JP2005113963A - Pressure vessel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure vessel manufacturing method capable of obtaining a high-strength and light pressure vessel while suppressing the manufacturing cost.
SOLUTION: A method of manufacturing a pressure vessel by forming an outer shell made of a fiber reinforced composite material on the outer periphery of a liner 10 and using a braider, a first carbon fiber bundle 20 is connected to a cylindrical portion 11 of the liner 10. Forming the composition 40 on the outer periphery of the liner 10 while orienting the second carbon fiber bundle 30 in the substantially circumferential direction of the liner 10, while orienting at a predetermined angle with respect to the axial direction of A resin impregnation curing step of forming an outer shell by impregnating the resin into the composition 40 and curing the resin.
[Selection] Figure 3

Description

  The present invention relates to a pressure vessel manufacturing method.

  Currently, pressure-resistant containers for storing and transporting pressurized gas and low-temperature gas such as CNG (Compressed Natural Gas) and CHG (Compressed Hydrogen Gas) have been put into practical use. Conventionally, metal pressure vessels with high strength and excellent gas barrier properties have been the mainstream, but metal pressure vessels are heavy, so they should be applied to fuel tanks for automobiles and spacecraft that require weight reduction. It was difficult. For this reason, in recent years, a relatively lightweight FRP outer pressure-resistant container in which an FRP (Fiber Reinforced Plastics) layer is formed on the outer periphery of a hollow liner has been proposed.

  As a method for forming the FRP layer on the outer periphery of the hollow liner, there is a FW (Filament Winding) method. The FW method is a method in which a fiber bundle is impregnated with a resin in advance to prepare a tow-shaped prepreg, and the FRP layer is formed by winding the tow-shaped prepreg around a liner. When this FW method is employed, it is possible to obtain an FRP exterior pressure resistant container that is relatively light and has high strength. However, when the FW method is adopted, there is a problem that it takes a long time to wind a continuous prepreg in a tow shape or a tape shape around the liner.

In order to solve such problems, in recent years, a “blading method” has been proposed in which a plurality of fiber bundles are assembled using a braider to form an FRP layer on the outer periphery of the liner (for example, Patent Document 1). Or refer to Patent Document 2.) When the “blading method” is employed, the pressure vessel manufacturing time can be shortened as compared with the case where the FW method is employed.
Japanese Patent Laid-Open No. 11-58540 (page 3, FIG. 4) Japanese Patent Laid-Open No. 7-256771 (second page, FIG. 2)

  By the way, in the conventional “blading method”, in order to reduce resistance during braiding, a fiber bundle not impregnated with resin such as dry CF (Carbon Fiber) is often used. Since there is no stickiness like prepreg, the fiber bundle may loosen during braiding. Such loosening of the fiber bundle is a major factor in reducing the strength of the FRP layer. Moreover, when the amount of fiber bundles is increased in order to ensure the strength of the FRP layer, there is a problem that the weight of the pressure vessel increases and the manufacturing cost increases.

  The subject of this invention is providing the pressure vessel manufacturing method which can obtain a high intensity | strength and lightweight pressure vessel, suppressing manufacturing cost, and the pressure vessel obtained by this manufacturing method.

  In order to solve the above problems, the invention according to claim 1 is characterized in that an outer shell made of a fiber reinforced composite material is provided on the outer periphery of a liner having a cylindrical portion and a curved dome portion connected to both ends of the cylindrical portion. Forming a pressure vessel by forming a first fiber bundle with a predetermined angle with respect to the axial direction of the cylindrical portion, using a braider, while the second fiber bundle is A composition forming step of forming a composition on the outer periphery of the liner by assembling while orienting in a substantially circumferential direction of the liner, and a resin impregnation curing step of forming the outer shell by impregnating the resin with a resin and curing the composition. It is characterized by providing.

  According to the first aspect of the present invention, the first fiber bundle is oriented at a predetermined angle with respect to the axial direction of the cylindrical portion of the liner, while the second fiber bundle is oriented substantially in the circumferential direction of the liner. The outer shell of the fiber reinforced composite material is formed by assembling and forming a composition on the outer periphery of the liner, and impregnating the composition with a resin and curing.

