JP7517283B2 - Manufacturing method of pressure vessel, pressure vessel, and nozzle for pressure vessel - Google Patents

Description

The present invention relates to a method for manufacturing a pressure vessel, a pressure vessel, and a nozzle for a pressure vessel.

Pressure vessels (also called high-pressure tanks, etc.) that store hydrogen inside and that are equipped with a cylindrical liner and a reinforcing part (reinforcing layer) that is formed using carbon fiber reinforced plastic (CFRP) and reinforces the liner have been known for some time (see, for example, Patent Document 1). A nozzle is firmly attached to the end of the liner in this pressure vessel. In other words, the protrusions on the nozzle are designed to bite into the reinforcing part (reinforcing layer).

The pressure vessel described in Patent Document 1 comprises a liner filled with gas, a reinforcing layer formed using fiber-reinforced resin in contact with the outer surface of the liner and covering the liner from the outside, and a nozzle attached to the liner. The nozzle is formed in an annular shape and comprises multiple nozzle body parts arranged at intervals in the circumferential direction, each having a locking claw (projection) that protrudes toward the reinforcing layer, and a crosspiece that connects multiple nozzle body parts adjacent in the circumferential direction in the circumferential direction. The nozzle is attached to the liner with the crosspiece deformed so that the locking claws (projection) of the multiple nozzle body parts are locked to the reinforcing layer.

Such pressure vessels can be manufactured, for example, by the Filament Winding (FW) method (Patent Document 1), in which a sheet of fiber-reinforced resin is attached to a liner, or the Resin Transfer Molding (RTM) method (Patent Document 2), in which a sheet of fiber (bundle) is attached to a liner and then impregnated with resin.

JP 2020-112189 A JP 2020-085199 A JP 2021-076174 A Japanese Patent Application Laid-Open No. 62-297586 JP 2004-028816 A

As mentioned above, the nozzle of the pressure vessel disclosed in Patent Document 1 is formed into a ring by the nozzle body, which is a rigid part with a screw groove, and the crosspiece, which is a thin-walled part that allows deformation. In order to assemble from the outside of the CFRP, the thin-walled crosspiece is deformed to reduce the inside diameter, and the locking claws (projections) of the nozzle body, which is a rigid part, are crimped and fixed to the CFRP.

However, in the nozzle of the pressure vessel described in Patent Document 1, when the matrix resin of the CFRP deforms in a high-temperature environment, the thin-walled portion allows for inward deformation (diameter reduction), which may cause the screw groove on the nozzle body to loosen from the fastening portion (manifold).

To address these concerns, it is conceivable to construct a nozzle (ring) using only multiple rigid parts arranged in the circumferential direction, in other words, to divide the nozzle made of rigid parts in the circumferential direction (see Patent Documents 3 to 5).

For example, the pressure vessel described in Patent Document 3 comprises a container body having a cylindrical opening end on at least one end side and filled with gas, a fiber-reinforced resin covering that covers the outer surface of the container body, and a cylindrical nozzle that is attached to the outer periphery of the opening end by fitting the protrusions into the covering that covers the outer periphery of the opening end and is configured by connecting multiple nozzle bodies having protrusions on their inner surface in the circumferential direction of the opening end, and the nozzle is connected by fitting a fitting formed on the end of the nozzle body in the circumferential direction.

However, even in the nozzle of the pressure vessel described in Patent Document 3, the fitting portion formed at the end in the circumferential direction of the nozzle body is simply fitted, so there is a possibility of inward deformation (diameter reduction) occurring when the matrix resin of the CFRP deforms in a high-temperature environment.

In addition, when manufacturing pressure vessels using the RTM method, in which fibers (bundles) are wrapped around a liner and a nozzle is attached from the outside of the fibers (bundles), and then the resin is impregnated, if the nozzle is made only of a rigid portion, there is an issue that it is difficult for the resin to impregnate the opposite side of the inlet side of the RTM mold unless it has a resin flow path.

In view of the above circumstances, the present invention aims to provide a method for manufacturing a pressure vessel, a pressure vessel, and a nozzle for a pressure vessel that can suppress inward deformation (diameter reduction) of the nozzle, suppress loosening of the screw between the nozzle and the fastening part (manifold), and improve resin impregnation during RTM.

