Heat-resistant structure for an aircraft and method for manufacturing a heat-resistant structure for an aircraft.

Abstract

To provide a heat-resistant structure of a flight body having a tip that can endure aerodynamic heating generated when moving at high speed in the atmosphere, and a method for manufacturing the heat-resistant structure of the flight body.SOLUTION: A heat-resistant structure of a flight body (1) comprises a tip (20, 30, 40, 50), and a body part (10). The tip is disposed at a tip of a front part relative to a direction (X) of travel of the flight body. The body part is disposed behind the tip relative to the direction of travel. The tip comprises a surface member (21, 31, 41, 51), a base (23, 33, 43, 53), and a heat insulation member (22, 32, 42, 52). The surface member is arranged on an exterior surface (241) of the tip, and has a melting point that is higher than a desired temperature. The surface member is joined to the body part by the base. The heat insulation member is arranged between the surface member and the base in order to insulate the base from the surface member.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] The present invention relates to a heat-resistant structure of a flying object and a method for manufacturing the heat-resistant structure of a flying object. For example, it can be suitably used for a heat-resistant structure of a flying object that moves at high speed in the atmosphere and has a surface temperature reaching 1600 °C or higher, and even 2000 °C or higher, and a method for manufacturing the heat-resistant structure of a flying object.

Background Art

[0002] When a flying object moves at high speed in the atmosphere, the tip portion of the flying object becomes extremely hot due to aerodynamic heating or the like. In particular, in the case of a flying object moving at supersonic speed in the atmosphere, there is a problem of shape stability at the tip portion so that the tip portion of the flying object does not melt, wear out, or change its shape due to aerodynamic heating. Also, there is a problem of heat insulation at the tip portion so that heat does not transfer from the tip portion, which has become hot due to aerodynamic heating, to the fuselage portion of the flying object. Furthermore, there is a problem of weight at the tip portion in order to appropriately maintain the overall weight balance of the flying object. However, no material that can solve these problems simultaneously is known.

[0003] For example, refractory metals such as tungsten are known to have very high melting points. However, when moving at high speeds through the atmosphere, the surface of the refractory metal oxidizes. The melting point of the oxide of the refractory metal is relatively low, and it may be consumed while moving at high speeds through the atmosphere. In the case of tungsten, its melting point is 3380°C, but in an oxygen atmosphere above 700°C it oxidizes to tungsten trioxide (WO3), and the melting point of this oxide is 1473°C. Therefore, in an oxygen atmosphere that reaches the order of 1600°C or even above 2000°C, tungsten is consumed. In addition, refractory metals have relatively high thermal conductivity, and the heat from a heated refractory metal may be transferred to the body. Furthermore, refractory metals have a relatively high specific gravity. Therefore, while constructing the nose section of an aircraft from fire-resistant metal is a conventional and common option, it is not suitable for aircraft that fly at high speeds in the atmosphere, where surface temperatures reach the order of 2000°C, and where it is desirable that the nose shape does not deteriorate even with agile attitude control.

[0004] As another example, ablators such as carbon phenol are known to wear down rapidly due to thermal decomposition. For example, resins such as phenol decompose at temperatures on the order of 200°C to 300°C. Placing an ablator on the surface of the aircraft can thermally protect the main body located inside, so constructing the tip of an aircraft with an ablator is a conventional and common option, but it is still unsuitable for the aircraft described above.

[0005] As another example, carbon fiber reinforced carbon composite materials are known for their high specific strength, meaning they possess both high strength and low specific gravity. However, carbon fiber reinforced carbon composite materials oxidize and rapidly degrade into gases such as carbon monoxide (CO) in oxidizing atmospheres above 400°C. Generally, oxidation resistance is imparted to carbon fiber reinforced carbon composite materials by applying silicon carbide (SiC) coatings, but even then, the oxidation resistance is poor and ineffective in environments above 1600°C. Furthermore, carbon fiber reinforced carbon composite materials have relatively high thermal conductivity, and the heat from heated carbon fiber reinforced carbon composite materials can be transferred to the fuselage. Therefore, although constructing the nose section of an aircraft moving at high speed through the atmosphere with carbon fiber reinforced carbon composite materials is a conventional and common option, it is still unsuitable for aircraft like those described above.

[0006] In relation to the above, Non-Patent Document 1 (Yi Zeng et al., "Microstructure and ablation behavior of carbon / carbon composites infiltrated with Zr-Ti", Carbon Volume 54, published in 2013, pp. 300-309) discloses a method for impregnating carbon fiber reinforced carbon composite materials with molten zirconium. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Yi Zeng et al., “Microstructure and ablation behavior of carbon / carbon composites infiltrated with Zr-Ti,” Carbon Volume 54, published 2013, pp. 300-309 [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above circumstances, one of the objectives of this disclosure is to provide a heat-resistant structure for an aircraft having a nose section capable of withstanding aerodynamic heating generated when moving at high speed through the atmosphere, and a method for manufacturing this heat-resistant structure for the aircraft. Other issues and novel features will become apparent from the description herein and the accompanying drawings. [Means for solving the problem]

[0009] The following describes the means for solving the problem using the numbers used in (Modes for Carrying Out the Invention). These numbers are added to clarify the correspondence between the description in (Claims) and (Modes for Carrying Out the Invention). However, these numbers should not be used to interpret the technical scope of the invention described in (Claims).

[0010] According to one embodiment, the heat-resistant structure of the aircraft (1) comprises a tip section (20, 30, 40, 50) and a body section (10). The tip section (20, 30, 40, 50) is located at the front of the aircraft (1) with respect to the direction of travel (X). The body section (10) is located behind the tip section (20, 30, 40, 50) with respect to the direction of travel (X). The tip section (20, 30, 40, 50) comprises a surface member (21, 31, 41, 51), a base section (23, 33, 43, 53), and a heat insulating member (22, 32, 42, 52). The surface member (21, 31, 41, 51) is located on the outer surface (241) of the tip section (20, 30, 40, 50) and has a melting point higher than a desired temperature. The base portions (23, 33, 43, 53) connect the surface members (21, 31, 41, 51) to the body portion (10). The heat insulating members (22, 32, 42, 52) are positioned between the surface members (21, 31, 41, 51) and the base portions (23, 33, 43, 53) to insulate the base portions (23, 33, 43, 53) from the surface members (21, 31, 41, 51).

[0011] According to one embodiment, the method for manufacturing the heat-resistant structure of the aircraft (1) includes manufacturing a front end (20, 30, 40, 50) positioned at the front of the aircraft (1) in the direction of travel (X), manufacturing a body section (10) positioned behind the front end (20, 30, 40, 50) in the direction of travel (X), and manufacturing the aircraft (1) by joining the front end (20, 30, 40, 50) and the body section (10). Manufacturing the tip portions (20, 30, 40, 50) includes manufacturing surface members (21, 31, 41, 51) that are provided to cover the surface of the tip portions (20, 30, 40, 50) and have a melting point higher than a desired temperature; manufacturing base portions (23, 33, 43, 53) that connect the surface members (21, 31, 41, 51) to the body portion (10); and arranging insulating members (22, 32, 42, 52) between the surface members (21, 31, 41, 51) and the base portions (23, 33, 43, 53) to insulate the base portions (23, 33, 43, 53) from the surface members (21, 31, 41, 51). Manufacturing a surface member (21, 31, 41, 51) involves immersing a carbon fiber reinforced carbon composite material (6) having the shape of a surface member (21, 31, 41, 51) in molten zirconium (72) such that zirconium is impregnated into at least the outer surface of the carbon fiber reinforced carbon composite material (6) and the carbon of the carbon fiber reinforced carbon composite material (the base material) reacts with the zirconium to form a zirconium alloy, and then removing the carbon fiber reinforced carbon composite material (6) from the molten zirconium (72) and cooling it. [Effects of the Invention]

