Method and apparatus for molding composite materials

Abstract

To suppress molding defects due to the shaping of a laminate.SOLUTION: There is provided a method for forming a composite material by shaping and curing a laminate formed by laminating a plurality of fiber sheets using a molding die. The composite material includes a product portion which is a portion to be formed as a product and a surplus portion connected to the product portion. The molding die has a first forming surface for forming the product portion, a second forming surface for forming the surplus portion and a recess for drawing in a portion of the laminate disposed on the second forming surface. The method comprises steps of: disposing the laminate in the molding die by making a portion of the laminate face the recess; covering the laminate with a covering member to airtightly seal a space between the covering member and the molding die; drawing the portion of the laminate into the recess by suctioning the atmosphere between the covering member and the molding die and shaping the laminate; and forming the composite material including the product portion and the surplus portion by curing the laminate after shaping.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a composite material molding method and a molding apparatus.

Background Art

[0002] Conventionally, there are known a composite material molding method and a molding apparatus for molding a composite material by forming a prepreg material on a non-planar portion of a layup mandrel, covering the prepreg material with a bag film, performing vacuum suction, and heat-curing the prepreg material (see, for example, Patent Document 1).

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of Invention

Problem to be Solved by Invention

[0004] Incidentally, as a composite material, there is a composite material having a shape changing portion called a joggled portion. The joggled portion is provided, for example, on a girder member having a concave cross-section extending in the longitudinal direction, and is a portion where the cross-sectional shape in a cross-section orthogonal to the longitudinal direction changes along the longitudinal direction. When molding a composite material, a pre-molded laminate obtained by laminating fiber sheets is shaped using a covering member such as a vacuum bag. However, in a composite material having a shape changing portion, wrinkles may occur around the shape changing portion, leading to molding defects.

[0005] Accordingly, an object of the present disclosure is to provide a composite material molding method and a molding apparatus that can suppress the occurrence of molding defects caused by shaping a laminate.

Means for Solving the Problem

[0006] The present disclosure is a method for molding a composite material, wherein a composite material is formed by shaping a laminate of multiple fiber sheets using a mold and curing a resin impregnated into the fiber sheets, the composite material includes a product portion which is the part to be molded as a product, and an excess portion connected to the product portion, the mold having a first molding surface for molding the product portion, a second molding surface for molding the excess portion, and a recess for drawing in a part of the laminate that is placed on the second molding surface, and the laminate The method comprises the steps of: positioning the laminate in the mold from the first molding surface to the second molding surface so that a portion of it faces the recess; covering the laminate with a covering member to airtightly seal the space between the covering member and the mold; drawing in the atmosphere between the covering member and the mold to draw in a portion of the laminate into the recess and shape the laminate; and curing the shaped laminate to form the composite material including the product portion and the excess portion.

[0007] The molding apparatus of the present disclosure is a molding apparatus for molding a composite material by forming a laminate of a plurality of fiber sheets and curing a resin impregnated into the fiber sheets, wherein the composite material includes a product portion which is a portion to be molded as a product and an excess portion connected to the product portion, and comprises a mold having a first molding surface for molding the product portion, a second molding surface for molding the excess portion and a recess for drawing in a part of the laminate which is placed on the second molding surface, a covering member which covers the laminate, and a suction device which sucks the atmosphere between the covering member and the mold while the space between the covering member and the mold is airtightly sealed. [Effects of the Invention]

[0008] According to this disclosure, it is possible to suppress the occurrence of molding defects due to the shaping of the laminate. [Brief explanation of the drawing]

[0009] [Figure 1]Figure 1 is an external perspective view of an example of a composite material formed by the composite material molding method and molding apparatus according to Embodiment 1. [Figure 2] Figure 2 is a schematic diagram showing a molding apparatus according to Embodiment 1. [Figure 3] Figure 3 shows an example of fixing a laminate. [Figure 4] Figure 4 shows an example of fixing a laminate. [Figure 5] Figure 5 is an explanatory diagram of the molding method for composite materials according to Embodiment 1. [Figure 6] Figure 6 is a schematic diagram showing a molding apparatus according to Embodiment 2. [Figure 7] Figure 7 is a schematic diagram showing the mold of the molding apparatus according to Embodiment 3. [Modes for carrying out the invention]

[0010] Embodiments relating to this disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit this disclosure. Furthermore, some components in the embodiments described below are substituted or substantially identical to those easily substituted by those skilled in the art. Moreover, the components described below can be combined as appropriate, and if there are multiple embodiments, each embodiment can be combined.

