JPH01127496A - Expansion truss structure - Google Patents

Abstract

PURPOSE: To provide high rigidity by forming a tetrahedron as a safe structure by eliminating looseness of the pin joining part by keeping a balance state of force by generating compressive force in a rib by a first/second wires tensioned between the mutual respective apexes to form the tetrahedron. CONSTITUTION: A structure is unfolded by push-expanding a space between a main slide hinge 11 and a synchronous slide hinge 14 by spring force of a coil spring 17. When the main slide hinge 11 comes near to a stopper 16, a first wire 13 between mutual upper surface side connectors 3a, between mutual lower surface side connectors 3b and 3c and between the connector 3a existing on the upper surface side free end and the connector 3c existing on the lower surface side free end is tensioned. Looseness of the pin joining part is eliminated since this wire 13 presses a connector 3 to the rib 12 side. Tensile force of the first wire 13 can be reliably increased since a second wire 18 is also simultaneously tensioned. Therefore, high rigidity can be obtained as a structure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a lightweight deployable truss structure with high retractability.

[Conventional technology]

In recent years, the performance and reliability of space shuttles, Ariane rockets, etc. have improved, and economic benefits have been created for space utilization. In particular, large deployable antennas are indispensable for communication in mobile bodies such as ships and vehicles, and deployable truss structures for constructing these antennas have been actively developed. On the other hand, in terms of scientific use, there are plans to build a huge space base, and the deployable truss structure as the basic structure of this base is an important development theme. This is because the unfolding structure method is believed to be the most economical way to construct huge structures in space.

Figure 4 shows the above expansion truss structure, published in the American academic journal r I
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It was shown in Vol. P-17, No. 4 (1969). This is a diagram showing a conventional deployable truss structure. In Figure 1, (1) is a bending member that forms a triangular lattice on the top and bottom surfaces of this truss structure and can be bent at the center, and (2) is a bending member on the top. A diagonal member that supports the triangular lattice on the bottom.

(3) is a connector for pin-coupling the bent member (1) and the diagonal member (2).

Figure 5 is an enlarged view of part A surrounded by a broken line circle in the fourth factor, where (4) is a web provided around the connector (3), the bent member (1) and the diagonal member. (2) to the combinator (3
) is connected with a pin.

Fig. 6 is an enlarged view of part B surrounded by the broken line circle in Fig. 4, and is a diagram showing details of the central bent part υ of the bent 9 member 11), and (5) in Fig. 1 shows the central part. A rotatable hinge lever (6) consisting of two fc plates connected by a pin is attached to the base of one of the hinge levers (5), and the hinge lever (6) is attached to the base of one of the hinge levers (5) in the direction of unfolding the bending member (1). (!5
), (7) is the bending member 1
1) and the hinge lever 15) with the connecting pin (7a
) and (7b) are the hinge lever (5) and the bending member (
The pin (70) that connects to tl' is a connecting pin that connects the bent members +ll at the center.

The above structure is composed of a plurality of tetrahedrons made up of three bent 9 members (1), three diagonal members (2), and three connectors (3). Also called a tetrahedral truss structure. FIG. 1 is a diagram showing the expansion truss structure in progress.

Next, the operation will be explained. The above-mentioned structure, which was initially restrained by a holding cable (not shown) in its stored form, becomes movable by cutting the holding cable with a detonator or the like in response to a command from the ground, and is then moved by the spring force of the spiral spring (6). Start expanding. For deployment, the hinge lever (5) is rotated by the spring force of the spiral spring (6), and the bending member (1) is extended while rotating the coupling pin (7C). Due to the extension of the bending member 111, the connectors (3) on the upper and lower surfaces spread radially, and 9 expansion progresses. When the bending member (1) extends linearly, 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 11) are balanced, and the bent member 11) stops moving. This is the developed shape, and the structure is connected only by a triangular lattice. A triangular lattice is basically a rigid and stable structure, and conventionally this type of structure was considered to be a very rigid structure suitable for deployable antennas or structures for space bases.

[Problem that the invention seeks to solve]

However, in the conventional structure, the connection points of each member are not actually concentrated at one point, so the structure is flexible and cannot even maintain its own shape. In other words, the triangular lattice is rigid only when the members are connected at the points shown in Figure 8, but in the conventional structure, the triangular lattice is rigid as shown in Figure 9. Not only does it lack rigidity because it has many hinge connection points, but it also results in an unstable link structure. In Figures 8 and 9, (8) is the basic member constituting the triangular lattice, (9) is the pin joint that connects the basic member (8), and +3) is the basic member of the pin joint (9) K. It is a connector that connects the member (8).

