Preforming method for complex hollow carbon fiber workpieces

Abstract

This invention relates to a method for preforming complex hollow carbon fiber workpieces, comprising a two-way split body and multiple multi-way split bodies. The two-way split body is composed of a single silicone core mold, and the multi-way split body is composed of a polyurethane core mold and a silicone core mold. The method includes the following steps: S1, splitting the complex structure into a single two-way split body and multiple multi-way split bodies; S2, covering the outer walls of the two-way split body and multiple multi-way split bodies with carbon fiber prepreg fabric, and rolling out the split carbon fiber workpiece; S3, removing the silicone core mold; S4, embedding air duct guide lines and air ducts into the carbon fiber workpiece, and connecting the air duct guide lines and air ducts; S5, pulling out the open end of the air duct; S6, fabricating a preforming mold; S7, assembling the carbon fiber workpiece into the mold; S8, assembling an air nozzle at the open end of the air duct and wrapping it tightly with tape; S9, injecting compressed air into the air duct. This invention features easy removal of the silicone core mold, overall preforming of the workpiece, and more stable molding.

Description

Technical Field

[0001] This invention relates to a method for preforming complex hollow carbon fiber workpieces, belonging to the field of carbon fiber preforming and forming technology. Background Technology

[0002] Currently, the main method for manufacturing carbon fiber components is to use an autoclave to mold prepreg. This method is costly and complex for projects with small production volumes and diverse structural designs. Especially for tubular carbon fiber components, designing the molds requires significant effort. Currently, tubular carbon fiber components are typically manufactured using anodized and anodized film compression molding, which involves contact inflation and pressure holding to achieve the molding process.

[0003] Tubular carbon fiber workpieces have a hollow internal structure. Before attaching the carbon fiber prepreg, a mandrel needs to be designed and manufactured according to the product structure to shape the carbon fiber prepreg. However, tubular carbon fiber workpieces usually have a complex multi-channel structure. Using a conventional mandrel, it is difficult to remove the mandrel after molding, which greatly affects the molding efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a preforming method for complex hollow carbon fiber workpieces, which solves the problem that it is difficult to extract tubular carbon fiber workpieces after conventional core mold shaping in the prior art.

[0005] The above-mentioned technical objective of the present invention is mainly achieved through the following technical solution: a method for preforming complex hollow carbon fiber workpieces, comprising a two-way split body and multiple three-way or more multi-way split bodies, wherein the two-way split body is composed of a single silicone core mold, and the multi-way split body is composed of a polyurethane core mold and at least one silicone core mold, comprising the following steps:

[0006] S1. Divide the complex structure into a single two-way split body and multiple three-way or more multi-way split bodies;

[0007] S2. Cover the outer wall of the two-way split body and the multi-way split body with carbon fiber prepreg and roll it up to form split carbon fiber workpieces.

[0008] S3. Remove the silicone core mold from step S2;

[0009] S4. Embed air duct guide lines in the split carbon fiber workpieces with multiple open ends, insert air ducts into carbon fiber workpieces with one end sealed by silicone rods, and connect the air duct guide lines and air ducts of adjacent carbon fiber workpieces.

[0010] S5. Pull the duct guide line to pull the duct opening end out from inside the carbon fiber workpiece;

[0011] S6. Design and manufacture pre-forming molds;

[0012] S7. Place the disassembled carbon fiber parts into the mold and assemble them into a complete carbon fiber part.

[0013] S8. Assemble the air nozzle at the open end of the pulled-out air duct and wrap it tightly with tape;

[0014] S9. Compressed air is pumped from the air nozzle into the air duct through the compressor;

[0015] The above method allows carbon fiber workpieces to be positioned by a combination of silicone core molds and polyurethane core molds, and pre-formed by covering them with carbon fiber prepreg. This makes it easier to remove the silicone core mold, and the polyurethane core mold is positioned at the multi-connection points of the carbon fiber workpiece, which can strengthen the structural strength and maintain the lightweight nature of the carbon fiber workpiece. At the same time, the carbon fiber workpiece can be formed as a whole after the assembly is completed, making the overall carbon fiber workpiece more stable.

[0016] Preferably, the multi-port connection of the multi-port split body is formed by a combination of a silicone core mold and a polyurethane core mold; the combination of the silicone core mold and the polyurethane core mold in the multi-port split body facilitates the rapid removal of the silicone core mold after the carbon fiber workpiece is pre-formed, while maintaining the shaping effect. At the same time, when the carbon fiber workpiece is heated and pressurized for molding, the polyurethane core mold can adhere to the inside of the carbon fiber workpiece, and can ensure the lightweight nature of the carbon fiber workpiece.

