Method for manufacturing fiber-reinforced resin structural members

Abstract

To provide a manufacturing method capable of simply manufacturing a structural member, in which accuracy of a shape of a mounting surface of a portion to be fastened with a bolt to another member is secured.SOLUTION: There is provided a manufacturing method for a fiber-refined resin structural member having a connecting portion including a hole portion into which a fastening member is inserted. The method comprises steps of: forming an uncured fiber-reinforced resin layer containing a matrix resin and reinforcing fibers before curing on a molding surface of a jig; curing the matrix resin to form a fiber-reinforced resin structural member; and removing the jig from the fiber-reinforced resin structural member. In the step of forming the uncured fiber-reinforced resin layer, the uncured fiber-reinforced resin layer is formed while a metal insert having a hole or a portion where the hole is to be formed is embedded in the uncured fiber-reinforced resin layer so that a part of the metal insert is in contact with the jig, and the hole or the part where the hole is to be formed is exposed on an outer surface of the uncured fiber-reinforced resin layer that is not in contact with the jig.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a fiber-reinforced resin structural member. [Background technology]

[0002] In recent years, with the aim of reducing the weight of vehicle bodies, it has been considered to manufacture structural members constituting the vehicle body using fiber-reinforced resin containing reinforcing fibers such as carbon fibers (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-193637 Summary of the Invention [Problem to be solved by the invention]

[0004] When a structural member made of fiber-reinforced resin is fastened to another member with a bolt, the shape and position of the mounting surface must be precisely defined to ensure high connection accuracy. For example, by using the surface formed by a mold as the mounting surface, the mounting surface can be made to have a precision equivalent to the precision of the molded surface of the mold. However, when using this manufacturing method, after molding the molded body, it is necessary to join a nut plate for bolt fastening to the surface opposite the mounting surface.

[0005] Furthermore, when the surface opposite the mounting surface is molded as a surface to be molded by a mold, it is possible to control the mounting surface by performing numerical control (NC) processing such as grinding or cutting on the mounting surface after molding to ensure precision in the shape and position of the mounting surface. However, grinding or cutting a fiber-reinforced resin molded body can cut the fibers, which can reduce the strength and rigidity of the structural member. Even when using this manufacturing method, it is still necessary to attach a nut plate for bolt fastening to the surface opposite the mounting surface after molding.

[0006] Therefore, the present disclosure has been made in consideration of the above problems, and an object of the present disclosure is to provide a manufacturing method that can easily manufacture a structural member that ensures the accuracy of the shape of the mounting surface at the location where the structural member is intended to be bolted to another member. [Means for solving the problem]

[0007] In order to solve the above-described problems, according to one aspect of the present disclosure, there is provided a method for manufacturing a fiber-reinforced resin structural member having a connection part including a hole into which a fastening member is inserted, the method including the steps of: forming an uncured fiber-reinforced resin layer containing an uncured matrix resin and reinforcing fibers on a molding surface of a jig; curing the matrix resin to form a fiber-reinforced resin structural member; and removing the jig from the fiber-reinforced resin structural member, wherein in the step of forming the uncured fiber-reinforced resin layer, a metal insert having a hole or a location where the hole is to be formed is embedded in the uncured fiber-reinforced resin layer so that a portion of the metal insert contacts the jig and the hole or the location where the hole is to be formed is exposed on an outer surface of the uncured fiber-reinforced resin layer that does not contact the jig. [Effects of the Invention]

