Internal reinforcing elements for plastic tanks for automobiles

Abstract

The present invention relates to an internal reinforcing element (1) for a plastic tank for a motor vehicle. According to the invention, this type of element comprises a central structure (10) comprising a first rib system (100) comprising at least three main ribs (1000) joined to one another and a second rib system (101) comprising at least two minor ribs (1010), the side of the main rib opposite the side forming the joint (14) and the side of the minor rib opposite the side joining the main rib defining a projection plane of the central structure having a first peripheral geometry (16), the first and second ends (11) and (12) located on either side of the central structure having welds (13) and the first and second ends having a second peripheral geometry forming a transition between the first and third peripheral geometries.

Description

[Technical field]

[0001] The present invention relates to an internal reinforcing element for a plastic automotive tank. More particularly, the present invention relates to a plastic automotive tank comprising an internal reinforcing element, and also to a method for manufacturing the plastic automotive tank.

[0002] The present invention is particularly applicable to plastic fuel tanks for hybrid vehicles. [Background technology]

[0003] Traditionally, fuel tanks in automobiles are designed to store a certain amount of fuel at a pressure approximately equal to atmospheric pressure. With the advent of hybrid vehicles, also called HEVs (Hybrid Electric Vehicles), MHEVs (Mild-Hybrid Electric Vehicles) or PHEVs (Plug-in Hybrid Electric Vehicles), i.e. vehicles that include a combustion engine and one or more electric motors and can run for months without using the combustion engine, it is preferable to maintain pressure in the tank to reduce the passage of gasoline vapors through an activated carbon filter, also called a canister. This is done, for example, by isolating the canister from the tank using a valve such as a Fuel Tank Isolation Valve (FTIV).

[0004] Since this type of plastic fuel tank is obtained by extrusion blow moulding of a parison, its size will fluctuate during its service life, firstly immediately after demolding when the material shrinks due to cooling, and also during its service life due to over- and under-pressurisation of the contents due to thermal expansion and ageing.

[0005] Plastic fuel tanks for automobiles, more specifically for hybrid automobiles, also called HEV (Hybrid Electric Vehicle), MHEV (Mild-Hybrid Electric Vehicle) or PHEV (Plug-in Hybrid Electric Vehicle), usually comprise an internal reinforcing element in the form of a strut connecting two opposing internal surfaces of the tank. Struts of this kind are required to withstand various tests, for example long-term ageing tests or handling drop tests from a height of one meter, without impairing the properties of the fuel tank. For example, document WO 2012 / 139962 discloses a circular strut of the "diabolo" type that withstands very well axial stresses due to tension / compression phenomena as well as ageing and durability tests. However, struts of this kind are very sensitive to stresses caused by bending and / or torsion phenomena.

[0006] Also known from document US 2002 / 0066737 is a fuel tank, whose upper and lower shells are connected by a honeycomb-shaped reinforcing structure. To perform its reinforcing function, this type of structure extends over almost the entire inner surface of the bottom and top walls of the tank. This results in a bulky reinforcing system and cannot be used for tanks of different shapes. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2012 / 139962 [Patent Document 2] US Patent Application Publication No. 2002 / 0066737 [Patent Document 3] International Publication No. 2007000454 [Patent Document 4] International Publication No. 2006095024 [Patent Document 5] International Publication No. 2006008308 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE PRESENT EMBODIMENT It is a primary object of the present invention to remedy these shortcomings of the prior art.

[0009] More specifically, in at least one embodiment, the object of the present invention is to provide a plastic tank reinforcing element for automobiles, capable of withstanding not only axial stresses resulting from tensile / compressive phenomena, but also bending and torsional phenomena, which internal reinforcing element can be easily obtained by injection molding.

[0010] Another object of the present invention, in at least one embodiment, is to provide a plastic fuel tank for an automobile that includes an internal reinforcing element.

[0011] It is yet another object of the present invention, in at least one embodiment, to provide a method for manufacturing a plastic fuel tank for an automobile that includes an internal reinforcing element. [Means for solving the problem]

[0012] According to a particular embodiment, the invention relates to an internal reinforcing element for a plastic tank for a motor vehicle.

