Manufacturing apparatus and method for manufacturing pressure tanks

Abstract

Due to insufficient resin impregnation into the fiber bundles, voids are formed within the fiber layer created when the fiber bundles are wound around the liner. [Solution] A manufacturing apparatus for producing a pressure tank by winding a fiber bundle around the surface of a hollow liner, comprising an impregnation mechanism for impregnating the fiber bundle with resin before it is wound around the liner. The impregnation mechanism comprises a first surface that supplies resin to the fiber bundle before it is wound around the liner, and a second surface that faces the first surface and sandwiches the fiber bundle between itself and the first surface before it is wound around the liner.

Description

Technical Field

[0001] The technology disclosed in the present specification relates to a manufacturing apparatus and a manufacturing method for manufacturing a pressure tank. Background Art

[0002] Patent Document 1 discloses a method of producing a tank including forming a resin-processed braided layer on a liner. According to Patent Document 1, a braiding machine is provided with a conical resin cone that contacts each fiber gathered from the braiding ring toward the liner from the back side of the fibers. Then, the resin in the grooves of the resin cone coats and / or impregnates the fibers before they are wound onto the liner. Prior Art Document Patent Document

[0003] Patent Document 1 Japanese National Publication of International Patent Application No. 2019-507850 Summary of the Invention Problems to be Solved by the Invention

[0004] As in Patent Document 1, in the process of feeding fibers toward the liner, each fiber that is impregnated with resin immediately before being wound onto the liner is individually a fiber bundle formed by gathering a plurality of fibers together as illustrated in Patent Document 1. Conventionally, when a fiber bundle immediately before being wound onto a liner is impregnated with resin in this manner, although resin adheres to the surface of the fiber bundle, the impregnation of resin between the fibers inside the fiber bundle has been insufficient. If the impregnation of resin into the fiber bundle is insufficient, a large number of voids called voids occur in the fiber layer formed as a result of winding the fiber bundle onto the liner. The presence of voids causes a reduction in the strength of the tank. Means for Solving the Problems

[0005] This specification discloses a manufacturing apparatus for producing a pressure tank by winding a fiber bundle around the surface of a hollow liner. The manufacturing apparatus includes an impregnation mechanism for impregnating the fiber bundle, which is a bundle of multiple fibers, with resin before it is wound around the liner. The impregnation mechanism includes a first surface that supplies the resin to the fiber bundle before it is wound around the liner, and a second surface that faces the first surface and sandwiches the fiber bundle between itself and the first surface before it is wound around the liner.

[0006] This specification discloses a manufacturing method for producing a pressure tank by winding a fiber bundle around the surface of a hollow liner. The manufacturing method comprises an impregnation step of impregnating the fiber bundle, which is a bundle of multiple fibers, with a resin, and a winding step of winding the resin-impregnated fiber bundle around the surface of the liner. The impregnation step includes passing the fiber bundle between a first surface that supplies the resin to the fiber bundle and a second surface facing the first surface, thereby sandwiching the fiber bundle between the first surface and the second surface.

[0007] According to the respective apparatus and method described above, the fiber bundle, before being wrapped around the liner, is sandwiched between a first surface and a second surface while receiving a supply of resin. As a result, the resin, which is compressed while sandwiched between the first and second surfaces, penetrates from the surface of the fiber bundle into the interior of the fiber bundle, and the fiber bundle is sufficiently impregnated with resin. Consequently, the generation of voids in the fiber layer formed as a result of the fiber bundle being wrapped around the liner is suppressed, and the strength of the pressure tank is improved. [Brief explanation of the drawing]

[0008] [Figure 1] A simplified diagram of the manufacturing equipment. [Figure 2] A simplified diagram showing a cross-section of the impregnation mechanism. [Figure 3] This figure shows a simplified cross-section of a different example of the impregnation mechanism than that shown in Figure 2. [Figure 4] This diagram shows an image of a cross-section of a conventional pressure tank. [Modes for carrying out the invention]

[0009] The main features of the embodiments described below are listed. These features can be combined in any way.

[0010] The manufacturing apparatus disclosed herein may further include a vibration mechanism that applies vibration to the resin in the region sandwiched between the first surface and the second surface. According to the above configuration, the vibration mechanism applies vibration to the resin in the region sandwiched between the first and second surfaces, thereby promoting the impregnation of the resin into the fiber bundle.

