JP3133056B2 - Synchronous drive mechanism for deployable antenna and ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a deployable antenna, for example, a deployable deployable antenna suitable for mounting on an artificial satellite, and also relates to a deployable antenna. The present invention relates to an annular body synchronous drive mechanism suitable for driving a hoop (annular body).

(Prior Art) A parabolic antenna (parabolic mirror) is widely known as an antenna for efficiently collecting radio waves. In a Cassegrain-type antenna that uses this parabolic antenna as the main reflector and a hyperbolic mirror as the sub-reflector, the primary radiator can be placed close to the main reflector, so the radio wave depends on the size of the primary radiator and amplifier. It is known as an antenna that can reduce the interference of light.

By the way, a parabolic antenna mounted on an artificial satellite is folded at the time of launch, and needs to be deployed in outer space after launch. For this reason, various foldable deployable antennas have been proposed in the past, and one of them is shown in NASA document CR-3558, as shown in FIG.
“LSST (HOOP / COLUMN) Maypole Antenna Development
HOOP / COLUMN antenna as described in “Program.” That is, the antenna 1 deployable as a mesh antenna has its outer periphery supported by a hoop (annular body) 2. In the center of the antenna 1 , Extendable columns (COLU
MN) 3 is arranged, and a primary radiator 4 is attached to the tip of the column 3. The hoop 2 and the support 3 are connected by a plurality of wires 5. When the support 3 is contracted,
Hoop 2 is folded and antenna 1 is also hoop 2
Is folded inside. This deployable antenna is excellent in that it is lightweight and has good storage efficiency.

(Problems to be Solved by the Invention) However, in the Cassegrain-type antenna, since the sub-reflector needs to be disposed so as to face the main reflector, the sub-reflector is disposed at one end of the support, and the primary radiation is performed. The vessel must be placed at the other end of the column. For this reason, the radio wave radiated from the primary radiator may be obstructed by the support, which causes a problem that a sufficient gain of the antenna cannot be obtained.

Therefore, in the antenna shown in FIG. 14 having a support at the center, four feeders 6 are provided in the primary radiator 4 in order to avoid radio wave interference by the support, and each feeder 6 provides one-fourth of the main reflector 1. Radio waves are supplied to the area and reflected by a quarter of this area. However, since only 1/4 of the main reflecting mirror 1 can be used as a reflecting mirror, there is a problem that the use efficiency of the reflecting mirror is poor.

As described above, in the antenna of the deployed structure having the support at the center, when the primary radiator and the sub-reflector are arranged so as to face the center of the main reflector, various problems are caused due to radio wave interference by the support. is there.

Also, since the sub-reflector is located at one end of the support,
There is a problem that the storage efficiency in the extending direction of the column is reduced. Furthermore, since the pillar is disposed at the center of the main reflecting mirror, the conventional electric design technique cannot be used, and the electric design of the antenna is complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a deployable antenna which can completely eliminate radio wave interference due to the presence of a support, improve storage efficiency, and has a simple structure, light weight and high rigidity.

Another object of the present invention is to provide a synchronous driving mechanism for an annular body suitable for the deployable antenna.

[Configuration of the Invention] (Means for Solving the Problems) A deployable antenna according to the present invention is provided with a deployable main reflector, and is arranged on one side of the main reflector and reflected by the main reflector. Radio wave supply means for supplying radio waves for
A base disposed on the other side of the main reflector, a plurality of joints and arms are alternately connected to each other, and a hoop to which a plurality of locations at an outer end of the main reflector are connected; While deploying the hoop by deploying the hoop by synchronizing all arms and driving them relative to one another so that the two arms connected to one joint and separated from each other are arranged in the arms, Driving means for a hoop that folds the hoop and stores the main reflector by synchronizing and driving all the arms to the joints so that the two arms connected to one joint are close to each other; A plurality of first supports for connecting the hoop and the radio wave supply means and a plurality of second supports for connecting the base and the hoop are provided.

(Operation) In the present invention, when the hoop is deployed by the driving means, the main reflector is deployed, and at the same time, the first and second supports are deployed. On the other hand, when the hoop is folded by the driving means, the main reflecting mirror is housed, and at the same time, the first and second supports are folded. As can be seen from this structure, the antenna according to the present invention differs from the conventional antenna in that
There is no need to provide a support at the center for deployment and storage of the main reflector. Therefore, there is no radio interference due to the presence of the support, and the antenna gain is sufficiently obtained. Further, the use efficiency of the main reflecting mirror does not decrease.