[0013] According to the invention, an internal reinforcing element of this kind is a central structure, a first rib system, referred to as the main rib system, including at least three main ribs joined to one another, each main rib having two opposing main faces, referred to as the main faces, joined to the other main ribs on one side, a central structure having at its central portion an interface between the at least three main ribs, said interface and said main ribs extending along an E-axis; a second rib system referred to as a minor rib system including at least two minor ribs located on opposite sides of a major rib and joined to each major surface of the major rib at one side so as to divide each major surface of the major rib into two major surface portions, the at least two minor ribs extending along an axis parallel to the E axis, each minor rib forming an angle greater than 0 degrees with the major rib with which it joins; A side surface of the main rib opposite to the side surface forming the joint and a side surface of the minor rib opposite to the side surface joining the main surface of the main rib define a projection surface of a central structure having a first peripheral geometric shape in the E-axis direction; The central structure, - a first end and a second end located on either side of the central structure, each end including a first rib system and a second rib system, the first end and the second end including a weld configured to be welded to the plastic tank, the first end and the second end having a second peripheral geometry forming a transition between the first peripheral geometry and a third peripheral geometry of the weld, the second geometry and the third geometry each corresponding to a geometry of a projection surface in the E-axis direction; Includes.

[0014] The basic principle of the invention is based on the presence of a central structure including a double rib system consisting of a first rib system, called the main rib system, including at least three main ribs joined to each other, and a second rib system, called the minor rib system, including at least two minor ribs located on either side of the main rib and joined on one side to each main surface of the main rib so as to divide each main surface of the main rib into two main surface parts, the double rib system extending into a first end and a second end located on either side of the central structure, the first end and the second end including welds configured to be welded to the plastic tank, the first end and the second end having a second peripheral geometry forming a transition between the first peripheral geometry and the third peripheral geometry of the welds, the second geometry and the third geometry each corresponding to the geometry of the projection plane in the E-axis direction that corresponds to the joints of the main ribs. Welds included on the first end and on the second end allow connection of two opposing internal surfaces of the tank via the internal reinforcing element by welding the internal reinforcing element to the internal walls.

[0015] The invention therefore relies on a completely novel and inventive approach to the internal reinforcing element, which is born out of the presence of two rib systems: the arrangement of a double rib system within the central structure and within the first and second ends of the internal reinforcing element results in an easily injection moldable internal reinforcing element that is able to withstand bending and torsional phenomena as well as axial stresses, in particular compressive forces acting in a direction parallel to the E axis. The first rib system in fact provides an assembly of main ribs that run parallel to the E axis and in at least two different directions. These main ribs are therefore able to effectively withstand stresses in the E axis direction. To this effective axial resistance, secondary ribs extending from the main rib faces (so as to divide each of the main rib faces into two main surface parts) add a particularly effective resistance to torsional or bending forces that may occur in a direction perpendicular to the E axis. In fact, the secondary ribs are able to act in a twist or bending direction that is additional to the direction of the main ribs, along at least one direction intersecting the direction of the main ribs to which they are joined. In this way, forces acting on the internal reinforcing element that tend to create a torsional moment or a bending force perpendicular to the E-axis, especially due to shear forces between two welds of the tank, are more easily transferred to one side of the main rib or one side of the secondary rib, thereby preventing bending or torsional forces on the internal reinforcing element. This type of structure is more effective than a honeycomb structure in preventing forces acting on the internal reinforcing element that tend to create a torsional moment or a bending force on the internal reinforcing element. Also, since the secondary ribs also intersect with the main faces of the main ribs, a different joint is obtained from the joints between the main ribs, so that stresses are not concentrated at the joints between the main ribs and therefore promote stress distribution on the internal reinforcing element. In this way, the secondary ribs transfer stresses to the entire internal reinforcing element, making it possible to effectively utilize the entire internal reinforcing element. The secondary ribs also help to avoid buckling of the main ribs. Furthermore, the internal reinforcing element can be more compact than a honeycomb structure and can be adapted to all types of tanks.

[0016] The expression "the side of the main rib opposite the side forming the joint and the side of the minor rib opposite the side joining the main surface of the main rib define a projection plane of the central structure having a first peripheral geometric shape in the E-axis direction" means that the projection plane in the E-axis direction is determined by the imaginary contact point of the side of the main rib opposite the side forming the joint and the side of the minor rib opposite the side joining the main surface of the main rib.

[0017] The phrase "the first end and the second end have a second perimeter geometry forming a transition between the first perimeter geometry and the third perimeter geometry of the weld" means that the second perimeter geometry gradually changes from the first geometry to the third geometry.

[0018] By "major surface" of a rib, we mean the larger surface of the rib adjacent to the smaller surface of the rib called the "side surface."

[0019] The phrase "each minor rib forms an angle greater than 0 degrees with the adjoining major rib" means that the minor rib intersects the major rib, in other words, the minor rib extends in a plane that is not parallel to the plane of the major rib.

