Manufacturing method for composite member joints

Abstract

To suppress the transformation of composite members formed of fiber-reinforced thermoplastic resin due to overheating in the method for manufacturing composite member joints.SOLUTION: The method of manufacturing a composite member joint 30 comprises a laminate forming process (S10) in which a conductive insert material 14 is sandwiched between bonded surfaces of a first composite member 10 and a second composite member 12 formed of a fiber-reinforced thermoplastic resin to form a laminate 20, a bonding process (S12) in which the laminate 20 is pressurized and the conductive insert material 14 is inductively heated to bond the first composite member 10 and the second composite member 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a composite member assembly.

Background Art

[0002] A fiber reinforced thermoplastic resin is a composite material obtained by reinforcing a thermoplastic resin with reinforcing fibers such as carbon fibers etc. Since fiber reinforced thermoplastic resins are lightweight and have high strength, they are widely used in aircraft parts and vehicle parts such as automobile parts etc. Conventionally, joining of composite members formed of fiber reinforced thermoplastic resins has been performed by pressurizing and heating with a heater such as a hot press (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when joining composite members formed of fiber reinforced thermoplastic resins with a heater such as a hot press, the outer surface on the opposite side to the joining surface of the composite members is heated from the outside, and the thermoplastic resin on the joining surface is fluidized or melted to perform the joining. Thus, joining of composite members with a heater such as a hot press is performed in a state where the outer surface of the composite member is overheated because it is necessary to fluidize or melt the thermoplastic resin on the joining surface. Therefore, in the composite member, alterations such as exposure or breakage of the reinforcing fibers contained in the fiber reinforced thermoplastic resin, and deterioration of the thermoplastic resin etc. may occur, so there is a possibility that the original design strength of the composite member cannot be ensured.

[0005] Therefore, an object of the present disclosure is to provide a method for manufacturing a composite member assembly capable of suppressing alteration due to overheating of a composite member formed of a fiber reinforced thermoplastic resin. [Means for solving the problem]

[0006] A method for manufacturing a composite member joint according to this disclosure comprises: a laminate formation step of forming a laminate by sandwiching a conductive insert material between the joining surfaces of a first composite member and a second composite member, which are made of fiber-reinforced thermoplastic resin; and a joining step of pressing the laminate and induction heating the conductive insert material to join the first composite member and the second composite member. The conductive insert material comprises a resin film layer formed of the same thermoplastic resin as the matrix resin of the first composite member and the second composite member, and a conductive film coated on the surface of the resin film layer, and the bonding process involves crushing the conductive film by pressurizing the laminate to form conductive particles. .

[0007] A method for manufacturing a composite member joint according to this disclosure comprises a laminate formation step of forming a laminate by sandwiching a conductive insert material between the joining surfaces of a first composite member and a second composite member, which are made of a fiber-reinforced thermoplastic resin, and a joining step of pressing the laminate and induction heating the conductive insert material to join the first composite member and the second composite member, The conductive insert material comprises a resin film layer formed of the same thermoplastic resin as the matrix resin of the first composite member and the second composite member, and a conductive film coated on the surface of the resin film layer. The resin film layer contains fibers.

[0008] In the method for manufacturing a composite member joint according to the present disclosure, the joining step may involve crushing the conductive film by applying pressure to the laminate to form conductive particles.

[0009] In the method for manufacturing a composite member assembly according to this disclosure, the conductive film may be a metal film.

[0010] In the method for manufacturing a composite member joint according to this disclosure, the conductive film may be formed of an intermetallic compound or high-carbon steel.

[0011] In the method for manufacturing a composite member joint according to this disclosure, the resin film layer may contain fibers. [Effects of the Invention]

[0012] According to the above configuration, it is possible to suppress deterioration due to overheating of the composite member formed of fiber-reinforced thermoplastic resin. [Brief explanation of the drawing]

[0013] [Figure 1]This flowchart shows the configuration for a method of manufacturing a composite member assembly in an embodiment of the present disclosure. [Figure 2] This figure illustrates the laminate formation process in an embodiment of the present disclosure. [Figure 3] This figure shows the configuration of the laminate in an embodiment of the present disclosure. [Figure 4] This is a diagram illustrating the joining process in an embodiment of the present disclosure. [Modes for carrying out the invention]

[0014] Embodiments of the present disclosure will be described in detail below with reference to the drawings. Figure 1 is a flowchart showing the configuration of a method for manufacturing a composite member joint. The method for manufacturing a composite member joint comprises a laminate formation step (S10) and a joining step (S12).

