FR3137434A1 - Attachment forming a reinforcement for a tank and corresponding manufacturing and shaping processes - Google Patents

Abstract

Tank (1) comprising a clip (7) passing through a body of the tank (1) via a well (6), the clip (7) forming ends bearing on respective parts of the body so as to reduce deformation of the body in a direction (D4) along which the clip (7) extends. Method for shaping such a fastener (7) and manufacturing such a tank (1). Figure for abstract: Fig. 1

Description

Attachment forming a reinforcement for a tank and corresponding manufacturing and shaping processes

The invention relates to the field of mechanical connections and is of particular interest for tanks intended to contain fluids under high pressure such as gas, liquefied gas or even hydrogen.

State of the prior art

The hydrogen, gas or liquefied gas tanks known in the prior art are generally formed of a body comprising a cylindrical jacket on which pre-impregnated technical fibers, for example made of carbon, are deposited by winding. filamentary, so as to form a shell capable of withstanding the pressure of such a fluid which typically ranges from 2 to 70 MPa in use, with admissible ruptures ranging from 8 to 157.5 MPa in rupture.

In general, the known reservoirs are bulky, expensive given in particular the time required to carry out the filament winding, and likely to undergo significant deformation under the effect of variations in pressure of the fluid carried.

Furthermore, the known tanks are poorly suited to current and future motorized vehicles which, on the one hand, for reasons of mass to be transported, have an increasingly restricted space to accommodate such tanks and, on the other hand, on the other hand, pose problems of energy autonomy.

The invention aims to remedy the aforementioned problems and in particular to respond to the need for additional autonomy of vehicles.

A particular aim of the invention is to provide a reservoir capable of storing a fluid of the biogas or hydrogen type, or more generally of containing a high pressure fluid.

Another aim of the invention is to provide a solution making it possible to maximize the useful storage volume with regard to the spaces actually available for this in vehicles such as a motor vehicle, aircraft, boat or other mobile equipment.

For this purpose, the subject of the invention is a fastener comprising a first end intended to be connected to a first part of a body of a tank and a second end intended to be connected to a second part of said body which extends facing said first part of the body, the first end and the second end being spaced apart from each other along a connection direction.

According to the invention, the first end of the fastener forms a first abutment surface extending around the connection direction and intended to come to bear on the first part of the body so as to prevent or limit movement of the first part of the body in a first direction according to the direction of connection.

Alternatively or preferably complementary, the second end of the fastener forms a second abutment surface extending around the direction of connection and intended to come to bear on the second part of the body so as to prevent or limit movement of the second part of the body in a second direction according to the connection direction, the second direction being opposite the first direction.

Such a fastener, also called a “tie”, makes it possible to increase the resistance of a tank to the pressure of the fluid carried in the tank, in particular by increasing the resistance to tensile forces.

The invention thus makes it possible to design high pressure tanks, capable of containing fluids such as gas, liquefied gas or hydrogen, and having a heteromorphic geometry.

Of course, a fastener according to the invention can also be used to reinforce a low pressure tank and/or having a cylindrical or other geometry, or more generally to connect different parts of another type of structure, or even to connect different structures between them.

In one embodiment, the first abutment surface and/or the second abutment surface are frustoconical.

In one embodiment, the first abutment surface and/or the second abutment surface have one or more radii of curvature.

Preferably, the fastener comprises one or more layers made up of fibers, the majority of which extend along the bonding direction.

The fastener can thus form a fibrous structure comprising a majority of fibers arranged longitudinally and grouped together by light braiding.

Such a fibrous structure makes it possible to respond specifically to tensile forces applied to the fastener, in particular by the body of the reservoir under the action of the pressure exerted by the fluid it contains.

The invention also relates to a tank for a transport device such as a motor vehicle, an aircraft or a boat, comprising a body which delimits a cavity intended to contain a fluid and at least one attachment as defined above .

According to the invention, the fastener connects said first part and said second part of the tank body to each other.

These parts of the body of the tank, arranged opposite each other, can be flat, convex or even concave walls, depending on the geometry of the body.

In one embodiment, the tank comprises at least one wall forming a well which passes through the cavity of the tank, the clip being housed in the well.

In one embodiment, the tank comprises at least one load distribution ring extending radially between the attachment and the wall forming the well.

In one embodiment, the reservoir comprises one or more anti-restriction nuts respectively housed in the first end and in the second end of the clip.

In one embodiment, the tank body includes a sealing liner and a braided shell over the liner.

The liner may comprise a material such as plastic capable of making the liner impermeable to the fluid contained in the cavity. More generally, the shirt may include a material of organic, plant, mineral or metallic origin.

The jacket preferably defines an internal surface which delimits the cavity and an external surface matching an internal surface of the shell.

In one embodiment, the well comprises a wall made integrally with the jacket. In other words, this wall can form a continuous extension of material with the shirt.

The attachment and the well in which it is housed form a reinforcement extending along a connection direction, which may be perpendicular or oblique relative to one and/or the other of the parts of the body which are connected to each other by this reinforcement.

It is preferred that this reinforcement, in particular the wall forming the well, forms an external surface circumferentially closed around the direction of connection along which it extends and that the entirety of this external surface delimits the cavity of the tank.

The wall of the well can simultaneously form a hollow space defining an opening passing through the reservoir in the connection direction.

