Folding jig, folding device, and folding method

Abstract

To provide a technology capable of smoothly folding back a cylindrical barrier layer.SOLUTION: A folding-back jig 100 folds back a bulging portion 61 of a first barrier layer 60 bulging out to one side in a first axis direction with respect to a trunk base body 50 to the other side in the first axis direction so as to cover an outer peripheral surface of the trunk base body 50. The folding-back jig 100 is equipped with a first guide portion 110 that has an outer peripheral surface 111 guiding the bulging portion 61 to the one side in the first axis direction, a folding-back portion 120 that is provided on the one side in the first axis direction with respect to the first guide portion 110, has a curved surface 121 recessed to the one side in the first axis direction, and folding back the bulging portion 61 to the other side in the first axis direction so as to cover the outer peripheral surface of the truck base body 50, and a second guide portion 130 that guides the bulging portion 61 folded back by the folding-back portion 120 to the other side in the first axis direction.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a folding jig, a folding device, and a folding method. [Background technology]

[0002] The pressure vessel liner disclosed in Patent Document 1 is composed of a first liner component and a second liner component. The first liner component is a straight cylindrical body with both ends open. The second liner component is roughly bowl-shaped and is joined to both ends of the first liner component. The end of the first liner component and the end of the second liner component are joined to form the pressure vessel liner.

[0003] The pressure vessel disclosed in Patent Document 2 has a liner (barrier layer) with gas barrier properties provided on the inner peripheral surface of an outer shell made of FRP to ensure sealing performance. The liner is made of synthetic resin such as high-density polyethylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-239966 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-21099 Summary of the Invention [Problem to be solved by the invention]

[0005] When a pressure vessel liner is constructed from multiple segments (for example, a cylindrical body segment and a bowl-shaped dome segment), as in the pressure vessel liner of Patent Document 1, a possible configuration is for the body segment to be inserted inside the dome segment. In this case, to ensure sealing performance, it is desirable to provide a barrier layer not only on the inner peripheral surface of the body segment but also on the outer peripheral surface. Therefore, a possible configuration is to fold back the axial end of the barrier layer provided on the inner peripheral surface of the body segment to cover the outer peripheral surface of the end of the body segment. However, when folding back the end of the cylindrical barrier layer toward the outer peripheral surface, the circumferential length of the folded back barrier layer increases, which can easily cause wrinkles, making it difficult to fold back smoothly.

[0006] The present invention was completed in view of the above circumstances, and an object of the present invention is to provide a technique that enables a cylindrical barrier layer to be smoothly folded back. [Means for solving the problem]

[0007] The folding jig of the present invention is a folding jig for use in manufacturing a barrel section segment that comprises a barrel base and a barrier layer provided so as to cover an inner peripheral surface of the barrel base, the barrel section segment being combined with a dome section segment to form a pressure vessel, the folding jig folding back an overhanging portion of the barrier layer that overhangs from the barrel base to one axial side to the other axial side so as to cover the outer peripheral surface of the barrel base, a first guide portion having an outer peripheral surface that guides the protruding portion toward one side in the axial direction; a folded portion that is connected to an end portion on one axial side of the first guide portion, has a curved surface that is recessed toward one axial side, and folds the protruding portion back toward the other axial side so as to cover an outer peripheral surface of the trunk base body; a second guide portion that guides the protruding portion folded back by the folded back portion to the other axial side; Equipped with.

[0008] The folding device of the present invention comprises: The folding jig; a heating unit that heats the first guide portion of the folding jig; Equipped with.

[0009] The folding method of the present invention comprises the steps of: A folding method for folding back the protruding portion of the barrier layer to the other axial direction side using the folding device, In a state where the folding jig is heated by the heating unit, the folding jig is brought into contact with the protruding portion, while moving the trunk portion base body relative to the folding jig toward one side in the axial direction, the first guide portion guides the protruding portion toward the one side in the axial direction; while moving the barrel portion base body relative to the folding jig toward one side in the axial direction, folding back the protruding portion guided by the first guide portion toward the other side in the axial direction so that the curved surface covers the outer peripheral surface of the barrel portion base body; A folding method in which the body base is moved relatively to the folding jig toward one side in the axial direction, and the protrusion portion folded back by the folding portion is guided toward the other side in the axial direction by the second guide portion. [Effects of the Invention]

[0010] According to the folding jig of the present invention, by moving the barrel base relative to the folding jig toward one side in the axial direction, the protruding portion is guided to the folding portion by the outer peripheral surface of the first guide portion. When the barrel base is further moved relative to the folding jig toward one side in the axial direction, the protruding portion is folded back toward the other side in the axial direction along the curved surface of the folding portion so as to cover the outer peripheral surface of the barrel base, and is guided toward the other side in the axial direction by the second guide portion. At this time, the protruding portion of the barrier layer contacts the curved surface provided in an annular shape, and is therefore folded back sequentially in an annular shape from the tip end to the base end of the protruding portion of the barrier layer and guided toward the other side in the axial direction, thereby preventing the circumferential length of the folded back portion from increasing, and allowing for smooth folding.

