Fastening structure and method of decomposing fastening structure

Abstract

To provide a fastening structure and a method of decomposing a fastening structure that enable an end of a drill to be easily positioned to a swaged portion when breaking the swaged portion by the drill.SOLUTION: A fastening structure 10 is configured such that a first plate member 14 and a second plate member 13 are fastened to each other by a swaged portion 19 swaged in a state where an attachment boss 17 protruding from a plate surface of the first plate member 14 is inserted into a boss insertion hole 18 provided in the second plate member 13, and is provided with an insertion portion 20 formed to protrude from a first surface 11A of plate surfaces of the fastening structure 10 at a position adjacent to the swaged portion 19 on the first surface 11A where the swaged portion 19 is disposed, the insertion portion into which a shaft portion 31 of a drill 30 for breaking the swaged portion 19 can be inserted. An axis S of the shaft portion 31 obliquely intersects with the first surface 11A and overlaps the swaged portion 19 in a state where the shaft portion 31 is inserted into the insertion portion 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a fastening structure and a method for disassembling a fastening structure. [Background technology]

[0002] A conventional method for assembling two plate-shaped members is a method of fastening them by crimping. For example, Patent Document 1 describes a door trim, an automotive interior material including an upper door trim and a lower door trim, in which a welding boss provided on the back surface of the lower door trim is inserted into a mounting hole provided in the upper door trim, and then an ultrasonic welding horn is used to weld and crimp the tip of the welding boss to integrate the two members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-262041 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for recycling the components of various products. To facilitate recycling, it is desirable for each component to be made of the same material, but if different materials are used, disassembly and separation work is required for recycling.

[0005] As described above, when two plate-like members are fastened by a plurality of crimped portions and disassembly and separation is required, a drill must be applied to each of the crimped portions to destroy them individually. However, it is not easy to position the tip of the drill at the center of a crimped portion, and the destruction of the crimped portions may not be completed in one go. Therefore, when there are a large number of crimped portions, the disassembly and separation process takes time and effort.

[0006] The technology disclosed in this specification was developed in consideration of the above circumstances, and aims to provide a fastening structure and a method for disassembling a fastening structure that allow the tip of a drill to be easily positioned relative to a fastening portion when the fastening portion is destroyed with a drill. [Means for solving the problem]

[0007] The technology disclosed in this specification, which was completed to solve the above-mentioned problems, is a fastening structure in which a plate-shaped first plate member and a second plate member are fastened together by a crimped portion that is crimped while an attachment boss protruding from the plate surface of the first plate member is inserted into a boss insertion hole provided in the second plate member, and the fastening structure has an insertion portion that protrudes from the first surface at a position adjacent to the crimped portion on the first surface on which the crimped portion is arranged, and into which the shank of a drill can be inserted to break the crimped portion, and when the shank is inserted into the insertion portion, the axis of the shank intersects the first surface obliquely and overlaps the crimped portion.

[0008] When disassembling a fastening structure having the above configuration, a worker first inserts the shank of a drill used to break the crimped portion into the fitting portion and abuts the tip of the drill against the first surface. With the shank of the drill inserted into the fitting portion in this manner, the fitting portion maintains the drill in a state in which its axis extends in a direction overlapping the crimped portion. Therefore, the worker can easily align the tip of the drill with the center of the crimped portion by simply sliding the shank of the drill relative to the fitting portion while it is inserted into the fitting portion. This facilitates the disassembly of the fastening structure.

[0009] The insertion portion may be configured such that the dimension between two adjacent protrusions rising from the first surface in a direction along the outer periphery of the crimping portion is less than the diameter of the shank of the drill.

[0010] The insertion portion may also be configured by providing a recessed notch cut out along the outer peripheral surface of the shank of the drill at the end of the protruding side of a standing wall rising from the first surface.

[0011] The first plate member and the second plate member are fastened by a plurality of the crimping portions, and when a plurality of imaginary concentric circles are set passing through each of the crimping portions with one point at the end of the fastening structure as the center of the concentric circles, each of the insertion portions may be arranged between the center of the concentric circles and each of the crimping portions.

[0012] According to the above configuration, when the worker stands at the center of the concentric circles, the fitting portion corresponding to each crimping portion is located in front of that crimping portion, so the worker can align the drill without having to move in line with the fitting portion or move the fastening structure, thereby making the disassembly work more efficient.

