WO2015001531A1

WO2015001531A1 - Tank for high and very high pressure fluids, particularly gas for supplying motor vehicles

Info

Publication number: WO2015001531A1
Application number: PCT/IB2014/062870
Authority: WO
Inventors: Matteo Hee Seung ILLESI
Original assignee: I.H.P. Composite S.R.L.
Priority date: 2013-07-04
Filing date: 2014-07-04
Publication date: 2015-01-08

Abstract

The present invention relates to a tank for high and very high pressure fluids, in particular gases for the power supply of motor vehicles, comprising an airtight core (2) and at least one external covering (3), the core (2) being associated with a reinforcement structure comprising a central body (10) joined to the core (2) and having at least two plates (11a, 11b) at least partly covered by the external covering (3), the two plates being opposite and joined together by means of at least one connection element (12).

Description

Description of Industrial Invention Patent having as title:

"TANK ^' FOR HIGH AND VERY HIGH PRESSURE FLUIDS, IN PARTICULAR GAS FOR SUPPLYING MOTOR VEHICLES".

Designated inventor: ILLESI MATTEO HEE SEUNG

TECHNICAL FIELD OF THE INVENTION

The present invention refers to a tank for high and very high pressure fluids, in particular gases for the power supply of motor vehicles.

STATE OF THE PRIOR ART

As is known, different gas types have shown to be excellent fuels for motor propulsion, in addition to being inexpensive and respectful of the environment.

Considering for example natural gas, often identified through its main component which is methane, which allows attaining optimal performances in terms of power, good motor functioning, reduced pollution and low power consumption.

Natural gas and other fuels have however the disadvantage of having very low density with respect to liquid fuels and such characteristic tends to complicate the storage and transport thereof on land vehicles .

However, the disadvantages of natural gas, hydrogen and other gases, with respect to liquid fuels, in terms of tank volume, can be overcome with the application of high pressures, which reach 200 bar and beyond.

The tanks used must therefore ensure very high safety standards, defined on the basis of international specifications and extremely severe tests.

For this reason, for example, the tanks for natural gas most widespread on the market are usually constituted by strong, heavy cylinders with cylindrical shape, made of high-strength steel.

Nevertheless, recently, natural gas tanks have been designed with more modern concept, shaped in such a manner so as to avoid taking away luggage space.

Such tanks are obtained by employing solutions that combine metal structure and composite fibers, in order to limit the final weight and at the same time ensure the necessary strength.

Such known tanks, even if they have been widely employed and are highly appreciated by the market, nevertheless have room for improvement.

On such matter, it is considered that one of the greatest stumbling blocks to the diffusion of gaseous fuels continues to be the weight of the tanks, which evidently tend to limit the capacity of the vehicles.

WO2007107851A2 teaches a tank for high pressure fluids according to the state of the art, which comprises respective reinforcement elements.

OBJECTS OF THE INVENTION

The main task of the present invention is therefore to obtain a tank capable of optimizing the weight/volume ratio.

In the scope of the abovementioned task, a particular object of the invention is to obtain a tank capable of combining maximum lightness with very high mechanical strength.

Another object of the invention is to obtain a tank which has a shape adapted to be situated with ease on board motor vehicles.

Not least object of the invention is to obtain a tank designed to meet absolute safety criteria.

Another object of the present invention is to provide a new reinforcement structure for pressurized tanks .

The abovementioned task, as well as the abovementioned objects and others that will be clearer hereinbelow, are achieved by a tank for high pressure fluids, in particular gases for the power supply of motor vehicles, comprising an airtight core shaped as a rounded disc and an external covering obtained by means of a wrapping made of composite material fiber with high mechanical tensile strength; said core being associated with a reinforcement structure; said tank being characterized in that said reinforcement structure comprises a central body joined to said core and at least partly covered by said external covering.

Preferably, the central body comprises at least two plates at least partly covered by the external covering, the two plates being opposite and joined together by means of at least one connection element.