In order to achieve the above object, the manufacturing method of the pressure vessel of the present invention includes a fiber winding step in which fibers are wound around the outer surface of a liner having a cylindrical opening end and filled with gas to form a fiber layer; a nozzle attachment step in which a cylindrical nozzle formed by arranging multiple nozzle components in the circumferential direction of the opening end is attached to the outer peripheral surface of the opening end with the inner surfaces of the multiple nozzle components in contact with the fiber layer formed on the outer peripheral surface of the opening end; and a resin impregnation molding step in which the fiber layer is impregnated with resin to form a fiber-reinforced resin covering that covers the outer surface of the liner. In the nozzle attachment step, the nozzle is attached to the outer peripheral surface of the opening end by fixing the multiple nozzle components to each other, and in the resin impregnation molding step, the resin is impregnated into the fiber layer while flowing through grooves that become resin flow paths provided at the contact points between the multiple nozzle components and the fiber layer.

In a preferred embodiment, the groove is provided from one end to the other end in the axial direction of the nozzle structure.

In another preferred embodiment, the groove is provided along the axial direction of the nozzle structure.

In another preferred embodiment, the groove is provided at the contact point between adjacent base structures.

In another preferred embodiment, in the base attachment step, the multiple base structures are fixed to each other with the circumferential ends of adjacent base structures in contact with each other.

In another preferred embodiment, in the base attachment step, an insertion protrusion provided on one of the adjacent base structures is passed through an insertion hole provided on the other of the adjacent base structures, and the multiple base structures are fixed to each other by rivet fixing, which presses and deforms the portion of the insertion protrusion protruding from the insertion hole to widen it.

In another preferred embodiment, the multiple base components are fixed to each other by bolting during the base attachment process.

The pressure vessel of the present invention is a pressure vessel comprising a liner having a cylindrical open end and filled with gas, a fiber-reinforced resin covering the outer surface of the liner, and a cylindrical nozzle configured by arranging a plurality of nozzle components in the circumferential direction of the open end and attached to the outer circumferential surface of the open end with the inner surfaces of the plurality of nozzle components in contact with the covering portion covering the outer circumferential surface of the open end, the nozzle being attached to the outer circumferential surface of the open end by fixing the plurality of nozzle components to each other, and a groove that serves as a resin flow path is provided at the contact point between the plurality of nozzle components and the covering portion.

In a preferred embodiment, the groove is provided from one end to the other end in the axial direction of the nozzle structure.

In another preferred embodiment, the groove is provided along the axial direction of the nozzle structure.

In another preferred embodiment, the groove is provided at the contact point between adjacent base structures.

In another preferred embodiment, the base is configured such that the circumferential ends of adjacent base structures are in contact with each other, and the multiple base structures are fixed to each other.

In another preferred embodiment, the base is fixed to the plurality of base components by riveting, in which an insertion protrusion provided on one of the adjacent base components is passed through an insertion hole provided on the other adjacent base component, and the portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to widen.

In another preferred embodiment, the base is secured to the base components by bolts.

The nozzle for a pressure vessel of the present invention is a nozzle for use with a pressure vessel having a cylindrical open end, a liner filled with gas, and a fiber-reinforced resin covering the outer surface of the liner, and is configured by arranging multiple nozzle components in the circumferential direction of the open end, has a cylindrical shape that can be attached to the outer circumferential surface of the open end with the inner surfaces of the multiple nozzle components in contact with the covering that covers the outer circumferential surface of the open end, can be attached to the outer circumferential surface of the open end by fixing the multiple nozzle components to each other, and is characterized in that grooves that become resin flow paths are provided at the contact points of the multiple nozzle components with the covering.

According to the present invention, by making the nozzle a divided structure of the nozzle component, which is a rigid part, it is possible to provide the structure required for attaching the nozzle to the pressure vessel while suppressing inward deformation (diameter reduction) of the nozzle and suppressing loosening of the screws between the nozzle and the fastening part (manifold), and by providing a groove as a resin flow path at the contact point (inner surface of the nozzle component) between the nozzle component and the fiber layer (coating part), it is possible to improve resin impregnation during RTM.

In addition, compared to a nozzle made of a single piece, for example, the simple shape of the nozzle makes it easier to manufacture and also makes it easier to impregnate with resin.

FIG. 2 is an enlarged cross-sectional view showing the open end side of the pressure vessel according to the embodiment. FIG. 2 is an enlarged perspective view showing the open end side of the pressure vessel according to the embodiment. FIG. 2 is a perspective view showing a base according to the embodiment. FIG. 4 is an enlarged cross-sectional view showing a locking claw of the base according to the embodiment. 3 is a cross-sectional view taken along line XX in FIG. 2. 1 is a process diagram showing a method for manufacturing a pressure vessel (RTM method) according to the present embodiment. FIG. 2 is an enlarged perspective view showing the open end side of the pressure vessel according to the present embodiment, illustrating the state before the mouthpiece is fixed (before the fastening portion is screwed). FIG. 2 is an enlarged front view showing the open end side of the pressure vessel according to the present embodiment, illustrating the state before the mouthpiece is fixed (before the fastening portion is screwed). FIG. 2 is an enlarged perspective view showing the open end side of the pressure vessel according to the present embodiment, illustrating the state after the mouthpiece has been fixed (after the fastening portion has been screwed). FIG. 2 is an enlarged front view showing the open end side of the pressure vessel according to the present embodiment, illustrating the state after the mouthpiece has been fixed (after the fastening portion has been screwed). FIG. 11 is a perspective view showing another example of a base according to the embodiment.