[0012] According to one embodiment, the tip of an aircraft having a heat-resistant structure manufactured by a method for manufacturing the heat-resistant structure of an aircraft can withstand aerodynamic heating that occurs when the aircraft moves at high speed through the atmosphere. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a perspective view showing one example of the configuration of an aircraft according to one embodiment. [Figure 2]Figure 2 is a graph showing an example of the time change in the surface temperature of the tip of an aircraft according to one embodiment as it moves at high speed through the atmosphere. [Figure 3A] Figure 3A is a cross-sectional view showing one example of the configuration of an aircraft according to one embodiment. [Figure 3B] Figure 3B is a partial cross-sectional view showing one example of the configuration of the tip according to one embodiment. [Figure 4A] Figure 4A is a cross-sectional view taken along the cross-sectional line AA shown in Figure 3A, illustrating one example of the configuration of the tip portion according to one embodiment. [Figure 4B] Figure 4B is a cross-sectional view taken along the cross-sectional line BB shown in Figure 3A, showing one example of the configuration of the tip portion according to one embodiment. [Figure 4C] Figure 4C is a partial cross-sectional view taken along the cross-sectional line CC shown in Figures 4A and 4B, illustrating one example of the configuration of the tip portion according to one embodiment. [Figure 4D] Figure 4D is a partial cross-sectional view taken along the cross-sectional line DD shown in Figures 4A and 4B, illustrating one example of the configuration of the tip portion according to one embodiment. [Figure 4E] Figure 4E is a perspective view of the portion included in range E shown in Figures 4A and 4B, showing one example of the configuration of the contact member and base according to one embodiment. [Figure 4F] Figure 4F is a perspective view of the portion included in the range F shown in Figures 4A and 4B, showing an example of the configuration of the contact member and base according to one embodiment. [Figure 5A] Figure 5A is an exploded perspective view showing one example of the configuration of a surface member, a heat insulating member, and a base according to one embodiment. [Figure 5B] Figure 5B is an exploded perspective view showing one example of the configuration of a surface member, a heat insulating member, and a base according to one embodiment. [Figure 6A] Figure 6A is a cross-sectional view showing a first state in an example of a method for manufacturing a surface member of an aircraft according to one embodiment. [Figure 6B] Figure 6B is a cross-sectional view showing a second state in an example of a method for manufacturing a surface member of an aircraft according to one embodiment. [Figure 6C]FIG. 6C is a cross-sectional view showing a third state in an example of a method for manufacturing a surface member of a flying object according to an embodiment. [Figure 7A] FIG. 7A is a cross-sectional view showing a first state in an example of a method for manufacturing a surface member of a flying object according to an embodiment. [Figure 7B] FIG. 7B is a cross-sectional view showing a second state in an example of a method for manufacturing a surface member of a flying object according to an embodiment. [Figure 7C] FIG. 7C is a cross-sectional view showing a third state in an example of a method for manufacturing a surface member of a flying object according to an embodiment. [Figure 8] FIG. 8 is a partial cross-sectional view showing a configuration example of a tip portion according to an embodiment. [Figure 9] FIG. 9 is a partial cross-sectional view showing a configuration example of a tip portion according to an embodiment. [Figure 10A] FIG. 10A is a partial cross-sectional view showing a configuration example of a tip portion according to an embodiment. [Figure 10B] FIG. 10B is a partial enlarged cross-sectional view obtained by enlarging a part of FIG. ********* [Figure 10C] FIG. 10C is a front view showing a configuration example of a C-shaped retaining ring according to an embodiment. [Figure 11A] FIG. 11A is an exploded perspective view showing a configuration example of a tip portion according to an embodiment. [Figure 11B] FIG. 11B is an exploded perspective view showing a configuration example of a tip portion according to an embodiment. [Figure 11C] FIG. 11C is a perspective view showing a configuration example of a tip portion according to an embodiment. [Figure 12A] FIG. 12A is a partial cross-sectional view taken along a section line G-G shown in FIG. 12B, showing a configuration example of a tip portion according to an embodiment. [Figure 12B] FIG. 12B is a cross-sectional view taken along a section line I-I shown in FIG. 12A, showing a configuration example of a surface member, a base portion, and a fastening member excluding a heat insulating member in a tip portion according to an embodiment. [Figure 13A]Figure 13A is an exploded perspective view of the area H shown in Figure 12B, showing an example of the configuration of a surface member, base, and fastening member according to one embodiment. [Figure 13B] Figure 13B is an exploded perspective view of the area H shown in Figure 12B, showing an example of the configuration of a surface member, base, and fastening member according to one embodiment. [Figure 14] Figure 14 is a partial cross-sectional view showing one example of the configuration of the tip according to one embodiment. [Figure 15] Figure 15 is a partial cross-sectional view showing one example of the configuration of the tip according to one embodiment. [Figure 16A] Figure 16A is an exploded perspective view showing one example of the configuration of the tip according to one embodiment. [Figure 16B] Figure 16B is an exploded perspective view showing one example of the configuration of the tip according to one embodiment. [Modes for carrying out the invention]

[0014] With reference to the attached drawings, embodiments for carrying out the heat-resistant structure for an aircraft and the method for manufacturing the heat-resistant structure for an aircraft according to the present invention will be described below.

[0015] (First Embodiment) As shown in Figure 1, the aircraft 1 according to one embodiment comprises a fuselage section 10 and a nose section 20. The nose section 20 is located at the front end of the aircraft 1 with respect to the direction of travel X. The fuselage section 10 is located behind the nose section with respect to this direction of travel X.

[0016] As shown in Figure 2, when the aircraft 1 moves at high speed through the atmosphere, the surface temperature of the tip 20 changes over time. In the graph in Figure 2, the horizontal axis represents time, and the vertical axis represents the surface temperature of the tip 20. In the example in Figure 2, the surface temperature of the tip 20 rises sharply when the aircraft 1 begins to move through the atmosphere, and then gradually decreases; however, the disclosure is not limited to this example.

[0017] When the flying object 1 travels through the atmosphere at a very high speed, such as supersonic speed, the surface of the flying object 1, particularly its tip 20, is heated by aerodynamic heating. At this time, this surface temperature may exceed the melting point of some materials.

[0018] As shown in Figure 3A, the fuselage portion 10 of the aircraft 1 according to one embodiment comprises a surface member 11 disposed on the outer surface of the fuselage portion 10 and a base portion 13 covered by the surface member 11. The tip portion 20 of the aircraft 1 according to one embodiment has a bell shape and comprises a surface member 21 disposed on the outer surface of the tip portion 20, a base portion 23 that connects the tip portion 20 to the base portion 13 of the fuselage portion 10, and a heat insulating member 22 disposed between the surface member 21 and a contact member 24. The tip portion 20 further comprises a contact member 24 that sandwiches the heat insulating member 22 between itself and the surface member 21. The contact member 24 is connected to the base portion 23 by a connecting member such as a bolt 25. As an example, the base portion 23 and the contact member 24 are made of the same material. In this case, the entirety of the contact member 24 and the base portion 23 can be said to be the base portion 23, and the contact member 24 can be said to be a part of the base portion 23.

[0019] In one embodiment, the surface member 21 comprises a heat-resistant material having a melting point higher than the desired temperature. For example, this temperature is the highest temperature reached by the surface of the aircraft 1 when it is heated by aerodynamic heating or the like as it moves through the atmosphere at the desired speed. The surface member 11 of the fuselage 10 may be made of an ablator.

[0020] In one embodiment, the heat insulating member 22 is configured to insulate the base portion 23 from the surface member 21. The heat insulating member 22 further blocks heat input from the surface member 21 to the contact member 24. As a result, the base portion 23 and the contact member 24 can be made of a material having a melting point lower than the maximum temperature reached by the surface temperature of the aircraft 1. The materials constituting the base portion 23 and the contact member 24 preferably have relatively high toughness and relatively low thermal conductivity. The base portion 13 of the fuselage portion 10 may also be made of the same material as the base portion 23 and the contact member 24.

[0021] In one embodiment, the base portion 23 is configured to connect the surface member 21 to the body portion 10. More specifically, the base portion 23 of the tip portion 20 is configured to connect to the base portion 13 of the body portion 10. The method of connecting the base portion 23 and the base portion 13 in one embodiment is not limited.

[0022] Figure 3B is a partial cross-sectional view showing one example of the configuration of the tip portion 20 according to one embodiment. The region 200 shown in Figure 3B corresponds to the front end of the tip portion 20 shown in Figure 3A with respect to the direction of travel of the aircraft 1. As shown in Figure 3B, the material of the surface member 21 does not have to be homogeneous. In the example of Figure 3B, the surface member 21 includes at least a layer of zirconium carbide on its outer surface as viewed from the aircraft 1. Zirconium carbide is a type of zirconium alloy and is produced by impregnating a carbon fiber reinforced carbon composite material, which is the base material, with zirconium, and reacting the carbon in this carbon fiber reinforced carbon composite material with zirconium. On the inner surface of the surface member 21 as viewed from the aircraft 1, there may be a layer of carbon fiber reinforced carbon composite material in which zirconium carbide has not been formed. The layer of carbon fiber reinforced carbon composite material in which zirconium carbide is not present is called the first layer 21A. The layer of carbon fiber reinforced carbon composite material in which zirconium carbide has been formed is called the second layer 21B. A layer of zirconium oxide (also called zirconia), which is produced by the oxidation of zirconium carbide, may be present on the outer surface of the surface member 21. This oxide layer may be formed when the aircraft 1 moves at high speed through an oxygen-containing atmosphere and is subjected to aerodynamic heating. This oxide film is called the third layer 21C. The carbon fiber reinforced carbon composite material of the first layer 21A has sufficient strength to maintain the shape of the surface member 21 even when the aircraft 1 moves at high speed through the atmosphere. The zirconium carbide of the second layer 21B and the zirconium oxide of the third layer 21C have melting points higher than the maximum temperature reached by the surface of the aircraft 1. Specifically, the melting point of zirconium carbide is 3532°C to 3540°C, and the melting point of zirconium oxide is 2715°C, and the surface of the surface member 21 has resistance to temperatures lower than these melting points.

