JP2010236587A - Fiber-reinforced plastic pressure vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure vessel having an FRP laminated structure to have excellent rapture resistance and light in weight. <P>SOLUTION: The FRP pressure vessel is a pressure vessel having an FRP laminated structure formed by winding glass fibers or carbon fibers impregnated with resin on a liner where the outer surface-side layer of the FRP laminated structure is a high angle helical winding layer wound at an orientation angle of 45 degrees to 60 degrees relative to the axial direction of a liner body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a laminated structure of an FRP pressure vessel.

  Pressure vessels formed by wrapping fiber reinforced plastic (hereinafter referred to as FRP) around metal or plastic liners are lightweight and strong, so they can be used as various high pressure vessels, especially natural gas tanks mounted on automobiles. It is illustrated.

  This pressure vessel generally has a cylindrical tank shape having a cylindrical body and mirrors at both ends thereof, and an opening through which gas enters and exits is provided at one or both of the central parts of the mirror. .

  The liner forms the inner surface of the pressure vessel, and an aluminum alloy is usually used from the viewpoint of weight reduction. In this case, the FRP laminated structure includes a hoop winding (an orientation angle of about 90 ° with respect to the axial direction of the liner barrel) and a helical winding (FRP wound around the entire liner). An orientation angle of about 10 to 20 ° with respect to the axial direction of the liner body is known. In many cases, these winding patterns are combined.

  That is, the cylindrical pressure vessel is designed so that the strength in the axial direction is greater than the strength in the circumferential direction in consideration of safety at the time of destruction. When this is expressed in terms of strain ratio, the ratio of axial strain to circumferential strain εΑ / εΗ becomes 0.9 to 1.0. The helical wound layer bears the axial strength, and the hoop wound layer bears the circumferential strength. Therefore, in this case, the outermost layer is generally a hoop winding layer for the purpose of preventing the helical winding layer from collapsing.

  In Patent Document 1, the conventional helical winding layer has a structure that covers the entire mirror part up to the base part, whereas the liner body part has an orientation angle of 40 to 75 ° with respect to the axial direction of the body part. The helical winding layer has a structure that does not cover the entire mirror part and is lightened. The outermost layer is hoop-wound.

  Patent Document 2 discloses a winding of a reinforcing fiber yarn in which an inner surface side is arranged at an angle of 5 to 50 ° and an outer surface side is arranged at an angle of 75 ° to 105 ° with respect to an axial direction of an inner shell made of a light alloy such as a thin aluminum alloy. By forming a layer and using a thermoplastic fiber such as a carbon fiber yarn as a reinforcing fiber yarn and an epoxy resin as a resin, the weight is reduced and the pressure resistance against repeated impacts is improved. Also in this case, the outer side hoop winding layer protects the inner side helical winding layer.

Japanese Patent Laid-Open No. 10-220691 JP-A-9-257193

  Applicable laws and regulations for FRP containers for general high-pressure gas using carbon fiber include “Technical Standards for Aluminum Alloy Liners / Carbon Fiber General Composite Containers” (common name) that meet the technical requirements stipulated in the Container Safety Regulations of the High Pressure Gas Safety Law. KHKS0121 (2005)) applies. In this standard, a drop test is defined as a test for confirming the impact resistance of a high-pressure vessel.

  The test involves a vertical drop test in which a high-pressure vessel is dropped from a height of 3m or more onto the floor surface with the vessel vertical, and then a horizontal drop test in which the vessel is dropped on the floor surface in a horizontal state. Then, the container is dropped in a steel angle on the floor (one side is 38 mm or more and 40 mm or less, and the thickness is 4.8 mm or more and 5 mm or less) while the container is horizontal.

  Then, the pressure cycle test is repeated 1000 times or more between the atmospheric pressure and the upper limit pressure equal to or higher than the maximum filling pressure in the container after the test. A burst test is performed after the pressure cycle test. The bursting performance requires that the bursting pressure is 90% or more of the designed bursting pressure, and the starting point of the bursting is the body of the container.

  In order to satisfy the above-described drop performance, it is necessary to greatly increase the number of FRP layers from the conventional design value, which increases the container weight of the pressure vessel, and there is a problem in economy.

  Accordingly, the present invention provides a high-pressure vessel having an FRP laminated structure that satisfies the drop test defined by the above-mentioned technical standards without increasing the thickness and weight of the high-pressure vessel in order to solve such problems. The purpose is to do.

