Concave part prepared from composite material and preparation method of concave part

Abstract

The invention provides an inner concave part prepared from a composite material and a preparation method thereof, and the preparation method comprises the following steps: S1, designing an inner concave part of a part to be prepared into an outer convex part, and preparing a weaving core mold corresponding to the outer contour of the part to be prepared with the outer convex part; s2, reinforcing fibers are woven on the weaving core mold through a weaving machine, a convex prefabricated body is prepared, and the inner wall of the convex prefabricated body is attached to the outer wall of the weaving core mold; s3, the outer convex part of the outer convex prefabricated body is pressed downwards, so that an inner concave prefabricated body is prepared; and S4, curing and forming the inwards-concave prefabricated body to prepare the part with the inwards-concave part. According to the manufacturing method, the prefabricated body of the outwards-convex part corresponding to the inwards-concave part is woven through the weaving core mold, and then the outwards-convex part is pressed downwards, so that production of the prefabricated body of the inwards-concave part is achieved, and manufacturing of parts with inwards-concave parts such as an unmanned aerial vehicle air inlet channel made of a carbon fiber material is achieved.

Description

Technical Field

[0001] The invention belongs to the field of preparation of inner concave parts of composite materials, and in particular relates to an inner concave part prepared from composite materials and a preparation method thereof. Background Art

[0002] Composite products with simple external shapes can be directly made into preforms by weaving, and then the preforms can be cured to obtain the corresponding parts. However, when there are parts with concave outer contours, the concave parts cannot be produced directly by weaving carbon fiber. For example, in the preparation process of carbon fiber drone air intakes, since the outer contour of the air intake has a concave arc segment, its concave part cannot be directly produced by three-dimensional weaving. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a concave part made of composite material and a preparation method thereof, so as to solve the problem that the preform of the concave part in the prior art cannot be directly produced by three-dimensional weaving.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a method for preparing a concave part from a composite material, comprising: S1: Designing the inner concave portion of the part to be prepared into an outer convex portion, and making the cross-sectional line length of the part to be prepared with the inner concave portion equal to the cross-sectional line length of the part to be prepared with the outer convex portion at the same position, and preparing a braiding core mold corresponding to the outer contour of the part to be prepared with the outer convex portion; S2: Weaving the reinforcing fibers on the weaving core mold by a weaving machine to prepare an outward convex preform, wherein the inner wall of the outward convex preform is in contact with the outer wall of the weaving core mold; S3: pressing down the convex part of the convex preform to prepare a concave preform; S4: solidifying and molding the inner concave preform, thereby preparing a part with an inner concave portion.

[0005] As an optional solution, in step S1, the specific steps of preparing a braiding core mold corresponding to the outer contour of the part to be prepared having the outer convex portion are: Compare the parts to be prepared with an outer convex portion and the parts to be prepared with an inner concave portion, and determine that the difference area between them is the filling area, and prepare a supplementary core mold separately according to the filling area, prepare a first concave core mold according to the parts to be prepared with the inner concave portion, and splice the first concave core mold and the supplementary core mold into a weaving core mold.

[0006] As an optional scheme, in step S3, before pressing down the convex part of the convex preform, the supplementary core mold is first removed from the weaving core mold, and then the convex part of the convex preform is pressed down into the concave part of the first concave core mold, and the inner wall of the concave preform is fit between the outer wall of the first concave core mold.

[0007] As an optional solution, in step S4, after the concave preform is solidified and formed into the concave part, the first concave core mold is taken out from the concave part.

[0008] As an optional solution, in step S1, the specific steps of preparing a braiding core mold corresponding to the outer contour of the part to be prepared having the outer convex portion are: The entire braiding core mold is directly formed in one piece according to the outer contour of the part to be prepared with the outer convex portion.

[0009] As an optional scheme, in step S3, before the convex part of the convex preform is pressed down, the braided core mold is taken out of the convex preform, a second concave core mold is prepared according to the part to be prepared with a concave part, the second concave core mold is placed in the convex preform, and then the convex part of the convex preform is pressed down into the concave part of the second concave core mold, and the inner wall of the concave preform is fit between the outer wall of the second concave core mold.

