JPH08156899A - Sun shield - Google Patents

Abstract

PURPOSE: To house a sun shield rolled in when a satelite is launched and expand the sun shield with the fixed rigidity and strength in space. CONSTITUTION: In a sun shield rolled, housed, launched and expanded in space to shield the external apparatus or the like from the sun beam and mounted on a satelite, a stiffner 2 formed of a straight-like shape memory effect alloy contracted under the fixed temperature to bend a sun shield base plate 1 is disposed in the direction of rolling in the sun shield and in a position parallel to the sun shield on either one of the surfaces of the sun beam plate 1 with both ends respectively disposed fixedly to both side edges of the sun shield base plate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sun shield which shields equipment mounted on an artificial satellite from sunlight, and more particularly to a sun shield which maintains a certain rigidity and strength in outer space.

[0002]

2. Description of the Related Art In general, among the equipment mounted on a spacecraft such as an artificial satellite, an infrared telescope for imaging the earth and other equipment installed outside the satellite include optical noise caused by sunlight. In order to avoid the influence of the above, an eaves-shaped sun shield is provided above the externally mounted device, and the sun shield blocks the irradiation of the externally mounted device with sunlight.

Conventionally, as a sun shield of this kind, a sun shield substrate is lightweight and has a certain strength, and can be rolled up when stored and has a constant spring property and a restoring force such that it becomes a flat plate when deployed. The composite material such as carbon glass fiber, etc., which we have, and metal etc. are formed into a thin flat plate shape, which is attached above the external equipment of the artificial satellite, and at the time of launching the artificial satellite, this flat sunshield substrate is rolled. It was stored in a rolled-up state, and when it reached outer space, it was used by unfolding it to cover the top of the equipment.

FIG. 5 is a schematic perspective view showing the state of the conventional sunshield in outer space, and FIG. 6 is a schematic side view showing the storage state of the conventional sunshield. FIG. 7 is a schematic perspective view showing fixing means of the sun shield at the time of storage.

[0005] As shown in these drawings, in the conventional sunshield, a sunshield substrate 1 in which a sunshield substrate 1 is fixed to an artificial satellite 10 at one end side in a short side direction.
At the time of storage, the sun shield substrate 1 is wound in a roll shape and the end is
It was held by a tying belt 12 fixed to zero.
The securing belt 12 has a lower end (not shown) fixed to the sun shield substrate 1 and an upper end as shown in FIG.
4 fixed to the edge of the satellite 10.

When unfolding, the tying belt 1
By releasing the fixing of 2, the sunshield substrate 1
The device itself is developed by its own restoring force and covers the upper side of the externally mounted device 3. Here, the securing belt 12
7, is connected to an intermediate member 13 that rotates about a rotation shaft 13a, as shown in FIG.

The intermediate member 13 has a pair of springs 15 disposed on one side, and is always pulled in one direction (the direction of the arrow shown in FIG. 7), and is fixed on the other side via a link. Pin 14 is connected. Further, a cable 16 is stretched on the other side of the intermediate member so that the intermediate member 13 is prevented from rotating by the pulling force of the spring 15, and the sunshield substrate 1 is stored in this state. Have been.

Therefore, the cable 16 holding the intermediate member 13 from the pulling force of the spring 15 is attached to the cutter 17.
, The intermediate member 13 is rotated about the rotation shaft 13a in the direction of the arrow in the drawing by the pulling force of the spring 15. As a result, the fixing pin 14 fixing the securing belt 12 also moves in the direction of the arrow in the drawing, so that the upper end of the securing belt 12 is released from being fixed by the fixing pin 14,
The lashing belt 12 becomes free, and the sunshield substrate 1 is deployed by its own restoring force.

Since the sunshield substrate 1 is made of a material having a certain strength and a spring property as described above, a force that always expands when it is wound in a roll shape acts. Accordingly, the sun shield substrate 1 can be easily deployed by releasing the fixation of the securing belt 12.

As a conventional technique using this type of sunshield, there is, for example, a sunshield thermal louver described in Japanese Utility Model Laid-Open Publication No. 62-37796.

[0011]

However, such a conventional sunshield is formed in an extremely thin flat plate shape due to the wrapping and storage, etc., and the strength and rigidity of the flat plate are limited by the material itself such as carbon glass fiber. It depended only on strength and rigidity. For this reason, the sunshield surface may be bent, distorted, or the like, which causes a problem that the externally mounted device of the artificial satellite is directly exposed to sunlight.

