Method for manufacturing fiber structure

Abstract

The present invention comprises: a first weaving step for positioning a first mandrel (30A) that is arranged along the axial direction, the first mandrel (30A) having a cylindrical part (31) and a disk part (32) that has a circumferential length greater than that of the cylindrical part (31), and for arranging axial yarns (13) along the first mandrel (30A) and causing circumferential yarns (14) to intersect the plurality of axial yarns (13) to weave a first fiber structure (16A); a movement step for moving the axial yarns (13) and the circumferential yarns (14) in an uncut state relative to a second mandrel (30B) that is of the same type as the first mandrel (30A) and is positioned in the axial direction of the first mandrel (30A); and a second weaving step for arranging the axial yarns (13) along the axial direction of the second mandrel (30B) and causing the circumferential yarns (14) to intersect the plurality of axial yarns (13) to weave a second fiber structure.

Description

Method for manufacturing a fiber structure 【0001】 This invention relates to a method for manufacturing a fiber structure. 【0002】 As a conventional technique related to a method for manufacturing a fiber structure, for example, a three-dimensional woven fabric disclosed in Patent Document 1 is known. The three-dimensional woven fabric disclosed in Patent Document 1 includes a tubular portion and a disk-shaped portion. The tubular portion is woven by a group of warp yarns arranged in a tubular shape and extending parallel to each other, and a weft yarn that intersects the group of warp yarns and extends in a spiral shape. The disk-shaped portion is formed by the warp yarns extending radially at one end of the tubular portion and the weft yarn from the tubular portion extending in a spiral shape to the radially extending warp yarns. 【0003】 This type of three-dimensional woven fabric is manufactured by, for example, a known circular loom. First, the tubular portion is formed, and then the disk-shaped portion is formed. After the disk-shaped portion is formed, all the warp yarns are cut to obtain the three-dimensional woven fabric. When manufacturing a plurality of three-dimensional woven fabrics, the weaving process of the tubular portion and the disk-shaped portion and the cutting process of the warp yarns after weaving may be repeated. 【0004】 Japanese Patent Application Laid-Open No. 4-108138 【0005】 By the way, in order to manufacture a plurality of fiber structures (three-dimensional woven fabrics), it is conceivable to use a mandrel in the manufacture of the three-dimensional woven fabric disclosed in Patent Document 1. However, each time a fiber structure is woven, a complicated operation is required to fix the starting ends of all the axial yarns (warp yarns) after cutting circumferentially to the end of the mandrel prior to weaving. Therefore, there is a problem that the manufacturing efficiency of the fiber structure is low. 【0006】 The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a fiber structure that can reduce the operation of fixing the starting ends of the axial yarns to the mandrel and improve the manufacturing efficiency of the fiber structure when manufacturing a plurality of fiber structures. 【0007】To solve the above problems, the present invention provides a method for manufacturing a fiber structure woven with a plurality of axial threads extending along the axial direction over the entire axial length of the tubular portion and the annular portion, having at least a tubular portion and an annular portion extending from the end of the tubular portion in increasing diameter and having a circumference longer than the circumference of the tubular portion, and circumferential threads extending spirally along the circumferential direction of the tubular portion and the annular portion, wherein a first mandrel and a second mandrel are prepared, each having at least a cylindrical portion and a disc portion having a circumference longer than that of the cylindrical portion, and the first mandrel is aligned along the axial direction The invention is characterized by comprising: a first weaving step of weaving a first fiber structure by arranging a mandrel, arranging the axial threads along the axial direction of the first mandrel, and intersecting the circumferential threads with the plurality of axial threads along the circumferential direction of the first mandrel; a transfer step of transferring the axial threads and the circumferential threads in an uncut state to a second mandrel arranged in the axial direction of the first mandrel; and a second weaving step of arranging the axial threads along the axial direction of the second mandrel and intersecting the circumferential threads with the plurality of axial threads along the circumferential direction of the second mandrel. 【0008】 In this invention, a first mandrel is positioned along the axial direction, and the first and second mandrels each have at least a cylindrical portion and a disc portion whose circumference is longer than that of the cylindrical portion. In the first weaving process, a first fiber structure is woven. In the transition process, the axial and circumferential threads are transferred to the second mandrel, which is positioned axially to the first mandrel, in an uncut state, and the second fiber structure is woven thereafter. Therefore, when weaving the first and second fiber structures in succession, it is not necessary to fix the starting ends of the axial threads to the second mandrel. As a result, when manufacturing multiple fiber structures, the work of fixing the starting ends of the axial threads to the mandrels can be reduced, thereby increasing the manufacturing efficiency of the fiber structures. 【0009】Furthermore, in the above-described method for manufacturing the fiber structure, the first weaving step, the transition step, and the second weaving step may be repeated in succession to form a continuous woven body including the first fiber structure and the second fiber structure. In this case, the tubular weaving step and the annular weaving step are repeated in succession to form a continuous woven body including the first fiber structure and the second fiber structure. Since a continuous woven body including the first fiber structure and the second fiber structure is formed, the axial threads are not cut during the weaving of the first fiber structure and the second fiber structure, and weaving is not interrupted by the cutting of axial threads, thereby increasing the manufacturing efficiency of the fiber structure. 【0010】 Furthermore, in the above-described method for manufacturing the fiber structure, the transition step is a step after the first weaving step, and includes a non-weaving step in which the plurality of axial yarns after weaving the first fiber structure are arranged along the axial direction of the disc portion of the second mandrel, and the circumferential yarns are arranged along the axial direction of the disc portion to form a non-woven portion extending from the first fiber structure, and the second fiber structure is woven after the non-weaving step. In this case, in the non-weaving step after weaving the first fiber structure, the plurality of axial yarns are arranged along the axial direction of the disc portion, and a non-woven portion is formed in which the circumferential yarns are arranged along the axial direction of the disc portion to form a non-woven portion extending from the first fiber structure. By forming a non-woven portion, the second fiber structure can be continuously woven following the first fiber structure without cutting the axial yarns. 