[0013] The fitting portion may be provided across the first plate member and the second plate member. With this configuration, even if the crimping portion is provided near the boundary of the second plate member, the fitting portion can be disposed regardless of the position of the boundary.

[0014] Another technology disclosed in this specification is a method for disassembling a fastening structure, which disassembles the above-mentioned fastening structure into the first plate member and the second plate member, and which sequentially performs the following steps: fitting the shank of the drill into the insertion portion and abutting the tip of the drill against the first surface; sliding the shank relative to the insertion portion to align the tip of the drill so that it is located at the center of the crimped portion; rotating the drill with the tip of the drill as the center of rotation so that the shank is arranged perpendicular to the first surface; and driving the drill to destroy the crimped portion and release the fastening between the first plate member and the second plate member. [Effects of the Invention]

[0015] The technology disclosed in this specification makes it possible to provide a fastening structure and a method for disassembling a fastening structure that allow the tip of a drill to be easily positioned relative to a fastened portion when breaking the fastened portion with a drill. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view showing a state in which a door trim according to an embodiment is placed on a workbench; [Figure 2] 1 showing a state in which a drill is inserted into the insertion portion; [Figure 3] 1 showing a state in which the drill is rotated and arranged perpendicular to the outer surface of the vehicle interior. [Figure 4] A perspective view of the fitting portion and the crimping portion [Figure 5] Partially enlarged plan view of Figure 1 [Figure 6] Partially enlarged plan view of Figure 1 [Figure 7] Partially enlarged plan view of Figure 1 [Figure 8] 10 is a cross-sectional view showing a state in which a drill is inserted into the insertion portion of the modified example (when the drill has not reached the crimped portion); [Figure 9] A plan view showing the state in which the drill is inserted into the insertion portion (when the drill has not reached the crimped portion) [Figure 10] A cross-sectional view showing the state in which a drill is inserted into the insertion portion (when the drill is disposed in the crimping portion) [Figure 11] FIG. 10 is a plan view showing a state in which a drill is inserted into the insertion portion (when the drill is disposed in the crimping portion); [Figure 12] Cross-sectional view showing the state when the drill is inserted into the insertion part (when the drill goes beyond the crimped part) [Figure 13] A plan view showing the state in which the drill is inserted into the insertion part (when the drill goes beyond the crimping part) [Figure 14] 10 is a perspective view of a fitting portion and a crimping portion according to another embodiment; [Figure 15] 10 is a perspective view of a fitting portion and a crimping portion according to another embodiment; [Figure 16]10 is a perspective view of a fitting portion and a crimping portion according to another embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the technology disclosed in this specification will be described in detail below with reference to Figures 1 to 7. Note that the X-axis, Y-axis, and Z-axis are shown in some of the drawings, and the directions of the axes are shown in the drawings. Furthermore, for multiple identical components, a reference numeral may be assigned to one component and the reference numerals of the other components may be omitted.

[0018] The fastening structure of this embodiment is a door trim 10, which is an interior material for a vehicle. FIG. 1 is a schematic diagram of an exterior surface 11A of the door trim 10 for a front side door disposed on the right side of the vehicle in the traveling direction, showing a plan view of the door trim 10 placed on a workbench (not shown). The door trim 10 is mainly composed of a generally plate-shaped trim board 11, and is attached to the interior side of a metal door inner panel (not shown) using clips or the like (not shown), thereby enhancing the design and livability of the vehicle interior. The trim board 11 is mainly composed of a synthetic resin material (thermoplastic resin material) such as polypropylene. The trim board 11 may also be composed of a composite material, for example, a mixture of plant fiber (e.g., kenaf) and synthetic resin.

[0019] The trim board 11 is formed by assembling a plurality of board members together. Although not shown in detail, the trim board 11 of this embodiment is mainly formed by an upper board 12, an ornament board 13, a middle board 14, a lower board 15, etc. Of these, the upper board 12 and the ornament board 13 have their interior surfaces (interior surfaces) covered with a skin material 16 made of natural leather, synthetic leather, fabric, or the like.

[0020] The above-mentioned board components are assembled using screws or thermal caulking. For example, the upper board 12 and the ornament board 13, and the ornament board 13 and the middle board 14 are fastened to each other by a plurality of caulking portions 19.