In addition, since the deployable antenna according to the present invention is configured by a so-called deployable mechanism including the hoop and the first and second supports, the deployable antenna can have a high rigidity and a stable structure as a whole. Since the rigidity can be increased in this manner, a sufficient tension can be applied to the main reflecting mirror, whereby the mirror surface accuracy of the main reflecting mirror can be sufficiently ensured. Further, by folding the hoop, the main reflector can be housed inside the hoop, so that a structure with a high efficiency of supply can be realized.

Furthermore, if the hoop drive means and the hoop synchronous drive mechanism are constituted by wires and pulleys, the reliability of deployment is increased and a lightweight structure can be achieved.

(Embodiment) FIGS. 1 to 4 show a deployment antenna according to a first embodiment of the present invention.

The deployable antenna is mounted on a satellite structure (base) 10 and transmits and receives radio waves. A primary radiator 11 transmits the radio waves transmitted from the primary radiator 11, and a sub-reflector 12 for reflecting the radio waves. A main reflector 13 composed of, for example, a mesh that radiates radio waves reflected by the sub-reflector 12 into space is provided.

The main reflecting mirror 13 is surrounded and supported by a foldable hoop (annular body) 14. The hoop 14 includes six joints 15a to 15f and six arms 16a to 16f for connecting these joints, and is formed in a hexagonal ring shape. Two hinges (not shown) each having one degree of freedom are mounted on each of the joints 15a to 15f, and the arms 16a to 16f are rotatably connected by the hinges. Each joint
A lock mechanism (not shown) for restraining the movement of the arm with respect to the joint when the hoop is deployed is incorporated in 15a to 15f. Further, a synchronous drive mechanism, which will be described in detail later with reference to FIGS. 6 to 10, is incorporated in these joints and arms.

By the drive of the synchronous drive mechanism, as shown in FIG. 2, all the arms 16a to 16f are synchronized so that the two arms connected to one joint are close to each other.
Moved with respect to 5e, the joints 15a, 15c, 15e move relatively upward, and the joints 15b, 15d, 15f move relatively downward. Thereby, the hoop 14 is folded and the main reflecting mirror is folded. Here, when the hoop is folded, the movements of the arms 16a to 16f need to be synchronized, and the movements of the joints 15a to 15f need to be synchronized. Details will be described later.

The joints 15a, 15c, 15e of the hoop 14 and the sub-reflector 12 are connected by three bendable sub-mirror supports (first supports) 17. Specifically, a joint fitting 18 having a joint (hinge) 19 having one degree of freedom is attached to each joint 15a, 15
c, 15e, and a joint fitting 20 having a joint (hinge) 21 having one degree of freedom
Mounted on Secondary mirror supports 17 are connected to these joints 19 and 21, respectively. These secondary mirror supports 17 also have a joint 22 with one degree of freedom.

The primary radiator 11 is attached to the satellite structure 10 by a fixing bracket 23. The fixing fitting 23 is also provided with a joint fitting 24 having a joint 25, and the hoop 14 is also provided with a joint fitting 26 having a joint 27 below the joints 15b, 15d, 15f. These joints 25 and 27 are connected by a bendable hoop support (second support) 28, respectively. These hoop supports 28 also have a joint 29 with one degree of freedom.

Each of the joints 19, 21, 22, 25, 27, and 29 has a lock mechanism (not shown) that locks the joint when the secondary mirror support 17 and the hoop support 28 are in the deployed state. Further, the secondary mirror support 17 and the hoop support 28 incorporate a torsion coil spring (not shown) for applying a deployment force when they are deployed.

When the hoop 14 is folded, the secondary mirror support 17 and the hoop support 28 are folded at the joints and are folded inside the hoop 14 in accordance with the movement of the hoop, as shown in FIG.

From the above, the deployment antenna according to the first embodiment is
It is folded as follows.

