DE102022116614A1 - TANK AND METHOD OF PRODUCTION - Google Patents

Abstract

A tank and a method for manufacturing the tank are provided, which are capable of preventing fiber misalignment during resin molding and suppressing deterioration in strength. The tank has a fibrous layer (17) comprising a helical layer (17A) having filaments (16) wrapped in a spiral form around an outer surface of a liner (12) and a braided layer (17E) having is formed in an overlapping manner on the outermost layer of the spiral layer (17A), the mesh layer (17E) having the fibers (16) wound so as to be woven alternately and having fiber intervals larger than that of the spiral layer (17A) are. The fiber layer (17) is impregnated with a resin (18).

Description

BACKGROUND

technical field

The invention relates to a fiber-reinforced tank and a method for its manufacture.

State of the art

Patent Literature 1 discloses a method of manufacturing a fiber-reinforced plastic (FRP) tank (hereinafter also referred to as a high-pressure tank). This manufacturing method first performs a coating step in which fibers are wrapped around a liner, then performs an impregnation step in which the fibers are impregnated with resin, and thereafter cures the resin by heating the resin-impregnated fibers.

Patent Literature 2 discloses a high-pressure tank (pressure vessel) manufactured using such a resin injection method (RTM method; RTM: Resin Transfer Molding). The high-pressure tank (pressure vessel) includes: a container main body having a cylindrical straight body part and a dome part having a hemispherical portion with a hemispherical shape and integrally formed at each end of the straight body part; a first reinforced portion formed by winding reinforcing fibers around an outer peripheral surface of one of the dome parts such that the reinforcing fibers are intertwined with each other; a second reinforcing portion formed by continuously spirally winding the reinforcing fibers around an outer peripheral surface of the straight body portion from the first reinforcing portion; and a third reinforcing portion formed by continuously winding the reinforcing fibers around an outer peripheral surface of the other dome member from the second reinforced portion in such a manner that the reinforcing fibers are intertwined with each other.

citation list

patent literature

• Patent Literature 1: JP 2020 - 085 199 A
• Patent Literature 2: JP 2020 - 026 817 A

EXECUTIVE SUMMARY

The above manufacturing method utilizing the RTM method separately performs the filament winding step and the resin impregnation step when manufacturing a high-pressure tank. However, fiber misalignment may occur in the straight body part during resin molding, resulting in deterioration of strength.

In view of this, the invention provides a tank and a method for manufacturing the tank capable of preventing fiber misalignment during resin molding and suppressing deterioration in strength.

In view of this, according to one aspect of the invention, a tank is disclosed, comprising: a hollow liner having a cylindrical straight body portion and a dome portion extending from an end portion of the straight body portion in an axial direction in an opposite direction to the straight body portion gradually narrowed; and a reinforcing layer formed on an outer surface of the liner by impregnating a fibrous layer comprising filaments wound in an overlapping manner in a radial direction with resin, the fibrous layer being a spiral layer or a ring layer containing the having fibers wound in a spiral shape or a ring shape around the outer surface of the liner, and comprising a braid layer formed in an overlapping manner on an outermost layer of the spiral layer or the ring layer, the braid layer having the fibers wound around so that they are woven alternately and have fiber intervals larger than that of the spiral layer or the ring layer, and the fiber layer is impregnated with the resin.

In some embodiments, the fibrous layer includes a first braid layer having the fibers wrapped in an alternately woven manner around an outer surface of the dome portion, a helical layer, or a hoop layer having the fibers woven from the first braid layer continuously in a spiral shape or a ring shape around an outer surface of the straight body portion, and a second mesh layer having the fibers wrapped on an outermost layer of the spiral layer or the ring layer so that they are continuously woven alternately from the first mesh layer and Having fiber intervals greater than that of the spiral layer or the ring layer, the fiber layer being impregnated with the resin.

According to a further embodiment of the invention, a method for producing a Disclosed tanks, the tank comprising: a hollow liner having a cylindrical straight body portion and a dome portion gradually narrowing from an end portion of the straight body portion in an axial direction in an opposite direction to the straight body portion; and a reinforcing layer formed on an outer surface of the liner by impregnating a fiber layer having fibers wound in an overlapping manner in a radial direction with resin, the method including: forming the fiber layer, the one spiral layer or an annular layer having the fibers wrapped in a spiral shape or an annular shape around the outer surface of the liner, and comprising a mesh layer formed in an overlapping manner on an outermost layer of the spiral layer or the annular layer, wherein the mesh layer has the fibers wound so that they are alternately woven and have fiber intervals larger than that of the spiral layer or the ring layer; and impregnating the fibrous layer comprising the braid layer formed in an overlapping manner on the outermost layer of the spiral layer or the ring layer with the resin.

