Method for laying three-dimensional composite material based on automatic yarn staying

Abstract

The invention discloses a method for laying a three-dimensional composite material based on automatic yarn standing, which realizes self-supply of fibers in the thickness direction while laying plane fibers, and provides a brand new technical scheme for preparation of the three-dimensional composite material. Compared with a traditional three-dimensional composite material forming method, the method solves the problems that the fiber prefabricated body is large in weaving damage, many in working procedures, high in requirement for composite equipment and the like, direct forming of the three-dimensional reinforced composite material can be achieved, a direct channel for compounding the fiber prefabricated body and the base body is opened, and the application prospect is wide.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite materials, and particularly relates to a manufacturing method of three-dimensional composite materials based on the automatic stationary yarn placement technology. Background Art

[0002] With the development of the national economy and materials technology, fiber-reinforced composite materials have been widely used, forming a relatively complete molding system. In particular, the automatic placement technology has realized the automated preparation of large-size and high-precision composite materials, playing an important role in the manufacturing of composite materials for commercial airliners. However, at present, the fiber-reinforced composite material forming process can only achieve fiber reinforcement in the plane direction, and the layers are connected by the matrix, resulting in limited performance improvement; for products that require fiber reinforcement between the plane layers, only the preform technology with textile technology can be relied on. The preform generally uses dry fiber molding, which increases the difficulty of matrix impregnation in the subsequent composite material manufacturing, and has great difficulty in controlling the quality uniformity and a long manufacturing cycle. Summary of the Invention

[0003] Based on the above technical problems, the present invention provides a method for directly designing and manufacturing three-dimensional composite materials by introducing connecting fibers between the plane layers.

[0004] The technical solution to achieve the object of the present invention is: A method for three-dimensional composite materials based on the automatic stationary yarn placement technology, comprising the following steps:

[0005] (1) According to the designed stationary yarn spacing, pre-place the guiding stationary yarn device capable of carrying fiber tows on the tooling for laying the plane tows, and introduce the fiber tows set in the guiding stationary yarn device into the stationary yarn holes of the tooling, ensuring that there is no interference between adjacent guiding stationary yarn devices, and lay the first layer of fiber tows on both sides of the guiding stationary yarn device along the first direction;

[0006] (2) After the first layer of fiber tows is laid, lay the second layer of fiber tows on both sides of the guiding stationary yarn device along the second direction. The second layer of fiber tows forms a certain angle with the first layer of fiber tows. After the second layer of fiber tows is laid, continue to lay the third layer of fiber tows on both sides of the guiding stationary yarn device along the set third direction. The third layer of fiber tows forms a certain angle with the second layer of fiber tows;

[0007] (3) Repeat the laying according to step (2), ensuring that there is a certain angle between the upper and lower adjacent layers of fiber tows until the specified thickness requirement is reached. Remove the guiding stationary yarn device, and retain the fiber tows set by the guiding stationary yarn device in the holes to form Z-direction fibers, obtaining the three-dimensional composite material.

[0008] In a preferred embodiment of the present invention, the shape of the guiding yarn retainer can be a spindle shape, an L shape, or a spherical structure that is convenient for rotation. The spindle shape refers to a structure with conical or tapered (frustum) ends and a cylindrical middle. The L shape is composed of two rectangular parallelepipeds at a 90° angle, and the ends of the rectangular parallelepipeds have a taper angle or taper (frustum).

[0009] In a preferred embodiment of the present invention, the yarn retaining holes are uniformly arranged in an array structure (m×n) on the laying tooling.

[0010] In a preferred embodiment of the present invention, for the diameter φ of the yarn retaining hole, the diameter of the Z-direction fiber is less than or equal to the diameter φ of the yarn retaining hole.

[0011] In a preferred embodiment of the present invention, the yarn retaining spacing refers to the center distance between two adjacent yarn retaining holes, and the yarn retaining spacing ≥ the length of the guiding yarn retainer.

[0012] In a preferred embodiment of the present invention, the second layer of fiber bundles forms a certain angle with the first layer of fiber bundles, and this angle is set as β1, where 0° < β1 ≤ 90°. The third layer of fiber bundles forms a certain angle with the second layer of fiber bundles, and this angle is set as β2, where 0° < β2 ≤ 90°.

[0013] In a preferred embodiment of the present invention, it is ensured that the upper and lower adjacent layers of fiber bundles form a certain angle, and this angle is set as θ, where 0° < θ ≤ 90°.

[0014] In a preferred embodiment of the present invention, the fiber bundle refers to a fiber bundle with or without adhesive.