[0023] A heat insulating member 22 is positioned on the first layer 21A of the surface member 21, in the direction viewed from the aircraft 1. Furthermore, a base portion 23 (and / or contact member 24) is positioned on the direction viewed from the aircraft 1 in the direction viewed from the heat insulating member 22. Thus, the heat-resistant structure of the aircraft 1 according to one embodiment comprises a three-layer structure including the surface member 21, the heat insulating member 22, and the base portion 23. In Figure 3B, the surface member 21, the heat insulating member 22, and the base portion 23 are shown as if there are gaps between them, but this is to distinguish them from the three-layer structure of the surface member 21, and in reality, it is preferable that the surface member 21, the heat insulating member 22, and the base portion 23 are in close contact with each other. However, there is no limitation on whether there are gaps between the surface member 21, the heat insulating member 22, and the base portion 23.

[0024] Referring to Figures 4A to 4F, a more specific example of the configuration of the tip portion 20 of the aircraft 1 according to one embodiment will be described. Figure 4A is a cross-sectional view taken along the cross-sectional line AA shown in Figure 3A, showing an example of the configuration of the tip portion according to one embodiment. Figure 4B is a cross-sectional view taken along the cross-sectional line BB shown in Figure 3A, showing an example of the configuration of the tip portion according to one embodiment. Figure 4C is a partial cross-sectional view taken along the cross-sectional line CC shown in Figures 4A and 4B, showing an example of the configuration of the tip portion according to one embodiment. Figure 4D is a partial cross-sectional view taken along the cross-sectional line DD shown in Figures 4A and 4B, showing an example of the configuration of the tip portion according to one embodiment. Figure 4E is a perspective view of the portion included in the range E shown in Figures 4A and 4B, showing an example of the configuration of the contact member 24 and base portion 23 according to one embodiment. Figure 4F is a perspective view of the portion included in the range F shown in Figures 4A and 4B, showing an example of the configuration of the contact member 24 and base portion 23 according to one embodiment.

[0025] As shown in Figures 4B and 4C, the surface member 21 is provided with surface member protrusions 211 that project from the inner surface of the surface member 21 toward the internal space of the surface member 21. Furthermore, as shown in Figure 4B, the surface member 21 is further provided with surface member recesses 212 adjacent to the surface member protrusions 211 in the circumferential direction R. Moreover, as shown in Figure 4B, the surface member 21 may be provided with a plurality of surface member protrusions 211 and a plurality of surface member recesses 212 arranged one adjacent to each other in the circumferential direction R.

[0026] As shown in Figures 4A and 4C, the contact member 24 is provided with a contact member projection 242 that protrudes outward from the outer surface of the contact member 24. Furthermore, as shown in Figure 4A, the contact member 24 is further provided with a contact member recess 243 adjacent to the contact member projection 242 in the circumferential direction R. In addition, as shown in Figure 4A, the contact member 24 may be provided with a plurality of contact member projections 242 and a plurality of contact member recesses 243 arranged one adjacent to each other in the circumferential direction R.

[0027] As shown in Figures 4C and 4D, the contact member 24 further includes an outer surface that serves as a clamping portion 241 for sandwiching the heat insulating member 22 between itself and the inner surface of the surface member 21.

[0028] As shown in Figures 4A, 4B, 4D, 4E, and 4F, the base portion 23 is provided with a circumferential restraint portion 231 that protrudes from rear to front with respect to the direction of travel X. The circumferential restraint portion 231 is formed to be insertable from front to rear so as to penetrate the surface member recess 212 and the contact member recess 243, which are in an overlapping state in the direction of travel X. At this time, the surface member projection 211 and the contact member projection 242 are in an overlapping state in the direction of travel X, and the circumferential restraint portion 231 is formed to restrain the surface member projection 211 and the contact member projection 242 so as not to rotate in the circumferential direction R.

[0029] As shown in Figures 4A, 4B, 4C, and 4D, the base 23 and the contact member 24 are connected by bolts 25, which act as connecting members. There may be multiple bolts 25. As shown in Figures 4E and 4F, bolt holes 250 are provided in the base 23 and the contact member 24 for connecting with the bolts 25.

[0030] As shown in Figure 4C, when the surface member projection 211 and the contact member projection 242 are overlapping in the direction of travel X, the contact member projection 242 is positioned in front of the surface member projection 211 with respect to the direction of travel X, and the contact member projection 242 is in contact with the front surface of the surface member projection 211.

[0031] An example of a manufacturing method for the tip portion 20 according to one embodiment will be described with reference to Figures 5A and 5B. Figure 5A is an exploded perspective view showing one example configuration of the surface member 21, contact member 24, and base portion 23 according to one embodiment. Figure 5B is an exploded perspective view showing one example configuration of the surface member 21, contact member 24, and base portion 23 according to one embodiment.

[0032] First, the heat insulating member 22 is inserted into the internal space of the surface member 21 from the rear opening relative to the direction of travel X of the surface member 21, and the heat insulating member 22 is positioned along the inner surface of the surface member 21. For clarity, the heat insulating member 22 is not shown in Figures 5A and 5B.

[0033] Next, the contact member 24 is inserted into the internal space of the surface member 21 through the opening of the surface member 21. At this time, the relative positional relationship between the surface member 21 and the contact member 24 is adjusted as appropriate by rotating in the circumferential direction R or the opposite direction. By doing so, the contact member projection 242 of the contact member 24 can pass through the surface member recess 212 of the surface member 21 in the direction of travel X. Here, the contact member recess 243 is formed so that the surface member projection 211 can pass through, and the surface member recess 212 is formed so that the contact member projection 242 can pass through. For example, the contact member recess 243 is formed in a shape that allows the surface member projection 211 to pass through, and the surface member recess 212 is formed in a shape that allows the contact member projection 242 to pass through.

[0034] After inserting the contact member 24 into the internal space of the surface member 21, the relative positional relationship between the contact member 24 and the surface member 21 is adjusted as appropriate while rotating in the circumferential direction R. By doing so, a state is obtained in which the surface member projection 211 and the contact member projection 242 overlap in the direction of travel X, and the surface member recess 212 and the contact member recess 243 overlap in the direction of travel X.

[0035] In this state, the base 23 is moved in the direction of travel X such that the circumferential restraining portion 231 of the base 23 penetrates the overlapping surface member recess 212 and the contact member recess 243, and the base 23 comes into contact with the contact member 24. At this time, as described above, the surface member projection 211 and the contact member projection 242 are restrained by the circumferential restraining portion 231, and the relative positional relationship between the surface member 21 and the contact member 24 in the circumferential direction R is restrained. Also at this time, the surface member projection 211 is restrained by the contact member projection 242 and the base 23 in the direction of travel X. In this state, by connecting the base 23 to the contact member 24 using a bolt 25, the surface member 21, the heat insulating member 22, the contact member 24 and the base 23 are connected, and the tip portion 20 in the state shown in Figures 4A to 4D is obtained.

[0036] In relation to the structure of the surface member 21 shown in Figure 3B, an example of a method for producing zirconium carbide by impregnating a carbon fiber reinforced carbon composite material 60 with zirconium 70 will be explained with reference to Figures 6A to 6C.

[0037] First, as shown in Figure 6A, a carbon fiber reinforced carbon composite material 60 and zirconium 70 are prepared. Next, as shown in Figure 6B, when the zirconium 70 is melted, the molten zirconium 71 impregnates the interior of the carbon fiber reinforced carbon composite material 60. As a result, as shown in Figure 6C, zirconium carbide 61 is obtained, which is produced by the reaction of zirconium 70 with carbon in the carbon fiber reinforced carbon composite material. Note that although the zirconium 70 prepared in Figure 6A is exemplified as being in pellet form, this disclosure is not limited to this example, and may be in powder form, paste form, or other form that can coat the surface of the carbon fiber reinforced carbon composite material 60.

[0038] An example of a method for manufacturing a surface member 21 according to one embodiment will be described with reference to Figures 7A to 7C, applying the method described with reference to Figures 6A to 6C.

[0039] First, as shown in Figure 7A, a carbon fiber reinforced carbon composite material 6 having the shape of the surface member 21 is attached to the lifting device 84. Also, molten zirconium 72 is prepared in a carbon crucible 82 heated by a carbon heater 83. The carbon crucible 82 may be placed on a crucible stand 81 and rotated.

[0040] Next, as shown in Figure 7B, the lifting device 84 is operated to lower the carbon fiber reinforced carbon composite material 6, and the carbon fiber reinforced carbon composite material 6 is immersed in the molten zirconium 72 in the carbon crucible 82 so that zirconium impregnates at least the outer surface of the carbon fiber reinforced carbon composite material 6 and the carbon and zirconium in the carbon fiber reinforced carbon composite material 6 react to form zirconium carbide.

[0041] Next, as shown in Figure 7C, the lifting device 84 is operated to raise the carbon fiber reinforced carbon composite material 6, from which zirconium carbide has been generated, and remove it from the carbon crucible 82 for cooling. The surface member 21 is obtained by immersing the carbon fiber reinforced carbon composite material 6 in molten zirconium 72 to generate zirconium carbide.