[0011] [Embodiment 1] Figure 1 is an external perspective view of an example of a composite material formed by the composite material molding method and molding apparatus according to Embodiment 1. Figure 2 is a schematic diagram of the molding apparatus according to Embodiment 1. Figures 3 and 4 show an example of fixing a laminate. Figure 5 is an explanatory diagram of the composite material molding method according to Embodiment 1.

[0012] The composite material molding method and molding apparatus 1 according to Embodiment 1 is an apparatus for molding a composite material F having a shape-changing section D. As shown in Figure 1, in Embodiment 1, the composite material F to be molded is a girder member (spar) with a predetermined direction as its longitudinal direction, and is deformed two-dimensionally so that it has a concave cross-section in an orthogonal plane perpendicular to the longitudinal direction. The shape-changing section D is, for example, called a juggle section. The juggle section is provided on a girder member extending in the longitudinal direction, and is a part in which the concave cross-sectional shape in the cross-section perpendicular to the longitudinal direction changes shape along the longitudinal direction, in other words, a part in which the length in the width direction perpendicular to the longitudinal direction changes. In other words, the shape-changing section D is a part that is deformed three-dimensionally by deforming the composite material F, which is deformed two-dimensionally in cross-section, in the longitudinal direction as well. Note that the shape-changing section D is not particularly limited to the above, and may be any part in which the shape changes.

[0013] In Embodiment 1, multiple fiber sheets are laminated in a mold 11 to form a laminate S with a shape-changing section D. Then, the resin impregnated in the laminate S is cured to form the composite material F shown in Figure 1. Alternatively, a laminate S formed in a planar shape by laminating multiple fiber sheets may be shaped into a shape with a shape-changing section D using the mold 11. In the shape-changing section D, the length of the laminate S in an orthogonal plane perpendicular to the longitudinal direction changes along the longitudinal direction during shaping, and the location of wrinkles can be predicted in advance based on this change. In Embodiment 1, a sheet in which reinforcing fibers are impregnated with resin is used as the fiber sheet, for example, a prepreg is used. In Embodiment 1, a prepreg was used as the fiber sheet, but the embodiment is not particularly limited to this configuration, and a dry reinforcing fiber sheet without resin may be used.

[0014] (molding equipment) The molding apparatus 1 will be described with reference to Figure 2. As shown in Figure 2, the molding apparatus 1 comprises a mold 11, a release film 12, a breather 14, a bag film (covering member) 15, and a suction device 16. The molding apparatus 1 may further include a pressing plate (pressing member) 13 to obtain the effects described later.

[0015] The mold 11 is a mold material for shaping the laminate S before molding, and it molds the post-molded composite material F which includes the product portion Fa and the excess portion Fb. Here, the composite material F shown in Figure 1 is the composite material F of the product portion Fa from which the excess portion Fb has been removed.

[0016] The mold 11 is elongated in the longitudinal direction. The mold 11 has a first molding surface for molding the product part Fa, a second molding surface for molding the excess part Fb, and a recess 21 formed on the second molding surface. Specifically, the mold 11 has an upper surface 11a, a lower surface 11b opposite the upper surface 11a, and a pair of side surfaces 11c provided on both sides in the width direction of the upper surface 11a and the lower surface 11b. Although not shown in the figures, the mold 11 also has an inclined surface provided on one side surface 11c for molding the shape change part D. The inclined surface is located between the narrow side surface 11c of the mold 11 and the wide side surface 11c of the mold 11, and is a tapered surface that slopes in the longitudinal direction of the mold 11. The first molded surface consists of an upper surface 11a, a portion of a pair of side surfaces 11c connected to the upper surface 11a on the upper surface 11a side, and a portion of an inclined surface connected to the upper surface 11a on the upper surface 11a side. The second molded surface consists of a lower surface 11b, a portion of a pair of side surfaces 11c connected to the lower surface 11b on the lower surface 11b side, and a portion of an inclined surface connected to the lower surface 11b on the lower surface 11b side. Here, the dotted line shown in Figures 2 to 4 is the boundary line separating the first molded surface and the second molded surface, in other words, the boundary line L separating the product portion Fa and the excess portion Fb of the composite material F.