As shown in FIG. 2, when a synchronous drive mechanism (not shown) is driven, all the arms 16a to 16f are synchronized so that the two arms connected to one joint come closer to each other. The joints 15a, 15c, and 15e move relatively upward, and the joints 15b, 15d, and 15f move relatively downward. At this time, the secondary mirror support 17 and the hoop support 28 are interlocked with the movement of the hoop, and are bent at the joints and folded inside the hoop 14 as shown in FIG. At the same time, the main reflecting mirror 13 is also folded. as a result,
As shown in FIG. 4, the sub-reflector 12 is located above and the primary radiator 11 is located below. Joints 15a, 15c, 15
e gathers upward in a ring, and the joints 15b, 15d, 15f gather downward in a ring. Further, the arms 16a to 16f are in a state of being arranged in parallel and adjacent. Most of the main reflector 13, the sub mirror support 17, and the hoop support 28 are stored inside the folded hoop 14.

When the satellite is launched into space, the deploying antenna is deployed in a reverse procedure to the folding procedure described above by driving the synchronous drive mechanism. In particular, after deployment
The joints 16a to 16f, the joints 15a to 15f, the respective joints and the sub mirror support 17 and the hoop support 28 are locked by a lock mechanism (not shown), thereby increasing the rigidity of each member.

In the first embodiment, the hoop is driven by a synchronous drive mechanism.
When 14 is deployed, the main reflector 13 is deployed, and at the same time, the supports 17, 28 are deployed. On the other hand, when the hoop 14 is folded by the synchronous drive mechanism, the main reflecting mirror 13 is stored, and at the same time, the supports 17, 28 are reduced and folded so as to be bent. Therefore, unlike a conventional antenna, there is no need to provide a support at the center for deployment and storage of the main reflector. Accordingly, radio interference due to the presence of the center support does not occur, and a sufficient antenna gain can be obtained. Further, the use efficiency of the main reflecting mirror does not decrease. This effect is the same as that of a general parabolic antenna, but is unique as a structure that can be folded small and has high rigidity.

Further, in the first embodiment, a rigid hoop 14 is arranged on the outer periphery of the main reflecting mirror 13, and the hoop 14 is provided with a sub-reflecting mirror.
Since the secondary radiator 12 and the primary radiator 11 are fixed via the secondary mirror support 17 and the hoop support 28, the rigidity of the whole deployed antenna can be increased and a stable structure can be achieved. As described above, since high rigidity is obtained, the mirror surface accuracy of the main reflecting mirror 13 formed of a mesh can be improved. This is because, when adjusting the main reflector, tension is normally applied to the wire, but if the stiffness of the hoop 14 and the supports 17, 28 serving as the basis for this tension adjustment is weak, the base is deformed for each adjustment. It is because.

Further, since the hoop 14 and the supports 17 and 28 can be simultaneously deployed, an antenna having a simple deployment operation and a small number of components can be realized.

Further, as shown in FIGS. 3 and 4, most of the secondary mirror support 17 and the hoop support 28 are stored inside the folded hoop 14, so that the storage efficiency of the deployed antenna is reduced. Can be very high. Also, when the deployable antenna is transported, it is extremely easy to transport because the antenna housing structure has no projection. Furthermore, the anti-lock device required for launching the deployable antenna into outer space is sufficient if only wires surrounding the deployable antenna are installed. Therefore, peripheral devices can be greatly simplified.

Furthermore, the presence of a lock mechanism (not shown) for restraining the hoop arm to the joint after deployment of the antenna allows the hoop and support to maintain high rigidity throughout the deployment of the antenna, and the main reflector Mirror accuracy can be further improved.

Although the hoop according to the first embodiment is formed in a regular hexagon, the hoop is not necessarily required to be a hexagon and is not limited to the number of corners. However, if it is not a regular polygon, it cannot be completely folded.

Further, while the supports 17, 28 are configured to fold inside the hoop 14, these supports may be configured to fold outside the hoop. In this case, it is disadvantageous in terms of storage efficiency, but has an advantage that it does not hinder the folding of the main reflecting mirror. Further, the supports 17, 28 may be constituted by a member that can be extended and contracted or a linear actuator.

FIG. 5 shows a deployment antenna according to a second embodiment of the present invention.

In this embodiment, the primary radiator 11 is arranged at the center of the main reflecting mirror 13. Further, six hoop supports 28 are provided, and these connect the lower sides of the joints 15a to 15f of the hoop and the fixing bracket 23.

Further, a wire 31 is stretched between the three secondary mirror supports 17. Similarly, below the joints 15b, 15d, 15f,
Between the hoop support 28 related to the joints 15a, 15c, 15e,
A wire 32 is stretched. Of course, the wires 32 may be stretched to connect the hoop supports 28.

