Airfoil structure including high-pressure gas tank and production method for same

Abstract

At present, many aircraft carry fuel inside wing structures. Carrying fuel inside wing structures has made it possible for aircraft to have lightweight airframe structures. However, it is extremely difficult for present airfoil structures to carry liquid hydrogen or high-pressure hydrogen. The present invention addresses the problem of providing a novel airfoil structure that can carry the gaseous hydrogen that is the issue when the fuel of an aircraft is to be changed from kerosine (a liquid fuel) to hydrogen (a gaseous fuel). The solution to the abovementioned problem can be applied to all gaseous fuels.

Description

Wing-shaped structure containing a high-pressure gas tank and its manufacturing method

[0001] The present invention relates to a wing-shaped structure that houses a high-pressure gas tank therein and a method for manufacturing the same.

[0002] Currently, there is an urgent need to develop aircraft that run on hydrogen fuel, which does not emit CO2. However, because hydrogen is a gas, it is impossible to load it inside the wings of existing aircraft like aircraft fuel (kerosene). If it were possible to load hydrogen fuel inside the wings of an aircraft, it would be possible to manufacture aircraft that do not emit CO2. Although it is difficult to load liquid hydrogen inside the wings, it may be possible to apply the manufacturing technology for honeycomb structures described in the "Prior Art Documents" to manufacture aircraft wing structures using honeycomb structures that house high-pressure hydrogen gas tanks.

[0003] Patent No. 6160876 US10,364,942 B2 US10,864,684 B2 JP2023-111622

[0004] Currently, most aircraft fuel is carried inside the wings. The problem this invention aims to solve is a new wing structure that can carry high-pressure gaseous hydrogen, which is an issue when switching aircraft fuel from kerosene (liquid fuel) to hydrogen (gaseous fuel). The method for solving these problems can be applied to all gaseous fuels. Means for solving the problem

[0005] It is extremely difficult to load liquid or high-pressure hydrogen into the wing structure of current aircraft. The new wing structure manufacturing method proposed in this invention involves integrating a hexagonal honeycomb structure containing a high-pressure gas tank into a pseudo-wing material, and then modifying the pseudo-wing material into a wing shape using computer simulation.

[0006] In other words, the method for manufacturing a wing-shaped structure according to the present invention is characterized in that the outer periphery of a metal gas tank into which gas can be injected is covered with a thermally foamable resin having a foaming ratio of 1.5, a honeycomb core with a hexagonal outer surface containing a high-pressure gas tank reinforced by wrapping fiber-reinforced plastic (FRP prepreg) around the outer periphery of the low-foaming thermally foamable resin is arranged along the wing shape, trapezoidal or triangular cells are arranged to fill in the irregularities on the outer periphery of the honeycomb core to form a pseudo-wing-shaped material, the surface of the pseudo-wing-shaped material is covered with modified cells to form a pseudo-wing, and the outer surface is covered with an outer skin of fiber-reinforced plastic (FRP prepreg) that conforms to the wing surface, and these are then heated and hardened.

[0007] The wing structure according to the present invention is formed by covering an airfoil with an outer skin made of fiber-reinforced plastic (FRP prepreg), a honeycomb core containing a thin metal tank arranged along the airfoil, a pseudo-airfoil material formed by joining trapezoidal or triangular cells that fill in the irregularities on the outer surface of the honeycomb core, and correction cells that fill in the gap between the pseudo-airfoil material and the outer skin. In this case, the gas may be hydrogen gas, and the airfoil structure may be the wing of an airplane, with the hydrogen gas as a fuel supply source.

[0008] Furthermore, the wing-shaped structure according to the present invention is characterized in that it contains a high-pressure gas tank in which the outer periphery of a thin metal tank capable of injecting and holding gas is covered with a low-expansion thermally foamable resin, and a fiber-reinforced plastic (FRP prepreg) is wrapped around the outer periphery of the thermally foamable resin, and the low-expansion thermally foamable resin completely fills any mechanical gaps that occur during manufacturing in the high-pressure gas tank assembly, thereby controlling the stress generated in the thin metal tank to a low level, thereby preventing fatigue failure due to hydrogen embrittlement that occurs in the thin metal tank.

