JP2001127535A - Expandable antenna reflecting mirror - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems of a conventional expandable antenna reflecting mirror that disturbance to the attitude is increased and a heat generated in a space unit cannot efficiently be dissipated because a membrane consisting of metallic meshes 2 whose size is nearly equal to a size of a large-sized radio wave reflecting plane is to be added to a rear side of an antenna mirror face in the case that a space use expandable antenna adopts a method that an entangling prevention membrane 7 is added to a rear side cable network 3 in order to prevent a capable network 23 keeping the shape of mirror surface from being entangled. SOLUTION: In this expandable antenna reflection mirror, plain knitting, tricot knitting, plain cord knitting, single atlas knitting, or double needle tricot wrap knitting with large meshes of knitting providing a high transmissivity is adopted for the membrane tensed in a way that its surrounding is surrounded by cables among the entire cables or parts of the cables in order to prevent the cable network 3 to keep the mesh shape of the mirror face from being entangled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflector for a large deployable antenna mounted on space equipment such as an artificial satellite.

[0002]

2. Description of the Related Art Larger antenna reflectors for space are required with the expansion of space use. This type of antenna is used by attaching it to a spacecraft such as an artificial satellite or a space station via a bracket or boom, etc., but since the launcher storage space at launch is limited, it is launched in a small folded state, The system is deployed in outer space. FIG. 6 shows an example of a deployable antenna reflector that has been conventionally studied. In FIG. 6, reference numeral 2 denotes a foldable metal mesh constituting a reflector surface, and reference numeral 3 denotes a foldable cable that retains the shape of the metal mesh 2. The network 4 is a tie cable connecting the mirror-side cable network 3a and the rear-side cable network 3b, and 5 is a network that deploys the metal mesh 2 and the cable network 3 on orbit, and that retains the metal mesh 2 and the cable network 3 after deployment. Structure 6 is a connector for collecting and connecting a plurality of cables, and 7 is a membrane surface stretched so as to surround the entire or a part between the cable networks 3 in order to prevent the cable networks 3 from being entangled. is there. The cable network 3 is made of a Kevlar cord having a low coefficient of linear expansion, high strength and high rigidity. The structure is a mirror-side cable network 3a stretched in a triangular shape to press the metal mesh 2 into a mirror-like shape. A tie cable 4 for pulling the mirror-side cable network 3a in the reverse direction (the side opposite to the radio wave reflection surface), and a rear-side cable network 3b that supports the other end of the tie cable 4 and extends in a triangular shape like the mirror side. , And the mirror-side cable network 3a is integrated with the metal mesh 2 while being sewn.
This antenna is housed in a rocket fairing having a diameter of about 2 m to 4 m, and is deployed in orbit after launch. At that time, the entanglement of the cable network 3 makes it impossible to deploy the antenna and causes loss of the entire mission. As an example of the entanglement, the connector 6 goes to the opposite side to the position where it should be originally located with respect to the other cable, and the other cable gets stuck before it returns to the correct position and cannot be returned. In some cases, the cable itself or another cable is bound and bound in such a way as to form a knot, and the restraint cannot be released even if the cable is stretched. As a countermeasure, a film surface is formed by stretching an entanglement prevention film 7 in which a plurality of yarns are stretched around the whole or a part of the cable network 3 so as to be surrounded by a cable in a vertical or horizontal direction. By causing the cable to behave as a single film in the housed state and during deployment, it has been performed to prevent the cable from becoming entangled as would occur when there is no film surface.

[0003]

However, since a film having substantially the same size as the large radio wave reflecting surface constituted by the metal mesh 2 is further added to the back side of the mirror surface of the antenna, the additional film is required. However, the satellite receives a lot of pressure from the solar wind, resulting in an increase in attitude disturbances that disturb the attitude of the satellite, and a large film surface enters the heat radiation field of view of the spacecraft body, which is generated in the spacecraft There is a problem that the generated heat cannot be efficiently dissipated.

The present invention has been made to solve the above-mentioned problems, and has an anti-entanglement film which has high deployment reliability, has small attitude disturbance, and does not hinder the heat radiation field of view of the spacecraft body. It is intended to obtain a deployable antenna reflector.