[0017] The recess 21 is provided on the second molding surface, and in Embodiment 1, is provided on the lower surface 11b. The recess 21 is formed, for example, by a curved surface that does not have any bent corners. The recess 21 is a hole or concave portion formed to be recessed into the lower surface 11b, for drawing a part of the laminate S disposed opposite to the lower surface 11b in the step of sucking the internal atmosphere described later. The recess 21 is provided in the longitudinal direction of the molding die 11 at a position where the shape change portion D is formed, in other words, at a position where wrinkles are predicted in advance to occur. Further, the recess 21 is provided, in a cross section orthogonal to the longitudinal direction of the molding die 11, at a position of the second molding surface (lower surface 11b) opposite to the surplus portion Fb corresponding to the product portion Fa of the composite material F where wrinkles are predicted to occur. Note that the recess 21 may be formed to extend along the longitudinal direction.

[0018] With respect to such a molding die 11, as shown in FIG. 2, the laminate S is wound around the molding die 11 in the circumferential direction, with the longitudinal direction of the molding die 11 serving as the axial direction of the central axis. Thereby, the laminate S is arranged on the molding die 11 in a state where a part thereof faces the recess 21.

[0019] Here, a description will be given of a part of the laminate S that faces the recess 21. The fiber sheet used for the laminate S is a unidirectional material in which fiber directions are aligned in a predetermined single direction. The laminate S is formed by laminating fiber sheets with different fiber directions. Let an orientation angle at which the fiber direction of the fiber sheet is the same as the longitudinal direction of the molding die 11 (composite material F) be 0°, and let an orientation angle at which the fiber direction is the width direction orthogonal to the longitudinal direction be 90°. In this case, the orientation angles of the fiber sheets included in the laminate S are 0°, 45° (+45°), 90°, and 135° (-45°). Here, the part of the laminate S that faces the recess 21 is a fiber sheet having an orientation angle of 90°. On the other hand, fiber sheets having an orientation angle other than 90° extend from the first molding surface to the second molding surface, but do not extend to a position facing the recess 21. In the step of sucking the internal atmosphere described later, a part of the laminate S at the position facing the recess 21 is drawn into the recess 21, whereby a circumferential tensile load is applied to the laminate S. The fiber direction of the fiber sheet having an orientation angle of 90° is the same direction as the tensile direction of the tensile load applied to the laminate S. Therefore, when a unidirectional material is used as the fiber sheet, by forming the part of the laminate S facing the recess 21 into a fiber sheet having an orientation angle of 90°, the tensile load is applied in the fiber direction of the fiber sheet. This suppresses fiber dispersion in the fiber sheets including other fiber sheets, thereby preventing a decrease in strength of the composite material F caused thereby. In Embodiment 1, a fiber sheet having an orientation angle of 90° is caused to face the recess 21, but the present invention is not particularly limited thereto, and any fiber sheet having an orientation angle larger than 45° and smaller than 135° may be used depending on the lamination pattern of the fiber sheets.

[0020] Furthermore, a portion of the laminate S facing the recess 21 is wrapped around the mold 11 at a position corresponding to the shape change portion D in the longitudinal direction of the mold 11. In other words, the recess 21 is formed on the second molding surface (lower surface 11b) on the extension of the shape change portion D of the composite material F to be molded, in the width direction perpendicular to the longitudinal direction of the mold 11. Note that a portion of the laminate S may be wrapped around the mold 11 along its entire length in the longitudinal direction. In Embodiment 1, a unidirectional material was used as the fiber sheet, but it may be a woven fabric or a nonwoven fabric, and is not particularly limited.

[0021] Here, with reference to Figures 2 to 4, the fixing of the laminate S wrapped around the mold 11 will be explained. The circumferential ends of the laminate S, which is wrapped around the mold 11 in the circumferential direction, are each fixed in order to secure a reaction force against tensile loads. In the example shown in Figure 2, the laminate S is wrapped around the mold 11 in a loop shape, and the circumferential ends of the laminate S are overlapped, with the overlapping portion where the ends overlap being fixed with a fixing member such as tape. At this time, the overlapping portion where the ends of the laminate S overlap is formed to face the recess 21.

[0022] In the example shown in Figure 3, the laminate S is wrapped around the mold 11 in a loop shape, similar to Figure 2, with both ends of the laminate S overlapping in the circumferential direction, and the overlapping portion where both ends overlap is fixed with a fixing member such as tape. In this case, unlike in Figure 2, the overlapping portion where both ends of the laminate S overlap is formed so as not to face the recess 21. In the examples shown in Figures 2 and 3, if fixing by friction between the ends is possible at the overlapping portion, the fixing member may be omitted. Also, in the example shown in Figure 3, the overlapping portion where both ends overlap may be provided so as to be located in the excess portion Fb.

[0023] In the example shown in Figure 4, the laminate S is wrapped around the mold 11 in a loop shape, and both ends of the laminate S are butted together so that they face each other. The butt joints where the ends meet are fixed with a fixing member 25 such as tape. In this case, the butt joints where the ends of the laminate S meet are formed so as not to face the recess 21. However, the butt joints may be formed to face the recess 21.