In other words, said well may comprise a wall forming a solid of revolution, or more generally a solid closed around the direction of connection that it constitutes.

In a non-limiting manner, the reinforcement and the well may have a generally annular or frustoconical geometry, which may be different on different sections of the reinforcement along the connection direction.

A tank comprising several reinforcements defining such hollow spaces can thus form a cellular structure, the jacket delimiting a volume comprising the fluid storage cavity crossed by cells formed by the hollow spaces of the reinforcements, in which fasteners can in particular be housed. respective conforming to the invention.

In one embodiment, the shell comprises a braid with interlacing of plies, that is to say braided fibers, some of which, called “binding bias fibers”, bind together different plies of the shell.

The following document describes principles known per se of braiding with interlacing of plies, also known under the name “3D-Interlock”: H. Lansiaux, D. Soulat, F. Boussu and A. R. Labanieh, Mechanical characterization of 3D interlock chain fabrics in linen with different numbers of layers, 24th French Mechanics Congress, Brest, August 26 to 30, 2019.

Such a braiding technique makes it possible to deposit, at the same time, on a mandrel made to the interior shape of the tank for example, a certain number of braids while interweaving them together in order to avoid, in use, any delamination or any movement between the different braids and thus bring them to work together.

This technique also allows the construction of a polymorphic shell, whether it is a shell presenting a simple or classic geometry of the cylindrical type or a complex heteromorphic geometry.

The shell may in particular comprise one or more layers comprising folds thus intertwined.

A shell made of braided fibers with interlaced plies makes it possible in particular to obtain excellent mechanical properties in terms of toughness and to improve the fatigue resistance of the tank compared to a shell made by filament winding.

The shell of the tank thus preferably forms a texture comprising mainly continuous technical fibers. These fibers can be of organic, plant, mineral or metallic origin.

The orientations of the respective fibers of the shell and the attachment make it possible to respond to loading conditions which are completely different between the body and the reinforcement(s). The reinforcement(s) are in fact particularly exposed to tensile forces when the pressure is internal to the tank. The structure of the body is exposed to all kinds of stresses, namely tensile, bending, compression or even shearing forces.

In one embodiment, the first abutment surface and/or the second abutment surface of the fastener rests on the shell so as to grip the shell between the liner on the one hand and the first and the other on the other hand. /or the second abutment surface, respectively.

Among other advantages, the invention makes it possible to manufacture tanks withstanding high internal functional pressures, compatible with the carriage of different types of fluid, for example natural gas at medium pressure (26 MPa in use and 47 MPa in rupture) or hydrogen at high or very high pressure (from 35 to 70 MPa in use and from 78.75 to 157.5 MPa in rupture), impervious to the fluid carried, particularly when it is a gas presenting molecules of very small sizes such as hydrogen, methane or butane molecules, and presenting resistance to different types of environment (e.g. acid, basic, humidity, salt spray, etc.), static mechanics pressure, vibration, shock, endurance, fatigue, aging, fire, ballistic and more generally mechanical, which increases their safety and reliability in use.

The invention also relates to a method of shaping a fastener as defined above.

This method comprises a step of deforming the first end and/or the second end of the fastener so that the first abutment surface and/or the second abutment surface can come to bear on the first part and/or the second part of the body, respectively.

The invention also relates to a method of manufacturing a reservoir as defined above, comprising a step of inserting, into the well, in the connection direction, a fastener as defined above.

According to a first variant, the method comprises, after insertion of the clip into the well, a step of deforming the first end and/or the second end of the clip according to the shaping process described above.

According to a second variant, the method comprises a step of deforming the first end and/or the second end of the fastener according to the shaping method described above and, after deformation:
– an insertion into the well of a first part of the fastener forming said first end, in said second direction,
– an insertion into the well of a second part of the fastener forming said second end, in said first direction,
– an assembly of the first part and the second part of the fastener so as to secure these parts to each other at least in translation in the direction of connection.

This assembly of the first part and the second part of the fastener can be carried out by gluing and/or screwing or by any appropriate means of joining.

In one embodiment, the method comprises, before inserting the clip into the well, a step of braiding the fibers with interlacing of plies so as to form the shell.

This braiding is preferably carried out on said jacket of the body of the tank, used as a mandrel.

In one embodiment, the method comprises a step of manufacturing the fastener by braiding the fibers forming this tie.

Other advantages and characteristics of the invention will appear on reading the detailed, non-limiting description which follows.

The detailed description which follows refers to the appended drawings in which:

is a schematic perspective view, partially cut away, of a tank according to the invention, comprising a body and a reinforcement connecting two parts of the body facing each other with respect to the other ;

is a partial schematic sectional view of a tank according to the invention and of tools making it possible to assemble an attachment of a reinforcement of the tank with the body of this tank;

is a partial schematic sectional view of a layer of the shell of a tank according to the invention, illustrating an example of assembly of fibers forming this layer;

is a partial schematic sectional view of a tank according to the invention and of tools making it possible to assemble an attachment of a reinforcement of the tank with the body of this tank, this tank being distinguished in particular from that of the in that the parts connected together by the reinforcement are walls inclined with respect to each other and with respect to a direction along which the reinforcement extends;

is a partial schematic sectional view of a tank according to the invention and of tools making it possible to assemble an attachment of a reinforcement of the tank with the body of this tank, this tank being distinguished in particular from that of the in that the reinforcement includes diffusers and anti-restriction nuts;

