REINFORCEMENT FOR A FUEL TANK

Description

1. Scope of the invention

[0001] The invention relates to the technical field of plastic tanks for motor vehicles, more particularly liquid fuel tanks. The invention generally relates to a frame for a plastic tank for motor vehicles comprising at least one means for attaching an internal tank reinforcement element.

[0002] More particularly, the invention relates to a plastic tank frame for a motor vehicle comprising at least one means for attaching an internal reinforcement element for a plastic tank for a motor vehicle.

[0003] The invention also relates to an assembly configured to be fixed inside a plastic tank for a motor vehicle, comprising said frame and at least one internal reinforcing element, as well as the plastic tank for a motor vehicle comprising said assembly. The invention also relates to a method for manufacturing a plastic tank for a motor vehicle. 2. Prior art solutions

[0004] Plastic fuel tanks obtained by blow molding from a parison undergo dimensional variations during their life, either firstly from the moment they come out of the mold, due to their cooling which is accompanied by a shrinkage of the material, or during their use, due in particular to overpressure or underpressure of their contents, or due to their thermal expansion during their life, or even due to their aging.

[0005] It is known to insert internal reinforcing elements within the tank during its manufacturing process. These internal reinforcing elements are intended to increase the resistance of the plastic tank to the mechanical stresses to which it is subjected during its lifespan.

[0006] Thus, US patent 2011 / 0226777 A1 discloses an assembly comprising a reinforcement and wall-connecting elements for the tank. These connecting elements have low rigidity, preventing them from providing internal reinforcement. The reinforcement also includes deformable structures along the longitudinal X direction of the vehicle for which the reinforcement is intended, the transverse Y direction of the vehicle, and the vertical Z direction of the vehicle. However, such an assembly has a limited capacity to adapt to dimensional variations in the tank. Furthermore, such an assembly exhibits insufficient compressive and tensile strength in the vertical direction of the vehicle.

[0007] A structure for attaching a noise-dampening baffle to a fuel tank is also known from patent US2016 / 0200192. The baffle may include an engagement portion with a reinforcing column connecting the upper and lower surfaces of the tank. The engagement portion comprises two arms, each ending in a curved section. The column is inserted into the engagement portion through a gap between the two curved sections, which opens the arms, which then close around the column due to their elasticity. Because the column is connected to both the upper and lower surfaces of the tank, the engagement portion can be stably secured.

[0008] Also known from patent US20219 / 0092159 is a fuel tank reinforcement pillar comprising a main body and a bracket mounted on the main body for attaching a tank component. The bracket is mounted on the main body via an engaged portion of the bracket, designed to engage with an engagement portion of the main body formed on an external circumferential portion of the main body. The engaged portion comprises two separate sections, which close onto the main body by means of two prongs on one section, each prong inserted into a through hole in the other section. Such a structure, involving various parts to mount the bracket to the main body, is quite complex. 3. Objectives of the invention

[0009] The invention aims in particular to overcome these drawbacks of the prior art.

[0010] To this end, the invention aims to provide an assembly comprising a frame for a plastic tank for a motor vehicle, the assembly also comprising at least one internal reinforcement element, said assembly having an increased capacity to adapt to dimensional variations of the tank, more particularly during the manufacture of said tank and exhibiting improved resistance to compression and stretching.

[0011] More specifically, an objective of the invention, in at least one of its embodiments, is to provide a frame comprising a fastening means configured to fix at least one internal reinforcing element, the frame and the at least one internal reinforcing element being able to form an assembly having an increased capacity to adapt to the dimensional variations of a plastic tank for a motor vehicle, more particularly during the manufacture of said tank.

[0012] The invention, in at least one of its embodiments, also aims to provide a plastic tank for a motor vehicle.

[0013] Another objective of the invention, in at least one of its embodiments, is to implement a method for manufacturing a plastic tank for a motor vehicle. 4. Description of the invention

[0014] The invention thus relates to a plastic tank frame for a motor vehicle according to claim 1 comprising at least one means for fixing an internal tank reinforcement element.

