Method for introducing normal yarns and weft yarns into three-dimensional woven fabric and three-dimensional woven fabric

Abstract

The invention discloses a method for introducing normal yarns and weft yarns into a three-dimensional woven fabric and the three-dimensional woven fabric, and belongs to the field of three-dimensional fabric weaving. The method comprises the following steps: in a three-dimensional four-step weaving process, after a standard cycle is finished, under the condition that the total yarn number is not increased, yarn on a moving spindle on the outermost side in the thickness direction is moved to penetrate through each row, so that normal yarn introduction of a current pattern knot is realized; the yarn on the outermost moving spindle in the width direction or the yarn on a certain moving spindle in the circumferential direction is moved to penetrate through all the columns, so that weft yarn introduction of the current pattern knot is achieved; and the next standard cycle is carried out after the normal yarn and the weft yarn are introduced. The method has extremely high designability, so that the continuity and the structural integrity of the three-dimensional fabric can be ensured; the interlayer connection of the fabric can be enhanced, and meanwhile, the straightness of the normal yarns and the weft yarns in the fabric can be effectively improved, so that the mechanical property of the composite material is improved.

Description

Technical Field

[0001] The invention relates to a method for introducing normal yarns and weft yarns into a three-dimensional woven fabric and the three-dimensional woven fabric, and belongs to the field of three-dimensional fabric weaving. Background Art

[0002] Textile composite materials are an advanced form of fiber-reinforced composite materials. They are made by obtaining a two-dimensional or three-dimensional textile reinforcement structure through a textile processing method, and then compounding it with a matrix material. It has many advantages such as a tight interwoven structure, good integrity, and excellent mechanical properties. The development of the aviation and aerospace industries has promoted the research of textile composite materials, and its application fields have continued to expand, playing an increasingly important role in aerospace, construction, fisheries, sports, military and other fields. Through the weaving method, the fiber yarn bundles are processed into a three-dimensional textile structure according to a certain interweaving rule, making it a flexible fiber aggregate with a certain shape and internal structure, which is called a three-dimensional woven fabric.

[0003] Three-dimensional four-step weaving represents the mainstream in the field of three-dimensional weaving. As its application field continues to expand, higher requirements are placed on composite materials. In order to improve the axial performance of three-dimensional woven fabrics, axial straight yarns are added on the basis of three-dimensional four-way; in order to improve the performance of three-dimensional woven fabrics in the plane, normal straight yarns and weft straight yarns are added on the basis of three-dimensional four-way. Researchers are increasingly studying the structure, weaving methods, and material properties of three-dimensional fabrics, but research on methods for adding normal yarns and weft yarns to three-dimensional woven fabrics is relatively lacking. The current method of adding normal yarns and weft yarns to three-dimensional woven fabrics is to manually put the yarns on the yarn storage rod into the fabric layer by layer and column by column. The existing yarn adding method has the following disadvantages:

[0004] ① The straightness of the normal yarn and weft yarn added to the fabric is difficult to control;

[0005] ② The normal yarn and weft yarn added to the fabric cannot achieve the length control of variable cross-section;

[0006] ③Poor designability;

[0007] ④ The normal yarn and weft yarn added to the fabric have no tension during the weaving process, which is not conducive to controlling the fabric shape;

[0008] ⑤The operation method is inefficient, time-consuming, labor-intensive and error-prone. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a method for introducing normal yarns and weft yarns into three-dimensional woven fabrics. The method can realize the overall weaving and manufacturing of special-shaped fabrics by introducing normal yarns and weft yarns into three-dimensional woven fabrics by using the tension of the main moving yarn belt. The method is simple and has wide applicability. The technical solution adopted by the present invention is as follows:

[0010] A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric. In a three-dimensional four-step weaving process, after a standard cycle is completed, without increasing the total number of yarns: the normal yarn of the current knot is introduced by moving the yarn on the outermost moving spindle in the thickness direction to pass through each row; the weft yarn of the current knot is introduced by moving the yarn on the outermost moving spindle in the width direction or the yarn on a moving spindle in the circumferential direction to pass through each column; and the next standard cycle is performed after the normal yarn and the weft yarn are introduced.

[0011] By adopting the above method, with one standard cycle as the frequency of adding normal yarns and weft yarns, according to the fabric performance requirements and the movement law of the weaving yarn bundles, without changing the movement law of the weaving yarn bundles inside the fabric, the number, angle and arrangement of the normal yarns and / or weft yarns to be added can be flexibly designed, and the introduction of normal yarns and / or weft yarns of various three-dimensional fabrics such as plate-shaped fabrics and conical fabrics can be realized.

