Manufacturing equipment for pressure vessels and blow molded products

Abstract

To provide reduce die cost.SOLUTION: A pressure container 10 has a blow molding 11, and an outer reinforcement layer 12 surrounding the blow molding 11. The blow molding 11 has a liner 14 that is blow-molded from parison 51 so that a shank 16 and a dome 17 are combined, and a pipe 15 in close contact with the outer peripheral surface of the shank 16.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pressure vessel and a manufacturing apparatus for a blow molded article. [Background technology]

[0002] Patent Document 1 discloses a pressure vessel in which a reinforcing layer is formed on the outer surface of a resin liner. This type of liner is molded into a predetermined shape by blow molding. In blow molding, a parison extruded from an extruder is sandwiched between dies and compressed air is blown into the parison to press the parison against the dies. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-189178 A Summary of the Invention [Problem to be solved by the invention]

[0004] The length of a pressure vessel varies depending on the volume of fluid to be stored. In order to manufacture pressure vessels of different lengths, it is necessary to prepare multiple types of molds corresponding to the lengths of the pressure vessels. This results in high mold costs.

[0005] The present invention was developed in view of the above circumstances, and has an object to reduce the cost of molds. [Means for solving the problem]

[0006] The pressure vessel of the first invention comprises: A blow molded body and an outer reinforcing layer surrounding the blow molded body, The blow molded body is a liner blow-molded using a parison as a material so that a body portion and a dome portion are integral with each other; and a pipe that is in intimate contact with the outer circumferential surface of the body.

[0007] The apparatus for producing a blow molded article according to the second aspect of the present invention comprises: A manufacturing apparatus for molding a blow molded article having a liner in which a body portion and a dome portion are integrally molded, comprising: a pipe that forms the body portion by contacting a cylindrical parison with the pipe; a mold for forming the dome portion by contacting the parison, When the mold is opened, the mold is detached from the liner and the pipe, and the pipe is integrated with the body portion. Effect of the Invention

[0008] According to the first invention, a liner of a predetermined shape can be molded by arranging a mold for molding the dome portion so that it is connected to the end of the pipe, and by bringing the parison into close contact with the mold and the pipe. When molding liners of different lengths, it is only necessary to change the length of the pipe, so the mold can be standardized. Only one type of mold is required for multiple types of liners of different lengths, so the cost of the mold can be reduced.

[0009] According to the second invention, when molding blow molded bodies of different lengths, it is only necessary to change the length of the pipe, so that the mold can be standardized. Only one type of mold is required for multiple types of blow molded bodies of different lengths, so the mold cost can be reduced. [Brief description of the drawings]

[0010] [Figure 1] 2 is a cross-sectional view showing a state before a mold is closed in a manufacturing process of a blow molded article by the manufacturing apparatus of Example 1. FIG. [Diagram 2] 3 is a side cross-sectional view showing a blow molded body molded in a mold that is in a clamped state in a manufacturing process of the blow molded body; FIG. [Diagram 3] FIG. 2 is a cross-sectional view of a pressure vessel molded by the manufacturing apparatus. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of the pressure vessel of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In the first invention, it is preferable that the inner diameter of the end of the pipe is smaller than the outer diameter of the portion of the outer circumferential surface of the liner adjacent to the pipe. With this configuration, it is possible to prevent the liner and the pipe from being misaligned in the axial direction.

[0012] In the first invention, the outer diameter of the end of the pipe is preferably larger than the outer diameter of the portion of the outer circumferential surface of the liner adjacent to the pipe. This configuration makes it possible to prevent the outer reinforcing layer from being misaligned in the axial direction with respect to the blow molded article.

[0013] In the first invention, it is preferable that the end of the pipe is formed with a tapered portion in which the outer circumferential surface is inclined with respect to the axis. With this configuration, it is possible to prevent stress from concentrating at the contact area between the end of the pipe and the outer reinforcing layer.

[0014] In the first and second aspects of the present invention, it is preferable that the pipe has an internal reinforcing layer having a higher rigidity than the liner, which can prevent deformation of the body of the liner.

[0015] In the second invention, it is preferable that the inner diameter of the end of the pipe is smaller than the inner diameter of the portion of the inner circumferential surface of the mold adjacent to the pipe. With this configuration, it is possible to prevent the liner and the pipe from being misaligned in the axial direction.

