JP2009276378A - Lightweight mirror and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight mirror that fasilitates molding of a rib structure and reduces cost thereof, and to provice a method of manufacturing the same. <P>SOLUTION: The method includes: a first foundation base material molding step of obtaining a first plate-like carbon foundation base member 18a by subjecting a foundation base material composed of carbon or composed of a mixed material composed of the carbon and silicon carbide as a principal component to compression molding; a cutting step of obtaining a carbon foundation molding 19 formed by cutting a plurality of recessed holes 5 of a hole direction aligned to a thickness direction of the first carbon foundation base member 18a into to the first carbon foundation base member 18a; a reaction sintering step of obtaining a rib structure 3A by causing reaction sintering of the carbon of the carbon foundation molding 19 with silicon 21 by impregnating the molten silicon 21 to the carbon foundation molding 19; and a step of joining a mirror function part 10A composed of a glass material to one surface of the rib structure 3A by directing the reflection surface outward. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lightweight mirror used for a telescope or an optical sensor mounted on a moving body such as an artificial satellite.

  A conventional light weight mirror is made of a plate-like glass material, and a mirror structure in which one surface is polished to form a mirror surface and a core formed of a plurality of concave holes is formed on the other surface, and glass It is made of a material having the same or substantially the same linear expansion coefficient as the material, and includes a plate-like back plate attached to the core side surface of the mirror structure to reinforce the mirror structure (for example, Patent Document 1) reference).

Japanese Patent Laid-Open No. 2002-182018

  Although the conventional method for forming a mirror structure of a light weight mirror is not specifically described in Patent Document 1, it is common to form a mirror structure by cutting a flat plate made of a glass material. is there. At this time, since the glass material is very hard, it is difficult to process the mirror structure and it takes a long time to process, so the cost of the conventional lighter mirror has increased.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to obtain a lightweight mirror that can easily form a rib structure and can reduce costs, and a method for manufacturing the same. To do.

  The manufacturing method of the weight reduction mirror by this invention is the 1st base material which gives a plate-shaped 1st carbon base material by performing compression molding to the base material which has carbon or the mixed material of carbon and silicon carbide as a main component A forming step, a cutting step for obtaining a carbon green body by forming a plurality of rib structure holes whose hole directions coincide with the thickness direction of the first carbon base member by cutting the first carbon base member, and carbon base molding The body is impregnated with molten silicon, and the reactive sintering process to obtain a rib structure by reaction-sintering carbon and silicon of the carbon green body, and the mirror function part made of glass material, with the reflective surface outward And a joining step of joining to one surface of the rib structure.

  According to the manufacturing method of the lightening mirror of this invention, the rib structure which has rigidity is obtained by carrying out reaction sintering of the carbon to the carbon of the carbon base molded object which cut the 1st carbon base member. . Therefore, the time required for the cutting process for forming the rib structure into a predetermined shape can be greatly shortened, and accordingly, the manufacturing cost of the lightweight mirror can be reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a front view of a lightweight mirror according to Embodiment 1 of the present invention, FIG. 2 is a rear view of the lightweight mirror according to Embodiment 1 of the present invention, and FIG. 3 is a cross-sectional view taken along arrows III-III in FIG. FIG. 4 and FIG. 4 are diagrams for explaining a method for manufacturing a light weight mirror according to Embodiment 1 of the present invention.

1 to 3, a lighter mirror 1A includes a mirror base material structure 2A composed of a rib structure 3A made of a material mainly composed of silicon carbide (SiC), and a first mirror body made of a glass material. 11a, and has a mirror function part 10A joined to one surface of the mirror base material structure part 2A.
The rib structure 3A has a disk shape with a predetermined thickness in which the first through-holes 4 are formed coaxially, and one surface in the thickness direction (hereinafter simply referred to as one surface) is directed from the outer peripheral edge to the center. Accordingly, the rotating paraboloid is inclined so as to gradually approach the other surface in the thickness direction (hereinafter simply referred to as the other surface). Further, the rib portion 6a is formed so that the concave holes 5 as a plurality of rib structure holes having the thickness direction of the rib structure 3A as the hole extending direction (hole direction) open to the other surface of the rib structure 3A. A plurality are formed so as to be adjacent to each other. Further, the other surface side of the rib structure 3A is disposed on a flat surface orthogonal to the axis. The recessed hole 5 adjacent to the outer peripheral wall 7 of the rib structure 3A is partitioned by the outer peripheral wall 7 and the rib portion 6a.

And the opening shape of the recessed hole 5 which is not adjacent to the outer peripheral wall 7 of 3 A of rib structures, and is divided only by the rib part 6a is formed in the equilateral triangle. Further, the opening of the recessed hole 5 adjacent to the outer peripheral wall 7 of the rib structure 3A and partitioned by the outer peripheral wall 7 and the rib portion 6a is connected so that the angle between them is 60 degrees. Each of the wall surfaces is surrounded by a curved surface between the portions of the outer peripheral wall 7 to which the end portion on the opposite side to the connecting portion of the wall surface is connected.
Here, silicon carbide, which is the main component of the rib structure 3A, is a material having a linear expansion coefficient close to zero on the order of 10 ⁻⁶ (1 / K), and thermal deformation due to temperature change of the rib structure 3A is extremely It is a small one.

  The first mirror body 11a constituting the mirror function unit 10A has a disk shape in which the second through hole 12 is formed coaxially. At this time, the first mirror body 11a is curved so as to have a curvature that matches the curved shape on the one surface side of the rib structure 3A. In addition, one surface side of the first mirror body 11a is polished to form a reflecting surface (mirror surface). The first mirror body 11a is bonded to one surface in the thickness direction of the rib structure 3A with the reflection surface facing outward.