As described above, three or more hoop supports 28 are provided, and the sub mirror support 17 and the joints 15a to 15f and the hoop support 28 are connected by the wires 31,32. Therefore, the rigidity of the deployable antenna can be increased as compared with the first embodiment. Thereby, the mirror accuracy of the antenna can be further improved.

Of course, it is possible to increase the number of the secondary mirror supports 17, but it is necessary to use a thin member so as not to interfere with radio waves. On the other hand, the hoop support 28 does not cause interference with radio waves, so that the hoop support 28 can be used as a fixed point of a cable or the like that supports the main reflecting mirror 13 formed of a mesh. Therefore, the hoop support 28 can be used as a basis for adjusting the mirror accuracy of the main reflecting mirror.

Next, a structure of a synchronous drive mechanism suitable for synchronously driving the hoop of the deployable antenna according to the present invention will be described with reference to FIGS. 6A to 8.

First, as shown in FIG. 7, in order for the hoop 14 to be unfolded and folded correctly, θ shown in FIG.
Arms 16a, 16b while ₁ and θ ₂ are maintained at the same value.
Needs to be driven relative to joint 15b, and the seventh
The joint is maintained while θ ₂ and θ ₃ shown in the figure are maintained at the same value.
15b and 15c need to be driven with respect to the arm 16b.

Therefore, maintaining the angle between the one joint 15b and one arm 16a connected thereto and (theta _1), the angle between the joint 15b and the other arm 16b connected thereto (theta ₂₎ and the equally Meanwhile, a first synchronization unit 41 that synchronizes these two arms 16a and 16b and rotates them relative to the joint 15b
When the first synchronization unit 41 is driven, the angle (θ) between one arm 16b and one joint 15b connected thereto is set.
₂ ) While keeping the angle (θ ₃ ) between the arm 16b and the other joint 15c connected to the arm 16b equal to each other, the second joint 15b and 15c are rotated with respect to the arm in synchronization with each other. And a synchronization unit 42 are provided.

The first and second synchronization units 41 and 42 will be described with reference to FIGS. 6A and 8. FIG. 6A is a diagram showing a specific configuration of the synchronization unit, and FIG. 8 is a diagram schematically showing a configuration of the synchronization unit.

A pair of rotating shafts 43 are rotatably supported by the joints 15b by bearings 43a. A pair of first shafts is attached to these pair of rotating shafts 43.
Pulley 44 is firmly fixed. A first wire 45 is wound around the pair of first pulleys 44 in a cross shape.
Although not shown in FIG. 8, as shown in FIG. 6A, these first pulleys 44 are not arranged in parallel but are arranged obliquely to each other. Therefore, as best shown in FIG. 6B, four guide rollers 46 are provided to prevent the first wire 45 from becoming entangled.

The ends of the arms 16a and 16b are fixed to these rotating shafts 43, respectively. Therefore, when one rotation shaft 43 rotates,
One of the first pulleys 44 rotates, and accordingly, the first wire 45 moves by the rotation angle of the first pulley 44, whereby the other first pulley 44 is moved to the first first pulley 44. As a result, the other rotating shaft 43 also rotates by the same angle as the one rotating shaft 43. As described above, the first wire 45 is wound in a cross shape. Therefore, one rotation shaft 43 and the other rotation shaft 43 rotate in directions opposite to each other.

Therefore, as shown in FIG.
After _one rotation of 180 ° -θ, the arm 16b makes _one rotation of 180 ° -θ, and the other rotating shaft 43 also has the same angle of 180 ° -θ.
₂ (= 180 ° -θ ₁ ), and the arm 16a
Rotate 180 ° -θ _twice , the same angle as 16b. That is, the arms 16a,
16b rotates synchronously. Thus, the first synchronization unit 41 is configured.

The driving force applying means for rotating one of the rotating shafts 43 includes:
As shown in FIG.6A, a motor 47 is provided,
The drive shaft of the motor 47 is connected to the rotation shaft 43 via a coupling 47a. In this case, the motor may be provided at at least one location. Also, instead of this motor 47, as shown in FIG. 6A,
A torsion coil spring 48 may be used. That is, the coil spring 48 is screwed when the hoop is stored. When the hoop is deployed, the coil spring 48 is loosened, and the restoring force is applied to the rotating shaft 43 as a rotating force. In this case, a means for fixing the hoop in the housed state is required. As this means, means for binding the entire hoop with a wire, means for fitting a ring member, and the like are employed, but are not particularly limited.

