Member joint structure and member jointing method

Abstract

To provide an improved member joint structure and member jointing method applicable to vehicle body structures using fiber-reinforced resin composites.SOLUTION: In a joint structure joining a first member and a second member, the first member has a core material made of a porous material with a honeycomb structure or a porous structure, a surface layer material made of a fiber-reinforced resin that covers part or all of the core material, and a solid portion formed in part of the core material in which a filler material is filled into the pores of the porous material and hardened, and the second member is joined to the solid portion of the first member.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a joining structure and joining method for members using a fiber-reinforced resin composite material. [Background technology]

[0002] With the aim of reducing the weight of vehicle bodies, development is underway for vehicle body structures made of composite materials using fiber-reinforced resins, typified by carbon fiber-reinforced resins (hereinafter also referred to as "fiber-reinforced resin composites"). Fiber-reinforced resin composites have high rigidity, and demonstrate high strength, particularly against tensile stress acting along the fiber orientation direction. When constructing a vehicle body structure using fiber-reinforced resin composites, a monocoque structure is generally used.

[0003] As an example of a vehicle body structure using a fiber-reinforced resin composite, Patent Document 1 discloses a tubular frame for a mobile body that includes a first pipe section and a second pipe section connected to the first pipe section via a connecting section, wherein the connecting section is a first connecting section that is tubular and has a first slit, and is arranged on a side surface so that a first opening of the first slit intersects with the axial direction of the first connecting section, and a second connecting section that is tubular and has substantially the same cross-sectional shape as the first connecting section and has a second slit, and is arranged on a side surface so that a second opening of the second slit intersects with the axial direction of the second connecting section, and the first pipe section and the second pipe section are connected by the first connecting section and the second connecting section engaging with each other via the first slit and the second slit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-75066 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although Patent Document 1 describes that multiple pipe sections may be formed from fiber-reinforced resin, it does not specifically disclose how to ensure strength when connecting by engaging the slits of the fiber-reinforced resin pipe sections. Also, when considering the vehicle body structure, a structure that is highly repairable is required in the event that part of the vehicle body is damaged in an accident, for example.

[0006] Therefore, the technology of the present disclosure has been made in consideration of the above problems, and an object of the present disclosure is to provide an improved component joining structure and component joining method that can be applied to vehicle body structures that use fiber-reinforced resin composite materials. [Means for solving the problem]

[0007] In order to solve the above problem, according to one aspect of the technology of the present disclosure, there is provided a joining structure for joining a first member and a second member, wherein the first member has a core material made of a porous material with a honeycomb structure or a porous structure, a surface layer material made of a fiber-reinforced resin and covering part or all of the core material, and a solid portion formed in part of the core material in which a filler material is filled into the pores of the porous material and hardened, and the second member is joined to the solid portion of the first member.

[0008] In addition, in order to solve the above problem, according to another aspect of the technology of the present disclosure, there is provided a method for joining members, comprising: an exposure step for forming an exposed portion in which a first member having a core material made of a porous material with a honeycomb structure or a porous structure and a surface layer material made of a fiber-reinforced resin and covering part or all of the core material is removed from the surface layer material to expose the core material; a filling step for filling a filler material into the pores of the porous material through the exposed portion to form a solid portion; and a joining step for joining a second member to the solid portion. [Effects of the Invention]

[0009] As described above, the technique of the present disclosure can provide an improved member joining structure and member joining method that can be applied to a vehicle body structure using a fiber-reinforced resin composite material. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a joining structure of members according to a first embodiment of the present disclosure. [Figure 2] 1 is an exploded perspective view showing the joining structure of members according to the embodiment. [Figure 3] FIG. 10 is a perspective view showing a coupling structure of members according to a modified example of the embodiment. [Figure 4] 4A to 4C are explanatory views showing an example of a method for manufacturing a first member used in the member connection structure according to the embodiment. [Figure 5] 5A and 5B are explanatory views showing a method for joining the first member and the second member according to the embodiment. [Figure 6] 5A and 5B are explanatory views showing a method for joining the first member and the second member according to the embodiment. [Figure 7] 5A and 5B are explanatory views showing a method for joining the first member and the second member according to the embodiment. [Figure 8] FIG. 10 is a perspective view showing a joining structure of members according to a second embodiment of the present disclosure. [Figure 9] 1 is an exploded perspective view showing the joining structure of members according to the embodiment. [Figure 10] 5A and 5B are explanatory views showing a method for joining the first member and the second member according to the embodiment. [Figure 11] 5A and 5B are explanatory views showing a method for joining the first member and the second member according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the technology 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.