[0020] The internal reinforcing element has a central axis connecting the first geometric shape, the second geometric shape, and the third geometric shape. The central axis passes through the center of the central structure and the centers of the first geometric shape, the second geometric shape, and the third geometric shape. The central axis overlaps with the E-axis. Optionally, the central axis is an axis of symmetry of the internal reinforcing element. According to one embodiment, the central axis is a longitudinal axis of the internal reinforcing element.

[0021] According to one embodiment, at the first and second ends, the major and minor ribs each extend along a plane not parallel to the E-axis, tapering to reach the weld.

[0022] According to one embodiment, the side of the major rib opposite the side forming the joint and the side of the minor rib opposite the side joining the major surface of the major rib do not interdigitate with the other first rib system and the other second rib system.

[0023] According to one embodiment, the central structure extends along the E-axis for a length at least as long as the E-axis length of each of the first and second ends.

[0024] Advantageously, the internal reinforcing element of a plastic tank for an automotive vehicle according to the invention has a first rib system, called main rib system, which comprises at least four main ribs joined to one another, each main rib being joined on one side to the other main ribs.

[0025] Thus, at least four main ribs joined together result in an internal reinforcing element that is highly resistant to bending and torsional phenomena as well as axial stresses and that can be easily injection moulded.The internal reinforcing element according to the invention thus advantageously comprises four main ribs joined together, a structure with four joined ribs generally avoided in the prior art, since it leads to sink marks, i.e. excess thickness of the tank wall.

[0026] According to a preferred embodiment, the internal reinforcing element of the plastic tank for an automobile according to the invention is such that the angle formed by two adjacent main ribs of the first main rib system is the same for all adjacent main ribs. For example, for a first rib system, referred to as a main rib system comprising three main ribs, each main rib being joined to the other main rib on one side, in this type of system the angle formed by two adjacent main ribs is equal to 120°. For a first rib system, referred to as a main rib system comprising four main ribs, the angle formed by two adjacent main ribs is equal to 90°.

[0027] Thus, an internal reinforcing element comprising a first rib system, referred to as a main rib system, in which all adjacent main ribs form the same angle, exhibits homogeneous resistance to bending and torsional phenomena as well as axial stresses, and an even distribution of mechanical stresses.

[0028] According to a preferred embodiment, the internal reinforcing element of the plastic tank for motor vehicles according to the invention has a main rib which forms a plane of symmetry with at least two secondary ribs which are located on either side of said main rib and which are joined to said main rib. In other words, the plane of the main rib forms an orthogonal plane of symmetry with the two secondary ribs which are joined to said main rib. Preferably, each main rib of the internal reinforcing element forms a plane of symmetry with at least two secondary ribs which are located on either side of said main rib and which are joined to each main face of the main rib with one side. The angle which the main rib forms with the secondary ribs is preferably smaller than or equal to 45 degrees. More preferably, this angle is equal to 45 degrees when the angle between the main ribs is equal to 90 degrees.

[0029] Thus, the internal reinforcing element, which comprises a main rib in a plane of symmetry with at least two minor ribs attached to it on either side of said main rib, has a homogeneous resistance to mechanical stresses.

[0030] According to a preferred embodiment, the internal reinforcing element of a plastic tank for a motor vehicle according to the invention has at least one main rib of the first main rib system which comprises, opposite the joint, a bifurcated fork-shaped side surface.

[0031] Thus, an internal reinforcing element comprising at least one main rib of the first main rib system comprising a bifurcated fork-shaped side opposite the junction has an improved homogeneous durability against mechanical stresses, in particular due to the improved transition and an excellent resistance of the welds to mechanical stresses. Preferably, all main ribs of the first main rib system comprise a bifurcated fork-shaped side opposite the junction.

[0032] According to an alternative embodiment to the preceding embodiment or in combination with the preceding embodiment, the internal reinforcing element of the plastic tank for an automotive vehicle according to the invention is characterized in that at least one main rib of the first main rib system comprises a hooked side opposite the joint.

[0033] By "hooked" it is meant that the major ribs have curved ends, for example in the shape of an ice hockey stick or a field hockey stick.

[0034] According to a preferred embodiment, the internal reinforcing element of the plastic tank for an automotive vehicle according to the invention has a first peripheral geometry of the central structure and a third peripheral geometry of the weld, each of which corresponds to a geometric shape of the projection surface in the E-axis direction, such that the area of ​​the projection surface of the third peripheral geometry is less than that of the first peripheral geometry. Preferably, the ratio of the area of ​​the projection surface of the first peripheral geometry to the area of ​​the projection surface of the third peripheral geometry is greater than or equal to 1.5, preferably greater than or equal to 2.