The following describes in detail an embodiment of the present invention with reference to the drawings. For ease of explanation, the arrow S shown in each drawing indicates the axial direction of the pressure vessel 10, the arrow R indicates the radial direction of the pressure vessel 10, and the arrow C indicates the circumferential direction of the pressure vessel 10. Therefore, in the following description, when the axial direction, radial direction, and circumferential direction are mentioned without special mention, they respectively indicate the axial direction, radial direction, and circumferential direction of the pressure vessel 10 (including the open end 14 described below).

(General configuration of pressure vessel)
1, a pressure vessel 10 according to this embodiment constitutes a part of a tank module (not shown) mounted on a fuel cell vehicle (not shown). The tank module is constituted by a plurality of pressure vessels 10 connected to each other via fastening parts 18 (described later) and the like.

The pressure vessel 10 is composed of a liner 12 as the vessel body filled with gaseous hydrogen, a reinforcing layer 16 as a covering part that covers and reinforces the outer surface of the liner 12 from the outside, and a cylindrical nozzle 20 attached via the reinforcing layer 16 to the outer circumferential surface of a cylindrical opening end 14 formed on both ends of the liner 12.

The liner 12 is formed into a generally cylindrical shape using a resin material such as polyamide synthetic resin. More specifically, the liner 12 has a cylindrical body portion 12A whose inner and outer diameters are constant in the middle of its length (axial direction), and shoulder portions 12B that form both sides of the length (axial direction) and gradually narrow toward the opposite side of the body portion 12A (outward in the axial direction).

The liner 12 has cylindrical open ends 14 that form both ends in the longitudinal direction (axial direction) (portions axially outboard of the shoulder portion 12B) and have inner and outer diameters that are smaller and generally constant than the body portion 12A and the shoulder portion 12B.

The reinforcing layer 16 is made of fiber-reinforced resin, and is formed by wrapping reinforcing (reinforcing) fibers (bundles) around the entire outer surface of the liner 12 in multiple layers and impregnating the wrapped fibers (layers) with resin. The thickness of the reinforcing layer 16 is configured to increase from the body portion 12A side of the liner 12 toward the opening end 14 side. Furthermore, the outer diameter of the part of the reinforcing layer 16 that corresponds to the opening end 14 of the liner 12 is approximately constant. In this embodiment, carbon fiber reinforced resin (CFRP) is used as an example of fiber reinforced resin (FRP).

A nozzle 20 is attached to the open end 14 of the liner 12, which is covered with the reinforcing layer 16, from above the reinforcing layer 16. A fastening portion 18 is then attached to the nozzle 20. As a result, the open end 14 on one side of the liner 12 is closed by the fastening portion 18, and the open end on the other side of the liner 12 (not shown) is connected to another pressure vessel 10 via the fastening portion (not shown). Note that Figure 1 shows the open end 14 on the side of the liner 12 that is closed by the fastening portion 18.

(Configuration of the cap)
2 and 3, the base 20 is formed in a cylindrical (annular) shape using a metal material. Specifically, the base 20 is composed of a plurality of (four in this embodiment) base constituent bodies 22 arranged in the circumferential direction. The base constituent bodies 22 extend in the axial direction with the radial direction as the thickness direction, and are formed in a plate shape curved radially outward when viewed from the axial direction.

The axially outer end face of the nozzle structure 22 has a flat surface 23 that is flush with the end face of the opening end 14 (reinforcement layer 16), and the axially inner end of the nozzle structure 22 is integrally formed with a flange portion 24 that is bent radially outward. The flange portion 24 of each nozzle structure 22 is formed so that when assembled, it has a substantially regular octagonal shape when viewed from the axial direction (see FIG. 10).

As shown in Figures 1 and 3, a number of locking claws 26 are formed as protrusions on the inner peripheral surface (inner surface) of each of the base configurations 22, and these locking claws 26 give the inner peripheral surface of each of the base configurations 22 a knurled shape. Each of the locking claws 26 is formed in a sawtooth shape with a sharp tip side (radially inward) in the protruding direction when viewed in a cross section cut along the axial and radial directions.

