CN113924437B

CN113924437B - Corrugated corner piece for constructing a sealing film of a can and folding system for forming corrugations in a corner piece

Info

Publication number: CN113924437B
Application number: CN202080041896.1A
Authority: CN
Inventors: 文森特·贝尔热; 奥利维耶·佩罗
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2019-04-29
Filing date: 2020-04-07
Publication date: 2023-06-16
Anticipated expiration: 2040-04-07
Also published as: FR3095356B1; FR3095356A1; JP2022531180A; CN113924437A; EP3963250A1; KR20220002406A; WO2020221566A1

Abstract

The invention relates to a corner piece (2) for constructing a sealing film (3) for a can, the corner piece (2) comprising a first plate (11) and a second plate (12) which are at an angle alpha of between 1 DEG and 179 DEG with respect to each other and joined at a fold line (13), the corner piece (2) comprising a corrugation (17) intersecting the fold line (13) and extending from one end to the other end of the corner piece (2), the corrugation (17) comprising: -a first portion (18) arranged in the first plate (11); -a second portion (19); -a central portion (20) formed astride the first plate (11) and the second plate (12); the central portion (20) has, in a cross section on a plane passing through the bending line (13), an inverted W-shaped profile with one concave recess (24) and two convex protrusions (22, 23) arranged laterally on either side of the concave recess (24).

Description

Corrugated corner piece for constructing a sealing film of a can and folding system for forming corrugations in a corner piece

Technical Field

The present invention relates to a corrugated corner member intended for use in constructing a sealing membrane for a tank for storing a fluid, such as liquefied gas.

The invention also relates to a bending system for producing such a corrugated corner member.

Background

In the prior art, sealed and thermally insulated tanks for storing liquefied gas are disclosed, which tanks are equipped with corrugated sealing membranes intended to be in contact with the liquefied gas stored in the tank and to seal the tank. The sealing membrane comprises a metal plate comprising a series of vertical corrugations protruding towards the inside of the tank and allowing the sealing membrane to deform, in particular due to the thermal and mechanical loads generated by the liquefied natural gas stored in the tank.

At the junction between the two walls of the can, the sealing film comprises corner parts which are connected to adjacent metal plates by welding to ensure a continuous seal. The corner member comprises two flanges which are inclined relative to each other and which are joined at the level of the intersection. The corner member includes a corrugation extending from one end of the corner member to the other end perpendicular to the intersection to allow deformation of the corner member in a lateral direction parallel to the intersection.

Such corner parts are particularly described and illustrated in document WO 2016030619. The corner piece described in the above document comprises a corrugation comprising: first and second portions formed in the first and second flanges of the corner member, respectively; and a central portion spanning an intersection extending between the first portion and the second portion. The first and second portions and the central portion have a profile that is generally semi-elliptical or triangular in shape. The corner members are prone to experiencing high loads in view of the fact that they are implanted in the areas of the tank most susceptible to sloshing phenomena, i.e. movement of the cargo within the tank.

Disclosure of Invention

One idea behind the invention is to propose a corner piece intended for the construction of a sealing membrane for a tank for storing fluids, which sealing membrane is mechanically better able to withstand sloshing phenomena.

Another idea behind the invention is to propose a corner piece with lower production costs, better fatigue strength, greater flexibility of traction on the axis of the bending line, and/or greater flexibility of rotation around the axis of the bending line.

According to one embodiment, the present invention provides a corner member intended for use in constructing a sealing film for a can, the corner member comprising a first flange and a second flange inclined relative to each other at an angle α of between 1 ° and 179 ° and including 1 ° and 179 ° and joined at the level of a bending line, the corner member comprising a corrugation intersecting the bending line and extending from one end to the other end of the corner member so as to enable the corner member to be deformed in a direction transverse to the corrugation, the corrugation comprising:

-a first portion formed in the first flange and extending from the first edge of the corner member in the direction of the bending line;

-a second portion formed in the second flange and extending from the second edge of the corner member in the direction of the bending line;

-a central portion formed astride the first and second flanges, the central portion extending between and being aligned with the first and second portions;

the central portion has, in a cross section on a plane passing through the bending line, an inverted W-shaped profile comprising a concave recess and two convex protrusions arranged laterally on respective opposite sides of the concave recess.

The advantage of a corner piece with such a central portion is therefore that it is less affected by sloshing phenomena in view of the form of the corner piece and, in particular, in view of the fact that the height of such a corner piece protruding towards the inside of the can is low compared to the central portion of the corner piece of the prior art. Such corner parts also have a good fatigue strength.

Furthermore, such a central portion gives the corner member greater flexibility to draw on the axis of the bending line and/or greater flexibility to rotate about the axis of the bending line. This can reduce the force applied to the corners of the tank due to the heat shrinkage phenomenon of the sealing film and/or the deformation phenomenon of the beams.

In the sense of the present description, the expression "plane through the bending line" means that the bending line lies in said plane. Furthermore, the plane concerned is advantageously a median plane, that is to say it divides the angle formed by the first flange and the second flange into two equal half angles.

According to other advantageous embodiments, such corner members may have one or more of the following features.

According to one embodiment, the corner members have a geometric configuration in the form of rectangular members that can be unfolded flat. In other words, the configuration of the corner members in the bellows region is such that the first portion, the second portion and the central portion do not cause any change in the length of the material in the corner members and therefore also do not cause a change in the thickness of the corner members.

According to one embodiment, the concave recess has a lower end in the shape of an arc or an elliptical arc.

According to one embodiment, the concave recess has the following depth and width: the depth and width decreasing in the direction of the corrugations from the bend line to the first portion such that the concave recess engages the top of the first portion; and the depth and width decreasing in the direction of the corrugations from the bend line to the second portion such that the concave recess engages the top of the second portion.

According to one embodiment, the first portion, the second portion and the convex protrusion protrude towards the inside of the angle α.

According to one embodiment, the first and second portions have a semi-elliptical or triangular profile of constant height.

According to one embodiment, the first flange and the second flange have a generally rectangular shape.

According to one embodiment, the present invention also provides a sealed and thermally insulated tank for storing a fluid, the tank comprising a sealing membrane comprising:

-a plurality of corrugated metal sheets welded to each other, the metal sheets comprising at least one corrugation protruding towards the interior of the can; and

At least one corner piece as described above, said corner piece connecting the metal plates of the sealing membrane at the junction between the two walls of the tank.

Such tanks may form part of an onshore storage facility, such as for storing LNG, or be installed in an offshore or deepwater floating structure, particularly a methane tanker, a Floating Storage and Regasification Unit (FSRU), a Floating Production and Storage and Offloading (FPSO) unit, or the like.

