Method for manufacturing pressure vessel, pressure vessel, and joint for pressure vessel

Abstract

The present invention provides a method for manufacturing a pressure vessel, a pressure vessel, and a joint for a pressure vessel. In a joint installation step (S24), a joint (20) is installed on the outer peripheral surface of an opening end (14) by fixing a plurality of joint structures (22) to each other. In a resin impregnation molding step (S26), resin is impregnated into the fiber layer while flowing through grooves (36) serving as resin flow paths provided in contact areas of the plurality of joint structures (22) with the fiber layer.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a pressure vessel, a pressure vessel, and a joint for the pressure vessel. Background Art

[0002] A pressure vessel (also known as a high-pressure tank) is known that includes a cylindrical liner and a reinforcement portion (reinforcement layer) formed of carbon fiber reinforced plastic (CFRP) to reinforce the liner. The pressure vessel stores hydrogen within the liner (see, for example, Japanese Patent Application Laid-Open No. 2020-112189). A joint is securely attached to the end of the liner. Specifically, a protrusion provided on the joint bites into the reinforcement portion (reinforcement layer).

[0003] The pressure vessel described in Japanese Patent Application Laid-Open No. 2020-112189 comprises: a liner filled with gas; a reinforcement layer formed using a fiber-reinforced resin in a state of contact with the outer surface of the liner and covering the liner from the outside; and a joint installed on the liner. The joint is formed in an annular shape and comprises: a plurality of joint main bodies having locking claws (protrusions) protruding toward the reinforcement layer side and arranged at intervals in the circumferential direction; and a crossbeam portion that connects a plurality of circumferentially adjacent joint main bodies in the circumferential direction. The joint is installed on the liner in a state in which the locking claws (protrusions) of the plurality of joint main bodies are locked in the reinforcement layer when the crossbeam portion is deformed.

[0004] The pressure vessel can be manufactured, for example, by a fiber winding (FW) method (Japanese Patent Application Laid-Open No. 2020-112189) in which a sheet of fiber-reinforced resin is attached to the liner, or an RTM (Resin Transfer Molding) method (Japanese Patent Application Laid-Open No. 2020-085199) in which a sheet of fiber (bundle) is attached to the liner and then impregnated with resin. Summary of the Invention

[0005] As described above, the pressure vessel joint disclosed in Japanese Patent Application Laid-Open No. 2020-112189 forms a ring with a rigid body (the joint body) formed with thread grooves and a thin-walled beam portion (the beam portion) that allows for deformation. Furthermore, to facilitate assembly from the outside of the CFRP, the thin-walled beam portion is deformed to reduce the inner diameter, and the locking claws (protrusions) of the rigid body (the joint body) are riveted to the CFRP.

[0006] However, in the joint of the pressure vessel described in Japanese Patent Application No. 2020-112189, when the matrix resin of the CFRP is deformed in a high-temperature environment, the presence of a thin-walled portion allows deformation inward (reduction in diameter), so the threaded connection between the thread groove provided in the main body of the joint and the fastening portion (manifold) may become loose.

[0007] To address such concerns, it is considered to form a joint (annular ring) consisting only of multiple rigid parts arranged in the circumferential direction, in other words, to divide the joint composed of rigid parts in the circumferential direction (see Japanese Patent Application Laid-Open No. 2021-076174, Japanese Patent Application Laid-Open No. 62-297586, and Japanese Patent Application Laid-Open No. 2004-028816).

[0008] For example, the pressure vessel described in Japanese Patent Application No. 2021-076174 comprises: a container body having a cylindrical open end at least on one end side and filled with gas inside; a covering portion made of fiber-reinforced resin covering the outer surface of the container body; a cylindrical joint, which is composed of a plurality of joint bodies having protrusions on the inner surface connected in the circumferential direction of the open end, and is installed on the outer circumferential surface of the open end by making the protrusion bite into the covering portion covering the outer circumferential surface of the open end, and the joint is connected by fitting the fitting portion formed at the end in the circumferential direction of the joint body.

[0009] However, in the joint of the pressure vessel described in Japanese Patent Application Laid-Open No. 2021-076174, since only the fitting portion formed at the circumferential end of the joint body is fitted, there is room for inward deformation (diameter reduction) when the matrix resin of the CFRP is deformed in a high-temperature environment.

[0010] In addition, when manufacturing a pressure vessel using the RTM method, which involves winding fibers (bundles) around a liner and assembling a joint from the outside of the fibers (bundles) and then impregnating the joint with resin, if the joint consists only of a rigid body, there is the following problem: if there is no resin flow path, it is difficult to impregnate the resin to the inlet side and the opposite side of the RTM mold.

[0011] In view of the above situation, the object of the present invention is to provide a method for manufacturing a pressure vessel, a pressure vessel and a joint for a pressure vessel, which can suppress the deformation (diameter reduction) of the joint toward the inside and suppress the loosening of the threads of the joint and the fastening part (manifold), and can improve the resin impregnation during RTM.