[0016] In the second invention, it is preferable that the end of the pipe has a tapered portion whose outer circumferential surface is inclined with respect to the axis. With this configuration, when an outer reinforcing layer is formed on the outer circumferential surface of the blow molded article, it is possible to prevent stress from concentrating on the contact area between the end of the pipe and the outer reinforcing layer.

[0017] In the second invention, the outer diameter of the end of the pipe is preferably larger than the inner diameter of a portion of the inner circumferential surface of the mold adjacent to the pipe. With this configuration, when an external reinforcing layer is formed on the outer circumferential surface of the blow molded article, the external reinforcing layer can be prevented from being misaligned in the axial direction with respect to the blow molded article.

[0018] <Example 1> A first embodiment of the present invention will be described below with reference to Figs. 1 to 4. In the following description, the up and down directions are defined as the directions shown in Figs. 1 to 4 as upward and downward, respectively. The left and right directions are defined as the directions shown in Figs. 1 to 4 as the directions shown in Figs. 1 to 4 as the directions shown in Figs.

[0019] As shown in Fig. 3, the pressure vessel 10 of this embodiment comprises a blow molded body 11, an outer reinforcing layer 12, and a mouthpiece 13. The blow molded body 11 is manufactured by a blow molding method using a manufacturing apparatus 30. The blow molded body 11 comprises a liner 14 and a pipe 15. One example of a material that can be used for the liner 14 is a mixed resin of high density polyethylene (HDPE) and ethylene-vinyl alcohol copolymer resin (EVOH).

[0020] As shown in Fig. 3, the pressure vessel 10 comprises a body portion 10A and a dome portion 10B. The body portion 10A is cylindrical with its axis oriented in the up-down direction (vertical direction). The upper dome portion 10B bulges upward from the upper end of the body portion 10A. The lower dome portion 10B bulges downward from the lower end of the body portion 10A. The body portion 10A of the pressure vessel 10 is composed of the body portion 11A of the blow molded body 11 and the body portion 12A of the external reinforcing layer 12. The dome portion 10B of the pressure vessel 10 is composed of the dome portion 11B of the blow molded body 11 and the dome portion 12B of the external reinforcing layer 12.

[0021] As shown in Fig. 3, the body 11A of the blow molded body 11 is cylindrical with its axis oriented in the up-down direction (vertical direction). The body 11A of the blow molded body 11 is composed of a body 16 of a liner 14 (described later) and a pipe 15. The dome portion 11B of the blow molded body 11 is composed of a dome portion 17 of the liner 14 (described later).

[0022] As shown in FIG. 3, the liner 14 includes a body 16 and upper and lower dome portions 17. The liner 14 is blow molded using a parison 51 (described later) as a material so that the body 16 and the dome portion 17 are integral with each other. The body 16 is cylindrical with its axis oriented in the up-down direction (vertical direction). The upper dome portion 17 is bulged upward from the upper end of the body 16. The lower dome portion 17 is bulged downward from the lower end of the body 16. A tubular portion 18 protruding in the up-down direction (vertical direction) is formed at the center of the dome portion 17. The dome portion 17 has a large diameter portion 17A with a large diameter provided on the pipe 15 side in the up-down direction (vertical direction) and a small diameter portion 17B with a small diameter provided on the opposite side to the pipe 15 side. The small diameter portion 17B protrudes in the up-down direction (vertical direction) in a tubular shape. A base 13 is attached to small diameter portion 17B. The outer diameter dimensions of the outer peripheral surfaces at both the upper and lower ends of body portion 16 are smaller than the maximum outer diameter dimension of the outer peripheral surface of dome portion 17. In other words, a step is formed between body portion 16 and dome portion 17.

[0023] As shown in Fig. 3, the pipe 15 is cylindrical with its axis oriented in the up-down direction (vertical direction). The pipe 15 constitutes an internal reinforcing layer having higher rigidity than the liner 14. The pipe 15 is made of, for example, metal or fiber-reinforced resin such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The pipe 15 is in close contact with the outer circumferential surface of the body 16. When molding liners 14 of different lengths, it is only necessary to change the length of the pipe 15, so that a mold 33, which will be described later, can be used in common.

[0024] As shown in Fig. 4, end 19 of pipe 15 is formed with a tapered section 21 whose outer circumferential surface is inclined with respect to the axis. Tapered section 21 is inclined so as to approach radially inward as it approaches the end in the up-down direction (vertical direction). An end face 22 exists radially inward from end 19 of pipe 15. End face 22 is provided between the inner circumferential surface of pipe 15 and tapered section 21. End face 22 is a surface perpendicular to the up-down direction.

