Ceramic matrix composite material integrated forming die and method for primary and secondary mirror supporting cylinders

Abstract

The invention discloses a ceramic matrix composite material integrated forming mold and method for a primary and secondary mirror supporting cylinder, and solves the problems that the existing primary and secondary mirror supporting cylinder is manufactured by a split manufacturing and assembling method, so that fibers of the primary and secondary mirror supporting cylinder are not continuous, and the sizes of all parts are easy to be out of tolerance. Comprising a cylinder inner mold, a cylinder outer mold, a bracket outer mold and a circular top cover, the cylinder inner mold comprises a circular plate inner mold, a cylinder inner mold and a square cylinder inner mold which are coaxially connected in sequence from bottom to top; the cylinder outer mold comprises N arc-shaped pressing outer molds arranged around the cylinder inner mold, and N is a positive integer greater than or equal to 2; the bracket outer mold comprises four bracket split molds; and the four bracket split dies are arranged around the upper section part of the cylindrical inner die and outside the square cylindrical inner die. The round supporting cylinder and the square supporting cylinder can be integrally formed, the strength of the primary and secondary mirror supporting cylinders is improved, and the problem that in a split structure forming process, the assembly difficulty is large due to the fact that the size of a single part is out of tolerance is solved.

Description

Technical Field

[0001] The invention relates to a primary and secondary mirror support tube, and in particular to a ceramic-based composite material integrated molding die and method for the primary and secondary mirror support tube. Background Art

[0002] The primary and secondary mirror support tubes are the most critical support structures of optical remote sensors. They are used to support optical detectors and related circuits and have high thermal stability and mechanical performance requirements. Figure 1 As shown, the primary and secondary mirror support tubes include a circular support tube 01, a square support tube 02, and a support bracket; the lower end of the circular support tube 01 is provided with an outward annular flange 03; the square support tube 02 is arranged at the top center of the circular support tube 01, and the side length of the square support tube 02 is smaller than the diameter of the circular support tube 01, so a connecting ring 06 is vertically connected between the lower end of the square support tube 02 and the upper end of the circular support tube 01; the support bracket includes four support plates 04 evenly arranged around the circular support tube 01 and the square support tube 02 and a support ring 05 arranged on the top of the four support plates 04; the four support plates 04 are respectively located at the centers of the four sides of the square support tube 02, and are respectively vertically connected to the four sides thereof, and are also connected to the outer wall of the upper section of the circular support tube 01. It can be seen that the primary and secondary mirror support tubes are a complex structure including a circular-to-square cylinder structure, which is generally made of ceramic-based composite materials. Ceramic matrix composites are a new type of thermal structural / functional integrated material that combines the performance advantages of metal materials, ceramic materials and carbon materials. It has the characteristics of high temperature resistance, low density, high specific strength, high specific modulus, oxidation resistance, ablation resistance, insensitivity to cracks, and no catastrophic damage. It is widely used in components.

[0003] At present, the round-to-square cylinder structure of SiC / SiC and C / SiC composite materials generally adopts split structure densification and finalization, and finally assembles the parts of each split structure. The mold of the parts of the split structure is formed by splicing a simple structure, and finally fixed and formed by bolts and pins. In this way, the dimensions between the various parts are prone to deviation, which often leads to greater difficulty in assembly and cannot meet the requirements of high-precision structural forming. Moreover, for the cylinder structure combining round and square, the finalization process is more difficult. Not only must the fiber have a high continuity, but also the appearance of the cylinder structure after finalization must be intact, and the final prepared primary and secondary mirror support cylinder must have a high strength. However, the primary and secondary mirror support cylinders made by the existing split production method cannot meet the requirements. Summary of the invention

[0004] In order to solve the technical problems that the existing primary and secondary mirror support tubes are made by a split production and reassembly method, resulting in the fibers having no continuity, the dimensions of the various components are prone to deviations, and the strength of the primary and secondary mirror support tubes cannot meet the requirements, the present invention provides a ceramic-based composite material integrated molding die and method for the primary and secondary mirror support tubes.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A ceramic matrix composite integrated molding die for a primary and secondary mirror support tube, which is special in that it includes a tube inner mold, a tube outer mold, a bracket outer mold and a circular top cover;

[0007] The inner mold of the cylinder comprises a circular plate inner mold, a cylindrical inner mold and a square cylinder inner mold which are coaxially connected in sequence from bottom to top; the circular plate inner mold is provided with a molding area which matches the annular flange of the primary and secondary mirror support cylinder to be prepared, and is used to make the annular flange; the outer walls of the cylindrical inner mold are all its molding areas, which are used to make the circular support cylinder of the primary and secondary mirror support cylinder to be prepared; the side walls of the square cylinder inner mold are all its molding areas, which are used to make the square support cylinder of the primary and secondary mirror support cylinder to be prepared; a connecting ring mold is vertically connected between the lower end of the square cylinder inner mold and the upper end of the cylindrical inner mold; the outer walls of the connecting ring mold are all its molding areas, which are used to make the connecting rings of the primary and secondary mirror support cylinders to be prepared;

