JP2001196843A - Expandable film antenna for outer space - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expandable film antenna for the outer space provided with a precise, inexpensive and reliably developed antenna mirror surface. SOLUTION: In the expandable film antenna for the outer space having a balloon film and an annular support positioned outside the periphery of the balloon film to support the balloon film, the annular support has synchronous development truss structure where constituting members are uniforms and developed at a controlled speed and the whole shape is deformed and developed similarly. Furthermore, a grid network formed of dielectric thin wires is connected to the outer surface of one or both of a film on a radio wave entering side and a film on a radio wave reflecting side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflatable membrane antenna for space use, and more particularly, to the formation of a mirror surface thereof.

[0002]

2. Description of the Related Art A conventional inflatable membrane antenna for a large space, for example, needs to be highly flexible or easily foldable in order to be housed in a launch vehicle. For this reason, the antenna mirror surface is composed of a radio wave reflection film using a metal mesh woven with fine gold-plated metal wires and a deployment structure that deploys this on orbit, and what is generally called a mesh mirror surface is used. Most were. However, the above-mentioned thin metal wire cannot form an infinitely thin line, and there is also a limitation in the method of knitting, so that only a mirror surface that can be formed at a low frequency of at most several gigahertz can be formed. Further, the above-mentioned mesh mirror surface is not economical because the material itself is expensive due to the use of gold plating, and a complicated and expensive deployment mechanism is required to expand the mesh. For this reason, observations at a frequency of about 50 GHz planned in the future, VSOP2 (10 m diameter, Japan, 2008)
And plans such as ARISE (14m diameter, USA, 2015) require new structures that are more economical and have higher surface accuracy.

[0003] The inflatable membrane antenna tested on the STARTAN 207 satellite launched in 1996 was developed as a mirror surface structure that satisfies the above requirements (RE Freeland et al, "
Validation of Unique Con
cept for a Low-cost, Light
tweight Space-deployable
Antenna Structure ", IAF-9
3-I. 1.204 (1993)). FIG. 7 shows the shape of the mirror of the inflatable membrane antenna in the orbit of the satellite, and FIG. 8 shows a sectional view of the mirror.

[0004] In Figs.
The satellite body 07 is attached to the satellite body 1, the storage box for storing the antenna mirror surface when stored, and 3 is an expansion strut, which supports the antenna mirror surface from the satellite body 2 side, and is provided by expansion means (not shown). Inflation gas can be inserted on the orbit. Reference numeral 4 denotes an expansion torus as an annular support. The annular support is located outside the peripheral edge of the balloon film 10 described later, and deploys the balloon film 10 to support the balloon film 10 in the deployed state. Expansion torus 4 of this example
Is attached to the distal end of the inflatable strut 3 and is inflated annularly on the track by the inflating means. Reference numeral 5 denotes a tension cable, one end of which is attached to the inner peripheral portion of the expansion torus 4 and the other end of which is connected to a suturing portion 6 which constitutes the peripheral edge of the antenna reflector. This suture part 6
Is a state in which a transmission film 7 made of, for example, a dielectric thin film as a radio wave incident side film disposed on the radio wave incident side and a plastic film 8 as a radio wave reflection side film having a radio wave reflection surface are overlapped. , Are circumferentially sewn portions, that is, portions where peripheral portions are sewn. Reference numeral 9 denotes an aluminum coat applied to the upper surface, that is, the concave surface of the plastic film 8 in order to increase the radio wave reflectance. Hereinafter, in the present specification, the peripheral edges of the radio wave incident side film (transmitting film 7) and the radio wave reflecting side film (plastic film 8) are sewn to each other, and are formed so as to be able to expand and contract by introducing and removing gas into the inside. The expanded body is referred to as a balloon film 10.