  The inventors have intensively studied the above-described problems and completed the invention, and the gist thereof is as follows.

  A first invention is a pressure vessel having an FRP laminated structure formed by winding glass fibers or carbon fibers impregnated with a resin around a liner, and as a layer on the outer surface side of the FRP laminated structure, a shaft of a liner body part The FRP pressure vessel is a high-angle helically wound layer having an orientation angle of 45 to 60 ° with respect to the direction.

  In the second invention, each layer forming the FRP laminated structure is composed of the same fiber, and the high-angle helically wound layer is a layer in which the glass fiber or the carbon fiber is wound at least one turn or more. The FRP pressure vessel according to the first aspect of the invention.

  By obtaining the FRP pressure vessel of the present invention, the strength and impact resistance can be greatly improved without increasing the thickness of the FRP fiber layer, and the size and weight can be reduced, and the drop test can be satisfied. .

It is the image figure which dropped the FRP pressure vessel of this invention on the steel angle. It is a figure which shows the cross-section laminated structure of the FRP pressure vessel of this invention. It is the image figure which dropped the conventional FRP pressure vessel on the steel angle. It is a figure which shows the cross-section laminated structure of the conventional FRP pressure vessel. It is a FRP pressure vessel which shows one embodiment of the present invention. It is a side view which shows the conventional FRP pressure vessel. It is a figure which shows the change of the burst pressure by an orientation angle.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 6 is a side view showing a conventional FRP pressure vessel. The liner 3 is made of an aluminum alloy, 5 is a barrel portion, 6 is a mirror portion, and 4 is a base portion for taking out high-pressure gas. A helical winding layer 2 is laminated on the outer surface side of the liner 3 and a hoop winding layer 1 is laminated on the outermost layer. The helically wound layer has a structure that covers the entire mirror part up to the base part, and the orientation angle is determined by the outer diameter ratio of the base / body part, but is generally 10 to 20 °. The outermost hoop winding layer 1 is wound on the liner body 5 with an orientation angle of about 90 ° with respect to the axial direction of the body.

  FIG. 5 shows one embodiment of the present invention, and the outermost layer shows a high-angle helical winding layer 2 having an orientation angle of 45 to 60 ° with respect to the axial direction of the liner body. .

  FIG. 3 shows an example of performing a drop test on a steel angle with a pressure vessel having an FRP laminated structure of a conventional FRP pressure vessel being horizontal. 4 is a cross-sectional view of the FRP laminated structure of the FRP pressure vessel used in FIG. 3, from the inner layer side to the hoop winding layer (90 °) 1.2 mm thickness, the intermediate layer is the helical winding layer (12 °) 0.9 mm, The outer layer has a hoop winding layer (90 °) of 1.1 mm, and the lamination thickness is 3.2 mm.

  Since the corner portion of the steel angle is an acute angle, it is deep in the hoop winding layer, and its damage range 12 extends to the helical winding layer as an intermediate layer (FIGS. 3 and 4). Therefore, the layer that bears the strength after dropping becomes the two layers 13 of the hoop winding layer on the inner surface side and the intermediate helical winding layer. Therefore, in the case of adopting this laminated structure, it is necessary to further increase the thickness of the outermost hoop winding layer in order to reduce damage caused by dropping.

  FIG. 1 is an example showing an embodiment in which a pressure vessel having an FRP laminated structure according to the present invention is leveled and a drop test is performed on a steel angle. The example of the present invention is an example in which a high-angle helical winding (orientation angle of 45 to 60 °), which is intermediate between a hoop winding and a helical winding having an orientation angle of 12 °, is wound in a cloth on the outermost layer. The orientation angle is determined with respect to the container axis direction. FIG. 2 shows an embodiment of a cross section of a laminated structure of FRP. From the inner layer side, the hoop winding layer (90 °) is 0.8 mm thick, the intermediate layer is a helical winding layer (12 °) 1.2 mm and the hoop winding layer (90 °) 0.8 mm, and the outermost layer is a high angle helical winding layer (55 °) 0.4 mm, the lamination thickness is 3.2 mm, which is the same thickness as the conventional example.

  As shown in FIG. 2, the damage range 12 of the drop test is stopped at the outermost high-angle helical winding layer, and the layer responsible for strength after dropping is the hoop winding layer (90 °) on the inner surface side and the intermediate helical winding. It becomes three layers 13 of a layer (12 °) and a hoop winding layer (90 °). According to the example of the present invention, it is possible to reduce the drop impact without increasing the stacking thickness.