According to another aspect of the present invention, a reinforcement structure is also provided for a tank for high and very high pressure fluids, comprising at least two opposite plates joined together by means of a plurality of walls transverse or orthogonal to the two plates, the walls of the plurality of walls being parallel and placed spaced from each other, at least one through hole being formed in at least one plate of the plates, such through hole leading on one side into a delimitation channel between two adjacent transverse walls and on the other side outside the reinforcement structure. BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the present invention will be clearer from the description of an embodiment of a tank, illustrated by way of example in the enclosed set of drawings in which:

figure 1 is a sectioned perspective view of the tank, subject-matter of the present invention;

figure 2 is a perspective view of the central body of the reinforcement structure according to the present invention;

figure 3 is a side view of the central body of the reinforcement structure according to the present invention;

figure 4 is a section of figure 3 taken along the axis IV-IV;

figure 5 is a section of figure 3 taken along the axis V-V;

figure 6 is a view similar to figure 1 of another tank embodiment according to the present invention.

In the set of drawings, equivalent parts or components are marked with the same reference numbers.

EMBODIMENTS OF THE INVENTION

With reference to the abovementioned figures, reference number 1 indicates overall a tank, for high and very high pressure fluids, in particular gases for the power supply of motor vehicles, which optimizes the useful space in the compartment where it is installed.

By way of a mere example, a tank 1 is described that is adapted, for example, to be situated in the spare wheel compartment of a vehicle, thus maximizing the capacity of the luggage compartment.

The tank 1 comprises an airtight core 2, substantially shaped as a rounded disc, and an external covering 3 made, in a per se known manner, by means of a wrapping of composite material fiber with high tensile mechanical strength.

Preferably, the core 2 is made with fluid seal and delimits one or preferably a pair of openings 2c for a reason that shall be presented hereinbelow.

In the particular embodiment illustrated in the enclosed figures, the core 2_. is constituted by two caps 2a and 2b joined together, for example integrally welded together along a line of contact, e.g. a contact circumference 4 and connected, preferably welded, to a reinforcement structure intended to ensure the non- deformability of the tank 1; the high internal pressure of the stored fluid tends to deform the tank, e.g. by expanding the upper and lower walls of the tank. Preferably, a first cap is provided for, if desired upper first cap 2a, and also a second cap 2b is provided for, if desired lower second cap, one or both, if desired, delimiting an opening 2c.

More particularly, the core 2 comprises a first body, if desired a substantially laminar and hollow body configured as a solid of revolution with multiple diameters around an axis of symmetry x-x or a geometric solid with multiple transverse perimeters around an axis of symmetry x-x, and such body has, from one side to the other, a first portion, e.g. substantially flat or slightly frustoconical or curved sector 2dl, then a connector edge portion, e.g. substantially curved with concavity directed towards the interior 2el, 2e2 of the tank and then a second portion, e.g. substantially flat or slightly frustoconical or curved sector 2d2. In such case, an opening 2c can be obtained in a respective substantially flat, slightly frustoconical or curved sector portion 2dl, 2d2, which thus would be substantially annular. If the core 2 comprises two caps, then each cap 2a, 2b can have a respective flat, slightly frustoconical or curved sector portion 2dl or 2d2 and a respective part 2el, 2e2 of the curved edge portion.

The first 2dl and the second portion 2d2 are connected by means of the connector edge portion 2el, 2e2.

Alternatively, the core 2 can also be configured as a parallelepiped, hence with square or rectangular cross section, or it can be substantially spherical.

In the present patent application with the expression "substantially laminar and hollow body configured as a solid of revolution with multiple diameters around an axis of symmetry x-x or a geometric solid with multiple transverse perimeters around an axis of symmetry x-x" it is intended an element delimited by a side wall with circular cross section (diameters) or square or rectangular cross section (transverse perimeters) of size that can vary from one side of the element itself to the other side.

