Pressure vessel

Abstract

To provide a pressure vessel that is improved in strength and is hard to cause fluid leakage.SOLUTION: A pressure vessel 1 is formed of a resin hollow liner 2 and an insert member 3, which are integrated by blow molding of the liner 2. The insert member 3 has a flange portion 25 and a cylindrical tube portion 26 that rises from the flange portion 25 and has an inner diameter opening 27. A portion of the liner 2 is in continuous contact with the end face of the flange portion 25 and the inner peripheral surface of the cylinder portion 26, and the liner 2 is integrally molded with the insert member 3 by performing blow molding with a parison inserted into the inner diameter opening 27. Since blow molding is performed with the liner 2 inserted inside the insert member 3, it is possible to prevent the occurrence of a pinched portion. With this, the strength can be improved, and it is possible to make it difficult for fluid to leak between the liner 2 and the insert member 3.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pressure vessel.

Background Art

[0002] As the background art of the present invention, there is the technology of Patent Document 1. This technology relates to a technique for manufacturing a liner of a pressure vessel for enclosing a high-pressure fluid or the like by blow molding. This resin liner is formed integrally with a base by inserting the base inside a parison which is a semi-fluid resin and performing blow molding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the molding around the base of Patent Document 1, since the parison is sandwiched from the outside with respect to the base by a split mold, a pinch part (a part with non-uniform thickness due to pinching) is generated in the liner part surrounding the outer peripheral part of the base. When such a pinch part is generated, a gap is likely to occur between the base and the liner, and there is a risk that the fluid enclosed leaks from the pressure vessel after manufacturing. Further, when the pinch part is formed, a location where stress concentrates due to the non-uniform thickness of the liner is generated, so there is a risk that the strength of the pressure vessel decreases.

[0005] Therefore, an object of the present invention is to provide a pressure vessel that improves strength and is less likely to leak fluid.

Means for Solving the Problems

[0006] The present invention relates to a pressure vessel in which a liner made of resin and an insert member are integrally formed by blow molding of the liner, wherein the insert member has a flange portion and a cylindrical tubular portion rising from the flange portion and having an inner diameter opening, and a part of the liner is continuously in contact with an end face of the flange portion and an inner peripheral surface of the tubular portion, and the liner is integrally formed with the insert member by inserting a parison through the inner diameter opening and performing the blow molding.

[0007] According to the present invention, since the liner is inserted inside the insert member and blow molded, generation of a pinch portion can be prevented. Thereby, improvement in strength can be achieved, and it is possible to make it difficult for fluid to leak from between the liner and the insert member.

[0008] Further, it is preferable that the liner has an injection / discharge port in contact with the inner diameter opening, and a blow pin having a stepped portion on an outer peripheral surface is inserted from the outside into a portion of the parison that becomes the injection / discharge port during the blow molding, so that a sealing surface is formed at the injection / discharge port.

[0009] According to the present invention, the molding cycle can be shortened and the molding accuracy of the sealing surface can be improved.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a pressure vessel with improved strength and difficult for fluid to leak.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Mode for Carrying Out the Invention

[0012] Hereinafter, a plurality of examples of embodiments of the present invention will be described. [First Embodiment] FIG. 1 is a longitudinal sectional view of a pressure vessel according to the first embodiment of the present invention. In each of the figures referred to below, for convenience, there may be cases where the upper side of the figure is the upper side and the lower side of the figure is the lower side, but this does not limit the present invention.

[0013] The pressure vessel 1 according to the present embodiment is a hollow container filled with a high-pressure fluid such as hydrogen gas as shown in FIG. 1. The pressure vessel 1 includes a liner 2, an insert member 3 such as a base, and a reinforcing layer 4. In the pressure vessel 1 of the present embodiment, insert members 3 are provided at the top and bottom, respectively, but only one of them may be provided.

[0014] The liner 2 is a resin-made hollow container and is a member that constitutes the inside of the pressure vessel 1. The liner 2 is formed with substantially the same thickness. The liner 2 includes a body portion 21, a shoulder portion 22, and an injection / discharge port 23. The body portion 21 is cylindrical and is a part that constitutes the central portion. The shoulder portion 22 extends in a direction orthogonal to the central axis C between the body portion 21 and the injection / discharge port 23. The shoulder portion 22 has an opening at the central portion and has a circular shape. The injection / discharge port 23 is continuous from the opening of the shoulder portion 22 and has a cylindrical shape. The injection / discharge port 23 is formed parallel to the central axis C. The injection / discharge port 23 is a part where fluid enters and exits.