[0012] In order to achieve the above-mentioned purpose, the manufacturing method of the pressure vessel of the present invention is characterized in that it includes the following steps: a fiber winding step, winding fibers on the outer surface of the liner to form a fiber layer, the liner having a cylindrical open end and filled with gas inside; a joint installation step, installing a cylindrical joint composed of a plurality of joint structures arranged in the circumferential direction of the open end on the outer peripheral surface of the open end in a state in which the inner surfaces of the plurality of joint structures are in contact with the fiber layer formed on the outer peripheral surface of the open end; and a resin impregnation molding step, impregnating the fiber layer with resin to form a fiber-reinforced resin covering portion covering the outer surface of the liner, in the joint installation step, the joint is installed on the outer peripheral surface of the open end by fixing the plurality of joint structures to each other, and in the resin impregnation molding step, the resin is impregnated into the fiber layer while flowing in a groove serving as a resin flow path provided in the contact portion of the plurality of joint structures that contact the fiber layer.

[0013] In a preferred embodiment, the groove is provided from one end portion to the other end portion of the joint structure in the axial direction.

[0014] In another preferred embodiment, the groove is arranged along the axial direction of the joint structure.

[0015] In another preferred embodiment, the groove is provided at a contact portion between adjacent joint structures.

[0016] In another preferred embodiment, in the joint mounting step, the plurality of joint structures are fixed to each other in a state where the ends of the adjacent joint structures in the circumferential direction are in contact with each other.

[0017] In another preferred embodiment, in the joint installation process, the plurality of joint structures are fixed to each other by riveting. In the riveting, an insertion protrusion provided on one side of the adjacent joint structure is inserted into an insertion hole provided on the other side of the adjacent joint structure, and a portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to widen.

[0018] In another preferred embodiment, in the joint mounting step, the plurality of joint structures are fixed to each other by bolting.

[0019] In addition, the pressure vessel of the present invention includes: a liner having a cylindrical open end and filled with gas inside; a covering portion made of fiber-reinforced resin, covering the outer surface of the liner; and a cylindrical joint, which is composed of a plurality of joint structures arranged in the circumferential direction of the open end and is installed on the outer peripheral surface of the open end in a state where the inner surfaces of the plurality of joint structures are in contact with the covering portion covering the outer peripheral surface of the open end. The pressure vessel is characterized in that the joint is installed on the outer peripheral surface of the open end by fixing the plurality of joint structures to each other, and a groove serving as a resin flow path is provided at the contact portion of the plurality of joint structures that are in contact with the covering portion.

[0020] In a preferred embodiment, the groove is provided from one end portion to the other end portion of the joint structure in the axial direction.

[0021] In another preferred embodiment, the groove is arranged along the axial direction of the joint structure.

[0022] In another preferred embodiment, the groove is provided at a contact portion between adjacent joint structures.

[0023] In another preferred embodiment, in the joint, the plurality of joint structures are fixed to each other in a state in which the ends of the adjacent joint structures in the circumferential direction are in contact with each other.

[0024] In another preferred embodiment, in the joint, a plurality of the joint structures are fixed to each other by riveting. In the riveting, an insertion protrusion provided on one side of the adjacent joint structure is inserted into an insertion hole provided on the other side of the adjacent joint structure, and a portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to widen.

[0025] In another preferred embodiment, in the joint, the plurality of joint structures are fixed to each other by bolts.

[0026] In addition, the joint for a pressure vessel of the present invention is used for a pressure vessel, which pressure vessel comprises: a liner having a cylindrical open end and filled with gas inside; and a covering portion made of fiber-reinforced resin, covering the outer surface of the liner, the characteristic of the joint being that the joint is composed of a plurality of joint structures arranged in the circumferential direction of the open end, and having a cylindrical shape that can be installed on the outer peripheral surface of the open end in a state where the inner surfaces of the plurality of joint structures are in contact with the covering portion covering the outer peripheral surface of the open end, the joint can be installed on the outer peripheral surface of the open end by fixing the plurality of joint structures to each other, and a groove serving as a resin flow path is provided at the contact portion of the plurality of joint structures that are in contact with the covering portion.

[0027] According to the present invention, by forming the joint into a split structure of the joint structure serving as a rigid body, it is possible to provide a structure required for installing the joint on a pressure vessel while suppressing deformation of the joint toward the inside (shrinkage) and suppressing loosening of the threads between the joint and the fastening portion (manifold), and by providing a groove serving as a resin flow path at the contact portion (inner surface of the joint structure) between the joint structure and the fiber layer (covering portion), the resin impregnation during RTM can be improved.

[0028] Furthermore, compared to a joint formed of an integral component, for example, the joint is easy to manufacture due to its simple shape, and is also easy to impregnate with resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0030] Figure 1 It is a cross-sectional view showing an enlarged view of the opening end portion side of the pressure vessel according to the present embodiment.