[0008] As described above, according to the present disclosure, a structural member can be manufactured in a simple manner while ensuring the accuracy of the shape of the mounting surface at the location where bolt fastening to another member is planned. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a joined structure including a fiber-reinforced resin structural member obtained by a manufacturing method according to an embodiment of the present disclosure. [Figure 2] 3 is an explanatory diagram showing a metal insert used in the structural member according to the embodiment; FIG. [Figure 3] FIG. 2 is an explanatory diagram showing a manufacturing method of the first reference example. [Figure 4]FIG. 10 is an explanatory diagram showing a manufacturing method of a second reference example. [Figure 5] 10 is an explanatory view showing a state in which a metal insert is placed on a jig in the manufacturing method of a structural member according to the embodiment. FIG. [Figure 6] 4 is an explanatory view showing a state in which first fiber-reinforced resin sheets are laminated in the manufacturing method of a structural member according to the embodiment. FIG. [Figure 7] 5 is an explanatory view showing a state in which a second fiber-reinforced resin sheet is laminated in the manufacturing method of a structural member according to the embodiment. FIG. [Figure 8] 4 is an explanatory view showing a state in which an uncured fiber reinforced resin layer is formed in the manufacturing method of the structural member according to the embodiment. FIG. [Figure 9] 3 is an explanatory diagram showing a structural member manufactured by the manufacturing method of a structural member according to the embodiment; FIG. [Figure 10] 10A and 10B are explanatory diagrams showing a modified example of the lamination method of the fiber reinforced resin sheet according to the embodiment. [Figure 11] 10 is an explanatory view showing another example of a metal insert used in the structural member according to the embodiment. FIG. [Figure 12] 10A and 10B are explanatory views showing a manufacturing method using another example of a metal insert. [Figure 13] 10A and 10B are explanatory views showing a manufacturing method using another example of a metal insert. [Figure 14] 10A and 10B are explanatory views showing a manufacturing method using another example of a metal insert. [Figure 15] FIG. 1 is an explanatory diagram showing a manufacturing method using a filament winding method. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0011] <1. Explanation of fiber-reinforced resin structural members> First, a fiber-reinforced resin structural member obtained by the method for producing a fiber-reinforced resin structural member according to the present disclosure will be described.

[0012] FIG. 1 shows a cross-sectional view of a joined structure including a fiber-reinforced resin structural member (hereinafter also simply referred to as "structural member") 10 obtained by a manufacturing method according to an embodiment of the present disclosure. The structural member 10 shown in FIG. 1 has a hollow cylindrical portion, and its cross-sectional shape is a closed cross-sectional shape that is continuous around the entire circumference. The structural member 10 has a connection portion 9 including a hole 11a into which a fastening member 5 is inserted, and is joined to another member 3 at the connection portion 9. Specifically, the structural member 10 and the other member 3 are joined by a fastening member (bolt) 5 and a nut 7 inserted so as to pass through an insertion hole 3a provided in the other member 3 and the hole 11a provided in the connection portion 9 of the structural member 10.

[0013] The structural member 10 is configured to include a fiber-reinforced resin laminate 13 and a metal insert 11. The reinforcing fiber may be, for example, carbon fiber, but other fibers may also be used, and a combination of multiple fibers may also be used. However, since carbon fiber has excellent mechanical properties, it is preferable that the reinforcing fiber include carbon fiber.

[0014] The matrix resin of the fiber-reinforced resin may be a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include polyethylene resin, polypropylene resin, polyvinyl chloride resin, ABS resin (acrylonitrile-butadiene-styrene copolymer synthetic resin), polystyrene resin, AS resin (acrylonitrile-styrene copolymer synthetic resin), polyamide resin, polyacetal resin, polycarbonate resin, polyester resin, PPS (polyphenylene sulfide) resin, fluororesin, polyetherimide resin, polyetherketone resin, and polyimide resin.

[0015] The matrix resin may be one of these thermoplastic resins or a mixture of two or more of them. Alternatively, the matrix resin may be a copolymer of these thermoplastic resins. When the thermoplastic resin is a mixture, a compatibilizer may be used in combination. Furthermore, a flame retardant such as a bromine-based flame retardant, a silicon-based flame retardant, or red phosphorus may be added to the thermoplastic resin.

[0016] Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, polyurethane resins, and silicone resins. One or a mixture of two or more of these thermosetting resins can be used as the matrix resin. When using these thermosetting resins, an appropriate curing agent or reaction accelerator may be added to the thermosetting resin.

[0017] The other member 3 is not particularly limited, and may be a member made of a fiber-reinforced resin composite material, or a metal member such as a steel plate. The other member 3 may also be a structural member manufactured by the manufacturing method of the present disclosure.