[0021] To explain some of these in more detail, a plurality of mounting bosses 17 are integrally formed on the outer surface of the vehicle cabin of middle board (an example of a first plate member) 14 along the upper edge in Fig. 1, protruding toward the outside of the vehicle cabin, and these mounting bosses 17 are inserted into boss insertion holes 18 formed in ornament board (an example of a second plate member) 13, and the tips of mounting bosses 17 are welded and crimped using an ultrasonic welding horn to form crimped portions 19 (see Fig. 2). Crimped portions 19 are generally flat and disk-shaped (see Fig. 4).

[0022] In recent years, there has been a demand for recycling the components of various products, and it is desirable to separate, recover, and reuse each board member of the door trim 10. When performing such dismantling and separation work, it is necessary to apply a drill 30 to each of the crimped portions 19 to break them individually, but this poses a problem in that it takes time and effort to position the tip 33 of the drill 30 at the desired position (center) of the crimped portion 19.

[0023] Therefore, the trim board 11 of this embodiment is configured to have an insertion portion 20 to facilitate the positioning operation of the drill 30. The insertion portion 20 will be described in detail below. The insertion portion 20 of this embodiment is configured by two protrusions 21 that rise up at positions adjacent to the crimping portion 19 on the exterior surface 11A (an example of the first surface) of the trim board 11 outside the vehicle interior.

[0024] As shown in FIG. 4, the two protrusions 21 are formed in the same shape and size as square prisms, and one side surface of each of them faces the other in a parallel state, and they stand up from the vehicle interior outer surface 11A of the trim board 11 along a direction substantially along the outer periphery of the caulking portion 19. The dimension L1 of the gap formed between these protrusions 21 is set to a dimension (L1 < D) smaller than the diameter D of the shaft portion 31 of the drill 30 described later used in the present embodiment. It can also be said that the dimension L1 between the two protrusions 21 is such that a part (a part in the circumferential direction) of the outer periphery of the shaft portion 31 of the drill 30 can be fitted between them to support the shaft portion 31 from the trim board 11 side.

[0025] Further, the rising dimension L2 of these protrusions 21 from the vehicle interior outer surface 11A is set to a dimension sufficiently higher than the height dimension of the caulking portion 19 (see FIGS. 2 and 3). Thereby, when the tip 33 of the drill 30 is brought into contact with the trim board 11 in a state where a part of the outer periphery of the shaft portion 31 of the drill 30 is fitted into the fitting portion 20 (between the two protrusions 21), the shaft portion 31 of the drill 30 is arranged in an inclined state with respect to the trim board 11 (see FIG. 2).

[0026] Note that the drill 30 used in the present embodiment has a configuration in which a conical (tapered) tip portion 32 is continuous with the tip of a round bar-shaped shaft portion 31. The angle of the tip 33 of the drill 30 used in the present embodiment is set to an angle close to a right angle (see FIG. 2).

[0027] As described above, a plurality of caulking portions 19 are provided on the trim board 11, and the fitting portions 20 are provided corresponding to each of the caulking portions 19. And each fitting portion 20 is arranged to be located between the center M of the concentric circles and each caulking portion 19 when a plurality of concentric circles passing through each caulking portion 19 are virtually set with the center M of the upper end center portion of the trim board 11 in FIG. 1 as the center. It can also be said that each fitting portion 20 is arranged on a straight line connecting the center M of the concentric circles and each caulking portion 19.

[0028] FIG. 1 is a plan view of the cabin outer surface 11A of the door trim 10 showing this state, and in FIG. 1, a worker P dismantling the door trim 10 (trim board 11) is shown above the door trim 10. When a plurality of concentric circles passing through each crimped portion 19 are virtually set with center M being the approximate center portion of the upper end of the door trim 10 facing the worker P, the fitting portions 20 corresponding to each crimped portion 19 are set to be located between the crimped portion 19 and the worker P. In other words, when the worker P visually checks each crimped portion 19, the fitting portions 20 corresponding to each crimped portion 19 are set to be located in front of the crimped portion 19 from the worker P's perspective. It can also be said that the fitting portions 20 are located inside the concentric circles passing through the crimped portions 19 corresponding to the fitting portions 20, on the side of the center M of the concentric circles.

[0029] With this configuration, the fitting portions 20 are provided in different members of the trim board 11 depending on the positions of the crimping portions 19. For example, the fitting portion 20A (two protrusions 21A) corresponding to the crimping portion 19A located to the left of the trim board 11 in FIG. 1 and fastening the ornament board 13 and the middle board 14 together is provided on the exterior surface of the vehicle interior of the ornament board 13, which has the boss insertion hole 18 corresponding to the crimping portion 19A (see FIGS. 2 and 5).

