JP2010066291A - Double-sided reflecting mirror and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided reflecting mirror capable of being made light in weight while preventing the change of optical performance and the lowering of heat resistance, and a method for manufacturing the same. <P>SOLUTION: A first reflecting mirror member 11 having a first reflecting mirror surface 2 on the front surface and a first lightening work part 11a on the back surface and a second reflecting mirror member 12 having a second reflecting mirror surface 3 on the front surface and a second lightening work part 12a on the back surface are manufactured from two C/C molded bodies 10. Then, by combining back surfaces of the first and second reflecting mirror members 11 and 12, impregnating the first and second reflecting mirror members 11 and 12 with melted metal silicon in a vacuum, making them react and turning C/C to C/SiC, the first and second reflecting mirror members 11 and 12 are bonded and integrated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a double-sided reflecting mirror of a reflecting optical system used for, for example, a space telescope and an infrared seeker, and a manufacturing method thereof.

  In space telescopes and infrared seekers, reflective optical systems that combine multiple reflectors are used. In such a reflecting optical system, it is necessary to firmly fix the reflecting mirrors to the fixing portion so that the positions of the reflecting mirrors can be accurately aligned and can withstand environmental conditions such as vibration when the rocket is launched. For this reason, as the number of reflecting mirrors increases, the time required for the adjustment for alignment becomes longer, the number of fixing parts increases, and the weight increases.

  On the other hand, in a conventional space reflecting optical system, the number of parts is reduced by using a double-sided reflecting mirror in which reflecting mirrors are formed on both sides in the optical system (for example, patents). Reference 1). Further, as such a double-sided reflecting mirror, one using foamed quartz as a base material is known (for example, see Patent Document 2). Further, as a mirror surface material for a lightweight double-sided reflector for space use, a material using a particle-dispersed silicon material containing silicon carbide as dispersed particles is known (for example, see Patent Document 3).

JP-A-10-2113747 JP-A-8-152507 JP 2004-317647 A

  In order to reduce the weight of the double-sided reflector as described above, a method of hollowing the base material is effective. However, in the conventional double-sided reflector that uses foamed quartz or particle-dispersed silicon material as the base material, it is difficult to cut out the inside of the base material because the reflective mirrors are formed on both sides of the base material. For this reason, in order to make the double-sided reflecting mirror hollow, it is necessary to integrate the reflecting mirrors prepared for each side by finally attaching them with an adhesive or mechanically connecting them with screws or the like.

  Among such integration methods, the method using an adhesive has a limitation in weight reduction because it is necessary to secure a sufficient adhesion area in order to maintain the adhesive strength. Moreover, since deformation due to moisture absorption occurs, the optical performance changes. Furthermore, the heat resistance has a limit depending on the physical properties of the adhesive. On the other hand, in the method of mechanically connecting with a screw or the like, it is necessary to form a mechanically connected portion, and a screw or the like is required, so that there is a limit to weight reduction.

  The present invention has been made to solve the above-described problems, and provides a double-sided reflector that can be reduced in weight while preventing a change in optical performance and a decrease in heat resistance, and a method for manufacturing the same. For the purpose.

  The double-sided reflecting mirror according to the present invention includes a first reflecting mirror surface, a second reflecting mirror surface located on the back side of the first reflecting mirror surface, and a cavity portion located between the first and second reflecting mirror surfaces. And a carbon fiber reinforced silicon carbide composite material is used as a base material of the reflecting mirror body.

  In the double-sided reflecting mirror of the present invention, since the carbon fiber reinforced silicon carbide composite material is used as the base material of the reflecting mirror body, the two reflecting mirror members having the carbon fiber reinforced carbon composite material as a base material are used as their carbon. The fiber reinforced carbon composite material can be integrated by converting it into a carbon fiber reinforced silicon carbide composite material. Therefore, the two reflecting mirror members can be integrated without using an adhesive or a screw, and the optical performance. It is possible to reduce the weight by providing a hollow portion while preventing a change in temperature and a decrease in heat resistance.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a perspective view showing a double-sided reflector according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view in the XY plane of the double-sided reflector of FIG. 1 taken along the line AA ′ (central portion of thickness d). 3 is a cross-sectional view taken along line BB ′ of the double-sided reflecting mirror of FIG.

