Liquid vehicle tank comprising a fastened component

Abstract

A liquid vehicle tank (1) having a wall made of a plastic material, the tank (1) comprising a component (3, 5) affixed to the wall, the component (3, 5) having a portion (10) embedded in the wall, the embedded portion (10) having an external surface (21) a part of which is chemically incompatible with the plastic material of the wall, wherein the tank (1) also comprises a strengthening element welded to the wall over the embedded portion (10) of the component (3, 5).

Claims

1. A liquid vehicle tank having a wall made of a plastic material, the tank comprising a component having a portion embedded in the tank wall, the component and the portion embedded in the tank being integrally formed, wherein the tank comprises at least one strengthening element welded to the tank wall, over the portion of the component embedded in the wall, to withstand the stress of the plastic material of the tank wall in a region surrounding the embedded portion of the component, wherein said portion embedded in the tank wall is achieved by burying said portion in a bloc of solid material forming the wall of the tank to trap the part within the tank wall such that said portion cannot be withdrawn from the bloc without opening the bloc which encapsulates said portion, and wherein the component and the strengthening element are two separate pieces the strengthening element being welded to the tank separately from the component and the embedded portion of the component.

2. The tank according to claim 1, wherein the strengthening element has a ring shape.

3. The tank according to claim 1, wherein the embedded portion has an external surface a part of which is chemically incompatible with the plastic material of the wall, and the strengthening element is welded to the wall over the embedded portion of the component.

4. The tank according to claim 1, wherein the wall has an opening and the component is affixed to the wall around the opening.

5. The tank according to claim 1, wherein an external surface of the embedded portion has a second part which is chemically compatible with the plastic material of the wall and which is welded to the wall of the tank.

6. The tank according to claim 1, wherein the part of an external surface of the component which is chemically incompatible with the plastic material of the wall is made of a liquid impermeable layer.

7. The tank according to claim 1, wherein the wall of the tank comprises a liquid impermeable barrier.

8. The tank according to claim 7, wherein the embedded portion of the component comprises an internal surface which follows the shape of the liquid impermeable barrier of the wall.

9. The tank according to claim 8, wherein the maximal distance between the internal surface of the embedded portion of the component and the fuel impermeable barrier of the wall is less than 200 μm.

10. The tank according to claim 8, wherein the internal surface of the embedded portion of the component comprises a projection.

11. Method for fastening a component to a wall of a tank, comprising the following steps: overmolding a portion of the component on a parison during blow molding of the parison so that the portion is at least partially embedded in the parison such that said portion is buried in a bloc of solid material forming the wall of the tank which traps the part within the tank wall such that said portion cannot be withdrawn from the bloc without opening the bloc which encapsulates said portion, the component and the embedded portion being integrally formed, welding a strengthening element to the wall over the portion of the component embedded in the wall to withstand the stress of the plastic material of the tank wall in a region surrounding the embedded portion of the component, and wherein the component and the strengthening element are two separate pieces the strengthening element being welded to the tank separately from the component and the embedded portion of the component.

12. The method according to claim 11, wherein an opening is drilled in the rigid wall through the portion of the component embedded in the parison.

13. The method according to claim 11, wherein an opening is obtained by piercing the parison during blow molding of the parison at the time the portion of the component is overmolded around the opening.

14. A liquid vehicle tank having a wall made of a plastic material, the tank comprising a component having a portion embedded in the tank wall, wherein the tank comprises at least one strengthening element welded to the tank wall, over the portion of the component embedded in the wall, to withstand the stress of the plastic material of the tank wall in a region surrounding the embedded portion of the component, wherein said portion embedded in the tank wall is achieved by burying said portion in a bloc of solid material forming the wall of the tank to trap the part within the tank wall such that said portion cannot be withdrawn from the bloc without opening the bloc which encapsulates said portion, and wherein the component and the strengthening element are two separate pieces and the strengthening element is attached to a radially outer end of the embedded portion of the component.

Description

(1) The invention will be better understood through the following figures which illustrate certain concrete aspects of the invention. The figures are only shown as examples and do not limit the scope of the present invention.

(2) FIG. 1 is a global view of a tank with two components welded thereon.

(3) FIG. 2 is a longitudinal sectional view of one of the components and the part of the tank receiving the component, according to a first embodiment of the invention.

(4) FIG. 3 is a longitudinal sectional view of one of the components and the part of the tank receiving the component, according to a second embodiment of the invention.

(5) FIG. 4 is a longitudinal sectional view of one of the components and the part of the tank receiving the component, according to a third embodiment of the invention.

(6) FIG. 5 is a longitudinal sectional view of one of the components and the part of the tank receiving the component, according to a fourth embodiment of the invention.

