Charge and shaping method

Abstract

To provide a charge capable of efficiently absorbing tensile force or compressive force and a shaping method . Provided is a charge (1) in which fiber sheets (11) are laminated, from fiber sheet (11A) to fiber sheet (11N), each sheet containing a plurality of fibers (12) the direction of which is aligned. Each division (13) is arranged so as not to overlap any others in the lamination direction. When a line along the lamination direction passing through division (13A) is defined as a reference line (Ld), a region on one side of the reference line (Ld) in the fiber direction is defined as a first region (R1), and a region on the other side of the reference line (Ld) in the fiber direction is defined as a second region (R2), the divisions (13) are alternately arranged in the first region (R1) or the second region (R2) from fiber sheet (11B) toward fiber sheet (11N), and the divisions (13) are arranged so as to be farther from the reference line (Ld) moving toward the fiber sheet (11N).

Description

Charging and shaping method

[0001] The present disclosure relates to a charging and shaping method.

[0002] Structural members such as aircraft have arbitrary cross-sectional shapes. One method for manufacturing structural members obtains a target shape using a laminate formed by flatly laminating a plurality of fiber sheets (this is referred to as a "charge").

[0003] As structural members of aircraft, there are long components with varying cross-sectional shapes, and long members having contours, joggles, and kinks (for example, spars, stringers, etc.). When these components are molded and manufactured from a charge, it is necessary to bend in the longitudinal direction while shaping the cross-sectional shape. At this time, since each fiber sheet contained in the charge (specifically, the reinforcing fibers contained in the fiber sheet) does not have stretchability in the fiber direction, wrinkles may occur in the charge when the charge is shaped or bent.

[0004] Patent Document 1 discloses a technique for performing shaping and bending using a charge formed by laminating fiber sheets containing reinforcing fibers provided with split portions in order to suppress the occurrence of such wrinkles.

[0005] International Publication No. 2021 / 059421

[0006] For example, when shaping or bending is performed using the charge of Patent Document 1, friction acting between adjacent fiber sheets in the lamination direction may change irregularly or abruptly in the lamination direction, and there is a possibility that tensile force or compressive force cannot be efficiently absorbed.

[0007] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a charge and a shaping method capable of efficiently absorbing tensile force or compressive force.

[0008] In order to solve the above problems, the charge and the shaping method employ the following measures.

[0009] A charge according to one aspect of the present disclosure is a charge comprising a plurality of fiber sheets, from a first fiber sheet to a k-th fiber sheet, each containing a plurality of fibers aligned in direction (k: a natural number of 3 or more), wherein each fiber contained in each fiber sheet has one division portion, and each division portion is arranged so as not to overlap with each other in the stacking direction of the fiber sheets, and with a line along the stacking direction passing through the division portion contained in the first fiber sheet as a reference line, a region on one side of the reference line in the fiber direction is designated as a first region, and a region on the other side of the reference line in the fiber direction is designated as a second region, the division portions are arranged alternately in the first region or the second region from the second fiber sheet toward the k-th fiber sheet, and each division portion is arranged so as to move toward the k-th fiber sheet, away from the reference line.

[0010] A shaping method according to one aspect of the present disclosure is a shaping method using the above-described charge, wherein the divided portion contained in the first fiber sheet is aligned with the location where the compressive or tensile force is most applied.

[0011] According to this disclosure, tensile or compressive forces can be absorbed efficiently.

[0012] This is a perspective view of an example of a member obtained by shaping a charge according to one embodiment of the present disclosure. This is a cross-sectional view of a charge according to one embodiment of the present disclosure, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction. This is a partially enlarged view of part F3 shown in Figure 2. This is a partially enlarged view of part F4 shown in Figure 3. This is a partially enlarged view of part F5 shown in Figure 3. This is a cross-sectional view of a charge according to Modification 1, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction. This is a cross-sectional view of a charge according to Modification 2, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction. This is a cross-sectional view of a charge according to Modification 2, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction. This is a cross-sectional view of a charge according to Modification 3, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction. This is a cross-sectional view of a charge according to Modification 4, in a cross-section perpendicular to the direction perpendicular to the fiber direction and the lamination direction.

[0013] Hereinafter, a charging and shaping method according to one embodiment of this disclosure will be described with reference to the drawings.

