JPH01127498A - Expansion truss structure - Google Patents

Abstract

PURPOSE: To provide high rigidity by forming a quadrangular pyramid as a stable 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 wire tensioned between the mutual respective apexes to form the quadrangular pyramid. 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 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 four rib 12 side. High rigidity can be easily obtained by forming a loosenessless structure by tensioning the wire 13 between the respective quadrangular pyramid apexes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a light-weight openable truss structure with high retractability.

[Conventional technology]

In recent years, the performance and reliability of space shuttles, rockets, etc. have improved, and economic benefits have emerged in space applications. 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, there are plans to build a huge space base for scientific purposes, and the deployable truss structure as the basic structure of this base has become an important development theme. This is because the deployable structure method is believed to be the most economical way to construct huge structures in space.

Figure 4 shows the above development truss structure as described in the American academic journal “I
ll! melt 'rRAII8AOTION8 O
NAIT]C1[A8AND PROPAGAT Engineering ONJ Volume P-11 No. 4 (19611) K. This is a diagram showing a conventional deployable truss structure. In Figure 1, +11 constitutes a triangular lattice on the upper and lower surfaces of this truss structure, and 19 bent members that can be bent at the center, (2) represent triangular lattices on the upper and lower surfaces. A diagonal member that supports the grid.

(3) is a connector that connects the bent member 11) and the diagonal member (2) with a pin.

FIG. 5 is an enlarged view of part A surrounded by the broken line circle in FIG. +21 t” connector (3) and pin-coupled.

Fig. 6 is an enlarged view of part B surrounded by the broken line circle in Fig. 4, and is a view showing details of the center bent part of the folded member 11). A rotatable hinge lever (6) consisting of two joined plates is attached to the base of one of the hinge levers (5), and is attached to the bent portion 9.
A spiral spring (7) rotates the hinge lever (5) in the direction of unfolding the member 11), and (7) is the bent member 11).
(7a) and (7b) are connecting pins that connect the hinge lever (5) and the bending member 11).
The pin (70) that connects the bent member (1
) It is a joining bin that joins comrades at the center.

The above structure is composed of a plurality of tetrahedrons made up of three bent 19 members (1), three diagonal members (2), and three connectors (3). Also called truss structure. FIG. 7 is a diagram showing the expansion truss structure in progress.

Next, the operation will be explained. Initially, the above-mentioned structure is restrained by a holding cable (not shown) in its stored shape, and then the structure is made movable by cutting the holding cable with a detonator or the like in response to a command from the ground. We will begin to expand our efforts. For deployment, the hinge lever (5) is rotated by the spring force of the spiral spring (6), thereby extending the bending member +1) while rotating it around the connecting pin (7C). As the bending member 11) expands, the connectors (3) on the upper and lower surfaces spread radially and unfold. 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) The balance, fold 19 member (1) 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 extremely rigid and 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, a triangular lattice is rigid only when each member is connected at one point as shown in Figure 8, but in the conventional structure, this triangular lattice is rigid at many points as shown in Figure 9. (Because it has a hinge connection point of (9) is a pin joint that connects the basic member (8), and (3) is a connector that connects the basic member (8) to the pin joint (9).

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

There was a corresponding problem that the required rigidity could not be achieved for the deployable antenna or the space base main body structure.

The present invention was made in order to solve the above-mentioned problems and provides a deployable truss structure which 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 to which a connector having a pin joint portion is connected at one end and a stopper at the other end, and a main slide that slides on the mandrel during deployment and finally comes to rest on the stopper VC. a hinge, four ribs extending radially with one end pin-coupled to the main two-ride hinge, a synchronous slide hinge that slides between one end of the mandrel and the main slide hinge, and one end pinned radially to the synchronous slide hinge. combined,
and the other end is pin-coupled to each of the four ribs 7'
? , a deployable truss structure comprising four synchronous beams and a coil spring provided between the main slide hinge and the synchronous slide hinge, and in which the axles are arranged so that adjacent ones are oriented in opposite directions. The ribs, excluding the free end ribs, are connected by connectors on the mandrels facing in opposite directions, and the connectors on the six rods are connected by diagonal members, and the mandrels are connected in opposite directions. between the connectors on the mandrel whose orientations are the same, between the other ends of the ribs that are the free ends of the deployable truss structure, and between the other ends of the ribs that are the free ends of the deployable truss structure and the connectors. A wire is attached between each of the truss structures and stretched between the two when the deployable truss structure is deployed.

[Effect]

In this invention, the wires stretched between the vertices of the square pyramid create compressive force on the ribs and achieve an equilibrium state of force, so the looseness of the pin-connected parts disappears and the basic module remains intact. A certain square pyramid has a stable structure9 and it is easy to obtain high rigidity.

Furthermore, since each of the square pyramids described above unfolds in synchronization with each other, the reliability of the deployment is increased, and external energy for deploying the square pyramids by the force of the spring becomes unnecessary.

