Molding die, shaping method, and method for designing molding die

Abstract

Provided are a molding die, a shaping method, and a method for designing the molding die enabling reduction of compression or tension generated in a laminate even when a peripheral length is limited. When a position where a kink line (111) is present in the Z-axis direction is a kink position (Zk), a position separated from the kink position (Zk) in the Z-axis direction is a separated position (Zs), a position between the kink position (Zk) and the separated position (Zs) in the Z-axis direction is an intermediate position (Zm), and the length of a connection surface (130) in a cross section orthogonal to the Z-axis is a circumferential length, the circumferential length at the kink position (Zk) is greater than the circumferential length at the separated position (Zs), and the circumferential length at the intermediate position (Zm) is less than the circumferential length at the intermediate position (Zm) of when the circumferential length linearly decreases from the kink position (Zk) to the separated position (Zs).

Description

Molding die, shaping method and molding die designing method

[0001] The present disclosure relates to a molding die, a shaping method and a molding die designing method.

[0002] Some aircraft components such as aircraft fuselages and main wings use composite materials, for example, carbon fiber reinforced plastic (CFRP). A CFRP-made structural member (composite structure) constituting an aircraft component has an arbitrary cross-sectional shape. As one of the methods for manufacturing such a composite structure, a laminate (also referred to as a "charge") is produced by laminating a plurality of fiber sheets (e.g., prepregs), and the laminate is shaped using a molding die, thereby imparting an arbitrary shape to the laminate.

[0003] One of such shapes is a kink shape. A molding die used when shaping a laminate into a kink shape has a bent kink surface and a flat plane intersecting (for example, orthogonal to) the kink surface.

[0004] When shaping the laminate using the molding die, if the laminate superimposed on the kink surface of the molding die is bent toward the flat plane of the molding die, the laminate is compressed on the flat plane, which causes strain and may generate wrinkles in the laminate. Such wrinkles are undesirable because they significantly reduce the strength of the component.

[0005] As a molding die for shaping a laminate into a kink shape, for example, there is a molding die disclosed in Patent Document 1.

[0006] Japanese Patent No. 4773713

[0007] In Patent Document 1, two surfaces are connected by a fillet surface. However, if the radius and radius of curvature of the fillet surface are at their maximum design values, the radius and radius of curvature cannot be increased further, and the perimeter of the fillet surface cannot be made long enough to absorb the compression that occurs in the laminate. Here, "if the radius of curvature of the fillet surface is at its maximum design value" refers to a situation where, for example, in a case where a large kink surface or flat surface of the molded product must be secured due to its connection with other parts, increasing the radius of curvature of the fillet surface further would reduce the kink surface and / or flat surface, making it impossible to secure the area necessary for connection with other parts.

[0008] This disclosure is made in view of these circumstances and aims to provide a mold, a shaping method, and a mold design method that can reduce compression or tension occurring in a laminate even when there are limitations on the circumference.

[0009] To solve the above problems, the mold, shaping method, and mold design method of this disclosure employ the following means.

[0010] A mold according to one aspect of the present disclosure comprises a first surface on which a laminate of multiple fiber sheets is superimposed, a second surface on which the laminate superimposed on the first surface is superimposed by bending the laminate, and a third surface connecting the first surface and the second surface, wherein when three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis, the first surface is bent convexly or concavely in the direction of the Y-axis by a kink line extending along the direction of the X-axis, the second surface intersects with the direction of the X-axis, and the third surface is curved convexly outward, and when the position where the kink line exists in the direction of the Z-axis is defined as the kink position, the position away from the kink position in the direction of the Z-axis is defined as the separation position, the position between the kink position and the separation position in the direction of the Z-axis is defined as the intermediate position, and the length of the third surface in a cross-section perpendicular to the Z-axis is defined as the circumference, (i) When the first surface is convex, the perimeter at the kink position is longer than the perimeter at the separation position, and the perimeter at the intermediate position is shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position. (ii) When the first surface is concave, the perimeter at the kink position is shorter than the perimeter at the separation position, and the perimeter at the intermediate position is longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position.