[0012] <<First embodiment>> <1-1. Component joint structure> First, a joining structure of members according to a first embodiment of the present disclosure will be described. 1 and 2 are explanatory diagrams showing a joining structure of members according to this embodiment: Fig. 1 is a perspective view showing the joining structure of members, and Fig. 2 is an exploded perspective view showing the joining structure of members.

[0013] The member joining structure 10 is a structure for joining a first member 20 and a second member 30, and includes the first member 20, the second member 30, and a coating layer 41. The present disclosure is characterized by the structure for joining the first member 20 and the second member 30, and the shapes of the first member 20 and the second member 30 are not limited to the examples shown in the drawings, and may have any shape.

[0014] The first member 20 has a core material 23 made of a porous material, a surface layer material 21 made of a fiber-reinforced resin that covers all or part of the core material 23, and a solid portion 25 formed in part of the core material 23 and formed by filling the pores of the porous material with a filler material that has been hardened. The second member 30 has a core material 33 made of a porous material, a surface layer material 31 made of a fiber-reinforced resin that covers all or part of the core material 33, and a solid portion 35 formed in part of the core material 33 and formed by filling the pores of the porous material with a filler material that has been hardened.

[0015] The first member 20 and the second member 30 are joined to each other at the solid portions 25, 35. The coating layer 41 is disposed so as to cover the periphery of the solid portions 25, 35 where the first member 20 and the second member 30 are joined.

[0016] The porous cores 23, 33 have a honeycomb or porous structure made of metal such as aluminum or resin, or a porous structure made of compressed fibers, and are lightweight while maintaining the desired rigidity. When using a porous material with a porous structure, it is preferable that the pores are connected to each other. This is advantageous in terms of forming the solid portions 25, 35 by filling them with a filler.

[0017] The surface layer materials 21, 31 are made of fiber-reinforced resin. The surface layer materials 21, 31 may be formed by laminating prepreg sheets, in which fibers are mixed with a matrix resin, around the core materials 23, 33 (layup), or by winding continuous fibers impregnated with a matrix resin around the core materials 23, 33. The surface layer material 21 includes continuous fibers oriented, for example, at angles of 0 degrees, ±45 degrees, and ±90 degrees relative to the extension direction of the first member 20 and the second member 30, respectively. The orientation angle and ratio of the continuous fibers are appropriately designed depending on the rigidity characteristics required of the member.

[0018] In this embodiment, the surface layer materials 21, 31 are formed using a fiber-reinforced resin in which carbon fiber is impregnated with a thermoplastic resin or a thermosetting resin as a matrix 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.

[0019] The thermoplastic resin may be one of the above resins or a mixture of two or more of them. Alternatively, the thermoplastic resin may be a copolymer of the above 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.

[0020] Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, polyurethane resins, and silicone resins. The thermosetting resin may be one of the above resins or a mixture of two or more of them. An appropriate curing agent or reaction accelerator may be added to the thermosetting resin.

[0021] The covering layer 41 has a similar configuration to the surface layer materials 21, 31. Although Fig. 2 shows a sheet-like covering layer 41 wrapped around the solid portions 25, 35, the method for forming the covering layer 41 is not limited to the example of wrapping a sheet-like fiber-reinforced resin, and the covering layer 41 may be formed by any method. It is preferable that the fibers are arranged continuously in the circumferential direction, but as shown in Fig. 2, the fibers do not have to be connected in the circumferential direction.

[0022] The solid portions 25, 35 are formed in a portion of the core material 23, 33 made of a porous material, and are solidified by filling the pores of the porous material with a filler material that is then hardened. The solid portions 25, 35 have higher rigidity than the non-solidified core material 23, 33. The filler material includes at least a thermosetting resin or a thermoplastic resin. The thermosetting resin or thermoplastic resin is not particularly limited as long as it can be hardened. The filler material preferably includes a filler such as short fibers, which are shortly chopped fibers. By including short fibers in the filler material, an increase in the weight of the solid portions 25, 35 can be suppressed.

[0023] The solid portions 25, 35 have mating portions 27, 37, respectively. In the member connection structure 10 according to this embodiment, the first member 20 and the second member 30 are mechanically connected by a mating structure or an engagement structure in which the mating portions 27, 37 formed on the solid portions 25, 35 fit into each other. In the example shown, the mating portion 27 of the first member 20 is a mating groove and the mating portion 37 of the second member 30 is a mating protrusion, but the mating portion 27 of the first member 20 may be a mating protrusion and the mating portion 37 of the second member 30 may be a mating groove, or each may have multiple mating portions.