The core 2 is preferably made of metal material with low thickness, such as steel, aluminum or another malleable material.

Nevertheless, it is not excluded that the core 2 may be constituted by only one piece or formed by a plurality of mutually joined elements so as to obtain a continuous body, or better yet a fluid sealed body.

According to the present invention, the reinforcement structure comprises a central body 10, at least partly covered by the external covering 3, if desired, as will be stated hereinbelow, covered with the interposition of an intermediate layer 20. Moreover, a reinforcement structure with a central body 10, as stated below, constitutes the sub ect-matter of the present invention even independent of a tank according to the present invention, although preferably such reinforcement structure is used in one such tank.

The core 2 delimits the housing zone RZ for the pressurized fluid (e.g. gas for the power supply of motor vehicles, such as methane) in the tank, if desired and preferably, as will also be stated hereinbelow, together with a portion of the reinforcement structure or better yet of the central body.

With particular reference to the embodiment illustrated in the figures, the central body 10 comprises two discoid elements or plates 11a and lib opposite each other, integrally joined by means of at least one connection element, e.g. a plurality of walls 12, preferably transverse or orthogonal to the plates 11a and lib as well as parallel and spaced from each other, e.g. symmetrically arranged, meeting the maximum stress resistance criteria. The walls 12 are preferably extended, for all or most of the extension or width of the plates 11a, lib, hence between edge portions of each of the same plates, thereby ensuring a support or constraint of the plates for the entire extension thereof .

Naturally, the transverse walls 12 could also be slightly tilted with respect to each other, or traverse or orthogonal to each other, for example arranged substantially radially, i.e. substantially lying in a plane passing through the axis x-x.

One or preferably both plates 11a, lib of the reinforcement structure are at least partly covered by the external covering 3, if desired with interposition of an intermediate layer 20 which will be described hereinbelow.

If desired, the transverse walls 12 have, during use, substantially vertical trim, while the plates comprise a first plate or top plate 11a and a second plate or base plate lib, both with substantially horizontal position during use.

The transverse walls .12 can be obtained in a single piece or enbloc with the plates 11a, lib or be connected, e.g. welded thereto or constrained via fitting with respective recessed or relief portions of the plates 11a, lib.

Preferably, the plates 11a, lib comprise a first face or external face 14c directed towards the tank exterior and a second face or internal face 14d directed towards the tank interior and towards the internal face of the other plate. Preferably, the first face or external face 14c of one or both plates 11a, lib is substantially flat or slightly frustoconical or curved sector.

Preferably, in one or both plates 11a, lib, at least one through hole 16a, 16b can then be formed, intended to place the interior of the housing zone RZ of the tank 1 in fluid communication with the exterior, such that it is possible to fill the tank with fluid, conveying fluid within such hole 16a, 16b.

Advantageously, one or both plates 11a, lib or better yet the external face 14c of one or both plates comprises/comprise a portion, if desired more external or more peripheral 14e, covered by the external covering 3 during use and, if provided by an intermediate layer 20 which will be better described hereinbelow, as well as a portion, if desired more internal or central 14f not covered by the external covering 3 and, if provided, by the intermediate layer 20 and the through hole 16a, 16b can then be formed in such internal or central portion 14f.

If desired, starting from the external face 14c of one or both plates 11a, lib, at least one annular rib 15a, 15b is extended, and in such case the external covering 3 encloses the external face 14c between the free edge of the respective plate 11a, lib and the annular rib 15a, 15b, such that the annular rib 15a, 15b constitutes a shoulder of internal delimitation of the external covering 3 and, if provided, of the intermediate layer.

Preferably, the through hole 16a, 16b leads internally to a zone not affected by the walls 12 and in fluid communication with the housing zone RZ, for example into a channel 22a delimited between at least two adjacent transverse walls 12; such channel is laterally open, i.e. such channel 22a is in fluid communication with the housing zone RZ of the tank, i.e. at the ends of the transverse walls 12, such channel 22a is not closed.