[0012] Furthermore, the three-dimensional woven fabric is a fabric with a circular or non-circular cross section formed by a three-dimensional four-step weaving method.

[0013] Furthermore, the annular fabric includes an annular, cylindrical, conical or special-shaped three-dimensional woven fabric.

[0014] Furthermore, the non-annular fabric includes a three-dimensional woven fabric with an I-shaped, L-shaped, T-shaped or U-shaped cross section.

[0015] Further, the method for introducing the normal yarn comprises the following steps connected in sequence:

[0016] (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle is arranged in every other column, and the outermost two rows of moving spindles are arranged alternately;

[0017] (2) the yarn on the uppermost layer of moving spindles is passed downward through each row at a set introduction angle and hung on the lowermost layer of moving spindles, so that the yarn on the moving spindles receiving the yarn is passed upward through each row at the same introduction angle and hung on the moving spindles giving the yarn;

[0018] (3) Continue with the next standard cycle of the three-dimensional four-step method;

[0019] (4) Repeat steps (2) and (3) until the fabric reaches the target size.

[0020] Furthermore, the introduction angle is 0-45°, and the introduction angle refers to the angle between the introduced normal yarn and the thickness direction of the fabric.

[0021] Further, when the three-dimensional woven fabric is a non-annular fabric, the method for introducing the weft yarn comprises the following steps connected in sequence:

[0022] (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle every other column, one spindle every other row, and the outermost two rows of moving spindles are staggered, and the outermost two columns of moving spindles are staggered;

[0023] (2) the yarns on the outermost odd-numbered columns of moving spindles are passed through each column along the width direction of the fabric and hung on the outermost even-numbered columns of moving spindles, and the yarns on the moving spindles receiving the yarns are passed through each column along the width direction of the fabric and hung on the moving spindles giving the yarns;

[0024] (3) Continue with the next standard cycle of the three-dimensional four-step method;

[0025] (4) Repeat steps (2) and (3) until the fabric reaches the target size.

[0026] Further, when the three-dimensional woven fabric is an annular fabric, the method for introducing the weft yarn comprises the following steps connected in sequence:

[0027] (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle is arranged in every other column, and the outermost two rows of moving spindles are arranged alternately;

[0028] (2) The yarn on any one of the moving spindles in each row of moving spindles is wound around the circumference of the layer once and then is still hung on the moving spindle;

[0029] (3) Continue with the next standard cycle of the three-dimensional four-step method;

[0030] (4) Repeat steps (2) and (3) until the fabric reaches the target size.

[0031] Furthermore, when the yarn used for weaving is multi-ply, some of the ply yarns can be selected to move, and the yarns that are not moved still maintain the original movement trajectory. This method improves the designability of adding normal yarns and weft yarns.

[0032] The present invention also provides a three-dimensional woven fabric woven by any one of the above methods.

[0033] Beneficial effects of the present invention:

[0034] 1. The three-dimensional fabric manufactured by the method of the present invention can solve technical problems such as special local load-bearing requirements of the fabric, complex shape, and overall weaving molding. The prepared three-dimensional fabric has good integrity and greatly improved mechanical properties, thereby improving the overall mechanical properties of the composite material.

[0035] 2. This method has extremely high designability and can ensure the continuity and structural integrity of the three-dimensional fabric; it makes the interlayer connection of the three-dimensional fabric deeper and the anti-delamination ability stronger, thereby improving the mechanical properties of the composite material.

[0036] 3. The present invention completely utilizes the existing knitting motion yarn for operation, and does not need to use a normal yarn system and a weft yarn system separately. The operation method is simple and has wide adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of a 3D quartz fiber plate obtained in Example 1 of the present invention. In the figure, the direction of the arrow is the weaving direction.

[0038] Figure 2 for Figure 1 Schematic diagram of the spindle arrangement after a cycle ends.

[0039] Figure 3 for Figure 2 Schematic diagram of the yarn shifting direction with normal yarn added to each column.

[0040] Figure 4 for Figure 2 Schematic diagram of the yarn shifting direction of the weft yarn added to each layer.

[0041] Figure 5 This is a schematic diagram of the 3D carbon fiber plate obtained in Example 2 of the present invention. In the figure, the direction of the arrow is the weaving direction.

