JP2008306567A - Membrane reflector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a membrane reflector for artificial satellites, giving less effects on the mirror surface accuracy due to a temperature change. <P>SOLUTION: The membrane reflector is constituted of a mirror surface part 1 of the membrane reflector, a rear-face structure 2 for supporting the mirror surface part 1 from the rear side, and a plurality of coupling members 3 for coupling the mirror surface part 1 and the rear face structure 2. The coupling member 3 has a first and a second tabular coupling ends which connect each of the coupling members 3 to the rear face structure 2 and the mirror surface part 1; and a flexible coupling part made of a fiber cloth material which is connected between the coupling ends of enhanced composite material impregnated with resin to these fiber cloths and hardening, and is supported so that the first and the second coupling ends can move relatively. The influence on mirror surface accuracy due to temperature change is reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a membrane reflector mounted on an artificial satellite, and in particular, combines a mirror surface portion, a back structure for supporting the mirror surface portion from the back side, and the mirror surface portion and the back structure. The present invention relates to a membrane reflector for mounting on an artificial satellite provided with a plurality of coupling members.

  At present, there are various types of reflectors mounted on satellites. For the purpose of reducing the weight of reflectors, the reflector surface is made of a composite material that uses biaxial or triaxial woven fabrics made of reinforcing fibers as reinforcement. There is a membrane reflector provided with a back structure that uses a thin plate (membrane) -like surface and supports the mirror surface portion from the back side to maintain the reflecting mirror surface. As a coupling component for coupling the mirror surface portion and the back structure of the membrane reflector, an L-shaped component, a box-shaped component, a cylindrical component, or a plate-shaped component having a curved portion has been proposed (for example, Patent Document 1).

  In addition, there are parts that are designed to connect the mirror reflector part of the membrane reflector and the membrane reflector back structure part at low cost and with little influence on the reflector mirror accuracy against temperature changes. (For example, refer to Patent Document 2).

JP-A-10-270922 (FIGS. 1-3 and 7) Japanese Patent Laying-Open No. 2005-217696 (FIG. 1)

  In the space environment, the mirror surface of the membrane reflector sometimes becomes a high temperature exceeding 100 degrees Celsius due to direct sunlight, and the member is extended and deformed due to the thermal expansion of the member. Also, when the spacecraft enters the shade of the earth, the temperature of the membrane reflector mirror surface portion suddenly drops and sometimes reaches -150 degrees Celsius or less. As a result of the thermal contraction of the member, the membrane reflector mirror surface is contracted and deformed.

  In the conventional structure of the membrane reflector mirror surface portion, since the membrane reflector mirror surface portion 1 and the membrane reflector back structure 2 are firmly coupled by the coupling member 3, the membrane reflector mirror surface portion 1 and the membrane reflector back surface structure 2 are extended or When the size of the shrinkage deformation is different, the reflector is warped or distorted. Due to the deformation of the membrane reflector mirror surface as described above, the phenomenon that the focal point of the radio wave reflected by the conventional membrane reflector mirror surface surface is deviated from the expected location is causing the deterioration of communication accuracy. It was.

  Preventing the warp and distortion of the membrane reflector mirror surface has been a problem to be solved in order to suppress the defocus of the radio wave, prevent the communication accuracy from being lowered, and improve the stability of communication.

  Accordingly, an object of the present invention is to prevent warping and distortion of the membrane reflector mirror surface in view of the above-mentioned problems, to suppress the defocusing of radio waves caused by the warping and distortion, to prevent deterioration in communication accuracy, and to stabilize communication. It is providing the membrane reflector which can improve.

  According to the present invention, an artificial satellite mounted comprising a mirror surface portion, a back structure for supporting the mirror surface portion from the back side, and a plurality of coupling members for connecting the mirror surface portion and the back structure. In the above membrane reflector, the coupling member includes a plate-shaped first coupling end coupled to the mirror surface portion, a plate-shaped second coupling end coupled to the back structure, and the first and A membrane reflector is provided that includes a flexible coupling portion that is coupled between the second coupling end portions so that the first and second coupling end portions can be relatively moved.