According to one embodiment, the present invention provides a vessel for transporting fluids, the vessel comprising a double hull and the tanks described above arranged in the double hull.

According to one embodiment, the invention also provides a method for loading or unloading a vessel of the above-mentioned type, wherein fluid is transported from a floating or onshore storage facility to the vessel's tank via insulated piping or from the vessel's tank to a floating or onshore storage facility.

According to one embodiment, the present invention also provides a fluid transfer system comprising: a vessel as described above; an insulated pipeline arranged such that a tank mounted in the hull of the vessel is connected to a floating or onshore storage facility; and a pump for: the flow of fluid is driven from the floating or onshore storage facility through the insulated pipeline to the tank of the vessel or from the tank of the vessel through the insulated pipeline to the floating or onshore storage facility.

According to an embodiment, the present invention also provides a bending system for forming the corner member described above, the bending system comprising:

-an upper frame and a lower frame, vertically movable relative to each other between a rest position and a bent position;

-two lower die pads, each having a first and a second bearing surface inclined at an angle α with respect to each other and intended to receive a first and a second flange, respectively, of a corner piece, said lower die pads being mounted to slide on a lower frame in a transversal direction between a closed position and a separated position;

-two movable assemblies mounted on the upper frame and arranged facing the first and second support surfaces of the lower die pad, respectively, each movable assembly comprising:

-a support;

-a stamping fixed to the support and intended for forming a first portion or a second portion of the corrugation in one or the other of the first flange and the second flange of the corner piece;

-two upper die pads arranged laterally on respective opposite sides of the stamping, each upper die pad comprising a main structure and a clamping structure having a clamping surface arranged facing and parallel to one of the first and second support surfaces of the lower die pad, such that: in an intermediate clamping position, the clamping surface clamps the corner member against one of the first and second support surfaces of the lower die pad, the clamping plate being mounted to slide laterally on the main structure of the upper die pads, each upper die pad being mounted to be movable on the support of the movable assembly in a direction orthogonal to the clamping surface of the upper die pad such that: during the relative movement from the rest position to the bent position, when the upper die pad reaches the intermediate clamping position, the upper die pad moves relative to the upper frame in the direction orthogonal to the clamping surface,

The support of each movable assembly is mounted so as to be movable on the upper frame in a direction parallel to the longitudinal direction of the stamping of the movable assembly;

-the bending system further comprises means for deforming a bending wire, said means for deforming said bending wire comprising:

-a central finger intended to be arranged facing the intersection between the bending line and the corrugation to be formed, the central finger being carried by the lower frame and intended to form a concave depression; and

-two fingers intended for deforming the bending line, said two fingers being arranged laterally on respective opposite sides of the central finger, said two fingers being mounted movable on the upper frame and arranged to form one and the other of said two convex protrusions, respectively.

Such a bending system is therefore simpler, in particular because the means for deforming the preformed bending line of such a bending system are simpler, so that it is not necessary to use a stamping of complex shape to manage the deformation of the bellows in the region close to the preformed bending line.

According to one embodiment, the two fingers are mounted on a finger support, the finger support being kinematically connected to the upper frame and to at least two upper die pads of one of the movable assemblies by a hinge mechanism configured to form a reducer that causes: during the relative movement between the upper and lower frames from the rest position to the bent position, the vertical relative movement of the finger support is reduced relative to the vertical relative movement between the upper and lower frames when the upper die pad is in the clamped position.

Due to the hinge mechanism of the means for deforming the preformed bend line, no dedicated actuator is required to decouple the vertical movement of the fingers from the vertical movement of the upper frame.

According to one embodiment, the articulation mechanism comprises at least a first set of four links comprising: a first upper link hinged to the upper frame about a first geometric axis; a second upper link hinged to the upper frame about a second geometric axis; a first lower link hinged to one of the upper die pads of one of the movable assemblies about a third geometric axis; and a second lower link hinged about a fourth geometric axis to the other of the upper die pads of the movable assembly, the first upper link and the first lower link being hinged about a fifth geometric axis to each other, the second upper link and the second lower link being hinged about a sixth geometric axis to each other, the first geometric axis, the second geometric axis, the third geometric axis, the fourth geometric axis, the fifth geometric axis and the sixth geometric axis being parallel to a horizontal direction orthogonal to the bending line, the finger support being connected on the one hand to the first upper link and/or the first lower link by means of a first sliding connection, and the finger support being connected on the other hand to the second upper link and/or the second lower link by means of a second sliding connection, the first sliding connection and the second sliding connection being arranged to vertically support the finger support.

According to one embodiment, the first sliding connection comprises a first physical shaft connected to the first upper link and/or to the first lower link, the first physical shaft being mounted to slide in a first slideway formed in the finger support, and the second sliding connection comprises a second physical shaft connected to the second upper link and/or to the second lower link, the second physical shaft being mounted to slide in a second slideway formed in the finger support.

According to one embodiment, the first slide and the second slide extend horizontally.

According to one embodiment, the first physical axis extends along a fifth geometric axis and the second physical axis extends along a sixth geometric axis.

According to one embodiment, the first and second geometric axes extend in a first horizontal plane, the third and fourth geometric axes extend in a second horizontal plane, the fifth and sixth geometric axes extend in a third horizontal plane, the third horizontal plane being vertically positioned between the first and second horizontal planes.

According to one embodiment, two fingers are mounted to slide laterally on the finger support. According to one embodiment, the two fingers are mounted to slide between a separated position and a closed position. According to one embodiment, the two fingers are urged towards the separated position of the two fingers by one or more return members.

According to one embodiment, the fingers have spherically shaped ends.

According to one embodiment, the fingers are removably secured to the finger support.

According to one embodiment, the hinge mechanism is removably secured to the upper frame, upper die pad and finger support.

According to one embodiment, the central finger has a spherically shaped end.

According to one embodiment, the central finger is removably secured to the lower frame.

Drawings

The invention will be better understood and other objects, details, features and advantages thereof will become more apparent in the course of the following description of specific embodiments thereof, given by way of non-limiting illustration only with reference to the accompanying drawings.

FIG. 1 is a partial cross-sectional view of a sealed and thermally insulated tank for storing a fluid in a corner region between two walls, according to one embodiment.

Fig. 2 is a perspective view of a bending system intended for forming corrugations in a corner member in an intermediate position where the corner member is clamped.

Fig. 3 is a side view of the bending system of fig. 2 in a resting position.

Fig. 4 is a cut-away perspective view of the bending system of fig. 2 in an intermediate clamping position.

Fig. 5 is another cut-away perspective view of the bending system of fig. 2 in an intermediate clamping position.

Fig. 6 is a cross-sectional view of the bending system of fig. 2 on plane P VI.

Fig. 7 is a detailed perspective view showing fingers for deforming a preformed bend line in a corner member.