In the above structure, an inexpensive aluminum-plated plastic film having a thickness of 6 μm is used as a radio wave reflection film instead of an expensive gold-plated mesh, and the film is expanded with nitrogen of 40 g or less instead of a complicated developing mechanism. By using a method of forming a parabolic surface, that is, a mirror surface, it was possible to form a smooth, high-precision mirror surface at low cost. But,
In the actual test, the following inconveniences occurred. That is, the expansion strut 3 and the expansion torus 4 are expanded on the track by expansion means (not shown), and after the expansion torus 4 expands, the permeable membrane 7 and the plastic are expanded by the expansion means (not shown). A gas such as nitrogen gas is injected into the inside of the balloon film 10 composed of the film 8 to expand the balloon film 10 and expand the plastic film 8 in a parabolic manner. A force in the direction of the center of the balloon film 10 acting on the erection cord 5,
The balloon film 10 is developed into a predetermined shape by balancing with the radial force of the balloon film 10 acting on the tension cable 5 by the expansion of the expansion torus 4.

However, the balloon membrane 10 failed to expand and deploy. The cause was that there was no control device for expansion and deployment,
It has been reported that a chaotic deployment has taken place and a pressure valve (not shown) that expands the mirror has failed (REF).
reeland et al, "Significa
once of the inflatable Ant
enna Experiment Technology
y ", AIAA-98-2104, SDM '98
(1998)). In addition to the above-mentioned disadvantages, variations in the material and thickness of the film material and variations in dimensions at the time of manufacturing directly act strongly on the developed shape of the balloon film 10, so that high mirror surface accuracy cannot be stably obtained. There were also problems with the points.

[0007]

As a mirror surface of a future inexpensive, high-precision, large-sized inflatable membrane antenna for space, an inflatable membrane structure is basically suitable. Unless the problem of stability against various variations such as the size at the time is solved, there is little possibility of obtaining a desired mirror surface. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an inflatable membrane antenna for space having an inexpensive, highly reliable, large and highly accurate inflatable membrane antenna mirror surface.

[0008]

According to the first aspect of the present invention, there is provided an inflatable space antenna for a space having a balloon film and an annular support positioned outside the periphery of the balloon film and supporting the balloon film. The annular support is characterized by a synchronously deployed truss structure in which the components are uniform, deploy at a controlled speed, and the overall shape is similarly deformed and deployed.

The invention of claim 2 is based on the invention of the inflatable film antenna for space according to claim 1, wherein one or both of the radio wave incident side film and the radio wave reflection side film of the balloon film is made of a thin dielectric line. It is characterized in that the formed lattice networks are joined.

[0010] The invention of claim 3 is claim 1 or claim 2.
In the inflatable membrane antenna for space according to the above, the synchronous deployment truss structure has a diagonal member that can be extended and retracted, and a plurality of parallelogram links having gears attached to ends of lower or upper transverse members are adjacent to each other. And a drive system that directly or indirectly controls the rotation of the gears so that the gears of the horizontal members mesh with each other.

[0011] The invention of claim 4 is the invention of claim 1 or claim 2.
In the inflatable membrane antenna for space according to the above, the synchronous deployment truss structure has a loop wire stretched diagonally,
A truss structure in which a plurality of parallelogram links each having a gear attached to an end of a lower or upper horizontal member are connected in series in a ring so that gears of adjacent horizontal members mesh with each other,
A drive system for directly or indirectly controlling the rotation of the gear is provided.

[0012] The invention of claim 5 is the invention of claim 1 or claim 2.
In the inflatable membrane antenna for space according to the above, the synchronous deployment truss structure has a diagonal member that can be extended and retracted, and a plurality of parallelogram links having pulleys attached to ends of lower or upper horizontal members are adjacent to each other. And a drive system for directly or indirectly controlling the rotation of the pulleys.

[0013] The invention of claim 6 is the invention of claim 1 or claim 2.
In the inflatable membrane antenna for space according to the above, the synchronous deployment truss structure has a loop wire stretched diagonally,
A truss structure in which a plurality of parallelogram links each having a pulley attached to an end of a lower or upper horizontal member are connected between pulleys of adjacent horizontal members via a belt, and the pulley is directly or indirectly connected. And a drive system for controlling rotation.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Embodiment 1
An embodiment of an annular support which is located outside the peripheral edge of the balloon membrane 10 and supports the balloon membrane 10 via the tension cable 5 in a state surrounding the balloon membrane 10 in an annular shape is shown. A synchronous deployment truss structure in which the members are uniform and deploy at a controlled speed, and the overall shape is similarly deformed and deployed. Hereinafter, the synchronous deployment truss structure will be described with reference to FIGS. 1 (a) to 1 (c). 1A and 1B are structural views of a mirror surface of an antenna. FIG. 1A is a plan view of the mirror surface as viewed from a radio wave axis, FIG. 1B is a side view of a balloon film 10, and FIG. Note that the same reference numerals as those in FIGS. 7 and 8 described as the related art have substantially the same or corresponding contents, and therefore description thereof will be omitted.