【0011】 Furthermore, in the above-described method for manufacturing the fiber structure, the disc portion may have an axial intersection surface that intersects the axial direction and extends circumferentially, and the axial intersection surface may be configured to have a conical inclined surface that is inclined with respect to the axial direction. In this case, since the disc portions of the first and second mandrels are provided with inclined surfaces, it is possible to weave annular portions continuously after weaving annular portions. 【0012】Furthermore, the above-described method for manufacturing the fiber structure may include a shaping step for shaping the first fiber structure and the second fiber structure obtained by cutting the continuous woven body. In this case, a fiber structure of a desired shape can be obtained by shaping the fiber structure obtained by cutting the continuous woven body. 【0013】 Furthermore, in the above-described method for manufacturing the fiber structure, a multilayer continuous woven body may be formed by weaving from one end in the axial direction to the other, and then weaving from the other end to the other in the axial direction. In this case, a multilayer continuous woven body containing multiple fiber structures can be formed. The required thickness of the tubular and annular portions of the fiber structure can be achieved. 【0014】 According to the present invention, it is possible to provide a method for manufacturing fiber structures that can improve the manufacturing efficiency of fiber structures by reducing the work required to fix the starting ends of axial threads to a mandrel when manufacturing multiple fiber structures. 【0015】This is a perspective view showing an overview of the fiber structure according to the first embodiment. This is an explanatory diagram illustrating the manufacturing process of the fiber structure according to the first embodiment. This is a perspective view of a continuous weaving body. This is a perspective view of a mandrel used in the manufacture of the fiber structure. This is an explanatory diagram illustrating the weaving of the fiber structure using an annular loom. (a) is an explanatory diagram illustrating the weaving of the first annular section, (b) is an explanatory diagram illustrating the weaving of the tubular section, (c) is an explanatory diagram illustrating the weaving of the second annular section, and (d) is an explanatory diagram illustrating the formation of the non-woven section. This is an explanatory diagram schematically illustrating the cutting of the continuous weaving body in the cutting process. This is an explanatory diagram schematically illustrating the shaping of the fiber structure in the shaping process. This is an explanatory diagram schematically illustrating the manufacture of a fiber structure according to a modified example. This is an explanatory diagram illustrating the manufacturing process of the fiber structure according to the second embodiment. (a) is a side view of the mandrel, and (b) is an explanatory diagram schematically illustrating the manufacture of the fiber structure. This is an explanatory diagram illustrating the manufacturing process of the fiber structure according to the third embodiment. (a) is a side view of the mandrel, and (b) is an explanatory diagram schematically illustrating the manufacture of the fiber structure. This is an explanatory diagram illustrating the weaving of a fiber structure according to the fourth embodiment. (a) is a diagram showing the weaving of the first fiber structure, (b) is a diagram showing the formation of a non-woven portion following the first fiber structure, (c) is a diagram showing the state in which a mandrel is inserted into the non-woven portion, (d) is a diagram showing the fixing of the mandrel in the non-woven portion and the cutting of the non-woven portion, and (e) is a diagram showing the weaving of the second fiber structure. This is an explanatory diagram illustrating the weaving of a fiber structure according to another example. 【0016】 (First Embodiment) Hereinafter, a method for manufacturing a fiber structure according to the first embodiment will be described with reference to the drawings. The fiber structure of this embodiment is a fiber structure suitable for manufacturing fiber-reinforced composite materials. A fiber-reinforced composite material can be obtained by compounding the fiber structure, for example, into a resin matrix. Fiber-reinforced composite materials have improved mechanical properties (mechanical properties) compared to the matrix itself, and can also be made lighter. 【0017】As shown in Figure 1, the fiber structure 10 of this embodiment has a cylindrical tubular portion 11 and a pair of annular portions 12 formed concentrically at both ends of the tubular portion 11. The tubular portion 11 is formed by a plain weave structure in the direction of the axis P of the tubular portion 11 (hereinafter referred to as the "axial direction"). The circumference of the tubular portion 11 is constant in the axial direction. 【0018】 The annular portion 12 is formed concentrically at the end of the cylindrical portion 11. The annular portion 12 extends in a direction that intersects the axis P of the cylindrical portion 11 almost perpendicularly and is formed circumferentially. Therefore, the annular portion 12 has a circumference longer than the circumference of the cylindrical portion 11. The annular portion 12 is formed by a plain weave structure. 【0019】 The fiber structure 10 has a number of axial threads 13 and circumferential threads 14. Multiple axial threads 13 are arranged in the tubular portion 11. Multiple axial threads 13 extend axially in the tubular portion 11 and radially extend outward from the tubular portion 11 in a direction intersecting the axial direction (radial direction) in the annular portion 12. In other words, multiple axial threads 13 extend along the axial direction over the entire axial length of the tubular portion 11 and the annular portion 12. The circumferential threads 14 extend circumferentially in the tubular portion 11 and also extend spirally in the axial direction, intersecting with the axial threads 13. In the annular portion 12, the circumferential threads 14 intersect with the multiple axial threads 13 extending radially and extend in a spiral shape radially outward from the tubular portion 11. Note that the circumferential threads 14 in the fiber structure 10 may be one or multiple. 【0020】 The axial threads 13 and circumferential threads 14 may be inorganic fibers such as carbon fibers, glass fibers, ceramic fibers, or metal fibers. Alternatively, the axial threads 13 and circumferential threads 14 may be high-strength organic fibers such as aramid fibers, poly-p-phenylenebenzobisoxazole fibers, polyarylate fibers, or ultra-high molecular weight polyethylene fibers. They are appropriately selected according to the required performance of the fiber-reinforced composite formed as the base material of the fiber structure. Carbon fibers are preferred when the required rigidity and strength of the fiber-reinforced composite material are high. 