FIG. 8 is a detailed view of the lower frame showing in detail the central finger for deforming the preformed bend line of the corner member.

Fig. 9 is a detailed view of the center finger of fig. 8.

Fig. 10 is a detailed view of the movable assembly secured to the upper frame.

Fig. 11 is a perspective view of a corner member according to the first embodiment.

Fig. 12 is a schematic outline view of a bend line between the first flange and the second flange of the corner member of fig. 11.

Fig. 13 is a perspective view of a corner member according to a second embodiment.

Fig. 14 is a perspective view of a corner member according to a third embodiment.

Fig. 15 is a schematic cut-away view of a methane tanker tank and a terminal for loading/unloading the tank.

Detailed Description

The bending system 1 and the associated method of use described hereinafter are intended for the production of a component, such as a corner component 2, for the construction of a sealing membrane 3 of a sealed and thermally insulated tank for storing liquefied gas.

As an example, fig. 1 shows the structure of a sealed and thermally insulated tank, equipped with such corner members 2 at the level of the corner formed between the two walls of the tank. Each wall of the tank comprises, from the outside to the inside of the tank: a support structure 4; a secondary thermal insulation barrier 5, the secondary thermal insulation barrier 5 comprising an insulation block held on the support structure 4 and anchored to the support structure 4 by a secondary holding member; a secondary sealing film 6, the secondary sealing film 6 resting on the insulating blocks of the secondary thermal insulation barrier 5; a primary thermal insulation barrier 7, the primary thermal insulation barrier 7 comprising an insulation block anchored to the secondary sealing membrane 6 by a primary holding member (not shown); and a primary sealing film 3, the primary sealing film 3 resting on an insulating block of the primary thermal insulation barrier 7 and intended to be in contact with the liquefied gas contained in the tank.

The primary sealing film 3 comprises a plurality of corrugated metal sheets 8 welded to each other. Each metal plate 8 comprises a parallel, so-called low, first series of corrugations 9 and a parallel, so-called high, second series of corrugations 10. The first series of corrugations 9 are perpendicular to the second series of corrugations 10. Here, the corrugations 9, 10 protrude towards the inside of the can.

In the corner region formed at the intersection between two adjacent walls of the can, the primary sealing film 3 comprises a corner part 2.

Such a corner piece 2 is shown in detail in fig. 11. The corner member 2 is obtained by bending a metal plate. The corner members 2 are preferably made of the same material as the metal plate 8. In particular, the metal plate may be made of stainless steel, aluminum,

Made into (I)>

I.e. the expansion coefficient is generally between 1.2x10 ^-6 And 2x10 ^-6 K ^-1 An alloy of iron and nickel in between, or from a coefficient of expansion of about 7x10 ^-6 K ^-1 Iron alloy with high manganese content. However, other metals or alloys are equally possible. For example, the metal plate has a thickness of about 1.2 mm. Other thicknesses are equally conceivable, it being known that thickening the metal sheet results in an increase in the cost of the metal sheet and in general in an increase in the rigidity of the corner part 2.

As shown in fig. 11, the corner member 2 includes a first flange 11 and a second flange 12, the first flange 11 and the second flange 12 being inclined with respect to each other and joined at the level of the bend line 13 or intersection. In the embodiment shown in fig. 11, the angle α formed between the first flange 11 and the second flange 12 is 90 °. However, in general and depending on the geometry of the tank, the angle α tends to take any value between 1 ° and 179 ° and including 1 ° and 179 °, and more particularly between 90 ° and 179 ° and including 90 ° and 179 °. Each of the first flange 11 and the second flange 12 has a generally rectangular parallelepiped shape and thus comprises two parallel lateral edges 14, 15 and an end edge 16 opposite to the other of the first flange 11 and the second flange 12.

The corner member 2 comprises a bellows 17, imparting flexibility to the bellows 17 enabling the bellows 17 to be deformed by the influence of thermal and mechanical loads generated by the liquefied gas stored in the tank. The bellows 17 extends from one end of the corner member 2 to the other end perpendicularly to the bending line 13. The corrugations 17 thus allow the corner members 2 to deform in a transverse direction parallel to the bend line 13. The corrugation 17 protrudes towards the inside of the lobe α formed between the first flange 11 and the second flange 12 of the corner member 2. Thus, when the corner member 2 is placed in position in the can, the corrugations 17 protrude towards the interior of the can.

As shown in fig. 1, the corner members 2 are arranged such that the corrugations 17 of the corner members 2 are positioned in alignment with one of the corrugations 9 of adjacent metal sheets 8 of one of the walls and the other wall. The corner parts 2 are connected to adjacent metal plates 8 by welding to ensure a continuous seal at the level of the corner areas.

Returning to fig. 11, it can be seen that the bellows 17 is divided into three parts, namely: a first portion 18 formed in the first flange 11 and parallel to the lateral edges 14, 15 of the first flange 11, a second portion 19 formed in the second flange 12 and parallel to the lateral edges 14, 15 of the second flange 12, and a central portion 20 arranged between the first portion 18 and the second portion 19, that is to say across the first flange 11 and the second flange 12 and thus comprising a bending line 13 between the first flange 11 and the second flange 12.

The first portion 18 extends from the end edge 16 of the first flange 11 in the direction of the bending line 13. Likewise, the second portion 19 extends from the end edge 16 of the second flange 12 in the direction of the bend line 13. The first portion 18 and the second portion 19 protrude toward the inside of the lobe α formed between the first flange 11 and the second flange 12. The first portion 18 and the second portion 19 have a generally triangular or semi-elliptical profile.

Fig. 12 shows the profile of the bending line 13 between the first flange 11 and the second flange 12. The profile includes a deformed region 21 having a generally inverted W shape. The deformation zone 21 is symmetrical with respect to the intersection between the bending line 13 and the axes of the first 18 and second 19 portions of the corrugation 17. The deformation region 21 has two

convex protrusions

22, 23, the two

convex protrusions

22, 23 extending toward the inside of the lobe formed between the first flange 11 and the second flange 12, and the two

convex protrusions

22, 23 being separated from each other by a concave recess 24. The bottom of concave depression 24 is advantageously positioned in substantially the same plane as the straight portion outside deformation zone 21 of bend line 13.

The lower end of the concave recess 24 has an arcuate, e.g., circular or elliptical, shape.

Further, as shown in fig. 11, the concave depression 24 extends over the entire central portion 20 of the bellows 17. The depth and width of the concave recess 24 decreases from the bend line 13 in the direction of one of the first and

second portions

18, 19 and the direction of the other of the first and

second portions

18, 19. The concave recess 24 is joined to the top of the first and

second portions

18, 19 and a concave transition occurs at the junction between the concave recess 24 and each of the first and

second portions

18, 19.