[0042] As shown in Figures 7A, 7B, and 7C, the carbon fiber reinforced carbon composite material 6 may be immersed in the molten zirconium 72 with the portion of the surface member 21 corresponding to the front end with respect to the direction of travel X facing downwards. By impregnating the carbon fiber reinforced carbon composite material 6 in the molten zirconium 72 from the front end first and withdrawing it from the molten zirconium 72 from the rear first, the time the carbon fiber reinforced carbon composite material 6 is immersed in the molten zirconium is longest at the front end of the surface member 21 and becomes shorter as it moves away from this end. As a result, the density of zirconium carbide in the heat-resistant material of the surface member 21 decreases continuously from front to rear with respect to the direction of travel X. Alternatively, the density of zirconium carbide in the heat-resistant material may be made uniform by impregnation over a sufficient period of time.

[0043] A method for manufacturing the aircraft 1 according to one embodiment will be described. First, as explained with reference to Figures 7A to 7C, a surface member 21 for covering the surface of the tip portion 20 is manufactured. Meanwhile, the heat insulating member 22, the base portion 23, and the contact member 24 shown in Figures 4A to 4F are manufactured. Next, as explained with reference to Figures 5A and 5B, the surface member 21, the heat insulating member 22, the base portion 23, and the contact member 24 are assembled to manufacture the tip portion 20. At this point, the heat-resistant structure of the aircraft 1 according to one embodiment is manufactured. Meanwhile, the fuselage portion 10 shown in Figure 1 is manufactured. Next, the tip portion 20 and the fuselage portion 10 are joined together to manufacture the aircraft 1.

[0044] As described above, according to one embodiment, a three-layer structure consisting of a surface member 21 as a heat-resistant material, a heat-insulating member 22, and a base 23 (and contact member 24) realizes a tip 20 that can withstand aerodynamic heating generated when moving at high speed in the atmosphere, and an aircraft body 1 equipped with this tip 20. Furthermore, because the volume of the contact member 24 is relatively large and its heat capacity is relatively large, heat generated at the front end of the surface member 21 is less likely to be transferred to the fuselage 10.

[0045] Furthermore, the surface member 21 may deform due to aerodynamic heating or other factors. Specifically, the surface member 21 may deform due to thermal expansion caused by aerodynamic heating or due to the load from dynamic pressure during flight. If the length of the surface member 21 in the direction of travel X increases, the reaction force due to this deformation is received by the front surface of the base 23 that abuts against the rear end of the surface member 21 in the direction of travel X. In this sense as well, it is preferable that the material constituting the base 23 is sufficiently robust.

[0046] Referring to Figure 8, one modified example of the tip portion 20 according to one embodiment will be described. As shown in Figure 8, a gasket 261 may be placed between the surface member 21 and the base portion 23. In the modified example shown in Figure 8, the gasket 261 relieves the stress caused by the deformation of the surface member 21.

[0047] Referring to Figure 9, another modification of the tip portion 20 according to one embodiment will be described. As shown in Figure 9, a disc spring 262 as a biasing device may be placed between the base portion 23 and the head of the bolt 25 as a connecting member. In the modification shown in Figure 9, the disc spring 262 as a biasing device biases the bolt 25 as a connecting member toward the rear with respect to the direction of travel X. Since the bolt 25 penetrates the base portion 23 and is fastened to the contact member 24, the disc spring 262 as a biasing device relieves the stress generated by the deformation of the surface member 21 due to aerodynamic heating or the like.

[0048] As explained above, according to the modified examples shown in Figures 8 and 9, the stress generated by the deformation of the surface member 21 due to aerodynamic heating or the like can be relieved inside the tip portion 20.

[0049] (Second Embodiment) The aircraft 1 according to this embodiment is obtained by connecting the tip 30 according to this embodiment to the fuselage 10 shown in Figure 3A, instead of the tip 20 of the aircraft 1 shown in Figure 3A. Below, the parts of the configuration of the tip 30 according to this embodiment that differ from the configuration of the tip 20 according to the first embodiment will be mainly described.

[0050] Referring to Figures 10A to 10C, an example of the configuration of the tip portion 30 according to one embodiment will be described. Figure 10A is a partial cross-sectional view showing an example of the configuration of the tip portion 30 according to one embodiment. Figure 10B is a partially enlarged cross-sectional view showing an enlarged part of Figure 10A. Figure 10C is a front view showing an example of the configuration of the C-type retaining ring 35 according to one embodiment.

[0051] As shown in Figures 10A and 10B, the tip portion 30 according to this embodiment, like the tip portion 20 according to the first embodiment shown in Figure 3B and the like, comprises a surface member 31 as a heat-resistant material, a heat insulating member 32, and a base portion 33. Furthermore, the tip portion 30 according to this embodiment comprises a fixing member 34 and a C-type retaining ring 35 as components corresponding to the contact member 24 according to the first embodiment. In addition, the tip portion 30 according to this embodiment comprises a nut 36 as a component corresponding to the bolt 25 as a connecting member according to the first embodiment.

[0052] As shown in Figures 10A and 10B, the surface member 31 is provided with a groove 313 that is provided around the inner wall surface of the surface member 31 in the circumferential direction R. Of the surface member 31, the portion that contacts the inner wall surface from the groove 313 to the rear end with respect to the direction of travel X is called the surface member projection 311, as in the first embodiment. The groove 313 is located in front of the surface member projection 311. Further in front of the groove 313 on the inner wall surface of the surface member 31, there is a projection provided that is provided around in the circumferential direction R. This projection is called the surface member contact portion 314. The surface member contact portion 314 protrudes from the inner wall surface of the surface member 31 toward the internal space of the surface member 31. Of the surface member 31, the portion between the surface member contact portion 314 and the groove 313 is called the surface member step portion 312.

[0053] As shown in Figures 10A and 10B, the C-type retaining ring 35 is fitted into the groove 313. When fitting the C-type retaining ring 35 into the groove 313, the spring portion 351 is deformed so that the two ends 352 and 353 move closer together, making the outer dimensions of the C-type retaining ring 35 smaller than the inner dimensions of the surface member 31. By moving the C-type retaining ring 35 in this state to the groove 313 and releasing the spring portion 351 so that the two ends 352 and 353 move apart, the C-type retaining ring 35 can be fitted into the groove 313.

[0054] As shown in Figure 10B, the outer periphery 342 of the fixing member 34 abuts against the stepped portion 312 of the surface member in the direction of travel X, and is sandwiched between the groove 313 and the surface member contact portion 314.

[0055] The fixing member 34 further includes a bolt portion 341 extending rearward with respect to the direction of travel X. The base portion 33 is provided with a through hole 331 through which the bolt portion 341 passes. A nut 36, which serves as a connecting member, is screwed onto the bolt portion 341 that has passed through the through hole 331 of the base portion 33. The nut 36 connects the base portion 33 and the fixing member 34. A washer 37 may be placed between the nut 36 and the base portion 33.

[0056] In addition, a portion of the internal space of the surface member 31 that is rearward with respect to the direction of travel X may be cylindrical. Also, a portion of the outer wall surface 320 of the heat insulating member 32 that is rearward with respect to the direction of travel X may be a cylindrical side surface.

[0057] An example of a manufacturing method for the tip portion 30 according to one embodiment will be described with reference to Figures 11A to 11C. Figure 11A is an exploded perspective view showing one example of the configuration of the tip portion according to one embodiment. Figure 11B is an exploded perspective view showing one example of the configuration of the tip portion according to one embodiment. Figure 11C is a perspective view showing one example of the configuration of the tip portion according to one embodiment.

[0058] First, the heat insulating material 32 is filled into the internal space of the surface member 31. Then, the opening of the surface member 31 is closed with the fixing member 34. The fixing member 34 is sandwiched between the surface member contact portion 314 of the surface member 31 and the C-shaped retaining ring 35 by fitting the C-shaped retaining ring 35 into the groove 313. Then, the base 33 is installed at the rear end of the surface member 31. At this time, the bolt portion 341 of the fixing member 34 is passed through the through hole 331 of the base 33, and the base 33 and the fixing member 34 are fastened together by screwing the nut 36 onto the bolt portion 341. A washer 37 may be placed between the base 33 and the nut 36. As a result, the surface member 31, the C-shaped retaining ring 35, the fixing member 34, and the base 33 are connected.

[0059] In this embodiment, the tip portion 30 has a relatively small volume of the fixing member 34 integrated with the base portion 33. As a result, the volume of the heat insulating member 32 filled inside the tip portion 30 is relatively large, and heat generated at the front tip of the surface member 31 is less likely to be transferred to the fixing member 34. In addition, there is a relatively high degree of freedom against thermal expansion, and stress due to this deformation is less likely to occur.

[0060] (Third embodiment) The aircraft 1 according to this embodiment is obtained by connecting the tip 40 according to this embodiment to the fuselage 10 shown in Figure 3A, instead of the tip 20 of the aircraft 1 shown in Figure 3A. Below, the parts of the configuration of the tip 40 according to this embodiment that differ from the configuration of the tip 20 according to the first embodiment will be mainly described.

