, and the outer reinforcing sheath. However, it is advantageous for the fiber material(s) of the tubular structure, the intermediate reinforcement means, and the outer reinforcing sheath to be the same, as this results in greater homogeneity within the pressurized gas reservoir.

[0043] According to one embodiment of the invention, the intermediate reinforcement means is an intermediate plate covering the fibers of the end portion of the fiber subassembly. This configuration makes it possible to obtain a pressurized gas reservoir with improved mechanical strength.

[0044] According to one embodiment of the invention, the composite pressurized gas reservoir comprises two tubular conduits and two tubular structures. Each tubular structure is inserted into a tubular conduit. The intermediate reinforcement means comprises at least one strip joining the end portions of the two tubular structures located on the same external face. This configuration allows the strips to be positioned at locations chosen to reduce shear stresses and thus obtain a composite pressurized gas reservoir offering improved mechanical strength while limiting the size and therefore the weight of the intermediate reinforcement means and, consequently, of the composite pressurized gas reservoir.

[0045] According to one embodiment of the invention, the fibers of an end part of another fiber subset are deployed on the intermediate reinforcement means so that the intermediate reinforcement means is sandwiched between the fibers of the end part of the fiber subset and the fibers of the end part of the other fiber subset.

[0046] The expression "so that the intermediate reinforcing means is sandwiched between the fibers of the end portion of the fiber subset and the fibers of the end portion of the other fiber subset" means that the intermediate reinforcing means is in contact with the fibers of the part end of the fiber subset and with the fibers of the end part of the other fiber subset.

[0047] According to one embodiment of the invention, the composite pressurized gas tank includes an additional reinforcement means positioned and fixed on the external surface such that the additional reinforcement means is sandwiched between the external surface and the fibers of the end portion of the fiber subset. This configuration reduces the shear stresses exerted on the pressurized gas tank and thus increases the mechanical strength of the composite pressurized gas tank.

[0048] The phrase "an additional reinforcing means is sandwiched between the outer surface and the fibers of the end portion of the fiber subset" means that the additional reinforcing means is positioned between the outer surface and the fibers of the end portion of the fiber subset. The additional reinforcing means is in contact with the outer surface and with the fibers of the end portion of a first fiber subset of the fiber set.

[0049] According to one embodiment of the invention, the additional reinforcement means is an additional plate covering the external surface on at least one periphery of the tubular conduit.

[0050] The additional reinforcement means is a plate extending over the external surface in contact with one perimeter of the tubular conduit, both perimeters of the tubular conduit, one perimeter of several tubular conduits (three, four, twenty, thirty, thirty-six, forty-five, fifty-five, sixty-five, seventy-five, eighty-five, ninety-five or one hundred tubular conduits) or both perimeters of several tubular conduits (three, four, twenty, thirty, thirty-six, forty-five, fifty-five, sixty-five, seventy-five, eighty-five, ninety-five or one hundred tubular conduits).

[0051] According to one embodiment of the invention, the additional reinforcement means and the intermediate reinforcement means comprise two joined or disjoined parts, one positioned in contact with the perimeter of the tubular conduit of the posterior external face of the plastic envelope and the other positioned in contact with the perimeter of the tubular conduit of the anterior external face of the plastic envelope.

[0052] According to one embodiment of the invention, the intermediate reinforcement means and the additional reinforcement means comprise fibers fixed in a third hardened resin.

[0053] According to one embodiment of the invention, the composite pressurized gas reservoir comprises an intermediate layer of vertically aligned carbon nanotubes positioned and fixed to the intermediate reinforcement means The intermediate reinforcement is sandwiched between the intermediate layer of vertically aligned carbon nanotubes and the end portion of the fiber subset. Alternatively, in the case of a composite gas pressure vessel where the fibers of the end portion of the other fiber subset are deployed on the intermediate reinforcement, the intermediate reinforcement is sandwiched between the intermediate layer of vertically aligned carbon nanotubes and the fibers of the end portion of the other fiber subset. Incorporating an intermediate layer of vertically aligned carbon nanotubes into the gas pressure vessel increases its mechanical strength.

[0054] Preferably, the intermediate reinforcement means is a plate having two faces: a front face and a back face. In this case, the layer of vertically aligned carbon nanotubes is in contact with the front or back face of the plate.

[0055] According to one embodiment of the invention, the composite pressurized gas tank comprises an additional layer of vertically aligned carbon nanotubes positioned and fixed on the additional reinforcement means such that the additional reinforcement means is sandwiched between the additional layer of vertically aligned carbon nanotubes and the fibers of the end part of the fiber subset or between the additional layer of vertically aligned carbon nanotubes and the external surface.

[0056] Integrating an additional layer of vertically aligned carbon nanotubes into the pressurized gas reservoir increases the mechanical strength of the pressurized gas reservoir.

[0057] Preferably, the additional reinforcement means is a plate having two faces: a front face and a back face. In this case, the layer of vertically aligned carbon nanotubes is in contact with the front or back face of the plate.

[0058] According to one embodiment of the invention, the first, second and / or third resins are thermoplastic resins or thermosetting resins.

[0059] According to one embodiment of the invention, the first, second and / or third resins are thermoplastic or thermosetting polymer resins, which may be an epoxy resin, a polyester resin or a polyurethane resin.

[0060] According to one embodiment of the invention, the resins impregnating the fiber subassemblies, the additional reinforcement means, the intermediate reinforcement means, and the external reinforcement sheath are of the same of a different nature. This configuration allows the use of resins with different properties depending on the desired effect.

[0061] According to one embodiment of the invention, the composite pressurized gas reservoir comprises an insert positioned on the top of the tubular structure, in a space between the central portion and an end portion of the fiber assembly formed during the deployment of the fibers from the end portions of the fiber subassemblies. The insert is positioned on the nth fiber subassembly, that is, on the last fiber subassembly. Thus, the positioning of the inserts makes it possible to exert pressure on the end portions and the (intermediate and / or additional) reinforcing means and therefore to obtain better support between the two end portions and the intermediate reinforcing means.

[0062] Preferably, the inserts are metal inserts or inserts made from carbon fibers cut and bonded together. In this way, the inserts are made of a material strong enough to enable them to fulfill their function of securing the tubular structures to the reinforcing means and the plastic casing.

[0063] According to one embodiment of the invention, the inserts are made of a material compatible with the first resin and / or the second resin. This configuration allows the first resin and / or the second resin to maintain the inserts in contact with the impregnated fibers of the impregnated fiber assembly and / or the external reinforcing sheath.