To explain in more detail, as shown in FIG. 4, the surface of each locking claw 26 facing the body portion 12A of the liner 12 is an inclined surface 26A that slopes axially outward as it approaches radially inward. In addition, the surface of each locking claw 26 opposite the surface facing the body portion 12A of the liner 12 is a vertical surface 26B that runs along the radial direction.

The area where the inclined surface 26A and the vertical surface 26B intersect is the tip 26C of each locking claw 26. The tip 26C of each locking claw 26 bites into (locks into) the outer periphery of the reinforcing layer 16 that covers the outer periphery of the opening end 14, so that the nozzle 20 is firmly (non-rotatably) attached to the opening end 14.

As shown in Figs. 1 and 5, a screw groove 28 is formed on the outer peripheral surface (outer surface) of each of the base components 22 (the screw groove 28 is omitted in Figs. 2 and 3). This screw groove 28 forms a helical male screw portion 29 that runs circumferentially and axially when the base 20 is attached to the open end 14 (when each of the base components 22 is connected and fixed). The female screw portion 19 of the fastening portion 18, which will be described later, is screwed into this male screw portion 29.

As shown in Figs. 2 and 3, a connecting and fixing portion 30 is formed at the circumferential end of each of the base constituents 22 to connect and fix each of the base constituents 22 in the circumferential direction. In this embodiment, the connecting and fixing portion 30 is configured as a rivet fixing portion that connects and fixes the multiple base constituents 22 arranged in the circumferential direction to each other. The connecting and fixing portion 30 is configured of a rivet hole 32 as an insertion hole formed at the circumferential end of one of the base constituents 22 adjacent to each other in the circumferential direction of the base 20, and a rivet protrusion 34 as an insertion protrusion formed at the circumferential end of the other base constituent 22 adjacent to each other in the circumferential direction of the base 20.

More specifically, the base 20 of this embodiment is composed of four base components, including a pair of base components formed in the same shape on the top and bottom (a pair of top and bottom components), and a pair of base components formed in the same shape on the left and right (a pair of left and right components).

At the circumferential (i.e., left and right) ends (four locations) of the paired upper and lower base components 22, the inner and outer axial ends are cut out on the outer periphery and formed into a flat surface. The rivet holes 32 are formed (at a total of eight locations) in the fixing portion 33 formed into a flat surface (see Figures 7 and 8).

The rivet protrusions 34 are formed at the circumferential (i.e., upper and lower) ends (four locations) of the paired left and right base components 22, protruding upward or downward (eight locations in total) at the inner and outer axial ends (see Figures 7 and 8). The vertical length of the rivet protrusions 34 is longer than the vertical depth (length) of the rivet holes 32.

Then, the rivet protrusion 34 of the adjacent nozzle component 22 (the left and right nozzle components 22 in this embodiment) is passed through the rivet hole 32 of the other adjacent nozzle component 22 (the upper and lower nozzle components 22 in this embodiment), and the tip of the rivet protrusion 34 protruding from the rivet hole 32 is pressed and deformed to widen (widen to a diameter larger than the rivet hole 32), and the widened deformation part 35 is pressed against the rivet hole 32 of the fixing part 33 (in other words, the fixing part 33 is held in a narrow pressure by the two widened deformation parts 35 provided at the axial inner and outer ends), so that the nozzle components 22 are connected and fixed in the circumferential direction (see Figures 9 and 10). In other words, a cylindrical nozzle 20 is formed.

When the rivet projections 34 are inserted into the rivet holes 32 and the base components 22 are connected and fixed to each other in the circumferential direction, the end (surface) 22A of one adjacent base component 22 in the circumferential direction is in contact with the end (surface) 22B of the other adjacent base component 22 in the circumferential direction. In other words, no gap is formed between the end (surface) 22A of one adjacent base component 22 in the circumferential direction and the end (surface) 22B of the other adjacent base component 22 in the circumferential direction (see Figures 7 to 10).

As shown in Figures 2, 3, and 5, the inner circumferential surface (inner surface) of the nozzle 20 has multiple grooves 36 (four in this embodiment) formed therein, which will become resin flow paths in the manufacturing process described below.

More specifically, the groove 36 is formed in a straight line (along the axial direction) on the inner peripheral surface (inner surface) of the base 20 from the axially inner end (one end) to the axially outer end (the other end). The groove 36 is formed in a concave shape when viewed in the axial direction. In addition, in this embodiment, the groove 36 is provided at the contact portions (four locations) between the circumferential (i.e., left and right) ends of the paired upper and lower base components 22 and the circumferential (i.e., top and bottom) ends of the paired left and right base components 22, that is, at the contact locations of the (circumferential ends of) the base components 22 adjacent in the circumferential direction of the base 20.