  In the figure, the reflecting mirror body 1 includes a first reflecting mirror surface 2, a second reflecting mirror surface 3 located on the back side of the first reflecting mirror surface 2, and a space between the first and second reflecting mirror surfaces 2 and 3. Are provided with a plurality of cavities 4 located at the same position. In this example, the radius of curvature of the first reflecting mirror surface 2 is R = 1000 mm, and the radius of curvature of the second reflecting mirror surface 3 is R = 2000 mm. The cavity 4 is arranged side by side in the circumferential direction of the reflector body 1. Further, an optical path hole 5 for securing an optical path is provided in the central portion of the reflecting mirror body 1.

  The reflecting mirror body 1 includes hollow disk-shaped first and second disk portions 1a and 1b facing each other, and a cylinder positioned between the first and second disk portions 1a and 1b at the inner diameter side end. The inner circumferential rib 1c, the outer circumferential rib 1d located between the first and second disk parts 1a, 1b at the outer diameter side end, and the radial between the first and second disk parts 1a, 1b And a plurality of radial ribs 1e.

  The first reflecting mirror surface 2 is provided on the first disc portion 1a. The second reflecting mirror surface 2 is provided on the second disc portion 1b. The cavity 4 and the optical path hole 5 are partitioned by the inner peripheral rib 1c. The adjacent cavities 4 are partitioned by radial ribs 1e. The outer peripheral rib 1d is provided with a plurality of openings 1f that allow the cavity 4 to communicate with the outside of the reflector main body 1.

  A carbon fiber reinforced silicon carbide (C / SiC) composite material is used as a base material of the reflector main body 1. In this example, the reflecting mirror body 1 is composed of only a C / SiC composite material.

  Next, a method for manufacturing the double-sided reflecting mirror will be described. FIG. 4 is a process diagram showing a manufacturing method of the double-sided reflecting mirror of FIG. 1 together with a perspective view. When manufacturing the double-sided reflecting mirror of FIG. 1, first, carbon fibers which are short fibers are stirred in binder-turbid water and uniformly dispersed (step S1). Here, a cellulose binder was used as the binder.

  Subsequently, after the moisture of the binder turbid water is removed under reduced pressure by a vacuum pump, the accumulated fiber lump is transferred to a mold and pressurized to form a predetermined shape (here, a disk shape) (step S2). Thereafter, the formed fiber lump is taken out from the mold and dried by heating in a drying furnace at 90 ° C. for 48 hours or longer (step S3). Thereby, the carbon fiber molded object which consists of carbon fiber and a binder is produced.

  Next, this carbon fiber molded body is impregnated with pitch (or may be a phenol resin) (step S4), and heated to about 1000 ° C. in vacuum or in an inert atmosphere with an inert gas such as argon or nitrogen. The agent component is carbonized to form a carbon fiber reinforced carbon (hereinafter referred to as C / C) composite material. Thereafter, the C / C composite material is graphitized by heat treatment at 2000 ° C. in an inert atmosphere (step S5). Thereby, the graphitized disk-shaped C / C molded object 10 is produced.

  Thereafter, machining is performed on the front surface and the back surface of the C / C molded body 10 (step S6). Specifically, the front surface of the C / C molded body 10 is ground so as to have a spherical shape (concave surface) having a desired radius of curvature (here, R = 1000 mm). Further, the back surface of the C / C molded body 10 is subjected to weight reduction (cutting) processing while leaving portions corresponding to the ribs 1c to 1e. Further, a circular hole to be the optical path hole 5 is provided in the central portion of the C / C molded body 10. Thereby, the 1st reflective mirror surface 11 in which the 1st reflective mirror surface 2 was provided in the front surface, and the 1st weight reduction process part 11a was provided in the back surface is produced.

  Further, another C / C molded body 10 is manufactured in the same procedure as described above, and the second reflecting mirror member 12 is manufactured from the C / C molded body 10 in the same procedure as the first reflecting mirror member 11. . At this time, the second reflecting mirror surface 3 having a radius of curvature R = 2000 mm is provided on the front surface of the second reflecting mirror member 12. Further, on the back surface of the second reflecting mirror member 12, a second lightening processing portion 12a similar to the first lightening processing portion 11a is provided.

