JP2000183640A - Expansion type skeleton structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion type skeleton structure with high precision and high stiffness, that is used for an expansion antenna with a large aperture and a spherical part of a structure in space or the like used for an artificial satellite. SOLUTION: This expansion type skeleton structure employs a truncated pyramid skeleton structure for a basic building block, which is formed by using an apex of a dual polyhedron of a quasi-regular polyhedron for an upper dace apex, using a cross point between a radiation line 4 passing from a center 3 of an inscribed sphere of the polyhedron to an upper dace apex 5 and a concentric spherical surface, having a radius larger than that of the inscribed sphere for a lower face apex 6 and using a part between the upper face apex and the lower face apex of the radiation line 4 for a ridge, and the side faces of the building blocks are used in common and a plurality of the blocks are connected. Furthermore, the outer shape of the building blocks kept to a truncated pyramid shape and the ridges are moved synchronously in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deployable frame structure having high accuracy and rigidity, which is used for a large-diameter deployable antenna used for an artificial satellite or a spherical portion of a space structure.

[0002]

2. Description of the Related Art In recent years, the reliability and economic efficiency of rockets that put satellites into orbit have been improved, and the advantages of using satellites have been increasing. In addition, since the demand for communication is increasing, it is desired to improve the quality and quantity of the satellite communication business. In particular, a large deployable antenna is required for communication of a moving object such as a ship or a vehicle, and a deployable frame structure for that purpose has been actively developed. In addition, as a basic structure for building large satellites such as space bases at low cost and high reliability,
An expandable frame structure (expandable truss structure) is an important development subject.
Various forms such as those described in JP-A-151630 and JP-A-6-224624 have been proposed.

[0003]

SUMMARY OF THE INVENTION Conventional Japanese Patent Laid-Open No. 1-15
The structure described in Japanese Patent No. 1630 has a frame structure composed of a mandrel having a connector and a slide hinge, and a pantograph-shaped oblique member as basic elements, and by combining a plurality of these, a large-scale structure can be easily manufactured. FIG. 7 is a configuration diagram of a framework structure in an unfolded state. The operation of this structure will be briefly described with reference to FIG. 7. In this deployable skeleton structure, the oblique member 45a or the oblique member 45b and the mandrel 4 are stored during storage.
2 is folded to a state close to zero, and the state is held by an external holding device (not shown). On the other hand, at the time of deployment, when the holding device is opened, the driving of a spiral spring (not shown) built in the pin coupling portion 48, the pin shaft of the connector 41, the pin shaft on the slide hinge 43, or the like. Oblique member 4 by force
5a and 45b are developed, whereby the angle θ increases. At this time, when the slide hinge 43 moves to a predetermined position, the slide hinge 43 comes in contact with the stopper 44 and the oblique members 45a, 4a.
The deployment operation of 5b stops. Also, the oblique members 45a, 45
b denotes a connector 41 or a slide hinge 43 at each end.
And the two oblique members 45a and 45b are pin-connected to each other in a pantograph shape at the pin joint portions 48 at the respective intermediate portions, so that the angle of development of all the oblique members 45a and 45b A certain angle θ becomes equal and synchronous development is possible. However, the above-mentioned deployable frame structure has the following problems. In other words, in order for the angle θ, which is the development angle in all the oblique members, to be equal and the synchronous deployment is possible, the oblique member becomes an isosceles trapezoid or a rectangular diagonal line, and isosceles trapezoid or All rectangles must be congruent.
Therefore, the top shape of the basic module is a regular hexagon,
The outer shape of the basic module is a regular hexagonal pyramid when the oblique member is a diagonal line of an equilateral trapezoidal shape, and a regular hexagonal prism when the oblique member is rectangular.
Since a regular hexagon is a plane-filled type, it is not possible to arrange regular hexagonal pyramids adjacent to each other.

