JP3641186B2 - Deployable truss structure and antenna device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a deployable truss structure and an antenna device using the same, and more particularly to a deployable truss structure used for a structure constituting a space base, an antenna device constructed in outer space, and the like.
[0002]
[Prior art]
In the field of space development, the development of a space station concept is underway. In this space station concept, various deployable truss structures including the skeleton of the space station and the support structure of the antenna are assembled on the ground in advance, folded and accommodated, and transported to space. A method to develop in space is considered and developed.
[0003]
An example of such a conventional deployable truss structure is shown in FIGS. 6 and 7 (see Japanese Patent Laid-Open No. 5-58396). In this unfolded truss structure, the members 42 joined in a quadrilateral shape around the central axis 41 are arranged radially, and the member 43 laid on the diagonal of the quadrilateral is driven to expand and contract to expand the truss structure. And storage operation is possible. The dimension 44 in the longitudinal direction when stored is approximately the length including the central axis 41 and the radius 45 when deployed.
[0004]
When this deployable truss structure is used as a frame structure of an antenna mirror surface, it is necessary to increase the diameter as much as possible in order to improve communication efficiency. On the other hand, it is desirable that the dimensions during storage (particularly the length during storage) be as small as possible in consideration of the cost of launch. One conventional method that satisfies this requirement is to connect a plurality of deployable truss structures 40 so as to function as a single deployable structure 50 as shown in FIG.
[0005]
[Problems to be solved by the invention]
However, even if a plurality of deployable truss structures 40 are connected, depending on the desired desired deployment size, the expansion effect of connecting a plurality of deployable truss structures may increase the total mass of the structure. There are cases where it is not worth the cost. For example, as shown in FIG. 7, it is remarkable that three desired deployment effective truss structures 40 are connected to obtain a desired antenna effective diameter 51. This is the polygonal shape of the outermost periphery of the structure after connection. This is due to the fact that is significantly different from circular.
[0006]
Also, depending on the desired deployment dimensions required, it may be possible to handle with a single deployable truss structure rather than connecting multiple deployable truss structures. In this case, it is necessary that one unfolded truss structure has a small size when stored, is lightweight, and can have a large outer diameter when unfolded.
[0007]
The dimension 44 in the longitudinal direction during storage is a dimension secured to the maximum extent possible within the launch rocket.
[0008]
In the conventional deployable truss structure 40, the radius 45 when deployed is smaller than the dimension 44 in the longitudinal direction at the time of storage, and the longitudinal dimension 44 secured in the margin of the launch rocket is fully utilized effectively. It is hard to say.
[0009]
Therefore, there has been a demand for a deployable truss structure that can effectively utilize the longitudinal dimension 44 secured to the maximum in the launch vehicle.
[0010]
Accordingly, an object of the present invention is to provide a deployable truss structure that solves the above-described problems of the prior art and that can effectively utilize the longitudinal dimension secured in the launch vehicle.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the deployable truss structure of the present invention is a deployable truss structure that can be folded and unfolded, and includes a center rod and a plurality of such that the center rod can be folded and unfolded radially. A frame structure having a plurality of connecting rods forming a four-sided link structure, an opening / closing means for folding and unfolding the frame structure, and being folded and unfolded together with the frame structure by the opening and closing means, An extension rod provided in connection with the frame structure so as to be able to project is provided.
[0012]
Further, the extension rod is more than the sum of the length of the connecting rod extending in the radial direction from the center rod of the four-sided link structure and the length of the connecting rod extending in the axial direction of the center rod of the four-sided link structure. It has a large length.
[0013]
The extension rod is a first extension rod that is foldably coupled to the center rod, and a joint portion that is foldably coupled to the first extension rod and provided to the connecting rod of the frame structure. And a second extension rod that is slidably held.