  That is, in forming the composition, the orientation direction of both types of fiber bundles is not inclined at a predetermined angle with respect to the axial direction of the liner as in the conventional braiding method, but one of the two types of fiber bundles. Only one is inclined at a predetermined angle with respect to the axial direction of the liner, and the other is oriented in the circumferential direction of the liner. For this reason, even if different tension is applied to the two types of fiber bundles (the first fiber bundle and the second fiber bundle) constituting the composition, no inconvenience occurs.

  Accordingly, since the tension applied to the first fiber bundle can be set larger than the tension applied to the second fiber bundle, the loosening of the first fiber bundle during the formation of the composition (during braiding) is prevented. Can do. Further, since the second fiber bundle can be bent and entangled with the first fiber bundle, the first fiber bundles can be bundled and made difficult to separate. As a result, the strength of the outer shell made of fiber reinforced composite material can be increased, and consequently the strength of the pressure vessel can be increased.

  According to the first aspect of the present invention, the first fiber bundle is oriented at a predetermined angle with respect to the axial direction of the liner, and the second fiber bundle is oriented substantially in the circumferential direction of the liner. Even if these two types of fiber bundles have different diameters, no inconvenience occurs. Therefore, as described above, the diameter of the first fiber bundle can be set larger than the diameter of the second fiber bundle while preventing the looseness of the first fiber bundle, so that the strength of the outer shell is increased. Is possible.

  Further, as described above, since the strength of the outer shell can be increased by preventing the loosening of the fiber bundle, it is not necessary to increase the fiber bundle in order to ensure the strength of the outer shell. Therefore, the pressure vessel can be reduced in weight and the manufacturing cost can be suppressed.

  The invention according to claim 2 is that, in the pressure vessel manufacturing method according to claim 1, the tension applied to the first fiber bundle is set larger than the tension applied to the second fiber bundle. Features.

  The invention according to claim 3 is characterized in that, in the pressure vessel manufacturing method according to claim 1 or 2, the diameter of the first fiber bundle is set larger than the diameter of the second fiber bundle. .

  According to the present invention, one fiber bundle is oriented while being inclined at a predetermined angle with respect to the axial direction of the liner, while the other fiber bundle is assembled while being oriented substantially in the circumferential direction of the liner, and the composition is formed on the outer periphery of the liner. Since it forms, loosening of the fiber bundle inside a composition can be prevented. And a high-strength outer shell can be formed by impregnating this composition with a resin and curing it. As a result, a high-strength and lightweight pressure-resistant container can be obtained while suppressing manufacturing costs.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a method for manufacturing a CNG tank by forming an outer shell made of a fiber-reinforced composite material on the outer periphery of the liner 10 (see FIG. 1 and the like) will be described. The CNG tank manufactured by the manufacturing method according to the present embodiment is a pressure vessel that can be filled with CNG of about 200 atm.

  First, the liner 10 is prepared with a material excellent in gas barrier properties (liner preparation step). In the present embodiment, the liner 10 is prepared by a blow molding method using a liquid crystal resin having excellent gas barrier properties and excellent dimensional stability and chemical resistance. As shown in FIG. 1, the liner 10 has a cylindrical portion 11 and a dome portion 12 formed at both ends of the cylindrical portion 11, and a metal base 13 is formed at the top of the dome portion 12. Is attached.

  Next, the large diameter carbon fiber bundle 20 is prepared by bundling about 12,000 carbon fibers, and the small diameter carbon fiber bundle 30 is prepared by bundling about 1000 carbon fibers (fiber bundle preparation step). ). The large diameter carbon fiber bundle 20 is the first fiber bundle in the present invention, and the small diameter carbon fiber bundle 30 is the second fiber bundle in the present invention. The large-diameter carbon fiber bundle 20 is wound around the first bobbin 100 of the braider (see FIG. 4), and the small-diameter carbon fiber bundle 30 is wound around the second bobbin (not shown) of the braider. Used in.

  Next, the large-diameter carbon fiber bundles 20 are supplied from a plurality of first bobbins 100 (see FIG. 4) arranged along the circumferential direction of the cylindrical portion 11 of the liner 10, and end portions 21 of these large-diameter carbon fiber bundles 20. Is attached to the substantially central portion in the axial direction of the cylindrical portion 11 of the liner 10 as shown in FIG. Further, one small-diameter carbon fiber bundle 30 is supplied from the second bobbin, and the end 31 of this small-diameter carbon fiber bundle 30 is attached to the substantially central portion in the axial direction of the cylindrical portion 11 of the liner 10 as shown in FIG. (Fiber bundle attaching process).