[0042] Figure 6 for Figure 5 Schematic diagram of the spindle arrangement after a cycle ends.

[0043] Figure 7 for Figure 6 Schematic diagram of yarn shifting direction with angled normal yarn added.

[0044] Figure 8 This is a schematic diagram of a carbon fiber round tube obtained in Example 3 of the present invention. In the figure, the direction of the arrow is the weaving direction.

[0045] Fig. 9 for Figure 8 Schematic diagram of the initial spindle arrangement of the circular tube.

[0046] Fig.10 for Fig. 9 Schematic diagram of the yarn shifting direction of each column with normal yarn added.

[0047] Fig.11 for Fig. 9 Schematic diagram of the yarn shifting direction of each layer of weft yarn.

[0048] Fig.12This is a schematic diagram of a quartz fiber round tube obtained in Example 4 of the present invention. In the figure, the direction of the arrow is the weaving direction.

[0049] Fig.13 for Fig.12 Schematic diagram of the initial spindle arrangement of the circular tube.

[0050] Fig.14 for Fig.13 Schematic diagram of the yarn shifting direction with angled normal yarn added to each column. DETAILED DESCRIPTION

[0051] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0052] In the embodiments, Tex refers to the fineness of the woven yarn bundle, that is, the weight of the yarn bundle per kilometer.

[0053] In the embodiments, the number of yarns refers to the number of spindles, and one yarn may be a plurality of ply yarns.

[0054] Example 1

[0055] Adopt the method of the present invention to weave as Figure 1 The fabric size of the rectangular plate with equal thickness is as follows: 200mm long × 100mm wide × 5mm thick. The weaving starts with the cross section at one end of the rectangular plate as the reference cross section, and the weaving direction is along the length direction of the rectangle. Figure 1 Indicated by the direction of the arrow.

[0056] This embodiment adopts a three-dimensional five-way braiding structure, and uses 195Tex quartz fiber for braiding. Two strands of moving yarn are plied together, two strands of stationary yarn are plied together, the mother-direction flower knot is 52mm / 10 flowers, the circumferential flower knot is 25mm / 10 flowers, and the fiber volume fraction is 52%, of which the weft yarn volume fraction is 4.7%, and the normal yarn volume fraction is 2.6%. The number of moving yarns required for the reference cross-section design is 640, arranged in 80 rows in 8 layers; the number of stationary yarns required is 553, arranged in 79 rows in 7 layers.

[0057] The method of adding normal yarn and weft yarn is explained in detail by drawing a knitting cycle of the plate. The steps are as follows:

[0058] (1) See Figure 2 , Figure 2 This is a schematic diagram of the spindle arrangement after a certain cycle of the block ends. In the figure, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the outermost yarns of each column of weaving yarn, and they are arranged one by one on the same side of the block. In the figure, A, B, C, D, E, F, G, and H are the outermost yarns of each layer of weaving yarn, and they are arranged one by one on the same side of the block.

[0059] (2) See Figure 3 When adding normal yarn, move the yarn on spindle 1 to spindle 2 along the column, so that a normal yarn is introduced into the column. Similarly, move the original yarn on spindle 2 to spindle 3 along the column, and so on, introduce normal yarn into each column, and finally add a yarn to the first spindle and remove a yarn from the last spindle to ensure the balance of the total number of yarns.

[0060] (3) See Figure 4 When adding weft yarn, move the yarn on spindle A to spindle B along the layer, so that a weft yarn is introduced into the layer. Similarly, move the original yarn on spindle B to spindle C along the layer, and so on, introduce weft yarn into each layer, and finally add a yarn to the first spindle and remove a yarn from the last spindle to ensure the balance of the total number of yarns.

[0061] (4) After the addition of normal yarn and weft yarn is completed, a weaving motion cycle is performed.

[0062] Repeat the above steps until the weaving is completed. The normal yarn and weft yarn are added once for each flower node of the obtained block.

[0063] In the existing three-dimensional weaving process, weaving is done by adding normal yarn and weft yarn. Another spool of yarn is used to wind the yarn on the spool into the braided fabric row by row (layer) to form normal (weft) yarn. The spool has no tension, and its operation accuracy is difficult to control. The normal (weft) yarn formed in this way is easy to bend in the fabric, resulting in low-density defects. At the same time, there will be a lot of hair on the surface of the fabric, affecting the neatness of the appearance.