Two

convex protrusions

22, 23 also extend over the entire central portion 20 of the bellows 17. In the embodiment shown, the height of the two

convex protrusions

22, 23 increases from the bend line 13 in the direction of one of the first and

second portions

18, 19 and in the direction of the other of the first and

second portions

18, 19 as the spacing of the two

convex protrusions

22, 23 decreases.

This configuration of the first and

second portions

18, 19 and the central portion 20 is obtained by bending only and thus has a configuration which can be flattened. In other words, the geometry of the corner piece 2 is such that the corner piece 2 can be produced by a shaping operation that does not result in any modification of the length of the material of the metal sheet or of the thickness of the metal sheet, which would otherwise tend to locally reduce the mechanical properties of the corner piece 2.

Fig. 13 and 14 show corner pieces 2 according to two other embodiments. The corner piece from fig. 13 and 14 differs from the corner piece 2 described above with reference to fig. 11 only in that: the angle a formed between the first flange 11 and the second flange 12 of the corner member 2 is about 105 ° and 165 °, respectively.

A bending system 1 capable of shaping the above-described corner member 2 and a method of using such a bending system 1 will now be described with reference to fig. 2 to 10. Conventionally, the longitudinal orientation of the bending system 1 corresponds to a projection in a horizontal plane of the axes of the first 18 and second 19 portions of the corrugation 17 to be shaped, and the "transverse" orientation then points transversely to said longitudinal direction.

First, a metal plate is bent in advance to form a first flange 11 and a second flange 12 that are inclined with respect to each other. Thereafter, corrugations 17 are formed in the corner member 2 by means of the bending system 1, as will be described below.

The bending system 1 comprises a lower frame 25 and an upper frame 26, the upper frame 26 being mounted so as to be vertically movable relative to the lower frame 25. The upper frame 26 is movable between a rest position and a bent position in which the corner member 2 is deformed to form the bellows 17. Thus, the upper frame 26 can exert pressure on the corner member 2, thereby enabling the corner member 2 to bend and the bellows 17 to be formed. The upper frame 26 is shown in the rest position of the upper frame 26 in fig. 3 and 6. The upper frame 26 is also shown in fig. 2, 4 and 5 in an intermediate clamping position in which the corner member 2 to be bent is sandwiched between

lower die pads

27, 28 and

upper die pads

42, 43, 44, 45 described below.

The lower frame 25 comprises two

lower die pads

27, 28, the two

lower die pads

27, 28 being arranged on respective opposite sides of the median longitudinal vertical plane. The two

lower die pads

27, 28 each have a first support surface 29 and a second support surface 30, the first support surface 29 and the second support surface 30 being inclined relative to each other at an angle corresponding to the angle α formed between the first flange 11 and the second flange 12 of the corner member 2. The first bearing surface 29 and the second bearing surface 30 are inclined such that the interior of the corner member 2 points downwards in the direction of the lower frame 25. In other words, the first and second bearing surfaces 29, 30 of each of the two

lower die pads

27, 28 are intended to receive the inner surfaces of the first and

second flanges

11, 12 of the corner member 2, respectively. The two

lower die pads

27, 28 are spaced apart from each other in the transverse direction such that: during the movement of the upper frame 26 from the rest position to the bent position, a stamping 31, described below, is allowed to be accommodated between the two

lower die pads

27, 28.

The two

lower die pads

27, 28 are each mounted to slide in a transverse horizontal direction on the lower frame 25 between a separated position shown in fig. 4 and a closed position not shown. To this end, as shown for example in fig. 5, each

lower die pad

27, 28 comprises two brackets 32, each of the two brackets 32 being mounted to slide on an associated guide rail 33 carried by the lower frame 25. A return member, such as an elastic member or a cylinder, not shown, urges the two

lower die pads

27, 28 toward the separated position of the

lower die pads

27, 28.

The lower frame 25 comprises abutment elements which are able to limit the travel of the

lower die pads

27, 28 with respect to the lower frame 25 and thus make it possible to define the separation position of said

lower die pads

27, 28 with respect to the lower frame 25. As shown for example in fig. 6, each abutment element comprises a flange 34, which flange 34 is fixed to the lower frame 25 along one of the edges of the lower frame 25 and which flange 34 comprises a threaded hole in which a laterally extending threaded screw 35 is positioned. The ends of the threaded screws 35 constitute abutment surfaces against which complementary abutment surfaces of one of the

lower die pads

27, 28 contact when the

lower die pads

27, 28 are in the separated position of the

lower die pads

27, 28.

For example, as shown in fig. 2, each

lower die pad

27, 28 advantageously comprises a base 36, said

lower die pad

27, 28 being mounted to slide on the lower frame 25 and two

wedges

37, 38 via the base 36, the two

wedges

37, 38 forming the first and second bearing surfaces 29, 30 of said

lower die pad

27, 28, respectively, and the two

wedges

37, 38 being mounted in a removable manner on the base 36. Here, the

wedges

37, 38 are mounted on the base 36 by means of angle irons 39. Each of the

wedges

37, 38 is fixed to an angle iron 39, for example by means of a set screw, and the angle iron 39 is fixed to the base 36, for example by means of a set screw. The shape of the angle iron 39 varies according to the angle a formed between the first flange 11 and the second flange 12 of the corner piece 2. The wedge-shaped

elements

37, 38 of the angle iron 39 and of the

lower die pad

27, 28 are then easily replaced by other angle irons 39 and wedge-shaped

elements

37, 38 adapted to bend the corner member 2 having a different angle α.

Furthermore, the bending system 1 comprises two

movable assemblies

40, 41, the

movable assemblies

40, 41 being for example visible in fig. 2 and being mounted movable on the upper frame 26.

The first movable assembly 40 is arranged to face the first support surface 29 of the

lower die pad

27, 28 and the second movable assembly 41 is arranged to face the second support surface 30 of the

lower die pad

27, 28. The first movable assembly 40 comprises two

upper die pads

42, 43, the two

upper die pads

42, 43 being arranged parallel to one and the other of the first support surfaces 29 of the

lower die pads

27, 28 and facing one and the other of the first support surfaces 29 of the

lower die pads

27, 28, and thus the two

upper die pads

42, 43 are intended to clamp the first flange 11 of the corner member 2 against the first support surfaces 29 of the

lower die pads

27, 28 when the

upper die pads

42, 43 are in the intermediate clamping position. In a similar manner, the second movable assembly 41 comprises two upper die pads 44, 45, the two upper die pads 44, 45 being arranged parallel to and facing one and the other of the second support surfaces 30 of the

lower die pads

27, 28, such that one and the other of the second support surfaces 30 of the lower die pads 27, 28: when the upper die pads 44, 45 are in the intermediate clamping position, the second flange 12 of the corner member 2 is clamped against the second bearing surface 30 of the

lower die pads

27, 28.