【0021】Next, a method for manufacturing the fiber structure 10 will be described. In the method for manufacturing the fiber structure 10 of this embodiment, multiple fiber structures 10 are manufactured by going through the steps shown in Figure 2. Specifically, the method for manufacturing the fiber structure 10 includes multiple weaving steps 20 for forming a continuous woven body 15 containing multiple unformed fiber structures 16, a transition step 21 for transferring axial threads 13 and circumferential threads 14 in an uncut state, a cutting step 22 for cutting the continuous woven body 15, and a shaping step 23 for shaping the cut continuous woven body 15. The continuous woven body 15 is a woven body having multiple unformed fiber structures 16 and an unwoven portion 27 which will be described next. The unformed fiber structure 16 has a tubular portion 11 and a pair of funnel-shaped annular portions 12. 【0022】 The weaving process 20 can be divided into a first weaving process 20A, which weaves the first fiber structure 16A, which is the fiber structure 16 to be woven first, and a second weaving process 20B, which weaves the second fiber structure 16B after the first fiber structure 16A has been woven. In this embodiment, the first fiber structure 16A is woven again after the second fiber structure 16B has been woven. The first fiber structure 16A and the second fiber structure 16B are basically the same shape. The weaving process 20 includes an annular weaving process 24 for weaving the annular portion 12 and a tubular weaving process 25 for weaving the tubular portion 11. The annular weaving process 24 and the tubular weaving process 25 are processes for weaving the fiber structure 16 in the continuous woven body 15 before shaping. In this embodiment, the first annular portion weaving process 24A, in which the annular portion 12 is woven radially from the outside toward the center, and the second annular portion weaving process 24B, in which the annular portion 12 is woven radially from the center toward the outside, may be described separately. The tubular portion weaving process 25 is a process in which the tubular portion 11 is woven by intersecting circumferential yarns 14 with a plurality of axial yarns 13. 【0023】The transition step 21 of this embodiment includes a non-weaving step 26 for forming non-weaving sections 27 in the continuous woven body 15. The non-weaving sections 27 are portions interposed between the first fiber structure 16A and the second fiber structure 16B, and between the second fiber structure 16B and the first fiber structure 16A, respectively, in the continuous woven body 15. The annular section weaving step 24, the tubular section weaving step 25, and the non-weaving step 26 are steps that are repeated according to the number of fiber structures 10 to be manufactured. As shown in Figure 3, the continuous woven body 15 is a woven body having fiber structures 16 before shaping and non-weaving sections 27. In the weaving step 20, the continuous woven body 15 is woven by an annular loom 40, which will be described later, but the first fiber structure 16A can be woven by going through the annular section weaving step 24, the tubular section weaving step 25, and the annular section weaving step 24. Furthermore, by going through the non-weaving process 26, the second fiber structure 16B can be continuously woven. 【0024】 The cutting step 22 is a process of individually cutting out the unformed fiber structures 16 from the continuous woven body 15. Specifically, in the cutting step 22, all axial threads 13 and circumferential threads 14 in the non-woven portion 27 are cut by a cutter (not shown). The unformed fiber structures 16 are obtained by removing the non-woven portion 27 from the continuous woven body 15. After the cutting step 22 is completed, the process proceeds to the forming step 23, which is a process of forming the fiber structures 16. In the forming step 23, the fiber structures 10 are obtained by forming the fiber structures 16 using a forming mold (not shown). After the forming step 23, for example, the fiber structures 10 may be impregnated with a matrix resin to obtain a fiber-reinforced composite material by the RTM method. 【0025】Next, the weaving of the continuous woven body 15 in the weaving process 20 will be described in detail. In this embodiment, the continuous woven body 15 is woven using a plurality of mandrels 30. In some cases, the mandrels 30 may be distinguished and described as follows: the mandrel 30 corresponding to the first fiber structure 16A will be called the first mandrel 30A, and the mandrel 30 corresponding to the second fiber structure 16B will be called the second mandrel 30B. As shown in Figure 4, the first mandrel 30A and the second mandrel 30B each have a cylindrical portion 31 and a disc portion 32. The cylindrical portion 31 is a cylindrical body and has an outer peripheral surface 33 that corresponds to the tubular portion 11 of the fiber structure 10. The disc portion 32 is a portion that has a longer circumference than the cylindrical portion 31. In this embodiment, disc portions 32 are provided at both ends of the cylindrical portion 31. The disc portion 32 includes an outer peripheral surface 34, an annular end surface 35 formed between the outer peripheral surface 34 and the outer peripheral surface 33 of the cylindrical portion 31, and a circular end surface 36 on the opposite side of the annular end surface 35. 【0026】 The outer circumferential surface 34 is the surface corresponding to the non-woven portion 27 of the continuous woven body 15. The annular end surface 35 corresponds to the axial intersection surface that intersects the axial direction and extends circumferentially. The annular end surface 35 is a substantially conical surface formed such that its circumference increases from the outer circumferential surface 33 to the outer circumferential surface 34 of the cylindrical portion 31. Therefore, the annular end surface 35 is a conical inclined surface that is inclined with respect to the axial direction. The pair of annular end surfaces 35 are the surfaces corresponding to the annular portion 12 of the fiber structure 10. The cylindrical portion 31 and the pair of disc portions 32 in this embodiment are separable, but may be formed integrally. The circular end surface 36 is a surface that is substantially perpendicular to the axial direction. 【0027】 The first mandrel 30A and the second mandrel 30B are connected in series according to the required number of fiber structures 10. The circular end faces 36 of the multiple mandrels 30 are connected to each other, so that the multiple mandrels 30 are connected in series concentrically. For example, if the continuous weaving body 15 is to contain five fiber structures 16, then five mandrels 30 should be connected. 