[0015] The insert member 3 is made of metal and is a member for fluid to enter and exit the pressure vessel 1. The insert member 3 includes a flange portion 25 and a cylindrical portion 26. The flange portion 25 has a ring shape and extends in the radially outward direction with respect to the central axis C. The cylindrical portion 26 rises from the flange portion 25 and has a cylindrical shape. The outer circumference of the cylindrical portion 26 expands toward the tip, but it may contract or may be constant. The opening of the cylindrical portion 26 is referred to as an "inner diameter opening portion 27".

[0016] The shoulder portion 22 of the liner 2 is in surface contact with the lower surface (end face) of the flange portion 25. Further, the injection / discharge port 23 of the liner 2 is in surface contact with the inner surface of the inner diameter opening portion 27 over the entire circumferential direction and in the direction of the central axis C. The liner 2 and the insert member 3 are integrally formed in the manufacturing stage described later. That is, the liner 2 is integrally formed with the insert member 3 by inserting a parison, which is a molten resin, through the inner diameter opening portion 27 and performing blow molding.

[0017] The reinforcing layer 4 is a resin layer that covers the outside of the pressure vessel 1. More specifically, the reinforcing layer 4 covers a part of the body portion 21 and the shoulder portion 22 of the liner 2 and also covers a part of the flange portion 25 and the cylindrical portion 26 of the insert member 3. The reinforcing layer 4 is formed, for example, by impregnating a reinforcing fiber with an adhesive and laminating it on the inner layer by filament winding. By providing the reinforcing layer 4, the strength of the pressure vessel 1 can be increased.

[0018] Next, a manufacturing method of the pressure vessel 1 shown in FIG. 1 will be described. This manufacturing method is realized by sequentially performing the following first to fourth steps.

[0019] (1) First step FIG. 2 is a longitudinal sectional view for explaining the first step and the second step of the manufacturing method of the pressure vessel according to the present first embodiment. As shown in FIG. 2, in the first step, a pair of upper and lower insert members 3 are held in a state of being clamped by a pair of molding dies 31. The molding dies 31, 31 are mold materials for blow-molding the liner 2. The molding dies 31, 31 are each movable in a direction approaching or separating from the central axis C. The inner surface of the molding die 31 is a molding surface 32 for molding the liner 2. The insert members 3 are held by the molding dies 31, 31 with their cylindrical portions 26 facing outward. Note that although the insert member 3 is held by the molding die 31, it may be held by a lifting device or other holding device.

[0020] (2) Second step After the first step, a parison 41 is inserted into each inner diameter opening 27 of each insert member 3 and into the hollow portion (cavity) in the clamped molding dies 31, 31. The parison 41 is a molten resin and has a cylindrical shape.

[0021] (3) Third step After the second step, a blow pin (not shown) is inserted inside the parison 41 and air is supplied to perform blow molding for transferring the parison 41 to the molding surface 32 of the molding die 31, the lower surface (end surface) of the flange portion 25 of the insert member 3, and the inner diameter opening 27 of the insert member 3. FIG. 3 is a longitudinal sectional view for explaining the third step of the manufacturing method of the pressure vessel according to the present embodiment. As shown in FIG. 3, the parison 41 is brought into close contact with the molding surface 32, the lower surface (end surface) of the flange portion 25 of the insert member 3, and the inner diameter opening 27 of the insert member 3 by the supply of air. In this way, the liner 2 can be formed using the parison 41 as a material. Then, the blow pin is removed, and when the molded liner 2 is cooled and solidified, the liner 2 is removed from the molding die 31. Also, The burr protruding outside the insert member 3 is cut and removed.

[0022] (4) Fourth process After the third process, a reinforcing layer 5 is formed on the outer periphery of the liner 2 and the insert member 3 (see Fig. 1). The reinforcing layer 5 is formed, for example, by filament winding in which reinforcing fibers impregnated with an adhesive are wound around the liner 2.