In some embodiments, the method includes the following: forming the fibrous layer, which includes a first braided layer comprising the fibers wrapped in an alternately woven manner around an outer surface of the dome portion, a helical layer, or an annular layer comprising the fibers of the first braid layer of are continuously wound in a spiral shape or a ring shape around an outer surface of the straight body portion, and a second braid layer comprising the fibers wound on an outermost layer of the spiral layer or the ring layer so as to be separated from the first braid layer of continuously alternately woven and having fiber intervals greater than that of the spiral layer or the ring layer; and impregnating the fibrous layer comprising the first braid layer, the spiral layer or the ring layer and the second braid layer with the resin.

In some embodiments, a tow prepreg made by impregnating fibers with a thermoplastic resin is used for part or all of the fibers of the braided layer.

In some embodiments, the resin includes a thermoset resin, where the thermoplastic resin has a melting temperature that is less than or equal to a cure temperature of the thermoset resin.

In some embodiments, the thermoplastic resin includes a thermoplastic resin that is compatible with the resin.

In some embodiments, the thermoplastic resin includes a thermoplastic resin that is of the same type as the resin.

According to one aspect of the invention, it is possible to prevent fiber misalignment during resin molding and suppress strength deterioration by changing the fiber winding manner according to the positions.

character list

• 1 12 is a side view schematically showing a high-pressure tank (fiber-wrapped liner) according to the embodiment;
• 2 12 is a sectional view schematically showing a structure of the high-pressure tank (fiber-wrapped liner) according to the embodiment;
• 3 12 is a schematic diagram showing a manufacturing machine (braiding machine) for winding fibers around a liner constituting the high-pressure tank according to the embodiment;
• 4 12 is a schematic diagram showing positions where fibers are fed when the fibers are wound around a dome portion of the high-pressure tank according to the embodiment;
• 5 12 is a schematic diagram showing positions where fibers are fed when the fibers are wound around a straight body portion of the high-pressure tank according to the embodiment;
• 6 12 is a vertical sectional view showing a preform placing step and a vacuum degassing step of a manufacturing apparatus (a mold for a resin injection method) of the high-pressure tank according to the embodiment;
• 7 12 is a vertical sectional view showing a resin molding step of the manufacturing device (the mold for the resin injection method) of the high-pressure tank according to the embodiment; and
• 8th 12 is a side view schematically showing another example of a high-pressure tank (a fiber-wrapped liner) according to the embodiment.

DETAILED DESCRIPTION

An exemplary embodiment of the invention is described below with reference to the drawings.

A description follows of an example of a high-pressure tank for fuel cell vehicles, which is an example of a tank. The tank to which the invention is applied is not limited to the high-pressure tank for fuel cell vehicles. The shape, material and the like of the liner and the preform constituting the tank are not limited to the illustrated example.

In the RTM process, carbon fibers are wrapped (wound) multiple times (in multiple layers) around a liner to form a preform with a fibrous layer on the outer surface of the liner, the fibrous layer of the preform is impregnated with epoxy resin, and the epoxy resin is cured, so as to form to manufacture a high-pressure tank for fuel cell vehicles, which has a fiber-reinforced resin layer including the carbon fibers and the epoxy resin on the outer periphery of the liner. The liner is a hollow resin (e.g., nylon resin) container that defines the interior of the high-pressure tank.

Since a high-pressure tank for fuel cell vehicles is a thick-layered, large-sized tank (with carbon fibers wrapped thickly), it is necessary to perform epoxy resin filling and impregnation at high speed and under high pressure. This can lead to fiber skew or the like. In particular, the straight body portion of the liner must be effectively reinforced by carbon fibers (see JP 2020 - 026 817 A ), and therefore the carbon fibers must be wrapped tightly (without gaps) around the straight body portion. For this reason, fiber misalignment may occur during resin impregnation in the RTM process, and performance degradation and quality failure tend to occur.

The embodiment then employs the following configuration.

- High pressure tank configuration -

First, a high-pressure tank 10 according to an embodiment of the invention will be described in detail based on the drawings. 1 and 2 12 are a side view and a sectional view schematically showing the high-pressure tank 10 (fiber-wrapped liner) according to the embodiment, respectively. It should be noted that the right half section of 1 shows a state in which the braid layer is removed in the outermost layer (outer surface). It should be noted that the drawings show an arrow D indicating an axial direction of the high-pressure tank 10 and an arrow R indicating a radial direction of the high-pressure tank 10 for the sake of simplicity, where applicable. Also, a portion of the high-pressure tank 10 (the liner 12) that is away from the center in the axial direction along a central axis CL of the high-pressure tank 10 is referred to as “an end portion in the axial direction”. Meanwhile, a portion of the high-pressure tank 10 (the liner 12) closer to the center is referred to as “a central portion in the axial direction”. The high-pressure tank 10 according to the embodiment is configured to be filled inside with, for example, hydrogen as a fuel, and mounted on a fuel cell vehicle (not shown) or the like.

