Fuel tank equipped with a reinforcement of its peripheral wall

Abstract

The invention relates to a fuel tank (10) made of plastics material for a motor vehicle, comprising: - a shell (12), comprising two areas (14, 16) which are delimited by a parting line (18), and forming an internal volume (20) of the tank (10), the shell (12) comprising a peripheral wall (22) comprising the parting line (18); and - a reinforcing element (24) for reinforcing the peripheral wall (22), the reinforcing element being substantially inside the tank (10) and extending from the parting line (18) towards the inside of the tank (10), the reinforcing element (24) being attached at a first attachment point (26) of a first internal face (28) of the peripheral wall (22), and at a second attachment point (30) internal to the tank (10) or of a second internal face of the peripheral wall (22). A first portion (34) of the reinforcing element (24) is attached in the parting line (18) at the first attachment point (26).

Description

Fuel tank equipped with a reinforcement of its peripheral wall

[0001] The invention relates to a plastic fuel tank for a motor vehicle, in particular a petrol tank, having a reinforcing element for its peripheral walls, as well as a method for manufacturing this tank.

[0002] Fuel tanks are subjected to internal pressure that tends to deform the walls. Typically, these tanks extend over a short height and internal reinforcement elements are used to connect the top and bottom walls of the tank so that these walls can withstand the internal pressure. One such example of a reinforcement element for the top and bottom walls of a fuel tank is described in US9027781. For taller tanks, it is necessary to also reinforce the peripheral wall of the tank, between the bottom and top walls.

[0003] Document WO2012 / 139961 already discloses a fuel tank comprising a reinforcing element for the peripheral wall. The tank is manufactured by blow molding using a method requiring the introduction into a parison of pieces of the reinforcing element which are fixed to two locations of the parison facing each other, by welding or riveting. After molding the parison, an opening is made in the wall of the tank and through this opening, the pieces are connected to form a pillar. Thus, a fuel tank is obtained in which a reinforcing element is fixed to the internal face of the peripheral wall of the tank. This method is quite complex to implement, and requires the creation of an opening in the wall of the tank, which subsequently constitutes a source of leaktightness of the tank.

[0004] To more simply manufacture a plastic fuel tank comprising an internal component fixed to its wall, it has been proposed in document US4952347 to introduce inside a parison the component carried by an insertion element, so that the insertion element is pinched in the internal peripheral surface of the parison between two cavities of the mold, while leaving a part of the insertion element protruding, external to the parison. Thus, the component is fixed in the joint plane of the tank when the mold is closed. After molding, the external part of the insertion element is then cut. Such a method is not possible for the manufacture of a fuel tank, in particular for a gasoline tank, because the wall of such a tank must act as an obstacle to fuel vapors and have a suitable fuel vapor permeation rate. The same is true at the joint plane.However, in the state-of-the-art tank, the cut-out area of ​​the insertion element constitutes a source of leakage.

[0005] Also known from document JPS5579121 is a plastic tank made from a parison and comprising a separation plate fixed in the joint plane of the tank. Also known from document FR3053936 is a multi-shell fuel tank, in which a component can be inserted into a space formed between the two shells. The outer shell consists of at least two shells and the component is fixed to the outer shell at the joint plane of its shells.

[0006] The invention aims in particular to provide a plastic fuel tank with reinforcement of its peripheral wall, which does not have the drawbacks mentioned above.

[0007] To this end, the invention relates to a plastic fuel tank for a motor vehicle, the tank comprising: - a shell made from a parison, the shell comprising two zones delimited by a joint plane and forming an internal volume of the tank intended to contain fuel, the shell comprising a peripheral wall comprising the joint plane, and - a reinforcing element of the peripheral wall, essentially internal to the tank, and extending from the joint plane towards the inside of the tank, the reinforcing element of the peripheral wall being fixed on the one hand at a first fixing point of a first internal face of the peripheral wall, and on the other hand at a second fixing point, said second fixing point being:. internal to the tank, or. one or more points of a second internal face of the peripheral wall.In the tank according to the invention, a first part of the reinforcing element of the peripheral wall is fixed in the joint plane at the level of the first fixing point.