[0009] Furthermore, the gas may be hydrogen gas and oxygen gas, and the wing structure containing the hydrogen gas tank and the oxygen gas tank may be the wing of an airplane, capable of flying at ultra-high altitudes where oxygen density is low by generating electricity using a hydrogen fuel cell that uses the hydrogen gas and oxygen gas as a fuel supply source.

[0010] Alternatively, the gas may be hydrogen gas and oxygen gas, and the wing structure containing the hydrogen gas tank and the oxygen gas tank may be the wing of an airplane, and the method may be a manufacturing method for a wing structure of an airplane that can fly at ultra-high altitudes where oxygen density is low by generating electricity using a hydrogen fuel cell that uses the hydrogen gas and oxygen gas as a fuel source.

[0011] Furthermore, the wing structure may be used for a radio base station for mobile phones and the like that flies at very high altitudes and is equipped with a hydrogen fuel cell, as an application for an aircraft having a wing that contains a high-pressure hydrogen gas tank inside.

[0012] FIG. 1 is a conceptual diagram of a wing structure containing a high-pressure gas tank before heat curing. FIG. 2 is a conceptual diagram of a hexagonal honeycomb cell. FIG. 3 is a conceptual diagram of the expansion force generated inside a hexagonal cell gas tank during heat curing. FIG. 4 is a conceptual diagram of a trapezoidal cell. FIG. 5 is a conceptual diagram of a triangular cell. FIG. 6 is a conceptual diagram of a honeycomb structure pseudo-wing material. FIG. 7 is a conceptual diagram of an wing-shaped modified cell A. FIG. 8 is a conceptual diagram of an wing-shaped modified cell B. FIG. 9 is a conceptual diagram of an wing-shaped modified cell C. FIG. 10 is a conceptual diagram of an wing-shaped outer formwork. FIG. 11 is a conceptual diagram of a cross section of a completed wing containing a high-pressure gas tank inside. FIG. 12 is a conceptual diagram of an aircraft wing structure for flying at very high altitudes.

[0013] The present invention will be described below in conjunction with the drawings. Hereinafter, a wing-shaped structure incorporating a high-pressure gas tank therein and a method for manufacturing the same according to the present invention will be described with reference to the drawings.

[0014] Figure 1 shows a conceptual diagram of an airfoil structure 1 containing a high-pressure gas tank before it is heat-cured. The airfoil structure 1 before it is heat-cured is composed of hexagonal honeycomb cells 2, trapezoidal cells 3, triangular cells 4, airfoil correction cells A5, B6, C7, and D8, and an unheat-cured wing skin 9. The unheat-cured wing skin 9 is made of special reinforced fiber prepreg such as carbon fiber, and is attached to the surface of the airfoil structure 1 in 4 to 8 circumferential divisions.

[0015] FIG. 2 shows a conceptual diagram of a hexagonal honeycomb cell 2. The hexagonal honeycomb cell 2 is composed of a high-pressure gas tank 10, a hexagonal thermally foamable resin 11, and a special reinforced fiber prepreg skin 12 made of carbon fiber or other pre-heat-cured material. The high-pressure gas tank 10 is enclosed within the hexagonal honeycomb cell, and the structure and manufacturing method of the high-pressure gas tank are described in detail in prior art documents. The hexagonal thermally foamable resin 11 is manufactured hollow so that it can accommodate the high-pressure gas tank 10. As described in detail in prior art documents, the structure and manufacturing method of the hexagonal honeycomb cell 2 are as follows: the high-pressure gas tank 10, which is a thin metal tank with a circular cross section, is surrounded by the thermally foamable resin 11 with a hexagonal outer surface, and the outer surface is covered with an uncured soft reinforced fiber prepreg skin 12, and a hexagonal structure is constructed by applying pressure and heat.

[0016] The hexagonal thermally foamable resin 11 is manufactured to be hollow so that it can contain the high-pressure gas tank 10, and its configuration and manufacturing method, as described in detail in prior art documents, involve attaching a low-magnification thermally foamable resin to the outer peripheral surface of a metal internal tube, wrapping uncured carbon fiber prepreg around the outer periphery of the low-magnification thermally foamable resin to reinforce the internal gas tank, attaching a high-magnification hexagonal thermally foamable resin having an outer hexagonal surface and an inner peripheral circle that contains the internal gas tank, attaching uncured carbon fiber prepreg to the hexagonal high-magnification thermally foamable resin, and heating to a temperature at which the carbon fiber prepreg will thermally harden.