[0011] According to the folding device of the present invention, heat can be transferred to the protruding portion of the barrier layer via the first guide portion, and the protruding portion of the barrier layer can be softened and then folded back at the folding portion, making it easier to fold back the protruding portion of the barrier layer.

[0012] According to the folding method of the present invention, the barrel base is moved relatively to the folding jig in one axial direction, and the protruding portion is guided to the folding portion by the outer peripheral surface of the first guide portion. When the barrel base is further moved relatively to the folding jig in one axial direction, the protruding portion is folded back to the other axial direction along the curved surface of the folding portion so as to cover the outer peripheral surface of the barrel base, and is guided to the other axial direction by the second guide portion. At this time, the protruding portion of the barrier layer contacts the annular curved surface, and is therefore folded back in an annular shape from the tip to the base end of the protruding portion of the barrier layer and guided to the other axial direction. This prevents the circumferential length of the folded portion from increasing, allowing for smooth folding. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a side view showing a pressure vessel of Example 1. [Figure 2] FIG. 1 is a cross-sectional view of a pressure vessel. [Figure 3] FIG. 2 is a cross-sectional view showing a portion of a pressure vessel near the boundary between a body section segment and a dome section segment. [Figure 4] FIG. 2 is a cross-sectional view taken along a plane including the axis of the folding jig. [Figure 5] FIG. 5 is an enlarged view showing a part of FIG. 4. [Figure 6] FIG. 2 is an explanatory diagram showing a cross section of a structure including a first barrier layer and a trunk base body before the protruding portion is folded back. [Figure 7] 7 is an explanatory view showing a state in which the protruding portion is brought into contact with the first guide portion of the folding jig in a step following FIG. 6.

[0033] FIG. [Figure 8] 8 is an explanatory view showing a state in which the protruding portion is folded back by the folding portion of the folding jig in a step following FIG. 7.

[0033] FIG. [Figure 9] 9 is an explanatory view showing a state in which the protruding portion is guided to the other side in the first direction by the second guide portion of the folding jig in a step subsequent to FIG. 8.

[0033] FIG. [Figure 10] 10 is an explanatory view showing a state in which folding back of the protruding portion by the folding back jig is completed in a step following FIG. 9. FIG. [Figure 11]11 is an explanatory view showing a state in which the protrusion is brought into close contact with the outer peripheral surface of the body base body by pressure applied by a press member in a step following FIG. 10. FIG. [Figure 12] 10A and 10B are explanatory diagrams showing the results of folding when a folding process is performed while changing the heating temperature of the folding jig and the pressing time of the folding jig against the protruding portion. DETAILED DESCRIPTION OF THE INVENTION

[0014] In the folding jig of the present invention, it is preferable that the diameter of the outer peripheral surface of the first guide portion decreases toward the other axial side. With this configuration, the barrier layer is less likely to abut against the first guide portion, and the protruding portion can be more easily guided toward the one axial side.

[0015] In the folding jig of the present invention, the second guide portion is preferably provided in an annular shape and covers at least a portion of the outer peripheral surface of the first guide portion. With this configuration, the second guide portion can press the protruding portion of the folded barrier layer against the outer peripheral surface of the barrel base. Therefore, the protruding portion of the folded barrier layer can cover the outer peripheral surface of the barrel base, forming a barrier layer that continuously covers the inner and outer peripheral surfaces of the barrel base.

[0016] In the folding device of the present invention, it is preferable that the heating section also heats the second guide section, and with this configuration, the folded-back protrusion section can be prevented from cooling and undergoing diameter contraction deformation due to the heated second guide section.

[0017] In the folding method of the present invention, it is preferable that the protruding portion be guided to one side in the axial direction by the first guide portion, the maximum diameter of which on the outer circumferential surface is smaller than the inner diameter of the barrier layer. With this configuration, the barrier layer is less likely to hit the first guide portion, and can be smoothly guided to the folded portion.