[0024] The fitting structure or engagement structure may be, for example, a wooden framework. A wooden framework is a joining structure in which each of the members to be joined is machined and fitted together. With a wooden framework, the first member 20 and the second member 30 can be firmly joined without using fasteners such as metal bolts. An adhesive may be placed in the gap between the respective fitting portions 27, 37.

[0025] In this embodiment, the first member 20 and the second member 30 are joined by fitting together fitting portions 27, 37 (fitting grooves and fitting protrusions) formed by machining such as cutting the solid portions 25, 35 of the first member 20 and the second member 30. The shapes, fitting configurations, and fitting directions of the fitting portions 27, 37 to be formed may be designed as desired, taking into consideration the rigidity required of the members or the stresses generated in the members.

[0026] The member connection structure 10 according to this embodiment is constructed by fitting together fitting portions 27, 37 (fitting grooves and fitting protrusions) of solid portions 25, 35 formed by processing a first member 20 and a second member 30, each of which has a porous core material 23, 33 covered with a fiber-reinforced resin surface layer material 21, 31. Therefore, by preparing members of any size in which a porous core material is covered with a fiber-reinforced resin surface layer material, it is possible to construct frame structures with a variety of combinations.

[0027] For example, the member connection structure 10 may be applied to a vehicle body structure. The vehicle body structure is formed by connecting structural members such as roof rails, rear pillars, front pillars, center pillars, and side sills, each of which has a pillar shape. The vehicle body structure is formed by connecting each structural member to each other using the member connection structure 10 according to this embodiment. Conventionally, in the case of a monocoque structure, dedicated products designed for each vehicle model in terms of length, thickness, and other dimensions of each structural member have been used, making it difficult to share structural members between different vehicle models, and the versatility of the structural members is low.

[0028] In contrast, in a vehicle body structure to which the member connection structure 10 according to this embodiment is applied, a variety of vehicle body structures can be constructed by preparing a plurality of structural members of any length and thickness, cutting the structural members to any length depending on the size of the vehicle body to be manufactured, and forming solid portions 25, 35 in appropriate positions and fitting portions 27, 37 (fitting grooves and fitting protrusions). Therefore, the members can be freely processed and joined together, which increases the versatility of the members.

[0029] Furthermore, for example, by having a plurality of fitting portions 27 in the first member 20, the first member 20 can function as a joint member, and a plurality of members can be joined via the first member 20. For example, as shown in Fig. 3, by employing the above-described member joining structure 10 as a configuration for joining a center pillar 51, a front side sill 53, and a rear side sill 55 of a vehicle body structure to joint members 57, a firmly joined vehicle body structure can be obtained without using welding or fastening members such as metal bolts.

[0030] Furthermore, with the member connection structure 10 according to this embodiment, for example, if a portion of the first member 20 is damaged, the damaged portion can be cut and removed, and a member (second member 30) can be prepared to replace the cut, damaged portion, and solid portions 25, 35 and fitting portions 27, 37 can be created, thereby repairing the first member 20. As a result, if a portion of the vehicle body structure is damaged, for example, the damaged portion can be easily repaired.

[0031] <1-2. How to join components> Next, a method for joining members using the member joining structure according to this embodiment will be described.

[0032] 4 to 7 are explanatory diagrams showing a method for joining a first member 20 and a second member 30. Here, the method for joining members will be explained using an example in which the first member 20 is repaired when part of the first member 20 is damaged. However, the method for joining members according to this embodiment is not limited to an example in which it is applied to repairing the first member 20, and is also applicable to cases in which any first member 20 and second member 30 are joined to each other.

[0033] FIG. 4 shows an example of a method for manufacturing the first member 20. For example, the first member 20 is manufactured by forming a surface layer material 21 made of carbon fiber reinforced resin so as to cover the periphery of an aluminum porous material (a honeycomb structure in the illustrated example). The method for forming the surface layer material 21 is not particularly limited. The first member 20 in its initial state does not include a solid portion or a fitting portion. This results in a first member 20 that has a predetermined rigidity and is lightweight.

[0034] Here, suppose that a portion of the first member 20 is damaged during use of the first member 20. In this case, as shown in Fig. 5, the portion of the first member 20 including the damaged portion 15 is cut and separated. Furthermore, a portion of the surface layer material 21 of the remaining first member 20 is removed to form an exposed portion 43 in which the core material 23 is exposed (exposure step).

