High pressure tank and its manufacturing method

Abstract

To provide a high pressure tank which prevents damage of a liner caused by cracks of fibers to achieve long life, and to provide a manufacturing method of the high pressure tank.SOLUTION: A high pressure tank 10 includes: a resin liner 12; a reinforcement layer 14 formed by multiple fiber layers formed by winding fibers 36 around an outer surface of the liner 12 multiple times; and a mouth ring 16a which is fixed to an axial end of the liner 12 and formed with a supply / discharge hole 17 for supplying / discharging a fluid to / from the liner 12. A starting end 36s, a start point of winding of the fibers 36, is arranged overlapping with the mouth ring 16a.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a high-pressure tank having a reinforcing layer covering the outer surface of a liner, and a method for manufacturing the same. [Background technology]

[0002] High-pressure tanks are widely used as containers for storing fluids such as gases and liquids. For example, high-pressure tanks are installed in fuel cell vehicles to store hydrogen gas to be supplied to the fuel cell system.

[0003] Known examples of this type of high-pressure tank include a resin liner that contains a hollow interior of the fluid, and a reinforcing layer made of fiber-reinforced resin that covers the outer surface of the liner to reinforce it (see, for example, Patent Document 1 below). The reinforcing layer is generally formed by a manufacturing method called filament winding. In filament winding, a resin-impregnated fiber-reinforced plastic (FRP) is wound multiple times around the outer wall of the liner, and the resin is then cured by heating. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-249147 A Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional filament winding, when the fibers start to be wound around the liner, a step occurs between the liner and the fiber end (starting end). The step causes a shear force to act on the fibers that overlap the step (the fibers in the innermost layer of the reinforcing layer), causing cracks in the fibers in the innermost layer. When the resin liner is pushed into the cracks in the fibers by the internal pressure of the high-pressure tank, the liner breaks at the point where it is pushed in. This can reduce the durability of the high-pressure tank.

[0006] In view of the above, an object of the present invention is to provide a high-pressure tank capable of extending its service life by preventing damage to the liner caused by cracks in the fibers, and a method for manufacturing the same. [Means for solving the problem]

[0007] A first aspect of the present invention is a high-pressure tank comprising a resin liner, a reinforcing layer consisting of a plurality of fiber layers formed by winding fiber multiple times around the outer surface of the liner, and a nozzle fixed to the axial end of the liner and having a supply and drainage hole for supplying and draining fluid to and from the liner, wherein a starting end, which is the beginning of the winding of the fiber, is positioned overlapping the nozzle.

[0008] A second aspect of the present invention is a method for manufacturing a high-pressure tank, comprising: an assembly providing step of providing an assembly in which a nozzle having a supply and drainage hole formed therein for supplying and draining fluid to and from a resin liner is fixed to an axial end of the liner; and a reinforcing layer forming step of forming a reinforcing layer consisting of a plurality of fiber layers by winding fiber a plurality of times on the outer surface of the liner of the assembly, wherein in the reinforcing layer forming step, a starting end, which is the beginning of the winding of the fiber, is positioned so as to overlap the nozzle. Effect of the Invention

[0009] According to the present invention, since the winding start of the fibers constituting the reinforcing layer is arranged overlapping the mouthpiece, the liner will not be damaged even if a crack (damage) occurs in the innermost layer of the reinforcing layer due to a step caused by the start end. Therefore, by preventing damage to the liner caused by cracks in the fibers, it is possible to extend the life of the liner. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view taken along an axial direction of a high-pressure tank according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view of the liner and reinforcing layer of the high-pressure tank shown in FIG. 1. [Diagram 3]FIG. 2 is a perspective view illustrating a helical winding. [Figure 4] FIG. 2 is a cross-sectional view of a main portion illustrating the position of the start end (winding start end) of the fiber. [Diagram 5] 4 is a flowchart of a method for manufacturing a high-pressure tank. [Figure 6] FIG. 6A is a diagram illustrating one embodiment of a method for fixing a fiber to a spinneret, and FIG. 6B is a diagram illustrating another embodiment of a method for fixing a fiber to a spinneret. [Figure 7] FIG. 4 is a cross-sectional view showing a main part of a first modified example of the high-pressure tank. [Figure 8] FIG. 11 is a cross-sectional view of a main portion showing a second modified example of the high-pressure tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1 is, for example, a fuel tank (hydrogen tank) mounted on a fuel cell vehicle. When the high-pressure tank 10 is mounted on a fuel cell vehicle, the high-pressure tank 10 is filled with hydrogen gas at high pressure. The hydrogen gas is supplied to the anode of a fuel cell (or a fuel cell stack) mounted on the fuel cell vehicle.