[0017] The special reinforced fiber prepreg skin 12 is a special reinforced fiber prepreg containing an uncured adhesive, manufactured by attaching multiple sheets to the surface of the hexagonal thermally foamable resin 11. The special reinforced fiber prepreg skin 12 is preferably divided into three to six sections in the circumferential direction. This is because, when the hexagonal thermally foamable resin 11 inside the hexagonal honeycomb cells 2 arranged in the honeycomb structure thermally expands, the circumferentially divided special reinforced fiber prepreg skins 12 shift in accordance with the thermal expansion. If the expansion and deformation of the hexagonal thermally foamable resin 11 is not hindered, the special reinforced fiber prepreg skins 12, such as the hexagonal honeycomb cells 2, trapezoidal cells 3, triangular cells, and wing-shaped modified cells arranged inside the wing structure 1, shift slightly and are pressurized to form a strong bond between them.

[0018] The axial stress generated in the high-pressure gas tank 10 is independent of the length of the gas tank. Therefore, the length of the high-pressure gas tank 10 can be made arbitrarily long. However, since there is a limit to the size of the manufacturing equipment used to manufacture the high-pressure gas tank 10, Figure 2 shows a diagram of two high-pressure gas tanks 10 connected together. The number of high-pressure gas tanks 10 connected together is arbitrary. In addition, there is no lengthwise restriction on the hexagonal thermally foamable resin 11 and the special reinforced fiber prepreg outer skin 12. Therefore, the length of the hexagonal honeycomb cells 2 can be made arbitrarily long.

[0019] If the strength of the wing allows, the amount of hydrogen fuel that can be carried in the high-pressure gas tank contained within the wing structure is (theoretically) infinite. In the case of liquid hydrogen, the weight of hydrogen fuel is about one-tenth of that of kerosene aviation fuel. An aircraft's takeoff performance and range are a battle against gravity. Lighter fuel means lighter aircraft weight, and the benefits are immeasurable. Incidentally, the density of liquid hydrogen and the density of high-pressure hydrogen gas at 800 atmospheres are almost the same.

[0020] 3 is a conceptual diagram of the expansion force generated inside the hexagonal honeycomb cells 2 during thermal curing. The concepts of the foaming expansion force generated in the hexagonal honeycomb cells 2 and the thermally foamable resin during thermal curing and the mechanical reaction force by the outer frame are explained using a metal thin plate tank 13, low-magnification thermally foamable resin 14, carbon fiber prepreg 15, hexagonal thermally foamable resin 16, hexagonal carbon fiber composite material 17, outer frame (upper) 18, outer frame (lower) 19, outer frame reinforcing member (A) 20, outer frame reinforcing member (B) 21, fastening bolts 22, fastening nuts 23, expansion pressure 24 due to air pressure, expansion pressure 25 due to the low-magnification thermally foamable resin 14, expansion pressure 26 due to the hexagonal thermally foamable resin 16, and mechanical reaction force 27 of the outer frame.

[0021] The expansion pressure 24 due to air pressure is the expansion force generated when the internal gas tank is filled with high-pressure air from the outside or when an appropriate amount of water is poured into the internal gas tank and the metal thin plate tank 13 is expanded by steam pressure. The expansion pressure 25 due to the low-magnification thermal foamable resin 14 is the expansion force generated in the low-magnification thermal foamable resin 14 heated to a high temperature when the carbon fiber prepreg 15 is thermally cured. The expansion pressure 26 due to the hexagonal thermal foamable resin 16 is the expansion force generated in the hexagonal thermal foamable resin 16 heated to a high temperature when the carbon fiber prepreg 15 is thermally cured. The mechanical reaction force 27 of the outer formwork is the sum of the expansion pressure 24 due to air pressure, the expansion pressure 25 due to the low-magnification thermal foamable resin 14, and the expansion pressure 26 due to the hexagonal thermal foamable resin 16. Therefore, the outer formwork (upper) 18, outer formwork (lower) 19, outer formwork reinforcing member (A) 20, outer formwork reinforcing member (B) 21, fastening bolts 22, and nuts 23 must be made of steel and their rigidity and structural strength must be sufficiently reinforced.