[0061] Referring to Figures 12A and 12B, an example of the configuration of the tip portion 40 according to one embodiment will be described. Figure 12A is a partial cross-sectional view showing an example of the configuration of the tip portion according to one embodiment. Figure 12B is a cross-sectional view taken along the cross-sectional line II shown in Figure 12A, showing an example of the configuration of the surface member 41, base portion 43, and fastening member 44 of the tip portion 40 according to one embodiment, excluding the heat insulating member 42.

[0062] As shown in Figures 12A and 12B, the tip portion 40 according to this embodiment, like the tip portion 20 according to the first embodiment shown in Figure 3B and the like, comprises a surface member 41 as a heat-resistant material, a heat insulating member 42, and a base portion 43. Furthermore, the tip portion 40 according to this embodiment includes a fastening member 44 as a component corresponding to the contact member 24 according to the first embodiment. In addition, the tip portion 40 according to this embodiment includes a bolt 45 corresponding to the bolt 25 as a connecting member according to the first embodiment.

[0063] As shown in Figure 12A, the surface member 41 is provided with surface member projections 411 that protrude from the entire circumference of the inner surface of the surface member 41 toward the internal space of the surface member 41. The surface member projections 411 are provided with through holes 412 that serve as passages connecting the outside and inside of the surface member 41. The surface member projections 411 are also provided with bolt through holes 413 through which bolts 45 pass.

[0064] As shown in Figure 12A, the base portion 43 includes a base projection 431 and a bolt through-hole 432. The base projection 431 is configured to block the through-hole 412 of the surface member 41. The bolt through-hole 432 is formed so that a bolt 45 can pass through it.

[0065] As shown in Figure 12A, the fastening member 44 is provided with a bolt hole 441 for screwing in a bolt 45. As shown in Figure 12B, the fastening member 44 may be divided into multiple fastening members 44 so that they can pass through the through hole 412 of the surface member projection 411 in order to be positioned in front of the surface member projection 411. To facilitate screwing in the bolt 45, the fastening member 44 may be temporarily fixed to the front surface of the surface member projection 411 with an adhesive or the like so that the position of the bolt hole 441 coincides with the position of the bolt through hole 413 of the surface member projection 411.

[0066] As shown in Figure 12A, the bolt 45 passes through the bolt through hole 432 of the base 43 and the bolt through hole 413 of the surface member projection 411, and is screwed into the bolt hole 441 of the fastening member 44.

[0067] A method for manufacturing the tip portion 40 according to one embodiment will be described with reference to Figures 13A and 13B. Figure 13A is an exploded perspective view of the area H shown in Figure 12B, showing one example configuration of the surface member 41, base portion 43, and fastening member 44 according to one embodiment. Figure 13B is an exploded perspective view of the area H shown in Figure 12B, showing one example configuration of the surface member 41, base portion 43, and fastening member 44 according to one embodiment.

[0068] First, the fastening member 44 is temporarily fixed to the front surface of the surface member projection 411 of the surface member 41 with an adhesive or the like. At this time, the fastening member 44 is inserted into the internal space of the surface member 41 by passing through the through hole 412 of the surface member 41. The fastening member 44 is also temporarily fixed so that the position of the bolt hole 441 and the position of the bolt through hole 413 of the surface member 41 coincide.

[0069] Subsequently, the heat insulating material 42 is filled into the internal space of the surface member 41. At this time, the heat insulating material 42 is placed into the internal space of the surface member 41 by passing through the through hole 412 of the surface member 41.

[0070] Subsequently, the base portion 43 is positioned at the rear end of the surface member 41 such that the base projection 431 closes the through hole 412 of the surface member 41. At this time, the position of the bolt through hole 432 of the base portion 43 is aligned with the bolt through hole 413 of the surface member projection 411 and the bolt hole 441 of the fastening member 44.

[0071] Subsequently, the bolt 45 is screwed into the bolt hole 441 of the fastening member 44 to fasten it. At this time, the bolt 45 passes through the bolt through hole 432 of the base 43 and the bolt through hole 413 of the surface member projection 411. As a result, the surface member 41 and the base 43 are joined together. In addition, the heat insulating member 42 is sandwiched between the surface member 41 and the base projection 431 of the base 43 in the direction of travel X.

[0072] As described above, each component of the tip portion 40 in this embodiment is fixed by a relatively simple structure.

[0073] (Fourth embodiment) The aircraft 1 according to this embodiment is obtained by connecting the tip 50 according to this embodiment to the fuselage 10 shown in Figure 3A, instead of the tip 20 of the aircraft 1 shown in Figure 3A. Below, the parts of the configuration of the tip 50 according to this embodiment that differ from the configuration of the tip 20 according to the first embodiment will be mainly described.

[0074] Referring to Figures 14 and 15, an example of the configuration of the tip portion 50 according to one embodiment will be described. Figure 14 is a partial cross-sectional view showing an example of the configuration of the tip portion 50 according to one embodiment. Figure 15 is a partial cross-sectional perspective view showing an example of the configuration of the tip portion 50 according to one embodiment.

[0075] As shown in Figure 14, the tip portion 50 according to this embodiment, like the tip portion 20 according to the first embodiment shown in Figure 3B and the like, comprises a surface member 51 as a heat-resistant material, heat insulating members 52A and 52B, and a base portion 53. Furthermore, the tip portion 50 according to this embodiment includes a comb-tooth member 54 as a component corresponding to the contact member 24 according to the first embodiment. In addition, the tip portion 50 according to this embodiment includes a bolt 56 as a component corresponding to the bolt 25 as a connecting member according to the first embodiment. The tip portion 50 according to this embodiment may further include a shim 55 for adjusting the positional relationship of the surface member 51, the base portion 53, and the comb-tooth member 54 in the direction of travel X.

[0076] As shown in Figures 14 and 15, the surface member 51 according to this embodiment is provided with surface member projections 511 that protrude from the entire circumference of the inner surface of the surface member 51 toward the internal space of the surface member 51. Engagement holes 512 are provided in the surface member projections 511. The portion of the internal space of the surface member 51 in front of the surface member projections 511 and the portion behind them are connected by the engagement holes 512, which act as a passage.

[0077] As shown in Figures 14 and 15, the comb-tooth member 54 comprises a base positioned behind the surface member projection 511, a plurality of shaft portions 542 extending forward from the base in a comb-tooth shape, and a plurality of return portions 541 provided at the tip of each of the shaft portions 542. These shaft portions 542 pass through the engagement holes 512 of the surface member projection 511, and these return portions 541 are positioned in front of the engagement holes 512 and protrude outward from the engagement holes 512. These return portions 541 are formed to engage with the surface member projection 511 and not move backward as long as they are positioned outside the engagement holes 512. In other words, each return portion 541 is connected to the base via one of the shaft portions 542 and locked into the engagement hole 512.

[0078] As shown in Figures 14 and 15, the base of the comb-tooth member 54 is provided with a through hole 543 through which the base portion 53 passes. Multiple shaft portions 542 are arranged around the through hole 543. The inner surface of the through hole 543 is cylindrical and is continuous with a portion of the surface of each shaft portion 542. The base of the comb-tooth member 54 is further provided with bolt holes 544 on the outside of the through hole 543 for screwing in bolts 56. Of the comb-tooth member 54, the base with the bolt holes 544 functions as a connecting portion for connecting with the bolts 56, which act as connecting members.

[0079] As shown in Figures 14 and 15, the base portion 53 is provided with a base projection 531 that penetrates the through hole 543 of the comb tooth member 54. The base projection 531 is cylindrical, and by positioning the base projection 531 to fill the inside of the through hole 543, the return portion 541 of the comb tooth member 54 is prevented from moving inward beyond the engagement hole 512.

[0080] As shown in Figure 14, the shim 55 is positioned between the comb-tooth member 54 and the base 53. The shim 55 has a through hole 551 through which the base projection 531 passes and a bolt through hole 552 through which the bolt 56 passes.

[0081] A method for manufacturing the tip portion 50 according to one embodiment will be described with reference to Figures 16A and 16B. Figures 16A and 16B are exploded perspective views showing one example configuration of the tip portion 50 according to one embodiment.

[0082] First, the space in front of the surface member projection 511 within the internal space of the surface member 51 is filled with the heat insulating member 52A. At this time, the heat insulating member 52A passes through the engagement hole 512 of the surface member projection 511. After that, the space behind the surface member projection 511 within the internal space of the surface member 51 is filled with the heat insulating member 52B. At this time, it is preferable to leave space for the shaft portion 542 and return portion 541 of the comb tooth member 54 and the base projection 531 of the base portion 53.

[0083] Next, the comb-tooth member 54 is installed on the surface member 51. At this time, the comb-tooth member 54 is installed on the surface member 51 such that the return portion 541 of the comb-tooth member 54 penetrates the engagement hole 512 of the surface member projection 511 and is positioned in front of the engagement hole 512.

[0084] Subsequently, the shim 55 is temporarily fixed to the rear surface of the comb tooth member 54 using an adhesive or the like. As a modified example, the shim 55 may be temporarily fixed to the front surface of the base 53.