[0031] Figure 2 It is a perspective view showing an enlarged view of the opening end portion side of the pressure vessel according to the present embodiment.

[0032] Figure 3 It is a perspective view showing the joint according to this embodiment.

[0033] Figure 4 It is a cross-sectional view showing an enlarged view of a locking claw of the joint according to the present embodiment.

[0034] Figure 5 yes Figure 2 Sectional view along line VV.

[0035] Figure 6 It is a process diagram showing a method (RTM method) for manufacturing a pressure vessel according to the present embodiment.

[0036] Figure 7 This is an enlarged perspective view showing the opening end portion side of the pressure vessel according to the present embodiment, and illustrates a state before the joint is fixed (before the fastening portion is screwed).

[0037] Figure 8 It is an enlarged front view showing the opening end side of the pressure vessel according to the present embodiment, and shows a state before the joint is fixed (before the fastening portion is screwed).

[0038] Figure 9 This is an enlarged perspective view showing the opening end portion side of the pressure vessel according to the present embodiment, and illustrates a state where the joint is fixed (the fastening portion is screwed).

[0039] Figure 10 It is an enlarged front view showing the opening end side of the pressure vessel according to the present embodiment, and shows a state after the joint is fixed (after the fastening portion is screwed).

[0040] Figure 11 It is a perspective view showing another example of the joint according to the present embodiment. DETAILED DESCRIPTION

[0041] The following describes embodiments of the present invention in detail with reference to the accompanying drawings. For ease of explanation, arrows S, as shown in the various figures, indicate the axial direction of the pressure vessel 10, arrows R indicate the radial direction of the pressure vessel 10, and arrows C indicate the circumferential direction of the pressure vessel 10. Therefore, in the following description, unless otherwise specified, references to the axial, radial, and circumferential directions represent the axial, radial, and circumferential directions of the pressure vessel 10 (including the open end 14 described below), respectively.

[0042] (Schematic structure of pressure vessel)

[0043] like Figure 1 As shown, the 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 configured to include a plurality of pressure vessels 10 connected to each other via fastening portions 18 described later.

[0044] The pressure vessel 10 is constructed to include: a liner 12, which serves as a container body filled with gaseous hydrogen; a reinforcement layer 16, which serves as a covering portion that covers the outer surface of the liner 12 from the outside to reinforce the liner 12; and a cylindrical joint 20, which is installed on the outer peripheral surface of the cylindrical open end 14 formed at both ends of the liner 12 through the reinforcement layer 16.

[0045] The liner 12 is formed into a generally cylindrical shape using a resin material such as a polyamide synthetic resin. More specifically, the liner 12 comprises a cylindrical main body 12A with a constant inner and outer diameter at the middle portion of the liner 12 in the longitudinal direction (axial direction), and shoulder portions 12B, which gradually taper toward the side opposite to the main body 12A (axially outward) and forming two side portions of the liner 12 in the longitudinal direction (axial direction).

[0046] In addition, the liner 12 has a cylindrical open end portion 14, which constitutes the two end portions of the liner 12 in the longitudinal direction (axial direction) (the portion that is axially further outward than the shoulder 12B), and has an inner diameter and an outer diameter that are smaller than the main body 12A and the shoulder 12B and are formed to be approximately constant.

[0047] The reinforcement layer 16 is made of fiber-reinforced resin and is formed by winding multiple layers of reinforcing fibers (bundles) around the entire outer surface of the liner 12 and impregnating the wound fibers (layers) with resin. The thickness of the reinforcement layer 16 increases from the main body 12A side of the liner 12 toward the open end 14 side. The outer diameter of the portion of the reinforcement layer 16 corresponding to the open end 14 of the liner 12 is substantially constant. In this embodiment, carbon fiber-reinforced resin (CFRP) is used as an example of fiber-reinforced resin (FRP).

[0048] In addition, a joint 20 is installed from above the reinforcing layer 16 at the open end 14 of the liner 12 covered by the reinforcing layer 16. Then, a fastening portion 18 is installed at the joint 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). Figure 1 1 shows the open end portion 14 of the liner 12 on one side closed by the fastening portion 18 .

[0049] (Connector structure)

[0050] like Figure 2 、 Figure 3 As shown, the joint 20 is formed of a metal material into a cylindrical (annular) shape. Specifically, the joint 20 is composed of a plurality (four in this embodiment) of joint structures 22 arranged in the circumferential direction. The joint structures 22 extend axially with the radial direction as the thickness direction and are formed into a plate shape that curves radially outward when viewed from the axial direction.

