The present disclosure relates to a member used for an aircraft, a satellite, or the like.
An aircraft includes a heat-generating section such as an electronic device, a battery, or an engine. Heat generated in the heat-generating section is released (exhausted) through a member called a heat passage member. Conventionally, as the heat passage member for an aircraft, a metal sheet or a jumper wire is used. Japanese Unexamined Utility Model (Registration) Application Publication No. 05-086799 discloses an example of a heat flow control body having a paper honeycomb core used in a satellite.
In recent years, a material of a member for an aircraft has been changed from metal to a composite material. In addition, use of an electronic device has been increased along with advancement of an aircraft. That is, in recent years, the amount of heat generated in a heat-generating section has been increased while thermal conductivity of a member for an aircraft has been decreased. Therefore, development of a technique capable of releasing heat generated in a heat-generating section efficiently has been desired.
An object of an aspect of the present disclosure is to provide a member capable of releasing heat generated in a heat-generating section of an aircraft, a satellite, or the like efficiently.
According to a first aspect of the present disclosure, there is provided a member comprising a first composite member containing a plastic reinforced with a thermally conductive carbon fiber containing one or both of a metal-coated carbon fiber and a pitch-based carbon fiber, wherein one end of the thermally conductive carbon fiber is disposed in a heat-generating section, and the other end of the thermally conductive carbon fiber is disposed in a heat-radiating section in a fiber direction.
According to a first aspect of the present disclosure, a first composite member contains a carbon fiber reinforced plastic reinforced with a thermally conductive carbon fiber containing a metal-coated carbon fiber and/or a pitch-based carbon fiber. One end of the thermally conductive carbon fiber is disposed in a heat-generating section, and the other end thereof is disposed in a heat-radiating section. Therefore, heat generated in the heat-generating section is transferred through the thermally conductive carbon fiber, and is released efficiently to the heat-radiating section. In addition, the first composite member can be used as a strength member for an aircraft, a satellite, or the like. Therefore, heat generated in the heat-generating section can be released to the heat-radiating section without separately disposing a dedicated heat passage member such as a metal sheet or a jumper wire. Therefore, heat generated in the heat-generating section is released efficiently to the heat-radiating section while suppressing an increase in a weight. In addition, the thermally conductive carbon fibers and a plastic are molded together, and therefore robustness is improved.
According to a first aspect of the present disclosure, there is provided a member comprising a first composite member containing a plastic reinforced with a thermally conductive carbon fiber containing one or both of a metal-coated carbon fiber and a pitch-based carbon fiber, wherein a central portion of the thermally conductive carbon fiber is disposed in a heat-generating section, and each of one end and the other end of the thermally conductive carbon fiber is disposed in a heat-radiating section in a fiber direction.
According to a second aspect of the present disclosure, a central portion of a thermally conductive carbon fiber is disposed in a heat-generating section, and each of one end and the other end thereof is disposed in a heat-radiating section. Therefore, heat generated in the heat-generating section is transferred through the thermally conductive carbon fiber, and is released efficiently to the heat-radiating section. Therefore, heat generated in the heat-generating section is released efficiently to the heat-radiating section while suppressing an increase in a weight. In addition, the thermally conductive carbon fibers and a plastic are molded together, and therefore robustness is improved.
The above and other objects, features, advantages and technical and industrial significance of this disclosure will be better understood by reading the following detailed description of presently preferred embodiments of the disclosure, when considered in connection with the accompanying drawings.
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. Components of the embodiments described below can be combined with one another appropriately. Some components are not used in some cases.
A first embodiment will be described.
At least a part of the fuselage 2, the main wing 3, the horizontal stabilizer 4, and the vertical stabilizer 5 is formed of a composite material. The composite material contains a carbon fiber reinforced plastic (CFRP) which is a plastic reinforced with a carbon fiber. Note that the composite material may contain a glass fiber reinforced plastic (GFRP) which is a plastic reinforced with a glass fiber.