[0024] The release film 12 is positioned to cover the outside of the laminate S wrapped around the mold 11. The release film 12 suppresses bonding between the laminate S and the bag film 15 and serves as a film for releasing the bag film 15 from the laminate S. The release film 12 may also be a peelable ply that can be peeled off from the laminate S.

[0025] The molding apparatus 1 of Embodiment 1 may further include a pressing plate 13. The pressing plate 13 may be used additionally to press the laminate S. The pressing plate 13 is positioned on the outside of the release film 12 and is positioned at a predetermined location on the laminate S where pressing is required. In Embodiment 1, the pressing plate 13 is positioned opposite the upper surface 11a and a pair of side surfaces 11c of the mold 11. The pressing plate 13 is formed in a plate shape and suppresses changes in the shape on the outside of the laminate S.

[0026] The breather 14 is positioned to cover the outside of the release film 12 and the pressure plate 13. The breather 14 forms a degassing circuit that becomes a flow path for the internal atmosphere of the bag film 15 during vacuum suction, which will be described later.

[0027] The bag film 15 is a bag-shaped film that contains the laminate S together with the mold 11. The bag film 15 hermetically seals its interior. Therefore, the inside of the bag film 15 and the mold 11 are hermetically sealed from the outside. The bag film 15 is provided with a suction hole 15a that is connected to a suction device 16. The bag film 15 applies a pressing force to the laminate S due to the pressure difference between the inside and outside (for example, atmospheric pressure) by vacuum suction of the internal atmosphere. Note that the bag film 15 is not particularly limited to atmospheric pressure, and a pressing force greater than atmospheric pressure may be applied to the laminate S by pressurizing it in an autoclave or the like.

[0028] The suction device 16 is connected to the suction hole 15a of the bag film 15 and creates a vacuum inside the bag film 15.

[0029] (Method for molding composite materials) Next, with reference to Figure 5, a method for molding composite material F using the molding apparatus 1 will be described. As shown in Figure 5, in the method for molding composite material F, first, a mold 11 with a recess 21 formed therein is prepared (step S1). Subsequently, in the method for molding composite material F, the laminate S is placed in the mold 1 with a part of the laminate S facing the recess 21 (step S2). In step S2, a fiber sheet is wrapped around the mold 11, and this is repeated several times to laminate the fiber sheet and form the laminate S. In step S2, at least a part of the laminate S, for example, a fiber sheet with an orientation angle of 90°, is wrapped around the circumferential direction of the mold 11 and positioned to face the recess 21. In step S2, the laminate S may be fixed in any of the fixing methods shown in Figures 2 to 4. In step S2, in order to remove air remaining between the layers of fiber sheet (to debulk), a vacuum may be drawn using a bag film 15 after every few layers have been laminated.

[0030] Next, in the method for molding the composite material F, a release film 12, a pressing plate 13, and a breather 14 are arranged in order on the outside of the laminate S wrapped around the mold 11 (step S3). Then, in the method for molding the composite material F, the laminate S wrapped around the mold 11 is placed inside the bag film 15 together with the release film 12, the pressing plate 13, and the breather 14 (step S4). In this way, in step S4, the laminate S is covered with the bag film 15, and the inside of the bag film 15 containing the mold 11 is airtightly sealed. Subsequently, in the method for molding the composite material F, the inside of the bag film 15 is vacuumed using a suction device 16, and the internal atmosphere of the bag film 15 is sucked out through the degassing circuit formed by the breather 14 (step S5). In step S5, when the inside of the bag film 15 is evacuated, the pressure difference between the inside and outside applies a pressing force to the laminate S via the bag film 15 and the release film 12. This causes a portion of the laminate S to be drawn into the recess 21 of the mold 11, thereby applying a circumferential tensile load to the laminate S. This applies a tensile load to the part of the laminate S where the length changes, suppressing the occurrence of wrinkles. In step S5, the laminate S is shaped according to the first and second molding surfaces of the mold 11. If the fiber sheet of the laminate S is a dry reinforced fiber sheet, a process of impregnating the fiber sheet with resin is performed after or simultaneously with step S5.