is a partial schematic sectional view of a tank according to the invention, showing a reinforcement comprising a diffuser and a clip having a curved end;

is a partial schematic sectional view of a tank according to the invention, showing a reinforcement comprising a diffuser and a clip having one end folded back on itself;

is a partial schematic sectional view of a tank according to the invention, showing a reinforcement comprising a diffuser and a clip having one end folded over an anti-restriction nut;

is a schematic perspective view, partially cut away, of a tank according to the invention, comprising several reinforcements oriented in a single direction, forming a network of mono-axial reinforcements;

is a schematic perspective view, partially cut away, of a tank according to the invention, comprising reinforcements oriented in two mutually orthogonal directions, forming a network of bi-axial reinforcements;

is a schematic perspective view, partially cut away, of a tank according to the invention, comprising reinforcements oriented in three mutually orthogonal directions, forming a network of tri-axial reinforcements;

is a schematic sectional view of a fastener according to the invention, comprising two parts fitted into each other and glued to each other;

is a schematic sectional view of a fastener according to the invention, comprising two shouldered parts fitted one inside the other and glued to one another;

is a schematic sectional view of a fastener according to the invention, comprising two parts fitted into each other and glued to each other, these parts forming grooves for receiving a bonding resin ;

is a schematic sectional view of a fastener according to the invention, comprising two shouldered parts fitted one inside the other and assembled with a ring, the assembly forming a chamber for receiving a bonding resin;

is a schematic sectional view of a fastener according to the invention, comprising two parts screwed to one another;

is a schematic sectional view of a fastener according to the invention, comprising two parts assembled together with a shrink ring;

is a schematic view in longitudinal section of a fastener according to the invention, comprising two parts assembled together with a ring forming locking notches;

is a schematic cross-sectional view of the fastener of the ;

is a schematic view in longitudinal section of a fastener according to the invention, comprising two assembled conical parts fitted one inside the other;

is a schematic cross-sectional view of the fastener of the .

Detailed description of embodiments

Figures 1 and 9 to 11 include a frame of reference defining three mutually orthogonal directions D1, D2 and D3. In this example, D1 is a longitudinal direction, D2 a first transverse direction and D3 a second transverse direction.

He is represented on the a tank 1 conforming to a first embodiment of the invention.

In this non-limiting example, the tank 1 is intended to equip a motor vehicle in order to supply it with fuel.

Tank 1 of the has a generally ovoid shape extending along a longitudinal axis A1, parallel to D1, so as to present two longitudinal ends 1A and 1B.

In this example, tank 1 has a transverse dimension, in particular along D2, which varies along axis A1. Starting from the longitudinal end 1A, this transverse dimension increases to a median longitudinal coordinate, then decreases to the longitudinal end 1B.

As an indication, the maximum transverse dimension of tank 1 according to D2, which is located in this case at said median longitudinal coordinate, can be approximately 500 mm.

The tank 1 comprises a body which is in this example provided with a jacket 2, a shell 3 and a reinforcement 4.

The jacket 2 forms an internal surface and an external surface defining a thickness of this jacket 2, which is in this example substantially constant in the different parts of the tank 1.

The internal surface of the jacket 2, which also forms an internal surface of the body of the tank 1, delimits a cavity 5 intended to contain a fluid under pressure constituting in this example said fuel.

In this example, cavity 5 is intended to contain a fluid fuel, gas or liquid, having a pressure of around 70 MPa.

The shell 3 also comprises an internal surface and an external surface defining a thickness of this shell 3, which is in this example substantially constant in the different parts of the tank 1.

Shell 3 forms an envelope of tank 1.

The internal surface of the shell 3 matches the external surface of the liner 2.

The jacket 2 and the shell 3 thus constitute a double-walled body and each have respective and complementary properties taking into account their respective material and manufacturing process (see further below).

The reinforcement 4 is in this example configured to connect two parts of the body to each other which are located opposite each other, these opposite parts forming two transverse ends of the body according to D2. The reinforcement 4 makes it possible to improve the mechanical resistance of the tank 1, taking into account in particular the pressures and depressions which it undergoes during its use.

The reinforcement 4 has a generally elongated shape along a direction D4, called “connection direction”, which is in this example parallel to the direction D2 and which passes through said median longitudinal coordinate of the tank 1.

In the non-limiting example of the , the reinforcement 4 comprises an external envelope 6, a fastener 7 also called a “tie” and two diffusers 8 (only one diffuser being visible in this figure).

The reinforcement 4 and its external envelope 6 comprise a central part 4A and end parts 4B and 4C respectively connected to said transverse ends of the body in the manner described further below.

In this example, the central part 4A of the envelope 6 of the reinforcement 4 has a generally cylindrical geometry defining an axis of symmetry which corresponds to the direction D4.

The end parts 4B and 4C have a flared geometry, in this case an increasing dimension from the respective end of the central part 4A to which they are connected towards the corresponding part of the jacket 2 to which they are connected.

The external envelope 6 of the reinforcement 4 defines, radially inside with respect to the direction D4, a hollow space which passes through the jacket 2 of the body of the tank 1 in the direction D4 so as to open onto the external surface of this jacket 2.

The envelope 6 thus forms a wall which extends circumferentially around D4, forming an internal surface and an external surface which define a thickness of this wall.