As in 1 and 2 As shown, the high-pressure tank 10 has a liner 12 as a container body. In one example, the liner 12 is blow molded from a liquid crystal resin material excellent in gas barrier property and dimensional stability, and has a cylindrical straight body portion 12A and a substantially hemispherical dome portion 12B integral with each of the opposite ends (each of the end openings) of the straight body portion 12A is trained. More specifically, the liner 12 has, in an intermediate portion of the liner 12 in the longitudinal direction (axial direction), the cylindrical straight body portion 12A having a constant inside diameter and outside diameter, and it has the dome portion 12B connecting each of the opposite side portions of the liner 12 in the longitudinal direction (axial direction) and gradually narrows (ie, has a decreasing diameter) in a direction opposite (toward the end portion in the axial direction) to the straight body portion 12A.

The dome portion 12B has, at its axial center portion, a cylindrical portion 12C protruding (outward) toward the end portion of the liner 12 in the axial direction along the central axis CL. The cylindrical portion 12C has a substantially constant inner diameter and outer diameter smaller than those of the straight body portion 12A.

The high-pressure tank 10 is formed by winding around the outer peripheral surface of the straight body portion 12A of the liner 12 and the outer peripheral surface of the dome portion 12B of the liner 12 (also referred to as fiber bundles) tape-like fibers 16 having a predetermined width in a layered form. The fiber 16 is made of fiber reinforced plastic (FRP) including, for example, glass fiber, carbon fiber, or aramid, and forms a fiber reinforced plastic (FRP) layer on the outer peripheral surface (outer surface) of the liner 12 as a reinforcing layer.

More specifically, the fibers 16 are wound in an alternately woven manner around the outer peripheral surface (outer surface) of the dome portion 12B (hereinafter, this may be referred to as “braid winding”), and the fibers 16 wound in a braided manner form a braid layer 17B as a first fiber layer. Then, the braid layer (first fiber layer) 17B is impregnated with a thermosetting resin 18 ( 7 ) and cured to form a reinforcing layer.

Meanwhile, the fibers 16 are spirally wound (hereinafter may be referred to as “spiral winding”) around the outer peripheral surface (outer surface) of the straight body portion 12A, and the spirally wound fibers 16 form a spiral layer 17A as a second fiber layer. Then, the spiral layer (second fiber layer) 17A is impregnated with a thermosetting resin 18 ( 7 ) and cured to form a reinforcing layer.

The spiral winding means that the fibers 16 are first wound around the entire outer peripheral surface of the straight body portion 12A at a predetermined winding angle +θ with respect to the central axis CL of the liner 12, and they are also wound at a predetermined winding angle -θ with respect to the central axis CL of the liner 12 an upper side thereof (in a crossing direction on the upper side of the fibers 16 wound at the winding angle +θ). That is, the spiral layer (second fiber layer) 17A is configured such that the fibers 16 are wound around the outer peripheral surface of the straight body portion 12A in at least two layers at a predetermined winding angle +θ and a predetermined winding angle -θ. It should be noted that the fibers (bundles) 16 are wound around (in a manner overlapped or stacked in the radial direction) in about several to several tens of layers, for example, although this depends on the internal pressure of the straight body portion 12A and the number of Fibers (bundles) 16 and the like depends.

As described above, braid winding means that the filaments 16 are wound around in an alternately woven manner, where braid winding means here that the filaments 16 are wound at a predetermined winding angle +θ and a predetermined winding angle -θ with respect to the central axis CL of the liner 12 be wound around the entire outer peripheral surface of the dome portion 12B.

Thus, the fibers 16 are wound at the same winding angle θ both times in the braid winding and in the helical winding. The winding angle θ can be within a range of θ=54.7°±10°, which includes tolerances, and in particular within the range of θ=54.7°±5°, especially within the range of θ=54.7° ± 1°.

This winding angle θ is an angle resulting from stresses (axial stress and hoop stress) on the straight body portion 12A when a predetermined internal pressure acts, or an angle resulting from the fact that the hoop stress is twice the axial stress . Namely, although the detailed calculation process is omitted here, calculation of a winding angle θ according to tensions based on netting theory can be tan ² θ=2, resulting in θ=54.7° (equilibrium angle).