[0064] In the fabric woven by the method of the present invention, the normal yarn and the weft yarn are the dynamic yarns normally participating in the weaving, and they are always under tension during the whole weaving process. There is no bending of the normal (weft) yarns, and there is no fuzz on the outer surface of the fabric, which maintains the continuity of the weaving yarns, increases the interlayer connection of the yarns, and effectively improves the anti-delamination ability of the fabric.

[0065] Example 2

[0066] Adopt the method of the present invention to weave as Figure 5 The fabric size of the rectangular plate with equal thickness is as follows: 200mm long × 100mm wide × 6mm thick. The weaving starts with the cross section at one end of the rectangular plate as the reference cross section, and the weaving direction is along the length direction of the rectangle. Figure 1 Indicated by the direction of the arrow.

[0067] This embodiment adopts a three-dimensional five-way braided structure, and uses 198Tex carbon fiber for braiding. Two strands of moving yarn are plied together, two strands of stationary yarn are plied together, the mother-direction flower knot is 58mm / 10 flowers, the circumferential flower knot is 28mm / 10 flowers, and the fiber volume fraction is 53%, of which the weft yarn volume fraction is 4.9% and the normal yarn volume fraction is 3.8%. The number of moving yarns required for the reference cross-section design is 490, arranged in 70 rows in 8 layers; the number of stationary yarns required is 414, arranged in 69 rows in 7 layers.

[0068] The method of adding 45 degrees normal yarn and 45 degrees weft yarn is explained in detail by drawing a knitting cycle of the plate. The steps are as follows:

[0069] (1) See Figure 6 , Figure 6 This is a schematic diagram of the spindle arrangement after a certain cycle of the block ends. In the figure, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the outermost yarns of each column of weaving yarn, and they are arranged one by one on the same side of the block. In the figure, A, B, C, D, E, F, G, and H are the outermost yarns of each layer of weaving yarn, and they are arranged one by one on the same side of the block.

[0070] (2) See Figure 7 When adding 45-degree normal yarn, the yarn on spindle 1 is moved to spindle 6 in an orderly manner across 4 columns, so that a normal yarn with an angle of +45 degrees to the outer boundary of the plate is introduced into the plate fabric. Similarly, the yarn on spindle 2 is moved to spindle 7 in an orderly manner across 4 columns, so that a normal yarn with an angle of -45 degrees to the outer boundary of the plate is introduced into the plate fabric. Similarly, the ±45 normal yarns of the main part of the plate are introduced. The corners of the plate are carried out by the cross-movement method. The specific operation is to move the yarn on spindle 6 to spindle A in an orderly manner across columns, and move the yarn on spindle 7 to spindle G in an orderly manner across columns, and so on to introduce the ±45 normal yarns of the corners of the plate. Finally, add a yarn to the left spindle and remove a yarn from the right spindle to ensure the balance of the total number of yarns. After the operation of adding ±45 normal yarns is completed, a weaving movement cycle is performed.

[0071] (3) Repeat the above steps until the weaving is completed. Each flower node of the obtained plate is added with ±45 normal yarn once.

[0072] In the existing three-dimensional weaving process, it is impossible to implement the operation of adding ±45 normal yarns.

[0073] In the fabric woven by the method of the present invention, the ±45 normal yarns are the dynamic yarns normally participating in the weaving, and they are always under tension during the whole weaving process. There is no bending of the normal (weft) yarns, and at the same time, there are no fuzzes on the outer surface of the fabric, which maintains the continuity of the weaving yarns, increases the interlayer connection of the yarns, and effectively improves the anti-delamination ability of the fabric.

[0074] Example 3

[0075] Adopt the method of the present invention to weave as Figure 8 The cylindrical workpiece shown has an inner diameter of φ80mm, a height of 200mm, and a wall thickness of 10mm. The weaving starts with the cross section at one end as the reference cross section, and the weaving direction is along the height direction of the cylinder. Figure 8 Indicated by the direction of the arrow.

[0076] This embodiment adopts a three-dimensional five-way braiding structure and uses T300-3K fiber for braiding. Three strands of moving yarn are plied together, three strands of stationary yarn are plied together, the mother-direction flower knot is 87mm / 10 flowers, the circumferential flower knot is 59mm / 10 flowers, and the fiber volume fraction is 54.4%, of which the weft yarn volume fraction is 5.5% and the normal yarn volume fraction is 4.3%. The number of moving yarns required for the reference cross-section design is 1908, which are arranged in 106 rows along the ring in 18 layers; the number of stationary yarns required is 1696, which are arranged in 106 rows along the ring in 16 layers.