[0008] The cylinder outer mold comprises N arc-shaped pressing outer molds arranged around the cylinder inner mold, N ≥ 2 and is a positive integer; adjacent arc-shaped pressing outer molds are detachably connected; each arc-shaped pressing outer mold is detachably connected to the circular plate inner mold; the height of the arc-shaped pressing outer mold is lower than the cylinder inner mold, so that the N arc-shaped pressing outer molds are wound outside the lower section of the cylinder inner mold;

[0009] The bracket outer mold includes four bracket sub-molds; the four bracket sub-molds are arranged around the upper section of the cylindrical inner mold and outside the square cylindrical inner mold; adjacent bracket sub-molds are detachably connected; each of the four bracket sub-molds is provided with a molding area matching the support plate and a quarter support ring of the primary and secondary mirror support cylinders to be prepared, for making the support plate and the support ring;

[0010] The circular top cover is detachably pressed onto the top of the four bracket split molds.

[0011] Further, the bracket split mold includes a first vertical template and a second vertical template;

[0012] The outer sides of the first vertical template and the second vertical template are provided with a molding area matching the support plate, and the inner sides of the lower ends of both are provided with a first notch and a second notch matching the generatrix of the upper section of the cylindrical inner mold and the outer wall of the square cylinder inner mold; an anisotropic buckle plate with an inner wall matching the upper section of the cylindrical inner mold and the outer wall of the square cylinder inner mold is provided between the side wall of the first notch and the side wall of the second notch, and can be buckled and pressed on the upper section of the cylindrical inner mold and the outside of the square cylinder inner mold; the inner walls of the anisotropic buckle plates are their molding areas; the inner sides of the upper ends of the first vertical template and the second vertical template are vertically connected to each other; an upper arc plate is vertically connected between the first vertical template and the second vertical template; the upper arc plate is arranged close to the upper ends of the first vertical template and the second vertical template, and is detachably connected to the circular top cover; the top surface of the upper arc plate is its molding area, which is used to make a support ring.

[0013] Furthermore, the upper end of the arc-shaped pressing outer mold is provided with an outward arc-shaped upper flange, and the lower end is provided with an outward arc-shaped lower flange;

[0014] The arc-shaped pressing outer mold is detachably connected to the circular plate inner mold via an arc-shaped lower flange;

[0015] A lower arc plate is vertically connected between the first vertical template and the second vertical template; the lower arc plate is arranged close to the lower ends of the first vertical template and the second vertical template, and is detachably connected to the arc upper flange.

[0016] Furthermore, the inner sides of the first vertical formwork and the second vertical formwork are provided with weight-reducing holes;

[0017] A reinforcement plate is vertically connected between the first vertical formwork and the second vertical formwork.

[0018] Furthermore, the bottom of the circular plate inner mold is provided with supporting legs.

[0019] A method for integrally forming a ceramic matrix composite material for a primary and secondary mirror support tube adopts the above-mentioned ceramic matrix composite material integrally forming mold for a primary and secondary mirror support tube, and its special feature is that it comprises the following steps:

[0020] Step 1, obtain a first carbon cloth whose height is greater than the length of the busbar of the cylinder inner mold and whose length is equal to the circumference of the outer circle of the cylinder inner mold, and wind the first carbon cloth to the outer wall of the cylinder inner mold, so that the first carbon cloth leaves an upper margin outside the upper end of the cylinder inner mold and a first lower margin outside the lower end of the cylinder inner mold; after cutting a plurality of busbar seams evenly side by side in the circumferential direction around the upper margin, fit the cut upper margin to the outer wall of the connecting ring mold and the square cylinder inner mold, and after cutting a plurality of busbar seams evenly side by side in the circumferential direction around the first lower margin, fit the cut first lower margin to the molding area on the circular plate inner mold, so that a meat-missing area is formed on the outer wall of the square cylinder inner mold and the molding area of ​​the circular plate inner mold, and the meat-missing area is filled with broken carbon cloth; the excess first carbon cloth is cut along the outer circle of the molding area of ​​the circular plate inner mold, and the excess first carbon cloth is cut along the upper end face of the square cylinder inner mold;