[0011] According to the manufacturing apparatus disclosed herein, a plurality of resin supply ports are formed on the first surface, and the impregnation mechanism may supply the resin to the fiber bundle from the plurality of resin supply ports. According to the above configuration, resin is supplied to the fiber bundle from a plurality of resin supply ports formed on the first surface, thereby promoting uniform impregnation of the fiber bundle with resin.

[0012] According to the manufacturing apparatus disclosed herein, the plurality of resin supply ports may be formed in a manner aligned with the direction in which the fiber bundle moves toward the liner. According to the above configuration, resin is supplied to the fiber bundle from a plurality of resin supply ports formed in the first surface, aligned along the direction in which the fiber bundle moves toward the liner. This promotes uniform impregnation of the fiber bundle with resin.

[0013] 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.

[0014] Figure 1 shows a simplified representation of the manufacturing apparatus 10 according to this embodiment. The manufacturing apparatus 10 is a device or system capable of manufacturing a pressure tank. The manufacturing apparatus 10 performs a method for manufacturing a pressure tank. The manufacturing apparatus 10 manufactures a pressure tank 22 by winding a fiber bundle around the surface of a hollow liner 20.

[0015] The liner 20 corresponds to the inner layer of the pressure tank 22. The liner 20 is, for example, a hollow cylindrical member, and is made of a resin such as nylon. The pressure tank 22 is a high-pressure tank for storing a high-pressure fluid such as hydrogen.

[0016] The liner 20 is transported at a predetermined speed along the first direction D1 by a transport mechanism (not shown), with its longitudinal direction facing the first direction D1. Figure 1 shows the manufacturing apparatus 10 from a viewpoint perpendicular to the first direction D1. The transport mechanism for transporting the liner 20 may be considered as part of the manufacturing apparatus 10. The configuration of the transport mechanism is not particularly limited. The transport mechanism may be, for example, a mechanism that transports the liner 20 using a robot arm, or a mechanism that transports the liner 20 along a rail. In the figure, the central axis Ax of the liner 20, parallel to the first direction D1, is shown. Also, in the figure, the front and back of the first direction D1 are shown.

[0017] As shown in Figure 1, multiple liners 20 are connected in series and transported continuously along the first direction D1. The multiple liners 20 are connected in series via pipes 24 with a diameter smaller than the diameter of the liners 20, with their internal spaces communicating. However, the liners 20 may also be transported individually along the first direction D1.

[0018] The manufacturing apparatus 10 includes a winding machine 30 and an impregnation mechanism 40. The winding machine 30 is a machine for winding a wire to which a predetermined tension is applied in a mesh pattern on the surface of an object to be wound, and includes a bobbin or the like on which the wire is wound. The winding machine 30 is also called a braiding machine or a braider. Here, the wire is fiber bundles 32. Each fiber bundle 32 is formed as a single strand by gathering a plurality of fibers (for example, carbon fibers). Although only two fiber bundles 32 are shown in a simplified manner in FIG. 1, the winding machine 30 is formed in an annular shape so as to surround the liner 20 around the central axis Ax, and supplies a plurality of fiber bundles 32, which is more than two, to the liner 20 from the periphery of the liner 20. The fiber bundles 32 moving toward the liner 20 are wound around the liner 20 while rotating around the central axis Ax in accordance with the movement of the winding machine 30 and being braided with each other as they approach the liner 20. A general description of the winding machine 30 is omitted below.

[0019] The impregnation mechanism 40 impregnates the fiber bundles 32 with resin R before the fiber bundles 32 are wound around the liner 20. The resin R is, for example, a thermosetting resin such as epoxy resin. The impregnation mechanism 40 is formed in an annular shape so as to surround the liner 20 around the central axis Ax. The impregnation mechanism 40 can also be regarded as a cylindrical body. The impregnation mechanism 40 is located upstream of the winding machine 30. The liner 20 passes through the inside of the winding machine 30 and the inside of the impregnation mechanism 40 respectively in the process of being conveyed from the rear to the front along the first direction D1.

[0020] FIG. 2 schematically shows a cross-section of the impregnation mechanism 40. In FIG. 2, the impregnation mechanism 40 is shown in an enlarged manner compared to FIG. 1. A resin supply path 44 is formed inside a main body 42 of the impregnation mechanism 40. The front surface of the main body 42 includes a first surface 46. The first surface 46 is an inclined surface along the moving direction of the fiber bundles 32 moving from the winding machine 30 toward the liner 20. At least a part of the first surface 46 may be a curved surface.