[0022] The requirements for high-pressure hydrogen gas tanks are as follows: (1) Structural strength (withstands a normal pressure of 70 MPa or more). (2) Hydrogen gas sealed at high pressure must not leak from the gas tank wall. (3) No fatigue failure due to hydrogen embrittlement must occur.

[0023] The expansion force shown in Figure 6 solves all of the problems required of a high-pressure hydrogen gas tank. The reasons are as follows: (1) Any mechanical gaps that exist between the thin metal tank 13 and the low-expansion thermally foamable resin 14 before thermal curing are completely filled by the expansion pressure 24 due to the air pressure of the thin metal tank 13, the expansion pressure 25 due to the low-expansion thermally foamable resin 14, and the low-expansion thermally foamable resin 14 that is heated to a high temperature, fluidizes, and expands.

[0024] (2) Mechanical gaps existing between the low-magnification thermally foamable resin 14 and the carbon fiber prepreg 15 reinforcing the thin metal tank before thermal curing are completely filled by the expansion pressure 24 due to air pressure, the expansion pressure 25 due to the low-magnification thermally foamable resin 14, and the low-magnification thermally foamable resin 14 that is heated to a high temperature, fluidizes, and expands. The low-magnification thermally foamable resin 14 completely fills the mechanical gaps existing between the thin metal tank 13 and the carbon fiber prepreg 15 reinforcing the thin metal tank 13, so the internal pressure of the high-pressure gas sealed in the thin metal tank 13 is directly transmitted to the carbon fiber prepreg 15 via the low-magnification thermally foamable resin 14. The compressive deformation of the low-magnification thermally foamable resin 14 can be controlled to be small. As a result, stress generated in the thin metal tank 13 can be controlled to be small. Therefore, fatigue failure due to hydrogen embrittlement occurring in the thin metal tank 13 of a high-pressure hydrogen gas tank can be prevented.

[0025] (3) Air bubbles that exist between the fibers of the uncured carbon fiber prepreg 15 that reinforces the thin metal plate tank and between the layers of the uncured carbon fiber prepreg 15 that reinforces the thin metal plate tank, which is wound in multiple layers, are compressed and removed by an expansion pressure 24 due to air pressure that pressurizes the uncured carbon fiber prepreg 15 from the inside, an expansion pressure 25 due to the low-magnification thermal foamable resin 14, and an expansion pressure 26 due to the hexagonal thermal foamable resin 16 that pressurizes the carbon fiber prepreg 15 that reinforces the thin metal plate tank from the outside before thermal curing.

[0026] (4) Mechanical gaps existing between the uncured carbon fiber prepreg 15 reinforcing the metal thin plate tank and the hexagonal thermo-foamable resin 16 are completely filled by the expansion pressure 26 of the hexagonal thermo-foamable resin 16 and the hexagonal thermo-foamable resin 16 that is heated to a high temperature, fluidizes, and expands.

[0027] (5) Any mechanical gaps that exist between the hexagonal thermally foamable resin 16 before heating and foaming and the uncured carbon fiber prepreg 17 attached to the outer periphery of the hexagonal thermally foamable resin 16 are completely filled by the expansion pressure 26 of the hexagonal thermally foamable resin 16 and the hexagonal thermally foamable resin 16 that is heated to a high temperature, fluidizes, and expands.

[0028] (6) Before being heat-cured, any mechanical gaps that exist between the uncured carbon fiber prepreg 17 and the steel outer forms 18, 19 are eliminated by the uncured carbon fiber prepreg 17 being pressed firmly against the steel outer forms (upper) 18 and (lower) 19 by the expansion pressure 26 of the hexagonal thermally foamable resin 16 and the mechanical reaction force 27 of the steel outer forms (upper) 18 and (lower) 19.