[0004] As a result, a plurality of regular hexagonal columnar basic modules are connected, and the upper surface formed by them is planar. Even when using triangles and squares as basic shapes,
By the same discussion, the top surface shape of the basic module becomes a regular triangle or a regular square. In some cases, a plurality of basic modules having a truncated triangular pyramid shape or a truncated quadrangular pyramid shape can be combined. However, since the angle formed by the ridge line of the truncated pyramid changes as it is developed, it is not possible to maintain the connection and develop. Therefore, Japanese Patent Laid-Open No. 1-15
The deployed shape of the deployable frame structure that can be realized by the method disclosed in Japanese Patent No. 1630 is flat. Or conversely, if you try to construct a spherical surface using a framework structure that uses a polygon that fills a plane as a basic element, if you do not introduce the necessary and sufficient backlash into the mechanism, it is impossible to develop the entire structure synchronously Have difficulty. These are different from the minute gaps required for the fitting of the hinges and the gaps generated in manufacturing, and are new play required to realize the unfolding operation, and are referred to as unfolding play.

Further, for example, a plurality of congruent regular hexagons are arranged on a plane so that their sides are shared, and are projected onto a spherical surface to determine the lengths of the hexagonal sides. In the case of realization, since a regular hexagon which is a plane-filled shape is projected on a spherical surface, most of the basic elements of the realized frame structure are obtained by distorting the regular hexagon, and the distortion differs depending on the place. Therefore, in this method, the entire skeleton structure cannot be formed by repeating the same basic element. In addition, since it is necessary to design a deployment mechanism corresponding to different distortions for each basic element, the deployment operation differs for each element, and it is extremely difficult to deploy the entire system synchronously.
That is, if there is no play in the mechanism for the above-mentioned reason, a plurality of coupled modules cannot be developed synchronously. However, the play in these mechanisms reduces the accuracy and rigidity of the frame structure,
Exercise other than the assumed expanding operation becomes possible, and there arises a problem that an unexpected movement is caused to cause the expanding operation to fail.

[0006] Japanese Patent Laid-Open Publication No. Hei 6-224624 discloses a parabolic deployable antenna that can reduce the amount of stand-off deformation that occurs during deployment and the deployment torque required for deployment. However, an enormous design process is required to synchronously deploy such a spherical deployable skeleton structure with minimal play in the deployment. In addition, since a basic element obtained by distorting a regular hexagon is used, there are many subtly different parts, which leads to an increase in cost and the like, which is not preferable in manufacturing. These problems originated in an attempt to realize a deployable skeleton structure having a plane-filled basic shape. Therefore, a basic design principle is required in order to overcome these problems and more easily design a deployable skeleton structure having a spherical surface.

The present invention has been made in order to solve such a problem, and when a large spherical structure such as a large-diameter antenna reflecting mirror surface support structure is constructed, play (development play) in the mechanism is reduced. It is an object of the present invention to obtain a deployable frame structure that can secure high rigidity and high accuracy without requiring it.

In the deployable skeleton structure according to the present invention, the vertices of the dual polyhedron of the quasi-regular polyhedron are set as the top vertices so as to form a spherical skeleton structure, and the radiation passing through the top vertices from the center of the inscribed sphere of the polyhedron is used. The intersection of a concentric sphere with a radius larger than the inscribed sphere is the lower surface vertex, and the truncated pyramid-shaped frame structure created by making the ridge between the upper surface vertex and the lower surface vertex of the radiation is the basic element. It has a structure in which a plurality of side surfaces are shared and connected to each other, and further, a mechanism is provided for synchronously moving the ridge lines while keeping the outer shape of the basic element as a truncated pyramid. In addition, it has a frame structure fixed to the ridge line position of the truncated pyramid-shaped basic element, and has a deployment mechanism on the side surface for moving the fixed skeleton structures of adjacent ridge line positions in parallel with each other, and performs parallel movement of the side surface sharing the ridge line. A synchronous mechanism for the motive period is provided in a frame structure having a fixed ridgeline position, and the deployment mechanisms are connected through a synchronous mechanism at the ridgeline position.

Further, the above-mentioned unfolding mechanism is constituted by a pantograph link mechanism which moves in a two-dimensional plane. Furthermore, a cable having tension generating means capable of eliminating play after deployment is stretched between upper surface nodes and lower surface nodes of the basic elements of the truncated pyramidal frame structure. In addition, while having a deployment force urging means for generating a deployment force on the hinge of the link mechanism in the truncated pyramid-shaped basic element, the figure obtained by connecting the hinges with a line segment, before being unfolded, becomes straight during deployment. A stopper for stopping rotation of the hinge and stopping deployment is provided at an appropriate position such as near the hinge position. Further, the deployment force urging means is constituted by a deployment spring or a deployment actuator. Still further, the apparatus further comprises a holding device for fixing the deployment mechanism in a predetermined shape.