【0028】The continuous weaving machine 15 is woven using the annular loom 40 shown in Figure 5. The annular loom 40 is equipped with an opening device 41. Numerous heddles 42 are arranged radially outside the mandrel 30 so as to surround the mandrel 30. Axial threads 13 are passed through the heddles 42. The opening device 41 alternately opens adjacent heddles 42. The axial threads 13 are supplied from the radially outside the heddles 42 toward the heddles 42. The opening device 41 moves back and forth in the axial direction of the mandrel 30, and the mandrel 30 can also move back and forth in the axial direction relative to the opening device 41. 【0029】 As shown in Figure 5, the annular loom 40 is equipped with a shuttle 43 that passes circumferential yarns 14 between open axial yarns 13. The shuttle 43 contains a bobbin (not shown) on which the circumferential yarns 14 are wound. The shuttle 43 is concentric with the mandrel 30 and passes circumferentially between the open axial yarns 13. 【0030】 In the manufacturing method of the fiber structure 10, the first step is the first annular section weaving step 24A in the weaving step 20. In the first annular section weaving step 24A, the starting end of the axial yarn 13 is fixed to the outer peripheral surface 34 of the disc portion 32 of the outermost mandrel 30 among the multiple mandrels 30. The axial yarn 13 is arranged circumferentially in the disc portion 32. The opening movement of the heddle 42 by the opening device 41 and the circumferential rotation of the shuttle 43 passing between the opened axial yarns 13 form a plain weave structure along the axial direction. As shown in Figure 6(a), the axial yarn 13 in the weave structure converge towards the cylindrical portion 31 along the annular end surface 35 of the disc portion 32. In addition, the circumferential yarn 14 in the weave structure extends circumferentially in the annular end surface 35 and also extends spirally toward the cylindrical portion 31, intersecting with the axial yarn 13. When the edge of the woven structure reaches the edge of the cylindrical portion 31, the weaving of the annular portion 12 is completed. The annular portion 12 is funnel-shaped because it follows the annular end face 35. In other words, in the first annular portion weaving process 24A, multiple axial threads 13 are aligned along the disc portion 32 in an axial crossing direction intersecting the axial direction, and circumferential threads 14 are woven into the multiple axial threads 13 in the disc portion 32 to weave the annular portion 12. 【0031】After weaving the annular portion 12, the process proceeds to the tubular portion weaving process 25, which weaves the tubular portion 11. In the tubular portion weaving process 25, the axial threads 13 are arranged circumferentially in the cylindrical portion 31. As shown in Figure 6(b), the opening movement of the heddle 42 by the opening device 41 and the circumferential rotation of the shuttle 43 passing through the opened axial threads 13 form a plain weave structure along the axial direction. In the woven structure, the axial threads 13 are aligned axially on the outer surface 33 of the cylindrical portion 31, and the circumferential threads 14 in the woven structure extend circumferentially on the outer surface 33 and also extend spirally in the axial direction, intersecting with the axial threads 13. When the woven structure reaches the end of the cylindrical portion 31 through weaving, the weaving of the tubular portion 11 is completed. 【0032】 After weaving the tubular portion 11, the process proceeds to the second annular portion weaving process 24B, in which the annular portion 12 is woven again. As shown in Figure 6(c), in the second annular portion weaving process 24B, the axial threads 13 are opened along the annular end face 35 of the disc portion 32. The circumferential threads 14 are passed through the opened axial threads 13 in the circumferential direction, but rotate in a spiral shape radially from the outer circumferential surface 33 of the cylindrical portion 31 to the outer circumferential surface 34 of the disc portion 32. In the annular portion 12, multiple axial threads 13 extend radially outward along the annular end face 35, forming a woven structure with the spiral circumferential threads 14. When the woven structure forming the annular portion 12 reaches the outer circumferential surface 34 of the disc portion 32, the annular loom 40 stops its opening movement. At this point, the first fiber structure 16 has been woven. In other words, in the second annular section weaving process 24B, multiple axial threads 13 are aligned along the disc section 32 in an axial direction intersecting the axial direction, and circumferential threads 14 are woven into the multiple axial threads 13 in the disc section 32 to weave the annular section 12. 【0033】Next, the process proceeds to the transition process 21, which is the non-weaving process 26. As shown in Figure 6(d), in the non-weaving process 26, the mandrel 30 is raised with the opening movement of the annular loom 40 stopped to form the non-weaving section 27. The axial yarns 13 that reach the outer circumferential surface 34 of the disc portion 32 extend along the axial direction on the outer circumferential surface 34. Even after reaching the circular end face 36, the axial yarns 13 continue to extend along the outer circumferential surface 34 of the disc portion 32 of the second mandrel 30B, which is the next (second) mandrel 30. On the other hand, the circumferential yarns 14 extend along the outer circumferential surface 34 as they occur. Even after reaching the circular end face 36, the circumferential yarns 14 continue to extend along the outer circumferential surface 34 of the disc portion 32 of the second mandrel 30B. 【0034】 Furthermore, when the axial yarn 13 reaches the annular end face 35, the non-weaving process 26 is completed and the weaving process 20 is resumed. In the first annular section weaving process 24A, the axial yarn 13 and circumferential yarn 14 are aligned with the annular end face 35 to weave the annular section 12. Once the annular section 12 is woven, the tubular section 11 is woven in the tubular section weaving process 25. Once the tubular section 11 is woven, the annular section 12 is woven in the second annular section weaving process 24B, and the second fiber structure 16B, which is the second fiber structure 16, is woven. The first annular section weaving process 24A, the tubular section weaving process 25, the second annular section weaving process 24B, and the non-weaving process 26 are repeated according to the number of fiber structures 10. In this embodiment, a number of fiber structures 16 corresponding to the number of mandrels 30 are woven. After the final fiber structure 16 in the continuous weaving body 15 has been woven, the non-weaving process 26 does not need to be performed. 【0035】 Once the continuous woven body 15 is woven, the process proceeds to the cutting process 22. As shown in Figure 7, in the cutting process 22, all axial threads 13 and circumferential threads 14 of the non-woven portion 27 of the continuous woven body 15 are cut by a cutter. After the axial threads 13 and circumferential threads 14 are cut, the mandrel 30 is removed. Note that in Figure 7, the mandrel 30 is not shown for the sake of explanation. After the mandrel 30 is removed, the excess axial threads 13 and circumferential threads 14 are cut and removed to obtain multiple fiber structures 16. 