[0015] According to the invention, at least one means for fixing the internal reinforcement element comprises at least one first structure configured to snap at least a part of the internal reinforcement element, said at least one first structure comprising at least two bodies movable relative to each other, each movable body being provided with a retaining means configured to retain the internal reinforcement element in the opposite direction to the snapping direction, and is characterized by at least one stop element projecting in the opposite direction to the snapping direction in order to provide a stop for the internal reinforcement element when the latter is snapped in.

[0016] The general principle of the invention is based on the presence of a means for fixing the internal reinforcement element, which simultaneously allows at least part of the internal reinforcement element to be snapped into place and the reinforcement element to be held in position after snapping in order to ensure a fixing with increased resistance to the mechanical stresses suffered by the assembly obtained during the manufacture of the tank and an increased ability to adapt to dimensional variations of the tank.The system must include at least one first structure comprising at least two bodies movable relative to each other, each movable body being equipped with a retaining means configured to hold the internal reinforcement element in the opposite direction to the snap-in direction. This allows at least a portion of the internal reinforcement element to be snapped into place. The presence of at least one stop element projecting in the opposite direction to the snap-in direction provides a stop for the internal reinforcement element when it is snapped into place. It is understood that this stop element is a separate element from the movable bodies; in particular, the retaining means configured to hold the internal reinforcement element in the opposite direction to the snap-in direction is not the same as the stop element.

[0017] Advantageously, the stop element holds the reinforcement element in place after snap-in. At least a portion of the internal reinforcement element is held in position and clamped by the combined force of the retention provided by the retaining means configured to hold the internal reinforcement element in the opposite direction to the snap-in direction, present on the moving bodies, and the at least one stop element. Furthermore, after snap-in, at least a portion of the internal reinforcement element is also held in position by the force exerted on it by the at least two moving bodies.

[0018] Thus, the invention is based on a completely new and inventive approach to a fastening method that increases the ability of an assembly comprising a frame and at least one internal reinforcing element to adapt to dimensional variations in the tank, and reduces the stresses generated by the presence of said assembly within the tank. This arrangement limits the relative displacements between the two parts along the two parallel axes, particularly with respect to the weld surface. The interconnection created between the internal reinforcing element and the frame ensures centering of the two parts and improved fastening.

[0019] By the expression,An "internal reinforcement element" refers to a structural component designed to connect two opposing walls of the tank. This internal reinforcement element limits tank deformation during pressurization. It is preferably welded at both ends to the plastic tank.

[0020] The term "tank" refers to a sealed container suitable for storing liquid fuel under various operating and environmental conditions. The tank according to the invention is made with a plastic wall, generally comprising an inner face on its concave portion and an outer face on its convex portion. Preferably, the tank is a plastic container for liquid fuel.

[0021] The expression "a first structure configured to snap into at least a part of the internal reinforcement element" means that at least a part of the reinforcement element, preferably the entire reinforcement element, is blocked by the fastening means and prevented from moving after snapping into place by its clamping between the retaining means present on the moving bodies and at least one stop element.

[0022] Advantageously, the at least one stop element has two surfaces, namely a first surface intended to form an axial stop surface for the internal reinforcement element in the snap-in direction, and a second surface intended to form a radial stop surface for the internal reinforcement element in a direction of rotation of the internal reinforcement element around an axis parallel to the axis of the axial stop.

[0023] Advantageously, at least one stop element is configured to engage with a receiving member of the internal reinforcing element such that, after snapping into place, the internal reinforcing element is prevented from rotating. It is understood that this receiving member may consist, in particular, of a specific receiving shape formed in the internal reinforcing element.

[0024] Advantageously, the plastic tank frame for motor vehicles according to the invention is such that at least a first structure is configured to snap into at least an internal part of the internal reinforcement element.