[0021] Step 2, obtain a second carbon cloth with a height greater than the busbar of the inner mold of the cylinder and a length equal to the circumference of the outer wall of the square cylinder inner mold, and wind the second carbon cloth to the outer wall of the square cylinder inner mold, so that the second carbon cloth leaves a second lower margin outside the lower end of the square cylinder inner mold; after cutting a plurality of busbars side by side evenly around the second lower margin in the circumferential direction, fit the cut second lower margin to the outer wall of the forming area of ​​the connecting ring mold, the cylinder inner mold and the circular plate inner mold, so that a meat-missing area is formed on the outer wall of the connecting ring mold, the cylinder inner mold and the circular plate inner mold, and the meat-missing area is filled with the broken carbon cloth;

[0022] Step 3, obtain a first annular carbon cloth whose inner and outer diameters match the molding area of ​​the circular plate inner mold, and fit it to the molding area of ​​the circular plate inner mold; obtain a third carbon cloth whose height and length match the outer wall of the cylindrical inner mold, and fit it to the outer wall of the cylindrical inner mold; obtain a second annular carbon cloth whose shape and size match the connecting ring mold, and fit it to the outer wall of the connecting ring mold; obtain a fourth carbon cloth whose height and length match the outer wall of the square cylinder inner mold, and fit it to the outer wall of the square cylinder inner mold; the first annular carbon cloth, the third carbon cloth, the second annular carbon cloth and the fourth carbon cloth are all whole cloths;

[0023] Step 4, repeating steps 1 to 3 until the thickness of the preform formed by all carbon cloths reaches a first preset value, and the outermost layer is a whole cloth;

[0024] Step 5, N arc-shaped pressing outer molds of the cylinder outer mold are installed around the lower section of the cylinder inner mold;

[0025] Step 6: Laminating multiple layers of the fifth carbon cloth on the molding areas of the four bracket sub-molds so that the thickness of all the fifth carbon cloths reaches the second preset value;

[0026] Step 7, four bracket sub-molds are installed around the upper part of the cylindrical inner mold and the outside of the square cylinder inner mold, and a circular top cover is pressed on the top of the four bracket sub-molds to obtain a mold to be deposited;

[0027] Step 8: Place the mold to be deposited in a chemical vapor deposition device, prepare the pyrolytic carbon interface layer and perform densification treatment, then remove the integrated molding mold to obtain the integrated primary and secondary mirror support tubes.

[0028] Furthermore, step 6 is specifically as follows:

[0029] Multiple layers of fifth carbon cloth are laminated on the first vertical template or the second vertical template molding area of ​​each bracket split mold, and multiple layers of fifth carbon cloth are laminated on the inner wall of the anisotropic gusset plate, so that the thickness of all fifth carbon cloths reaches the second preset value.

[0030] Furthermore, after step 1 and before step 2, a punching step is also included:

[0031] Pre-drilling sewing holes on the outer mold of the cylinder and the outer mold of the bracket;

[0032] After step 7 and before step 8, the sewing step also includes:

[0033] The seams of the corresponding carbon cloths are sewn through the sewing holes, and the sewing principle is one hole and one needle.

[0034] Further, in step 4, the first preset value range is 2 mm to 3 mm;

[0035] In step 6, the second preset value range is 2 mm to 3 mm.

[0036] Furthermore, in step 8, the thickness of the prepared pyrolytic carbon interface layer is in the range of 150 nm to 250 nm.

[0037] Beneficial effects of the present invention:

[0038] 1. The present invention is provided with an integrated cylinder inner mold including a cylindrical inner mold and a square cylinder inner mold, which can make the circular support cylinder and the square support cylinder integrally formed, without the need for separate production and reassembly, without the need for fixing and riveting by pins, and will not cause dimensional deviations between the components, thereby improving the strength of the primary and secondary mirror support cylinders and avoiding the problem of greater assembly difficulty caused by the dimensional deviation of a single part in the split structure molding process.

[0039] 2. The ceramic-based composite integrated molding mold and method for the primary and secondary mirror support tubes provided by the present invention, when bonding carbon cloth, firstly bond the entire cloth from the cylindrical inner mold to the square cylindrical inner mold, and then bond the entire cloth from the square cylinder inner mold to the cylindrical inner mold, and also bond the entire cloth to the circular plate inner mold, the cylindrical inner mold, the connecting ring mold, and the square cylinder inner mold respectively, thus ensuring the continuity of the carbon cloth fibers in both the longitudinal and circumferential directions, further improving the strength of the primary and secondary mirror support tubes.

[0040] 3. The integrated molding die of the ceramic-based composite material for the primary and secondary mirror support tube provided by the present invention is also provided with a tube outer mold composed of N arc-shaped pressing outer molds, and a circular top cover is provided. The four bracket sub-molds can be closely attached to each other, so that all the bonded carbon cloths are pressed by the corresponding modules, which can avoid the expansion and deformation of the preform parts during the deposition process and improve the product quality.