[0008] Thus, a fuel tank is proposed in which the reinforcing element of the peripheral wall is fixed in the joint plane, although it may seem dissuasive to use the inside of the joint plane as a fixing point in a fuel tank, due to the risks of evaporative loss. In the tank according to the invention, the risk of evaporative loss is controlled by the fact that the reinforcing element is fixed on an internal face of the peripheral wall. In other words, in the tank according to the invention, the reinforcing element is entirely surrounded by the internal face of the peripheral wall. The peripheral wall is not interrupted at the joint plane. The first part of the reinforcing element of the peripheral wall is surrounded by the peripheral wall, which reduces leaks. This type of fixing is particularly advantageous because the joint plane constitutes a robust zone of double thickness of the tank wall.The manufacture of this tank does not require making an opening in its wall after molding, which is particularly advantageous in terms of gas permeability.

[0009] In the fuel tank within the meaning of the invention, the shell generally consists of a multi-layer structure, and comprises at least one structural layer and a barrier layer, generally at least one barrier layer surrounded by at least two structural layers. In this tank, the barrier layer bypasses the first part of the reinforcing element. The structural layer is a layer of polymer material, typically polyethylene or polyamide, which gives the multi-layer structure its mechanical strength. The barrier layer is a layer of polymer material, typically an ethylene-vinyl alcohol copolymer (EVOH), which gives very low gas permeation.

[0010] The reinforcing element is therefore positioned at a particularly fragile joint plane, because the joint plane of a multi-layer wall is more fragile than that of a single-layer wall. Indeed, in these multi-layer walls, only the structural layers contribute to the mechanical resistance. Furthermore, the formation of the joint plane in a multi-layer wall is particularly delicate to achieve, because during compression at the closing of the mold, the integrity of the structure of each layer must be preserved. It was therefore counter-intuitive to fix the reinforcing element of the peripheral wall in the joint plane of a tank equipped with a multi-layer wall.

[0011] The invention is particularly advantageous when the tank is relatively high, for example when it has a height greater than 200 mm, preferably greater than 300 mm.

[0012] “Fuel” means a fuel according to standard EN228 in particular, composed of a mixture of light hydrocarbons, mainly C7H16.

[0013] For the purposes of the invention, the term "internal" means an element located inside the internal volume of the tank, in contact with the fuel contained in the tank. The internal reinforcing element of the tank according to the invention is said to be "essentially internal to the tank" because the majority of it is located inside the internal volume of the tank, with the exception of the portion located in the joint plane. The term "one point or several points of a second internal face of the peripheral wall" means one or several fixing points within the peripheral wall.

[0014] The parting line is a weld line between the two areas of the parison intended to form the tank wall on their periphery. This line corresponds to the location of the mold closure. At the parting line, the parison is compressed by the mold. Thus, at the first attachment point, the first part of the peripheral wall reinforcement element is overmolded into the parting line.

[0015] The invention is particularly advantageous when the fuel is gasoline.

[0016] The invention also relates to a plastic fuel tank for a motor vehicle, the tank comprising: - a shell made from a parison, the shell comprising two zones delimited by a joint plane and forming an internal volume of the tank intended to contain fuel, the shell comprising a peripheral wall comprising the joint plane, and - a reinforcing element of the peripheral wall, essentially internal to the tank, and extending from the joint plane towards the inside of the tank, the reinforcing element of the peripheral wall being fixed on the one hand at a first fixing point of a first internal face of the peripheral wall, and on the other hand at a second fixing point, said second fixing point being internal to the tank.In the tank according to the invention, a first part of the reinforcing element of the peripheral wall is fixed in the joint plane at the first fixing point, and the shell of the fuel tank further comprises a first wall and a second wall substantially located opposite each other with respect to the peripheral wall, and the second fixing point internal to the tank is located at a support piece extending between the first wall and the second wall. The support piece is fixed to at least one of these walls.

