Method for forming structure

Abstract

A method for molding a structure capable of improving the tensile strength of a jointed structure is provided. A jointed structure capable of improving strength is also provided. In the method for molding a structure, in a setting step, first and second prepregs 11f, 11s are provided in a cavity C. The first and second prepregs 11f, 11s overlap in a specific range SA in a third direction perpendicular to the first and second directions, where a first direction in which the first carbon fibers 11b extend and a second direction in which the second carbon fibers 11b extend cross each other. In a mold clamping step, after the setting step, the first mold 23 and the second mold 25 are clamped. In a pressurizing step, pressure is applied so that the first and second prepregs 11f, 11s are integrated in the cavity C. In an injection step, an injection material 39 is injected into the cavity C. In a hole drilling step, a needle 27 is inserted from a tip portion 27a into the specific range SA in a third direction, and a connection hole 51a is formed by the needle 27.

Description

[Technical field]

[0001] The present invention relates to a method for forming a structure. By law Regarding. [Background technology]

[0002] A conventional joint structure is disclosed in Patent Document 1. This joint structure is formed by joining two CFRP (Carbon Fiber Reinforced Plastics) structures having carbon fibers in a matrix made of a thermoplastic resin or a thermosetting resin with each other by a rivet.

[0003] Compared to metal structures, CFRP structures are lightweight yet strong, and have excellent fatigue and corrosion properties. In particular, a joined structure in which multiple CFRP structures are joined with rivets does not require the use of adhesives, and therefore exhibits advantages such as shortened joining time, low cost, and high durability. For this reason, joined structures are expected to be widely used in parts in fields such as automobiles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2012 / 117737 Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the above-mentioned conventional joined structure is obtained by punching two structures together with a rivet, the carbon fibers in each structure are easily cut by the rivet, and the tensile strength in the direction along the joint surface of the structures is impaired.

[0006] In particular, in a joined structure in which the carbon fibers in the first structure extend in a first direction and the carbon fibers in the second structure extend in a second direction intersecting the first direction, such as perpendicular to the first direction, and the first and second structures are joined as described above, the carbon fibers in the first structure are easily cut in the first direction by the joining holes through which the rivets penetrate, and the carbon fibers in the second structure are also easily cut in the second direction by the same joining holes, resulting in a decrease in the tensile strength of the joined structure in both the first and second directions.

[0007] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a method for forming a structure that can improve the tensile strength of a joint structure. Another aim of the present invention is to provide a joint structure that can improve its strength. [Means for solving the problem]

[0008] The method for forming the structure of the first teaching is to form a unidirectional molded structure in a first base material made of a first thermoplastic resin. only A first prepreg having a plurality of first carbon fibers extending in one direction and a second matrix made of a second thermoplastic resin. only a preparation step of preparing a second prepreg having a plurality of second carbon fibers extending in a direction parallel to the axis of the first mold, a first mold, a second mold forming a cavity together with the first mold, and a needle having a pointed tip; a setting process of providing the first prepreg in the cavity and providing the second prepreg in the cavity such that a first direction in which the first carbon fibers extend and a second direction in which the second carbon fibers extend intersect and overlap within a specific range in a third direction perpendicular to the first direction and the second direction; a mold clamping step of clamping the first mold and the second mold after the setting step; a pressurizing step of pressurizing the first prepreg and the second prepreg so as to integrate them in the cavity during or after the mold clamping step; The method further comprises a step of inserting the needle from the tip portion into the specific area in the third direction during or after the pressurizing step to form a connection hole with the needle.

[0009] In the molding method of the first teaching, in the setting process, the first direction in which the first carbon fiber extends and the second direction in which the second carbon fiber extends are crossed, and in the mold clamping process, the first prepreg and the second prepreg are integrated together, making it possible to mold structures such as trusses.

[0010] In particular, in the hole drilling process, the needle is inserted from its sharp tip in the third direction into the specific area where the first prepreg and the second prepreg overlap, so that the first carbon fiber in the first prepreg is gradually pushed outward from the needle by the tip of the needle in the first base material, and the second carbon fiber in the second prepreg is also gradually pushed outward from the needle by the tip of the needle in the second base material. Therefore, both the carbon fiber in the first prepreg and the carbon fiber in the second prepreg are difficult to cut. In this way, the resulting structure has a connection hole in which cutting of the surrounding carbon fibers is suppressed.

[0011] In addition, in the molding method of the first teaching, the first prepreg and the second prepreg are restrained within the cavity while the hole drilling process is performed, which is an insert PCM (Pre-Preg Compression Molding) method, and the structure is less likely to deform and has high dimensional accuracy.

[0012] The second teaching is a method for molding a structure, which includes a first matrix material made of a first thermoplastic resin and a plurality of first carbon fibers extending in only one direction. The first carbon fiber is a rod-shaped carbon fiber that is long in a first direction in which the first carbon fiber extends. A first prepreg; A rod-shaped second prepreg having a plurality of second carbon fibers extending in only one direction within a second base material made of a second thermoplastic resin, the second prepreg being long in a second direction in which the second carbon fibers extend; a preparation step of preparing a first mold, a second mold forming a cavity together with the first mold, a needle having a sharp tip, and an injection material including a third thermoplastic resin to be injected into the cavity; The first prepreg is provided in the cavity. and placing the second prepreg in the cavity so as to overlap in a third direction perpendicular to the first direction and the second direction in a specific range where the first direction and the second direction intersect. A setting process for providing the a mold clamping step of clamping the first mold and the second mold after the setting step; During or after the mold clamping process, With respect to the specified range The needle is Record number a hole making step of making a connection hole with the needle by entering the needle in three directions; and an injection step of injecting the injection material into the cavity during or after the hole drilling step, The third thermoplastic resin is the first thermoplastic resin. and the second thermoplastic resin It has a higher melting point than The injection step is characterized in that the injection material is injected while leaving the needle in the connection hole.

