CN114311730A - Composite material light shield, forming die and preparation method thereof - Google Patents

Abstract

The invention provides a composite material light shield, a forming mold and a preparation method thereof, comprising the steps of: S1, laying at least one layer of prepreg on the water-soluble core mold according to the layup sequence and layup angle; S2, placing Each water-soluble mandrel is guided and inserted by the positioning shaft in turn, and the positioning shafts interspersed with the water-soluble mandrel are respectively fixed with the upper and lower templates; The outer surface and the forming surface of the flanging flange are laid for the skin; S4, the outer split and the outer pressure ring are installed in sequence to complete the assembly of the composite material hood forming mold; S5, the composite material is shaded by the forming mold. The cover is pre-compacted and cured; S6. After curing, the mold is disassembled and the water-soluble core mold is removed by dissolving with water. The light shield of the present invention is integrally formed through a prepreg laying process, thereby obtaining a small-scale composite material light shield that cannot be produced by conventional processes.

Description

Composite material light shield, forming mold and preparation method thereof

technical field

The invention belongs to the technical field of composite material application, and in particular relates to a composite material light shield, a forming mold and a preparation method thereof.

Background technique

Resin-based fiber reinforced composite hoods are widely used in aerospace, satellite structures, camera structures and other fields due to their lightweight, high-strength mechanical properties and excellent dimensional stability.

The traditional composite material hood preparation processes include metal mold process, vacuum bag process, autoclave process, and vacuum injection molding process. Because the above processes all need to use rigid (metal or other materials) inner molds for the forming of the hood, the inner cavity space of the medium and large size hoods is abundant, which can allow the installation and demoulding operation requirements of the rigid inner mold split. For the hood (within diameter less than 100mm), the operating space of the inner cavity of the hood is small, which is not enough to support the installation and demoulding operation of the rigid inner mold split; The method of winding the prepreg wire by the method or dry method causes the defects that the thermal expansion coefficient of the inner grid and the skin do not match and the mechanical properties are poor.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned defects in the prior art, the present invention proposes a composite material light shield, a molding die and a preparation method thereof, which can prepare a small-sized composite material light shield device that cannot be produced by a conventional process, and at the same time, compared with the traditional dry method Or the process of forming reinforcing rib by wet winding of filaments, the thermal expansion coefficient of the reinforcing rib prepared by this method can be designed, and its mechanical properties are better. For achieving the above object, the present invention adopts following concrete technical scheme:

A composite material hood forming mold, comprising: an upper template, a lower template, an outer pressure ring, an outer split, a water-soluble core mold and a positioning shaft;

Pressing through holes are correspondingly arranged in the preset areas of the upper template and the lower template. When the mold is closed, the pressure through holes are used to pressurize the axial direction of the composite material light shield forming mold. The preset area is that the inner diameter is larger than the outer split. the outer diameter of the annular area;

Threaded holes of the outer pressure ring are uniformly distributed in the circumferential direction, and the threaded holes of the pressure ring are used to pressurize the outer splits radially through the threaded parts;

The radius of the outer split lobe is adapted to the radius of the outer pressure ring, and there are at least three outer split lobes, which are placed on the inner side of the outer pressure ring and circumferentially distributed on the outer surface of the hood to be formed;

The water-soluble mandrel is located in the outer lobes distributed in the circumferential direction, and the central axis of the water-soluble mandrel is provided with a connecting through hole;

The positioning shaft passes through the connecting through hole and is used to connect each water-soluble mandrel;

The positioning shafts are respectively connected with the upper template and the lower template.

Preferably, the pressurized through holes of the upper template are evenly distributed on the circumference of the upper template;

The pressure through holes of the lower template are evenly distributed on the circumference of the lower template, so that the screw rods pass through the pressure through holes of the upper template and the pressure through holes of the lower template in turn, and the pressure through holes of the composite material hood are realized by cooperating with the nut. Axial compression.

Preferably, both ends of the positioning shaft are provided with positioning holes, and the positioning holes are used for positioning and connecting the positioning shaft with the upper template and the lower template.

Preferably, the outer wall of the water-soluble core mold is provided with a groove, and the groove direction is directed to the axis of the water-soluble core mold, and the groove is used to form a reinforcing rib cavity in the light shield to be formed.

Preferably, the upper template, the lower template, the outer pressure ring, the outer split lobe and the positioning shaft are all metal materials.