[0085] Subsequently, the base portion 53 is placed at the rear end of the surface member 51. At this time, the base projection 531 of the base portion 53 penetrates the through hole 543 of the comb tooth member 54. In this state, the return portion 541 of the comb tooth member 54 can no longer move inside the engagement hole 512. Therefore, the return portion 541 cannot be disengaged from the engagement hole, and the comb tooth member 54 cannot move backward.

[0086] Subsequently, the bolt 56 is screwed into the bolt hole 544 of the comb-tooth member 54. At this time, the bolt 56 passes through the bolt through hole 532 of the base 53 and the bolt through hole 552 of the shim 55. As a result, the surface member 51, the comb-tooth member 54, and the base 53 are joined together. In addition, the heat insulating member 52 is sandwiched between the surface member 51 and the base projection 531 of the base 53 in the direction of travel X.

[0087] As described above, according to this embodiment, there is no need to provide bolt holes or bolt through holes in the surface member 51 which is configured to include a layer of zirconium carbide 61.

[0088] The invention made by the inventor has been described in detail based on embodiments above, but it goes without saying that the present invention is not limited to these embodiments and can be modified in various ways without departing from its essence. Furthermore, the features described in the embodiments can be freely combined within a range that does not contradict the technical aspects.

[0089] In each of the embodiments described above, a heat-resistant structure of the aircraft 1 having layers of zirconium carbide and zirconium oxide on the surface of the surface member 21 has been described. As one variation of each embodiment, a surface member 21 having layers of tantalum carbide (TaC) and tantalum oxide (Ta2O5) may be used instead of zirconium carbide and zirconium oxide. The melting point of tantalum carbide is 2985°C, and the melting point of tantalum oxide is 1872°C. The heat-resistant structure according to this variation is resistant to temperatures up to these melting points. As another variation, a surface member 21 having layers of hafnium carbide (HfC) and hafnium oxide (HfO2) may be used instead of zirconium carbide and zirconium oxide. The melting point of hafnium carbide is 3900°C, and the melting point of hafnium oxide is 2758°C. The heat-resistant structure according to this variation is resistant to temperatures lower than these melting points.

[0090] The heat-resistant structure of the aircraft 1 described in each embodiment can be understood, for example, as follows.

[0091] (1) The heat-resistant structure of the aircraft 1 according to the first embodiment comprises a tip section 20, 30, 40, 50 and a body section 10. The tip sections 20, 30, 40, 50 are located at the front of the aircraft 1 with respect to the direction of travel X. The body section 10 is located behind the tip sections with respect to the direction of travel. The tip sections 20, 30, 40, 50 comprise surface members 21, 31, 41, 51, base sections 23, 33, 43, 53 and heat insulating members 22, 32, 42, 52. The surface members 21, 31, 41, 51 are located on the outer surface of the tip sections 20, 30, 40, 50 and have a melting point higher than the desired temperature. The base sections 23, 33, 43, 53 connect the surface members 21, 31, 41, 51 to the body section 10. The insulating members 22, 32, 42, and 52 are positioned between the surface members 21, 31, 41, and 51 and the base members 23, 33, 43, and 53 to insulate the base members 23, 33, 43, and 53 from the surface members 21, 31, 41, and 51.

[0092] The heat-resistant structure of the aircraft 1 according to the first embodiment has a three-layer structure in which surface members 21, 31, 41, and 51 having high melting points, heat insulating members 22, 32, 42, and 52, and base parts 23, 33, 43, and 53 are stacked in this order, thereby protecting the fuselage portion 10 of the aircraft 1 from heat generated at the front end in the direction of travel of the aircraft 1.

[0093] (2) The heat-resistant structure of the aircraft 1 according to the second embodiment is the heat-resistant structure of the aircraft 1 according to the first embodiment, wherein the surface members 21, 31, 41, and 51 are provided with a heat-resistant material containing a zirconium alloy on at least the outer surface of the carbon fiber reinforced carbon composite material 6 having the shape of the surface members 21, 31, 41, and 51.

[0094] The heat-resistant structure of the aircraft 1 according to the second embodiment has the effect of having excellent heat resistance by arranging a heat-resistant material having a very high melting point on its outer surface.

[0095] (3) The heat-resistant structure of the aircraft 1 according to the third embodiment is the heat-resistant structure of the aircraft 1 according to the second embodiment, wherein the density of the zirconium alloy in the heat-resistant material decreases continuously from front to rear with respect to the direction of travel X.

[0096] The heat-resistant structure of the aircraft 1 according to the third embodiment has the effect of effectively utilizing the heat-resistant performance of the heat-resistant structure by placing the part of the heat-resistant material with the highest heat resistance performance at the front tip, which is the hottest point when the aircraft 1 moves through the atmosphere. Furthermore, by continuously changing the heat resistance performance of the heat-resistant material, the stress caused by the temperature distribution of the heat-resistant material is continuously distributed, thereby preventing damage to the insulation material.

[0097] (4) The heat-resistant structure of the aircraft 1 according to the fourth embodiment is the heat-resistant structure of the aircraft 1 according to any of the first to third embodiments, wherein the surface members 21, 31, 41, 51 are provided with surface member protrusions 211, 311, 411, 511 that project from the inner surface of the surface members 21, 31, 41, 51 toward the internal space of the surface members 21, 31, 41, 51. The tip portions 20, 30, 40, 50 further comprise contact members 24, 34, 35, 44, 54 and connecting members 25, 36, 45, 56. At least a portion of the contact members 24, 35, 44, 54 are positioned in front of the surface member protrusions 211, 311, 411, 511 in the direction of travel and contact the front surface of the surface member protrusions 211, 311, 411, 511. The connecting members 25, 36, 45, and 56 connect the contact members 24, 34, 35, 44, and 54 to the bases 23, 33, 43, and 53. The bases 23, 33, 43, and 53 are provided with base contact surfaces that receive reaction forces from the surface members 21, 31, 41, and 51 from the front.

[0098] The heat-resistant structure of the aircraft 1 according to the fourth embodiment has the effect of receiving the reaction forces from the surface members 21, 31, 41, and 51 at the bases 23, 33, 43, and 53 by connecting the surface members 21, 31, 41, and 51 to the bases 23, 33, 43, and 53.

[0099] (5) The heat-resistant structure of the aircraft 1 according to the fifth embodiment is the heat-resistant structure of the aircraft 1 according to the fourth embodiment, wherein the contact member 24 comprises a clamping portion 241 and a contact member projection 242. The clamping portion 241 clamps the heat-insulating member 22 between itself and the inner surface. The contact member projection 242 protrudes outward from the outer surface of the contact member 24 and contacts the front surface of the surface member projection 211. The connecting member 25 comprises a bolt 25 that fastens the base portion 23 to the contact member 24.

[0100] The heat-resistant structure of the aircraft 1 according to the fifth embodiment has the effect of reducing the volume of the heat-insulating member 22 by connecting the surface member 21 and the contact member 24 and sandwiching the heat-insulating member 22 between them.

[0101] (6) The heat-resistant structure of the aircraft 1 according to the sixth embodiment is the heat-resistant structure of the aircraft 1 according to the fifth embodiment, wherein the abutment member 24 further comprises an abutment member recess 243. The abutment member recess 243 is arranged adjacent to the abutment member projection 242 in the circumferential direction R perpendicular to the direction of travel, and is formed so that the surface member projection 211 can pass through when the abutment member 24 is moved in the direction of travel into the internal space of the surface member 21. The surface member 21 further comprises a surface member recess 212. The surface member recess 212 is arranged adjacent to the surface member projection 211 in the circumferential direction R, and is formed so that the abutment member projection 242 can pass through when the abutment member 24 is moved in the direction of travel into the internal space of the surface member 21. The base portion 23 comprises a circumferential restraint portion 231. The circumferential restraint portion 231 is formed to be insertable from rear to front so as to restrain the surface member 21 and the abutment member 24 in the circumferential direction R, by penetrating the overlapping surface member recesses 212 and 243 when the base portion 23 is moved in the direction of travel so as to abut the abutment member 24, with the abutment member projection 242 positioned in front of the surface member projection 211 with respect to the direction of travel X.

[0102] The heat-resistant structure of the aircraft 1 according to the sixth embodiment has the effect of restraining the surface member 21 and the contact member 24 by the base 23 so that they do not rotate relative to each other in the circumferential direction R.

[0103] (7) The heat-resistant structure of the aircraft 1 according to the seventh embodiment is the heat-resistant structure of the aircraft 1 according to the fifth or sixth embodiment, wherein the tip portion 20 further comprises a gasket 261. The gasket 261 is positioned between the surface member 21 and the base portion 23 to relieve stress generated by the heating and deformation of the surface member 21.

[0104] The heat-resistant structure of the aircraft 1 according to the seventh embodiment has the effect of mitigating the stress generated when the surface member 21 is heated and deformed.