[0017] Preferably, the multi-channel splitting body includes a Y-shaped splitting body, a T-shaped splitting body, and an annular splitting body; the multi-channel splitting body includes a Y-shaped splitting body, a T-shaped splitting body, and an annular splitting body to realize multi-segment pre-forming of carbon fiber workpieces, so as to facilitate mold opening and core mold extraction.

[0018] Preferably, a mating portion for forming a carbon fiber workpiece is provided between adjacent ends of the two-way split body and the multiple multi-way split bodies; the above-mentioned mating portion is provided to facilitate the formation of a carbon fiber workpiece interface when covering carbon fiber prepreg, and to facilitate the connection and combination between the split carbon fiber workpieces.

[0019] Preferably, the split carbon fiber workpieces produced in step S2 are interlocked and connected to each other; the bonding and combination of the above-mentioned split carbon fiber workpieces makes the molding process more convenient, and the tubular structure is maintained in a continuous state after the connection and molding.

[0020] Preferably, the duct opening end and the air nozzle are sealed together in step S7; the sealed connection between the duct opening end and the air nozzle facilitates the connection of an external air injection device through the air nozzle to inject compressed air into the duct to support and shape the inner cavity of the carbon fiber workpiece, and avoids air leakage during air injection.

[0021] Preferably, in step S8, compressed air at 0.2 MPa is injected into the duct. The 0.2 MPa of compressed air injected into the duct can just support the duct, so that the duct supports the inner wall of the carbon fiber workpiece, ensuring that the inner cavity of the carbon fiber workpiece can be supported during pressure molding, and the inner wall of the carbon fiber workpiece can be leveled.

[0022] Therefore, the present invention has the characteristics of shaping carbon fiber workpieces through a combined core mold, facilitating the extraction of the silicone core mold, pre-forming the workpiece as a whole, and making the molding more stable. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the disassembled body of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the carbon fiber workpiece after it is assembled in the mold according to the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the carbon fiber workpiece after it is placed into the air duct of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0027] like Figure 1-3 As shown, a method for preforming complex hollow carbon fiber workpieces includes a two-way split body 1 and multiple three-way or more multi-way split bodies 2. The two-way split body 1 is composed of a single silicone core mold 12, and the multi-way split body 2 is composed of a polyurethane core mold 13 and at least one silicone core mold 12. The method includes the following steps:

[0028] S1. Divide the complex structure into a single two-way split body and multiple three-way or more multi-way split bodies;

[0029] S2. Cover the outer wall of the two-way split body and the multi-way split body with carbon fiber prepreg and roll it up to form split carbon fiber workpieces.

[0030] S3. Remove the silicone core mold from step S2;

[0031] S4. Embed air duct guide lines in the split carbon fiber workpieces with multiple open ends, insert air ducts into carbon fiber workpieces with one end sealed by silicone rods, and connect the air duct guide lines and air ducts of adjacent carbon fiber workpieces.

[0032] S5. Pull the duct guide line to pull the duct opening end out from inside the carbon fiber workpiece;

[0033] S6. Design and manufacture pre-forming molds;

[0034] S7. Place the disassembled carbon fiber parts into the mold and assemble them into a complete carbon fiber part.

[0035] S8. Assemble the air nozzle at the open end of the pulled-out air duct and wrap it tightly with tape;

[0036] S9. Compressed air is pumped into the air duct from the air nozzle through the compressor.

[0037] After the shape and structure of the carbon fiber workpiece are designed and formed, silicone and polyurethane materials are designed and manufactured into a core mold in the shape of the carbon fiber workpiece according to the designed structure of the carbon fiber workpiece. The two-way split body is formed by the silicone core mold. The surface of the formed two-way split body is covered with multiple layers of carbon fiber prepreg cloth until the split carbon fiber workpiece is formed. The multi-way split body is formed by combining silicone core mold and polyurethane core mold. The polyurethane material is lightweight and can be heated and fused and fixed to the inner wall of the carbon fiber workpiece. It will not loosen and does not need to be removed. It does not affect the lightweight of the carbon fiber workpiece. The surface of the formed multi-way split body is covered with multiple layers of carbon fiber prepreg cloth until the split carbon fiber workpiece is formed. After the carbon fiber prepreg cloth is covered, all silicone core molds are pulled out to form the split carbon fiber workpiece.