[0014]
The first extension rod has a length substantially equal to or shorter than the length of the connecting rod extending in the axial direction of the center rod of the four-sided link structure at the time of deployment, and the second extension rod is at the time of deployment. The length of the connecting rod extending in the radial direction from the center rod of the four-sided link structure is substantially equal to or shorter than the sum of the length of the connecting rod extending in the axial direction of the center rod. And
[0015]
The frame structure has diagonal connecting rods that are constructed on diagonal lines of the four-sided link structure and whose end portions can be bent, and the first extension rods constitute a part of the diagonal connecting rods. It is characterized by.
[0016]
It can be stored in a storage space having a predetermined length in the longitudinal direction when folded.
[0017]
The extension rod has a length larger than the predetermined longitudinal length.
[0018]
The antenna device according to the present invention is characterized in that a reflecting mirror surface on which a portable conductive film is stretched in a parabolic shape is formed on one surface of the deployable truss structure.
[0019]
In the above-described invention, since the extension rod is provided, the deployable truss structure at the time of storage can be made small and lightweight, while the effective diameter of the deployable truss structure at the time of deployment can be increased. it can.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the deployable truss structure of the present invention will be described in detail with reference to the drawings.
The deployable truss structure can be folded and unfolded, and has a length in the longitudinal direction equal to or less than a predetermined length when folded. Here, the predetermined length means the dimension 22 in the longitudinal direction of the storage space 21 secured to the maximum extent in the launch vehicle. The unfolded truss structure has a longitudinal length 24 substantially equal to this predetermined length when folded.
[0021]
As shown in FIG. 4, the deployable truss structure 30 has a center bar 2 erected at the center, and radially protrudes, for example, in eight directions around the center bar 2 at an angle equally dividing the circumference. Thus, eight frame structures 1 are formed.
[0022]
As shown in FIG. 2, each frame structure 1 includes a first connecting rod 3 and a second connecting rod 4 which are foldably coupled to both ends of the center rod 2, and end portions of the connecting rods 3 and 4. And a third connecting rod 5 installed therebetween. A set of the first connecting rod 3, the second connecting rod 4, and the third connecting rod 5 is a quadrilateral shape having the central rod 2 as one side, and is joined to be bent at a node.
[0023]
The deployable truss structure includes an opening / closing means 8 for folding and unfolding the frame structure 1. Further, the deployable truss structure includes an extension bar 9 that is opened and closed in conjunction with the frame structure 1 by the opening / closing means 8 and attached to the frame structure 1 so as to be able to project outside the frame structure 1 when deployed.
[0024]
The extension rod 9 includes a first extension rod 10 that is foldably coupled to the upper end of the center rod 2, and a second extension rod 11 that is foldably coupled at a bent portion 12 at the end of the first extension rod 10. And have. The second extension rod 11 is slidably held by a joint portion 13 provided in the vicinity of the coupling point between the first coupling rod 3 and the third coupling rod 5 and projects outside the framework structure 1.
[0025]
The joint portion 13 is provided so as to be rotatable around a rotation axis in a direction perpendicular to the paper surface of FIG. Since the joining portion 13 is rotatable about a turning axis perpendicular to the paper surface of FIG. 2, the second extension rod 11 is interlocked with the opening and closing means 8 being folded and unfolded by the opening / closing means 8. 2, while being slidably held, the bent portion 12 is rotated in the plane of FIG.
[0026]
At the time of unfolding, the angle formed by the first extension rod 10 and the second extension rod 11 in the bent portion 12 is as close to 180 degrees as possible, for example, about 160 degrees. Thereby, the total length of the extension rod 9, that is, the sum of the length of the first extension rod 10 and the length of the second extension rod 11 can be made as large as possible.
[0027]
Further, the frame structure 1 is constructed on a diagonal of a quadrilateral formed by the first connecting rod 3, the second connecting rod 4, the third connecting rod 5, and the center rod 2, and the end portions thereof are folded. It has a bendable diagonal connecting rod 14. The diagonal connecting rod 14 can ensure rigidity in the plane of the four-sided link structure formed by the first connecting rod 3, the second connecting rod 4, the third connecting rod 5, and the center rod 2. .