[0064] According to one embodiment of the invention, locking means are positioned on the inserts. Thus, this configuration makes it possible to hold in place the inserts on which the locking means are positioned.

[0065] According to one embodiment of the invention, the blocking means are resin-impregnated fiber discs.

[0066] According to one embodiment of the invention, the inner plastic casing includes a tubular fitting equipped with a valve allowing the inlet and outlet of gas from the composite pressurized gas tank. The fact that the inner plastic casing includes a tubular fitting equipped with a valve allows the filling and emptying of the gas contained in the composite pressurized gas tank.

[0067] The invention also relates to a method for manufacturing a composite pressurized gas tank conforming to the aforementioned composite pressurized gas tank. The method comprises the following steps:

[0068] Step 1: Obtaining an inner plastic casing delimiting an internal volume intended to house a pressurized gas, the inner casing in plastic material comprising an external surface having a posterior external face and an anterior external face opposite the posterior external face, and a tubular conduit traversing the internal volume and opening onto the posterior and anterior external faces,

[0069] Step 2: Obtaining a tubular structure comprising a set of fibers made up of several fiber subsets, said set of fibers having a central part and two end parts positioned on either side of the central part,

[0070] Step 3: Insertion of said tubular structure into the tubular conduit,

[0071] Step 4: Deployment of the fibers of an end portion of a subset of fibers on the outer surface of the inner plastic casing,

[0072] If the fibers of the end portion of the fiber subset deployed at the step 4 are pre-impregnated with a resin called "end-piece resin", so skip to step 6, otherwise continue to step 5.

[0073] Step 5: Impregnation of the end fibers of the fiber subset deployed in step 4 with a resin called the "end part resin",

[0074] Step 6: Application of an intermediate reinforcing means to the fibers of the end part of the subset of fibers impregnated by the resin called "end part resin",

[0075] Step 7: Deployment of the fibers from one end portion of another fiber subset onto the intermediate reinforcement means affixed in step 6,

[0076] If the fibers of the end portion of the other subset of deployed fibers In step 7, they are pre-impregnated with a resin called "end part resin," so skip to step 9; otherwise, continue to step 8.

[0077] Step 8: Impregnation of the end fibers of the other subset of fibers deployed in step 7 with a resin called the "end-part resin,"

[0078] Step 9: Formation of an outer sheath to reinforce the inner sheath in plastic, the outer reinforcing layer being formed from a polymer reinforced with fibers impregnated by a second resin,

[0079] Step 10: Hardening of the resin known as the "end part resin" and of the second resin,

[0080] Step 11: Obtaining the pressurized gas reservoir made of composite material.

[0081] The term “apposition” in relation to the additional reinforcing means, respectively the intermediate reinforcing means, means that the additional reinforcing means, respectively and the intermediate reinforcing means, is in contact with the fibers on which it is applied.

[0082] The expressions "deployment of the fibers of an end portion of a subset of fibers on the external surface of the inner plastic sheath" " and "deployment of fibers from one end part of another subset of fibers on the intermediate reinforcing means" mean that the deployed fibers are in contact with the external surface and with the intermediate reinforcing means respectively.

[0083] The expression "previously impregnated" in "If the fibers of the end part of the fiber subset deployed in step 4 are previously impregnated with a resin called "end part resin" then skip to step 6, otherwise continue to step 5" means that the fibers of the end part have been impregnated with the resin called "end part resin" before obtaining a tubular structure.

[0084] Thus, in this process, with a set of fibers consisting of N fiber subsets where N is a natural integer greater than or equal to 2, the steps of deployment and impregnation of the fibers of the two end parts, when the fibers of the two end parts are not pre-impregnated before the insertion of the tubular structure into the tubular conduit, consist of deploying the fibers of the two end parts of a first of the N fiber subsets and impregnating them with the resin called "end part resin", then repeating this operation with the fibers of the two end parts of each of the remaining Nl subsets.

[0085] The expression "a set of fibers consisting of several subsets of fibers" means that it is possible to divide all the fibers in the set of fibers into N groups of fibers, the term "groups" being referred to here as subsets. Thus, when N equals 2, the fibers in the set of fibers are divided into two subsets of fibers such that the set of fibers consists of a first subset of fibers and a second set of fibers. When N equals 3, the fibers in the set of fibers are divided into three subsets of fibers such that the set of fibers consists of a first subset of fibers, a second subset of fibers, and a third set of fibers.In the case where N equals 4, the fibers in the fiber set are divided into four fiber subsets such that the fiber set consists of a first fiber subset, a second fiber subset, a third fiber subset, and a fourth fiber set.

[0086] Implementing a deployment step followed by a fiber impregnation step for a subset of fibers makes it possible to obtain a layer of deployed-impregnated fibers, for example, a first layer of deployed-impregnated fibers for the first of the N fiber subsets. Thus, the expression "repeat this operation with the fibers of the two end parts of each of the remaining Nl subsets" means that after obtaining the first layer of deployed-impregnated fibers, followed by the obtaining of a second layer of deployed-impregnated fibers (in the case where N is greater than or equal to 2), then - possibly - the obtaining of a third layer of deployed-impregnated fibers (in the case where N is greater than or equal to 3) and so on until all the fibers of the two end parts of the fiber set are deployed and impregnated in N successive layers.

[0087] Implementing a hardening operation of the resin called "end part resin" impregnated on the deployed-impregnated fibers of a subset of deployed-impregnated fibers makes it possible to obtain a layer of deployed-impregnated-hardened fibers, for example, a first layer of deployed-impregnated-hardened fibers in the case of the first of the N subsets of deployed-impregnated fibers. Thus, after obtaining a first layer of deployed-impregnated-cured fibers, there follows the obtaining of a second layer of deployed-impregnated-cured fibers (in the case where N is greater than or equal to 2), then - possibly - the obtaining of a third layer of deployed-impregnated-cured fibers (in the case where N is greater than or equal to 3) and so on until all the fibers of the two end parts of the fiber assembly are deployed, impregnated and cured in N successive layers.

[0088] In this process, applying the fibers from both end portions of the fiber subassemblies in successive layers to the external surface of the internal plastic casing allows intermediate reinforcing means to be sandwiched between these layers, thereby reducing shear stresses. This process thus makes it possible to obtain a pressurized gas tank made of composite material with improved mechanical strength.

[0089] According to one embodiment of the invention, the method for manufacturing a pressurized gas tank made of composite material comprises, after the step of inserting said tubular structure into the tubular conduit and before the step of deploying the fibers of the two end parts of a subset of fibers on the external surface of the internal plastic casing, a step of applying an additional reinforcement means to the external surface of the internal plastic casing.

