A method of controlling a ply profile in an automated fiber placement molding process

Abstract

The application discloses a method for controlling a layer profile of an automatic fiber placement forming process, and relates to the technical field of composite material forming, and comprises the following steps: S1, positioning and arranging a forming tool below an automatic fiber placement machine; S2, extending an extended part of a target laying profile outward along the laying direction of the automatic fiber placement machine, the automatic fiber placement machine being capable of integrally laying the target laying profile and the extended part on the forming tool, fixing a positioning and cutting auxiliary tool on the forming tool and covering a position corresponding to the extended part; S3, starting laying by the automatic fiber placement machine, laying the target laying profile on the forming tool and laying the extended part on the positioning and cutting auxiliary tool; and S4, cutting along the joint of the target laying profile and the extended part to obtain the target laying profile. The application can accurately control the target laying profile by separating the target laying profile and the extended part through the positioning and cutting auxiliary tool in combination with the original structure of the automatic fiber placement machine and the original process of automatic fiber placement.

Description

Technical Field

[0001] This invention relates to the field of composite material molding technology, and in particular to a method for controlling the layup profile in an automated fiber placement molding process. Background Technology

[0002] Automatic fiber placement is an advanced composite material manufacturing technology. It uses a computer-controlled automatic fiber placement head to precisely lay prepreg tows on the surface of a mold according to design requirements. Then, through heating, curing and other processes, high-performance composite material products are formed.

[0003] When using automated fiber placement technology to manufacture composite products, the edges of the laid-out layers are often straight or jagged, typically not matching the desired lay-up contour. Generally, this is addressed by setting allowance zones and then controlling the contour shape through machining after laying. However, for sub-layouts within the overall product lay-up, layouts with enclosed edges, or lay-up products with special requirements such as smooth, curved edges, if the target lay-up contour does not match straight or jagged edges, machining cannot control the lay-up contour. This necessitates adjustments by the designer during the product design phase to accommodate the automated fiber placement process, increasing the complexity of the production process and limiting production efficiency.

[0004] Therefore, how to provide an automated filament placement method that facilitates control of the layup profile is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the layup profile in an automated filament placement process, so as to solve the problems existing in the prior art, realize the control of the layup profile in the automated filament placement process, reduce process complexity, and improve production efficiency.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a method for controlling the layup profile in an automated filament placement process, comprising the following steps:

[0007] S1: Position the forming fixture below the automatic filament laying machine;

[0008] S2: The target laying outline extends outward along the laying direction of the automatic filament placement machine to form an extension. The automatic filament placement machine can integrally lay the target laying outline and the extension on the forming fixture. The positioning and cutting auxiliary fixture is fixed on the forming fixture and covers the position corresponding to the extension.

[0009] S3: The automatic filament placement machine begins laying the filaments. The target filament outline is laid on the forming fixture, and the extension is laid on the positioning and cutting auxiliary fixture.

[0010] S4: Cut along the junction of the target paving outline and the extension to obtain the target paving outline.

[0011] Furthermore, the forming fixture is provided with multiple target holes near its outer edge, and positioning targets are installed in the target holes. In step S1, the coordinates of the positioning targets are obtained by the positioning probe and the forming fixture is positioned below the automatic filament laying machine.

[0012] Furthermore, a projection target is installed inside the target hole. In step S2, the coordinates of the projection target are obtained by laser projection and the area corresponding to the extension is projected onto the forming fixture to form a projection area. The positioning and cutting auxiliary fixture is fixed on the projection area.

[0013] Furthermore, it also includes step S5: compacting the cut edges of the target laying contour obtained in step S4.

[0014] Furthermore, the compaction is achieved using either a vacuum bag vacuuming method or a pressure roller trajectory retracing method. The vacuum bag vacuuming method uses sealing strips, non-porous isolation films, or vacuum bags as sealed cavities to vacuum and compact the cut edges of the target laying contour. The pressure roller trajectory retracing method uses the pressure rollers of the automatic filament placement machine to press the target laying contour along the laying trajectory of the automatic filament placement machine, thus compacting the cut edges of the target laying contour.

[0015] Furthermore, the extension distance of the extended portion is greater than the maximum tolerance of the laying accuracy of the target laying profile.

[0016] Furthermore, the positioning and cutting auxiliary tooling is made of fiberglass epoxy board.

[0017] The present invention discloses the following technical effects:

[0018] 1. This application combines the existing structure and process of the automatic filament placement machine, and uses a positioning and cutting auxiliary tooling to separate the target filament placement outline and the extension part, thereby enabling precise control of the target filament placement outline.

[0019] 2. Compared with the traditional automatic filament placement process, although this application requires the addition of an extension section, its technical difficulty is far less than the corresponding adjustments made by the designer for the automatic filament placement forming process, and the process complexity is greatly reduced.

[0020] 3. The forming fixture and positioning and cutting auxiliary fixture are positioned by a target, which can improve the installation accuracy of the forming fixture and positioning and cutting auxiliary fixture. After the target laying contour is cut, the accuracy is high and the error is small, which is conducive to improving product quality.