[0014] [About the Member] Figure 1 shows an example of a member obtained by shaping the charge 1 of this embodiment (referred to as "member 100"). Member 100 includes, for example, a reference surface portion 110 that is elongated in a predetermined direction, a first surface portion 120 that is elongated in a predetermined direction and connected to the first long side of the reference surface portion 110, and a second surface portion 130 that is elongated in a predetermined direction and connected to the second long side of the reference surface portion 110. In the cross-section of member 100 with a cutting plane perpendicular to the predetermined direction, the first surface portion 120 intersects with the reference surface portion 110, and the second surface portion 130 intersects with the reference surface portion 110. Also, in the same cross-section, the first surface portion 120 and the second surface portion 130 extend in different directions (opposite directions) relative to the reference surface portion 110.

[0015] The reference surface portion 110 has an inclined portion 111 formed thereon, the thickness of which gradually changes along a predetermined direction. For convenience, the boundary line between the flat portion of the reference surface portion 110 and the inclined portion 111 is defined as boundary 111a and 111b. Boundaries 111a and 111b are formed only on one surface of the reference surface portion 110 (the surface facing forward in Figure 1). The other surface of the reference surface portion 110 (the surface facing away in Figure 1) is a flat surface. The thickness (plate thickness) of the reference surface portion 110 begins to decrease at boundary 111a and becomes constant again at boundary 111b.

[0016] The first surface portion 120 has an inclined portion 121 formed thereon, whose thickness gradually changes along a predetermined direction. The position and range of this inclined portion 121 correspond to the position and range of the inclined portion 111 of the reference surface portion 110. For convenience, the boundary lines between the flat portion of the first surface portion 120 and the inclined portion 121 are defined as boundaries 121a and 121b. The position of boundary 121a corresponds to boundary 111a of the reference surface portion 110, and the position of boundary 121b corresponds to boundary 111b of the reference surface portion 110. Furthermore, boundaries 121a and 121b are formed only on one surface of the first surface portion 120 (the surface facing upward in Figure 1). The other surface of the first surface portion 120 (the surface facing downward in Figure 1) is a flat surface. The thickness (plate thickness) of the first surface portion 120 begins to decrease at boundary 121a and becomes constant again at boundary 121b.

[0017] The second surface portion 130 has an inclined portion 131 formed thereon, whose thickness gradually changes along a predetermined direction. The position and range of this inclined portion 131 correspond to the position and range of the inclined portion 111 of the reference surface portion 110. For convenience, the boundary lines between the flat portion of the second surface portion 130 and the inclined portion 131 are defined as boundaries 131a and 131b. The position of boundary 131a corresponds to boundary 111a of the reference surface portion 110, and the position of boundary 131b corresponds to boundary 111b of the reference surface portion 110. Furthermore, boundaries 131a and 131b are formed only on one surface of the second surface portion 130 (the surface facing upward in Figure 1). The other surface of the second surface portion 130 (the surface facing downward in Figure 1) is a flat surface. The thickness (plate thickness) of the second surface portion 130 begins to decrease at boundary 131a and becomes constant again at boundary 131b.

[0018] [About the Charge] As shown in Figure 2, Charge 1 is formed by stacking multiple fiber sheets 11 in the stacking direction. In Figure 2, Charge 1 is formed by stacking fiber sheets 11 from fiber sheet 11A (first fiber sheet) to fiber sheet 11N. However, the number of stacked fiber sheets 11 can be changed as appropriate.

[0019] Charge 1 may include, in addition to fiber sheet 11, other fiber sheets with a fiber direction different from that of fiber sheet 11. Note that in Figure 2, only fiber sheet 11, which has a fiber direction of 0 degrees, is shown among the multiple fiber sheets included in Charge 1.

[0020] Each fiber sheet 11 is in sheet form. Each fiber sheet 11 contains multiple fibers. The multiple fibers 12 are aligned in their fiber direction and arranged parallel to a direction perpendicular to the lamination direction. Examples of the types of fibers 12 include reinforcing fibers such as carbon fibers and glass fibers. The fiber sheet 11 is impregnated with resin. Examples of resins used for impregnation include thermosetting resins (e.g., epoxy resin, polyimide, polyurethane, unsaturated polyester, etc.) and thermoplastic resins (e.g., polyamide, polyethylene, polystyrene, polyvinyl chloride, etc.).

[0021] In a predetermined region R0 of charge 1 along the fiber direction, each fiber 12 has one dividing portion 13. Here, the fiber 12 included in the fiber sheet 11A is defined as "fiber 12A," and similarly, fibers 12B to 12N are defined below. Furthermore, the dividing portion 13 included in fiber 12A is defined as "dividing portion 13A," and similarly, dividing portions 13B to 13N are defined below.

[0022] Each divided section 13 is arranged so as not to overlap with each other in the stacking direction across the entire range of charge 1.