As the material of the first mirror body 11a, a glass material having the same or substantially the same linear expansion coefficient as that of silicon carbide is used. For example, an ultra-low expansion glass ceramic material such as Clear Serum-Z (registered trademark of OHARA INC.), An ultra-low expansion amorphous glass material having a SiO ₂ —TiO ₂ composition, and the like. The linear expansion coefficients of these materials are materials closer to zero than the order of 10 ⁻⁶ (1 / K), and the thermal deformation due to the temperature change of the first mirror body 11a is very small like the rib structure 3A. Is.

  Here, in general, when materials having different linear expansion coefficients are joined and used, thermal stress is generated in each material due to temperature change due to the difference in linear expansion coefficient. However, the linear expansion coefficients of the first mirror body 11a and the rib structure 3A are the same or substantially the same. Therefore, although the 1st mirror body 11a is comprised with the glass material of a brittle material, the thermal stress which generate | occur | produces in the 1st mirror body 11a is very small, and the 1st mirror body 11a is not damaged by a thermal stress. .

  Since the plurality of lightening mirrors 1A configured as described above are formed so that the concave holes 5 are adjacent to each other via the rib portion 6a having a predetermined wall thickness, the rigidity and lightness of the lightening mirror 1A are ensured. Has been realized. At this time, silicon carbide, which is the main material of the rib structure 3A, is a lighter material that is higher in rigidity and lighter than the glass material. Therefore, according to the lighter mirror 1A, it is possible to achieve higher rigidity and lighter weight than a conventional lighter mirror made of only a glass material.

Next, a method for manufacturing the lighter mirror 1A will be described.
The manufacturing method of the lightweight mirror 1A includes a mirror base material structure manufacturing process and a joining process.
First, the mirror base material structure manufacturing process will be described with reference to FIG.
The mirror base material structure manufacturing process includes a first green base material forming process, a first graphitizing process, a cutting process, and a reactive sintering process.
In the first base material forming step, as shown in FIG. 4A, the carbon base material 15 as a base material in which the carbon fiber powder and the binder powder are mixed corresponds to the shape of the rib structure 3A. The mold 16a is filled in a pressurized state. Thereby, the carbon base material 15 is compression-molded to form a plate-like first carbon base member 18a that can be cut. In addition, what consists of phenol resin etc. can be used for a binder, for example.

Next, in the first graphitization treatment step, the first carbon base member 18a is impregnated with coal tar pitch, and then, as shown in FIG. 4B, in the furnace 17 filled with an inert gas, The mold 16a filled with the mixed material of the first carbon base member 18a and the coal tar pitch is moved. And the temperature in the furnace 17 is raised to 2000 degree | times or more, and after a predetermined time passes, the temperature is lowered. As a result, the binder is carbonized, and the material in the mold 16a is substantially free of impurities other than carbon to become graphite.
In the following description, a solid body obtained after graphitization of the first carbon base member 18a bonded with the binder will be described as the first carbon base member 18a.

  Next, in the cutting process, the first carbon base member 18a is taken out from the mold 16a. Further, as shown in FIG. 4C, a plurality of concave holes 5 are formed in the first carbon base member 18a by cutting using an NC (Numerical Control) machine 20. The first carbon base member 18 a formed with the concave holes 5 is referred to as a carbon base molded body 19.

  Next, in the reaction sintering step, as shown in FIG. 4 (d), a carbon green body 19 is disposed in the furnace 17, and silicon (Si) 21 is further disposed on the carbon green body 19. . Then, the temperature in the furnace 17 is increased to 1600 degrees or more, and after a predetermined time has elapsed, the temperature in the furnace 17 is decreased. Thereby, the melted silicon 21 is impregnated into the carbon green body 19, and the carbon of the carbon green body 19 and the silicon 21 react to form silicon carbide. That is, as shown in FIG. 4E, a rib structure 3A mainly composed of silicon carbide is obtained.

  Although the rib structure 3A is mainly composed of silicon carbide, a part of the silicon 21 melted after the reaction sintering process remains alone without reacting with the carbon of the carbon green body 19, or the carbon is silicon. It does not react with 21 and remains alone. At this time, if at least about 80% of the volume of the rib structure 3A is made of silicon carbide, the rib structure 3A has sufficient rigidity.

Next, the joining process will be described.
Although not shown, in the joining step, a first mirror body 11a is prepared in which the reflecting surface is configured on one surface side by polishing and the second through hole 12 is formed coaxially. Then, paste glass frit is applied to one surface of the rib structure 3A so that one surface of the first mirror body 11a faces outward, and the other surface and one surface of the rib structure 3A face each other through the glass frit. Placed in the furnace. At this time, the first through hole 4 of the rib structure 3A and the second through hole 12 of the first mirror body 11a are made to correspond to each other.

Then, the temperature in the furnace is raised above the melting point of the glass frit, and after a predetermined time has elapsed, the temperature in the furnace is lowered. Thereby, since the glass frit once melted is solidified, the rib structure 3A and the first mirror body 11a are integrated, and the lighter mirror 1A shown in FIGS. 1 to 3 is obtained.
Note that the melting point of the glass frit is lower than the melting point of the first mirror body 11a and the rib structure 3A with a margin.

Here, the reason why the first mirror body 11a (mirror function part 10A) is prepared separately from the rib structure 3A (mirror base material structure part 2A) will be described.
If a reflecting surface is to be formed on one surface side of the rib structure 3A, the mirror surface needs to be formed by polishing one surface side of the rib structure 3A after the reaction sintering step. However, as described above, the rib structure 3A is made of a material having higher rigidity than the glass material. Accordingly, it is possible to shorten the time for forming the mirror surface by polishing the first mirror body 11a and forming the mirror surface, rather than polishing one surface of the rib structure 3A. Therefore, the first mirror body 11a is prepared separately from the rib structure 3A.