[0011] A shaping method according to one aspect of the present disclosure is a shaping method for shaping a laminate using the above-described mold, comprising the steps of: overlapping the laminate onto the first surface; and bending the laminate, which is overlapped onto the first surface, toward the second surface along the third surface.

[0012] A mold design method according to one aspect of the present disclosure comprises a first surface on which a laminate of multiple fiber sheets is stacked, a second surface on which the laminates stacked on the first surface are stacked by bending the laminates stacked on the first surface, and a third surface connecting the first surface and the second surface, wherein when three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis, the first surface is bent convexly or concavely in the direction of the Y-axis by a kink line extending along the direction of the X-axis, the second surface intersects with the direction of the X-axis, and the third surface is curved convexly outward, wherein the position where the kink line exists in the direction of the Z-axis is defined as the kink position, the position away from the kink position in the direction of the Z-axis is defined as the separation position, the position between the kink position and the separation position in the direction of the Z-axis is defined as the intermediate position, and the length of the third surface in a cross-section perpendicular to the Z-axis is defined as the circumference. (i) If the first surface is convex, the perimeter at the kink position is made longer than the perimeter at the separation position, and the perimeter at the intermediate position is made shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position; (ii) If the first surface is concave, the perimeter at the kink position is made shorter than the perimeter at the separation position, and the perimeter at the intermediate position is made longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position.

[0013] According to this disclosure, compression or tension occurring in the laminate can be reduced even when there are limitations on the circumference.

[0014] This is a perspective view showing the process of shaping a charge using a mold according to the first embodiment of this disclosure. This is a perspective view of the mold according to the first embodiment of this disclosure. This is a partially enlarged view of the mold in Figure 2. This is a perspective view of a mold according to a comparative example. This is a perspective view of a mold according to a comparative example (showing fiber direction). This is a perspective view of a mold according to the first embodiment of this disclosure (showing fiber direction). This is a perspective view of a mold according to the second embodiment of this disclosure. This is a partially enlarged view of the mold in Figure 7. This is a perspective view of a mold according to a comparative example (showing fiber direction). This is a perspective view of a mold according to the second embodiment of this disclosure (showing fiber direction).

[0015] Hereinafter, a first or second embodiment of the mold and shaping method relating to this disclosure will be described with reference to the drawings. In the following description, the three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis.

[0016] [First Embodiment] As shown in Figure 1, the mold 100 is for shaping a flat laminate (charge) 10 which is composed of multiple fiber sheets stacked together.

[0017] A fiber sheet, for example, contains multiple reinforcing fibers aligned so that their fiber directions are parallel to each other. Examples of fiber sheets include prepregs, in which reinforcing fibers are pre-impregnated with resin, and dry sheets, which are composed of reinforcing fibers and are not pre-impregnated with resin. Examples of fibers include carbon fibers and glass fibers. Examples of resins include thermosetting resins (e.g., epoxy resins, polyimides, polyurethanes, unsaturated polyesters) and thermoplastic resins (e.g., polyamides, polyethylenes, polystyrenes, polyvinyl chlorides).

[0018] As shown in Figure 2, the mold 100 includes a kink surface (first surface) 110, a flat surface (second surface) 120, and a connecting surface (third surface) 130.

[0019] The kink surface 110 is a mountain-shaped surface that is bent convexly in the Y-axis direction by a kink line 111 extending along the X-axis direction. In Figure 1, the kink surface 110 is formed by two flat surfaces connected by the kink line 111 in a relatively inclined state. When viewing the mold 100 along the X-axis direction, the kink surface 110 is symmetrical, for example, in the Z-axis direction. As shown in Figure 1, the kink surface 110 is the surface to which the charge 10 is first superimposed during the shaping of the charge 10.