[0028]
The first extension rod 10 forms the same straight line as the diagonal connecting rod 14 in the unfolded state, and constitutes a part of the diagonal connecting rod 14. A bent portion 12 that is a connection point between the first extension rod 10 and the second extension rod 11 is provided on the diagonal connecting rod 14. The first extension rod 10 does not necessarily need to form the same straight line as the diagonal connecting rod 14 in the unfolded state, and the bent portion 12 can be provided on a portion other than the diagonal connecting rod 14.
[0029]
The diagonal connecting rod 14 has a bent portion 15 on the side closer to the center rod 2 than the position of the bent portion 12. With the folding and unfolding operation by the opening / closing means 8, the diagonal connecting rod 14 can be bent in two at the bent portion 15. With the folding and unfolding operation by the opening / closing means 8, the diagonal connecting rod 14 is bent at the bent portion 15. The position of the bent portion 15 on the diagonal connecting rod 14 is set to a position at which the frame structure 1 can be stably folded and unfolded by the opening / closing means 8. By setting the position of the bent portion 12 on the side farther from the center rod 2 than the position of the bent portion 15, the entire length of the extension rod 9, that is, the length of the first extension rod 10 and the second extension rod. The sum with the length of 11 can be made large.
[0030]
As shown in FIG. 3, the opening / closing means 8 includes an upper member 16a attached to the center bar 2 so as to be movable up and down, a lower member 16b, and a spring member 17 mounted between the upper member 16a and the lower member 16b. A first operating member 18 hinged between the upper member 16a and the first extension rod 10 (and / or the diagonal connecting rod 14), and a hinge between the lower member 16b and the first operating member 18. And a second operating member 19 coupled thereto.
[0031]
By pulling down the upper member 16a and the lower member 16b along the center rod 2, the first operation member 18 and the second operation member 19 bring the first extension rod 10 and the diagonal connecting rod 14 closer to the center rod 2 side. Accordingly, the extension rod 9 is bent at the bent portion 12 into the first extension rod 10 and the second extension rod 11, and the diagonal connecting rod 14 is bent at the bent portion 15.
[0032]
Next, the folding and unfolding operation of the unfolded truss structure will be described with reference to FIGS.
[0033]
FIG. 1 shows a state in which a deployable truss structure stored in a storage space 21 provided in a launch rocket is stored. The diagonal connecting rod 14 is bent into a “<” shape and stored between the first connecting rod 3 and the second connecting rod 4. As will be described later, the extension bar 9 is slightly shorter than the length 22 in the longitudinal direction of the storage space 21, so that it extends into the storage space 21 without jumping out in the longitudinal direction of the storage space 21.
[0034]
FIG. 2 shows the form of the unfolded truss structure of the present invention when unfolded. When the state shown in FIG. 1 is expanded to the state shown in FIG. 2, depending on the opening / closing means 8, the extension rod 9 and the diagonal connecting rod 14 are pushed up, and the first connecting rod 3 and the second connecting rod 4 are rotated around the nodes. To open the four-sided link structure composed of the center rod 2 and the connecting rods 3, 4, 5. The diagonal connecting rod 14 reaches the position where the in-plane rigidity of the four-sided link structure is maintained, that is, the vicinity on the diagonal line. In conjunction with this operation, the extension rod 9 rotates and translates while its posture is constrained by the bent portion 12 and the joint portion 13. When the deployment shown in FIG. 2 is completed, the tip of the second extension rod 11 projects outward from the third connecting rod 5. As a result, the deployable truss structure during deployment obtains the outermost diameter R. The length of the outermost diameter R is larger than the length 22 in the longitudinal direction of the storage space 21, as will be described later.
[0035]
FIG. 4 is a view showing an unfolding operation of the unfolding truss structure 30. 4 (a) shows the folded state, FIGS. 4 (b) and 4 (c) show the folded state (in the middle of unfolding), and FIG. 4 (d) shows the unfolded state. When stored (FIG. 4 (a)) is stored in the cylindrical storage space 21, and when expanded (FIG. 4 (d)), it expands into a polygonal shape having an outermost diameter R of 22 or more when stored. . In addition, since the rigidity of the 2nd extension stick | rod 11 projected outside is low, when it becomes a problem on a function, you may provide the member which supports this.