[0012] The sunlight is transmitted by an infrared telescope for imaging the earth,
In order to generate optical noise (for example, blurring in a camera, a telescope, etc.) for equipment installed outside the artificial satellite, it is necessary to completely block the noise. However, in the outer space, various external forces such as attitude control of the satellite itself and vibration of a motor are applied in addition to external factors such as solar wind (solar pressure), magnetic force, and fine particles. Deflection, distortion, etc., occur easily and frequently on the shield, making it difficult to completely block sunlight.

In general, as means for increasing the rigidity or the like of a flat plate, a stiffener is mounted on the back or front surface of the flat plate, or the center of the flat plate is bulged in a round or triangular shape (hereinafter referred to as a roof shape). It is known that the sun shield is used. However, in the case of a sun shield, it is necessary to wrap it in a roll shape so as not to hinder the launch of the artificial satellite, and thus simply stiffen the stiffener or the like. The rigidity and strength cannot be increased by using a member or by forming the shape into a roof shape or the like.

In addition, since it is necessary to meet the demand for weight reduction and miniaturization of the entire spacecraft, it is difficult to separately provide a special structure only for reinforcing the sunshield in the outer space. On the other hand, a method of increasing rigidity and strength by pulling the sunshield with a string or the like as if the sail of a sailing boat is stretched was considered, but the structure is unnecessarily complicated, and it can not be expected that much effect By that
In reality, hiring has been postponed.

The present invention has been proposed in order to solve the problems of the conventional techniques described above.
It is an object of the present invention to provide a sun shield that can be rolled up and stored when a satellite is launched, and that can be deployed with a certain rigidity and strength in outer space by using only a lightweight and simple structure.

[0016]

In order to achieve the above object, the sun shield according to claim 1 of the present invention is stored in a roll shape and launched, and is deployed in outer space to shield external equipment from sunlight. In the sun shield attached to the artificial satellite, a stiffener made of a linear shape memory alloy that bends at a constant temperature and swells the center of the sun shield is arranged on one surface of the sun shield. It is as a configuration.

The sun shield according to claim 2 is a sun shield attached to an artificial satellite, which is stored in a roll shape and launched, and which is deployed in outer space and shields external equipment from sunlight. A stiffener made of a linear shape memory alloy that contracts at a constant temperature and swells the central portion of the sunshield substrate is disposed on one surface of the substrate.

Further, the sun shield according to the third aspect is configured such that a part or all of the stiffener is formed in a coil spring shape.

The sun shield according to a fourth aspect of the present invention is configured such that the sun shield is provided with a stiffener support for locking an intermediate portion of the stiffener.

The sun shield according to claim 5 has a structure in which the stiffeners are provided in parallel with at least two or more in the longitudinal direction of the sun shield.

[0021]

According to the sunshield of the present invention having the above configuration, when the artificial satellite is launched, the stiffener is linear and integrated with the plane of the sunshield, so that the sunshield can be rolled up and stored. . On the other hand, in space, the stiffener is curved or shortened due to the shape change of the shape memory alloy due to solar heat, so the sun shield automatically expands at the center with the stiffener shape change It becomes a mold shape,
A certain rigidity and strength can be maintained, and the equipment mounted on the outside of the satellite can be protected from sunlight.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sunshield according to the present invention will be described below with reference to the drawings. The sun shield of this example is characterized in that the sun shield is automatically configured to have a roof-like shape with a bulged central portion due to a change in shape of the shape memory alloy. The structure is similar to that of the conventional sun shield shown in FIGS. Therefore, the same reference numerals are given to the same parts as those in the related art, and the detailed description is omitted.

FIG. 1 is a schematic perspective view showing the first embodiment of the sunshield of the present invention in outer space.
(A) shows the state before the shape change of the stiffener, and (b) shows the state after the shape change. FIG. 2 shows the sun shield of FIG.
(A) is a front view of a state before a shape change of a stiffener, (b) is a state after a shape change. As shown in these figures, a sunshield according to the present embodiment includes a sunshield substrate 1 attached to the outside of an artificial satellite 10 and a sunshield substrate 1.
On the back surface (or front surface) of the stiffener 2 arranged in parallel with the winding direction of the sun shield substrate 1.

The sunshield substrate 1 is lightweight, can be rolled up when stored, and has a constant spring property and a restoring force such that it becomes a flat plate when deployed, for example, a composite material such as carbon glass fiber or the like. , Or made of metal, etc., these members are formed into a flat plate shape,
In order to prevent the temperature of the sun shield itself from rising, the surface is treated with aluminum evaporated Teflon.

