JP2002249099A - Multilayer heat insulating sheet for spacecraft and insulating method for spacecraft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer heat insulating sheet for a spacecraft preventing the heat intrusion from the outside and having superior permeability. SOLUTION: This multilayer heat insulating sheet for the spacecraft with a multilayer structure has permeable interlayer clearances between respective layers. This insulating sheet is characterized in that air passages are formed from the front side and the rear side of the multilayer heat insulating sheet for the spacecraft, the both air passages from the front side and the rear side are formed by deviating their positions so as to prevent the direct communication between the both passages, and the length of the both air passages are so formed as to reach arbitrary interlayer clearances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer heat insulating sheet for a spacecraft having a multilayer structure which covers all or a part of a spacecraft, and a method of insulating a spacecraft using the multilayer heat insulating sheet for a spacecraft.

[0002]

2. Description of the Related Art A conventional multilayer heat insulating sheet for a spacecraft will be described with reference to FIGS. In FIG. 5, the multi-layer heat insulating sheet 1 for a spacecraft covers a whole or a part of the periphery of the spacecraft 2 and performs a function of reducing heat exchange between the spacecraft 2 and the space 3. In FIG. 6, the multilayer heat insulating sheet 1 for a spacecraft generally comprises a foil or thin film layer component 4 on which a metal having a low emissivity, for example, aluminum having a small infrared emissivity, is deposited. Are layered alternately (for example, 10 = 10 layers), and the surface side (space 3 side) And the back side (spacecraft 2 side), that is, on both sides, the foil-shaped layer constituting members 4 and 4 are located, and this is also referred to as multilayer insulation. Since the heat insulating net 5 is formed of a material having elasticity, even if the multilayer heat insulating sheet 1 is once expanded by an internal air pressure described later, it is restored when the pressure disappears.

[0003]

When the spacecraft 2 covered with the spacecraft heat insulating sheet (hereinafter also referred to as a heat insulating sheet) 1 as described above is launched into the outer space 3, the pressure drop causes the heat to be insulated. Air on the spacecraft 2 side covered with sheet 1
(Hereinafter, referred to as internal air) may expand, and the heat insulating sheet 1 may be broken or peeled to be damaged. When tearing or peeling occurs, the heat insulation efficiency at the damaged portion is reduced, which adversely affects the temperature control function of the spacecraft 2.

Conventionally, as one of the means for solving the above problem, a required number of needle holes 6 are formed in the heat insulating sheet 1 so that the needle holes 6 can be traced when the needle is pulled out. The needle hole 6 cannot flexibly cope with the amount of internal air that expands. For example, such a needle hole 6 has poor air permeability and is not necessarily sufficient to quickly release internal air that has rapidly expanded due to a sudden change in air pressure. Further, since the needle hole 6 is formed to penetrate the heat insulating sheet 1 linearly, there is a possibility that heat input from the outside such as sunlight may be allowed.

[0005] As another means for solving the above problem, when covering the spacecraft 2, there has been proposed a method in which the heat insulating sheet 1 is folded at a corner position so as to prevent the spacecraft 2 from being torn or peeled. Since the pressure applied by the internal air cannot be accurately calculated in advance, there is a problem in reliability.

[0006] The present invention solves the above-mentioned problems, can efficiently release the internal air expanded due to a decrease in atmospheric pressure, and can efficiently prevent heat input such as light (sunlight) from the outside. An object of the present invention is to provide a multi-layer heat insulating sheet for a spacecraft provided with an air passage, and to provide a heat insulating method for a spacecraft.

[0007]

According to a first aspect of the invention, there is provided a multilayer heat insulating sheet for a spacecraft, wherein an air passage formed through the multilayer heat insulating sheet for a spacecraft having elasticity has a linear or radial cut. It is characterized by being formed by.

[0008] The invention of a multilayer heat insulating sheet for a spacecraft according to a second aspect of the present invention relates to a multilayer heat insulating sheet for a spacecraft having a multilayer structure having an air gap between the respective layers, wherein the multilayer heat insulating sheet for the spacecraft is formed from the front side and the back side. Each ventilation path was formed, and both ventilation paths from the front side and the back side were formed so as to be shifted from each other so as not to directly communicate with each other, and the length of both ventilation paths was formed so as to reach an arbitrary interlayer gap. It is characterized by the following.