  In the fiber bundle attaching step, the end portion of each carbon fiber bundle is impregnated with a thermoplastic resin that is heated and melted, and the impregnated portion is fused and attached to the cylindrical portion 11 of the liner 10. To.

  Next, as shown in FIG. 2, the liner 10 is gently rotated in the circumferential direction while being moved in the axial direction (arrow A direction). While continuously supplying the large-diameter carbon fiber bundle 20 from the first bobbin 100 and continuously supplying the small-diameter carbon fiber bundle 30 from the second bobbin, the cylindrical portion 11 and the dome portion 12 of the liner 10 are assembled. A composition 40 (see FIG. 3B) is formed on the outside (composition formation step).

  In this composition forming step, the large-diameter carbon fiber bundle 20 is inclined by a predetermined angle with respect to the axial direction of the cylindrical portion 11 of the liner 10 by rotating the liner 10 in the circumferential direction (FIG. 2). And FIG. 3 (b)). The value of the angle (orientation angle) formed by the large-diameter carbon fiber bundle 20 and the axial direction of the cylindrical portion 11 is set according to the ratio (diameter ratio) between the diameter of the cylindrical portion 11 and the diameter of the base 13. can do. For example, when the diameter ratio is 5: 1, the orientation angle is set to about 20 °. Further, the small-diameter carbon fiber bundle 30 is oriented in the circumferential direction of the liner 10 (see FIGS. 2 and 3B).

  Further, in the composition forming step, a predetermined tension is applied to the large-diameter carbon fiber bundle 20 and the small-diameter carbon fiber bundle 30 by using tension adjusting means (not shown) provided in the first bobbin 100 and the second bobbin. Add In the present embodiment, loosening of the large diameter carbon fiber bundle 20 is prevented by setting the tension applied to the large diameter carbon fiber bundle 20 relatively large.

  In the composition forming step, the movement of the liner 10 is stopped when the composition 40 reaches the base of the base 13 of the liner 10 as shown in FIG. Then, as shown in FIG. 4B, the first bobbin 100 is rotated by φ ° in the circumferential direction of the liner 10. Thereafter, the liner 10 is moved in the reverse direction (arrow B direction: see FIG. 2), and the formation of the composition 40 is continued.

  The value of φ is set in the range of about 135 ° to about 180 °. As described above, the first bobbin 100 is rotated by φ ° in the circumferential direction of the liner 10 before reversing the moving direction of the liner 10 from the arrow A direction to the arrow B direction, so that the large-diameter carbon fiber bundle 20 is reversed. It can be prevented from being oriented in a state bent in the direction. That is, as shown in FIG. 4B, the large-diameter carbon fiber bundle 20 can be oriented so as to be wound around the dome portion 12 of the liner 10.

  The composition 40 having a predetermined thickness is formed outside the cylindrical portion 11 and the dome portion 12 of the liner 10 by the composition forming process as described above. Then, when the formation of the composition 40 is finished, the small-diameter carbon fiber bundle 30 is cut.

  Next, as shown in FIG. 5, by moving the liner 10 in the axial direction (arrow B direction) while rotating the liner 10 in the circumferential direction (arrow C direction), the large-diameter carbon fiber bundle 20 and the cylindrical portion 11 of the liner 10 and It winds around the dome part 12 and forms the winding layer 50 of predetermined thickness on the composition 40 (winding layer formation process). Then, the edge part of the large diameter carbon fiber bundle 20 is fixed with the method similar to a fiber bundle attachment process.

  Subsequently, the composition 40 and the wound layer 50 are impregnated with a thermoplastic resin melted by heating. Thereafter, the impregnated thermoplastic resin is cured by natural cooling to form an outer shell made of fiber-reinforced composite material (resin impregnation curing step). By going through the above process group, a CNG tank which is a pressure vessel is obtained.

  In the manufacturing method according to the embodiment described above, the large-diameter carbon fiber bundle 20 is oriented at a predetermined angle with respect to the axial direction of the cylindrical portion 11 of the liner 10, while the small-diameter carbon fiber bundle 30 is aligned with the liner 10. A composition 40 is formed outside the liner 10 while being oriented in a substantially circumferential direction, and the composition 40 is impregnated with a thermoplastic resin and cured to form an outer shell made of fiber-reinforced composite material.