[0015] In a preferred embodiment of the present invention, the fiber bundle refers to a spread fiber bundle or a non-spread fiber bundle.

[0016] In a preferred embodiment of the present invention, in the guiding yarn retainer for setting the fiber bundle, the fiber bundle is arranged at the central position of the guiding yarn retainer.

[0017] Compared with the prior art, the present invention obtains a three-dimensional composite material through fiber placement. While being able to achieve direct or indirect molding, it can also achieve the "self-supply" of fibers in the thickness direction, providing a brand-new technical solution for the preparation of three-dimensional composite materials. Compared with the traditional composite material molding method, this method solves the problems faced by traditional preform-reinforced composite materials, such as large fiber weaving damage, multi-process preparation, and low equipment versatility. It can achieve the direct molding of Z-direction fiber-reinforced composite materials, with a short overall preparation process, high efficiency, and easy integrated molding, and has good application prospects.

[0018] The present invention can also directly manufacture three-dimensional composite materials based on various planar forming technologies such as the filament winding process. The present invention uses non-impregnated or impregnated fiber bundles, which can not only prepare preforms (and then obtain composite materials through compounding), but also directly obtain a three-dimensional composite material.

[0019] It should be understood that all combinations of the foregoing concepts and additional concepts described in more detail below can be regarded as part of the inventive subject matter of the present application as long as such concepts do not conflict with each other. In addition, all combinations of the claimed subject matter are regarded as part of the inventive subject matter of the present application.

[0020] The foregoing and other aspects, embodiments, and features of the teachings of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of exemplary embodiments, will be apparent from the following description or learned through the practice of specific embodiments in accordance with the teachings of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are not intended to be drawn to scale. In the drawings, the corresponding operation steps in each figure are labeled with text in the figure. For clarity, not every step part is described in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the drawings, wherein:

[0022] Figure 1 is a laying diagram of the spindle-shaped guiding yarn retainer of the present invention, a: 0° laying, b: 90° laying.

[0023] Figure 2 is a laying diagram of the L-shaped guiding yarn retainer of the present invention, a: 0° laying, b: 90° laying.

[0024] Figure 3 is a laying diagram of the spherical guiding yarn retainer of the present invention, a: 0° laying, b: 90° laying.

[0025] Figure 4 is a structural diagram of the laying tooling of the present invention.

[0026] Figure 5 is the laying effect diagram of the guiding yarn retainer on the laying tooling.

[0027] Figure 6 is the effect diagram after the laying of the first layer of fiber filaments.

[0028] Figure 7 is a working process diagram of the fiber laying device.

[0029] Figure 8 is a structural diagram of the flipper and the fiber laying head in the fiber laying device.

[0030] Figure 9 It is the effect diagram after the laying of the second layer of fiber tows.

[0031] Figure 10 It is the laying schematic diagram of different perspectives of the embodiment of the present invention, a: three-dimensional, b: cross-section, c: top view.

[0032] Figure 11 It is the schematic diagram of the laying process of different angles of the embodiment of the present invention. Detailed implementation manners

[0033] In order to better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0034] In the present invention, various aspects of the present invention are described with reference to the accompanying drawings, and many illustrative embodiments are shown in the drawings. The embodiments of the present invention are not necessarily intended to cover all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those concepts and embodiments described in more detail below, can be implemented in any of a number of ways, because the concepts and embodiments disclosed in the present invention are not limited to any implementation manner. In addition, some aspects disclosed in the present invention can be used alone, or in any suitable combination with other aspects disclosed in the present invention.

[0035] The core of the present invention is that when laying planar fibers, through design and control, a Z-direction connection fiber channel is reserved; a guiding yarn anchor is installed at the upper end of the channel to hang the Z-direction fibers. The guiding yarn anchor mainly has two functions. One is the guiding function. When laying fibers in a plane and increasing the length of the hole channel, under the push of the laying head and changing the position in the plane, it ensures that the laying position and accuracy of the planar fibers are not affected; the other is the yarn anchoring function. While the position in the plane changes, as the planar fibers increase, the yarn anchor automatically lifts the corresponding height and pulls the fibers in the hole channel to increase the length. Through the organic cooperation of these two functions, while increasing the planar thickness, the Z-direction yarn anchoring length is increased to achieve "self-supply".