  According to the manufacturing method of the lightweight mirror 1A, the rib structure 3A having rigidity is obtained by reacting and sintering silicon to carbon of the carbon base molded body 19 obtained by cutting the first carbon base member 18a that is easy to cut. It has gained. Therefore, the time required for cutting for forming the rib structure 3A into a predetermined shape can be greatly shortened. Thereby, even if the lightweight mirror 1A is enlarged, the lightweight mirror 1A can be manufactured in a short time. Moreover, the manufacturing cost of the lightweight mirror 1A can be reduced with a significant reduction in the time required for cutting.

In the first embodiment, the main opening shape of the recessed hole 5 is described as being formed in an equilateral triangle, but the recessed hole 5 is not limited to being formed in an equilateral triangular opening shape. For example, the opening shape of the concave hole 5 may be other polygons such as other triangles, squares, and hexagons of regular triangles, or those formed by curves. However, by making the opening shape of the recessed hole 5 hexagonal, the rigidity of the rib structure 3A becomes higher than that of the other recessed hole opening shape.
Moreover, the opening shape of the recessed hole 5 is not limited to what is unified, You may form the recessed hole 5 which has a triangular or square opening shape in 3 A of rib structures.

  Moreover, although the 1st graphitization process process demonstrated as what is performed before a cutting process, it may be performed with respect to the carbon base green body 19 before the reaction sintering process after a cutting process. Further, even if the first graphitization treatment step is not performed, impurities other than carbon in the carbon green body 19 do not inhibit the reaction between carbon and silicon in the reaction sintering step, and the reaction sintering step. If the rib structure 3A obtained in (1) has high rigidity mainly composed of silicon carbide, the first graphitization treatment step is not particularly required.

  Further, the mirror base material structure manufacturing process is not limited to the above. In the above description, the first carbon base member 18a is obtained by compression molding the carbon base material 15 obtained by adding a binder to carbon fiber powder in the first base base material forming step. However, the first carbon base member 18a may be obtained by compression-molding a base base material in which silicon carbide powder is previously mixed with carbon fiber powder by a method such as cold isostatic pressing in the first base base material forming step. Good. Even when silicon carbide powder is mixed with carbon fiber powder in advance, if the carbon base molded body is impregnated with silicon by a reaction sintering process and carbon and silicon of the carbon base molded body are reacted, a rigid rib structure can be obtained. can get.

Embodiment 2. FIG.
FIG. 5 is a sectional view of a lightening mirror according to Embodiment 2 of the present invention.
In FIG. 5, a rib structure 3B constituting the mirror base material constituting part 2B of the light weight mirror 1B has a disk shape with a predetermined thickness in which the first through holes 4 are formed coaxially. A plurality of the recessed holes 5 are formed so as to be adjacent to each other through the rib portion 6b so as to open on one surface of the rib structure 3B. The other surface of the rib structure 3B is a flat surface orthogonal to the axis. Moreover, the height of the rib part 6b which divides the recessed hole 5 becomes low gradually toward the rib part 6b arrange | positioned at the center side of the rib structure 3B from the rib part 6b arrange | positioned at the outer peripheral wall 7 side. ing. At this time, the rib part 6b is shape | molded so that each end surface may contact | connect the rotation paraboloid centering on the axial center of the rib structure 3B.

The first mirror body 11a is joined to the rib structure 3B so as to close the opening of the recessed hole 5.
Other configurations of the lightening mirror 1B are the same as those in the first embodiment.

As for the weight reduction mirror 1B, the wall of the one surface side is comprised by the 1st mirror body 11a, and the wall of the other surface side is comprised by the bottom wall of the rib structure 3B. Since the linear expansion coefficient of the first mirror body 11a and the linear expansion coefficient of the rib structure 3B are substantially equal, the light weight mirror 1B is compared to the light weight mirror 1A in which the opening of the recessed hole 5 is exposed on the other surface. The linear expansion coefficients on the one surface side and the other surface side approach symmetry.
Therefore, according to the lighter mirror 1B, when the ambient temperature changes, the one surface side and the other surface side contract in the same manner. Therefore, in addition to the effect of the lighter mirror 1A, the heat applied to the first mirror body 11a. The effect that the influence of stress can be suppressed as much as possible is obtained. That is, the effect that the risk of breakage of the first mirror body 11a can be reduced is obtained.

Further, in the joining process of the manufacturing method of the lighter mirror 1B, although not shown, glass frit is applied to the end face of the rib portion 6b on the opening side of the recessed hole 5, and the first mirror body 11a and the rib structure 3B are made of glass. It arrange | positions in a furnace so that it may face through a frit.
Then, the temperature in the furnace is raised above the melting point of the glass frit, and after a predetermined time has elapsed, the temperature in the furnace is lowered. As a result, the once melted glass frit is solidified, so that the rib structure 3B and the first mirror body 11a are integrated, and the lighter mirror 1B shown in FIG. 5 is obtained.
Other manufacturing methods of the lighter mirror 1B are the same as those in the first embodiment.

  According to the second embodiment, the rib structure 3B containing silicon carbide as the main component is formed by applying silicon to the first carbon base member 18a that is easily cut, as in the first embodiment. Since it is obtained by diffusing, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
6 is a cross-sectional view of a lightening mirror according to Embodiment 3 of the present invention.
In FIG. 6, the rib structure 3C constituting the mirror base material structure 2C of the light weight mirror 1C is formed so that base material through holes 8a as rib structure holes are opened on both sides of the rib structure 3C. ing. At this time, the opening shape at both ends of the base material through hole 8a is an equilateral triangle. And the adjacent base material through-hole 8a is divided by the rib part 6c which has predetermined | prescribed wall thickness.
Other configurations of the lightening mirror 1C are the same as those in the first embodiment.