  Then, the back surfaces of the first and second reflecting mirror members 11 and 12 thus obtained are combined (step S7). Thereafter, the first and second reflecting mirror members 11 and 12 are impregnated and reacted in a vacuum with molten metal silicon, and C / C is converted to C / SiC, thereby making the first and second reflecting mirror members 11. , 12 are joined and integrated (step S8). At this time, at the interface between the first and second reflecting mirror members 11 and 12, a part of the impregnated silicon reacts with carbon and changes to silicon carbide, whereby the first and second reflecting mirror members 11, 12 is firmly integrated.

  Finally, finishing grinding and mirror polishing are performed on the first and second reflecting mirror surfaces 2 and 3 one by one (steps S9 and S10). Thereby, the reflector main body 1 of FIG. 1 which is a C / SiC molded body is produced.

  In such a double-sided reflector, since the C / SiC composite material is used as the base material of the reflector main body 1, the two reflector members 11 and 12 having the C / C composite material as a base material are connected to each other. C / C can be integrated by changing to C / SiC. Therefore, the two reflecting mirror members 11 and 12 can be integrated without using an adhesive or a screw, and the optical performance can be changed. It is possible to reduce the weight by providing the cavity 4 while preventing the heat resistance from decreasing.

In addition, since the reflecting mirror surfaces 2 and 3 are formed on both surfaces of the integrated reflecting mirror body 1, the number of optical components can be reduced when applied to a space telescope, an infrared seeker, etc. The optical system can be made thinner than when a mirror is used.
Furthermore, the C / SiC composite material has excellent characteristics as a reflector material for satellites.

  Furthermore, in the method for manufacturing a double-sided reflector as described above, the back surfaces of the first and second reflector members 11 and 12 in which the C / C composite material is used as a base material are combined and fused silicon. The first and second reflecting mirror members 11 and 12 are impregnated, and C / C is converted into C / SiC so that the first and second reflecting mirror members 11 and 12 are integrated. It is possible to integrate the two reflecting mirror members 11 and 12 without using, etc., and to reduce the weight by providing the hollow portion 4 while preventing a change in optical performance and a decrease in heat resistance.

  Furthermore, since the C / C composite material is excellent in machinability and has high mechanical strength, the machining time can be shortened during machining for weight reduction, and the disk portions 1a, 1b and ribs 1c˜ 1e can be thinned.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. The appearance of the double-sided reflector according to Embodiment 2 is the same as that of FIG. FIG. 5 is a cross-sectional view of the double-sided reflector according to Embodiment 2, and corresponds to the same cross section as FIG. Further, FIG. 6 is a cross-sectional view showing a state before the double-sided reflecting mirror of FIG. 5 is integrated, and corresponds to a cross section taken along the line CC ′ and DD ′ of FIG.

  In the second embodiment, when machining is performed on the front surface and the back surface of the graphitized C / C molded body 10 (step S6 in FIG. 4), a plurality of positioning portions are provided on the back surface of the first reflecting mirror member 11. Protrusions 13 are provided. In addition, a plurality of concave portions 14 are provided on the back surface of the second reflecting mirror member 12 as positioning portions to which the convex portions 13 are fitted. These convex portions 13 and concave portions 14 are provided on the radial rib 1e. Other configurations and manufacturing methods are the same as those in the first embodiment.

  In such a double-sided reflector manufacturing method, positioning is performed when the back surfaces of the first and second reflecting mirror members 11 and 12 are combined with the back surfaces of the first and second reflecting mirror members 11 and 12. Since the convex portion 13 and the concave portion 14 are provided, when the first and second reflecting mirror members 11 and 12 are combined, both can be precisely aligned in a short time.