[0023] Furthermore, each divided portion 13 is arranged in a predetermined region R0 from the fiber sheet 11B toward the fiber sheet 11N according to a predetermined rule. Specifically, when a line along the lamination direction passing through the divided portion 13A is defined as a reference line Ld, the region on one side of the reference line Ld in the fiber direction (left side in Figure 2) is defined as the first region R1, and the region on the other side of the reference line Ld in the fiber direction (right side in Figure 2) is defined as the second region R2, then (1) the divided portions 13 are alternately arranged in the first region R1 or the second region R2 toward the fiber sheet 11B (second fiber sheet) toward the fiber sheet 11N, and (2) each divided portion 13 is arranged so as it moves away from the reference line Ld toward the fiber sheet 11N from the fiber sheet 11A.

[0024] By arranging the divided sections 13 in this manner, the distance in the fiber direction between adjacent divided sections 13 in the stacking direction increases as you move towards the fiber sheet 11N. Therefore, the friction acting between adjacent fiber sheets 11 in the stacking direction increases as you move towards the fiber sheet 11N. Conversely, the friction acting between adjacent fiber sheets 11 in the stacking direction decreases as you move back from the fiber sheet 11N (towards the fiber sheet 11A). This will be explained in detail using Figures 3, 4, and 5 as examples. As shown in Figure 3, if we let D1 be the distance in the fiber direction between divided section 13A and divided section 13B adjacent to divided section 13A in the stacking direction, and D2 be the distance in the fiber direction between divided section 13B and divided section 13C adjacent to divided section 13B in the stacking direction, then D2 is greater than D1. Here, for example, we compare the case where (i) as shown in Figure 4, the left end of fiber sheet 11A and fiber sheet 11B (the left end in the predetermined region R0) is pulled to the left and the right end of fiber sheet 11A and fiber sheet 11B (the right end in the predetermined region R0) is pulled to the right, and the case where (ii) as shown in Figure 5, the left end of fiber sheet 11B and fiber sheet 11C (the left end in the predetermined region R0) is pulled to the left and the right end of fiber sheet 11B and fiber sheet 11C (the right end in the predetermined region R0) is pulled to the right. Fiber sheet 11A and fiber sheet 11B overlap by a distance D1, and fiber sheet 11B and fiber sheet 11C overlap by a distance D2. It is clear that the greater the overlapping distance (area), the greater the frictional force acting between the fiber sheets 11. Therefore, in the case of (ii) shown in Figure 5, the friction acting between the fiber sheets 11 is greater than in the case of (i) shown in Figure 4. Conversely, in the case of (i) shown in Figure 4, the friction acting between the fiber sheets 11 is smaller than in the case of (ii) shown in Figure 5.

[0025] In the forming process, the fiber sheets 11 are positioned so that their surfaces coincide with the reference surface portion 110, and then the fiber sheets 11 are stacked one by one. The fiber direction may also be aligned with the longitudinal direction of the member 100. At this time, the fiber sheets 11 are used as a reference to fold the portion corresponding to the first surface portion 120 and the portion corresponding to the second surface portion 130, using the fiber sheet 11 as a reference.

[0026] It is preferable to position the charge 1 such that the division portion 13A is located at the point where the compressive or tensile force along the fiber direction is most pronounced. Here, "located at the point where the compressive or tensile force is most pronounced" includes not only cases where the position of the division portion 13A perfectly coincides with the point where the compressive or tensile force is most pronounced, but also cases where the position of the division portion 13A is slightly offset from that point. In Figure 1, the points where the tensile force is most pronounced are the boundaries 121a and 131b located on the outermost surface of the charge 1. On the other hand, the surface opposite to the surface where boundaries 121a and 131b exist is a flat surface, so the compressive force acting on it is small or negligible. In other words, the tensile force decreases as you move away from the boundaries 121a and 131b in the lamination direction (thickness direction). In Figure 1, the points where the compressive force is most pronounced are the boundaries 121b and 131a located on the outermost surface of the charge 1. On the other hand, the surface opposite to the surface where boundaries 121b and 131a exist is a flat surface, so the compressive force acting on it is small or negligible. In other words, the tensile force decreases as you move away from the boundary 121b and boundary 131a in the stacking direction (thickness direction).

[0027] When a tensile force acts on the charge 1 in a predetermined region R0, the divided portion 13 is formed, for example, by cutting the fiber 12. On the other hand, when a compressive force acts on the charge 1 in the predetermined region R0, the divided portion 13 is formed, for example, by removing a portion of the fiber 12.