  The lightweight mirror 1C configured as described above is formed in the rib structure 3C so that the base material through hole 8a is partitioned by the rib portion 6c having a predetermined wall thickness. The rigidity is secured and the weight is reduced. At this time, since the main material of the rib structure 3C is silicon carbide, according to the lightening mirror 1C, similarly to the lightening mirror 1A, compared to the conventional lightening mirror made of only a glass material, Further increase in rigidity and weight can be achieved.

In the manufacturing method of the lighter mirror 1C, the base material through hole 8a is formed instead of forming the concave hole 5 in the cutting process in the manufacturing method of the lighter mirror 1A.
Other manufacturing methods of the lighter mirror 1C are the same as those in the first embodiment.

  According to the manufacturing method of the lighter mirror 1C, the carbon base material obtained by cutting the rib structure 3C mainly composed of silicon carbide on the first carbon base member 18a that can be easily cut, as in the first embodiment. It is obtained by diffusing silicon in the molded body 19. Therefore, the same effect as in the first embodiment can be obtained.

Embodiment 4 FIG.
FIG. 7 is a cross-sectional view of a lightening mirror according to Embodiment 4 of the present invention, and FIG. 8 is a view for explaining a manufacturing method of the lightening mirror according to Embodiment 4 of the present invention.

In FIG. 7, the mirror base material structure 2D of the light weight mirror 1D includes a rib structure 3A and a first reinforcing member 22 that is coaxially integrated with the rib structure 3A. The first reinforcing member 22 is made of the same material as the rib structure 3A, and is joined to the other surface of the rib structure 3A. At this time, the 1st reinforcement member 22 is joined to the end surface of the rib part 6a of 3 A of rib structures so that each of the recessed holes 5 may be closed. The exposed surface of the first reinforcing member 22 constitutes the other surface of the mirror base material structure 2D, and the exposed surface is a flat surface orthogonal to the axis. Further, the third through hole 23 is formed in the first reinforcing member 22 so as to correspond to the first through hole.
Other configurations of the lightening mirror 1D are the same as those in the first embodiment.

According to the lightweight mirror 1D configured as described above, the first reinforcing member 22 is joined to the end surface of the rib portion 6a of the rib structure 3A so as to close each of the recessed holes 5. The effect that the rigidity of the mirror base material structure 2D can be further increased is obtained.
In addition, the lighter mirror 1D has a wall on one side formed by the first mirror body 11a and the bottom wall of the rib structure 3A, and a wall on the other side formed by the first reinforcing member 22. Since the linear expansion coefficient of the first mirror body 11a and the linear expansion coefficients of the rib structure 3A and the first reinforcing member 22 are substantially the same, compared to the lightweight mirror 1A in which the opening of the recessed hole 5 is exposed on the other surface, The light weight mirror 1D has a linear expansion coefficient that is symmetric with respect to the one surface side and the other surface side.
Therefore, in the lighter mirror 1D, when the ambient temperature changes, the one surface side and the other surface side contract in the same manner, and therefore, in addition to the effect of the lighter mirror 1A, the influence of the thermal stress applied to the first mirror body 11a. Can be suppressed as much as possible. That is, the effect that the risk of breakage of the first mirror body 11a can be reduced is obtained.

Next, a method for manufacturing the lighter mirror 1D will be described.
The manufacturing method of the lightweight mirror 1D includes a mirror base material structure manufacturing process and a joining process.
First, the mirror base material structure manufacturing process will be described with reference to FIG.
The manufacturing process of the mirror base material structure of the light weight mirror 1D includes a first base material forming process, a second carbon base material forming process, a first graphitizing process, a second graphitizing process, a cutting process, carbon It has a base body joining process and a reaction sintering process.

  The first base material forming step is the same as the first base material forming step of the manufacturing method of the lightening mirror 1A. Then, the second base material forming process proceeds simultaneously with the first base material forming process. That is, as shown in FIG. 8A, the carbon fiber powder and the binder are respectively attached to the separate molds 16a and 16b corresponding to the shapes of the rib structure 3A and the first reinforcing member 22, respectively. The carbon base material 15 mixed with powder is filled in a pressurized state. As a result, the carbon base material 15 is compression-molded to form plate-like first carbon base member 18a and second carbon base member 18b that can be cut in the dies 16a and 16b, respectively.

  Further, the first graphitization treatment step is the same as the first graphitization treatment step of the method for manufacturing the lightening mirror 1A. And a 2nd graphitization process process advances simultaneously with a 1st graphitization process process. That is, as shown in FIG. 8B, the first carbon base member 18a and the second carbon base member 18b packed in the molds 16a and 16b are graphitized as in the first embodiment.

  Next, in the cutting step, as shown in FIG. 8 (c), the carbon base body 19 is formed by forming the concave holes 5 in the first carbon base member 18a by cutting as in the first embodiment. It has gained. The second carbon base member 18b is not cut.

  Next, in the carbon body bonding step, as shown in FIG. 8 (d), the second carbon body member 18b is bonded to the carbon body so as to close each of the openings of the recessed holes 5 of the carbon body molded body 19. Adhere to the molded body 19. Here, an integrated product of the bonded carbon base molded body 19 and the second carbon base member 18 b is a carbon base joined body 25.