[0015] Figure 2 is a diagram illustrating the laminate formation process (S10). Figure 3 is a diagram showing the structure of the laminate 20. The laminate formation process (S10) is a process of forming a laminate 20 by sandwiching a conductive insert material 14 between the joining surfaces of a first composite member 10 and a second composite member 12, which are made of fiber-reinforced thermoplastic resin.

[0016] The first composite member 10 and the second composite member 12 are formed of fiber-reinforced thermoplastic resin. Fiber-reinforced thermoplastic resin is a fiber-reinforced thermoplastic resin composite material in which a matrix resin made of thermoplastic resin is reinforced with reinforcing fibers.

[0017] Examples of thermoplastic resins that can be used include polyetherimide (PEI) resin, polyamide (PA) resin, polycarbonate (PC) resin, polyphenylene sulfide (PPS) resin, and polyetheretherketone (PEEK) resin.

[0018] As the reinforcing fiber, for example, carbon fiber, silicon carbide fiber (SiC fiber), silicon nitride fiber (Si3N4 fiber), graphite fiber, glass fiber, aramid fiber, etc. can be used. As the reinforcing fiber, long fiber, short fiber, whisker, etc. can be used. The form of the reinforcing fiber can be, for example, 3D fabric, 2D fabric such as plain weave or satin weave, unidirectional material, etc.

[0019] The conductive insert material 14 is laminated by being sandwiched between the joint surfaces of the first composite member 10 and the second composite member 12. The conductive insert material 14 can be formed of a conductive material. By sandwiching and laminating the conductive insert material 14 between the joint surfaces of the first composite member 10 and the second composite member 12, the joint surfaces of the first composite member 10 and the second composite member 12 can be heated by induction heating as described later.

[0020] The conductive insert material 14 may have a resin film layer 16 formed of the same thermoplastic resin as the matrix resin of the first composite member 10 and the second composite member 12, and a conductive film 18 covering the surface of the resin film layer 16.

[0021] The resin film layer 16 has a function of filling the gaps between the respective conductive particles 22 when a plurality of conductive particles 22 are formed by pressurizing and crushing the conductive film 18 in the bonding step (S12) described later. Further, the resin film layer 16 has a function of suppressing the formed conductive particles 22 in the bonding step (S12) from penetrating the matrix resins of the first composite member 10 and the second composite member 12. Furthermore, the resin film layer 16 has a function of enhancing the handling property of the conductive insert material 14.

[0022] The resin film layer 16 is made of the same thermoplastic resin as the matrix resin of the first composite member 10 and the second composite member 12. For example, if the matrix resin of the first composite member 10 and the second composite member 12 is polyetherimide (PEI) resin, then the resin film layer 16 is also made of polyetherimide (PEI) resin. By making the resin film layer 16 of the same thermoplastic resin as the matrix resin of the first composite member 10 and the second composite member 12 in this way, the bonding strength of the composite member joint can be increased when the first composite member 10 and the second composite member 12 are joined and integrated.

[0023] The thickness of the resin film layer 16 should be, for example, between 10 μm and 100 μm. If the thickness of the resin film layer 16 is less than 10 μm, it becomes difficult to fill the voids of the conductive particles 22 formed in the bonding process (S12) described later, and the conductive particles 22 tend to penetrate the matrix resin of the first composite member 10 and the second composite member 12. If the thickness of the resin film layer 16 is greater than 100 μm, the amount of thermoplastic resin supplied to the bonding surface of the first composite member 10 and the second composite member 12 tends to be excessive, which may reduce the bonding strength of the composite member joint.

