Forming die and forming process of carbon fiber composite skin

Abstract

The invention relates to the technical field of composite material preparation, and particularly discloses a carbon fiber composite material skin forming mold and a forming process thereof.Carbon fiber one-way prepreg and carbon fiber fabric prepreg are used as raw materials, integrated curing forming is conducted in a prepreg flanging and twisting mode, it is ensured that fibers at corners are continuous, and the carbon fiber composite material skin is obtained. The strength and the rigidity in the main force bearing direction are provided; the mold structure and the process are simple and easy to operate, continuous fiber increase of the overall strength of the product is ensured through mold design and layering design, the processing risk is avoided, the product quality is stable, the appearance size of the product is accurate and controllable, and the mold is suitable for large-batch production.

Description

Technical Field

[0001] The invention relates to the technical field of composite material preparation, and in particular to a forming die and a forming process of a carbon fiber composite material skin. Background Art

[0002] With the continuous development of weapons and equipment, the requirements for weight reduction, stealth, impact resistance, high temperature resistance and other performance are getting higher and higher. Traditional metal materials are becoming increasingly difficult to meet the requirements. Composite materials have become the basis for the development of military equipment, and their application level has become one of the standards for measuring the advancement of weapons and equipment development.

[0003] As the cost of composite materials decreases, the proportion of composite materials used in weapons and equipment continues to increase. The composite material of the skin greatly reduces the total weight of the equipment, increases the flight speed of the equipment, and increases its launch range. Summary of the invention

[0004] The purpose of the present invention is to provide a forming die and a forming process for a carbon fiber composite material skin, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides a forming die for a carbon fiber composite material skin, comprising:

[0006] A lower die, wherein a product groove is formed on the lower die, and a plurality of positioning pins and a plurality of threaded holes are provided on the lower die;

[0007] A side baffle, wherein the side baffle is installed on one side of the lower die through the positioning pin, and the side baffle is fixed to the lower die through bolts and the threaded holes; the product groove is enclosed by the side baffle to form a product cavity;

[0008] An upper cover plate, wherein the upper cover plate is arranged at one end of the top of the lower die, the upper cover plate is installed on the lower die through the positioning pin, and the upper cover plate and the lower die are fixed by bolts and the threaded holes; the upper cover plate is used to install a drilling jig bushing with forming and hole-making functions.

[0009] A forming process of a carbon fiber composite material skin specifically comprises the following steps:

[0010] S1, laying the first prepreg in the product cavity of the lower mold, and flanging the first prepreg at the position of the upper cover plate;

[0011] S2, filling twisted strips at the flange of the first prepreg and compacting the twisted strips;

[0012] S3, laying out the second prepreg, flanging the second prepreg at the position of the twisted strip, and compacting the second prepreg at the twisted strip;

[0013] S4, filling the twisted strips at the flange of the second prepreg and compacting the twisted strips;

[0014] S5, laying out multiple layers of the second prepreg in sequence to obtain a preliminarily formed product;

[0015] S6, curing the preliminarily formed product and making holes in the cured product;

[0016] S7. De-mould the product after hole making, and perform trimming and installation of wire screw sleeves.

[0017] Preferably, the first prepreg is a carbon fiber fabric prepreg, and the second prepreg is a carbon fiber unidirectional prepreg.

[0018] Preferably, the wire screw sleeve is installed at the angle between the upper cover plate and the lower mold of the product, and the thickness of the product at the installation position of the wire screw sleeve is 10 mm.

[0019] Preferably, the hole-making direction of the product is consistent with the normal direction of the hole-making position.

[0020] Preferably, each prepreg layer of the product is laid to the edge of the product groove.

[0021] Preferably, the step S5 comprises:

[0022] S5.1. When the last two layers of carbon fiber unidirectional prepreg are laid, the side baffle is installed on the lower mold with bolts, and the gap between the lower mold and the side baffle is filled and compacted with carbon fiber unidirectional prepreg;

[0023] S5.2. Remove the side baffles and lay the last two layers of carbon fiber unidirectional prepreg on the lower mold to cover the entire product.

[0024] Preferably, before the step S6, the bolts for fixing the side baffles are removed.

[0025] Preferably, before drilling holes in the cured product, auxiliary materials on the cured product are removed, and a drilling jig bushing is installed on the upper cover plate.

[0026] A carbon fiber composite material skin is prepared by adopting the above-mentioned carbon fiber composite material skin molding process.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] 1. Most of the existing skins are made of aluminum alloy, and the overall weight is heavy. The present invention uses carbon fiber unidirectional prepreg and carbon fiber fabric prepreg as raw materials, and adopts the method of prepreg flanging and twisting to solidify and form the whole, which reduces the overall weight by about 50%.

[0029] 2. The present invention proposes a molding process for composite material skins, which ensures the continuity of fibers and the requirements of internal and external surfaces through mold structure design. The carbon fiber prepreg can accurately control the resin content of the product, strictly control the weight of the product, and ensure the stability of product batches.