 Next, the second synchronization unit will be described.

A pair of second pulleys 51 are connected via a bearing 52 to a pair of rotating shafts.
Instructed to rotate to 43. As shown in FIG. 8, the second pulley 51 of one joint 15b and the other joint 15c
The second wire 53 is wound around the second pulley 51. The second pulley 51 is fixed to the joints 15a, 15b
It is fixed to.

Accordingly, in FIG. 8, when the rotation shaft 43 of the joint 15b rotates and the arm 16b rotates accordingly, the joint 15c and the second pulley 51 thereof rotate relative to the rotation shaft 43. Will do. That is, although the arm 16b actually rotates, the joint 15c fixed to the arm 16b
Of the joint 15b revolves around the rotation axis 43 of the joint 15b, and accordingly, the joint 15c revolves around the rotation axis 43 of the joint 15b.

Accordingly, the second wire 53 rotates by the rotation angle of the second pulley 51 of the joint 15c, and the second pulley 51 of the joint 15b also rotates by the same rotation angle relative to the rotation shaft 43 thereof. As a result, the joint 15b also rotates relative to the rotation axis 43. That is, the joint 15b and the joint 15c are driven in synchronization with the arm 16b.

Specifically, as shown in FIG.
When 80 ° - [theta] ₂ is rotated, the joint 15c and the second pulley 51 of which is, 180 ° - [theta] _{3 (=} 180 ° - [theta] with respect to the arm 16b
₂ ), the joint 15b and the second pulley 51 thereof are also rotated at the same angle 180 by the action of the second wire 53.
Only DEG - [theta] ₂ to rotate relative to the arm 16b. Thus, the second synchronization unit 42 is configured.

As described above, when the rotation shaft 43 is rotated, the arms 16a and 16b are driven by the first synchronization unit 41 in synchronization with the joint 15b, and the joints are driven by the second synchronization unit 42.
The joint 15b and the joint 15c are driven in synchronization with the arm 16b. Therefore, all the arms and joints constituting the hoop are driven synchronously.

As described above, since the synchronization unit is constituted by the pulley and the wire, the number of parts is small, the assembly is easy, the weight is low, and the reliability is high. In particular, a deployment mechanism incorporating the synchronous drive mechanism according to the present invention is more suitable for a deployment mechanism for space than using a gear or the like from the viewpoint of vacuum lubrication.

Next, a modified example of the synchronous drive mechanism will be described with reference to FIGS. 9 and 10. FIG. This modification mainly relates to a modification of the first synchronization unit 41.

That is, with respect to one rotation shaft 43, two first pulleys
44a and 44b are fixed. One first wire 63a is hung between the first pulley 44a of one rotating shaft 43 and the first pulley 44a of the other rotating shaft 43 via guide rollers 61 and 62. I have. The ends of the one first wire 63a are fixed to the first pulley 44a via metal fittings (not shown). Similarly, the first pulley of one rotating shaft 43
44b and the first pulley 44b of the other rotating shaft 43,
One first wire 63b is hung via the guide rollers 64 and 65.

Also in this case, when the first pulleys 44a, 44b fixed thereto rotate with the rotation of the one rotation shaft 43, the other rotation shaft 43 and the first pulleys 44a, 44a, 44
b rotates in the opposite direction, so that the arms 16a and 16b
Rotate synchronously with b. Therefore, all the arms and joints constituting the hoop are driven synchronously.

In this modified example, the wiring of the wire at the joint is easier than in the above-described embodiment, and the length and tension of the first wire can be adjusted. Although not particularly shown, the length and tension of the first wire can be adjusted by an operator inserting a hand or a tool through an opening formed in the arm.

FIG. 11 shows a deployment antenna according to a third embodiment of the present invention. In this figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The deployment antenna 100 includes a primary radiator 11 and a sub-reflector 12.
A main reflector 13, three sub-mirror supports 101 a, 101 b, 101 c supporting the sub-reflector 12, and a hoop 14 supporting, for example, the main reflector 13 formed of a mesh around the sub-mirror 13. 3. Fix the hoop 14 to the satellite structure 10 via the fixing bracket 23.
It is composed of book hoop supports 102a, 102b, 102c.