〔Example〕

FIG. 1 is a diagram showing a deployable truss structure in a deployed shape showing an embodiment of the present invention, (button), (31)) is a connector having a pin joint part, and (5c) is a diagram of the deployable truss structure. a connector at the other end of the rib, which is the free end;
ul is a mandrel with a connector (3) attached to the tip.

Adjacent mandrels are arranged with opposite axial directions. Qn is a main slide hinge that slides on the mandrel (I; α is a rib whose one end is radially pin-coupled to the main slide hinge αB and can be expanded in a direction perpendicular to the axial direction of the mandrel; Connector on tII (3a)
In the opposite direction, it is pin-coupled to a connector (3b) mounted on an adjacent reversely oriented mandrel DI. Further, the rib that becomes the free end of the deployable truss structure is connected to a connector (3C).

(13 is a connector attached to the tip of the shaft member (5
a) Between each other + (sb) Between each other, between the connectors (5C) arranged at the free ends of the above deployable truss structure.

and a peripheral connector (3a) mounted on the mandrel and a connector (3a) disposed at the free end of the deployable truss structure.
C) with wires attached between each other.

It is set so as to be pulled when the above-mentioned deployable truss structure is deployed.

(2) is the connector (3a) on the top side and the connector (5) on the bottom side.
b) A diagonal member that connects (3C) with a pin connection.

I is a synchronous slide hinge that slides on the shaft between the connector (3) and the main slide hinge αυ, and μ9 is a synchronous beam with one end pin-connected to the synchronous slide hinge I and the other end pin-connected to the rib Q3. shows.

Figure 2 is an enlarged view of part C in Figure 1, where tte is a stopper that determines the bottom dead center of the main slide hinge when it is deployed.
(In is a coil spring that provides a driving force to deploy the deployable truss structure of the present invention, and θ is the angle between the shaft Qυ and the rib α, which is set to be around 90° when deployed.

The unfolding operation of the fc deployable truss structure constructed as described above will be explained below. The deployable truss structure of the present invention has a connector 1 such as (3a) on the mandrel IJI and a main sliding hinge (111) on the mandrel H during storage.

Another connector 9, for example (3t
+), iThe triangle with three vertices is collapsed,
The rib c3 shown in Fig. 2 and the center* (the angle θ of Il are zero. The expansion is done by pushing apart the main slide hinge αD and the synchronous slide hinge 114) by the spring force of the coil spring αD. . Main slide hinge 1 above
As the distance between 111 and synchronous slide hinge 0 increases,
The distance between the connector (3a) on the shaft lJe and the main slide hinge aυ increases, but the distance between the connector (3a) and the connector (5b) on the above side remains constant at g+ member (2). Furthermore, the distance between the connector (3b) on the above side and the main sliding hinge 1111 is also maintained at the length of the rib σ2, so the triangle made up of the three vertices expands, and the distance between the above rib u3 and The angle θ formed by the mandrel 0I increases. When the angle θ between the rib α and the shaft CI increases, the another connector (5b) and the other connector (5b) provided at the other end of another rib 03 that is pin-coupled with one end of the main slide hinge QnK. The distance between connectors 1, for example (5a), also increases. Main slide above.

When the hinge 0 comes close to the stopper ■, the upper side connectors (5a) and the lower side connectors (!ib), (ja
) The wires +13 are stretched between each other, as well as between the connector (mu) with the upper free end 1C and the connector (3C) with the lower free end 1c6. The 9-year I continues to be stretched until the main slide hinge αD hits the stopper 1I11. The stretched wire salt 3 is the connector (3) t-rib I1
Since it is pressed against the 3 side, there is no looseness at the pin joint,
The deployment truss structure is a highly rigid structure.

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, this invention has the effect that high rigidity can be easily obtained because the shear wire is stretched between the vertices of each quadrangular pyramid to create a structure without backlash.

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, the reliability of the deployment is improved, and the deployment is achieved with a self-cutting blade. There is an effect of 0

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a deployable truss structure after deployment showing an embodiment of the present invention, FIG. 2 is a diagram showing a member joint in the embodiment of the invention, and the third factor A diagram showing a shape in the middle of development. Fig. 4 is a diagram of the developed shape of the conventional example, Fig. 5 is a diagram showing the diagonal member joint part of the conventional example, and Fig. 6 is a diagram showing the mechanism of the bent member of the triangular lattice in the conventional example. , FIG. 1 is a diagram showing a shape in the middle of development in a conventional example, FIG. 8 is a physical model of a conventionally considered triangular lattice, and FIG. 9 is 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, (I is the mandrel, +
Ill is the main slide hinge, 112 is a rib, the mouth is a wire, fill is a synchronous slide hinge, α9 is a synchronous beam, αe is a stopper, and the fin is a coil spring. In the figures, 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. four 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 four synchronous beams whose ends are pin-coupled to the four 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. between a plurality of frames, the connectors on the mandrels having the same orientation, the other ends of the ribs, which become the free ends of the deployable truss structure, and the free ends of the deployable truss structure. A deployable truss structure characterized by comprising a wire between the other end of the rib and the connectors, and stretched between the respective connectors when the deployable truss structure is deployed.