More specifically, the

upper die pads

42, 43, 44, 45 each comprise a main structure 46 and a clamping plate 47, the clamping plate 47 having a clamping surface intended to contact against the corner member 2. Each clamping plate 47 is mounted to slide on a respective main structure 48 in parallel to the transverse direction. Thus, the clamping plate 47 of each of the first movable assembly 40 and the second movable assembly 41 is movable between a closed position and a separated position. For this purpose, as shown in fig. 6, the clamping plate 47 includes a lateral groove 49, in which lateral groove 49 a sliding guide pin 50 is fixed to the main structure 48. A return member, e.g. an elastic member, not shown, urges the clamping plate 47 towards the separated position of the clamping plate 47.

When the

upper die pads

42, 43, 44, 45 are in the intermediate clamped position and the stamping 31 deforms the corner member 2 to form the corrugation 17, the clamping plates 47 of the

upper die pads

42, 43, 44, 45 and the

lower die pads

27, 28 are laterally movable, and therefore the

lower die pads

27, 28 and the clamping plates 47 move toward their closed position due to the pulling force exerted by the corner member 2 as the corner member 2 bends. This therefore avoids modification of the thickness of the corner member 2 when bending the corner member 2.

Each of the first movable assembly 40 and the second movable assembly 41 comprises a support 51 provided with a stamping 31, as shown in fig. 5, which stamping 31 is arranged laterally between the two

upper die pads

42, 43, 44, 45 of said first movable assembly 40 or second movable assembly 41. The stamping 31 of the first movable assembly 40 and the stamping 31 of the second movable assembly 41 are used to form the first portion 18 and the second portion 19 of the bellows 17, respectively. Each stamping 31 has a V-shaped cross-section corresponding to the generally triangular or semi-elliptical cross-section of the first and

second portions

18, 19 of the corrugation 17 to be formed. The V-shaped cross-section of the stamping 31 of the first movable assembly 40 extends lengthwise in a direction parallel to the first bearing surface 29 of the

lower die pads

27, 28, while the V-shaped cross-section of the stamping, not shown, of the second movable assembly 41 extends lengthwise in a direction parallel to the second bearing surface 30 of the

lower die pads

27, 28.

Each

upper die pad

42, 43, 44, 45 is mounted on a support 51 of the respective

movable assembly

40, 41 for movement in a direction normal to the clamping surface of the clamping plate 47. As shown for example in fig. 2, the movement of the

upper die pads

42, 43, 44, 45 with respect to the support 51 takes place by means of guiding means comprising, for each

upper die pad

42, 43, 44, 45, two guiding tubes 52, said two guiding tubes 52 being fixed to said

upper die pad

42, 43, 44, 45 and oriented orthogonally to the clamping surface of said

upper die pad

42, 43, 44, 45. The guide tube 52 slides within a hole formed in the support 51. Further, a plurality of elastic members 53, such as compression springs or air cylinders, have first ends supported on the

upper die pads

42, 43, 44, 45 and second ends supported on the support 51. Accordingly, the elastic member 53 exerts an elastic force, tending to move the

upper die pads

42, 43, 44, 45 and the support 51 away from each other in a direction orthogonal to the clamping surfaces of the

upper die pads

42, 43, 44, 45. In the illustrated embodiment, the first end of each resilient member 53 is received within a blind bore formed in the

upper die pad

42, 43, 44, 45 and the second end is received within a blind bore formed in the support 51.

The support 51 of each of the first movable assembly 40 and the second movable assembly 41 is mounted so as to slide with respect to the upper frame 26 in a direction parallel to the longitudinal direction of the stamping 31 of said first movable assembly 40 or second movable assembly 41. To this end, in the illustrated embodiment, the support 51 of each of the movable assemblies includes a rail 54, each rail 54 being mounted to slide within a bracket 55 fixed to the upper frame 26. In another alternative embodiment, the support 51 of each of the first and second

movable assemblies

40, 41 comprises two brackets, each of which is mounted to slide on a rail carried by the upper frame 26.

In the advantageous embodiment shown, the support 51 of each of the first movable assembly 40 and the second movable assembly 41 is mounted to slide on the intermediate element 56. In other words, in the embodiment shown, the bracket 55 of each first movable assembly 40 or second movable assembly 41 is fixed to one of the intermediate elements 56. Each of the intermediate elements 56 is fixed to the upper frame 26 by means of a removable upper wedge 57 shown in detail in fig. 10. The upper wedge 57 is fixed to the upper frame 26 by means of a fixing member on the one hand and to one of the intermediate elements 56 by means of a fixing member on the other hand. By replacing this upper wedge 57 with another upper wedge having another angle, the inclination of the clamping surfaces of the stamping 31 and the

upper die pads

42, 43, 44, 45 can thus easily be adapted to the bending of corner members 2 having different angles α.

Further, each of the first and second

movable assemblies

40, 41 includes a cam surface 58, as shown in fig. 5, the cam surface 58 being adapted to cooperate with a cam follower 59 mounted on the lower frame 25 when the upper frame 26 is moved from the rest position of the upper frame 26 to the flexed position of the upper frame 26. Here, the cam follower 59 is an idler roller having a horizontal axis extending in the lateral direction. Further, in the embodiment shown in fig. 5, a cam surface 58 is provided at the end of the stamping 31. The cam surface 58 is a surface orthogonal to the clamping surface of the

upper die pad

42, 43, 44, 45 of the first movable assembly 40 or the second movable assembly 41. Due to the sliding mounting of the first or second

movable assemblies

40, 41 on the upper frame 26 and due to the cooperation between the cam surfaces 58 and the cam followers 59, the support 51, and thus the stamping 31, of each of the first or second

movable assemblies

40, 41 is moved in a direction orthogonal to the clamping surfaces of the

upper die pads

42, 43, 44, 45 of the

movable assemblies

40, 41, that is to say in a direction orthogonal to the

flanges

11, 12 of the facing corner piece 2, when the upper frame 26 is moved vertically from the rest position of the upper frame 26 to the bent position of the upper frame 26.

Furthermore, the bending system 1 comprises means for deforming the bending line between the first flange 11 and the second flange 12 of the corner member 2.