[0018] When joining a fiber-reinforced resin structural member 10 to another member 3, if the shape and position of the attachment surface are not precise, the joining strength may decrease and the resulting joined structure may deviate from the designed dimensions. To address this, a metal insert 11 having a hole 11a is provided in the connection portion 9 of the structural member 10 of the present disclosure. The metal insert 11 prevents the thickness of the connection portion 9 from deviating from the designed value and functions to ensure the precision of the shape and position of the attachment surface of the other member 3.

[0019] 2 is an explanatory diagram showing the metal insert 11 used in the structural member 10 shown in FIG. 2 shows a front view and a side view of the metal insert 11. The metal insert 11 has a conical shape with flat surfaces on both axial ends, and a hole 11a is provided along the axis. Of the flat surfaces on both ends of the metal insert 11, the end face with the larger diameter is arranged on the inner side of the structural member 10. Furthermore, of the flat surfaces on both ends of the metal insert 11, the end face with the smaller diameter is arranged on the outer side of the structural member 10.

[0020] By providing the metal inserts 11 embedded and exposed on both the inner and outer sides of the structural member 10 in the connecting portion 9, the thickness of the connecting portion 9 can be set to a desired design value. Furthermore, the metal inserts 11 can prevent variations in the shape of the mounting surface due to manufacturing conditions, etc. Therefore, it is possible to prevent a decrease in the accuracy of the shape and position of the mounting surface.

[0021] Furthermore, since the metal insert 11 has a shape in which the diameter decreases from the inside to the outside of the structural member 10, the contact area between the metal insert 11 and the fiber reinforced resin laminate 13 increases, thereby increasing the bonding strength between the metal insert 11 and the fiber reinforced resin laminate 13. Furthermore, since the metal insert 11 has this shape, it is possible to prevent the metal insert 11 from detaching from the fiber reinforced resin laminate 13 even when a load is applied to the other member 3 in a direction away from the structural member 10.

[0022] <2. Manufacturing method according to reference example> Next, before describing a method for manufacturing a fiber-reinforced plastic structural member 10 according to the present disclosure, a method for manufacturing a fiber-reinforced plastic structural member according to a reference example will be described.

[0023] 3 is an explanatory diagram showing a manufacturing method of a first reference example in which a fiber reinforced resin laminate 101 is molded around a molding jig 109 and then a nut plate 107 is attached. In the manufacturing method of the first reference example, a fiber reinforced resin sheet (prepreg) is laminated (laid up) around the molding jig 109, the fiber reinforced resin is cured, and then the molding jig 109 is removed to mold the fiber reinforced resin laminate 101.

[0024] After molding the fiber reinforced resin laminate 101, a nut plate 107 is aligned with the inner peripheral surface of the fiber reinforced resin laminate 101 and bonded thereto, for example, with an adhesive. Thereafter, or before bonding the nut plate 107, holes 102 into which fastening members are inserted are formed. At this time, in the manufacturing method of the first reference example, the mounting surface 105 to which another member is bonded is the surface opposite to the molding surface 103 formed by the molding jig 109. For this reason, in order to ensure the accuracy of the shape and position of the mounting surface 105 to which another member is bonded, NC processing such as grinding or polishing is performed using a jig 108.

[0025] As described above, the manufacturing method of the first reference example requires, after molding the fiber reinforced resin laminate 101, a step of aligning and joining the nut plate 107 to the inner peripheral surface of the fiber reinforced resin laminate 101, and a step of forming the hole 102. NC machining is also required to ensure the precision of the mounting surface 105, making the manufacturing method complicated. Furthermore, there is a risk that the fibers may be cut when the mounting surface 105 is subjected to NC machining, which may result in a decrease in the strength or rigidity of the fiber reinforced resin laminate 101.

[0026] 4 is an explanatory diagram showing a manufacturing method of a second reference example in which two separately molded fiber reinforced resin laminate halves 111, 117 are joined to form the fiber reinforced resin laminate 110, and then the nut plate 125 is attached. In the manufacturing method of the second reference example, fiber reinforced resin sheets (prepregs) are laminated on the molding surfaces inside the molding dies 121, 123, respectively, and the fiber reinforced resin is cured. After that, the fiber reinforced resin laminate halves 111, 117 detached from the molding dies 121, 123 are joined to form the fiber reinforced resin laminate 110.