【0036】Once multiple fiber structures 16 are obtained, the process proceeds to the shaping step 23. In the shaping step 23, all fiber structures 16 are shaped to obtain multiple fiber structures 10. Specifically, as shown in Figure 8, the funnel-shaped annular portion 12 of the fiber structure 16 is shaped into a flange shape, thereby transforming the fiber structure 16 into a fiber structure 10. The shaping of the fiber structure 16 can be done using a shaping mold (not shown). The fiber structure 10 obtained by shaping can then be impregnated with a matrix resin, for example, to obtain a fiber-reinforced composite material by the RTM method. 【0037】 The manufacturing method of the fiber structure 10 according to this embodiment has the following effects: (1) A first mandrel 30A is arranged along the axial direction, and the first mandrel 30A and the second mandrel 30B each have at least a cylindrical portion 31 and a disc portion 32 whose circumference is longer than that of the cylindrical portion 31. In the first weaving process 20A, the first fiber structure 16A is woven. In the transition process 21, the axial yarn 13 and circumferential yarn 14 are transferred to the second mandrel 30B, which is arranged in the axial direction of the first mandrel 30A, in an uncut state, and the second fiber structure 16B is woven thereafter. Therefore, when weaving the first fiber structure 16A and the second fiber structure 16B in succession, it is not necessary to fix the starting end of the axial yarn 13 to the second mandrel 30B. As a result, when manufacturing multiple fiber structures 16, the work of fixing the axial yarn 13 to the mandrel 30 can be reduced, thereby increasing the manufacturing efficiency of the fiber structure 10. 【0038】 (2) The tubular weaving process 25 and the annular weaving process 24 are repeated in succession to form a continuous woven body 15 containing a plurality of fiber structures 16. Therefore, the axial threads 13 are not cut during the weaving of the first fiber structure 16A and the second fiber structure 16B, and weaving is not interrupted by the cutting of the axial threads 13, thereby increasing the manufacturing efficiency of the fiber structure 10. 【0039】(3) In the non-weaving process 26 after weaving the first fiber structure 16A, a plurality of axial yarns 13 are arranged along the axial direction of the disc portion 32, and a non-weaving portion 27 is formed in which circumferential yarns 14 are arranged along the axial direction of the disc portion 32 and extend from the first fiber structure 16A. By forming the non-weaving portion 27, the second fiber structure 16B can be continuously woven following the first fiber structure 16A without cutting the axial yarns 13. 【0040】 (4) The disc portion 32 has an outer peripheral surface 34 and an annular end surface 35, the annular end surface 35 being a conical inclined surface that is inclined with respect to the axial direction. Since the disc portion 32 of the mandrel 30 is provided with an annular end surface 35, it is possible to weave a fiber structure 16 having annular portions 12 at both ends of the cylindrical portion 11. 【0041】 (5) The method for manufacturing the fiber structure 10 includes a shaping step 23 in which the fiber structure 16 obtained by cutting the continuous woven body 15 is shaped. Therefore, by shaping the fiber structure 16 obtained by cutting the continuous woven body 15, a fiber structure 10 of a desired shape can be obtained. 【0042】 (6) By forming non-woven sections 27 on the continuous woven body 15, the cutting of the fiber structure 16 in the cutting process 22 becomes easier. The longer the axial length of the non-woven section 27, the wider the range of cutting positions can be, and the less need there is to make the cutting position highly precise. 【0043】 (Modified Version) A modified version of this embodiment will now be described. In this modified version, it is possible to manufacture the fiber structure 50 shown in Figure 9. The fiber structure 50 has a tubular portion 11 and an annular portion 12 provided at one end of the tubular portion 11, while the other end does not have an annular portion 12. In this case, the weaving process 20 consists of a tubular portion weaving process 25, an annular portion weaving process 24, and a non-weaving process 26. A continuous woven body 51 including a pre-formed fiber structure 52 (first fiber structure 52A and second fiber structure 52B) having a funnel-shaped annular portion 12 is woven through the weaving process 20. The mandrel 53 (first mandrel 53A, second mandrel 53B) used for the fiber structure 52 according to the modified version has, for example, a cylindrical portion 31 and a disc portion 32 provided at only one end of the cylindrical portion 31. 【0044】 In the cutting step 22, when the first fiber structure 52A and the second fiber structure 52B are cut out from the continuous woven body 51, in the subsequent shaping step 23, the first fiber structure 52A and the second fiber structure 52B are each shaped, and a plurality of fiber structures 10 are obtained. The annular part weaving step 24 is the second annular part weaving step 24B, but it may be the first annular part weaving step 24A. 【0045】 (Second Embodiment) Next, a method for manufacturing a fiber structure according to the second embodiment will be described. In this embodiment, the shape of the mandrel and the weaving process are different from those of the first embodiment. For the same configurations as those in the first embodiment in this embodiment, the descriptions in the first embodiment are incorporated and common reference numerals are used. 【0046】 As shown in FIG. 10, the weaving process 60 in the manufacturing method of this embodiment can be distinguished into a first weaving process 60A for weaving the first fiber structure 16A and a second weaving process 60B for weaving the second fiber structure 16B after the weaving of the first fiber structure 16A. The first weaving process 60A and the second weaving process 60B are composed of a first annular part weaving process 24A, a cylindrical part weaving process 25, and a second annular part weaving process 24B. Although this embodiment does not have a non-woven process 26, the initial weaving in the first annular part weaving process 24A of the second weaving process 60B corresponds to a transition process. The continuous woven body 61 of this embodiment is woven by using a plurality of mandrels 62. As shown in FIG. 11(a), the first mandrel 62A and the second mandrel 62B have a cylindrical part 31 and a conical disk part 63. The disk part 63 is a part having a circumference longer than that of the cylindrical part 31. In this embodiment, disk parts 63 are provided at both ends of the cylindrical part 31 respectively. The disk part 63 includes a circular end face 64 serving as an end face and an annular end face 65 whose circumference becomes longer from the outer peripheral surface 33 of the cylindrical part 31 toward the circular end face 64. The disk part 63 is a part having a circumference longer than that of the cylindrical part 31. The annular end face 65 of the disk part 63 is a surface corresponding to the annular part 12 of the fiber structure 10. 