[0010] The deployable skeleton structure according to the present invention has a structure in which a dual polyhedron of a quasi-regular polyhedron is used as a basic shape and a plurality of truncated pyramid-shaped basic elements are shared by sharing a plurality of side surfaces thereof. When constructing a large structure such as a support structure, by repeating one kind of truncated pyramidal frame structure, not only a part of the approximate spherical surface but also the entire approximate spherical surface so that the whole has uniform high rigidity The deployable skeleton structure to be formed can be easily constructed. Further, since the present invention can be implemented with a dual polyhedron of all quasi-regular polyhedrons as a basic shape, a plurality of different skeleton structures can be created by the same procedure for a sphere having a certain size and a radius of curvature, and a skeleton structure can be formed. Appropriate ones can be selected according to the demands imposed. Furthermore, in the dual polyhedron of the quasi-regular polyhedron used in the present invention, there is an inscribed sphere in contact with the inner center of the polygon constituting each surface. By arranging at the apex of the upper surface, the reflecting spherical surface can be stretched on the upper surface of the expandable skeleton structure without interfering with the expandable skeleton structure. Actually, even if the stand-off is shorter, no interference occurs, and it is possible to realize a deployable frame structure in which the reflecting spherical surface can be easily mounted. In addition, since the perpendiculars set at the center positions of the respective surfaces intersect at one point, a reflector such as a solar light concentrator which does not require high accuracy can be configured only by stretching a reflection plane on the upper surface of the basic element.

[0011] Further, the deployable frame structure according to the present invention comprises:
The expansion operation is performed by synchronizing and translating the multiple ridge lines included in the basic element, and therefore, by using a mechanism that can translate the ridge lines without using the play for expansion, such as a pantograph link mechanism, the expansion is performed. It is possible to construct a deployable frame structure that forms a substantially spherical surface or a part thereof that does not require play, and can maintain high accuracy and strength of the structure, and realize a stable deploying operation. At this time, the hinge offset can be provided in consideration of the thickness of the member without adding a play to the pantograph link mechanism. By the action of the cable stretched with tension in the unfolded state, or by fixing the unfolding mechanism with the internal force remaining in the unfolded state, minute play present on hinges and the like disappears, maintaining a stable shape. Frame structure with high precision.

Further, according to the expandable frame structure of the present invention, the unfolding of the parallelogram link mechanism hinge, which is a truncated pyramid-shaped basic element, from the parallelogram to the rectangle is performed before the hinge is connected to the hinge. By providing a stopper at the hinge position to stop the rotation of the hinge so that it ends, it is possible to eliminate from the unfolding operation a peculiar mechanism form in which the unfolding does not progress even if the unfolding force is applied, generating an excessive unfolding force. Therefore, it is possible to obtain a deployable skeleton structure which can be stably deployed without causing any damage, has a low possibility of structural damage, and has high reliability.

[0013]