[0041] 4. When cutting the busbar seams, the present invention cuts multiple busbar seams evenly around the cylindrical inner mold or the square cylindrical inner mold in the circumferential direction. In this way, even if the size of the parts is slightly deformed during the chemical vapor deposition process, the deformation will be very uniform, which can ensure that the parts have a better size after deposition and improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the structure of the primary and secondary mirror support tube to be prepared in the present invention;

[0043] 01-circular support cylinder, 02-square support cylinder, 03-annular flange, 04-support plate, 05-support ring, 06-connecting ring;

[0044] Figure 2 It is a structural schematic diagram of an embodiment of a ceramic-based composite material integrated molding die for primary and secondary mirror support tubes of the present invention;

[0045] Figure 3 Schematic diagram of the structure of the inner mold of the cylinder in an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of the structure of the outer mold of the cylinder in the embodiment of the present invention;

[0047] Figure 5 is a schematic structural diagram of the outer mold of the bracket in an embodiment of the present invention;

[0048] Figure 6 This is one of the structural diagrams of step 1 in an embodiment of the present invention;

[0049] Figure 7 This is the second structural diagram of step 1 in the embodiment of the present invention;

[0050] Figure 8 This is one of the structural diagrams of step 2 in an embodiment of the present invention;

[0051] Fig. 9 This is the second structural diagram of step 2 in the embodiment of the present invention;

[0052] Fig.10 is a schematic diagram of the structure of step 3 in an embodiment of the present invention;

[0053] Fig.11 is a schematic diagram of the structure of step 5 in an embodiment of the present invention;

[0054] Fig.12 It is a structural diagram of step 6 in an embodiment of the present invention.

[0055] Figure Number:

[0056] 1-cylinder inner mold, 11-circular plate inner mold, 12-cylinder inner mold, 13-square cylinder inner mold, 14-connecting ring mold, 15-leg, 2-cylinder outer mold, 21-arc-shaped pressing outer mold, 211-arc-shaped upper flange, 212-arc-shaped lower flange, 3-bracket outer mold, 31-bracket split mold, 311-first vertical template, 312-second vertical template, 313-heterotropic buckle plate, 314-upper arc plate, 315-lower arc plate, 316-weight reduction hole, 317-reinforcement plate, 4-round top cover, 5-first carbon cloth, 51-upper margin, 52-first lower margin, 6-crushed carbon cloth, 7-second carbon cloth, 71-second lower margin, 81-first annular carbon cloth, 82-third carbon cloth, 83-second annular carbon cloth, 84-fourth carbon cloth, 9-fifth carbon cloth. DETAILED DESCRIPTION

[0057] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0058] An embodiment of the present invention provides a ceramic matrix composite material integrated molding die for a primary and secondary mirror support tube, such as Figure 2 As shown, the integrated molding mold includes a cylinder inner mold 1, a cylinder outer mold 2, a bracket outer mold 3 and a circular top cover 4.

[0059] like Figure 3 As shown, the cylinder inner mold 1 comprises a circular plate inner mold 11, a cylindrical inner mold 12 and a square cylinder inner mold 13 which are coaxially connected in sequence from bottom to top; three legs 15 are provided at the bottom of the circular plate inner mold 11. The circular plate inner mold 11 is provided with a molding area which matches the annular flange 03 of the primary and secondary mirror support cylinder to be prepared, and is used to make the annular flange 03; the outer walls of the cylindrical inner mold 12 are all its molding areas, which are used to make the circular support cylinder 01 of the primary and secondary mirror support cylinder to be prepared; the side walls of the square cylinder inner mold 13 are all its molding areas, which are used to make the square support cylinder 02 of the primary and secondary mirror support cylinder to be prepared; a connecting ring mold 14 is vertically connected between the lower end of the square cylinder inner mold 13 and the upper end of the cylindrical inner mold 12; the outer walls of the connecting ring mold 14 are all its molding areas, which are used to make the connecting ring 06 of the primary and secondary mirror support cylinder to be prepared;

[0060] like Figure 4As shown, the cylinder outer mold 2 includes three arc-shaped pressing outer molds 21 arranged around the cylinder inner mold 12; adjacent arc-shaped pressing outer molds 21 are detachably connected; each arc-shaped pressing outer mold 21 is detachably connected to the circular plate inner mold 11; the height of the arc-shaped pressing outer mold 21 is lower than the cylinder inner mold 12, so that the cylinder outer mold 2 is wound outside the lower section of the cylinder inner mold 12; the upper end of each arc-shaped pressing outer mold 21 is provided with an outward arc-shaped upper flange 211, and the lower end is provided with an outward arc-shaped lower flange 212; the arc-shaped pressing outer mold 21 is detachably connected to the circular plate inner mold 11 through the arc-shaped lower flange 212;

[0061] The bracket outer mold 3 includes four bracket sub-molds 31; the four bracket sub-molds 31 are arranged around the upper part of the cylindrical inner mold 12 and the outside of the square cylindrical inner mold 13; adjacent bracket sub-molds 31 are detachably connected; the four bracket sub-molds 31 are respectively provided with molding areas matching the support plate 04 and a quarter support ring 05 of the primary and secondary mirror support cylinders to be prepared, which are used to make the support plate 04 and the support ring 05.

