JP4236328B2 - Heat-resistant structure and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-resistant structure made of fiber-reinforced composite material used in spacecraft, and more particularly to a heat-resistant structure having an ablation function and a method for manufacturing the same.
[0002]
[Prior art]
This type of heat-resistant structure constitutes, for example, the bottom of a space capsule that enters the atmosphere, and is used as a means of protection against aerodynamic heating when entering the atmosphere. It has the function of cooling with latent heat. Such ablation materials are described in pages 506 to 508, 528, 529, and 529 of “Enhanced Edition / Aerospace Engineering Handbook” published by Maruzen on April 25, 1983. .
[0003]
In recent years, heat-resistant structures used for the bottom of space capsules include a structure in which carbon fiber cloth is laminated as a reinforcing material, and this laminate is impregnated with a thermosetting resin and subjected to a curing treatment. This heat-resistant structure is formed by laminating cloth so as to be oblique with respect to the axis, and forming the outer surface into a substantially spherical surface so that the cloth layer appears on the outer side. In addition, the gas generated by the vaporization of the resin is preferably released from the interlayer of the cloth.
[0004]
[Problems to be solved by the invention]
By the way, it is very important not only to improve the function of the heat-resistant structure used in the spacecraft as described above, but also to reduce the weight. For example, in order to achieve weight reduction and lower thermal conductivity, it is more advantageous to have a structure in which crosses orthogonal to the axis are stacked rather than a structure in which crosses oblique to the axis are stacked. However, when a structure in which crosses orthogonal to the axis are laminated, there is a problem in that delamination of the cloths easily occurs when subjected to aerodynamic heating. In addition, there is a method of chop molding using a cloth chop or a fiber chop, but in this case, there is a problem that the strength is reduced as compared with a laminated structure of cloth. Therefore, in the conventional heat resistant structure, further improvement has been demanded in order to improve the function and reduce the weight.
[0005]
OBJECT OF THE INVENTION
The present invention has been made in view of the above-described conventional situation , and in a heat-resistant structure for a spacecraft made of a fiber-reinforced composite material whose outside is substantially spherical, it is possible to sufficiently obtain an ablation function and strength. An object of the present invention is to provide a heat-resistant structure that can be reduced in weight and a manufacturing method thereof.
[0006]
[Means for Solving the Problems]
A heat-resistant structure according to the present invention is, as claimed in claim 1, a heat-resistant structure for a spacecraft made of a fiber-reinforced composite material whose outer surface is substantially spherical, and has a central portion of the spherical surface with respect to the axis. It has a central laminated part formed by laminating crosses in a direction orthogonal to each other , and on the outer peripheral side of the central laminated part, in a direction from the center to the outer peripheral side, a cross in a direction that intersects the outer surface at an acute angle is laminated. outer circumferential laminated section comprising a structure having a as claimed in claim 2, the inner peripheral side of the outer circumferential laminated section, a structure in which a stepped portion engaged with the inner side of the central laminated part, as claimed in claim 3, the central laminated part In the center part of the slab, a structure including a tip laminated part having a slit and a cross in a direction perpendicular to the axis is provided, and as a fourth aspect , a gas vent passage is provided in the central part of the spherical surface. The above configuration solves the conventional problems. And a means for.
[0007]
A method of manufacturing a refractory structure according to the present invention, as claimed in claim 5, used upon manufacturing a refractory structure according to claim 3 or 4, to form a plurality of slits at predetermined intervals cross slit The cross is laminated in a state where the crosses are sequentially formed to form the tip laminated portion, and as claimed in claim 6 , the slit in the cross is formed in the center of the cross and within a range of 1/2 each of the vertical and horizontal dimensions of the cross. The above configuration is used as means for solving the conventional problems.
[0008]
[Effects of the Invention]
In the heat-resistant structure according to claim 1 of the present invention, in the heat-resistant structure for a spacecraft made of fiber-reinforced composite material whose outer side is substantially spherical, a cross in a direction perpendicular to the axis is formed in the central portion. Since it has a central laminated part that is laminated, the thermal conductivity of the central part that becomes the highest temperature when subjected to aerodynamic heating is lowered by the central laminated part, and the central laminated part is limited to a limited range of the central part. By providing this, it becomes difficult for delamination of cloth to occur, and moreover, since a cloth layer appears on the outside of the central laminated portion, gas generated by aerodynamic heating can escape well from the cloth layer.