Embodiment 3 FIG.
Next, FIG. 7 is a cross-sectional view showing a state before integration of the double-sided reflector according to Embodiment 3 of the present invention, and corresponds to a cross section taken along the line CC ′ and DD ′ of FIG. . In the second embodiment, the first reflecting mirror member 11 is provided with the convex portion 13 and the second reflecting mirror member 12 is provided with the concave portion 14. In the third embodiment, the first reflecting mirror member 11 is convex. Both the part 13 and the recessed part 14 were provided, and both the convex part 13 and the recessed part 14 were provided also in the 2nd reflective mirror member 12. FIG. Other configurations and manufacturing methods are the same as those in the second embodiment.

  Also by such a manufacturing method, when combining the 1st and 2nd reflective mirror members 11 and 12, both position alignment can be performed precisely in a short time.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. The appearance of the double-sided reflector according to Embodiment 4 is the same as that of FIG. FIG. 8 is a cross-sectional view of a double-sided reflecting mirror according to Embodiment 4, which corresponds to the same cross section as FIG. Further, FIG. 9 is a cross-sectional view showing a state before the double-sided reflecting mirror of FIG. 8 is integrated, and corresponds to a cross section taken along lines EE ′ and FF ′ of FIG.

  In the fourth embodiment, when machining is performed on the front surface and the back surface of the graphitized C / C molded body 10 (step S6 in FIG. 4), a plurality of positioning portions are provided on the back surface of the first reflecting mirror member 11. Protrusions 15 are provided. A plurality of recesses 16 are provided on the back surface of the second reflecting mirror member 12 as positioning portions to which the protrusions 15 are fitted. These convex portions 15 and concave portions 16 are provided on the outer peripheral rib 1d. Other configurations and manufacturing methods are the same as those in the first embodiment.

  In such a double-sided reflector manufacturing method, positioning is performed when the back surfaces of the first and second reflecting mirror members 11 and 12 are combined with the back surfaces of the first and second reflecting mirror members 11 and 12. Since the convex portion 15 and the concave portion 16 are provided, when the first and second reflecting mirror members 11 and 12 are combined, both can be precisely aligned in a short time.

In the fourth embodiment, the first reflecting mirror member 11 is provided with the convex portion 15, and the second reflecting mirror member 12 is provided with the concave portion 16. However, the first reflecting mirror member 11 has the convex portion 15 and the concave portion. 16 may be provided, and both the convex portion 15 and the concave portion 16 may be provided also in the second reflecting mirror member 12.
Moreover, you may implement combining Embodiment 4 and Embodiment 2,2.

Embodiment 5 FIG.
Next, FIG. 10 is a cross-sectional view showing a state before integration of the double-sided reflector according to Embodiment 5 of the present invention, and corresponds to a cross section taken along lines EE ′ and FF ′ of FIG. .

  In the fifth embodiment, when machining the front and back surfaces of the graphitized C / C molded body 10 (step S6 in FIG. 4), a plurality of positioning portions are provided on the back surface of the first reflecting mirror member 11. Protrusions 17 are provided. In addition, a plurality of concave portions 18 as positioning portions into which the convex portions 17 are fitted are provided on the back surface of the second reflecting mirror member 12. The convex portion 17 and the concave portion 18 are provided on the inner peripheral rib 1c at intervals in the circumferential direction. Other configurations and manufacturing methods are the same as those in the first embodiment.

  In such a double-sided reflector manufacturing method, positioning is performed when the back surfaces of the first and second reflecting mirror members 11 and 12 are combined with the back surfaces of the first and second reflecting mirror members 11 and 12. Since the convex portion 17 and the concave portion 18 are provided, when the first and second reflecting mirror members 11 and 12 are combined, both can be precisely aligned in a short time.

In the fifth embodiment, the first reflecting mirror member 11 is provided with the convex portion 17 and the second reflecting mirror member 12 is provided with the concave portion 18. However, the first reflecting mirror member 11 has the convex portion 17 and the concave portion. 18 may be provided, and both the convex portion 17 and the concave portion 18 may be provided also in the second reflecting mirror member 12.
Moreover, you may implement combining Embodiment 5 and at least any one of Embodiment 2, 3, and Embodiment 4. FIG.

Embodiment 6 FIG.
Next, FIG. 11 is a perspective view showing a double-sided reflector according to Embodiment 6 of the present invention, and FIG. 12 is an XY plane at the position of the line GG ′ of the double-sided reflector of FIG. FIG. 13 is a sectional view taken along line HH ′ of the double-sided reflecting mirror of FIG.