As explained above, conventional deployable truss structures using bent members are basically unstable structures.

There was a fatal problem in that the required rigidity could not be achieved in the structure of the deployable antenna or the space base itself.

The present invention was made to solve the above-mentioned problems, and provides a deployable truss structure that is structurally stable and highly rigid in an expanded shape.

[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 stopper at the other end, and a main slide which slides on the mandrel during deployment and finally comes to rest against the stopper. a hinge, one end of which is pin-coupled to the main slide hinge and three ribs extending radially; one end of the mandrel, a synchronous slide hinge that slides between the main slide and the Fuji, and one end of which is connected to the synchronous slide hinge; radially pin-coupled,
and the other end is pin-coupled to each of the three ribs.
It is equipped with a main synchronous beam and a coil spring provided between the main slide hinge and the synchronous slide hinge, and the center rods are arranged so that adjacent ones are opposite to each other, and the truss structure can be freely expanded. A plurality of frames in which the ribs, excluding the end ribs, are connected by connectors on mandrels facing in opposite directions, and the connectors on the mandrels in opposite directions are joined by diagonal members, and the mandrels have the same orientation. between the connectors on the mandrel that become and a first wire stretched between each when the deployable truss structure is deployed;
One end is attached to the main slide hinge, and the other end is attached to the middle point of each of the three first wires stretched in a triangular shape around the main slide hinge, and the structure is tensioned when the deployable truss structure is deployed. A second wire is attached.

[Function] In this invention, the first and second wires stretched between the vertices constituting the tetrahedron generate compressive force on the ribs and achieve a force equilibrium state, so that they are pin-coupled. The looseness of the parts disappears, and the tetrahedron that is the basic module becomes a stable structure, making it easy to obtain high rigidity.

Furthermore, since each of the above-described tetrahedrons is expanded synchronously, the reliability of the expansion is increased, and external energy is not required to expand the tetrahedrons due to the force of the spring.

〔Example〕

FIG. 1 is a diagram showing a deployable truss structure in a deployed shape showing one embodiment of the present invention, (5a), (3b)
is a connector having a pin joint part, (50) is a connector provided at the other end of the rib that is the free end of the deployable truss structure, and H is a mandrel with connector (3) attached to the tip.

Adjacent mandrels are arranged with opposite axial directions. dll is a main slide hinge that slides on the mandrel QQ, and σ2 is a rib whose one end is radially pin-coupled to the main slide hinge συ and can be expanded in a direction perpendicular to the axial direction of the mandrel. Connector (3a) of
It is in the opposite direction. It is pin-coupled to a connector (5b) attached on the adjacent oppositely oriented mandrel (11). Also, the rib that becomes the free end of the deployable truss structure is connected to the connector (3C).
is combined with

0 is a connector (6a
) between each other, (3b) between each other, between the connectors (5C) arranged at the free ends of the deployable truss structure.

and nine peripheral connectors (3a) mounted on said mandrel and connectors (3a) disposed at the free ends of said deployable truss structure.
C) one wire attached to the other and set to be tensioned when the deployable truss structure is deployed.

(2) is the connector (3a) on the top side and the connector (!) on the bottom side.
11)) and (3c) by a pin connection.

I is a synchronous slide hinge that slides on the shaft between the connector (3) and the main slide hinge συ, and the synchronous slide hinge is connected with a pin at one end to the above-mentioned synchronous slide hinge I, and the other end is connected to the rib σ2 with a pin, and the next synchronous Showing beams. Figure 2 is an enlarged version of part C in Figure 1, and the US shows the main slide hinge (111
A stopper that determines the bottom dead center of tJ? ) is a coil spring that provides a driving force to deploy the deployable truss structure of the present invention, and α barrel is a coil spring between the midpoint of the first wire fi3 stretched in a triangular shape around the main slide hinge α11 and the main slide hinge αυ. A soft second wire with low axial rigidity is stretched across the shaft and produces tension on the first wire 〇 when unfolded. It is set to be.

The unfolding operation of the deployable truss structure configured as described above will be explained below. The deployable truss structure of this invention is
When retracted, the connector 1 (5a) on the mandrel utt and the main slide hinge (111) on the mandrel α.