Synchronous deployment truss 12 as annular support
Is a mirror outermost periphery, that is, a balloon film 1 as shown in FIG.
0, a plurality of parallelogram links located outside the periphery of
The structure is such that the sides are shared with each other to form a regular polygon and are connected in a ring shape. FIG. 2 shows in detail the structure and operation of the basic period portion of the synchronous deployment truss 12 shown in FIG. 1, and FIG. 2 (a) shows the shape when stored in a rocket, and FIG. ) Is the shape in the middle of development, Fig. 2
(C) shows the shape after the development is completed.

In FIG. 2A to FIG. 2C, 13
Are horizontal members forming a pair of upper and lower horizontal sides parallel to the horizontal direction that constitute each of the above parallelogram links, 13a is a horizontal member as an upper horizontal side, and 13b is a lower horizontal side. The horizontal member as a side is shown. Similarly, 14 is a vertical member forming a pair of left and right vertical sides parallel to the vertical direction forming each parallelogram link, and 14a is a vertical side positioned relatively on the left side in the figure. The vertical member 14b indicates a vertical member as a vertical side located on the right side thereof. Each adjacent parallelogram link is a vertical member 14 as a vertical side.
Are shared with each other and connected in series in a ring. That is,
In the illustrated embodiment 1, one adjacent horizontal member 13a and the other horizontal member 13b are pin-coupled so as to share the vertical member 14.

Reference numeral 15 denotes a stretchable diagonal member as an extendable diagonal member that runs so as to connect diagonal lines of each parallelogram link. As shown in FIG.
Both ends of the diagonal member 15 are pin-connected to the upper end side of a and the lower end side of the other adjacent vertical member 14b. In this case, each elastic diagonal member 1 of the adjacent parallelogram link
5 are arranged symmetrically with respect to the shared vertical member 14. In this way, the mounting positions of the gear terminals 16 are not alternately arranged but are aligned at the upper or lower stage, thereby preventing interference between members. In FIG. 2B, the angle θ in the figure indicates the rotation angle of the horizontal member 13 with respect to the vertical member 14 at the time of development.

FIG. 3 is an exploded view showing details of the joint between the horizontal member 13 and the vertical member 14 shown in FIG. Reference numeral 16 in the drawing denotes a gear terminal having a meshing tooth at an end. The gear terminal 16 has a shaft hole and is attached to an end of the horizontal member 13. Reference numeral 17 denotes a pin terminal attached to the other end of the horizontal member 13, and reference numeral 18 denotes a vertical member terminal attached to an end of the vertical member 14 and interposed so that the gear terminals 16 of the adjacent horizontal member 13 mesh with each other. is there. The vertical member terminal 18 has a bearing hole for bearing two adjacent gear terminals 16, 16. Pins 19, 19 are inserted as shaft holes of the two gear terminals 16, 16, pass through the bearing holes of the vertical member terminal 18, and pin as a gear shaft for pin-connecting the horizontal member 13 and the vertical member 14. It is. 20 is a C-clip attached to the tip of the pins 19, 19, and 21 is attached at one or more places in place of the clip 20, and an output shaft is connected to the pin 19, via a housing. It is a control motor as a deployment control means constituting a drive system attached to the vertical member terminal 18.

FIG. 4 is a cross-sectional view showing the structure of the stretchable oblique member 15 as the stretchable oblique member shown in FIG. Reference numeral 22 in the figure denotes an outer pipe, 23 denotes a pin terminal attached to the end of the outer pipe 22 and connected to the vertical member 14 through a terminal similar to the vertical member terminal 18 not shown,
24 is an inner pipe that moves inside the outer pipe 22;
5 is attached to the end of the inner pipe 24,
4 is a pin terminal which is pin-coupled to 4;
A spring terminal 27 attached to the other end is a coil spring which is attached between the pin connector 23 and the spring terminal 26 and serves as urging means for constantly generating a force for bringing the both closer together.