For this reason, a solution adopted by the present invention is that a vertex position of a dual polyhedron of a quasi-regular polyhedron is defined as a top vertex, and the radiation passing through the top vertex from the center of the inscribed sphere of the polyhedron. The basic element is a truncated pyramid-shaped frame structure formed by defining the intersection of a concentric spherical surface having a radius larger than the inscribed sphere as the lower surface vertex and the ridge between the upper surface vertex and the lower surface vertex of the same radiation. A frame structure in which a plurality of the skeletons are shared by sharing the side surfaces of the base elements, and further, the ridge lines can be synchronously translated while the outer shape of the basic element is a truncated pyramid. Wherein the truncated pyramid-shaped basic element includes a synchronization mechanism and a deployment mechanism, wherein the synchronization mechanism is fixed at the ridgeline position, and the deployment mechanism is between the synchronization mechanisms fixed at adjacent ridgeline positions. Can be expanded An expandable skeleton structure, comprising: a pantograph / link mechanism that moves in a two-dimensional plane; Between the upper surface nodes and between the lower surface nodes of the truncated pyramidal basic element,
A deployable skeleton structure comprising tension generating means capable of eliminating play after deployment, wherein the synchronization mechanism includes deployment force urging means for applying a deployment force to the deployment mechanism. An expandable skeleton structure, wherein the deployment force urging means is a deployment spring, and the deployment force urging means is a deployment actuator. A deployment type frame structure characterized by comprising a holding device for fixing the deployment mechanism.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First Embodiment FIGS. 1 to 4 are views showing a first embodiment of the present invention. FIG. 1 is an exploded view in which the present invention is implemented for a quasi-regular polyhedral dual polyhedron in which all surfaces form a rhombus. FIG. 2 is a perspective view showing a schematic shape during and after deployment of the skeleton structure, FIG. 2 is a perspective view showing a partial schematic shape after deployment of the deployable skeleton structure according to the above embodiment, and FIG. FIG. 4 is a perspective view showing the shape of the framework structure as one of the basic elements during and after deployment, and FIG. 4 is a perspective view showing a part of the synchronization mechanism and the deployment mechanism near the ridge line 11 in FIG. In these figures, 1 is the upper surface, 2 is the lower surface, 3 is the center of the inscribed sphere, 4 is the radiation, 5 is the upper surface vertex, and 6 is the lower surface vertex. Here, the inscribed sphere is an inscribed sphere that comes into contact with the dual polyhedron of the quasi-regular polyhedron at an incenter position of a polygon constituting each surface. The radiation is a straight line passing through the center of the inscribed sphere.

The basic structure of the expandable frame structure shown in FIG. 1 is a truncated pyramid frame structure in which the upper surface and the lower surface are diamond-shaped and the ridge connecting the upper surface vertex and the lower surface vertex is on the radiation. Have a structure in which a plurality of are linked to each other. The basic element has a mechanism that changes the distance between the upper surface vertices or the lower surface vertex while keeping the angle between the ridge lines constant, and has a mechanism that can synchronously translate the ridge line while keeping the outer shape of the basic element as a truncated pyramid. This is a deployed frame structure. However, in the specific configuration of the frame structure, the members of the frame structure on the sides of the truncated pyramid are not limited to those in which the nodes of the frame structure are specifically present on the vertices, and the envelope shape conforms to the truncated pyramid. You can do it if it does. In the above description, only four surfaces out of the surfaces constituting the dual polyhedron of the quasi-regular polyhedron are shown, but the number of surfaces is not limited to this, and Any number of continuous surfaces may be used.

Furthermore, in these figures, 7 is a common upper surface member, 8 is a common lower surface member, 9 is a vertex vertical member, 10 is a deployment mechanism, 11 is a synchronization mechanism, and 12 is a cable as tension generating means. . In FIG. 3, all cables are omitted to avoid complexity. The length of the cable is adjusted in advance so that a predetermined tension is generated in the deployed state. However, in the mechanism illustrated in FIGS. 1 to 4, this cable may be omitted. The deployment mechanism 10 and the synchronization mechanism 11 form a side surface of a truncated pyramid-shaped frame structure, and this portion is also referred to as a side frame. Two adjacent truncated pyramid-shaped frame structures are adjacent to each other while sharing a side frame.

In FIG. 4, 13 (a-d) are upper members of the developing mechanism, 14 (ad) are lower members of the developing mechanism, and 15 (ad).
(A) to (e) are unfolding mechanism vertical members, which are connected by upper surface pin hinges 16 (a to e) and lower surface pin hinges 17 (a to e) as shown in FIG. Is done. Pantograph member 18 (ad)
Is one end of a slide hinge 19 (a to c), and the other end is a fixed pin connecting part 20 (a to c), and a deployment mechanism vertical member 15 (a, c).
c, e) coupled to the pantograph member 18 (ad)
The pins are connected to each other at the free pin connecting portions 21 (a, b), but are not connected to the deployment mechanism vertical member 15 (b, d).
In addition, by setting a hinge position and a stopper that restricts the hinge operation constituting the deployment mechanism as necessary, it is possible to eliminate from the deployment operation a specific mechanism form in which the deployment does not progress even when the deployment force is applied. It is possible.