[0029] (7) Before being pressurized and heat-cured, the carbon fiber prepreg 17 contains many air bubbles between the fibers and between the multiple layers of the laminate. These air bubbles disappear when the uncured hexagonal carbon fiber prepreg 17 is pressed strongly against the steel outer mold (upper) 18 and outer mold (lower) 19 by the expansion pressure 26 of the hexagonal thermally foamable resin 16 and the mechanical reaction force 27 of the steel outer mold (upper) 18 and outer mold (lower) 19. To ensure the reaction force of the steel outer mold (upper) 18 and outer mold (lower) 19, it is preferable to increase the expansion ratio of the hexagonal thermally foamable resin 16.

[0030] The structural strength of the high-pressure gas tank 10 contained within the honeycomb-structured hexagonal cell gas tank 2 manufactured using the patented technology disclosed in these prior art documents has been evaluated and proven through a water pressure test with a pressure resistance of 100 MPa.

[0031] Figure 4 shows a conceptual diagram of a trapezoidal cell 3. The trapezoidal cell 3 used here is shaped like the previously described hexagonal honeycomb cell 2, split in half, and is shaped to fit into the recesses formed on the upper surfaces of the hexagonal honeycomb cells 2 arranged along the airfoil. The trapezoidal cell 3 is composed of a trapezoidal thermally foamable resin 29 and a trapezoidal outer skin 28 made of special reinforced fiber prepreg. The trapezoidal cell 3 is manufactured by attaching multiple uncured trapezoidal outer skins 28 made of special reinforced fiber prepreg to the surface of the trapezoidal thermally foamable resin 29. The thermally foamable resin is a thermoplastic plastic such as polypropylene (PP) mixed with a thermal foaming agent. The approximate shape is molded by plastic extrusion, and then dimensional precision is achieved by machining. Therefore, there is no limit to the length of the trapezoidal cell 3.

[0032] Figure 5 shows a conceptual diagram of a triangular cell 4. The triangular cell 4 used here has a shape in which two faces of the above-mentioned hexagonal honeycomb cell 2 are inclined, and is shaped to fit into recesses formed on the lower and partial upper faces of the hexagonal honeycomb cells 2 arranged along the airfoil shape. The triangular cell 4 is made of triangular thermally foamable resin 30 and a triangular skin 31 made of special reinforced fiber prepreg. The triangular cell 4 is manufactured by attaching multiple uncured triangular skins 31 made of special reinforced fiber prepreg around the surface of the triangular thermally foamable resin 30. There are no lengthwise manufacturing limitations on the triangular cell 4.

[0033] Figure 6 shows a conceptual diagram of a honeycomb structure pseudo airfoil material 32. The honeycomb structure pseudo airfoil material 32 is composed of hexagonal honeycomb cells 2, trapezoidal cells 3, and triangular cells 4. The honeycomb structure pseudo airfoil material 32 is a model used in computer simulations. There are no restrictions on the length direction of the hexagonal honeycomb cells 2, trapezoidal cells 3, and triangular cells 4. Therefore, there are no restrictions on the wing area, wing thickness, or wing length of the honeycomb structure pseudo airfoil material 32.

[0034] Even if the honeycomb structure pseudo-airfoil material 32 is made to resemble a cross-sectional airfoil shape in this way, it will not become an accurate airfoil shape, so the shape must be determined accurately through computer simulation and the material must conform to that shape. For this purpose, correction cells are attached to the surface of the honeycomb structure pseudo-airfoil material 32.

[0035] Figure 7 shows a conceptual diagram of the airfoil correcting cell (A) 5. The airfoil correcting cell (A) 5 is composed of a correcting cell (A) thermally foamable resin 33 and a correcting cell (A) outer skin 34 made of uncured special reinforced fiber prepreg. The shape of the correcting cell (A) thermally foamable resin 33 is determined by computer simulation, taking into account aerodynamic characteristics. There are no manufacturing limitations in the length direction of the correcting cell (A) outer skin 34 made of uncured special reinforced fiber prepreg and the correcting cell (A) thermally foamable resin 33. Therefore, there are no limitations in the length direction of the airfoil correcting cell (A) 5.

