A three-dimensional fabric for a single-hole member and a forming method

Abstract

The application discloses a kind of single-hole component three-dimensional fabric and forming method, comprising the following steps: step 1: the model of three-dimensional fabric is sliced along vertical Z direction with a certain height, the profile information of each slice is obtained, according to fabric layer density, the number of unit layers included by each slice is obtained;Step 2: prepare each fiber layer;Step 3: fiber layer and fiber felt are stacked and laid, and unit layer is obtained by needling;Step 4: according to the profile information of each slice and the number of unit layers contained by each slice, each unit layer is cut;Step 5: according to the number of layers of three-dimensional fabric data, profile information, matrix cross-sectional size arrangement design is carried out, suitable steel needle and limiting device are selected, and Z direction matrix array is formed;Step 6: unit layer is placed on the top of steel needle according to fabric profile, and unit layer is pressed down and compacted by using puncture equipment, until the required height of fabric is reached, then steel needle is replaced by fiber, and three-dimensional fabric is obtained.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to a three-dimensional fabric for single-hole components and a forming method thereof. Background Technology

[0002] Carbon fiber woven puncture preform-reinforced C / C composites have become the preferred ablation-resistant material for hot-end components such as throat liners in solid rocket motors due to their excellent overall structural properties, erosion resistance, and ease of mass production. Under the high-temperature (2700℃~3400℃), high-pressure (4MPa~10MPa), and high-speed erosion (>1500m / s) thermal environment of solid rocket motors, the dimensional changes in the C / C throat liner profile caused by combustion gas ablation affect the combustion gas velocity and thermal energy conversion efficiency, thereby impacting the engine's operating condition.

[0003] The differences in throat liner ablation structure are related to the temperature, component concentration, and flow rate of the combustion gas, but the woven structure has a more significant impact on the ablation microstructure. Although the puncture reinforcement structure is uniformly distributed in a regular pattern within the material, the woven structure in different regions will differ after the throat liner is processed into an irregularly shaped rotating structure. A reasonable fiber preform design will help improve the ablation resistance of the component.

[0004] The patent "A Preparation Method of Carbon / Carbon Throat Liner" (CN 115448744 B) describes a preparation method of a carbon / carbon throat liner, which consists of a main structure, an inner functional layer, and an outer functional layer. The main structure is a carbon fiber piercing piece with alternating layers of non-woven fabric and felt, shaped like a hollow cylinder. A layer of carbon felt is wrapped around both the inner and outer sides of the main structure. The inner and outer functional layers are formed by carbon fiber through-and-through composite, and then machined. This method has a single fiber direction, which weakens the interlacing of yarns in the throat area. This makes it easy for the piercing yarns to be ablated and exposed, resulting in overall peeling and damage to the integrity of the structural unit of the ablated surface. The functional layer is fixed to the main structure by circumferential piercing fibers, which may lead to detachment or delamination, posing a significant risk and requiring extensive processing in the later stages.

[0005] Therefore, improving the interlacing of yarns in the throat region, ensuring the integrity of the ablation surface structural unit, and improving the overall ablation resistance of the throat region have become problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a three-dimensional fabric for single-hole components and a molding method thereof, so as to improve the interlacing of yarns in the throat region, ensure the integrity of the ablation surface structural unit, and improve the overall ablation resistance of the throat region.

[0007] To achieve the purpose of the appeal, the present invention provides the following technical solution:

[0008] A method for molding a three-dimensional fabric for a single-hole component, wherein the volume density of the three-dimensional fabric gradually decreases from the center to the periphery, the molding method comprising the following steps:

[0009] Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a predetermined height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer.

[0010] Step 2: Prepare each fiber layer according to the performance requirement that the bulk density of each fiber layer gradually decreases from the center to the periphery;

[0011] Step 3: Lay out the fiber layer and fiber felt in layers and needle-punch to obtain unit layers;

[0012] Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice;

[0013] Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array;

[0014] Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

[0015] Furthermore, in step 2, the fiber layer is designed as a regular N-sided spiderweb-like fabric with a gradually decreasing surface density from the center outwards, where N ≥ 4. The preparation method specifically includes:

[0016] Step 2.1: Design the spider web fabric, which includes multiple warp yarns and cross yarns. Each warp yarn includes at least two bundles of carbon fibers, and each cross yarn includes at least one bundle of carbon fibers.