The synchronization mechanism vertical member 22 is located at the vertex vertical member 9, and the synchronization mechanism slide hinge 23 moves thereon.
The projecting member of the synchronization mechanism slide hinge 23 is connected to the slide hinge 19a by a slide hinge. When the synchronization mechanism slide hinge 23 is pulled up by the contraction force of the deployment spring 24 as a deployment force urging means, the slide hinge 19a is also pulled up. , Deployment movement occurs. However, a deployment actuator or the like that generates a deployment force may be used instead of the deployment spring 24 as the deployment force urging means. The overhang members of the synchronization mechanism slide hinge 23 are the same as the number of the side frames that meet the apex vertical members, and the connection of the different side frames is synchronized by connecting in the same manner as all the deployment mechanisms.

When the present invention is applied to a quasi-regular polyhedron dual polyhedron in which each surface other than FIG. 1 forms a rhombus, it can be carried out in the same manner as in FIGS. Next, the operation of the deployable skeleton structure shown in FIGS. 1 to 4 according to the first embodiment of the present invention will be described. FIG. 1 shows the schematic shapes of the two frame structures, but the development proceeds in the order of up and down. The basic element moves parallel to the ridge line while maintaining the truncated pyramid to enlarge the rhombus on the upper surface and the lower surface. Since the rhombus on the upper surface or the lower surface is always similar, if the center 3 of the inscribed sphere is fixed, the radiation passing through the vertices of the polyhedron can be matched regardless of the progress of the development. That is, as each vertex of the polyhedron moves radially on the same radiation as the deployment progresses, the framework structure is developed in the radial direction.

Further, details of the operation of the above-mentioned deployable frame structure will be described with reference to FIGS. In the first embodiment, at the time of storage, the angle θ formed by the skeleton upper surface members 13 (a to f) shown in FIG. 4 is folded to a state close to zero, and an external holding device (not shown) is used. Alternatively, the state is held by a holding device (not shown) that fixes the synchronization mechanism slide hinge 23 to the synchronization mechanism vertical member 22. At the time of unfolding, when the holding device is opened, the slide hinge 1 generated by the unfolding spring 24 is moved by the driving force to move the synchronizing mechanism slide hinge 23 upward.
Move 9a upward. The driving force to the slide hinge 19a is constituted by the pantograph members 18 (ad), the slide hinges 19 (ac), the fixed pin connecting portions 20 (ac), and the free pin connecting portions 21 (a, b). Is transmitted to the pantograph, and the distance between the points 15a, 15c, and 15e is increased, and the angle θ is increased, whereby the development proceeds. All frame upper surface members 13 (af) and all frame lower surface members 14 (a
To f) become straight lines and the angle θ becomes 180 degrees, the upper surface pin hinge 16 (a
To e) and the movement of the lower surface pin hinges 17 (ae) are restricted, and the deployment operation stops in the state of FIG. 2 or FIG. At this time, the length of the cable 12 is adjusted in advance so as to be stretched between the upper surface node and the lower surface node with a predetermined tension. This tension generates an internal force that compresses the unfolding mechanism in a direction to decrease the distance between adjacent upper surface nodes or lower surface nodes. Therefore, the upper surface pin hinges 16 (a to e), the lower surface pin hinges 17 (a to e), and the slide Hinge 19 (a-
c), the backlash included in the fixed pin connecting portions 20 (ac) and the free pin connecting portions 21 (a, b) is eliminated, and the deployable skeleton structure according to the present invention has a highly accurate structure.

Incidentally, the frame deploying structure is held in a state where the synchronous mechanism slide hinge 23 is pulled upward by the driving force generated by the deploying spring 24 in the deployed state.
When the synchronization mechanism slide hinge 23 is fixed to the synchronization mechanism vertical member 22 by a holding device (not shown) such as an appropriate latch mechanism, the frame deployment structure can be more firmly fixed.

The overhang members of the synchronization mechanism slide hinge 23 are the same as the number of the side frames that meet the apex vertical members 9.
By connecting in the same way as all the deployment mechanisms, the deployment of the different lateral frames is synchronized. The deployment mechanisms on adjacent side frames of the truncated pyramid are linked via a synchronization mechanism. As a result, since all the deployment mechanisms of the truncated pyramid are deployed synchronously, the deployment of the framework structure of the truncated pyramid is as shown in FIG. 3, and the polygon connecting the top nodes in order with a line segment always maintains a rhombus. . Meanwhile, since the vertical members 15 of the same side skeleton are kept parallel to each other, the angle formed by the vertex vertical members 9 (synchronous mechanism vertical members 22) at both ends of the side skeleton is constant.