[0036] A method for automatically laying three-dimensional composites with yarn anchoring includes the following steps:

[0037] Step (1): Design of yarn-anchoring holes

[0038] The laying tooling is composed of a square plate and a support frame. Yarn-anchoring holes are uniformly arranged in an array (m×n) on the plate. The diameter of the yarn-anchoring holes is φ, and the spacing of the yarn-anchoring holes is set according to the required yarn-anchoring spacing d, and the yarn-anchoring holes can pass through a fiber tow of a certain specification (the diameter of the fiber tow is less than or equal to the diameter φ of the yarn-anchoring holes); the structural schematic diagram of the laying tooling is as Figure 4 shown.

[0039] Step (2): Design of the guiding yarn anchor

[0040] The shape of the guide yarn stop can be designed as a one-dimensional (shuttle-shaped), two-dimensional (L-shaped), or three-dimensional (spherical) structure. The shuttle-shaped structure refers to a structure with cones or tapers (truncated cones) at both ends and a cylinder in the middle. The L-shaped structure is composed of two rectangular blocks at 90°, and the two ends of the rectangular blocks have cone angles or tapers (truncated cones). The spherical structure guide yarn stop does not need to rotate during the yarn stopping and laying process, and the design of the cone angle or taper is mainly to realize the rotation of the guide yarn stop. All three guide yarn stops can carry fiber bundles of sufficient length, and the carried fiber bundles are located in the center of the guide yarn stop, which is conducive to the rotation of the guide yarn stop.

[0041] The schematic diagrams of the three guide yarn retainers when laid in the direction of 0° (x coordinate direction) and 90° (y coordinate direction) are as follows: Figures 1-3 As shown, the 0° direction may be the direction where the horizontal row of yarn-stationing holes (x-coordinate direction) are located, and correspondingly, the 90° direction is the direction where the vertical row of yarn-stationing holes (y-coordinate direction) are located.

[0042] Step (3): Place the yarn guide and lay the yarn

[0043] According to the designed yarn stop spacing, the yarn stop spacing d refers to the center distance between two adjacent yarn stop holes in the longitudinal or transverse direction. The spacing can be determined according to material requirements, such as 1mm, 5mm, etc. The guide yarn stop with fiber tows (Z-direction fibers) is placed on the layup tooling in the first direction in advance. The laying effect of the guide yarn stop is as follows: Figure 5 As shown, the fiber bundles carried by the guide yarn stoppers are introduced into the yarn stop holes of the layering tooling, and adjacent guide yarn stops will not affect each other. Then, the expanded fiber bundles or non-expanded fiber bundles with or without glue are laid as raw materials. On the layering tooling, the first layer of fiber bundles is laid in sequence along the first direction on both sides of the guide yarn stoppers through the fiber laying device until the specified size requirements are met. The effect after the first layer of fiber bundles is laid is shown in Figure 6 shown.

[0044] Figure 7The working process of the fiber laying device is given. After the first layer of fiber tows is laid, the directions of the fiber laying head and the paddle of the fiber laying device are adjusted. The paddle of the fiber laying device rotates the guide yarn stopper by a certain angle and then rotates to a second direction. At the same time, the fiber laying head of the fiber laying device lays the second layer of fiber tows along the second direction. The angle formed by the first direction and the second direction is set to α1 (0°<α1≤90°, more preferably, 5°≤α1≤90°), and the fiber tows of the second layer form a certain angle β1 (0°<β1≤90°, more preferably, 5°≤β1≤90°) with the fiber tows of the first layer. 1≤90°), α1=β1. After the second layer of fiber bundles is laid, the guide yarn stopper is continued to be rotated by the paddle of the laying device to rotate it to a certain angle to the third direction. At the same time, the laying head of the laying device lays the third layer of fiber bundles along the third direction. The angle formed by the second direction and the third direction is set to α2 (0°<α2≤90°, more preferably, 5°≤α2≤90°), and the third layer of fiber bundles forms a certain angle β2 with the second layer of fiber bundles (0°<β2≤90°, more preferably, 5°≤β2≤90°), α2=β2.

[0045] like Figure 8 As shown, the fiber placement device includes a fiber placement head and a paddle. The fiber placement head is a conventional tool in the industry and can achieve precise placement of planar fiber bundles. At the same time, the paddle integrated in the front of the fiber placement head can realize the rotation of the guide yarn stop to change its angle and make way for the placement of the fiber bundle. At the same time, after laying a layer of planar fiber bundles, the fiber placement head and the paddle can be rotated to lay the next layer of planar fiber bundles. The width of the paddle can be larger than the gap between two adjacent guide yarn stops in the horizontal or vertical direction. Its function is to realize the rotation of the guide yarn stop. During the movement of the entire fiber placement device, the paddle drives the guide yarn stop to rotate, and the fiber placement head places the fiber bundle in that direction to the specified position. Figure 8 Only one placement head is shown in the figure, but multiple placement heads can work in parallel to improve efficiency. Figure 9 shown.