The groove 36 is provided on the inner periphery (inner surface) of the nozzle structure 22 that contacts the fiber layer (formed on the outer surface of the opening end 14 of the liner 12) when the nozzle 20 is attached to the opening end 14, and serves as a resin flow path through which the molten resin (matrix resin) flows during the resin impregnation molding process of the manufacturing process described below.

(Pressure vessel manufacturing process)
Next, the process of manufacturing the pressure vessel 10 according to this embodiment, in particular the process of attaching the mouthpiece 20 according to this embodiment to the open end 14 of the liner 12 will be described.

The manufacturing process of this embodiment is a process for manufacturing a pressure vessel 10 by the RTM method, and includes a liner forming process (S21), a fiber winding process (S22), a nozzle arrangement process (S23), a nozzle attachment process (S24), a fastener attachment process (S25), a resin impregnation molding process (S26), and a CFRP process (S27), as an example of which is shown in FIG. 6.

First, a substantially cylindrical liner 12 is formed (liner formation process: S21).

Next, a sheet-like fiber (bundle) is wound around the outer surface of the liner 12 (fiber winding process: S22). Carbon fiber (CF) is used as an example of the fiber. By winding the fiber (bundle) around the liner 12, a fiber layer 17 (Figures 7 to 10) is formed on the outer surface of the liner 12. At this time, the fiber (bundle) is wound so that the thickness of the fiber layer 17 at the opening end 14 is thicker than that at the body portion 12A and the shoulder portion 12B.

The liner forming process (S21) and the fiber winding process (S22) can be collectively referred to as an intermediate body preparation process, which prepares an intermediate body in which fibers (bundles) are wound around the outer surface of the liner 12.

Then, as shown in Figures 7 and 8, the nozzle 20 is placed on the outer periphery of the opening end 14 of the liner 12 (the outer periphery of the fiber layer 17) (slot placement process: S23). That is, the multiple nozzle components 22 that make up the nozzle 20 are placed in the circumferential direction of the opening end 14 (the screw groove 28 is omitted in Figure 7). As a result, the tip portions 26C of the multiple locking claws 26 formed on each nozzle component 22 of the nozzle 20 are placed facing (with a gap) the outer periphery of the fiber layer 17.

9 and 10, the nozzle 20 (the multiple nozzle components 22 constituting it) is brought close to the fiber layer 17 (crimped), the connecting and fixing portion 30 of the nozzle 20 is connected and fixed, and the nozzle 20 is reduced in diameter (slot attachment process: S24) (the screw groove 28 is omitted in FIG. 9). That is, the pair of left and right nozzle components 22 are moved radially inward, and their inner circumferential surfaces (the multiple locking claws 26) are pressed against the outer circumferential portion of the fiber layer 17 (from the left and right direction) to hold them. Next, the pair of upper and lower nozzle components 22 are moved radially inward, and the rivet protrusions 34 of the left and right nozzle components 22 are inserted into the rivet holes 32 of the upper and lower nozzle components 22, while the inner circumferential surfaces (the multiple locking claws 26) of the pair of upper and lower nozzle components 22 are pressed against the outer circumferential portion of the fiber layer 17 (from the top and bottom direction) to hold them. Then, the tip of the rivet projection 34 protruding from the rivet hole 32 is pressed and deformed to widen (widen to a diameter larger than the rivet hole 32), and the widened deformation portion 35 is pressed against the rivet hole 32 of the fixed portion 33 (in other words, the two widened deformation portions 35 provided at the axially inner and outer ends hold the fixed portion 33 in a narrow pressure). As a result, each of the nozzle components 22 moves radially inward (reduced in diameter), and the circumferential end (surface) 22A of one adjacent nozzle component 22 comes into contact with the circumferential end (surface) 22B of the other adjacent nozzle component 22, while the adjacent nozzle components 22 are connected and fixed to each other, and the multiple locking claws 26 bite into the fiber layer 17. As a result of the above, the nozzle 20 is attached to the open end 14 of the liner 12 via the fiber layer 17.

In addition, in the nozzle attachment process (S24) in which the cylindrical nozzle 20 is attached to the outer circumferential surface of the open end 14, when the nozzle 20 (or the multiple nozzle components 22 constituting it) is crimped to the fiber layer 17, fibers may be pinched at the circumferential ends of each nozzle component 22, and the nozzle 20 (or the multiple nozzle components 22 constituting it) may not be possible to sufficiently press it in. In this embodiment, by setting grooves 36 at the contact points of adjacent nozzle components 22 (their circumferential ends) in the circumferential direction of the nozzle 20, the nozzle 20 (or the multiple nozzle components 22 constituting it) can be crimped without fibers being pinched at the circumferential ends of each nozzle component 22.