[0024] The resin film layer 16 may contain fibers. The fibers included in the resin film layer 16 can be carbon fibers, silicon carbide fibers (SiC fibers), silicon nitride fibers (Si3N4 fibers), graphite fibers, glass fibers, aramid fibers, etc. The fibers included in the resin film layer 16 should preferably be the same as the reinforcing fibers of the fiber-reinforced thermoplastic resin in the first composite member 10 and the second composite member 12. For example, if the reinforcing fibers of the fiber-reinforced thermoplastic resin in the first composite member 10 and the second composite member 12 are carbon fibers, then the fibers included in the resin film layer 16 should be carbon fibers. The fibers included in the resin film layer 16 can take the form of short fibers such as chopped fibers or whiskers. The resin film layer 16 can be constructed, for example, by dispersing these short fibers or whiskers.

[0025] The conductive film 18 is a film formed of a conductive material. The conductive film 18 is coated on the surface of the resin film layer 16. The conductive film 18 may be coated on only one surface of the resin film layer 16, or on both surfaces of the resin film layer 16. The conductive film 18 has the function of heating and fluidizing or melting the matrix resin at the bonding surface of the first composite member 10 and the second composite member 12 and the resin film layer 16 when inductively heated in the bonding process (S12) described later.

[0026] Furthermore, the conductive film 18 has the function of forming multiple conductive particles 22 when it is pressurized and crushed in the bonding process (S12) described later. Since the conductive particles 22 are formed by the crushing of the conductive film 18, the conductive particles 22 have an uneven shape. The conductive particles 22 bite into the matrix resin and reinforcing fiber bundles of the first composite member 10 and the second composite member 12, thereby increasing the bonding strength of the composite member joint.

[0027] The conductive film 18 can be composed of, for example, a metal film, a carbon film, a graphite film, etc. If the conductive film 18 is formed of a metal film, multiple metal particles are formed when the metal film is pressurized and crushed in the bonding step (S12) described later. If the conductive film 18 is formed of a carbon film, multiple carbon particles are formed when the carbon film is pressurized and crushed in the bonding step (S12) described later. The coating method for the conductive film 18 is not particularly limited, but general coating methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD) can be applied. For physical vapor deposition (PVD), for example, vacuum deposition, sputtering, and ion plating can be used.

[0028] The conductive film 18 is preferably deposited by sputtering. When the conductive film 18 is deposited by sputtering, the surface roughness of the conductive film 18 can be made rougher. This makes it easier to crush the conductive film 18 when it is pressed and crushed in the bonding process (S12) described later. In addition, when the conductive film 18 is deposited by sputtering, it is possible to reduce the thermal effects caused by the deposition of the resin film layer 16.

[0029] The conductive film 18 is preferably composed of a metal film. By making the conductive film 18 a metal film, during induction heating such as high-frequency heating described later, it is possible to selectively heat only the metal film while suppressing the heating of reinforcing fibers such as carbon fibers, making it possible to limit the heating area to only the matrix resin of the bonding surface when bonding.

[0030] The metal film is preferably formed from a brittle metal material. Forming the metal film from a brittle metal material makes it easier for the metal film to break when it is pressurized during the joining process (S12) described later. Brittle metal materials can include intermetallic compounds and high-carbon steel. Forming the metal film from an intermetallic compound or high-carbon steel makes it even easier to break. Furthermore, the metal film is preferably formed from an intermetallic compound. Forming the metal film from an intermetallic compound makes it even easier to break than forming it from high-carbon steel.

[0031] Intermetallic compounds such as titanium aluminides and nickel aluminides can be used. Titanium aluminides include TiAl, Ti3Al, TiAl2, Ti2Al5, and TiAl3. Nickel aluminides include NiAl, NiAl3, Ni2Al3, Ni5Al3, and Ni3Al. For high-carbon steel, carbon steel containing 0.6% by mass or more of carbon can be used. These intermetallic compounds and high-carbon steels can be deposited as films, for example, by sputtering.

[0032] The thickness of the conductive film 18 should be, for example, between 10 μm and 100 μm. If the thickness of the conductive film 18 is less than 10 μm, the conductive film 18 will be too thin, making it difficult to break up the conductive film 18 in the bonding process (S12) described later. If the thickness of the conductive film 18 is greater than 100 μm, the conductive film 18 will be too thick, making it difficult to break up the conductive film 18 in the bonding process (S12) described later.