[0020] As shown in Figure 2, plane 120 is a flat surface intersecting the X-axis direction. In the case of Figure 2, plane 120 is perpendicular to the X-axis direction. When viewing the mold 100 along the X-axis direction, plane 120 is located opposite to the direction in which the kink surface 110 is convex. When viewing the mold 100 along the X-axis direction, plane 120 has a shape that is symmetrical, for example, with respect to the Z-axis direction. As shown in Figure 1, plane 120 is the surface on which the charge 10 is superimposed when the charge 10 is folded over the kink surface 110 during the shaping of the charge 10.

[0021] As shown in Figure 2, the connecting surface 130 is a surface that is curved outward and convex, connecting the kink surface 110 and the plane 120. The connecting surface 130 has a shape that is symmetrical, for example, with respect to the Z-axis direction when the mold 100 is viewed along the X-axis direction.

[0022] Here, the boundary line between the kink surface 110 and the connecting surface 130 is defined as "boundary line L11," and the boundary line between the plane 120 and the connecting surface 130 is defined as "boundary line L12." The length of the connecting surface 130 in a cross-section perpendicular to the Z-axis is called the "perimeter." In Figure 2, the cross-section at an arbitrary position Zz in the direction of the Z-axis is shown by cross-hatching. In this cross-section, the distance / length along the connecting surface 130 from boundary line L11 to boundary line L12 is the "perimeter."

[0023] As shown in Figures 2 and 3, (1) the position where the kink line 111 exists in the Z-axis direction is defined as the kink position Zk, (2) the position away from the kink position Zk in the Z-axis direction is defined as the separation position Zs, and (3) the position between the kink position Zk and the separation position Zs in the Z-axis direction is defined as the intermediate position Zm. Note that the separation position Zs does not necessarily have to be the position of the end / end face of the mold 100 in the Z-axis direction. Also, the intermediate position Zm does not necessarily have to be the midpoint between the kink position Zk and the separation position Zs, but can be any position between the kink position Zk and the separation position Zs.

[0024] In the mold 100 of this embodiment, the perimeter at the kink position Zk is longer than the perimeter at the separation position Zs. Here, as shown in Figure 3, the point on the boundary line L11 at the kink position Zk is defined as "endpoint Pk1", the point on the boundary line L12 at the kink position Zk is defined as "endpoint Pk2", the point on the boundary line L11 at the separation position Zs is defined as "endpoint Ps1", and the point on the boundary line L12 at the separation position Zs is defined as "endpoint Ps2". In this case, the perimeter at the kink position Zk is the distance / length along the connecting surface 130 from end point Pk1 to end point Pk2, and the perimeter at the separation position Zs is the distance / length along the connecting surface 130 from end point Ps1 to end point Ps2.

[0025] A hypothetical line segment connecting endpoint Pk1 and endpoint Ps1 is defined as "line segment Lv11," and a hypothetical line segment connecting endpoint Pk2 and endpoint Ps2 is defined as "line segment Lv12." In Figure 3, each line segment is represented by a dashed line. Line segment Lv11 slopes linearly from endpoint Pk1 to endpoint Ps1 when the mold 100 is viewed from, for example, the X-axis direction. Similarly, line segment Lv12 slopes linearly from endpoint Pk2 to endpoint Ps2 when the mold 100 is viewed from, for example, the X-axis direction. Line segments Lv11 and Lv12 are not parallel to each other and gradually approach each other towards the separation position Zs. Therefore, the hypothetical perimeter from the kink position Zk to the separation position Zs becomes linearly smaller (shorter).

[0026] In the mold 100 of this embodiment, the perimeter at the intermediate position Zm is shorter than the aforementioned hypothetical perimeter (the perimeter at the same intermediate position Zm when the perimeter decreases linearly from the kink position Zk to the separation position Zs). Here, a point on the boundary line L11 at the intermediate position Zm is defined as "endpoint Pm1", and a point on the boundary line L12 at the intermediate position Zm is defined as "endpoint Pm2". In this case, the perimeter at the intermediate position Zm is the distance / length along the connecting surface 130 from endpoint Pm1 to endpoint Pm2.