As described above, the synchronous deployment truss structure of the first embodiment has the extendable and oblique member 15, and the gear terminals 16 and 16 are mounted as gears at the lower or upper end of the horizontal member 13. A plurality of parallelogram links are connected to the gears of the adjacent horizontal members 13, ie, the gear terminal 1.
A structure having a truss structure in which rings 6 and 16 are connected in series in a ring, and a control motor 21 as a drive system for directly or indirectly controlling the rotation of the gear (gear terminal 16). It is. Hereinafter, the operation of the synchronous deployment truss structure will be described with reference to FIGS. First, an expansion strut 3 for electrically and mechanically coupling the satellite main body 2 and the mirror surface of the expansion membrane antenna by an expansion device or a deployment mechanism (not shown), or a function corresponding to the function performed by the expansion strut 3. Inflate or unfold the item. After being developed, a parallelogram link stored in a zigzag shape as shown in FIG. 2A by a drive system (drive means) such as a release mechanism (not shown) in response to a command from the ground, for example. As shown in FIG. 2B, the coil spring 27 built in the elastic
By reducing the length of the stretchable diagonal member 15 by the contraction force, the link shape of the parallelogram is developed so as to approach a rectangle.

During deployment, the horizontal member 13 rotates from zero to 90 degrees with respect to the vertical member 14, but since this rotation angle θ is transmitted to the adjacent horizontal member 13 by the gear terminal 16, all the parallelograms are rotated. The shape links rotate simultaneously by the same angle, resulting in the same deformed shape. In this case, the rotation speed of the horizontal member 13 can be controlled by the control motor 21 to a desired or predetermined speed.

As described above, in the synchronous deployment truss 12 shown in the first embodiment, the parallelogram links connected in a ring are synchronized in the same manner as described above, and have the same shape and concentric circles all at once. As it unfolds, the balloon membrane 10 supported in the ring of a series of parallelogram links that loop around the ring is evenly spread through the tie 5. That is, in the synchronous deployment truss 12 designed in a circumferential shape, the diameter of the circle in the middle of deployment is almost SIN [θ] times the diameter after deployment, and thus the value of the rotation angle θ and the rate of change (speed). Is controlled, the balloon film 10 can be spread uniformly at a predetermined speed. Then, after the synchronous deployment truss 12 is completely deployed (rotational angle θ = 90 degrees), a gas such as air or nitrogen is inserted into the balloon film 10 by, for example, an air insertion tube (not shown) as gas insertion means. Then, the balloon film 10 expands in a parabolic manner as shown in FIG.

In the first embodiment, as shown in FIG. 1B, dielectric films are formed on both outer surfaces of the transmission film 7 as the radio wave incident side film and the dielectric film 8 as the radio wave reflection side film of the balloon film 10. A triangular grid formed by body wires, for example, stretched cables, is joined. The lattice network 11 attached to the outer surface of the balloon film 10 may be provided on one of the radio wave incident side film and the radio wave reflection side film of the balloon film 10. or,
The lattice is not limited to a triangular shape, and may have an appropriate shape. As described above, by covering the surface of the balloon film 10 with the grid net 11, a predetermined surface accuracy is achieved under a predetermined pressure.

For example, if the average radius of curvature of the balloon membrane 10 is ρ, the membrane tension is N, the radius of the circumcircle of the average triangular lattice of the lattice network 11 is R, and the tension of the cable is T, the obtained balloon membrane 10 Is given by [Equation 1]. [Equation 1] δ = 0.2 × [R ² / (2ρ)] × [T / (N × L)] Considering that the optimum surface accuracy δ obtained by the mesh development mirror surface is given by [Equation 2]. Then, in the normal design range (1 >> [T / (N × L)]), the optimum surface accuracy of the balloon film is much better than the optimum surface accuracy obtained by the mesh development mirror surface. You can see that. [Equation 2] δ> 0.2 × [R ² / (2ρ)] Even when the material of the balloon film 10 varies, the shape of the balloon film 10 is suppressed to local deformation because of the lattice network 11. Therefore, there is little possibility that the surface accuracy is significantly deteriorated.