[0033] The joining process (S12) involves pressurizing the laminate 20 and induction heating the conductive insert material 14 to join the first composite member 10 and the second composite member 12. Figure 4 is a diagram illustrating the joining process (S12).

[0034] In the joining process (S12), the laminate 20 is pressurized and the conductive insert material 14 is induction heated to join the first composite member 10 and the second composite member 12. Pressurizing the laminate 20 allows for closer contact between the joining surfaces of the first composite member 10 and the second composite member 12 and the conductive insert material 14. Furthermore, if the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, pressurizing the laminate 20 causes the conductive film 18 of the conductive insert material 14 to be crushed, forming a plurality of conductive particles 22. Since the conductive particles 22 are formed by crushing the conductive film 18, they have uneven protrusions. When these conductive particles 22 are pressed, they bite into the matrix resin and reinforcing fiber bundles of the first composite member 10 and the second composite member 12, thereby increasing the joining strength of the composite member joint 30. More specifically, the conductive particles 22 penetrate the matrix resin and reinforcing fiber bundles of the first composite member 10 and the second composite member 12, thereby increasing the shear strength of the joint surface of the composite member joint 30 and improving the joint strength.

[0035] By induction heating the conductive insert material 14, the matrix resin at the joining surface of the first composite member 10 and the second composite member 12 is heated, causing it to fluidize or melt, thereby joining the first composite member 10 and the second composite member 12 and forming the composite member joint 30. More specifically, the conductive insert material 14 is induction heated, causing the matrix resin at the joining surface of the first composite member 10 and the second composite member 12 to be heated above the glass transition temperature of the thermoplastic resin, causing it to fluidize or melt, and joining the first composite member 10 and the second composite member 12. Since the joining is performed by induction heating of the conductive insert material 14, the heating area is limited to the joining surface of the first composite member 10 and the second composite member 12 and its vicinity. This makes it possible to suppress deterioration of the first composite member 10 and the second composite member 12 due to heating.

[0036] When the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, the conductive insert material 14 is induction heated, causing the matrix resin at the joining surface of the first composite member 10 and the second composite member 12, and the resin film layer 16 of the conductive insert material 14 to be heated above the glass transition temperature of the thermoplastic resin, resulting in fluidization or melting, and the first composite member 10 and the second composite member 12 to be joined. Since the conductive insert material 14 is induction heated for joining, the heating area is limited to the joining surface of the first composite member 10 and the second composite member 12 and its vicinity. This makes it possible to suppress deterioration of the first composite member 10 and the second composite member 12 due to heating. In addition, the thermoplastic resin of the fluidized or melted resin film layer 16 fills the gaps between the conductive particles 22 formed at the joining surface of the first composite member 10 and the second composite member 12.

[0037] The pressurization of the laminate 20 and the induction heating of the conductive insert material 14 may be performed simultaneously or separately. For example, the first composite member 10 and the second composite member 12 may be joined by induction heating of the conductive insert material 14 while pressurizing the laminate 20. Alternatively, the first composite member 10 and the second composite member 12 may be joined by pressurizing the laminate 20 immediately after induction heating of the conductive insert material 14.

[0038] Furthermore, if the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, in addition to the above bonding method, the conductive insert material 14 may be induction heated immediately after the laminate 20 has been pre-pressurized, and the laminate 20 may be fully pressurized immediately after the conductive insert material 14 has been induction heated, thereby bonding the first composite member 10 and the second composite member 12. Pre-pressurizing the laminate 20 in a cold state before induction heating the conductive insert material 14 makes it easier to generate cracks in the conductive film 18. This makes it easier to pulverize the conductive film 18 when the laminate 20 is fully pressurized immediately after the conductive insert material 14 has been induction heated.