At this time, the dome portion 12B is subject to a smaller stress when internal pressure acts as compared with the straight body portion 12A, and thus requires a lower level of reinforcement as compared with the straight body portion 12A. Consequently, the dome portion 12B adopts the braid winding (braid layer 17B) having large fiber intervals, less dense fibers (low density) and low strength as the basic structure as compared with the spiral winding (spiral layer 17A), while the straight body portion 12A (see the right half section of 1 ) the spiral winding (spiral layer 17A) with small fiber intervals, dense fibers (high density) and high strength compared with the braid winding (braid layer 17B) is employed.

It should be noted that although the detailed structure description is omitted here, the change from the braided winding (braided layer 17B) in the dome portion 12B to the spiral winding (spiral layer 17A) in the straight body portion 12A and vice versa reverses the change from the spiral winding (spiral layer 17A) in the straight body portion 12A to the braid winding (braid layer 17B) in the dome portion 12B seen in a direction crossing the axial direction along the center axis XL of the liner 12, close to the boundary portion between the straight body portion 12A and the dome portion 12B within a range of a predetermined length in the axial direction.

Also, although not shown, in one example, one of the cylindrical portions 12C has a sealing plug fitted therein, while the other of the cylindrical portions 12C has a nozzle plug fitted therein and a valve is mounted on the nozzle plug.

As in 3 As shown, the fibers 16 are wrapped around the outer peripheral surface of the liner 12 using a known finishing machine (also referred to as a braider) 40 . As in 4 and 5 As shown, the fabrication machine 40 includes a plurality of coils 42, 44 circumferentially arranged in two rows. The fibers 16 fed from the plurality of bobbins 42, 44 in the respective rows are wound around the liner 12 extending in the axial direction along the central axis CL (in 3 to the left), more specifically, around the outer peripheral surface of one of the dome portions 12B, around the outer peripheral surface of the straight body portion 12A, and then around the outer peripheral surface of the other of the dome portions 12B in that order.

It should be noted that, as in 4 1, in braid-winding the fibers 16 around one and the other of the dome portions 12B, the plurality of coils 42 connected to each other by solid lines and the plurality of coils 44 connected to each other by imaginary lines, as in FIG Circumferentially arranged to be offset from each other on the inside in the radial direction and the outside in the radial direction. Then, the manufacturing machine 40 is driven such that while the plurality of coils 42 connected to each other by the solid lines and the plurality of coils 44 connected to each other by the imaginary lines move in opposite directions to each other, the Coils 42, 44 are sequentially exchanged, that is, the inner one in the radial direction is exchanged for the outer one in the radial direction and the outer one in the radial direction is exchanged for the inner one in the radial direction. Meanwhile, as in 5 As shown, in spirally winding the fibers 16 around the straight body portion 12A, the plurality of coils 42 connected to each other by the solid lines and the plurality of coils 44 connected to each other by the imaginary lines in the circumferential direction arranged on the outside in the radial direction and the inside in the radial direction, respectively. Then, the manufacturing machine 40 is driven such that the plurality of coils 42 connected to each other by the solid lines and the plurality of coils 44 connected to each other by the imaginary lines move in opposite directions to each other.

Besides the basic structure described above, the dome portion 12B by the braid winding (braid layer 17B) with large fiber intervals, less dense fibers (low density) and low strength and the straight body portion 12A by the spiral winding (spiral layer 17A) with small fiber intervals, dense fibers (high density) and high strength (see the right half section of 1 ), the embodiment employs the following configuration to prevent misalignment of the fibers (particularly, the fibers 16 of the spiral layer 17A in the straight body portion 12A) during resin molding.

Namely, the fibers 16, as in 1 and 2 is continuously wound in an alternately weaving manner from the mesh layer 17B to form a mesh layer 17E on the outermost layer of the spiral layer 17A (consisting of about several to several tens of layers, for example).

More specifically, after the fibers 16 in the outermost layer of the braided layer 17B are wound on the outer peripheral surface (outer surface) of the dome portion 12B in an alternately woven manner (i.e., after braid winding), the fibers 16 become continuous therefrom (i.e., without braid winding to switch to spiral winding) on top of the spiral layer 17A (the spiral layer 17A adjacent to the braid layer 17B) on the outer peripheral side (outer surface) of the straight body portion 12A (the portion 17E in 2 ) wrapped around in an alternately woven manner. After the fibers 16 on top of the spiral layer 17A are wound around the outer peripheral surface (outer surface) of the straight body portion 12A in an alternately weaving manner, the fibers 16 are continuously wound therefrom on the top of the braid layer 17B (the braid layer 17B adjacent to the spiral layer 17A) on the outer peripheral surface (outer surface) of the other of the dome portions 12B is wound around in an alternately woven manner, thereby further forming the braided layer 17B on the outer peripheral surface (outer surface) of the other of the dome portions 12B.