[0018] In the folding method of the present invention, when the radial thickness of the barrel base body at the seal point between the barrel section segment and the dome section segment is defined as the base thickness dimension, it is preferable that the protruding portion be guided to the other axial side by the folded-back portion, whose radial size is equal to or smaller than the base thickness dimension. With this configuration, the distance between the second guide portion and the barrel base body becomes relatively small, making it easier for the protruding portion of the folded-back barrier layer to be sandwiched between the second guide portion and the barrel base body. This makes it easier to bring the protruding portion of the folded-back barrier layer into close contact with the barrel base body.

[0019] In the folding method of the present invention, it is preferable that the protruding portion guided to the other axial side by the second guide portion is pressed toward the barrel base body by a press member. This configuration makes it easier to bring the protruding portion of the folded barrier layer into close contact with the barrel base body.

[0020] Example 1 A first embodiment of the present invention will be described below with reference to FIGS.

[0021] (Configuration of pressure vessel) The pressure vessel 10 of this embodiment has a cylindrical capsule shape, as shown in Figure 1. The pressure vessel 10 is mounted on a vehicle, for example, and used as a container filled with high-pressure hydrogen gas. Note that in the pressure vessel 10 shown in Figures 1 to 6, the diameter, axial length, thickness of each layer, etc. are exaggerated, and the configuration shown in Figures 1 to 6 is merely an example.

[0022] As shown in Figure 2, the pressure vessel 10 comprises a body section 20, a dome section section 30, and an external reinforcing layer 40. The pressure vessel 10 is formed by combining the body section 20 and the dome section section 30. The external reinforcing layer 40 surrounds the combined body section 20 and dome section section 30. The pressure vessel 10 is provided with a nozzle 11 as shown in Figure 1. Note that Figure 2 shows the pressure vessel 10 before the nozzle 11 is attached. The pressure vessel 10 has barrier properties. In this Example 1, barrier properties are defined as the ability to prevent or inhibit a fluid (such as hydrogen gas) filled inside the pressure vessel 10 from permeating the pressure vessel 10 and leaking to the outside of the pressure vessel 10.

[0023] As shown in FIG. 2, the trunk segment 20 has a trunk base body 50 and a first barrier layer 60. The trunk base body 50 is cylindrical and long in the axial direction (along the axis L1). The inner diameter of the trunk base body 50 is constant over its entire length. The outer diameter of the trunk base body 50 is constant over its entire length, excluding a recess 51 (described later). The trunk base body 50 is made of fiber-reinforced resin such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The trunk base body 50 is formed by, for example, hoop-winding fiber bundles (not shown) impregnated with liquid thermosetting resin, or fiber bundles impregnated with thermosetting resin and brought to a semi-cured state (prepreg fiber) using, for example, a filament winding method. The fiber bundles are made of filament-like fibers such as carbon fiber, glass fiber, or Kepler fiber.

[0024] As shown in FIG. 3, recesses 51 are provided on both axial ends of the outer peripheral surface of the barrel base body 50. The recesses 51 are provided around the entire circumference of the axis. The portion of the barrel base body 50 where the recesses 51 are provided is thinner than the other portion of the barrel base body 50 (the portion toward the center in the axial direction). The outer dimensions of the recesses 51 decrease toward the outside in the axial direction. The recesses 51 include a first tapered portion 51A and a second tapered portion 51B. The first tapered portion 51A and the second tapered portion 51B form a two-step slope. The slope angle of the first tapered portion 51A is larger than the slope angle of the second tapered portion 51B.

[0025] As shown in FIG. 2, the first barrier layer 60 is provided so as to cover the entire inner peripheral surface of the body base body 50. The first barrier layer 60 is cylindrical. The first barrier layer 60 corresponds to an example of the "barrier layer" of the present disclosure. The first barrier layer 60 has barrier properties. Examples of materials that can be used for the first barrier layer 60 include EVOH (ethylene-vinyl alcohol copolymer) and PA6 (nylon 6). The first barrier layer 60 is used for the purpose of blocking or inhibiting the fluid stored in the pressure vessel 10 from permeating to the outside.

[0026] The first barrier layer 60 has a pair of protruding portions 61. The protruding portions 61 protrude from both axial ends of the barrel base body 50 in the axial direction (the axial direction (first axial direction) of the axis L1 shown in FIG. 2 ) and, as shown in FIG. 3 , are folded back to cover both axial ends of the outer peripheral surface of the barrel base body 50. Hereinafter, the axial direction of the axis L1 will be referred to as the first axial direction. Specifically, as shown in FIG. 3 , the protruding portions 61 of the first barrier layer 60 cover the recess 51 (first tapered portion 51A, second tapered portion 51B), the first end face 52A, and the second end face 52B. The first end face 52A is an end face of the barrel base body 50 in the first axial direction. The second end face 52B is an end face that continues toward the center in the first axial direction with respect to the second tapered portion 51B.