[0030] In contrast, for example, in Figure 1, the insertion portion 20B (two protrusions 21B) corresponding to the fastening portion 19B located in the center of the trim board 11 and fastening the upper board 12 and the ornament board 13 together is provided on the upper board 12 side where the mounting boss 17 corresponding to the fastening portion 19B is provided, rather than on the ornament board 13 where the boss insertion hole 18 corresponding to the fastening portion 19B is provided (see Figure 6).

[0031] 1 and corresponding to the crimping portion 19C fastening the upper board 12 and ornament board 13, one of the two protrusions 21C is provided on the ornament board 13 in which the boss insertion hole 18 corresponding to the crimping portion 19C is provided, and the other is provided on the upper board 12 in which the mounting boss 17 corresponding to the crimping portion 19C is provided. In other words, the fitting portion 20C is provided so as to straddle one of the members (the ornament board 13) and the other member (the upper board 12) that are fastened to each other (see FIG. 7).

[0032] Next, a method for disassembling the door trim 10 (trim board 11) of this embodiment will be described with reference to Figures 2 and 3, which are cross-sectional views of the crimped portion 19A. When breaking the crimped portion 19A that fastens the ornament board 13 and the middle board 14, first, a part of the outer circumferential surface of the shank 31 of the drill 30 is fitted into the fitting portion 20A (between the two protrusions 21A), and the tip 33 of the drill 30 is brought into contact with the upper surface of the crimped portion 19A (see Figure 2). The axis S of the drill 30 is disposed at an angle that intersects obliquely with the trim board 11.

[0033] 2, the angle of the tip 33 of the drill 30 is set to an angle close to a right angle, and by adjusting the angle of the shank 31 relative to the crimped portion 19 (trim board 11) so that the outer circumferential surface of the conical tip 32 abuts against the upper surface of the crimped portion 19, the tip 33 of the drill 30 is preset to be located in the center of the crimped portion 19. In other words, the angle of the tip 33 of the drill 30, the diameter D of the shank 31, the distance of the fitting portion 20 from the crimped portion 19, the dimension L1 between the two protrusions 21 of the fitting portion 20, and the rising dimension L2 are preset so that the tip 33 of the drill 30 is located in the center of the crimped portion 19 when the drill 30 is positioned as described above.

[0034] Once the tip 33 of the drill 30 is positioned in the center of the crimped portion 19 in this manner, the drill 30 is then rotated around the tip 33 of the drill 30 as a rotation center so that the shank 31 is perpendicular to the cabin exterior surface 11A (the upper surface of the crimped portion 19A) of the trim board 11 (see FIG. 3). The drill 30 is then driven to destroy the crimped portion 19A. This releases the fastening by the crimped portion 19A, making it possible to disassemble the ornament board 13 and the middle board 14.

[0035] Furthermore, in the above-described series of operations, when worker P visually observes the crimping portion 19A, the insertion portion 20A corresponding to the crimping portion 19A is located in front of the crimping portion 19A from the worker P's perspective, so worker P can easily align the drill 30 without having to move his or her body position to match the orientation of the insertion portion 20A or rotate the door trim 10.

[0036] Next, the effects will be described. In this embodiment, the door trim 10 (trim board 11) is formed by fastening a plate-shaped middle board 14 and an ornament board 13 together with a crimped portion 19 formed by inserting mounting bosses 17 protruding from the surface of the middle board 14 into boss insertion holes 18 formed in the ornament board 13, and the trim board 11 is provided with an insertion portion 20 that protrudes from the exterior surface 11A of the vehicle cabin at a position adjacent to the crimped portion 19 on the exterior surface 11A of the vehicle cabin where the crimped portion 19 is located, and into which a shank 31 of a drill 30 for breaking the crimped portion 19 can be inserted. When the shank 31 is inserted into the insertion portion 20, the axis S of the shank 31 obliquely intersects the exterior surface 11A of the vehicle cabin and overlaps the crimped portion 19.

[0037] When disassembling the trim board 11 configured as described above, the worker P first fits the shank 31 of the drill 30 used to break the crimped portion 19 into the fitting portion 20 and abuts the tip 33 of the drill 30 against the exterior surface 11A of the vehicle cabin. With the shank 31 fitted into the fitting portion 20 in this manner, the fitting portion 20 keeps the axis S of the drill 30 extending in a direction overlapping the crimped portion 19. Therefore, the worker P can easily align the tip 33 of the drill 30 with the center of the crimped portion 19 by simply sliding the shank 31 of the drill 30 relative to the fitting portion 20 while it remains fitted in the fitting portion 20. In other words, the disassembly of the trim board 11 is facilitated.