As shown in FIGS. 1 and 2, the frame structures of the adjacent truncated pyramids are connected by sharing the side frames, so that the entire frame structure is also developed synchronously. Also,
When the deployment actuator is used instead of the deployment spring 24, the deployment of the entire structure can be easily synchronized by synchronizing the actuators arranged in the plurality of synchronization mechanisms. In addition, when the present invention is applied to a quasi-regular polyhedron dual polyhedron in which each surface other than FIG.

Second Embodiment FIGS. 5 and 6 are views showing a second embodiment according to the present invention. FIG. 5 shows the present invention for a dual polyhedron of a quasi-regular polyhedron in which all surfaces are pentagonal. A perspective view showing a schematic shape during deployment and after deployment in the deployed deployment frame structure,
FIG. 6 is a perspective view showing the arrangement of the deploying mechanism of the deployable frame structure according to the above embodiment. In these figures, 3
1 is the upper surface, 32 is the lower surface, 33 is the center of the inscribed sphere, 34 is the radiation, 35 is the vertex of the upper surface, 36 is the vertex of the lower surface, 37 is the deployment mechanism A, and 38 is the deployment mechanism B. Except that each surface shown in the first embodiment of the present invention forms a rhombus, each surface of the quasi-regular polyhedron dual polyhedron does not become an equilateral polygon as shown in FIG. As described above, a second embodiment is an embodiment in which the present invention is applied to a quasi-regular polyhedron dual polyhedron in which each surface is not an equilateral polygon.

Similar to the first embodiment, the deployable frame structure shown in FIG. 5 has a truncated pyramid-shaped frame structure in which the upper surface and the lower surface are pentagonal and the ridge connecting the upper surface apex and the lower surface apex rides on the radiation. It has a structure in which a plurality of truncated pyramid-shaped frame structures are shared by sharing the sides. The basic element has a mechanism that changes the distance between the upper surface vertices or the lower surface vertex while keeping the angle between the ridge lines constant, and has a mechanism that can synchronously translate the ridge line while keeping the outer shape of the basic element as a truncated pyramid. It is a deployable frame structure. However, in the specific configuration of the frame structure, the members of the frame structure on the sides of the truncated pyramid are not limited to those in which the nodes of the frame structure are specifically present on the vertices, and the envelope shape conforms to the truncated pyramid. You can do it if it does. Also, in the above description, only five surfaces out of the surfaces constituting the dual polyhedron of the quasi-regular polyhedron are shown. However, the number of surfaces is not limited to this, and the quasi-regular polyhedron has a dual polyhedron. Any number of continuous surfaces may be used.

Also in the second embodiment, the configuration of the truncated pyramid-shaped basic elements is shown in FIG. 2, the operation of the deployable frame structure is shown in FIG. 3, and the basic configurations of the deployment mechanism and the synchronization mechanism are the same as in FIG. I do. As shown in FIGS. 5 and 6, the adjacent truncated pyramid-shaped basic elements are connected to each other while sharing the side skeleton, so that the development proceeds in synchronization even in the entire skeleton structure. Unlike the first embodiment, in the second embodiment, since each surface of the polyhedron does not become an equilateral polygon, there are vertices where sides of different lengths meet. At such vertices, not all of the side frame deployment mechanisms that meet one vertex longitudinal member can be mechanically connected via a synchronization mechanism. However, each deployment mechanism is mechanically connected to one or more adjacent deployment mechanisms via a synchronization mechanism. In the example shown in FIG. 6, the unfolding mechanism A and the unfolding mechanism B are not mechanically connected via any synchronization mechanism, but the unfolding mechanism A and the inner unfolding mechanism are not connected. In each of B, the adjacent deployment mechanism units are mechanically connected via a synchronization mechanism unit. Further, the unfolding mechanism A and the unfolding mechanism B are connected at five ridge line positions, and unfold as a whole under the constraint conditions.