[0010] As an optional solution, in step S4, after the concave preform is solidified and formed into the concave part, the second concave core mold is taken out from the concave part.

[0011] As an optional solution, the braided core mold is made of a water-soluble release material.

[0012] The present invention provides an inner concave part made of a composite material, which is obtained by adopting the above-mentioned preparation method.

[0013] As described above, the concave part made of composite material and the preparation method thereof proposed by the present invention have at least the following beneficial effects: 1. The present application produces a preform of a convex part corresponding to a concave part by weaving a core mold, and then presses down the convex part, thereby realizing the production of the preform of the concave part, thereby realizing the preparation of parts with concave parts such as carbon fiber drone air intakes; 2. The present application can also realize the production of special-shaped parts by setting up water-soluble demoulding materials, that is, after the production is completed, the water-soluble demoulding materials are dissolved by water, so that the core mold in the special-shaped parts can be taken out, thereby realizing the production of special-shaped parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic structural diagram of a supplementary core mold and a first concave core mold in a first shape of the present invention; Figure 2 The part to be prepared having an outer convex portion corresponding to the first shape of the present invention is shown; Figure 3 The first concave core mold is shown in the first shape of the present invention; Figure 4 The first concave part prepared by the present invention is shown; Figure 5 It is a schematic structural diagram of a supplementary core mold and a first concave core mold in a second shape of the present invention; Figure 6 The part to be prepared is shown as having an outer convex portion in the second shape of the present invention; Figure 7 The first concave core mold is shown in the first shape of the present invention; Figure 8 The second concave part prepared by the present invention is shown; Fig. 9 The part to be prepared having an outer convex portion corresponding to the first shape of the present invention is shown; Fig.10 Shown is a second braiding core mold in the first shape of the present invention; Fig.11 The part to be prepared having an inner concave portion corresponding to the first shape of the present invention is shown; Fig.12 The second concave core mold corresponding to the first shape of the present invention is shown; Fig.13 The part to be prepared having an outer convex portion corresponding to the second shape of the present invention is shown; Fig.14 Shown is a second braiding core mold in a second shape of the present invention; Fig.15 The part to be prepared having an inner concave portion corresponding to the second shape of the present invention is shown; Fig.16 Shown is the second concave core mold corresponding to the second shape of the present invention.

[0015] In the figure: 1. a part to be prepared having an inner concave portion; 2. a part to be prepared having an outer convex portion; 3. First braiding core mold; 31. Supplementary core mold; 32. First concave core mold; 4. A second braiding core mold; 41. A second concave core mold. DETAILED DESCRIPTION

[0016] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0017] See also Figures 1 to 16 . It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0018] The following embodiments are only for illustration purposes and can be combined with each other, and are not limited to the contents presented in the following single embodiments.

[0019] In this embodiment, the preparation of a carbon fiber UAV air intake pipe is taken as an example. See also Figure 1-Figure 8 The present invention provides a method for preparing a concave part using a composite material, comprising: S1: Designing the inner concave portion of the part to be prepared into an outer convex portion, and making the cross-sectional length of the part to be prepared 1 with the inner concave portion equal to the cross-sectional length of the part to be prepared 2 with the outer convex portion at the same position, and preparing a braiding core mold corresponding to the outer contour of the part to be prepared 2 with the outer convex portion. In this embodiment, the braiding core mold is the first braiding core mold 3; In the step S1, the specific steps of preparing the first braiding core mold 3 corresponding to the outer contour of the part to be prepared 2 with an outer convex portion are: comparing the part to be prepared 2 with an outer convex portion and the part to be prepared 1 with an inner concave portion, and obtaining the difference area between them as the supplementary area, preparing a supplementary core mold 31 separately according to the supplementary area, preparing a first inner concave core mold 32 according to the part to be prepared 1 with an inner concave portion, and splicing the first inner concave core mold 32 and the supplementary core mold 31 into the first braiding core mold 3; Here, the fixing method after the first inner concave core mold 32 and the supplementary core mold 31 are spliced ​​is not limited, as long as it does not affect the demoulding of the supplementary core mold 31, the splicing between the first inner concave core mold 32 and the supplementary core mold 31 can be bonded by glue, etc.; The first braiding core mold 3 is made of a water-soluble demoulding material, and the first braiding core mold 3 can be easily taken out by dissolving the first braiding core mold 3 in water; The water-soluble demoulding material is not limited here. It has a certain strength after shaping and can be soluble in water but not in resin. It can be a soluble sand mold, a soluble salt mold, etc. S2: Weaving the reinforcing fibers on the first weaving core mold 3 by a weaving machine to prepare an outward convex preform, wherein the inner wall of the outward convex preform is fitted with the outer wall of the first weaving core mold 3; The braiding machine is not limited here, and the braiding machine can be a single-ring braiding machine, a three-ring interlaced braiding machine, a four-ring interlaced braiding machine, etc.; The reinforcing fiber is not limited here, and the reinforcing fiber can be one or more of glass fiber, quartz fiber, basalt fiber, carbon fiber, aramid fiber, etc.