Alternatively, the through hole for delivery and suction of the fluid into/from the tank could also be obtained in another point of the tank, even if desired not in the central body (for such purpose, see the embodiment illustrated in figure 6) , in such case the same could be obtained, for example, in a component, if desired metal, embedded and extended within the external covering 3, within the core 2 and, if provided, also within an intermediate layer 20 which will be described hereinbelow.

Naturally, the transverse walls 12 can also be suitably perforated, so as to not block the passage of the fluid from one point of the housing zone RZ to the other.

Preferably, also the other channels 22b delimited between the other transverse walls 12 of the central body 10 can be in fluid communication with the housing zone RZ, thus being open towards the outside, even if, as will be stated below, such channels may also be provided with reinforcing or stiffening separators for the central body of the reinforcement structure.

One or each discoid element or plate 11a, lib preferably comprises an external edge advantageously delimiting a first circumferential seat, respectively indicated with 13a and 13b, conceived for abutting corresponding internal circular sections 5a and 5b of the core 2 against the central body 10 and joining such sections to such body, e.g. via welding; more particularly, such circular sections 5a and 5b delimit the openings 2c. If the core comprises two caps 2a, 2b, then the internal circular edges 5a and 5b are obtained on the opposite faces of the caps 2a and 2b.

Preferably, the external edge of the plates 11a, lib will be substantially complementary or capable of being form coupled to the internal edge 5a, 5b of the core 2 and, still more preferably, core 2 and plates 11a, lib will be connected with fluid seal. For such purpose, the core 2 can be coupled to the plates 11a, lib or better yet to the central body 10, by molding it around the latter, or if the core is constituted by two or more caps 2a, 2b, bringing the latter around the central body 10 and then joining them and welding them close to the latter.

For such purpose, the housing zone RZ of the fluid in the tank is delimited by the core 2 and by the plates 11a, lib connected to each other with fluid seal, if desired by welding, starting from the exterior, the delimitation edges of the circumferential seats 13a, 13b of the plates 11a, lib with the delimitation edges of the openings 2c of the core 2. The connection element or the plurality of transverse walls 12 are instead advantageously extended within the housing zone RZ for the fluid in the tank. Nevertheless, it is not excluded that the housing zone RZ for the fluid in the. tank may be delimited with fluid seal only by the core 2.

Preferably, the substantially flat or slightly frustoconical portions 2dl, 2d2 are abutted against the external edge of the plates 11a, lib and delimit therewith the housing zone RZ, preferably, as stated above, with fluid seal. For such purpose, the substantially flat or slightly frustoconical portions 2dl, 2d2 can, during use, be substantially aligned with a respective plate 11a, lib and, preferably, with an external face 14c of a respective plate 11a, lib.

The first circumferential seats 13a and 13b are preferably connected to the external faces 14c of the plates 11a, lib, whose peripheral portions 14e actually constitute second circumferential seats, substantially concentric with the first; circular crown portions of the external covering 3 are superimposed on and joined to such second circumferential seats with the interposition, if provided, of the intermediate layer 20.

As stated above, starting from an internal or central portion of one or both external faces 14c, annular ribs or circular edges 15a and 15b can be extended, against which the external covering 3 and, if provided, the intermediate layer 20 can be laid or abutted.

In the discoid elements or plates 11a, lib, if desired centrally thereto, holes 16a and 16b can be obtained in fluid communication with the interior of the tank 1, which can be provided with threaded fillers 17a and 17b that allow the installation of means for inserting and drawing the fluid to be used in the tank.

The transverse walls 12 can be suitably reinforced by means of a plurality of connection separators 18a, 18b being extended as a bridge between two adjacent transverse walls 12, if desired at least one first rib 18a and at least one second rib 18b with radial extension with reference to the symmetry axis x-x of the core 2 or the tank 1. The connection separators 18a, 18b are fixed, if desired formed integrally with the or welded to the respective transverse walls 12. Naturally, if a channel 22a is provided as · stated above, connection separators 18a, 18b will not be provided for therein, or the same will be suitably perforated or with extension less than the height of the respective walls, such to leave a passage window for the fluid from the hole 16a, 16b to the housing zone RZ .