The internal surface of the envelope 6 delimits said hollow space.

The external surface of the envelope 6 is a circumferentially closed surface around the direction D4. In this example, the entirety of this external surface delimits the cavity 5 of the tank 1 so that the cavity 5 extends all around the reinforcement 4.

The external envelope 6 of the reinforcement 4 thus forms a well which passes through the cavity 5.

In this example, the external envelope 6 of the reinforcement 4 is made integrally with the jacket 2, in this case with parts of the jacket 2 forming said transverse ends of the body, so as to form a continuous extension of material.

In a non-limiting manner, the envelope 6 and the jacket 2 comprise a thermoplastic material, making it possible to ensure a sealing function to the fluid contained in the cavity 5.

The external envelope 6 of the reinforcement 4 is in this example made from a part previously manufactured by machining, injection, roto-molding or even extrusion-blowing.

In the present description, the subassembly comprising in continuity of material the jacket 2 and the external envelope 6 of the reinforcement 4 is called “membrane”.

In a non-limiting manner, the membrane can be obtained by crystallization or crosslinking of thermoplastic material constituted on the one hand by said prefabricated part and on the other hand by wall elements held in relation to each other using a appropriate tooling, or more generally by implementing any shaping process such as roto-molding, blowing, or other molding or casting technique, so as to create an assembly by adhesion of material elements.

A method of assembling such a membrane (liner 2 and external envelope 6 of reinforcement 4) with the other elements of a reinforcement 4 and a shell will now be described, with particular reference to Figures 2 and 3. 3 of a tank 1 according to the invention.

Shell 3 is first braided onto the membrane using a ply interlacing braiding process, with the membrane being used as a mandrel during braiding.

In this example, four layers are successively braided on the mandrel.

Each of the layers comprises an assembly of fibers which are in this example carbon fibers and which are braided so as to form five plies.

Conventionally, depending on their arrangement in the assembly, the fibers are called "axial fibers" when they are arranged in a substantially linear manner and "bias fibers" when they are arranged so as to successively intersect d other fibers.

There schematically shows a sectional view of a part of a layer C1 of the shell 3, in which the assembled folds P1-P5 define a thickness of the layer C1 in a direction D5. Each of the folds P1-P5 comprises a series of axial fibers 21, also called "longis", which are spaced from each other in a direction D6 perpendicular to the direction D5 and to a direction D7 along which they extend. The axial fibers 21 specifically increase the mechanical resistance of the layer C1 in the direction D7, making it possible in particular to reduce the deformations of the shell 3 in this direction.

Layer C1 of the comprises ten bias fibers braided on the axial fibers 21, including two external bias fibers 22 and eight binding bias fibers 23-30.

One of the external bias fibers 22 is braided around the axial fibers 21 of the ply P1. The other external bias fiber 22 is braided around the axial fibers 21 of the ply P5. The external bias fibers 22 make it possible to smooth the external surfaces of layer C1.

The binding bias fibers 23-30 are braided so as to connect the plies P1 to P5 to each other.

More precisely, the binding bias fibers 23 and 24 connect the folds P1 and P2 to each other, the binding bias fibers 25 and 26 connect the folds P2 and P3 to each other, the Binding bias fibers 27 and 28 connect the plies P3 and P4 to each other, and binding bias fibers 29 and 30 connect the plies P4 and P5 to each other.

Thus, the binding bias fibers 23-30 are braided so as to each connect two respective adjacent plies, for example the plies P1 and P2, so that two non-adjacent plies of the layer C1, for example the plies P1 and P3 , are not linked together directly, but indirectly via, in this example, the fold P2.

In this example, the binding bias fibers 24, 26, 28 and 30 are braided so as to evolve along parallel curves in directions D5 and D6 and in phase opposition to the binding bias fibers 23, 25, 27 and 29 (see ).

The different layers of the shell 3 can be braided in a similar manner, preferably by modifying the relative orientation of the axial fibers 21 from one layer to another, so as to provide the shell 3 with improved mechanical resistance according to several directions of space.

The shell 3 thus forms a fibrous texture which can essentially consist of intertwined continuous fibers.

Of course, the number of layers of the shell 3 and/or the number of plies per layer and/or the number of plies directly connected together by binding bias fibers can be modified depending on the desired mechanical properties. Likewise, other technical fibers can be used to braid the shell 3, for example fibers made of glass, basalt, aramid, linen, hemp or even mixed fibers comprising, for example, polyamide or polyethylene filaments. . The braiding of the shell 3 can also be carried out using a combination of such technical fibers and thermoplastic filaments.

Such a braiding process makes it possible to deposit layers of dry material in the form of several folds of fibers intertwined with each other, one by one or two by two or even more depending on the needs. This operation can be reproduced several times, by stacking layers, in the same direction or in different directions in order to ensure a good framework of contextures capable of responding to the pressure forces generated by the fluid on the shell 3 of the tank 1.

Such a braiding process makes it possible to make the deposited fibers conform to the required shapes without fiber distortion and provides considerably improved properties in terms of tenacity, particularly in comparison with filament winding.

After braiding the shell 3 on the mandrel formed by said membrane, that is to say by the jacket 2 and by the external envelope 6 of the reinforcement 4, the hollow space constituted by this external envelope 6 is covered by the shell 3.