The hoop 14 has six arms 16a, 16b, 16c, 16d, 16e,
16f and six joints 15a, 15b, 15c, 15d, 15e, and 15f. Joints 15a, 15b, 15c, 15d, 15e, 15f
Three of the joints 15b, 15d, and 15f have a secondary mirror support 101a,
The joint fitting 18 for connecting 101b and 101c is another 3
Hoop supports 102a, 102b, 1 are provided for each joint 15a, 15c, 15e.
Joint fittings 26 for connecting 02c are fixed respectively.

The difference between FIG. 11 and FIG. 1 is that the secondary mirror supports 101a, 101b,
That is, the position of the joint where the 101c and the hoop supports 102a, 102b, 102c are connected is different. Also, the secondary mirror supports 101a, 101b, 101c and the hoop supports 102a, 102b, 102c
Is not a foldable member but a linear member. Also, the joints 103 and 104 are provided with secondary mirror supports 101a, 101b and 101c and hoop supports 102a and 102b,
It is provided at both ends of 102c. A lock mechanism (not shown) is mounted on each of the joints 103 and 104. The secondary mirror supports 101a, 101b, 10
1c and the hoop supports 102a, 102b, 102c are similarly firmly fixed to the locked hoop 14. Also, each joint
Torsional coil springs can be attached to 103 and 104 to apply a deployment force.

In the deployable antenna 100 having such a configuration, similarly to the first embodiment, a rigid hoop 14 is arranged on the outer periphery of the antenna, and the sub-reflecting mirror 12 is mounted on the hoop 14 with the sub-mirror supports 101a and 101a.
Since it is fixed via b and 101c, the overall rigidity is high and the structure is stable. In addition, this deployment antenna 100
Are different from the first embodiment in that the secondary mirror supports 101a, 101b, 10
1c and hoop support 102a, 102b, 102c have less freedom,
It has a simpler mechanism. Therefore, in the embodiment shown in FIG. 11, the degree of freedom of the secondary mirror supports 101a, 101b, 101c and the hoop supports 102a, 102b, 102c is reduced due to the restriction of the shape after storage, the deployment operation is simplified, and the weight is reduced. Therefore, a highly reliable deployable antenna can be realized.

Further, since the deployable antenna 100 has no structure at the center of the antenna similarly to the first embodiment, it has a very advantageous structure electrically. In FIG. 11, hoop 14
Is composed of hexagons, but need not be hexagonal, and is not limited to the number of corners. However, it cannot be completely folded unless it is a regular polygon.

Next, FIG. 12 and FIG.
This will be described with reference to FIG. Figure 12 shows the deployment antenna 100
It is a perspective view in the middle of folding. Figure 13 shows the deployment antenna
FIG. 3 is a perspective view after 100 is stored.

The joints 15a, 15b, 15c, 15d, 15
Each of e and 15f is provided with two hinges (bearings) having one degree of freedom, and two arms are attached to one joint so as to be freely rotatable. In a position where the arm is completely opened (when forming a hexagon), the joint and the arm are connected by a lock mechanism (not shown), and the rotation is restricted. Conversely, when fully folded, the six arms 16
a, 16b, 16c, 16d, 16e, 16f are parallel, and three joints 15a,
15c and 15e are located on the upper side, and the remaining three joints 15b, 15d and 15f are located on the lower side. Secondary mirror support 101a, 101b, 10
1c is the lower joints 15b, 15d, 15f, and the hoop supports 102a, 102b, 102c are the upper joints 15a, 15c.
c and 15e respectively. For this reason, after storage, these secondary mirror supports 101a, 101b, 101c and hoop supports 102a, 102b, 102c are connected to the arms 16a, 16b, 16c, 16d, 16e, 16
Stored between f. Therefore, as in the first embodiment, the secondary mirror supports 101a, 101b, 101c and the hoop supports 102a,
02b and 102c are not folded inside the hoop 14.