[0028] In the case of Figure 1, for example, a boundary 121a on one side of the first surface portion 120 (the side facing upward in Figure 1) and a boundary 121b on which a compressive force acts are formed. Therefore, the shape is designed so that a tensile force and a compressive force act on one side of the charge 1. In this case, two adjacent predetermined regions R0 are set in the charge 1, and the tensile force is absorbed in the first predetermined region R0 (the divided portion 13A included in the first predetermined region R0 is located at the boundary 121a), and the compressive force is absorbed in the second predetermined region R0 (the divided portion 13A included in the second predetermined region R0 is located at the boundary 121b). The same applies to the second surface portion 130.

[0029] [Effect] The friction acting between adjacent fiber sheets 11 in the lamination direction increases as you move from fiber sheet 11A to fiber sheet 11N. Conversely, the friction acting between adjacent fiber sheets 11 in the lamination direction decreases as you move from fiber sheet 11N to fiber sheet 11A, meaning that the fiber sheets 11 become easier to slide. Here, for example, by placing the fiber sheet 11 that is easiest to slide at the location where the greatest tensile or compressive force is applied, the tensile or compressive force can be absorbed efficiently, thus suppressing the occurrence of wrinkles. In particular, when shaping is performed such that tensile and compressive forces are applied to one side of charge 1, the tensile or compressive force can be absorbed efficiently.

[0030] [Modification 1] As described above, in the lamination direction (thickness direction), the tensile and / or compressive forces decrease as you move away from the boundary 121a and boundary 131b. Therefore, as shown in Figure 6, the divided portion 13 may be omitted for fibers 12 on which no tensile and / or compressive forces act or on which tensile and / or compressive forces can be ignored. In the case of Figure 6, the divided portion 13 for fibers 12M and 12N is omitted. Here, "tensile and / or compressive forces can be ignored" means, for example, that even if tensile and / or compressive forces act on the fiber 12, the tensile and / or compressive forces can be absorbed by the slight expansion and contraction of the fiber 12 itself.

[0031] This configuration prevents the fibers 12 contained in the fiber sheet 11 from being unnecessarily divided, thus preventing a decrease in the strength of charge 1.

[0032] [Modification 2] Each divided portion 13 only needs to be arranged toward the fiber sheet 11N according to a predetermined rule, and does not necessarily have to be arranged toward the fiber sheet 11N from the fiber sheet 11B according to a predetermined rule. In other words, the starting position of the regular arrangement of the divided portions 13 does not necessarily have to be divided portion 13B. In the case of Figures 7 and 8, each divided portion 13 is arranged toward the fiber sheet 11N from the fiber sheet 11D according to a predetermined rule in a predetermined region R0. In other words, the starting position of the regular arrangement of the divided portions 13 is divided portion 13D. However, the charge 1 is still positioned such that the position of the divided portion 13A coincides with the location where the compressive or tensile force along the fiber direction is most pronounced.

[0033] [Modification 3] As shown in Figure 9, the charge 1 comprises a first layer L1 and a second layer L2. The second layer L2 is stacked on the first layer L1 in the stacking direction. Each of the first layer L1 and the second layer L2 has the same configuration as the charge 1 in the embodiments up to Modification 2 described above. For distinction, a "′" has been added to each reference numeral corresponding to the second layer L2.

[0034] The first layer L1 and the second layer L2 are arranged symmetrically in the lamination direction. Therefore, the fiber sheet 11A and the fiber sheet 11A' face each other and are adjacent in the lamination direction. Such a charge 1 is useful for shaping such that a tensile or compressive force acts on the central region in the lamination direction (the region where the divided portion 13A and the divided portion 13A' are located).

[0035] [Modification 4] As shown in Figure 10, in Modification 3 (see Figure 9), fiber sheet 11A and fiber sheet 11A' may be made common. In this case, divided portion 13A and divided portion 13A' will be the same.

[0036] [Note] The disclosure described above can be understood, for example, as follows:

[0037] A charge (1) according to a first aspect of the present disclosure is a charge in which a plurality of fiber sheets (11) from a first fiber sheet (11A) to a k-th fiber sheet are laminated (k: a natural number of 3 or more), each fiber contained in each fiber sheet having one division portion (13), and each division portion is arranged so as not to overlap with each other in the lamination direction of the fiber sheets, and a line along the lamination direction passing through the division portion (13A) contained in the first fiber sheet is defined as a reference line (Ld), and a region on one side of the reference line in the fiber direction is defined as a first region (R1), and a region on the other side of the reference line in the fiber direction is defined as a second region (R2), and each division portion is alternately arranged in the first region or the second region toward the k-th fiber sheet from the second fiber sheet (12B), and each division portion is arranged so as to move toward the k-th fiber sheet, it moves away from the reference line.