[0025] Thus, a first structure configured to snap into place at least one internal portion of the internal reinforcement element allows for improved fixation of the internal reinforcement element, with the movable bodies ensuring that the movement of the internal reinforcement element is limited in all directions. Indeed, the force exerted on the internal portion of the internal reinforcement element by the movable bodies can be applied in a greater number of directions.

[0026] The expression "an internal part of the internal reinforcement element" means a hollowed-out part of the internal reinforcement element, such as, for example, a through hole or a blind hole.

[0027] According to a preferred embodiment, the plastic tank frame for motor vehicles according to the invention is such that the first structure is configured to snap into place at least one external part of the internal reinforcement element.

[0028] Thus, a first structure configured to snap at least an external part of the internal reinforcement element allows a less strong fixing of the internal reinforcement element in the direction of welding of the internal reinforcement element while ensuring an increased fixing of the internal reinforcement element in the other directions, the moving bodies taking over the external parts of the internal reinforcement element not located at the welding points.

[0029] The expression "moving bodies coming into contact with external parts of the internal reinforcement element not located at the weld points" means that the moving bodies are brought into contact with external parts of the internal reinforcement element not located at the weld points and exert pressure on them.

[0030] According to a preferred embodiment, the plastic tank frame for a motor vehicle according to the invention is such that the at least two bodies movable relative to each other are tabs.

[0031] Thus, bodies that move relative to each other and have a tongue-like shape allow for a good compromise between rigidity and flexibility of the moving bodies.

[0032] According to a preferred embodiment, the plastic tank frame for motor vehicles according to the invention is such that the retention means configured to retain the internal reinforcement element is in the form of a recess or a projection.

[0033] Thus, a retention means configured to retain the internal reinforcement element in the form of a recess or a projection allows for easier manufacturing of mobile bodies.

[0034] According to a preferred embodiment, the plastic tank support for a motor vehicle according to the invention is such that at least one stop element comprises a rod, preferably a ribbed rod. The rod advantageously has an X, U, V, or W shape.

[0035] Thus, a stop element comprising a rod allows for simpler adjustment of the stop's positioning. The term "rod" refers to an elongated part extending along a principal axis, projecting from a surface of the primary structure along that axis.

[0036] According to a preferred embodiment, the plastic tank reinforcement for a motor vehicle according to the invention is based on a material selected from the group of materials consisting of high-density polyethylene (HDPE), polyoxymethylene (POM), polyamide (PA), polyphthalamide (PPA), and polyketone (PK). Preferably, the reinforcement is in the form of a single piece.

[0037] According to a preferred embodiment, the plastic fuel tank frame for motor vehicles according to the invention comprises means for supporting fuel tank components such as a vent or fluid line, a valve such as a check valve, a Roll Over Valve (ROV), or a Fill Limit Vent Valve (FLVV), a temperature sensor, a level sensor, or a quality sensor. The frame may also include or serve as a support for a deflector, also called a noise baffle or anti-slosh baffle. Preferably, the fuel tank components and / or the deflector are attached to the frame by means of a clip. This clip allows for easy handling and attachment of the fuel tank components and / or the deflector to the frame.

[0038] According to a preferred embodiment, the plastic tank frame for motor vehicles according to the invention is such that it comprises a deformable link connecting the frame and at least one means for fixing the internal reinforcement element, said link being configured to deform in order to allow relative displacement of the frame and at least one means for fixing the internal reinforcement element with respect to each other under the effect of external mechanical stress on the frame.

[0039] Thus, a deformable link reduces stress on the reinforcement. This stress is linked to temperature and pressure variations within the tank, which generate deformations through the displacement of the internal reinforcement element(s) relative to one another. These displacements generate stress on the reinforcement if no deformable link is present on the reinforcement itself, and therefore between the reinforcement and the internal reinforcement element(s). Preferably, the deformable link allows deformations along axes parallel to the weld surface of the internal reinforcement element on the tank.