According to the first embodiment, when the antenna is deployed, the synchronous deploying truss 12 is provided with the contractible elastic diagonal member 15.
Are arranged diagonally, and the parallelogram links are developed synchronously by the gear terminal 16 and are developed by the control motor 21 at a desired speed. In addition, it can spread uniformly and slowly, and the reliability of deployment is enhanced. That is, since the synchronous deployment truss 12 is completely synchronized by the gear terminal 16 and the deployment speed is controlled to a desired value by the control motor 21,
Material damage due to variation in expansion is avoided, and the balloon film 10
Can provide reliable and stable expansion. Further, since the surface of the balloon film 10 is covered with a lattice network 11 formed of a dielectric cable, it is possible to provide an inflatable film antenna for space having a mirror surface which is less affected by variations in film material and dimensions. Can be.

Further, in the first embodiment, the grid net 11 is attached to the outer surfaces of both the transmission film 7 and the plastic film 8, but the same effect can be obtained only by the surface of the plastic film 8. This is effective when a mirror surface is used in a high frequency band such as the Ku to Ka band, and even if a slight blocking of radio waves becomes a problem. In this case, since the symmetry of the net shape is broken, an accurate detailed balance calculation and a manufacturing method are required.
In addition, although a triangular mesh is used as the mesh shape of the grid network 11, a qualitatively equivalent effect can be obtained with a square or a hexagon. This is useful when easy manufacturing or an interface with special accessories is required. That is, by replacing a grid with a triangular mesh with a square or hexagonal grid, it can be manufactured at low cost or can be adapted to a special interface. Further, by attaching a triangular lattice network formed of, for example, a dielectric cable to the outside of the balloon film 10, a high-precision mirror surface resistant to variations in materials or manufacturing can be obtained. In addition, the position of the gear terminal 16 of the synchronous deployment truss 12 is set at the end of the vertical member 14 to which the telescopic diagonal member 15 is not attached. Can achieve the same effect. This is effective when interference between the gear terminal 16 and other members must be avoided.

Embodiment 2 FIG. In the second embodiment, in the structure of the synchronous deployment truss 12 of the first embodiment, the deployment is synchronized by using a pulley instead of the gear, that is, the gear terminal 16. This will be described with reference to FIG. FIG. 5 shows the pulleys 28 and 28 of the adjacent horizontal member 13.
FIG. 4 is a side view showing a state where the two gears meet each other (corresponding to a state where the gear terminals 16 and 16 are meshed with each other), omitting a vertical member terminal 18 having a bearing hole for supporting or bearing both pulleys 28 and 28. is there. In FIG. 5, reference numeral 28 denotes a pulley attached to the cross member 13 instead of the gear terminal 16, and reference numeral 29 denotes a synchronous belt which is wound in a state where the pulleys 28 are brought into contact with each other. is there.

Next, the operation of the synchronous deployment truss structure will be described. Since the synchronous belt 29 is stretched between the parallelogram pulleys 28 adjacent to each other in such a manner as to draw a figure of eight, as in the case of the gear terminal 16 of the first embodiment, The rotation angle θ of the horizontal member 13 is transmitted to the adjacent horizontal member 13. In the first embodiment,
If a temperature difference or an extreme temperature change occurs between the adjacent gear terminals 16, 16, the gear terminals 16 mesh with each other, and the contact resistance increases, so that transmission of the development angle may not be performed efficiently. However, since the synchronous belt 29 is used in the second embodiment, by imparting an appropriate elasticity to the synchronous belt 29, perfect synchronization is somewhat sacrificed. Since there is no contact between the lateral member 13 and the gear, the development angle can be transmitted without increasing the contact resistance. Therefore, the second embodiment is extremely effective when used on an orbit with severe thermal environment.

Embodiment 3 The third embodiment is different from the synchronous deployment truss structure of the first embodiment in that the telescopic diagonal member 15 is used.
In addition, a driving force for deployment and deployment speed control are realized by using a wire and a rotating drum instead of the control motor 21. This will be described with reference to FIGS. 6A to 6C. FIG. 6A is a diagram showing a shape at the time of storage, FIG. 6B is a diagram showing a shape during deployment, and FIG. 6C is a diagram showing a shape after deployment.
2 (a) to 2 (c) in FIG.