[0090] The expression "application of an additional reinforcing means to the external surface of the internal plastic casing" means that the additional reinforcing means is in contact with the external surface.

[0091] Positioning an additional reinforcement means directly on the external surface of the internal plastic casing makes it possible to obtain a pressurized gas tank made of composite material with improved mechanical resistance through a reduction of shear stresses.

[0092] According to one embodiment of the invention, with a pressurized gas tank made of composite material comprising M intermediate reinforcement means where M is a natural integer greater than or equal to 1, the process of manufacturing such a tank comprises, before step 9 of forming an outer reinforcement shell of the inner plastic shell and after step 8 of impregnation with a resin called "end part resin" of the fibers of the two end parts of the other subset of fibers deployed in step 7, a step of positioning the M intermediate reinforcement means by repeating steps 6 to 8 until all the intermediate reinforcement means are positioned between the fibers of an end part of one subset of fibers and the fibers of an end part of another subset of fibers.

[0093] According to one embodiment of the invention, the process for manufacturing a pressurized gas tank made of composite material comprises, after the step of deploying and impregnating the fibers of the end part of the fiber sub-assembly and before the step of applying an intermediate reinforcement means to said deployed-impregnated fibers, a step of applying an intermediate layer of vertically aligned carbon nanotubes to said deployed-impregnated fibers.

[0094] According to one embodiment of the invention, the process for manufacturing a pressurized gas tank made of composite material comprises, after the step of applying an intermediate reinforcement means and before the deployment of the fibers of the end part of the other fiber subset, a step of applying an intermediate layer of carbon nanotubes aligned vertically on said intermediate reinforcement means.

[0095] According to one embodiment of the invention, the method for manufacturing a pressurized gas tank made of composite material comprises, after the step of inserting said tubular structure into the tubular conduit and before the step of applying an additional reinforcement means to the external surface of the internal plastic casing, a step of applying an additional layer of vertically aligned carbon nanotubes to the external surface of the internal plastic casing.

[0096] According to one embodiment of the invention, the method for manufacturing a pressurized gas tank made of composite material comprises, after the step of applying an additional reinforcement means to the external surface of the internal plastic casing and before the step of deploying the fibers of the end part of the fiber subset, a step of applying an additional layer of carbon nanotubes aligned vertically on the additional reinforcement means.

[0097] The application of an additional layer of vertically aligned carbon nanotubes to the external surface of the inner plastic casing, respectively to the additional reinforcement means, means that the additional layer of vertically aligned carbon nanotubes is in contact with the external surface of the inner plastic casing, respectively with the additional reinforcement means.

[0098] The application of an intermediate layer of vertically aligned carbon nanotubes to the deployed-impregnated fibers, respectively to the intermediate reinforcement means, means that the intermediate layer of vertically aligned carbon nanotubes is in contact with the deployed-impregnated fibers, respectively with the intermediate reinforcement means.

[0099] The positioning of the additional layer of vertically aligned carbon nanotubes and of intermediate layers of vertically aligned carbon nanotubes makes it possible to reduce shear stresses and thus improve the mechanical resistance of the pressurized gas reservoir.

[0100] According to one embodiment of the invention, the external reinforcing sleeve is positioned between the end portions of two subassemblies. This configuration allows the external reinforcing sleeve to remain in the desired position around the plastic sleeve and thus to obtain better mechanical resistance of the pressurized gas tank.

[0101] According to one embodiment of the invention, in order to deploy the fibers of the two end portions of a fiber assembly or sub-assembly onto the external surface of the plastic casing, a tool (for example, a mechanical tool) or blown air is applied at the inlets of the tubular conduit (i.e., at the two opposite peripheries of the tubular conduit). The use of a tool or blown air facilitates a circumferential deployment of the fibers so as to distribute them substantially evenly over the two opposite peripheries of the tubular conduit. Preferably, the tool or blown air is applied to dry fibers, i.e., before an impregnation step with the so-called "end portion resin" of the fibers of the two end portions of the fiber assembly or sub-assembly.Indeed, if the tool or blown air is applied to fibers impregnated with resin, these fibers will be sticky and it will be more difficult to deploy them evenly.

[0102] In the step of obtaining a tubular structure of the process of manufacturing a pressurized gas tank made of composite material, the fibers of the central part are either dry, or previously impregnated with a resin called "central part resin", or fixed in a hardened or partially hardened resin called "central part resin".

[0103] It should be noted that the resin referred to as the "central part resin" is not necessarily the same as the resin referred to as the "end part resin". It should also be noted that the first resin of the composite pressurized gas tank is formed by combining the "central part resin" and the "end part resin".

[0104] According to one embodiment of the invention, in the case where the fibers of the central part are dry at the stage of obtaining a tubular structure, the process of manufacturing a pressurized gas tank made of composite material includes, after the stage of inserting the tubular structure into the tubular conduit and before the stage of forming the external reinforcing envelope around the internal plastic envelope, a stage of impregnating the fibers of the central part with a resin called "central part resin".The impregnation of the fibers in the central part of the tubular structure is achieved by infusing resin (under vacuum or pressure) into a resin channel within the tubular structure. The resin channel is formed in the center of the tubular structure and / or at its periphery, so as to impregnate the central part of the tubular structure throughout its entire volume (i.e., at least 70% of the total surface area of ​​the fibers in the central part of the fiber assembly is covered by resin) and / or on its surface. This configuration allows for better resin impregnation of the entire central part.

[0105] According to one embodiment of the invention, the hardening step of the so-called "end resin" and the second resin in the process for manufacturing a composite pressurized gas tank consists of successively hardening the so-called "end resin" and then the second resin. This allows for separate control of the hardening quality of the first resin and the hardening quality of the second resin.

[0106] More specifically, the successive hardening step of the first resin and then the second resin consists of hardening the first resin impregnated on the spread-impregnated fibers of the two end parts of the first of the N fiber subsets, then repeating this operation with the spread-impregnated fibers of each of the remaining Nl subsets, and then hardening the second resin.

[0107] According to one embodiment of the invention, the hardening step of the so-called "end resin" and the second resin in the process of manufacturing a composite pressurized gas tank consists of simultaneously hardening the so-called "end resin" and the second resin. This minimizes the number of steps in the manufacturing process.

[0108] According to an alternative embodiment of the invention, the step of simultaneously curing the first resin and the second resin consists of curing simultaneously the first resin impregnated onto the deployed fibers of the two end parts of the N fiber subsets and the second resin.