[0027] Boundary line L11 is a line (for example, a bent line or a curved line) that passes through the three endpoints Pk1, Pm1, and Ps1. Similarly, boundary line L12 is a line (for example, a bent line or a curved line) that passes through the three endpoints Pk2, Pm2, and Ps2. Here, when viewing the mold 100 along the Y-axis, boundary line L11 bulges convexly away from line segment Lv11 and approaches the plane 120. Similarly, when viewing the mold 100 along the X-axis, boundary line L12 bulges convexly away from line segment Lv12 and approaches the kink surface 110. Furthermore, boundary line L11 from endpoint Pk1 to endpoint Pm1 and boundary line L12 from endpoint Pk2 to endpoint Pm2 are not parallel. Furthermore, the boundary line L11 from endpoint Pm1 to endpoint Ps1 and the boundary line L12 from endpoint Pm2 to endpoint Ps2 are not parallel.

[0028] [Effect] Figure 4 shows a mold 300 as a comparative example. The mold 300 includes a kink surface 310 on which a kink line 311 is formed, a flat surface 320, and a connecting surface 330. The configuration of the kink surface 310 and the flat surface 320 is the same as the configuration of the kink surface 110 and the flat surface 120 of the mold 100. On the other hand, the perimeter of the connecting surface 330 decreases linearly from the kink position Zk to the separation position Zs. In other words, the perimeter of the connecting surface 330 is set to what is called a "virtual perimeter" in the mold 100. Therefore, the boundary line L31 between the kink surface 310 and the connecting surface 330 coincides with what is called a "virtual line segment Lv11" in the mold 100, and the boundary line L32 between the flat surface 320 and the connecting surface 330 coincides with what is called a "virtual line segment Lv12" in the mold 100.

[0029] As shown in Figure 5, when the charge 10 is formed using the mold 300, compression occurs in the charge 10 such that the fibers overlap at the kink position Zk on the plane 320. In particular, the degree of compression is more pronounced in the region closer to the fiber tips. This compression of the charge 10 is relieved as the circumference at the kink position Zk becomes longer than the circumference at the separation position Zs (or as the circumference at the separation position Zs becomes shorter than the circumference at the kink position Zk). However, if there is a limit to the maximum circumference at the kink position Zk (or a limit to the minimum circumference at the separation position Zs) due to the relationship with other parts, the compression of the charge 10 may not be completely relieved. Note that the solid line indicated by FO in Figure 5 represents the fiber direction (the same applies to Figure 6).

[0030] Therefore, in this embodiment, as shown in Figure 3, the perimeter at the intermediate position Zm is made shorter than the virtual perimeter at the same intermediate position Zm. As a result, as shown in Figure 6, compared to the case where the perimeter decreases linearly from the kink position Zk to the separation position Zs, the charge 10 superimposed on the plane 120 at the intermediate position Zm is slightly compressed in the Z-axis direction. Consequently, the compression of the charge 10 occurring at the kink position Zk, which is located laterally to the intermediate position Zm in the Z-axis direction, is mitigated. In other words, the compression of the charge 10 occurring at the kink position Zk is distributed in the Z-axis direction. Therefore, even if there is a limit to the maximum perimeter at the kink position Zk, for example, the compression occurring in the charge 10 at the kink position Zk can be reduced.

[0031] The circumference at the kink position Zk and / or separation position Zs is determined by taking into consideration at least the shape of other parts that will be attached to the part molded from the charge 10 using the mold 100.

[0032] [Second Embodiment] The mold 200 of this embodiment is a mold 100 of the first embodiment in which the shape of the kink surface 110 has changed from a mountain shape to a valley shape.