6A to 6C, reference numeral 30 in the drawings denotes a loop wire. One end of this one loop wire 30 is fixed to the rotary drum 32 described later, and the other end extends to the synchronous deployment truss 12 side. Loop wire 30 extending to synchronous deployment truss 12 side
Is disposed so as to extend at a diagonal position of each parallelogram link constituting the synchronous deployment truss 12, that is, at a position of the oblique member 15, and makes a round in the circumferential direction of the synchronous deployment truss 12. I have. Reference numeral 31 denotes a transmission pulley, which is attached to the vertical member 14 of each parallelogram link, changes the direction of the loop wire 30 and shifts the loop wire 30 to the adjacent parallelogram link. The rotating drum 32 is a drum that winds and unwinds the loop wire 30,
It is equipped in two places.

Next, the operation of the third embodiment will be described. First, at the time of storage, when a mirror holding mechanism (not shown) is released, the rotary drum 32 rotates to start winding the loop wire 30. As the loop wire 30 is wound up, the loop wire 30 is arranged on the diagonal of each parallelogram link while being turned by the transmission pulley 31, so that the loop wire 30 is synchronously developed according to the shortening of the diagonal. Each parallelogram link constituting the truss 12 is shown in FIG.
As shown in (b), the horizontal member 13 rotates and deforms toward a rectangular shape. The rotation angle θ of the lateral member 13 is
Synchronization is achieved by the gear terminal 16 in the case of the first embodiment and by the synchronous belt 29 in the case of the second embodiment, and the development, that is, the rotation speed is achieved by controlling the rotation speed of the rotary drum 32. In the third embodiment, each parallelogram is hung on the appropriately arranged transmission pulley 31 without using the telescopic member 15 having a complicated telescopic mechanism component used in the first or second embodiment. Since one loop wire 30 extending on the diagonal line of the link is wound by a rotating drum, a lightweight and inexpensive synchronous deployment truss can be obtained.

[0032]

According to the first aspect of the present invention, a conventional inflating torus is developed by a synchronous deploying truss in which the constituent members are deployed uniformly and at a controlled speed, and the overall shape is deformed and deployed similarly. Because of the replacement, it is possible to provide a space expansion antenna having a mirror surface capable of controlling the shape during expansion.

According to the second aspect of the present invention, since the lattice network is attached to the outer surface of the balloon film, a space expansion antenna having a high-precision antenna mirror surface with little mirror deterioration even with respect to variations in materials and dimensions. Can be provided.

According to the third aspect of the present invention, the parallelogram link having the diagonal member which can be extended and contracted and the gear attached to the end of the horizontal member is formed into an annular shape so that the gears of the adjacent horizontal member mesh with each other. Since the synchronous deployment truss structure includes a truss structure connected in series and a drive system for rotating the gear, a space expansion antenna having an antenna mirror surface capable of expansion and deployment control can be provided.

According to the fourth aspect of the present invention, a parallelogram link having a loop wire stretched on a diagonal line and having a gear mounted on an end of the horizontal member is connected to a gear of a horizontal member adjacent to each other. A synchronous expansion truss structure including a truss structure connected in series in a ring so as to mesh with each other, and a drive system for rotating the gears, so that a space expansion antenna having an antenna mirror surface capable of expansion and deployment control is provided. Can be provided.

According to the fifth aspect of the present invention, a plurality of parallelogram links having a diagonal member which can be extended and contracted, and a pulley attached to an end of the horizontal member, and a belt between the pulleys of the adjacent horizontal members. Since the synchronous deployment truss structure includes the coupled truss structure and the drive system for rotating the pulley, it is possible to provide a space expansion antenna having an antenna mirror surface capable of controlling expansion and deployment. Further, by replacing the gear terminal with a pulley and a synchronous belt, even under severe thermal deformation, deployment synchronization can be ensured with a low resistance.