To open this hollow space towards the outside of the body formed by the jacket 2 and the shell 3, openings can be made in the shell 3 by spacing out the fibers which constitute it using a tool such as a conical tip, so as not to cut the fibers and allow the shell 3 to retain its mechanical properties.

There illustrates a non-limiting example in which the reinforcement 4 comprises only the external envelope 6 and the fastener 7.

The fastener 7 comprises in this example carbon fibers mainly arranged in a longitudinal/unidirectional manner, that is to say a majority of fibers extending along the direction D4.

In this example, these fibers are connected and held together by light braiding, using a few fibers which can also be made of carbon.

Such an arrangement of fibers allows, when the attachment 7 is assembled with the other parts of the tank 1, to form a reinforcement 4 capable of resisting tensile forces exerted on this reinforcement 4 under the action of the pressure of the fluid carried into cavity 5.

Of course, other technical fibers or different combinations of fibers can be used to form the fastener 7, including for example glass fibers. Alternatively, the fastener 7 may comprise another material in combination or not with such an assembly of fibers.

In this example, the fastener 7 is manufactured in the form of a substantially tubular part having a first end 9A and a second end 9B spaced apart from each other along the connection direction D4.

After making the openings in the shell 3, by spacing the fibers (see above), the prefabricated fastener 7 is introduced into the well, that is to say in the hollow space formed by the external envelope 6 of the reinforcement 4, via one of these openings, by moving the attachment 7 in translation in direction D4.

In this example, after insertion of the fastener 7 in the well, the ends 9A and 9B are simultaneously deformed so as to fold them against the body of the tank 1, for example by moving two bells (not shown) moved along a shaft (not shown) which passes through the attachment 7 in direction D4.

In reference to the , the ends 9A and 9B of the fastener 7 are thus folded against parts 10 of the shell 3 which delimit said openings obtained by spacing of fibers.

In this example, the parts 10 of the shell 3 thus find themselves enclosed between, on the one hand, surfaces 201A and 201B of the fastener 7 called "stop surfaces" and, on the other hand, the membrane, in l occurrence of a part of the jacket 2 and a part of the external envelope 6 of the reinforcement 4, ensuring a robust mechanical connection between the reinforcement 4 and the body of the tank 1.

There shows a tool comprising a mold 31, metallic or composite, and an axis 32 passing through the attachment 7 in direction D4. The mold 31 is held in support on the external surface of the shell 3 by tightening nuts 33 cooperating with the axis 32, so as to hold in position the assembly of the body of the tank 1 and the pre-positioned reinforcement 4 using the aforementioned bells (not shown). Alternatively, all or part of the step of deforming the ends 9A and 9B of the fastener 7 can be carried out directly by the mold 31 rather than by bells.

The assembly of the reinforcement 4 and the body of the tank 1 is then consolidated by injection of a thermosetting resin via orifices (not shown) made in the tooling, after formation of a vacuum in the space delimited by the mold 31 and the membrane integrating the jacket 2 which provides a counter-mold function.

In this example, the injection is carried out using a process known under the Anglo-Saxon name “Vacuum-Assisted Resin Transfer Molding” (VARTM).

The assembly is then subjected to heat treatment in order to stiffen the resin.

The thermosetting resin can be replaced by a thermoplastic type resin, in particular with low viscosity allowing injection into the fibrous structure of the shell 3, or even by a bio-sourced resin.

Alternative consolidation processes can be implemented, for example the process known under the Anglo-Saxon name “Resin Transfer Molding” (RTM) or an infusion process, or even consolidation by thermocompression for example when the shell 3 and/or or the fastener 7 comprise a mixture of technical fibers and thermoplastic matrix filaments.

At the end of such an assembly, the ends 9A and 9B of the fastener 7 thus form surfaces 201A and 201B which extend in this example circumferentially around D4.

The surfaces 201A and 201B present in this example a frustoconical geometry, forming a curve which has a single radius of curvature, so as to extend radially outwards relative to D4.

The surfaces 201A and 201B thus constitute stops capable of limiting deformation of the body of the tank 1 in the direction D4.

In particular, the abutment surface 201A makes it possible to prevent or at least limit movement in a first direction along D4 of the part of the body resting on this surface 201A, that is to say the part of the body located towards the top of the , this first meaning going in this case from the bottom to the top of the . The stop surface 201B makes it possible to prevent or limit movement in a second direction along D4 of the part of the body resting on this surface 201B, that is to say the part of the body located towards the bottom of there , this second direction going from the top to the bottom of the .

There shows tools similar to that of the which is specifically adapted to the assembly of a reinforcement 4 with a tank body 1 having parts connected by the reinforcement 4 which are inclined with respect to the connection direction D4. The preceding description applies by analogy to this embodiment.

The tools of the differs in particular from that of the in that it comprises heads 41 forming molds, centered on the axis 32 in openings of the mold 31. The heads 41 are arranged at the ends 9A and 9B of the attachment 7 so as to keep them folded against the shell 3 and optionally allow them to finalize their conformation. For comparison, in the example of the , the geometry of the folded ends 9A and 9B of the fastener 7 results in particular from the shape of the molds 31 themselves and/or of said bells.

The preceding description also applies by analogy to the embodiment of the which is essentially distinguished from that of the in that the reinforcement 4 also includes diffusers 8 and nuts 51.