[0009]
Further, in the above heat-resistant structure, the outer peripheral laminated portion is provided on the outer peripheral side of the central laminated portion, and the cross of the outer peripheral laminated portion is at an acute angle with respect to the outer surface in the direction from the center to the outer peripheral side. Since the crossing direction, that is, the direction along the flow of gas generated in the central laminated portion when subjected to aerodynamic heating, the delamination of the cloth is prevented and good degassing is performed.
[0010]
In the heat-resistant structure according to claim 2 of the present invention, since the stepped portion that engages the inside of the central laminated portion is provided on the inner peripheral side of the outer laminated portion, the load on the central laminated portion due to air resistance is stepped. Deterred by the division.
[0011]
In the heat-resistant structure according to claim 3 of the present invention, a cross having a slit and a direction perpendicular to the axis is laminated at a further central portion of the central laminated portion that becomes the highest temperature when subjected to aerodynamic heating. Therefore, the resin filled in the slit is gasified and released by aerodynamic heating, and degassing is further improved by the slit.
[0012]
In the heat-resistant structure according to claim 4 of the present invention, since the gas vent passage is provided at the center of the substantially spherical surface, the gas is vented from the center when subjected to aerodynamic heating, and the entire outer surface is excellent. Degassing is performed.
[0013]
In a method for manufacturing a heat-resistant structure according to claim 5 of the present invention, the heat-resistant structure according to claim 3 or 4 , that is, the outer side has a substantially spherical shape and a tip laminated part is provided in the central part of the central laminated part. When manufacturing a heat resistant structure or a heat resistant structure provided with a gas vent passage in the center, a cloth having a plurality of slits formed at predetermined intervals is used. The resin, which is a hardener and a gas generation source, is filled in the slit so that gas can be generated, and the cross is laminated in a state where the slits are sequentially crossed to form the tip laminated portion. Therefore, the strength in the direction along the surface of the cloth is ensured, and a part of the slit is continuously formed in the cloth stacking direction to form a gas vent passage.
[0014]
In the method for manufacturing a heat-resistant structure according to claim 6 of the present invention, the slit in the cloth is formed in the center of the cloth and in the range of 1/2 of the vertical and horizontal dimensions of the cloth. The flat state of the cloth and the slit shape are prevented from being damaged.
[0015]
【The invention's effect】
According to the heat-resistant structure according to claim 1 of the present invention, in the heat-resistant structure for a spacecraft made of fiber-reinforced composite material whose outside is substantially spherical, sufficient strength can be secured by the central laminated portion. At the same time, the thermal conductivity of the central part, which is the highest temperature when subjected to aerodynamic heating, is smaller than that of the cross laminated diagonally, and the structure becomes thinner and lighter as the thermal conductivity decreases. Can be realized. In addition, by providing the central laminated portion in a limited range of the central portion of the structure, it is possible to prevent the delamination of the cloth when subjected to aerodynamic heating and to prevent the interlayer of the cloth on the outside of the central laminated portion. Therefore, good degassing can be performed and an excellent ablation function can be obtained.
[0016]
Further, according to the heat structure described above, the outer circumferential laminated portion provided on the outer peripheral side of the central laminated part, it is possible to prevent cross delamination when subjected to aerodynamic heating, the outer side of the outer peripheral laminate part Oite from the cross between the layers can provide good venting, you are possible to obtain an excellent ablation capabilities.
[0017]
According to the heat-resistant structure according to claim 2 of the present invention, the same effect as in claim 1 can be obtained, and the central laminated portion by air resistance is provided by the step provided on the inner circumferential side of the outer circumferential laminated portion. The load on the cloth is restrained, and the delamination of the cloth in the central laminated portion can be more reliably prevented.
[0018]
According to the heat-resistant structure according to claim 3 of the present invention, the same effects as in claims 1 and 2 can be obtained, and the slits are filled when subjected to aerodynamic heating in the tip laminated portion. A sufficient gas generation amount can be obtained by the resin, and the gas can be vented more satisfactorily by the slit, and the ablation function can be further enhanced.
[0019]
According to the heat-resistant structure according to claim 4 of the present invention, the same effects as those of claims 1 to 3 can be obtained, and aerodynamic heating is applied by the punched passage provided in the central portion of the substantially spherical surface. At the same time, the gas can be vented well from the center, and the gas can be vented from the entire outer surface to further enhance the ablation function.
[0020]
According to the method for manufacturing a heat-resistant structure according to claim 5 of the present invention, when the heat-resistant structure according to claim 3 or claim 4 is manufactured, a cross having a plurality of slits is used, and the slits cross in order. Since the tip laminate is formed by laminating cloth in the state, it is fully filled with the resin that is both a hardener and a gas source without the need for drilling to fill the resin. The resin can be easily filled even after lamination, and the strength in the direction along the surface of the cloth can be secured, and the gas vent passage can be formed very easily in the direction of lamination of the cloth. Thus, a heat-resistant structure that provides the same effect as that of the third or fourth aspect can be obtained.