In such a deployment antenna, the secondary mirror support 101a, 101b, 101c and the hoop support
Mechanical interference between 102a, 102b, 102c and main reflecting mirror 13 can be eliminated. Therefore, in the structure of the deployed antenna, the deployment of the mesh antenna serving as the main reflecting mirror 13 is not hindered, and the reliability can be improved as compared with the first embodiment. Further, since the hoop 14 and the secondary mirror supports 101a, 101b, 101c and the hoop supports 102a, 102b, 102c are simultaneously deployed, an antenna with a simpler deployment operation and a reduced number of components can be realized.

After storing the deployable antenna 100, the secondary mirror support 101a,
101b, 101c and hoop support 102a, 102b, 102c,
The hoop 14 is housed so as to be inserted between the arms constituting the hoop 14, does not interfere with the folded main reflector 13, and has a structure with high storage efficiency. Further, such a structure of the deployable antenna has a structure that is very portable because there is no protrusion. Furthermore, it is sufficient for the lock device necessary for launching the deployable antenna to the outer space to be installed around the wire that bundles the deployable antenna. Therefore, peripheral devices can be greatly simplified. In FIG. 13, the secondary mirror supports 101a, 101b, 101c
And the hoop supports 102a, 102b, 102c are depicted by a single member, but if these secondary mirror support and hoop support are structured to expand and contract as seen in the antenna of a car, the height of the stored state can be increased. It can be shortened, and the storage efficiency can be further improved. This method is particularly effective when the number of corners of the hoop is increased, and the secondary mirror support and the hoop support do not hinder the folding of the main reflector.

The present invention is not limited to the embodiment described above. That is, the above-described synchronous driving mechanism for an annular body can be used for something other than an antenna. For example, it is suitable for opening and closing tents, umbrellas, large antennas, and the like.

Further, the deployable antenna of the present invention extends the three secondary mirror supports 101a, 101b, 101c by telescope means or the like,
The gain can be increased by adjusting the angle of the sub-reflector.

[Effect of the Invention] In the present invention, since the sub-reflector is supported by a plurality of sub-mirror supports, there is no structure that interferes with radio waves at the center of the main reflector. Therefore, it is possible to configure the deployable antenna in consideration of the simplicity of the electric design. In addition, the secondary mirror support, the hoop support, and the hoop are all configured by an unfolding mechanism, and the unfolding mechanism is simultaneously folded. A highly efficient structure can be realized.
On the other hand, since the secondary mirror support, the hoop support, and the hoop are all disposed outside the antenna after deployment, an integrated structure with high overall rigidity can be realized. Since the rigidity can be increased in this way, the mirror surface accuracy of the main reflecting mirror can be sufficiently ensured. In particular, since the hoop support does not interfere with radio waves, there is an advantage that the hoop support can be used as a fixed point of a cable or the like that supports a main reflector formed of a mesh.

Since the deployment antenna of the present invention can increase the number of hoop supports, and can install wires between the secondary mirror support and between the hoop support and the hoop joint,
It is lighter and more rigid than conventional antennas. Further, a hoop support can be used as a reference point required for adjusting the mirror surface accuracy.

Further, in the present invention, since a wire and a pulley having a simple structure are used as the synchronous drive mechanism of the hoop member, a highly reliable and lightweight structure can be realized.

Further, the driving means of the hoop and the synchronous driving mechanism of the hoop are constituted by wires and pulleys. Therefore, the reliability of deployment is high, and the entire apparatus can be made a lightweight structure.

[Brief description of the drawings]

FIG. 1 is a perspective view of a deployable antenna according to a first embodiment of the present invention, FIG. 2 is a perspective view of a hoop showing the hoop of the deployable antenna shown in FIG. 1 in the middle of folding, and FIG. 1
FIG. 4 is a side view of the upper part of the deployable antenna showing how the secondary mirror support is folded, FIG. 4 is a perspective view of the deployable antenna in a stored state, and FIG. 5 is a deployable antenna according to a second embodiment of the present invention. FIG. 6A is a view showing a synchronous drive mechanism of a hoop (annular body) according to the present invention, and is a sectional view of an arm and a joint constituting the hoop (annular body). FIG. 6B is a sectional view of FIG. FIG. 7 is a schematic view showing the arrangement of the guide rollers and wires, FIG. 7 is a schematic view showing the movement of the arms and joints of the hoop (annular body), and FIG. FIG. 9 is a perspective view schematically showing the principle of the present invention, and FIG. 9 is a view showing a synchronous drive mechanism of the hoop (annular body) according to the present invention, and is a cross-sectional view of an arm and a joint constituting the hoop (annular body) FIG. 10 is a schematic diagram showing the arrangement of the guide rollers and wires of FIG. Fig, 11 Fig third of the present invention
FIG. 12 is a perspective view of the deployment antenna according to the embodiment of the present invention, FIG. 12 is a perspective view showing the deployment antenna shown in FIG. 11 in the middle of folding,
FIG. 13 is a perspective view of a stored state of the deployable antenna shown in FIG. 11, and FIG. 14 is a perspective view of a conventional deployable antenna. 10 ... satellite structure (base), 11 ... primary radiator (radio wave supply means), 12 ... sub-reflector (radio wave supply means), 13 ... main reflector, 14 ... hoop (annular body), 15a ~ 15f …… joint,
16a to 16f: arm, 17: secondary mirror support (first support), 28: hoop support (second support), 4
1,42... First and second synchronization units (driving means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 1/00-1/10 H01Q 1/27-1/52 H01Q 15/00-19/32