[0020] S3: pressing down the convex part of the convex preform to prepare a concave preform; In step S3, before pressing down the convex part of the convex preform, the supplementary core mold 31 is first removed from the first weaving core mold 3, and then the convex part of the convex preform is pressed down into the concave part of the first concave core mold 32, and the inner wall of the concave preform is fit with the outer wall of the first concave core mold 32.

[0021] Since the present embodiment removes the supplementary core mold 31 from the first weaving core mold 3, and at least one end face of the supplementary core mold 31 is coplanar with the first weaving core mold 3, there is no limitation on the shape of the part, and the outer contour of the part is a closed shape, and as long as the supplementary core mold 31 can be removed from between the convex preform and the first concave core mold 32, it will be sufficient.

[0022] S4: curing the inner concave preform to form a part having an inner concave portion; In the step S4, after the concave preform is solidified and formed into a concave part, the first concave core mold 32 is taken out from the concave part; The curing and molding of the inner concave preform described herein may be performed by vacuum process (VARI) injection molding, or may be performed by other methods that can perform curing and molding on the entire preform.

[0023] In Example 2, the preparation of a carbon fiber drone air intake pipe is taken as an example. See also Figure 9-Figure 16 The present invention provides a method for preparing a concave part using a composite material, comprising: S1: Design the inner concave portion of the part to be prepared into an outer convex portion, and make the cross-sectional length of the part to be prepared 1 with the inner concave portion equal to the cross-sectional length of the part to be prepared 2 with the outer convex portion at the same position, and prepare a braiding core mold corresponding to the outer contour of the part to be prepared 2 with the outer convex portion. In this embodiment, the braiding core mold is the second braiding core mold; In step S1, the specific steps of preparing the second braiding core mold 4 corresponding to the outer contour of the part 2 to be prepared having the outer convex portion are: According to the outer contour of the part 2 to be prepared with the outer convex portion, the entire braiding core mold is directly formed in one piece, and the braiding core mold formed in one piece is the second braiding core mold 4; The second braiding core mold 4 is made of a water-soluble demoulding material, and the second braiding core mold 4 can be easily taken out by dissolving the second braiding core mold 4 in water; When preparing the second braiding core mold 4 , a water-soluble adhesive may be added to the water-soluble demoulding material, thereby increasing the strength of the prepared second braiding core mold 4 .

[0024] S2: Weaving the reinforcing fibers on the second weaving core mold 4 by a weaving machine to prepare an outward convex preform, wherein the inner wall of the outward convex preform is fitted with the outer wall of the second weaving core mold 4; The braiding machine is not limited here, and the braiding machine can be a single-ring braiding machine, a three-ring interlaced braiding machine, a four-ring interlaced braiding machine, etc.; The reinforcing fiber is not limited here, and the reinforcing fiber can be one or more of glass fiber, quartz fiber, basalt fiber, carbon fiber, aramid fiber, etc.

[0025] S3: pressing down the convex part of the convex preform to prepare a concave preform; In step S3, before the convex part of the convex preform is pressed down, the second weaving core mold 4 is taken out of the convex preform, and a second concave core mold 41 is prepared according to the part 1 to be prepared with a concave part, and the second concave core mold 41 is placed in the convex preform, and then the convex part of the convex preform is pressed down into the concave part of the second concave core mold 41, so that the inner wall of the concave preform fits with the outer wall of the second concave core mold 41.

