JP2000289700A - Heat-resisting structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resisting structure which is made in a light weight, as well as can obtain the ablation function and the strength sufficiently, and its manufacturing method, in a heat-resisting structure made of a fiber-reinforced compound material having the outer side of almost a spherical form. SOLUTION: A heat-resisting structure A having the center lamination part 1 made by laminating a cross C1 in the direction orthogonal to the axial line B is provided at the center part of almost a spherical surface, and a good gas removal is carried out without generating the peeling between layers of the cross C1, as well as realizing the reduction of the heat conductivity at the center part, and the light weight of the full body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant structure made of fiber-reinforced composite material used for spacecraft,
The present invention relates to a heat-resistant structure having an ablation function and a method for manufacturing the same.

[0002]

2. Description of the Related Art A heat-resistant structure of this type constitutes, for example, the bottom of a space capsule that enters the atmosphere and is used as a means for protecting against aerodynamic heating when entering the atmosphere. And has a function of cooling by the latent heat. Such ablation material is described in No. 506 of “Augmented Edition Aerospace Engineering Handbook” published by Maruzen on April 25, 1983.
Pp. 508, 528, 529, etc.

In recent years, as a heat-resistant structure used for the bottom of a space capsule, there is a heat-resistant structure obtained by laminating a carbon fiber cloth as a reinforcing material, impregnating the laminate with a thermosetting resin, and performing a hardening treatment. . In this heat-resistant structure, a cloth is laminated so as to be oblique to the axis, and the outside is formed into a substantially spherical surface so that a layer of the cloth appears on the outside, so that the outside is subjected to aerodynamic heating. In addition, the gas generated by the vaporization of the resin is desirably released from between the layers of the cloth.

[0004]

By the way, it is very important for the heat-resistant structure used in the spacecraft as described above not only to improve its function but also to reduce its weight.
For example, to reduce weight and reduce thermal conductivity, it is better to use a structure in which diagonal crosses are stacked with respect to the axis.
It is advantageous to adopt a structure in which crosses perpendicular to the axis are stacked. However, when a structure in which cloths orthogonal to the axis are laminated is used, there is a problem that delamination of cloths easily occurs when subjected to aerodynamic heating.
In addition, there is a method of performing chop molding using a cross chop or a fiber chop. However, in this case, there is a problem that 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]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and is intended to provide a heat-resistant structure made of fiber-reinforced composite material having a substantially spherical outer surface so as to sufficiently obtain an ablation function and strength. It is an object of the present invention to provide a heat-resistant structure capable of realizing weight reduction as well as a method of manufacturing the same.

[0006]

According to a first aspect of the present invention, there is provided a heat-resistant structure made of a fiber-reinforced composite material having a substantially spherical outer surface. A structure having a central laminated portion formed by laminating crosses in a direction orthogonal to the axis, and as a second aspect, on the outer peripheral side of the central laminated portion, in the direction from the center to the outer peripheral side, with respect to the outer surface thereof And an outer peripheral laminated portion formed by laminating cloths in a direction intersecting at an acute angle. As a third aspect, a step portion is provided on the inner peripheral side of the outer peripheral laminated portion to engage with the inside of the central laminated portion. According to a fourth aspect of the present invention, there is provided a configuration in which a central laminated portion is provided with a leading end laminated portion having a slit and a cross in a direction orthogonal to an axis laminated in a central portion. A configuration in which a gas vent path is provided in the center of the spherical surface And has a means for solving the conventional problems with the configuration described above.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a heat-resistant structure, wherein a cross-section having a plurality of slits formed at predetermined intervals is used for manufacturing the heat-resistant structure according to the fourth or fifth aspect. The tip is formed by laminating cloths in a state in which the slits intersect in order, and the slits in the cloth are located at the center of the cloth and each in a range of 縦 of the vertical and horizontal dimensions of the cloth. The above configuration is used as means for solving the conventional problems.