[0036]
FIG. 4 shows an example in which eight frame structures 1 projecting radially in eight directions are formed. If the space and weight during storage are allowed in the launch rocket, the number of frame structures 1 is further increased. May increase. A larger number of frame structures 1 is advantageous because the effective diameter (diameter of the inscribed circle) can be increased. Further, although the effective diameter is small, the number of the frame structures 1 may be reduced in order to reduce weight and save space.
[0037]
Next, the length dimension of the extension rod 9 will be described.
[0038]
In the four-sided link structure formed by the first connecting rod 3, the second connecting rod 4, the third connecting rod 5, and the center rod 2, the length of the first connecting rod 3 and the second connecting rod 4 Is A, and the length of the third connecting rod 5 is B. The first extension rod 10 may have a length slightly shorter than the length A and approximately equal to the length A. Here, the first extension rod 10 substantially overlaps with the center rod 2 when it is folded around the upper end 2 a of the center rod 2, and the first extension rod 10 protrudes from the lower end 2 b of the center rod 2. There is no. The second extension rod 11 may have a length slightly shorter than the length (A + B) and approximately equal to the length (A + B). Here, when the second extension rod 11 is turned around the upper end 2a of the center rod 2 and folded, the bent portion 12 is positioned in the vicinity of the lower end 2b of the center rod 2, so that the upper end 2a of the center rod 2 is To the tip of the second extension rod 11 does not exceed the length B. Accordingly, the extension bar 9 can have a length that is slightly shorter than the length (2A + B) and approximately equal to the length (2A + B) as a whole. As a result, the length of the outermost diameter R can be made larger than the longitudinal length 22 of the storage space 21 (a length substantially equal to the length (A + B)).
[0039]
Next, referring to FIG. 5, the relationship between the size of the storage space 21 provided in the launch rocket and the size of the framework structure 1 of the deployable truss structure and the conventional framework structure 50 according to the present invention. explain.
[0040]
FIG. 5A schematically shows a storage space 21 in which the unfolded truss structure is stored in a folded state. The storage space 21 has a longitudinal dimension 22 secured to the maximum extent in the launch vehicle. The dimension 22 has a length approximately equal to the length (A + B).
[0041]
FIG. 5 (c) shows a conventional skeleton structure 50 that does not include the extension rod 9. The frame structure 50 has a length A in the axial direction and a length B in the radial direction. In this case, the outermost diameter R that the conventional deployable truss structure can take is the length B, which is smaller than the dimension 22 in the longitudinal direction of the storage space 21.
[0042]
On the other hand, FIG. 5 (b) shows the frame structure 1 including the extension rod 9. The frame structure 1 has a length A in the axial direction and the entire length (2A + B) of the extension rod 9 in the radial direction. In this case, the outermost diameter R that the deployable truss structure 30 can take is a length (2A + B), which can be larger than the dimension 22 in the longitudinal direction of the storage space 21.
[0043]
As described above, according to the present embodiment, since the extension rod 9 including the first extension rod 10 and the second extension rod 11 is provided, the longitudinal direction of the storage space 21 is defined as the outermost diameter R at the time of deployment. It can be larger than the dimension 22.
[0044]
Further, by taking the length of the first extension rod 10 as the length A and the length of the second extension rod 11 as the length (A + B), the outermost diameter R that the deployable truss structure 30 can take is increased. The length can be approximately close to (2A + B).
[0045]
As a result, the deployable truss structure during storage can be made small and lightweight, while the effective diameter of the deployable truss structure during deployment can be increased.
[0046]
Next, an example in which the deployable truss structure 30 is applied as the support structure 35 for supporting the mirror surface of the antenna device will be described with reference to FIG.
[0047]
The support structure 35 is provided with a standoff 31 at the tip of the extension rod 9 in the unfolded truss structure 30 shown in FIG. 4 and the like, and a rubbing conductive film 32 is stretched in a parabolic shape using this as a support. A mirror surface is formed. When stored in the storage space 21, the portable conductive film 32 enters inside the folded member, and the whole is folded into a cylindrical shape and stored in the storage space 21.