[0030] 3. The mold structure and process of the present invention are simple and easy to operate. The mold design and layer design ensure that the fibers continuously increase the overall strength of the product and avoid processing risks. The product quality is stable, the product size is precisely controllable, and it is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the composite material skin forming mold after assembly of the present invention;

[0033] Figure 2 It is a schematic diagram of a disassembled composite material skin forming mold of the present invention;

[0034] Figure 3 It is a schematic diagram of laying out the composite material skin of the present invention;

[0035] In the figure: 1. Lower die; 2. Side baffle; 3. Upper cover plate; 4. Locating pin; 5. Product groove; 6. Threaded hole; 7. Drilling jig bushing. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0037] like Figures 1 to 3 As shown, the present invention provides a forming die for a carbon fiber composite material skin, comprising:

[0038] A lower die 1 is provided with a product groove 5, and a plurality of positioning pins 4 and a plurality of threaded holes 6 are provided on the lower die 1;

[0039] Side baffle 2, the side baffle 2 is installed on one side of the lower mold 1 through the positioning pin 4, and the side baffle 2 and the lower mold 1 are fixed by bolts and threaded holes 6; the product groove 5 is enclosed by the side baffle 2 to form a product cavity;

[0040] The upper cover plate 3 is arranged at one end of the top of the lower mold 1. The upper cover plate 3 is installed on the lower mold 1 through the positioning pin 4, and the upper cover plate 3 and the lower mold 1 are fixed by bolts and threaded holes 6; the upper cover plate 3 is used to install the drilling mold bushing 7 with forming and hole making functions.

[0041] The upper cover plate 3 of the present invention is both a forming mold and a hole making tool. After the forming is completed, the drilling jig bushing 7 can be installed before the hole making to make the hole. It can ensure that the hole making is completed without demoulding, and the position accuracy and size accuracy of the hole making are guaranteed.

[0042] A forming process of a carbon fiber composite material skin specifically comprises the following steps:

[0043] S1, laying the first prepreg in the product cavity of the lower mold 1, and flanging the first prepreg at the position of the upper cover plate 3;

[0044] S2, filling twisted strips at the flange of the first prepreg and compacting the twisted strips;

[0045] S3, laying out the second prepreg, flanging the second prepreg at the position of the twisted strip, and compacting the second prepreg at the twisted strip;

[0046] S4, filling the twisted strips at the flange of the second prepreg and compacting the twisted strips;

[0047] S5, laying out multiple layers of the second prepreg in sequence to obtain a preliminarily formed product;

[0048] S6, curing the preliminarily formed product and making holes in the cured product;

[0049] S7. De-mould the product after hole making, and perform trimming and installation of wire screw sleeves.

[0050] According to a further optimized solution, the first prepreg is a carbon fiber fabric prepreg, and the second prepreg is a carbon fiber unidirectional prepreg.

[0051] According to a further optimization scheme, the wire screw sleeve is installed at the angle between the upper cover plate 3 and the lower die 1 of the product, and the thickness of the product at the installation position of the wire screw sleeve is about 10 mm.

[0052] The solution is further optimized so that the hole making direction of the product is consistent with the normal direction of the hole making position.

[0053] To further optimize the solution, each prepreg layer of the product is laid to the edge of the groove 5 of the product.

[0054] To further optimize the solution, step S5 includes:

[0055] S5.1. When the carbon fiber unidirectional prepreg is laid to the last two layers, the side baffle 2 is installed on the lower mold 1 with bolts, and the gap between the lower mold 1 and the side baffle 2 is filled and compacted with the carbon fiber unidirectional prepreg;

[0056] S5.2, remove the side baffle 2, and lay the last two layers of carbon fiber unidirectional prepreg on the lower mold 1 to cover the product as a whole.

[0057] To further optimize the solution, before step S6, the bolts used to fix the side baffle 2 are removed.

[0058] To further optimize the solution, before drilling holes in the solidified product, the auxiliary materials on the solidified product are removed, and a drilling jig bushing 7 is installed on the upper cover plate 3.

[0059] A carbon fiber composite material skin is prepared by adopting the above-mentioned carbon fiber composite material skin molding process.

[0060] The forming process of the carbon fiber composite material skin provided by the present invention is that before laying, the upper cover plate 3 is first positioned on the lower mold 1, and the side baffle 2 is not installed temporarily. The carbon fiber fabric prepreg is laid on the lower mold 1 as the first layer, and the upper cover plate 3 is flanged to ensure the continuity of the fiber. After the first layer is laid, a small amount of twisted strips are filled in the corners and compacted before laying the carbon fiber unidirectional prepreg. The carbon fiber unidirectional prepreg remains continuous at the corners of the lower mold 1 and the upper cover plate 3, and then the twisted strips are continued to be filled, and the twisted strips are quantitatively filled.

[0061] When the carbon fiber unidirectional prepreg is laid to the last two layers, fix the side baffle 2 with the positioning pin 4, tighten the side baffle 2 with the bolts, and fill and compact the gap between the lower mold 1 and the side baffle 2 with the carbon fiber unidirectional prepreg. After compaction, remove the side baffle 2, lay the last two layers of carbon fiber unidirectional prepreg on the lower mold 1 to cover the product as a whole, and the layers at the upper cover 3 are slightly higher than the edge of the upper cover 3 mold. All layers of the product are laid to the edge of the product groove 5 to ensure that no material extrusion occurs when the side baffle 2 is molded.