[0077] The method of adding normal yarn and weft yarn to the ring is explained in detail by drawing a knitting cycle. The steps are as follows:

[0078] (1) See Fig. 9 , Fig. 9 This is a schematic diagram of the spindle arrangement after a certain cycle of the ring is completed. In the figure, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the yarns in the outermost and innermost circles of each column of braiding yarn, and they are arranged in alternate ways on the same side of the ring. In the figure, A, B, C, D, and E are any yarns in each layer of braiding yarn.

[0079] (2) See Fig.10 When adding normal yarn, move the yarn on spindle 1 to spindle 2 along the column, so that a normal yarn is introduced into the column. Similarly, move the original yarn on spindle 2 to spindle 3 along the column, and so on, and introduce normal yarn into each column.

[0080] (3) See Fig.11 When adding weft yarn, the yarn on spindle A is wound around the layer and still hung on the original spindle A, so that a weft yarn is introduced into the layer. Similarly, the yarn on spindle B is wound around the layer and still hung on the original spindle B, and so on, each layer is introduced with weft yarn. After the addition of normal yarn and weft yarn is completed, a weaving motion cycle is performed.

[0081] (4) Repeat the above steps until the weaving is completed. The normal yarn and the weft yarn are added once for each flower node of the obtained cylinder.

[0082] In the existing three-dimensional weaving process, the weaving is realized by adding normal yarn and weft yarn to the cylinder. Another shaft of yarn is used to wind the yarn on the spool into the braided fabric row by row (layer) to form normal (weft) yarn. The spool has no tension, and its operation accuracy is difficult to control. The formed normal (weft) yarn is easy to bend in the fabric, resulting in low-density defects. At the same time, there will be a lot of hair on the surface of the fabric, affecting the neatness of the appearance.

[0083] In the cylindrical fabric woven by the method of the present invention, the normal yarn and the weft yarn are the dynamic yarns normally participating in the weaving, and they are always under tension during the whole weaving process. There is no bending of the normal (weft) yarns, and there is no fuzz on the outer surface of the fabric, which maintains the continuity of the weaving yarns, increases the interlayer connection of the yarns, and effectively improves the anti-delamination ability of the fabric.

[0084] Example 4

[0085] Adopt the method of the present invention to weave as Fig.12 The cylindrical part shown has an inner diameter of φ80mm, a height of 200mm, and a wall thickness of 5mm. The weaving starts with the cross section at one end as the reference cross section, and the weaving direction is along the height direction of the cylinder. Fig.10 Indicated by the direction of the arrow.

[0086] This embodiment adopts a three-dimensional five-way braiding structure and uses 195TEX quartz yarn for weaving. Two strands of moving yarn are plied together, two strands of stationary yarn are plied together, the mother-direction flower knot is 62mm / 10 flowers, the circumferential flower knot is 40mm / 10 flowers, and the fiber volume fraction is 54.9%, of which the weft yarn volume fraction is 5.2%, and the angled normal yarn volume fraction is 4.2%. The number of moving yarns required for the reference cross-section design is 1704, which are arranged in 142 rows along the ring in 12 layers; the number of stationary yarns required is 1420, which are arranged in 142 rows along the ring in 10 layers.

[0087] The method of adding angled normal yarn and weft yarn to a ring is described in detail using a knitting cycle diagram. The steps are as follows:

[0088] (1) See Fig.13 , Fig.13 This is a schematic diagram of the spindle arrangement after a certain cycle of the ring is completed. In the figure, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are the yarns in the outermost and innermost circles of each column of braiding yarn, and they are arranged in alternate ways on the same side of the ring. In the figure, A, B, C, D, and E are any yarns in each layer of braiding yarn.

[0089] (2) See Fig.14When adding normal yarn, the weaving yarn on spindle 1 is moved through the fabric to spindle 4 in an orderly manner, thus introducing a normal yarn with a positive angle, and the angle varies according to the number of columns spanned. Similarly, the yarn on spindle 2 is moved through the fabric to spindle 5 in an orderly manner, thus introducing a normal yarn with a negative angle, and the angle varies according to the number of columns spanned. Similarly, normal yarns with positive and negative angles are introduced into the entire circle of fabric. When adding weft yarn, the method of adding weft yarn is the same as that in Example 3. After the operations of adding normal yarn and adding weft yarn are completed, a weaving motion cycle is performed.