  That is, only one of the two types of carbon fiber bundles is oriented while being inclined at a predetermined angle with respect to the axial direction of the liner 10, while the other is oriented substantially in the circumferential direction of the liner 10. There is no inconvenience even if different tensions are applied to different types of carbon fiber bundles.

  Accordingly, the tension applied to the large-diameter carbon fiber bundle 20 can be set larger than the tension applied to the small-diameter carbon fiber bundle 30, so that loosening of the large-diameter carbon fiber bundle 20 during formation of the composition (during braiding) is prevented. can do. As a result, the strength of the outer shell made of fiber reinforced composite material can be increased, and as a result, the strength of the CNG tank can be increased.

  Further, in the manufacturing method according to the embodiment described above, the diameter of one carbon fiber bundle oriented at a predetermined angle with respect to the axial direction of the liner 10 is set to the other carbon oriented in the substantially circumferential direction of the liner. Since the diameter is larger than the diameter of the fiber bundle, the strength of the outer shell can be increased. Moreover, since the strength of the outer shell can be increased by preventing the loosening of the carbon fiber bundle as described above, it is not necessary to increase the fiber bundle in order to ensure the strength of the outer shell. Therefore, the weight of the CNG tank can be reduced and the manufacturing cost can be suppressed.

  In the above embodiment, the example in which the liner 10 is prepared using the liquid crystal resin has been described. However, the material of the liner 10 is not limited to the liquid crystal resin. For example, the liner 10 can also be prepared using another synthetic resin having a gas barrier property such as high density polyethylene or a metal material such as an aluminum alloy. Moreover, although the example which shape | molded the liner 10 by the blow molding method was shown in the above embodiment, the liner 10 can also be shape | molded using an injection molding method etc.

  Moreover, in the manufacturing method which concerns on the above embodiment, the example which set ratio (diameter ratio) of the diameter of the large diameter carbon fiber bundle 20 and the diameter of the small diameter carbon fiber bundle 30 to about 12: 1 is shown. However, the diameter ratio can be changed as appropriate. For example, in order to further increase the strength of the outer shell of the CNG tank, the diameter of the large-diameter carbon fiber bundle 20 can be relatively increased, and the diameter ratio can be set to about 24: 1.

  Moreover, in the manufacturing method according to the above embodiment, the example in which the composition 40 and the wound layer 50 are impregnated with the “thermoplastic resin” and cured in the resin impregnation curing step is shown. "Thermosetting resin" can be employed instead of "."

  Moreover, in the manufacturing method according to the above-described embodiment, an example in which the first and second fiber bundles (the large-diameter carbon fiber bundle 20 and the small-diameter carbon fiber bundle 30) are prepared using “carbon fibers” is shown. However, it is also possible to prepare the first and second fiber bundles by adopting “glass fiber” or “aramid fiber”.

It is explanatory drawing for demonstrating the fiber bundle attachment process of the pressure vessel manufacturing method which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the composition formation process of the pressure-resistant container manufacturing method which concerns on embodiment of this invention. Same as above It is explanatory drawing for demonstrating the orientation state of the large diameter carbon fiber bundle at the time of reversing the moving direction of a liner in the composition formation process of the pressure vessel manufacturing method which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the winding layer formation process of the pressure-resistant container manufacturing method which concerns on embodiment of this invention.

Explanation of symbols

10 liner 11 cylindrical portion 12 dome portion 20 large-diameter carbon fiber bundle (first fiber bundle)
30 Small diameter carbon fiber bundle (second fiber bundle)
40 Composition

Claims (3)

A method of manufacturing a pressure vessel by forming an outer shell made of a fiber-reinforced composite material on the outer periphery of a liner having a cylindrical portion and a curved dome portion connected to both ends of the cylindrical portion,
Using a braider, the first fiber bundle is oriented at a predetermined angle with respect to the axial direction of the cylindrical portion, while the second fiber bundle is assembled while being oriented substantially in the circumferential direction of the liner. Forming a composition on the outer periphery; and
A resin impregnation curing step of forming the outer shell by impregnating and curing the resin in the composition;
A pressure-resistant container manufacturing method comprising:   The pressure vessel manufacturing method according to claim 1, wherein a tension applied to the first fiber bundle is set larger than a tension applied to the second fiber bundle.   The pressure vessel manufacturing method according to claim 1 or 2, wherein the diameter of the first fiber bundle is set larger than the diameter of the second fiber bundle.

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