In the reaction sintering step, the carbon base assembly 25 is placed in the furnace 17 as shown in FIG. Then, silicon 21 is placed on the carbon base assembly 25. Then, after raising the temperature in the furnace 17 to be equal to or higher than the melting point of the silicon 21, the temperature in the furnace 17 is lowered when a predetermined time has elapsed. As a result, the melted silicon 21 diffuses into the carbon base assembly 25, and the carbon of the carbon base assembly 25 and the silicon 21 react to form silicon carbide. That is, as shown in FIG. 8 (f), the carbon green body 19 and the second carbon green body member 18b become the rib structure 3A and the first reinforcing member 22 mainly composed of silicon carbide, and the rib structure. A mirror base material structure 2D in which the body 3A and the first reinforcing member 22 are integrated is obtained.
In addition, the joining process is the same as that of Embodiment 1, and the weight reduction mirror 1D is obtained by implementing a joining process.

  According to the fourth embodiment, rib structure 3A mainly composed of silicon carbide is obtained in the same manner as in the first embodiment. Further, in the carbon base body bonding step, the second carbon base member 18b is bonded to the carbon base body 19 so as to close each of the openings of the recessed holes 5 of the carbon base body 19 and the carbon base body 25 is bonded. Have gained. Furthermore, by diffusing silicon into the carbon base bonded body 25 in the reaction sintering step, the mirror base material structure portion 2D in which the first reinforcing member 22 and the rib structure 3A each having silicon carbide as a main component are integrated. It has gained. Thereby, in addition to the effect of the manufacturing method of the weight reduction mirror 1A of Embodiment 1, the effect that the rigidity of mirror base material structure part 2D can be improved further is acquired.

  In the fourth embodiment, the first reinforcing member 22 is described as being joined to the other surface of the rib structure 3A. However, the first reinforcing member 22 is attached to the other surface of the rib structure 3C of the lightening mirror 1C. The same effect as that of the lighter mirror 1D can be obtained even with the lighter mirror obtained by bonding.

Further, although the first base material forming step and the second base material forming step have been described as proceeding simultaneously, the first base material forming step and the second base material forming step may be performed separately.
Further, although the first graphitization treatment step and the second graphitization treatment step have been described as proceeding simultaneously, the first graphitization treatment step and the second graphitization treatment step may be performed separately.

Moreover, although the 1st graphitization process process and the 2nd graphitization process process were demonstrated as what is performed before a cutting process, you may perform with respect to the carbon base | substrate joined body 25 before a reaction sintering process. Furthermore, even if the first graphitization treatment step and the second graphitization treatment step are not performed, impurities other than carbon in the carbon base assembly 25 inhibit the reaction between carbon and silicon in the reaction sintering step. If the mirror base material structure 2D obtained in the reactive sintering step has high rigidity mainly composed of silicon carbide, the first graphitization treatment step and the second graphitization treatment step are particularly There is no need to do it.

  Further, in the carbon base body bonding step, the second carbon base member 18b is bonded to the carbon base green body 19 so as to close each of the openings of the recessed holes 5 of the carbon base green body 19, and the carbon base body bonded body 25. Explained as getting. However, in the carbon body bonding step, another carbon body formed body in which the recessed holes 5 are formed in the second carbon body member 18b is formed, and the respective recessed holes of the carbon body formed body 19 and the other carbon body formed bodies are formed. 5 may be used to obtain a carbon-based bonded body by bonding between the opening side end faces.

Embodiment 5 FIG.
FIG. 9 is a cross-sectional view of a lightening mirror according to Embodiment 5 of the present invention.
In FIG. 9, the lightening mirror 1E is made of the same material as the mirror functional unit 10A (first mirror body 11a), and includes a glass plate 26 as a second reinforcing member joined to the other surface of the rib structure 3A. ing.
The glass plate 26 has a disk shape in which a fourth through hole 27 having the same diameter as the first through hole 4 and the second through hole 12 is formed coaxially. The glass plate 26 is coaxially joined to the rib structure 3 </ b> A with the fourth through hole 27 corresponding to the first through hole 4.
Other configurations of the lightening mirror 1E are the same as those in the first embodiment.

The light weight mirror 1E has a wall on one side made up of the first mirror body 11a and the bottom wall of the rib structure 3A, and a wall on the other side made up of a glass plate 26 made of the same material as the first mirror body 11a. ing. Since the linear expansion coefficient of the first mirror body 11a and the glass plate 26 and the linear expansion coefficient of the rib structure 3A are substantially equal, the weight can be reduced as compared with the light weight mirror 1A in which the opening of the recessed hole 5 is exposed on the other surface. The mirror 1E has a linear expansion coefficient that is nearly symmetrical between the one surface side and the other surface side.
Therefore, according to the lighter mirror 1E, when the ambient temperature changes, the one surface side and the other surface side expand and contract in the same manner. Therefore, in addition to the effect of the lighter mirror 1A, the heat applied to the first mirror body 11a. The effect that the influence of stress can be suppressed as much as possible is obtained. That is, the risk of damage to the first mirror body 11a can be reduced.

  In the fifth embodiment, the glass plate 26 is joined to the other surface of the rib structure 3A. However, the glass plate 26 is attached to the mounting surface of the first mirror body 11a of the rib structures 3B and 3C. Even if it is bonded to the opposite surface (other surface) or bonded to the exposed surface side of the first reinforcing member 22 of the mirror base material structure 2D, it is affected by the thermal stress applied to the first mirror body 11a. The effect which suppresses as much as possible is acquired.