[0027] As shown in FIG. 2, the dome section segment 30 has a dome section base 31 and a second barrier layer 32. The dome section base 31 is a hemispherical portion connected to the longitudinal end of the body base 50. The diameter of the dome section base 31 decreases with increasing distance from the body base 50. The thickness of the dome section base 31 is smaller than the thickness of the body base 50 (the thickness of the portion excluding the recess 51). The dome section base 31 is made of a fiber-reinforced resin such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The dome section base 31 is formed by, for example, laminating fiber bundles (not shown) impregnated with a liquid thermosetting resin or fiber bundles impregnated with a semi-cured thermosetting resin (prepreg fiber) by, for example, a hand layup method, and then dividing the molded product into halves. The fiber bundle is made by bundling thread-like fibers made of carbon fiber, glass fiber, Kepler fiber, etc. At the top of the dome section segment 30, a mouthpiece 11 is provided, as shown in FIG.

[0028] 2, the second barrier layer 32 is provided so as to cover the inner peripheral surface of the dome portion base body 31. The second barrier layer 32 has the same configuration as the first barrier layer 60. The end of the second barrier layer 32 on the trunk section 20 side covers the end face 31A of the dome portion base body 31.

[0029] 3, the end of the body section section 20 is inserted inside the end of the dome section section 30, and the body section 20 and the dome section section 30 are joined together. The first barrier layer 60 covering the end of the body section section 20 (more specifically, the first tapered section 51A, the second tapered section 51B, and the second end face 52B) is in contact with the second barrier layer 32 covering the end of the dome section section 30. The first barrier layer 60 and the second barrier layer 32, which are in contact with each other, are crushed by the end of the body section section 20 and the end of the dome section section 30, generating a repulsive force (restoring force), and ensuring sealing at the boundary between the body section base body 50 and the dome section base body 31.

[0030] The external reinforcing layer 40 is made of a fiber-reinforced resin, such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The external reinforcing layer 40 is formed so as to cover the entire outer periphery of the body section segment 20 and the entire outer periphery of the dome section segment 30. The external reinforcing layer 40 is formed by helically winding, for example, by a filament winding method. The external reinforcing layer 40 is formed by winding, for example, fiber bundles (not shown) impregnated with liquid thermosetting resin or fiber bundles impregnated with thermosetting resin in a semi-cured state (prepreg fiber) around the outer surfaces of the body section segment 20 and the dome section segment 30, which rotate around the axis L1 (see FIG. 2). The fiber bundles are made by bundling thread-like fibers made of carbon fiber, glass fiber, Kepler fiber, or the like.

[0031] (Configuration of folding jig) 4 is used in manufacturing the trunk section 20. The folding jig 100 is a jig that folds the protruding portion 61 of the first barrier layer 60, which protrudes from the trunk base body 50 to one side in the first axial direction, toward the other axial direction so as to cover the outer peripheral surface of the trunk base body 50.

[0032] The folding jig 100 is a rotating body that rotates about an axis L2 shown in Fig. 4. As shown in Fig. 4, the folding jig 100 includes a first guide portion 110, a folding portion 120, and a second guide portion 130.

[0033] As shown in Fig. 4, the first guide portion 110 has an outer peripheral surface 111 that guides the protruding portion 61 to one side in the first axial direction. The first guide portion 110 has a truncated cone shape. The outer peripheral surface 111 of the first guide portion becomes smaller in diameter toward one side in the axial direction of the axis L2 (referred to as the second axial direction). This makes it less likely that the first barrier layer 60 will hit the first guide portion 110, and makes it easier to smoothly guide the first barrier layer 60 to the other side in the second axial direction.

[0034] The folded portion 120 folds the protruding portion 61 back toward the other side in the first axial direction so as to cover the outer peripheral surface of the trunk base body 50. The folded portion 120 is provided so as to connect to the end portion of the first guide portion 110 on the other side in the second axial direction. The folded portion 120 has a curved surface 121 that is recessed toward the other side in the second axial direction. The curved surface 121 is annular in shape with the axis L2 as its center. The inner edge of the curved surface 121 connects seamlessly to the edge portion of the first guide portion 110 on the other side in the second axial direction. The cross section of the curved surface 121 (a cross section cut along a plane including the axis L2) is semicircular.

