JPH0617605B2 - Deployable truss structure - Google Patents

Description

The present invention relates to a lightweight deployable truss structure having a high retractability.

[Prior Art] In recent years, the performance and reliability of space shuttles, alien rockets, etc. have been improved, and economical merits have been created for space utilization. In particular, large deployable antennas are indispensable for communication of moving bodies such as ships and vehicles, and deployable truss structure methods that constitute them have been actively developed. On the other hand, in terms of scientific utilization, there is a plan to create a huge space base, and the deployment truss structure as a basic structural method of this base is an important development theme. This is because the expansion structure method is considered to be the most economical method for constructing a huge structure in space.

Fig. 4 shows the above-mentioned expanded truss structure based on the American academic journal "IEEE
TRANSACTIONS ON ANTENNAS AND PROPAGATION "AP-17
It is a diagram showing the conventional deployable truss structure shown in Volume 4 (1969). In the figure, (1) constitutes the triangular lattice of the upper and lower surfaces of this truss structure, and it should be bent at the center. The possible bending members, (2) is a diagonal member supporting the upper and lower triangular lattices, and (3) is a connector for pin-connecting the bending member (1) and the diagonal member (2).

FIG. 5 is an enlarged view of A surrounded by a broken line circle in FIG. 4, and (4) is a web provided around the connector (3), which includes the bending member (1) and the slant member (2). ) Is pin-connected to the connector (3).

FIG. 6 is an enlarged view of the portion B surrounded by the broken line circle in FIG. 4, showing the details of the central bending portion of the bending member (1). In the figure, (5) is a pin at the central portion. A rotatable hinge lever consisting of two plates joined together, (6) is the hinge lever (5) above
A spiral spring which is attached to one of the roots and rotates the hinge lever (5) in a direction to expand the bending member (1), and (7) is the bending member (1) and the hinge lever (5). (7a) and (7b) are pins for connecting the hinge lever (5) and the bending member (1), and (7c) is a bending member.
(1) A connecting pin that connects the two in the center.

The above structure has three bending members (1) and three diagonal members (2).
It is also called a tetrahedron truss structure because it has a structure in which a plurality of tetrahedrons composed of and three connectors (3) are connected. FIG. 7 is a diagram showing a state in which the deployable truss structure is being deployed.

Next, the operation will be described. Initially, the structure constrained by a holding cable (not shown in the retracted shape) becomes movable by cutting the holding cable with a blast tube etc. by a command from the ground, and it is expanded by the spring force of the spiral spring (6). Get started. For expansion, the hinge member (5) is rotated by the spring force of the spiral spring (6) to extend the bending member (1) while rotating it around the coupling pin (7c). By the extension of the bending member (1), the connectors (3) on the upper and lower surfaces spread radially and the expansion progresses. When the bending member (1) progresses in a straight line, the rotational torque generated by the spring force of the hinge lever (5) and the spiral spring (6) and the contact surface pressure on the bending surface of the bending member (1) are The balance and bending member (1) stop the movement. This is an expanded shape, and the structure is a shape that is connected only by the triangular lattice. The triangular lattice is basically a rigid and stable structure. Conventionally, this kind of structure was very rigid and was considered to be suitable for a deployable antenna or a space station structure.

[Problems to be solved by the invention]

However, in the conventional structure, the connecting points of each member are not concentrated at one point in reality, so that the structure is not flexible enough to hold the shape of oneself. That is, the triangular lattice is rigid only when the connecting condition of each member is connected at one point as shown in FIG. 8, but in the conventional structure, this triangular lattice is many as shown in FIG. Not only does it lack rigidity because it has the hinge connection point, but it also leads to an unstable link structure. In addition, in FIG. 8 and FIG.
(8) is a basic member that constitutes a triangular lattice, (9) is the above basic member
A pin joint for connecting (8) and (3) are connectors for connecting the basic member (8) by the pin joint (9).

As described above, the conventional deployable truss structure using bent members is basically an unstable structure, and thus there is a fatal problem that the deployable antenna or the space base body structure cannot provide the required rigidity. .

The present invention has been made to solve the above problems, and provides a deployable truss structure which is structurally stable and has high rigidity in the shape after deployment.