[0017] Step 2.2: Fix the fiber bundle position at one end of the longitudinal yarn using a yarn bobbin, then stretch the fiber bundle along the diagonal of the regular N-sided polygon, passing it through the heddle holes twice along the way, and fix the end position to the heddle.

[0018] Step 2.3: After all the warp yarns are fixed, the cross yarns are wound around the warp yarns using a yarn guide rod. Each cross yarn is wound around the warp yarn to form a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn form a plain weave with at least one upper and one lower section under the action of the heddle. The cross yarns interweave and are fixed between the warp yarns. The starting and ending points of each cross yarn have the opposite interweaving pattern to the warp yarns being wound, and the starting point is inside the ending point. When one round of cross yarn is finished, the next round of cross yarn is wound from the center of the regular N-sided shape outwards, from dense to sparse. That is, the spacing between adjacent cross yarns increases from the center of the regular N-sided shape outwards, and the interweaving pattern of each round of cross yarns and warp yarns is opposite to the interweaving pattern of the adjacent rounds. This completes the preparation of the regular N-sided spider web fabric of the fiber layer.

[0019] Step 2.4: Complete the preparation of all fiber layers in sequence according to steps 2.1 to 2.3.

[0020] A method for molding a three-dimensional fabric for a single-hole component, wherein the three-dimensional fabric has a uniform internal volume density, the molding method comprising the following steps:

[0021] Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a certain height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer.

[0022] Step 2: Prepare multiple fiber layers with the same density;

[0023] Step 3: Lay out the fiber layer and fiber felt in layers and needle-punch to obtain unit layers;

[0024] Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice;

[0025] Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array;

[0026] Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

[0027] Furthermore, in step 2, the fiber layer is designed as a regular N-sided spiderweb-like fabric with the same surface density from the center outwards, where N≥4. The preparation method specifically includes:

[0028] Step 2.1: Design the spider web fabric, which includes multiple warp yarns and cross yarns. Each warp yarn includes at least two bundles of carbon fibers, and each cross yarn includes at least one bundle of carbon fibers.

[0029] Step 2.2: Fix the fiber bundle position at one end of the longitudinal yarn using a yarn bobbin, then stretch the fiber bundle along the diagonal of the regular N-sided polygon, passing it through the heddle holes twice along the way, and fix the end position to the heddle.

[0030] Step 2.3: After all the warp yarns are fixed, the cross yarns are wound around the warp yarns using a yarn guide rod. Each cross yarn is wound around the warp yarn to form a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn form a plain weave with at least one upper and one lower section under the action of the heddle. The cross yarns interweave and are fixed between the warp yarns. The starting and ending points of each cross yarn have the opposite interweaving pattern to the warp yarns being wound, and the starting point is inside the ending point. When one round of cross yarn is finished, the next round of cross yarn is wound from the center of the regular N-sided shape outwards with the same density. That is, the spacing between adjacent cross yarns from the center of the regular N-sided shape outwards is the same, and the interweaving pattern of each round of cross yarns and warp yarns is opposite to the interweaving pattern of the adjacent rounds. This completes the preparation of the regular N-sided spider web fabric of the fiber layer.

[0031] Step 2.4: Complete the preparation of all fiber layers in sequence according to steps 2.1 to 2.3.

[0032] A method for molding a three-dimensional fabric for a single-hole component, wherein the three-dimensional fabric has a high volume density in the middle and a low volume density at the top and bottom, the molding method comprising the following steps:

[0033] Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a certain height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer.

[0034] Step 2: Prepare each fiber layer according to the required fiber layer density. The prepared fiber layers include high-density fiber layers and low-density fiber layers.