Note that at least a part of the fuselage 2, the main wing 3, the horizontal stabilizer 4, and the vertical stabilizer 5 may be formed of a metal such as an aluminum alloy (duralumin).
In the present embodiment, at least a part of a member of the aircraft 1 contains a metal-coated carbon fiber reinforced plastic which is a plastic reinforced with a metal-coated carbon fiber (MC). The plastic reinforced with a metal-coated carbon fiber is also referred to as MC-CFRP. The metal-coated carbon fiber is a thermally conductive carbon fiber having thermal conductivity.
The composite member 11 contains a plurality of the metal-coated carbon fibers 12. Each of the metal-coated carbon fibers 12 is long in a first direction. The plurality of metal-coated carbon fibers 12 is arranged in parallel in a second direction perpendicular to the first direction. In addition, the plurality of metal-coated carbon fibers 12 is disposed in a third direction perpendicular to the first direction and the second direction.
In the following description, a longitudinal direction (first direction) of the metal-coated carbon fibers 12 is referred to as a fiber direction at need. In addition, in the following description, a direction (second direction) in which the plurality of metal-coated carbon fibers 12 is arranged in parallel is referred to as a parallel direction at need. In addition, in the following description, a direction (third direction) in which the plurality of metal-coated carbon fibers 12 is stacked is referred to as a stacked direction at need.
The plurality of metal-coated carbon fibers 12 is disposed at intervals in each of the parallel direction and the stacked direction. The plastic 13 is disposed among the plurality of metal-coated carbon fibers 12. In the present embodiment, the plastic 13 contains epoxy resin.
For example, the carbon fiber 15 of the metal-coated carbon fiber 12 has a diameter of 5 μm or more and 10 μm or less. A surface of the carbon fiber 15 is coated with the metal 16. The metal 16 has a higher thermal conductivity than the carbon fiber 15. The plastic 13 has a lower thermal conductivity than the metal 16 and the carbon fiber 15. That is, the plastic 13 has a lower thermal conductivity than the metal-coated carbon fiber 12.
In the present embodiment, the metal 16 is nickel. The metal-coated carbon fiber 12 is a nickel-coated carbon fiber. Note that the metal 16 may be at least one of gold, silver, and copper.
As illustrated in (step B) in
The parallel direction is a direction in which the plurality of metal-coated carbon fibers 12 disposed in the fiber direction is arranged. The fiber direction is perpendicular to the parallel direction.
A sheet-like member including the plastic 13 and the plurality of metal-coated carbon fibers 12 disposed in the parallel direction and hardened with the plastic 13 is referred to as a prepreg sheet 17.
As illustrated in (step C) in
The stacking direction is a direction in which the plurality of prepreg sheets 17 is stacked. The stacking direction is perpendicular to the fiber direction and the parallel direction.
A stacked body of the prepreg sheets 17 is subjected to a heat treatment at a high temperature at a high pressure with a heating and pressing device called an autoclave. The composite member 11 of a stacked body in which the plurality of prepreg sheets 17 is stacked is thereby manufactured.
Note that in the present embodiment, all the metal-coated carbon fibers 12 in the plurality of prepreg sheets 17 are disposed in the same direction, that is, so-called one direction stacking is performed. So-called cross-ply stacking in which the metal-coated carbon fibers 12 in the first prepreg sheet 17 are disposed in the first direction and the metal-coated carbon fibers 12 in the second prepreg sheet 17 overlapping the first prepreg sheet 17 are disposed in the second direction crossing the first direction of the first prepreg sheet 17 may be performed.
For example, the member 20 may be manufactured by stacking a prepreg sheet containing the metal-coated carbon fibers 12 and a prepreg sheet containing the carbon fibers not coated with metal, and subjecting the stacked body to a heat and pressure treatment with an autoclave.