Next, a method for manufacturing the lighter mirror 1E will be described.
In the joining process of the manufacturing method of the light weight mirror 1E, although not shown, a pasted glass frit is applied to one surface of the rib structure 3A and the end surface of the rib portion (the other surface of the rib structure 3A), and the first mirror body The other surface of 11a and one surface of the glass plate 26 are arranged in the furnace so as to match the one surface and the other surface of the rib structure 3A, respectively. Then, the temperature in the furnace is raised above the melting point of the glass frit, and after a predetermined time has elapsed, the temperature in the furnace is lowered. Thereby, since the glass frit once melted is solidified, the rib structure 3A, the first mirror body 11a, and the glass plate 26 are integrated, and the lighter mirror 1E shown in FIG. 9 is obtained.
Other manufacturing methods of the lighter mirror 1E are the same as those in the first embodiment.

  According to the fifth embodiment, the rib structure 3A mainly composed of silicon carbide is obtained in the same manner as the manufacturing method of the lightening mirror 1A. Therefore, according to the manufacturing method of the lightweight mirror 1E, the same effect as the manufacturing method of the lightweight mirror 1A can be obtained.

Embodiment 6 FIG.
FIG. 10 is a front view of a lightening mirror according to Embodiment 6 of the present invention.
In FIG. 10, the mirror functional unit 10B of the lightening mirror 1F is made of the same material as that of the first mirror body 11a, and is formed by a plurality of second mirror bodies 11b each serving as a mirror divided body. Each of the second mirror bodies 11b has an equilateral triangular flat plate shape, and one surface thereof is polished to constitute a reflecting surface.
And the 2nd mirror body 11b is joined to 3 A of rib structures in the state arrange | positioned regularly with almost no clearance at one surface of the rib structure 3A in the thickness direction with the reflection surface facing outward.
The other configuration of the light weight mirror 1F is the same as that of the first embodiment.

  The mirror function unit 10B of the lightening mirror 1F is composed of a plurality of second mirror bodies 11b. Therefore, the second mirror body 11b is molded or polished to form a reflecting surface, as compared with the first mirror body 11a in which the mirror functional unit 10A is configured by a single member like the lightweight mirror 1A. Cheap. Further, even if one of the second mirror bodies 11b is damaged during the manufacturing process, it can be easily replaced. Thereby, in the light weight mirror 1F, in addition to the effect of the light weight mirror 1A, the product yield is increased, so that the manufacturing cost can be suppressed.

Further, the linear expansion coefficients of the second mirror body 11b and the rib structure 3A are substantially equal. However, when the rib structure 3A is enlarged, if the ambient temperature of the lightening mirror 1F varies, the rib structure 3A and the mirror function A difference occurs in the amount of distortion of the portion 10B. However, since the mirror function unit 10B is constituted by the plurality of divided second mirror bodies 11b, the thermal stress generated individually in each of the second mirror bodies 11b is absorbed between the adjacent second mirror bodies 11b. Can be made.
Therefore, according to the lighter mirror 1F, in addition to the effect of the lighter mirror 1A, an effect that the risk of breakage of the mirror function unit 10B can be reduced.

In the joining step of the manufacturing method of the lightening mirror 1F, although not shown, a plurality of second mirror bodies 11b are arranged on one surface of a rib structure 3A coated with paste-like glass frit and arranged in the furnace. And after raising the temperature in a furnace to the temperature more than melting | fusing point of a glass frit and making it pass for a predetermined time, the temperature in a furnace is lowered | hung. Thereby, since the glass frit once melted is solidified, the rib structure 3A and the second mirror body 11b are integrated, and the lightening mirror 1F shown in FIG. 10 is obtained.
Other manufacturing methods of the lighter mirror 1F are the same as those in the first embodiment.

  According to the sixth embodiment, rib structure 3A mainly composed of silicon carbide is obtained in the same manner as in the first embodiment. Therefore, according to the manufacturing method of the lightweight mirror 1F, the same effect as the manufacturing method of the lightweight mirror 1A can be obtained.

  In the sixth embodiment, the outer shape of each of the second mirror bodies 11b is assumed to be an equilateral triangle. However, the outer shape of the second mirror body 11b is not limited to that of an equilateral triangle, and other various shapes. It may be a square or one having a curved outer shape. Moreover, it is not limited to what comprises the mirror function part 10B with the 2nd mirror body 11b of a single external shape, The mirror function part 10B may be comprised with the 2nd mirror body which consists of a some external shape.

Embodiment 7 FIG.
11 is a front view of a lightening mirror according to Embodiment 7 of the present invention, FIG. 12 is a cross-sectional view taken along arrow XII-XII in FIG. 11, and FIG. 13 is an enlarged view of part A in FIG.

11 to 13, in the rib structure 3D constituting the mirror base material structure 2E of the light weight mirror 1G, a base material through hole 8b as a rib structure hole is opened on both surfaces of the rib structure 3D. , Adjacent to each other through the rib portion 6d. At this time, the opening shape of the base material through hole 8b is a regular hexagon.
Further, the mirror function unit 10C is constituted by a plurality of third mirror bodies 11c as mirror divided bodies having a reflecting surface on one surface. Each of the third mirror bodies 11c is a flat plate having a regular hexagonal outer shape slightly larger than the opening shape of the base material through hole 8b, and one surface thereof is polished to constitute a reflecting surface. More specifically, the length of each side of the third mirror body 11c is longer than the length of each side of the base material through hole 8b by half the wall thickness of the rib portion 6d.

Then, each of the third mirror bodies 11c has the reflecting surface (one surface) facing outward so that each of the openings on one surface side of the rib structure 3D is closed, and the rib structure 3D There are almost no gaps on one side, and they are regularly arranged. At this time, each of the third mirror bodies 11c is joined to the rib structure 3D so that a region having a length half the wall thickness of the rib portion 6d from each outer edge portion is supported by one end face of the rib portion 6d. ing.
Other configurations of the lighter mirror 1G are the same as those in the first embodiment.