【0047】As shown in Fig. 11(b), the continuous woven body 61 of this embodiment is composed only of a plurality of fiber structures 16 before shaping, and does not have a non-woven part 27. The plurality of continuous woven bodies 61 are woven by repeating the first annular part weaving process 24A, the cylindrical part weaving process 25, and the second annular part weaving process 24B. That is, in the weaving of the continuous woven body 61, the first annular part weaving process 24A follows the second annular part weaving process 24B. In the cutting process 22 after weaving, by cutting between the annular parts 12, a plurality of fiber structures 16 are obtained. By shaping all the fiber structures 16 obtained by cutting, the fiber structure 10 can be obtained. 【0048】 The manufacturing method of the fiber structure 10 according to this embodiment has the same effect as the effect (1) of the first embodiment. Also, since the non-woven part 27 is not formed in the continuous woven body 61, the consumption amount of the axial yarn 13 and the circumferential yarn 14 can be suppressed as compared with the case of cutting the continuous woven body 15 provided with the non-woven part 27. 【0049】 (Third Embodiment) Next, a method for manufacturing a fiber structure according to the third embodiment will be described. In this embodiment, the shape of the mandrel and the weaving process are different from those of the first embodiment, and there is no shaping process. In this embodiment, for the same configuration as that of the first embodiment, the description of the first embodiment is incorporated and common reference numerals are used. 【0050】 As shown in Fig. 12, the manufacturing method of the fiber structure 50 of this embodiment includes a weaving process 70 for forming a continuous woven body 71 and a cutting process 72 for cutting the continuous woven body 71. The weaving process 70 can be distinguished into a first weaving process 70A for weaving the first fiber structure 50A and a second weaving process 70B for weaving the second fiber structure 50B after the weaving of the first fiber structure 50A. The first fiber structure 50A and the second fiber structure 50B are basically the same in shape. The continuous woven body 71 is a woven body including the fiber structure 50 and the non-woven part 27. The fiber structure 50 has the same configuration as the modified example, but may be described separately from the first fiber structure 50A and the second fiber structure 50B. 【0051】Next, the weaving of the continuous woven body 71 in the weaving process 70 will be described in detail. In this embodiment, the continuous woven body 71 is woven using a first mandrel 73A and a second mandrel 73B. As shown in Figure 13, the first mandrel 73A and the second mandrel 73B each have a cylindrical portion 31 and a disc portion 74. The disc portion 74 is a part having a circumference longer than that of the cylindrical portion 31. In this embodiment, disc portions 74 are provided at both ends of the cylindrical portion 31. The disc portion 74 has an outer peripheral surface 75, an annular end surface 76 formed between the outer peripheral surface 75 and the outer peripheral surface 33 of the cylindrical portion 31, and a circular end surface 77 on the opposite side of the annular end surface 76. The annular end surface 76 and the circular end surface 77 are surfaces that are substantially perpendicular to the axial direction of the first mandrel 73A and the second mandrel 73B. 【0052】 The outer circumferential surface 75 is the surface corresponding to the non-woven portion 27 of the continuous woven body 71. Of the pair of annular end surfaces 76, one is the surface corresponding to the annular portion 12 of the first fiber structure 50A or the second fiber structure 50B, and the other is the surface corresponding to the non-woven portion 27. The cylindrical portion 31 and the disc portion 74 may be integrally formed or they may be separable from each other. 【0053】 The first mandrel 73A and the second mandrel 73B are connected in series according to the required number of fiber structures 50. The circular end faces 77 of the first mandrel 73A and the second mandrel 73B are connected to each other, so that the first mandrel 73A and the second mandrel 73B are connected in series concentrically. For example, if the continuous weaving body 71 is to contain five fiber structures 50, then five mandrels 73 should be connected. 【0054】The continuous weaving body 71 is woven using a circular loom 40. As shown in Figure 12, in the manufacturing method of the fiber structure 50, the first step is the tubular section weaving step 25 in the first weaving step 70A. In the tubular section weaving step 25, the starting end of the axial yarn 13 is fixed to the end of the cylindrical section 31 of the first mandrel 73A. In the tubular section weaving step 25, a plain weave structure is formed along the axial direction. In the tubular section weaving structure, the axial yarn 13 follows the axial direction on the outer surface 33 of the cylindrical section 31, and the circumferential yarn 14 in the tubular section weaving structure extends circumferentially on the outer surface 33 and also extends spirally in the axial direction, intersecting with the axial yarn 13. When the tubular section weaving reaches the end of the cylindrical section 31, the weaving of the tubular section 11 is completed. 【0055】 After weaving the tubular portion 11, the process proceeds to the annular portion weaving process 24, which weaves the annular portion 12. In the annular portion weaving process 24, a plain weave structure is formed along the annular end surface 76 of the disc portion 74. The circumferential yarns 14 rotate in a spiral shape in the radial direction, from the outer surface 33 of the cylindrical portion 31 to the outer surface 75 of the disc portion 74. In the annular portion 12, multiple axial yarns 13 extend radially outward, forming a woven structure with the spiral circumferential yarns 14. When the woven structure forming the annular portion 12 reaches the outer surface 75 of the disc portion 74, the weaving of the first fiber structure 50A is completed, and the annular loom 40 stops its opening movement. 【0056】 Next, in the transition process 21, which is the non-weaving process 26, the opening movement of the annular loom 40 is stopped, and multiple mandrels 73 are raised to form the non-weaving section 27. The axial yarns 13 that reach the outer circumferential surface 75 of the disc portion 74 extend along the axial direction on the outer circumferential surface 75. Even when the axial yarns 13 reach the circular end face 77, they continue to extend along the outer circumferential surface 75 of the disc portion 74 of the next (second) mandrel 73B. Furthermore, when the axial yarns 13 reach the annular end face 76, they extend along the annular end face 76 toward the radial center. 【0057】Meanwhile, the circumferential yarn 14 extends axially along the outer surface 75 as it is meant to. Even after reaching the circular end face 77, the circumferential yarn 14 continues to extend along the outer surface 75 of the disc portion 74 of the next (second) mandrel 73B. Furthermore, when the circumferential yarn 14 reaches the annular end face 76, it extends along the annular end face 76 toward the radial center. In the non-weaving process 26, the axial yarn 13 and the circumferential yarn 14 extend along the outer surface 75 and annular end face 76 of the second mandrel 73B without forming a woven structure. 