According to the sixth aspect of the present invention, a plurality of parallelogram links each having a loop wire stretched on a diagonal line and having a pulley attached to an end of the cross member are connected to the cross member of the adjacent cross member. A truss structure in which pulleys are connected with a belt,
Since the synchronous deployment truss structure includes a drive system for rotating the pulley, a space expansion antenna having an antenna mirror surface capable of controlling expansion and deployment can be provided.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a mirror surface of an antenna according to a first embodiment;
(A) is a mirror plan view from the radio axis, (b) is a balloon film 1
0 is a side view showing the structure of the synchronous deployment truss.

FIGS. 2A and 2B are diagrams showing in detail the structure and operation of a basic period portion of the synchronous deployment truss according to the first embodiment, wherein FIG. (C) is a diagram showing the shape after the development is completed.

FIG. 3 is an exploded view showing details of a joint between a horizontal member and a vertical member according to the first embodiment.

FIG. 4 is a cross-sectional view illustrating a configuration of an elastic oblique member as the oblique member according to the first embodiment.

FIG. 5 is a side view showing a state where pulleys of horizontal members adjacent to each other in Embodiment 2 meet each other.

FIGS. 6A and 6B are diagrams showing a synchronously deployed truss structure according to the third embodiment, wherein FIG. 6A is a diagram showing a shape at the time of storage, FIG. 6B is a diagram showing a shape during deployment, and FIG. It is.

FIG. 7 is a perspective view of a conventional space expansion antenna.

FIG. 8 is a sectional view of the mirror surface of FIG. 7;

[Explanation of symbols]

1 satellite, 2 storage box, 3 inflatable strut, 4 inflatable torus, 5 cable, 6 suture, 7 permeable membrane, 8
Plastic film, 9 Aluminum coat, 10 Balloon film, 1
1 lattice network, 12 synchronous deployment truss (annular support),
13 horizontal member, 14 vertical member, 15 telescopic diagonal material, 16
Gear terminal (gear), 18 vertical member terminal, 21 control motor (drive system / deployment control means), 22 outer pipe, 24
Inner pipe, 28 pulley, 29 synchronous belt, 30
Loop wire, 31 transmission pulley, 32 rotating drum (drive system / deployment control means).

Claims (6)

[Claims] 1. An inflatable membrane antenna for space having a balloon membrane and an annular support positioned outside the periphery of the balloon membrane and supporting the balloon membrane, wherein the annular support has a uniform component. An inflatable membrane antenna for space, characterized in that it has a synchronous deployment truss structure that deploys at a controlled speed and deforms and deploys in a similar manner in overall shape. 2. The method according to claim 1, wherein a lattice network formed by a dielectric thin wire is joined to one or both of the outer surfaces of the radio wave incident side film and the radio wave reflection side film of the balloon film. An inflatable membrane antenna for space as described in the above. 3. The synchronous deployment truss structure has a diagonal member that can be extended and retracted, and a plurality of parallelogram links each having a gear attached to an end of a lower or upper transverse member and a gear of a transverse member adjacent to each other. 3. The truss structure according to claim 1, wherein the truss structure includes a truss structure connected in series in a ring so that the gears mesh with each other, and a drive system that directly or indirectly controls the rotation of the gear. 4. Inflatable membrane antenna for space. 4. The synchronous deployment truss structure has a loop wire stretched diagonally, and a plurality of parallelogram links having gears attached to ends of lower or upper cross members are adjacent to each other. 2. A structure comprising a truss structure which is annularly connected in series so that gears of a lateral member mesh with each other, and a drive system which directly or indirectly controls the rotation of the gears. Item 3. An inflatable film antenna for space according to item 2. 5. The synchronous deployment truss structure has a diagonal member that can be extended and retracted, and a plurality of parallelogram links each having a pulley attached to an end of a lower or upper horizontal member, and pulleys of adjacent horizontal members. 3. The space according to claim 1, wherein the truss structure has a truss structure in which the pulleys are connected via a belt, and a drive system that directly or indirectly controls the rotation of the pulley. Inflatable membrane antenna. 6. The synchronous deployment truss structure has a loop wire stretched diagonally, and a plurality of parallelogram links each having a pulley attached to an end of a lower or upper cross member are adjacent to each other. 3. A structure comprising a truss structure in which pulleys of a horizontal member are connected via a belt, and a drive system for directly or indirectly controlling the rotation of the pulleys. An inflatable membrane antenna for space as described in the above.