pressure vessel

Abstract

Because the pressure vessel was cylindrical, it was difficult to say that the volume for storing the fluid was efficiently secured. [Solution] A pressure vessel capable of storing fluid comprises a plurality of main body sections that form a space inside, and one or more connecting sections that connect the main body sections to each other. The main body sections and connecting sections are connected alternately in series, and the connecting sections are bent. The cross-section of the main body sections perpendicular to the longitudinal direction is substantially rectangular. The main body sections have reinforcing members that connect pairs of opposing surfaces within the space.

Description

Technical Field

[0001] The technology disclosed in this specification relates to pressure vessels.

Background Art

[0002] Patent Document 1 discloses a pressure vessel for storing a fluid. The pressure vessel of Patent Document 1 alternately has a cylindrical tube as a liner cavity and a flexible connector, and can be folded inside the housing by bending the flexible connector portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, since the pressure vessel has a cylindrical shape, it has been difficult to efficiently secure a volume for storing a fluid.

Means for Solving the Problems

[0005] This specification discloses a pressure vessel capable of storing a fluid. The pressure vessel includes a plurality of main body portions that form a space inside, and one or more connection portions that communicate the main body portions with each other. The main body portions and the connection portions are alternately connected in series, and the connection portions are bent. A cross-section perpendicular to the longitudinal direction of the main body portion is substantially square.

[0006] According to the above configuration, a cross-section of the main body portion of the pressure vessel that is perpendicular to the longitudinal direction is substantially square. Therefore, compared with the conventional case where such a cross-section is circular, more of the above volume can be secured.

Brief Description of the Drawings

[0007] [Figure 1] A cross-sectional view showing a pressure vessel. [Figure 2] Cross-sectional view along line II-II in Figure 1. [Figure 3] Cross-sectional view along line III-III in Figure 1. [Figure 4] A cross-sectional view showing a magnified view of the vicinity of one end of the main body to which the nozzle is attached. [Figure 5] A diagram showing a modified pressure vessel housed in the underfloor space of a vehicle. [Figure 6] A diagram showing a conventional pressure vessel housed in the underfloor space of a vehicle. [Modes for carrying out the invention]

[0008] This embodiment will be described with reference to the drawings. Each figure is for illustrative purposes only, and this embodiment is not limited to what is shown. Also, since each figure is illustrative, some parts may be omitted.

[0009] Figure 1 shows a simplified cross-sectional view of a pressure vessel 10 according to this embodiment. The pressure vessel 10 is capable of storing a fluid. The fluid is, for example, a fuel gas such as hydrogen. In each figure, the X and Y directions are shown as appropriate for ease of explanation. The X and Y directions are orthogonal. The pressure vessel 10 comprises a plurality of main body sections 20 that form a space inside, and one or more connecting sections 30 that connect the main body sections 20 to each other. Since the connecting sections 30 connect the main body sections 20 to each other, a space is naturally formed inside them.

[0010] According to Figure 1, the main body 20 is elongated in the Y direction, with openings 23 at both ends in the Y direction. In Figure 1, the Y direction corresponds to the longitudinal direction of the main body 20. The main body 20 comprises a body portion 21 with a substantially constant cross-sectional shape perpendicular to the longitudinal direction, and tapered portions 22 that are at both ends of the body portion 21 in the longitudinal direction. The tapered portions 22 gradually or stepwise narrow the cross-sectional area perpendicular to the longitudinal direction from the body portion 21 toward the openings 23. Hereinafter, the cross-section of the main body 20 perpendicular to the longitudinal direction will be referred to as the "first cross-section".

[0011] According to Figure 1, the multiple main body sections 20 are arranged side by side along the X direction (one direction). Furthermore, the multiple main body sections 20 are positioned at approximately the same location in the Y direction. Looking at the pressure vessel 10 as a whole, the main body sections 20 and connecting sections 30 are connected alternately in series. The connecting section 30 is bent between the opening 23 of one main body section 20 and the opening 23 of another main body section 20. According to Figure 1, the connecting section 30 curves approximately 180 degrees in a U-shape, connecting adjacent main body sections 20 in the X direction. In such a pressure vessel 10, the main body sections 20 located at one end to the main body section 20 located at the other end are connected in a continuous line in the X direction.

