JPH0352010Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to improvements in the deployment mechanism of offset-type antennas that are mounted on, for example, artificial satellites, are folded into a small size at the time of launch, and are deployed in space to form an antenna surface. .

(Conventional technology and its problems) As a conventional antenna of this type, the
There is something like the one disclosed in No. 113504. Its structure is shown in FIGS. 4 to 6. Figure 4 shows the folded state before unfolding the antenna, and Figure 5 shows the folded state before unfolding the antenna.
The figure shows the unfolded state. FIG. 6 shows the antenna deployment mechanism. Each of the ribs 22 is rotatable about a shaft 24 provided on the holding portion 21 . The shaft 24 is arranged so that the ribs 22 are radial when the antenna is expanded. When the ribs 22 are opened radially, the conductive mesh 23 stuck to the ribs 22 and recessed opens to form an antenna surface. All ribs 22 are provided with an unfolding mechanism as shown in FIG. A coil spring 27 is attached to the shaft 24, and the rib 22 is applied with a force in the folding direction of the arrow. Further, one end of a wire 26 is fixed to the rib 22, and the wire 26 passes through a guide roller 25 attached to the holding portion 21 and reaches a winding drum of a wire winding device (not shown). When launching an artificial satellite, the rib 22 is folded into a small size by the force of the coil spring 27, but the wire 2
6 is wound up with a winding device, the rib 22 rotates in the direction of the arrow and the antenna unfolds.

As described above, the conventional antenna deployment mechanism has a structure in which independent rotational force is applied to all the constituent ribs, resulting in a complicated structure and an increase in weight. Furthermore, it is necessary to synchronize the rotation of the ribs so that the mesh 23 is not damaged due to excessive force when the ribs rotate independently in this manner. Also, if you increase the number of ribs to improve the precision of the antenna surface,
The weight increases further, making it difficult to synchronize rotation.

It is an object of the present invention to provide an antenna deployment mechanism that does not have such drawbacks.

(Means for solving the problem) The unfolding mechanism of the foldable antenna of the present invention is as follows:
As shown in the figure, there are multiple ribs that can freely rotate around a hinge provided at one end, a conductive mesh attached to these ribs, and a structure that is oriented so that the ribs expand radially when rotated. A deployment mechanism for deploying the ribs of a folding antenna to form a mirror surface of the antenna, comprising a holding part to which the hinges are attached, and a means for rotating the ribs, the ribs being fixed to the shafts of each of the hinges. , these shafts are connected to each other, and a rotating means for rotating the connected shafts is provided.

(Embodiment) An embodiment of the present invention is shown in FIGS. 1 to 3. In this example, the second aspect of the invention was selected. The hinge consists of a shaft and bearing 2, and rib 1
The end is fixed to this shaft. The nine bearings 2 are radially attached to the holding part 1 so that the nine ribs 5 are expanded radially. The nine shafts are connected to each other by a universal joint 4. A gear 8 is attached to the fifth shaft 3a counted from both ends, that is, the central shaft 3a. Rotation means are motor 6 and reducer 7
It is attached to the holding part 1.
At this time, the output gear 9 of the reducer 7 and the gear 8 are meshed. A stopper 10 is provided at a holding portion below the central rib 5a fixed to the central shaft 3a, and a limit switch (not shown) is attached to the top of the stopper 10. When the rib 5a rotates and operates the limit switch, the motor 6 is stopped. Rib 5 for stopper 10
The height is such that when a rotates to a predetermined angle, a limit switch is activated. A shaft 3b to which eight ribs 5b excluding the center rib 5a are fixed.
As shown in FIG. 3, a coil spring 11 is attached to the rib 5b, and this coil spring 11 applies a force in the direction of expansion shown by the arrow to the rib 5b, contrary to the case of the conventional expansion mechanism described at the beginning. There is. During rotation, rotational force is transmitted from the central shaft 3a to the adjacent shaft 3b via the universal joint, but the universal joint has some play, and the shaft is twisted by the torque transmitted. This backlash and twist are added in order, causing a delay in rotation between the central rib 5a and the rib 5b.
This delay becomes larger as the rib 5b is farther away from the center. In order to reduce this difference, the coil spring 11 is used to apply force to the rib 5b in the direction of expansion. Further, a latch mechanism (not shown) is attached to the top of the stopper 12 of the eight ribs 5b. These latching mechanisms
Hold b at that angle. In this way, the antenna mirror surface is kept in a predetermined shape.