[0035] Step 3: Lay out the high-density fiber layer and the low-density fiber layer with the corresponding number of fiber mats respectively, and needle punch them to obtain the high-density unit layer and the low-density unit layer respectively, wherein the number of fiber mats corresponding to the high-density fiber layer is not less than the number of fiber mats corresponding to the low-density fiber layer.

[0036] Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice;

[0037] Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array;

[0038] Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

[0039] Furthermore, in step 2, the same fiber layer is designed as a regular N-sided spiderweb-like fabric with the same surface density from the center outwards, where N≥4. The preparation method specifically includes:

[0040] Step 2.1: Design the spider web fabric to include multiple longitudinal and transverse yarns. Each longitudinal yarn includes at least two bundles of carbon fibers, and each transverse yarn includes at least one bundle of carbon fibers. The number of transverse yarns in the high-density fiber layer is greater than the number of transverse yarns in the low-density fiber layer.

[0041] Step 2.2: Fix the fiber bundle position at one end of the longitudinal yarn using a yarn bobbin, then stretch the fiber bundle along the diagonal of the regular N-sided polygon, passing it through the heddle holes twice along the way, and fix the end position to the heddle.

[0042] Step 2.3: After all the warp yarns are fixed, the cross yarns are wound around the warp yarns using a yarn guide rod. Each cross yarn is wound around the warp yarn to form a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn form a plain weave with at least one upper and one lower section under the action of the heddle. The cross yarns interweave and are fixed between the warp yarns. The starting and ending points of each cross yarn have the opposite interweaving pattern to the warp yarns being wound, and the starting point is inside the ending point. When one round of cross yarn is finished, the next round of cross yarn is wound from the center of the regular N-sided shape outwards with the same density. That is, the spacing between adjacent cross yarns from the center of the regular N-sided shape outwards is the same, and the interweaving pattern of each round of cross yarns and warp yarns is opposite to the interweaving pattern of the adjacent rounds. This completes the preparation of the regular N-sided spider web fabric of the fiber layer.

[0043] Step 2.4: Complete the preparation of all fiber layers in sequence according to steps 2.1 to 2.3.

[0044] Furthermore, in step 2, the fiber clusters distributed in the unit layer are at multiple angles or orthogonal.

[0045] Furthermore, it also includes warp yarns arranged in a non-diagonal manner that pass through the center point of a regular N-gon.

[0046] Furthermore, the warp yarns are arranged in a non-diagonal manner, passing through the center point of the regular N-gon, and are perpendicular to the cross yarns.

[0047] A three-dimensional fabric for a single-hole component, the three-dimensional fabric being prepared using the method described above.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] (1) This invention achieves multi-angle weaving of fibers in the planar direction by designing the interlacing pattern of the horizontal and vertical yarns, which improves the multi-directional mechanical properties of the fabric and the multi-directional conduction of heat energy, and avoids the unbalanced mechanical properties and single thermal conduction direction caused by single-direction fibers.

[0050] (2) By changing the structure and content of fiber layer and fiber felt in unit layer, the fabric density gradient and gas ablation heat energy are rapidly transferred to the surrounding area. Under the premise of ensuring high density in the ablation zone and the mechanical properties of the fabric, the density of the non-ablation zone is reduced, which not only reduces the overall weight of throat liner and saves raw material usage, but also improves the overall ablation resistance of the fabric.

[0051] (3) In the XY fiber layer stage, the present invention changes the interlacing direction and pre-puncture angle of the fibers to improve the interlacing with the Z direction fibers. The weaving unit as a whole is synergistically ablated, which improves the overall ablation resistance of the fabric and avoids the overall peeling after ablation exposure. At the same time, the multi-angle fiber interlacing method improves the mechanical properties of the fabric in all directions.

[0052] (4) While ensuring the fabric size, the XY plane fiber layer and fiber felt pre-needled to form a unit layer. The outline of the unit layer changes with the curved surface during the superposition stage, realizing the fabric conformal preparation. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the structure of the variable density fabric of the present invention.

[0054] Figure 2 This is a schematic diagram of the X-Y plane fiber layer structure in Embodiment 1 of the present invention.