[0033] As shown in Figure 7, the mold 200 includes a kink surface (first surface) 210, a flat surface (second surface) 220, and a connecting surface (third surface) 230.

[0034] The kink surface 210 is a valley-shaped surface bent concavely in the Y-axis direction by a kink line 211 extending along the X-axis direction. In Figure 7, the kink surface 210 is formed by two flat surfaces connected by the kink line 211 in a relatively inclined state. When viewing the mold 200 along the X-axis direction, the kink surface 210 is symmetrical, for example, in the Z-axis direction. The kink surface 210 is the surface to which the charge 10 is first superimposed during the shaping of the charge 10.

[0035] Plane 220 is a flat surface intersecting the X-axis direction. In the case of Figure 7, plane 220 is perpendicular to the X-axis direction. When viewing the mold 200 along the X-axis direction, plane 220 is located opposite to the direction in which the kink surface 210 is concave. When viewing the mold 200 along the X-axis direction, plane 220 has a shape that is symmetrical, for example, with respect to the Z-axis direction. Plane 220 is the surface on which the charge 10 is superimposed when the charge 10 is folded over the kink surface 210 during the shaping of the charge 10.

[0036] The connecting surface 230 is a surface that is curved outward and convex, connecting the kink surface 210 and the plane 220. The connecting surface 230 has a shape that is symmetrical, for example, with respect to the Z-axis when the mold 200 is viewed along the X-axis.

[0037] Here, the boundary line between the kink surface 210 and the connecting surface 230 is defined as "boundary line L21," and the boundary line between the plane 220 and the connecting surface 230 is defined as "boundary line L22." The length of the connecting surface 230 in a cross-section perpendicular to the Z-axis is called the "perimeter." In Figure 7, the cross-section at an arbitrary position Zz in the direction of the Z-axis is shown by cross-hatching. In this cross-section, the distance / length along the connecting surface 230 from boundary line L21 to boundary line L22 is the "perimeter."

[0038] As shown in Figures 7 and 8, (1) the position where the kink line 211 exists in the Z-axis direction is defined as the kink position Zk, (2) the position away from the kink position Zk in the Z-axis direction is defined as the separation position Zs, and (3) the position between the kink position Zk and the separation position Zs in the Z-axis direction is defined as the intermediate position Zm. Note that the separation position Zs does not necessarily have to be the position of the end / end face of the mold 200 in the Z-axis direction. Also, the intermediate position Zm does not necessarily have to be the midpoint between the kink position Zk and the separation position Zs, but can be any position between the kink position Zk and the separation position Zs.

[0039] In the mold 200 of this embodiment, the perimeter at the kink position Zk is shorter than the perimeter at the separation position Zs. Here, as shown in Figure 8, the point on the boundary line L21 at the kink position Zk is defined as "endpoint Pk1", the point on the boundary line L22 at the kink position Zk is defined as "endpoint Pk2", the point on the boundary line L21 at the separation position Zs is defined as "endpoint Ps1", and the point on the boundary line L22 at the separation position Zs is defined as "endpoint Ps2". In this case, the perimeter at the kink position Zk is the distance / length along the connecting surface 230 from end point Pk1 to end point Pk2, and the perimeter at the separation position Zs is the distance / length along the connecting surface 230 from end point Ps1 to end point Ps2.

[0040] A hypothetical line segment connecting endpoint Pk1 and endpoint Ps1 is defined as "line segment Lv21," and a hypothetical line segment connecting endpoint Pk2 and endpoint Ps2 is defined as "line segment Lv22." In Figure 8, each line segment is represented by a dashed line. Line segment Lv21 slopes linearly from endpoint Pk1 to endpoint Ps1 when the mold 200 is viewed from, for example, the X-axis direction. Similarly, line segment Lv22 slopes linearly from endpoint Pk2 to endpoint Ps2 when the mold 200 is viewed from, for example, the X-axis direction. Line segments Lv21 and Lv22 are not parallel and gradually move away from each other towards the separation position Zs. Therefore, the hypothetical perimeter from the kink position Zk to the separation position Zs increases linearly (becomes longer).