  The sixth embodiment is different from the first embodiment in that the optical path hole 5 is not provided. For this reason, the back surface of the 1st disc part 1a and the back surface of the 2nd disc part 1b are integrated in those center parts.

  When manufacturing such a double-sided reflector, when the front and back surfaces of the graphitized C / C molded body 10 are machined (step S6 in FIG. 4), the first and second reflector members 11 and 12 are used. In the central part of the back surface of each other, a joint part joined to each other is provided. Other configurations and manufacturing methods are the same as those in the first embodiment.

  Also with such a double-sided reflecting mirror and its manufacturing method, it is possible to reduce the weight by providing the cavity 4 while preventing changes in optical performance and a decrease in heat resistance.

In the method for manufacturing a double-sided reflector as shown in the sixth embodiment, a positioning unit as shown in the second to fifth embodiments may be provided.
Further, the arrangement of the ribs 1c to 1e and the radius of curvature of the reflecting mirror surfaces 2 and 3 are not limited to those of the first to sixth embodiments.
Furthermore, when providing the convex parts 13, 15, and 17 and the recessed parts 14, 16, and 18, those numbers and shapes are not specifically limited.

It is a perspective view which shows the double-sided reflective mirror by Embodiment 1 of this invention. It is sectional drawing in the XY plane in the position of the A-A 'line | wire of the double-sided reflective mirror of FIG. It is sectional drawing which follows the B-B 'line | wire of the double-sided reflective mirror of FIG. It is process drawing which shows the manufacturing method of the double-sided reflective mirror of FIG. 1 with a perspective view. It is sectional drawing of the double-sided reflective mirror by Embodiment 2 of this invention. It is sectional drawing which shows the state before integration of the double-sided reflective mirror of FIG. It is sectional drawing which shows the state before integration of the double-sided reflective mirror by Embodiment 3 of this invention. It is sectional drawing of the double-sided reflective mirror by Embodiment 4 of this invention. It is sectional drawing which shows the state before integration of the double-sided reflective mirror of FIG. It is sectional drawing which shows the state before integration of the double-sided reflective mirror by Embodiment 5 of this invention. It is a perspective view which shows the double-sided reflective mirror by Embodiment 6 of this invention. It is sectional drawing in the XY plane in the position of the G-G 'line | wire of the double-sided reflective mirror of FIG. It is sectional drawing which follows the H-H 'line | wire of the double-sided reflective mirror of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Reflector main body, 2 1st reflective mirror surface, 2nd reflective mirror surface, 4 cavity part, 11 1st reflective mirror member, 12 2nd reflective mirror member, 13, 15, 17 Convex part (positioning part) , 14, 16, 18 Recess (positioning part).

Claims (4)

Reflection provided with a first reflecting mirror surface, a second reflecting mirror surface located on the back side of the first reflecting mirror surface, and a cavity portion located between the first and second reflecting mirror surfaces With mirror body,
A double-sided reflecting mirror characterized in that a carbon fiber reinforced silicon carbide composite material is used as a base material of the reflecting mirror body. A step of combining the back surfaces of the first and second reflecting mirror members in which a reflecting mirror surface is provided on the front surface, a weight reduction processing portion is provided on the back surface, and a carbon fiber reinforced carbon composite material is used as a base material; And the first and second reflecting mirror members are impregnated with molten silicon, and the carbon fiber reinforced carbon composite material is made into a carbon fiber reinforced silicon carbide composite material, whereby the first and second reflecting mirror members are The manufacturing method of the double-sided reflective mirror characterized by including the process of integrating. The method further comprises a step of providing a positioning portion for positioning the back surfaces of the first and second reflecting mirror members when the back surfaces of the first and second reflecting mirror members are combined with each other. Item 3. A method for producing a double-sided reflecting mirror according to Item 2.   The said positioning part contains the recessed part provided in one of the said 1st and 2nd reflective mirror member, and the convex part which is provided in the other and is fitted to the said recessed part. Manufacturing method of a double-sided reflector.

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