[0062] like Figure 5 As shown, the bracket split mold 31 includes a first vertical template 311 and a second vertical template 312; the outer sides of the first vertical template 311 and the second vertical template 312 are provided with a molding area matching the support plate 04, and the inner sides of the lower ends of both are provided with a first notch and a second notch matching the generatrix of the upper section of the cylindrical inner mold 12 and the outer wall of the square cylinder inner mold 13; between the side wall of the first notch and the side wall of the second notch is provided an anisotropic buckle plate 313 whose inner wall matches the upper section of the cylindrical inner mold 12 and the outer wall of the square cylinder inner mold 13, which can be buckled on the upper section of the cylindrical inner mold 12 and the outside of the square cylinder inner mold 13; the inner walls of the anisotropic buckle plates 313 are all its molding areas; the inner sides of the upper ends of the first vertical template 311 and the second vertical template 312 are vertically connected to each other. An upper arc plate 314 and a lower arc plate 315 are vertically connected between the first vertical template 311 and the second vertical template 312; the upper arc plate 314 is arranged near the upper ends of the first vertical template 311 and the second vertical template 312, and is detachably connected to the circular top cover 4; the lower arc plate 315 is arranged near the lower ends of the first vertical template 311 and the second vertical template 312, and is detachably connected to the arc upper flange 211. The inner sides of the first vertical template 311 and the second vertical template 312 are provided with weight-reducing holes 316; a reinforcing plate 317 is also vertically connected between the first vertical template 311 and the second vertical template 312.

[0063] The circular top cover 4 is detachably press-fitted on the top of the four bracket split molds 31 .

[0064] The primary and secondary mirror support tubes are prepared by using the ceramic matrix composite material integrated molding die for the primary and secondary mirror support tubes, which specifically includes the following steps:

[0065] Step 1: Figure 6As shown, a first carbon cloth 5 having a height greater than the busbar length of the cylinder inner mold 1 and a length equal to the outer circumference of the cylinder inner mold 1 is obtained, and the first carbon cloth 5 is wound around the outer wall of the cylinder inner mold 12, so that the first carbon cloth 5 has an upper margin 51 outside the upper end of the cylinder inner mold 12 and a first lower margin 52 outside the lower end of the cylinder inner mold 12; after cutting 6 busbar seams evenly side by side in the circumferential direction around the upper margin 51, the cut upper margin 51 is attached to the outer wall of the connecting ring mold 14 and the square cylinder inner mold 13, and after cutting 6 busbar seams evenly side by side in the circumferential direction around the first lower margin 52, the cut first lower margin 52 is attached to the molding area on the circular plate inner mold 11, so that meat-missing areas are formed on the outer wall of the square cylinder inner mold 13 and the molding area of ​​the circular plate inner mold 11, as shown in FIG. Figure 7 As shown, the missing area is filled with shredded carbon cloth 6; the excess first carbon cloth 5 is cut off along the outer circle of the molding area of ​​the circular plate inner mold 11, and the excess first carbon cloth 5 is cut off along the upper end surface of the square tube inner mold 13; as the name suggests, the busbar tailoring is the tailoring along the corresponding busbar in the length direction.

[0066] Punching step: pre-punch sewing holes on the outer mold 2 of the cylinder and the outer mold 3 of the bracket, with the hole center spacing being 6 to 10 mm and the hole diameter being 3 to 5 mm;

[0067] Step 2: Figure 8 As shown, a second carbon cloth 7 having a height greater than the generatrix of the cylinder inner mold 1 and a length equal to the circumference of the outer wall of the square cylinder inner mold 13 is obtained, and the second carbon cloth 7 is wound around the outer wall of the square cylinder inner mold 13, so that the second carbon cloth 7 has a second lower margin 71 outside the lower end of the square cylinder inner mold 13; after 6 generatrix seams are cut side by side evenly in the circumferential direction around the second lower margin 71, the cut second lower margin 71 is attached to the outer wall of the forming area connecting the ring mold 14, the cylinder inner mold 12 and the circular plate inner mold 11, so that the outer walls of the connecting ring mold 14, the cylinder inner mold 12 and the circular plate inner mold 11 are all formed with a meat-less area, as shown in FIG. Fig. 9 As shown, the missing meat area is filled by the broken carbon cloth 6;