When the deployable skeleton structure according to the present invention is used for a deployable antenna reflector used in space communication or the like, a holding member such as a stand-off is provided at an appropriate position such as the top surface apex of a basic element polyhedron. , And a metal mesh or a film surface coated with a reflective coating may be stretched as a reflective surface via the standoff. Also, when used in a reflector provided for a purpose other than communication, for example, a solar light concentrator, the reflection surface can be easily formed in the same manner. The first and second embodiments are merely examples to which the present invention is applied, and tension generating means such as a cable, deployment force urging means such as a spring, and holding means such as a stopper exist conventionally. Obviously, the configuration can be replaced with a configuration that can achieve the same function. Also, the present invention may be embodied in any other form without departing from its spirit or essential characteristics. Therefore, the above-described embodiment is merely an example in all aspects and should not be interpreted in a limited manner.

[0028]

As described above, according to the present invention,
Since the unfolding operation is performed by synchronizing and translating a plurality of ridge lines included in the truncated pyramid-shaped basic element with a quasi-regular polyhedron dual polyhedron as a basic shape, the unfolding operation is performed without the need for unfolding play. It is possible to construct a deployable frame structure that forms not only the part but also the entire spherical surface. Further, the deployable frame structure of the present invention has a basic shape of a quasi-regular polyhedral dual polyhedron, a truncated pyramid-shaped frame structure having a polygon on the upper surface and a lower surface as a basic element, and sharing the side surfaces thereof and connecting them. By repeating one kind of truncated pyramid-shaped frame structure, it is easy to construct a large-scale, roughly spherical deployable frame structure such as the support structure of a large-diameter deployable antenna or the spherical portion of a space structure. can do. Furthermore, in the dual polyhedron of the quasi-regular polyhedron used in the present invention, there is an inscribed sphere in contact with the inner center of the polygon constituting each surface. By arranging at the apex of the upper surface, the reflecting spherical surface can be stretched on the upper surface of the expandable skeleton structure without interfering with the expandable skeleton structure. In fact, even shorter standoffs do not interfere,
It is possible to realize a deployable frame structure in which the reflecting spherical surface can be easily stretched.
In addition, since the perpendiculars set at the center positions of the respective surfaces intersect at one point, a reflector such as a solar light concentrator which does not require high accuracy can be configured only by stretching a reflection plane on the upper surface of the basic element. The present invention can execute a dual polyhedron of all quasi-regular polyhedrons as a basic shape, so that a plurality of different frame structure plans can be created for a sphere having a certain size and a radius of curvature, and an appropriate You can choose one. For example, a skeleton structure having a basic shape of a quasi-regular polyhedron dual polyhedron consisting only of a rhombus and a pentagonal quasi regular polyhedron dual polyhedron is designed, and structural weight, number of parts,
By comparing and examining the structural strength, structural accuracy, etc., the optimum one can be selected. Further, in the deployable frame structure according to the present invention,
The deployment mechanism that constitutes the basic element is basically composed of a pantograph link mechanism that moves in a two-dimensional plane, so that even if the member has a finite thickness, the play for deployment is introduced. Since the hinge offset considering the thickness of the member can be provided without any problem, various adverse effects due to backlash can be avoided, and a frame structure that has high structural accuracy and rigidity, and can be stably and reliably deployed can be realized. Furthermore,
In the unfolded state, by the action of the cable stretched with tension or by fixing the unfolding mechanism while leaving the internal force in the unfolding mechanism, minute backlash existing in hinges etc. disappears and a stable shape is maintained As a result, a deployable frame structure having high accuracy is obtained. In the first embodiment, the deployment mechanism of the side frame structure sharing the vertex vertical member is synchronously deployed by the synchronization mechanism provided on the vertex vertical member. Since the side frame structure and the apex vertical member are shared, all the deployment mechanisms are connected, and as a result, all the deployment mechanisms are deployed in synchronization. Even in the second embodiment, since the adjacent truncated pyramid-shaped basic elements are connected to each other while sharing the side skeleton, the development proceeds in synchronization with the entire skeleton structure.
However, since each face of the polyhedron does not become an equilateral polygon, each deployment mechanism is not mechanically connected to all the deployment mechanisms of the side skeletons that meet at the vertex vertical members, but it is always one or more. It is mechanically connected to an adjacent deployment mechanism via a synchronization mechanism. That is, in any of the embodiments, the deployment of the entire structure can be easily synchronized, and a reliable and highly reliable deployment type frame structure can be obtained. Furthermore, according to the deployable frame structure of the present invention, by setting the hinge position and the stopper that limits the hinge operation, a specific mechanism form in which the deployment does not progress even when the deployment force is applied is eliminated from the deployment operation. Without additional auxiliary force generation position to supplement the specificity of the mechanism, by a small number of expander force generators, the expander operates stably without generating excessive expander force, A highly reliable deployable frame structure with low possibility of structural damage can be obtained. Furthermore, since the deployable frame structure can be fixed by fixing the deployment mechanism with the holding device, the deployment operation can be stopped in any form during deployment. Further, when the deployment force is generated by the actuator, excellent effects such as reversing the deployment force to reverse the deployment operation and enabling the storage operation can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic shape during and after deployment in a deployable skeleton structure in which the present invention is applied to a dual polyhedron portion of a quasi-regular polyhedron in which each surface forms a rhombus.