[0021] The resin supply path 44 reaches the first surface 46. The opening of the resin supply path 44 on the first surface 46 is the resin supply port 48. Resin R is supplied to the resin supply path 44 by pressure from a pump (not shown). The resin R that has traveled through the resin supply path 44 is supplied onto the first surface 46 from the resin supply port 48. Accordingly, the first surface 46 having the resin supply port 48 acts to supply the resin R to the fiber bundle 32 before the fiber bundle 32 is wound around the liner 20. When the first surface 46 is viewed from the front, the resin supply port 48 may be formed, for example, in an annular shape around the central axis Ax, either continuously or intermittently.

[0022] The impregnation mechanism 40 includes a second surface 52 opposite to the first surface 46. As shown in Figure 2, the impregnation mechanism 40 includes a cover 50 that covers the first surface 46 from the front. The cover 50 covers all or part of the first surface 46 from the front. Similarly to the main body 42 of the impregnation mechanism 40, the cover 50 is also formed in an annular shape centered on the central axis Ax. In other words, the surface of the cover 50 that faces the first surface 46 is the second surface 52. The resin R supplied from the resin supply port 48 onto the first surface 46 fills a region (gap) sandwiched between the first surface 46 and the second surface 52.

[0023] The fiber bundle 32 moving from the winding machine 30 toward the liner 20 passes between the first surface 46 and the second surface 52. Stated differently, the first surface 46 and the second surface 52 sandwich the fiber bundle 32 before the fiber bundle 32 is wound around the liner 20 between each other. According to such a configuration, the fiber bundle 32 moving from the winding machine 30 toward the liner 20 is impregnated with the resin R when passing between the first surface 46 and the second surface 52. Even though it is described that the first surface 46 and the second surface 52 sandwich the fiber bundle 32, the gap between the first surface 46 and the second surface 52 is naturally set to a width that does not hinder the movement of the fiber bundle 32. Accordingly, the first surface 46 and the second surface 52 indirectly sandwich the fiber bundle 32 via the resin R that fills the gap between the first surface 46 and the second surface 52.

[0024] In this way, the impregnation mechanism 40 performs an "impregnation process" in which the fiber bundle 32 is impregnated with resin. The impregnation process includes passing the fiber bundle 32 between the first surface 46 and the second surface 52, so that the fiber bundle 32 is sandwiched between the first surface 46 and the second surface 52. Each of the multiple fiber bundles 32 that have been impregnated with resin R is then wound around the surface of the liner 20. In other words, the manufacturing apparatus 10 equipped with the winding machine 30 ultimately performs a "winding process" in which the resin-impregnated fiber bundles 32 are wound around the surface of the liner 20.

[0025] During the winding process, a fiber layer 26 is formed on the surface of the liner 20. If the fiber bundle 32 is a bundle of carbon fibers, the fiber layer 26 becomes a carbon fiber reinforced plastic (CFRP) layer made of carbon fibers and resin R. In Figure 1, the liner 20 after the fiber layer 26 has been formed, i.e., the pressure tank 22, is shown in gray for clarity, in front of the position where the fiber bundle 32 is wound. Also in Figure 1, the liner 20 before the fiber layer 26 has been formed is shown behind the position where the fiber bundle 32 is wound. The pressure tank 22 with the formed fiber layer 26 is then transported, for example, to a curing furnace (not shown), where it is cured at a predetermined curing temperature to become a finished product.

[0026] Figure 4 is an image showing a cross-section of a conventional pressure tank 1, illustrating the cross-sections of the liner 2 and the fiber layer 3. The fiber layer 3 is formed on the outside of the liner 2. As described above, if the resin impregnation into the fiber bundle is insufficient, numerous voids 4 will occur within the fiber layer 3 formed by winding the fiber bundle around the liner. Such voids 4 will cause a decrease in the strength of the hardened fiber layer 3, and consequently, a decrease in the strength of the pressure tank 1.

[0027] To address these challenges, this embodiment sandwiches the fiber bundle 32 between the first surface 46 and the second surface 52 while the resin R is being supplied to the fiber bundle 32, before it is wrapped around the liner 20. As a result, the resin R, which is compressed while sandwiched between the first surface 46 and the second surface 52, penetrates from the surface of the fiber bundle 32 into the interior of the fiber bundle 32, and the resin R sufficiently impregnates the spaces between the fibers inside the fiber bundle 32. Consequently, the generation of voids in the fiber layer 26 is suppressed, and the strength of the pressure tank 22 is improved.