[0012] Figure 2 is a cross-sectional view taken along line II-II in Figure 1. Figure 2 shows the shape of the first cross-section of the main body 20. As shown in Figure 2, the first cross-section is approximately rectangular. An approximately rectangular shape refers to a shape that has two pairs of opposing planes (the pair of planes 25a and 25b, and the pair of planes 26a and 26b) and four corners connecting these four planes. The four corners of the first cross-section are more accurately described as curved rather than being right angles between planes. Furthermore, the opposing planes forming the first cross-section do not need to be strictly parallel, and each plane may be slightly curved.

[0013] Since the connecting portion 30 is a tube that connects the opening 23 of one main body portion 20 to the opening 23 of another main body portion 20, its cross-section perpendicular to the flow direction is basically narrower than the first cross-section of the body portion 21. However, in this embodiment, it is not essential that the cross-section of the connecting portion 30 is narrower than the first cross-section of the body portion 21. In other words, the main body portion 20 may not have a tapered portion 22, and both ends of the body portion 21 may be openings 23. In this case, the body portion 21 and the connecting portion 30 are directly connected.

[0014] Figure 3 is a cross-sectional view taken along line III-III in Figure 1. The main body portion 20 has a reinforcing member 24 that connects a pair of opposing surfaces within the space of the main body portion 20. In Figure 3, a wire 24a is shown that connects a pair of opposing surfaces 25a and surface 25b of the main body portion 20 in a wave-like manner. The wire 24a is made of carbon fiber reinforced plastic (CFRP), which is a composite material of carbon fiber and resin. In other words, the reinforcing member 24 comprises one or more wires 24a that extend in the longitudinal direction of the main body portion 20 while stitching together the pair of surfaces.

[0015] In Figure 3, the multiple black dots within the main body 20 each represent a cross-section of a wire 24a. Similarly, in Figure 2, the multiple lines drawn in a grid pattern within the main body 20 each represent a wire 24a. In other words, within the space of the main body 20, the spaces between pairs of surfaces 25a, 25b, and between other opposing pairs of surfaces 26a, 26b, are stitched together by multiple wires 24a. The reinforcing member 24 comprises such multiple wires 24a. In Figure 1, the reinforcing member 24 is omitted.

[0016] A brief explanation of a manufacturing method for the pressure vessel 10 is provided below. In the following, the pressure vessel 10 in the state before the connection portion 30 is bent will be referred to as the pressure vessel 10 before bending. First, a liner, which will serve as the base material for the pressure vessel 10 before bending, is prepared. The liner is made of a resin such as nylon, for example. The liner is a hollow body in which a main body-shaped portion having a shape corresponding to the main body portion 20 and a connection-shaped portion having a shape corresponding to the connection portion 30 before bending are alternately and linearly integrally molded. Wire is wound around the outer surface of such a liner using a winding machine, for example, in a mesh or spiral pattern. The winding machine is also called a braiding machine or braider. The wire wound around the liner is also CFRP, which is carbon fiber impregnated with resin. By winding the wire with the winding machine, a CFRP fiber layer 27 is formed to cover the outer surface of the liner.

[0017] Simultaneously with the winding of the wire by the winding machine, the wire 24a is sewn onto the liner by the sewing machine. The sewing method of the wire 24a by the sewing machine can vary, for example, a running stitch or a so-called machine stitch that connects the upper thread (wire 24a) and the lower thread (wire 24a). By sewing the wire 24a with the sewing machine, the wire 24a penetrates the space inside the liner, and a reinforcing member 24 is provided, for example, as shown in Figure 3.

[0018] The liner, winding machine, and sewing machine move relative to each other along the longitudinal direction of the liner. For example, the winding machine and sewing machine are fixed in position, while the liner moves relative to them along its longitudinal direction. As a result of this movement, the sewing of the wire 24a by the sewing machine and the winding of the wire by the winding machine are performed in parallel. This allows for the efficient manufacture of the pressure vessel 10 before bending, while keeping the portion of the wire 24a other than the portion that penetrates the space of the main body 20 within the fiber layer 27, as shown in Figure 3. The pressure vessel 10 manufactured in this way before bending is then bent at the connection portion 30 into a roughly U-shape to become the pressure vessel 10 with the shape shown in Figure 1.

[0019] As described above, according to the present embodiment, the pressure vessel 10 has a first cross section that is substantially rectangular. Therefore, compared with the conventional configuration in which the cross section perpendicular to the longitudinal direction of the pressure vessel is circular, a larger volume for storing fluid can be ensured.