[0013] In the molding method of the second teaching, in the hole punching step, the needle is inserted from its sharp tip in the third direction into a specific area of ​​the first prepreg, so that the first carbon fiber in the first prepreg is gradually pushed radially outward by the tip of the needle within the first base material, making it difficult for the carbon fiber in the first prepreg to be cut.

[0014] hole Since the injection process is performed during or after the punching process, this is an insert injection molding method, and the first prepreg and the injection material are molded integrally in the structure, which makes it more practical. In particular, since the injection material is injected into the cavity, the injection material also molds the connection holes, and the connection holes can be shaped to a desired shape. If the injection process is performed during the punching process, the first thermoplastic resin of the first prepreg can be heated so as to be softened by the temperature of the injection material, and the need to soften a specific range of the first thermoplastic resin during the punching process can be reduced or eliminated. Furthermore, if the injection process is performed during the punching process, the molding cycle time of the structure can be shortened, and the manufacturing cost can be reduced.

[0015] In this way, the resulting structure is prevented from cutting the surrounding carbon fibers and has a connection hole of a preferred shape.

[0016] The structures obtained by the molding methods of the first and second teachings are made of thermoplastic resin and carbon fiber, and are therefore called CFRTP (Carbon Fiber Reinforced Thermo Plastics, also known as thermoplastic CFRP (Carbon Fiber Reinforced Plastics)). Compared to metal structures, these structures are lightweight yet strong, and also have excellent fatigue properties and corrosion resistance.

[0017] The bonded structure of the third teaching is a structure obtained by the above molding method, and the structure is laminated, connection a mating member having an insertion hole that aligns with the hole; The connection hole and the insertion hole have a plurality of fifth carbon fibers extending in one direction within a fifth base material made of a fifth thermoplastic resin, The fifth carbon fiber is long in the third direction in which the fifth carbon fiber extends, The structure is characterized in that a rivet is provided to join the structure and the mating member.

[0018] The joint structure of the third teaching is made by joining the structure obtained in the first and second teachings to the mating material with rivets, so the tensile strength in the direction along the joint surface of the structure is unlikely to be impaired. In addition, since this joint structure does not require the use of adhesive, it exhibits advantages such as shortening the joining time, reducing costs, and providing high durability. Effect of the Invention

[0019] According to the method for molding a structure of the present invention, it is possible to obtain a joined structure having improved tensile strength. Also, according to the joined structure of the present invention, it is possible to improve the strength. [Brief description of the drawings]

[0020] [Figure 1] FIG. [Diagram 2] FIG. 11 is a schematic cross-sectional view showing a first mold, a second mold, and a needle during a preparation step according to a reference example. [Diagram 3] FIG. 11 is a schematic cross-sectional view according to a reference example showing a first mold, a second mold, a needle, a first prepreg, and a second prepreg during a setting step. [Figure 4] 5A to 5C are schematic cross-sectional views showing a first mold, a second mold, a needle, a first prepreg, and a second prepreg during a mold clamping step and a pressure application step according to a reference example. [Diagram 5] FIG. 11 is a schematic enlarged cross-sectional view of a first prepreg and a second prepreg at an early stage of a clamping step and a pressurizing step according to a reference example. [Figure 6] FIG. 4 is a schematic enlarged cross-sectional view of a first prepreg and a second prepreg at the end of a mold clamping step and a pressure step according to a reference example. [Figure 7] FIG. 4 is a schematic cross-sectional view according to a reference example showing a first mold, a second mold, a needle, a first prepreg, and a second prepreg during a hole-making step. [Figure 8] FIG. 11 is a schematic enlarged cross-sectional view of a first prepreg, a second prepreg, and a needle during a hole punching step according to a reference example. [Figure 9] FIG. 2 is an enlarged cross-sectional view of a main portion of a structure obtained by the molding method of the reference example. [Figure 10] FIG. 2 is an enlarged plan view of a part of a cross section showing a structure obtained by the molding method of the reference example. [Figure 11] FIG. 2 is an enlarged, partially sectional, back view of a structure obtained by the molding method of the reference example. [Figure 12] FIG. 1 is a plan view of a structure obtained by the molding method of a reference example. [Figure 13] FIG. 2 is a cross-sectional view of a structure obtained by the molding method of the reference example and a counterpart material. [Figure 14] FIG. 4 is a cross-sectional view of a main part of a joint structure according to a reference example. [Figure 15] FIG. 2 is a schematic cross-sectional view showing a first mold, a second mold, and a needle during a preparation step according to the first embodiment. [Figure 16] 4 is a schematic cross-sectional view showing a first mold, a second mold, a needle, and a first prepreg during a setting step and a mold clamping step in Example 1. FIG. [Figure 17] 3 is a schematic cross-sectional view illustrating a first mold, a second mold, a needle, a first prepreg, and an injected material during an injection process and a hole punching process according to the first embodiment. FIG. [Figure 18]FIG. 2 is a cross-sectional view of two structures obtained by the molding method of Example 1 and a counterpart material. [Figure 19] FIG. 2 is a cross-sectional view of a main portion of the joined structure of Example 1. [Figure 20] FIG. 11 is a schematic cross-sectional view showing the first mold, the second mold, and the needle during a preparation step according to the second embodiment. [Figure 21] FIG. 11 is a schematic cross-sectional view according to Example 2, showing a first mold, a second mold, a needle, a first prepreg, and a second prepreg during a setting step. [Figure 22] 10 is a schematic cross-sectional view according to Example 2, showing a first mold, a second mold, a needle, a first prepreg, and a second prepreg during a mold clamping step and a pressure applying step. FIG. [Figure 23] FIG. 11 is a schematic cross-sectional view according to Example 2, showing a first mold, a second mold, a needle, a first prepreg, a second prepreg, and an injected material during an injection process and a hole punching process. [Figure 24] FIG. 11 is a cross-sectional view of a structure obtained by the molding method of Example 2 and a counterpart material. [Diagram 25] FIG. 6 is a cross-sectional view of a main portion of a joined structure of Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In the first to third teachings, the first thermoplastic resin constituting the first base material of the first prepreg, the second thermoplastic resin constituting the second base material of the second prepreg, the third thermoplastic resin constituting the injection material, the fourth thermoplastic resin capable of constituting the needle, and the fifth thermoplastic resin constituting the fifth base material of the rivet may be polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAC), polyurethane (PUR), polytetrafluoroethylene (PTFE), acrylonitrile butadiene styrene (ABS) resin, acrylonitrile styrene copolymer (AS resin), acrylic (PMM), etc. A) resin, polyamide (PA), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (modified PPE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), cyclic polyolefin (COP), polyphenylene sulfide (PPS), polysulfone (PSF), polyethersulfone (PES), amorphous polyarylate (PAR), polyaryletherketone (PAEK), polyetherketoneketone (PEKK), polyetheretherketone (PEEK), thermoplastic polyimide (PI), polyamideimide (PAI), etc. can be used. The first to fifth thermoplastic resins may be the same or different.