[0012] The high-pressure tank 10 may be a tank applied to a vehicle other than a fuel cell vehicle. The high-pressure tank 10 may be a fuel gas tank for storing a fuel gas other than hydrogen gas, a gas tank used in equipment for filling the fuel gas tank with the gas, or a gas tank used for transporting the gas. The high-pressure tank 10 may be a tank for storing compressed natural gas or liquefied petroleum gas.

[0013] The high-pressure tank 10 includes a liner 12 having a fluid storage chamber 13 (filling chamber) formed therein, a reinforcing layer 14 covering the liner 12, and nozzles 16a, 16b fixed to both ends of the liner 12.

[0014] The liner 12 is made of, for example, high density polyethylene (HDPE) resin that exhibits hydrogen barrier properties. In this case, HDPE resin is inexpensive and easy to process, so there is an advantage that the liner 12 can be produced easily and at low cost. In addition, HDPE resin has excellent strength and rigidity, making it suitable for the liner 12 of the high-pressure tank 10.

[0015] The liner 12 has a hollow body portion 18 having a substantially cylindrical shape, and a first dome portion 20a and a second dome portion 20b provided at both ends of the body portion 18 as gradually converging portions. In this embodiment, the inner and outer diameters of the body portion 18 are substantially constant. The inner and outer diameters of the body portion 18 may be tapered toward the first dome portion 20a and the second dome portion 20b, respectively. The first dome portion 20a and the second dome portion 20b constitute both ends of the liner 12 in the axial direction.

[0016] An annular recess 22 recessed toward the inside in the axial direction of the liner 12 is provided on the inner periphery of each of the first dome section 20a and the second dome section 20b. A cylindrical protrusion 24 protruding toward the outside in the axial direction of the liner 12 is provided in the center of the annular recess 22. A male thread 26 is provided on the outer periphery of the cylindrical protrusion 24. A female thread 28 provided on the inner periphery of the nozzles 16a, 16b is screwed into the male thread 26 of the cylindrical protrusion 24, thereby fixing the nozzles 16a, 16b to the liner 12.

[0017] The nozzles 16a and 16b are cylindrical members having a supply / drain hole 17 for supplying and discharging fluid to and from the liner 12, and are made of, for example, metal. One nozzle 16a and the other nozzle 16b have the same configuration, so the configuration of one nozzle 16a will be described below as a representative example. The other nozzle 16b does not necessarily have to be provided.

[0018] The nozzle 16a has an internal thread 28 on its inner periphery. The internal thread 28 of the nozzle 16a is screwed into the external thread 26 of the cylindrical protrusion 24, thereby fixing the nozzle 16a to the liner 12. The nozzle 16a has an annular flange portion 30 interposed between the liner 12 and the reinforcing layer 14, and a cylindrical tubular portion 32 integrally connected to the flange portion 30 and having a smaller diameter than the flange portion 30.

[0019] The flange portion 30 is disposed in the annular recess 22 of the liner 12. A back surface 30b (surface facing the storage chamber 13) of the flange portion 30 abuts the liner 12 (specifically, the annular recess 22). A front surface 30a (surface opposite the storage chamber 13) of the flange portion 30 abuts the reinforcing layer 14. The tubular portion 32 protrudes from the flange portion 30 toward the outside in the axial direction of the liner 12. A tip of the tubular portion 32 is exposed from the reinforcing layer 14.