[0017] As the second fixing point is internal to the tank, and fixed to a support part, the reinforcing element of the peripheral wall thus has a reduced length, limited to the distance to be covered between the first fixing point and the support part, which promotes the resistance of this reinforcing element to internal pressure.

[0018] Furthermore, such a peripheral wall reinforcement element is easy to install because the support piece is attached to the first and / or second wall of the parison before the mold is closed. The support piece, to which the peripheral wall reinforcement element is attached, helps to maintain the latter before the mold is closed in a position allowing its first part to be located opposite a portion of the parison intended to form the parting plane.

[0019] Optionally, the peripheral wall is substantially vertical. Also optionally, the plane of the joint plane is perpendicular to the peripheral wall.

[0020] Advantageously, at the outer end of the joint plane, the two zones of the shell forming the joint plane are brought closer together, which gives the end of the joint plane a more compact appearance compared to the rest of the joint plane. This local bringing together of the two zones makes it possible to reduce the distance between the barrier layers of each of the two zones. In fact, there is a maximum of 100 µm between the two barrier layers. This standardizes the thickness of the shell in the joint plane, between the zone in which the reinforcing element is present, and the end zone. This reduces the leakage rate in the zone where the reinforcing element is not present.

[0021] Preferably, the parison is tubular.

[0022] Advantageously, the peripheral wall reinforcement element comprises a rupture zone configured so that the reinforcement can deform or break in the event of an impact. The rupture zone may consist of a local thinning or an orifice provided in the reinforcement. In the event of an impact, the rupture zone will break, thus preventing rupture of the tank wall.

[0023] Depending on other optional fuel tank features, taken alone or in combination:

[0024] – The second attachment point is one or more points on the second internal face, and is located in the joint plane. In this embodiment, a second part of the reinforcing element of the peripheral wall is fixed in the joint plane at the second attachment point. This uses a relatively simple-to-manufacture reinforcing element, the function of which is to connect at least two points on the internal faces of the peripheral wall of the tank. The second attachment point has the same advantages in terms of attachment as the first attachment point.

[0025] In the case where the second fixing point comprises two points of the second internal face, these two points are advantageously distributed on either side of a straight line located in the plane of the joint plane, and connecting the first fixing point to a point of the second internal face, opposite the first fixing point with respect to the internal volume of the tank, and these two points are arranged opposite each other with respect to the straight line. Advantageously, a point of the second fixing point is located on the straight line.

[0026] The peripheral wall reinforcing element may have the shape of a linear beam. The peripheral wall reinforcing element may also have an angled shape. In one embodiment, the peripheral wall reinforcing element may also have a fork shape comprising at least two branches. In this case, the second attachment point comprises attachment points distributed around the straight line, and the peripheral wall reinforcing element comprises as many second parts as branches.

[0027] – The fuel tank shell further comprises a first wall and a second wall substantially located opposite each other with respect to the peripheral wall, and the second attachment point is internal to the tank, and located at a support piece extending between the first wall and the second wall, the support piece being fixed to at least one of these walls, the support piece being able to be an internal reinforcement of the first and second walls, an anti-sway baffle, or a support piece arranged in the tank to provide a second attachment point. In this embodiment, the reinforcing element of the peripheral wall thus has a reduced length, limited to the distance to be covered between the first attachment point and the support piece, which promotes the resistance of this reinforcing element to internal pressure.Furthermore, when attached to a support part having another functionality in the tank, such as a baffle or a reinforcement of the first and second walls, such a peripheral wall reinforcement element makes it possible to limit the size and the quantity of material used. In addition, such a peripheral wall reinforcement element is easy to install because the support part is attached to the first and / or second walls of the parison before the mold is closed. The support part, to which the peripheral wall reinforcement element is attached, helps to maintain the latter before the mold is closed in a position allowing its first part to be located opposite a portion of the parison intended to form the joint plane.Advantageously, the support piece is fixed to both the first wall and the second wall, which is the case for an internal reinforcement of the first and second walls, which is generally welded to the first and second walls.Advantageously, the reinforcing element of the peripheral wall and the support piece are manufactured in a single piece, for example are molded.Advantageously, stiffening ribs are positioned at the junction of the reinforcing element of the peripheral wall and the support piece.In one embodiment, the first and second walls are substantially perpendicular to the peripheral wall. In one embodiment, the first and second walls are parallel to the plane of the joint plane.