[0055] Figure 3 This is a schematic diagram of the X-Y plane fiber layer structure in Embodiment 2 of the present invention.

[0056] Figure 4 This is a schematic diagram of the pre-needle puncture structure in Embodiment 2 of the present invention. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0058] Example 1

[0059] Combination Figure 1A three-dimensional fabric for single-hole components with a volume density that gradually decreases from the center to the periphery, with a height of 200 mm and an interlayer density of 50 layers / cm. In the figure, 1 is the high-density area and 2 is the low-density area.

[0060] The specific molding method steps are as follows:

[0061] 1) Slice the three-dimensional CAD model of the three-dimensional fabric component every 2mm along the Z-direction (each slice contains 10 unit layers), and obtain a total of 100 slice contour data of the component;

[0062] 2) Based on the performance requirement of three-dimensional fabrics where the volume density gradually decreases from the center to the edges, one of the XY fiber layers is designed as a quadrilateral spiderweb-like fabric with a gradually decreasing surface density from the center to the edges, such as... Figure 2 It uses T700-12K carbon fiber wide fiber bundles, with a fiber bundle width of 20mm. In the diagram, 3 represents the warp yarn, 4 represents the weft yarn (4a is the starting end of a loop of weft yarn, 4b is the ending end of a loop of weft yarn), 5 represents the yarn bobbin, and 6 represents the heddle wire. The preparation steps are as follows:

[0063] ① Spider web fabric includes warp yarns 3 and cross yarns 4, such as Figure 2 Each longitudinal yarn 3 contains two bundles of 3 broadened fibers, and each transverse yarn 4 contains one bundle of broadened fibers.

[0064] ② The fiber position is fixed at one end of the longitudinal yarn using yarn tube 5, and then the fiber is stretched out along the diagonal, passing through the heddle hole twice along the way, and the end position is fixed at heddle 6.

[0065] ③ After all the warp yarns 3 are fixed, the yarn guide rod is used to wind the cross yarns 4 between the warp yarns 3. During the winding process, the broadened fiber bundles in each warp yarn 3 form a plain weave with one-down-two-up or two-down-one-up under the action of the heddle 6. The same cross yarn 4 and warp yarn 3 form multiple interlacing points. Figure 2 The enlarged view shows one of the interlacing points. The interlacing patterns of the horizontal yarn 4 and the vertical yarn 3 at adjacent interlacing points are opposite (for example, the interlacing pattern of the horizontal yarn 4 and the vertical yarn 3 at the current interlacing point is black-white-black). Figure 2 As shown in 4a, the interlacing pattern of the previous and next interlacing points is white-black-white, which makes the interlacing of the horizontal yarn 4 and the vertical yarn 3 tighter. In this way, the horizontal yarn 4 interlacs with the vertical yarn 3 to fix the horizontal yarn 4. The starting end 4a and the ending end 4b of the horizontal yarn 4 have the opposite interlacing pattern to the vertical yarn 3 (e.g., Figure 2As shown in the enlarged view, the horizontal yarn 4 is a single, broadened fiber bundle. This bundle starts at the beginning 4a and winds clockwise for one revolution, then returns at the end 4b to the current vertical yarn 3, forming a complete loop. The beginning 4a is inside the end 4b. Once one loop of horizontal yarn 4 is completed, the next loop begins, winding from the center outwards, gradually decreasing in density. The interlacing pattern of the horizontal yarn 4 and the vertical yarn 3 in each loop is opposite to that of the adjacent loops (for example, if the horizontal yarn in the current loop interlaces with the vertical yarn at a certain interlacing point in a black-white-black pattern, then the horizontal yarn in the adjacent loop will interlac with the vertical yarn at the same interlacing point in a white-black-white pattern; this opposite interlacing pattern prevents the horizontal yarn from slipping or loosening). This completes a layer with a density starting at 80 g / m² in the central region. 2 Gradually decrease to 20g / m² in all directions 2 Preparation of quadrilateral spider web-like fabric.