[0020] A pipe (not shown) is connected to the base 16a for supplying hydrogen gas to the anode or for replenishing hydrogen gas from a hydrogen replenishing source.

[0021] The reinforcing layer 14 is formed from fiber reinforced plastic (FRP) in which reinforcing fibers are impregnated with a resin base material. That is, the reinforcing layer 14 is a laminate formed by winding resin-impregnated fibers 36 (filaments, hereinafter simply referred to as "fibers 36") multiple times by filament winding, and then curing the resin by, for example, heating. Examples of FRP include CFRP and GFRP.

[0022] 2, the reinforcing layer 14 has an inner laminated portion 40 on the inner circumferential side including the start of winding of the fibers 36, an outer laminated portion 44 on the outer circumferential side including the end of winding of the fibers 36, and an intermediate laminated portion 42 interposed between the inner laminated portion 40 and the outer laminated portion 44. The dashed dotted line in FIG. 2 indicates the boundary between the first dome portion 20a and the trunk portion 18.

[0023] The inner laminate portion 40 is a laminate formed by laminating a plurality of low helical layers 46 formed by low helical winding of the fibers 36. Therefore, in the high-pressure tank 10, the innermost layer of the reinforcing layer 14 formed by low helical winding is the low helical layer 46. Similarly, the outer laminate portion 44 is a laminate formed by laminating a plurality of low helical layers 46 formed by low helical winding of the fibers 36.

[0024] Helical winding is a method of winding in which the fiber 36 is wound so that its extending direction is inclined at a predetermined inclination angle θ with respect to the longitudinal direction (axis a) of the body portion 18 of the liner 12, as shown in Fig. 3. In this specification, "low helical winding" refers to a case where the inclination angle θ is about 40° or less. Fig. 3 illustrates a case where the inclination angle θ is about 10°. In addition, in this specification, "high helical winding" refers to a case where the inclination angle exceeds about 40°.

[0025] In FIG. 2, the intermediate laminate 42 interposed between the inner laminate 40 and the outer laminate 44 is a mixed laminate of a hoop layer 50 formed by hoop winding the impregnated fiber 36 and a high helical layer 48 formed by high helical winding. The hoop layer 50 and the high helical layer 48 are alternately laminated. Hoop winding is a winding method in which the fiber 36 is wound so that its extension direction is approximately perpendicular to the longitudinal direction of the body 18 of the liner 12. The intermediate laminate 42, particularly the hoop layer 50, ensures the pressure resistance of the body 18. The intermediate laminate 42 may be formed only from a plurality of hoop layers 50 (the high helical layer 48 may not be provided).

[0026] As shown in Fig. 4, a starting end 36s, which is a portion where the fiber 36 starts to be wound around the liner 12 during filament winding, is disposed so as to overlap the die 16a. Specifically, the starting end 36s of the fiber 36 is disposed so as to overlap the flange portion 30. The starting end 36s of the fiber 36 abuts against the surface 30a of the flange portion 30. Note that in Fig. 4, the reinforcing layer 14 is shown by virtual lines for ease of understanding.

[0027] An example of a method for manufacturing the high-pressure tank 10 will be described below.

[0028] As shown in Fig. 5, the manufacturing method of the high-pressure tank 10 includes an assembly providing step S1 and a reinforcing layer forming step S2. In the assembly providing step S1, an assembly 58 (see Fig. 6A) is provided in which a cap 16a having a supply and drainage hole 17 for supplying and draining a fluid to and from the liner 12 is fixed to an axial end of a resin liner 12. In the reinforcing layer forming step S2, a reinforcing layer 14 made of a plurality of fiber layers is formed by winding the fiber 36 a plurality of times (filament winding) around the outer surface of the liner 12 of the assembly 58. In the reinforcing layer forming step S2, a starting end 36s, which is the start of winding the fiber 36, is arranged to overlap the cap 16a (flange portion 30).

[0029] In the reinforcing layer forming step S2, for example, the following method can be adopted.