FIG. 2 is a perspective view showing a partial schematic shape after deployment of the deployable skeleton structure of FIG. 1;

3 is a perspective view showing the shape of the framework structure of one basic element in FIG. 2 during and after deployment.

FIG. 4 is a perspective view showing a part of a synchronization mechanism and a deployment mechanism of FIG. 2;

FIG. 5 is a perspective view showing a schematic shape during and after deployment of a deployable frame structure according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a mechanical connection relationship of a deployment mechanism unit of FIG. 5;

FIG. 7 is a configuration diagram of a skeleton structure in a deployed state as a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper surface 2 Lower surface 3 Center of inscribed sphere 4 Radiation 5 Upper surface vertex 6 Lower surface vertex 7 Shared upper surface member 8 Shared lower surface member 9 Vertex vertical member 10 Deployment mechanism 11 Synchronization mechanism 12 Cable 13 Deployment mechanism upper member 14 Deployment mechanism lower member 15 Deployment mechanism vertical member 16 Upper surface pin hinge 17 Lower surface pin hinge 18 Pantograph member 19 Slide hinge 20 Fixed pin connection part 21 Free pin connection part 22 Synchronization mechanism vertical member 23 Synchronization mechanism slide hinge 24 Deployment spring 31 Upper surface 32 Lower surface 33 Center of inscribed sphere 34 Radiation 35 top vertex 36 bottom vertex 37 deployment mechanism A 38 deployment mechanism B

Claims (8)

[Claims] 1. A vertex position of a dual polyhedron of a quasi-regular polyhedron is defined as an upper surface vertex, and an intersection between a ray passing from the center of the inscribed sphere of the polyhedron to the upper surface apex and a concentric sphere having a radius larger than the inscribed sphere is defined as a lower surface apex. And, as a basic element, a truncated pyramid-shaped skeleton structure created by making a ridge between an upper surface vertex and a lower surface vertex of the radiation, a structure in which a plurality of side surfaces of the basic element are shared to form a combined structure, A deployable skeleton structure wherein the ridge lines can be moved in parallel in a synchronized manner while keeping the outer shape of the basic element as a truncated pyramid. 2. The truncated pyramid-shaped basic element includes a synchronization mechanism and a deployment mechanism, wherein the synchronization mechanism is fixed at the ridge line position, and the deployment mechanism is between the synchronization mechanisms fixed at adjacent ridge line positions. The deployable skeleton structure according to claim 1, further comprising a mechanism that can be deployed by using (1). 3. The deployable frame structure according to claim 3, wherein said deploying mechanism comprises a pantograph link mechanism moving in a two-dimensional plane. 4. A tension generating means for eliminating backlash after development is provided between upper surface nodes and between lower surface nodes of the truncated pyramid-shaped basic element. The deployable frame structure according to claim 3. 5. The deployable frame structure according to claim 2, wherein said synchronization mechanism includes a deployment force urging means for applying a deployment force to the deployment mechanism. object. 6. The deployable skeleton structure according to claim 5, wherein said deploying force urging means is a deployable spring. 7. The deployable skeleton structure according to claim 5, wherein the deployment force urging means is a deployment actuator. 8. The deployable skeleton structure according to claim 2, further comprising a holding device for fixing the deploying mechanism.