When the nozzle 20 is attached to the open end 14, a helical male thread portion 29 is formed by the screw groove 28 formed on the outer periphery of each nozzle component 22. Therefore, the fastening portion 18 can be attached to the open end 14 of the liner 12 by screwing the helical female thread portion 19 formed on the fastening portion 18 into this male thread portion 29 (fastening portion attachment process: S25).

The liner 12, with the nozzle 20 and fastening portion 18 attached to the open end 14, is set in a mold, and resin is injected into the mold to impregnate the fiber layer 17 with the resin, forming a reinforcing layer 16 made of fiber-reinforced resin (resin impregnation molding process: S26).

In this embodiment, a groove 36 is provided on the inner peripheral surface of the nozzle 20 (where it comes into contact with the fiber layer 17). In the resin impregnation molding process (S26) in which the fiber layer 17 is impregnated with resin to form the reinforcing layer 16, the resin (matrix resin) flows through the groove 36, allowing the resin to be smoothly and uniformly impregnated from the inlet side of the RTM mold to the other side, and the multiple locking claws 26 are locked to the reinforcing layer 16.

The liner 12 with the reinforcing layer 16 formed thereon is removed from the mold (demolded) to produce the pressure vessel 10 (CFRP process: S27).

(Actions and Effects of the Present Embodiment)
The manufacturing method of the pressure vessel 10 of this embodiment described above includes a fiber winding step (S22) of winding fibers around the outer surface of the liner 12 having a cylindrical opening end 14 and filled with gas to form a fiber layer, a nozzle attachment step (S24) of attaching a cylindrical nozzle 20 formed by arranging a plurality of nozzle assemblies 22 in the circumferential direction of the opening end 14 to the outer peripheral surface of the opening end 14 with the inner surfaces of the plurality of nozzle assemblies 22 in contact with the fiber layer formed on the outer peripheral surface of the opening end 14, and a nozzle attachment step (S25) of applying resin to the fiber layer. and a resin impregnation molding process (S26) of impregnating the liner 12 with a fiber-reinforced resin to form a reinforcing layer (coating portion) 16 that covers the outer surface of the liner 12. In the nozzle attachment process (S24), the nozzle 20 is attached to the outer peripheral surface of the opening end 14 by fixing the multiple nozzle components 22 to each other, and in the resin impregnation molding process (S26), the resin is caused to flow into grooves 36 that serve as resin flow paths and are provided at the points of contact between the multiple nozzle components 22 and the fiber layer, while the resin is impregnated into the fiber layer.

In other words, the manufacturing method of the pressure vessel 10 having the nozzle 20 of this embodiment includes an intermediate body preparation process for preparing an intermediate body having fibers wound around the liner 12, a nozzle attachment process (S24) for attaching the nozzle 20 to the intermediate body, and a resin impregnation molding process (S26) for impregnating the fiber layer of the intermediate body with resin after the nozzle attachment process (S24). The nozzle 20 is made of a plurality of nozzle components 22 arranged in the circumferential direction, and is attached to the intermediate body by fixing the plurality of nozzle components 22 to each other, and grooves 36 that serve as resin flow paths are provided at the contact points of the plurality of nozzle components 22 with the intermediate body.

The pressure vessel 10 of this embodiment includes a liner 12 having a cylindrical opening end 14 and filled with gas, a fiber-reinforced resin reinforcement layer (covering) 16 covering the outer surface of the liner 12, and a cylindrical nozzle 20 configured by arranging multiple nozzle components 22 in the circumferential direction of the opening end 14 and attached to the outer circumferential surface of the opening end 14 with the inner surfaces of the multiple nozzle components 22 in contact with the reinforcement layer (covering) 16 covering the outer circumferential surface of the opening end 14. The nozzle 20 is attached to the outer circumferential surface of the opening end 14 by fixing the multiple nozzle components 22 to each other, and a groove 36 that becomes a resin flow path is provided at the contact point between the multiple nozzle components 22 and the reinforcement layer (covering) 16.

Furthermore, the nozzle 20 for the pressure vessel 10 of this embodiment is a nozzle 20 used for a pressure vessel 10 having a cylindrical opening end 14, a liner 12 filled with gas inside, and a fiber-reinforced resin reinforcing layer (covering portion) 16 covering the outer surface of the liner 12, and is configured by arranging multiple nozzle components 22 in the circumferential direction of the opening end 14, and has a cylindrical shape that can be attached to the outer circumferential surface of the opening end 14 with the inner surfaces of the multiple nozzle components 22 in contact with the reinforcing layer (covering portion) 16 covering the outer circumferential surface of the opening end 14, and can be attached to the outer circumferential surface of the opening end 14 by fixing the multiple nozzle components 22 to each other, and a groove 36 that becomes a resin flow path is provided at the contact point between the multiple nozzle components 22 and the reinforcing layer (covering portion) 16.