[0105] (8) The heat-resistant structure of the aircraft 1 according to the eighth embodiment is the heat-resistant structure of the aircraft 1 according to the fifth or sixth embodiment, wherein the tip portion 20 further comprises a biasing device 262. The biasing device 262 biases a bolt 25 that penetrates the base portion 23 and fastens to the contact member 24 toward the rear, thereby relieving stress generated by the heating and deformation of the surface member 21.

[0106] The heat-resistant structure of the aircraft 1 according to the eighth embodiment has the effect of mitigating the stress generated when the surface member 21 is heated and deformed.

[0107] (9) The heat-resistant structure of the aircraft 1 according to the ninth embodiment is the heat-resistant structure of the aircraft 1 according to the fourth embodiment, wherein the surface member 31 further comprises a groove 313 and a surface member contact portion 314. The groove 313 is provided in front of the surface member projection 311 and around the inner wall surface 310 of the surface member 31 in a circumferential direction R perpendicular to the direction of travel. The surface member contact portion 314 is provided in front of the groove 313 and protrudes from the surface member projection 311 toward the internal space. The contact members 34 and 35 each comprise a C-type retaining ring 35 and a fixing member 34. The C-type retaining ring 35 is fitted into the groove 313. The fixing member 34 is sandwiched between the C-type retaining ring 35 and the surface member contact portion 314. The fixing member 34 comprises a bolt portion 341 extending to the rear. The base portion 33 has a hole through which the bolt portion 341 passes when it is connected to the contact members 34 and 35. The connecting member 36 has a nut 36 for fastening the bolt portion 341 to the base portion.

[0108] The heat-resistant structure of the aircraft 1 according to the ninth embodiment has the effect of connecting the surface member 31 and the fixing member 34 and securing a space between them for arranging the heat insulating member 32.

[0109] (10) The heat-resistant structure of the aircraft 1 according to the tenth embodiment is the heat-resistant structure of the aircraft 1 according to the fourth embodiment, wherein the surface member projection 411 is provided with a passage 412 for filling the internal space of the surface member 41 with an insulating member 42 from the outside. The connecting member 45 connects the base 43 to the surface member 41 by fastening it to the contact member 44 through the surface member projection 411. The base 43 is provided with a base projection 431 that closes the passage 412 by fastening the base 43 to the surface member 41.

[0110] The heat-resistant structure of the aircraft 1 according to the tenth embodiment has the effect of being able to fix each component with a relatively simple structure.

[0111] (11) The heat-resistant structure of the aircraft 1 according to the eleventh embodiment is the heat-resistant structure of the aircraft 1 according to the fourth embodiment, wherein the surface member projection 511 includes a passage 512 provided for filling the internal space of the surface member 51 with heat insulating members 52A and 52B from the outside. The abutment member 54 includes a coupling portion 544 that is coupled to the coupling member 56, a plurality of return portions 541 that are connected to the coupling portion 544 and locked to the passage 512, a plurality of shaft portions 542 that each connect the plurality of return portions 541 to the coupling portion 544, and a through hole 543 around which the plurality of shaft portions 542 are arranged. The base portion 53 includes a base projection 531 that, when the base portion 53 is coupled to the abutment member 54, passes through the through hole 543 and restrains the plurality of return portions 541 so that they do not come off the surface member projection 511.

[0112] The heat-resistant structure of the aircraft 1 according to the 11th embodiment has the effect of not requiring bolt holes or bolt through holes to be provided in the surface member 51.

[0113] The method for manufacturing the heat-resistant structure of the aircraft 1 described in each embodiment can be understood, for example, as follows.

[0114] (1) A method for manufacturing the heat-resistant structure of the aircraft 1 according to the first embodiment includes manufacturing tip portions 20, 30, 40, and 50 that are positioned at the front of the aircraft 1 in the direction of travel, manufacturing a fuselage portion 10 that is positioned behind the tip portions 20, 30, 40, and 50 in the direction of travel X, and manufacturing the aircraft 1 by joining the tip portions 20, 30, 40, and 50 and the fuselage portion 10. Manufacturing the tip portions 20, 30, 40, and 50 includes manufacturing surface members 21, 31, 41, and 51 that are provided to cover the surface of the tip portions 20, 30, 40, and 50 and have a melting point higher than a desired temperature; manufacturing base portions 23, 33, 43, and 53 that connect the surface members 21, 31, 41, and 51 to the body portion 10; and arranging insulating members 22, 32, 42, and 52 between the surface members 21, 31, 41, and 51 and the base portions 23, 33, 43, and 53 to insulate the base portions 23, 33, 43, and 53 from the surface members 21, 31, 41, and 51. Manufacturing the surface members 21, 31, 41, and 51 involves immersing a carbon fiber reinforced carbon composite material 6 having the shape of the surface members 21, 31, 41, and 51 in molten zirconium so that zirconium impregnates at least the outer surface of the carbon fiber reinforced carbon composite material 6 and the carbon of the carbon fiber reinforced carbon composite material, which is the base material, reacts with the zirconium to form a zirconium alloy, and then removing the carbon fiber reinforced carbon composite material 6 from the molten zirconium and cooling it.

[0115] The first embodiment of the method for manufacturing the heat-resistant structure of the aircraft 1 provides the effect of protecting the fuselage 10 of the aircraft 1 from heat generated at the front end in the direction of travel of the aircraft 1 by manufacturing a heat-insulating structure having a three-layer structure in which surface members 21, 31, 41, and 51 having high melting points, heat-insulating members 22, 32, 42, and 52, and base parts 23, 33, 43, and 53 are stacked in this order. Furthermore, the second embodiment of the method for manufacturing the heat-resistant structure of the aircraft 1 provides excellent heat resistance by arranging a heat-resistant material having a very high melting point on the outer surface.

[0116] (2) The method for manufacturing the heat-resistant structure of the aircraft 1 according to the second embodiment is the heat-resistant structure of the aircraft 1 according to the first embodiment, wherein the manufacturing of the surface member is to impregnate the carbon fiber reinforced carbon composite material with molten zirconium starting from the front end and to pull it out of the molten zirconium starting from the rear, such that the density of the zirconium alloy in the carbon fiber reinforced carbon composite material decreases continuously from front to rear in the direction of travel. It also includes.

[0117] The method for manufacturing the heat-resistant structure of the aircraft 1 according to the second embodiment has the effect of effectively utilizing the heat-resistant performance of the heat-resistant structure by manufacturing it so that the part of the heat-resistant material with the highest heat resistance is placed at the front tip, which is the hottest point when the aircraft 1 moves through the atmosphere. Furthermore, the method for manufacturing the heat-resistant structure of the aircraft 1 according to the second embodiment has the effect of preventing damage to the insulation material by continuously distributing the stress caused by the temperature distribution of the heat-resistant material by manufacturing it so that the heat resistance performance of the heat-resistant material is continuously changed. [Explanation of symbols]

[0118] 1. Flying object 10 Torso 11 Surface member 13 Base 20 Tip 200 areas 21 Surface member 211 Surface member protrusions 212 Surface member recess 22 Insulation material 23 Base 231 Circumferential restraint part 24 Contact Member 241 Clamping part (outer surface) 242 Contact member projection 243 Contact member recess 25 bolts (connecting members) 250 bolt holes 261 Gasket 262 Disc spring (biasing device) 30 Tip 31 Surface material 310 Interior wall surface 311 Surface member protrusions 312 Surface member stepped portion 313 Groove 314 Surface member contact part 32 Insulation material 320 Exterior wall surface 33 Base 331 Through hole 34 Fixing members (connecting members) 341 Bolt section 342 Outer periphery 35 C-type retaining ring (contact member) 351 Spring section 352 End 353 End 36. Nut (connecting component) 37 Washers 40 Tip 41 Surface member 411 Surface member protrusions 412 Through-hole (passage) 413 Bolt through hole 42 Insulation material 43 Base 431 Base protrusion 432 Bolt through holes 44 Fastening members (contact members) 441 bolt holes 45 bolts (connecting members) 50 Tip 51 Surface member 511 Surface member protrusions 512 Engagement hole (passage) 52A, 52B Insulation material 53 Base 531 Base protrusion 532 Bolt through holes 54 Comb teeth member (contact member) 541 Return section 542 Shaft 543 Through hole 544 Bolt holes (connecting parts) 55 Sims 551 Through hole 552 Bolt through hole 56 Bolts (connecting members) 6. Carbon Fiber Reinforced Carbon Composite Materials 60 Carbon fiber reinforced carbon composite materials 61 Zirconium carbide 70 Zirconium 71 Molten Zirconium 72 Zirconium molten metal 81 Crucible stand 82 Carbon Crucible 83 Carbon Heater 84 Lifting device

Claims

1. The tip is positioned at the front end relative to the direction of the aircraft's movement, A body portion positioned behind the tip portion with respect to the aforementioned direction of travel, Equipped with, The aforementioned tip portion is A surface member disposed on the outer surface of the tip portion and having a melting point higher than the desired temperature, The base portion that connects the surface member to the body portion, The system comprises a heat insulating member disposed between the surface member and the base, which insulates the base from the surface member. The surface member is A heat-resistant material containing a zirconium alloy is provided on at least the outer surface of a carbon fiber reinforced carbon composite material having the shape of the surface member, The heat-resistant material is formed such that the density of the zirconium alloy decreases continuously from the front to the rear in the direction of travel. Heat-resistant structure for aircraft.