According to a third aspect of the present invention, in the multilayer heat insulating sheet for a spacecraft according to the second aspect, the lengths of both air passages from the front side and the back side are formed so as to cross each other at an arbitrary plurality of interlayer gaps. It is characterized by having been done.

[0010] The invention of claim 4 is the invention of claim 2 or claim 3.
In the multilayer heat insulating sheet for a spacecraft described in (1), one or both of the air passages are formed with cuts.

The invention of claim 5 is the invention of claim 2 or claim 3.
The multi-layer heat insulating sheet for a spacecraft described in (1), wherein one or both of the air passages is formed by a hole.

The invention of claim 6 is the invention of claim 2 or claim 3.
The multi-layer heat insulating sheet for a spacecraft according to the item (1), characterized in that one of the two air passages is cut, and the other air passage is a hole.

[0013] The invention of claim 7 is the invention of claim 4 or claim 6.
Wherein the cut is a radial cut.

The invention of claim 8 is the invention of claim 5 or claim 6.
Wherein the hole is a hollow hole.

According to a ninth aspect of the present invention, there is provided a spacecraft heat insulation method for covering a spacecraft in whole or in part with a plurality of spacecraft multilayer heat insulation sheets. The sheet is formed by appropriately penetrating an air passage, and the multilayer heat insulating sheets for spacecraft are overlapped so that the air passages formed in the multilayer heat insulating sheets for spacecraft do not match.

According to a tenth aspect of the present invention, in the heat insulating method for a spacecraft according to the ninth aspect, the ventilation path is formed by a cut or a hollow hole.

According to an eleventh aspect of the present invention, in the heat insulating method for a spacecraft according to the tenth aspect, the cut is a radial cut.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 The multi-layer heat insulating sheet for a spacecraft according to the first embodiment shows a form in which an air passage formed through the heat insulating sheet from the front side to the back side is formed as, for example, a cross cut as one of the radial cuts. This will be described with reference to FIG. FIG. 1 is a perspective view showing a part of a multilayer heat insulating sheet 10 for a spacecraft that covers the entire spacecraft 2.

In FIG. 1, reference numeral 10 denotes a multilayer heat insulating sheet for a spacecraft according to the present invention (hereinafter also referred to as a heat insulating sheet). The heat insulating sheet 10 has a multilayer structure basically similar to the conventional multilayer heat insulating sheet 1 for a spacecraft. However, the inside air (internal air) wrapped in the heat insulating sheet 10 is
An air passage leading to (space 3) is formed by a cut 11 formed to penetrate from the front side to the back side of the heat insulating sheet 10, that is, from the outside to the inside. That is, the cut formed in each of the layers 4 and 5 constituting the heat insulating sheet 10 is overlapped so that (11) coincides with the thickness direction of the heat insulating sheet. In the illustrated embodiment, it is formed together with the needle hole 6, but only the cut 11 may be provided instead of the needle hole 6.

The cut 11 shown in the first embodiment is formed in a shape in which two straight lines intersect, that is, in a cross shape, but may be formed in a shape formed by one straight line, that is, in a single character shape. (Not shown) may be cuts in which three or more straight lines are developed radially (not shown). Note that the cross shape is also a radial shape composed of four straight lines.

By providing the cut 11 having the above-described shape as a ventilation path, the cut 11 is broken according to the expansion pressure of the internal air covered with the heat insulating sheet 10 and the internal air passes therethrough. The internal air can be released flexibly according to the amount of expansion of the internal air. or,
Even if the internal air suddenly expands or is generated in an amount exceeding the calculation, it is possible to respond more flexibly than a conventional ventilation path using only the needle hole 6.

Further, unlike the conventional needle hole 6, when the expansion pressure of the internal air does not act, the heat insulating net 5 (FIG. 6)
The incision 11 is not broken by the elasticity of the elastic material and remains in a closed state, so that unnecessary heat input from the outside can be efficiently prevented. When the internal pressure decreases due to the passage of the internal air, the cut 11 is closed by the elasticity of the layer constituting members 4 and 5 themselves.