[0005]

The deployable antenna reflector according to the present invention is entirely or partially surrounded by a cable so as not to cause entanglement in the cable network 3 holding the mirror-surface mesh shape. The membrane surface stretched in a shape is a plain weave of open spaces with high transmittance, tricot knitting, plain cord knitting, single atlas knitting, or double needle tricot wrap knitting.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a view for explaining a first embodiment according to the present invention, and is a view showing a configuration of an open plain weave used for an entanglement prevention film 7 for preventing entanglement of a cable network 3 of a deployable antenna reflector. is there. This membrane is composed of vertical and horizontal fibers that intersect sequentially, and the distance between adjacent fibers is widely taken up to 50 mm. Other configurations are the same as those of the related art. In the figure, reference numeral 1 denotes a fiber constituting a woven fabric, in which an aramid fiber of 50 denier is used.
Other fibers can be used as long as required properties such as rigidity, coefficient of linear expansion, rate of deformation due to moisture absorption, radiation resistance, and ultraviolet resistance are satisfied. Since this film has a small number of fibers per unit width, the transmittance of electromagnetic waves can be increased. For example, when a film having a transmittance of 50% is used,
Of the attitude disturbances caused by the solar wind, the disturbances increased by adding the film surface can be halved. As for the heat radiation visual field interference, for example, when a film having a transmittance of 50% is used, half of the visual field area obstructed by the added film is transmitted, so that the interference rate can be halved. Thus, by using a film having a high transmittance, the attitude disturbance can be reduced, and the rate of obstructing the heat radiation field of view of the spacecraft body can be reduced. The entanglement prevention film 7
If the eyes are too wide, the entanglement such that the connectors 6 and other protrusions enter the eyes and do not come off occurs, and the interval between the adjacent fibers satisfies the transmittance. It is desirable to select an appropriate value within the range.

Embodiment 2 FIG. 2 is a view for explaining a second embodiment according to the present invention, and is a diagram showing a tricot knitting structure used for an entanglement prevention film 7 for preventing entanglement of the cable network 3 of the deployable antenna reflector.
The tricot knitting is described in “Ken Hen Zenshu” (published by Textile Technology Journal Co., Ltd.), published on October 1, 1982, edited by Nippon Meyer K.K. This knitted fabric has high transmittance,
Are intertwined in a loop, so that there is no misalignment and the eyes do not spread. If the eyes are too wide, the entanglement occurs such that the connectors 6 and other protrusions will not enter the eyes and will not come off. Therefore, the tricot knit, which does not widen the eyes, is suitable as a film for preventing entanglement. I have.

Embodiment 3 FIG. 3 is a view for explaining a third embodiment according to the present invention, and is a diagram showing a configuration of a plain cord knitting used for an entanglement prevention film 7 for preventing entanglement of the cable network 3 of the deployable antenna reflector. . The plain cord knitting is described in the “warp knitting complete collection” described in the second embodiment. Since this knitted fabric has a high transmittance and can be flat on the back surface, the surface is smooth and the resistance due to rubbing between the developing surfaces can be reduced.

Embodiment 4 FIG. 4 is a view for explaining a fourth embodiment according to the present invention, and is a view showing a configuration of a single atlas knitting used for an anti-entanglement film 7 for preventing an entanglement of a cable network 3 of a deployable antenna reflector. . The single atlas knitting is shown in the “Warp knitting complete collection” described in the second embodiment. This knitted fabric has high transmittance, but is less likely to be frayed because the fibers 1 are arranged in a zigzag pattern, and reduces the possibility of damage to the entanglement prevention film 7 when it is repeatedly deployed in the manufacturing and testing processes on the ground. You can do it.

Embodiment 5 FIG. 5 is a view for explaining a fifth embodiment according to the present invention, and is a view showing a configuration of a double needle tricot wrap knitting used for an anti-entanglement film for preventing an entanglement of a cable network 3 of a deployable antenna reflector. is there. The double needle tricot wrap knitting is shown in the “Warp knitting complete works” described in the second embodiment. While having high transmittance, this knitted fabric has a large in-plane elongation that can reduce the effect on shape accuracy after deployment, and has a feature that is robust and difficult to unravel, so it is repeatedly deployed in the manufacturing and testing processes on the ground In this case, the possibility that the entanglement prevention film 7 is damaged can be reduced.