[0035] The second guide portion 130 guides the protruding portion 61 folded back by the folded-back portion 120 to one side in the second axial direction. The second guide portion 130 is provided radially outward of the folded-back portion 120. The second guide portion 130 protrudes to one side in the second axial direction. The curved surface 121 is annular and has its center on the axis L2. The inner surface of the second guide portion 130 is continuous with the outer edge of the curved surface 121. The diameters of the inner surface and the outer surface of the second guide portion 130 are constant in the second axial direction. The second guide portion 130 covers a portion of the outer peripheral surface of the first guide portion 110 on the base end side (a portion on the other side in the second axial direction). Specifically, the second guide portion 130 covers a portion of the outer peripheral surface of the first guide portion 110 from the base end (a portion on the other side in the second axial direction). This allows the protruding portion 61 of the first barrier layer 60, which has been folded back by the second guide portion 130, to be pressed against the outer peripheral surface of the barrel base body 50. Therefore, the outer peripheral surface of the barrel base body 50 can be covered by the protruding portion 61 of the folded back first barrier layer 60, and the first barrier layer 60 can be formed to continuously cover the barrel base body 50 from the inner peripheral surface to the outer peripheral surface.

[0036] (Configuration of loopback device) The folding device includes a folding jig 100 and a heating unit (not shown). The heating unit heats the folding jig 100. The heating unit is configured as, for example, a band heater, and is wound around the axis L2 on the folding jig 100 (for example, the portion on the other side in the second axial direction relative to the second guide unit 130). The heating unit heats the first guide unit 110, the folded unit 120, and the second guide unit 130.

[0037] By heating the first guide portion 110 by the heating portion, heat can be transferred to the protruding portion 61 of the first barrier layer 60 via the first guide portion 110. Therefore, the protruding portion 61 can be softened and then folded back at the folding portion 120. This makes it easier to fold back the protruding portion 61 of the first barrier layer 60.

[0038] By heating the second guide portion 130 by the heating portion, the projecting portion 61 folded back by the heated second guide portion 130 can be prevented from cooling and bending radially inward.

[0039] (Method of folding the first barrier layer) Next, a method for folding back the first barrier layer 60 will be described. The folding back of the first barrier layer 60 is performed during the manufacturing process of the body section 20. Note that, although the folding back process for only one of the protruding portions 61 of the first barrier layer 60 will be described below, the folding back process is also performed for the other protruding portion 61 in the same manner. Note that, when folding back the protruding portion 61 using the folding jig 100, the second axial direction of the folding jig 100 and the first axial direction of the body section 20 are made parallel to each other. Specifically, one side in the first axial direction becomes the same as the other side in the second axial direction, and the other side in the first axial direction becomes the same as one side in the second axial direction.

[0040] First, as shown in FIG. 6, a structure is prepared in which the first barrier layer 60 is provided on the inner peripheral surface of the trunk base body 50 and the protruding portion 61 has not yet been folded back.

[0041] Next, the folding jig 100 is prepared in advance by a heating unit. For example, the folding jig 100 is heated to 110°C to 150°C.

[0042] Next, as shown in FIG. 7 , the first guide portion 110 of the folding jig 100 is brought into contact with the tip of the protruding portion 61 of the first barrier layer 60. Specifically, the first guide portion 110 is inserted radially inside the protruding portion 61, and the outer peripheral surface 111 of the first guide portion 110 is brought into contact with the inner peripheral surface of the protruding portion 61 for a certain period of time (e.g., 30 seconds). Here, the trunk base body 50 is moved to one side in the first axial direction (the other side in the second axial direction) relative to the folding jig 100, whereby the first guide portion 110 guides the protruding portion 61 to one side in the first axial direction (the other side in the second axial direction). In this way, the folding jig 100 is brought into contact with the protruding portion 61 while being heated by the heating unit. This allows heat to be transferred to the protruding portion 61 via the first guide portion 110, softening the protruding portion 61 before folding it back at the folding portion 120. Therefore, the protruding portion 61 of the first barrier layer 60 can be easily folded back.

[0043] Because the diameter of the outer peripheral surface 111 of the first guide portion decreases toward one side in the second axial direction, only the tip of the cylindrical protrusion portion 61 can be brought into contact with the outer peripheral surface 111 of the first guide portion, as shown in Fig. 7. This makes the temperature at the tip end of the protrusion portion 61 higher than the temperature at the base end. This allows the protrusion portion 61 to soften from the tip end side, making it easier to fold back, while delaying the softening of the base end side of the protrusion portion 61 so that it does not buckle.