(7) FIG. 1 shows a tank 1 comprising two components 3, 5 welded thereon. The first component of the tank 1 is a nipple 3 located in the upper part of the tank 1 and an inlet check valve 5 located in the lower part of the tank 1.

(8) The shape of the tank 1 has no importance in the context of this invention. The only relevant geometrical feature of the tank is its shape in the part 3a, 5a around each component 3, 5.

(9) Nipple 3 and inlet check valve 5 are components which connect to the tank 1 in order to allow a fluid communication between the inside and the outside of the tank, by means external pipes (not shown). The invention is not limited to such components allowing a fluid circulation between the inside and the outside of the tank. In other words, the components 3, 5 may be closed at one end to carry out a specific function which would not be a circulation of liquid.

(10) In the following figures, sectional views are represented of component 5. However, it could be any one of the two components 3, 5 of FIG. 1, which are given only as examples of possible components weldable to a tank recording to the invention.

(11) In the sectional view of FIG. 2, part 5a of the tank wall 7 is represented with a hole 7a. The component wall 9 is represented with an opening 9a in front of the hole 7a. The component has a cylindrical shape in this example but any shape of the component would be acceptable. It comprises a portion 10 which is embedded in the tank wall.

(12) The tank wall 7 and the component wall 9 each comprise an impermeable layer 11, respectively 13, which prevents the liquid present inside the tank 1 from passing through the tank wall 7 or through the component wall 9. In this example, the tank impermeable layer 11 is included inside the tank wall 7 and is roughly located in the middle of the thickness of the tank wall 7. The component impermeable layer 13 covers the internal face of the component wall 9 and wraps its portion embedded in the tank wall. In this example, the tank is a fuel tank and the impermeable layers 11 and 13 are fuel impermeable layers made of EVOH.

(13) Since the component impermeable layer 13 is chemically incompatible with the plastic material of the tank wall, the embedded portion 10 has an external surface which is covered by chemically incompatible with the plastic material of the tank wall.

(14) Thus, after having penetrated in the tank wall 7, the portion 10 of the component embedded in the tank wall does not merge with the material of the tank wall but is only clamped in the tank wall. The clamping part of the tank wall around the embedded portion 10 of the component may open and release the component 5.

(15) To prevent such a release, a strengthening ring 15 is welded to the tank wall, over the embedded portion 10 of the component. The strengthening ring 15 is made of a material which is chemically compatible with the material of the tank wall 7. Preferably, it is harder than the material of the tank wall.

(16) In other words, the strengthening ring 15 is welded to the tank wall 7 to withstand the stress of the plastic material of the tank wall in a region surrounding the embedded portion 10 of the component 5.

(17) On the internal side of the embedded portion 10 of the component, facing the inside of the tank, a sharp shape 17 of the component increases the leak-tighness of the welding, by lengthening the escape way 19 (represented by a dashed line) for the liquid coming from inside the tank.

(18) In the embodiment of FIG. 3, the component 5 has an embedded portion 10 which is not entirely covered by the component impermeable layer. It leaves a surface 21 of the component, on the embedded portion 10, free for welding with the tank wall 7.

(19) At the same time, it leaves an outside (i.e. not embedded in the tank wall) surface 23 of the component free for welding with the strengthening ring 15 when the latter is subsequently welded to the tank wall. This further reinforces the mechanical resistance of the welding.

(20) FIG. 4 shows a combination of the embodiments of FIGS. 2 and 3: the embedded portion 10 of the component has a sharp internal face 25 for the improvement of the leak-tighness of the welding, and the strengthening ring is welding to the component for the improvement of the mechanical resistance of the welding.

(21) FIG. 5 shows another embodiment in which the component is integrally made of an impermeable material. In this case, the component is merely clamped inside the tank wall, as the component of FIG. 2, and the solidity of the welding results from the welding of the strengthening ring, over the embedded portion 10 of the component.

(22) The invention is not limited to the above embodiments and other embodiments exists and will appear clearly to one skilled in the art. For example, the filler pipe and the fuel tank can both be multilayer structures.

(23) The invention can also be applied to a fluid tank. More precisely, the invention can be applied to a gas tank, for example a tank for the storage of hydrogen or ammonia gas.

(24) In an alternative embodiment, the invention relates to a gas tank having a wall made of a plastic material, the gas tank comprising a component having a portion embedded in the gas tank wall. The gas tank is such that it comprises at least one strengthening element welded to the gas tank wall to withstand the stress of the plastic material of the gas tank wall in a region surrounding the embedded portion of the component. The gas tank wall can be made of a monolayer or multilayer structure. In case of multilayer structure, it can comprise a gas impermeable layer.