[0041] In the mold 200 of this embodiment, the perimeter at the intermediate position Zm is longer than the aforementioned hypothetical perimeter (the perimeter at the same intermediate position Zm when the perimeter decreases linearly from the kink position Zk to the separation position Zs). Here, a point on the boundary line L21 at the intermediate position Zm is defined as "endpoint Pm1", and a point on the boundary line L22 at the intermediate position Zm is defined as "endpoint Pm2". In this case, the perimeter at the intermediate position Zm is the distance / length along the connecting surface 230 from endpoint Pm1 to endpoint Pm2.

[0042] Boundary line L21 is a line (for example, a bent or curved line) that passes through the three endpoints Pk1, Pm1, and Ps1. Similarly, boundary line L22 is a line (for example, a bent or curved line) that passes through the three endpoints Pk2, Pm2, and Ps2. Here, when viewing the mold 200 along the Y-axis, boundary line L21 bulges convexly away from line segment Lv21 and away from the plane 220. Similarly, when viewing the mold 200 along the X-axis, boundary line L22 bulges convexly away from line segment Lv22 and away from the kink surface 210. Furthermore, boundary line L21 from endpoint Pk1 to endpoint Pm1 and boundary line L22 from endpoint Pk2 to endpoint Pm2 are not parallel. Furthermore, the boundary line L21 from endpoint Pm1 to endpoint Ps1 and the boundary line L22 from endpoint Pm2 to endpoint Ps2 are not parallel.

[0043] [Effect] Figure 9 shows a mold 400 as a comparative example. The mold 400 includes a kink surface 410 on which a kink line 411 is formed, a flat surface 420, and a connecting surface 430. The configuration of the kink surface 410 and the flat surface 420 is the same as the configuration of the kink surface 210 and the flat surface 220 of the mold 200. On the other hand, the perimeter of the connecting surface 430 increases linearly from the kink position Zk to the separation position Zs. In other words, the perimeter of the connecting surface 430 is set to what is called a "virtual perimeter" in the mold 200. Therefore, the boundary line L41 between the kink surface 410 and the connecting surface 430 coincides with what is called a "virtual line segment Lv21" in the mold 200, and the boundary line L42 between the flat surface 420 and the connecting surface 430 coincides with what is called a "virtual line segment Lv22" in the mold 200.

[0044] When the charge 10 is shaped using the molding die 400, tension that separates fibers from each other occurs in the charge 10 at the kink position Zk of the flat surface 420. In particular, the degree of tension becomes more remarkable in a region closer to the tip of the fibers.

[0045] Therefore, in the present embodiment, the perimeter at the intermediate position Zm is set longer than the virtual perimeter at the same intermediate position Zm. As a result, as shown in FIG. 10, compared to the case where the perimeter increases linearly from the kink position Zk to the separated position Zs, the charge 10 superimposed on the flat surface 220 at the intermediate position Zm is slightly pulled in the Z-axis direction. Accordingly, the tension generated in the charge 10 at the kink position Zk located laterally of the intermediate position Zm in the Z-axis direction is conversely alleviated. In other words, the tension generated in the charge 10 at the kink position Zk is dispersed in the Z-axis direction. Therefore, even when there is a restriction on the minimum value of the perimeter at the kink position Zk, for example, the tension generated in the charge 10 at the kink position Zk can be reduced.

[0046] It should be noted that the perimeter at the kink position Zk and / or the separated position Zs is determined in consideration of at least the shape of other components attached to a component molded from the charge 10 using the molding die 200.

[0047] [Supplementary Note] The molding die, the shaping method, and the design method of the molding die according to one embodiment of the present disclosure described above can be grasped, for example, as follows.