[0044] The maximum diameter of the outer peripheral surface of the first guide portion 110 (the diameter of the end portion on the other side in the second axial direction) is defined as A1, and the inner diameter of the first barrier layer 60 is defined as A2. In the method of folding back the first barrier layer 60 of the present disclosure, A1 is set to be smaller than A2. With this configuration, the first barrier layer 60 is less likely to hit the first guide portion 110, and the protruding portion 61 can be smoothly guided to the folded-back portion 120.

[0045] 8, the folding jig 100 is further pressed toward the other side in the first axial direction (one side in the second axial direction) with respect to the protruding portion 61. That is, the trunk base body 50 is further moved toward the one side in the first axial direction relative to the folding jig 100. As a result, the protruding portion 61, guided by the first guide portion 110, is folded back toward the other side in the first axial direction (one side in the second axial direction) so that the curved surface 121 of the folding portion 120 covers the outer peripheral surface of the trunk base body 50. Specifically, the protruding portion 61 is folded back toward the other side in the first axial direction (one side in the second axial direction) by moving along the curved surface 121 from the inner edge to the outer edge. At this time, the protruding portion 61 of the first barrier layer 60 contacts the curved surface 121 arranged in a circular ring shape, and is sequentially folded back in a circular shape from the tip to the base end of the protruding portion 61 of the first barrier layer 60 and guided to the other side in the first axial direction (one side in the second axial direction), thereby preventing the circumferential length of the folded back portion from expanding and allowing for smooth folding.

[0046] 9, the folding jig 100 is further pushed toward the other side in the first axial direction (one side in the second axial direction) relative to the protruding portion 61. That is, the trunk base body 50 is further moved toward the one side in the first axial direction relative to the folding jig 100. As a result, the protruding portion 61 folded back by the folding portion 120 is guided toward the other side in the first axial direction (one side in the second axial direction) by the second guide portion 130.

[0047] With the second guide portion 130 heated by the heating unit, the overhang portion 61 is guided by the second guide portion 130 to the other side in the first axial direction (one side in the second axial direction). Therefore, heat can be transferred to the folded over overhang portion 61 via the second guide portion 130. This makes it possible to prevent the folded over overhang portion 61 from being deformed by contraction in diameter by the heated second guide portion 130. That is, when viewed in cross section as shown in FIG. 9 , it is possible to prevent the tip of the overhang portion 61 from bending radially inward. This makes it possible for the folded over portion of the overhang portion 61 to cover the outer periphery of the recess 51 without coming into contact with the outer periphery of the unfolded portion of the overhang portion 61.

[0048] 10, the folding jig 100 is further pressed toward the other side in the first axial direction (one side in the second axial direction) relative to the protruding portion 61. That is, the trunk base body 50 is further moved toward one side in the first axial direction relative to the folding jig 100. As a result, the entire area of ​​the recessed portion 51 of the trunk base body 50 is covered by the protruding portion 61, and the pressing of the folding jig 100 is completed. In this way, the protruding portion 61 is folded toward the other side in the first axial direction (one side in the second axial direction) so as to cover the outer peripheral surface of the trunk base body 50 (specifically, the recessed portion 51, the first end face 52A, and the second end face 52B).

[0049] The folding jig 100 is pressed against the protruding portion 61 at a constant speed. The time from the start to the end of pressing the folding jig 100 against the protruding portion 61 is defined as the pressing time. The pressing time is, for example, 5 to 45 seconds.

[0050] Next, after the folding jig 100 has been pressed in, the folded jig 100 and the folded jig 100 are maintained in their pressed-in state for a certain period of time (e.g., 60 seconds), thereby causing the protruding portion 61 to adhere tightly to the outer peripheral surface (specifically, the recess 51, the first end face 52A, and the second end face 52B) of the body base body 50. This completes the body section 20.

[0051] 11, the folding jig 100 is pulled out from the barrel section 20. Thereafter, the protruding portion 61 covering the outer peripheral surface of the barrel base body 50 (specifically, the recessed portion 51, the first end face 52A, and the second end face 52B) is pressed toward the barrel base body 50 by a press member (not shown). The press member is, for example, a mold shaped to match the outer shape of the end portion of the barrel base body 50 (the portion where the recessed portion 51 is provided). This makes it easier to bring the folded protruding portion 61 into tight contact with the barrel base body 50.