[0066] ④ Following the previous steps, complete the preparation of all layers of quadrilateral spider web-like fabric.

[0067] 3) The XY fiber layer is coated with a surface density of 70 g / m². 2 The fiber mats are laid in layers to complete the pre-needling of the unit layer. The fiber clusters in the unit layer are orthogonal (perpendicular) with a needle density of 8 needles / cm. 2 .

[0068] 4) Based on the two-dimensional contour information of each slice and the number of unit layers it contains, input the information into the automated cutting equipment to cut each unit layer.

[0069] 5) Based on the layer data and layer contour data of the component, design the matrix cross-sectional size layout, select appropriate steel pins and limiting devices, and form a Z-axis matrix array with a spacing of 2.0mm×2.0mm;

[0070] 6) Evenly place the XY-plane fiber unit layers on top of the steel needles according to the fabric outline. Use a puncture device to press the material down layer by layer and compact it, controlling the interlayer density to 50 layers / cm until the required fabric height is achieved. Then, replace the steel needles with two strands of T800-6K carbon fiber to obtain a bulk density of 0.87 g / cm³. 3 It gradually decreased to 0.57 g / cm³ towards the surrounding area. 3 Three-dimensional fabric for single-hole components.

[0071] Preferably, the fibers in the XY fiber layer can also be raw yarn or a combination of raw yarn and yarn of different widths, and the fiber raw materials can be one or more mixed.

[0072] Preferably, the fiber layer and fiber felt are stacked in a balanced or unbalanced manner, that is, one fiber layer to one fiber felt, or one fiber layer to multiple fiber felts, or multiple fiber layers to one fiber felt, or multiple fiber layers to multiple fiber felts.

[0073] Preferably, the structure and content of the fiber layer and fiber felt in different regions of the Z-direction where the fiber layers are superimposed or in a single unit layer of the XY plane unit layer can be controlled.

[0074] Preferably, the bulk density of the fabric is (0.5-0.9) g / cm³. 3 .

[0075] Example 2

[0076] A three-dimensional fabric for single-hole components with multi-angled fibers, high density, and high ablation resistance. The three-dimensional fabric has the same internal volume density, a height of 150 mm, and an interlayer density of 30 layers / cm.

[0077] The specific molding steps are as follows:

[0078] 1) Slice the 3D CAD model of the component every 1mm along the Z-axis (each slice contains 3 unit layers), and obtain a total of 150 slice contour data of the component;

[0079] 2) Based on the performance requirements of the fabric, the XY fiber layer is designed as an octagonal spiderweb-like fabric. Both the warp and weft yarns in the spiderweb are made of T300-3K carbon fiber, with the warp yarns comprising 4 strands of carbon fiber and the weft yarns comprising 3 strands of carbon fiber. The same weaving process as in Example 1 is used, except that the weft yarns are evenly spaced between the warp yarns. The weaving is completed sequentially to a surface density of 180 g / m². 2 Preparation of octagonal spiderweb-like fabrics. (e.g.) Figure 3 .

[0080] 3) Apply the XY fiber layer to a 60g / m 2 The fiber mat is layered and laid out to complete the pre-needling of the unit layer. The fiber clusters distributed in the unit layer have multiple angles (which can be a combination of oblique and orthogonal or a combination of oblique and oblique). Figure 4 In the figure, 7 represents the XY fiber layer, 8 represents the fiber mat, and 9 represents the fiber clusters in the unit layer. The needle-punching density is 10 needles / cm. 2 .

[0081] 4) Based on the two-dimensional contour information and layer number requirements of each layer, input them into the automated cutting equipment to cut each unit layer.

[0082] 5) Based on the layer data and layer contour data of the component, design the matrix cross-sectional size layout, select appropriate steel pins and limiting devices, and form a Z-axis matrix array with a spacing of 1.5mm×1.5mm;

[0083] 6) Place the XY plane fiber unit layers evenly on top of the steel needles according to the fabric outline. Use a puncture device to press the material down layer by layer and compact it, controlling the interlayer density to 30 layers / cm until the required fabric height is achieved. Then, replace the steel needles with two strands of T300-2K carbon fiber to obtain a fabric bulk density of 0.9 g / cm³. 3 Three-dimensional fabric for single-hole components.