[0051] Furthermore, the axially outer end surface of the joint structure 22 has a flat surface 23 that is flush with the end surface of the opening end 14 (reinforcement layer 16), and a flange portion 24 that is curved toward the radial outer side is integrally formed at the axially inner end of the joint structure 22. In addition, the flange portion 24 of each joint structure 22 is formed so that, when viewed from the axial direction, the assembled shape is a substantially regular octagon (see FIG. Figure 10 ).

[0052] like Figure 1 、 Figure 3 As shown, a plurality of locking claws 26 are formed as protrusions on the inner circumference (inner surface) of each joint structure 22. The inner circumference of each joint structure 22 is knurled by these multiple locking claws 26. Each locking claw 26 is formed into a sharp serrated shape on the front end side (radially inner side) in the protruding direction when viewed in cross-section along the axial and radial directions.

[0053] To explain in more detail, Figure 4As shown, the surface of each locking claw 26 facing the main body 12A side of the liner 12 is an inclined surface 26A that tilts axially outward as it moves radially inward. In addition, the surface of each locking claw 26 on the side opposite to the surface facing the main body 12A side of the liner 12 is a vertical surface 26B along the radial direction.

[0054] The intersection of the inclined surface 26A and the vertical surface 26B forms a tip end 26C of each locking claw 26. The tip end 26C of each locking claw 26 bites into (locks) the outer periphery of the reinforcing layer 16 covering the outer periphery of the opening end 14, thereby forming a structure in which the joint 20 is firmly (non-rotatably) attached to the opening end 14.

[0055] In addition, if Figure 1 、 Figure 5 As shown, a thread groove 28 is formed on the outer peripheral surface (outer surface) of the joint structure 22 (in Figure 2 、 Figure 3 (The thread groove 28 is omitted in the figure). The thread groove 28 forms a spiral external thread portion 29 along the circumferential and axial directions when the joint 20 is attached to the open end portion 14 (when the joint structures 22 are connected and fixed). Furthermore, the internal thread portion 19 of the fastening portion 18, described later, screws into the external thread portion 29.

[0056] In addition, if Figure 2 、 Figure 3 As shown, a connecting and fixing portion 30 is formed at the circumferential end of each joint structure 22 for connecting and fixing the joint structures 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 a plurality of joint structures 22 arranged in the circumferential direction to each other. The connecting and fixing portion 30 is composed of a rivet hole 32 serving as a through hole and a rivet protrusion 34 serving as a through protrusion. The rivet hole 32 is formed at the circumferential end of one joint structure 22 adjacent to the joint 20 in the circumferential direction, and the rivet protrusion 34 is formed at the circumferential end of the other joint structure 22 adjacent to the joint 20 in the circumferential direction.

[0057] More specifically, the joint 20 of this embodiment is composed of four joint structures including a top-bottom pair (upper and lower pair) of joint structures formed in the same shape and a left-right pair (left-right pair) of joint structures formed in the same shape.

[0058] At the circumferential ends (i.e., left and right) of the upper and lower paired joint structures 22, the outer circumferential sides of the axially inner and outer ends are cut away to form a flat surface. Rivet holes 32 are formed in the fixing portion 33 formed in the above-mentioned flat surface (a total of eight locations) (see Figure 7 、 Figure 8 ).

[0059] The caulking protrusions 34 are formed at the circumferential (i.e., upper and lower) ends (four locations) of the left and right paired joint structures 22 and at the axially inner and outer ends thereof so as to protrude upward or downward (eight locations in total) (see FIG. Figure 7 、 Figure 8 ). In addition, the vertical length of the caulking protrusion 34 is longer than the vertical depth (length) of the caulking hole 32.

[0060] Furthermore, the rivet protrusion 34 of the adjacent joint structure 22 (in this embodiment, the upper and lower joint structures 22) is inserted into the rivet hole 32 of the adjacent joint structure 22 (in this embodiment, the left and right joint structures 22), and the front end portion of the rivet protrusion 34 protruding from the rivet hole 32 is pressed and deformed to widen the front end portion (widened to a diameter larger than the rivet hole 32), and the widened deformed portion 35 is pressed against the rivet hole 32 of the fixing portion 33 (in other words, the fixing portion 33 is clamped and held by the two widened deformed portions 35 provided at the axially inner and outer ends), thereby connecting and fixing each joint structure 22 in the circumferential direction (refer to FIG. Figure 9 、 Figure 10 ). That is, a cylindrical joint 20 is formed.

[0061] The structure is such that when the rivet protrusions 34 are inserted into the rivet holes 32 and the joint structures 22 are connected and fixed to each other in the circumferential direction, the circumferential end (surface) 22A of one adjacent joint structure 22 abuts against the circumferential end (surface) 22B of another adjacent joint structure 22. In other words, the structure is such that no gap is formed between the circumferential end (surface) 22A of one adjacent joint structure 22 and the circumferential end (surface) 22B of another adjacent joint structure 22 (see FIG. Figures 7 to 10 ).