  According to the membrane reflector of the present invention, the mirror reflector mirror surface is prevented from warping and distortion, radio wave defocusing caused by mirror surface warping and distortion is suppressed, communication accuracy is prevented from being lowered, and communication stability is improved. Can be made.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing the entire membrane reflector of the present invention, FIG. 2 is a partial perspective view showing a state where a thin plate-like reflecting mirror surface portion is supported by a back structure by a connecting member, and FIG. It is a perspective view which shows the detailed structure of a member. 1 to 3, a membrane reflector for mounting on an artificial satellite according to the present invention includes a thin plate-like mirror surface portion 1 that forms a reflecting mirror surface, and a back surface for supporting the mirror surface portion 1 from the rear surface side that is the convex surface side of the reflecting mirror surface. The structure 2 and a plurality of coupling members 3 that couple the mirror surface portion 1 and the back structure 2 are provided.

  The mirror surface portion 1 of the membrane reflector is a thin plate (membrane) -like film-like member made of a composite material using a biaxial or triaxial fabric made of reinforcing fibers as a reinforcing material, and the mirror surface portion 1 acts as a predetermined reflecting mirror. Thus, it is supported by the back structure 2 from the back side.

  In the illustrated example, the back structure 2 is formed by combining long plate-like beam members 4 having a width dimension in the axial direction of the membrane reflector and having a substantially rectangular shape as a whole in a triangular truss shape. As shown in FIG. 2, the illustrated beam member 4 has a substantially T-shaped cross section, and a T-shaped horizontal bar increases the rigidity of the beam member 4. The lower end of the T-shaped vertical bar of the beam member 4, that is, the side edge 5 on the mirror surface portion 1 side of the beam member 4 is located close to the mirror surface portion 1, and the side edge 5 on the mirror surface portion 1 side is It is coupled to the mirror surface portion 1 by a coupling member 3.

  As shown well in FIG. 3, the coupling member 3 is coupled to the mirror-shaped portion 1 and a plate-like first coupling end 6 coupled to the side edge 5 of the beam member 4 of the back structure 2. It is connected between the plate-like second coupling end portion 7 and the first and second coupling end portions 6 and 7 so that the first and second coupling end portions 6 and 7 can be supported so as to be relatively movable. A flexible connecting portion 8 is provided, and the first and second coupling end portions 6 and 7 and the flexible connecting portion 8 are generally L-shaped as a whole. The mirror surface portion 1 can be coupled to the back structure 2 by using only such an L-shaped coupling member alone or two facing each other.

  The first and second joint ends 6 and 7 are reinforced composite materials obtained by impregnating and curing a resin in a fiber fabric, for example, an aromatic polyamide fiber or a fiber obtained by impregnating a resin such as an epoxy resin into a carbon fiber and curing the fiber. A woven material (CFRP). The flexible connecting portion 8 is a fiber fabric that is not impregnated with resin. For example, a composite material plate material once impregnated with resin is made, and a portion corresponding to the flexible connecting portion 8 is creased to form a resin in this portion. It can be formed by removing or the like. Thus, the coupling member 3 is manufactured from a composite material that is lightweight and has a very small coefficient of thermal expansion.

  The illustrated coupling member 3 includes two sets of the first coupling end 6, the second coupling end 7, and the flexible coupling portion 8 combined in such an L shape, and these are coupled to each other by the coupling portion 9. Thus, one-piece connecting member 3 is formed. The first coupling end portions 6 are opposed to each other, and the beam member 4 of the back structure 2 is sandwiched therebetween and can be coupled and supported by an adhesive or the like. The second coupling end 7 extends from the first coupling end 6 at a right angle in a direction away from the beam member 4 of the back structure 2. A flexible connecting portion 8 is provided between the first coupling end 6 and the second coupling end 7.

  The outer end portions of the second coupling end portion 7 are coupled to each other by a coupling portion 9 extending in parallel with the second coupling end portion 7. The connecting portion 9 is also formed of the same fiber-reinforced composite material as the first and second connecting end portions 7 and 8, and is connected to the mirror surface portion 1 by an adhesive or the like, and from both ends of the connecting portion 10. It has a relatively short rising portion 11 that rises, and is connected to the second coupling end portion 7 by this rising portion 11. As described above, the second coupling end portion 7 is slightly separated from the coupling portion 10 and coupled to the mirror surface portion 1 via the coupling portion 9.