[0027] After forming the fiber reinforced resin laminate 110, the nut plate 125 is aligned with the inner circumferential surface of the fiber reinforced resin laminate 110 and bonded thereto, for example, with an adhesive. After that, or before bonding the nut plate 125, a hole 112 into which a fastening member is inserted is formed.

[0028] As such, in the manufacturing method of the second reference example, after forming the fiber reinforced resin laminate 110, a process of aligning and joining the nut plate 125 to the inner surface of the fiber reinforced resin laminate 110 and a process of forming the hole portion 112 are required, making the manufacturing method complicated.

[0029] 3. Manufacturing method according to the present disclosure Next, a method for manufacturing a fiber-reinforced resin structural member 10 according to an embodiment of the present disclosure will be described. In the manufacturing method according to this embodiment, a method is adopted in which a fiber-reinforced resin sheet (prepreg) is laminated on the surface of a jig. In the following description, of the flat surfaces on both ends of the metal insert 11 shown in FIG. 2, the surface with the larger area will be referred to as the bottom surface, and the surface with the smaller area will be referred to as the top surface.

[0030] 5 to 9 are explanatory views showing a method for manufacturing a structural member 10 according to this embodiment. Each figure shows a cross-sectional view including a portion corresponding to the connection portion 9 of the structural member 10, and a plan view of the portion corresponding to the connection portion 9 as viewed from the outside.

[0031] As shown in Fig. 5, a jig 21 corresponding to the three-dimensional shape of the cylindrical fiber-reinforced resin laminate to be molded is prepared, and the metal insert 11 shown in Fig. 2 is fixed so that its lower surface is in contact with the jig 21. At this time, even when the position of the metal insert 11 needs to be aligned, this can be done relatively easily because it is aligned when aligning the metal insert 11 on the outer peripheral surface of the jig 21. The metal insert 11 is fixed to the jig 21 by any appropriate means that can easily fix it to the jig 21.

[0032] Next, as shown in FIG. 6, the uncured first fiber reinforced resin sheet 15a is wrapped around a jig 21 and stacked. At this time, at the position of the metal insert 11, the metal insert 11 is exposed from the surface between the continuous fibers so that the fibers do not hang over at least the hole 11a of the metal insert 11. An opening in which the metal insert 11 is to be placed is formed in the first fiber reinforced resin sheet 15a. The opening may be provided in the first fiber reinforced resin sheet 15a in advance, or may be formed by widening the gaps between the continuous fibers when stacking the first fiber reinforced resin sheets 15a. The first fiber reinforced resin sheet 15a is stacked so that at least a portion of the edge of the opening covers part or all of the outer circumferential edge of the metal insert 11.

[0033] 7, an uncured second fiber-reinforced resin sheet 15b is further wound and laminated on the first fiber-reinforced resin sheet 15a. At this time, at the position of the metal insert 11, the metal insert 11 is exposed from the surface between the continuous fibers so that the fibers do not hang over at least the hole 11a of the metal insert 11. Similarly, an opening in which the metal insert 11 is to be placed is formed in the second fiber-reinforced resin sheet 15b. Furthermore, the second fiber-reinforced resin sheet 15b is laminated so that at least a part of the edge (rim) of the opening covers part or all of the outer circumferential edge of the metal insert 11.

[0034] Since the metal insert 11 fixed to the jig 21 has a shape in which the diameter decreases from the jig 21 side toward the outside, when each fiber reinforced resin sheet is wound, the metal insert 11 is pressed toward the jig 21 with the top surface of the metal insert 11 exposed through the gaps between the continuous fibers, which makes it easy for the continuous fibers to slip along the inclined surface of the metal insert 11. Note that the orientation direction of the continuous fibers in the fiber reinforced resin sheet shown in Figures 6 and 7 is an example, and the orientation direction of the continuous fibers is not particularly limited.