[0039] The means of applying pressure to the laminate 20 is not particularly limited, as long as the joint surfaces of the first composite member 10 and the second composite member 12 can be brought into close contact with the conductive insert material 14, and the conductive film 18 of the conductive insert material 14 can be crushed. For example, pressure rollers, pressure belts, and press devices can be used as the means of applying pressure to the laminate 20. When pressure rollers or pressure belts are used as the means of applying pressure to the laminate 20, continuous joining can be performed along the joint surface, so joining work can be performed efficiently even for large structures. Also, since pressure rollers and pressure belts are smaller devices than press devices, joining work can be performed in the final assembly process of aircraft parts and vehicle parts, for example, or in on-site work.

[0040] The means for pressurizing the laminate 20 may include using a pressure roller and a pressure belt in parallel. By using a small-diameter roller for the pressure roller, it is possible to easily generate cracks in the conductive film 18 of the conductive insert material 14. This makes it easier to crush the conductive film 18 when the laminate 20 is pressurized with the pressure belt. The small-diameter roller is, for example, a roller with a diameter of about 20 mm to 30 mm.

[0041] The pressure applied to the laminate 20 is not particularly limited, as long as the joint surfaces of the first composite member 10 and the second composite member 12 can be in close contact with the conductive insert material 14, and the conductive film 18 of the conductive insert material 14 can be crushed. The pressure applied to the laminate 20 can be, for example, from 0.1 MPa to 10 MPa.

[0042] The induction heating means for the conductive insert material 14 is not particularly limited as long as it can heat the thermoplastic resin, which is the matrix resin of the first composite member 10 and the second composite member 12, to above its glass transition temperature by induction heating the conductive insert material 14. If the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, the induction heating means only needs to be able to heat the thermoplastic resin of the matrix resin of the first composite member 10 and the second composite member 12 and the resin film layer 16 to above their glass transition temperature by induction heating the conductive film 18. A high-frequency induction heating device equipped with a general coil can be used as the induction heating means for the conductive insert material 14.

[0043] When using a pressure roller and a pressure belt in parallel as means of pressurizing the laminate 20, it is preferable to provide an induction heating device between the pressure roller and the pressure belt. When the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, the laminate 20 can be pre-pressurized with a pressure roller to generate cracks in the conductive film 18, the cracked conductive film 18 can be induction heated, and the laminate 20 can be fully pressurized with a pressure belt, thereby joining the first composite member 10 and the second composite member 12 while crushing the cracked conductive film 18.

[0044] The induction heating frequency and output are set so that when the conductive insert material 14 is induction heated, the thermoplastic resin of the matrix resin of the first composite member 10 and the second composite member 12 is heated to above its glass transition temperature. If the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, the induction heating frequency and output are set so that when the conductive film 18 is induction heated, the thermoplastic resin of the matrix resin of the first composite member 10 and the second composite member 12 and the resin film layer 16 are heated to above their glass transition temperature. This allows the matrix resin of the first composite member 10 and the second composite member 12 and the thermoplastic resin of the resin film layer 16 to be fluidized or melted. The induction heating frequency can be, for example, from 10 kHz to 10 MHz.

[0045] Furthermore, the induction heating frequency and output can be appropriately selected considering the material and thickness of the conductive insert material 14, and, if the conductive insert material 14 is composed of a resin film layer 16 and a conductive film 18, the material and film thickness of the conductive film 18. Moreover, if conductive fibers such as carbon fibers are used for the reinforcing fibers of the first composite member 10 and the second composite member 12, the induction heating frequency and output should be selected to suppress heating of the reinforcing fibers of the first composite member 10 and the second composite member 12. This further suppresses deterioration of the first composite member 10 and the second composite member 12 due to overheating.

[0046] The above-described method for manufacturing composite member joints can be suitably applied to aircraft parts. Aircraft parts include, for example, wings and fuselages. In the final shape assembly process and on-site work, pressing operations using large press machines are usually difficult. According to the above-described method for manufacturing composite member joints, joining operations can be performed using small devices such as pressure rollers or pressure belts, so joining operations can be carried out in the final shape assembly process and on-site work.

[0047] As described above, with the above configuration, the first and second composite members, which are made of fiber-reinforced thermoplastic resin, are joined by induction heating of a conductive insert material interposed at the joining surface of the first and second composite members. As a result, the joining surface of the first and second composite members and its vicinity are heated locally during joining. This suppresses deterioration due to overheating of the first and second composite members, thereby ensuring the original design strength of the composite members. Furthermore, because the joining surface of the first and second composite members and its vicinity are heated locally during joining, the cooling time can be shortened compared to joining using a heater such as a hot press. This makes it possible to improve the productivity of the composite member joint.