In other words, the fibers 16 in the outermost layer of the fiber layer comprising the braided layer 17B on the outer peripheral surface of one of the dome portions 12B of the liner 12, the spiral layer 17A on the outer peripheral surface of the straight body portion 12A, and the braided layer 17B on the outer peripheral surface of the other of the dome portions 12B are wound around (along the entire length of the liner 12 in the axial direction) in an alternately weaving manner to form the braided layer (17B, 17E, 17B). It should be noted that the mesh layer 17E to be formed on the outermost layer of the spiral layer 17A in an overlapping or stacked manner may be only one layer or multiple layers (about several layers, for example) thick. 2 12 shows an example in which only one layer of the braided layer 17A is formed.

In this way, on the outermost layer of the spiral layer 17A, which is prone to fiber misalignment due to small fiber intervals and dense fibers (high density), the braided layer 17A is formed with large fiber intervals and less dense fibers (low density), obtained by alternate weaving of the fibers (continuous from the braid layer 17B) and is thus less prone to fiber misalignment. (In other words, the outermost layer of the spiral layer 17A, which is prone to fiber misalignment, is covered with the braid layer 17E, which is less prone to fiber misalignment.) This can cause fiber misalignment during resin molding, which will be described later 16 prevent.

As described above, to form the high-pressure tank 10, a fiber layer 1 comprising the braid layer 17B, the spiral layer 17A and the braid layer 17E and formed by winding the fibers 16 in a layered form around the liner 12 is coated with an uncured , thermosetting resin (for example, a mixture of an epoxy resin and a hardener; this may simply be referred to as "resin" in this specification) 18 having fluidity, and then heated to harden the thermosetting resin.

- Manufacturing process for high-pressure tank -

A method of manufacturing the high-pressure tank 10 having the configuration described above will now be described in detail based on the drawings.

- filament winding step -

The high-pressure tank 10 according to the embodiment is formed by first winding the fibers 16 around the outer peripheral surface of the liner 12 . Namely, the fibers 16, as in 3 until 5 shown are successively fed from the plurality of bobbins 42, 44 to the manufacturing machine 40 and first wound in a braided manner around the outer peripheral surface of one of the dome portions 12B to form the braided layer 17B (first step). More specifically, the fibers 16 are wound around the dome portion 12B in a braided manner from the end portion opposite to the straight body portion 12A to the end portion close to the straight body portion 12A to form the braided layer 17B.

After the end of braiding the fibers 16 around the outer peripheral surface of one of the dome portions 12B, the fibers 16 are then spirally wound around the outer peripheral surface of the straight body portion 12A to form the spiral layer 17A (second step). More specifically, the fibers 16 are successively wound around the straight body portion 12A from the end portion near one of the dome portions 12B to the end portion near the other of the dome portions 12B to form the spiral layer 17A. It should be noted that the changeover from the braided winding in the dome portion 12B to the spiral winding in the straight body portion 12A near the boundary portion between the dome portion 12B and the straight body portion 12A occurs within a range of a predetermined length in the axial direction by the Arrangement of the plurality of coils 42, 44 of the manufacturing machine 40 ( 4 and 5 ) is changed within a predetermined time. At this time, the filaments 16 can be easily changed from braid winding to spiral winding at the same winding angle θ within the above range.

After the end of spirally winding the filaments 16 around the outer peripheral surface of the straight body portion 12A, the filaments 16 are then wound in a braided manner around the outer peripheral surface of the other of the dome portions 12B to form the braided layer 17B (third step). More specifically, the fibers 16 are successively braided around the dome from the end portion close to the straight body portion 12A to the end portion opposite to the straight body portion 12A portion 12B to form the braided layer 17B. It should be noted that the changeover from the spiral winding in the straight body portion 12A to the braided winding in the dome portion 12B can also be performed near the boundary portion between the straight body portion 12A and the dome portion 12B within a range of a predetermined length in the axial direction , by the arrangement of the plurality of coils 42, 44 of the manufacturing machine 40 ( 4 and 5 ) is changed within a predetermined time. At this time, the filaments 16 can be easily changed from spiral winding to braid winding at the same winding angle θ within the above range.

It should be noted that the winding angle θ of the fibers 16 wound around one and the other of the dome portion 12B and the straight body portion 12A is within the range of θ=54.7°±10°, for example.