As illustrated in
For example, the heat-generating section of the aircraft 1 includes at least one of the electronic device 9, the battery 10, and the engine 6 of the aircraft 1. In addition, the heat-generating section includes a housing of the electronic device 9. For example, the heat-radiating section of the aircraft 1 includes the fuel tank 7 of the aircraft 1. Note that the heat-radiating section of the aircraft 1 may be an external space (space facing an outer surface of the fuselage 2) of the aircraft 1.
The composite member 11 is a plate-like member. In the example illustrated in
The carbon fiber of the carbon fiber reinforced plastic in the composite member 21 is not coated with metal. A thermal conductivity of the composite member 21 in the fiber direction is lower than a thermal conductivity of the composite member 11 in the fiber direction. A thermal conductivity of the composite member 21 in the parallel direction is lower than a thermal conductivity of the composite member 11 in the fiber direction. A thermal conductivity of the composite member 21 in the stacked direction is lower than a thermal conductivity of the composite member 11 in the fiber direction.
The thermal conductivity of the composite member 21 in the parallel direction may be equal to or lower than the thermal conductivity of the composite member 11 in the parallel direction. The thermal conductivity of the composite member 21 in the stacking direction may be equal to or lower than the thermal conductivity of the composite member 11 in the stacking direction.
The composite member 21 is not disposed in each of the one end 12A and the other end 12B of the metal-coated carbon fibers 12. Each of the one end 12A and the other end 12B of the metal-coated carbon fibers 12 is exposed. The one end 12A of the metal-coated carbon fibers 12 is in contact with the heat-generating section. The one end 12A of the metal-coated carbon fibers 12 may face the heat-generating section with a gap. The other end 12B of the metal-coated carbon fibers 12 is in contact with the heat-radiating section. The other end 12B of the metal-coated carbon fibers 12 may face the heat-radiating section with a gap.
It may be possible that the composite member 21 is disposed on the front surface of the composite member 11 and is not disposed on the back surface of the composite member 11. It may be possible that the composite member 21 is disposed on the back surface of the composite member 11 and is not disposed on the front surface of the composite member 11. It may be possible that the composite member 21 is not disposed on both of the front and back surfaces of the composite member 11.
The metal-coated carbon fibers 12 are disposed in the fiber direction of the member 20. The plastic 13 is disposed among the plurality of metal-coated carbon fibers 12 in each of the parallel direction and the stacking direction of the member 20. The thermal conductivity of the member 20 in the fiber direction is larger than the thermal conductivity of the member 20 in each of the parallel direction and the stacking direction.
Heat of the heat-generating section is absorbed by the metal-coated carbon fibers 12 through the one end 12A. The heat absorbed by the metal-coated carbon fibers 12 is transferred through the metal-coated carbon fibers 12, and is released (exhausted) from the other end 12B.
The thermal conductivity of the member 20 in each of the parallel direction and the stacking direction is smaller than the thermal conductivity of the member 20 in the fiber direction. Therefore, heat of the metal-coated carbon fibers 12 is exclusively moved in the fiber direction. Transfer of heat of the metal-coated carbon fibers 12 in the parallel direction and the stacking direction is suppressed.
In the present embodiment, the composite member 21 is disposed in each of the front and back surfaces of the composite member 11 in the stacking direction. The heat transfer coefficient of the composite member 21 in each of the fiber direction, the parallel direction, and the stacking direction is smaller than the heat transfer coefficient of the composite member 11 in the fiber direction. Therefore, release of heat of the metal-coated carbon fibers 12 from a surface of the composite member 21 is suppressed.
As described above, according to the present embodiment, the composite member 11 contains the metal-coated carbon fiber reinforced plastic 14 reinforced with the metal-coated carbon fibers 12, the one end 12A of the metal-coated carbon fibers 12 is disposed in the heat-generating section of the aircraft 1, and the other end 12B of the metal-coated carbon fibers 12 is disposed in the heat-radiating section of the aircraft 1. The metal 16 of the metal-coated carbon fibers 12 has a high thermal conductivity. Therefore, heat generated in the heat-generating section is transferred through the metal-coated carbon fibers 12, and is released efficiently to the heat-radiating section.