[0022] In the first to third teachings, the first, second, fourth, and fifth carbon fibers are filaments. The first, second, fourth, and fifth carbon fibers may be PAN (Polyacrylonitrile)-based or pitch-based. The first, second, fourth, and fifth carbon fibers may have the same diameter or different diameters. The number and density of the first carbon fibers in the first prepreg, the number and density of the second carbon fibers in the second prepreg, the number and density of the fourth carbon fibers that may be in the needle, and the number and density of the fifth carbon fibers in the rivet may be the same or different.

[0023] In the first and second teachings, the first and second prepregs may be so-called semipregs in which the carbon fibers are incompletely impregnated with the thermoplastic resin, in addition to those in which the carbon fibers are completely impregnated with the thermoplastic resin. The first and second prepregs may be rods such as prismatic or cylindrical rods, or may be sheets. It is also possible to use third and fourth prepregs similar to the first and second prepregs. In addition, the shape of the structure is not limited in the molding direction of the first and second teachings.

[0024] In the first teaching, the pressurizing step may be performed during or after the mold clamping step. If the pressurizing step is performed during the mold clamping step, the molding cycle time of the structure can be shortened, and the manufacturing cost can be reduced. If the pressurizing step is performed after the mold clamping step, the pressure can be easily adjusted.

[0025] In the first teaching, the hole-making step may be performed during or after the pressurizing step. If the hole-making step is performed during the pressurizing step, the molding cycle time of the structure can be shortened, and the manufacturing cost can be reduced.

[0026] In the first teaching, the preparation step may prepare an injection material containing a third thermoplastic resin to be injected into the cavity. The molding method preferably includes an injection step of injecting the injection material into the cavity before, during, or after the hole-making step. In this case, the method is an insert injection molding method, and the structure is not only integrated with the first prepreg and the second prepreg, but is also molded by the injection material, which increases the practicality. In particular, since the injection material is injected into the cavity, the injection material also molds the connection holes, and the connection holes can be arranged in a preferred shape. If the injection step is performed during the hole-making step, the first thermoplastic resin of the first prepreg and the second thermoplastic resin of the second prepreg can be heated so as to be softened by the temperature of the injection material, and the need to soften the first thermoplastic resin and the second thermoplastic resin in a specific range during the hole-making step can be reduced or eliminated. In addition, if the injection step is performed during the hole-making step, the molding cycle time of the structure can be shortened, and the manufacturing cost can be reduced.

[0027] In the first teaching, the third thermoplastic resin preferably has a melting point higher than the first and second thermoplastic resins, in which case the first and second thermoplastic resins are reliably softened or melted by the temperature of the injected material, increasing the integrity of the structure and improving the dimensional accuracy of the structure including the connection holes.

[0028] In the first teaching, in the pressurizing step, it is preferable to heat so that the first thermoplastic resin and the second thermoplastic resin in a specific range are softened. In this case, the first base material of the first prepreg and the second base material of the second prepreg are more likely to be integrated. The heating temperature is preferably equal to or higher than the thermal deformation temperature of at least one of the first thermoplastic resin and the second thermoplastic resin. It may be equal to or lower than the melting point of at least one of the first thermoplastic resin and the second thermoplastic resin.

[0029] In the first teaching, in the hole making step, it is preferable to heat the first and second thermoplastic resins in a specific range so that they are softened. If the injection step is not performed before or during the hole making step, the first and second carbon fibers are more likely to move in the first and second base materials by the tip of the needle, and are less likely to be cut. The heating temperature is preferably equal to or higher than the thermal deformation temperature of at least one of the first and second thermoplastic resins. It may be equal to or lower than the melting point of at least one of the first and second thermoplastic resins.

[0030] In the second teaching, the third thermoplastic resin preferably has a higher melting point than the first thermoplastic resin, in which case the first thermoplastic resin is softened or melted by the temperature of the injected material, increasing the integrity of the structure and improving the dimensional accuracy of the structure including the connection holes.

[0031] In the second teaching, in the preparation step, a second base material made of a second thermoplastic resin is formed in one direction. onlyA second prepreg having a plurality of second carbon fibers extending in a direction perpendicular to the first direction can be prepared. In the setting step, it is preferable to provide the second prepreg in the cavity so that the first direction in which the first carbon fibers extend and the second direction in which the second carbon fibers extend intersect in a specific range and overlap in a third direction. In the hole drilling step, it is preferable to insert a needle from its tip into the specific range in the third direction to form a connection hole with the needle. In this case, a connection hole can be formed in a structure that integrally includes the first prepreg and the second prepreg.