In the case where the cut 11 has a cross shape as shown in the figure, the central intersection is freely expanded in a square shape from a closed state according to the inflation pressure of the internal air. The ventilation performance can be enhanced as compared with the cut in the shape of a circle.

When the cuts 11 have a radial shape other than the cross shape (not shown), depending on the number of lines formed radially, for example, three cuts have a triangular shape, and four have a triangular shape. In the same manner as the cross, it has a square shape, and the number increases more than five, so that it becomes more circular.Each of them expands freely from the closed state at the center according to the expansion pressure of the internal air. The ventilation performance can be increased.

As described above, according to the first embodiment, even if the internal air expands due to a change in air pressure after being launched into space, the cut 11 as a ventilation path is formed according to the expansion pressure.
Can be freely expanded, so that damage such as tearing or peeling of the multi-layer heat insulating sheet 10 for a spacecraft can be prevented. or,
Except when the internal air escapes, the cut 11 of the ventilation path is closed without breaking, so that unnecessary heat input from the outside can be efficiently prevented.

Embodiment 2 FIG. In the first embodiment, the ventilation path (11) is formed so as to linearly penetrate from the inside to the outside in the same manner as in the related art, whereas in the second embodiment, the ventilation path is formed in a straight line. The ventilation path is formed by using the interlayer gap between the layers constituting the heat insulating sheet 10 as a communication path without penetrating through the heat insulating sheet 10. This is because the multilayer structure (layer components 4 and 5) of the heat insulating sheet 10 is, for example, layered so that clothes are layered, so that the layer (4) and the layer (5) or the layer (4) are This is made by paying attention to the point that a permeable interlayer gap 45 (about several microns) is generated between the layer constituting members. Hereinafter, this will be described with reference to FIG. FIG. 2 is an explanatory diagram showing an outline of the configuration.

In the second embodiment, the front side of the heat insulating sheet 10
From the (outer side) and the back side (inner side), a pair of air passages formed in the direction penetrating the heat insulating sheet 10 are not passed directly to the opposite sides, respectively. 45.
Hereinafter, the air passage from the front side is also referred to as a front air passage 11A, and the air passage from the back side is also referred to as a back air passage 11B.

The pair of air passages (the front air passage 11A and the back air passage 11B) are shifted in formation position between the front side and the back side so as not to directly communicate with each other. Is formed so as to reach at least one of several interlayer gaps 45 in the heat insulating sheet 10, and the pair of air passages are formed in the interlayer gap 4.
5, the internal air flows from the back side ventilation path 11B through the interlayer gap 45,
It is possible to escape to the outside from the front side ventilation path 11A formed nearest.

More specifically, when the internal air that has entered from the back side air passage 11B reaches the length, that is, the depth where the back side air passage 11B is formed, it reaches the layer (4) that forms the interlayer gap 45. Thus, the vehicle cannot travel straight and attempts to diffuse in the interlayer gap 45, but escapes to the outside, that is, the front side, via the nearest front air passage 11A reaching the interlayer gap 45. In this case, by forming the front side and back side air passages 11A and 11B with the notches 11 similar to those described in the first embodiment, the second embodiment also exhibits the same operation and effect as in the first embodiment. Can be done. Further, in the second embodiment, since the ventilation path is not formed in a straight line as compared with the first embodiment, unnecessary heat input from the outside can be more efficiently prevented.

Further, since the front and rear air passages 11A and 11B of the second embodiment are non-through holes that do not penetrate the multilayer heat insulating sheet 10 linearly unlike the first embodiment, both air passages are provided. The paths 11A and 11B may be formed as simple holes, for example, holes hollowed out so as to be hollow. In FIG. 2, this hollow hole 12 is formed in the back side ventilation path 11B as a ventilation path. When the ventilation path is formed as such a hole 12, the ventilation performance can be remarkably improved as compared with the notch 11. On the other hand, if the back side ventilation path 11A is formed as a hollow hole 12 (FIG. 2),
The heat input from the front air passage 11A hits the layer (4) located at the deepest part of the front air passage 11A, and the heat input from the layer (4) from the layer (4) to the back side is efficient. Well blocked.