In addition, the composite member 11 can be used as a strength member for the aircraft 1. Therefore, heat generated in the heat-generating section can be released to the heat-radiating section without separately disposing a dedicated heat passage member such as a metal sheet or a jumper wire, disposed in prior art. Therefore, heat generated in the heat-generating section of the aircraft 1 is released efficiently to the heat-radiating section while suppressing an increase in the weight of the aircraft 1.
In the present embodiment, the composite member 11 contains a stacked body obtained by stacking the plurality of prepreg sheets 17, each of which contains the plurality of metal-coated carbon fibers 12 disposed in the parallel direction crossing the fiber direction, in the stacking direction crossing the fiber direction and the parallel direction. The thermal conductivity of the member 20 in the fiber direction is larger than the thermal conductivity of the member 20 in the parallel direction and the thermal conductivity of the member 20 in the stacking direction. This imparts anisotropy to the thermal conductivity, and transfer of heat generated in the heat-generating section in the parallel direction and the stacking direction is suppressed, and is released efficiently to the heat-radiating section. For example, when a member or a device which is undesirable for being heated is present in at least one of the parallel direction and the stacking direction of the member 20, the member 20 with anisotropy in the thermal conductivity suppresses transfer of heat to the member or the device.
In the present embodiment, the composite member 11 is a plate-like member, and the member 20 contains the composite member 21 containing a carbon fiber reinforced plastic, disposed on the front surface and/or the back surface of the composite member 11. The composite member 11 is thereby supported by the composite member 21, and the strength is maintained. In addition, the composite member 21 has a smaller thermal conductivity than the composite member 11 in the fiber direction. Therefore, when a member or a device which is undesirable for being heated is present in at least one of the parallel direction and the stacking direction of the member 20, the composite member 21 suppresses transfer of heat to the member or the device.
In addition, in the present embodiment, each of the one end 12A and the other end 12B of the metal-coated carbon fibers 12 is not coated with the composite member 21 or the like, but is exposed. Since the one end 12A is exposed, heat generated in the heat-generating section is absorbed efficiently by the metal 16 of the metal-coated carbon fibers 12 through the one end 12A. Since the other end 12B is exposed, heat generated in the heat-generating section and moving in the metal 16 of the metal-coated carbon fibers 12 is released efficiently by the heat-radiating section through the other end 12B. As described above, each of the one end 12A and the other end 12B of the metal-coated carbon fibers 12 is exposed in the present embodiment. Therefore, heat generated in the heat-generating section is released efficiently from the heat-radiating section.
In the present embodiment, the heat-generating section of the aircraft 1 includes the electronic device 9 of the aircraft 1. The heat-radiating section of the aircraft 1 includes the fuel tank 7 of the aircraft 1. Heat generated in the electronic device 9 is thereby efficiently released to the fuel tank 7 even when use of the electronic device 9 is increased along with advancement of the aircraft 1 and heat generated in the electronic device 9 is increased.
A second embodiment will be described. In the following description, the same reference signs are given to components which are the same as or equal to the components in the above embodiment, and description thereof is simplified or omitted.
A third embodiment will be described. In the following description, the same reference signs are given to components which are the same as or equal to the components in the above embodiments, and description thereof is simplified or omitted.
The outer plate 30 and the shear tie 31 are fixed with a fastener 51. The outer plate 30 and the shear tie 31 are fixed by connecting a collar (nut) 37 to an end of the fastener 51. A washer 41 and a spacer 42 are disposed between the collar 37 and the shear tie 31.
The collar 37, the washer 41, and the spacer 42 are covered with a cap 44. The cap 44 is disposed so as to be in close contact with the shear tie 31.