[0090] (3) Repeat the above steps until the weaving is completed. Each flower node of the obtained cylinder is added with an angled normal yarn and a hoop weft yarn.

[0091] In the existing three-dimensional weaving process, it is impossible to achieve cylindrical weaving with angled normal yarns.

[0092] In the cylindrical fabric woven by the method of the present invention, the normal yarn and the weft yarn are the dynamic yarns normally participating in the weaving, and they are always under tension during the whole weaving process. There is no bending of the normal (weft) yarns, and there is no fuzz on the outer surface of the fabric, which maintains the continuity of the weaving yarn and increases the interlayer connection of the yarn, thereby effectively improving the anti-delamination ability of the fabric.

Claims

1. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric, characterized in that: In the three-dimensional four-step weaving process, after a standard cycle is completed, without increasing the total number of yarns: The normal yarn introduction of the current flower section is achieved by moving the yarn on the outermost moving spindle in the thickness direction to pass through each row; The weft yarn of the current flower section is introduced by moving the yarn on the outermost moving spindle in the width direction or the yarn on a certain moving spindle in the circumferential direction to pass through each column; The next standard cycle is carried out after the normal yarn and the weft yarn are introduced.

2. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to claim 1, characterized in that: The three-dimensional woven fabric is a fabric with a circular or non-circular cross section formed by a three-dimensional four-step weaving method.

3. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to claim 2, characterized in that: The annular fabric includes an annular, cylindrical, conical or special-shaped three-dimensional woven fabric.

4. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to claim 2, characterized in that: The non-annular fabric includes a three-dimensional woven fabric having an I-shape, an L-shape, a T-shape or a U-shape in cross section.

5. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to any one of claims 1 to 4, characterized in that: The method for introducing the normal yarn comprises the following steps connected in sequence: (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle is arranged in every other column, and the outermost two rows of moving spindles are arranged alternately; (2) the yarn on the uppermost layer of moving spindles is passed downward through each row at a set introduction angle and hung on the lowermost layer of moving spindles, so that the yarn on the moving spindles receiving the yarn is passed upward through each row at the same introduction angle and hung on the moving spindles giving the yarn; (3) Continue with the next standard cycle of the three-dimensional four-step method; (4) Repeat steps (2) and (3) until the fabric reaches the target size.

6. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to claim 5, characterized in that: The introduction angle is 0 to 45 degrees, and the introduction angle refers to the angle between the introduced normal yarn and the thickness direction of the fabric.

7. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to any one of claims 1 to 4, characterized in that: When the three-dimensional woven fabric is a non-annular fabric, the method for introducing the weft yarns comprises the following steps connected in sequence: (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle every other column, one spindle every other row, and the outermost two rows of moving spindles are staggered, and the outermost two columns of moving spindles are staggered; (2) the yarns on the outermost odd-numbered columns of moving spindles are passed through each column along the width direction of the fabric and hung on the outermost even-numbered columns of moving spindles, and the yarns on the moving spindles receiving the yarns are passed through each column along the width direction of the fabric and hung on the moving spindles giving the yarns; (3) Continue with the next standard cycle of the three-dimensional four-step method; (4) Repeat steps (2) and (3) until the fabric reaches the target size.

8. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to any one of claims 1 to 4, characterized in that: When the three-dimensional woven fabric is an endless fabric, the method for introducing the weft yarns comprises the following steps connected in sequence: (1) After a standard cycle of the three-dimensional four-step method is completed, the arrangement of the outermost moving spindles is: one spindle is arranged in every other column, and the outermost two rows of moving spindles are arranged alternately; (2) The yarn on any one of the moving spindles in each row of moving spindles is wound around the circumference of the layer once and then is still hung on the moving spindle; (3) Continue with the next standard cycle of the three-dimensional four-step method; (4) Repeat steps (2) and (3) until the fabric reaches the target size.

9. A method for introducing normal yarns and weft yarns into a three-dimensional woven fabric according to claim 1, characterized in that: When the yarn used for weaving is multi-ply, some of the ply yarns can be selected to move, and the yarns that are not moved still maintain the original movement trajectory.

10. A three-dimensional woven fabric prepared according to the method of any one of claims 1 to 9.

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