[0048]
Since the support structure 35 is formed on the basis of the deployable truss structure 30, a reflecting mirror surface having an effective radius larger than the dimension 22 in the longitudinal direction of the storage space 21 can be formed.
[0049]
It is also possible to form a larger composite deployable truss structure by arranging a plurality of deployable truss structures 30 with a predetermined distribution.
[0050]
【The invention's effect】
As described above, according to the configuration of the present invention, since the extension rod is provided, it is possible to provide a deployable truss structure that is small and lightweight when stored and can secure a large effective diameter when deployed.
[Brief description of the drawings]
FIG. 1 is a view showing a configuration of a framework structure constituting a deployable truss structure according to the present invention when stored.
FIG. 2 is a view showing a form at the time of deployment of a framework structure constituting the deployable truss structure of the present invention.
FIG. 3 is an enlarged view showing the vicinity of the center bar of the frame structure shown in FIG. 2;
FIGS. 4A and 4B are views showing the unfolding operation of the unfolded truss structure according to the present invention, where FIG. 4A shows a state during storage, FIGS. 4B and 4C show a state during operation, and FIG. Indicates the state at the time of deployment.
FIG. 5 is a view showing the relationship between the size of the storage space (a) and the effective diameter of the deployable truss structure in comparison between the case of the present invention (b) and the conventional case (c).
6A and 6B are diagrams showing a conventional unfolded truss structure, in which FIG. 6A shows a state during storage, FIG. 6B shows a state during operation, and FIG. 6C shows a state during deployment.
FIG. 7 is a view showing an example in which three conventional deployable truss structures are connected to increase the diameter.
FIG. 8 is a diagram showing an example in which a deployable antenna is configured by stretching a portable conductive film on the deployable truss structure of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Frame structure 2 which comprises the expansion | deployment type truss structure of this invention Center rod 3 1st connection rod 4 2nd connection rod 5 3rd connection rod 8 Opening-closing means 9 Extension rod 10 1st extension rod 11 2nd extension Rod 12 Bending portion 14 Diagonal connecting rod 15 Bending portion 21 Storage space 22 Longitudinal dimension 30 of storage space Expandable truss structure 35 according to the present invention Expandable truss structure stretched with portable conductive film

Claims (6)

In the unfoldable truss structure that can be folded and unfolded,
A center bar,
A frame structure having a plurality of connecting rods forming a plurality of four-sided link structures that can be folded and expanded radially with the center rod as one side;
Opening and closing means for folding and unfolding the framework structure;
An unfolding type comprising: an extension rod which is folded and unfolded together with the frame structure by the opening / closing means and connected to the frame structure so as to be able to project outside the frame structure at the time of expansion. Truss structure. The extension rod is longer than the sum of the length of the connecting rod extending in the radial direction from the center rod of the four-sided link structure and the length of the connecting rod extending in the axial direction of the center rod of the four-sided link structure. The unfoldable truss structure according to claim 1, having a thickness. The extension rod is
A first extension bar foldably coupled to the center bar;
A second extension rod that is foldably coupled to the first extension rod and is slidably held at a joint provided on the connecting rod of the frame structure;
The deployable truss structure according to claim 1, wherein The first extension rod has a length substantially equal to or shorter than the length of the connecting rod extending in the axial direction of the center rod of the four-sided link structure when deployed.
Is the second extension rod substantially equal to the sum of the length of the connecting rod extending radially from the center rod of the four-sided link structure and the length of the connecting rod extending in the axial direction of the center rod when deployed? 4. The deployable truss structure according to claim 3, having a shorter length. The frame structure has diagonal connecting rods that are constructed on diagonal lines of the four-sided link structure and whose end portions can be bent, respectively.
The unfoldable truss structure according to claim 3, wherein the first extension rod constitutes a part of the diagonal connecting rod. 6. An antenna device, wherein a reflecting mirror surface on which a portable conductive film is stretched in a parabolic shape is formed on one surface of the deployable truss structure according to any one of claims 1 to 5.

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