[0008]

In the heat-resistant structure according to the first aspect of the present invention, in the heat-resistant structure made of a fiber-reinforced composite material having a substantially spherical outer surface, a cross in a direction perpendicular to the axis is formed at the central portion. Since the central laminated portion is provided, the thermal conductivity of the central portion, which becomes the highest temperature when subjected to aerodynamic heating, is reduced by the central laminated portion, and the central laminated portion is limited to a limited area of the central portion. By providing the cloth, delamination of the cloth is less likely to occur, and the cloth layer appears outside the central laminated portion, so that the gas generated by the aerodynamic heating can escape well from the layers of the cloth.

In the heat resistant structure according to claim 2 of the present invention, an outer peripheral laminated portion is provided on an outer peripheral side of the central laminated portion,
In the direction from the center to the outer peripheral side, the cross of the outer peripheral laminated portion crosses at an acute angle to the outer surface, that is, the direction along the flow of gas generated in the central laminated portion when subjected to aerodynamic heating. As a result, delamination of the cloth is prevented, and good degassing is performed.

[0010] In the heat-resistant structure according to claim 3 of the present invention, since the step portion engaging with the inside of the central laminated portion is provided on the inner peripheral side of the outer peripheral laminated portion, the step to the central laminated portion due to air resistance is provided. The load is suppressed by the step.

The heat-resistant structure according to claim 4 of the present invention has a slit at a further central portion of the central laminated portion, which is heated to the highest temperature when subjected to aerodynamic heating, and has a cross in a direction perpendicular to the axis. Is provided, the resin filled in the slit is gasified and released by aerodynamic heating, and the slit further improves degassing.

In the heat-resistant structure according to the fifth aspect of the present invention, since the gas vent path is provided in the center of the substantially spherical surface, the gas is vented even from the center when subjected to aerodynamic heating, and the entire outer surface is formed. Good degassing is performed.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a heat-resistant structure according to the fourth aspect, that is, a heat-resistant structure having a substantially spherical outer surface and a top laminated portion at a central portion of the central laminated portion. When fabricating a heat-resistant structure equipped with or a heat-resistant structure provided with a gas vent passage in the center, a cross formed with a plurality of slits at predetermined intervals is used, so that a sufficient amount will be obtained when subsequently subjected to aerodynamic heating. The resin, which is both a hardening material and a gas generation source, is filled into the slits so that the gas can be generated. Therefore, the strength in the direction along the surface of the cloth is ensured, and a part of the slit is continuous in the lamination direction of the cloth to form a gas vent passage.

In the method for manufacturing a heat-resistant structure according to claim 7 of the present invention, the slits in the cloth are formed at the center of the cloth and within the respective half-width and width-dimensions of the cloth. At this time, it is possible to prevent the planar state of the cloth and the shape of the slit from being impaired.

[0015]

According to the heat-resistant structure according to the first aspect of the present invention, in the heat-resistant structure made of a fiber-reinforced composite material having a substantially spherical outer surface, sufficient strength can be ensured by the central laminated portion. At the same time, the thermal conductivity of the central part, which becomes the hottest when subjected to aerodynamic heating, is smaller than that obtained by diagonally laminating the cloth, 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 area of the central portion of the structure, delamination of the cloth when subjected to aerodynamic heating can be prevented, and the interlayer of the cloth outside the central laminated portion can be prevented. Therefore, good degassing can be performed, and an excellent ablation function can be obtained.

According to the heat-resistant structure of the second aspect of the present invention, the same effect as that of the first aspect can be obtained, and in addition, in the outer peripheral laminated portion provided on the outer peripheral side of the central laminated portion,
It is possible to prevent delamination of the cloth when subjected to aerodynamic heating, to perform good degassing between the cloth layers outside the outer peripheral laminated portion, and to obtain an excellent ablation function.

According to the heat-resistant structure according to the third aspect of the present invention, the same effect as that of the second aspect can be obtained, and the stepped portion provided on the inner peripheral side of the outer peripheral laminated portion can reduce the air resistance. The load on the central laminated portion is suppressed, and delamination of the cloth in the central laminated portion can be more reliably prevented.

According to the heat-resistant structure according to the fourth aspect of the present invention, the same effects as those of the first to third aspects can be obtained. A sufficient amount of gas generation can be obtained by the filled resin, and the slits can further improve the gas release and the ablation function can be further enhanced.