[0021]
According to the method for manufacturing a heat-resistant structure according to claim 6 of the present invention, the same effect as in claim 5 can be obtained, and the formation range of the slit in the cloth is limited, so that the cloth is laminated. In addition, it is possible to prevent the flat state of the cloth and the shape of the slits from being damaged, the cloth can be easily handled, and the cloth can be laminated regularly and accurately. It is possible to obtain a heat resistant structure including the tip laminated portion.
[0022]
【Example】
Hereinafter, an embodiment of a heat-resistant structure according to the present invention and a method for manufacturing the heat-resistant structure will be described with reference to the drawings.
[0023]
A heat-resistant structure A shown in FIG. 1 constitutes the bottom of a space capsule that re-enters the atmosphere, and has a substantially spherical shape with an outer surface protruding downward, and is formed of a fiber-reinforced composite material. It is.
[0024]
The fiber reinforced composite material is formed by using a carbon fiber as a reinforcing fiber and laminating a cloth in which the carbon fiber is woven vertically and horizontally. In addition, the fiber reinforced composite material uses a cloth impregnated with a thermosetting resin in advance, or a thermosetting resin with the lamination of the cloth, or impregnates the thermosetting resin after the lamination of the cloth, and then pressurizes and A CFRP (carbon fiber reinforced plastic) is obtained by applying a heat curing treatment.
[0025]
The heat-resistant structure A includes the central laminated portion 1 in the central portion of the substantially spherical surface, the outer laminated portion 2 on the outer peripheral side of the central laminated portion 1, and the tip laminated portion 3 in the central portion of the central laminated portion 1. The housing space 4 for the mounted device is formed inside. At this time, the center laminated part 1 is formed in a substantially disk shape, and a heat insulating material 5 is provided on the inside thereof. On the other hand, the outer peripheral laminated portion 2 is formed in an annular shape, and a flange portion 6 for attaching an upper cover (not shown) of the space capsule is provided at the outer peripheral end portion.
[0026]
The central laminated portion 1 is formed by laminating a cross C1 in a direction orthogonal to the axis B of the structure A. The outer peripheral laminated portion 2 is formed by laminating a cross C2 in a direction intersecting at an acute angle θ with respect to the outer surface in the direction from the center of the structure to the outer peripheral side. The front-end laminated portion 3 is formed by laminating a cross C <b> 3 having a slit and orthogonal to the axis B. At this time, each of the stacked portions 1 to 3 is in a state in which the layers of the crosses C1 to C3 appear on the outside.
[0027]
Moreover, the outer periphery laminated part 2 has the step part 7 engaged with the inner side of the center laminated part 1 on the inner peripheral side over the perimeter. Furthermore, the front-end | tip laminated | stacked part 3 has the degassing channel | path 8 in the center part of a substantially spherical surface. These laminated parts 1 to 3 can be combined with those molded and hardened separately from each other, and can also be hardened after combining those molded separately from each other. Further, cutting or the like is also performed so that the outer side becomes a predetermined approximate spherical surface.
[0028]
Here, the front-end | tip lamination | stacking part 3 is manufactured in the way shown in FIG. In this production, a cloth C3 in which a plurality of slits S are formed at a predetermined interval is used. At this time, the cross C3 is formed with a slit S in the center and within a range (x, y) of ½ each of the vertical and horizontal dimensions a and b. By limiting the range in which the slits S are formed in this way, the cross C3 is not damaged in the planar state and the shape of the slits S when laminated, and the handling becomes easy, regularly and accurately. Can be stacked.
[0029]
And the front-end | tip lamination | stacking part 3 is formed by laminating | stacking the cross C3 in the state which the slit S cross | intersects in order. By laminating in this manner, the strength in the direction along the surface of the cross C3 is not impaired by the slits S, and as shown in FIG. The degassing passage 8 can be easily formed continuously in the stacking direction of the cross C3. In addition, although the case where it laminated | stacked so that the slit S might orthogonally showed in the figure, you may laminate | stack so that the slit S may cross | intersect at 45 degree | times in order, for example.
[0030]
The tip laminated part 3 manufactured in this way is filled with resin that is a curing material and also a gas generation source when subjected to aerodynamic heating, and is filled with resin after the cloth C3 is laminated. It is also easy to do, and no drilling or the like for filling the resin is required.