[0032] In the second teaching, the third thermoplastic resin preferably has a melting point higher than the first and second thermoplastic resins, in which case the first and second thermoplastic resins soften or melt depending on the temperature of the injected material, increasing the integrity of the structure and improving the dimensional accuracy of the structure including the connection holes.

[0033] In the second teaching, it is preferable to apply pressure to integrate the first and second prepregs in the cavity during the mold clamping process, which increases the integrity of the structure and improves the dimensional accuracy of the structure including the connection holes.

[0034] In the first and second teachings, the needle has a plurality of fourth carbon fibers extending in one direction in a fourth matrix made of a fourth thermoplastic resin. The fourth carbon fiber is long in the third direction. In this case, the needle can be used as a CFRTP rivet as it is.

[0035] In the first and second teachings, it is preferable that the first direction and the second direction are perpendicular to each other in the setting step. In this case, a structure with high strength can be obtained without the need to weave the carbon fibers.

[0036] In the first and second teachings, the first prepreg and the second prepreg are rod-shaped, and the specific range can be a portion where the first prepreg and the second prepreg intersect. In this case, if a truss or lattice-shaped structure is molded, the joining holes are also formed in the intersecting portions, so that the joined structure can be widely applied to automobiles, aircraft, spacecraft, ships, trains, buildings, etc.

[0037] The joint structure of the third teaching has a high peel strength in the third direction because the rivet is also made of CFRTP. The shaft or intermediate body disclosed in Patent No. 6840410 or Patent No. 6901063 can be used as the CFRTP rivet, and the fastening method and fastening device disclosed in these documents can be used.

[0038] In the third teaching, the mating material may be a metal, a CFRTP, or a thermosetting CFRP, so long as it has an insertion hole that matches the joining hole.

[0039] below, Reference examples and Specific embodiments of the present invention 1, 2 and The following will explain this with reference to the drawings.

[0040] ( Reference example ) Reference example The present invention embodied the first teaching, which does not include an injection process, and the third teaching. First, in a preparation process, a plurality of prepregs 11 shown in FIG. 1(A) were prepared. These prepregs 11 are rod-shaped in the shape of a rectangular column, and have a plurality of carbon fibers 11b extending only in the length direction within a base material 11a. The base material 11a is a thermoplastic resin. These prepregs 11 correspond to the first and second prepregs 11f and 11s, the base material 11a corresponds to the first and second base materials 11a made of the first and second thermoplastic resins, and the carbon fibers 11b correspond to the first and second carbon fibers 11b.

[0041] 2, a molding device 21 was prepared. The molding device 21 was equipped with a first die 23, a second die 25, and a plurality of needles 27. The first die 23 and the second die 25 were designed to be movable relative to each other to clamp the die.

[0042] A first molding surface 23a is recessed from the parting surface 21a of the first mold 23. As shown in Figures 12 and 13, the first molding surface 23a is adapted to fit three first prepregs 11f extending in the left-right direction of the page. Reference example12 and 13, the left-right direction on the paper is the first direction.

[0043] 2, second mold 25 has second molding surface 25a recessed from parting surface 21b. First molding surface 23a of first mold 23 and second molding surface 25a of second mold 25 form cavity C. Second molding surface 25a is made up of three first portions 251a, three second portions 252a, and an infinite number of third portions 253a.

[0044] The first portion 251a faces the first molding surface 23a, and three first prepregs 11f are fitted in the left-right direction of the paper as shown in Figures 12 and 13. The sum of the depth of the first molding surface 23a from the parting surface 21a and the depth of the first portion 251a from the parting surface 21b is equal to the thickness of the first prepregs 11f.

[0045] 2, the second portion 252a is recessed to be continuous with the first portion 251a. The second portion 252a is adapted to fit three second prepregs 11s extending in the vertical direction of the paper in FIG. 12 and in the thickness direction of the paper in FIG. Reference example In this case, the second direction is the up-down direction of the paper in Fig. 12 and the thickness direction of the paper in Fig. 2 and Fig. 13. Therefore, the first prepreg 11f and the second prepreg 11s are perpendicular to each other and overlap each other in nine specific areas SA.

[0046] As shown in Fig. 2, the length from the bottom surface of the first molding surface 23a to the bottom surface of the second portion 252a is smaller than the sum of the thickness of the first prepreg 11f and the thickness of the second prepreg 11s. Therefore, when the first mold 23 and the second mold 25 are clamped by matching the mold parting surface 21a and the mold parting surface 21b, the first prepreg 11f and the second prepreg 11s are pressurized in the specific range SA and integrated, but the first prepreg 11f and the second prepreg 11s have excess material in each specific range SA. Therefore, the third portion 253a is formed between the first portion 251a and the second portion 252a, and the material is molded in each third portion 253a.

[0047] The first die 23 is provided with a needle hole 23b extending vertically toward each specific range SA. The second die 25 is also provided with a needle hole 25b extending vertically toward each specific range SA so as to coincide with the needle hole 23b. A metal needle 27 is movably provided in each needle hole 23b, 25b. The needle 27 is composed of a conically pointed tip portion 27a and a cylindrical portion 27b extending cylindrically coaxially with the tip portion 27a. The needle 27 in the needle hole 23b protrudes from the tip portion 27a into the cavity C and can protrude until the cylindrical portion 27b is positioned within the cavity C.

[0048] Moreover, heating holes 23c are formed around each needle hole 23b in the first die 23. Moreover, heating holes 25c are formed around each needle hole 25b in the second die 25. The heating holes 23c around each needle hole 23b and the heating holes 25c around each needle hole 25b are connected to each other so that a heat medium such as oil at a predetermined temperature can be circulated.

[0049] In the setting step, as shown in Fig. 3, a first prepreg 11f is provided in the cavity C, and a second prepreg 11s is provided. Specifically, the first prepreg 11f is fitted to the first molding surface 23a of the first mold 23, and the second prepreg 11s is fitted to the second part 252a of the second mold 23. The first prepreg 11f and the second prepreg 11s are overlapped in a third direction perpendicular to the first and second directions in each specific range SA. The third direction is the up-down direction on the paper surface of Fig. 3.