[0031] Next, in the method for molding the composite material F, the shaped laminate S is placed in a heating furnace 27 together with the bag film 15 and heated to cure the resin impregnated into the laminate S (step S6). In step S6, the shaped laminate S is heat-cured to form the composite material F, which includes the product portion Fa and the excess portion Fb. The heating furnace 27 may be an oven without pressurization or an autoclave with pressurization. In other words, during the heat curing of the laminate S, the laminate S may be heated under pressurization or heated under atmospheric pressure. Then, in the method for molding the composite material F, the molded composite material F is released from the mold 11, and the excess portion Fb of the molded composite material F is removed by trimming (step S7), thereby obtaining the product portion Fa of the composite material F with the shape change portion D shown in Figure 1. After step S7 is executed, the method for molding the composite material F is completed.

[0032] [Embodiment 2] Next, Embodiment 2 will be described with reference to Figure 6. In Embodiment 2, in order to avoid redundant descriptions, only the parts that differ from Embodiment 1 will be described, and parts that have the same configuration as Embodiment 1 will be denoted by the same reference numerals. Figure 6 is a schematic diagram showing a molding apparatus according to Embodiment 2.

[0033] The molding apparatus 31 of Embodiment 2 differs from Embodiment 1 in that the position of the recess 33 formed in the mold 11 is different, and the apparatus configuration is such that the mold 11 is placed on a base plate 35. Similar to Embodiment 1, the molding apparatus 31 comprises a mold 11, a release film 12, a pressing plate 13, a breather 14, a bag film 15, and a suction device (not shown). The molding apparatus 31 also further comprises a base plate 35 on which the mold 11 is placed. Note that the release film 12 and the pressing plate 13 are the same as in Embodiment 1, so their description is omitted.

[0034] The mold 11 has a recess 33 formed on its second molding surface, specifically on the lower surface 11b side of one side 11c. The recess 33 may be provided not only on the lower surface 11b side of one side 11c, but also on the lower surface 11b side of the other side 11c, and two recesses 33 may be arranged facing each other. In other words, there may be one recess 33, two recesses 33, or at least one.

[0035] As shown in Figure 6, the laminate S is formed on the first molding surface of the mold 11 and on the lower surface 11b of one side surface 11c. At this time, the laminate S is placed on the mold 11 with a portion of it, specifically one end in the width direction, facing the recess 33.

[0036] Here, the fixing of the laminate S placed in the mold 11 will be described. Both ends of the laminate S in the width direction, placed in the mold 11, are fixed in order to secure a reaction force against tensile load. Specifically, both ends of the laminate S in the width direction are located on a pair of side surfaces 11c of the mold 11, and both ends are fixed to the mold 11 with fixing members such as tape.

[0037] The base plate 35 is a flat base plate with a suction hole 15a that is connected to a suction device. The breather 14 is positioned to cover the outside of the mold 11, release film 12, and pressure plate 13 which are installed on the base plate 35, with its periphery positioned on the base plate 35 and facing the suction hole 15a. The bag film 15 is positioned to cover the outside of the mold 11, release film 12, pressure plate 13, and breather 14 which are installed on the base plate 35, and is fixed to the base plate 35 via a sealing material 36. As a result, the space between the bag film 15 and the base plate 35 is airtightly sealed.

[0038] In this method of forming a composite material F using a mold 11, a release film 12 and a pressing plate 13 are placed on the laminate S positioned in the mold 11 and then placed on a base plate 35. Subsequently, in the method of forming the composite material F, a breather 14 and a bag film 15 are placed over the laminate S, including the mold 11, which is positioned on the base plate 35, and the internal atmosphere between the bag film 15 and the base plate 35 is sucked out. As a result, one end of the laminate S is drawn into the recess 33 of the mold 11, and a tensile load is applied to the laminate S. This applies a circumferential tensile load to the part of the laminate S where the length changes, thereby suppressing the occurrence of wrinkles.

[0039] [Embodiment 3] Next, Embodiment 3 will be described with reference to Figure 7. In Embodiment 3, in order to avoid redundant descriptions, only the parts that differ from Embodiments 1 and 2 will be described, and parts that have the same configuration as Embodiments 1 and 2 will be denoted by the same reference numerals. Figure 7 is a schematic diagram showing the mold of the molding apparatus according to Embodiment 3.

[0040] The molding die 11 of the molding apparatus 41 in Embodiment 3 includes a molding die body 45 and an attachment part 46 that can be attached to and detached from the molding die body 45. A mating groove is formed on the lower surface 11b of the molding die body 45 for fitting the attachment part 46. A recess 21 is formed in the attachment part 46. The recess 21 is formed, for example, along the longitudinal direction of the molding die 11, and the attachment part 46 is detachably provided in the mating groove formed on the lower surface 11b of the molding die body 45, and is provided along the recess 21 in the longitudinal direction. Multiple attachment parts 46 may be provided depending on the shape of the recess 21. For example, when optimizing molding conditions according to the conditions of the laminate S, it is possible to aim for molding by sequentially attaching attachment parts 46 with different recess shapes 21.