The means for deforming the bending line comprise a central finger 60 and two

fingers

61, 62, as shown in particular in fig. 4. Two

fingers

61 and 62 are arranged laterally on respective opposite sides of the central finger 60. The means for deforming the bend line is intended to deform the region of the bend line 13 to impart a general W shape to the bend line 13 as described above with reference to fig. 12. For example, as shown in fig. 6, the center finger 60 is fixed to the lower frame 25 and protrudes upward in the direction of the upper frame 26. The central finger 60 is positioned so as to be arranged facing the intersection between the bending line 13 and the axes of the first and

second portions

18, 19 of the corrugation 17. For example, as shown in fig. 4, when the corner member 2 rests on the

lower die pads

27, 28, the central finger 60 is flush with the bend line 13 of the corner member 2. The

fingers

61, 62 are arranged on respective opposite sides of the central finger 60 to lie in the same transverse plane as the central finger 60. The

fingers

61, 62 are carried by the upper frame 26.

The two

fingers

61, 62 are intended to deform the bending line 13 to form the two

convex protrusions

22, 23 of the W-shaped deformation zone 21, while the central finger 60 is intended to form the concave depression 24.

As shown in fig. 7, two

fingers

61, 62 are mounted to slide on a finger support 63. The two

fingers

61, 62 are more specifically mounted to slide in a horizontal transverse direction between a separated position as shown in fig. 7 and a closed position, not shown. To this end, as shown in fig. 7, each

finger

61, 62 is fixed to a bracket that is mounted on a rail that is fixed to a finger support 63. The return member 64, here a coil spring, urges the two

fingers

61, 62 towards the separated position of the two

fingers

61, 62. Furthermore, the finger support 63 comprises

abutment elements

65, 66, which abutment

elements

65, 66 are able to limit the lateral travel of the

fingers

61, 62 and thus the separation position of said

fingers

61, 62. To this end, as shown in fig. 7, the

abutment elements

65, 66 each comprise a flange 67 fixed to the finger support 63. A transversely extending threaded screw 68 is mounted in a hole formed in each of the flanges 67. One of the ends of each of the threaded screws constitutes an abutment surface against which the bracket to which one of the

fingers

61, 62 is fixed contacts when the one of the

fingers

61, 62 is in its separated position.

Furthermore, the finger support 63 is kinematically connected to the upper frame 26 and to the

upper die pads

42, 43, 44, 45 by a hinge mechanism, as shown for example in fig. 2 and 6. The hinge mechanism comprises at least a first set of four links, namely a first upper link 68 and a second upper link 69 and a first lower link 70 and a second lower link 71. However, as shown for example in fig. 2, the articulation mechanism advantageously comprises a first set of four links and a second set of four links identical to each other, that is to say that each of the four links in one of the sets is parallel to and has the same articulation geometry axis as one of the four links in the other set. The two sets of four links are arranged on respective opposite sides of the transverse median plane, respectively, so that force symmetry can be ensured.

The two sets of four links are identical, only one of the two sets being described below. Returning to fig. 6, it can be seen that the first and second

upper links

68 and 69 are hinged to the upper frame 26 about the first and second geometric axes a and B, respectively. The first lower link 70 and the second lower link 71 are hinged on one and the other of the two

upper die pads

42, 43 of the same movable assembly, here the first movable assembly 40, respectively, about a third geometric axis C and a fourth geometric axis D. The first upper link 68 and the first lower link 70 are hinged to each other about a fifth geometric axis E, while the second upper link 69 and the second lower link 71 are hinged to each other about a sixth geometric axis F.

The six geometric hinge axes A, B, C, D, E and F are horizontal and parallel to the longitudinal direction. Axes a and B extend in a first horizontal plane, axes C and D extend in a second horizontal plane, and axes E and F extend in a third horizontal plane vertically arranged between the first and second horizontal planes.

The finger support 63 is connected to the first upper link 68 and/or the first lower link 70 by a first sliding connection. In the illustrated embodiment, the first sliding connection is formed by a physical shaft 72 and a ramp 73, the physical shaft 72 forming a fifth axis E that pivots the first upper link 68 relative to the first lower link 70, the ramp 73 being formed in the finger support 63. The physical shaft 72 slides horizontally in the slideway 73. The slideway 73 extends in a horizontal transverse direction. The finger support 63 is connected to the second lower link 69 and/or the second lower link 71 by a second sliding connection. The second sliding connection is formed by a physical shaft 74 and a slideway 75, the physical shaft 74 forming a sixth axis F which pivots the second upper link 69 relative to the second lower link 71, the slideway 75 being formed in the finger support 63 and the physical shaft 74 sliding horizontally in the slideway 75. The slide 75 extends in a horizontal lateral direction.

The six geometric axes A, B, F, D, C, E define a deformable articulated hexagon configured such that: during the movement of the upper frame 26 from the rest position of the upper frame 26 to the bent position of the upper frame 26, the hexagonally formed by the six geometric axes A, B, F, D, C, E deforms and more particularly flattens when the

upper die pads

42, 43, 44, 45 reach an intermediate clamping position of the

upper die pads

42, 43, 44, 45, in which the

upper die pads

42, 43, 44, 45 clamp the corner piece 2 against the

lower die pads

27, 28. When the

upper die pads

42, 43, 44, 45 are in the intermediate clamping position of the

upper die pads

42, 43, 44, 45, the vertical relative movement of the finger supports 63 and thus the

fingers

61, 62 thus becomes less than the vertical movement of the upper frame 26. In other words, the hinge mechanism is configured to form the following reducer: the reducer is such that the vertical relative movement of the

fingers

61, 62 is reduced relative to the vertical relative movement of the upper frame 25.

Furthermore, according to an advantageous embodiment, the vertical movement of the finger support 63 with respect to the upper frame 26 is guided by guiding means. In the embodiment shown, the guiding means comprise two guiding tubes 76, in particular shown in fig. 6, the two guiding tubes 76 being fixed to the finger support 63. The guide tube 76 extends vertically and slides within a hole 77 formed in the upper frame 26.

The hinge mechanism, i.e. the first set of four links and the second set of four links, is advantageously removably mounted. The kinematic nature of the finger support 63 with respect to the upper frame 26 can be modified according to the geometry of the corner member 2 desired to be bent.

Also, as shown in fig. 7 and 9, the

fingers

61, 62 and the central finger 60 are also removably secured to the bending system. Furthermore, it can be seen that the ends of the

fingers

61, 62 and the central finger 60 have a spherical shape.

The method of using the bending system 1 will now be described in detail.

First, a metal plate is bent in advance to form the corner member 2 including the first flange 11 and the second flange 12 inclined with respect to each other.

The corner member 2 manufactured in this way is then positioned on the first and second support surfaces 29, 30 of the

lower die pads

27, 28. The lobe α of the corner member 2 is directed towards the lower frame 25 such that the inner surfaces of the first flange 11 and the second flange 12 rest on the first bearing surface 29 and the second bearing surface 30 of the

lower die pads

27, 28.