[0040] According to a preferred embodiment, the plastic tank frame for a motor vehicle comprises a receiving element configured to receive an insertion means, such as an insertion rod, used during tank manufacturing to insert an assembly including the frame into a parison. This receiving element advantageously takes the form of a hole or a blind hole.

[0041] According to a preferred variant, the plastic tank reinforcement for motor vehicles is such that it comprises a plurality of through holes. Preferably, the reinforcement is also provided with stiffening means such as ribs.

[0042] Thus, the presence of through holes in the frame allows for easier movement of the liquid contained in the tank. The presence of stiffening elements on the frame allows it to better withstand the stresses associated with attaching a component to the frame and the stresses experienced by the frame itself within a fuel tank.

[0043] Another object of the invention is to provide a plastic tank assembly for a motor vehicle according to claim 13, comprising a plastic tank frame for a motor vehicle according to the invention and an internal reinforcing element configured to be snapped onto the frame. Preferably, the internal reinforcing element is either in the form of a pillar, preferably cylindrical, or in the form of a diabolo, or in the form of a retention device. Preferably, the retention device comprises a wall having a central recess, a portion of the wall comprising reinforcing ribs. The wall of the retention device may be flat or curved. Said reinforcing element preferably comprises, at its two ends, two overmolded portions made of a material suitable for welding to the tank walls.The internal reinforcement element preferably consists of a central portion made of polyoxymethylene (POM), polyphthalamide (PPA), polyketone (PK), polyamide (PA), or metal, and two overmolded portions made of high-density polyethylene (HDPE). The internal reinforcement element preferably includes a zone of mechanical weakness capable of causing breakage when subjected to high stresses from forces exerted on the tank. This zone of mechanical weakness takes the form of a smaller cross-section, at least one notch, or a reduced wall thickness. The internal reinforcement element may include a hollow portion, particularly in the central part of the reinforcement element.

[0044] Another object of the invention is to provide a plastic tank for a motor vehicle according to claim 16 comprising an assembly for a plastic tank for a motor vehicle according to the invention.

[0045] An object of the invention is also to provide a method for manufacturing a plastic tank for a motor vehicle according to claim 17.

[0046] According to an advantageous implementation of the method for manufacturing a plastic tank for a motor vehicle according to the invention, said method includes a step of fixing, more precisely snapping, an internal reinforcement element to a frame for a plastic tank for a motor vehicle according to the invention. 5. List of figures

[0047] Other features and advantages of the invention will become clearer upon reading the following description of a preferred embodiment, given by way of simple illustrative and non-limiting example, and the accompanying drawings, among which: there figure 1 presents an assembly for a plastic tank for a motor vehicle according to the invention, the figure 2 illustrates a means for fixing an internal reinforcing element of a frame according to the invention, the figure 3 illustrates the connection between an internal reinforcing element and a reinforcement according to the invention. 6. Description of at least one embodiment of the invention