[0025] As shown in FIG. 4, the portion 23 of the dome portion 17 on the pipe 15 side is a portion of the outer circumferential surface of the liner 14 adjacent to the pipe 15. The portion 23 of the dome portion 17 on the pipe 15 side is in contact with the pipe 15. As shown in FIG. 3, the inner diameter dimension L1 of the end 19 of the pipe 15 is smaller than the outer diameter dimension L2 of the portion 23 of the dome portion 17 on the pipe 15 side. As a result, the end 19 of the pipe 15 overlaps with the portion 23 of the dome portion 17 on the pipe 15 side in the vertical direction. Therefore, the end 19 of the pipe 15 and the portion 23 of the dome portion 17 on the pipe 15 side interfere with each other, preventing the liner 14 and the pipe 15 from being misaligned in the vertical direction (axial direction).

[0026] 4, tapered portion 21 is connected without any step to the outer circumferential surface of portion 23 of dome portion 17 on the pipe 15 side. That is, in the radial direction of liner 14, the height of the step between body portion 16 and dome portion 17 is approximately the same as the length of end face 22 of pipe 15.

[0027] The external reinforcing layer 12 surrounds the blow molded body 11. The external reinforcing layer 12 is made of fiber-reinforced resin such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP). The external reinforcing layer 12 is formed so as to cover the entire outer periphery of the pipe 15 and the entire outer periphery of the dome portion 17. The external reinforcing layer 12 is formed by, for example, a filament winding method. That is, the external reinforcing layer 12 is formed by winding, for example, a fiber bundle (not shown) impregnated with a liquid thermosetting resin or a fiber bundle impregnated with a thermosetting resin in a semi-cured state (prepreg fiber) on the outer surface of the blow molded body 11 rotating around its axis. The fiber bundle is a bundle of thread-like fibers made of carbon fiber, glass fiber, Kepler fiber, etc.

[0028] 3, the maximum outer diameter L3 of the end 19 of the pipe 15 is larger than the outer diameter L2 of the portion 23 of the dome portion 17 on the pipe 15 side. The outer diameter L3 is, for example, the outer diameter at the radially outermost position (the position farthest from the axis of the pipe 15) of the tapered portion 21. This results in a configuration in which a part of the external reinforcement layer 12 is positioned outward in the up-down direction from the end 19 of the pipe 15. Therefore, interference between the end 19 of the pipe 15 and a part of the external reinforcement layer 12 can be prevented to cause the external reinforcement layer 12 to be misaligned in the up-down direction (axial direction) with respect to the blow molded body 11.

[0029] The manufacturing apparatus 30 is an apparatus for molding the blow molded article 11. As shown in Fig. 1, the manufacturing apparatus 30 includes a blow molding machine 31, an air supply means 32, a pipe 15, and four dies 33. The blow molding machine 31 is disposed above the air supply means 32, the pipe 15, and the four dies 33. The blow molding machine 31 extrudes a cylindrical parison 51, which is the material for the blow molded article 11, vertically downward.

[0030] As shown in FIG. 1, the air supply means 32 includes a rod 34, a support portion 35, and an air supply portion (not shown). The rod 34 is made of, for example, metal. The rod 34 is L-shaped. An air supply passage (not shown) is formed inside the rod 34. The rod 34 is supported by the support portion 35. A straight portion on the tip side of the rod 34 stands upright along the vertical direction. A plurality of exhaust holes 36 for discharging air inside to the outside are formed in the straight portion on the tip side of the rod 34. A pair of nozzles 13 are attached to the straight portion on the tip side of the rod 34 at positions sandwiching the plurality of exhaust holes 36 from above and below. The nozzles 13 are fitted to the outer peripheral surface of the rod 34. The air supply portion is configured as a compressor. The air intake portion supplies compressed air to the air supply passage from the base end side (opposite the tip side) of the rod 34.

[0031] 1, the pipe 15 is disposed so as to surround the straight portion at the tip side of the rod 34. For example, the outer peripheral surface of the pipe 15 is supported by a support member (not shown). The pipe 15 is provided at a central position between the pair of nozzles 13 in the vertical direction (the direction along the straight portion at the tip side of the rod 34). When molding liners 14 of different lengths, it is only necessary to change the length of the pipe 15, and therefore the mold 33 can be shared.