This sunshield substrate 1 is supported by a sunshield support 11 fixed to the artificial satellite 10 like the conventional sunshield shown in FIGS. 5 to 7, and when the artificial satellite 10 is launched. Is rolled up and stored, and when it reaches the outer space, the fixing by the lashing belt 12 and the fixing pin 14 is released and unfolded,
The state shown in FIG. 1A is obtained, and the upper part of the externally mounted device 3 is covered.

The stiffener 2 disposed on the back surface of the sun shield substrate 1 is formed in a straight long plate shape, and is made of a shape memory alloy in the same length as the width of the sun shield substrate 1 in the winding direction. Is formed, and in this embodiment,
They are arranged at both ends and at approximately three central positions.

The shape memory alloy forming the stiffener 2 is in the form of a straight long plate and is integrated with the plane of the sun shield substrate 1 at the time of launching the artificial satellite 10, that is, at room temperature, and when the sun shield substrate 1 is rolled up. Also, the shape is memorized and formed so that when the artificial satellite 10 reaches outer space and receives sunlight, it is curved into a roof shape at a constant temperature. The transformation temperature of the stiffener 2 is preferably set to 30 ± 5 ° C.

The sun shield substrate 1 of the stiffener 2
At least, both ends of the stiffener 2 are fixed to both side edges of the sunshield substrate 1. In the present embodiment, the entire surface of the stiffener 2 is attached to the sunshield substrate 1 with an adhesive or the like. It is fixed. This stiffener 2
It is preferable that the bonding portion is adhered to the entire surface of the sunshield substrate 1, but any number of portions may be bonded as long as the shape of the sunshield substrate 1 can be changed.

As a result, when the artificial satellite 10 receives solar heat, that is, when the external equipment 3 of the artificial satellite 10 is irradiated with sunlight, the stiffener 2 is curved in a roof shape, and therefore the sign shield substrate 1 is formed. Also automatically becomes a roof-shaped shape with a bulged central portion as shown in FIG. 1B, and protects the externally mounted device 3 from sunlight with a certain rigidity and strength.

In order to ensure that the sunshield substrate 1 has a roof shape, in this embodiment, the stiffener 2 is formed to have the same length as the widthwise direction of the sunshield substrate 1. 1 The back surface is attached from one side edge to the other side edge, but not limited to this, the stiffener 2 is formed shorter than the lateral direction of the sun shield substrate 1, and only the central portion of the sun shield substrate 1 is formed. It can also be attached to. In this case, the material of the stiffener 2 can be saved and the weight of the artificial satellite can be reduced. In addition, in the present embodiment, the stiffeners 2 are arranged at three positions on the back surface of the sunshield substrate 1, but the stiffeners 2 may be arranged at any number of positions or one position.

Next, the operation of the sun shield of this embodiment having the above-described configuration will be described. First, at the time of launching the artificial satellite 10, since it is at room temperature, FIG.
As shown in the figure, the stiffener 2 has a straight rod shape and is integrated with the plane of the sunshield substrate 1.
Is stored by being wound into a roll.

When the satellite 10 reaches the outer space, the securing belt 1 is moved in the same manner as the conventional sunshield shown in FIG.
By releasing the fixing of 2, the sunshield substrate 1 is developed into a flat plate shape by its own restoring force.

When the sunshield substrate 1 is developed in a flat plate shape, when the solar heat is received, the stiffener 2 is curved due to the shape change of the shape memory alloy and changes into a roof shape. As a result, as shown in FIG. 2B, the sunshield substrate 1 also automatically takes the shape of a roof, and can maintain a certain rigidity and strength.
Is protected from sunlight. Since the stiffener 2 and the sunshield substrate 1 are always in close contact, the sunshield substrate 1
This also increases the rigidity and strength of the device.

Next, a second embodiment of the sunshield according to the present invention will be described with reference to FIG. 3A and 3B show a second embodiment of the sunshield of the present invention. FIG. 3A is a front view showing a state before the shape change of the stiffener and FIG. 3B is a front view showing a state after the shape change. In the present embodiment, as shown in FIG. 3B, the stiffener 2 is formed by contracting the shape at a constant temperature and storing the shape so that the length thereof is shortened. Only both ends of the stiffener 2 are fixed to the edge by screws or the like.