[0035] 6, a filler is filled into the pores of the porous material of the core material 23 through the exposed portion 43 to form the solid portion 25 (filling step). In the illustrated example, after filler 45 is poured into the pores of the porous material of the core material 23, uncured resin 49 is supplied by an injection device 47 to fill the pores, and the filler 45 and uncured resin 49 are cured to form the solid portion 25. Furthermore, the solid portion 25 is machined to form the fitting portion 27 (a fitting groove in the illustrated example) (cutting step).

[0036] Next, as shown in FIG. 7, a second member 30 is prepared to replace the portion including the cut damaged portion 15. For example, the second member 30 is prepared by cutting an appropriate length from the first member 20 manufactured as shown in FIG. 4, and then performing the above-described exposing, filling, and cutting processes to produce a second member 30 having a fitting portion 37 shaped to fit into the fitting portion 27 of the first member 20. Next, the fitting portion 27 of the first member 20 and the fitting portion 37 of the second member 30 are fitted together to join the first member 20 and the second member 30 (joining process). An adhesive may be applied to the gap between the fitting portions 27, 37 to bond them together. Then, a coating layer 41 made of carbon fiber reinforced resin is disposed so as to cover the outer peripheral surfaces of the solid portions 25, 35 where the fitting portion 27 of the first member 20 and the fitting portion 37 of the second member 30 are provided, and then cured. This completes the joined structure 10 of members according to this embodiment.

[0037] In this way, the method for joining members according to this embodiment allows pre-prepared fiber-reinforced resin composite members to be freely processed and firmly joined together, thereby increasing the versatility of the members and enabling the efficient production of a variety of products using the members.

[0038] Furthermore, according to the method for joining members according to this embodiment, if a part of a member is damaged, it can be repaired by replacing that part of the member and firmly joining it together. Therefore, if a part of the vehicle body structure is damaged, for example, the part of the structural member can be repaired and the vehicle can continue to be used.

[0039] <<Second embodiment>> <2-1. Component joint structure> Next, a joining structure of members according to a second embodiment of the present disclosure will be described.

[0040] In the joining structure of the members according to the first embodiment, the first member and the second member are joined by fitting together fitting portions provided in solid portions formed in a portion of the core material of each of the first member and the second member, whereas in the joining structure of the members according to the second embodiment, the first member and the second member are joined by surface-bonding solid portions formed in a portion of the core material of each of the first member and the second member using an adhesive.

[0041] Figures 8 and 9 are explanatory diagrams showing the connection structure of members according to this embodiment: Figure 8 is a perspective view showing the connection structure of members, and Figure 9 is an exploded perspective view showing the connection structure of members.

[0042] Similar to the joining structure of the members according to the first embodiment, the first member 120 and the second member 130 each have a core member 123 made of a porous material, a surface layer member 121 made of a fiber-reinforced resin that covers part or all of the core member 123, and a solid portion 125 formed in part of the core member 123 with a filler material that has been filled into the pores of the porous material and then hardened. The basic configuration other than the method of joining the first member 120 and the second member 130 can be the same as in the first embodiment, so a detailed description will be omitted.

[0043] In this embodiment, the solid portions 125, 135 of the first member 120 and the second member 130 have joining surfaces where they are joined to each other. The joining surfaces of the solid portions 125, 135 are solid surfaces in which the pores of a porous material are filled with a filler material, and the first member 120 and the second member 130 are joined by surface adhesion. A coating layer 141 is arranged to cover either or both of the solid portion 125 of the first member 120 and the solid portion 135 of the second member 130 so that the solid portions 125, 135 are not exposed to the outside when the first member 120 and the second member 130 are joined together.

[0044] The adhesive may be a resin-based adhesive such as an epoxy resin, a urethane resin, or an acrylic resin. Among these, a resin that is highly compatible with the resin that constitutes the filler filled in the solid portions 125 and 135 is preferred.

[0045] Even with the connection structure 110 for members according to this embodiment, the first member 120 and the second member 130 can be firmly connected without using fasteners such as metal bolts. Furthermore, even with the connection structure 110 for members according to this embodiment, the versatility of the members can be increased, and by preparing members of any size in which a core material made of a porous material is covered with a surface layer material made of fiber-reinforced resin, it is possible to configure frame structures with a variety of combinations. Furthermore, even with the connection structure 110 for members according to this embodiment, if a portion of the first member 120 is damaged, the first member 120 can be easily repaired.

[0046] <2-2. How to join components> Next, a method for joining members using the member joining structure according to this embodiment will be described.