When the corner member 2 has been positioned correctly, the upper frame 26 is moved downwards from the rest position of the upper frame 26 to the bent position of the upper frame 26. During the movement of the upper frame 26 to the bending position of the upper frame 26, the

upper die pads

42, 43, 44, 45 reach an intermediate clamping position in which the first flange 11 and the second flange 12 of the corner member 2 are clamped between the clamping plates 47 of the

upper die pads

42, 43, 44, 45 and the

lower die pads

27, 28.

When the

upper die pads

42, 43, 44, 45 reach the intermediate clamping position of the

upper die pads

42, 43, 44, 45, the cam surface 58 of each of the first and second

movable assemblies

40, 41 cooperates with a respective cam follower 59 rigidly attached to the lower frame 25 such that: as the upper frame 26 continues to travel toward the flexed position of the upper frame 26, the first and second

movable assemblies

40, 41 move toward each other and each stamping 31 moves in a manner orthogonal to either the first or

second flanges

11, 12 of the corner component 2. Thus, the stamping 31 deforms the first flange 11 and the second flange 12 of the corner member 2, thereby forming the first portion 18 and the second portion 19 of the corrugation 17.

The corner member 2 is clamped between the bearing surfaces of the

lower die pads

27, 28 and the clamping surfaces of the clamping plates, said corner member 2 being deformed by the stamping exerts a traction force on the

lower die pads

27, 28 and the clamping plates 47, which moves the

lower die pads

27, 28 and the clamping plates 47 to the closed position of the

lower die pads

27, 28 and the clamping plates 47. The

lower die pads

27, 28 and the clamping plate 47 are then moved to the closed position of the

lower die pads

27, 28 and the clamping plate 47 in synchronism with the movement of the stamping 31. This makes it possible to ensure that: when the corner member 2 is being bent, there is no or little modification of the thickness of the corner member 2.

Furthermore, the means for deforming the bending lines 13 deform the bending lines at the same time as the first flange 11 and the second flange 12 of the corner member 2 are deformed by the stamping 31. The two fingers deform the bending line 13 towards the lower frame 25 on respective opposite sides of the central finger 60, while the central finger 60 exerts a reaction force in the direction of the upper frame 26, which makes it possible to form a deformation zone in the bending line 13 having the general W shape described above. Upon deformation, the corner member 2 also exerts a lateral force on the

fingers

61, 62, which causes the

fingers

61, 62 to move.

Referring to fig. 15, a cut-away view of a methane tanker 170 shows a generally prismatic sealed and insulated tank 171 mounted in a double hull 172 of the tanker. The walls of the tank 171 include: a primary sealing barrier intended to be in contact with LNG contained in the tank; a secondary sealing barrier disposed between the primary sealing barrier and the double hull 172 of the ship; and two insulating barriers respectively disposed between the primary and secondary sealing barriers and between the secondary sealing barrier and the double case 172.

The loading/unloading pipelines 173, which are arranged on the top deck of the ship in a manner known per se, can be connected to an offshore or port terminal by means of suitable connectors for transferring LNG cargo from the tanks 171 or to the tanks 171.

Fig. 15 shows an example of an offshore terminal comprising a loading and unloading station 175, an underwater pipeline 176 and a land facility 177. The loading and unloading station 175 is a stationary offshore facility that includes a mobile arm 174 and a tower 178 supporting the mobile arm 174. The traveling arm 174 carries a bundle of insulated flexible tubes 179 that can be connected to the load/unload conduit 173. The orientable moving arm 174 is adapted to all methane tanker loading targets. A connecting conduit, not shown, extends inside the tower 178. The loading and unloading station 175 enables the methane tank 170 to be loaded and unloaded from the onshore facility 177, or the loading and unloading station 175 enables the methane tank 170 to be loaded and unloaded to the onshore facility 177. The onshore facility 177 comprises liquefied gas storage tanks 180 and connection pipes 181 connected to the loading or unloading station 175 via underwater pipes 176. The underwater piping 176 enables the transfer of liquefied gas between the loading or unloading station 175 and the onshore facility 177 over a long distance, e.g., 5km, which enables the methane tanker 170 to remain located at a greater distance from the shore during loading and unloading operations.

Pumps on board the ship 170, and/or on land facilities 177, and/or loading and unloading stations 175 are used to generate the pressure required to deliver the liquefied gas.

Alternatively, the corner members described above may equally be used to manufacture cans comprising only one sealing membrane. Such tanks are generally used for transporting liquid gases boiling above-55 ℃ at atmospheric pressure.

While the invention has been described in connection with a number of specific embodiments, it is evident that the invention is in no way limited to these embodiments and that the invention comprises combinations of the described means and all technical equivalents, if they fall within the scope of the invention as defined by the claims.

Use of the verb "comprise," "include" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. A corner member (2) for constructing a sealing membrane (3) for a can, the corner member (2) comprising a first flange (11) and a second flange (12), the first flange (11) and the second flange (12) being inclined relative to each other at an angle α between 1 ° and 179 ° and comprising 1 ° and 179 °, and the first flange (11) and the second flange (12) being joined at the level of a bending line (13), the corner member (2) comprising a corrugation (17), the corrugation (17) intersecting the bending line (13) and extending from one end to the other end of the corner member (2) to enable the corner member (2) to be deformed in a direction transverse to the corrugation (17), the corrugation (17) comprising:

-a first portion (18), said first portion (18) being formed in said first flange (11) and extending from a first edge of said corner part (2) in the direction of said bending line (13);

-a second portion (19), said second portion (19) being formed in said second flange (12) and extending from a second edge of said corner member (2) in the direction of said bending line (13);

-a central portion (20), the central portion (20) being formed astride the first flange (11) and the second flange (12), the central portion (20) extending between the first portion (18) and the second portion (19) and being aligned with the first portion (18) and the second portion (19);

the central portion (20) has, in a section on a plane passing through the bending line (13), an inverted W-shaped profile comprising a concave recess (24) and two convex protrusions (22, 23), the bending line lying in the plane dividing the angle formed by the first and second flanges into two equal half angles, the two convex protrusions (22, 23) being arranged laterally on respective opposite sides of the concave recess (24).

2. Corner part (2) according to claim 1, wherein the corner part (2) has a geometric configuration in the form of a rectangular part which can be unfolded flat.

3. Corner part (2) according to claim 1 or 2, wherein the concave recess (24) has a lower end in the shape of a circular arc or an elliptical arc.

4. Corner part (2) according to claim 1 or 2, wherein the concave recess (24) has the following depth and width: the depth and width decreasing in the direction of the corrugations (17) from the bend line (13) to the first portion (18) such that the concave recess (24) engages the top of the first portion (18); and the depth and width decrease in the direction of the corrugations (17) from the bend line (13) to the second portion (19) such that the concave recess (24) engages the top of the second portion (19).