In this manner, at a constant temperature,
By reducing the length of the stiffener 2, both edge portions of the sun shield substrate 1 are pulled inward, and the sun shield substrate 1 is a roof type in which the center portion swells as shown in FIG. 3B. It has a shape and can maintain constant rigidity and strength as in the first embodiment.

Next, a third embodiment of the sunshield according to the present invention will be described with reference to FIG. FIG. 4 is a front view showing a third embodiment of the sun shield of this embodiment, (a) showing a state before the shape change of the stiffener and (b) showing a state after the shape change.

This embodiment is different from the second embodiment in that
This is related to a modification of the stiffener 2 that changes its shape shortly when it receives solar heat. In the present embodiment, at least a part of the stiffener 2 is a spring 2a formed in the shape of a coil spring, and the spring 2a is formed in the middle portion of the spring 2a at the center of the sunshield substrate 1 in the winding direction, that is, the width direction.
There is provided a stiffener support portion 4 for locking the.

In general, in the shape change of the shape memory alloy, since the change rate when the length changes short is not so large, the shrinkage amount may be insufficient for the change in the roof type shape of the sun shield 1. Therefore, in this embodiment, a part of the stiffener 2 is a spring 2a formed of a shape memory alloy.

That is, when the shape memory alloy is formed in a coil spring shape, the amount of shrinkage increases, so that the sunshield substrate 1 can be more reliably made into a roof shape. In this embodiment, the stiffener 2 is partially attached to the spring 2a.
However, if necessary, the entire stiffener 2 may be formed in a coil spring shape.

Further, in this embodiment, the stiffener support portion 4 is provided at the center of the winding direction of the sun shield substrate 1, so that the sun shield substrate 1 has a symmetrical roof type with the stiffener support portion 4 as the center. Becomes Thereby, there is an effect that the strength and rigidity of the sun shield substrate 1 are further increased. The stiffener support portion 4 can be omitted if necessary.

[0041]

As described above, according to the sunshield of the present invention, the sunshield can be rolled up and stored at the time of launching an artificial satellite by using only a small, lightweight, and simple structure. Constant rigidity,
It can be deployed while maintaining strength.

[Brief description of drawings]

FIGS. 1A and 1B are schematic perspective views showing a state of a sunshield according to a first embodiment of the present invention in outer space, wherein FIG. 1A shows a state before a stiffener shape is changed, and FIG.

FIGS. 2A and 2B are front views of the sun shield in FIG. 1 showing a state before a stiffener shape change and a state after a stiffener shape change.

FIGS. 3A and 3B are front views showing a second embodiment of the sun shield according to the present embodiment, in which FIG. 3A shows a state before the stiffener shape is changed, and FIG.

FIGS. 4A and 4B are front views showing a third embodiment of the sun shield according to the present invention, in which FIG. 4A shows a state before a stiffener shape change, and FIG.

FIG. 5 is a schematic perspective view showing a state of a conventional sunshield in outer space.

FIG. 6 is a schematic side view of a main part showing a stored state of a conventional sunshield.

FIG. 7 is a schematic perspective view showing a fixing means for storing a conventional sunshield.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sunshield board 2 ... Stiffener 2a ... Spring 3 ... External mounting device 4 ... Stiffener support 10 ... Artificial satellite 11 ... Sunshield support 12 ... Fixing belt 13 ... Intermediate member 13a ... Rotating shaft 14 ... Fixing pin 15 ... Spring 16 ... Cable 17 ... Cutter

Claims (5)

[Claims] 1. A sun shield mounted on an artificial satellite, which is stored in a roll and is launched, and which is deployed in outer space and shields external equipment from sunlight, on one surface of a sun shield substrate, A sun shield having a stiffener made of a linear shape memory alloy which is curved at a constant temperature and swells out the central portion of the sun shield substrate. 2. A sun shield mounted on an artificial satellite, which is stored in a roll shape and launched, and which is deployed in outer space and shields external equipment from sunlight, on one surface of a sun shield substrate, A sun shield having a stiffener made of a linear shape memory alloy that contracts at a constant temperature and swells the central portion of the sun shield substrate. 3. The sun shield according to claim 2, wherein a part or all of the stiffener is formed in a coil spring shape. 4. The sun shield according to claim 3, wherein a stiffener supporting portion for locking an intermediate portion of the stiffener is provided on the sun shield substrate. 5. The stiffener is provided in parallel with at least two or more in the longitudinal direction of the sun shield.
The sunshield according to 3 or 4.