[0052] FIG. 12 is an explanatory diagram showing the results of the folding process when the heating temperature of the folding jig 100 and the time for which the folding jig 100 is pressed against the protruding portion 61 are changed. The heating temperatures of the folding jig 100 were 110°C, 130°C, and 150°C. The time for preheating the folding jig 100 by the heating unit was 30 seconds. The pressing times were 5 seconds, 10 seconds, 15 seconds, 30 seconds, and 45 seconds. After the pressing is completed, the time for maintaining the pressed state between the folding jig 100 and the folding jig 100 is 60 seconds. The folding result "◯" means that the folding was successful without buckling or wrinkling in the protruding portion 61. The folding result "X" means that buckling or wrinkling occurred in the protruding portion 61 during folding. From the results shown in FIG. 12, it can be seen that the higher the heating temperature of the folding jig 100, the shorter the pressing time, so that the protruding portion 61 can be folded without buckling or wrinkling.

[0053] (Effects of this embodiment) The effects of this Example 1 will be described below. In the folding jig 100 and folding method of this Example 1, the barrel base body 50 is moved relatively to one side in the first axial direction with respect to the folding jig 100, and is guided to the folding portion 120 by the outer peripheral surface 111 of the first guide portion 110. When the barrel base body 50 is further moved relatively to one side in the first axial direction with respect to the folding jig 100, the overhanging portion 61 is folded back to the other side in the first axial direction along the curved surface 121 of the folding portion 120 so as to cover the outer peripheral surface of the barrel base body 50, and is guided to the other side in the first axial direction by the second guide portion 130. At this time, the overhanging portion 61 of the first barrier layer 60 comes into contact with the curved surface 121 provided in an annular shape, and therefore the overhanging portion 61 of the first barrier layer 60 is folded back sequentially in an annular shape from the tip end to the base end and guided to the other side in the first axial direction. This prevents the circumferential length of the folded-back portion from increasing, enabling smooth folding. This makes it difficult for wrinkles to form in the protruding portion 61, improving the formability of the first barrier layer 60. Furthermore, it is not necessary to cover the inner and outer peripheral surfaces of the body base body 50 with separate barrier layers, and the inner and outer peripheral surfaces of the body base body 50 can be covered in a continuous manner with a single first barrier layer 60. This reduces manufacturing costs.

[0054] In the folding jig 100 of this Example 1, the outer peripheral surface 111 of the first guide portion 110 has a diameter that decreases toward the other side in the first axial direction (one side in the second axial direction). With this configuration, the first barrier layer 60 is less likely to abut against the first guide portion 110, and the protruding portion 61 is more likely to be smoothly guided toward the one side in the first axial direction (the other side in the second axial direction).

[0055] In the folding jig 100 of this first embodiment, the second guide portion 130 is provided in an annular shape and covers a portion of the outer peripheral surface 111 of the first guide portion 110. With this configuration, the protruding portion 61 of the first barrier layer 60 folded back by the second guide portion 130 can be pressed against the outer peripheral surface of the barrel base body 50. Therefore, the protruding portion 61 of the folded back first barrier layer 60 can cover the outer peripheral surface of the barrel base body 50, and the first barrier layer 60 can be formed to continuously cover the inner peripheral surface and the outer peripheral surface of the barrel base body 50.

[0056] In the folding device of the present embodiment 1, heat can be transferred to the protruding portion 61 of the first barrier layer 60 via the first guide portion 110, and the protruding portion 61 of the first barrier layer 60 can be softened and then folded back at the folding portion 120. This makes it easier to fold back the protruding portion 61 of the first barrier layer 60.

[0057] In the folding device of the present embodiment 1, the heating section also heats the second guide section 130. According to this configuration, it is possible to prevent the diametrically contracting deformation of the folded-back protrusion section 61 by the heated second guide section 130.

[0058] In the folding method of the present embodiment 1, the protruding portion 61 is guided to one side in the first axial direction (the other side in the first axial direction) by the first guide portion 110, the maximum diameter of whose outer peripheral surface is smaller than the inner diameter of the first barrier layer 60. With this configuration, the first barrier layer 60 is less likely to hit the first guide portion 110, and can be smoothly guided to the folded portion 120.

[0059] In the folding method of the present Example 1, the protruding portion 61 guided by the second guide portion 130 to the other side in the first axial direction (one side in the second axial direction) is pressed toward the trunk base body 50 by a press member. This configuration makes it easier to bring the protruding portion 61 of the folded first barrier layer 60 into close contact with the trunk base body 50.