[0032] The four dies 33 mold the parison 51 into a blow molded body 11 of a predetermined shape in a clamped state. The upper pair of dies 33 face each other at the upper end of the pipe 15 in parallel to the clamping and opening directions (left and right directions in FIG. 1) as shown in FIG. 1. The lower pair of dies 33 face each other at the lower end of the pipe 15 in parallel to the clamping and opening directions (left and right directions in FIG. 1). Each die 33 has the same shape. Each die 33 has a cavity 37 formed by recessing the facing surface of the die 33 facing each other in the vertical and horizontal directions. The inner surface of the cavity 37 includes a molding surface for molding the entire area of ​​the dome portion 17 of the liner 14 into a predetermined shape, and a surface that fits into the end 19 of the pipe 15 to position the pipe 15. The upper pair of dies 33 are clamped concentrically with the parison 51 by approaching each other in the left and right directions, and are opened by moving away from each other in the left and right directions. Similarly, the pair of lower dies 33 are clamped concentrically with the parison 51 by approaching each other in the left-right direction, and are opened by moving away from each other in the left-right direction.

[0033] As shown in FIG. 1, the inner surface of the cavity 37 includes a first molding surface 41, a second molding surface 42, a first fitting surface 43, and a second fitting surface 44. The inner surface of the cavity 37 is connected in the order of the first molding surface 41, the second molding surface 42, the first fitting surface 43, and the second fitting surface 44 from the outside (the side opposite to the pipe 15) to the inside (the pipe 15 side) in the vertical direction. The first molding surface 41 is a surface having a semicircular cross section with the same diameter over the entire vertical direction. The first molding surface 41 is a surface having a semicircular cross section with the same diameter as the diameter of the nozzle 13. The second molding surface 42 is a surface having a semicircular cross section whose diameter increases from the first molding surface 41 side to the first fitting surface 43 side. The first molding surface 41 and the second molding surface 42 are smoothly connected in the vertical direction. The first fitting surface 43 is inclined with respect to the axis of the rod 34. The first fitting surface 43 is inclined so as to move away from the center of the second fitting surface 44 toward the outside in the radial direction. The first fitting surface 43 has the same shape as the tapered portion 21 of the opposing pipe 15. That is, in a plane perpendicular to the circumferential direction (for example, the cut surface in FIG. 1), the length of the first fitting surface 43 and the length of the tapered portion 21 are the same. The second fitting surface 44 is a semicircular surface having the same diameter over the entire vertical direction. The second fitting surface 44 is a semicircular surface having the same diameter as the diameter of the outer circumferential surface of the pipe 15.

[0034] 2, a portion 45 on the pipe 15 side (an end portion on the first fitting surface 43 side) of the second molding surface 42 of the mold 33 is a portion of the inner circumferential surface of the mold 33 adjacent to the pipe 15. An inner diameter dimension L1 of the end portion 19 of the pipe 15 is smaller than an inner diameter dimension L4 of the portion 45 on the pipe 15 side of the second molding surface 42. This makes it possible to prevent the liner 14 and the pipe 15 from being misaligned in the axial direction.

[0035] 2, the outer diameter L3 of the end 19 of the pipe 15 is larger than the inner diameter L4 of a portion 45 on the pipe 15 side of the second molding surface 42 of the mold 33. This makes it possible to prevent the outer reinforcing layer 12 from being misaligned in the axial direction with respect to the blow molded body 11 when the outer reinforcing layer 12 is formed on the outer peripheral surface of the blow molded body 11.

[0036] Next, the manufacturing procedure of the blow molded body 11 will be described. First, as shown in FIG. 1, the pipe 15 is arranged so as to surround the straight portion at the tip end side of the rod 34. With the pair of dies 33 on both the upper side and the lower side in a state of being open, the parison 51 is extruded between the pair of dies 33 on the upper side and between the pair of dies 33 on the lower side. The parison 51 is extruded between the rod 34 and the inner peripheral surface of the pipe 15. When a predetermined length of the parison 51 is extruded, as shown in FIG. 2, the pair of dies 33 on both the upper and lower sides are brought close to each other and clamped. The die 33 is arranged so as to be connected to the end 19 of the pipe 15. The first fitting surface 43 of the die 33 is brought into surface contact with the tapered portion 21 of the pipe 15. A part of the outer peripheral surface of the pipe 15 on the end 19 side (a part excluding the tapered portion 21) is brought into surface contact with the second fitting surface 44 of the die 33. When the die is clamped, the parison 51 is surrounded by the pair of dies 33 on both the upper and lower sides and the pipe 15, and is housed in a housing (not shown).