[0062] In addition, if Figure 2 、 Figure 3 、 Figure 5 As shown, a plurality of (four in this embodiment) grooves 36 serving as resin flow paths in a manufacturing process described later are formed on the inner peripheral surface (inner surface) of the joint 20 .

[0063] More specifically, the groove 36 is formed in a straight line (along the axial direction) on the inner circumferential surface (inner surface) of the joint 20, extending from the axially inner end (one end) to the axially outer end (the other end). Furthermore, the groove 36 is formed into a concave shape when viewed along the axial direction. Furthermore, in this embodiment, the groove 36 is provided at the contact points (four locations) between the circumferential ends (i.e., left and right) of the upper and lower paired joint structures 22 and the circumferential ends (i.e., upper and lower) of the left and right paired joint structures 22, that is, at the contact points between (the circumferential ends of) the circumferentially adjacent joint structures 22 in the joint 20.

[0064] The above-mentioned groove 36 is arranged on the inner peripheral portion (inner surface) of the joint structure 22 which contacts the fiber layer (formed on the outer surface of the open end portion 14 of the liner 12) when the joint 20 is installed to the open end portion 14, and becomes a resin flow path for the molten resin (matrix resin) to flow in the resin infusion molding process of the manufacturing process to be described later.

[0065] (Pressure Vessel Manufacturing Process)

[0066] Next, a process of manufacturing the pressure vessel 10 according to the present embodiment, particularly a process of attaching the joint 20 according to the present embodiment to the open end portion 14 of the liner 12 will be described.

[0067] The manufacturing process of this embodiment is a process of manufacturing the pressure vessel 10 by RTM method. Figure 6 As one example shown in , it includes a lining forming process (S21), a fiber winding process (S22), a joint configuration process (S23), a joint installation process (S24), a fastening portion installation process (S25), a resin impregnation molding process (S26), and a CFRP process (S26).

[0068] First, the substantially cylindrical liner 12 is formed (liner forming step: S21 ).

[0069] Next, sheet-shaped fibers (bundles) are wound around the outer surface of the liner 12 (fiber winding step: S22). As an example of the fibers, carbon fibers (CF) are used. By winding the fibers (bundles) around the liner 12, a fiber layer 17 ( Figures 7 to 10 ) In addition, at this time, the fibers (bundle) are wound so that the thickness of the fiber layer 17 at the opening end portion 14 is thicker than that at the main body portion 12A and the shoulder portion 12B.

[0070] The liner forming step ( S21 ) and the fiber winding step ( S22 ) may be collectively referred to as an intermediate product preparing step of preparing an intermediate product in which fibers (bundles) are wound around the outer surface of the liner 12 .

[0071] Then, if Figure 7 、 Figure 8 As shown, the joint 20 is arranged on the outer peripheral side of the opening end 14 of the liner 12 (the outer peripheral side of the fiber layer 17) (joint arrangement process: S23). That is, a plurality of joint structures 22 constituting the joint 20 are arranged in the circumferential direction of the opening end 14 (in the Figure 7 The thread groove 28 is omitted.) Thus, the front end portions 26C of the large number of locking claws 26 formed in each joint structure 22 of the joint 20 are arranged facing the outer peripheral surface of the fiber layer 17 (with a gap therebetween).

[0072] Then, if Figure 9 、 Figure 10 As shown, the joint 20 (a plurality of joint structures 22 constituting the joint 20) is brought close to (riveted) the fiber layer 17, and the connecting and fixing portion 30 of the joint 20 is connected and fixed, so that the diameter of the joint 20 is reduced (joint installation process: S24) (in Figure 9 The thread groove 28 is omitted. That is, the left and right paired joint structures 22 are moved radially inward, and their inner peripheral surfaces (the plurality of locking claws 26) are pressed (from the left and right direction) against the outer peripheral portion of the fiber layer 17 to maintain the connection. Next, the upper and lower paired joint structures 22 are moved radially inward, and while the rivet protrusions 34 of the left and right joint structures 22 are inserted into the rivet holes 32 of the upper and lower joint structures 22, the inner peripheral surfaces (the plurality of locking claws 26) of the upper and lower paired joint structures 22 are pressed (from the upper and lower direction) against the outer peripheral portion of the fiber layer 17 to maintain the connection. Then, the front end portion of the rivet protrusion 34 protruding from the rivet hole 32 is pressed and deformed to widen the front end portion (widen to a diameter larger than the rivet hole 32), and the widened deformed portion 35 is pressed against the rivet hole 32 of the fixing portion 33 (in other words, the fixing portion 33 is clamped and held by the two widened deformed portions 35 provided at the axially inner and outer ends). As a result, each joint structure 22 moves radially inward (shrinks in diameter), and the circumferential end portion (surface) 22A of an adjacent joint structure 22 abuts the circumferential end portion (surface) 22B of another adjacent joint structure 22. At the same time, the adjacent joint structures 22 are connected and fixed to each other, and the multiple locking claws 26 bite into the fiber layer 17. As a result, the joint 20 is attached to the open end portion 14 of the liner 12 via the fiber layer 17.