[0023] According to the pressure vessel 1 and its manufacturing method described above, by inserting the parison 41 into the inner diameter opening 27, the injection / discharge port 23 of the liner 2 after blow molding can be brought into close contact with the inside of the inner diameter opening 27 with a uniform thickness. That is, since the parison 41 is within the inner diameter opening 27 of the insert member 3, when the mold halves 31, 31 are clamped, the parison 41 forming the injection / discharge port 23 will not be crushed by the mold halves 31, 31. As a result, a pinched portion (a portion with non-uniform thickness due to pinching) is not formed at the injection / discharge port 23, so that leakage of fluids such as hydrogen gas between the liner 2 and the insert member 3 can be suppressed. Also, since the pinched portion is not formed, the injection / discharge port 23 can be made to have a uniform thickness, and concentration of stress on a part of the injection / discharge port 23 can be avoided, so that the strength can be improved.

[0024] [Second Embodiment] Each of the embodiments described below basically has the structure of the pressure vessel 1 described in the first embodiment and is manufactured by a substantially similar manufacturing method. Therefore, in each of the following embodiments, description of configurations common to the embodiments described previously is omitted, and the same reference numerals are used for the same members and the like. The second embodiment is different from the first embodiment in that it has a sealing surface for installing a seal member.

[0025] FIG. 4 is a longitudinal sectional view around the insert member in a pressure vessel formed using a blow pin having a stepped portion in the second embodiment of the present invention. Note that the reinforcing layer 5 is not shown. As shown in FIG. 4, in the pressure vessel 1A of the second embodiment, a stepped portion 28 is formed at the tip of the injection / discharge port 23. The injection / discharge port 23 has a constant outer diameter as in the first embodiment. The stepped portion 28 is composed of a stepped bottom surface 28a and a stepped side surface 28b rising from the outer edge of the stepped bottom surface 28a. A seal member 55 (e.g., an O-ring or the like) is attached to the stepped portion 28. The stepped bottom surface 28a is a portion that serves as the seal surface of the seal member 55. By attaching the seal member 55 to the stepped portion 28, for example, when a valve (not shown) is connected to the insert member 3, leakage of fluid can be prevented.

[0026] FIG. 5 is a longitudinal sectional view around the insert member in a state where a blow pin is inserted into the inlet of a parison in the third step of the method for manufacturing a pressure vessel according to the second embodiment of the present invention. As shown in FIG. 5, the blow pin 51 has a cylindrical shape and includes a large-diameter portion 52 on the base end side and a small-diameter portion 53 having a cylindrical shape and a smaller diameter than the large-diameter portion 52. The outer diameter of the large-diameter portion 52 is larger than the inner diameter of the parison 41 and smaller than the outer diameter. Also, the outer diameter of the large-diameter portion 52 is smaller than the inner diameter opening 27. The injection / discharge port 23 is formed by the outer peripheral surface of the blow pin 51 and the inner diameter opening 27.

[0027] In addition, a ring-shaped stepped portion 54 is formed by the large-diameter portion 52 and the small-diameter portion 53. When the stepped portion 54 is inserted from the outside (the outside along the central axis C) with respect to the portion that becomes the injection / discharge port 23 of the parison 41, it is a portion that forms the seal surface described later at the inlet portion of the portion that becomes the injection / discharge port 23.

[0028] When blow molding is performed in the third step, the blow pin 51 is inserted from the inside of the parison 41 and from the outside along the central axis C. The insertion position is the portion that becomes the injection / discharge port 23 of the parison 41 It is inserted so that the tip of the large-diameter portion 52 is positioned below the end face of the cylindrical portion 26. Thereby, a forming surface of the injection / discharge port 23 is formed between the outer peripheral surface of the blow pin 51 and the inner diameter opening 27. That is, by performing blow molding in the state shown in FIG. 5, while forming the injection / discharge port 23, the step bottom surface 28a and the step side surface 28b can be formed at the tip of the injection / discharge port 23 by the step portion 54.

[0029] Conventionally, when forming the seal surface, after performing blow molding, the tip of the injection / discharge port 23 or a part of the insert member 3 was cut. However, according to this method, there are problems that the man-hours increase, the seal surface is not stable, and the sealing performance is not stable. In this regard, according to the present embodiment, since the seal surface (step bottom surface 28a) can be formed using the blow pin 51, there is no need to perform separate work, and the seal surface can be formed simultaneously with the blow molding process (third process). Thereby, the molding cycle can be shortened. Further, since it is formed by the step portion 54 of the blow pin 51, the molding accuracy of the seal surface can be improved, and the sealing performance can also be stabilized.

[0030] [Third Embodiment] The third embodiment is different from the first embodiment in that it includes a seal surface for installing a seal member, and the structure of the seal surface is different from that of the second embodiment.