2. In the heat-resistant structure of the aircraft according to claim 1, The surface member is The surface member is provided with a projection that extends from the inner surface of the surface member toward the internal space of the surface member, The aforementioned tip portion is At least a portion of the contact member is positioned in front of the surface member projection with respect to the direction of travel, and contacts the surface in front of the surface member projection, The system further comprises a connecting member that connects the contact member and the base, The aforementioned base is, It includes a base contact surface that receives a reaction force from the surface member from the front. Heat-resistant structure for aircraft.

3. In the heat-resistant structure of the aircraft according to claim 2, The aforementioned contact member is A clamping portion that holds the heat insulating member between the inner surface and the clamping portion, The abutment member comprises a projection that protrudes outward from the outer surface of the abutment member and abuts against the surface in front of the surface member projection, The aforementioned connecting member is Bolts that fasten the base to the contact member Equipped with Heat-resistant structure for aircraft.

4. A tip portion positioned at the front end of the aircraft in the direction of travel, It comprises a body portion positioned behind the tip portion with respect to the aforementioned direction of travel, The aforementioned tip portion is A surface member disposed on the outer surface of the tip portion and having a melting point higher than the desired temperature, The base portion that connects the surface member to the body portion, The system comprises a heat insulating member disposed between the surface member and the base, which insulates the base from the surface member. The surface member is The surface member is provided with a projection that extends from the inner surface of the surface member toward the internal space of the surface member, The aforementioned tip portion is At least a portion of the contact member is positioned in front of the surface member projection with respect to the direction of travel, and contacts the surface in front of the surface member projection, The system further comprises a connecting member that connects the contact member and the base, The aforementioned base is, It is equipped with a base contact surface that receives the reaction force from the surface member from the front. The aforementioned contact member is A clamping portion that holds the heat insulating member between the inner surface and the clamping portion, The contact member comprises a contact member projection that protrudes outward from the outer surface of the contact member and contacts the surface in front of the surface member projection, The aforementioned connecting member is The base portion is equipped with bolts for fastening to the contact member. The aforementioned contact member is The abutment member recess is further provided, which is arranged adjacent to the abutment member projection in the circumferential direction perpendicular to the direction of travel, and is formed so that the surface member projection can pass through when the abutment member moves into the internal space of the surface member in the direction of travel. The surface member is The surface member further comprises a recess that is arranged adjacent to the surface member projection in the circumferential direction and is formed so that the contact member projection can pass through when the contact member moves in the direction of travel into the internal space of the surface member, The aforementioned base is, With the abutment member projection positioned in front of the surface member projection in the direction of travel, the base is moved in the direction of travel to abut the abutment member, and the circumferential restraint portion is provided, which is formed to be insertable from the rear to the front so as to penetrate the overlapping surface member recess and the abutment member recess and restrain the surface member and the abutment member in the circumferential direction. Heat-resistant structure for aircraft.

5. In the heat-resistant structure of the aircraft according to claim 3 or 4, The aforementioned tip portion is The facility further comprises a gasket positioned between the surface member and the base to relieve stress generated by the deformation of the surface member due to heating. Heat-resistant structure for aircraft.

6. In the heat-resistant structure of the aircraft according to claim 3 or 4, The aforementioned tip portion is The bolt, which penetrates the base and is fastened to the contact member, is biased toward the rear. The device further comprises a biasing device for relieving stress generated when the surface member is heated and deformed. Heat-resistant structure for aircraft.

7. A tip portion positioned at the front end of the aircraft in the direction of travel, It comprises a body portion positioned behind the tip portion with respect to the aforementioned direction of travel, The aforementioned tip portion is A surface member disposed on the outer surface of the tip portion and having a melting point higher than the desired temperature, The base portion that connects the surface member to the body portion, The system comprises a heat insulating member disposed between the surface member and the base, which insulates the base from the surface member. The surface member is The surface member is provided with a projection that extends from the inner surface of the surface member toward the internal space of the surface member, The aforementioned tip portion is At least a portion of the contact member is positioned in front of the surface member projection with respect to the direction of travel, and contacts the surface in front of the surface member projection, The system further comprises a connecting member that connects the contact member and the base, The aforementioned base is, It is equipped with a base contact surface that receives a reaction force from the surface member from the front, The surface member is A groove is provided in front of the surface member projection and around the inner wall surface of the surface member in a circumferential direction perpendicular to the direction of travel, A surface member contact portion provided in front of the groove and protruding toward the internal space from the surface member projection, Furthermore, The aforementioned contact member is A C-shaped retaining ring fitted into the groove, The C-shaped retaining ring and the fixing member sandwiched between the surface member contact portion are provided. The aforementioned fixing member is The bolt portion extends to the rear, The aforementioned base is, The contact member is provided with a hole through which the bolt portion passes when it is connected to the contact member, The aforementioned connecting member is The bolt portion is equipped with a nut for fastening to the base. Heat-resistant structure for aircraft.

8. A tip portion positioned at the front end of the aircraft in the direction of travel, It comprises a body portion positioned behind the tip portion with respect to the aforementioned direction of travel, The aforementioned tip portion is A surface member disposed on the outer surface of the tip portion and having a melting point higher than the desired temperature, The base portion that connects the surface member to the body portion, The system comprises a heat insulating member disposed between the surface member and the base, which insulates the base from the surface member. The surface member is The surface member is provided with a projection that extends from the inner surface of the surface member toward the internal space of the surface member, The aforementioned tip portion is At least a portion of the contact member is positioned in front of the surface member projection with respect to the direction of travel, and contacts the surface in front of the surface member projection, The system further comprises a connecting member that connects the contact member and the base, The aforementioned base is, It is equipped with a base contact surface that receives a reaction force from the surface member from the front, The surface member protrusion is It includes a passage provided for filling the internal space of the surface member with the heat insulating material from the outside, The connecting member fastens its base to the surface member by penetrating the projection of the surface member and fastening it to the contact member. The aforementioned base is, The base portion is provided with a base projection that closes the passage by fastening the base portion to the surface member. Heat-resistant structure for aircraft.

9. A tip portion positioned at the front end of the aircraft in the direction of travel, It comprises a body portion positioned behind the tip portion with respect to the aforementioned direction of travel, The aforementioned tip portion is A surface member disposed on the outer surface of the tip portion and having a melting point higher than the desired temperature, The base portion that connects the surface member to the body portion, The system comprises a heat insulating member disposed between the surface member and the base, which insulates the base from the surface member. The surface member is The surface member is provided with a projection that extends from the inner surface of the surface member toward the internal space of the surface member, The aforementioned tip portion is At least a portion of the contact member is positioned in front of the surface member projection with respect to the direction of travel, and contacts the surface in front of the surface member projection, The system further comprises a connecting member that connects the contact member and the base, The aforementioned base is, It is equipped with a base contact surface that receives a reaction force from the surface member from the front, The surface member protrusion is It includes a passage provided for filling the internal space of the surface member with the heat insulating material from the outside, The aforementioned contact member is The coupling portion that connects to the coupling member, A plurality of return portions connected to the aforementioned joint and locked into the aforementioned passage, Multiple shaft portions, each connecting to the aforementioned multiple return portions, The facility comprises a through hole in which the plurality of shaft portions are arranged around the periphery, The aforementioned base is, With the base portion connected to the contact member, the multiple It is equipped with a base projection that restrains the return portion so as not to detach from the surface member projection. Heat-resistant structure for aircraft.

10. To manufacture the front end that is positioned at the front of the aircraft in relation to its direction of travel, To manufacture a fuselage section positioned behind the front end in the direction of travel, This includes manufacturing the aircraft by joining the aforementioned front end and the aforementioned fuselage, Manufacturing the aforementioned tip portion To manufacture a surface member that covers the surface of the tip portion and has a melting point higher than a desired temperature, To manufacture a base for connecting the surface member to the body portion, This includes placing an insulating member between the surface member and the base to insulate the base from the surface member, Manufacturing the aforementioned surface member involves, The carbon fiber reinforced carbon composite material having the shape of the surface member is immersed in molten zirconium such that zirconium is impregnated into at least the outer surface of the carbon fiber reinforced carbon composite material, and the carbon of the carbon fiber reinforced carbon composite material, which is the base material, reacts with the zirconium to form a zirconium alloy. This includes withdrawing the carbon fiber reinforced carbon composite material from the molten zirconium and cooling it, Manufacturing the surface member further includes impregnating the carbon fiber reinforced carbon composite material with the molten zirconium first from the front end and withdrawing it from the molten zirconium first from the rear end, thereby continuously shortening the immersion time in the molten zirconium as the surface member moves from the front to the rear, so that the density of the zirconium alloy in the carbon fiber reinforced carbon composite material decreases continuously as it moves from the front to the rear with respect to the direction of travel. A method for manufacturing the heat-resistant structure of an aircraft.

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