JP2012138777A - Antenna reflector and correction method for radio wave reflection mirror plane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: a radio wave reflection mirror plane of an antenna reflector installed on an artificial satellite uses a composite material formed from carbon fiber or the like in view of weight reduction, radio wave reflection properties and shape stability, and when the composite material is employed for a radio wave reflection mirror plane, a process for hardening resin under a semi-cured state in the manufacturing process is required; however, in the curing process, the mirror plane precision of the reflector is generally deteriorated because molding distortion is generated in the composite material.SOLUTION: A radio wave reflective member is mounted at a generation position of molding distortion of a radio wave reflection mirror plane by a hardening process. The mounting of the radio wave reflective member is implemented by adhesive fixing, fiber bundle sewing or by other means. By locally disposing the radio wave reflective member, the shape of the radio wave reflection mirror plane is corrected to provide an antenna with high mirror plane precision.

Description

  The present invention relates to an antenna reflector provided in, for example, an artificial satellite.

  In general, the reflector of a reflector provided in an antenna for satellite installation is made of a composite material using carbon fiber or the like from the viewpoint of light weight, radio reflectivity, and shape stability. The structure of the reflector is, for example, a sandwich panel method in which the material of the radio wave reflecting mirror surface is a composite material, and the core layer is crimped from both sides with this composite material, a dual reflector method in which two reflectors are combined, and metal or a synthetic material is plated. There are various types of structures such as a mesh method in which the mesh is a radio wave reflecting mirror surface.

A manufacturing characteristic when the composite material is applied to a radio wave reflecting mirror surface is that a curing process for curing a semi-cured resin such as carbon fiber impregnated with the resin is necessary in the manufacturing process.
In the process of curing the resin in the composite material, molding distortion occurs in the composite material, so that the mirror surface accuracy of the reflector generally deteriorates.

  In addition, the radio wave reflecting mirror surface made of composite material has a bonding process with a member having rigidity such as the back structure, so that the mirror surface accuracy of the reflector is generally deteriorated due to the effect of hardening and shrinkage of the adhesive in the bonding process. To do.

Although the mirror surface accuracy is deteriorated due to such a cause, the deterioration of the mirror surface accuracy causes a defocus of the radio wave in the reflector, and the stability of satellite communication using the reflector is lowered.
Conventionally, for the purpose of suppressing the deterioration of the mirror surface accuracy of the reflector, various methods have been proposed, such as making the prepreg impregnated with resin into two layers (see, for example, Patent Document 1).

JP 2001-148611 A

In the antenna reflector described in Patent Document 1, the deformation due to molding distortion is reduced by combining the surfaces of the prepregs impregnated with a semi-cured resin into the triaxial fabric in the membrane reflector or the backs of the two layers. A method for suppressing the deterioration of the shape accuracy of the mirror surface is proposed.
However, although the method proposed in Patent Document 1 is effective when the target reflector is a membrane reflector, there is a problem that it cannot be applied to a reflector of a sandwich panel type other than the membrane reflector.

  In general, the membrane reflector requires a bonding process between the radio wave reflecting mirror surface and the back surface structure. However, in the method described in Patent Document 1, the mirror surface accuracy generated in the bonding process between the radio wave reflecting mirror surface and the back surface structure can be improved. There was a problem that deterioration could not be reduced.

  The present invention has been made in order to solve the problem, and an object thereof is to provide an antenna reflector capable of improving the stability of communication.

  The antenna reflector mounted on the artificial satellite according to the present invention includes a radio wave reflection material that is a separate component from the radio wave reflection mirror surface in a region of the radio wave reflection mirror surface of the antenna reflector.

  According to the present invention, it is possible to suppress the deterioration of the mirror surface accuracy that occurs during the manufacturing process of the antenna reflector when the composite material is used for the mirror surface, and it is possible to improve the stability of communication using the antenna reflector.

It is a perspective view which shows the electromagnetic wave reflector surface which concerns on Embodiment 1 of this invention. It is the figure which showed the front view of the electromagnetic wave reflector surface which concerns on Embodiment 1 of this invention. It is sectional drawing of the electromagnetic wave reflector surface which concerns on Embodiment 1 of this invention. It is a cross-sectional enlarged view of the radio wave reflecting mirror surface according to the first embodiment of the present invention. It is the figure which showed the partial front view of the electromagnetic wave reflector surface which concerns on Embodiment 2 of this invention. It is a cross-sectional enlarged view of the radio wave reflecting mirror surface according to the second embodiment of the present invention. It is the figure which showed the partial front view of the electromagnetic wave reflector surface which concerns on Embodiment 3 of this invention. It is a cross-sectional enlarged view of the radio wave reflecting mirror surface according to the third embodiment of the present invention. It is a figure showing the outline of the structure of the artificial satellite.