A method for preparing a composite material light shield, comprising the steps of:

S1, according to the first layup sequence and layup angle, lay the prepreg on the water-soluble mandrel;

S2. Use the positioning shaft to guide and insert each water-soluble mandrel on which the prepreg has been laid, and fix the two ends of the positioning shaft with the water-soluble mandrel inserted with the upper template and the lower template;

S3. According to the second layering sequence and layering angle, the skin is laid on the outer surface of the fixed water-soluble core mold and the forming surface of the flanging flange on the upper template;

S4. Install the outer split valve and the outer pressure ring in sequence to complete the assembly of the composite material hood forming mold;

S5, pre-compacting and curing the composite material hood through the molding die;

S6. After curing, remove the pressure ring, the outer split, the upper template, the lower template and the positioning shaft, and then remove the water-soluble mandrel with water.

Preferably, the thickness of a single layer of the prepreg is 0.05mm-0.2mm, and the volume content of fibers in the prepreg is 60±3%.

Preferably, the fiber of the prepreg is any one of carbon fiber, glass fiber, quartz fiber, and high silica fiber;

The resin of the prepreg is any one of cyanate resin, epoxy resin, bismaleamide resin, polyimide resin, and phthalic cyanide resin.

A composite material light shield is manufactured by the above method.

The present invention can achieve the following technical effects:

1. The ultra-small size composite material light shield, forming mold and preparation method thereof of the present invention can prepare small-scale composite material light shield devices that cannot be produced by conventional processes. The defect of the mismatch of thermal expansion coefficient between the hood skin and the stiffener, the stiffener and the skin have the advantage of better mechanical properties.

2. The ultra-small-sized composite material light shield and the forming mold of the present invention have simple structure and low cost, and can be applied to the preparation of small-sized composite material parts in other aerospace fields.

Description of drawings

1 is a schematic diagram of the overall structure of a composite material light shield molding die according to an embodiment of the present invention;

Fig. 2 is the sectional view at A-A of Fig. 1;

Fig. 3 is a flow chart of a method for preparing a composite light shield according to an embodiment of the present invention;

Fig. 4 is the schematic diagram of the groove position on the water-soluble mandrel of an embodiment of the present invention;

FIG. 5 is a schematic diagram of a composite material light shield according to an embodiment of the present invention.

Reference number:

Upper template 1, lower template 2, outer pressure ring 3, pressure ring threaded hole 31,

Outer split 4, water-soluble mandrel 5, groove 51, positioning shaft 6, positioning hole 61,

The hood 7, the reinforcing rib 71, the groove 72, the flanging 8, the flanging flange 9, and the forming surface 91 of the flanging flange.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The purpose of the present invention is to provide a composite material light shield, a forming mold and a preparation method thereof. A composite material light shield, a forming mold and a preparation method thereof provided by the present invention will be described in detail below with specific examples.

FIG. 1 shows the overall structure of a composite material hood forming mold of the present invention, combined with FIG. 2 , including: an upper template 1, a lower template 2, an outer pressure ring 3, an outer split 4, and a water-soluble core mold 5 and positioning axis 6;

The water-soluble mandrel 5 is serially inserted on the positioning shaft 6 in sequence, and the outer peripheries of the water-soluble mandrel 5 and the flanging flange 9 on the upper template 1 are sequentially fixed with an outer split 4 and an outer pressure ring 3, and the outer pressure ring 3. The radial direction of the water-soluble mandrel 5 and the flanging flange 9 is fastened by the radial pressure of the outer split 4; The pressurized through hole on 2 realizes the pressurization and fastening of the upper template 1 and the lower template 2, and completes the assembly of the composite material hood forming mold.

In a preferred embodiment of the present invention, the central axis of the water-soluble core mold 5 is provided with a connecting through hole, and the diameter of the connecting through hole is adapted to the diameter of the positioning shaft 6, so that each water-soluble core mold 5 can be connected in series on the positioning axis 6.

At the same time, both ends of the positioning shaft 6 are provided with positioning holes, and the positioning holes are used for positioning the positioning shaft 6 with the upper template 1 and the lower template 2, and at the same time, the three are connected by pressing bolts.

The outer periphery of the water-soluble mandrel 5 is provided with three outer splits 4, and the three outer splits 4 enclose the water-soluble mandrel 5;

An outer pressure ring 3 is sleeved on the outer circumference of the three outer segments 4 of the cylinder formed by the enclosure. The outer pressure ring 3 has several pressure ring threaded holes 31 evenly distributed in the circumferential direction. The radial direction of the ring is the same; the threaded hole 31 of the pressure ring is matched with the matching bolt, and the bolt is tightened to realize the radial pressure of the outer split 4, so that the outer split 4 and the water-soluble core mold 5 are formed. The composite material in the cavity is fully contacted to ensure the pressurization pressure when the composite material is formed.