[0046] And so on. After each layer is laid, the direction of the guiding yarn anchor needs to be changed by a certain angle, and it is ensured that the fiber tows in the upper and lower adjacent layers (i.e., the fiber tow in the i-th layer and the fiber tow in the (i + 1)-th layer, i = 1, 2, 3... n) form a certain angle θ (0° < θ ≤ 90°, more preferably, 5° ≤ θ ≤ 90°). During the whole process, the value of the angle θ can be fixed or variable. For example, the planar fiber bundles can be laid in cycles of 0° / 5°, 0° / 45°, 0° / 90°, or 0° / 45° / 90°, or can be laid in cycles of 0° / 5° / 10° / 15° / 20°... / 90°, 0° / 30° / 45° / 60° / 90°, or 0° / 90° / 45° / 0° / 90°, etc. As the number of laid layers increases, the thickness increases, and the implanted length of the fiber tows (Z-direction fibers) also increases with the increase in the number of laid layers until the specified thickness requirement is reached. Then, the guiding yarn anchor is removed, and the fiber tows (Z-direction fibers) on it are left in the channels to form Z-direction fibers, thereby realizing the "self-supply" of Z-direction fibers, and finally, the three-dimensional composite material as described is obtained directly or indirectly.

[0047] Example 1: Automatic yarn anchoring by the "spindle-shaped guiding yarn anchor"

[0048] (1) 0° / 90° ply

[0049] The size of the three-dimensional composite material (fabric) to be prepared is 200mm * 200mm * 10mm. The T700-12K carbon fiber spread yarn (width 8mm) is laid flat. The shuttle-shaped guiding yarn retainer has a diameter of 1mm and a length of 8mm. The fiber tow as the Z-direction fiber (the Z-direction fiber tow specification ≤ hole diameter to ensure the Z-direction fiber tow can pass through) is suspended at the center of the shuttle-shaped guiding yarn retainer. The diameter of each yarn retaining hole of the laying tooling is 1mm, and the hole spacing is 9mm, arranged in an m×n structure in an array pattern. The laying is carried out by the 0° / 90° method. According to the 9mm yarn retaining spacing, the guiding yarn retainer with the fiber tow is pre-placed on the laying tooling in the 0° direction, and the fiber tow carried by the guiding yarn retainer is introduced into the yarn retaining holes, ensuring that there is no interference between adjacent guiding yarn retainers. Then, the T700-12K carbon fiber spread yarn is used as the raw material for laying. The first layer of fiber tow is laid along the 0° direction until the specified size requirement is met. After the first layer of fiber tow is laid, under the action of the laying head and the flipper of the fiber laying device, the guiding yarn retainer is rotated to the 90° direction, and at the same time, the second layer of fiber tow is laid along the 90° direction. After the second layer of fiber tow is laid, continue to rotate the laying head and the flipper of the fiber laying device to make the guiding yarn retainer reach the 0° direction, and lay the third layer of fiber tow, and so on. After each layer is laid, the direction of the laying head and the flipper of the fiber laying device needs to be changed, so that the direction of the guiding yarn retainer changes accordingly, ensuring that the i-th layer of fiber tow and the (i + 1)-th layer of fiber tow form a 90° angle. As the number of laying layers increases, the thickness increases, and the implanted length of the fiber tow also increases with the increase in the number of laying layers until the specified thickness requirement is reached. Remove the guiding yarn retainer, leaving the fiber tow in the hole to form the Z-direction fiber, thus realizing the "self-supply" of the Z-direction fiber, and finally obtaining the three-dimensional composite material. Figure 10 It is the laying schematic diagram of different perspectives in this embodiment.