The action of the transverse walls 12 is assisted by the external covering 3 and, in the embodiment illustrated in the figures, by an intermediate layer 20 which completely encloses or incorporates the core 2 being joined to the discoid elements 11a and lib. If an intermediate layer 20 is provided, then the central body 10 or better yet the plates 11a, lib are at least partly covered by the external covering 3 with interposition of the intermediate layer 20.

In such case, the reinforcement structure comprises a central body 10 and an intermediate layer 20, preferably integrally joined together and at least partly covered by the external covering 3.

The intermediate layer 20, if provided, is coupled to the central body 10 in a manner such to completely enclose or incorporate the core 2, for example the two caps 2a and 2b, which in turn preferably have opposite faces joined, e.g. welded, to the same central body 10.

It was found to be particularly advantageous to obtain the intermediate layer 20 by means of a wrapping made of composite material fiber with high mechanical tensile strength, e.g. carbon fiber or with other materials with substantially equivalent mechanical properties .

Preferably, the intermediate layer 20 is formed or molded directly on the tank 1 or better yet on the central body 10 and core 2 assembled together, before obtaining the external covering 3.

Nevertheless, nothing prevents separately obtaining the intermediate layer 20 and then applying it to the assembled-together central body 10 and core 2; in this case, the intermediate layer 20 could be composed of preformed elements that during use can be assembled with each other.

In another embodiment, not illustrated in the enclosed figures, the intermediate layer 20 is incorporated in the external covering 3 that has zones with different strength. Advantageously, the intermediate layer 20 is composed of two half-shells that can be coupled together, along an axial plane, in order to form a casing with mating or complementary form with respect to that of the core 2.

The intermediate layer 20 can comprise a second body, if desired a substantially laminar and hollow body configured as a solid of revolution with multiple diameters around an axis of symmetry x-x or a geometric solid with multiple transverse perimeters around the symmetry axis x-x, such intermediate layer 20 has, from one side to the other:

- a first section, for example substantially flat or slightly frustoconical or curved sector 20a enclosing from the outside and, preferably, in abutment against a first substantially flat, slightly frustoconical or curved sector portion 2dl of the core 2 as well as, if provided, against an external or peripheral portion 14e of a plate 11a;

- a connector edge section, for example substantially curved 20b with concavity directed towards the interior of the tank 1 and enclosing from the outside and preferably in abutment against the edge portion 2el and 2e2 of the core 2; and

- a second section, for example substantially flat or slightly frustoconical or curved sector 20c enclosing from the outside and, preferably, in abutment against the second substantially flat, slightly frustoconical or curved sector portion 2d2 of the core 2 as well as, if provided, against an external or peripheral portion 14e of the other plate 11a.

The first 20a and the second section 20c are connected by means of the connector edge section 20b.

In such case, the intermediate layer 20 delimits an opening 20d in one or both substantially flat sections 20a, 20c, such opening/openings 20d has/have external diameter or profile substantially complementary to a respective annular rib 15a, 15b.

Alternatively, the intermediate layer 20 can also be configured as a parallelepiped, hence with square or rectangular cross section, or it can be substantially spherical.

Preferably, the intermediate layer, if provided, encloses and preferably abuts from the outside against the core 2; if one or more portions 14e of the central body 10 are provided, the intermediate layer 20 encloses and abuts against one such portion or portions 14e.