[0028] – The support piece is an internal reinforcement of the first and second walls. This provides a solution for reinforcing both the peripheral wall and the first and second walls. In one embodiment, the internal reinforcement of the first and second walls serves as a support piece for at least two reinforcing elements of the peripheral wall. In one embodiment, the first attachment points of two reinforcing elements of the peripheral wall are aligned.

[0029] Preferably, the internal reinforcing element of the first and second walls is either in the form of a pillar in the form of a column, preferably cylindrical, or in the form of a diabolo, or in the form of a retention member. Preferably, the retention member comprises a wall provided with a central recess, a portion of the wall comprising reinforcing ribs. The wall of the retention member may be flat or curved. Said reinforcing element of the first and second walls preferably comprises, on its two ends, two overmolded parts made of a material capable of being welded to the first and second walls of the tank. The internal reinforcing element of the first and second walls is preferably made of a central portion based on polyoxymethylene (POM), polyphthalamide (PPA), polyketone (PK), polyamide (PA), metal and two overmolded parts made of high-density polyethylene (HDPE).The internal reinforcing element of the first and second walls preferably comprises a zone of mechanical weakness capable of causing the breakage of said element when the latter is subjected to high stresses emanating from the forces exerted on the tank. This zone of mechanical weakness is in the form of a weaker section, at least one notch or a smaller thickness of the wall. The internal reinforcing element of the first and second walls may comprise a hollow portion, more particularly in the central portion of the reinforcing element.

[0030] – The peripheral wall reinforcing element is manufactured, at least in its first part, from a material identical to the material of an internal layer of the peripheral wall. Thus, the peripheral wall reinforcing element can be fixed by welding to the internal layer of the peripheral wall, inside the joint plane. In this embodiment, the heat of the portion of the parison placed in contact with the first part of the peripheral wall reinforcing element melts a surface portion of the first part, thus allowing the first part to be fixed in the joint plane. In this embodiment, the first part is for example made of polyethylene or polyamide, depending on the material of the internal layer of the peripheral wall. Advantageously, when the second fixing point is one or more points on the second internal face, the second part(s) have the same characteristic.Alternatively, the reinforcing element of the peripheral wall is made of a material different from the material of the inner layer of the peripheral wall. Materials such as polyamide and polyacetal are particularly advantageous because they have good tensile strength. In this embodiment, the first part has through holes and the fixing is carried out by riveting, that is to say by the fusion together of the two inner layers of the shell in the joint plane, through the hole, which constitutes a good mechanical anchoring. Advantageously, ribs constitute the periphery of the through holes. Indeed, during molding, air could be trapped in the through holes, which would be unfavorable to fusion. The ribs present on the periphery of the through holes prevent air from being trapped in the through holes. The ribs can also be straight.They may be located on the periphery of the first part. Preferably, the ribs have a height relative to the solid surface of the first part of the reinforcing element of the peripheral wall of approximately 1 mm, and a width of approximately 0.7 mm. The term "width of the rib" means its small dimension measured in a plane parallel to the surface of the first part. Advantageously, when the second fixing point is a point or several points on the second internal face, the second part or parts have the same characteristic.