[0050] (2) 0° / 45° laying

[0051] The size of the three-dimensional composite material (fabric) to be prepared is 300mm * 300mm * 6mm. The T700-12K carbon fiber spread yarns (widths of 8mm and 5.3mm) are laid flat. The shuttle-shaped guiding yarn retainer has a diameter of 1mm and a length of 8mm. The fiber tow serving as the Z-direction fiber (the Z-direction fiber tow specification ≤ the hole diameter to ensure the Z-direction fiber tow can pass through) is suspended at the center of the shuttle-shaped guiding yarn retainer. The diameter of each yarn retaining hole of the laying tooling is 1mm, and the hole spacing is 9mm, arranged in an m×n structure in an array pattern. The laying is carried out by the 0° / 45° method. According to the 9mm yarn retaining spacing, the guiding yarn retainers with fiber tows are pre-placed on the laying tooling in the 0° direction, and the fiber tows carried by the guiding yarn retainers are introduced into the yarn retaining holes, ensuring that there is no interference between adjacent guiding yarn retainers. Then, the T700-12K carbon fiber spread yarns are used as raw materials for laying. The first layer of fiber tow (8mm) is laid along the 0° direction until the specified size requirements are met. After the laying of the first layer of fiber tow is completed, under the action of the laying head and the pusher of the fiber laying device, the guiding yarn retainer is rotated to the 45° direction, and at the same time, the second layer of fiber tow (5.3mm) is laid along the 45° direction. After the laying of the second layer of fiber tow is completed, the laying head and the pusher of the fiber laying device are continuously rotated to make the guiding yarn retainer reach the 0° direction, and the third layer of fiber tow (8mm) is laid. And so on. Each time a layer is laid, the direction of the laying head and the pusher of the fiber laying device needs to be changed, so that the direction of the guiding yarn retainer changes accordingly, ensuring that the i-th layer of fiber tow and the (i + 1)-th layer of fiber tow form a 45° angle. As the number of laying layers increases, the thickness increases, and the implanted length of the fiber tow also increases with the increase in the number of laying layers until the specified thickness requirement is reached. The guiding yarn retainer is removed, and the fiber tow is left in the hole to form the Z-direction fiber, thus realizing the "self-supply" of the Z-direction fiber. Finally, a three-dimensional composite material is obtained. Figure 11 This is the laying schematic diagram of different perspectives in this embodiment.

[0052] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope defined in the claims.

Claims

1. A method for three-dimensional material based on automatic yarn parking and laying, wherein the three-dimensional material includes three-dimensional composite materials and preforms, characterized in that It includes the following steps: (1) According to the designed yarn parking spacing, pre-place the guiding yarn parking device capable of carrying fiber bundles on the tooling for laying the planar yarn layer, and introduce the fiber bundles set in the guiding yarn parking device into the yarn parking holes of the tooling to ensure that there is no interference between adjacent guiding yarn parking devices, and lay the first layer of fiber bundles on both sides of the guiding yarn parking device along the first direction; (2) After the laying of the first layer of fiber bundles is completed, lay the second layer of fiber bundles on both sides of the guiding yarn parking device along the second direction. The second layer of fiber bundles forms a certain angle with the first layer of fiber bundles. After the laying of the second layer of fiber bundles is completed, continue to lay the third layer of fiber bundles on both sides of the guiding yarn parking device along the third direction. The third layer of fiber bundles forms a certain angle with the second layer of fiber bundles; (3) Repeat the laying according to step (2) to ensure that there is a certain angle between the upper and lower adjacent layers of fiber bundles until the specified thickness requirement is reached. Remove the guiding yarn parking device and retain the fiber bundles set by the guiding yarn parking device in the holes to form Z-direction fibers and obtain the three-dimensional material.

2. The method according to claim 1, wherein The guiding yarn parking device is of a shuttle shape, L shape, or spherical structure.

3. The method according to claim 2, wherein The shuttle shape structure refers to a structure with conical or tapered ends and a cylindrical middle. The L shape structure is composed of two rhombuses combined at 90°.

4. The method according to claim 1, wherein The yarn parking holes are uniformly arranged in an array structure on the laying tooling.

5. The method according to claim 1, characterized in that The diameter of the Z-direction fibers is less than or equal to the diameter of the yarn parking holes.

6. The method according to claim 1, wherein The yarn parking spacing refers to the center distance between two adjacent yarn parking holes, and the yarn parking spacing ≥ the length of the guiding yarn parking device.

7. The method according to claim 1, characterized in that, The second layer of fiber bundles forms a certain angle with the first layer of fiber bundles, and this angle is set as β1, 0° < β1 ≤ 90°. The third layer of fiber bundles forms a certain angle with the second layer of fiber bundles, and this angle is set as β2, 0° < β2 ≤ 90°.

8. The method according to claim 1, wherein Ensure that there is a certain angle between the upper and lower adjacent layers of fiber bundles, and this angle is set as θ, 0° < θ ≤ 90°.

9. The method according to claim 1, characterized in that, The fiber bundle refers to a fiber bundle with or without glue; the fiber bundle refers to a spread fiber bundle or a non-spread fiber bundle.

10. The method according to claim 1, characterized in that The fiber bundle is arranged at the central position of the guiding yarn parking device.

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