That is, in this embodiment, the nozzle 20 is constructed in segments, and when assembled from the outside of the CFRP, the circumferential ends of each nozzle component 22 are brought into contact with each other to ensure the rigidity of the ring (no reduction in diameter).

According to this embodiment, the nozzle 20 has a divided structure of the nozzle constituent 22, which is a rigid part (more specifically, a circular ring structure in which multiple nozzle constituents 22, which are divided and arranged in the circumferential direction, are fixed to each other), which provides the structure required to attach the nozzle 20 to the pressure vessel, while suppressing inward deformation (diameter reduction) of the nozzle 20 and suppressing loosening of the screws between the nozzle 20 and the fastening part 18 (manifold). In addition, by providing a groove 36 as a resin flow path at the contact point (inner surface of the nozzle constituent 22) between the nozzle constituent 22 and the fiber layer 17 (coating part), it is possible to improve the resin impregnation during RTM (in other words, it is possible to efficiently impregnate the fiber layer 17 with resin during RTM).

In addition, compared to a nozzle made of a single unit, for example, the simple shape of the nozzle 20 makes it easier to manufacture and also makes it easier to impregnate with resin.

More specifically, by providing a groove 36 on the inner peripheral surface of the die 20 (where it comes into contact with the fiber layer 17), the resin (matrix resin) flows through the groove 36, improving the resin impregnation from the inlet side of the RTM mold to the opposite side.

In addition, when the nozzle 20 (or the multiple nozzle components 22 constituting it) is crimped to the fiber layer 17, fibers may be pinched at the circumferential ends of each nozzle component 22, and the nozzle 20 (or the multiple nozzle components 22 constituting it) may not be pressed in sufficiently. In this embodiment, by setting grooves 36 at the contact points of adjacent nozzle components 22 (their circumferential ends) in the circumferential direction of the nozzle 20, the nozzle 20 (or the multiple nozzle components 22 constituting it) can be crimped without fibers being pinched at the circumferential ends of each nozzle component 22.

The pressure vessel 10 according to this embodiment has been described above with reference to the drawings, but the pressure vessel 10 according to this embodiment is not limited to the one shown in the drawings, and the design can be modified as appropriate within the scope of the gist of the present invention. For example, the liner 12 may have a cylindrical opening end 14 on at least one end.

The gas filled in the liner 12 is not limited to hydrogen. For example, gases such as helium and nitrogen can also be filled in the liner 12. The reinforcing layer 16 can also be made of fiber reinforced plastic (FRP) and is not limited to being made of carbon fiber reinforced plastic (CFRP).

The number of nozzle components 22 constituting the nozzle 20 is not limited to the four shown in the figure. The number of nozzle components 22 constituting the nozzle 20 is appropriately designed and changed depending on the outer diameter of the opening end 14 (including the thickness of the reinforcing layer 16) and the circumferential length of the nozzle components 22, etc.

The connecting and fixing part 30 that connects and fixes the multiple nozzle components 22 that make up the nozzle 20 is not limited to the rivet fixing shown in the figure. For example, the multiple nozzle components 22 may be connected and fixed to each other by bolt fastening, welding, melting, adhesion, etc., and attached to the outer circumferential surface of the opening end 14. FIG. 11 shows an example in which the multiple nozzle components 22 are connected and fixed to each other by bolt fastening to form a cylindrical nozzle 20, and shows an example in which a bolt 38 is used instead of the rivet protrusion 34 and the widening deformation part 35 in FIG. 3. Also, a bolt may be formed (protruding) instead of the rivet protrusion 34 in FIG. 3, a nut may be placed on the fixing part 33 side, and the bolt and nut may be used to connect and fix. In the case of the above-mentioned nozzle division structure, unless the annular ring (the nozzle) is fixed, the diameter cannot be reduced inward, but it can move outward. In particular, when the nozzle 20 is assembled to the fiber layer 17 before RTM, there is no binding force, and there is a risk that it will come off before being set in the RTM mold. Therefore, a method of fastening the split base structure, such as riveting or bolting as described above, is required.

In addition, the number of grooves 36 provided on the inner surface of the base 20 is not limited to the four shown in the figure. In addition, the shape and position of the grooves 36 provided on the inner surface of the base 20 are not limited to the shape and position shown in the figure.