[Means for solving problems]

The deployable truss structure according to the present invention includes a mandrel having a connector having a pin joint at one end and a mandrel having a stopper at the other end, and a main slide hinge that slides on the mandrel at the time of unfolding and finally comes to rest on the stopper. And three ribs extending radially from one end of the main slide hinge by pin coupling, a synchronous slide hinge sliding between one end of the mandrel and the main slide hinge, and one end radially pin coupling to the synchronous slide hinge. And three coil beams, the other ends of which are pin-coupled to the three ribs, respectively, and a coil spring provided between the main slide hinge and the synchronous slide hinge, and the directions of the mandrels are adjacent to each other. The ribs are arranged so that they are in opposite directions, and the ribs, except the ribs that are the free ends of the expanded truss structure, are A plurality of skeletons formed by connecting diagonally-connected connectors on mandrels that are connected with each other and opposite to each other, between the connectors on the mandrels with the same direction of the mandrel, and the expanded truss structure described above. Between the other ends of the ribs, which are the free ends of the expanded truss structure, and between the other ends of the ribs, which are the free ends of the expanded truss structure, and the above-mentioned connectors. It is attached with a wire to be hung.

[Action]

In the present invention, the wire stretched between the vertices forming the tetrahedron causes a compressive force on the rib to realize a balanced state of force, so that the looseness of the pin-coupled portion disappears and the basic module is used. A certain tetrahedron has a stable structure, and it becomes easy to obtain high rigidity.

Further, since the slanting members connecting the connectors on the mandrel which are opposite to each other can bear both the tension and the compression force, the synchronism of the expansion is improved.

Furthermore, since each of the above-mentioned tetrahedra expands in synchronization with each other, the reliability of the expansion increases, and the external energy for expanding the tetrahedron by the force of the spring is unnecessary.

〔Example〕

FIG. 1 is a diagram showing a deployable truss structure in a deployed configuration showing an embodiment of the present invention. (3a) and (3b) are connectors having pin joints, and (3c) is freedom of the deployed truss structure. A connector at the other end of the rib which is the end, (10) is a connector at the tip (3)
The mandrel attached with the adjacent mandrel is arranged such that the axial directions of the adjacent mandrels are opposite to each other. (11) is a main slide hinge that slides on the mandrel (10), and (12) has one end radially pin-connected to the main slide hinge (11) and can be deployed in a direction orthogonal to the axial direction of the mandrel The ribs are in the opposite direction to the connector (3a) on the mandrel (10), and are adjacent to each other in opposite directions.
(10) Pin-coupled to the connector (3b) mounted above.
The ribs that form the free ends of the expanded truss structure are
It is connected to c).

(13) is a connector (3a) attached to the tip of the mandrel (10)
Mutually, (3b) Mutually, connectors (3c) arranged at free ends of the deployable truss structure, and peripheral connector (3a) mounted on the mandrel and the deployable truss structure. The wire is attached between the connectors (3c) arranged at the free ends of the above, and is set so as to be pulled when the deployable truss structure is deployed.

(2) is a diagonal member that connects the upper surface side connector (3a) and the lower surface side connectors (3b), (3c) by pin connection, and (14) is the connector (3) and the main slide hinge (11). Synchronous slide hinges (15) that slide on the mandrel between the two are pinned at one end to the synchronous slide hinge (14) and pinned at the other end on the rib (12). Note that (2) is an oblique member in which the upper surface side connector (3a) and the lower surface side connectors (3b), (3c) are connected by pin connection. Fig. 2 is an enlarged view of part c in Fig. 1, and (16) is a stopper that determines the bottom dead center of the main slide hinge (11) during deployment,
(17) is a coil spring that gives a driving force for deploying the deployable truss structure of the present invention, and θ is an angle formed by the mandrel (11) and the rib (12), and is set to be about 90 ° when deployed. Has been done.