[0068] Step 3: Fig.10 As shown, a first annular carbon cloth 81 whose inner and outer diameters match the molding area of ​​the circular plate inner mold 11 is obtained, and it is attached to the molding area of ​​the circular plate inner mold 11; a third carbon cloth 82 whose height and length match the outer wall of the cylindrical inner mold 12 is obtained, and it is attached to the outer wall of the cylindrical inner mold 12; a second annular carbon cloth 83 whose shape and size match the connecting ring mold 14 is obtained, and it is attached to the outer wall of the connecting ring mold 14; a fourth carbon cloth 84 whose height and length match the outer wall of the square cylinder inner mold 13 is obtained, and it is attached to the outer wall of the square cylinder inner mold 13; the first annular carbon cloth 81, the third carbon cloth 82, the second annular carbon cloth 83 and the fourth carbon cloth 84 are all whole cloths;

[0069] Step 4, repeating steps 1 to 3 until the thickness of the preform formed by all carbon cloths reaches a first preset value, and the outermost carbon cloth is a whole cloth; the first preset value range is 2 mm to 3 mm; 2.5 mm is preferred in this embodiment;

[0070] Step 5: Fig.11 As shown, the three arc-shaped pressing outer molds 21 of the cylinder outer mold 2 are installed around the lower section of the cylinder inner mold 12, and positioning pins, bolts and nuts are installed;

[0071] Step 6: Fig.12 As shown, multiple layers of fifth carbon cloth 9 are attached to the molding area of ​​the first vertical template 311 or the second vertical template 312 of each bracket split mold 31, and multiple layers of fifth carbon cloth 9 are attached to the inner wall of the anisotropic gusset plate 313, so that the thickness of all fifth carbon cloth 9 reaches the second preset value. The second preset value ranges from 2mm to 3mm; 2.5mm is preferred in this embodiment;

[0072] Step 7: install four bracket sub-molds 31 around the upper part of the cylindrical inner mold 12 and the outside of the square cylindrical inner mold 13, and press the circular top cover 4 on the top of the four bracket sub-molds 31, and install the positioning pins, bolts, and nuts to obtain the mold to be deposited;

[0073] Sewing steps: sew the seams of the corresponding carbon cloth through the sewing holes. The sewing principle is one hole and one needle.

[0074] Step 8: Place the mold to be deposited in a chemical vapor deposition device, prepare the pyrolytic carbon interface layer and perform densification treatment, then remove the integrated molding mold to obtain an integrated primary and secondary mirror support tube. The thickness of the prepared pyrolytic carbon interface layer ranges from 150nm to 250nm. Specifically, it includes:

[0075] 8.1. Place the mold to be deposited in a chemical vapor deposition device to prepare a pyrolytic carbon interface layer. The thickness of the interface layer is tested by SEM, and the thickness of the pyrolytic carbon interface layer is required to be about 150nm to 250nm. After the pyrolytic carbon interface layer is prepared, the mold and preform are subjected to high temperature treatment in a chemical vapor deposition device at a temperature of about 1800℃ to 1900℃.

[0076] 8.2. Place the mold and preform after completing step 8.1 into a chemical vapor deposition device for densification treatment to prepare a silicon carbide substrate with a required part density of about 1.85 g / cm3 to 1.9 g / cm3 to obtain an integrated primary and secondary mirror support tube.

[0077] During the whole process of sticking the carbon cloth, ensure that the carbon cloth fits tightly to the mold without wrinkles; ensure that the tailoring is misaligned as much as possible. The carbon cloth used in this embodiment is plain carbon cloth.

[0078] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A ceramic matrix composite integrated molding die for primary and secondary mirror support tubes, characterized in that: It comprises a cylinder inner mold (1), a cylinder outer mold (2), a bracket outer mold (3) and a circular top cover (4); The cylinder inner mold (1) comprises a circular plate inner mold (11), a cylindrical inner mold (12) and a square cylinder inner mold (13) which are coaxially connected in sequence from bottom to top; the circular plate inner mold (11) is provided with a molding area which matches the annular flange (03) of the primary and secondary mirror support cylinder to be prepared, and is used to make the annular flange (03); the outer wall of the cylindrical inner mold (12) is its molding area, which is used to make the circular support cylinder (01) of the primary and secondary mirror support cylinder to be prepared; the side walls of the square cylinder inner mold (13) are its molding areas, which are used to make the square support cylinder (02) of the primary and secondary mirror support cylinder to be prepared; a connecting ring mold (14) is vertically connected between the lower end of the square cylinder inner mold (13) and the upper end of the cylindrical inner mold (12); the outer wall of the connecting ring mold (14) is its molding area, which is used to make the connecting ring (06) of the primary and secondary mirror support cylinder to be prepared; The cylindrical outer mold (2) comprises N arc-shaped pressing outer molds (21) arranged around the cylindrical inner mold (12), N ≥ 2 and is a positive integer; adjacent arc-shaped pressing outer molds (21) are detachably connected; each arc-shaped pressing outer mold (21) is detachably connected to the circular plate inner mold (11); the height of the arc-shaped pressing outer mold (21) is lower than that of the cylindrical inner mold (12), so that the N arc-shaped pressing outer molds (21) are wound outside the lower section of the cylindrical inner mold (12); The support outer mold (3) comprises four support sub-molds (31); the four support sub-molds (31) are arranged around the upper section of the cylindrical inner mold (12) and the outside of the square cylinder inner mold (13); adjacent support sub-molds (31) are detachably connected; each of the four support sub-molds (31) is provided with a molding area matching the support plate (04) and a quarter support ring (05) of the primary and secondary mirror support cylinders to be prepared, and is used to manufacture the support plate (04) and the support ring (05); The circular top cover (4) is detachably press-fitted on the top of the four bracket split molds (31).

2. The ceramic matrix composite integrated molding die for the primary and secondary mirror support tubes according to claim 1, characterized in that: The bracket split mold (31) comprises a first vertical template (311) and a second vertical template (312); The outer sides of the first vertical template (311) and the second vertical template (312) are provided with a molding area matching the support plate (04), and the inner sides of the lower ends of both are provided with a first notch and a second notch matching the generatrix of the upper section of the cylindrical inner mold (12) and the outer wall of the square cylindrical inner mold (13); between the side wall of the first notch and the side wall of the second notch is provided an anisotropic buckle plate (313) whose inner wall matches the upper section of the cylindrical inner mold (12) and the outer wall of the square cylindrical inner mold (13), and which can be buckled and pressed on the upper section of the cylindrical inner mold (12) and the outer wall of the square cylindrical inner mold (13); The inner wall of the anisotropic buckle plate (313) is its molding area; the inner sides of the upper ends of the first vertical template (311) and the second vertical template (312) are vertically connected to each other; an upper arc plate (314) is vertically connected between the first vertical template (311) and the second vertical template (312); the upper arc plate (314) is arranged close to the upper ends of the first vertical template (311) and the second vertical template (312), and is detachably connected to the circular top cover (4); the top surface of the upper arc plate (314) is its molding area, which is used to make the support ring (05).

3. The ceramic matrix composite integrated molding die for the primary and secondary mirror support tubes according to claim 2, characterized in that: The upper end of the arc-shaped pressing outer mold (21) is provided with an outward arc-shaped upper flange (211), and the lower end is provided with an outward arc-shaped lower flange (212); The arc-shaped pressing outer mold (21) is detachably connected to the circular plate inner mold (11) via an arc-shaped lower flange (212); A lower arc plate (315) is vertically connected between the first vertical template (311) and the second vertical template (312); the lower arc plate (315) is arranged close to the lower ends of the first vertical template (311) and the second vertical template (312), and is detachably connected to the arc-shaped upper flange (211).

4. The ceramic matrix composite integrated molding die for the primary and secondary mirror support tubes according to claim 3, characterized in that: The first vertical template (311) and the second vertical template (312) are provided with weight-reducing holes (316) on their inner sides; A reinforcing plate (317) is also vertically connected between the first vertical template (311) and the second vertical template (312).

5. The ceramic matrix composite integrated molding die for the primary and secondary mirror support tubes according to any one of claims 1 to 4, characterized in that: The bottom of the circular plate inner mold (11) is provided with supporting legs (15).