[0109] According to one embodiment of the invention, where the fibers of the central part are pre-impregnated with a resin called the "central part resin" during the tubular structure formation stage, the manufacturing process for a composite gas pressure tank includes a step of curing the resin called the "central part resin." This curing step of the "central part resin" is carried out either simultaneously with the curing of the resin called the "end part resin" and the second resin, or successively. The successive curing step of the "central part resin" consists of successively curing the resin called the "central part resin," then the resin called the "end part resin," and then the second resin.Alternatively, the successive hardening step of the so-called "central part resin" consists of successively hardening the so-called "end part resin", then the so-called "central part resin", then the second resin.

[0110] According to one embodiment of the invention, the hardening of the resin (the first, second and third resins) is achieved by applying a heat treatment or a UV treatment.

[0111] According to one embodiment of the invention, the hardening of the first resin, the second resin and / or the third resin is carried out immediately after the positioning of the element impregnated by this resin (one of the fiber sub-assemblies, an additional reinforcement means, an intermediate reinforcement means and / or the external reinforcement envelope).

[0112] According to one embodiment of the invention, the hardening of the first resin, the second resin and / or the third resin is carried out after the formation of the outer reinforcing envelope.

[0113] According to one embodiment of the invention, the tubular structure, the additional reinforcing means, the intermediate reinforcing means, and the outer reinforcing sheath are subjected to a treatment designed to harden their resins (the first, second, and third resins) simultaneously. This configuration allows for greater homogeneity within the "tubular structure / reinforcing means / outer reinforcing sheath" assembly.

[0114] According to one embodiment of the invention, partial hardening of the resin referred to as the "central part resin" is carried out before positioning the tubular structure in the tubular conduit. Partial hardening means that only a portion of the resin impregnated onto the central part fibers is fully hardened or that partial crosslinking (i.e., hardening lasting the (Half the time required to achieve complete and uniform hardening of the resin impregnated onto the fibers of the central section.) This characteristic allows the central section of the tubular structure to achieve the desired viscosity, thus enabling better handling of the tubular structure.

[0115] According to one embodiment of the invention, a partial hardening of the resin referred to as the "end-piece resin" is carried out after the end-piece fibers have been impregnated and before their deployment on the external surface of the plastic casing. This characteristic thus gives the impregnated fibers the desired viscosity, thereby allowing for better handling of the element in question.

[0116] The invention also relates to a vehicle comprising a pressurized gas tank made of composite material conforming to the aforementioned pressurized gas tank made of composite material. Brief description of the figures

[0117] Other features and advantages of the invention will become more apparent upon reading the following description of a preferred embodiment, given by way of simple illustrative and non-limiting example, and the accompanying drawings, among which:

[0118] [Fig-1] presents a vertical section of the pressurized gas tank made of composite material according to the invention where intermediate reinforcement means in the form of a plate covering the fibers of the end parts of the fiber sub-assembly can be observed.

[0119] [Fig.2a] presents the intermediate reinforcement means for covering the fibers of the end parts of the fiber subset and [Fig.2b] presents a top view of the fibers of the end parts of the other fiber subset illustrating the positioning step of the intermediate reinforcement means.

[0120] [Fig.3] presents a vertical section of the pressurized gas tank made of composite material according to the invention where intermediate reinforcement means can be observed in the form of strips joining the two end parts of a tubular structure.

[0121] [Fig.4] [Fig.4] presents a top view of the pressurized gas tank made of composite material according to the invention where intermediate reinforcement means can be observed in the form of strips joining the two end parts of the two tubular structures located on the same external face.

[0122] [Fig. 5] shows a vertical cross-section of the composite pressurized gas tank according to the invention, where intermediate and additional reinforcing means in the form of plates covering respectively can be observed. the fibers of the two end parts of the fiber subset and the external surface of the internal plastic sheath.

[0123] [Fig.6] presents a cross-sectional view of one of the two end parts of a structure tubular where an intermediate layer of vertically aligned carbon nanotubes and an additional layer of vertically aligned carbon nanotubes can be observed.

[0124] [Fig.7] shows a section of a layer of aligned carbon nanotubes vertically.

[0125] [Fig.8] presents a top view of a way of deploying the fibers of the two end parts of the fiber assembly.

[0126] [Fig.9] presents a vertical cross-section of the pressurized gas reservoir made of composite where two tubular structures can be observed and the fibers of the two end parts of one tubular structure are superimposed with those of the other tubular structure.

[0127] [Fig. 10] presents a vertical section of the pressurized gas tank made of composite material where two tubular connection positions equipped with a valve can be observed, allowing the entry and exit of a gas from the inner plastic casing.

[0128] [Fig.lia] and [Fig. 11b] illustrate two possibilities for winding the outer reinforcement envelope.

[0129] [Fig. 12] illustrates the possible position of the fiber attachment point to start winding fibers impregnated with a second resin onto the inner plastic casing.

[0130] [Fig. 13] illustrates the possible positions of the tubular fitting equipped with a valve allowing the entry and exit of a gas from the inner plastic casing.

[0131] [Fig. 14] presents a vertical section of the inner plastic casing illustrating the step of obtaining by molding the inner plastic casing, according to the invention, on which the weld joints between the different areas of the pressurized gas tank made of composite material can be observed.

[0132] [Fig. 15] presents a vertical section of the inner plastic envelope illustrating the step of forming the tubular conduits, according to the invention, obtained by cutting the weld joints.

[0133] [Fig. 16a] presents a vertical section of the inner plastic casing illustrating the step of inserting the tubular structures into the tubular conduits, according to the invention.

[0134] [Fig. 16b] presents a vertical section of the plastic envelope illustrating the step of inserting a tubular structure impregnated by a resin around the periphery of the fiber assembly.

[0135] [Fig. 16c] presents a vertical section of the plastic envelope illustrating the step of inserting a tubular structure impregnated by a resin over the entire volume of the central part of the fiber assembly.

[0136] [Fig. 17] presents a vertical section of the inner plastic casing illustrating the step of applying the additional reinforcing means to the outer surface of the inner plastic casing.

[0137] [Fig. 18a] and [Fig. 18b] present a vertical section of the plastic envelope illustrating the step of opening the fibers of the two end parts of the fiber assembly through the use of blown air ([Fig. 18a]) or a tool ([Fig. 18b]).

[0138] [Fig. 19] presents a vertical section of the inner plastic envelope illustrating the step of applying the additional fiber reinforcement means to the two end parts of a fiber subset.

[0139] [Fig.20] presents a vertical section of the inner plastic envelope illustrating the step of applying the intermediate reinforcing means, according to the invention, to the fibers of the two end parts of the fiber subassembly.