5. Corner part (2) according to claim 1 or 2, wherein the first portion (18), the second portion (19) and the convex protrusions (22, 23) protrude towards the inside of the angle a.

6. Corner piece (2) according to claim 1 or 2, wherein the first portion (18) and the second portion (19) have a semi-elliptical or triangular profile of constant height.

7. Corner part (2) according to claim 1 or 2, wherein the first flange (11) and the second flange (12) have a substantially rectangular shape.

8. A sealed and thermally insulated tank for storing a fluid, the tank comprising a sealing membrane (3), the sealing membrane (3) comprising:

-a plurality of corrugated metal plates (8) welded to each other, the metal plates (8) comprising at least one corrugation protruding towards the interior of the can; and

-at least one corner part (2) according to any one of claims 1 to 7, the corner part (2) connecting the metal plates of the sealing membrane (3) at a junction between two walls of the tank.

9. A vessel (170) for transporting a fluid, the vessel comprising a double hull (172) and a tank (171) according to claim 8 arranged in the double hull.

10. A fluid transfer system, the fluid transfer system comprising: the vessel (170) of claim 9; -insulated piping (173, 179, 176, 181) arranged such that the tanks (171) mounted in the double hull of the vessel are connected to a floating or onshore storage facility (177); and a pump for: the method may further comprise driving a flow of fluid from the floating or onshore storage facility through the insulated pipeline to the tank of the vessel or driving a flow of the fluid from the tank of the vessel through the insulated pipeline to the floating or onshore storage facility.

11. A method of loading or unloading a vessel (170) according to claim 9, wherein fluid is transported from a floating or onshore storage facility (177) to the tank (171) of the vessel through insulated piping (173, 179, 176, 181) of the fluid transfer system according to claim 10, or from the tank (171) of the vessel to the floating or onshore storage facility (177).

12. Bending system (1) for forming a corner part (2) according to any one of claims 1 to 7, comprising:

-an upper frame (26) and a lower frame (25), the upper frame (26) and the lower frame (25) being vertically movable relative to each other between a rest position and a bent position;

-two lower die pads (27, 28), each having a first support surface (29) and a second support surface (30), the first support surface (29) and the second support surface (30) being inclined with respect to each other at the angle α and intended to receive the first flange (11) and the second flange (12), respectively, of the corner member (2), the lower die pads (27, 28) being mounted to slide on the lower frame (25) in a transverse direction between a closed position and a separated position;

-two movable assemblies (40, 41), two of said movable assemblies (40, 41) being mounted on said upper frame (26) and being arranged facing said first support surface (29) and said second support surface (30) of said lower die pad (27, 28), respectively, each movable assembly (40, 41) comprising:

-a support (51);

-a stamping (31), the stamping (31) being fixed to the support (51) and intended for forming the first portion (18) or the second portion (19) of the bellows (17) in one or the other of the first flange (11) and the second flange (12) of the corner part (2);

-two upper die pads (42, 43, 44, 45) arranged laterally on respective opposite sides of the stamping (31), each upper die pad (42, 43, 44, 45) comprising a main structure (46) and a clamping structure (47), the clamping structure (47) having a clamping surface arranged facing one of the first and second support surfaces (29, 30) of the lower die pad (27, 28) and parallel to said one of the first and second support surfaces (29, 30) of the lower die pad (27, 28), such that: in an intermediate clamping position, the clamping surface clamps the corner member (2) against one of the first and second bearing surfaces (29, 30) of the lower die pads (27, 28), the clamping structure (47) being mounted to slide laterally on the main structure (46) of the upper die pads (42, 43, 44, 45), each upper die pad (42, 43, 44, 45) being mounted to be movable on the support (51) of the movable assembly (40, 41) in a direction orthogonal to the clamping surface of the upper die pad (42, 43, 44, 45) such that: during the relative movement from the rest position to the bending position, when the upper die pad (42, 43, 44, 45) reaches the intermediate clamping position, the upper die pad (42, 43, 44, 45) moves relative to the upper frame (26) in the direction orthogonal to the clamping surface,

-the support (51) of each movable assembly (40, 41) is mounted so as to be movable on the upper frame (26) in a direction parallel to the longitudinal direction of the stamping (31) of the movable assembly (40, 41);

-the bending system further comprises means for deforming the bending wire (13), the means for deforming the bending wire (13) comprising:

-a central finger (60), said central finger (60) being intended to be arranged facing the intersection between the bending line (13) and the corrugation (17) to be formed, said central finger (60) being carried by the lower frame (25) and intended to form the concave depression (24); and

-two fingers (61, 62), the two fingers (61, 62) being intended for deforming the bending line (13), the two fingers (61, 62) being arranged laterally on respective opposite sides of the central finger (60), the two fingers (61, 62) being mounted movable on the upper frame (26) and being arranged to form one and the other of the two convex protrusions (22, 23), respectively.

13. Bending system (1) according to claim 12, wherein the two fingers (61, 62) are mounted on a finger support (63), the finger support (63) being kinematically connected to the upper frame (26) and to at least two of the upper die pads (42, 43, 44, 45) of one of the movable assemblies (40, 41) by a hinge mechanism configured to form a reducer such that: during the relative movement between the upper frame (26) and the lower frame (25) from the rest position to the bent position, when the upper die pad (42, 43, 44, 45) is in the intermediate clamping position, the vertical relative movement of the finger support (63) is reduced relative to the vertical relative movement between the upper frame (26) and the lower frame (25).

14. Bending system (1) according to claim 13, wherein the hinge mechanism comprises at least a first set of four links comprising: -a first upper link (68), said first upper link (68) being hinged on said upper frame (26) about a first geometric axis (a); -a second upper link (69), said second upper link (69) being hinged on said upper frame (26) about a second geometric axis (B); -a first lower link (70), said first lower link (70) being hinged on one of said upper die pads (42, 43, 44, 45) about a third geometric axis (C); and a second lower link (71), said second lower link (71) being hinged on a further one of said upper die pads (42, 43, 44, 45) about a fourth geometric axis (D), said first upper link (68) and said first lower link (70) being hinged to each other about a fifth geometric axis (E), said second upper link (69) and said second lower link (71) being hinged to each other about a sixth geometric axis (F), said first geometric axis (a), said second geometric axis (B), said third geometric axis (C), said fourth geometric axis (D), said fifth geometric axis (E) and said sixth geometric axis (F) being parallel to a horizontal direction orthogonal to said preformed bending line (13), said finger support (63) being connected to said first upper link (68) and/or to said first lower link (70) by means of a first sliding connection on the one hand, and said finger support (63) being connected to said second support (63) or to said finger support (71) by a second sliding connection on the other hand.