[0041] The shape of the recess 21 in the cross-section perpendicular to the longitudinal direction may be changed according to the shape of the composite material F being molded. If the composite material F is, for example, a girder member in which the size within the cross-section decreases from one side to the other in the longitudinal direction, the recess 21 may change so that the cross-sectional shape within the cross-section decreases from one side to the other in the longitudinal direction. In Embodiment 3, the shape of the recess 21 may be changed by changing the attachment part 46 to the mold body 45. In Embodiment 3, the attachment part 46 and the fitting groove are provided on the lower surface 11b of the mold body 45, but they may be provided on the side surface 11c instead of the lower surface 11b.

[0042] In Embodiments 1 to 3, the case of molding a composite material F having a shape-changing portion D has been described, but it may also be applied to a composite material F without a shape-changing portion D, that is, a girder member (spar) that is deformed two-dimensionally so that its cross-section is concave in an orthogonal plane perpendicular to the longitudinal direction. In this case, the formation of wrinkles that occur at corners and the like formed on the girder member can be suppressed without relying on the shape-changing portion D.

[0043] As described above, the composite material molding method and molding apparatus 1 described in Embodiments 1 to 3 can be understood, for example, as follows.

[0044] A method for molding a composite material according to the first embodiment is a method for molding a composite material F by shaping and curing a laminate S made of multiple fiber sheets using a mold 11, wherein the composite material F includes a product portion Fa which is the part to be molded as a product, and an excess portion Fb connected to the product portion Fa, and the mold 11 has a first molding surface for molding the product portion Fa, a second molding surface for molding the excess portion Fb, and a recess 21 for drawing in a part of the laminate S which is placed on the second molding surface, and a part of the laminate S The process includes: step S2 of positioning the laminate S in the mold 11 with the recess 21 facing the laminate; step S4 of covering the laminate S with a covering member (bag film 15) to airtightly seal the space between the covering member and the mold 11; step S5 of drawing in the atmosphere between the covering member and the mold 11 to pull a portion of the laminate S into the recess 21 and shape the laminate S; and step S6 of curing the shaped laminate S to form the composite material F including the product portion Fa and the excess portion Fb.

[0045] With this configuration, by drawing a portion of the laminate S into the recess 21, the laminate S can be shaped while a tensile load is applied to it. Therefore, the occurrence of molding defects due to the shaping of the laminate S can be suppressed. In contrast, in conventional molding methods in which the entire mold is covered with a bag film, the pressing force due to the internal-external pressure difference applied during the molding process acts in the direction normal to the molded surface, and wrinkles in the juggle portion could not be efficiently eliminated. In the configuration of this disclosure, by drawing a portion of the laminate S into it, a tensile load can be applied to the laminate S during the shaping process or molding process, thereby suppressing the occurrence of molding defects.

[0046] In a second embodiment, in a method for molding a composite material F according to the first embodiment, the composite material F is a girder member that is elongated in the longitudinal direction and deformed in an orthogonal plane perpendicular to the longitudinal direction, the product portion Fa has a shape-changing portion D whose shape changes, and the shape-changing portion D is a portion of the girder member that is deformed in a plane including the longitudinal direction.

[0047] With this configuration, even with a composite material F having a shape-changing section D, the occurrence of molding defects due to the shaping of the laminate S can be suppressed.

[0048] In a third embodiment, in a method for molding a composite material F according to the second embodiment, the fiber sheet is a unidirectional material in which the fiber direction is aligned in one direction, and the laminate S is formed by laminating the fiber sheets with different fiber directions. If the orientation angle in which the fiber direction of the fiber sheet is in the same direction as the longitudinal direction is set to 0°, and the orientation angle in which it is perpendicular to the longitudinal direction is set to 90°, then the recess 21 is formed on the second molding surface on the extension of the shape change portion D in the direction perpendicular to the longitudinal direction, and in the step of placing the laminate S in the molding die 11, the fiber sheet having an orientation angle greater than 45° and less than 135° is placed opposite the recess 21 as part of the laminate S that faces the recess 21.

[0049] With this configuration, even when a unidirectional material is used as the fiber sheet, the unraveling of the fibers in the fiber sheet is suppressed, and the laminate S can be suitably shaped.

[0050] In a fourth embodiment, a method for molding a composite material F according to any one of the first to third embodiments further comprises the step of removing the excess portion Fb of the molded composite material F.