Then, with regard to the external covering 3, it preferably comprises a third body, if desired substantially hollow and configured as a solid of revolution with multiple diameters around an axis of symmetry x-x or a ^' geometric solid with multiple transverse perimeters around the symmetry axis x-x; such third body has, from one side to the other, if an intermediate layer 20 is provided:

- a first length, for example flat or slightly frustoconical or curved sector 3a enclosing from the outside and, preferably, in abutment against a first flat, slightly frustoconical or curved sector section 20a;

a second connector length, for example substantially curved 3b with concavity directed towards the interior of the tank 1 and enclosing from the outside and, preferably, in abutment against the substantially curved edge section 20b with concavity directed towards the interior of the tank 1; and

- a third length, for example flat or slightly frustoconical or curved sector 3c enclosing from the outside and, preferably, in abutment against the second flat, slightly frustoconical or curved sector section 20c.

The first length 3a and the third length 3c are connected by means of the second connector length 3b.

The external covering preferably delimits an opening 3d in one or both substantially flat lengths 3a, 3c, such opening/openings 3d has/have diameter or external profile substantially complementary to a respective annular rib 15a, 15b.

In such case, if desired, the annular rib/ribs

15a, 15b has/have the following, starting from the respective plate 11a, lib: a first section 15c with greater external section or diameter, on which during use the intermediate layer 20 is engaged, or better yet the internal edge thereof for delimiting the respective opening 20d, and then a second section 15d, connected to the first and with diameter or external section smaller than the latter, on which the external covering 3 is engaged, or better yet the internal edge thereof for delimiting the respective opening 3d.

The external covering 3 can also be configured as a parallelepiped, hence with square or rectangular cross section, or it can be substantially spherical.

Advantageously, the external covering 3 encloses and, preferably, abuts from the outside against the intermediate layer 20.

If instead an intermediate layer 20 is not provided for, then:

the first length that is flat or slightly frustoconical or curved sector 3a will enclose from the outside and, preferably, will be in abutment against a first substantially flat, slightly frustoconical or curved sector portion 2dl of the core 2 as well as, if provided, against an external or peripheral portion 14e of a plate 11a;

- the second substantially curved length 3b will enclose from the outside and, preferably, will abut against the edge portion 2el, 2e2 of the core 2; and the third length that is flat or slightly frustoconical or curved sector 3c will enclose from the outside and, preferably, will be in abutment against the second substantially flat, slightly frustoconical or curved sector portion 2d2 of the core 2 as well as, if provided, against an external or peripheral portion 14e of the other plate 11a.

If the intermediate layer 20 is not provided, the external covering 3 advantageously encloses and, preferably, abuts from the outside against the core 2; if one or more portions 14e of the central body 10 are provided, the external covering 3 encloses and abuts against the portion (s) 14e.

With a structure as stated above, a tank according to the present invention has an external covering 3 wrapped around a core 2 and a reinforcement structure comprising a central body 10 and if desired an intermediate layer 20, so as to have a housing zone RZ that has a substantially annular part around the central body 10 as well as, preferably, a series of channels 18a, 18b delimited between the transverse walls 12 of the central body 10.

The tank 1 therefore has an entirely new structure constituted by the central body 10 which joins, in a manner such to form a single body, the two opposite faces of a casing formed by the core 2, with gas and/or liquid seal, on which an external covering 3 is superimposed, the latter being made of composite material with high mechanical tensile strength, all of the above being bonded together.

The benefits of a tank and a reinforcement structure thus structured are numerous and significant.

The tank and a reinforcement structure according to the present invention in fact allow optimizing the weight/volume ratio.

The tank and the reinforcement structure thus allow combining maximum lightness with very high mechanical strength.

The tank, due to its form, also results easily placeable on board motor vehicles, preferably in the spare wheel compartment.

A further characteristic of the tank according to the invention is that of being absolutely safe, in respect of that provided by relevant laws and regulations .

It has in practice been observed that the tank for high and very high pressure fluids, in particular gases for the power supply of motor vehicles, according to the invention, fully accomplishes the predetermined objects.

The tank thus conceived is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept; in addition, all details can be substituted for other technically equivalent elements.

In practice, the materials used, as long as they are compatible with the specific use, as well as the contingent size and shapes can be of any type, in accordance with the requirements and the state of the art .