[0031] – The first part has ribs and / or depressions on its surface. The ribs promote fusion because they are fused to the inner layer of the peripheral wall, and the depressions allow mechanical anchoring. Advantageously, the depressions are through holes, also allowing fastening by riveting. Preferably, ribs constitute the periphery of the depressions. Preferably, the first part has ribs, and more preferably ribs and depressions. Preferably, the ribs have a height relative to the solid surface of the first part of the reinforcing element of the peripheral wall of approximately 1 mm, and a width of approximately 0.7 mm. Advantageously, when the second fixing point is one or more points on the second inner face, the second part(s) have the same characteristic.

[0032] – The tank shell has grooves in the vicinity of the first attachment point. The grooves made near the overmolding area of ​​the reinforcing element locally allow the tank shell to bend, thus dissipating the energy that would be due to an impact. Indeed, the presence of the reinforcing element could generate a fragility of the tank wall in its vicinity, making this area more fragile in the event of an impact. Preferably, the grooves extend along straight lines parallel to the length of the first part. The length of the first part is its dimension in a plane parallel to the joint plane, in a radial direction relative to the central axis of the tank.

[0033] – The first part has a length of at least 10 mm, preferably 15 mm, and a width of at least 20 mm, preferably 30 mm. These dimensions allow effective anchoring of the reinforcement of the peripheral wall. Advantageously, when the second fixing point is a point or points on the second internal face, the second part or parts have the same characteristics.

[0034] The invention also relates to a method for manufacturing the tank as described above, comprising the following steps: - the peripheral wall reinforcing element is mounted on an insertion member, - the parison in the molten state and the peripheral wall reinforcing element mounted on said insertion member are introduced into a mold comprising cavities, so that each zone of the parison is positioned opposite a cavity, and so that the peripheral wall reinforcing element is surrounded by the parison, and the first part of the peripheral wall reinforcing element is located opposite an internal portion of a peripheral part of the mold cavities, - the mold is brought into an intermediate closed position so that the peripheral wall reinforcing element is held between the cavities, - the insertion member is removed,- the mold is brought into a final closing position so that the first part of the reinforcing element of the peripheral wall is clamped by the internal portion of the peripheral part of the mold cavities and the final blowing of the parison is carried out by pressing it onto the mold cavities using pressurized gas, and - the tank is removed from the mold., Brief description of the figures

[0035] The invention will be better understood on reading the following description given solely by way of example, and made with reference to the appended drawings in which:

[0036] is a partial perspective view of a fuel tank according to one embodiment of the invention, in which a reinforcing element of the peripheral wall is visible in transparency.

[0037] is a view of a section of part of the hull of the tank of the.

[0038] is a schematic view of a section of the tank at the joint plane, in which the reinforcing element of the peripheral wall is not shown.

[0039] is a representation of four successive steps of the method of manufacturing a fuel tank according to one embodiment of the invention.

[0040] is a perspective view of a part of the joint plane of the tank according to the invention, in which a part of a reinforcing element of the peripheral wall is visible in transparency.

[0041] is a view of a cross-section of the joint plane and a portion of the reinforcing element of the peripheral wall of the tank of the.

[0042] is a top view of the portion of the peripheral wall reinforcement element of the.

[0043] is a perspective view of a portion of the joint plane of a tank according to an embodiment of the invention, in which a portion of the reinforcing element of the peripheral wall of the tank is visible in transparency.

[0044] is a perspective view of the portion of the peripheral wall reinforcing element of the. Detailed description

[0045] Figures 1 and 2 show a fuel tank according to an embodiment of the invention, designated by the general reference 10. In the other figures, elements similar to those of the preceding figures are designated by identical references. The tank 10 is a plastic tank for a motor vehicle. It comprises a shell 12 which comprises two zones 14, 16 delimited by a joint plane 18 and forming an internal volume 20 of the tank 10. The internal volume 20 is intended to contain fuel. The shell 12 comprises a peripheral wall 22 comprising the joint plane 18.