[0048] The molding die (100, 200) according to the first aspect of the present disclosure comprises: a first surface (110, 210) on which a laminate (10) formed by laminating a plurality of fiber sheets is superimposed; a second surface (120, 220) on which the laminate is superimposed by bending the laminate superimposed on the first surface; and a third surface (130, 230) connecting the first surface and the second surface. When three mutually orthogonal axes are defined as an X-axis, a Y-axis, and a Z-axis, the first surface is convexly or concavely bent in the Y-axis direction at a kink line (111, 211) extending along the X-axis direction, the second surface intersects the X-axis direction, and the third surface is convexly curved toward the outside. When a position where the kink line exists in the Z-axis direction is defined as a kink position (Zk), a position separated from the kink position in the Z-axis direction is defined as a separated position (Zs), a position between the kink position and the separated position in the Z-axis direction is defined as an intermediate position (Zm), and the length of the third surface on a cut surface orthogonal to the Z-axis is defined as a perimeter: (i) when the first surface has a convex shape, the perimeter at the kink position is longer than the perimeter at the separated position, and the perimeter at the intermediate position is shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separated position; (ii) when the first surface has a concave shape, the perimeter at the kink position is shorter than the perimeter at the separated position, and the perimeter at the intermediate position is longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separated position.

[0049] When the first surface is convex, the perimeter at the kink position is longer than the perimeter at the separation position, and the perimeter at the intermediate position is shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position. Therefore, compared to the case where the perimeter decreases linearly from the kink position to the separation position, the laminate superimposed on the second surface at the intermediate position is slightly compressed in the Z-axis direction. This alleviates the compression of the laminate that occurs at the kink position located to the side of the intermediate position. In other words, the compression of the laminate that occurs at the kink position is distributed in the Z-axis direction. Therefore, even if there is a limit to the maximum perimeter at the kink position, for example, the compression that occurs in the laminate at the kink position can be reduced. When the first surface is concave, the perimeter at the kink position is shorter than the perimeter at the separation position, and the perimeter at the intermediate position is longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position. Therefore, compared to the case where the perimeter increases linearly from the kink position to the separation position, the laminate superimposed on the second surface at the intermediate position is slightly pulled in the Z-axis direction. This relieves the tension on the laminate that occurs at the kink position located laterally to the intermediate position. In other words, the tension on the laminate that occurs at the kink position is distributed in the Z-axis direction. Therefore, even if there is a limit to the minimum value of the perimeter at the kink position, for example, the tension generated in the laminate at the kink position can be reduced.

[0050] A shaping method according to a second aspect of the present disclosure is a shaping method for shaping a laminate using a mold described in the first aspect, comprising the steps of: overlapping the laminate onto the first surface; and bending the laminate, which is overlapped onto the first surface, toward the second surface along the third surface.

[0051] A mold design method according to a third aspect of the present disclosure comprises a first surface on which a laminate of multiple fiber sheets is superimposed, a second surface on which the laminate superimposed on the first surface is superimposed by bending the laminate, and a third surface connecting the first surface and the second surface, wherein when three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis, the first surface is bent convexly or concavely in the direction of the Y-axis by a kink line extending along the direction of the X-axis, the second surface intersects with the direction of the X-axis, and the third surface is curved convexly outward, wherein when the position where the kink line exists in the direction of the Z-axis is defined as the kink position, the position away from the kink position in the direction of the Z-axis is defined as the separation position, the position between the kink position and the separation position in the direction of the Z-axis is defined as the intermediate position, and the length of the third surface in a cross-section perpendicular to the Z-axis is defined as the circumference, (i) If the first surface is convex, the perimeter at the kink position is made longer than the perimeter at the separation position, and the perimeter at the intermediate position is made shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position; (ii) If the first surface is concave, the perimeter at the kink position is made shorter than the perimeter at the separation position, and the perimeter at the intermediate position is made longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position.

[0052] In the mold design method according to the fourth aspect of the present disclosure, in the third aspect, the perimeter at the kink position and / or the separation position is determined by taking into consideration at least the shape of other parts to be attached to the part molded from the laminate.