[0035] In this manner, an appropriate number of fiber reinforced resin sheets are repeatedly stacked, and the uncured fiber reinforced resin layer 15 is formed while the metal insert 11 is embedded in the fiber reinforced resin layer 15 so that the upper surface of the metal insert 11, including the hole 11a, is exposed on the outer surface of the fiber reinforced resin layer 15, as shown in Fig. 8. At this time, the continuous fibers contained in the uncured fiber reinforced resin layer 15 are arranged without interruption around the upper surface of the metal insert 11. Furthermore, by stacking the fiber reinforced resin sheets so that the orientation directions of the continuous fibers contained in the fiber reinforced resin sheets are crossed, or by using a fiber reinforced resin sheet (cross material) containing continuous fibers oriented in multiple directions, the metal insert 11 can be held down by the continuous fibers so as to surround the periphery of the upper surface of the metal insert 11.

[0036] Next, the uncured fiber reinforced resin layer 15 laminated on the jig 21 is cured, and then the jig 21 is removed, thereby obtaining the fiber reinforced resin structural member 10 as shown in FIG. 9.

[0037] This allows for the production of a structural member 10 in which the metal insert 11 and the fiber-reinforced resin laminate 13 are joined over a relatively large area, and the periphery of the hole 11a, which becomes the connection portion 9 with another member, is strongly reinforced with continuous fibers. Also, because the thickness of the structural member 10 at the connection portion 9 is formed to a thickness determined by the metal insert 11, the positional accuracy of the connection portion 9 can be improved. Furthermore, because the upper surface of the metal insert 11 is exposed at the connection portion 9 with the other member, the accuracy of the shape of the attachment surface with the other member can also be ensured.

[0038] In addition, when stacking fiber-reinforced resin sheets while embedding the metal insert 11, multiple fiber-reinforced resin sheets may be stacked so that one fiber-reinforced resin sheet contacts the surface of the metal insert 11 facing the jig 21 or the surface opposite the jig 21.

[0039] 10 shows an example in which a first fiber-reinforced resin sheet 15c to be laminated first on a jig 21 is arranged so as to be in contact with the metal insert 11, and fiber-reinforced resin sheets to be laminated thereafter are arranged so as not to be in contact with the metal insert 11, thereby forming a fiber-reinforced resin layer 15. By laminating in this manner, it is possible to increase the bonding strength between the metal insert 11 and the fiber-reinforced resin laminate 13 of the structural member 10 obtained by curing the fiber-reinforced resin layer 15.

[0040] Furthermore, the shape of the metal insert is not limited to the example shown in Fig. 2. The metal insert may have any shape as long as a portion thereof comes into contact with the jig 21 during manufacturing of the structural member, the upper surface on which the hole 11a is formed can be exposed to the outer surface when the uncured fiber reinforced resin layer is laminated, and the metal insert can be embedded in the uncured fiber reinforced resin layer.

[0041] FIG. 11 is an explanatory diagram showing another configuration example of a metal insert. FIG. 11 shows a front view and a side view of a metal insert 31. The metal insert 31 has flat surfaces on both axial ends, a large diameter in the axial center, and a diameter that decreases toward both axial ends. The metal insert 31 has a hole 31a formed along the axis. Because the metal insert 31 has a shape in which the diameter decreases toward both axial ends, the contact area between the metal insert 31 and the fiber-reinforced resin laminate 13 increases, thereby increasing the bonding strength between the metal insert 31 and the fiber-reinforced resin laminate 13. Furthermore, because the metal insert 31 has the same shape, fiber-reinforced resin sheets can be stacked so as to sandwich the metal insert 31. This prevents the metal insert 31 from detaching from the fiber-reinforced resin laminate 13 even when a load is applied to the structural member 10 from another member 3.

[0042] 12 to 14 are explanatory views showing a method for manufacturing a structural member provided with the metal insert 31 shown in FIG. When using metal inserts 31, first, as shown in Fig. 12, a plurality of fiber-reinforced resin sheets 15d, each having an opening 16 in which a metal insert 31 is to be placed, are stacked on the molding surface of a jig 21. The openings 16 may be provided in the fiber-reinforced resin sheets 15d in advance, or may be formed by widening the gaps between the continuous fibers when stacking the fiber-reinforced resin sheets 15d. In this case, too, by forming the openings 16 without interrupting the continuous fibers contained in the fiber-reinforced resin sheets 15d, it is possible to prevent a decrease in the strength or rigidity of the structural member.