[0046] The tank 10 also comprises a reinforcing element 24 of the peripheral wall 22, essentially internal to the tank 10. The reinforcing element 24 extends from the joint plane 18 towards the interior of the tank 10. The reinforcing element 24 of the peripheral wall 22 is fixed at a first fixing point 26 of a first internal face 28 of the peripheral wall 22. The reinforcing element 24 of the peripheral wall 22 is also fixed at a second fixing point 30, visible on the.

[0047] In the embodiment of the, the second attachment point 30 is internal to the tank 10.

[0048] In another embodiment, shown diagrammatically in the, which is a schematic view of a section of the tank at the joint plane, the second fixing point 30 comprises several points of a second internal face 32 of the peripheral wall 22. A straight line d located in the plane of the joint plane is shown, and connecting the first fixing point 26 to a point 33 of the second internal face 32, opposite the first fixing point 26 with respect to the internal volume 20 of the tank 10. In the embodiment shown diagrammatically in the, the second fixing point 30 comprises two points distributed on either side of the straight line d. These two points 30 are arranged opposite each other with respect to the straight line d. Another point of the second fixing point 30 is located on the straight line d.

[0049] In the tank 10 according to the invention, a first part 34 of the reinforcing element 24 of the peripheral wall 22 is fixed in the joint plane 18 at the level of the first fixing point 26.

[0050] As seen for example in the, the reinforcing element 24 of the peripheral wall 22 is entirely surrounded by the peripheral wall 22. The peripheral wall 22 is not interrupted at the joint plane 18. The first part 34 of the reinforcing element 24 of the peripheral wall is surrounded by the peripheral wall. The shell 12 is made of a structure in several layers, not shown, and comprises at least one structural layer and a barrier layer. The barrier layer bypasses the first part 34 of the reinforcing element 24.

[0051] In the embodiments shown, the peripheral wall 22 is substantially vertical, and the plane of the joint plane 18 is perpendicular to the peripheral wall 22.

[0052] As can be seen in particular on the, at the outer end 36 of the joint plane 18, the two zones 14, 16 of the shell 12 forming the joint plane 18 are brought closer together, which gives the end 36 of the joint plane 18 a more compact appearance compared to the rest of the joint plane. This local bringing together of the two zones 14, 16 makes it possible to reduce the distance between the barrier layers of each of the two zones 14, 16.

[0053] It can be seen that the shell 22 of the tank 10 further comprises a first wall 36 and a second wall 38 substantially located opposite each other relative to the peripheral wall 22. In the embodiment of the, the second attachment point 30 is internal to the tank 10, and located at a support piece 40 extending between the first wall 36 and the second wall 38. The support piece 40 is fixed to at least one of these walls 36, 38. In the embodiment of the, the support piece 40 is an internal reinforcement of the first 36 and second 38 walls, and this internal reinforcement 40 of the first 36 and second 38 walls is fixed to the first 36 and second 38 walls.

[0054] In the embodiment of the, the reinforcing element 24 of the peripheral wall 22 and the internal reinforcement 40 of the first 36 and second 38 walls are manufactured in a single piece. They are molded. In the embodiment of the, stiffening ribs 42 are positioned at the junction of the reinforcing element 24 of the peripheral wall and the support piece 40.

[0055] In the embodiment shown in the, the first 36 and the second 38 wall are substantially perpendicular to the peripheral wall 22, and are parallel to the plane of the joint plane 18.

[0056] Furthermore, the internal reinforcement 40 of the first 36 and second 38 walls shown on the laser of the support part for two reinforcement elements 24 of the peripheral wall, and the first fixing points 26 of the two reinforcement elements 24 of the peripheral wall are aligned.