With regard to the differences between a tank according to the present invention and those in accordance with the state of the art, e.g. such as those taught by WO2007107851A2, it will be observed that none of the tanks proposed up to now has a reinforcement structure with a pair of plates connected and partially covered by an external covering, nor connected to a core as stated above.

The reinforcement structure according to the present invention is particularly advantageous because it provides high strength, well-distributed over the entire width of the tank, due in particular to the presence of the discoid elements or plates at least partly covered by the external covering. Hence, it is simple to manufacture, and does not even involve assembly difficulties.

It should also be observed that, according to a preferred aspect of the present invention, the structure of the central body, the connection (if desired via welding) thereof to the core as above- indicated with fluid seal as well as the support provided by the central body to the external covering (if desired with interposition of the intermediate layer) ensures the obtainment of a tank much stronger and more reliable than the solutions proposed up to now .

Modifications and variants of the invention are possible within the protective scope defined by the claims .

Claims

1. Tank for high and very high pressure fluids, in particular gases for the power supply of motor vehicles, comprising an airtight core (2) shaped as a rounded disc and at least one external covering (3) obtained by means of a wrapping made of composite material fiber, said core (2) being associated with a reinforcement structure, said tank being characterized in that said reinforcement structure comprises a central body (10) joined to said core (2), said central body (10) comprising at least two plates (11a, lib) at least partly covered by said external covering (3) , said at least two plates being opposite and joined together by means of at least one connection element (12) .

2. Tank according to claim 1, characterized in that said core (2) comprises a first portion (2dl), a connector edge portion (2el, 2e2) and a second portion (2d2), said first (2dl) and said second portion (2d2) being connected by means of said connector edge portion (2el, 2e2), said first (2dl) and said second portion (2d2) each being connected with fluid seal with a respective one of said at least two plates (11a, lib) .

3. Tank according to claim 2, characterized in that said core (2) comprises a first substantially laminar and hollow body configured as a solid of revolution with multiple diameters around an axis of symmetry (x- x) or a geometric solid with multiple transverse perimeters around an axis of symmetry (x-x) , said first body having, from one side to the other:

- a first portion that is substantially flat or slightly frustoconical or curved sector (2dl);

- an edge portion that is substantially curved with concavity directed towards the interior (2el, 2e2) of said tank; and

- a second portion that is substantially flat or slightly frustoconical or curved sector (2d2),

said substantially flat, slightly frustoconical or curved sector portions (2dl, 2d2) each being connected with fluid seal with a respective one of said at least two plates (11a, lib) .

4. Tank according to claim 2 or 3, characterized in that each of said first (2dl) and second (2d2) portions of said core (2) delimits an opening (2c) and in that the external edge of each plate of said at least two plates (11a, lib) is joined with the delimitation edge of a respective opening (2c) , in a manner such that said first (2dl) and second (2d2) portion of said core (2) delimit with said plates (11a, lib) with fluid seal the housing zone (RZ) of the fluid in said tank.

5. Tank according to any one of the claims 2 to 4, characterized in that said reinforcement structure comprises an intermediate layer (20) covered by said external covering (3), said intermediate layer (20) comprising:

- a first section (20a) enclosing from the outside said first portion (2dl) of said core (2);

- a connector edge section (20b) enclosing from the outside said connector edge portion (2el, 2e2) of said core (2) ; and

a second section (20c) enclosing from the outside said second portion (2d2) of said core (2),

said first (20a) and said second section (20c) being connected by means of said connector edge section (20b) .