[0035] According to a preferred embodiment, the internal reinforcing element of the plastic tank for a motor vehicle according to the invention has a first peripheral geometric shape of the projection of the central structure in the direction of the E axis which is a polygon, preferably a regular polygon, preferably a square. In the case of a non-regular polygon, a parallelepiped, preferably a rectangle, is the preferred shape.

[0036] According to a preferred embodiment, the internal reinforcing element of a plastic tank for a motor vehicle according to the invention has a third peripheral geometric shape inscribed in the first peripheral geometric shape.

[0037] According to a preferred embodiment, the internal reinforcing element of the plastic tank for a motor vehicle according to the invention has a third peripheral geometry of the projection of the weld in the E-axis direction which is circular. A circular connection surface with the tank wall allows for a good distribution of stresses. Preferably, the first peripheral geometry of the central structure is rectangular, i.e. rectangular, and the third peripheral geometry of the weld is circular, i.e. circular.

[0038] According to a preferred embodiment, the internal reinforcing element of a plastic tank for a motor vehicle according to the invention comprises gripping means in the form of cutouts or gripping ribs adapted to be fastened to a support.

[0039] The presence of such gripping means makes it possible to insert internal reinforcing elements into the tank when it is manufactured.

[0040] According to a preferred embodiment, the internal reinforcing element of the plastic tank for automobiles according to the invention has an angle formed by two adjacent main ribs that is approximately equal to 90 degrees.

[0041] According to a preferred embodiment, the internal reinforcing element of the plastic tank for automobiles according to the invention has an angle formed by the main rib and the secondary rib that is approximately equal to 45 degrees.

[0042] Preferably, the internal reinforcing element comprises four main ribs, two of which form an angle of 90 degrees, and two minor ribs on each main rib, the two minor ribs being located on either side of the main rib and joined at one side to each main surface of the main rib, the at least two minor ribs extending along the E axis, each minor rib forming an angle of 45 degrees with the main rib to which it is joined.

[0043] According to a preferred embodiment, the internal reinforcing element of the plastic tank for automobiles according to the invention has a main rib thickness that is at least 1.25 times the thickness of the secondary ribs.

[0044] According to a preferred embodiment, the internal reinforcing element of the plastic tank for automobiles according to the invention has a central structure, a first end and a second end which are monoblock assemblies.

[0045] Such a monoblock assembly facilitates the manufacture of the reinforcing element and at the same time exhibits good resistance to mechanical stresses, since the manufacture of the reinforcing element is based solely on the injection moulding process and there are no "post-injection moulding" assembly operations.

[0046] According to a preferred embodiment, the internal reinforcing element of the plastic tank for a motor vehicle according to the invention has as its main material selected from among polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphthalamide (PPA), polyetheretherketone (PEEK), polyamideimide (PAI), polyaryletherketone (PAEK), polyamide (PA), polyketone (PK) and polyethylene (PE), preferably polyethylene (PE), more preferably high density polyethylene (HDPE). Advantageously, the material constituting the internal reinforcing element comprises fibres such as glass fibres, carbon fibres, polymer fibres (e.g. polyamides, in particular aromatic polyamides such as aramids), or natural fibres such as hemp or sisal. Preferably glass fibres (E-glass, S-glass or other types). For example, the material comprising fibres is a reinforced composite material. The fibre content is less than 20%, preferably less than 15%, more preferably less than 10%. The expression "fiber content less than 20%, preferably less than 15%, more preferably less than 10%" means that the volume or weight fiber content, preferably the volume fiber content, is less than 20%, preferably less than 15%, more preferably less than 10%.

[0047] According to a preferred embodiment, the internal reinforcing element of a plastic tank for an automotive vehicle according to the invention has an E axis which is the central axis of symmetry of a first rib system, called the main rib system, of said internal reinforcing element. Preferably, the E axis is also the axis of symmetry of a second rib system, called the secondary rib system, of said internal reinforcing element.

[0048] Such an internal reinforcing element, whose E axis is the central axis of symmetry of a first rib system, called the main rib system of said internal reinforcing element, and preferably of a second rib system, called the secondary rib system of said internal reinforcing element, is capable of exhibiting equal mechanical resistance in all directions of stress.

[0049] According to a preferred embodiment, the internal reinforcing element of a plastic tank for a motor vehicle according to the invention has a weld at its first end and at its second end configured to be welded to the plastic tank, the weld comprising a weld stud and / or a weld rib.