[0073] Furthermore, in the joint installation step (S24) of attaching the cylindrical joint 20 to the outer circumferential surface of the open end portion 14, there is a possibility that when the joint 20 (the plurality of joint structures 22 constituting the joint 20) is riveted to the fiber layer 17, the fibers may be pinched between the circumferential ends of each joint structure 22, preventing the joint 20 (the plurality of joint structures 22 constituting the joint 20) from being fully pressed in. In this embodiment, by providing grooves 36 at the contact portions of (the circumferential ends of) circumferentially adjacent joint structures 22 of the joint 20, the joint 20 (the plurality of joint structures 22 constituting the joint 20) can be riveted without pinching the fibers between the circumferential ends of each joint structure 22.

[0074] When the joint 20 is mounted on the open end portion 14, the spiral external thread portion 29 is formed by the thread groove 28 formed on the outer peripheral portion of each joint structure 22. Therefore, by screwing the spiral internal thread portion 19 formed on the fastening portion 18 into the external thread portion 29, the fastening portion 18 can be mounted on the open end portion 14 of the liner 12 (fastening portion mounting step: S25).

[0075] The liner 12 with the joint 20 and the fastening portion 18 installed at the open end 14 is placed in a mold, and resin is injected into the mold to impregnate the fiber layer 17 with the resin, thereby forming the reinforcement layer 16 composed of fiber-reinforced resin (resin impregnation molding process: S26).

[0076] In this embodiment, a groove 36 is set on the inner peripheral surface of the joint 20 (the part in contact with the fiber layer 17), so that in the resin impregnation molding process (S26) of impregnating the fiber layer 17 with resin to form the reinforcement layer 16, the resin (matrix resin) flows through the groove 36, so that the resin from the inlet side to the opposite side of the RTM mold can be smoothly and roughly evenly impregnated, and multiple locking claws 26 are locked in the reinforcement layer 16.

[0077] The pressure vessel 10 can be manufactured by removing the liner 12 on which the reinforcement layer 16 is formed from the mold (demolding) (CFRP forming step: S27 ).

[0078] (Functions and Effects of the Present Embodiment)

[0079] In the manufacturing method of the pressure vessel 10 of the present embodiment described above, the method includes: a fiber winding step (S22) of winding fibers on the outer surface of the liner 12 to form a fiber layer, the liner 22 having a cylindrical open end 14 and filled with gas; a joint installation step (S24) of installing a cylindrical joint 20 composed of a plurality of joint structures 22 arranged in the circumferential direction of the open end 14 on the outer circumferential surface of the open end 14 in a state in which the inner surfaces of the plurality of joint structures 22 are in contact with the fiber layer formed on the outer circumferential surface of the open end 14; and a resin In the impregnation molding process (S26), the resin is impregnated into the fiber layer to form a fiber-reinforced resin reinforcement layer (covering portion) 16 covering the outer surface of the lining 12. In the joint installation process (S24), the joint 20 is installed on the outer peripheral surface of the open end 14 by fixing the plurality of joint structures 22 to each other. In the resin impregnation molding process (S26), the resin is impregnated into the fiber layer while flowing in the grooves 36 serving as resin flow paths provided in the contact portions of the plurality of joint structures 22 that contact the fiber layer.

[0080] In other words, in the manufacturing method of the pressure vessel 10 with the joint 20 of this embodiment, it includes: an intermediate preparation step, preparing an intermediate formed by winding fibers on the liner 12; a joint installation step (S24), installing the joint 20 on the intermediate; and a resin impregnation molding step (S26), impregnating the fiber layer of the intermediate with resin after the joint installation step (S24), the joint 20 is composed of a plurality of joint structures 22 arranged in the circumferential direction, and is installed on the intermediate by fixing the plurality of joint structures 22 to each other, and a groove 36 serving as a resin flow path is provided at the contact parts of the plurality of joint structures 22 that contact the intermediate.

[0081] In addition, the pressure vessel 10 of the present embodiment includes: a liner 12 having a cylindrical open end 14 and filled with gas inside; a reinforcement layer (covering portion) 16 made of fiber-reinforced resin, covering the outer surface of the liner 12; and a cylindrical joint 20, which is composed of a plurality of joint structures 22 arranged in the circumferential direction of the open end 14, and is installed on the outer peripheral surface of the open end 14 in a state where the inner surfaces of the plurality of joint structures 22 are in contact with the reinforcement layer (covering portion) 16 covering the outer peripheral surface of the open end 14, wherein the joint 20 is installed on the outer peripheral surface of the open end 14 by fixing the plurality of joint structures 22 to each other, and a groove 36 serving as a resin flow path is provided at the contact portion of the plurality of joint structures 22 that are in contact with the reinforcement layer (covering portion) 16.