【0058】 When the axial yarn 13, which moves radially towards the center along the annular end face 76, reaches the outer circumferential surface 33 of the cylindrical portion 31 in the second mandrel 73, the annular loom 40 resumes its opening motion. The resumption of the opening motion allows the axial yarn 13 and the circumferential yarn 14 to weave a tubular portion 11, which will become the second fiber structure 50B. Once the weaving of the tubular portion 11 is complete, the weaving of the annular portion 12 using the axial yarn 13 and the circumferential yarn 14 is continued, so that the continuous woven body 71 includes both the first fiber structure 50A and the second fiber structure 50B. A non-woven portion 27 is interposed between the first fiber structure 50A and the second fiber structure 50B. One end of the non-woven portion 27 in the axial direction is connected to the annular portion 12 of the previously formed fiber structure 50, and the other end is connected to the tubular portion 11 of the next formed fiber structure 50. Furthermore, in this embodiment, since the first fiber structure 50A is woven after the second fiber structure 50B, a non-woven portion 27 is interposed between the second fiber structure 50B and the first fiber structure 50A. 【0059】 Depending on the number of first fiber structures 50A and second fiber structures 50B contained in the continuous weaving body 71, the tubular section weaving process 25, the annular section weaving process 24, and the non-weaving process 26 are repeated, and multiple fiber structures 50 are continuously woven. After multiple fiber structures 50 have been continuously woven, the weaving process 70 ends with the annular section weaving process 24. Once the weaving process 70 is complete, the process proceeds to the cutting process 72. 【0060】In the cutting step 72, all axial threads 13 and circumferential threads 14 of the non-woven portion 27 in the continuous woven body 71 are cut by a cutter (not shown). After the axial threads 13 and circumferential threads 14 are cut, the mandrel 73 is removed. After the mandrel 73 is removed, the excess axial threads 13 and circumferential threads 14 are cut and removed to obtain a plurality of fiber structures 50. A fiber-reinforced composite material can be obtained by impregnating the obtained plurality of fiber structures 50 with, for example, a matrix resin. 【0061】 The manufacturing method of the fiber structure 50 according to this embodiment provides the same effects as the effects (1) and (2) of the first embodiment. Furthermore, even when using a mandrel 73 having an annular end face 76 that is substantially perpendicular to the axial direction of the mandrel 73, the shaping process can be omitted by forming the non-woven portion 27 on the outer peripheral surface 34 and the annular end face 76, thereby reducing the manufacturing cost of the fiber structure 50. 【0062】 (Fourth Embodiment) Next, a method for manufacturing a fiber structure according to the fourth embodiment will be described. This embodiment differs from the first embodiment in that a second mandrel is inserted into the non-woven portion formed after the first weaving process before proceeding to the second weaving process. In this embodiment, the same components as in the first embodiment will be described by referring to the explanation of the first embodiment and common reference numerals will be used. 【0063】 As shown in Figure 14, in this embodiment, the transition step 80 includes a mandrel insertion step 81 in addition to the non-weaving step 26. The mandrel insertion step 81 is a step of inserting a mandrel 30 into the non-weaving portion 27 that is formed after weaving of the fiber structure 16 before shaping. In this embodiment, the cutting step 22 for cutting out the first fiber structure 16A is performed in parallel with the second weaving step 20B. Therefore, the required number of first fiber structures 16A and second fiber structures 16B can be obtained by using only the first mandrel 30A and the second mandrel 30B. 【0064】The manufacturing method of the fiber structure 10 of this embodiment will now be described in detail. In this embodiment, in the first annular weaving process 24A, the starting end of the axial yarn 13 is fixed to the outer circumferential surface 34 of the disc portion 32 of the first mandrel 30A. As shown in Figure 15(a), the first fiber structure 16A is woven by the opening movement of the annular loom 40. Next, as shown in Figure 15(b), with the opening movement of the annular loom 40 stopped, the first mandrel 30A is raised to form a cylindrical non-woven portion 27. Next, as shown in Figure 15(c), the second mandrel 30B is inserted into the cylindrical non-woven portion 27 from below. As the second mandrel 30B is inserted into the non-woven portion 27, the axial yarn 13 is positioned on the outer circumferential surface 34 of the disc portion 32 of the second mandrel 30B. 【0065】 Next, as shown in Figure 15(d), weaving is started to form the woven portion C in order to fix the non-woven portion 27 to the second mandrel 30B. After fixing the non-woven portion 27 to the second mandrel 30B, weaving of the second fiber structure 16B using the second mandrel 30B is started. The axial yarns 13 and circumferential yarns 14 of the non-woven portion 27 are cut after the non-woven portion 27 is fixed to the second mandrel 30B. The cutting of the non-woven portion 27 may be performed immediately after the non-woven portion 27 is fixed, or it may be performed in parallel with the first annular portion weaving process 24A using the second mandrel 30B. In other words, after the non-woven portion 27 is fixed to the second mandrel 30B, it is possible to remove the first mandrel 30A and the first fiber structure 16A and weave the second fiber structure 16B in parallel. Alternatively, the first mandrel 30A may be removed from the first fiber structure 16A that has been separated by cutting the non-woven portion 27 during weaving. The removed first mandrel 30A may be set aside, for example, for weaving the next first fiber structure 16A. 【0066】As shown in Figure 15(e), the first fiber structure 16A and the second fiber structure 16B are obtained when the weaving of the second fiber structure 16B is completed. Furthermore, when weaving the fiber structure 16, the non-woven portion 27 is formed immediately following the weaving of the second fiber structure 16B, the first mandrel 30A which was removed after cutting the non-woven portion 27 is inserted into the non-woven portion 27, and weaving is performed using the first mandrel 30A. Then, the fiber structure 10 is obtained by shaping the first fiber structure 16A and the second fiber structure 16B. 