The diffusers 8 are here rigid rings comprising for example a reinforced thermoplastic material each enclosed between a respective end portion of the outer casing 6 of the reinforcement 4 and the shell 3 after folding down the ends 9A and 9B of the clip 7.

Such diffusers 8 make it possible to improve the distribution of loads on the shell 3, in particular when the ends 9A and 9B of the clip 7 are folded down.

The nuts 51 are also rigid rings which may include a reinforced thermoplastic material and which in this example have an ogive shape.

The nuts 51 are respectively housed in the ends 9A and 9B of the fastener 7, which are folded down so as to provide axial retention of the nuts 51 in direction D4 (see And described further below).

In this example, the tooling and the fastener 7 are in fact configured so that, when the ends 9A and 9B of the fastener 7 are folded, the nuts 51 are enveloped by a radially internal surface of the ends 9A and 9B and a radially external surface of the ends 9A and 9B, forming said abutment surfaces 201A and 201B, comes to bear on the shell 3.

The nuts 51 are configured to work in compression, so as to achieve an anti-stricture function capable of reducing the phenomena of sliding of the ends of the reinforcement 4 relative to the shell 3.

Such anti-restriction nuts 51 are particularly useful for tanks 1 intended to contain a fluid under high or very high pressure, such as hydrogen.

In a non-limiting manner, the diffusers 8 and the nuts 51 can include materials of the polyurethane, polyamide or even polyethylene type, and be reinforced by glass, carbon or other fibers.

Figures 6 to 8 show other examples of reinforcements 4 illustrating different geometries of the end 9A of the attachment 7, after folding against a corresponding part of the body of a tank 1 according to the invention. The preceding description obviously applies by analogy to these embodiments.

In each of the embodiments of Figures 6 to 8, the reinforcement 4 comprises a diffuser 8 extending radially between the attachment 7 and the membrane of the body of the tank 1. According to D4, the diffuser 8 extends both to the level of the central part 4A and a portion of the end part 4C of the envelope 6 forming the well. The abutment surface 201A formed by the end 9A visible in these figures has a curved geometry with a double radius of curvature.

In the example of the , the end 9A of the clip 7 has a fold forming an annular arm 202 extending radially towards the inside of the clip 7, facing the part of the end 9A forming the abutment surface 201A. Such an arm 202 makes it possible to reinforce the resistance of the end 9A of the attachment 7 to sliding when the body of the reservoir 1 is stressed by the fluid contained in the cavity 5.

The end 9A of the attachment 7 of the is folded in a similar manner, around an anti-restriction nut 51, so as to constitute a reinforcing end 4 similar to that of the .

Of course, the end 9B of the reinforcement 4, not visible in Figures 6 to 8, can have a geometry similar to that which has just been described, so as to form a symmetrical reinforcement 4.

Before deformation of the ends 9A and 9B of the fastener 7, epoxy resin can be sprayed on the hull 3, in particular at the level of the parts 10, in order to avoid their relaxation and consequently their displacement.

Numerous variants can be implemented on the basis of the preceding description, both in terms of the geometry of the attachment 7 and the other parts of the tank 1, or even of the members constituting the reinforcement 4 which may or may not include one or more elements including diffusers 8 and/or anti-restriction nuts 51 and/or other members. For example, in an embodiment not shown, annular wall elements (not shown) made of fabric or fibers can be arranged between the fastener 7 and/or diffusers 8 and/or nuts 51 and/or the membrane of the body of the tank 1 so as to improve the distribution of loads.

Referring again to the embodiment of the , the reinforcement 4 of the tank 1 is in this case similar to that illustrated on the , the anti-restriction nuts 51 being however not represented on the .

Tank 1 of the further comprises a filling nozzle 61 integrated into the structure of the shell 3 at the longitudinal end 1A of this tank 1.

The nozzle 61 is configured to establish fluid communication between the cavity 5 and the exterior of the reservoir 1, with a view to filling it or sampling the fluid it contains.

It follows from the preceding description that the invention makes it possible to produce a composite tank 1, in this case having a body formed of an internal jacket 2 impermeable to the transported fluid and a braided shell 3 both monolithic, capable of 'endure very high pressures while considerably improving the aspects of fatigue, aging and explosion safety. In particular, depending on the geometry of the tank 1, one or more reinforcements similar to any of the reinforcements 4 described above make it possible to significantly reduce the deformations of the body and to design a tank 1 of varied shape, conformable to the location reserved for its installation in a vehicle. A tank 1 according to the invention makes it possible in particular to withstand pressures of several tens of MPa.

In particular, the shows a tank 1 of ovoid shape comprising a single reinforcement 4.

Figures 9 to 11 show other examples of heteromorphic reservoirs 1 conforming to the invention, which can be manufactured according to the same principles as those which have just been described.

Tank 1 of the is described below only according to its differences compared to tank 1 of the , it being understood that the preceding description applies by analogy.

In the example of the , the body of the tank 1 has a generally flattened shape, in this case a dimension along the direction D2, or height, relatively small compared to its dimensions along D1 and D3.

As an indication, the height according to D2 of tank 1 can be approximately 100 mm.

The jacket 2 and the shell 3 of the body define different parts 101-103 which define the shape of the tank 1. The parts 101 and 102 have a generally planar shape defining a lower wall 101 and an upper wall 102 of the body which extend parallel , facing each other. The parts 103 form side walls connecting the walls 101 and 102 so as to form rounded edges of the tank 1.