[0028] The manufacturing apparatus 10 may further include a vibration mechanism 60 that applies vibration to the resin R in the region sandwiched between the first surface 46 and the second surface 52. For example, the lid 50 is vibratable and substantially serves as the vibration mechanism 60. The lid 50 as the vibration mechanism 60 may, for example, have an ultrasonic transducer built in and apply ultrasonic vibration to the resin R and fiber bundle 32. Alternatively, the lid 50 as the vibration mechanism 60 may perform a dynamic vibration operation that repeats movements approaching the first surface 46 and movements away from the first surface 46 at a predetermined period, rather than fine vibrations such as ultrasonic vibration. In this way, by applying vibration to the resin R and fiber bundle 32 in the region sandwiched between the first surface 46 and the second surface 52, the impregnation of the resin R into the interior of the fiber bundle 32 is further promoted.

[0029] Figure 3 shows a simplified cross-section of an impregnation mechanism 40, which is a different example from Figure 2. In Figure 3, the cross-section of the impregnation mechanism 40 is shown in a larger size than in Figure 2. However, in Figure 3, all hatching indicating the cross-section has been omitted for the sake of clarity. According to Figure 3, a plurality of resin supply ports 58 are formed on the first surface 46. The impregnation mechanism 40 may also be configured to supply resin R to the fiber bundle 32 from the plurality of resin supply ports 58. Each of the plurality of resin supply ports 58 has a smaller opening size in the direction in which the first surface 46 tilts toward the liner 20 compared to the resin supply port 48 shown in Figure 2. Also, according to Figure 3, the plurality of resin supply ports 58 are arranged at least along the direction in which the first surface 46 tilts toward the liner 20, that is, the direction in which the fiber bundle 32 moves toward the liner 20.

[0030] According to Figure 3, inside the main body 42, the resin supply passage 44 has an expanding supply passage 54 that widens along the first surface 46 before reaching the first surface 46. Multiple nozzles 56 extend from the expanding supply passage 54 toward the first surface 46, and each opening on the first surface 46 of the multiple nozzles 56 serves as one of the multiple resin supply ports 58. The resin R, which has expanded from the resin supply passage 44 toward the expanding supply passage 54 under pressure from a pump (not shown), is supplied to the fiber bundle 32 from the resin supply ports 58 of the multiple nozzles 56.

[0031] Since the nozzle 56 has finer pores compared to the resin supply passage 44 and the expanded supply passage 54, the resin R that passes through the nozzle 56 is discharged at high speed from the resin supply port 58 and heads toward the fiber bundle 32. As a result, the resin R penetrates into the interior of the fiber bundle 32 while loosening it at multiple locations. Therefore, uniform and deep impregnation of the interior of the fiber bundle 32 by the resin R is further promoted. In the configuration shown in Figure 3, the lid 50 can also be given the function of a vibration mechanism 60.

[0032] 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]

[0033] 10: Manufacturing equipment, 20: Liner, 22: Pressure tank, 26: Fiber layer, 30: Winding machine, 32: Fiber bundle, 40: Impregnation mechanism, 42: Main body, 44: Resin supply path, 46: First surface, 48: Resin supply port, 50: Lid, 52: Second surface, 54: Enlarged supply path, 56: Nozzle, 58: Resin supply port, 60: Vibration mechanism

Claims

1. A manufacturing apparatus for producing a pressure tank by wrapping a fiber bundle around the surface of a hollow liner, The system includes an impregnation mechanism that impregnates the fiber bundle with resin before the fiber bundle is wrapped around the liner. The impregnation mechanism is, A first surface that supplies the resin to the fiber bundle before it is wrapped around the liner, A manufacturing apparatus comprising: a first surface and a second surface facing the first surface, which sandwiches the fiber bundle between itself and the first surface before it is wrapped around the liner.

2. The manufacturing apparatus according to claim 1, further comprising a vibration mechanism that applies vibration to the resin in the region sandwiched between the first surface and the second surface.

3. Multiple resin supply ports are formed on the first surface. The manufacturing apparatus according to claim 1, wherein the impregnation mechanism supplies the resin to the fiber bundle from the plurality of resin supply ports.

4. The manufacturing apparatus according to claim 3, wherein the plurality of resin supply ports are formed in a line along the direction in which the fiber bundle moves toward the liner.

5. A manufacturing method for producing a pressure tank by wrapping a fiber bundle around the surface of a hollow liner, An impregnation step in which the fiber bundle is impregnated with resin, The process includes a winding step of winding the fiber bundle impregnated with the resin around the surface of the liner, A manufacturing method comprising the impregnation step of passing the fiber bundle between a first surface that supplies the resin to the fiber bundle and a second surface that faces the first surface, thereby sandwiching the fiber bundle between the first surface and the second surface.

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