10 Pressure vessel 12 Liner 14 Open end 16 Reinforcing layer (covering portion)
18 Fastening portion 19 Female screw portion 20 Base 22 Base structure 26 Locking claw (projection portion)
28 Thread groove 29 Male thread portion 30 Connection fixing portion 32 Rivet hole (insertion hole)
33 Fixing portion 34 Rivet protrusion (insertion protrusion)
35 Widening deformation portion 36 Groove

Claims (15)

a fiber winding step of winding fibers on an outer surface of a liner having a cylindrical open end and filled with a gas to form a fiber layer;
a die attachment process for attaching a cylindrical die formed by arranging a plurality of die assemblies in a circumferential direction of the opening end to the outer circumferential surface of the opening end in a state in which inner surfaces of the plurality of die assemblies are in contact with the fiber layer formed on the outer circumferential surface of the opening end;
and a resin impregnation molding step of impregnating the fiber layer with resin to form a fiber-reinforced resin covering part covering the outer surface of the liner,
In the base attachment step, the base is attached to the outer circumferential surface of the opening end by fixing the plurality of base structures to each other;
a resin impregnation molding step of impregnating the fiber layer with the resin while causing the resin to flow through grooves that serve as resin flow paths and that are provided at the contact points between the plurality of nozzle structures and the fiber layer. 2. The method for producing a pressure vessel according to claim 1,
The method for manufacturing a pressure vessel, wherein the groove is provided from one end to the other end in the axial direction of the nozzle structure. 3. The method for producing a pressure vessel according to claim 2,
The method for manufacturing a pressure vessel, wherein the groove is provided along the axial direction of the nozzle structure. 2. The method for producing a pressure vessel according to claim 1,
A method for manufacturing a pressure vessel, characterized in that the groove is provided at a contact point between adjacent nozzle structures. 2. The method for producing a pressure vessel according to claim 1,
a nozzle assembly for attaching a nozzle to a nozzle member including a nozzle member attached to the nozzle member, the nozzle member being fixed to the nozzle member by a nozzle member attached to the nozzle member; 2. The method for producing a pressure vessel according to claim 1,
A method for manufacturing a pressure vessel, characterized in that in the nozzle attachment process, an insertion protrusion provided on one of the adjacent nozzle components is passed through an insertion hole provided on the other adjacent nozzle component, and the multiple nozzle components are fixed to each other by rivet fixing, which presses and deforms the portion of the insertion protrusion protruding from the insertion hole to expand it. 2. The method for producing a pressure vessel according to claim 1,
4. A method for manufacturing a pressure vessel, comprising the steps of: fastening the plurality of nozzle components to one another by bolting in the nozzle mounting step. a liner having a cylindrical open end and filled with gas;
A fiber-reinforced resin covering portion covering an outer surface of the liner;
a cylindrical base configured by arranging a plurality of base assemblies in a circumferential direction of the opening end, the base being attached to the outer circumferential surface of the opening end in a state in which inner surfaces of the plurality of base assemblies are in contact with a covering portion that covers the outer circumferential surface of the opening end,
the base is attached to the outer circumferential surface of the opening end by fixing the plurality of base structures to each other,
A pressure vessel, characterized in that grooves that serve as resin flow paths are provided at contact points between the plurality of nozzle structures and the covering portion. 9. The pressure vessel of claim 8,
A pressure vessel, characterized in that the groove is provided from one end to the other end in the axial direction of the base structure. 10. The pressure vessel of claim 9,
A pressure vessel, wherein the groove is provided along an axial direction of the nozzle structure. 9. The pressure vessel of claim 8,
The pressure vessel, characterized in that the groove is provided at a contact point between adjacent ones of the nozzle structures. 9. The pressure vessel of claim 8,
The pressure vessel is characterized in that the base is formed by fixing the plurality of base components to each other with circumferential ends of adjacent base components in contact with each other. 9. The pressure vessel of claim 8,
The pressure vessel is characterized in that the nozzles are fixed to each other by rivet fixing, in which an insertion protrusion provided on one of the adjacent nozzle structures is passed through an insertion hole provided on the other adjacent nozzle structure, and the portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to expand it. 9. The pressure vessel of claim 8,
A pressure vessel, wherein the nozzle comprises a plurality of nozzle components fixed to each other by bolt fixing. A nozzle used for a pressure vessel including a liner having a cylindrical open end and filled with a gas, and a fiber-reinforced resin covering part covering an outer surface of the liner,
a plurality of base assemblies are arranged in a circumferential direction of the opening end, the base assemblies have a cylindrical shape that can be attached to the outer circumferential surface of the opening end in a state in which inner surfaces of the plurality of base assemblies are in contact with the covering portion that covers the outer circumferential surface of the opening end,
the plurality of base structures can be attached to the outer circumferential surface of the opening end by fixing the base structures to each other,
A base characterized in that grooves that serve as resin flow paths are provided at contact points between the plurality of base structures and the covering portion.

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