The outer plate 30 includes a carbon fiber reinforced plastic layer 32, a glass fiber reinforced plastic layer 34, and a copper paint layer 39.
A heat-generating section of the aircraft 1 is disposed at the lower end of the shear tie 31. A heat-radiating section of the aircraft 1 is disposed at the upper left end of the shear tie 31.
The other end 12B of the metal-coated carbon fibers 12 in the composite member 11 and the heat-radiating section of the aircraft 1 may be disposed at the upper right end of the shear tie 31. The other end 12B of the metal-coated carbon fibers 12 in the composite member 11 and the heat-radiating section of the aircraft 1 may be disposed at each of the upper right end and the upper left end of the shear tie 31. The one end 12A of the metal-coated carbon fibers 12 in the composite member 11 and the heat-generating section of the aircraft 1 may be disposed at the upper right end and/or the upper left end of the shear tie 31. The other end 12B of the metal-coated carbon fibers 12 in the composite member 11 and the heat-radiating section of the aircraft 1 may be disposed at the lower end of the shear tie 31.
As described above, the composite member 11 and the composite member 21 may be bent, or may be processed into an arbitrary shape (three-dimensional shape).
In each of the above embodiments, a pitch-based carbon fiber may be disposed in place of the metal-coated carbon fibers 12, or together with the metal-coated carbon fibers 12. The pitch-based carbon fiber is a thermally conductive carbon fiber at least having a higher thermal conductivity than a PAN carbon fiber.
Each of the above embodiments has been described as the example in which the member 20 is used for a structural member of the aircraft 1. The member 20 may be used for a structural member of a satellite.
The fiber direction, the parallel direction, and the stacking direction are perpendicular to one another in each of the above embodiments. The fiber direction and the parallel direction may cross each other, for example, at an angle of 80 degrees or more and 100 degrees or less. The fiber direction and the stacking direction may cross each other, for example, at an angle of 80 degrees or more and 100 degrees or less. The parallel direction and the stacking direction may cross each other, for example, at an angle of 80 degrees or more and 100 degrees or less.
As described above, the first composite member may contain a stacked body obtained by stacking a plurality of prepreg sheets, each of which contains a plurality of the thermally conductive carbon fibers disposed in a parallel direction crossing the fiber direction, in a stacking direction crossing the fiber direction and the parallel direction, and a thermal conductivity in the fiber direction is larger than a thermal conductivity in each of the parallel direction and the stacking direction.
This acquires anisotropy in the thermal conductivity. Therefore, transfer of heat generated in the heat-generating section in a parallel direction and a stacking direction is suppressed, and is released efficiently to the heat-radiating section.
As described above, the first composite member may be a plate-like member, the member includes a second composite member containing a plastic reinforced with a carbon fiber, disposed on one or both of front and back surfaces of the first composite member, and each of the one end and the other end of the thermally conductive carbon fiber is exposed.
The first composite member is thereby supported by a second composite member, and the strength is maintained. Each of the one end and the other end of the thermally conductive carbon fiber is not covered with the second composite member but is exposed. Therefore, heat generated in the heat-generating section is released efficiently from the heat-radiating section.
As described above, the heat-generating section may include an electronic device of an aircraft, and the heat-radiating section includes a fuel tank of the aircraft.
Heat generated in an electronic device is thereby efficiently released to a fuel tank even when an amount of heat generated in the electronic device is increased.
An aspect of the present disclosure provides a member capable of releasing heat generated in a heat-generating section efficiently.
Although this disclosure has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.
Number | Date | Country | Kind |
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2014-245346 | Dec 2014 | JP | national |
This application is a national stage of PCT International Application No. PCT/JP2015/080002, filed on Oct. 23, 2015, which claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2014-245346 filed in Japan on Dec. 3, 2014.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2015/080002 | 10/23/2015 | WO | 00 |