  When the mirror surface portion 1 is coupled to the beam member 4 of the rear structure 2 by such a coupling member 3, the side edge 5 of the beam member 4 is not in contact with the mirror surface portion 1 at least at the coupling portion, and is slightly in between. When a gap is formed and an external force is applied, the angular position between the mirror surface portion 1 and the back structure 2 can be changed by the deformation of the flexible connecting portion 8 of the coupling member 3.

  In FIG. 1, the movement and rotation associated with the coupling member 3 are depicted as axes X, Y and Z and coordinate axes representing rotation angles θx, θy and θz about the respective axes. When the coupling member 3 of FIG. 1 is used, it has one degree of freedom of rotation (θx direction) in which only θx rotation around the X axis is allowed from the fiber direction of the flexible connecting portion 8 of the coupling member 3 and the like. It has a structure.

  The arrangement of the coupling member 3 is determined by relaxing the deformation constraint in accordance with the deformation mode of the mirror surface portion 1 and the back surface structure 2 of the membrane reflector, and taking the strength and electrical viewpoint into consideration. For example, it is desirable that the rotation axis with one degree of freedom of rotation be orthogonal to an axial line extending in the radial direction connecting each coupling point from the center of the mirror surface portion of the membrane reflector. In this case, in particular, when an L-shaped coupling member is used, a wedge-shaped member is attached to the surface of the first coupling end portion coupled to the beam member 4 of the back structure 2 as necessary to bond the coupling surface. Can be tilted to adjust the angle.

  By disposing the coupling member 3 having such a flexible connecting portion 8, the mirror surface portion 1 of the membrane reflector does not have an angular constraint on the warp and distortion of the back structure 2 of the membrane reflector. The mirror surface portion 1 can avoid deformation.

Embodiment 2. FIG.
FIG. 4 is a partial perspective view showing another embodiment of the membrane reflector of the present invention. The difference from that shown in FIG. 2 is that a notch 13 is provided at the joining position of the joining member 12 on the side edge 5 of the beam member 4 of the back structure 2, and the notch 13 causes the mirror surface portion 1 and the joining member 3 to be connected. And the distance between the side edge 14 of the notch 13, which is the connection point (fulcrum) between the connection member 3 and the beam member 4, is increased.

  Since the notch 13 is provided in the beam member 4 of the back structure 2 as described above, according to the structure of FIG. 4, the mirror surface portion 1 is not only rotated θx but also the Y axis due to the bending and displacement of the flexible connecting portion 8. It is also possible to move in the Z-axis direction, and one degree of freedom of rotation and two degrees of freedom of translation by angular deformation are given.

  Further, the coupling member 12 can also be made of a reinforced composite material in which the flexible coupling portion 8 is made by impregnating and curing a resin to a fiber fabric in the same manner as the first and second coupling end portions 6 and 7. In this case, it is possible to reduce the out-of-plane rigidity and increase the in-plane rigidity by using the fiber resin composite material as the raw material, for example, by bending the thin plate molded product as shown in FIG. Thus, one degree of freedom of rotation (θx direction) and two degrees of freedom of translation (Y direction, Z direction) can be given.

  The arrangement of the coupling member 12 is determined from the strength and electrical viewpoint, while relaxing the deformation constraint according to the deformation mode of the membrane reflector mirror surface portion 1 and the membrane reflector back structure 2. For example, it is desirable that the rotation axis with one rotation degree of freedom (in the θx direction) be orthogonal to an axis extending in the radial direction connecting each coupling point from the center of the membrane reflector mirror surface. It is desirable that the translation direction (Y direction, Z direction) with two translational degrees of freedom be parallel to the axis extending in the radial direction connecting each coupling point from the center of the membrane reflector mirror surface. Also in this case, if necessary, the angle can be adjusted by attaching a wedge-shaped member to the surface of the first coupling end portion coupled to the beam member 4 of the back structure 2 and inclining the coupling surface.

  By disposing the coupling member 12, the membrane reflector mirror surface portion 1 does not have displacement restraint or angle restraint with respect to the warp or distortion of the membrane reflector back structure 2, so that the membrane reflector mirror surface portion 1 can avoid deformation. .

  Various modifications can be made to the coupling member used in the membrane reflector of the present invention. For example, the coupling member is made of a single continuous resin member, and the thickness of the flexible connecting portion 8 is made smaller than the thicknesses of the first and second coupling end portions 6 and 7 to increase flexibility. You can also.