[0048] According to the above configuration, conductive particles formed by crushing the conductive film of the conductive insert material under pressure bite into the matrix resin or reinforcing fiber bundles at the joint surfaces of the first and second composite members, thereby increasing the joint strength of the composite member joint.

[0049] According to the above configuration, the first and second composite members, which are made of fiber-reinforced thermoplastic resin, are joined by induction heating of a conductive insert material interposed at the joining surfaces of the first and second composite members. This allows the joining process to be completed in a shorter time than when using ultrasonic bonding. This makes it possible to improve the productivity of the composite member joint.

[0050] According to the above configuration, the first composite member and the second composite member, which are made of fiber-reinforced thermoplastic resin, are joined by induction heating of a conductive insert material interposed at the joining surface of the first composite member and the second composite member. This makes it possible to reduce the thickness of the adhesive layer compared to when adhesive is used for joining. As a result, the shear strength of the joint of the composite member joint can be increased, thereby improving the joint strength.

[0051] According to the above configuration, since the first composite member and the second composite member, which are made of fiber-reinforced thermoplastic resin, are joined by induction heating of a conductive insert material interposed at the joining surface of the first composite member and the second composite member, it is possible to easily manufacture even complex-shaped parts and large parts. [Explanation of Symbols]

[0052] 10 First Composite Member 12 Second Composite Member 14. Conductive insert material 16. Resin film layer 18 Conductive film 20 Laminate 22 Conductive particles 30 Composite member joint 40 aircraft parts 42 Outer panels 44 Ribs

Claims

1. A method for manufacturing a composite member joint, A laminate formation step involves forming a laminate by sandwiching a conductive insert material between the joining surfaces of a first composite member and a second composite member, which are made of fiber-reinforced thermoplastic resin, A bonding step in which the laminate is pressurized and the conductive insert material is inductively heated to join the first composite member and the second composite member, A method for manufacturing a composite member joint, comprising: The conductive insert material comprises a resin film layer formed of the same thermoplastic resin as the matrix resin of the first composite member and the second composite member, and a conductive film coated on the surface of the resin film layer. The bonding step is a method for manufacturing a composite member bond, wherein the bonding step involves crushing the conductive film by applying pressure to the laminate to form conductive particles.

2. A method for manufacturing a composite member joint according to claim 1, The conductive film is a metal film, and the method is for manufacturing a composite member assembly.

3. A method for manufacturing a composite member joint according to claim 2, A method for manufacturing a composite member joint, wherein the conductive film is formed of an intermetallic compound or high-carbon steel.

4. A method for manufacturing a composite member joint according to any one of claims 2 to 3, The resin film layer includes fibers, and the method is for manufacturing a composite member assembly.

5. A method for manufacturing a composite member joint, A laminate formation step involves forming a laminate by sandwiching a conductive insert material between the joining surfaces of a first composite member and a second composite member, which are made of fiber-reinforced thermoplastic resin, A bonding step in which the laminate is pressurized and the conductive insert material is inductively heated to join the first composite member and the second composite member, A method for manufacturing a composite member joint, comprising: The conductive insert material comprises a resin film layer formed of the same thermoplastic resin as the matrix resin of the first composite member and the second composite member, and a conductive film coated on the surface of the resin film layer. The resin film layer includes fibers, and the method is for manufacturing a composite member assembly.

6. A method for manufacturing a composite member joint according to Claim 5, The bonding step is a method for manufacturing a composite member bond, wherein the bonding step involves crushing the conductive film by applying pressure to the laminate to form conductive particles.

7. A method for manufacturing a composite member joint according to Claim 5, The conductive film is a metal film, and the method is for manufacturing a composite member assembly.

8. A method for manufacturing a composite member joint according to Claim 7, A method for manufacturing a composite member joint, wherein the conductive film is formed of an intermetallic compound or high-carbon steel.

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