[0020] Also, from the perspective of ensuring strength against the pressure of the fluid, it can be said that the conventional circular cross section is superior to the substantially rectangular first cross section. However, in the present embodiment, the main body portion 20 is configured to have a reinforcing member 24 that connects the opposing surfaces. Thereby, the main body portion 20 can ensure strength against the pressure of the fluid while having a substantially rectangular first cross section.

[0021] In addition, by using an integrally formed liner as a base material and performing the above-described winding and sewing in parallel to manufacture the entire pressure vessel 10 before bending, compared with the conventional method of manufacturing a pressure vessel by joining a plurality of parts having different thicknesses and shapes, the number of parts and the number of man-hours can be reduced, and the pressure vessel 10 can be manufactured at a low cost.

[0022] Regarding the connection portion 30, the cross section perpendicular to its flow path direction can take various shapes. The cross section perpendicular to the flow path direction of the connection portion 30 may be substantially rectangular like the main body portion 20, or may be either circular or oval. An oval basically includes a pair of substantially parallel straight lines and a pair of arcs connecting these straight lines, but may also include an ellipse in a broad sense. Further, regardless of its cross-sectional shape, the connection portion 30 may have a so-called bellows structure in which mountain folds and valley folds are repeated. By forming the connection portion 30 into a bellows structure, it becomes easy to bend the connection portion 30.

[0023] In the pressure vessel 10, a base 40 is provided at one end of the main body portion 20 located at one end of the series connection among the plurality of main body portions 20. In FIG. 1, as shown by the two-dot chain line, bases 40 are attached to one ends of the main body portion 20 located at one end and the main body portion 20 located at the other end in the X direction.

[0024] Figure 4 shows an enlarged cross-sectional view of the vicinity of one end of the main body 20 to which the nozzle 40 is attached. According to Figure 4, the main body 20 has a liner 50 as an inner layer and a fiber layer 27 as an outer layer. Note that the liner 50 is not shown in the other figures except for Figure 4 for simplification. At one end of the main body 20, for example, a predetermined range (the range near the opening) close to the opening 23 of the tapered portion 22 is a tube with approximately the same diameter as the opening 23, and the nozzle 40 is attached to the outside of the range near the opening. The nozzle 40 is made of metal, for example, and is formed in an annular shape.

[0025] The outer circumferential surface of the jaw 40 has a screw groove 41 for screwing in the fastening portion 60, which will be described later. On the other hand, the inner circumferential surface of the jaw 40 has a plurality of locking claws 42. When the jaw 40 is crimped into the vicinity of the opening of the main body 20, the plurality of locking claws 42 bite into the outer circumferential surface of the fiber layer 27, thereby locking the jaw 40 to the main body 20.

[0026] The fastening portion 60 is fastened to the nozzle 40 from the outside. In other words, the fastening portion 60 is fastened to the nozzle 40 by screwing the female thread portion formed on the inside of the fastening portion 60 into the thread groove 41 of the nozzle 40. In the example in Figure 4, a part of the fastening portion 60 is inserted into the inside of the opening 23, sealing the opening 23. The fastening portion 60 may also be structured to connect the opening 23 to a flow path outside the pressure vessel 10 (not shown).

[0027] As described above, the reinforcing member 24 includes a wire 24a that extends in the longitudinal direction of the main body 20 while sewing together opposing surfaces of the main body 20. In this embodiment, one end of the wire 24a may be fixed at a position away from the mouthpiece 40 at one end of the main body 20 to which the mouthpiece 40 is provided. In Figure 4, the wire 24a is shown as a solid line within the fiber layer 27. The end of the wire 24a is embedded within the fiber layer 27 at a position where the locking claw 42 of the mouthpiece 40 cannot reach. In other words, as described above, when sewing the wire 24a with a sewing machine and winding the wire with a winding machine are performed in parallel, one end of the wire 24a is embedded at a predetermined position within the fiber layer 27 where the locking claw 42 cannot reach, at one end of the main body 20 to which the mouthpiece 40 will be attached later. The end treatment of the wire 24a is performed similarly at one end of the main body 20 located at one end in the X direction as shown in Figure 1, and at the other end of the main body 20. With this configuration, contact between the locking claws 42 and the wire 24a within the fiber layer 27 is avoided. Therefore, the engagement of the locking claws 42 with the fiber layer 27 is not hindered, and the end cap 40 is firmly locked to the main body 20.