[0082] Moreover, the joint 20 for the pressure vessel 10 of the present embodiment is used for the pressure vessel 10, which comprises: a liner 12 having a cylindrical open end 14 and filled with gas inside; and a reinforcement layer (covering portion) 16 made of fiber-reinforced resin, covering the outer surface of the liner 12, wherein the joint 20 is composed of a plurality of joint structures 22 arranged in the circumferential direction of the open end 14, and has a cylindrical shape that can be installed on the outer peripheral surface of the open end 14 in a state where the inner surfaces of the plurality of joint structures 22 are in contact with the reinforcement layer (covering portion) 16 covering the outer peripheral surface of the open end 14, and the joint 20 can be installed on the outer peripheral surface of the open end 14 by fixing the plurality of joint structures 22 to each other, and a groove 36 serving as a resin flow path is provided at the contact portion of the plurality of joint structures 22 that contacts the reinforcement layer (covering portion) 16.

[0083] That is, in this embodiment, the joint 20 is divided and the ends of the joint structures 22 in the circumferential direction are brought into contact when assembled from the outside of the CFRP, thereby ensuring rigidity as a ring (no reduction in diameter).

[0084] According to this embodiment, by forming the joint 20 into a split structure of the joint structure 22 as a rigid body portion (in detail, a circular ring structure formed by fixing a plurality of joint structures 22 that are split and arranged in the circumferential direction to each other), it is possible to provide a structure required for installing the joint 20 on the pressure vessel while suppressing the deformation of the joint 20 toward the inside (shrinkage) and suppressing the loosening of the threads of the joint 20 and the fastening portion 18 (manifold), and by providing a groove 36 as a resin flow path at the contact portion between the joint structure 22 and the fiber layer 17 (covering portion) (the inner surface of the joint structure 22), the resin impregnation during RTM can be improved (in other words, the resin can be efficiently impregnated into the fiber layer 17 during RTM).

[0085] Furthermore, for example, compared to a joint formed of an integral component, the joint 20 is easy to manufacture due to its simple shape, and is also easy to impregnate with resin.

[0086] More specifically, by providing grooves 36 on the inner peripheral surface of the joint 20 (the portion in contact with the fiber layer 17 ), the resin (matrix resin) flows through the grooves 36 , thereby improving the resin impregnation from the inlet side of the RTM mold to the opposite side.

[0087] Furthermore, when the joint 20 (the plurality of joint structures 22 constituting the joint 20) is riveted to the fiber layer 17, there is a possibility that the fibers may be pinched between the circumferential ends of each joint structure 22, preventing the joint 20 (the plurality of joint structures 22 constituting the joint 20) from being fully pressed in. In this embodiment, by providing grooves 36 at the contact locations of (the circumferential ends of) circumferentially adjacent joint structures 22 of the joint 20, the joint 20 (the plurality of joint structures 22 constituting the joint 20) can be riveted without pinching the fibers between the circumferential ends of each joint structure 22.

[0088] While the pressure vessel 10 according to this embodiment has been described above with reference to the accompanying drawings, the pressure vessel 10 according to this embodiment is not limited to the illustrated configuration and can be modified as appropriate without departing from the spirit of the present invention. For example, the liner 12 only needs to have a cylindrical open end portion 14 on at least one end.

[0089] The gas filled in the liner 12 is not limited to hydrogen. For example, gases such as helium and nitrogen may be filled in the liner 12. The reinforcement layer 16 may be made of fiber reinforced plastic (FRP) and is not limited to carbon fiber reinforced plastic (CFRP).

[0090] In addition, the number of joint structures 22 constituting the joint 20 is not limited to four as shown in the figure. The number of joint structures 22 constituting the joint 20 can be appropriately changed in design according to the outer diameter of the opening end 14 (including the thickness of the reinforcing layer 16) and the circumferential length of the joint structure 22.

[0091] In addition, the connection fixing portion 30 that connects and fixes the multiple joint structures 22 constituting the joint 20 is not limited to the riveting fixation shown in the figure. For example, the multiple joint structures 22 can be connected and fixed to each other by bolt fastening, welding, welding, bonding, etc., thereby being installed on the outer peripheral surface of the opening end portion 14. Figure 11 In FIG. 1 , an example of a cylindrical joint 20 is shown in which a plurality of joint structures 22 are connected and fixed to each other by bolts, and a bolt 38 is used instead of Figure 3 In addition, it is also possible to replace the rivet protrusion 34 and the widening deformation portion 35. Figure 3The rivet protrusion 34 is formed with a bolt (protrudingly provided), and a nut is arranged on the side of the fixing portion 33, and the bolt and nut are connected and fixed. In addition, in the case of the above-mentioned split joint structure, if the ring (joint) is not fixed, it cannot be reduced in diameter toward the inside, but can be moved toward the outside. In particular, when the joint 20 is assembled to the fiber layer 17 before RTM, there is no restraint force, and there is a possibility that it will fall off in a disorderly manner before being placed in the RTM mold. Therefore, a method of fixing the split joint structure such as riveting or bolting as described above is required.