[0036] Figure 8 shows a conceptual diagram of the airfoil correcting cell (B) 6. The airfoil correcting cell (B) 6 is composed of a correcting cell (B) thermal foamable resin 35 and a correcting cell (B) outer skin 36 made of uncured special reinforced fiber prepreg. The shape of the correcting cell (B) thermal foamable resin 35 is determined by computer simulation, taking into account aerodynamic characteristics. There are no manufacturing limitations in the length direction of the correcting cell (B) outer skin 36 made of uncured special reinforced fiber prepreg and the correcting cell (B) thermal foamable resin 35. Therefore, there are no limitations in the length direction of the airfoil correcting cell (B) 6.

[0037] Figure 9 shows a conceptual diagram of the airfoil correcting cell (C) 7. The airfoil correcting cell (C) 7 is composed of a correcting cell (C) thermal foamable resin 37 and a correcting cell (C) skin 38 made of uncured special reinforced fiber prepreg. The shape of the correcting cell (C) thermal foamable resin 37 is determined by computer simulation, taking into account aerodynamic characteristics. There are no manufacturing limitations in the length direction of the correcting cell (C) skin 38 made of uncured special reinforced fiber prepreg and the correcting cell (C) thermal foamable resin 37. Therefore, there are no limitations in the length direction of the airfoil correcting cell (C) 7.

[0038] Figure 10 shows a conceptual diagram of the wing-shaped correcting cell (D) 8. The wing-shaped correcting cell (D) 8 is composed of a correcting cell (D) thermal foaming resin 39 and a correcting cell (D) skin 40 made of uncured special reinforced fiber prepreg. The shape of the correcting cell (D) thermal foaming resin 39 is determined by computer simulation, taking into account aerodynamic characteristics. There are no manufacturing limitations in the length direction of the correcting cell (D) skin 40 made of uncured special reinforced fiber prepreg and the correcting cell (D) thermal foaming resin 39. Therefore, there are no limitations in the length direction of the wing-shaped correcting cell (D) 8.

[0039] In this way, the pseudo-airfoil material 32 is made into a pseudo-airfoil shape that imitates the airfoil, and the special reinforced fiber prepreg skin 12 before hardening is attached to this to finish the airfoil structure, and a formwork is used for baking and hardening the airfoil structure to finish it.

[0040] Figure 11 shows a cross-sectional conceptual diagram of an airfoil outer form 41. The airfoil outer form 41 is composed of an airfoil outer form (upper) 42, an airfoil outer form (lower) 43, fastening bolts 44, and fastening nuts 45. The shapes of the airfoil outer form (upper) 42 and the airfoil outer form (lower) 43 are determined by computer simulation, taking aerodynamic characteristics into consideration. The airfoil outer form (upper) 42 and the airfoil outer form (lower) 43 are manufactured from materials that are easy to cut, such as wood, mild steel, or aluminum. There are no manufacturing limitations on the lengthwise direction of the airfoil outer form (upper) 42 and the airfoil outer form (lower) 43.

[0041] Figure 12 shows a cross-sectional conceptual diagram of a completed wing structure 46 containing a high-pressure gas tank inside. The completed wing structure 46 containing a high-pressure gas tank inside is manufactured by placing the wing structure 1 before heat curing inside the wing outer form 41 and heating it in an atmospheric pressure heating oven 47. The wing structure 1 is an wing before heating that contains a high-pressure gas tank.

[0042] The pre-heat-cured wing structure 1 is manufactured by assembling pre-heat-cured wing shape correcting cells A5, B6, C7, and D8 onto a pre-heat-cured honeycomb structure pseudo-wing mold 32, and then attaching a pre-heat-cured special reinforced fiber prepreg skin 12 to the periphery. The special reinforced fiber prepreg is a soft woven fabric made of special reinforced fibers such as carbon fiber impregnated with adhesive.

[0043] Before heat curing, special reinforced fiber prepreg 12 is attached to all of the cells that make up the wing structure 1. The outer skin 12 made of the special reinforced fiber prepreg is divided into multiple parts in the circumferential direction of each cell and attached with overlapping parts.