[0140] [Fig.21] presents a vertical section of the inner plastic envelope illustrating the step of apposition, according to the invention, of the fibers of the two end parts of another subset of fibers on the intermediate reinforcement means.

[0141] [Fig.22] presents a vertical section of the inner plastic envelope illustrating the step of inserting an insert, according to the invention, onto the fibers of the two end parts of another subset of fibers.

[0142] [Fig.23] presents a vertical section of the pressurized gas tank made of composite material illustrating the step of forming the outer reinforcing shell around the inner plastic shell, by winding fibers impregnated with a second resin.

[0143] [Fig.24] presents a vertical section of the plastic envelope illustrating the step of impregnating the dry fibers of the central part with a resin by a resin infusion technique in one (or more) resin channel(s) inside the tubular structure.

[0144] [Fig.25a] and [Fig.25b] show the positioning of the resin channel(s) inside the tubular structure of the resin impregnation step of the central part of [Fig.24]. The resin channel(s) is / are positioned at the center of the tubular structure ([Fig.25a]) or at the periphery ([Fig.25b]). Detailed description

[0145] In the figures, the size of some elements may be exaggerated and not drawn to scale for illustrative purposes.

[0146] In the figures, the fibers of the two end portions are impregnated with resin before the tubular structure is inserted into the tubular conduit. The configuration in which the fibers of the two end portions are impregnated with resin after the tubular structure has been inserted into the tubular conduit is not shown in the figures.

[0147] Figure 1 is a vertical cross-section of the composite gas reservoir 2 according to the invention, showing intermediate reinforcement means 1611, 1612, 1613 in the form of plates covering the fibers of the end portions 11, 12 of the fiber subassembly 131, 132. The plastic casing 20, also called a "liner," is designed to house a pressurized gas and thus forms a circumscribed space, thereby delimiting an internal volume capable of containing a pressurized gas. The external surface 2000 of the plastic casing 20 is shown in Figure 1. The plastic casing 20 may have a square or rectangular parallelepiped shape in which tubular conduits 200 pass through the internal volume of the plastic casing 20 and open onto the posterior external face 201 and the anterior external face 202 of the casing 20.The tubular conduits 200 can thus be distributed equidistant from each other within the plastic casing 20 to delineate different zones within the composite gas pressure tank 2. The tubular conduits comprise a central zone 2001 and two end zones 2003, positioned at each end of the central zone 2001, such that the end zones 2003 connect the central zone 2001 to the rear 201 and front 202 external faces of the outer surface 2000 of the plastic casing 20. The two end zones 2003 are flared and each has a bowl-shaped depression zone 2004. The central zone 2001 of the tubular conduits 200 is cylindrical. In this figure, two tubular structures 1 for reinforcing the mechanical resistance of the composite gas pressure tank 2 to pressure variations can be seen.Each of these tubular structures 1 is positioned within a separate tubular conduit 200. It can be observed in this [Fig. 1] that the tubular structures 1 have cross-sections substantially equal to the cross-sections of the tubular conduits 200, both at the central zone 2001 of the tubular conduit 200 and at the central portion 10 of the tubular structure 1. More precisely, for the tubular structure 1 to be inserted into the tubular conduit 200, the cross-section of the tubular structure 1 must be less than or equal to the cross-section of the tubular conduit 200. The tubular structures 1 fill the space formed by the tubular conduits 200. The tubular structures 1 comprise a set of fibers 13 including a central portion 10 and two end portions 11, 12. When the tubular structure 1 is positioned... In a tubular conduit 200, the fibers of the fiber assembly 13 are substantially parallel to the elongation direction of the tubular conduit 200; that is, the angle between the fibers of the fiber assembly 13 and the elongation direction of the tubular conduit 200 is not greater than 5°. Preferably, the ends of the fibers of two end portions 11, 12 have a beveled shape to maximize their contact with the plastic sheath 20. This beveled shape is defined so that the fibers can fill the depression area 2004, maximizing their contact with the plastic sheath 20. Preferably, the fibers of two end portions 11, 12 are flexible enough to adhere to the external surface 2000 of the plastic sheath 20.The tubular structures 1 are defined to connect two opposite faces (the posterior outer face 201 and the anterior outer face 202) of the plastic casing 20. The central area 2001 of the tubular conduits 200 and the tubular structures 1 is cylindrical. Intermediate reinforcing means 1611, 1612, 1613 can be seen in this figure. These intermediate reinforcement means 1611, 1612, 1613 of the inner plastic casing 20 are positioned and fixed on the fibers of an end part of a subset of fibers 131, 132. These intermediate reinforcement means 1611, 1612, 1613 are plates covering the fibers of the end part 11,12 of the subset of fibers 131, 132 on which they are positioned (case represented in the [Fig.1]) or strips joining the end parts 11,12 of the two tubular structures 1 located on the same external face (case not shown in [Fig. 1]). Also in this figure, the fibers of an end part 11,12 of another subset of fibers 131, 132 are deployed on the intermediate reinforcing means 1611, 1612, 1613 so that each intermediate reinforcing means 1611, 1612, 1613 is sandwiched between the fibers of the end part 11,12 of the subset of fibers 131, 132 and the fibers of the end part 11,12 of the other subset of fibers 131, 132.

[0148] Figure 2a shows the intermediate reinforcement means 1611, 1612, 1613 for covering the fibers of the end portions 11, 12 of the fiber subset. Figure 2b shows a top view of the fibers of the end portions 11, 12 of the other fiber subset, illustrating the positioning step of the intermediate reinforcement means 1611, 1612, 1613. The intermediate reinforcement means 1611, 1612, 1613 include openings 165 for the passage of tubular structures 1 so that they can fill the tubular conduits 200. A tubular structure 1 is inserted into each tubular conduit 200, and the two end portions 11, 12 of each tubular structure 1 are unfolded. An insert 14 is positioned at each space formed by the separation of the fibers of each set of impregnated fibers.

[0149] Figure 3 shows a vertical cross-section of the pressurized gas tank made of composite material 2 according to the invention, where intermediate reinforcement means 1611, 1612, 1613 can be observed in the form of strips 1611b joining the two end portions 11, 12 of a tubular structure 1. This figure reproduces the characteristics of Figure 1 with respect to the characteristics other than the intermediate reinforcement means 1611, 1612, 1613. These intermediate reinforcement means 1611, 1612, 1613 of the inner plastic casing 20 are positioned and fixed on the fibers of an end portion 11, 12 of a subset of fibers.Also in this figure, the fibers of an end portion 11,12 of another fiber subset can be deployed on the intermediate reinforcing means 1611, 1612, 1613 so that each intermediate reinforcing means 1611, 1612, 1613 is sandwiched between the fibers of the end portion 11, 12 of the fiber subset and the fibers of the end portion 11, 12 of the other fiber subset.