A number of pressurized through holes are correspondingly set in the preset areas of the upper template 1 and the lower template 2, and the axial direction of the composite material light shield molding die is pressurized through the pressurized through holes when the mold is closed. The preset area is an inner diameter greater than the annular area of the outer diameter of the outer split 4;

In a preferred embodiment of the present invention, the pressure through holes of the upper template 1 are evenly distributed on a circle on the circumference of the upper template 1; the pressure through holes of the lower template 2 are evenly distributed on a circle on the circumference of the lower template 2, The positions of the pressure through holes on the two circles correspond one by one, so that the screw can pass through the pressure through holes on the upper template 1 and the pressure through holes on the lower template 2, and realize the composite material hood by cooperating with the nut. Axial pressurization of the forming die.

In order to form the reinforcing rib 71 as shown in FIG. 5 in the shade 7 to be formed, a groove 51 is provided on the outer wall of the water-soluble core mold 5. In a preferred embodiment of the present invention, as shown in FIG. 4 , The grooves 51 are arranged at both ends of the water-soluble mandrel 5 to facilitate the laying of the prepreg when preparing the light shield 7 .

In order to make the light shield 7 to be formed have a flanging structure, a flanging flange is provided on the side of the upper template 1 that is fixed with the positioning shaft 6 .

The upper template 1 , the lower template 2 , the outer pressure ring 3 , the outer split 4 and the positioning shaft 6 of the composite material hood forming die of the present invention are all metal materials, and die steel or No. 45 steel can be selected.

Fig. 3 shows the process of preparing the light shield by utilizing the above-mentioned composite material light shield molding die of the present invention. The composite material light shield of the present invention is obtained by integral molding through the prepreg laying process. Referring to Fig. 1, the following steps are included:

S1. Lay the prepreg on the water-soluble mandrel according to the first layup sequence and the layup angle.

Specifically, at least one layer of prepreg is respectively laid on the water-soluble mandrel. In a preferred embodiment of the present invention, the prepreg is a resin-based fiber reinforced composite material.

The fiber of the prepreg is any one of carbon fiber, glass fiber, quartz fiber and high silica fiber; the resin of the prepreg is cyanate resin, epoxy resin, bismaleamide resin, polyimide resin , any one of phthalic cyanide resin; the thickness of the single layer of the prepreg is 0.05mm-0.2mm, and the volume content of the fiber in the prepreg is 60±3%.

S2. Use the positioning shaft to guide and insert each water-soluble mandrel on which the prepreg has been laid, and fix the positioning shaft inserted with the water-soluble mandrel to the upper template and the lower template.

In a preferred embodiment of the present invention, in order to enable the hood 7 to be connected with other components, a flanging flange is provided on one side of the upper formwork, so that the flanging flange is in contact with the outer lobe on the positioning shaft, The flange 8 of the hood 7 is formed.

Further, through the positioning holes on the positioning shaft, the fixing of the water-soluble mandrel to the upper template and the lower template is completed by using bolts.

S3. Lay the skin on the outer surface of the fixed water-soluble core mold and the forming surface of the flanging flange according to the second layering sequence and the layering angle.

In a preferred embodiment of the present invention, as shown in FIG. 2 , the forming surface 91 of the flanged flange is a surface abutting against the outer split 4 .

The second layering sequence and layering angle of the skin can be the same as or different from the first layering sequence and layering angle in step S1, and the skin is a resin-based fiber reinforced composite material with the same composition as the prepreg.

S4. Install the outer split valve and the outer pressure ring in sequence to complete the assembly of the composite material hood forming mold.

After the laying of the skin is completed, three outer lobes are installed on the outer circumference of the positioning shaft fixed with the upper template and the lower template, and an outer pressure ring is installed on the outer surface of the cylinder formed by the three outer lobes. Circle the threaded holes, and tighten the bolts to pressurize the outer split.

S5 , pre-compacting and curing the composite material light shield through a molding die.

In a preferred embodiment of the present invention, by tightening the bolts matched with the threaded holes of the pressure ring, and tightening the nuts matched with the screws passing through the upper template and the lower template, the composite material can be compressed in the radial and axial directions at the same time. Pre-compaction of the hood.