[0050] The invention also relates to a plastic tank for a motor vehicle, comprising an internal reinforcing element according to the invention.

[0051] The present invention also relates to a method for manufacturing a plastic tank for an automobile tank, the method comprising the steps of: 1. Parison extrusion 2. Insertion of an internal reinforcing element according to the invention into the parison before or after blow molding 3. Welding of internal reinforcing elements to the tank wall.

[0052] According to an advantageous embodiment, the method for manufacturing a plastic tank for an automobile tank according to the invention is characterized in that the insertion of the reinforcing element into the parison is carried out before the blow moulding of the tank. Preferably, the parison is cylindrical and, preferably after a step of isolating the lower part of the cylindrical parison, an internal reinforcing element is inserted into the cylindrical parison. After said step of isolating the lower part of the parison, a pre-blow moulding step is preferably carried out. Advantageously, when inserting the internal reinforcing element into the cylindrical parison, said internal reinforcing element comprises gripping means in the form of a cut-out adapted to be fixed to a support, by which it can be fixed to a support, which can include other components such as deflectors, also called baffles, valves, ventilation or fuel lines, sensors, which can be quality and / or level sensors.

[0053] The expression "blow molding of a tank" means that a parison is blown into a tank shape in a mold.

[0054] According to an alternative embodiment of the above-mentioned advantageous embodiment, the method for producing a plastic tank for an automobile tank according to the invention is characterized in that the insertion of the internal reinforcing element into the parison is carried out after the blow moulding of the tank. Preferably, at the outlet of the extrusion system, the parison is in the form of two strips. When the mould is reopened before the final blow moulding, the internal reinforcing element is inserted into the already blow moulded parison. The internal reinforcing element is inserted using a robot arm and / or a centre core. Advantageously, when the internal reinforcing element is inserted into the parison in the form of two strips at the outlet of the extrusion system, said internal reinforcing element comprises gripping means in the form of gripping ribs. The gripping ribs allow the fixing and positioning of the internal reinforcing element on the robot arm and / or the centre core before fixing inside the tank. The expression "centre core" means a central part configured to be inserted between two mould halves during the manufacture of a plastic tank, said core being described, for example, in documents WO2007000454, WO2006095024 or WO2006008308.

[0055] Other characteristics and advantages of the invention will become more apparent on reading the following non-limiting and purely reference-based description of preferred embodiments and the accompanying drawings, in which: [Brief description of the drawings]

[0056] [Figure 1] FIG. 2 is an elevated perspective view of an internal reinforcing element. [Diagram 2] FIG. 2 shows a longitudinal section of an internal reinforcing element. [Diagram 3] FIG. 2 shows a first cross-section of an internal reinforcing element. [Figure 4] FIG. 2 shows a second cross section of the internal reinforcing element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] With reference to figure 1, an embodiment of an internal reinforcing element according to the invention is presented. The internal reinforcing element 1 extends vertically along the Z axis and horizontally in the (X,Y) plane so as to form an orthogonal coordinate system (X,Y,Z). The internal reinforcing element 1 is A central structure 10, a first rib system 100, referred to as main rib system 100, comprising four main ribs 1000 joined to each other, each main rib 1000 having two opposite main faces 1000f, referred to as main faces 1000f, joined on one side to the other main ribs 1000, a central structure 10 having in its central part the joints of the four main ribs 1000, said joints 14 and said main ribs 1000 extending along an E axis parallel to the Z axis, indicated by reference number 15; a second rib system 101, referred to as minor rib system 101, comprising at least two minor ribs 1010, said at least two minor ribs 1010 being located on either side of the main rib 1000 and being joined at one side to each of the main surfaces 1000f of the main rib 1000 so as to divide each of the main surfaces 1000f of the main rib into two main surface portions 1000f1, 1000f2, said at least two minor ribs 1010 extending along an axis parallel to the E axis, each minor rib 1010 forming an angle equal to 45 degrees with the main rib 1000 to which it joins; The side of the main rib 1000 opposite the side forming the joint and the side of the minor rib 1010 opposite the side joining the main surface 1000f of the main rib 1000 define a projection plane of the central structure 10 having a first peripheral geometric shape 16 in the E-axis direction; A central structure 10; a first end 11 and a second end 12 located on either side of the central structure 10, each including a first rib system 100 and a second rib system 101, the first end 11 and the second end 12 including a weld 13 configured to be welded to the plastic tank, the first end 11 and the second end 12 having a second peripheral geometry 16' forming a transition between the first peripheral geometry 16 of the weld 13 and a third peripheral geometry, the second geometry 16' and the third geometry each corresponding to the geometry of a projection surface in the E-axis direction; Includes.