In the embodiment, then, after the braid winding of the fibers 16 in the outermost layer of the braid layer 17B is completed, without making the above-described changeover from the braid winding in the coupling portion 12B to the helical winding in the straight body portion 12A, the fibers 16 are continuously wound therefrom to a braided manner around the outer peripheral surface of the straight body portion 12A (specifically, the outer peripheral surface of the spiral layer 17A on the outer peripheral surface of the straight body portion 12A) to form the braided layer 17E. In addition, after the end of the braid winding of the fibers 16 around the outer peripheral surface of the straight body portion 12A (specifically, the outer peripheral surface of the spiral layer 17A on the outer peripheral surface of the straight body portion 12A), the fibers 16 become continuous therefrom (without the above-described change from the spiral winding in the straight body portion 12A for braid winding in the dome portion 12B) is wound in a braided manner around the outer peripheral surface of the other of the dome portions 12B to form the braid layer 17B.

In other words, the fibers 16 in the outermost layer of the braided layer 17B and the like are successively laid from the end portion of one of the dome portions 12B opposite to the straight body portion 12A to the end portion of the other of the dome portions 12B opposite to the straight body portion 12A (along the entire length of the liner 12 in the axial direction) in a braided manner to form the braided layer (17B, 17E, 17B).

By winding the fibers 16 as described above, the braid layer 17E is continuously formed from the braid layer 17B on the outermost layer of the spiral layer 17A in an overlapping (stacked) manner.

Through the above-described steps, the fibers 16 are finally wound (in an overlapping or stacked manner in the radial direction) in about several to several tens of layers, for example, to form a preform 11 ( 6 and 7 ) as an intermediate body having on the outer peripheral surface (outer surface) of the hollow liner 12 the fiber layer 17 (ie, the braided layer 17B, the spiral layer 17A, and the braided layer 17E) formed by winding the fibers 16.

- Resin Pouring Step (Resin Injection Step) -

The preform 11 ( 6 and 7 ) comprising the fibrous layer 17 formed by the winding of the filaments 16 around the hollow liner 12 as described above is molded in a mold 50 (also referred to as a cavity between a lower mold 60 and an upper mold 80) for a Resin injection method placed as a manufacturing device. In the mold 50, the thermosetting resin 18 is poured. The fibrous layer 17 (or the fibers 16 thereof) are impregnated with the thermosetting resin 18 and then heated to cause the thermosetting resin 18 to harden.

As in 6 and 7 1, a vacuum degassing tube 62 coupled to a vacuum pump 61 is embedded in the mold 50 (lower mold 60 in the illustrated example).

Also embedded in the mold 50 (in the upper mold 80 in the illustrated example) is a resin injection pipe 82 (also referred to as a resin injection gate) coupled to a resin injector 81 .

In order to impregnate the fibrous layer 17 (or the fibers 16 thereof) of the preform 11 with the thermosetting resin 18, first, the vacuum pump 61 is operated in a state where the preform 11 is in the mold 50 (between the lower mold 60 and the upper Mold 80) having the above configuration is placed, which is kept at a predetermined temperature (a temperature equal to or higher than a curing temperature of the thermosetting resin 18) (in other words, after completion of mold clamping) controlled for vacuum degassing of the mold 50 ( 6 ).

After stopping (or completing) the above vacuum degassing, the thermosetting resin 18 is poured into the mold 50 by driving the resin injector 81 ( 7 ).

Consequently, the (uncured) resin 18 poured (injected) into the mold 50 (cavity) through the resin injection tube 82 penetrates into the spiral layer 17A and the braid layer 17B via the braid layer 17E (i.e., via the fibrous layer 17). Since the outermost ply of the preform 11 (or the fibrous layer 17 thereof) comprises the braid layer 17E, which is less prone to fiber misalignment (in other words, since the outermost ply of the preform 11 is covered with the braid layer 17E, which is less prone to At this time, misalignment of the fibers 16 (especially the fibers 16 of the spiral layer 17A in the straight body portion 12A) during the molding (impregnation) of the resin 18 can be suppressed. With the large fiber intervals and less dense fibers (low density) compared to the spiral layer 17A (spiral winding), the braid layer 17E (braid winding) will also not block the pouring (impregnation) of the resin 18 into the spiral layer 17A on the inside.

After the lamination of the fiber layer 17 is completely impregnated with the resin 18, resin pouring is stopped and then heating and curing are performed, thereby forming a fiber-reinforced resin layer on the outer periphery of the liner 12 as a reinforcing layer. Thereby, it is possible to obtain the high-pressure tank 10 excellent in corrosion resistance, which can achieve weight reduction and low cost, and is also easy to carry and handle.

As described above, when a high-pressure tank for fuel cell vehicles is manufactured by the RTM impregnation technology, it is necessary to perform epoxy resin filling and impregnation on the thick-layered, large-sized tank (with carbon fibers thickly wound) at a high speed and under high pressure. This process may result in misalignment of carbon fibers wrapped around the preform, reduction in fiber width, and the like, resulting in reduction in productivity and deterioration in tank performance.