[0150] Figure 4 shows a top view of the composite pressurized gas tank 2 according to the invention, where intermediate reinforcement means 1611, 1612, 1613 in the form of strips 1611b joining the two end portions of the two tubular structures located on the same external face can be observed. As illustrated in this figure, the strips 1611b are positioned horizontally, vertically, or transversely.

[0151] Figure 5 shows a vertical cross-section of the composite pressurized gas tank 2 according to the invention, in which intermediate reinforcement means 1611, 1612, 1613 and additional reinforcement means 162 can be observed in the form of plates covering respectively the fibers of the two end portions 11, 12 of the fiber subassembly 131, 132 and the external surface 2000 of the inner plastic casing 20. This figure reproduces the features of Figure 1. In this figure, additional reinforcement means 162 can be observed positioned and fixed on the external surface 2000 such that each additional reinforcement means 162 is sandwiched between the external surface 2000 and the fibers of the end portion 11, 12 of the fiber subassembly 131, 132.The additional reinforcement means 162 are additional plates 162a covering the external surface 2000 on at least one periphery 2005, 2006 of the tubular conduit 200. The intermediate reinforcement means 1611, 1612, 1613 are intermediate plates 1611a, 1612a, 1613a covering the fibers of the end parts 11,12 of the fiber subset.

[0152] Fig. 6 presents a cross-sectional view of one of the two end parts 11, 12 of a tubular structure 1 where an intermediate layer of vertically aligned carbon nanotubes 232 and an additional layer of nanotubes can be observed of vertically aligned carbon 231. In this figure, it can be observed that the intermediate layer of vertically aligned carbon nanotubes 232 and the additional layer of vertically aligned carbon nanotubes 231 are positioned respectively on or under the intermediate reinforcing means 1611, 1612, 1613 and the additional reinforcing means 162.

[0153] Figure 7 shows a cross-section of a layer of vertically aligned carbon nanotube arrays (VANTAs). In this figure, the carbon nanotubes have a length of 43.50 pm. A layer of vertically aligned carbon nanotubes consists of a microstructure made up of carbon nanotubes oriented with their longitudinal axis perpendicular to the surface of the element on which they are positioned. In our case, the element on which they are positioned is the outer surface, the intermediate reinforcing means, the additional reinforcing means, or the fibers of the two end portions of the fiber sub-assembly.

[0154] Figure 8 shows a top view of a way of deploying the two end portions 11, 12. The fibers of the fiber subassemblies 131, 132, 133 of the fiber assembly 13 are separated into several fiber groups so as to cover the outer surface of the plastic casing discontinuously. Only in the area near the tubular conduit 200 are the fiber subassemblies 131, 132, 133 partially overlapped.

[0155] Fig. 9 presents a vertical section of the pressurized gas reservoir made of composite material 2 where two tubular structures 1 can be observed and the two end parts 11, 12 of the impregnated fiber subassemblies of one tubular structure 1 are superimposed with those of the other tubular structure 1.

[0156] Fig. 10 shows a vertical section of the composite material pressurized gas reservoir 2 where two positions 30, 31 of tubular fitting 17 equipped with a valve 15 can be observed allowing the entry and exit of a gas from the composite material pressurized gas reservoir 2.

[0157] Fig. 11a and 11b present two possibilities for winding the outer reinforcing envelope 21 around the plastic envelope 20.

[0158] Fig. 12 shows the possible position of the attachment point 18 of the fibers to start the winding of fibers impregnated by a second resin on the plastic sheath to form the outer reinforcing sheath 21.

[0159] Fig. 13 illustrates the possible positions 30, 31, 32 of the tubular fitting equipped with a valve allowing the inlet and outlet of a gas from the composite pressurized gas reservoir 2. The tubular fitting is not shown in Fig. 13.

[0160] Figure 14 shows a vertical cross-section of the inner plastic casing 20 illustrating the step of obtaining the inner casing by molding. A plastic material 20, according to the invention, on which the weld seams 22 between the different zones of the composite material 2 pressurized gas tank can be observed. This figure reproduces the characteristics of [Fig. 1] when these characteristics are shown in [Fig. 14]. The weld seams 22 between the different zones of the composite material 2 pressurized gas tank are shown in this figure. These weld seams 22, due to the shape of the mold, are formed during the molding of the plastic material casing 20.

[0161] Figure 15 shows a vertical cross-section of the inner plastic casing 20 illustrating the step of forming the tubular conduits 200, according to the invention, obtained by cutting the weld joints. This figure reproduces the characteristics of Figure 14 when these characteristics are shown in Figure 15.

[0162] Figure 16a shows a vertical cross-section of the inner plastic casing 20 illustrating the insertion step of the tubular structures 1 into the tubular conduits 200, according to the invention. In this figure, the fibers of the end portions 11, 12 are dry; they are not impregnated with resin, while the fibers of the central portion 10 are impregnated with resin. This figure reproduces the characteristics of Figure 1 when these characteristics are shown in Figure 16a.

[0163] Fig. 16b shows a vertical cross-section of the plastic casing 20 illustrating the step of inserting a tubular structure 1 impregnated with a resin around the periphery of the fiber assembly 13. In the figure, on the left is shown the tubular structure 1 with resin impregnated along the entire length of the fibers of the central part 10 of the fiber assembly 13 and around the periphery of the central part 10 of the fibers of the fiber assembly 13. In the center of the figure is shown the partial hardening step of the resin (i.e. a hardening that has lasted half the time required to obtain total hardening) impregnating the fiber assembly 13.On the right of the figure is shown the insertion step into the tubular conduit 200 of the tubular structure 1 impregnated by a resin on the periphery and along the entire length of the fibers of the central part 10 of the fiber assembly 13, allowing it to facilitate the manipulation of the fibers of the fiber assembly 13 to insert them into the tubular conduit 200.

[0164] Figure 16c shows a vertical cross-section of the plastic casing 20 illustrating the step of inserting a tubular structure 1 impregnated with resin over the entire volume of the fiber assembly 13. In the figure, on the left, is shown the tubular structure 1 with resin impregnated over the entire length of the fibers in the central part 10 of the fiber assembly 13 and throughout the entire volume of the fibers in the central part 10 of the fiber assembly 13 (i.e., at least 70% of the total surface area of ​​the fibers in the fiber assembly 13 is covered by the resin). resin). In the center of the figure and to the right of the figure are represented the same steps as those of [Fig. 16b].