[0058] The first peripheral geometry 16, the second peripheral geometry 16' and the third peripheral geometry each extend in a plane parallel to the (X, Y) plane. The internal reinforcing element 1 resists bending and torsional forces as well as axial stresses acting in a direction parallel to the Z axis. The first rib system 100 provides a primary rib 1000 assembly that extends in a direction parallel to the E axis, i.e. in a plane parallel to the E axis. The primary rib 1000 can thus act in compression along the E axis and in twisting in a direction perpendicular to the E axis towards the side of the primary rib 1000. The secondary ribs 1010 that are joined to the primary face 1000f of the primary rib 1000 and also extend in a plane parallel to the E axis can act in twisting along at least one direction that crosses the direction of the primary rib 1000 to which they are joined, specifically in a direction perpendicular to the E axis towards the side of the secondary rib 1010.

[0059] The internal reinforcing element shown in Fig. 1 comprises a circular third peripheral geometry of the projection of the welds 13 in the direction of the E axis and a rectangular first peripheral geometry of the central structure 10. The first peripheral geometry 16 of the central structure 10 and the third peripheral geometry of the welds 13, which correspond respectively to the geometry of the projection in the direction of the E axis, are such that the area of ​​the projection of the third peripheral geometry is less than the area of ​​the first peripheral geometry 16. Preferably, the ratio of the area of ​​the projection of the first peripheral geometry 16 to the area of ​​the projection of the third peripheral geometry is 1.5 or more, preferably 2 or more. The welds 13 of the first end 11 and the second end 12, which are adapted to be welded to the plastic tank, comprise a weld stud 130 and a weld rib 131. The internal reinforcing element 1 also comprises gripping means 18 in the form of a cutout 180 or a gripping rib 181, which are adapted to be fixed to a support. The main rib 1000 of the first main rib system 100 includes a bifurcated fork-shaped side 17 opposite the joint. The internal reinforcing element 1 is mainly made of high density polyethylene, and the central structure 10, the first end 11 and the second end 12 located on either side of the central structure 10 are a monoblock assembly.

[0060] The internal reinforcing element 1 has a central axis connecting the first geometric shape 16, the second geometric shape 16', and the third geometric shape. This central axis passes through the center of the central structure 10 and the centers of the first geometric shape 16, the second geometric shape 16', and the third geometric shape. The central axis overlaps with the E axis.

[0061] In the illustrated embodiment, the central axis is the axis of symmetry of the internal reinforcing element 1, the central axis being the longitudinal axis of the internal reinforcing element. At the first end 11 and the second end 12, the main rib 1000 and the minor rib 1010 each extend along a plane not parallel to the E axis, tapering off to reach the weld 13.

[0062] In the illustrated embodiment, the central structure 10 extends along the E-axis for a length at least as long as the E-axis lengths of the first end 11 and the second end 12. More specifically, the length of the central structure 10 exceeds the length of each of the first end 11 and the second end 12.

[0063] FIG. 2 shows a longitudinal section of the internal reinforcing element 1 shown in FIG. A central structure 10, a first rib system 100, referred to as a main rib system 100, comprising four main ribs 1000 joined to each other, each main rib 1000 being joined to the other main ribs 1000 on one side, a central structure 10 having in its central part the joints of the four main ribs 1000, said joints and said main ribs 1000 extending along the E-axis 15; a second rib system 101, referred to as minor rib system 101, comprising at least two minor ribs 1010, said at least two minor ribs 1010 being located on either side of the main rib 1000 and being joined at one side to each of the main surfaces 1000f of the main rib 1000 so as to divide each of the main surfaces 1000f of the main rib 1000 into two main surface portions 1000f1, 1000f2, said at least two minor ribs 1010 extending along an axis parallel to the E-axis 15; the side of the main rib 1000 opposite the side forming the joint and the side of the secondary rib 1010 opposite the side joining the main surface of the main rib 1000 define a projection plane of a central structure having a first peripheral geometric shape in the direction of the E-axis 15; A central structure 10; a first end 11 and a second end 12 located on either side of the central structure 10, each comprising a first rib system 100 and a second rib system 101, the first end 11 and the second end 12 comprising a weld 13 configured to be welded to the plastic tank, the first end 11 and the second end 12 having a second peripheral geometry forming a transition between the first peripheral geometry and a third peripheral geometry of the weld 13, the second geometry and the third geometry each corresponding to the geometry of a projection plane in the direction of the E-axis 15; Includes.