  The mirror function unit 10C of the light weight mirror 1G is configured by a plurality of divided third mirror bodies 11c. Therefore, according to the lighter mirror 1G, in addition to the effect of the lighter mirror 1A, the product yield is improved, so that the manufacturing cost can be reduced and the risk of damage to the mirror function unit 10C can be reduced. The effect is obtained.

In the manufacturing method of the lighter mirror 1G, the base material through hole 8b is formed instead of forming the concave hole 5 in the cutting process in the manufacturing method of the lighter mirror 1A.
In the joining process of the manufacturing method of the lightening mirror 1G, although not shown, paste-like glass frit is applied to the end surface of the rib portion 6d, and each of the third mirror bodies 11c is supported on the end surface of the rib portion 6d. Such an array is arranged in the furnace. Then, the temperature in the furnace is raised to a temperature equal to or higher than the melting point of the glass frit, and after a predetermined time has elapsed, the temperature in the furnace is lowered. Thereby, since the glass frit once melted is solidified, the rib structure 3D and the third mirror body 11c are integrated, and the weight-reduced mirror 1G shown in FIGS. 11 to 13 is obtained.
The other manufacturing method of the light weight mirror 1G is the same as that of the first embodiment.

  In the seventh embodiment, a rib structure 3D mainly composed of silicon carbide is obtained in the same manner as in the first embodiment. Therefore, according to the manufacturing method of the lightweight mirror 1G, the same effect as the manufacturing method of the lightweight mirror 1A can be obtained.

  In the seventh embodiment, each of the third mirror bodies 11c closes each of the openings on one surface side of the rib structure 3D, and the wall thickness of the rib portion 6d from each outer edge portion. It has been described that the half length region is joined to the rib structure 3D so as to be supported by one end face of the rib portion 6d. However, for example, when the opening shape of the base material through hole is an equilateral triangle, a third mirror body having a shape corresponding to a quadrangle formed by the outer shapes of two adjacent base material through holes is prepared, and the outer edge of the third mirror body is prepared. The rib structure and the third mirror body may be joined so that the portion is supported by the end face of the rib portion that partitions the adjacent base material through hole. That is, when the third mirror body 11c is joined to the side of the rib structure that has the opening of the base material through hole (or the concave hole), the outer edge of the third mirror body 11c is supported by the end face of the rib portion. If it is joined to the rib structure as described above, it is not necessary to open each of the base material through holes, and it is not necessary to match the outer shape of the base material through holes.

Embodiment 8 FIG.
14 is a cross-sectional view of a lightening mirror according to an eighth embodiment of the present invention, FIG. 15 is a cross-sectional view taken along the line XV-XV in FIG. 14, and FIG.

  14-16, the mirror function part 10D of the weight reduction mirror 1H is comprised by the disk shaped 4th mirror body 11d, and the one surface side is grind | polished and becomes a reflective surface. A plurality of cut groups 28 are formed on the other surface of the fourth mirror body 11d (joint surface with the rib structure 3A).

Each of the cut groups 28 has a plurality of first cuts 28a extending in a predetermined direction with a predetermined interval from each other, and extending so as to be orthogonal to each of the first cuts with a predetermined interval between each other. The plurality of second cuts 28b.
Each of the first cuts 28a and each of the second cuts 28b are formed so as to connect two points on the outer peripheral edge of the fourth mirror body 11d. Each of the first cuts 28a is formed so that the depth direction thereof coincides with the thickness direction of the fourth mirror body 11d. At this time, as shown in FIG. 16, each of the first cuts 28a is formed in an aperture shape in which the area in a cross section perpendicular to the depth direction increases toward the other surface side of the fourth mirror body 11d. Although not shown, each of the second cuts 28b is also formed in the same opening shape as the first cuts 28b.

The fourth mirror body 11d is joined to the rib structure 3A with the other surface aligned with one surface of the rib structure 3A.
Other configurations of the lightening mirror 1H are the same as those in the first embodiment.

According to the weight-reducing mirror 1H configured as described above, the cut group 28 is formed on the other surface of the fourth mirror body 11d. Thereby, if there is a difference between the distortion amount of the rib structure 3A and the distortion amount of the fourth mirror body 11d due to a slight difference between the linear expansion coefficient of the fourth mirror body 11d and the linear expansion coefficient of the rib structure 3A. However, the thermal stress applied to the fourth mirror body 11d is absorbed by the cut group 28. Therefore, in addition to the effect of the first embodiment, the effect that the fourth mirror body 11d can be prevented from being damaged can be obtained.
The manufacturing method of the lighter mirror 1H is the same as that of the first embodiment. That is, a rib structure 3A mainly composed of silicon carbide is obtained in the same manner as in the first embodiment. Therefore, according to the manufacturing method of the lightweight mirror 1H, the same effect as the manufacturing method of the lightweight mirror 1A can be obtained.

  In the eighth embodiment, a plurality of first cuts 28a extending in a predetermined direction and a plurality of second cuts orthogonal to the extending direction of the plurality of first cuts 28a are formed on the other surface of the fourth mirror body 11d. It has been described that the cut group 28 made of 28b is formed. Further, the first cut 28a and the second cut 28b have been described as being formed so as to connect two points on the outer peripheral edge of the fourth mirror body 11d. However, the cut group 28 is not limited to the one formed by a plurality of first cuts and a plurality of second cuts. The cut group 28 may be formed with a plurality of cuts so as to intersect at a predetermined angle, or may be formed with discrete cuts of a predetermined length on the other surface of the fourth mirror body 11d.

  Furthermore, even if the cut group 28 is configured on each other surface of the second mirror body 11b constituting the mirror function 1B and each other surface of the third mirror body 11c constituting the mirror function unit 1C, The effect of preventing breakage of the mirror body 11b and the third mirror body 11c is obtained.