[0165] Figure 17 shows a vertical cross-section of the inner plastic casing 20 illustrating the step of applying the additional reinforcing means 162 to the external surface 2000 of the internal plastic envelope 20. This figure has the same characteristics as [Fig. 16a].

[0166] Figure 18 shows a vertical cross-section of the plastic casing 20 illustrating the step of opening the fibers of the two end portions 11, 12 of the fiber assembly 13 using blown air ([Fig. 18a]) (the application points of which are located by the arrows 23) or a tool 24 ([Fig. 18b]). For this purpose, the blown air or the tool 24 is applied at the two opposite peripheries 2005, 2006 of the tubular conduit 200.During this step of opening the fibers of the two end parts 11,12, the gas contained in the pressurized gas reservoir made of composite material 2 exerts a pressure P on the tubular structure 1 compensating for the pressure exerted by the blown air or the tool 24 applying in undesired areas and thus allowing the tool not to deform the pressurized gas reservoir made of composite material 2 and not to change the position of the fibers of the central part 10 of the tubular structure 1 in the tubular conduit 200. .

[0167] Figure 19 shows a vertical cross-section of the inner plastic casing Figure 20 illustrates the step of applying the fibers from the two end portions 11, 12 of a fiber subset 131 to the additional reinforcing means 162. This figure has the same characteristics as [Fig. 17]. These fibers from the two end portions 11, 12 of the fiber subset 131 are then unfolded and positioned on the external surface 2000 of the plastic casing 20. This operation can be described as peeling a banana, and the banana peel is unfolded so that it can be applied to the skin of the hand of the person holding the banana. The fiber subset 131 of the fiber set 13 comprises a number of fibers between 30% and 40% of the total number of fibers in the fiber set 13. After deploying the fiber subset 131 on the additional reinforcing means 162, the fiber subset 131 is impregnated with a first resin and then the first resin is cured.

[0168] Figure 20 shows a vertical cross-section of the inner plastic casing 20 illustrating the step of applying the intermediate reinforcing means 1611, 1612, 1613, according to the invention, to the fibers of the two end parts 11, 12 of the fiber subassembly 131. This figure reproduces the same characteristics as [Fig. 19],

[0169] Figure 21 shows a vertical cross-section of the inner plastic casing 20 illustrating the step of apposition, according to the invention, of the fibers of the two parts The end fibers 11, 12 of another subset of fibers 131, 132 are attached to the intermediate reinforcing means 1611, 1612, 1613. This figure has the same characteristics as [Fig. 20]. These fibers from the two end portions 11, 12 of the other subset of fibers 1611, 1612, 1613 are then unfolded and positioned on the intermediate reinforcing means 1611, 1612, 1613. This operation can be described as peeling a banana, and the banana peel is unfolded so that it can be applied to the skin of the hand of the person holding the banana. The other fiber subset 131, 132 of the fiber set 13 comprises a number of fibers between 30% and 40% of the total number of fibers in the fiber set 13. After deploying the other fiber subset 131, 132 on the intermediate reinforcement means 1611, 1612, 1613, the fiber subset 131, 132 is impregnated with a first resin and then the first resin is cured.

[0170] Fig. 22 shows a vertical section of the inner plastic sheath 20 illustrating the step of inserting an insert 14, according to the invention, onto the fibers of the two end parts 11, 12 of another subset of fibers 131, 132. This figure has the same characteristics as Fig. 21.

[0171] Figure 23 shows a vertical cross-section of the composite pressurized gas tank 2 illustrating the step of forming the outer reinforcing shell 21 around the inner plastic shell 20 by winding fibers impregnated with a second resin. This figure has the same characteristics as Figure 22.

[0172] Figure 24 shows a vertical cross-section of the plastic casing 20 illustrating the resin impregnation step of the fibers in the central part 10 by a resin infusion technique in one (or more) resin channel(s) 25 inside the tubular structure 1, allowing the tubular structure 1 to be impregnated throughout its entire volume. The channel 25 is shown as a dashed line in Figure 24. The two arrows represent the two resin inlets in the channel 25.

[0173] Fig. 25a and 25b present a horizontal section of the plastic envelope 20 illustrating the resin impregnation step of the fibers of the central part 10 by a resin infusion technique in one (or more) resin channel(s) 25 inside the tubular structure 1 at the center of the tubular structure 1 (Fig. 25a) or at the periphery of the tubular structure 1 (Fig. 25b). According to this method, the impregnation of the fibers of the central part 10 is carried out by an infusion of resin (under vacuum or by pressure) into one (or more) resin channel(s) 25 inside the tubular structure 1. The resin channel 25 is formed in the center of the tubular structure 1 ([Fig.25a]) and / or at the periphery of the tubular structure 1 ([Fig.25b]), so as to be able to impregnate the tubular structure 1 over its entire volume and / or on its surface.

[0174] The invention also relates to a vehicle comprising a pressurized gas tank made of composite material 2 conforming to the aforementioned pressurized gas tank made of composite material 2. List of references

[0175] 1: tubular structure 2: Pressurized gas tank made of composite material 10: central part 11, 12: two end parts 13: set of fibers 14: insert 15: valve 17: Tubular fitting 18: fixing point 20: inner plastic casing 21: External reinforcement layer 22: weld joints 23: arrows 24: tool 25: canal 30, 31, 32: possible positions of the tubular fitting 131, 132, 133: subset of fibers 162: additional reinforcement means 162a: additional plate 165: Openings 200: tubular conduit 201: posterior external surface 202: anterior external face 231: additional layer of vertically aligned carbon nanotubes 232: intermediate layer of vertically aligned carbon nanotubes 1611, 1612, 1613: intermediate reinforcement method 1611a, 1612a, 1613a: intermediate plate 1611b: strip 2000: external surface 2001: central zone 2003: two zones at the extremities 2004: Depression zone 2005, 2006: surrounding areas

Claims

Demands

1. A pressurized gas reservoir made of composite material (2) comprising: - an inner plastic casing (20) delimiting an internal volume for holding a pressurized gas, the inner plastic casing (20) comprising an external surface (2000) having a rear external face (201) and an anterior external face (202) opposite the rear external face (201), and a tubular conduit (200) passing through the internal volume and opening onto the rear external face (201) and the anterior external face (202), - a tubular structure (1) inserted into the tubular conduit (200) and comprising a fiber assembly (13) consisting of several fiber subassemblies (131, 132, 133), said fiber assembly (13) having a central portion (10) and two end portions (11, 12) positioned on either side of the central portion (10), the fibers of the two end portions (11,12) being deployed on the external surface (2000) and said fiber assembly (13) being fixed in a first hardened resin, and - an external reinforcing sheath (21) of the internal plastic sheath (20), the external reinforcing sheath (21) being formed from a fiber-reinforced polymer fixed in a second hardened resin, characterized in that it comprises an intermediate reinforcing means (1611, 1612, 1613) of the internal plastic sheath (20) positioned and fixed on the fibers of an end portion (11, 12) of a subset of fibers (131, 132, 133).