[0084] Example 3

[0085] A three-dimensional fabric for single-hole components with high intermediate density and low top and bottom density has a high density zone height of 60 mm and a total fabric height of 180 mm. The interlayer density in the high density zone is 30 layers / cm, and the low density zone is 18 layers / cm.

[0086] The specific molding steps are as follows:

[0087] 1) Slice the 3D CAD model of the component along the Z-axis height. The high-density area in the middle is sliced ​​every 1 mm (each slice contains 3 unit layers), and a total of 60 slice contour data of the high-density area is obtained. The upper and lower low-density areas are sliced ​​every 1.8 mm (each slice contains 1 unit layer), and a total of 120 layers of the component in the upper and lower low-density areas are obtained, along with the layer data and slice contour data of the 120 layers.

[0088] 2) Based on the performance requirements of the fabric, the XY fiber layer is designed to be 200g / m². 2 With 100g / m 2 Two types of octagonal spiderweb-like fabrics with different areal densities. Both the warp and weft yarns in the spiderweb are made of T800-6K carbon fiber. The high-density fabric has warp yarns containing 3 strands of carbon fiber and weft yarns containing 3 strands of carbon fiber, while the low-density fabric has warp yarns containing 3 strands of carbon fiber and weft yarns containing 1 strand of carbon fiber. The same weaving process as in Example 1 is used, except that the weft yarns in the same fiber layer are evenly spaced between the warp yarns. The fabrics are wound sequentially to achieve an areal density of 200 g / m². 2 With 100g / m 2 Preparation of octagonal spider web-like fabric.

[0089] 2) Apply the XY fiber layer to a 60g / m 2 Fiber mats are laid in layers. The high-density areas in the middle consist of one layer of fiber mat followed by one layer of fiber mat, with the fiber layers having a surface density of 200 g / m². 2 The upper and lower low-density areas use one fiber layer on top of three fiber mats, with the fiber layer having a surface density of 100 g / m². 2Then, pre-needling of the unit layer is completed. The fiber clusters in the middle high-density region unit layer have multiple angles, while the fiber clusters in the upper and lower low-density region unit layers have orthogonal angles. The needle density in the middle high-density region is 20 needles / cm. 2 The needle density in the upper and lower low-density areas is 10 needles / cm. 2 .

[0090] 3) Based on the two-dimensional contour information and layer number requirements of each layer, input them into the automated cutting equipment to cut each unit layer.

[0091] 4) Based on the layer data and layer contour data of the component, design the matrix cross-sectional size layout, select appropriate steel pins and limiting devices, and form a Z-axis matrix array with a spacing of 2.4mm×2.4mm;

[0092] 5) Evenly place the XY fiber unit layers on top of the steel needles according to the fabric outline. Use a puncture device to press and compact the material layer by layer, controlling the interlayer density in the middle high-density area to be 30 layers / cm and the interlayer density in the upper and lower low-density areas to be 18 layers / cm until the required fabric height is achieved. Then, replace the steel needles with four strands of T300-2K carbon fiber to obtain an intermediate density of 0.9 g / cm³. 3 The density is 0.65 g / cm³. 3 Three-dimensional fabric for single-hole components.