[0038] For carbon fiber workpieces with multiple open ends, air duct guide lines need to be pre-embedded inside. For carbon fiber workpieces with only one open end, air ducts are inserted inside using glue rods. For carbon fiber workpieces with multiple open ends that need to be connected to the carbon fiber workpieces with air ducts already inserted, one end of the air duct guide line is connected to the end of the air duct, and the air duct guide line is pulled to allow the air duct to enter the interior of the carbon fiber workpiece with multiple open ends and protrude from the other end. After all the air ducts are placed in, the carbon fiber workpiece is placed in a pre-designed pre-forming mold and assembled into a complete carbon fiber workpiece. Then, an air nozzle is connected to the open end of the air duct and sealed tightly with tape. Finally, compressed air is injected into the air duct through a compressor to complete the pre-forming of the carbon fiber workpiece. After that, the carbon fiber workpiece needs to be heated and pressurized to be fully formed.

[0039] like Figure 1-3 As shown, the multi-port connection of the multi-port split body 2 is formed by the combination of silicone core mold 12 and polyurethane core mold 13. The multi-port split body 2 includes a Y-shaped split body 21, a T-shaped split body 22 and an annular split body 23. The adjacent ends of the two-port split bodies 1 and the multiple multi-port split bodies 2 are provided with a mating part 11 for forming a carbon fiber workpiece interface. The split carbon fiber workpieces produced in step S2 are interlocked and connected to each other. The air duct 3 opening end in step S7 is sealed to the air nozzle 31. The air duct 3 in step S8 is filled with 0.2 MPa compressed air.

[0040] The multi-channel splitting body includes a Y-shaped splitting body, a T-shaped splitting body, and an annular splitting body. The two splitting bodies, along with the Y-shaped, T-shaped, and annular splitting bodies, are used to form different and split carbon fiber workpieces. After forming, they can be assembled into a complete carbon fiber workpiece. There are joints between each pair of adjacent split carbon fiber workpieces to facilitate bonding with glue, so that the split carbon fiber workpieces can be spliced ​​together completely. After the complete carbon fiber workpiece is pre-formed, the air nozzle at the opening end of the air duct is connected to an external compressor. The compressor injects 0.2 MPa compressed air into the air duct. The outer wall of the air duct, which is filled with compressed air and bulges, is pressed tightly against the inner wall of the carbon fiber workpiece and maintains support. After the carbon fiber workpiece is thoroughly pressurized and shaped, the air duct needs to be removed.

Claims

1. A method for preforming complex hollow carbon fiber workpieces, characterized in that, The device includes a two-way splitter (1) and multiple three-way or more multi-way splitters (2). The two-way splitter (1) is composed of a single silicone core mold, and the multi-way splitter (2) is composed of a polyurethane core mold and at least one silicone core mold. The multi-way connection of the multi-way splitter (2) is formed by combining the silicone core mold and the polyurethane core mold. The polyurethane core mold is used to be permanently left at the multi-way connection after molding. The device includes the following steps: S1. Divide the complex structure into a single two-way split body and multiple three-way or more multi-way split bodies; S2. Cover the outer wall of the two-way split body and the multi-way split body with carbon fiber prepreg and roll it up to form split carbon fiber workpieces. S3. Extract the silicone core mold from step S2, leaving the polyurethane core mold inside the carbon fiber workpiece of the multi-channel split body. S4. Embed air duct guide lines in the split carbon fiber workpieces with multiple open ends, insert air ducts into carbon fiber workpieces with one end sealed by silicone rods, and connect the air duct guide lines and air ducts of adjacent carbon fiber workpieces. S5. Pull the duct guide line to pull the duct opening end out from inside the carbon fiber workpiece; S6. Design and manufacture pre-forming molds; S7. Place the disassembled carbon fiber parts into the mold and assemble them into a complete carbon fiber part. S8. Assemble the air nozzle at the open end of the pulled-out air duct and wrap it tightly with tape; S9. Compressed air is pumped into the air duct from the air nozzle through the compressor.

2. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: The multi-port connection of the multi-port split body (2) is formed by a combination of a silicone core mold and a polyurethane core mold.

3. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: The multi-channel split body (2) includes a Y-shaped split body (21), a T-shaped split body (22), and a ring-shaped split body (23).

4. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: A mating part (11) for forming a carbon fiber workpiece is provided between adjacent ends of the two-way split body (1) and the multiple multi-way split bodies (2).

5. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: The split carbon fiber workpieces produced in step S2 are interlocked and connected to each other.

6. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: In step S7, a sealed connection is made between the duct opening and the air nozzle.

7. The method for preforming complex hollow carbon fiber workpieces according to claim 1, characterized in that: In step S8, compressed air at 0.2 MPa is injected into the air duct.

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