Method for Producing a Pressure Vessel and Pressure Vessel

Abstract

A pressure vessel and a method for producing a pressure vessel are provided. The pressure vessel has a liner and a fiber-reinforced laminate, which surrounds the liner and has a first fiber layer and a second fiber layer, which are incorporated in a matrix material. The method includes: a) providing the liner for storing a fluid, having a cylindrical region and two cap regions at opposite ends of the cylindrical region, b) wrapping a fibrous material impregnated with matrix material around the liner at the cap regions and the cylindrical region to produce the first fiber layer, which is already permeated with matrix material, c) arranging the second fiber layer around the first fiber layer, wherein the second fiber layer is formed by at least one braided sleeve of dry fibers, and d) curing or consolidating the matrix material without supplying additional matrix material to produce the fiber-reinforced laminate.

Claims

1.-10. (canceled)

11. A method for producing a pressure vessel, comprising: a) providing a liner for storing a fluid, having a cylinder region and two cap regions at opposite ends of the cylinder region; b) wrapping the liner at the cap regions and the cylinder region with a fiber material impregnated with matrix material, to produce a first fiber layer already imbued with matrix material; c) arranging a second fiber layer around the first fiber layer, the second fiber layer having been formed by at least one braided sleeve of dry fibers; and d) curing or consolidating the matrix material, without supplying additional matrix material, to produce a fiber-reinforced laminate surrounding the liner.

12. The method according to claim 11, wherein the impregnated fiber material used in step b) comprises wet-impregnated rovings, pre-impregnated rovings, hybrid rovings, unidirectionally fiber-reinforced tapes, or prepregs.

13. The method according to claim 11, wherein the first fiber layer is produced by fiber winding with wet-impregnated rovings.

14. The method according to claim 11, wherein the first fiber layer is produced by wrapping the liner with a prepreg.

15. The method according to claim 11, wherein the second fiber layer is produced by overbraiding the liner and the first fiber layer with dry fibers.

16. The method according to claim 11, wherein the second fiber layer is applied by enrobing with at least one prefabricated braided sleeve.

17. The method according to claim 11, wherein the curing in step d) takes place in an oven process.

18. The method according to claim 11, wherein the curing in step d) takes place in a temperature-conditioned mold.

19. A pressure vessel, comprising: a liner for storing a fluid, with a cylinder region and two cap regions at opposite ends of the cylinder region; a fiber-reinforced laminate which surrounds the liner and has a first fiber layer and a second fiber layer, which are incorporated in a common matrix material, wherein the first fiber layer is wound around the liner at the cap regions and the cylinder region, and the second fiber layer is formed of at least one braided sleeve which is arranged around the first fiber layer.

20. The pressure vessel according to claim 19, wherein the pressure vessel is a hydrogen tank for a motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 shows a section of an illustrative pressure vessel in a view in longitudinal section;

[0036] FIG. 2 shows a schematic representation of a liner; and

[0037] FIG. 3 shows a schematic representation of the pressure vessel at different points in time of the method, in a cross section.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 shows a longitudinal section through an illustrative pressure vessel 1 in the form of a hydrogen tank for a motor vehicle. Only the left half of the pressure vessel 1 is represented in FIG. 1. The pressure vessel 1 may in particular have a rotationally symmetrical design.

[0039] The pressure vessel has a liner 10; see FIG. 2. The liner 10 has a cylinder region 12 and two cap regions 14A, 14B at the ends of the cylinder region 12. In FIG. 1 only one cap region 14A, and also part of the cylinder region 12, is represented. In the cap region 14A there may additionally be a connector 20 provided for the mounting of a valve, a so-called “boss”. This may, for example, be a metal component with a thread, which is mounted onto the cap region 14A of the liner 10. At the other end of the cylinder region 12, the liner 10 has a second cap region 14B, not represented in FIG. 1, and in this region, for example, a closure or a further connection facility may be provided.

[0040] Formed on the outside around the liner 10 is a fiber-reinforced laminate 30. The fiber-reinforced laminate has a first fiber layer 32 and a second fiber layer 34. The first fiber layer 32 is wound around the liner 10, with one or more plies of fibers one above another being able to form the first fiber layer 32. Formed on the outside on the first fiber layer 32 is a second fiber layer 34. The second fiber layer 34 takes the form of a braid and may be formed by one or more braid plies. The first and second fiber layers 32, 34 each extend over the cylinder region and the cap regions of the liner.

[0041] Both fiber layers are embedded in a common matrix material 36.

[0042] FIG. 3 shows the production of the pressure vessel 1. The liner 10 is provided first in step A. The liner 10 is preferably a thermoplastic blow-molded element. Connectors or closures, not represented in FIG. 3, may be integrated in or mounted onto the liner 10.

[0043] In step B the first fiber layer 32 is applied. This is done by winding multiple layers of fibers, overloaded with resin, around the liner 10, so that the first fiber layer 32 is already imbued with the matrix material 36. The first fiber layer 32 is wound both onto the cap regions 14A, 14B and onto the cylinder region 12. Winding is accomplished preferably in a wet winding process.

[0044] In step C the second fiber layer 34 is arranged around the first fiber layer 32. The second fiber layer 34 is applied as a dry braid. For this purpose the braid may be provided as a prebraided sleeve and may be drawn over the liner 10 and the first fiber layer 34. Alternatively the braid of dry fibers is braided directly onto the first fiber layer 34. In this case it is preferred if the braid angle in the cylinder region 12 is constant. In the cap region 14A, 14B, the braid angle may vary and is preferably smaller than in the cylinder region 12.

[0045] In step D the matrix material 36 is cured to form the fiber-reinforced laminate. Because fibers overloaded with resin are used for the first fiber layer 32, sufficient matrix material 36 is applied in the winding process itself in order to infiltrate the braid 34 as well. Additional matrix material 36 is therefore not added in either step C or step D. The matrix material 36 is cured at elevated temperature, in an oven process, for example. The increased temperature lowers the viscosity of the matrix material 36, which also saturates the applied braid 34, represented by the arrows in FIG. 3. After the curing operation, both the first and the second fiber layers are incorporated in the matrix material 36. For curing, the layer structure may alternatively also be introduced into a compression mold (not represented), where the workpiece is additionally provided with an external pressure from the outside and press-molded. During this procedure, the liner may be filled with a fluid and placed under an internal pressure P for shape retention.

[0046] Alternatively to the method described, it is also possible to use a thermoplastic matrix material 36, in which case, for example, the first fiber layer 32 in the form of thermoplastic fiber tape may be wound around the liner 10. For deposition on the liner 10 and for subsequent infiltration of the braid 34, the thermoplastic matrix material may be heated, for example. The subsequent consolidation may take place with or without compression mold.

LIST OF REFERENCE SYMBOLS

[0047] 1 pressure vessel [0048] 10 liner [0049] 12 cylinder region [0050] 14A, 14B cap regions [0051] 20 connector [0052] 30 fiber-reinforced laminate [0053] 32 first fiber layer [0054] 34 second fiber layer [0055] 36 matrix material [0056] P internal pressure [0057] A, B, C, D method steps