In this embodiment, the outermost layer of the preform, which has fiber bundles tightly wound by high-density spiral winding with a small gap between the carbon fiber bundles and the like, has a thin fiber layer (braid layer 17E) formed by weaving of fiber bundles is formed by braid winding or the like and thus is less prone to misalignment of fiber bundles and has a large gap between the fiber bundles.

Since the thin layer of carbon fibers is less prone to misalignment and the carbon fiber width will not be reduced, the embodiment can suppress performance degradation. Since the embodiment employs the braid winding (braid layer 17E) which has a large gap between the carbon fibers, even with such countermeasures against fiber tangles, fiber tangles can be avoided without impairing resin impregnation properties.

Consequently, since the embodiment can prevent carbon fiber misalignment, fiber width reduction, and the like during epoxy resin molding, it is possible to obtain the high-pressure tank 10 that can achieve improved resin impregnation properties, improved tank performance, and excellent surface quality.

As described above, according to the embodiment, it is possible to prevent misalignment of the fibers 16 and reduction in fiber width during resin molding to suppress the deterioration in strength by changing the manner of winding the fibers 16 according to the positions.

It should be noted that, for example, in order to surely prevent fiber misalignment during resin molding, for part or all of the fibers 16 (of the braid layer 17E) to be wound in a braided manner in the outermost layer of the fiber layer 17, such as in 8th As shown, a tow prepreg 19 made by impregnating fibers (e.g., carbon fibers) with a thermoplastic resin (e.g., epoxy resin) can be used. In other words, the fibers 16 can be partially or completely replaced by the tow prepreg 19, and the outermost layer of the fiber layer 17 can then be formed by wrapping the tow prepreg 19 around it in a braided manner.

In this case, when winding the outermost layer with the manufacturing machine 40, the plurality of bobbins 42, 44 must be partially or completely replaced with bobbins loaded with the tow prepreg 19 for winding the outermost layer. When the preform 11 formed by winding the tow prepreg 19 in a braided manner in the outermost layer of the fiber layer 17 is placed in the mold 50 maintained at a predetermined temperature (a temperature equal to or higher than a curing temperature of the thermosetting resin 18), for example, if the thermoplastic resin of the tow prepreg 19 has a melting temperature equal to or lower than the curing temperature of the thermosetting resin 18, the thermoplastic resin of the tow prepreg 19 melts, whereby the fibers of the tow prepreg 19 (ie, the fibers of the mesh layer 17E) are bonded to the fibers 16 of the spiral layer 17A on the inside, and also the fibers 16 of the spiral layer 17A are bonded to each other. This can more effectively prevent fiber misalignment during resin molding. In addition, since the thermoplastic resin of the tow prepreg 19 is bonded to the liner 12 in the innermost layer, it is possible to more effectively prevent fiber misalignment.

Since the thermoplastic resin of the tow prepreg 19 forms a reinforcing layer (fiber-reinforced resin layer) together with the thermosetting resin 18 (i.e., the resin with which the fiber layer 17 is impregnated), care should be taken that the thermoplastic resin has excellent compatibility with the thermosetting resin 18 and has high adhesiveness. The thermoplastic resin of the tow prepreg 19 may be a thermoplastic epoxy resin of the same type as the epoxy resin of the thermosetting resin 18, for example. Thus, for the thermoplastic resin of the tow prepreg 19, an epoxy resin having both thermosetting and thermoplastic properties (a melting temperature equal to or lower than a curing temperature) can be used.

Thus, in the embodiment, when several tens of carbon fibers are wound around by multifilament winding (FW) such as braid winding, the carbon fiber coils are partially or completely replaced with tow prepregs (TPP) containing a thermoplastic epoxy resin having excellent compatibility with the epoxy resin with which the fiber layer is impregnated, and have a high adhesive power, in which case the winding of the thin outermost layer takes place. This can prevent fiber misalignment during resin molding when RTM molding is done.

Since this embodiment works in the same manner as the embodiment based on 1 , 2 and the like, can prevent carbon fiber misalignment, fiber width reduction, and the like during epoxy resin molding, consequently, it is possible to obtain the high-pressure tank 10 that can achieve improved resin impregnation properties, improved tank performance, and excellent surface quality.

Although in the embodiment described above the braid layer 17E is formed in an overlapping manner on the entire surface of the outermost layer of the fibrous layer 17 (spiral layer 17A) (so that it covers the entire outer peripheral surface of the spiral layer 17A), it should be noted that the Braid layer 17A may of course be formed in an overlapping manner on only a part of the surface of the outermost layer of fibrous layer 17 (spiral layer 17A).