[0043] Next, as shown in Figure 13, the metal insert 31 is placed in the opening 16 of the fiber reinforced resin sheet 15d so that a portion of the metal insert 31 contacts the jig 21 and at least a portion of the outer edge of the metal insert 31 covers the edge of the opening 16 of the fiber reinforced resin sheet 15d.

[0044] 14, a plurality of fiber reinforced resin sheets 15d each having an opening in which a metal insert 31 is to be placed are stacked so that at least a part of the edge of the opening covers a part of the metal insert 31. The opening may also be provided in the fiber reinforced resin sheets 15d in advance, or may be formed by widening the gaps between the continuous fibers when stacking the fiber reinforced resin sheets 15d.

[0045] As a result, the top surface of the metal insert 31, which has the hole 31a at the center, is exposed to the outside, while the area surrounding the center is sandwiched between the fiber-reinforced resin layers 15. This increases the bonding strength of the metal insert 31, resulting in a structural member with improved strength at the connection portion with other members. Furthermore, even with this metal insert 31, the thickness and shape of the structural member at the connection portion can be manufactured to desired design values, and the accuracy of the shape and position of the connection portion with other members can be improved.

[0046] Furthermore, the method for forming the uncured fiber-reinforced resin layer on the molding surface of the jig 21 is not limited to the lay-up method described in the above embodiment, and any method may be employed. For example, if the structural member is a hollow cylindrical structural member, the uncured fiber-reinforced resin layer may be formed by employing a filament winding method in which continuous fibers are continuously wound around the jig 21.

[0047] 15 is an explanatory diagram showing a state in which continuous fibers are wound around a jig 21 by the filament winding method. Even in the case of the filament winding method, after the metal insert 11 is placed at a predetermined position on the jig 21, the uncured fiber-reinforced resin layer 17 can be formed around the jig 21 by rotating and moving the jig 21 or a mechanism for leading out the continuous fibers in the axial direction while leading out the continuous fibers impregnated with a matrix resin from around the jig 21. Even in this case, since the metal insert 11 has a shape in which the diameter decreases from the jig 21 side toward the outside, the continuous fibers can be easily wound without hanging over the top surface of the metal insert 11.

[0048] Therefore, the upper surface of the metal insert 11 is exposed between the continuous fibers, which increases the accuracy of the position of the connection portion and ensures the accuracy of the shape of the attachment surface with other components. Furthermore, even with the filament winding method, the metal insert 11 can be held down by the continuous fibers so as to surround the periphery of the upper surface of the metal insert 11. Therefore, even if a load is applied to another component in a direction away from the structural component, the metal insert 11 can be prevented from detaching from the fiber-reinforced resin laminate.

[0049] As described above, according to the method for manufacturing a fiber-reinforced resin structural member of this embodiment, a metal insert 11 having a hole 11a is placed at a position on the molding surface of the jig 21 that corresponds to the connection portion with another member, and a fiber-reinforced resin layer is formed while embedding the metal insert 11 in the uncured fiber-reinforced resin layer so that the hole 11a is exposed on the outer surface of the uncured fiber-reinforced resin layer. This eliminates the need to attach a nut plate to the inside of the cylindrical fiber-reinforced resin laminate after forming the fiber-reinforced resin laminate.

[0050] Furthermore, in the structural member manufactured by the manufacturing method according to this embodiment, the connection portion with another member is controlled to a desired design value by the metal insert 11. Therefore, the accuracy of the shape and position of the mounting surface of the other member can be guaranteed.

[0051] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to these examples. It is clear that a person skilled in the art to which the present disclosure pertains can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these naturally fall within the technical scope of the present disclosure. Furthermore, combinations of the above-described embodiments and each modified example also naturally fall within the technical scope of the present disclosure.