[0093] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for molding a three-dimensional fabric for a single-hole component, wherein the volume density of the three-dimensional fabric gradually decreases from the center to the periphery, characterized in that, The molding method includes the following steps: Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a predetermined height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer. Step 2: Prepare each fiber layer according to the performance requirement that the bulk density of each fiber layer gradually decreases from the center to the periphery; In step 2, the fiber layer is designed as a regular N-sided spiderweb-like fabric with density gradually decreasing from the center outwards, where N≥4. The specific preparation method includes: Step 2.1: Design the spider web fabric to include multiple longitudinal yarns (3) and transverse yarns (4), each longitudinal yarn (3) including at least two bundles of carbon fibers, and each transverse yarn (4) including at least one bundle of carbon fibers; Step 2.2: The fiber bundle position is fixed at one end of the longitudinal yarn (3) using a yarn bobbin (5), and then the fiber bundle is stretched out along the diagonal of the regular N-sided polygon, passing through the heddle hole twice along the way, and the end position is fixed at the heddle (6). Step 2.3: After all the warp yarns (3) are fixed, the cross yarns (4) are wound around the warp yarns (3) using a yarn guide rod. After each cross yarn (4) is wound around the warp yarn (3), it forms a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn (3) form a plain weave with at least one upper and one lower section under the action of the heddle (6). The cross yarns (4) interweave and are fixed between the warp yarns (3). The starting end (4a) and the ending end (4b) of each cross yarn (4) are connected to the warp yarns. The interlacing pattern of the winding longitudinal yarn (3) is opposite, and the starting end (4a) is inside the ending end (4b). When a round of horizontal yarn (4) is finished, the next round of horizontal yarn (4) is wound from the center of the regular N-sided polygon outwards, from dense to sparse. That is, the distance between adjacent horizontal yarns (4) from the center of the regular N-sided polygon outwards becomes larger and larger, and the interlacing pattern of each round of horizontal yarn (4) and longitudinal yarn (3) is opposite to the interlacing pattern of the adjacent rounds. Thus, the preparation of the regular N-sided spider web fabric of the fiber layer is completed. Step 2.4: Complete the preparation of all fiber layers sequentially according to steps 2.1 to 2.3; Step 3: Lay out the fiber layer and fiber felt in layers and needle-punch to obtain unit layers; Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice; Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array; Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

2. A method for molding a three-dimensional fabric for a single-hole component, wherein the three-dimensional fabric has a uniform internal volume density, characterized in that... The molding method includes the following steps: Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a certain height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer. Step 2: Prepare multiple fiber layers with the same density; In step 2, the fiber layer is designed as a regular N-sided spider web-like fabric with the same surface density from the center outwards, where N≥4. The specific preparation method includes: Step 2.1: Design the spider web fabric to include multiple longitudinal yarns (3) and transverse yarns (4), each longitudinal yarn (3) including at least two bundles of carbon fibers, and each transverse yarn (4) including at least one bundle of carbon fibers; Step 2.2: The fiber bundle position is fixed at one end of the longitudinal yarn (3) using a yarn bobbin (5), and then the fiber bundle is stretched out along the diagonal of the regular N-sided polygon, passing through the heddle hole twice along the way, and the end position is fixed at the heddle (6). Step 2.3: After all the warp yarns (3) are fixed, the cross yarns (4) are wound around the warp yarns (3) using a yarn guide rod. After each cross yarn (4) is wound around the warp yarn (3), it forms a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn (3) form a plain weave with at least one upper and one lower section under the action of the heddle (6). The cross yarns (4) interweave and are fixed between the warp yarns (3). The starting end (4a) and the ending end (4b) of each cross yarn (4) are connected to the warp yarns. The interlacing pattern of the winding longitudinal yarn (3) is opposite, and the starting end (4a) is inside the ending end (4b). When a round of horizontal yarn (4) is finished, the next round of horizontal yarn (4) is wound from the center of the regular N-sided polygon outwards with the same density. That is, the spacing between adjacent horizontal yarns (4) from the center of the regular N-sided polygon outwards is the same, and the interlacing pattern of each round of horizontal yarn (4) and longitudinal yarn (3) is opposite to the interlacing pattern of the adjacent rounds. Thus, the preparation of the fiber layer regular N-sided spider web fabric is completed. Step 2.4: Complete the preparation of all fiber layers in sequence according to steps 2.1 to 2.3; Step 3: Lay out the fiber layer and fiber felt in layers and needle-punch to obtain unit layers; Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice; Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array; Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