[0092] The number of grooves 36 provided on the inner surface of the joint 20 is not limited to the four shown in the figure. The shape and position of the grooves 36 provided on the inner surface of the joint 20 are also not limited to the shape and position shown in the figure.

Claims

1. A method for manufacturing a pressure vessel, characterized in that: The process includes the following steps: a fiber winding step of winding fibers around an outer surface of an inner liner to form a fiber layer, the inner liner having a cylindrical open end and filled with gas; a joint installation step of installing a tubular joint formed by arranging a plurality of the joint structures in a circumferential direction of the open end portion on the outer peripheral surface of the open end portion, with the inner surfaces of the plurality of joint structures in contact with the fiber layer formed on the outer peripheral surface of the open end portion; and A resin impregnation molding step of impregnating the fiber layer with resin to form a fiber-reinforced resin covering portion covering the outer surface of the liner. In the joint installation step, the joint is installed on the outer peripheral surface of the open end by fixing a plurality of the joint structures to each other. In the resin infusion molding step, the resin is impregnated into the fiber layer while flowing through grooves serving as resin flow paths provided at contact locations of the plurality of joint structures with the fiber layer.

2. The method for manufacturing a pressure vessel according to claim 1, wherein: The groove is provided from one end portion to the other end portion of the joint structure in the axial direction.

3. The method for manufacturing a pressure vessel according to claim 2, wherein: The groove is provided along the axial direction of the joint structure.

4. The method for manufacturing a pressure vessel according to claim 1, wherein: The grooves are provided at contact locations of adjacent joint structures.

5. The method for manufacturing a pressure vessel according to claim 1, wherein: In the joint mounting step, the plurality of joint structures are fixed to each other in a state where the ends of the adjacent joint structures in the circumferential direction are in contact with each other.

6. The method for manufacturing a pressure vessel according to claim 1, wherein: In the joint installation process, the plurality of joint structures are fixed to each other by riveting. In the riveting, an insertion protrusion provided on one side of the adjacent joint structure is inserted into an insertion hole provided on the other side of the adjacent joint structure, and a portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to widen.

7. The method for manufacturing a pressure vessel according to claim 1, wherein: In the joint mounting step, the plurality of joint structures are fixed to each other by bolting.

8. A pressure vessel comprising: an inner liner having a cylindrical open end and filled with gas; a covering portion made of fiber-reinforced resin, covering an outer surface of the liner; and The cylindrical joint is composed of a plurality of joint structures arranged in the circumferential direction of the opening end, and is mounted on the outer peripheral surface of the opening end in a state where the inner surfaces of the plurality of joint structures are in contact with the covering portion covering the outer peripheral surface of the opening end. The pressure vessel is characterized in that The joint is mounted on the outer peripheral surface of the opening end by fixing a plurality of the joint structures to each other. Grooves serving as resin flow paths are provided at contact locations of the plurality of joint structures that come into contact with the covering portion.

9. The pressure vessel according to claim 8, characterized in that The groove is provided from one end portion to the other end portion of the joint structure in the axial direction.

10. The pressure vessel according to claim 9, characterized in that The groove is provided along the axial direction of the joint structure.

11. The pressure vessel according to claim 8, characterized in that The grooves are provided at contact locations of adjacent joint structures.

12. The pressure vessel according to claim 8, characterized in that In the joint, the plurality of joint structures are fixed to each other in a state where the ends of the adjacent joint structures in the circumferential direction are in contact with each other.

13. The pressure vessel according to claim 8, characterized in that In the joint, the plurality of joint structures are fixed to each other by riveting. In the riveting, an insertion protrusion provided on one side of the adjacent joint structure is inserted into an insertion hole provided on the other side of the adjacent joint structure, and the portion of the insertion protrusion protruding from the insertion hole is pressed and deformed to widen.

14. The pressure vessel according to claim 8, wherein In the joint, the plurality of joint structures are fixed to each other by bolt fastening.

15. A joint for a pressure vessel comprising: a liner having a cylindrical open end and filled with gas; and a covering portion made of a fiber-reinforced resin covering an outer surface of the liner, wherein: The joint is composed of a plurality of joint structures arranged in a circumferential direction of the open end portion, and has a cylindrical shape capable of being mounted on the outer peripheral surface of the open end portion in a state where the inner surfaces of the plurality of joint structures are in contact with the covering portion covering the outer peripheral surface of the open end portion. The joint can be mounted on the outer peripheral surface of the opening end by fixing a plurality of the joint structures to each other. Grooves serving as resin flow paths are provided at contact locations of the plurality of joint structures that come into contact with the covering portion.

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