When the motor 6 rotates, its rotational force is transferred to the reducer 7
Through the gear 8 and the drive shaft 3 fixed to it
Rotate a. The drive shaft 3a rotates the driven shafts 3b on both sides connected by the universal joint 4, which in turn rotate the driven shafts 3b on both sides. Ribs 5b fixed to each driven shaft 3b in this way
rotates and unfolds. The center rib 5a is the stopper 1
When the value reaches 0 and the limit switch is activated, the motor 6 stops. At the same time, the other ribs 5b abut against the stopper 12 and are fixed in that position by their respective latching mechanisms. At this time, due to the force of the coil spring 11, the rib 5b not only rotates in time with the rotation of the rib 5a, but also is strongly pressed against the stopper 12, so that the latch mechanism operates reliably.

In the second aspect of the present invention, the gear 8 may be attached to any of the nine shafts, but if it is attached to the central shaft and used as the drive shaft 3a as in this embodiment, the rotational force is transferred to the right. and can be transmitted to the left driven shaft 3b in a well-balanced manner.

During deployment, the difference in rotation of the other ribs 5b with respect to the central rib 5a remains within the range of the sum of the backlash of the joint and the torsion of the shaft, and does not become larger than that. In addition, ribs 5a, 5b
Since there is slack in the mesh until the expansion of the ribs 5a and 5b is completed, there is no excessive force applied to the mesh that could cause damage during expansion. No consideration is required.

The means for transmitting and receiving rotational force to the shaft is not limited to the above-mentioned combination of gears and gearboxes. Pulley and belt or drum and wire combinations can also be used. Alternatively, a link can be attached to the shaft and this link can be rotated by another link connected by a joint.

(Effects of the invention) The unfolding mechanism of the foldable antenna of the invention applies rotational force to multiple ribs using one rotation means, so the structure is simple, the operation is reliable, and the weight is relatively light. . Moreover, the movement of each rib is inherently synchronized, so there is no risk of the mesh breaking during deployment.

[Brief explanation of the drawing]

FIG. 1 is a front view of one embodiment of the present invention. FIG. 2 is an enlarged sectional view of the drive shaft of the embodiment shown in FIG. 1, taken at right angles. FIG. 3 is an enlarged sectional view of the driven shaft of the embodiment shown in FIG. 1, taken at right angles. 4 and 5 are drawings of a foldable antenna equipped with a conventional deployment mechanism, in which FIG. 4 shows the folded state and FIG. 5 shows the unfolded state, and in both figures, a is the front view. Figure, b is a side view. FIG. 6 is an enlarged sectional view of the unfolding mechanism shown in FIG. 4, cut at right angles to the axis of the rib. 1... Holding part, 2 is bearing, 3a... Drive shaft, 3
b...Driven shaft, 4...Universal joint, 5a, 5b...
...Rib, 6...Motor, 7...Reducer, 8...Gear, 9...Output gear, 10...Stopper, 11...
... Coil spring, 12 ... Stopper, 21 ... Holding part, 22 ... Rib, 23 ... Conductive mesh, 2
4... shaft, 25... guide roller, 26... wire, 27... coil spring.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of ribs that are freely rotatable around a hinge provided at one end, a conductive mesh attached to these ribs, and the ribs expand radially when rotated. In the unfolding mechanism for rotating and unfolding the rib of a folding antenna, the mechanism comprises a holding part to which the hinge is attached in a direction such that the rib is rotated, and a means for rotating the rib to form a mirror surface of the antenna. 1. A mechanism for deploying a foldable antenna, characterized in that it is fixed to a shaft of each hinge, these shafts are connected to each other, and one rotation means is provided for rotating the connected shafts. (2) The unfolding mechanism for a foldable antenna according to claim 1 of the utility model registration claim, in which the axes of the hinges are connected by a universal joint. (3) The rotating means consists of a motor and a speed reducer, and one gear is fixed to the shaft of a connected hinge, and this gear meshes with the output gear of the speed reducer. Scope of the Utility Model Registration Claims 1. Deployment mechanism of the foldable antenna according to item 1. (4) The unfolding mechanism for a foldable antenna according to claim 1, wherein the means for transmitting rotational force to the axis of the hinge is any one of a belt, a wire, and a link.