The unfolding operation of the unfolding truss structure configured as described above will be described below. The deployable truss structure of the present invention is
When stored, the connector on the mandrel (10), such as (3a) and the mandrel (1
Main slide hinge (11) above and main slide hinge above
A triangle having three vertices at another connector, for example, (3b), which is connected to the other end of the rib (12) whose one end is pin-connected to (11), is collapsed, and the rib shown in FIG. The angle θ between 12) and the mandrel (10) is zero. The main slide hinge (11) and the synchronous slide hinge (14) are deployed by the spring force of the coil spring (17).
It is done by expanding the space. When the distance between the main slide hinge (11) and the synchronous slide hinge (14) increases, the connector (3a) on the mandrel (10) and the main slide hinge (1).
Although the distance between 1) increases, the distance between the connector (3a) and the other connector (3b) is kept constant by the slant member (2). ) And the main slide hinge (11) are also held by the length of the rib (12), the triangle consisting of the above three vertices widens, and the rib (12) and the mandrel (1)
The angle θ formed by 0) increases. When the angle θ formed by the ribs (12) and the mandrel (10) increases, the other connector (3b) and another rib whose one end is pin-connected to the main slide hinge (11).
Still another connector provided at the other end of (12), such as (3c),
The distance between them also increases. When the main slide hinge (11) comes close to the stopper (16), the upper surface side connectors (3a) are
The wire (13) is stretched between the lower surface side connectors (3b), (3c) and between the upper surface side free end connector (3a) and the lower surface side free end connector (3c). . The wire (13) continues to be stretched until the main slide hinge (11) hits the stopper (16). The stretched wire (13) connects the connector (3) to the rib (1
Since it is pressed to the 2) side, there is no play in the pin joint,
The deployable truss structure has high rigidity.

Further, the slant member (2) is pinned between the connectors (3a) and (3b), (3a) and (3c) on the mandrel (10) which are opposite to each other, and the connectors (3a) and (3b). ), The distance between (3a) and (3c) is maintained at a constant length, so that good synchronism of expansion can be obtained.

FIG. 3 shows a diagram of the deployable truss structure of the present invention in the process of being deployed.

〔The invention's effect〕

As described above, the tension member is stretched between the apexes of each tetrahedron as described above, so that a high rigidity can be obtained because of the structure without rattling, and between the connectors on the mandrel which are opposite to each other,
There is an effect that the synchronism of the expansion can be obtained by the pin connection with the oblique member.

Further, according to the present invention, since the synchronous beam for synchronizing the expansion and the coil spring for supplying the expansion energy are provided between the rib and the mandrel, the expansion is synchronized, the reliability of the expansion is increased, and the expansion is achieved by itself. effective.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a deployed truss structure showing an embodiment of the present invention, FIG. 2 is a diagram showing a member connecting portion in the embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a diagram showing a shape in the middle of unfolding, FIG. 4 is a diagram showing a shape after unfolding in a conventional example, FIG. 5 is a diagram showing a diagonal member connecting portion in the conventional example, and FIG. 6 is a bent triangular lattice in the conventional example. FIG. 7 is a view showing a mechanism of the bending member, FIG. 7 is a view showing a shape in the middle of development in the conventional example,
The figure shows the physical model of the triangular lattice that was previously considered, 9th
The figure shows an actual physical model of the triangular lattice in the conventional example. In the figure, (1) is a bending member, (2) is a diagonal member, (3) is a connector, (4) is a web, (5) is a hinge lever, (6) is a spiral spring, and (7) is a connection. Pin, (8) basic member, (9) pin joint, (10) mandrel, (11) main slide hinge, (12) rib, (13) wire, (14) synchronous slide hinge, ( 1
5) is a synchronizing beam, (16) is a stopper, and (17) is a coil spring. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A mandrel having a connector having a bin joint at one end and a stopper at the other end, a main slide hinge sliding on the mandrel, and one end radially connecting with a pin to the main slide hinge. And three ribs that can be deployed in respective predetermined directions with respect to the axial direction of the mandrel, a synchronous slide hinge that slides between one end of the mandrel and a main slide hinge, and one end of which is radially pin-coupled to the synchronous slide hinge. And three other ends of which the other ends are pin-coupled to the three ribs, respectively, and a coil spring provided between the main slide hinge and the synchronous slide hinge, and the mandrel is adjacent to each other. The ribs are arranged so that they are arranged in opposite directions, and the ribs, except the ribs that are the free ends of the expanded truss structure, are connected by mutually opposite mandrel connectors, and However, the distance between the connectors on the mandrel in opposite directions should be kept constant regardless of the distance between the main slide hinge and the synchronous slide hinge, which increases with the deployment of the deployment truss structure. Between a plurality of skeletons that are pin-joined by holding slant members, between the connectors on the mandrel in which the direction of the mandrel is the same, between the other ends of the ribs that are the free ends of the deployed truss structure, and The invention is characterized in that it has a tension member which is provided between the other end of the rib which is a free end of the deployable truss structure and the above-mentioned connector, and which is stretched between the respective members when the deployable truss structure is deployed. Deployable truss structure.