This will be specifically described. For example, in the case where the heat insulating sheet 10 is composed of ten layers from the first layer foil or film layer (4) to the tenth layer foil or film layer (4) from the front side to the back side. When the front air passage 11A is formed from the first layer (4) to the fourth layer (4) and the back air passage 11B is formed from the tenth layer (4) to the fifth layer (5). The two air passages 11A and 11B are communicated only by one interlayer gap 45 between the fourth layer (4) and the fifth layer (5).

In the second embodiment, the length of the front and rear air passages 11A and 11B is set to be equal to the number of the plurality of interlayer gaps 4.
5 may be formed to cross each other. As in the above example, the heat insulating sheet 10 has 10 layers from the first layer of the foil or film layer (4) to the tenth layer of the same foil or film layer (4) from the front side to the back side. The following is a description of the case.

The case where the front side air passage 11A and the back side air passage 11B are formed by crossing each other means, for example,
A is formed from the first layer (4) to the sixth layer (4), and the back side air passage 11B is formed from the tenth layer (4) to the fourth layer (4). Layer (4) to 6th
The two air passages 11A and 11B are communicated with each other through a plurality of (two in this case) interlayer gaps 45 and 45 up to the layer (4). As described above, the ventilation performance increases as the number of interlaminable gaps 45 that can be shared by the front side ventilation path 11A and the back side ventilation path 11B increases.

In the second embodiment, a pair of front air passages 11A and back air passages 11B forming a ventilation passage are formed so as to cross each other so as to increase the number of inter-layer gaps 45 that can communicate with each other. While preventing the internal air, the internal air can be further efficiently discharged to the outside.

In the second embodiment, one or both of the pair of air passages (the front air passage 11A and the back air passage 11B) may be formed by the cuts 11 described in the first embodiment. One or both may be formed, for example, as a hollow hole 12, or one may be a notch 11, and the other ventilation path may be a hollow hole 12 as well. In FIG. 2, the front side air passage 11A is cut 11
Thus, the back side ventilation path 11B is formed by hollow holes 12, 12.

Embodiment 3 FIG. Embodiment 3 relates to a spacecraft heat insulation method in which all or a part of the spacecraft is covered with a plurality of multilayer spacecraft heat insulating sheets. This is shown in FIGS. 3 and 4.
It will be described based on. 3 and 4 are explanatory diagrams respectively showing examples in which two heat insulating sheets 10 are covered and covered in a part of the spacecraft 2.

In FIG. 3, two heat insulating sheets 10, 1
In the case where the spacecraft 2 is covered with the upper and lower sheets 0 in a vertical manner, the heat insulating sheets 10 and 10 are formed by penetrating through appropriately shaped air passages, and the two heat insulating sheets 1
The air passages formed at 0 and 10 are superposed with their positions shifted so that they do not coincide with each other. In such a case, a gap similar to the interlayer gap 45 described in the second embodiment is formed on the overlapped surface, so that the cut 11 as a ventilation path of one of the heat insulating sheets 10 is formed. The front side air passages in the second embodiment and the holes 12 as the air passages of the other heat insulating sheet 10 correspond to the back side air passages in the second embodiment, respectively. 2 can be the same as
Therefore, substantially the same functions and effects as those of the second embodiment can be obtained.

When the method of the third embodiment is used, the ventilation path of the heat insulating sheet 10 to be used may have any cross-sectional shape. For example, in order to significantly improve the air permeability as compared with the conventional case, it is best to form the hole through the hollow hole 12 as described in the second embodiment. 3 and 4
Is formed by forming a cross-shaped cut 11 in a portion corresponding to the front air passage 11A, and penetrating a hollow hole 12 in a portion corresponding to the back air passage 11B. Reference numeral 13 in FIG. 3 denotes an adhesive tape that bonds the heat insulating sheets 10 and 10 to each other in order to fix them. Also, FIG.
The reference numeral 14 denotes two heat insulating sheets 10 to be superimposed on each other,
It is a detachable tape called Velcro sewn on opposing surfaces of the multilayer heat insulating sheets 10 and 10 in order to attach the 10 to each other.

According to the method according to the third embodiment, it is only necessary to simply form a penetrating air passage for each of the heat insulating sheets 10 to be stacked. As compared with the case, the operation of forming the ventilation path becomes extremely simple. For example, it is only necessary to perform a punching operation for forming a ventilation path as a single unit for each heat insulating sheet 10. Therefore, the amount of work can be significantly reduced. In addition, substantially the same operation and effect as those of the first and second embodiments can be exerted.