[0028] The pressure vessel 10 is housed, for example, in the space under the floor of a vehicle. The vehicle referred to here is a fuel cell vehicle or a hydrogen engine vehicle that uses hydrogen stored in the pressure vessel 10 as fuel to generate electricity or power. Figure 6 shows a conventional pressure vessel 1 housed in the underfloor space A of a vehicle. The pressure vessel 1 is a typical cylindrical hydrogen tank with a circular cross-section perpendicular to its longitudinal direction. Part of the underfloor space A is defined by a body member 70 that separates the above and below the floor of the vehicle.

[0029] The body member 70 has a protrusion 71 that projects downward at a predetermined position. The body member 70 and the protrusion 71 are part of the vehicle body. The protrusion 71 is, for example, a floor cross member for improving the rigidity of the vehicle body. As shown in Figure 6, conventionally, the presence of the protrusion 71 created a dead space B between the body member 70 and the pressure vessel 1. Also, the pressure vessel 1 was miniaturized so that it could be housed in the underfloor space A at a position below the protrusion 71.

[0030] In view of this situation, as a modification of this embodiment, the main body portion 20 may have an uneven shape that conforms to the shape of the vehicle body, defining at least a part of the space in which the pressure vessel 10 is housed. Figure 5 shows the pressure vessel 10 according to the modification, housed in the underfloor space A of the vehicle. In Figure 5, only the main body portion 20 of the pressure vessel 10 is shown in cross-section from the same viewpoint as in Figure 3.

[0031] As shown in Figure 5, a recess 28 is formed on the upper surface of the main body 20, that is, on the surface facing the body member 70, at a position corresponding to the protrusion 71, in order to avoid contact with the protrusion 71. The recess 28 is formed in the body portion 21. As can be seen from the above explanation, since the outer surface of the body portion 21 is flat, it is easier to form the recess 28 compared to the conventional pressure vessel 1 which has a cylindrical shape. Naturally, the area of ​​the body portion 21 in which the recess 28 is formed has a narrower first cross-section than the area of ​​the body portion 21 in which the recess 28 is not formed.

[0032] The fact that the main body portion 20 has a recess 28 means that, relative to the recess 28, the main body portion 20 also has a protruding portion. Therefore, the shape of the recess 28 and its surrounding area is a concrete example of an uneven shape that conforms to the shape of the vehicle body. In such an example, by avoiding contact with the protrusion 71 using the recess 28, the pressure vessel 10 can be housed using space B of the underfloor space A. In other words, the pressure vessel 10 can be made larger and its volume increased while effectively utilizing the limited underfloor space A of the vehicle. In Figure 5, only one main body portion 20 is shown, but it can be understood that multiple main body portions 20 arranged in the X direction, corresponding to the length of the protrusion 71 in the X direction, each have a recess 28.

[0033] In the pressure vessel 10 of this embodiment, the presence of a liner is not essential. The pressure vessel 10 may, for example, have a configuration without a liner, at least in its post-manufacturing form. Furthermore, the pressure vessel 10 may be manufactured using a method that does not use a liner.

[0034] The specific examples of the technologies disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]

[0035] 10: Pressure vessel, 20: Main body, 21: Body, 22: Tapered section, 23: Opening, 24: Reinforcement member, 24a: Wire, 25a, 25b, 26a, 26b: Surface, 27: Fiber layer, 28: Recess, 30: Connection part, 40: Nozzle, 41: Screw groove, 42: Locking claw, 50: Liner, 60: Fastening part, 70: Body member, 71: Protrusion

Claims

1. A pressure vessel capable of storing fluids, Multiple main body parts that form a space inside, It comprises one or more connecting parts that connect the aforementioned main body parts, The main body and the connecting parts are connected alternately in series, and the connecting parts are bent. A pressure vessel in which the cross-section perpendicular to the longitudinal direction of the main body is approximately rectangular in shape.

2. The pressure vessel according to claim 1, wherein the main body portion has a reinforcing member that connects a pair of opposing surfaces within the space.

3. The reinforcing member comprises one or more wires extending in the longitudinal direction while stitching together the pair of surfaces, Of the multiple main body parts, one end of the main body part located at one end of the series connection is provided with a socket. The pressure vessel according to claim 2, wherein one end of the wire is fixed at the one end of the main body portion on which the nozzle is provided, at a position away from the nozzle.

4. The pressure vessel according to claim 1, wherein the main body has an uneven shape that conforms to the shape of the vehicle body, defining at least a portion of the space in which the pressure vessel is housed.

5. The pressure vessel according to claim 1, wherein the cross-section of the connection portion perpendicular to the flow path direction is circular, oval, or substantially rectangular.

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