Said main slide hinge (IIIK) has one end connected to the pin-connected rib to another connector 2 connected to the other end of 2, for example (5b
) The triangle whose three vertices are r is collapsed, and the angle θ between the rib nz and the shaft Ql shown in FIG. 2 is zero. Deployment is performed by pushing apart the main slide hinge Qυ and the synchronous slide hinge α by the spring force of the coil spring aη. When the distance between the main slide hinge Qυ and the synchronous slide hinge u4 increases, the distance between the connector (3a) on the shaft oI and the main slide hinge I increases, but the distance between the connector (3a) and the side The distance to the connector (3b) is maintained at a constant length by the diagonal member (2), and the distance between the connector (3b) on the above side and the main slide hinge Ql1 is also maintained by the length of the rib α2. Therefore, the triangle formed by the three vertices expands, and the angle θ between the rib σ2 and the shaft H increases. When the angle θ between the rib α2 and the shaft +t1 increases, the connector (3b) on the above side and another rib σ2 provided at the other end of which one end is pin-coupled to the main slide hinge aυ. Connector 1 For example (!i
c) The distance between , also increases. Above main slide hinge σ
When B comes near stopper 00 (K comes, the soil surface side connector (3
a) Mutual, lower side connector (3b), (5Q)
The first wire αJ is stretched between each other, and between the connector (5a) at the free end on the soil surface side and the connector (3C) at the free end on the lower surface side. The above-mentioned first wire α (continues to be stretched until the main slide hinge aυ hits the stopper α [[. There is no play in the parts, and the deployable truss structure becomes a highly rigid structure.Also, when the deployable truss structure is deployed.

Since the second wire 08 is also stretched at the same time, it is possible to ensure the tension of the first wire 0.

FIG. 3 shows a diagram of the deployable truss structure of the present invention in the middle of deployment.

〔Effect of the invention〕

As explained above, in this invention, the first wire is stretched between the vertices of each tetrahedron, and the second wire is used to ensure the tension of the first wire, so there is no looseness at the joint ( As for the structure, it has the effect of easily obtaining high rigidity.

In addition, this invention has a synchronization beam that synchronizes the deployment between the rib and the mandrel, and a coil spring that supplies the deployment energy, so the deployment is synchronized and the reliability of deployment is improved.9. It has the effect of achieving deployment with a self-blade.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of a deployable truss structure after deployment showing an embodiment of this invention, Fig. 2 is a diagram showing a member combination in an embodiment of this invention, and Fig. 3 is a diagram showing an embodiment of this invention. A diagram showing a shape in the middle of development. Figure 4 shows the developed shape of the conventional example. Fig. 5 is a diagram showing the diagonal member joining part in the conventional example, Fig. 6 is a diagram showing the mechanism of the bent member of the triangular lattice in the conventional example, and Fig. 7 is a diagram showing the shape of the conventional example in the middle of expansion. Figure 8 is a diagram of a physical model of a triangular lattice that has been conventionally considered. FIG. 9 shows an actual physical model diagram of a triangular lattice in a conventional example. In the figure, 11) is a bent member, and (2) is a diagonal member. (3) is a connector, (4) is a web, (5) is a hinge lever, (6) is a spiral spring, (7) is a connecting pin, (8) is a basic member, (9) is a pin joint, and all is a stem. , αυ
is the main slide hinge, α2 is the rib, (13 is the first wire, α4 is the synchronous slide hinge, 19 is the synchronous beam, I
e is a stopper. Ilη is a coil spring, and α樟 is a second wire. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A mandrel having a connector having a pin joint portion at one end and a stopper at the other end, a main slide hinge that slides on the mandrel, one end of which is radially pin-coupled to the main slide hinge, and the mandrel has a stopper at the other end. three ribs that can be expanded in directions perpendicular to the axial direction, a synchronous slide hinge that slides between one end of the mandrel and the main slide hinge, one end of which is radially pin-coupled to the synchronous slide hinge, and the other It is equipped with three synchronous beams whose ends are pin-coupled to the three ribs, a coil spring provided between the main slide hinge and the synchronous slide hinge, and the directions of the mandrels are opposite to each other. The ribs are arranged in a similar manner and the ribs excluding the ribs which become the free ends of the deployable truss structure are connected by connectors on the mandrels facing in opposite directions, and the connectors on the mandrels facing in opposite directions are joined by diagonal members. a plurality of skeletons, and connections on the mandrels in which the mandrels are oriented in the same direction, between the other ends of the ribs that become the free ends of the deployable truss structure, and ribs that become the free ends of the deployable truss structure. between the other end and the connector,
When the deployment truss structure is deployed, the first wire is stretched between each other, and the first wire is attached at one end to the main slide hinge and the other end is stretched in a triangular shape around the main slide hinge. A deployable truss structure comprising: a second wire attached to each intermediate point of the three first wires and stretched during deployment of the deployable truss structure.