Claims (6)

(57) [Claims] 1. An expandable main reflector, radio wave supply means disposed on one side of the main reflector and supplying radio waves for reflection by the main reflector, A base disposed on the other side, a plurality of joints and an arm are alternately connected to each other, and a hoop supporting a plurality of locations at an outer end of the main reflector; and a hoop disposed in the joint and the arm. While the two arms connected to one joint are separated from each other and all arms are synchronously driven with respect to the joints, the hoop is deployed to deploy the main reflector,
A driving means for a hoop that folds the hoop and stores the main reflector by synchronizing and driving all arms with respect to the joint such that two arms connected to one joint are close to each other; A plurality of first connecting the hoop and the radio wave supply means.
And a plurality of second supports for connecting the base and the hoop. 2. A plurality of first supports for connecting said hoop and said radio wave supply means extend when said hoop is deployed, supporting said radio wave supply means with respect to said hoop, and folding said hoop. The deployable antenna according to claim 1, wherein the deployable antenna is sometimes reduced. 3. The plurality of second supports connecting the base and the hoop extend when the hoop is deployed to support the hoop relative to the base and contract when the hoop is folded. The deployment antenna according to claim 1, wherein: 4. The driving means for the hoop maintains an angle between one joint and one arm connected thereto substantially equal to an angle between this joint and the other arm connected thereto. A first synchronizing unit that synchronously rotates these two arms with respect to the joint; and, when the first synchronizing unit is driven, forms one arm and one joint connected thereto. A second synchronization unit for synchronously rotating the two joints with respect to the arm while maintaining the angle and the angle between the arm and the other joint connected thereto substantially equal. The deployment antenna according to claim 1, wherein 5. One of the joints has a pair of rotation shafts rotatably supported, the first synchronization unit includes a pair of first pulleys fixed to the pair of rotation shafts, respectively, A first wire wound around the pair of first pulleys in a cross shape, wherein the second synchronization unit is rotatably supported by the pair of rotation shafts, respectively, and A fixed pair of second pulleys, and a second wire wound around the second pulley of the joint and the second pulley of the joint next to the joint. The deployable antenna according to claim 4, wherein 6. A synchronous driving mechanism for an annular body for unfolding or folding an annular body in which a plurality of joints and arms are alternately connected, wherein one joint and one arm connected thereto are provided. A first synchronizing unit for synchronously rotating the two arms with respect to the joint while maintaining substantially the same angle between the joint and the other arm connected thereto; When the first synchronization unit is driven, the angle formed between one arm and one joint connected thereto and the angle formed between this arm and the other joint connected thereto are kept substantially equal. A second synchronizing unit for synchronizing these two joints and rotating with respect to this arm; and applying a driving force to the first synchronizing unit so that the two arms connected to one joint are separated from each other. And said Driving force applying means for applying a driving force to the first synchronization unit and folding the annular body so that the two arms connected to one joint are close to each other while deploying the body, The one joint has a pair of rotation shafts rotatably supported, the first synchronization unit includes a pair of first pulleys fixed to the pair of rotation shafts, and the pair of first pulleys. A first wire wound around the pulley in a cross shape, wherein the second synchronization unit is rotatably supported by the pair of rotation shafts, and is fixed to the joint. A second pulley; and a second wire wound around a second pulley of the joint and a second pulley of a joint next to the joint. Drive mechanism.