[0026] In order to replace the second concave core mold 41 into the concave preform, the concave preform can be a cylinder with a straight center line, or a cylinder with an arc-shaped center line, etc. The main requirement is that the second concave core mold 41 can be completely replaced in the concave preform. Since the second concave core mold 41 is replaced in the convex preform and the convex part of the convex preform is pressed down, the preparation of the concave preform is achieved. Therefore, the position of the concave part of the second concave core mold 41 can be at any position of the second weaving core mold 4.

[0027] S4: curing the inner concave preform to form a part having an inner concave portion; In the step S4, after the concave preform is solidified and formed into a concave part, the second concave core mold 41 is taken out from the concave part; The curing and molding of the inner concave preform described herein may be performed by vacuum process (VARI) injection molding, or may be performed by other methods that can perform curing and molding on the entire preform.

[0028] The present invention provides a concave part made of a composite material, which is obtained by adopting the above-mentioned preparation method.

[0029] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a concave part from a composite material, characterized in that: include: S1: Designing the inner concave portion of the part to be prepared into an outer convex portion, and making the cross-sectional line length of the part to be prepared with the inner concave portion equal to the cross-sectional line length of the part to be prepared with the outer convex portion at the same position, and preparing a braiding core mold corresponding to the outer contour of the part to be prepared with the outer convex portion; S2: Weaving the reinforcing fibers on the weaving core mold by a weaving machine to prepare an outward convex preform, wherein the inner wall of the outward convex preform is in contact with the outer wall of the weaving core mold; S3: pressing down the convex part of the convex preform to prepare a concave preform; S4: solidifying and molding the inner concave preform, thereby preparing a part with an inner concave portion.

2. The method for preparing a concave part from a composite material according to claim 1, characterized in that: In step S1, the specific steps of preparing a braiding core mold corresponding to the outer contour of the part to be prepared having an outer convex portion are: Compare the parts to be prepared with an outer convex portion and the parts to be prepared with an inner concave portion, and determine that the difference area between them is the filling area, and prepare a supplementary core mold separately according to the filling area, prepare a first concave core mold according to the parts to be prepared with the inner concave portion, and splice the first concave core mold and the supplementary core mold into a weaving core mold.

3. The method for preparing a concave part from a composite material according to claim 2, characterized in that: In step S3, before pressing down the convex part of the convex preform, the supplementary core mold is first removed from the weaving core mold, and then the convex part of the convex preform is pressed down into the concave part of the first concave core mold, and the inner wall of the concave preform is fit with the outer wall of the first concave core mold.

4. The method for preparing a concave part from a composite material according to claim 3, characterized in that: In the step S4, after the inner concave preform is solidified and formed into the inner concave part, the first inner concave core mold is taken out from the inner concave part.

5. The method for preparing a concave part from a composite material according to claim 1, characterized in that: In step S1, the specific steps of preparing a braiding core mold corresponding to the outer contour of the part to be prepared having an outer convex portion are: The entire braiding core mold is directly formed in one piece according to the outer contour of the part to be prepared with the outer convex portion.

6. The method for preparing a concave part from a composite material according to claim 5, characterized in that: In step S3, before the convex part of the convex preform is pressed down, the braided core mold is taken out of the convex preform, a second concave core mold is prepared according to the part to be prepared with a concave part, the second concave core mold is placed in the convex preform, and then the convex part of the convex preform is pressed down into the concave part of the second concave core mold, and the inner wall of the concave preform is fit with the outer wall of the second concave core mold.

7. The method for preparing a concave part from a composite material according to claim 6, characterized in that: In the step S4, after the inner concave preform is solidified and formed into the inner concave part, the second inner concave core mold is taken out from the inner concave part.

8. The method for preparing a concave part from a composite material according to claim 1, characterized in that: The braided core mold is made of water-soluble demoulding material.

9. A concave part made of composite material, characterized in that: The method is obtained by the preparation method according to any one of claims 1 to 8.

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