Embodiment 1 FIG.
FIG. 9 schematically shows a general artificial satellite. A main body 50 of the artificial satellite is provided with a solar cell panel 51, an antenna reflector 52, and the like. The antenna reflector 52 includes a curved radio wave reflecting mirror surface 1 (also referred to as a reflector 1), a back structure 53 provided on the back surface of the radio wave reflecting mirror surface 1, and supporting the radio wave reflecting mirror surface 1.

  FIG. 1 is a configuration example of a radio wave reflecting mirror surface 1 according to the first embodiment. The skin material 11a and the skin material 11b are adhered to both surfaces of the core material 12 such as aluminum with an adhesive, and form a sandwich structure reflector. Here, out of the skin materials 11a and 11b on both surfaces of the core material 12, the skin material 11a is a radio wave reflecting surface that reflects radio waves. As the material for the skin materials 11a and 11b, a composite material such as CFRP (carbon fiber composite material) is used from the viewpoint of light weight and shape stability due to low thermal expansion. As the core material 12, a lightweight honeycomb structure, that is, a honeycomb core is used.

  Next, a method for manufacturing the radio wave reflecting mirror surface 1 will be described. The carbon fiber woven fabric impregnated with the thermosetting resin and the core material are heated and cured on a mirror mold so that the resin is cured and the radio wave reflecting mirror surface 1 is formed. More specifically, the skin materials 11a and 11b after heat curing are brought into close contact with both surfaces of the core material 12 via an adhesive, and the skin materials 11a and 11b are bonded to the core material 12 by heating them. At this time, by applying a vacuuming pressure and a direct pressing force to the core material 12 and the skin materials 11a and 11b on the mirror mold, the skin material is elastically deformed, and the core material 12 and the skin materials 11a and 11b. The shape error is absorbed, and the skin material adheres to the core material. In this manner, the skin materials 11a and 11b are brought into close contact with the core material 12 to elastically deform the skin materials 11a and 11b, so that molding distortion generated during heat curing is removed and the radio wave reflecting mirror surface 1 is brought close to an ideal shape. Yes.

  Next, the antenna reflector 52 is manufactured by combining the radio wave reflecting mirror surface 1 with the back structure 53.

  A characteristic in the process of the antenna reflector 52 manufactured in this way is that a curing process is required in which a semi-cured resin such as carbon fiber impregnated with the resin is cured by heating. In this curing process, molding distortion occurs in the carbon fiber composite material, and the mirror surface accuracy of the radio wave reflecting mirror surface 1 deteriorates due to the remaining molding distortion.

  In the first embodiment, in order to correct this molding distortion, the specular surface is locally corrected using the radio wave reflecting material 2 as an additional part.

FIG. 2 is a front view of the radio wave reflecting mirror surface 1 according to the first embodiment. 3 is a cross-sectional view taken along line AA in FIG.
In the cross-sectional view of FIG. 3, the molding distortion 20 generated in the curing process remains on a part of the radio wave reflecting mirror surface 1, and the molding distortion 20 causes a mismatch with the designed mirror surface shape 100.
In the first embodiment, the radio wave reflecting material 2 as an additional part is locally added to the mismatched portion, so that the radio wave reflecting surface of the radio wave reflecting mirror surface 1, that is, the shape of the skin material 11a is the design mirror surface shape 100. Modify to match.

  The mismatched portion with the specular shape is identified by image processing using a camera image, for example. The shape is corrected by adding the radio wave reflecting material 2 to the identified skin material 11a.

Adhesive 3 is used for fixing the skin material 11 a and the radio wave reflecting material 2.
The material of the radio wave reflecting material 2 is preferably the same material as the skin material 11 of the radio wave reflecting mirror surface 1 from the viewpoint of shape stability due to temperature change in outer space.
Moreover, it is desirable to use an epoxy resin or a cyanate resin for the adhesive 3 from the viewpoint of heat resistance in outer space and outgas.

  As described above, in the antenna reflector according to the first embodiment, the radio wave reflecting material is bonded to the distorted portion of the radio wave reflecting surface generated by the curing process with the adhesive. As a result, the shape of the radio wave reflecting surface is corrected, and the stability of communication can be improved.

  Although the antenna reflector having the sandwich structure has been described in the first embodiment, the present invention may be applied to other antenna reflectors such as an antenna reflector using a membrane (film) as a radio wave reflecting surface, and the reflector method is not limited.