[0011]

According to the deployable antenna reflector according to the present invention, the entanglement can be reliably prevented by the film surface of the entanglement prevention film stretched between the cable networks, and furthermore, the film surface due to the solar wind caused by the film surface can be prevented. An increase in attitude disturbance and a decrease in the heat radiation field of view of the spacecraft main body can be reduced, and the mountability to the spacecraft can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an open plain weave used for an entanglement prevention film according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a tricot knitting structure used for an anti-entanglement film according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of plain cord knitting used for an anti-entanglement film according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a single atlas knitting used for an anti-entanglement film according to a fourth embodiment of the present invention.

FIG. 5 is a view showing a configuration of a double needle tricot wrap knitting used for an anti-entanglement film according to a fifth embodiment of the present invention.

FIG. 6 is a diagram showing an example of a deployable antenna reflecting mirror according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiber 2 Metal mesh 3 Cable network 3a Mirror side cable network 3b Back side cable network 4 Tie cable 5 Deployment structure 6 Connector 7 Membrane surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 1/28 H01Q 1/28 15/14 15/14 Z F term (Reference) 4L002 AA06 AC07 CA01 CA02 EA04 EA05 FA06 4L048 AA25 AA42 AA44 AA48 BA01 BA02 CA15 DA24 5J020 AA03 BA09 BA19 BD04 CA02 CA05 5J046 AA07 AA09 AA19 AB18 AB19 DA01 DA02 KA03 KA04 KA07 PA07 PA09

Claims (6)

[Claims] 1. A metal mesh forming a radio wave reflecting surface of an antenna, a cable network holding the shape of the metal mesh, and a entanglement formed so as to be entirely or partially surrounded by a cable between all or a part of the cable network. Having a membrane to prevent, and expand the metal mesh and the cable network from a folded state,
A deployable antenna reflector having a deployable structure for holding the metal mesh and the cable network after deployment, wherein the entanglement prevention film is a plain weave with high transmittance of electromagnetic waves. 2. A metal mesh forming a radio wave reflection surface of an antenna, a cable network retaining the shape of the metal mesh, and a entanglement formed by being surrounded by a cable over the whole or a part of the cable network. Having a membrane to prevent, and expand the metal mesh and the cable network from a folded state,
A deployable antenna reflector having a deployable structure for retaining the metal mesh and the cable network after deployment, wherein the entanglement prevention film is a tricot knitted fabric having high electromagnetic wave transmittance. 3. A metal mesh forming a radio wave reflection surface of an antenna, a cable network holding the shape of the metal mesh, and a entanglement formed so as to be surrounded by a cable in a whole or a part between the cable networks. Having a membrane to prevent, and expand the metal mesh and the cable network from a folded state,
A deployable antenna reflector having a deployable structure for retaining the metal mesh and the cable network after deployment, wherein the entanglement prevention film is a plain cord knitted fabric having high electromagnetic wave transmittance. 4. A metal mesh forming a radio wave reflection surface of an antenna, a cable network retaining the shape of the metal mesh, and a entanglement formed so as to be surrounded by a cable on the whole or a part of the cable network. Having a membrane to prevent, and expand the metal mesh and the cable network from a folded state,
A deployable antenna reflector having a deployable structure for holding said metal mesh and cable network after deployment, wherein said entanglement preventing film is a single atlas knitted fabric having high electromagnetic wave transmittance. 5. A metal mesh forming a radio wave reflecting surface of an antenna, a cable network holding the shape of the metal mesh, and a entanglement formed so as to be surrounded by a cable in a whole or a part between the cable networks. Having a membrane to prevent, and expand the metal mesh and the cable network from a folded state,
In the deployable antenna having a deployable structure for holding the metal mesh and the cable network after deploying, the deployable antenna reflection is characterized in that the entanglement preventing film is a double needle tricot wrap knitted fabric having high electromagnetic wave transmittance. mirror. 6. The electromagnetic wave has a transmittance of 50% to 98%.
The deployable antenna according to any one of claims 1 to 5, further comprising: