Composite material light shield of variable cross-section grating and manufacturing method thereof

Abstract

The invention provides a composite material light shield of a variable cross-section grating and a manufacturing method of the composite material light shield, and belongs to the technical field of fiber reinforced resin matrix composite materials. The problems of difficult demolding, poor structural stability, insufficient rigidity and low imaging precision of the existing light shield processed by adopting a mold closing process are solved. The light shield comprises a light shield body, a grating set and an outer flange, the light shield body is oval, the grating set is arranged on the inner wall of the light shield body, the outer flange is arranged on the outer side of the light shield body, and the light shield forming mold comprises a core mold and a mold shell. The core molds are arranged in the mold shell and are all hollow elliptic cylinders. The non-imaging stray light blocking device is mainly used for blocking non-imaging stray light in a space environment in a satellite space camera.

Description

Technical Field

[0001] The invention belongs to the technical field of fiber-reinforced resin-based composite materials, and in particular relates to a composite material sunshade and a manufacturing method thereof. Background Art

[0002] The sunshade plays a vital role in the stable operation of satellite space cameras. The sunshade not only needs to block non-imaging stray light in the space environment, but also must be able to withstand the shock and vibration encountered by the satellite during transportation and launch. The sunshade needs to have high dimensional stability, resistance to extreme space environments, high strength and low mass. Therefore, carbon fiber composite materials have become an ideal material for making sunshades.

[0003] In the prior art, carbon fiber composite material sunshades mostly adopt a closing mold process, but the traditional closing mold process has uneven pressure distribution, which can easily lead to poor molding of sunshades with complex structures and thin thicknesses. In addition, the molding molds used in the closing mold process need to be calculated very precisely to ensure the geometric accuracy and surface quality of the sunshades. However, the complex molding molds are not convenient for demolding sunshades with complex structures and thin walls. After demolding, burrs are easily generated at the cut corners, making it difficult to form perfectly. In addition, if the sunshade is not designed properly, it may lead to insufficient rigidity and poor stability, affecting the use of the sunshade. Summary of the invention

[0004] In view of this, the present invention aims to propose a composite light shield with a variable cross-section grating and a manufacturing method thereof, so as to solve the problems of difficult demolding, poor structural stability, insufficient rigidity and low imaging accuracy of the existing light shield manufactured by the mold closing process.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a composite light shield with a variable-section grating, the light shield is made of carbon fiber composite material, the light shield includes a light shield body, a grating group and an outer flange, the light shield body is a hollow elliptical cylinder, the grating group includes four gratings of different sizes, the four gratings of different sizes are arranged on the inner wall of the light shield body, the inner diameters of the four gratings of different sizes gradually increase from top to bottom, and the outer flange is arranged on the outside of the light shield body.

[0006] Furthermore, a 45° cutting angle is set at the edges of the grating.

[0007] Furthermore, the thickness of the sunshade body is 1.5mm, the total height is 310mm, the outer flange is arranged at 175.4mm away from the upper end surface of the sunshade body, the thickness of the outer flange 10 is 3mm, and the four different sizes of gratings are arranged from top to bottom on the upper end surface of the sunshade body, 236.5mm, 164.5mm and 98.5mm away from the lower end surface of the sunshade body, and the grating thickness is 1.5mm.

[0008] A forming mold for processing a composite material sunshade of the above-mentioned variable-section grating, comprising a core mold and a mold shell, wherein the core mold is arranged inside the mold shell, the core mold is a hollow elliptical cylinder, the core mold comprises an inner cylinder, a positioning ring and an inner petal mold, the inner cylinder is arranged on the inner side of the positioning ring, the inner petal mold is arranged on the outer side of the positioning ring, a 45° cut-angle surface is arranged at the connection between the top surface of the inner petal mold and the mold shell, and the inner petal mold comprises four groups of hollow elliptical cylinders, the four groups of hollow elliptical cylinders are stacked and connected, and a 45° cut-angle surface is arranged at the connection between the four groups of hollow elliptical cylinders.

[0009] Furthermore, a notch is arranged on the outer circle of the inner cylinder, a through hole is arranged on the surface of the positioning ring, the notch corresponds to the position of the through hole of the positioning ring, the inner cylinder is connected to the positioning ring through the notch and the through hole, threaded holes are arranged on the upper and lower end faces of the inner cylinder, and the upper and lower end faces of the inner cylinder are connected to the mold shell through the threaded holes.

[0010] Furthermore, each group of the hollow elliptical cylinders includes a number of templates connected in sequence along the circumferential direction, and threaded holes are arranged on the several templates. The four groups of hollow elliptical cylinders are connected to the through holes on the positioning ring via the threaded holes on the templates.

[0011] Furthermore, the mold shell includes an outer flap mold, an upper pressure cover and a lower pressure cover, the outer flap mold is arranged on the outside of the inner flap mold, the upper pressure cover is arranged above the inner cylinder, and the lower pressure cover is arranged below, and a 45° cut-angle profile is arranged around the lower end surface of the upper pressure cover, the outer flap mold includes an outer upper flap mold and an outer lower flap mold, the outer upper flap mold and the outer lower flap mold each include a plurality of flap molds, and the plurality of flap molds are connected in sequence along the circumferential direction, and an outward-turned flange is arranged at the connection between the outer upper flap mold and the outer lower flap mold, the outer side of the upper pressure cover is in contact with the inner wall of the outer upper flap mold, and the outer side of the lower pressure cover is in contact with the inner wall of the outer lower flap mold.

[0012] Furthermore, the lower end surface of the upper pressure cover and the end surface of the lower pressure cover are both elliptical steps, the upper pressure cover and the lower pressure cover are provided with a plurality of through holes along the vertical direction, and the inner cylinder is connected with the through holes on the upper pressure cover and the lower pressure cover through threaded holes.

[0013] Furthermore, the lower pressure cover is provided with a plurality of ejection holes along the vertical direction.

[0014] A method for manufacturing a composite light shield of a variable cross-section grating, using a molding die of the composite light shield of a variable cross-section grating, specifically comprises the following steps:

[0015] S1: Apply a release agent to the outer surface of the inner split mold and the inner surface of the outer split mold, apply a prepreg with a thickness of 0.75 mm on the outer surface of the inner split mold, and make the prepreg and the template completely fit together, the prepreg is a carbon fiber composite material;

[0016] S2: Connect the inner cylinder with the lower gland, assemble several templates of the inner split mold on the outside of the positioning ring, and install the positioning ring on the outside of the inner cylinder;

[0017] S3: Apply prepreg on the surface of the inner split mold and the 45° cut-angle surface from bottom to top. When the prepreg is laid to the height of the connection between the outer upper split mold and the outer lower split mold, extend the prepreg outward, cover the outer lower split mold on the inner split mold, and lay the extended prepreg on the upper end surface of the outer flange of the outer lower split mold;

[0018] S4: Coating prepreg on the surface of the inner split mold from top to bottom, and when the prepreg is laid to the height of the connection between the outer upper split mold and the outer lower split mold, extending the prepreg outward, laying the extended prepreg on the upper end surface of the outward flange of the outer lower split mold, and putting the outer upper split mold on the inner split mold;

[0019] S5: Connect the upper gland to the inner cylinder;

[0020] S6: The forming mold is pre-compacted and then solidified, and then cooled and demolded after solidification. The upper pressure cover, the outer split mold, the inner split mold, the positioning ring, the inner cylinder and the lower pressure cover are demolded in sequence, and the blank is polished smooth after demolding.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The sunshade of the present invention adopts a molding process design, the mold combination form is simple, the operation difficulty is low, and the single-piece production cycle is short, which ensures effective control of the wall thickness of the structure and improves the demoulding efficiency;

[0023] 2. The sunshade of the present invention is made of a carbon fiber composite material with low deadweight and high stability. The one-piece molding technology has high molding efficiency and strong structural reliability. The surface of the carbon fiber composite material sunshade is in good condition and has uniform thickness. The overall dimensions and mounting hole positions are reasonable.

[0024] 3. The present invention can filter out stray light and scattered light by arranging four gratings of different sizes on the inner wall of the light shield, adapt to incident light of different angles, thereby improving imaging clarity, and can reduce the number of required optical elements and simplify the optical path. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the axial structure of a composite light shield of a variable-section grating according to the present invention;

[0027] Figure 2 It is a schematic diagram of the side structure of a composite material sunshade of a variable-section grating according to the present invention;

[0028] Figure 3 It is a schematic cross-sectional structure diagram of a composite material sunshade of a variable-section grating according to the present invention;

[0029] Figure 4 It is a schematic diagram of the axial structure of a forming mold of a composite material sunshade with a variable cross-section grating according to the present invention;

[0030] Figure 5 It is a front structural schematic diagram of a molding die for a composite material sunshade with a variable cross-section grating according to the present invention;

[0031] Figure 6 It is a schematic cross-sectional structure diagram of a molding die for a composite material sunshade with a variable cross-section grating according to the present invention;

[0032] Figure 7 It is a schematic diagram of the front structure of the inner cylinder of the molding die of the composite material sunshade of the variable cross-section grating according to the present invention;

[0033] Figure 8 It is a schematic diagram of the top structure of the inner cylinder of the molding die of the composite material sunshade of the variable cross-section grating according to the present invention;

[0034] Fig. 9 It is a front structural schematic diagram of a positioning ring of a molding die for a composite material sunshade with a variable cross-section grating according to the present invention;

[0035] Fig.10 It is a schematic diagram of the side structure of a positioning ring of a molding die for a composite material sunshade with a variable cross-section grating according to the present invention;

[0036] Fig.11 It is a schematic diagram of the top structure of a positioning ring of a molding die for a composite material sunshade with a variable cross-section grating according to the present invention;

[0037] Fig.12 It is a schematic diagram of the axial structure of the inner petal mold of the molding mold of the composite material sunshade with a variable cross-section grating according to the present invention;

[0038] Fig.13 It is a front structural schematic diagram of an inner petal mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0039] Fig.14 It is a schematic cross-sectional structure diagram of an inner petal mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0040] Fig.15 for Fig.14 A partial enlarged view of the middle A;

[0041] Fig.16 It is a schematic diagram of the axial structure of the upper outer petal mold of the molding mold of the composite material sunshade with a variable cross-section grating according to the present invention;

[0042] Fig.17 It is a front structural schematic diagram of an upper outer split mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0043] Fig.18 It is a schematic cross-sectional structure diagram of an upper outer petal mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0044] Fig.19 It is a schematic diagram of the axial structure of the lower outer petal mold of the molding mold of the composite material sunshade with a variable cross-section grating according to the present invention;

[0045] Fig. 20 It is a front structural schematic diagram of a lower outer petal mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0046] Fig.21 It is a schematic cross-sectional structure diagram of a lower outer petal mold of a molding mold for a composite material sunshade with a variable cross-section grating according to the present invention;

[0047] Fig. 22 It is a schematic diagram of the top structure of an upper pressure cover of a forming mold of a composite material sunshade with a variable cross-section grating according to the present invention;

[0048] Fig.23 It is a schematic cross-sectional structure diagram of an upper pressure cover of a forming die of a composite material sunshade with a variable cross-section grating according to the present invention;

[0049] Fig.24 It is a schematic diagram of the top structure of the lower pressing cover of the molding die of the composite material sunshade with variable cross-section grating according to the present invention;

[0050] Fig.25 The present invention is a schematic cross-sectional structural diagram of a lower pressing cover of a molding die for a composite material sunshade with a variable-section grating according to the present invention.

[0051] In the figure:

[0052] 1. Inner cylinder; 2. Positioning ring; 3. Inner petal mold; 4. Outer upper petal mold; 5. Outer lower petal mold; 6. Upper pressure cover; 7. Lower pressure cover; 8. Sunshade body; 9. Grating assembly; 10. Outer flange. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0054] See also Figure 1-3 The present embodiment is described, a composite material sunshade of variable cross-section grating, the sunshade is made of carbon fiber composite material, the sunshade includes a sunshade body 8, a grating group 9 and an outer flange 10, the sunshade body 8 is a hollow elliptical cylinder, and the space waste is reduced by setting the sunshade body 8 as a hollow elliptical cylinder, the grating group 9 includes gratings of four different sizes, the four different sizes of gratings are arranged on the inner wall of the sunshade body 8, the inner diameters of the four different sizes of gratings gradually increase from top to bottom, the grating and the outer flange 10 are arranged on the outside of the sunshade body 8, the grating is used to prevent non-imaging light from entering the lens, so the grating includes a light-transmitting part and a light-impermeable part, in this embodiment, the sizes of the light-impermeable parts of the grating are 66mm, 48.5mm, 34mm and 19.5mm from high to low.

[0055] The sunshade of the present invention can block stray light from entering with high efficiency and high precision by setting four gratings of different sizes, thereby preventing the imaging of the space camera from being affected and improving the imaging accuracy of the space camera. The bearing capacity of the sunshade is increased and the stability of the overall structure of the sunshade is improved through the one-piece molding technology, thereby reducing the risk of instability of the sunshade structure.

[0056] The edges of the gratings are all provided with a 45° cut angle, which reduces light reflection and scattering and screens specific light.

[0057] The thickness of the sunshade body 8 is 1.5mm, and the total height is 310mm. The outer flange 10 is arranged at a distance of 175.4mm from the upper end surface of the sunshade body 8, and the thickness of the outer flange 10 is 3mm. The four different sizes of gratings are arranged from top to bottom on the upper end surface of the sunshade body 8, 236.5mm, 164.5mm and 98.5mm from the lower end surface of the sunshade body 8, and the thickness of the grating is 1.5mm. By designing the height and thickness of the sunshade, the requirements of light weight, high strength and high stability are met. The present invention can maintain a good shape and will not cause bending deformation due to load due to the thin thickness and long length of the grating. The above-mentioned size and structural design can enable the sunshade to maintain good rigidity and prevent deformation.

[0058] See also Figure 4-25To illustrate the present embodiment, a forming mold for a composite material sunshade for processing the above-mentioned variable-section grating comprises a core mold and a mold shell, wherein the core mold and the mold shell are both made of 45# steel, the core mold is arranged inside the mold shell, the core mold is a hollow elliptical cylinder, the core mold comprises an inner cylinder 1, a positioning ring 2 and an inner petal mold 3, the inner cylinder 1 is arranged on the inner side of the positioning ring 2, the inner petal mold 3 is arranged on the outer side of the positioning ring 2, a 45° cut-angle surface is arranged at the connection between the top surface of the inner petal mold 3 and the mold shell, the inner petal mold 3 comprises four groups of hollow elliptical cylinders, the four groups of hollow elliptical cylinders are stacked and connected, 45° cut-angle surfaces are arranged at the connection between the four groups of hollow elliptical cylinders, and the 45° cut-angle surface is used for processing the grating group 9.

[0059] The composite material sunshade with variable cross-section grating designed by the present invention has a simple mold combination form, low operation difficulty, short single-piece production cycle, thin product outer wall, easy demoulding, and perfect molding of the product grating cutting corner after demoulding. The composite material sunshade with variable cross-section grating has a good surface condition and uniform thickness, and the overall size and installation hole position meet the design requirements.

[0060] A notch is arranged on the outer circle of the inner cylinder 1, and a through hole is arranged on the surface of the positioning ring 2. The notch corresponds to the position of the through hole of the positioning ring 2. The inner cylinder 1 is connected to the positioning ring 2 through the notch and the through hole. The bolt is inserted into the through hole of the positioning ring 2 and clamped in the notch of the inner cylinder 1 to prevent the positioning ring 2 from shaking in the circumferential direction. Threaded holes are arranged on the upper and lower end faces of the inner cylinder 1. The upper and lower end faces of the inner cylinder 1 are connected to the mold shell through the threaded holes. The bolts are inserted through the mold shell into the threaded holes on the upper and lower end faces of the inner cylinder 1 to realize the connection between the inner cylinder 1 and the mold shell.

[0061] Each group of the hollow elliptical cylinders includes a number of templates connected in sequence along the circumferential direction, and threaded holes are arranged on the templates. The four groups of hollow elliptical cylinders are connected to the through holes on the positioning ring 2 through the threaded holes on the templates. The bolts are screwed into the threaded holes of the templates and inserted into the through holes of the positioning ring 2, so that the templates are spliced ​​into four groups of hollow elliptical cylinders. The four groups of hollow elliptical cylinders are stacked in sequence to form an inner petal mold 3. By arranging the inner petal mold 3 into a number of templates, it is convenient for later demoulding.

[0062] The mold shell includes an outer flap mold, an upper pressure cover 6 and a lower pressure cover 7. The outer flap mold is arranged on the outside of the inner flap mold 3. The upper pressure cover 6 is arranged above the inner cylinder 1, and the lower pressure cover 7 is arranged below. A 45° beveled surface is arranged around the lower end surface of the upper pressure cover 6. The outer flap mold includes an outer upper flap mold 4 and an outer lower flap mold 5. The outer upper flap mold 4 and the outer lower flap mold 5 both include a plurality of flap molds, which are connected in sequence along the circumferential direction to form an outer upper flap mold 4 and an outer lower flap mold 5 with outward-turned flanges. The outer upper flap mold 4 and the outer lower flap mold 5 are arranged as a separate structure to facilitate demoulding. Outward-turned flanges are arranged at the connection between the outer upper flap mold 4 and the outer lower flap mold 5. The outer side of the upper pressure cover 6 is in contact with the inner wall of the outer upper flap mold 4, and the outer side of the lower pressure cover 7 is in contact with the inner wall of the outer lower flap mold 7.

[0063] The lower end surface of the upper pressure cover 6 and the end surface of the lower pressure cover 7 are both elliptical steps. The upper pressure cover 6 and the lower pressure cover 7 are provided with a plurality of through holes along the vertical direction. The inner cylinder 1 is connected with the through holes on the upper pressure cover 6 and the lower pressure cover 7 through threaded holes.

[0064] The lower pressure cover 7 is provided with a plurality of ejection holes along the vertical direction, so as to facilitate ejection of the inner split mold 3 and the positioning ring 2 during demoulding.

[0065] A method for manufacturing a composite light shield of a variable cross-section grating, using the molding die of the composite light shield of the variable cross-section grating, comprises the following steps:

[0066] S1: Apply a release agent to the outer surface of the inner split mold 3 and the inner surface of the outer split mold, first apply a prepreg with a thickness of 0.75 mm on the outer surface of the inner split mold 3, and lay it alternately in a certain order using specific laying angles of 0°, 90°, 45°, and -45°, and make the prepreg completely fit the template, and at the same time, drive out the bubbles between the prepreg layers, and the prepreg is a carbon fiber composite material;

[0067] S2: Connect the inner cylinder 1 with the lower gland 7, insert the screw into the through hole of the lower gland 7 and screw it into the threaded hole on the lower surface of the inner cylinder 1 to connect the lower gland 7 with the inner cylinder 1, assemble several templates with 0.75mm inner split mold 3 and install them on the outside of the positioning ring 2 through bolts, and then install the positioning ring 2 with the inner split mold 3 installed on the outside of the inner cylinder 1;

[0068] S3: Prepreg is applied on the surface of several modules of the inner split mold 3 and the 45° cut angle from bottom to top. When the prepreg is laid to the height of the connection between the outer split upper mold 4 and the outer split lower mold 5, the prepreg is extended 30mm outward in the horizontal direction. Because the carbon fiber composite material has a certain rigidity, the extended prepreg will stand upright on the outside of the inner split mold 3. The prepreg is laid using a specific laying angle of 0°, 90°, 45°, and -45° and laid alternately in a certain order, thereby extending multiple layers of prepreg standing upright on the outside of the inner split mold 3. When the outer split lower mold 5 is turned outward, the prepreg is stretched to the outside of the outer split mold 3. When the thickness of the prepreg on the inner petal mold 3 below the flange height reaches 1.5mm, all the petals of the outer lower petal mold 5 are installed on the outside of the inner petal mold 3 on which the prepreg is laid, and then the extended prepreg is laid on the upper surface of the outer flange of the outer lower petal mold 5. When laying, first lay a layer of extended prepreg on the upper surface of the outer flange of the outer lower petal mold 5, lay another layer of prepreg thereon, and then lay another layer of extended prepreg, that is, lay a layer of prepreg on each layer of extended prepreg, and the thickness of the prepreg laid on the outward flange of the outer lower petal mold 5 reaches 1.5mm;

[0069] S4: Apply prepreg on each template of the inner flap mold 3 from top to bottom. The prepreg is laid using specific laying angles of 0°, 90°, 45°, and -45° and in a certain order of alternating laying. The thickness of the prepreg on the outer surface of the inner flap mold 3 above the height of the connection between the outer lower flap mold 5 and the outer upper flap mold 4 reaches 1.5mm. When the prepreg is laid to the height of the connection between the outer upper flap mold 4 and the outer lower flap mold 5, 30mm of prepreg is thrown outward in the horizontal direction, and another layer of prepreg is laid on top of the thrown prepreg, that is, a layer of prepreg is laid on top of each layer of extended prepreg. When the thickness of the prepreg on the outer flange of the outer lower flap mold 5 reaches 3mm, all flap molds of the outer upper flap mold 4 are installed on the outside of the inner flap mold 3 with the prepreg laid.

[0070] S5: Connect the upper gland 6 to the inner tube 1, insert the screw into the through hole of the upper gland 6 and screw it into the threaded hole on the upper surface of the inner tube 1 to connect the upper gland 6 to the inner tube 1;

[0071] S6: The molding mold sleeve is evacuated for pre-compaction, and then sent into the autoclave for curing. During curing, it is kept at 100°C for two hours, and then the temperature is raised to 150°C and kept for another two hours. After the curing is completed, it is cooled in the autoclave. When the mold temperature drops to no more than 30°C, it is cooled and molded and demolded. When demolding, the upper pressure cover 6, the outer petal mold, the inner petal mold 3, the positioning ring 2, the inner cylinder 1 and the lower pressure cover 7 are demolded in order. After demolding, the blank is polished smooth to obtain a light shield of a variable-section grating composite material.

[0072] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A composite light shield with a variable cross-section grating, characterized in that: The sunshade is made of carbon fiber composite material, and comprises a sunshade body (8), a grating group (9) and an outer flange (10); the sunshade body (8) is a hollow elliptical cylinder; the grating group (9) comprises gratings of four different sizes; the four gratings of different sizes are arranged on the inner wall of the sunshade body (8); the inner diameters of the four gratings of different sizes gradually increase from top to bottom; and the outer flange (10) is arranged on the outer side of the sunshade body (8).

2. The composite light shield of a variable cross-section grating according to claim 1, characterized in that: The edges of the gratings are all provided with a 45° cutting angle.

3. The composite light shield of a variable cross-section grating according to claim 1, characterized in that: The thickness of the hood body (8) is 1.5 mm, and the total height is 310 mm. The outer flange (10) is arranged at a distance of 175.4 mm from the upper end surface of the hood body (8), and the thickness of the outer flange 10 is 3 mm. The four different sizes of gratings are arranged from top to bottom on the upper end surface of the hood body (8), 236.5 mm, 164.5 mm and 98.5 mm from the lower end surface of the hood body (8), and the grating thickness is 1.5 mm.

4. A forming die for a composite light shield with a variable cross-section grating as claimed in claim 1, characterized in that: The invention comprises a core mold and a mold shell, wherein the core mold is arranged inside the mold shell, the core mold is a hollow elliptical cylinder, the core mold comprises an inner cylinder (1), a positioning ring (2) and an inner flap mold (3), the inner cylinder (1) is arranged inside the positioning ring (2), the inner flap mold (3) is arranged outside the positioning ring (2), a 45° cut-angle profile is arranged at the connection between the top surface of the inner flap mold (3) and the mold shell, and the inner flap mold (3) comprises four groups of hollow elliptical cylinders, the four groups of hollow elliptical cylinders are stacked and connected, and a 45° cut-angle profile is arranged at the connection between the four groups of hollow elliptical cylinders.

5. The composite light shield of a variable cross-section grating according to claim 4, characterized in that: The outer circle of the inner cylinder (1) is provided with a notch, and the surface of the positioning ring (2) is provided with a through hole, the notch corresponds to the position of the through hole of the positioning ring (2), the inner cylinder (1) is connected to the positioning ring (2) via the notch and the through hole, the upper and lower end surfaces of the inner cylinder (1) are provided with threaded holes, and the upper and lower end surfaces of the inner cylinder (1) are connected to the mold shell via the threaded holes.

6. The forming die of the composite material sunshade of the variable cross-section grating according to claim 5, characterized in that: Each group of hollow elliptical columns comprises a plurality of templates connected in sequence along the circumferential direction, and threaded holes are arranged on the plurality of templates. The four groups of hollow elliptical columns are connected to the through holes on the positioning ring (2) via the threaded holes on the templates.

7. The forming die of the composite material sunshade of the variable cross-section grating according to claim 4, characterized in that: The mold shell comprises an outer flap mold, an upper pressure cover (6) and a lower pressure cover (7). The outer flap mold is arranged on the outer side of the inner flap mold (3). The upper pressure cover (6) is arranged above the inner cylinder (1), and the lower pressure cover (7) is arranged below. A 45° beveled profile is arranged around the lower end surface of the upper pressure cover (6). The outer flap mold comprises an outer upper flap mold (4) and an outer lower flap mold (5). The outer upper flap mold (4) and the outer lower flap mold (5) both comprise a plurality of flap molds, which are connected in sequence along the circumferential direction. An outward-turned flange is arranged at the connection between the outer upper flap mold (4) and the outer lower flap mold (5). The outer side of the upper pressure cover (6) is in contact with the inner wall of the outer upper flap mold (4), and the outer side of the lower pressure cover (7) is in contact with the inner wall of the outer lower flap mold (7).

8. The forming die of the composite material sunshade of the variable cross-section grating according to claim 7, characterized in that: The lower end surface of the upper pressure cover (6) and the end surface of the lower pressure cover (7) are both elliptical steps. The upper pressure cover (6) and the lower pressure cover (7) are provided with a plurality of through holes in the vertical direction. The inner cylinder (1) is connected to the through holes on the upper pressure cover (6) and the lower pressure cover (7) through threaded holes.

9. The forming die of the composite material sunshade of the variable cross-section grating according to claim 8, characterized in that: The lower pressure cover (7) is provided with a plurality of ejection holes along the vertical direction.

10. A method for manufacturing a composite light shield of a variable cross-section grating, characterized in that: A molding die for a composite light shield using a variable cross-section grating according to any one of claims 5 to 9 comprises the following steps: S1: applying a release agent to the outer surface of the inner split mold (3) and the inner surface of the outer split mold, and applying a prepreg with a thickness of 0.75 mm to the outer surface of the inner split mold (3) so that the prepreg is completely attached to the template, wherein the prepreg is a carbon fiber composite material; S2: connecting the inner cylinder (1) to the lower gland (7), assembling a plurality of mold plates of the inner split mold (3) on the outside of the positioning ring (2), and installing the positioning ring (2) on the outside of the inner cylinder (1); S3: Coating prepreg on the surface of the inner split mold (3) and the 45° cut-angle surface from bottom to top, and when the prepreg is laid to the height of the connection between the outer upper split mold (4) and the outer lower split mold (5), extending the prepreg outward, putting the outer lower split mold (5) on the inner split mold (3), and laying the extended prepreg on the upper end surface of the outward flange of the outer lower split mold (5); S4: coating the prepreg on the surface of the inner split mold (3) from top to bottom, and extending the prepreg outward when the prepreg is laid to the height of the connection between the outer split upper mold (4) and the outer split lower mold (5), and laying the extended prepreg on the upper end surface of the outward flange of the outer split lower mold (5), and putting the outer split upper mold (4) on the inner split mold (3); S5: Connecting the upper gland (6) to the inner cylinder (1); S6: The forming mold is pre-compacted and then solidified, and then cooled and demoulded after solidification. The upper pressure cover (6), the outer split mold, the inner split mold (3), the positioning ring (2), the inner cylinder (1) and the lower pressure cover (7) are demoulded in sequence, and the blank is polished smooth after demoulding.

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