[0048] We present, in relation to the figure 1An embodiment of an assembly 4 for a plastic tank for a motor vehicle according to the invention, comprising a frame 1 and internal reinforcing elements 2. The internal reinforcing element 2 is intended to connect two opposing walls of the tank. The frame 1 for the plastic tank for a motor vehicle includes at least one means 10 for attaching an internal reinforcing element 2 to the tank. The frame 1 includes a deformable link 11 connecting the frame 1 and the means 10 for attaching the internal reinforcing element 2, said link 10 being capable of deforming to allow relative displacement of the frame 1 and the means 10 for attaching the internal reinforcing element 2 with respect to each other under the effect of an external mechanical stress on the frame 1.The frame 1 also includes a receiving element 12 configured to receive an insertion means, such as an insertion rod, for inserting the assembly 4 into a parison during tank manufacturing. This receiving element 12 is advantageously in the form of a hole or a blind hole. The frame 1 is made of a material selected from the group of materials consisting of high-density polyethylene (HDPE), polyoxymethylene (POM), polyamide (PA), polyphthalamide (PPA), and polyketone (PK). The frame 1 also includes support means 3 for fuel tank components such as a pump, a level sensor, a pressure sensor, a temperature sensor, and a valve such as a check valve, a roll-over valve (ROV), or a fill-limit vent valve (FLVV), or for venting and fuel lines. The frame 1 also includes a plurality of through holes 13.Preferably, the reinforcement 1 is also provided with stiffening means such as ribs (not shown). The internal reinforcement elements 2 are in the form of a pillar 21, preferably cylindrical, or in the form of a diabolo. The internal reinforcement elements 2 may also be in the form of a retention device 20 comprising a wall with a central recess, a portion of the wall comprising reinforcing ribs. The wall of the retention device may be flat or curved. These reinforcement elements 2 preferably comprise, at both ends, two overmolded portions made of a material suitable for welding to the walls of the tank.The internal reinforcement elements 2 are preferably made of a central part based on polyoxymethylene (POM), polyphthalamide (PPA), polyketone (PK), polyamide (PA), metal, and two overmolded parts made of high-density polyethylene (HDPE). The internal reinforcement elements preferably include a zone of mechanical weakness capable of causing breakage of said elements when they are subjected to high stresses from forces exerted on the tank.

[0049] There figure 2presents a means 10 for attaching an internal reinforcement element of the tank to a frame 1. Said means 10 comprises at least a first structure 100 configured to snap into place at least a portion of the internal reinforcement element, said at least a first structure comprising at least two movable bodies 1000 in the form of tabs 10000, each movable body 1000 being provided with a retaining means 10001 configured to retain the internal reinforcement element 2 in the opposite direction to the snap-in direction, said retaining means 10001 being in the form of a projection, and at least one stop element 1001 comprising a U-shaped rod. The stop element 1001 projects in the opposite direction to the snap-in direction in order to provide a stop for the internal reinforcement element 2 when the latter is snapped into place. The first structure 100 is configured to snap into at least one internal part of the internal reinforcement element 2.The stop element 1001, combined with the retaining means 10001, forms a vise such that, after snapping, at least a portion of the internal reinforcing element 2 is held in position and clamped by the combined retention provided by the retaining means 10001 and at least one stop element 1001. The stop element 1001 has at least two stop surfaces: a first surface intended to form an axial stop surface for the internal reinforcing element 2 in the snapping direction, and a second surface intended to form a radial stop surface for the internal reinforcing element 2 in a direction of rotation of the internal reinforcing element 2 about an axis parallel to the axis of the axial stop. More specifically, in the example of the... figure 2, the axial stop surface corresponds to the U-shaped front face of the element 1001, extending substantially parallel to the rear face of the first structure 100, and the radial stop surface corresponds to one or more of the surfaces of the element 1001 extending substantially perpendicular to the rear face of the first structure 100.

[0050] There figure 3This illustrates the connection between an internal reinforcing element 2 and a reinforcement 1 according to the invention, forming part of a plastic tank assembly for a motor vehicle according to the invention. The connection is made using a means 10 comprising at least a first structure 100 configured to snap into place at least a portion of the internal reinforcing element 2, said at least a first structure 100 comprising four movable bodies 1000 in the form of tabs, each movable body 1000 being provided with a retaining means 10001 configured to retain the internal reinforcing element 2 in the opposite direction to the snap-in direction, said retaining means 10001 being in the form of a projection, and at least one stop element. The first structure 100 is configured to snap into place at least an internal portion 200 of the internal reinforcing element 2.The internal reinforcement element 2 is in the form of a retention device 20 comprising a wall 201 with a central recess 200, and a portion of the wall 201 comprising reinforcing ribs 2010. The wall of the retention device is curved. The reinforcement element preferably comprises, at its two ends, two overmolded portions made of a material suitable for welding to the tank walls. The internal reinforcement element preferably consists of a central portion 202 made of polyoxymethylene (POM), polyphthalamide (PPA), polyketone (PK), polyamide (PA), or metal, and two overmolded portions made of high-density polyethylene (HDPE) 203, 204. The internal reinforcement element preferably includes a zone of mechanical weakness capable of causing the element to break when subjected to high stresses from forces exerted on the tank.