6. Tank according to claim 5, characterized in that said intermediate layer (20) comprises a second substantially laminar and hollow body configured as a solid of revolution with multiple diameters around an axis of symmetry (x-x) or a geometric solid with multiple transverse perimeters around said axis of symmetry (x-x), said intermediate layer (20) having, from one side to the other:

- a first section that is substantially flat or slightly frustoconical or curved sector (20a) enclosing from the outside said first portion (2dl) of said core (2) ;

a substantially curved edge section with concavity directed towards the interior of the tank (20b) and enclosing from the outside said connector edge portion (2el, 2e2) of said core (2); and

- a second section that is substantially flat or slightly frustoconical or curved sector (20c) enclosing from the outside said second portion (2d2) of said core (2).

7. Tank according to any one of the claims 2 to 6, characterized in that said external covering (3) comprises :

- a first length (3a) enclosing from the outside said first portion (2dl) of said core (2) or said first section (20a) of said intermediate layer (20);

- a second connector length (3b) enclosing from the outside said connector edge portion (2el, 2e2) of said core (2) or said connector edge section (20b) of said intermediate layer (20) ; and

- a third length (3c) . enclosing from the outside said second portion (2d2) of said core (2) or said second section (20c) of said intermediate layer (20), said first (3a) and said third length (3c) being connected by means of said second connector length (3b) .

8. Tank according to any one of the preceding claims, characterized in that said at least one connection element comprises a plurality of walls (12) transverse or orthogonal to said at least two plates (11a, lib), said walls (12) of said plurality of walls being parallel and placed at a distance from each other, or tilted with respect to each other, or substantially radially arranged, i.e. substantially lying in a plane passing through an axis of symmetry (x-x) of said tank.

9. Tank according to any one of the preceding claims, characterized in that in at least one plate of said plates (11a, lib), at least one through hole (16a, 16b) is formed that is intended to place the interior of a fluid housing zone (RZ) of said tank (1) in fluid communication with the outside.

10. Tank according to claim 8 and 9, characterized in that said at least through hole (16a, 16b) internally leads into a channel (22a) delimited between at least two adjacent transverse walls (12), and such channel (22a) is laterally open, i.e. said channel (22a) is in fluid communication with said housing zone (RZ).

11. Tank according to claim 9 or 10, characterized in that at least one plate of said plates (11a, lib) has a portion (14e) covered by said external covering (3) and a portion (14f) not covered by said external covering (3), said at least one through hole (16a, 16b) being formed in said non-covered portion (14f).

12. Tank according to any one of the preceding claims, characterized in that said plates (11a, lib) each comprise an external face (14c) directed towards the exterior of said tank and an internal face (14d) directed towards the interior of said tank and towards the internal face (14d) of the other plate, and in that starting from the external face (14c) of at least one of said plates (11a, lib), at least one annular rib (15a, 15b) is extended, said external covering (3) enclosing said external face (14c) between said annular rib (15a, 15b) and the free edge of the respective plate (11a, lib), such that said annular rib (15a, 15b) constitutes a shoulder of internal delimitation of said external covering (3).

13. Reinforcement structure for a tank for high and very high pressure fluids, comprising at least two opposite plates (11a, lib) joined together by means of at least one connection element (12) and in that, in at least one plate of said plates (11a, lib), at least one through hole (16a, 16b) is formed leading on one side into a zone not affected by said connection element (12) and on the other side outside the reinforcement structure .

14. Reinforcement structure according to claim 13, characterized in that said connection element comprises a plurality of walls (12) transverse or orthogonal to said at least two plates (11a, lib) , said walls (12) of said plurality of walls being parallel and placed at a distance from each other and in that said at least one through hole (16a, 16b) on one side leads to a channel of delimitation (22a) between two adjacent transverse walls.

15. Reinforcement structure according to claim 14, characterized in that said delimitation channel (22a) is open towards the outside at at least one end thereof .

16. Reinforcement structure according to claim 13, 14 or 15, characterized in that said plates (11a, lib) comprise a face (14c) that is external during use and a face (14d) that is internal during use, and in that starting from the external face (14c) of at least one of said plates (11a, lib), at least one annular rib (15a, 15b) is extended, said at least one through hole (16a, 16b) being provided within the area enclosed by said annular rib (15a, 15b) .