[0031] FIG. 6 is a longitudinal sectional view around the insert member in a pressure vessel formed using a blow pin having a step portion in the third embodiment of the present invention. As shown in FIG. 6, the injection / discharge port 23 includes a base portion 23a and a diameter-expanded portion 23b having a larger diameter than the base portion 23a. A step portion 54 is formed by the base portion 23a and the diameter-expanded portion 23b. The step portion 54 is composed of a step bottom surface 54a and a step side surface 54b rising from the outer edge of the step bottom surface 54a. A seal member 55 (for example, an O-ring or the like) is attached to the step portion 54. The step bottom surface 54a is a portion that becomes the seal surface of the seal member 55.

[0032] Inside the cylindrical portion 26 of the insert member 3, a stepped portion 29 is formed. The stepped portion 29 is composed of a stepped bottom surface 29a and a stepped side surface 29b that rises from the outer edge of the stepped bottom surface 29a. The stepped portion 54 of the injection / discharge port 23 is in close contact along the shape of the stepped portion 29 of the insert member 3.

[0033] FIG. 7 is a longitudinal sectional view of the blow pin and the insert member in the third embodiment of the present invention. FIG. 8 is a longitudinal sectional view around the insert member in a state where the blow pin in the third embodiment of the present invention is inserted from the inlet of the parison. As shown in FIG. 7, the blow pin 71 includes a large-diameter portion 72, a medium-diameter portion 73, and a small-diameter portion 74. A first stepped portion 75 is formed by the large-diameter portion 72 and the medium-diameter portion 73. A second stepped portion 76 is formed by the medium-diameter portion 73 and the small-diameter portion 74. The outer diameter of the large-diameter portion 72 is the same as the outer diameter of the stepped side surface 29b of the stepped portion 29. The outer diameter of the medium-diameter portion 73 is the same as the inner diameter of the inner diameter opening portion 27. The height of the medium-diameter portion 73 is smaller than the height of the stepped side surface 29b of the stepped portion 29. The region surrounded by the outer peripheral surfaces of the insert member 3 and the blow pin 71 becomes the portion for forming the injection / discharge port 23. Further, the second stepped portion 76 is the portion for forming the stepped bottom surface 54a that serves as a seal surface when the parison 41 is pushed in.

[0034] As shown in FIG. 8, when blow molding is performed in the third step, the blow pin 71 is inserted from the inside of the parison 41 and from the outside along the central axis C. At this time, it is inserted so that the tip of the large-diameter portion 72 is flush with the end surface of the cylindrical portion 26. The injection / discharge port 23 is formed by the region surrounded by the outer peripheral surfaces of the insert member 3 and the blow pin 71. At the same time, the stepped portion 54 where the seal member 55 is arranged is formed.

[0035] According to this embodiment, since the sealing surface (the bottom surface 54a of the step) can be formed using the blow pin 71, there is no need to perform separate operations, and the sealing surface can be formed simultaneously with the blow molding process (the third process). As a result, the molding cycle can be shortened. Further, since the first step portion 75 and the second step portion 76 of the blow pin 71 are used for molding, the molding accuracy of the sealing surface can be improved, and the sealing performance can also be stabilized. Further, according to the blow pin 71, a diameter-expanded portion 23b can be formed in the injection / discharge port 23.

[0036] Although the embodiments of the present invention have been described above, design changes can be appropriately made without departing from the spirit of the present invention.

Explanation of Reference Numerals

[0037] 1, 1A, 1B Pressure vessel 2 Liner 3 Insert member 23 Injection / discharge port 27 Inner diameter opening 31 Mold 41 Parison 51, 71 Blow pin

Claims

**Claim 1** A pressure vessel formed by integrating a liner of a resin-made hollow container and an insert member by blow molding of the liner, wherein the insert member has a flange portion and a cylindrical tubular portion rising from the flange portion and having an inner diameter opening, a part of the liner is in continuous contact with the end face of the flange portion and the inner peripheral surface of the tubular portion, and the liner is integrally formed with the insert member by inserting a parison through the inner diameter opening and performing the blow molding. A pressure vessel characterized by the above is provided. **Claim 2** The liner has an injection / discharge port in contact with the inner diameter opening, and a blow pin having a stepped portion on its outer peripheral surface is inserted from the outside into the portion of the parison that becomes the injection / discharge port during the blow molding, so that a sealing surface is formed at the injection / discharge port. The pressure vessel according to claim 1, characterized by the above.

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