[0050] In the mold clamping process and pressurizing process, while circulating a high-temperature heat medium through the heating holes 23c and 25c, the first mold 23 and the second mold 25 are clamped together as shown in FIG. 4, and the first prepreg 11f and the second prepreg 11s are pressurized to integrate them in the cavity C. At this time, as shown in FIG. 5, the first prepreg 11f and the second prepreg 11s first come into contact with each other in the specific range SA. Furthermore, when the clamping of the first mold 23 and the second mold 25 is completed, the first prepreg 11f and the second prepreg 11s are pressurized in the specific range SA as shown in FIG. 6, and the material is left over. The left over material is molded in each third portion 253a of the second mold 25.

[0051] During this time, the first and second thermoplastic resins of the first and second prepregs 11f and 11s in the specific range SA are softened by the temperature of the heat medium. The heating temperature is appropriately set depending on the thermoplastic resins of the first and second prepregs 11f and 11s. Therefore, the first and second carbon fibers 11b are relatively flexibly deformed and are not damaged. In this way, the first base material 11a of the first prepreg 11f and the second base material 11a of the second prepreg 11s are suitably integrated by the insert PCM method while suppressing damage to the first and second carbon fibers 11b.

[0052] Then, in the hole making process, while circulating a high-temperature heat medium through the heating holes 23c and 25c, the needle 27 is inserted into the specific range SA from the tip 27a in the third direction as shown in Figures 7 and 8. As a result, the first carbon fiber 11b in the first prepreg 11f is gradually pushed outward radially from the needle 27 by the tip 27a of the needle 27 within the first base material 11a. Also, the second carbon fiber 11b in the second prepreg 11s is gradually pushed outward radially from the needle 27 by the tip 27a of the needle 27 within the second base material 11a.

[0053] During this time, the first and second thermoplastic resins of the first and second prepregs 11f and 11s in the specific range SA are softened by the temperature of the heat medium. Therefore, the first and second carbon fibers 11b are easily moved by the tip 27a of the needle 27 within the first and second base materials 11a and are less likely to be cut. In this way, the resulting structure 51 has a connection hole 51a in which cutting of the surrounding first and second carbon fibers 11b is suppressed.

[0054] While leaving the needles 27 in each connecting hole 51a, the circulation of the high-temperature heat medium to the heating holes 23c, 25c is stopped and a low-temperature heat medium is circulated to the heating holes 23c, 25c, or the circulation of the high-temperature heat medium to the heating holes 23c, 25c is stopped and time is allowed to pass, and the first and second thermoplastic resins in the specific range SA are brought to room temperature. Then, the first mold 23 and the second mold 25 are opened, and a structure 51 is obtained. The connecting holes 51a shown in Figures 9 to 11 are formed in this structure 51.

[0055] In addition, in this molding method, the hole punching process is performed while the first prepreg 11f and the second prepreg 11s are bound and integrated within the cavity C, so that the structure 51 is less likely to deform and has high dimensional accuracy. In addition, since the pressurizing process is performed during the mold clamping process, the molding cycle time of the structure 51 can be shortened, and the manufacturing cost can be reduced.

[0056] Since the structure 51 is made of CFRTP, it is lighter and stronger than a metal structure, and has excellent fatigue and corrosion resistance. In particular, the structure 51 has a first prepreg 11f having a plurality of first carbon fibers 11b extending in a first direction in the first matrix 11a made of a first thermoplastic resin, and the second prepreg 11s having a plurality of second carbon fibers 11b extending in a second direction in the second matrix 11a made of a first thermoplastic resin, so that the structure 51 can exhibit high tensile strength in the first and second directions. In addition, since the first and second directions are perpendicular to each other, the structure 51 has high strength without the need to weave the 1.2 carbon fibers 11b. Furthermore, since the first prepreg 11f and the second prepreg 11s are made of the same type of thermoplastic resin, the matrix 11a is easily softened in the mold clamping process and the hole punching process, and the structure 51 is easily integrated.

[0057] Then, in the joining process, as shown in FIG. Reference example The structure 51 and the mating member 61 obtained in step 1 are joined by a CFRTP rivet 71 to form a joined structure 81. In this case, the fastening method and fastening device disclosed in Japanese Patent No. 6840410 and Japanese Patent No. 6901063 are adopted.

[0058] The rivet 71 is composed of a first head 71a, a second head 71b, and a shaft 71c integral with the first head 71a and the second head 71b. The first head 71a, the second head 71b, and the shaft 71c are composed of a fifth base material 71d made of a fifth thermoplastic resin and a fifth carbon fiber 71e extending in the third direction. Although a metal plate is used as the mating material 61, it may be CFRTP or thermosetting CFRP.

[0059] The joint structure 81 obtained in this manner has a rivet 71 that is also CFRTP, and in particular, exhibits high peel strength in the third direction as well, since the first head 71a, the second head 71b, and the fifth carbon fiber 71e in the shaft 71c are not cut.

[0060] Reference exampleIt is also possible to make the needle 27 not of metal but of CFRTP and leave it in the structure 51, and to join the structure 51 and the mating material 61 by transforming the needle 27 into a rivet 71, thereby forming a joined structure 81.

[0061] the above Reference example In the above, the first and second thermoplastic resins are heated and softened in the pressurizing step and the hole-making step, but depending on the types of the first and second thermoplastic resins, the pressurizing step and the hole-making step may be performed at room temperature.

[0062] In addition, Reference example In the above, the hole-making step was performed after the pressurizing step, but the hole-making step may be performed simultaneously with the pressurizing step. In this case, the molding cycle time of the structure 51 can be shortened, and the manufacturing cost can be reduced.