[0021] 4. After the target paving outline is obtained by cutting, there are cavities at the cut edges due to bridging. This application uses a vacuum bag vacuuming method or a roller track retracing method to compact the material, which can avoid quality problems. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the outline structure of the target is provided;

[0024] Figure 2 This is a schematic diagram of the forming tooling structure;

[0025] Figure 3 Schematic diagram of the auxiliary tooling structure for positioning and cutting;

[0026] Figure 4 A schematic diagram of the automatic fiber placement machine;

[0027] Among them, 1. forming tooling; 2. target hole; 3. positioning and cutting auxiliary tooling; 4. target laying outline; 5. extension part. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] Reference Figures 1-4 This invention provides a method for controlling the layup profile in an automated filament layup process, comprising the following steps:

[0032] S1: As Figure 1 As shown, the forming fixture 1 is made of steel or composite material. The forming fixture 1 is designed for the product where the target layup is located, and its surface curvature is within the range allowed by the automatic fiber placement machine. Eleven target holes 2 are provided near the outer edge of the forming fixture 1, with each target hole 2 evenly spaced. Positioning targets are installed in the target holes 2. The coordinates of the positioning targets are obtained through a positioning probe, and the forming fixture 1 is positioned below the automatic fiber placement machine. Depending on the equipment, the automatic fiber placement machine can also use other methods to position the forming fixture 1.

[0033] S2: The target layup contour 4 extends outward along the laying direction of the automatic filament placement machine to form an extension 5. The extension distance is greater than the maximum tolerance of the layup accuracy of the target layup contour 4. The specific extension length is adjusted by programming the automatic filament placement machine. The automatic filament placement machine can integrally lay up the target layup contour 4 and the extension 5 on the forming fixture 1. A projection target is installed in the target hole 2. The coordinates of the projection target are obtained by laser projection, and the area corresponding to the extension 5 is projected onto the forming fixture 1 to form a projection area, such as... Figure 4 As shown, the positioning and cutting auxiliary fixture 3 is made of fiberglass epoxy board. The positioning and cutting auxiliary fixture 3 is bonded and fixed to the projection area by pressure-sensitive adhesive tape or other auxiliary components. The bonding positions of the pressure-sensitive adhesive tape are spaced apart from the target laying contour 4. Figure 1 and Figure 4 As shown, the shape of the positioning and cutting auxiliary tooling 3 is adapted to the target laying contour 4, and the outer edge of the positioning and cutting auxiliary tooling 3 is the contour line of the target laying contour 4.

[0034] S3: The automatic yarn placement machine performs process preparation, including yarn threading, programming simulation, and program testing. After the process preparation is completed, the automatic yarn placement machine begins to lay the yarn. The laying material is carbon fiber prepreg tape. The target laying contour 4 is laid on the forming fixture 1, and the extension 5 is laid on the positioning and cutting auxiliary fixture 3.

[0035] S4: The target laying profile 4 is obtained by cutting the prepreg tape along the junction of the target laying profile 4 and the extension 5 with a cutting blade.

[0036] S5: Compact the cut edges of the target laying contour 4 obtained in step S4. In this embodiment, the pressure roller trajectory retracing method is adopted. The pressure roller of the automatic filament laying machine rolls the target laying contour 4 according to the laying trajectory of the automatic filament laying machine. During the rolling process, the prepreg tape stops outputting and the cut edges of the target laying contour 4 are compacted by the pressure roller.

[0037] Example 2

[0038] When misalignment or other issues occur in the target laying contour 4, causing the prepreg tape to extend beyond the contour line in the width direction and requiring edge trimming, the method disclosed in Example 1 is used to complete the process.

[0039] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0040] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for controlling the layup profile in an automated filament placement process, characterized in that, Includes the following steps: S1: Position the forming fixture (1) below the automatic filament laying machine; S2: The target laying outline (4) extends outward along the laying direction of the automatic filament laying machine to form an extension (5). The automatic filament laying machine can integrally lay the target laying outline (4) and the extension (5) on the forming fixture (1). The positioning and cutting auxiliary fixture (3) is fixed on the forming fixture (1) and covers the position corresponding to the extension (5). S3: The automatic filament laying machine starts laying, the target laying outline (4) is laid on the forming fixture (1), and the extension part (5) is laid on the positioning and cutting auxiliary fixture (3); S4: Cut along the junction of the target paving outline (4) and the extension (5) to obtain the target paving outline (4). S5: Compact the cut edges of the target laying contour (4) obtained in step S4.

2. The method for controlling the layup profile in an automated filament placement process according to claim 1, characterized in that, The forming fixture (1) has multiple target holes (2) near its outer edge. Positioning targets are installed in the target holes (2). In step S1, the coordinates of the positioning targets are obtained by the positioning probe and the forming fixture (1) is positioned below the automatic filament laying machine.

3. The method for controlling the layup profile in an automated filament placement process according to claim 2, characterized in that, A projection target is installed in the target hole (2). In step S2, the coordinates of the projection target are obtained by laser projection and the area corresponding to the extension part (5) is projected onto the forming tool (1) to form a projection area. The positioning and cutting auxiliary tool (3) is fixed on the projection area.

4. The method for controlling the layup profile in an automated filament placement process according to claim 1, characterized in that, The compaction is carried out by vacuum bag vacuuming or roller track retracing. The vacuum bag vacuuming method uses sealing strips, non-porous isolation film or vacuum bags as a sealed cavity to vacuum and compact the cut edge of the target laying contour (4). The roller track retracing method uses the rollers of the automatic filament laying machine to press the target laying contour (4) according to the laying trajectory of the automatic filament laying machine to compact the cut edge of the target laying contour (4).

5. The method for controlling the layup profile in an automated filament placement process according to claim 1, characterized in that, The extension distance of the extension (5) is greater than the maximum tolerance of the laying accuracy of the target laying profile (4).

6. The method for controlling the layup profile in an automated filament placement process according to claim 1, characterized in that, The positioning and cutting auxiliary tooling (3) is made of fiberglass epoxy board.

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