[0051] With this configuration, the product portion Fa of the composite material F can be suitably formed by removing the excess portion Fb of the composite material F that has been drawn into and molded in the recess 21.

[0052] In a fifth embodiment, in a method for molding a composite material F according to any one of the first to fourth embodiments, the covering member is a bag film 15 that houses the laminate S together with the mold 11.

[0053] With this configuration, the laminate S can be housed in the bag film 15 together with the mold 11 to form the laminate S, thus making the configuration of the molding apparatus 1 compact.

[0054] In a sixth embodiment, in a method for molding a composite material F according to any one of the first to fifth embodiments, the mold 11 is elongated in the longitudinal direction, and in step S2 of placing the laminate S in the mold 11, the laminate S is wrapped around the mold 11 in the circumferential direction, with the longitudinal direction as the axial direction of the central axis, thereby placing the laminate S in the mold 11.

[0055] With this configuration, the laminate S can be easily positioned to conform to the molding surface of the mold 11 simply by wrapping it around the circumferential direction of the mold 11.

[0056] In a seventh aspect, in a method for molding a composite material F according to the sixth aspect, in the step of placing the laminate S in the mold 11, the circumferential ends of the laminate S, which is wrapped around the mold 11 in the circumferential direction, are overlapped.

[0057] With this configuration, by overlapping both ends of the laminate S, a reaction force can be applied to both ends of the laminate S. Therefore, even if a part of the laminate S is pulled into the recess 21, a suitable tensile load can be applied to the laminate S.

[0058] In the eighth aspect, in the method for molding a composite material F according to the sixth aspect, in the step of placing the laminate S in the mold 11, the circumferential ends of the laminate S, which is wrapped around the mold 11 in the circumferential direction, are butted together and joined.

[0059] With this configuration, by joining the ends of the laminate S together, a reaction force can be applied to both ends of the laminate S. Therefore, even if a part of the laminate S is pulled into the recess 21, a suitable tensile load can be applied to the laminate S.

[0060] In the ninth aspect, in a method for molding a composite material F according to any one of the first to eighth aspects, in step S4, which airtightly seals the space between the covering member and the mold 11, a pressing member (pressing plate 13) for pressing the laminate S to conform to the mold 11 is placed on the laminate S.

[0061] In this configuration, when a tensile load is applied to the laminate S, the laminate S will tend to become circular due to the principle of minimum free energy (principle of minimum potential energy). At this time, by pressing the laminate S toward the mold 11 with the pressing member, the pressing member's rigidity in the pressing direction prevents the laminate S from becoming circular, and the laminate S can be made to conform to the shape of the mold 11. It is desirable to chamfer the ends of the pressing member because the contact pressure with the laminate S becomes locally high and a footprint is transferred to the laminate S, but chamfering is not required.

[0062] A molding apparatus according to the tenth embodiment is a molding apparatus 1 for molding a composite material F by shaping and curing a laminate S made of multiple fiber sheets, wherein the composite material F includes a product portion Fa which is the part to be molded as a product, and an excess portion Fb connected to the product portion Fa, and comprises a mold 11 having a first molding surface for molding the product portion Fa, a second molding surface for molding the excess portion Fb, and a recess 21 arranged on the second molding surface for drawing in a part of the laminate S, a covering member (bag film 15) that covers the laminate S, and a suction device 16 that sucks the atmosphere between the covering member and the mold 11 while the space between the covering member and the mold 11 is airtightly sealed.

[0063] With this configuration, by drawing a portion of the laminate S into the recess 21, the laminate S can be shaped while a tensile load is applied to it. Therefore, the occurrence of molding defects due to the shaping of the laminate S can be suppressed.

[0064] In the eleventh embodiment, in the molding apparatus according to the tenth embodiment, the composite material F is elongated in the longitudinal direction and is a girder member deformed in an orthogonal plane perpendicular to the longitudinal direction, the size in the orthogonal plane decreases from one side in the longitudinal direction to the other, and the cross-sectional shape of the recess 21 decreases from one side in the longitudinal direction to the other in the orthogonal plane.

[0065] With this configuration, the magnitude of the tensile load can be appropriately changed by changing the size of the cross-sectional shape of the recess 21 according to its size within the orthogonal plane (cross-section) of the composite material.

[0066] In a twelfth aspect, in a molding apparatus according to the tenth or eleventh aspect, the mold 11 includes a mold body 45 and an attachment portion 46 which is detachable from the mold body 45 and has the recess 21 formed thereon.