[0063] Note that a heater wire may be provided in the heating hole 23c or the heating hole 25c of the molding device 21. Also, the first die 23 and the second die 25 may not be provided with the heating hole 23c or the heating hole 25c, and only the needle 27 may be heated and inserted into the needle hole 23b, 25b.

[0064] Example 1 ) Working Example 1 This is a concrete embodiment of the second teaching in which the second prepreg is not prepared, and the third teaching. First, in the preparation step, Reference example Similarly, a plurality of prepregs 11 shown in FIG. 1(A) were prepared.

[0065] 15, a molding device 33 was prepared. The molding device 33 includes a first die 35, a second die 37, and a plurality of needles 27. The first die 35 and the second die 37 are capable of moving relative to each other to clamp the die.

[0066] The first mold 35 has a first molding surface 35a recessed from the parting surface 21a. The first molding surface 35a is Reference example Similarly, the three first prepregs 11f are fitted together by extending in the left-right direction of the paper.

[0067] A second molding surface 37a is recessed from the parting surface 21b of the second mold 37. The first molding surface 35a of the first mold 35 and the second molding surface 37a of the second mold 37 form a cavity C. The second molding surface 37a is composed of three first portions 371a and a second portion 372a.

[0068] The first portion 371a faces the first molding surface 35a and is adapted to fit in the left-right direction of the paper surface of the three prepregs 11. The sum of the depth of the first molding surface 35a from the parting surface 21a and the depth of the first portion 371a from the parting surface 21b is equal to the thickness of the prepregs 11. The second portion 372a is spaced apart from the top, right, left, front and rear surfaces of each prepreg 11 when the bottom surface of each prepreg 11 is in contact with the bottom surface of the first molding surface 35a.

[0069] The first and second dies 35 and 37 are formed with needle holes 35b and 37b. The needle holes 35b and 37b are configured as follows: Reference example The first and second dies 35 and 37 have the same needle holes 23b and 25b. Reference example The heating holes 23c and 25c of the first and second molds 23 and 25 are not formed. Reference example This is similar to the molding device 21.

[0070] Furthermore, an injection material 39 was prepared. The injection material 39 contains a third thermoplastic resin and is in a molten state, and is to be injected into the cavity C from a gate (not shown). The third thermoplastic resin of the injection material 39 has a higher melting point than the thermoplastic resin of the prepreg 11.

[0071] In the setting step, as shown in Fig. 16, the prepreg 11 is provided in the cavity C. In addition, in the mold clamping step, the first mold 35 and the second mold 37 are clamped together.

[0072] Then, in the injecting process and the hole-making process, as shown in Fig. 17, the injection material 39 is injected into the cavity C. At the same time, the needle 27 is advanced from the tip 27a into the specific range SA in the third direction so that the cylindrical portion 27b of the needle 27 reaches the needle hole 37b while penetrating the injected material 39 in the cavity C. Therefore, the carbon fibers 11b in the prepreg 11 are gradually pushed radially outward from the needle 27 by the tip 27a of the needle 27 within the base material 11a. Therefore, the carbon fibers 11b of the prepreg 11 are less likely to be cut.

[0073] At this time, since the injection process is performed during the hole punching process, the thermoplastic resin in the specific range SA is softened by the temperature of the injection material 39, and the carbon fibers 11b are easily moved in the base material 11a by the tip 27a of the needle 27, and are less likely to be cut. During this time, it is possible to eliminate the need to soften the thermoplastic resin in the specific range SA. In addition, even if the connection hole 53a formed in the prepreg 11 by the needle 27 becomes an undesirable shape, the injection material 39 is injected in the injection process while leaving the needle 27 in the connection hole 53a, so that the insert injection molding method is performed and the connection hole 53a can be adjusted to a desirable shape by the injection material 39. In addition, if the injection process is performed during the hole punching process, the molding cycle time of the structure 53 can be shortened, and the manufacturing cost can be reduced.

[0074] The thermoplastic resin and the injection material 39 are brought to room temperature, and the first mold 35 and the second mold 37 are opened to obtain structures 53. The obtained structures 53 are made of the prepreg 11 and the injection material 39 provided on five surfaces of the prepreg 11 except for the bottom surface. In each structure 53, cutting of the surrounding carbon fibers 11b is suppressed, and a connection hole 53a having a preferable shape is formed.

[0075] As shown in FIG. 18, three structures 53 are arranged in the thickness direction of the paper and in the left-right direction. Reference exampleSimilarly, a counterpart material 61 was prepared. The prepregs 11 of the structures 53 arranged in the thickness direction of the paper correspond to the first prepregs 11f, and the prepregs 11 of the structures 53 arranged in the left-right direction of the paper correspond to the second prepregs 11s.

[0076] And, as shown in Figure 19, Reference example Similarly, each structure 53 and the counterpart member 61 were joined by a CFRTP rivet 71. In this manner, a joined structure 83 was obtained.

[0077] Working Example 1 Structure 53 of Reference example The same effect as that of the embodiment can be obtained. 1 The joint structure 83 Reference example The same effect can be achieved.

[0078] Working Example 1 The needle 27 is not necessarily made of metal, but is made of CFRTP and left in the structure 53. The needle 27 can be transformed into a rivet 71 to join the structure 53 and the mating material 61 to form a joined structure 83.

[0079] Working Example 1 So, the injection process was carried out during the hole drilling process, hole The injection step may be performed after the punching step, in which case the needle 27 remains in the cavity C and the injected material 39 also forms a connecting hole.

[0080] Example 2 ) Working Example 2 The embodiment embodies the first teaching and the third teaching for carrying out the injection process. 2 This is a concrete embodiment of the second teaching and the third teaching for preparing a second prepreg. First, in the preparation step, Reference Example and Example 1 Similarly, a plurality of prepregs 11 shown in FIG. 1(A) were prepared.