2. Composite material pressurized gas tank (2) according to the preceding claim, wherein the intermediate reinforcement means (1611, 1612, 1613) is an intermediate plate (1611a, 1612a, 1613a) covering the fibers of the end portion (11,12) of the fiber subset (131, 132, 133).

3. A composite material pressurized gas reservoir (2) according to claim 1, comprising two tubular conduits (200) and two tubular structures (1), each tubular structure (1) being inserted into a tubular conduit (200), the intermediate reinforcing means (1611, 1612, 1613) comprising at least one strip (1611b) joining the end parts (11,12) of the two tubular structures (1) located on the same external face.

4. Composite material pressurized gas tank (2) according to any one of the preceding claims, wherein the fibers of an end portion (11,12) of another fiber subset (131, 132, 133) are deployed on the intermediate reinforcing means (1611, 1612, 1613) such that the intermediate reinforcing means (1611, 1612, 1613) is sandwiched between the fibers of the end portion (11,12) of the fiber subset (131, 132, 133) and the fibers of the end portion (11,12) of the other fiber subset (131, 132, 133).

5. A composite material pressurized gas tank (2) according to any one of the preceding claims, comprising an additional reinforcement means (162) positioned and fixed on the external surface (2000) such that the additional reinforcement means (162) is sandwiched between the external surface (2000) and the fibers of the end portion (11,12) of the fiber subset (131, 132, 133).

6. Composite material pressurized gas reservoir (2) according to the preceding claim, wherein the additional reinforcement means (162) is an additional plate (162a) covering the external surface (2000) on at least one perimeter (2005, 2006) of the tubular conduit (200).

7. Composite gas pressure tank (2) according to any one of the two preceding claims, wherein the intermediate reinforcing means (1611, 1612, 1613) and the additional reinforcing means (162) comprise fibers fixed in a third cured resin.

8. A composite pressurized gas tank (2) according to any one of the preceding claims, comprising an intermediate layer of vertically aligned carbon nanotubes (232) positioned and fixed onto the intermediate reinforcement means (1611, 1612, 1613) such that the intermediate reinforcement means (1611, 1612, 1613) is sandwiched between the intermediate layer of vertically aligned carbon nanotubes (232) and the end portion (11, 12) of the fiber subassembly (131, 132, 133) or, in the case of a composite pressurized gas tank (2) according to claim 4, the reinforcement means intermediate (1611, 1612, 1613) is sandwiched between the intermediate layer of vertically aligned carbon nanotubes (232) and the fibers of the end part (11,12) of the other subset of fibers (131, 132, 133).

9. Composite material pressurized gas tank (2) according to the preceding claim taken in combination with any one of claims 5 to 7, comprising an additional layer of vertically aligned carbon nanotubes (231) positioned and fixed on the additional reinforcement means (162) such that the additional reinforcement means (162) is sandwiched between the additional layer of vertically aligned carbon nanotubes (231) and the fibers of the end portion (11,12) of the fiber subset (131, 132, 133) or between the additional layer of vertically aligned carbon nanotubes (231) and the external surface (2000).

10. A method for manufacturing a pressurized gas tank made of composite material (2) according to any one of the preceding claims, the method comprising the following steps: - Step 1: Obtaining an inner plastic casing (20) delimiting an internal volume for holding a pressurized gas, the inner plastic casing (20) comprising an external surface (2000) having a rear external face (201) and an anterior external face (202) opposite the rear external face (201), and a tubular conduit (200) passing through the internal volume and opening onto the rear external face (201) and the anterior external face (202), - Step 2: Obtaining a tubular structure (1) comprising a fiber assembly (13) consisting of several fiber subassemblies (131, 132, 133), said fiber assembly (13) having a central portion (10) and two end portions (11, 12) positioned at on either side of the central part (10),- Step 3: Insertion of said tubular structure (1) into the tubular conduit (200), - Step 4: Deployment of the fibers of an end portion (11, 12) of a fiber subset (131, 132, 133) on the external surface (2000), If the fibers of the end portion (11, 12) of the fiber subset (131, 132, 133) deployed in step 4 are previously, impregnated with a resin called "end-section resin," then skip to step 6; otherwise, continue to step 5. - Step 5: Impregnation of the end-section fibers (11, 12) of the fiber subset (131, 132, 133) deployed in step 4 with a resin called "end-section resin." - Step 6: Application of an intermediate reinforcing means (1611, 1612, 1613) to the end-section fibers (11, 12) of the fiber subset (131, 132, 133) impregnated with the "end-section resin." - Step 7: Deployment of the end-section fibers (11, 12) of another fiber subset (131, 132, 133) onto the intermediate reinforcing means. (1611, 1612, 1613) affixed in step 6, If the fibers of the end part (11,12) of the other subset of fibers (131, 132, 133) deployed in step 7 are previously impregnated with a resin called "end part resin" then skip to step 9,otherwise continue to step 8, - Step 8: Impregnation with a resin called the "end part resin" of the end part fibers of the other subset of fibers deployed in step 7, - Step 9: Formation of an outer reinforcing sheath (21) of the inner plastic sheath (20), the outer reinforcing sheath (21) being formed from a polymer reinforced with fibers impregnated by a second resin, - Step 10: Curing of the resin called the "end part resin" and the second resin, - Step 11: Obtaining the pressurized gas reservoir made of composite material (2).

11. A manufacturing method according to the preceding claim, wherein step 10 consists of successively hardening the resin called "end part resin" and then the second resin.

12. A manufacturing method according to claim 10, wherein step 10 consists of simultaneously hardening the so-called "end part resin" and the second resin.

13. Method of manufacturing a pressurized gas tank made of composite material (2) according to any one of claims 10 to 12, comprising after step 3 and before step 4, a step of applying an additional reinforcing means (162) to the external surface (2000) of the internal plastic casing (20).

14. Vehicle comprising a pressurized gas tank made of composite material according to any one of claims 1 to 9.

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