[0057] In the embodiment shown in the, the reinforcing element 24 of the peripheral wall 22 is made of a material identical to the material of an inner layer of the peripheral wall 22. As seen in particular in Figures 6 and 9, the first part 34 has ribs 44 and depressions 46 on the surface. The ribs 44 promote fusion because they are fused to the inner layer of the peripheral wall 22, and the depressions 46 allow mechanical anchoring. In the figures, the depressions 46 are through-holes, also allowing fastening by riveting, and ribs 44 constitute the periphery of the through-holes. Indeed, during molding, air could be trapped in the through-holes 46, which would be unfavorable to fusion. The ribs 44 present on the periphery of the through-holes prevent air from being trapped in the through-holes.As seen in the, the first portion 34 of the peripheral wall reinforcing element also comprises rectilinear ribs 44 positioned at the periphery of the first portion 34. In the embodiment shown, the ribs 44 have a height h relative to the solid surface of the first portion 34 of the peripheral wall reinforcing element of approximately 1 mm, and a width l1 of approximately 0.7 mm. The width l1 and the height h are shown in the.

[0058] As seen in the, the shell 12 of the tank 10 has grooves 48 in the vicinity of the first fixing point 26. In the embodiment shown in the, the grooves 48 extend along straight lines parallel to the length L of the first part 34.

[0059] In this embodiment, the first part 34 has a length L of at least 10 mm, preferably 15 mm, and a width l2 of at least 20 mm, preferably 30 mm.

[0060] As seen in the, the shell 12 is made from a parison 50. In this embodiment, the parison 50 is tubular.

[0061] In the embodiment of the manufacturing method according to the invention shown diagrammatically in Figures 4, two reinforcing elements 24 of the peripheral wall are introduced into the parison 50, which are fixed to an internal reinforcement 40 of the first and second walls. In this embodiment, a mold 52 comprising cavities 54 is used. Each cavity 54 is equipped with a mounting structure 56 movable in translation in a recess 58.

[0062] In the implementation mode shown in Figures 4, the following steps are carried out.

[0063] Prior to the step shown in Figure 4a, the set of reinforcing elements 24 and the internal reinforcement 40 are mounted on an insertion member 60. The parison 50 in the molten state and the reinforcing element 24 of the peripheral wall mounted on said insertion member 60 are introduced into the mold 52, so that each zone 14, 16 of the parison 50 is positioned opposite an imprint 54, and so that the reinforcing element 24 of the peripheral wall is surrounded by the parison 50, and the first part 34 of the reinforcing element 24 of the peripheral wall is located opposite an internal portion of a peripheral part 62 of the imprints 54 of the mold. This step is shown in Figure 4a. The impressions 54 are brought closer to the parison 50, and thanks to the mounting structure 56, the parison 50 in the molten state is brought closer to a free end of the internal reinforcement 40 of the first and second walls.This makes it possible to weld each free end of the internal reinforcement 40 to a zone 14, 16 of the parison 50, which is shown in Figure 4b. The mold 52 is then brought into an intermediate closing position visible in Figure 4b, so that the reinforcing element 24 of the peripheral wall 22 is held between the cavities 54, then the insertion member 60 is removed. In Figures 4c and 4d, the insertion member 60 is no longer present but its outline is shown to symbolize the place where it was previously positioned. The mold 52 is then brought into a final closing position so that the first part 34 of the reinforcing element 24 of the peripheral wall 22 is clamped by the internal portion of the peripheral part 62 of the cavities 54 of the mold 52, which is shown in Figure 4c. The final blowing of the parison 50 is then carried out by pressing it onto the cavities 54 of the mold 52 using pressurized gas.Blowing is symbolized in Figure 4d by the arrows pointing towards the mold 52.

[0064] Subsequently, the tank is removed from the mold 52, which is not shown in Figures 4.