[0081] 20, a molding device 41 was prepared. The molding device 41 includes a first die 43, a second die 45, and a plurality of needles 27. The first die 43 and the second die 45 are capable of moving relative to each other to clamp the die.

[0082] The first mold 43 has a first molding surface 43a recessed from the parting surface 21a. The first molding surface 43a is Reference example Similarly, the three first prepregs 11f are fitted together by extending in the left-right direction of the paper.

[0083] A second molding surface 45a is recessed from the parting surface 21b in the second mold 45. The first molding surface 43a of the first mold 43 and the second molding surface 45a of the second mold 45 form a cavity C. The second molding surface 45a is composed of three first portions 451a, three second portions 452a, and a third portion 453a.

[0084] The first portion 451a faces the first molding surface 43a, and the three first prepregs 11f are fitted in the left-right direction of the drawing. The sum of the depth of the first molding surface 43a from the parting surface 21a and the depth of the first portion 451a from the parting surface 21b is equal to the thickness of the first prepregs 11f.

[0085] The second portion 452a is recessed to be continuous with the first portion 451a. The second portion 452a is adapted to fit three second prepregs 11s extending in the thickness direction of the paper surface of Fig. 20. Therefore, the first prepregs 11f and the second prepregs 11s are perpendicular to each other and overlap in nine specific ranges SA.

[0086] The third portion 453a abuts the bottom surface of the first prepreg 11f against the bottom surface of the first molding surface 43a, and when the second prepreg 11s is fitted to the second portion 452a, it is spaced apart from the top, right, left, front and rear surfaces of the first prepreg 11f and the second prepreg 11s.

[0087] The length from the bottom surface of the first molding surface 43a to the bottom surface of the second portion 452a is smaller than the sum of the thicknesses of the first prepreg 11f and the second prepreg 11s. Therefore, when the parting surface 21a and the parting surface 21b are brought together and the first mold 43 and the second mold 45 are clamped, the first prepreg 11f and the second prepreg 11s are pressurized and integrated in the specific range SA, but the first prepreg 11f and the second prepreg 11s have excess material in each specific range SA. Therefore, the material bulges out into the third portion 453a.

[0088] The first and second dies 43 and 45 are formed with needle holes 43b and 45b. The needle holes 43b and 45b are configured as follows: Reference Example and Example 1 The first and second dies 43 and 45 have the same needle holes 23b, 25b, 35b, and 37b. Reference example The heating holes 23c and 25c of the first and second molds 23 and 25 are not formed. Reference example This is similar to the molding device 21.

[0089] Furthermore, an injection material 39 was prepared. The injection material 39 contains a third thermoplastic resin and is in a molten state, and is to be injected into the cavity C from a gate (not shown). The third thermoplastic resin of the injection material 39 has a higher melting point than the first and second thermoplastic resins of the first and second prepregs 11f and 11s.

[0090] In the setting step, as shown in Fig. 21, the first and second prepregs 11f, 11s are provided in the cavity C, similarly to Example 1. In the mold clamping step and pressurizing step, as shown in Fig. 22, the first mold 43 and the second mold 45 are clamped together, and the first prepreg 11f and the second prepreg 11s are pressurized to be integrated into one body in the cavity C.

[0091] Then, as the injection process and the hole making process, as shown in Fig. 23, the injection material 39 is injected into the cavity C. At the same time, the needle 27 is advanced from the tip 27a into the specific range SA in the third direction so that the cylindrical portion 27b of the needle 27 penetrates the injection material 39 in the cavity C and reaches the needle hole 37b. Therefore, the first and second carbon fibers 11b in the first and second prepregs 11f, 11s are gradually pushed radially outward of the needle 27 by the tip 27a of the needle 27 within the first and second base materials 11a. Therefore, the first and second carbon fibers 11b of the first and second prepregs 11f, 11s are not easily cut.

[0092] At this time, since the injection process is performed during the hole punching process, the first and second thermoplastic resins in the specific range SA are softened by the temperature of the injection material 39, and the first and second carbon fibers 11b are easily moved in the first and second base materials 11a by the tip portions 27a of the needles 27, and are less likely to be cut. During this time, it is possible to eliminate the need to soften the first and second thermoplastic resins in the specific range SA. In addition, even if the connection holes 55a formed by the needles 27 in the first and second prepregs 11f and 11s become undesirable shapes, the injection material 39 is injected in the injection process while leaving the needles 27 in the connection holes 55a, so that the injection material 39 becomes an insert injection molding method, and the connection holes 55a can be adjusted to a desirable shape by the injection material 39. In addition, if the injection process is performed during the hole punching process, the molding cycle time of the structure 53 can be shortened, and the manufacturing cost can be reduced.

[0093] The first and second thermoplastic resins and the injection material 39 are brought to room temperature, and the first mold 43 and the second mold 45 are opened to obtain structures 55. The obtained structures 55 are made of the first and second prepregs 11f, 11s, and the injection material 39 provided on five surfaces of the first and second prepregs 11f, 11s except for the bottom surfaces. In each structure 55, cutting of the surrounding first and second carbon fibers 11b is suppressed, and a connection hole 55a having a preferable shape is formed.

[0094] As shown in FIG. 24, three structures 55 are arranged in the thickness direction of the paper. Reference Example and Example 1Similarly, a mating member 61 was prepared. Then, as shown in FIG. Reference Example and Example 1 Similarly, the structure 55 and the counterpart member 61 were joined by the CFRTP rivet 71. In this manner, a joined structure 85 was obtained.

[0095] Working Example 2 Structure 55 of Reference Example and Example 1 The same effect as that of the embodiment can be obtained. 2 The joint structure 85 Reference Example and Example 1 The same effect can be achieved.

[0096] Working Example 2 The needle 27 is also not made of metal, but is made of CFRTP and left in the structure 55, and the needle 27 can be transformed into a rivet 71 to join the structure 55 and the mating material 61 to form a joined structure 85.