3. A method for molding a three-dimensional fabric for a single-hole component, wherein the three-dimensional fabric has a high volume density in the middle and a low volume density at the top and bottom, characterized in that... The molding method includes the following steps: Step 1: Slice the three-dimensional fabric model along the vertical Z direction at a certain height, and obtain the layer outline information of each slice. Based on the fabric layer density, obtain the number of unit layers included in each slice. Each unit layer includes a fiber layer. Step 2: Prepare each fiber layer according to the required fiber layer density. The prepared fiber layers include high-density fiber layers and low-density fiber layers. In step 2, the same fiber layer is designed as a regular N-sided spider web-like fabric with the same surface density from the center outwards, where N≥4. The specific preparation method includes: Step 2.1: Design the spider web fabric to include multiple longitudinal yarns (3) and transverse yarns (4). Each longitudinal yarn (3) includes at least two bundles of carbon fibers, and each transverse yarn (4) includes at least one bundle of carbon fibers. The number of transverse yarns (4) in the high-density fiber layer is greater than the number of transverse yarns (4) in the low-density fiber layer. Step 2.2: The fiber bundle position is fixed at one end of the longitudinal yarn (3) using a yarn bobbin (5), and then the fiber bundle is stretched out along the diagonal of the regular N-sided polygon, passing through the heddle hole twice along the way, and the end position is fixed at the heddle (6). Step 2.3: After all the warp yarns (3) are fixed, the cross yarns (4) are wound around the warp yarns (3) using a yarn guide rod. After each cross yarn (4) is wound around the warp yarn (3), it forms a regular N-sided shape. During the winding process, the broadened fiber bundles in each warp yarn (3) form a plain weave with at least one upper and one lower section under the action of the heddle (6). The cross yarns (4) interweave and are fixed between the warp yarns (3). The starting end (4a) and the ending end (4b) of each cross yarn (4) are connected to the warp yarns. The interlacing pattern of the winding longitudinal yarn (3) is opposite, and the starting end (4a) is inside the ending end (4b). When a round of horizontal yarn (4) is finished, the next round of horizontal yarn (4) is wound from the center of the regular N-sided polygon outwards with the same density. That is, the spacing between adjacent horizontal yarns (4) from the center of the regular N-sided polygon outwards is the same, and the interlacing pattern of each round of horizontal yarn (4) and longitudinal yarn (3) is opposite to the interlacing pattern of the adjacent rounds. Thus, the preparation of the fiber layer regular N-sided spider web fabric is completed. Step 2.4: Complete the preparation of all fiber layers in sequence according to steps 2.1 to 2.3; Step 3: Lay out the high-density fiber layer and the low-density fiber layer with the corresponding number of fiber mats respectively, and needle punch them to obtain the high-density unit layer and the low-density unit layer respectively, wherein the number of fiber mats corresponding to the high-density fiber layer is not less than the number of fiber mats corresponding to the low-density fiber layer. Step 4: Trim each unit layer according to the layer outline information of each slice and the number of unit layers contained in each slice; Step 5: Based on the layer number data and layer outline information of the three-dimensional fabric, design the matrix cross-sectional size layout, select appropriate steel needles and limiting devices, and form a Z-axis matrix array; Step 6: Place the unit layer on top of the steel needle according to the fabric outline, use the piercing device to press down and compact the unit layer until the required fabric height is reached, and then use fibers to replace the steel needle to obtain a three-dimensional fabric.

4. The method for forming a three-dimensional fabric for a single-hole component according to any one of claims 1-3, characterized in that, In step 2, the fiber clusters distributed in the unit layer are at multiple angles or orthogonal.

5. The method for forming a three-dimensional fabric for a single-hole component according to claim 1, 2, or 3, characterized in that, It also includes the warp yarns (3) set in a non-diagonal manner that pass through the center point of the regular N-gon.

6. The method for forming three-dimensional fabric for single-hole components according to claim 4, characterized in that, The longitudinal yarn (3) is set in a non-diagonal manner, passing through the center point of the regular N-gon, and is perpendicular to the transverse yarn (4).

7. A three-dimensional fabric for a single-hole component, characterized in that, The three-dimensional fabric is prepared by the method described in any one of claims 1-6.

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