[0060] <Other Examples> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments are also included within the technical scope of the present invention. (1) In the first embodiment, in the folding back step of the first barrier layer 60, the radial size of the folded back portion 120 may be set as follows. The radial thickness (base thickness) of the body base body 50 at the seal point between the dome section section 30 and the body section section 20 is defined as A3. The base thickness is the value obtained by subtracting the inner diameter from the outer diameter of the body base body 50 at the seal point. The radial size of the folded back portion 120 is defined as A4. A4 is set to be equal to or smaller than A3. With this configuration, the distance between the second guide section 130 and the body base body 50 becomes relatively small, making it easier for the folded back overhanging portion 61 to be sandwiched between the second guide section 130 and the body base body 50. This makes it easier to bring the folded back overhanging portion 61 of the first barrier layer 60 into close contact with the body base body 50. (2) In the first embodiment, in the folding process of the first barrier layer 60, the folding jig 100 is pressed against the protruding portion 61 at a constant speed. However, the pressing speed may be changed from the start to the end of the pressing. (3) In the first embodiment, the diameter of the outer peripheral surface 111 of the first guide portion 110 decreases toward one side over the entire second axial direction, but such a configuration may be provided on only a portion of the outer peripheral surface 111. For example, the outer peripheral surface 111 may have a portion with a constant diameter. (4) In the first embodiment, the cross-sectional shape of the curved surface 121 of the folded portion 120 is a semicircular arc shape. However, other shapes may be used as long as they are recessed toward the other side in the second axis direction. [Explanation of symbols]

[0061] 10...Pressure vessel 11...Socket 20...Body division 30...Dome section division body 31...Dome base 31A…End face 32...Second barrier layer 40...External reinforcement layer 50...Body base 51...recess 51A...First tapered section 51B...Second tapered section 52A…First end surface 52B…Second end face 60...First barrier layer (barrier layer) 61...Protruding part 100...Folding jig 110...First guide section 111...Outer surface 120...Folded section 121...Curved surface 130...Second guide section L1: Axis of the body segment L2: Axis of the folding jig

Claims

1. a folding jig for use in manufacturing a barrel section segment that comprises a barrel base and a barrier layer provided so as to cover an inner peripheral surface of the barrel base, the barrel section segment being combined with a dome section segment to form a pressure vessel, the folding jig folding back an overhanging portion of the barrier layer that overhangs from the barrel base to one axial side to the other axial side so as to cover the outer peripheral surface of the barrel base, a first guide portion having an outer peripheral surface that guides the overhang portion toward one side in the axial direction; a folded portion that is continuous with an end portion on one axial side of the first guide portion, has a curved surface that is recessed toward one axial side, and folds the protruding portion back toward the other axial side so as to cover an outer peripheral surface of the trunk portion base body; a second guide portion that guides the protruding portion folded back by the folded back portion toward the other axial direction; A folding jig comprising:

2. The folding jig according to claim 1 , wherein the outer circumferential surface of the first guide portion has a diameter that decreases toward the other axial side.

3. The folding jig according to claim 1 or 2, wherein the second guide portion is annular and covers at least a portion of the outer circumferential surface of the first guide portion.

4. The folding jig according to any one of claims 1 to 3; a heating unit that heats the first guide portion of the folding jig; A folding device comprising:

5. The folding device according to claim 4 , wherein the heating section also heats the second guide section.

6. 6. A folding method for folding back the protruding portion of the barrier layer to the other axial direction side using the folding device according to claim 4 or 5, In a state where the folding jig is heated by the heating unit, the folding jig is brought into contact with the protruding portion, the trunk portion base body is moved relative to the folding jig toward the one axial direction, while the first guide portion guides the overhang portion toward the one axial direction; while moving the barrel portion base body relative to the folding jig toward one side in the axial direction, folding back the protruding portion guided by the first guide portion toward the other side in the axial direction so that the curved surface covers the outer peripheral surface of the barrel portion base body; A folding method in which the body base is moved relatively to the folding jig toward one side in the axial direction, and the protrusion portion folded back by the folding portion is guided toward the other side in the axial direction by the second guide portion.

7. The folding method according to claim 6 , wherein the protruding portion is guided to one side in the axial direction by the first guide portion, the maximum diameter of which on the outer circumferential surface is smaller than the inner diameter of the barrier layer.

8. When the radial thickness of the body base body at the seal point between the body base body and the dome section segment set in the body section segment is defined as a base thickness dimension, A folding method according to claim 6 or claim 7, wherein the protrusion portion is guided to the other axial side by the folding portion, the radial dimension between the first guide portion and the second guide portion being equal to or less than the thickness dimension of the base body.

9. 9. The folding method according to claim 6, wherein the protruding portion guided to the other axial side by the second guide portion is pressed toward the body base body by a press member.

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