The tank 1 comprises in this example a series of reinforcements 4 as described above and which are each configured to connect the parts 101 and 102 of the body to each other.

The reinforcements 4 are distributed in the tank 1 being spaced two by two at a substantially constant distance in direction D1 and in direction D3.

Of course, the geometry, position and number of reinforcements 4 can be modified without departing from the scope of the invention, depending on the distribution of forces in the tank 1 during its use, which depends in particular on the geometry of the body.

There shows another example of tank 1 according to the invention which is described below only according to its differences compared to tank 1 of the , the preceding description applying by analogy.

Tank 1 of the has a dimension in direction D2 relatively greater than the height of the tank of the .

The upper part of the body comprises several upper walls 104-108 facing the lower wall 101 as well as two transverse walls 109.

The upper walls 104, 106 and 108 are parallel to the lower wall 101 while the upper walls 105 and 107 are inclined relative to the walls 104, 106 and 108 so as to create a bulge in the tank 1 at its central longitudinal part. .

As an indication, the maximum height of tank 1, that is to say the distance along D2 between the lower wall 101 and the upper wall 106, can be approximately 150 mm.

Concerning said transverse walls 109, only one of which is visible on the , these are parallel to directions D1 and D2 and are distant from each other in direction D3 so as to define a constant width of tank 1.

The reinforcements 4 comprise on the one hand reinforcements 121 similar to those of the tank of the , that is to say reinforcements 121 connecting the lower wall 101 and the upper part of the body to each other. The reinforcements 4 also comprise reinforcements 122 which connect the transverse walls 109 of the body to each other and which in this case have a connection direction perpendicular to these walls 109 and to the direction connection of reinforcements 121.

Reinforcements 4 of tank 1 of the thus extend by intersecting in two different directions of space, in this case D2 and D3, forming a bi-axial network of reinforcements 4.

There shows another example of tank 1 according to the invention which is described below only according to its differences compared to tank 1 of the , the preceding description applying by analogy.

The upper part of the body comprises two upper walls 131 and 132 facing the lower wall 101, two lower longitudinal walls 133 and two upper longitudinal walls 134.

The upper walls 131 and 132 are parallel to the lower wall 101.

The distance along D2 between the lower wall 101 and the upper wall 131 is greater than the distance along D2 between the lower wall 101 and the upper wall 132, forming a stepped tank.

As an indication, the maximum height of tank 1, that is to say the distance along D2 between the lower wall 101 and the upper wall 131, can be approximately 400 mm.

The lower longitudinal walls 133, only one of which is visible on the , are substantially parallel to directions D2 and D3 and are spaced apart from each other in direction D1 so as to define a length of tank 1.

One of the upper longitudinal walls 134 provides the connection between one of the lower longitudinal walls 133 and the upper wall 131, while the other upper longitudinal wall (not visible on the ) ensures the connection between the upper wall 131 and the upper wall 132.

The upper longitudinal walls 134 face each other and extend in a plane slightly oblique to the plane D2-D3.

The reinforcements 4 include reinforcements 121 similar to the reinforcements 121 of the tank of the , that is to say reinforcements 121 connecting the lower wall 101 and the upper part of the body to each other, as well as reinforcements 122 similar to the reinforcements 122 of the tank of the , connecting the transverse walls 109 of the body to each other. The reinforcements 4 also include reinforcements 123, some of which connect the two lower longitudinal walls 133 to each other and others which connect the two upper longitudinal walls 134 to each other.

Reinforcements 4 of tank 1 of the thus extend crisscrossing in three different directions of space, in this case D1, D2 and D3, forming a tri-axial network of reinforcements 4.

It follows from these different non-limiting examples that the invention makes it possible to create polymorphic tanks which can include a network of multi-axial/multi-directional reinforcements.

Numerous variations can be made to these embodiments. For example, concerning the shell 3, this may comprise a peripheral layer comprising intertwining of metal filaments such as copper, in order to protect the tank 1 against electrostatic charges.

In one embodiment, the tank 1 may comprise a dimensional control device formed by an interweaving of optical, inductive or laser-charged filaments allowing the detection of defects or failures generated during the life of the tank 1.

In one embodiment, certain wells formed during the production of the membrane can be used not to produce additional reinforcements but to fix the tank 1 to a vehicle, for example using fixing studs passing through these wells.

Furthermore, the jacket 2 and/or the external envelope 6 of the reinforcement(s) 4 may be devoid of fibers, which makes it possible to reduce the cost, or on the contrary include fibers, for example to improve the adhesion of these elements. .

The geometries described above and shown in the figures are in no way restrictive. In addition to the polymorphic and heteromorphic geometry of the body of the tank 1, the possible reinforcement(s) 4 and/or their external envelope 6 may have a circular, oval, square, hexagonal or other section.

Of course, a tank according to the invention can be used in a transport device other than a motor vehicle, for example in an aircraft or in a railway or naval vehicle.

In addition, the fasteners 7 described above can be formed in two parts assembled with each other, for example in the manner illustrated in one of Figures 12 to 21, each of these parts forming a respective ends 9A and 9B.