[0064] The internal reinforcing element shown in Fig. 2 comprises a circular third peripheral geometry of the projection of the weld 13 in the direction of the E-axis 15. The internal reinforcing element 1 also comprises gripping means 18 in the form of a cut-out 180 or a gripping rib 181 adapted to be fastened to a support. The main rib 1000 of the first main rib system 100 comprises a bifurcated fork-shaped side surface 17 opposite the joint.

[0065] Figure 3 shows a first cross-section in a plane parallel to the (X, Y) plane of the central structure 10 of the internal reinforcing element 1. The cross-section is along the plane indicated by the dotted line indicated in Figure 2 with reference A. The central structure 10 comprises a first rib system 100, called the main rib system 100, which comprises four main ribs 1000 joined to each other, each main rib 1000 being joined to the other main ribs 1000 on one side, the central structure 10 having in its central part a joint 14 of the four main ribs 1000. The main ribs 1000 of the first main rib system 100 comprise a hooked side opposite the joint 14. The angle formed by two adjacent main ribs 1000 is approximately equal to 90 degrees. The central structure 10 comprises a second rib system 101, called the secondary rib system 101, which comprises eight secondary ribs 1010. The two minor ribs 1010 are located on both sides of the main rib 1000, and are joined to each main surface 1000f of the main rib 1000 at one side so as to divide each main surface 1000f of the main rib into two main surface portions 1000f1, 1000f2, and form an angle equal to 45 degrees between each minor rib 1010 and the main rib 1000 to which it is joined. Note that the first peripheral geometric shape 16 of the projection plane in the E-axis direction (not shown because it is perpendicular) of the central structure 10 is a polygon.

[0066] In the illustrated embodiment, the side of the main rib 1000 opposite the side forming the joint 14 and the side of the minor rib 1010 opposite the side joining the major surface 1000f of the main rib 1000 do not interdigitate with the other first rib system 100 and the other second rib system 101.

[0067] Figure 4 shows a second cross-section of the central structure 10 of the internal reinforcing element 1 in a plane parallel to the (X, Y) plane. The cross-section is along the plane indicated by the dotted line indicated in Figure 2 with reference B. The central structure 10 comprises a first rib system 100, called the main rib system 100, which comprises four main ribs 1000 joined to each other, each main rib 1000 being joined to the other main ribs 1000 on one side, the central structure 10 having a joint 14 of the four main ribs 1000 in its central part. The main ribs 1000 of the first main rib system 100 comprise a bifurcated fork-shaped side 17 opposite the joint 14. The angle formed by two adjacent main ribs 1000 is approximately equal to 90 degrees. The central structure 10 comprises a second rib system 101, called the secondary rib system 101, which comprises eight secondary ribs 1010. The two minor ribs 1010 are located on both sides of the main rib 1000, and are joined to each main surface 1000f of the main rib 1000 at one side so as to divide each main surface 1000f of the main rib into two main surface portions 1000f1, 1000f2, and form an angle equal to 45 degrees between each minor rib 1010 and the main rib 1000 to which it is joined. Note that the second peripheral geometric shape 16' of the projection plane in the E-axis direction (not shown because it is perpendicular) of the central structure is a polygon. [Explanation of symbols]

[0068] 1 Internal reinforcement element 10 Central structure 11 First end 12 Second end 13 Welding 14 Joint 15 E-axis 16 First Periphery Geometry 16' Second Perimeter Geometry 17 Fork-shaped side 18 Gripping means 100 First rib system, main rib system 101 Second rib system, secondary rib system 130 Welding stud 131 Welded Rib 180 Cutout 181 Gripping rib 1000 Main Rib 1000f, 1000f1, 1000f2 main surface 1010 Secondary rib