[0065] The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. List of references

[0066] 10: tank12: shell14, 16: areas of the shell delimited by the joint plane18: joint plane20: internal volume of the tank22: peripheral wall24: reinforcing element of the peripheral wall26: first fixing point28: first internal face30: second fixing point32: second internal face33: point opposite the first fixing point34: first part of the reinforcing element36: first wall38: second wall40: support part, reinforcement of the first and second walls42: stiffening rib44: rib46: depression48: groove50: parison52: mold54: impression56: mounting structure58: recess60: insertion member62: peripheral partd: straightl1: width of the ribh: height of the ribL: length of the first part2: width of the first part

Claims

Fuel tank (10) made of plastic for a motor vehicle, the tank (10) comprising: - a shell (12) made from a parison (50), the shell (12) comprising two zones (14, 16) delimited by a joint plane (18) and forming an internal volume (20) of the tank (10) intended to contain fuel, the shell (12) comprising a peripheral wall (22) comprising the joint plane (18), and - a reinforcing element (24) of the peripheral wall (22), essentially internal to the tank (10), and extending from the joint plane (18) towards the inside of the tank (10), the reinforcing element (24) of the peripheral wall (22) being fixed on the one hand at a first fixing point (26) of a first internal face (28) of the peripheral wall (22), and on the other hand at a second fixing point (30), said second fixing point (30) being internal to the tank (10),characterized in that a first portion (34) of the reinforcing element (24) of the peripheral wall (22) is fixed in the joint plane (18) at the first fixing point (26), in which the shell (12) of the fuel tank (10) further comprises a first wall (36) and a second wall (38) substantially located opposite each other with respect to the peripheral wall (22), and the second fixing point (30) internal to the tank (10) is located at a support piece (40) extending between the first wall (36) and the second wall (38), the support piece (40) being fixed to at least one of these walls (36, 38)., The fuel tank (10) of claim 1, wherein the support member (40) is an internal reinforcement of the first (36) and second (38) walls, an anti-sway baffle, or a support member arranged in the tank (10) to provide a second attachment point (30). Fuel tank (10) according to the preceding claim, wherein the support piece (40) is an internal reinforcement of the first (36) and second (38) walls. Fuel tank (10) according to any one of the preceding claims, wherein the reinforcing element (40) of the peripheral wall (22) is manufactured, at least in its first part (34), from a material identical to the material of an internal layer of the peripheral wall (22). Fuel tank (10) according to the preceding claim, wherein the first part (34) has ribs (44) and / or depressions (46) on the surface. A fuel tank (10) according to any preceding claim, wherein the shell (12) of the tank (10) has grooves (48) in the vicinity of the first attachment point (26). Fuel tank (10) according to any one of the preceding claims, wherein the first part (34) has a length (L) of at least 10 mm, preferably 15 mm, and a width (l2) of at least 20 mm, preferably 30 mm. A method of manufacturing the tank (10) according to any one of the preceding claims, comprising the following steps: - the reinforcing element (24) of the peripheral wall (22) is mounted on an insertion member (60), - the parison (50) is introduced in the molten state and the reinforcing element (24) of the peripheral wall (22) mounted on said insertion member (60) into a mold (52) comprising cavities (54), so that each zone (14, 16) of the parison (50) is positioned opposite a cavity (54), and so that the reinforcing element (24) of the peripheral wall (22) is surrounded by the parison (50), and so that the first part (34) of the reinforcing element (24) of the peripheral wall (22) is located opposite an internal portion of a peripheral part (62) of the cavities (54) of the mold (52),- the mold (52) is brought into an intermediate closing position so that the reinforcing element (24) of the peripheral wall (22) is held between the cavities (54),- the insertion member (60) is removed,- the mold (52) is brought into a final closing position so that the first part (34) of the reinforcing element (24) of the peripheral wall (22) is clamped by the internal portion of the peripheral part (62) of the cavities (54) of the mold (52) and the final blowing of the parison (50) is carried out by pressing it onto the cavities (54) of the mold (52) using the pressurized gas, and- the reservoir (10) is removed from the mold (52).,

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