  The coupling member 15 shown in FIG. 5 includes a plate-shaped first coupling end portion 6 coupled to the back structure 2, a plate-shaped second coupling end portion 7 coupled to the mirror surface portion 1, the first and first components. This is an L-shaped coupling member 15 comprising a flexible coupling portion 16 that is coupled between two coupling end portions 6 and 7 and supports the first and second coupling end portions 6 and 7 so as to be relatively movable. In this example, the coupling member 15 is a single resin member that is integrally continuous as a whole, and the thickness of the flexible coupling portion 16 is smaller than the thickness of the first and second coupling end portions 6 and 7. .

  FIG. 5 also shows an example in which a bonding surface adjusting member 18 for inclining the bonding surface 17 of the coupling member 3 with the back structure 2 is provided at the first coupling end 6. Inclining the bonding surface 16 using the bonding surface adjusting member 17 in this way means that, for example, the rotation axis with one degree of freedom of rotation (in the θx direction) is a radiation that connects each coupling point from the center of the mirror surface portion 1 of the membrane reflector. When orthogonal to the axis extending in the direction, or when the translation direction of two translational degrees of freedom (Y direction, Z direction) is parallel to the axis extending radially from the center of the membrane reflector mirror surface portion, It may be necessary. As described above, the bonding surface adjusting member 18 can be attached to the surface of the first coupling end portion 6 and the angle can be adjusted by inclining the coupling surface 16 as necessary.

  In the L-shaped coupling member 19 shown in FIG. 6, the flexible connecting portion 20 is a flexible fiber woven material, and the first and second coupling end portions are fixed to both ends of the fiber woven material. Resin material 21. This coupling member 19 also gives a degree of freedom to support the mirror surface portion 1.

It is a schematic perspective view which shows the membrane reflector of this invention. It is a schematic perspective view which shows the coupling member between the mirror surface part of a membrane reflector of this invention, and a back surface structure. It is a schematic perspective view which shows the coupling member of the membrane reflector of this invention. It is a schematic perspective view which shows another coupling member of the membrane reflector of this invention. It is a schematic perspective view which shows the coupling member of the membrane reflector of this invention. It is a schematic side view which shows another coupling member of the membrane reflector of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Mirror surface part, 2 Back surface structure 3, 12, 15, 19 Connection member, 4 Beam member, 5 Side edge, 6 1st connection end part, 7 2nd connection end part, 8, 16 Flexible connection part, 9 Connection part, 13 notch, 14 side edge, 17 joint surface, 18 joint surface adjustment member.

Claims (6)

In a membrane reflector for satellite installation comprising a mirror surface portion, a back surface structure for supporting the mirror surface portion from the back surface side, and a plurality of coupling members for connecting the mirror surface portion and the back surface structure,
The coupling member includes a plate-shaped first coupling end coupled to the back structure, a plate-shaped second coupling end coupled to the mirror surface portion, and between the first and second coupling ends. And a flexible connecting part that supports the first and second coupling end parts so that they can move relative to each other.   2. The membrane reflector according to claim 1, wherein the flexible connecting portion is a fiber woven material, and the first and second coupling end portions are a reinforced composite material obtained by impregnating and curing the fiber woven material with a resin. .   The said flexible connection part is a fiber woven material, The said 1st and 2nd joint end part is the resin material fixed to the both-ends extension part of the said fiber woven fabric, The Claim 1 or 2 characterized by the above-mentioned. Membrane reflector.   3. The coupling member according to claim 1 or 2, wherein the coupling member is a single resin member continuous integrally, and the thickness of the flexible coupling portion is smaller than the thickness of the first and second coupling end portions. The membrane reflector as described.   The membrane reflector according to any one of claims 1 to 4, wherein, of the coupling members, a joint surface with a back structure is inclined. The coupling member includes two sets of the first coupling end, the second coupling end, and the flexible coupling,
The first coupling end portions are opposed to each other and sandwich the back structure therebetween.
The second coupling end extends from the flexible connecting portion in a direction away from the back structure,
The coupling member further includes a coupling portion coupled to an outer end of the second coupling end portion and fixed to the mirror surface portion to couple the second coupling end portions to each other. The membrane reflector of any one of 1-5.

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