[0052] For example, in the above embodiment, the metal insert 11 is used with the hole 11a formed in advance, but the hole into which the fastening member for attaching another member is inserted may be formed after the structural member is molded. In this case, the uncured fiber-reinforced resin layer may be formed so that the location of the hole in the metal insert is exposed on the outer surface. [Explanation of symbols]

[0053] 5: Fastening member, 9: Connection portion, 10: Fiber reinforced resin structural member, 11: Metal insert, 11a: Hole portion, 13: Fiber reinforced resin laminate, 15: Fiber reinforced resin layer, 15a: First fiber reinforced resin sheet, 15b: Second fiber reinforced resin sheet, 16: Opening, 21: Jig

Claims

1. A method for manufacturing a fiber-reinforced resin structural member having a connection portion including a hole portion into which a fastening member is inserted, comprising: forming an uncured fiber reinforced resin layer containing an uncured matrix resin and reinforced fibers on a molding surface of a jig; a step of curing the matrix resin to form the fiber-reinforced resin structural member; and removing the jig from the fiber-reinforced resin structural member, In the step of forming the uncured fiber reinforced resin layer, A method for manufacturing a fiber-reinforced resin structural member, comprising: embedding a metal insert having the hole portion or a location where the hole portion is to be formed, the metal insert having a cone-shaped portion whose diameter decreases in a direction from the jig side to away from the jig, into the uncured fiber-reinforced resin layer so that a portion of the metal insert contacts the jig and the hole portion or the location where the hole portion is to be formed is exposed on an outer surface of the uncured fiber-reinforced resin layer that does not contact the jig.

2. The metal insert has a conical shape with a maximum diameter at the portion in contact with the jig and a minimum diameter at the portion farthest from the jig; In the step of forming the uncured fiber reinforced resin layer, After the metal insert is placed on the molding surface of the jig, 2. A method for manufacturing a fiber-reinforced resin structural member according to claim 1, wherein a plurality of fiber-reinforced resin sheets, each having an opening in which the metal insert is placed, are stacked so that at least a portion of the edge of the opening covers the inclined surface of the conical metal insert.

3. A method for manufacturing a fiber-reinforced resin structural member having a connection portion including a hole portion into which a fastening member is inserted, comprising: forming an uncured fiber reinforced resin layer containing an uncured matrix resin and reinforced fibers on a molding surface of a jig; a step of curing the matrix resin to form the fiber-reinforced resin structural member; and removing the jig from the fiber-reinforced resin structural member, In the step of forming the uncured fiber reinforced resin layer, A metal insert having the hole portion or a planned location for forming the hole portion, wherein the diameter of the first cone-shaped portion is maximum at the axial center and the diameter decreases toward the jig in the axial direction, and a second cone-shaped portion having a diameter decreasing toward the jig in the axial direction. A plurality of fiber-reinforced resin sheets each having an opening in which the metal insert having the metal insert is placed are stacked on the molding surface of the jig, The metal insert is placed in the opening of the fiber reinforced resin sheet so that a portion of the metal insert contacts the jig, the hole or the planned formation location of the hole is exposed on an outer surface of the uncured fiber reinforced resin layer that does not contact the jig, and the inclined surface of the first cone-shaped portion of the metal insert covers the edge of the opening of the fiber reinforced resin sheet, A method for manufacturing a fiber-reinforced resin structural member further comprising stacking a plurality of fiber-reinforced resin sheets, each having an opening into which the metal insert is placed, so that at least a portion of the edge of the opening covers the inclined surface of the second cone-shaped portion of the metal insert, thereby forming the uncured fiber-reinforced resin layer.

4. The plurality of fiber-reinforced resin sheets are stacked so that one fiber-reinforced resin sheet contacts the jig-side surface or the surface opposite the jig side of the metal insert. A method for manufacturing a fiber-reinforced resin structural member according to claim 2 or 3.

5. The metal insert has a conical shape with a maximum diameter at the portion in contact with the jig and a minimum diameter at the portion farthest from the jig; The fiber-reinforced resin structural member is a hollow cylindrical structural member, In the step of forming the uncured fiber reinforced resin layer, 2. The method for manufacturing a fiber-reinforced resin structural member according to claim 1, wherein the metal insert is placed on the molding surface of the jig, and then the uncured fiber-reinforced resin layer is formed by a filament winding method so as to cover the inclined surface of the conical metal insert.

Images