[0037] After the molds are closed, the parison 51 is inflated by the air supply means 32 and pressed against the inner surface of the mold 33 and the inner circumferential surface of the pipe 15. As a result, as shown in FIG. 2, a blow molded article 11 is obtained that has a liner 14 in which a body portion 16 and a dome portion 17 are integrally molded, and that is molded into a predetermined shape. The body portion 16 is molded by bringing the parison 51 into contact with the inner circumferential surface of the pipe 15. The upper dome portion 17 is molded by bringing the parison 51 into contact with the inner surfaces of the upper pair of molds 33. The lower dome portion 17 is molded by bringing the parison 51 into contact with the inner surfaces of the lower pair of molds 33.

[0038] After the parison 51 has hardened to a certain extent, the mold 33 is opened. When the mold 33 is open, the mold 33 is detached from the liner 14 and the pipe 15, and the pipe 15 is integrated with the body 16. The pipe 15 is in close contact with the outer circumferential surface of the body 16. The blow molded article 11 is removed from the mold 33 and moved to a cooling booth (not shown) and cooled over time. This completes the manufacturing process of the blow molded article 11.

[0039] The effects of the present embodiment 1 will be described below. According to the pressure vessel 10 and the manufacturing apparatus 30 for the blow molded article 11 of the present embodiment 1, the mold 33 for molding the dome portion 17 is arranged so as to be continuous with the end 19 of the pipe 15. The parison 51 is brought into close contact with the mold 33 and the pipe 15, thereby making it possible to mold the liner 14 in a predetermined shape. When molding liners 14 of different lengths, it is only necessary to change the length of the pipe 15, so that the mold 33 described below can be made common. Only one type of mold 33 is required for a plurality of types of liners 14 of different lengths, so the cost of the mold 33 can be reduced.

[0040] Additionally, the inner diameter L1 of the end 19 of the pipe 15 is smaller than the outer diameter L2 of a portion 23 of the dome portion 17 on the pipe 15 side (a portion of the outer circumferential surface of the liner 14 adjacent to the pipe 15). This makes it possible to prevent the liner 14 and the pipe 15 from being misaligned in the vertical direction (axial direction).

[0041] Additionally, the outer diameter L3 of the end 19 of the pipe 15 is larger than the outer diameter L2 of a portion 23 (a portion of the outer circumferential surface of the liner 14 adjacent to the pipe 15) of the dome portion 17. This makes it possible to prevent the outer reinforcing layer 12, which will be described later, from being misaligned in the vertical direction (axial direction) with respect to the blow molded body 11.

[0042] In addition, a tapered portion 21 is formed on the outer circumferential surface of the end 19 of the pipe 15, with the outer circumferential surface being inclined with respect to the axis. This makes it possible to prevent stress from concentrating on the contact area between the end 19 of the pipe 15 and the outer reinforcing layer, compared to a configuration without the tapered portion 21 (a configuration in which the end 19 of the pipe 15 is angular).

[0043] In addition, the pipe 15 constitutes an internal reinforcing layer having higher rigidity than the liner 14. This makes it possible to prevent the body portion 16 of the liner 14 from being deformed.

[0044] Additionally, the inner diameter L1 of the end 19 of the pipe 15 is smaller than the inner diameter L4 of a portion 45 of the second molding surface 42 on the pipe 15 side (a portion of the inner circumferential surface of the mold 33 adjacent to the pipe 15). This makes it possible to prevent the liner 14 and the pipe 15 from being misaligned in the axial direction.

[0045] Additionally, the outer diameter dimension L3 of the end 19 of the pipe 15 is larger than the inner diameter dimension L4 of a portion 45 (a portion of the inner circumferential surface of the mold 33 adjacent to the pipe 15) on the second molding surface 42 of the mold 33. This makes it possible to prevent the outer reinforcing layer 12 from being misaligned in the axial direction with respect to the blow molded body 11 when the outer reinforcing layer 12 is formed on the outer circumferential surface of the blow molded body 11.