Although the fibers are spirally wound (by spiral winding) around the outer peripheral surface of the straight body portion 12A to form a spiral layer, the fibers may also be wound (by ring winding) in a ring shape around the outer peripheral surface of the straight body portion 12A to form a ring layer by appropriately setting a winding angle θ, for example.

In addition, the material of the liner 12 is not limited to liquid crystal resin, for example. The liner 12 may be made of, for example, another synthetic resin having gas barrier properties, such as high-density polyethylene, or a light metal, such as aluminum alloy. In addition, the liner 12 is not limited to being manufactured by blow molding and may be manufactured by injection molding or the like.

Although the embodiment of the invention has been described in detail with reference to the drawings, the specific construction is not limited thereto and design changes may be made as long as they fall within the scope of the invention as defined by the claims.

Reference List

10

high-pressure tank (tank)

11

preform

12

lining

12A

Straight body section

12B

dome section

12C

Cylindrical section

16

fiber

17

fiber layer

17A

spiral layer

17B

braid layer (first braid layer)

17E

braid layer (second braid layer)

18

Thermosetting resin (resin)

19

tow prepreg

50

shape

60

lower form

80

upper form

CL

central axis

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• JP 2020085199 A [0003]
• JP 2020026817 A [0003, 0018]

Claims (8)

A tank comprising: a hollow liner having a cylindrical straight body portion and a dome portion gradually narrowing from an end portion of the straight body portion in an axial direction in a direction opposite to the straight body portion; and a reinforcing layer formed on an outer surface of the liner by impregnating a fibrous layer comprising filaments wound in an overlapping manner in a radial direction with resin, the fibrous layer being a spiral layer or a ring layer containing the having fibers wound in a spiral shape or a ring shape around the outer surface of the liner, and comprising a braid layer formed in an overlapping manner on an outermost layer of the spiral layer or the ring layer, the braid layer having the fibers wound around so that they are woven alternately and have fiber intervals larger than that of the spiral layer or the ring layer, and the fiber layer is impregnated with the resin. tank up claim 1 , wherein the fibrous layer comprises a first braid layer comprising the fibers wound in an alternately woven manner around an outer surface of the dome portion, a spiral layer or a ring layer comprising the fibers extending continuously from the first braid layer in a spiral form or a ring shape wrapped around an outer surface of the straight body portion, and comprising a second mesh layer having the fibers wrapped on an outermost layer of the spiral layer or the ring layer so that they are continuously woven from the first mesh layer alternately and fiber intervals larger than that of the spiral layer or the ring layer, and the fibrous layer is impregnated with the resin. A method of manufacturing a tank, the tank comprising: a hollow liner having a cylindrical straight body portion and a dome portion gradually narrowing from an end portion of the straight body portion in an axial direction in a direction opposite to the straight body portion; and a reinforcing layer formed on an outer surface of the liner by impregnating with resin a fiber layer having fibers wound in an overlapping manner in a radial direction, the method comprising: Forming the fibrous layer comprising a spiral layer or a ring layer having the fibers wound in a spiral shape or a ring shape around the outer surface of the liner and a braid layer laid in an overlapping manner on an outermost layer of the spiral layer or the hoop layer, the braided layer having the fibers wound so as to be woven alternately and having fiber intervals larger than those of the spiral layer or the hoop layer; and impregnating the fibrous layer comprising the braid layer formed in an overlapping manner on the outermost layer of the spiral layer or the ring layer with the resin. Process for manufacturing a tank claim 3 , comprising: forming the fibrous layer comprising a first braid layer comprising the filaments wrapped in an alternately woven manner around an outer surface of the dome portion, a helical layer or a hoop layer comprising the filaments separated from the first braid layer continuously wound in a spiral shape or a ring shape around an outer surface of the straight body portion, and a second braid layer having the fibers wound on an outermost layer of the spiral layer or the ring layer so as to extend from the first braid layer are continuously alternately woven and have fiber intervals greater than that of the spiral layer or the ring layer; and impregnating the fibrous layer comprising the first braid layer, the spiral layer or the ring layer and the second braid layer with the resin. Process for manufacturing a tank claim 3 wherein a tow prepreg made by impregnating fibers with a thermoplastic resin is used for part or all of the fibers of the braided layer. Process for manufacturing a tank claim 5 , wherein the resin comprises a thermosetting resin and the thermoplastic resin has a melting temperature that is less than or equal to a curing temperature of the thermosetting resin. Process for manufacturing a tank claim 5 , wherein the thermoplastic resin comprises a thermoplastic resin that is compatible with the resin. Process for manufacturing a tank claim 5 , wherein the thermoplastic resin is a thermoplastic resin which is of the same type as the resin.

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