[0030] In the embodiment shown in FIG. 6A, the fiber 36 is wound around the nozzle 16a (the tubular portion 32). Next, the formation of the fiber layer (low helical winding) is started. At that time, the second portion 36b of the fiber 36 is fixed to the nozzle 16a by overlapping the third portion 36c, which is the other portion of the fiber 36, on the second portion 36b that crosses the surface 30a of the flange portion 30 of the nozzle 16a from the first portion 36a of the fiber 36 wound around the tubular portion 32. Next, the fiber 36 is cut at a position P between the first portion 36a (wound portion) and the second portion 36b (overlapped portion) of the fiber 36, and the first portion 36a is removed from the nozzle 16a (the tubular portion 32). After that, the fiber 36 is wound around the liner 12 (and the nozzle 16a) to form a plurality of fiber layers (reinforcement layer 14) (see FIG. 2).

[0031] In the embodiment shown in Fig. 6B, the fibers 36 are arranged in a ring shape on the surface 30a of the flange portion 30 of the nozzle 16a. Next, the overlapping portions of the fibers 36 arranged in a ring shape are bonded together. This fixes the fibers 36 to the nozzle 16a. After that, the fibers 36 are wound around the liner 12 (and the nozzle 16a) to form a plurality of fiber layers (reinforcement layer 14) (see Fig. 2).

[0032] The high-pressure tank 10 configured as above provides the following effects.

[0033] As shown in FIG. 4, in the high-pressure tank 10, the start end 36s, which is the winding start of the fiber 36 constituting the reinforcing layer 14, is arranged overlapping the nozzle 16a, so that even if a crack (breakage) occurs in the innermost layer fiber 36 of the reinforcing layer 14 due to a step caused by the start end 36s, the liner 12 will not be broken. That is, even if a crack occurs in the innermost layer fiber 36 of the reinforcing layer 14 due to a step caused by the start end 36s, the crack is located at a position overlapping the nozzle 16a, so the liner 12 will not be pushed out by the internal pressure and enter the crack. Therefore, it is possible to prevent breakage of the liner 12 caused by the crack. Therefore, it is possible to extend the life of the high-pressure tank 10.

[0034] In the high-pressure tank 10, the start end 36s of the fiber 36 is arranged so as to overlap the flange portion 30 of the nozzle 16a. Since the start end 36s of the fiber 36 is arranged so as to overlap the flange portion 30 in this manner, the start end 36s of the fiber 36 can be easily positioned with respect to the nozzle 16a during filament winding.

[0035] In the high-pressure tank 10, the flange portion 30 is disposed between the liner 12 and the reinforcing layer 14. With this configuration, even if a crack occurs in the innermost fiber 36 of the reinforcing layer 14 due to a step caused by the start end 36s of the fiber 36, the flange portion 30 of the nozzle 16a is interposed between the crack and the liner 12, and the liner 12 does not come into contact with the crack. Therefore, damage to the liner 12 caused by the crack can be more effectively prevented.

[0036] Generally, when the innermost layer of the reinforcing layer is a low helical layer, at least one hoop winding is performed during filament winding to fix the starting end of the fiber winding, and the angle is changed to the low helical layer. In this case, a transition layer (a layer in which the angle of the fiber gradually changes to connect the hoop winding part at the start of winding and the low helical layer) needs to be provided between the hoop winding at the start of winding and the low helical layer. However, the transition layer does not contribute to pressure resistance, so FRP is wasted. In contrast, in the high-pressure tank 10 according to this embodiment, the starting end 36s of the fiber 36 is arranged overlapping the nozzle 16a, so that the low helical layer 46 can be formed from the start of winding of the fiber 36 without the transition layer being interposed during filament winding. In other words, the transition layer can be eliminated, so that the high-pressure tank 10 can be made lighter and less expensive.

[0037] 7 (first modified example), a protective member 60 is provided spanning the mouthpiece 16a (flange portion 30) and the liner 12. The protective member 60 is, for example, a resin sheet-like member formed in an annular shape along the flange portion 30. The protective member 60 is disposed between the flange portion 30 and the reinforcing layer 14.