Embodiment 2. FIG.
In the first embodiment, the radio wave reflecting material 2 is bonded to the skin material of the radio wave reflecting mirror surface with an adhesive. However, in the second embodiment, the radio wave reflecting material 2 is sewn and fixed to the radio wave reflecting mirror surface using a fiber bundle. .
FIG. 5 is a diagram showing a front view of the radio wave reflecting mirror surface 1 at a location where the radio wave reflecting material 2 in Embodiment 2 is fixed. Here, the radio wave reflecting material 2 is sewn around the radio wave reflecting mirror surface 1 using a fiber bundle 4. FIG. 6 is a cross-sectional view taken along the line AA in FIG.
The shape and mounting position of the radio wave reflecting material 2 are the same as the shape and position of the region where the mirror surface shape of the radio wave reflecting mirror surface 1 does not match the designed mirror surface shape, and the radio wave reflecting material 2 matches the designed mirror surface shape. So that it is placed locally.
As a sewing method, holes are formed in the radio wave reflecting mirror surface 1 and the radio wave reflecting material 2 so that the fiber bundle penetrates in advance, and the fiber bundle is passed and fixed.
The material of the radio wave reflector 2 is preferably the same material as that of the radio wave reflector 1 from the viewpoint of shape stability due to temperature changes in outer space. The fiber bundle 4 is preferably made of carbon fiber having a low coefficient of thermal expansion or Kevlar fiber having radio wave permeability.

  As described above, in the antenna reflector according to the second embodiment, the radio wave reflecting material 2 is sewn by the fiber bundle 4 to the distorted portion of the radio wave reflecting surface generated by the curing process. As a result, the shape of the radio wave reflecting surface is corrected without going through a curing process by using an additional adhesive, and the stability of communication can be improved.

Embodiment 3 FIG.
In the second embodiment, the radio wave reflecting material 2 is sewn and fixed to the radio wave reflecting mirror surface using the fiber bundle 4, but in the third embodiment, the unidirectional material fiber reinforced resin 5 is used to fix the radio wave reflecting material. 2 is fixed to the radio wave reflecting mirror surface 1.
FIG. 7 is a front view of the radio wave reflecting mirror surface 1 at a location where the radio wave reflecting material 2 in Embodiment 2 is fixed. Here, the radio wave reflecting material 2 is sewn around the radio wave reflecting mirror surface 1 using a unidirectional material fiber reinforced resin 5. FIG. 8 shows an AA cross-sectional view of FIG.
The shape and mounting position of the radio wave reflecting material 2 are the same as the shape and position of the region where the mirror surface shape of the radio wave reflecting mirror surface 1 does not match the designed mirror surface shape, and the radio wave reflecting material 2 matches the designed mirror surface shape. So that it is placed locally.
As a sewing method, holes are formed in advance so that the unidirectional material fiber reinforced resin 5 penetrates the radio wave reflecting mirror surface 1 and the radio wave reflecting material 2, and the unidirectional material fiber reinforced resin 5 is passed through and fixed.
The material of the radio wave reflector 2 is preferably the same material as that of the radio wave reflector 1 from the viewpoint of shape stability due to temperature changes in outer space.
As the unidirectional material fiber reinforced resin 5, for example, a carbon fiber reinforced resin having a low coefficient of thermal expansion or a Kevlar fiber reinforced resin having radio wave permeability is preferably used.
As a procedure for fixing the radio wave reflector 2, the unidirectional fiber reinforced material before resin curing described in the present embodiment may be used, and after passing through the fiber bundle 4 as in the second embodiment, A procedure of impregnating with resin may be used.

  As described above, in the antenna reflector according to the third embodiment, the radio wave reflecting material 2 is sewn by the unidirectional material fiber reinforced resin 5 to the distorted portion of the radio wave reflecting surface generated by the curing process. As a result, the radio wave reflecting material 2 can be firmly fixed, the shape of the radio wave reflecting surface can be corrected, and the stability of communication can be improved.

  DESCRIPTION OF SYMBOLS 1 Radio wave reflecting mirror surface, 2 Radio wave reflecting material, 3 Adhesive agent, 4 Fiber bundle, 5 Unidirectional material Fiber reinforced resin, 11a, 11b Skin material, 12 Core material, 20 Molding distortion location, 50 Artificial satellite, 51 Solar cell panel, 52 Antenna reflector, 53 Back structure.

Claims (8)

An antenna reflector, comprising: a radio wave reflecting material that is a separate component from the radio wave reflecting mirror surface in an area of a radio wave reflecting mirror surface of an antenna reflector mounted on an artificial satellite. The antenna reflector according to claim 1, wherein the radio wave reflector is fixed to an area of the radio wave reflector surface with an adhesive. The antenna reflector according to claim 2, wherein the adhesive is an epoxy resin or a cyanate resin. 2. The antenna reflector according to claim 1, wherein the radio wave reflecting material is stitched with a fiber bundle in a region of the radio wave reflecting mirror surface. The antenna reflector according to claim 4, wherein the fiber bundle is a Kevlar fiber. 2. The antenna reflector according to claim 1, wherein the radio wave reflecting material is stitched to a region of the radio wave reflecting mirror surface with a unidirectional fiber reinforced resin. 7. The antenna reflector according to claim 1, wherein one region of the radio wave reflecting mirror surface is a strained portion formed on the radio wave reflecting mirror surface. A radio wave reflecting mirror surface correcting method, comprising: correcting a shape of the radio wave reflecting mirror surface by attaching a separate wave reflecting material to a strained portion formed on a radio wave reflecting mirror surface of an antenna reflector mounted on an artificial satellite.

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