S6. After curing, remove the pressure ring, the outer split, the upper template, the lower template and the positioning shaft, and then dissolve the water-soluble mandrel with water.

In a preferred embodiment of the present invention, after the curing process of the hood is completed, the bolts are loosened, the pressure ring, the outer splitter, the upper template, the lower template and the positioning shaft are removed in sequence, and then the water-soluble core is removed by dissolving with water. mold to obtain an ultra-small size composite material light shield as shown in Figure 5.

A composite material light shield is prepared by using the above-mentioned composite material light shield forming mold and the above-mentioned composite material light shield preparation method.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

The above specific embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made according to the technical concept of the present invention shall be included in the protection scope of the claims of the present invention.

Claims (9)

1. The utility model provides a combined material lens hood forming die which characterized in that includes: the device comprises an upper template, a lower template, an external pressing ring, an external split, a water-soluble core mold and a positioning shaft;

pressurizing through holes are correspondingly arranged in preset areas of the upper template and the lower template, the pressurizing through holes are used for pressurizing the composite material hood forming die in the axial direction during die assembly, and the preset areas are annular areas with inner diameters larger than the outer diameter of the outer split;

pressing ring threaded holes are uniformly distributed in the circumferential direction of the external pressing ring, and the pressing ring threaded holes are matched with the threaded piece to perform circumferential pressurization on the external split;

the radius of the outer segments is matched with that of the outer pressing ring, and at least three outer segments are arranged on the inner side of the outer pressing ring and are circumferentially distributed on the outer circular surface of the light shield to be molded;

the water-soluble core mold is positioned in the outer split distributed in the circumferential direction, and a connecting through hole is formed in the central shaft of the water-soluble core mold;

the positioning shaft penetrates through the connecting through hole and is used for connecting each water-soluble core mold;

the positioning shaft is respectively connected with the upper template and the lower template.

2. The composite material light shield molding die of claim 1, wherein the pressurizing through holes of the upper mold plate are uniformly distributed on the circumference of the upper mold plate;

the pressurizing through holes of the lower template are uniformly distributed on the circumference of the lower template, so that a screw rod sequentially penetrates through the pressurizing through holes of the upper template and the pressurizing through holes of the lower template; the screw rod is matched with the nut to realize axial pressurization of the composite material light shield forming die.

3. The composite material light shield forming die as claimed in claim 1, wherein positioning holes are formed at both ends of the positioning shaft, and the positioning holes are used for positioning and connecting the positioning shaft with the upper mold plate and the lower mold plate.

4. The composite material shade forming mold according to claim 1, wherein the outer wall of the water-soluble core mold is provided with a groove, the grooving direction of the groove points to the axis of the water-soluble core mold, and the groove is used for forming a rib cavity in the shade to be formed;

and a flanging flange is arranged on one side of the upper template and is used for forming the flanging with the forming light shield.

5. The composite light shield molding mold of claim 1, wherein the upper mold plate, the lower mold plate, the outer pressing ring, the outer segments and the positioning shaft are all made of metal materials.

6. A method for preparing a composite material light shield is characterized by comprising the following steps:

s1, laying prepreg on the water-soluble core mould according to the first laying sequence and the laying angle;

s2, guiding and penetrating each water-soluble core mold after the prepreg is laid by using a positioning shaft, and fixing the positioning shaft penetrated with the water-soluble core mold with an upper template and a lower template;

s3, performing skin laying on the outer surface of the water-soluble core mould and the molding surface of the flanging flange on the upper template, which are fixed, according to a second laying sequence and a laying angle;

s4, sequentially mounting an outer split and an outer pressing ring to complete the assembly of the composite material light shield forming die;

s5, pre-compacting the composite material light shield through a forming die, and curing;

and S6, after the solidification is finished, the pressurizing ring, the outer split, the upper template, the lower template and the positioning shaft are disassembled, and then the water-soluble core mold is removed by water solution.

7. The method of claim 6, wherein the prepregs have a thickness of 0.05mm to 0.2mm and the volume content of the fibers in the prepregs is 60 ± 3%.

8. The method for preparing a composite material light shield according to claim 6, wherein the fiber of the prepreg is any one of carbon fiber, glass fiber, quartz fiber and high silica fiber;

the resin of the prepreg is any one of cyanate resin, epoxy resin, bismaleimide resin, polyimide resin and phthalocyanic resin.

9. A composite light shield made by the method of any of claims 6-9.

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