【0067】 This embodiment provides the same effects as the first embodiment (1). Furthermore, this embodiment allows for the production of multiple fiber structures 16 without weaving a continuous woven body. Since cutting the non-woven portion 27 does not hinder the progress of the weaving process 20, efficient production of fiber structures 10 is possible. In addition, since the required number of fiber structures 16 can be produced using only two mandrels 30, it is not necessary to have a number of mandrels 30 corresponding to the number of fiber structures 16, thereby reducing the production cost of the fiber structures 10. Moreover, the work of fixing the starting end of the axial yarn 13 to the disc portion 32 of the mandrel 30 only needs to be done before weaving the first fiber structure 16. Before weaving the second and subsequent fiber structures 16, the mandrel 30 is inserted into the non-woven portion 27 and fixed by the woven portion C, so the work of fixing the starting end of the axial yarn 13 to the disc portion 32 of the mandrel 30 does not occur. Therefore, the cumbersome task of fixing the starting end of the axial yarn 13 to the disc portion 32 of the mandrel 30 can be greatly reduced, enabling the manufacture of a more efficient fiber structure 10. 【0068】 The present invention is not limited to the embodiments described above (including variations), and various modifications are possible within the scope of the invention. For example, it may be modified as follows. 【0069】○ In the above embodiments (including modified examples), the cases in which three or two fiber structures are woven are described as examples, but the invention is not limited thereto. There is no particular limit to the number of fiber structures woven, as long as there are multiples. The weaving process can be repeated according to the number of fiber structures woven. Also, when forming a continuous woven body, the number of fiber structures included in the continuous woven body can be multiple. ○ In the first to third embodiments (including modified examples), a continuous woven body containing multiple fiber structures is woven by weaving from one mandrel to the other in the axial direction of the mandrels with multiple mandrels connected, but the invention is not limited thereto. For example, as shown in Figure 16, a multilayer continuous woven body 90 may be formed by weaving from one mandrel to the other in the axial direction of the mandrel 30, and then weaving from the other mandrel to the first mandrel in the axial direction of the mandrel 30. By obtaining a multilayer continuous woven body 90, the required thickness of the fiber structure 16 can be reliably achieved. ○ In the above embodiments (including modified examples), the annular end face of the disc portion of the mandrel is exemplified as an inclined surface that is inclined with respect to the axial direction of the mandrel, or a surface that is substantially perpendicular to the axial direction, but it is not limited to these. The annular end face may be a curved surface that expands in a bell shape in the axial direction of the mandrel, or a curved surface that expands in a spindle shape in the axial direction of the mandrel. ○ In the above embodiments (including modified examples), the material of the mandrel was not described, but it may be made of resin in addition to metal. Also, the mandrel may be formed of a material that disappears with heat, for example. When a heat-dissipating mandrel is used, the work of removing the mandrel from the fiber structure can be omitted. 【0070】10, 50 Fiber structure 11 Tubular section 12 Annular section 13 Axial yarn 14 Circumferential yarn 15, 51, 71, 90 Continuous woven body 16, 52 Fiber structure (before shaping) 16A, 50A, 52A First fiber structure 16B, 50B, 52B Second fiber structure 20, 60, 70 Weaving process 20A, 60A, 70A First weaving process 20B, 60B, 70B Second weaving process 21, 80 Transition process 22, 72 Cutting process 23 Shaping process 24 Annular section weaving process 25 Tubular section weaving process 26 Non-woven process 27 Non-woven section 30, 53, 62, 73 Mandrel 30A, 53A, 62A, 73A First mandrel 30B, 53B, 62B, 73B Second mandrel 31 Cylindrical section 32, 63, 74 Disc section 33 Outer surface (cylindrical section) 34, 75 Outer surface (disc section) 35, 65, 76 Annular end surface (disc section) 36, 64, 77 Circular end surface (disc section) 40 Annular loom 41 Opening device 42 Heddles 43 Shuttle 81 Mandrel insertion process C Weaving section P Axis

Claims

1. A method for manufacturing a fiber structure woven with a plurality of axial threads extending along the axial direction over the entire axial length of the tubular portion and the annular portion, wherein the fiber structure comprises at least a tubular portion, an annular portion extending from the end of the tubular portion to increase in diameter and having a circumference longer than the circumference of the tubular portion, and circumferential threads extending spirally along the circumferential direction of the tubular portion and the annular portion, wherein a first mandrel and a second mandrel are prepared, each having at least a cylindrical portion and a disc portion having a circumference longer than that of the cylindrical portion, the first mandrel is positioned along the axial direction, the axial threads are arranged along the axial direction of the first mandrel, and the circumferential threads are intersected with the plurality of axial threads along the circumferential direction of the first mandrel to weave a first fiber structure, and a transfer step is made to transfer the axial threads and the circumferential threads in an uncut state to the second mandrel which is positioned in the axial direction of the first mandrel, A method for manufacturing a fiber structure, comprising: a second weaving step of arranging the axial yarns along the axial direction of the second mandrel and weaving a second fiber structure by intersecting the plurality of axial yarns with circumferential yarns along the circumferential direction of the second mandrel.

2. The method for manufacturing a fiber structure according to claim 1, characterized in that the first weaving step, the transition step, and the second weaving step are repeated in succession to form a continuous woven body including the first fiber structure and the second fiber structure.

3. The method for manufacturing a fiber structure according to claim 1 or 2, wherein the transition step is a step after the first weaving step, and includes a non-weaving step in which the plurality of axial yarns after weaving the first fiber structure are arranged along the axial direction of the disc portion of the second mandrel, and the circumferential yarns are arranged along the axial direction of the disc portion to form a non-woven portion extending from the first fiber structure, and the second fiber structure is woven after the non-weaving step.

4. The method for manufacturing a fiber structure according to claim 1 or 2, characterized in that the disc portion has an axial intersecting surface that intersects the axial direction and extends over the circumferential direction, and the axial intersecting surface comprises a conical inclined surface that is inclined with respect to the axial direction.

5. The method for manufacturing a fiber structure according to claim 2, characterized by comprising a shaping step for shaping the first fiber structure and the second fiber structure obtained by cutting the continuous woven body.

6. The method for manufacturing a fiber structure according to claim 2, characterized in that a multilayer continuous woven body is formed by weaving from one side to the other in the axial direction, and then weaving from the other side to the one side in the axial direction.

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