[0067] With this configuration, the shape of the recess 21 can be easily changed by replacing the attachment part 46 with the mold body 45. [Explanation of symbols]

[0068] 1 Molding equipment 11 Molding mold 12 Release film 13. Pressing plate (pressing member) 14 Breather 15. Bag film (covering material) 16 Suction device 21 Indentation 31 Molding apparatus (Embodiment 2) 33. Indentation 41 Molding apparatus (Embodiment 3) 45. Molding mold body 46 Attachment section D Shape change section F Composite material Fa Product Parts Fb surplus portion S Laminate

Claims

1. In a method for molding composite materials, in which a laminate of multiple fiber sheets is formed using a mold, and a resin impregnated into the fiber sheets is cured to form a composite material, The composite material includes a product portion which will be molded as a product, and an excess portion which is connected to the product portion. The mold has a first molding surface for molding the product portion, a second molding surface for molding the excess portion, and a recess for drawing in a portion of the laminate that is placed on the second molding surface. The steps include: placing the laminate in the mold from the first molding surface to the second molding surface so that a portion of the laminate faces the recess; The steps include covering the laminate with a covering member to airtightly seal the space between the covering member and the mold, The steps include: drawing in the atmosphere between the covering member and the mold, causing a portion of the laminate to be drawn into the recess, and shaping the laminate; A method for molding a composite material, comprising the step of curing the laminate after shaping to form the composite material including the product portion and the excess portion.

2. The composite material is a girder member that is elongated in the longitudinal direction and deformed in an orthogonal plane perpendicular to the longitudinal direction. The aforementioned product part has a shape-changing portion whose shape changes, The method for forming a composite material according to claim 1, wherein the shape-changing portion is a portion of the girder member that has been deformed in a plane including the longitudinal direction.

3. The aforementioned fiber sheet is a unidirectional material in which the fiber direction is aligned in one direction. The laminate is formed by laminating the fiber sheets with different fiber directions. If we define the orientation angle at which the fiber direction of the fiber sheet is in the same direction as the longitudinal direction as 0°, and the orientation angle at which it is perpendicular to the longitudinal direction as 90°, The recess is formed on the second molded surface along the extension of the shape-changing portion in a direction perpendicular to the longitudinal direction. The method for molding a composite material according to claim 2, wherein in the step of arranging the laminate in the mold, the fiber sheet having an orientation angle greater than 45° and less than 135° is placed facing the recess as part of the laminate that faces the recess.

4. The method for molding a composite material according to claim 1, further comprising the step of removing the excess portion of the composite material after molding.

5. The method for molding a composite material according to claim 1, wherein the covering member is a bag film that houses the laminate together with the mold.

6. The aforementioned mold is elongated in the longitudinal direction. The method for molding a composite material according to claim 1, wherein in the step of arranging the laminate in the mold, the laminate is wrapped around the mold in the circumferential direction, with the longitudinal direction as the axial direction of the central axis, and the laminate is arranged in the mold.

7. The method for molding a composite material according to claim 6, wherein in the step of placing the laminate in the molding die, the circumferential ends of the laminate wrapped around the molding die are overlapped.

8. The method for molding a composite material according to claim 6, wherein in the step of placing the laminate in the mold, the circumferential ends of the laminate, which is wrapped around the mold in the circumferential direction, are butted together and joined.

9. The method for molding a composite material according to claim 1, wherein in the step of airtightly sealing the space between the covering member and the mold, a pressing member for pressing the laminate to conform to the mold is placed on the laminate.

10. In a molding apparatus for forming a composite material by shaping a laminate of multiple fiber sheets and curing a resin impregnated into the fiber sheets, The composite material includes a product portion which will be molded as a product, and an excess portion which is connected to the product portion. A mold having a first molding surface for molding the product portion, a second molding surface for molding the excess portion, and a recess for drawing in a portion of the laminate placed on the second molding surface, A covering member that covers the laminate, A molding apparatus comprising: a suction device for sucking the atmosphere between the covering member and the molding die while the space between the covering member and the molding die is airtightly sealed.

11. The composite material is elongated in the longitudinal direction and is a girder member deformed in an orthogonal plane perpendicular to the longitudinal direction, wherein the cross-sectional shape in the orthogonal plane changes from one side to the other in the longitudinal direction. The molding apparatus according to claim 10, wherein the recess has a cross-sectional shape that changes within the orthogonal plane from one side in the longitudinal direction to the other side.

12. The molding apparatus according to claim 10, wherein the molding die comprises a molding die body and an attachment portion having the recess formed thereon, which is detachable from the molding die body.

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