In the examples of Figures 12 to 15, the parts of the fastener 7 are fitted into each other and glued to each other using an epoxy resin. In this regard, gorges 211 ( ) or a room 212 ( ) can be made to receive such a resin and/or a ring 213 ( ) can be used for example to simplify the geometry of the parts forming the ends 9A and 9B and/or to simplify assembly.

The parts of the fastener 7 can also be assembled together by screwing ( ) or using a shrink-fitted internal ring 221 ( ), the latter being able to be inserted after cooling so as to achieve tightening by thermal expansion.

In the example of Figures 18 and 19, the parts of the fastener 7 are mounted on an internal ring 231 having locking notches 232 which extend along the direction D4 and which are circumferentially spaced from each other. The parts of the fastener 7 to be assembled include complementary notches allowing these parts to be inserted onto the ring 231 by translating them along D4 after having placed them in a first angular position relative to the ring 231. Said parts of the fastener 7 are then blocked along D4 relative to the ring 231 by placing them in a second angular position relative to the ring 231. In this example, heads 233 are fixed to the ends of the fastener 7 in order to improve the resistance of the ends 9A and 9B to the stresses of the body of the tank 1.

Figures 20 and 21 show yet another example of fastener 7 comprising two conical-shaped parts, one of these parts, internal, comprising notches 241 allowing its deformation with a view to its insertion into the other part, external. After fitting together these internal and external parts, a ring 242 is force-fitted so as to exert a radial holding force on the internal and external parts of the fastener 7.

A clip 7 in two parts, for example according to one of the embodiments of Figures 12 to 21 or according to other variants not shown, makes it possible to simplify the manufacture and assembly of the clip 7 on the body of the tank 1 This also makes it possible to conform the ends 9A and 9B, for example by deformation, before mounting the fastener 7 on the body of the tank 1.

By way of example, the part of the fastener 7 forming the end 9A can be inserted into the well through one of the openings made in the shell 3 in the manner described above, in this case in said second direction, while the part of the fastener 7 forming the end 9B can be inserted into the well following said first direction through another opening in the shell 3, these parts being able to be secured to each other at the using one of the techniques described above with reference to Figures 12 to 21.

Claims (10)

Attachment (7) comprising a first end (9A) intended to be connected to a first part of a body of a tank (1) and a second end (9B) intended to be connected to a second part of said body which is extends opposite said first part of the body, the first end (9A) and the second end (9B) being spaced apart from each other along a connection direction (D4), characterized in that :
– the first end (9A) of the fastener (7) forms a first abutment surface (201A) extending around the connection direction (D4) and intended to come to bear on the first part of the body so as to prevent or limit movement of the first part of the body in a first direction according to the connection direction (D4), and/or
– the second end (9B) of the fastener (7) forms a second abutment surface (201B) extending around the direction of connection and intended to come to bear on the second part of the body so as to prevent or limit a movement of the second part of the body in a second direction in the connection direction (D4), the second direction being opposite the first direction. Fastener (7) according to claim 1, in which the first abutment surface (201A) and/or the second abutment surface (201B) are frustoconical and/or have one or more radii of curvature. Fastener (7) according to claim 1 or 2, comprising one or more layers made up of fibers, the majority of which extends along the connection direction (D4). Tank (1) for a transport device such as a motor vehicle, an aircraft or a boat, comprising a body which delimits a cavity (5) intended to contain a fluid and at least one attachment (7) according to any one of claims 1 to 3, the fastener (7) connecting said first part and said second part of the tank body to each other. Tank (1) according to claim 4, comprising at least one wall (6) forming a well which passes through the cavity (5) of the tank (1), the attachment (7) being housed in the well. Tank (1) according to claim 5, comprising at least one load distribution ring (8) extending radially between the attachment (7) and the wall (6) forming the well and/or comprising one or more nuts ( 51) anti-restriction respectively housed in the first end (9A) and in the second end (9B) of the clip (7). Tank (1) according to any one of claims 4 to 6, in which the body of the tank (1) comprises a sealing jacket (2) and a shell (3) braided on the jacket (2), the first surface of stop (201A) and/or the second stop surface (201B) being supported on the shell (3) so as to grip the shell (3) between on the one hand the liner (2) and on the other hand the first and/or second abutment surface, respectively. Method of shaping a fastener (7) according to any one of claims 1 to 3, comprising a step of deforming the first end (9A) and/or the second end (9B) of the fastener ( 7) so that the first abutment surface (201A) and/or the second abutment surface (201B) can come to bear on the first part and/or the second part of the body, respectively. Method of manufacturing a reservoir (1) according to any one of claims 4 to 7 including the characteristics of claim 5, comprising a step of inserting, into the well, in the connection direction (D4), a clip (7) according to any one of claims 1 to 3 and, after insertion of the clip (7) into the well, a step of deforming the first end (9A) and/or the second end (9B ) of the fastener (7) according to the method of claim 8. Method of manufacturing a tank (1) according to any one of claims 4 to 7 including the characteristics of claim 5, comprising a step of deforming the first end (9A) and/or the second end (9B) of the fastener (7) according to the method of claim 8 and, after deformation:
– an insertion into the well of a first part of the fastener (7) forming said first end (9A), in said second direction,
– an insertion into the well of a second part of the fastener forming said second end, in said first direction,
– an assembly of the first part and the second part of the fastener so as to secure these parts to each other at least in translation in the direction of connection.