[0047] 10 and 11 are explanatory diagrams showing a method for joining a first member 120 and a second member 130. Here, the method for joining members will be explained using an example in which the first member 120 is repaired when part of the first member 120 is damaged. However, the method for joining members according to this embodiment is not limited to an example in which it is applied to repairing the first member 120, but can also be applied to the case in which any first member 120 and second member 130 are joined to each other.

[0048] Assume that a portion of the first member 120 manufactured as shown in FIG. 4 is damaged during use. In this case, as shown in FIG. 10, a portion of the first member 120 including the damaged portion 115 is cut and separated. Furthermore, a portion of the surface layer material 121 is removed from the remaining first member 120 to form an exposed portion 143 that exposes the core material 123 (exposure process). Next, a filler is filled into the pores of the porous material of the core material 123 through the exposed portion 143 to form a solid portion 125 (filling process). In the illustrated example, after a filler 145 is poured into the pores of the porous material of the core material 123, an injection device 147 supplies uncured resin 149 to fill the pores, and the filler 145 and uncured resin 149 are cured to form the solid portion 125.

[0049] Next, as shown in FIG. 11 , a second member 130 is prepared to replace the portion including the cut damaged portion 115. For example, the second member 130 is prepared by cutting an appropriate length from the first member 120 manufactured as shown in FIG. 4 , and then performing the above-described exposing and filling processes to produce the second member 130 having a solid portion 135. Next, the solid portion 125 of the first member 120 and the solid portion 135 of the second member 130 are joined using an adhesive to join the first member 120 and the second member 130 (joining process). Then, a coating layer 141 made of carbon fiber reinforced resin is disposed so as to cover the outer peripheral surfaces of the solid portion 125 of the first member 120 and the solid portion 135 of the second member 130, and then cured. In this manner, the joined structure 110 of members according to this embodiment is constructed.

[0050] As described above, according to the method for joining components of this embodiment, pre-prepared fiber-reinforced resin composite members can be freely processed and firmly joined together. This increases the versatility of the members, allowing for the efficient production of a variety of products using the members. Furthermore, according to the method for joining components of this embodiment, if a portion of a member is damaged, it is possible to replace that portion of the member and repair it by firmly joining it. Therefore, for example, if a portion of a vehicle body structure is damaged, it is possible to continue using the vehicle by repairing that portion of the structural member.

[0051] Although preferred embodiments of the technology of the present disclosure have been described in detail above with reference to the accompanying drawings, the technology of the present disclosure is not limited to these examples. It is clear that a person skilled in the art of the technology 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 also 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 first embodiment, an example was described in which the fitting portion that connects the first member and the second member has a timber frame structure, but the fitting portion is not limited to a timber frame structure. As long as the fitting portions formed on the first member and the second member have shapes that can fit or engage with each other and are configured to fit together, the same effects as those described above can be obtained.

[0053] In addition, in each of the above embodiments, the second member is configured as a member having a core material, a surface layer material, and a solid portion, similar to the first member, but the second member does not have to be a fiber-reinforced resin composite material as long as at least the solid portion is solidified. Even in this case, the same effects as those of the above embodiments can be obtained. [Explanation of symbols]

[0054] 10: Bonded structure 20: First member 21: Surface material 23: Core material 25: Solid part 27: Fitting part 30: Second member 31: Surface material 33: Core material 35: Solid part 37: Fitting part 41: Covering layer 43:Exposed part 110: Bonded structure 115: Damaged area 120: First member 121: Surface material 123: Core material 125: Solid part 130: Second member 135: Solid part 141: Covering layer 143:Exposed part

Claims

1. A joining structure for joining a first member and a second member, The first member is a core material made of a porous material having a honeycomb structure or a porous structure; A surface layer material made of fiber reinforced resin that covers part or all of the core material; a solid portion formed in a part of the core material and in which a filler material is filled into the pores of the porous material and hardened, A member connection structure, wherein the second member is connected to the solid portion of the first member.

2. The member connection structure according to claim 1 , wherein the first member and the second member are mechanically connected by a fitting structure or an engagement structure.

3. The joining structure of members according to claim 1 , wherein the joining surface of the second member is bonded to a part or all of a surface of the solid portion of the first member, thereby joining the first member and the second member.

4. The member connection structure according to claim 1 , wherein the first member and the second member are structural members of a vehicle body.

5. an exposing step of forming an exposed portion by removing a part of the surface layer material from a first member having a core material made of a porous material having a honeycomb structure or a porous structure and a surface layer material made of a fiber-reinforced resin and covering a part or all of the core material; and a filling step of filling a filler into the pores of the porous material through the exposed portion to form a solid portion; a joining step of joining a second member to the solid portion; A method for joining members, comprising:

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