  In the second, fourth, and fifth embodiments, each of the light weight mirrors 1B, 1D, and 1E has an opening of the concave hole 5 as a rib structure hole, respectively, the first mirror body 11a, the first reinforcing member 22, And it demonstrated as what is plugged up by the glass plate 26. FIG. When the lightening mirrors 1B, 1D, and 1E having such a configuration are used in an environment of atmospheric pressure different from that at the time of manufacturing the lightening mirrors 1B, 1D, and 1E, the small holes communicate with the inside and outside of the recessed holes 5. Thus, it is desirable to form the mirror base material structures 2B and 2D on the side opposite to the bonding surface of the mirror function part 10A.

It is a front view of the weight reduction mirror which concerns on Embodiment 1 of this invention. It is a rear view of the weight reduction mirror which concerns on Embodiment 1 of this invention. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1. It is a figure explaining the manufacturing method of the weight reduction mirror which concerns on Embodiment 1 of this invention. It is sectional drawing of the weight reduction mirror which concerns on Embodiment 2 of this invention. It is sectional drawing of the weight reduction mirror which concerns on Embodiment 3 of this invention. It is sectional drawing of the weight reduction mirror which concerns on Embodiment 4 of this invention. It is a figure explaining the manufacturing method of the weight reduction mirror which concerns on Embodiment 4 of this invention. It is sectional drawing of the weight reduction mirror which concerns on Embodiment 5 of this invention. It is a front view of the weight reduction mirror which concerns on Embodiment 6 of this invention. It is a front view of the weight reduction mirror which concerns on Embodiment 7 of this invention. It is XII-XII arrow sectional drawing of FIG. It is the A section enlarged view of FIG. It is sectional drawing of the weight reduction mirror which concerns on Embodiment 8 of this invention. It is XV-XV arrow sectional drawing of FIG. It is the B section enlarged view of FIG.

Explanation of symbols

  1A to 1H Lightweight mirror, 3A to 3D Rib structure, 5 Concave hole (Rib structure hole), 8a, 8b Base material through hole (Rib structure hole), 10A to 10D Mirror function part, 11b Second mirror body (Mirror (Divided body), 11c third mirror body (mirror divided body), 18a first carbon base material, 18b second carbon base member, 19 carbon base molded body, 21 silicon, 22 first reinforcing member, 26 glass plate (first 2 reinforcing members), 28a, 28b.

Claims (13)

A first base material forming step of obtaining a plate-like first carbon base member by subjecting the base material mainly composed of carbon or a mixed material of carbon and silicon carbide to compression molding;
A cutting step of forming a plurality of rib structure holes whose hole directions coincide with the thickness direction of the first carbon base member by cutting the first carbon base member to obtain a carbon base formed body;
A reaction sintering step of impregnating molten carbon into the carbon base molded body, and reacting and sintering carbon of the carbon base molded body and the silicon to obtain a rib structure;
A bonding step of bonding a mirror functional unit made of a glass material to one surface of the rib structure with a reflecting surface facing outward;
The manufacturing method of the weight reduction mirror characterized by providing.   The method for producing a light-weight mirror according to claim 1, wherein the first carbon base member or the carbon base compact is subjected to graphitization prior to the reaction sintering step. A second base material forming step of obtaining a plate-like second carbon base member by compressing the base material mainly composed of carbon or a mixed material of carbon and silicon carbide;
A carbon green body bonding step of bonding the second carbon green body member to the carbon green body molded body so as to close the opening of the rib structure hole after the cutting process,
In the reaction sintering step, the second carbon base member is impregnated with molten silicon together with the carbon base compact, and the carbon of the carbon base compact and the second carbon base member are reacted with the silicon. The method of manufacturing a lightweight mirror according to claim 1, wherein the first reinforcing member integrated with the rib structure is manufactured.   Prior to the reaction sintering step, graphitization is performed on the first carbon base member and the second carbon base base material before the cutting step, or on the joined body of the first base green body and the second carbon base member. 4. The method for manufacturing a light weight mirror according to claim 3, wherein the treatment is performed. A rib structure mainly composed of silicon carbide formed so that a plurality of rib structure holes whose thickness direction is the hole direction are adjacent to each other through the rib portion;
A mirror functional part made of a glass material having a linear expansion coefficient equal to or substantially the same as that of silicon carbide, which is bonded to one surface in the thickness direction of the rib structure with the reflecting surface facing outward;
A lightweight mirror comprising:   6. The lightweight mirror according to claim 5, wherein the mirror function unit is divided into a plurality of mirror divided bodies.   7. The lightweight mirror according to claim 5, wherein the rib structure hole is formed so as to open on both surfaces of the rib structure in the thickness direction.   7. The lightweight mirror according to claim 5, wherein the rib structure hole is formed so as to open on the other surface in the thickness direction of the rib structure.   The lightening mirror according to claim 7 or 8, wherein a first reinforcing member made of the same material as that of the rib structure is joined to the other surface in the thickness direction of the rib structure.   7. The lightweight mirror according to claim 5, wherein the rib structure hole is formed so as to open on one surface in the thickness direction of the rib structure.   The lightweight mirror according to claim 9, wherein a second reinforcing member made of the same material as that of the mirror function part is joined to an exposed surface of the first reinforcing member.   The second reinforcing member made of the same material as that of the mirror function part is bonded to the other surface in the thickness direction of the rib structure, wherein the second reinforcing member is any one of claims 7, 8, and 10. The lightweight mirror according to item.   The light-weight mirror according to any one of claims 5 to 12, wherein a cut is formed on the other surface of the mirror function part.

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