[0044] When the wing structure 1 housed inside the wing outer form 41 is placed in a heating oven 46 and heated, the thermally foamable resin that makes up the cells of the wing structure 1 heats and expands. This expansion pressure and the mechanical reaction force of the wing outer form 41 firmly pressurize the special reinforced fiber prepreg skin 12 of all the cells that make up the completed wing structure 46, and at the same time adhesively harden the special reinforced fiber FRP of each cell of this adhesively hardened honeycomb structure. The special reinforced fiber FRP of each cell becomes the spars and ribs of the aircraft wing.

[0045] Figure 13 shows a conceptual diagram 48 of an aircraft wing for flying at very high altitudes. Aircraft with wing shapes that house high-pressure gas tanks have a wide range of applications, but one example is a radio base station for mobile phones and other devices that is equipped with hydrogen fuel cells and flies at very high altitudes. Radio base stations for mobile phones and other devices do not require high speed, but the higher the flying altitude, the better. However, in the case of aircraft flying at very high altitudes, oxygen cannot be replenished from the air because the air density is low. Therefore, high-pressure oxygen gas and high-pressure hydrogen gas must be prepared inside the aircraft.

[0046] A conceptual diagram 48 of the wing shape of an aircraft flying at very high altitudes is composed of a pseudo-wing shape of the aircraft flying at very high altitudes and a computer simulation wing shape 49. The pseudo-wing shape of the aircraft flying at very high altitudes is composed of hexagonal honeycomb cells 2, trapezoidal cells 3, and triangular cells 4. A manufacturing method of a high-pressure gas tank contained in a hexagonal honeycomb cell 2 is shown in FIG. 3. The hexagonal honeycomb cell 2 is divided into a hydrogen gas tank 50 and an oxygen gas tank 51. In the case of a hydrogen fuel cell, if the internal pressure of the high-pressure gas tank contained in the hexagonal honeycomb cell 2 is the same, the volume ratio of the hydrogen gas tank 50 to the oxygen gas tank 51 is 2:1. Therefore, in the case of a high-pressure gas tank contained in a hexagonal honeycomb cell 2, the ratio of the number of hydrogen gas tanks 50 to the number of oxygen gas tanks 51 is 2:1.

[0047] The difference between the pseudo-airfoil of an aircraft flying at very high altitude and the honeycomb structure pseudo-airfoil of Figure 6 is that the oxygen gas tank has one more hexagonal honeycomb cell 2. The number of trapezoidal cells 3 remains the same, but two more triangular cells have been added. As a result, the computer-simulated airfoil 49 is different from the computer-simulated airfoil of Figure 6.

[0048] A honeycomb-structured wing has no length limitations. As long as the wing's structural strength allows, an infinite amount of fuel can be carried. Additionally, hydrogen fuel is lightweight. Even liquid hydrogen weighs one-tenth the weight of aviation fuel (kerosene). Reducing the aircraft's weight makes it possible to fly at ultra-high altitudes exceeding 20,000 meters, where the air density is low. In conclusion, an aircraft with a wing containing internal high-pressure hydrogen gas tanks and high-pressure oxygen gas tanks can fly at ultra-high altitudes exceeding 20,000 meters, where the air density is low. By attaching a solar power generation system to the surface, an ideal radio base station can be created for long-term flight at ultra-high altitudes, powered by a hydrogen fuel system and a solar power generation system-powered storage battery.

[0049] The shape and purpose of the airfoil housing a high-pressure gas tank within the present invention may be varied in many ways. Although the present invention has been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are defined by the appended claims and are included within the scope of the present invention. Although the present invention has been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are defined by the appended claims and are included within the scope of the present invention.