[0031]
The heat-resistant structure A having the above-described structure is obtained by using the cloths C1 to C3 as reinforcing materials, so that sufficient strength is ensured as a whole, and the cloths C1 and C3 orthogonal to the axis B are laminated. Due to the central laminated portion 1 and the tip laminated portion 3, the thermal conductivity of the central portion that becomes the highest temperature when subjected to aerodynamic heating is smaller than that obtained by obliquely laminating the cloth, and this thermal conductivity is reduced. As a result, the structure is made thinner and lighter.
[0032]
And when the space capsule re-enters the atmosphere, the heat-resistant structure A acts as a protection means against aerodynamic heating and protects the mounted equipment from high heat. That is, the heat-resistant structure A has an ablation function in which the resin in each of the stacked portions 1 to 3 is vaporized by aerodynamic heating and is cooled by the latent heat.
[0033]
At this time, the heat-resistant structure A employs the central laminated portion 1 and the tip laminated portion 3 formed by laminating the crosses C1 and C3 orthogonal to the axis B at the central portion where the temperature is highest. Since the range of the portions 1 and 3 is limited to the central portion, and the load on the central laminated portion 1 due to air resistance is suppressed by the step portion 7 of the outer circumferential laminated portion 2, the central laminated portion 1 and the tip laminated portion 3 Thus, delamination between the cloths C1 and C3 is reliably prevented.
[0034]
Further, in the center laminated portion 1 and the tip laminated portion 3, gas is removed from the outer layers of the crosses C1 and C3. In particular, in the tip laminated portion 3, the resin filled in the slits S is vaporized. A sufficient gas generation amount can be obtained, and the gas can be vented more smoothly by the slit S, and further, gas can be vented from the gas vent passage 8 provided at the center.
[0035]
Furthermore, in the outer peripheral laminated portion 2, the gas released from the central laminated portion 1 side flows at high speed along the outer surface, but in the direction from the center of the structure A to the outer peripheral side, that is, in the gas flow direction. On the other hand, since the cloth C2 intersects at an acute angle θ, delamination of the cloth C2 is performed without causing delamination of the cloth C2.
[0036]
Thus, when the heat-resistant structure A is subjected to aerodynamic heating, gas is vented from the entire outer surface including the center, and a good ablation function can be obtained.
[0037]
The details of the structure of the heat-resistant structure according to the present invention are not limited to the above-mentioned embodiments, and the diameter and thickness of the center laminated portion and the tip laminated portion are the overall size and the outer surface. It is appropriately selected depending on the curvature.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view for explaining one embodiment of a heat-resistant structure according to the present invention.
FIG. 2 is a perspective view for explaining a procedure for forming a tip laminated portion by the method for manufacturing a heat-resistant structure according to the present invention.
FIG. 3 is a cross-sectional view illustrating a gas vent passage formed by stacking cloth shown in FIG.
[Explanation of symbols]
A Heat-resistant structure B Axis C1-C3 Cross S Slit 1 Center lamination part 2 Outer circumference lamination part 3 Tip lamination part 7 Step part 8 Gas vent passage

Claims (6)

A heat-resistant structure for a spacecraft made of fiber-reinforced composite material, the outer surface of which is substantially spherical, and a central laminated portion formed by laminating a cross in a direction perpendicular to the axis on the central portion of the substantially spherical surface A heat-resistant structure comprising an outer peripheral laminated portion formed by laminating a cross in a direction intersecting at an acute angle with respect to the outer surface in the direction from the center to the outer peripheral side on the outer peripheral side of the central laminated portion. body.   The heat-resistant structure according to claim 1, wherein a stepped portion that engages with the inside of the central laminated portion is provided on the inner circumferential side of the outer circumferential laminated portion.   The heat-resistant structure according to claim 1 or 2, further comprising: a tip laminated portion formed by laminating a cross having a slit and a direction orthogonal to the axis at a central portion of the central laminated portion.   The heat-resistant structure according to any one of claims 1 to 3, wherein a gas vent passage is provided at a central portion of the substantially spherical surface.   When manufacturing the heat-resistant structure according to claim 3 or 4, using a cloth in which a plurality of slits are formed at a predetermined interval, the cloth is laminated in a state where the slits are sequentially crossed to form a tip laminated portion. A method for producing a heat-resistant structure, which is characterized.   6. The method for manufacturing a heat-resistant structure according to claim 5, wherein the slit in the cloth is formed in the center of the cloth and within a range of 1/2 of the vertical and horizontal dimensions of the cloth.

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