[0038] In this case, the starting end 36s of the fiber 36 is disposed on the protective member 60 at a position overlapping the flange portion 30 as viewed from the axial direction of the liner 12. That is, the starting end 36s of the fiber 36 overlaps the flange portion 30 via the protective member 60. In this way, even if the starting end 36s of the fiber 36 is not in direct contact with the spine 16a but is disposed at a position overlapping the flange portion 30 as viewed from the axial direction of the liner 12, this is also included in the configuration in which "the starting end 36s, which is the start of winding of the fiber 36, is disposed overlapping the spine 16a."

[0039] Note that, instead of or in addition to the protective member 60, a liquid gasket may be disposed so as to overlap the flange portion 30. Such a configuration is also included in the configuration in which "the starting end 36s, which is the start of winding of the fiber 36, is disposed so as to overlap the spinneret 16a."

[0040] In the embodiment (second modified example) shown in Fig. 8, the flange portion 64 of the spinneret 62 is disposed inside the liner 12. In this configuration, the liner 12 is disposed on the surface 64a side of the flange portion 64. The start end 36s of the fiber 36 is disposed on the liner 12 at a position overlapping the flange portion 30 when viewed from the axial direction of the liner 12. In other words, the start end 36s of the fiber 36 overlaps the flange portion 64 with the liner 12 interposed therebetween.

[0041] Even in such a case, the liner 12 is not pushed out into the crack by the internal pressure of the storage chamber 13 and does not enter the crack, so damage to the liner 12 due to the crack can be prevented. In this way, even when the starting end 36s of the fiber 36 is not in direct contact with the nozzle 62, but is positioned so as to overlap the flange portion 64 when viewed from the axial direction of the liner 12, this is also included in the configuration in which "the starting end 36s, which is the beginning of winding of the fiber 36, is positioned overlapping the nozzle 62."

[0042] The above embodiment can be summarized as follows.

[0043] The above embodiment discloses a high-pressure tank (10) comprising a resin liner (12), a reinforcing layer (14) consisting of multiple fiber layers formed by winding fiber (36) multiple times around the outer surface of the liner, and a nozzle (16a) fixed to the axial end of the liner and having a supply and drainage hole (17) for supplying and draining fluid to and from the liner, in which a starting end (36s) of the fiber, which is the beginning of the winding, is positioned overlapping the nozzle.

[0044] In the above-mentioned high-pressure tank, the nozzle has a flange portion (30) overlapping the liner and a tubular portion (32) protruding from the flange portion axially outward from the liner, and the starting end of the fiber is arranged overlapping the flange portion.

[0045] In the above-mentioned high-pressure tank, the flange portion is disposed between the liner and the reinforcing layer.

[0046] In the above-mentioned high-pressure tank, the flange portion is disposed inside the liner.

[0047] In the above-mentioned high-pressure tank, the innermost layer of the plurality of fiber layers is a low helical layer (46).

[0048] The above embodiment also discloses a method for manufacturing a high-pressure tank (10) including an assembly providing step (S1) for providing an assembly (58) in which a nozzle (16a) having a supply and drainage hole (17) for supplying and draining a fluid to and from a resin liner (12) is fixed to an axial end of the liner, and a reinforcing layer forming step (S2) for forming a reinforcing layer (14) consisting of a plurality of fiber layers by winding fiber (36) a plurality of times on the outer surface of the liner of the assembly, in which a starting end (36s), which is the beginning of winding the fiber, is placed overlapping the nozzle in the reinforcing layer forming step.

[0049] In the above-mentioned method for manufacturing a high-pressure tank, the nozzle has a flange portion (30) overlapping the liner and a tubular portion (32) protruding from the flange portion axially outward from the liner, and in the reinforcing layer forming process, the starting ends of the fibers are positioned so as to overlap the flange portion.