[0062] After paving is completed, the side baffle 2 is fixed in the corresponding position using the positioning pin 4 before packaging without installing bolts, so as to ensure that the position of the side baffle 2 is fixed during the curing process and that the side of the product can be continuously pressurized.

[0063] The thickness of the product groove 5 in the lower mold 1 is set according to the product lower difference, which can ensure the product thickness and prevent excessive loss of resin during the curing process.

[0064] After curing, the auxiliary materials are removed, and the drilling template bushing 7 is installed on the upper cover plate 3 to make holes. When making holes, the inner and outer surface layers are all fabric prepregs to avoid surface splitting; the hole making direction is consistent with the normal direction of the carbon fiber ply to avoid overall internal splitting.

[0065] After the hole making is completed, the demoulding operation is carried out, and after the demoulding is completed, the edges are trimmed and the wire screw sleeves are installed.

[0066] The present invention mainly adopts carbon fiber unidirectional prepreg as raw material to ensure the continuity of fibers at the corners and provide strength and rigidity in the main load-bearing direction; the prepreg is integrally solidified and formed by flanging and twisting, and the filling amount of twisted strips can be strictly controlled by the upper cover plate 3 and the side baffle plate 2, which can effectively control the weight of the product, ensure stable product quality and weight consistency, and ensure the stability of product batches.

[0067] The composite material skin prepared by the present invention has the advantages of light weight, convenient installation, etc. The molding process is simple and easy to operate, the product size is precisely controllable, the surface is smooth and flat, and it is suitable for mass production.

[0068] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A forming die for a carbon fiber composite material skin, characterized in that: include: A lower die (1), wherein a product groove (5) is formed on the lower die (1), and a plurality of positioning pins (4) and a plurality of threaded holes (6) are provided on the lower die (1); A side baffle (2), wherein the side baffle (2) is installed on one side of the lower mold (1) via the positioning pin (4), and the side baffle (2) and the lower mold (1) are butt-jointed and fixed via bolts and the threaded holes (6); the product groove (5) is enclosed by the side baffle (2) to form a product cavity; An upper cover plate (3), the upper cover plate (3) being arranged at one end of the top of the lower die (1), the upper cover plate (3) being mounted on the lower die (1) via the positioning pin (4), and the upper cover plate (3) and the lower die (1) being fixed by abutting against each other via bolts and the threaded holes (6); the upper cover plate (3) being used for mounting a drilling jig bushing (7) having forming and hole-making functions.

2. A carbon fiber composite material skin forming process, characterized in that: Using the molding die according to claim 1 specifically comprises the following steps: S1, laying a first prepreg in the product cavity of the lower mold (1), and flanging the first prepreg at the position of the upper cover plate (3); S2, filling twisted strips at the flange of the first prepreg and compacting the twisted strips; S3, laying out the second prepreg, flanging the second prepreg at the position of the twisted strip, and compacting the second prepreg at the twisted strip; S4, filling the twisted strips at the flange of the second prepreg and compacting the twisted strips; S5, laying out multiple layers of the second prepreg in sequence to obtain a preliminarily formed product; S6, curing the preliminarily formed product and making holes in the cured product; S7. De-mould the product after hole making, and perform trimming and installation of wire screw sleeves.

3. The forming process of the carbon fiber composite material skin according to claim 2, characterized in that: The first prepreg is a carbon fiber fabric prepreg, and the second prepreg is a carbon fiber unidirectional prepreg.

4. The forming process of the carbon fiber composite material skin according to claim 2, characterized in that: The wire screw sleeve is installed at the angle between the upper cover plate (3) and the lower die (1) of the product, and the thickness of the product at the installation position of the wire screw sleeve is 10 mm.

5. The forming process of the carbon fiber composite material skin according to claim 2, characterized in that: The hole making direction of the product is consistent with the normal direction of the hole making position.

6. The forming process of the carbon fiber composite material skin according to claim 2, characterized in that: Each prepreg layer of the product is laid to the edge of the product groove (5).

7. The forming process of the carbon fiber composite material skin according to claim 3, characterized in that: The S5 step includes: S5.

1. When the last two layers of carbon fiber unidirectional prepreg are laid, the side baffle (2) is mounted on the lower mold (1) using bolts, and the gap between the lower mold (1) and the side baffle (2) is filled and compacted using the carbon fiber unidirectional prepreg; S5.

2. Remove the side baffle (2) and lay the last two layers of carbon fiber unidirectional prepreg on the lower mold (1) to cover the entire product.

8. The forming process of the carbon fiber composite material skin according to claim 7, characterized in that: Before the step S6, the bolts used to fix the side baffle (2) are removed.

9. The forming process of the carbon fiber composite material skin according to claim 2, characterized in that: Before drilling holes in the solidified product, the auxiliary materials on the solidified product are removed, and a drilling jig bushing (7) is installed on the upper cover plate (3).

10. A carbon fiber composite material skin, characterized in that: The carbon fiber composite material skin is prepared by the molding process described in any one of claims 2 to 9.

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