Claims

1. A frame (1) for a plastic tank for a motor vehicle, comprising at least one means (10) for attaching an internal reinforcing element (2) of the tank which is intended to connect two opposite walls of said tank, characterized in that the at least one means (10) for attaching the internal reinforcing element (2) comprises at least one first structure (100) configured to snap-fit at least a portion of the internal reinforcing element (2), said at least one first structure (100) comprising: - at least two bodies (1000) that are movable relative to each other, each movable body (1000) being provided with a holding means (10001) configured to hold the internal reinforcing element (2) in a direction opposite to the snap-fitting direction, and characterized in that the first structure (100) comprises - at least one stop element (1001), separate from the movable bodies (1000), protruding in a direction opposite to the snap-fitting direction in order to provide a stop for the internal reinforcing element (2) when said element is snap-fit into place.

2. The frame (1) for a plastic tank for a motor vehicle as claimed in claim 1, such that the at least one stop element (1001) combined with the holding means (10001) form a clamp so that after snap-fitting, the at least a portion of the internal reinforcing element (2) is held in position and clamped by the combination of the hold provided by the holding means (10001) and the at least one stop element (1001).

3. The frame (1) for a plastic tank for a motor vehicle as claimed in either one of claims 1 or 2, such that said at least one first structure (100) is configured to snap-fit at least an internal portion of the internal reinforcing element (2).

4. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that said at least one first structure (100) is configured to snap-fit at least an external portion of the internal reinforcing element (2).

5. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the at least two bodies (1000) that are movable relative to each other are tabs (10000).

6. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the holding means (10001) configured to hold the internal reinforcing element (2) takes the form of a recess or a protrusion.

7. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the at least one stop element (1001) comprises a rod.

8. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the frame comprises support means (3) for supporting components of the fuel tank such as a ventilation or liquid line, a valve, a temperature sensor, a level sensor, a pressure sensor or a quality sensor.

9. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the frame comprises at least one component selected from among a noise-reducing baffle or slosh baffle, a valve, a ventilation or liquid line, a temperature sensor, a level sensor, a pressure sensor or a quality sensor.

10. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that it comprises a deformable connection (11) connecting the frame (1) and the at least one means (10) for attaching the internal reinforcing element (2), said connection (11) being designed to deform in order to allow a relative movement of the frame (1) and of the at least one means (10) for attaching the internal reinforcing element (2) with respect to one another when subjected to a mechanical load external to the frame (1).

11. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the frame comprises an accommodating member (12) configured to accommodate an insertion means such as an insertion rod for example.

12. The frame (1) for a plastic tank for a motor vehicle as claimed in any one of the preceding claims, such that the frame comprises a plurality of through-holes (13).

13. An assembly (4) for a plastic tank for a motor vehicle comprising a frame (1) for a motor vehicle tank as claimed in any one of claims 1 to 12 and an internal reinforcing element (2) configured to be snap-fit onto the frame (1).

14. The assembly (4) for a plastic tank for a motor vehicle as claimed in claim 13, such that the reinforcing element is selected from among a pillar (21) and a holding member (20).

15. The assembly (4) for a plastic tank for a motor vehicle as claimed in claim 14, such that the holding member (20) comprises a wall (201) provided with a central recess (200), a portion of the wall (201) comprising reinforcing ribs 2010).

16. A plastic tank for a motor vehicle comprising an assembly (5) for a plastic tank for a motor vehicle as claimed in any one of claims 13 to 15.

17. A method for manufacturing a plastic tank for a motor vehicle comprising a step of snap-fitting an internal reinforcing element (2) to a frame (1) for a plastic tank for a motor vehicle as claimed in any one of claims 1 to 12.