[0050] 1... Wing-shaped structure before heat curing, 2... Hexagonal honeycomb cell, 3... Trapezoidal cell, 4... Triangular cell, 5... Wing-shaped modified cell A, 6... Wing-shaped modified cell B, 7... Wing-shaped modified cell C, 8... Wing-shaped modified cell D, 9... Wing skin before heat curing, 10... High-pressure gas tank, 11... Hexagonal thermal foaming resin, 12... Special reinforced fiber prepreg skin before heat curing, 13... Metal thin plate tank, 14... Low-magnification thermal foaming Resin, 15... Carbon fiber prepreg reinforcing metal thin plate tank, 16... Hexagonal thermal foaming resin, 17... Hexagonal carbon fiber prepreg, 18... Outer form (upper), 19... Outer form (lower), 20... Reinforcing member of outer form (A), 21... Reinforcing member of outer form (B), 22... Fastening bolt, 23... Fastening nut, 24... Expansion pressure by air pressure, 25... Expansion pressure by low-magnification thermal foaming resin, 26... Hexagonal thermal foaming resin Expansion pressure due to expansion, 27... Mechanical reaction force of outer formwork, 28... Trapezoidal outer skin, 29... Trapezoidal thermal foam resin, 30... Triangular thermal foam resin, 31... Triangular outer skin, 32... Honeycomb structure pseudo-wing shape, 33... Modified cell (A) thermal foam resin, 34... Modified cell (A) outer skin, 35... Modified cell (B) thermal foam resin, 36... Modified cell (B) outer skin, 37... Modified cell (C) thermal foam resin, 38... Modified cell (C) outer skin, 39... Modified cell (D) thermo-foamable resin, 40...Modified cell (D) outer skin, 41...wing outer formwork, 42...wing outer formwork (top), 43...wing outer formwork (bottom), 44...fastening bolts, 45...fastening nuts, 46...completed wing form containing high-pressure gas tank, 47...atmospheric pressure heating oven, 48...conceptual diagram of wing form for aircraft flying at ultra-high altitudes, 49...computer simulation wing form, 50...hydrogen gas tank, 51...oxygen gas tank.

Claims

1. A method for manufacturing a wing-shaped structure containing a high-pressure gas tank, characterized in that the outer periphery of a thin metal tank capable of injecting and holding gas is covered with a heat-foamable resin having an expansion ratio of 2 to 5 times, and multiple honeycomb cores with hexagonal outer surfaces containing a high-pressure gas tank reinforced by wrapping fiber-reinforced plastic (FRP prepreg) around the outer periphery of the low-expansion heat-foamable resin are arranged along an airfoil shape, trapezoidal or triangular cells are arranged to fill in the unevenness around the outer periphery of the honeycomb core to form a pseudo-wing-shaped material, the surface of the pseudo-wing-shaped material is covered with modified cells to form an aircraft wing shape, and the outer surface is further covered with an outer skin of fiber-reinforced plastic (FRP prepreg) that conforms to the wing surface, and the above is heated and hardened.

2. A wing-shaped structure formed by covering an airfoil with an outer skin of fiber-reinforced plastic (FRP prepreg), a honeycomb core containing a thin metal tank inside which can inject and hold gas arranged along the airfoil, a pseudo-wing-shaped material formed by combining trapezoidal or triangular cells that fill in the unevenness of the outer surface of the honeycomb core, and correction cells that fill in the space between this pseudo-wing-shaped material and the outer skin.

3. The wing structure according to claim 2, wherein the gas is hydrogen gas, the wing structure is an airplane wing, and the hydrogen gas is used as a fuel supply source.

4. A wing-shaped structure as described in claim 2, characterized in that it contains a high-pressure gas tank assembly manufactured by covering the outer periphery of a thin metal tank capable of injecting and retaining gas with a low-expansion thermally foamable resin and wrapping fiber-reinforced plastic (FRP prepreg) around the outer periphery of the thermally foamable resin, in which the low-expansion thermally foamable resin completely fills any mechanical gaps that occur during manufacturing, thereby minimizing the stress generated in the metal tube and preventing fatigue failure due to hydrogen embrittlement that occurs in the thin metal tank.

5. The wing structure of an aircraft as described in claim 4, wherein the gas is hydrogen gas and oxygen gas, and the wing structure containing the hydrogen gas tank and the oxygen gas tank is configured as an airplane wing, and the aircraft can fly at ultra-high altitudes where oxygen density is low by generating electricity using a hydrogen fuel cell that uses the hydrogen gas and oxygen gas as a fuel supply source.

6. The wing structure according to claim 4, which is used for a radio base station for mobile phones and the like that flies at very high altitudes and is equipped with a hydrogen fuel cell, for use in an aircraft having a wing that contains a high-pressure hydrogen gas tank inside.

Images