According to the heat-resistant structure according to the fifth aspect of the present invention, the same effects as those of the first to fourth aspects can be obtained. When receiving the gas, the gas can be satisfactorily vented from the center, and the ablation function can be further enhanced by satisfactorily degassing the entire outer surface.

According to the method for manufacturing a heat-resistant structure according to claim 6 of the present invention, in manufacturing the heat-resistant structure according to claim 3 or 4, a cloth having a plurality of slits is used, and Since the cloths are laminated in a state of intersecting in order to form the top laminated part, there is no need to perform any drilling or the like to fill the resin, and the resin that is both a hardening material and a gas generation source is sufficient. The resin can be easily filled even after lamination, and the strength in the direction along the cloth surface can be secured. Thus, a heat-resistant structure having the same effect as that of the third or fourth aspect can be obtained.

According to the method of manufacturing a heat-resistant structure according to claim 7 of the present invention, the same effect as in claim 6 can be obtained, and the formation range of the slit in the cloth is limited. When laminating, it is possible to prevent the planar state of the cloth and the shape of the slit from being impaired, to facilitate the handling of the cloth, and to laminate the cloth regularly and accurately, A heat-resistant structure provided with a high-quality tip laminated portion can be obtained.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a heat-resistant structure according to the present invention and a method of manufacturing the heat-resistant structure will be described below with reference to the drawings.

The heat-resistant structure A shown in FIG. 1 constitutes the bottom of the space capsule which re-enters the atmosphere, has an approximately spherical outer surface projecting downward, and has a fiber-reinforced composite structure. Made of material.

The fiber reinforced composite material is formed by using carbon fibers as reinforcing fibers and laminating cloths woven with the carbon fibers vertically and horizontally. In addition, the fiber reinforced composite material, using a cloth previously impregnated with a thermosetting resin, or a thermosetting resin with the lamination of the cloth, or impregnating the thermosetting resin after lamination of the cloth, then pressurized and By performing a heating hardening process, it becomes CFRP (carbon fiber reinforced plastic).

The heat-resistant structure A is provided with a central laminated portion 1 at a central portion of a substantially spherical surface, an outer peripheral laminated portion 2 on an outer peripheral side of the central laminated portion 1, and a central portion of the central laminated portion 1,
It has a configuration in which the front end lamination part 3 is provided, and forms a housing space 4 for mounted equipment inside. At this time, the central laminated portion 1 is formed in a substantially disk shape, and a heat insulating material 5 is provided inside the central laminated portion 1.
Is provided. 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 an outer peripheral end thereof.

The central laminated portion 1 is formed by laminating crosses 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 crossing at an acute angle θ with respect to the outer surface in a direction from the center of the structure to the outer peripheral side.
The leading end laminated portion 3 has a slit and is formed by laminating a cross C3 in a direction orthogonal to the axis B. At this time, each of the lamination parts 1 to 3 has a cross C1 on the outside.
To C3 appear.

The outer laminated portion 2 has a stepped portion 7 which engages with the inside of the central laminated portion 1 over the entire periphery on the inner peripheral side. Further, the front end laminated portion 3 has a gas vent passage 8 at the center of the substantially spherical surface. These laminated parts 1 to 3
It is also possible to combine those that are molded and cured separately from each other, or it is also possible to perform the curing treatment after combining each molded separately, and the outside is a predetermined roughly spherical surface. Cutting and the like are also performed so that

Here, the tip laminated portion 3 is manufactured in the manner shown in FIG. In this manufacturing, a cloth C3 having a plurality of slits S formed at predetermined intervals is used. At this time, the cross C3 is located at the center thereof and each of the vertical and horizontal dimensions a and b is 1
The slit S is formed in the range (x, y) of / 2.
By limiting the range in which the slits S are formed in this way, the cloth C3 can be easily handled without laminating the planar state and the shape of the slits S during lamination, and can be regularly and accurately formed. Can be laminated.

The leading end laminated portion 3 is formed by laminating cloths C3 in a state where the slits S intersect in order. By laminating in this way, the strength in the direction along the surface of the cloth C3 is not impaired by the slits S. Further, as shown in FIG. The gas vent passage 8 can be easily formed continuously in the stacking direction of the cloth C3. Although the figure shows a case in which the slits S are stacked so as to be orthogonal, for example, the slits S may be stacked so as to intersect at 45 degrees in order.