[0040]

According to the first aspect of the present invention, since the penetrating air passage is formed by cutting, the internal air can be released to the outside according to the pressure more flexibly as compared with the conventional needle hole. In addition to preventing breakage or peeling of the multilayer heat insulating sheet for use, heat input from the outside can be prevented, and the temperature control function of the spacecraft can be guaranteed.

According to each of the second to seventh aspects of the present invention, heat input from the outside can be efficiently prevented, and the ventilation performance of the ventilation path can be further improved. The multilayer heat insulating sheet can be prevented from being damaged such as tearing or peeling, and the temperature control function of the spacecraft can be guaranteed.

According to each of the eighth to eleventh aspects of the present invention, any of the above-mentioned inventions requires only a very simple processing operation of forming a multilayer heat insulating sheet for a spacecraft through an air passage. The same functions and effects as the second to seventh aspects of the invention can be exerted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a multilayer heat insulating sheet for a spacecraft according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating an outline of a configuration according to a second embodiment;

FIG. 3 is an explanatory diagram illustrating a method according to a third embodiment.

FIG. 4 is an explanatory diagram showing another method of the third embodiment.

FIG. 5 is a perspective view showing a state in which the spacecraft is covered with a multilayer heat insulating sheet for the spacecraft.

FIG. 6 is an explanatory view showing a multilayer structure of a multilayer heat insulating sheet for a spacecraft.

[Explanation of symbols]

1. Conventional multi-layer heat insulating sheet for spacecraft (heat insulating sheet), 2
Spacecraft, 3 space, 4 layer structural member (layer), 5 layer structural member (layer), 10 multilayer heat insulating sheet (heat insulating sheet) for spacecraft of the present invention 11 notch (air passage), 11A front air passage, 11B6 Back vent, 45 interlayer clearance.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takayasu Nozawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsui Electric Co., Ltd. (72) Inventor Yasunori Niki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F term (reference) in Mitsubishi Electric Corporation 3H036 AA09 AC03 AD09 AE04 4F100 BA02 BA05 BA06 DC11A DC11B GB90 JD02 JJ02 JJ02A JJ02B

Claims (11)

[Claims] 1. A multilayer heat insulating sheet for a spacecraft, wherein an air passage formed through the elastic multilayer heat insulating sheet for a spacecraft having a linear or radial cut is formed. 2. A multi-layer heat insulating sheet for a spacecraft having a multi-layered structure having an air gap between each layer, wherein ventilation paths are respectively formed from a front side and a back side of the multi-layer heat insulating sheet for a space machine. A multi-layer heat insulating sheet for a spacecraft, characterized in that both air passages from are formed so as to be shifted from each other so as not to directly communicate with each other, and that the length of both air passages reaches an arbitrary interlayer gap. 3. The length of both air passages from the front side and the back side is:
The multilayer heat insulating sheet for a spacecraft according to claim 2, wherein the multilayer heat insulating sheet is formed so as to cross each other in a plurality of arbitrary interlayer gaps. 4. The multi-layer heat insulating sheet for a spacecraft according to claim 2, wherein one or both of the air passages is formed by cutting. 5. The multilayer heat insulating sheet for a spacecraft according to claim 2, wherein one or both of the air passages is formed by a hole. 6. The multilayer heat insulating sheet for a spacecraft according to claim 2, wherein one of the air passages is a cut, and the other air passage is a hole. 7. The multilayer heat insulating sheet for a spacecraft according to claim 4, wherein the cut is a radial cut. 8. The multilayer heat insulating sheet for a spacecraft according to claim 5, wherein the holes are hollow holes. 9. A spacecraft heat insulating method in which a plurality of spacecraft multilayer heat insulating sheets cover all or a part of the spacecraft in a superimposed manner. A spacecraft multi-layer heat insulating sheet is overlapped so that air passages formed in each spacecraft multi-layer heat insulating sheet do not coincide with each other. 10. The heat insulation method for a spacecraft according to claim 9, wherein the air passage is formed by a cut or a hollow hole. 11. The heat insulating method for a spacecraft according to claim 10, wherein the cut is a radial cut.