[0050] In the above-described method for manufacturing a high-pressure tank, the reinforcing layer forming step includes a step of winding the fiber around the cylindrical portion, a step of overlapping a third portion (36c) of the fiber on a second portion (36b) of the fiber that crosses the surface (30a) of the flange portion from a first portion (36a) of the fiber that is wound around the cylindrical portion, thereby fixing the second portion of the fiber to the nozzle, and a step of cutting the fiber at a position between the first portion and the second portion to form the reinforcing layer. 1 and removing the portion from the base.

[0051] In the above-mentioned method for manufacturing a high-pressure tank, the reinforcing layer forming process includes a process of arranging the fibers in a ring shape on the flange portion, and a process of bonding overlapping portions of the fibers arranged in a ring shape.

[0052] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0053] 10...High pressure tank 12...Liner 14... Reinforcing layer 16a, 16b... Cap 30: flange portion 32: cylindrical portion 36...Fiber 36s...Beginning

Claims

1. A resin liner and a reinforcing layer formed by winding fibers multiple times on the outer surface of the liner and including a plurality of fiber layers; a nozzle fixed to an axial end of the liner and having a supply and drainage hole for supplying and draining a fluid to and from the liner; A high-pressure tank comprising: the nozzle has a flange portion overlapping the end portion of the liner when viewed in the axial direction, and a cylindrical portion protruding from the flange portion toward an outer side in the axial direction of the liner, The flange portion is disposed between the liner and the reinforcing layer, A high-pressure tank, wherein a starting end where the fibers begin to wind is positioned so as to overlap the end portion of the liner and the flange portion when viewed in the axial direction.

2. 2. The high-pressure tank according to claim 1, A high-pressure tank, wherein an innermost layer of the plurality of fiber layers is a low helical layer.

3. an assembly providing step of providing an assembly in which a mouthpiece having a supply and drainage hole for supplying and draining a fluid to and from a resin liner is fixed to an axial end of the resin liner; a reinforcing layer forming step of forming a reinforcing layer consisting of a plurality of fiber layers by winding a fiber a plurality of times on an outer surface of the liner of the assembly; A method for manufacturing a high-pressure tank having the nozzle has a flange portion overlapping the end portion of the liner when viewed in the axial direction, and a cylindrical portion protruding from the flange portion toward an outer side in the axial direction of the liner, The flange portion is disposed between the liner and the reinforcing layer, In the reinforcing layer forming process, a starting end of the fiber is positioned so as to overlap the end of the liner and the flange portion when viewed in the axial direction.

4. An assembly providing step of providing an assembly in which a nozzle having a supply and drainage hole for supplying and draining a fluid to and from a resin liner is fixed to an axial end of the resin liner; a reinforcing layer forming step of forming a reinforcing layer consisting of a plurality of fiber layers by winding a fiber a plurality of times on an outer surface of the liner of the assembly; A method for manufacturing a high-pressure tank having the nozzle has a flange portion overlapping the liner and a cylindrical portion protruding from the flange portion to an axially outer side of the liner, In the reinforcing layer forming step, a starting end of the fiber is arranged so as to overlap the flange portion, The reinforcing layer forming step includes: winding the fibers on the tubular portion; a step of fixing the second portion of the fiber to the nozzle by overlapping a third portion of the fiber on a second portion of the fiber that extends from a first portion wound around the cylindrical portion to a surface of the flange portion; cutting the fiber at a position between the first portion and the second portion to remove the first portion from the mouthpiece.

5. An assembly providing process for providing an assembly in which a nozzle having a supply and drainage hole for supplying and draining a fluid to and from a resin liner is fixed to an axial end of the resin liner; a reinforcing layer forming step of forming a reinforcing layer consisting of a plurality of fiber layers by winding a fiber a plurality of times on an outer surface of the liner of the assembly; A method for manufacturing a high-pressure tank having the nozzle has a flange portion overlapping the liner and a cylindrical portion protruding from the flange portion to an axially outer side of the liner, In the reinforcing layer forming step, a starting end of the fiber is arranged so as to overlap the flange portion, The reinforcing layer forming step includes: disposing the fibers in a ring shape on the flange portion; and bonding overlapping portions of the fibers arranged in a ring shape together.

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