Claims

1. An internal reinforcing element (1) for a plastic tank for an automobile, said internal reinforcing element (1) comprising a central structure (10), a first rib system (100), referred to as a main rib system (100), comprising at least three main ribs (1000) joined to one another, each main rib (1000) being joined on one side to the other main ribs (1000), said central structure (10) having at its central portion joints (14) of the at least three main ribs (1000), said joints (14) and said main ribs (1000) extending along an E-axis (15); a second rib system (101), referred to as minor rib system (101), comprising at least two minor ribs (1010), said at least two minor ribs (1010) being located on either side of a main rib (1000) and joined to said main rib (1000) on one side, said at least two minor ribs (1010) extending along an axis parallel to said E-axis (15), each minor rib (1010) forming an angle greater than 0 degrees with said main rib (1000) with which it joins; a side of the main rib (1000) opposite to the side forming the joint (14) and a side of the minor rib (1010) opposite to the side joining the main rib (1000) define a projection plane of the central structure (10) having a first peripheral geometric shape (16) in the E-axis (15) direction; The central structure (10), - a first end (11) and a second end (12) located on either side of the central structure (10), each comprising the first rib system (100) and the second rib system (101), the first end (11) and the second end (12) comprising a weld (13) configured to be welded to a plastic tank, the first end (11) and the second end (12) having a second peripheral geometry (16') forming a transition between a first peripheral geometry (16) and a third peripheral geometry of the weld (13), the second geometry (16') and the third geometry each corresponding to a geometry of the projection surface in the direction of the E-axis (15); In the internal reinforcing element (1), The at least two minor ribs (1010) are joined to each major surface (1000f) of the main rib (1000) so as to divide each major surface (1000f) of the main rib into two major surface portions (1000f1, 1000f2). An internal reinforcing element (1).

2. 2. The internal reinforcing element (1) of a plastic tank for an automobile according to claim 1, wherein the first rib system (100), referred to as the main rib system (100), comprises at least four main ribs (1000) joined to one another, each main rib (1000) being joined on one side to the other main ribs (1000).

3. 3. The internal reinforcing element (1) of a plastic tank for an automobile according to claim 1 or 2, wherein the angle formed by two adjacent main ribs (1000) of the main rib system (1000) is the same for all adjacent main ribs (1000).

4. 4. An internal reinforcing element (1) for a plastic tank for an automobile according to claim 1, wherein the main rib (1000) forms a symmetrical plane with respect to the at least two secondary ribs (1010) located on either side of the main rib (1000) and joined to it.

5. 5. An internal reinforcing element (1) for a plastic tank for an automotive vehicle according to claim 1, wherein at least one main rib (1000) of the first main rib system (100) comprises a bifurcated fork-shaped side (17) opposite the joint (14).

6. 6. The internal reinforcing element (1) of a plastic tank for an automotive vehicle according to claim 1, wherein the first peripheral geometric shape (16) of the projection surface in the direction of the E-axis (15) of the central structure (10) is a polygon, preferably a regular polygon.

7. 7. An internal reinforcing element (1) for a plastic tank for an automotive vehicle according to claim 1, wherein the third peripheral geometric shape of the projection surface of the weld (13) in the direction of the E-axis (15) is circular.

8. 8. An internal reinforcing element (1) for a plastic tank for a motor vehicle according to claim 1, comprising gripping means (18) in the form of cut-outs (180) or gripping ribs (181) adapted to be fastened to a support.

9. 9. An internal reinforcing element (1) for a plastic tank for automobiles according to any one of claims 1 to 8, wherein the angle formed by two adjacent main ribs (1000) is approximately equal to 90 degrees.

10. 10. An internal reinforcing element (1) for a plastic tank for motor vehicles according to any one of claims 1 to 9, wherein said angle formed by the main rib (1000) and the secondary rib (1010) is approximately equal to 45 degrees.

11. 11. The internal reinforcing element (1) of a plastic tank for an automotive vehicle according to any one of claims 1 to 10, wherein the central structure (10), the first end portion (11) and the second end portion (12) are a monoblock assembly.

12. 12. The internal reinforcing element (1) of a plastic tank for an automotive vehicle according to any one of claims 1 to 11, wherein the main material is selected from among polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphthalamide (PPA), polyetheretherketone (PEEK), polyamideimide (PAI), polyaryletherketone (PAEK), polyamide (PA), polyketone (PK) and polyethylene (PE), preferably polyethylene (PE), more preferably high density polyethylene (HDPE).

13. 13. An internal reinforcing element (1) of a plastic tank for automotive vehicles according to any one of claims 1 to 12, wherein the E-axis (15) is the central axis of symmetry of the first rib system (100), referred to as the main rib system (100) of the internal reinforcing element (1).

14. A plastic tank for a motor vehicle comprising an internal reinforcing element according to any one of claims 1 to 13.

15. Each of the following steps:

1. Extrusion of the parison; 2. Insertion, before or after blow moulding, of an internal reinforcing element (1) according to any one of claims 1 to 13 into the parison; 3. Welding the internal reinforcing element (1) to the tank wall; A method for manufacturing a plastic tank for an automobile tank, comprising:

Images