6. A method for integrally forming a ceramic matrix composite material for a primary and secondary mirror support tube, using the ceramic matrix composite material integrally forming mold for a primary and secondary mirror support tube according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Obtain a first carbon cloth (5) having a height greater than the generatrix length of the cylindrical inner mold (1) and a length equal to the outer circumference of the cylindrical inner mold (1), and wind the first carbon cloth (5) around the outer wall of the cylindrical inner mold (12) so that the first carbon cloth (5) has an upper margin (51) outside the upper end of the cylindrical inner mold (12) and a first lower margin (52) outside the lower end of the cylindrical inner mold (12); cut a plurality of generatrix seams evenly side by side in the circumferential direction around the upper margin (51), and then pass the cut upper margin (51) to the connecting ring mold (14) and the square cylindrical inner mold (13) ) is fitted on the outer wall of the square tube inner mold (13), a plurality of generatrix seams are cut evenly and side by side around the first lower surplus (52) in the circumferential direction, and the cut first lower surplus (52) is fitted on the molding area on the circular plate inner mold (11), so that a meat-missing area is formed on the outer wall of the square tube inner mold (13) and the molding area of ​​the circular plate inner mold (11), and the meat-missing area is filled with the shredded carbon cloth (6); the excess first carbon cloth (5) is cut off along the outer circle of the molding area of ​​the circular plate inner mold (11), and the excess first carbon cloth (5) is cut off along the upper end surface of the square tube inner mold (13); Step 2, obtaining a second carbon cloth (7) having a height greater than the generatrix of the cylinder inner mold (1) and a length equal to the circumference of the outer wall of the square cylinder inner mold (13), and winding the second carbon cloth (7) around the outer wall of the square cylinder inner mold (13) so that the second carbon cloth (7) leaves a second lower margin (71) outside the lower end of the square cylinder inner mold (13); cutting a plurality of generatrix seams evenly and side by side in the circumferential direction around the second lower margin (71), and fitting the cut second lower margin (71) to the outer wall of the forming area of ​​the connecting ring mold (14), the cylinder inner mold (12) and the circular plate inner mold (11), so that a meat-missing area is formed on the outer wall of the connecting ring mold (14), the cylinder inner mold (12) and the circular plate inner mold (11), and the meat-missing area is filled by the broken carbon cloth (6); Step 3, obtaining a first annular carbon cloth (81) whose inner and outer diameters match the molding area of ​​the circular plate inner mold (11), and affixing it to the molding area of ​​the circular plate inner mold (11); obtaining a third carbon cloth (82) whose height and length match the outer wall of the cylindrical inner mold (12), and affixing it to the outer wall of the cylindrical inner mold (12); obtaining a second annular carbon cloth (83) whose shape and size match the connecting ring mold (14), and affixing it to the outer wall of the connecting ring mold (14); obtaining a fourth carbon cloth (84) whose height and length match the outer wall of the square cylinder inner mold (13), and affixing it to the outer wall of the square cylinder inner mold (13); the first annular carbon cloth (81), the third carbon cloth (82), the second annular carbon cloth (83) and the fourth carbon cloth (84) are all whole cloths; Step 4, repeating steps 1 to 3 until the thickness of the preform formed by all carbon cloths reaches a first preset value, and the outermost layer is a whole cloth; Step 5, N arc-shaped pressing outer molds (21) of the cylinder outer mold (2) are installed around the lower section of the cylinder inner mold (12); Step 6: Laminating multiple layers of the fifth carbon cloth (9) on the molding areas of the four bracket sub-molds (31) so that the thickness of all the fifth carbon cloths (9) reaches a second preset value; Step 7, four bracket sub-molds (31) are installed around the upper part of the cylindrical inner mold (12) and the outside of the square cylindrical inner mold (13), and the circular top cover (4) is pressed on the top of the four bracket sub-molds (31) to obtain a mold to be deposited; Step 8: Place the mold to be deposited in a chemical vapor deposition device, prepare the pyrolytic carbon interface layer and perform densification treatment, then remove the integrated molding mold to obtain the integrated primary and secondary mirror support tubes.

7. The method for integrated molding of ceramic matrix composite materials for primary and secondary mirror support tubes according to claim 6, characterized in that: Step 6 is as follows: Multiple layers of fifth carbon cloth (9) are bonded to the molding area of ​​the first vertical template (311) or the second vertical template (312) of each bracket split mold (31), and multiple layers of fifth carbon cloth (9) are bonded to the inner wall of the anisotropic buckle plate (313), so that the thickness of all fifth carbon cloths (9) reaches a second preset value.

8. The method for integrated molding of ceramic matrix composite materials for primary and secondary mirror support tubes according to claim 7, characterized in that: After step 1 and before step 2, the following punching steps are also included: Pre-drilling sewing holes on the outer mold of the barrel (2) and the outer mold of the bracket (3); After step 7 and before step 8, the sewing step also includes: The seams of the corresponding carbon cloths are sewn through the sewing holes, and the sewing principle is one hole and one needle.

9. The method for integrated molding of ceramic matrix composite materials for primary and secondary mirror support tubes according to claim 7 or 8, characterized in that: In step 4, the first preset value range is 2 mm to 3 mm; In step 6, the second preset value range is 2 mm to 3 mm.

10. The method for integrated molding of ceramic matrix composite materials for primary and secondary mirror support tubes according to claim 9, characterized in that: In step 8, the thickness of the prepared pyrolytic carbon interface layer ranges from 150 nm to 250 nm.

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