[0053] 10 Charge 100 Molding die 110 Kinked surface (1st surface) 111 Kinked line 120 Plane (2nd surface) 130 Connecting surface (3rd surface) 200 Molding die 210 Kinked surface (1st surface) 211 Kinked line 220 Plane (2nd surface) 230 Connecting surface (3rd surface) 300 Molding die (comparative example) 310 Kinked surface 311 Kinked line 320 Plane 330 Connecting surface 400 Molding die (comparative example) 410 Kinked surface 411 Kinked line 420 Plane 430 Connecting surface FO Fiber direction L11 Boundary line L12 Boundary line L21 Boundary line L22 Boundary line L31 Boundary line (comparative example) L32 Boundary line (comparative example) L41 Boundary line (comparative example) L42 Boundary line (comparative example) Lv11 line segment Lv12 line segment Lv21 line segment Lv22 line segment Pk1 endpoint Pk2 endpoint Pm1 endpoint Pm2 endpoint Ps1 endpoint Ps2 endpoint

Claims

1. A laminate comprising a first surface on which multiple fiber sheets are stacked is superimposed, a second surface on which the laminates are superimposed by bending the laminate superimposed on the first surface, and a third surface connecting the first surface and the second surface, wherein when the three mutually orthogonal axes are the X-axis, Y-axis, and Z-axis, the first surface is bent convex or concave in the direction of the Y-axis by a kink line extending along the direction of the X-axis, the second surface intersects with the direction of the X-axis, and the third surface is curved convexly outward, and when the position where the kink line exists in the direction of the Z-axis is defined as the kink position, the position away from the kink position in the direction of the Z-axis is defined as the separation position, the position between the kink position and the separation position in the direction of the Z-axis is defined as the intermediate position, and the length of the third surface in a cross-section perpendicular to the Z-axis is defined as the circumference, (i) When the first surface is convex, the perimeter at the kink position is longer than the perimeter at the separation position, and the perimeter at the intermediate position is shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position; (ii) When the first surface is concave, the perimeter at the kink position is shorter than the perimeter at the separation position, and the perimeter at the intermediate position is longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position; a mold.

2. A shaping method for shaping a laminate using the mold described in claim 1, comprising the steps of: overlapping the laminate onto a first surface; and bending the laminate, which is overlapped onto the first surface, toward the second surface along a third surface.

3. A mold design method comprising: a first surface on which a laminate of multiple fiber sheets is superimposed; a second surface on which the laminate superimposed on the first surface is superimposed by bending the laminate superimposed on the first surface; and a third surface connecting the first surface and the second surface, wherein when three mutually orthogonal axes are defined as the X-axis, Y-axis, and Z-axis, the first surface is bent convexly or concavely in the direction of the Y-axis by a kink line extending along the direction of the X-axis, the second surface intersects with the direction of the X-axis, and the third surface is curved convexly outward, wherein when the position where the kink line exists in the direction of the Z-axis is defined as the kink position, the position away from the kink position in the direction of the Z-axis is defined as the separation position, the position between the kink position and the separation position in the direction of the Z-axis is defined as the intermediate position, and the length of the third surface in a cross-section perpendicular to the Z-axis is defined as the circumference, A method for designing a mold, comprising: (i) when the first surface is convex, making the perimeter at the kink position longer than the perimeter at the separation position, and making the perimeter at the intermediate position shorter than the perimeter at the intermediate position when the perimeter decreases linearly from the kink position to the separation position; and (ii) when the first surface is concave, making the perimeter at the kink position shorter than the perimeter at the separation position, and making the perimeter at the intermediate position longer than the perimeter at the intermediate position when the perimeter increases linearly from the kink position to the separation position.

4. The mold design method according to claim 3, wherein the circumference at the kink position and / or the separation position is determined by taking into consideration at least the shape of other parts to be attached to the part molded from the laminate.

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