[0097] In addition, the above embodiment 2 Although the injection step is performed during the hole punching step, it may be performed before or after the hole punching step. When the injection step is performed before or after the hole punching step, the needle 27 remains in the cavity C, and the injection material 39 is also molded with a connecting hole.

[0098] The inventors have used PP (polypropylene) as the thermoplastic resin and injection material of the prepreg 11 in the examples. 1 A plurality of structures 53 were molded, and a lattice-shaped joint structure 83 was manufactured using each structure 53. This joint structure 83 was lightweight yet high in strength, and also had excellent fatigue properties and corrosion resistance, making it suitable for use as a cover member for a battery case.

[0099] In the above, the present invention Reference Example and Examples 1 and 2 The present invention has been described in accordance with the above. Reference Example and Examples 1 and 2 It goes without saying that the present invention is not limited to the above and can be modified as appropriate without departing from the spirit of the present invention.

[0100] for example, Reference Example and Examples 1 and 2In the above, a rod-shaped prepreg 11 having a rectangular prism shape as shown in Fig. 1(A) is used, but a rod-shaped prepreg 13 having a cylindrical shape as shown in Fig. 1(B) may also be used. This prepreg 13 also has a plurality of carbon fibers 13b extending only in the length direction within the base material 13a. Alternatively, a sheet-shaped prepreg 15 as shown in Fig. 1(C) may also be used. This prepreg 15 also has a plurality of carbon fibers 15b extending only in the length direction within the base material 15a.

[0101] In addition, 1、2 In the above, the injected material 39 is applied to five surfaces of the prepreg 11 or the first and second prepregs 11f, 11s excluding the bottom surface, but the injected material may be applied to the entire surface of the prepreg 11 or the first and second prepregs 11f, 11s, or may be applied only to specific portions.

[0102] Furthermore, according to the present invention, in order to manufacture parts and the like that are lightweight, high-strength, highly heat-resistant and highly wear-resistant, it is possible to obtain structures and joined structures using super engineering plastics by using low-melt PAEK as the thermoplastic resin for the prepreg and PEEK as the injection material.

[0103] Although the first and second prepregs 11, 13, and 15 have carbon fibers 11b, 13b, and 15b extending only in the length direction, they may have carbon fibers that extend in the length direction while twisting around. [Industrial Applicability]

[0104] The present invention can be used for parts in the fields of automobiles, aircraft, spacecraft, ships, trains, buildings, and the like. [Explanation of symbols]

[0105] 11a, 13a, 15a...Base metal (1st base metal, 2nd base metal) 11b, 13b, 15b, 71e...carbon fiber (first carbon fiber, second carbon fiber, 71e...fourth carbon fiber) 11, 13, 15...prepreg (11f...first prepreg, 11s...second prepreg) 23, 35, 43…Type 1 C...Cavity 25, 37, 45…2nd type 27a...Tip 27...Needle SA: Specific range 51a, 53a, 55a...Connection holes 51, 53, 55...Structure 39…Injection material 61a…insertion hole 61…Mating material 71…Rivet 81, 83...joint structure

Claims

1. a preparation step of preparing a first prepreg having a plurality of first carbon fibers extending in only one direction within a first base material made of a first thermoplastic resin, a first mold, a second mold forming a cavity together with the first mold, a needle having a pointed tip, and an injection material including a third thermoplastic resin and to be injected into the cavity; a setting step of providing the first prepreg in the cavity; a mold clamping step of clamping the first mold and the second mold after the setting step; a hole making step of inserting the needle from the tip portion into a specific area of ​​the first prepreg in a third direction perpendicular to the first direction during or after the mold clamping step to form a connection hole with the needle; and an injection step of injecting the injection material into the cavity during or after the hole drilling step, The third thermoplastic resin has a melting point higher than that of the first thermoplastic resin, A method for molding a structure, comprising the steps of: injecting the injection material while leaving the needle in the connection hole in the injection step.

2. In the preparation step, a second prepreg is prepared, the second prepreg having a plurality of second carbon fibers extending in only one direction within a second base material made of a second thermoplastic resin; In the setting step, the second prepreg is provided in the cavity so that a first direction in which the first carbon fibers extend and a second direction in which the second carbon fibers extend intersect and overlap in the third direction in the specific range, In the hole making step, the needle is inserted from the tip portion into the specific area in the third direction to form a connection hole with the needle, 2. The method for molding a structure according to claim 1, wherein the third thermoplastic resin has a melting point higher than those of the first thermoplastic resin and the second thermoplastic resin.

3. A method for molding a structure as described in claim 1 or 2, wherein the hole drilling step is carried out at room temperature.

4. 3. The method for molding a structure according to claim 2, further comprising a pressurizing step of pressurizing the first prepreg and the second prepreg so as to integrate them in the cavity during the mold clamping step.

5. 3. The method for molding a structure according to claim 2, wherein the needle has a plurality of fourth carbon fibers extending in one direction within a fourth matrix made of a fourth thermoplastic resin.

6. The method for molding a structure according to claim 2 , wherein in the setting step, the first direction and the second direction are perpendicular to each other.

7. The first prepreg and the second prepreg are rod-shaped, 7. The method for molding a structure according to claim 6, wherein the specific area is a portion where the first prepreg and the second prepreg intersect.

8. A method for molding a structure as described in claim 1 or 2, wherein the needle is movably arranged on the first mold and / or the second mold.

9. The method of claim 1 or 2 further comprises: a structural body obtained by the molding method of claim 1 or 2; and a mating member laminated with the structural body and having an insertion hole aligned with the joining hole, A joint structure characterized in that the connection hole and the insertion hole have a plurality of fifth carbon fibers extending in one direction within a fifth base material made of a fifth thermoplastic resin, and a rivet is provided to join the structure and the mating material.

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