[0046] <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 above-mentioned Example 1, the inner diameter dimension L1 of the end 19 of the pipe 15 was set to be smaller than the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17). However, the inner diameter dimension L1 of the end 19 of the pipe 15 may be the same as the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17), or may be larger than the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17). (2) In the above-mentioned Example 1, the outer diameter dimension L3 of the end 19 of the pipe 15 was set to be larger than the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17). However, the outer diameter dimension L3 of the end 19 of the pipe 15 may be the same as the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17), or may be smaller than the outer diameter dimension L2 of the portion of the outer surface of the liner 14 adjacent to the pipe 15 (portion 23 on the pipe 15 side of the dome portion 17). (3) In the above Example 1, the inner diameter dimension L1 of the end 19 of the pipe 15 was set to be smaller than the inner diameter dimension L4 of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42). However, the inner diameter dimension L1 of the end 19 of the pipe 15 may be set to be the same dimension L4 as the inner diameter dimension of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42), or larger than the inner diameter dimension L4 of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42). (4) In the above Example 1, the outer diameter L3 of the end of the pipe was set larger than the inner diameter L4 of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42). However, the outer diameter L3 of the end 19 of the pipe 15 may be the same as the inner diameter L4 of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42), or may be smaller than the inner diameter L4 of the portion of the inner surface of the mold 33 adjacent to the pipe 15 (portion 45 on the pipe 15 side of the second molding surface 42). (5) In the above embodiment 1, the end 19 of the pipe 15 is formed with the tapered portion 21. However, the end 19 of the pipe 15 may have a shape that does not include the tapered portion 21. (6) In the above-described first embodiment, instead of the tapered portion 21, a curved portion that is convex radially outward may be provided. (7) In the above Example 1, the pipe 15 constitutes an internal reinforcing layer having higher rigidity than the liner 14, but the material of the pipe 15 may be one having the same rigidity as the liner 14 or one having lower rigidity than the liner 14. [Explanation of symbols]

[0047] 10...Pressure vessel 11...Blow molded body 11A: Body of blow molded body 11B: Dome portion of blow molded body 12…External reinforcement layer 14. Liner 15...Pipe (internal reinforcement layer) 16…Liner body 17…Dome part of liner 21...Tapered section 23: The pipe side of the dome (the part of the outer periphery of the liner adjacent to the pipe) 30...Manufacturing equipment 33…Mold 51...Parison

Claims

1. A blow molded body and an outer reinforcing layer surrounding the blow molded body, The blow molded body is a liner blow-molded using a parison as a material so that a body portion and a dome portion are integral with each other; A pipe in close contact with the outer circumferential surface of the body, an inner diameter dimension of the end of the pipe is smaller than an outer diameter dimension of a portion of an outer circumferential surface of the dome portion adjacent to the pipe; A pressure vessel, wherein a step is formed between an outer peripheral surface of the body portion and a portion of an outer peripheral surface of the dome portion adjacent to the pipe.

2. a maximum outer diameter of the end of the pipe is larger than an outer diameter of a portion of an outer circumferential surface of the dome portion adjacent to the pipe; 2. The pressure vessel according to claim 1, wherein the outer peripheral surface of the portion of the end of the pipe that has the maximum outer diameter and the portion of the outer peripheral surface of the dome portion adjacent to the pipe are seamlessly connected via a tapered portion of the pipe.

3. 3. The pressure vessel according to claim 1, wherein the end of the pipe is formed with a tapered portion whose outer circumferential surface is inclined with respect to the axis.

4. 4. The pressure vessel according to claim 1, wherein the pipe constitutes an inner reinforcing layer having a higher rigidity than the liner.

5. A manufacturing apparatus for molding a blow molded article having a liner blow molded using a parison as a material so that a body portion and a dome portion are integral with each other, and a pipe in close contact with an outer peripheral surface of the body portion, comprising: the pipe that forms the body portion by contacting the cylindrical parison; and two pairs of dies for forming the dome portions at the upper and lower end portions of the body portion by contacting the parison, One pair of molds is arranged so as to be connected only to the upper end of the pipe, and the other pair of molds is arranged so as to be connected only to the lower end of the pipe, and the parison is tightly attached to the molds and the pipe, thereby forming the liner into a predetermined shape; In a state where the mold is opened, the mold is detached from the liner and the pipe, and the pipe is integrated with the body portion.

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