The tip laminated portion 3 thus manufactured
The resin which is a hardening material and also a gas generating source when subjected to aerodynamic heating is sufficiently filled in the slit S, and it is easy to fill the resin after laminating the cloth C3. There is no need for drilling or the like.

In the heat-resistant structure A having the above-described structure, since the cloths C1 to C3 are used as the reinforcing material, sufficient strength is secured as a whole, and the cloths C1 and C3 perpendicular to the axis B can be secured. Due to the central laminated portion 1 and the distal laminated portion 3 formed by lamination, the heat conductivity of the central portion, which becomes the highest temperature when subjected to aerodynamic heating, is smaller than that obtained by obliquely laminating the cloth. Along with the decrease in the rate, the structure has been made thinner and lighter.

Then, when the space capsule re-enters the atmosphere, the heat-resistant structure A serves as a defense against aerodynamic heating to protect 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 cooled by the latent heat.

At this time, the heat-resistant structure A has crosses C1, C3 orthogonal to the axis B at the center where the temperature is highest.
Are adopted, the range of these laminated portions 1 and 3 is limited to the central portion, and the load on the central laminated portion 1 due to air resistance is reduced. Since it is suppressed by the step 7 of the outer peripheral laminated portion 2, the crosses C <b> 1, C <b> 3
Is surely prevented from being delaminated.

In the center lamination portion 1 and the tip lamination portion 3, degassing is performed between the outer layers of the cloths C 1 and C 3. In particular, in the tip lamination portion 3, the resin filled in the slit S is filled. As a result, a sufficient amount of gas can be obtained, and the slit S allows the gas to be released more smoothly, and also allows the gas to be released from the gas release passage 8 provided at the center.

Further, in the outer peripheral laminated portion 2, the gas discharged from the central laminated portion 1 flows at a high speed along the outer surface. Since the cross C2 intersects the flow direction at an acute angle θ, the cross C2
Degassing is performed between the layers of the cloth C2 without delamination of the cloth C2.

In this way, 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.

The details of the structure of the heat-resistant structure according to the present invention are not limited to those of the above-described embodiment, and the diameter and thickness of the central laminated portion and the laminated portion at the end are all large. It is appropriately selected according to the curvature of the outer surface and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating an embodiment of a heat-resistant structure according to the present invention.

FIG. 2 is a perspective view for explaining a method of forming a tip end laminated portion by a method of 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 cloths shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List A Heat-resistant structure B Axis C1-C3 Cross S Slit 1 Central laminated part 2 Outer peripheral laminated part 3 Tip laminated part 7 Stepped part 8 Gas release passage

Claims (7)

[Claims] 1. A heat-resistant structure made of a fiber-reinforced composite material having a substantially spherical outer surface, wherein a central laminated portion formed by laminating a cross in a direction orthogonal to an axis is provided at a central portion of the substantially spherical surface. A heat-resistant structure comprising: 2. An outer peripheral laminated portion formed by laminating a cross in a direction intersecting at an acute angle with respect to an outer surface thereof in a direction from the center to the outer peripheral side on the outer peripheral side of the central laminated portion. The heat-resistant structure according to claim 1. 3. The heat-resistant structure according to claim 2, wherein a step portion is provided on the inner peripheral side of the outer peripheral laminated portion so as to engage inside the central laminated portion. 4. A central stacking portion comprising a tip stacking portion having a slit and having a cross in a direction perpendicular to an axis line stacked at a central portion of the center stacking portion. A heat-resistant structure according to any one of the above. 5. The heat-resistant structure according to claim 1, wherein a gas vent path is provided at a central portion of the substantially spherical surface. 6. When manufacturing the heat-resistant structure according to claim 4 or 5, a cloth having a plurality of slits formed at a predetermined interval is used, and the cloths are stacked in a state where the slits intersect in order, and a tip laminated portion is formed. Forming a heat-resistant structure. 7. The method for manufacturing a heat-resistant structure according to claim 6, wherein the slit in the cloth is formed at the center of the cloth and within each half of the vertical and horizontal dimensions of the cloth.