  Next, FIG. 7 shows the result of investigating the change in burst pressure after the drop test when the orientation angle of the helical wound layer is changed. In the test, a drop test and a burst test were performed on a container having the same laminated structure up to the outermost layer and changing the winding angle of only the outermost layer. In the drop test and the burst test, a burst test was performed after performing a drop test in accordance with “Technical Standard for Aluminum Composite Liner / Carbon Fiber General Composite Container” (commonly called KHKS0121 (2005)).

  The horizontal axis represents the winding angle of the outermost helical winding layer, and the vertical axis represents the change in burst pressure after the drop test as a ratio to the burst pressure of the non-drop test material. According to the “Technical Standards for Aluminum Composite Liner / Carbon Fiber General Composite Containers” (commonly known as KHKS0121 (2005)), “the container has a carbon fiber stress at the maximum filling pressure of 3% of the carbon fiber stress at the minimum burst pressure. In the specimen used in this test, the angle range satisfying the regulation is 44 degrees or more.

  Therefore, when the orientation angle is less than 45 degrees, the stress standard in the design is not satisfied. Moreover, if it exceeds 60 degree | times, the burst pressure after a drop test will fall to 70% or less. Therefore, it can be seen from the stress analysis and the drop test / burst test results that the preferred angle of the helical wound layer is 45-60 °. If the orientation angle is in the range of 40 to 60 °, the burst performance after dropping can ensure up to 70% of the normal burst pressure.

  The outermost high-angle helically wound layer is preferably a layer wound with one or more layers of glass fibers or carbon fibers. This is because the impact resistance can be increased. Preferably, one or more layers are wound. The high-angle helical is the strongest winding method against the impact of the angle sticking in the direction perpendicular to the fiber.

  In addition, the layer of the FRP laminated structure in this invention means the lamination | stacking wound around the liner at the same angle using the same fiber. In addition, the laminated thickness mentioned above described one Example, and is not restricted to this. It is determined appropriately depending on the application, part, and required quality.

  Specific examples will be described below.

  The pressure vessel liner is made of an aluminum alloy and has an outer diameter of 103 mm, a barrel thickness of 1.5 mm, a length of 420 mm, a base portion outer diameter of 31 mm, and a capacity of 2.8 L. Hoop winding layer (90 °) 0.8 mm, helical winding layer (12 °) 1.2 mm, hoop winding layer (90 °) 0.8 mm, high angle helical winding layer (55 °) 0.4 mm as the outermost layer, all A pressure vessel having a laminated structure with a thickness of 3.2 mm and, as a comparative example, a hoop winding layer (90 °) 1.2 mm, a helical winding layer (12 °) 0.9 mm, a hoop winding layer (90 °) from the inner surface side After creating a pressure vessel with a laminated structure with a thickness of 1.1 mm and a total thickness of 3.2 mm, and performing a drop test according to “Technical Standards for Aluminum Composite Liner / Carbon Fiber General Composite Container” (commonly known as KHKS0121 (2005)) ,rupture A test was conducted. The results are shown in Table 1.

  It was 50-70 Mpa in the comparative example with respect to design strength 62 Mpa. On the other hand, in the present invention example, a strength of 80 MPa or more was obtained.

  Compared with the comparative example, the example of the present invention can greatly improve the drop impact performance, and a lighter container can be manufactured. The FRP stacking amount was 2.8 L container, which was 1700 g in the comparative example, but the same performance could be obtained at 1600 g in the present invention example.

The present invention can be used in various industrial fields as a general high-pressure gas container.
Examples include a fuel cell hydrogen container, a home medical oxygen container, a digestion carbon dioxide container, and the like.

DESCRIPTION OF SYMBOLS 1 Hoop winding 2 Helical winding 3 Liner 4 Base part 5 Trunk part 6 Mirror part 11 Angle 12 Damage range 13 Load bearing part after drop test

Claims (2)

  A pressure vessel having an FRP laminated structure formed by winding glass fibers or carbon fibers impregnated with a resin around a liner, and serving as an outer surface side layer of the FRP laminated structure with respect to the axial direction of the liner body 45 An FRP pressure vessel characterized by being a high-angle helically wound layer having an orientation angle of ˜60 °.   Each layer forming the FRP laminated structure is composed of the same fiber, and the high-angle helically wound layer is a layer in which the glass fiber or carbon fiber is wound at least one turn or more. Item 2. The FRP pressure vessel according to Item 1.

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