[0038] Since each divided section is alternately arranged in the first or second region from the second fiber sheet toward the kth fiber sheet, and each divided section is arranged so as it moves toward the kth fiber sheet, the distance in the fiber direction between adjacent divided sections in the lamination direction increases toward the kth fiber sheet. Therefore, the friction acting between adjacent fiber sheets in the lamination direction increases toward the kth fiber sheet. Conversely, the friction acting between adjacent fiber sheets in the lamination direction decreases as you move away from the kth fiber sheet, that is, the fiber sheets become easier to slide. Here, for example, by placing the fiber sheet that slides most easily at the location where the greatest tensile or compressive force is applied, the tensile or compressive force can be absorbed efficiently, thus suppressing the occurrence of wrinkles. In particular, when shaping is performed such that tensile and compressive forces act on one side of the charge, the tensile or compressive force can be absorbed efficiently.

[0039] In the charge (1) according to a second aspect of the present disclosure, in the first aspect, each of the divisions is arranged to move away from the reference line as it moves from the second fiber sheet toward the k fiber sheet.

[0040] Since each divided portion is arranged so as to be separated from the reference line as going from the second fiber sheet toward the k-th fiber sheet, the friction acting between fiber sheets adjacent to each other in the lamination direction decreases as going from the k-th fiber sheet toward the first fiber sheet, that is, the fiber sheets are facilitated to slide.

[0041] In the charge (1) according to the third aspect of the present disclosure, in the first aspect or the second aspect, a (k+1)-th fiber sheet including a plurality of fibers with aligned directions is laminated on the k-th fiber sheet, and each of the fibers included in the (k+1)-th fiber sheet does not have a divided portion.

[0042] Since each fiber included in the (k+1)-th fiber sheet does not have a divided portion, for example, by arranging the (k+1)-th fiber sheet on a side where no tensile force and / or compressive force acts, or a side where tensile force and / or compressive force can be ignored, the fibers included in the fiber sheet are prevented from being unnecessarily divided, and a reduction in the strength of the charge is prevented.

[0043] The shaping method according to the fourth aspect of the present disclosure is a shaping method using a charge according to any one of the first to third aspects, wherein the divided portion included in the first fiber sheet is aligned with locations (121a, 121b, 131a, 131b) on which compressive force or tensile force acts most.

[0044] Since the divided portion included in the first fiber sheet is aligned with the location on which compressive force and / or tensile force acts most, tensile force or compressive force can be absorbed efficiently, and generation of wrinkles is efficiently suppressed.

[0045] 1 Charge 11 (11A to 11N) Fiber sheet 12 (12A to 12N) Fiber 13 (13A to 13N) Divided portion 11' (11A' to 11G') Fiber sheet 12' (12A' to 12G') Fiber 13' (13A' to 13G') Divided portion L1 First layer L2 Second layer Ld Reference line R0 Predetermined region R1 First region R2 Second region 100 Member 110 Reference surface portion 111 Inclined portion 111a Boundary 111b Boundary 120 First surface portion 121 Inclined portion 121a Boundary 121b Boundary 130 Second surface portion 131 Inclined portion 131a Boundary 131b Boundary

Claims

1. A charge comprising a plurality of fiber sheets, from a first fiber sheet to a k-th fiber sheet, each containing a plurality of fibers aligned in direction (k: a natural number of 3 or more), wherein each fiber contained in each fiber sheet has one division portion, and each division portion is arranged so as not to overlap with each other in the stacking direction of the fiber sheets, and with a line along the stacking direction passing through the division portion contained in the first fiber sheet as a reference line, the region to one side of the reference line in the fiber direction is designated as the first region, and the region to the other side of the reference line in the fiber direction is designated as the second region, wherein each division portion is alternately arranged in the first region or the second region toward the k-th fiber sheet, and each division portion is arranged so as it moves toward the k-th fiber sheet.

2. The charge according to claim 1, wherein each of the divisions is arranged to move away from the reference line as it moves from the second fiber sheet toward the k fiber sheet.

3. The charge according to claim 1, wherein a (k+1) fiber sheet containing a plurality of fibers aligned in direction is laminated on the k fiber sheet, and each of the fibers contained in the (k+1) fiber sheet does not have a divided portion.

4. A shaping method using a charge according to any one of claims 1 to 3, wherein the divided portion contained in the first fiber sheet is aligned with the location where the compressive force or tensile force is most applied.

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