[0038] In addition, the insertion portion 20 is configured such that the dimension L1 between two protrusions 21 that rise side by side from the outer surface 11A of the vehicle interior in a direction along the outer periphery of the crimping portion 19 is less than the diameter D of the shank 31 of the drill 30.

[0039] In addition, the middle board 14 and the ornament board 13 are fastened by a plurality of fastening portions 19, and when one point (central portion) at the upper end of the trim board 11 is set as the center M of the concentric circles and a plurality of imaginary concentric circles passing through each fastening portion 19 are set, each insertion portion 20 is arranged between the center M of the concentric circles and each fastening portion 19.

[0040] According to the above configuration, when the worker P stands at a position that is the center of the concentric circles, the fitting portion 20 corresponding to each crimping portion 19 is located in front of that crimping portion 19, so the worker P can align the drill 30 without having to move in accordance with the fitting portion 20 or move the trim board 11, thereby making the disassembly work more efficient.

[0041] Furthermore, some of the fitting portions 20 are provided across the middle board 14 and the ornament board 13. With this configuration, even if the crimping portion 19 is provided near the boundary between the ornament board 13 and the middle board 14, the fitting portions 20 can be arranged regardless of the position of the boundary.

[0042] Furthermore, this embodiment is a disassembly method for disassembling the middle board 14 and ornament board 13 of the trim board 11 described above, and is a method that sequentially carries out the following steps: fitting the shank 31 of the drill 30 into the insertion portion 20 and abutting the tip 33 of the drill 30 against the outer surface 11A of the vehicle interior; sliding the shank 31 relative to the insertion portion 20 to align the tip 33 of the drill 30 so that it is located at the center of the crimping portion 19; rotating the drill 30 around the tip 33 of the drill 30 as the rotation center so that the shank 31 is arranged perpendicular to the outer surface 11A of the vehicle interior; and driving the drill 30 to destroy the crimping portion 19 and release the fastening between the middle board 14 and the ornament board 13.

[0043] <Modification> Modifications of the above embodiment will be described with reference to Figures 8 to 13. Note that only configurations different from the above embodiment will be described below, and configurations that are the same as those in the above embodiment will be given the same reference numerals, and similar configurations will be given reference numerals that are 100 larger than the reference numerals in the above embodiment, and duplicated explanations will be omitted.

[0044] In the trim board 111 of this modification, the fitting portion 120 is positioned slightly farther away from the crimping portion 19 than in the above embodiment, and the height dimension L3 is set to be slightly larger. Also, the drill 130 used in this modification has a tip portion 132 that is more elongated and a tip 133 that has an acute angle.

[0045] When disassembling the trim board 111 having such an insertion portion 120 (two protrusions 121), first, a part of the outer peripheral surface of the shank 131 of the drill 130 is inserted into the insertion portion 120 (between the two protrusions 121), and the tip 133 of the drill 130 is brought into contact with the cabin outer surface 11A of the trim board 111. The axis S of the drill 130 is disposed at an angle that intersects the trim board 111 obliquely. The axis S is also overlapped with the crimped portion 19.

[0046] At this time, because the shank 131 of the drill 130 is fitted into the fitting portion 120, the fitting portion 120 restricts movement of the axis S in a direction away from the state where it overlaps with the crimped portion 19. Specifically, regardless of whether the tip 133 of the drill 130 is disposed in a state where it does not reach the crimped portion 19 (see FIGS. 8 and 9), whether it is disposed at the crimped portion 19 (see FIGS. 10 and 11), or whether it is disposed beyond the crimped portion 19 (see FIGS. 12 and 13), the axis S of the shank 131 is in a state of extending in a direction where it overlaps with the crimped portion 19 (passes through the crimped portion in a plan view), and movement in a direction away from the state where it overlaps with the crimped portion 19 is restricted.

[0047] Next, if the tip 133 of the drill 130 is out of alignment with the center of the crimped portion 19 (see FIGS. 8-9 and 12-13), the shank 131 is slid relative to the fitting portion 120 to move the tip 133 of the drill 130 to the center of the crimped portion 19. At this time, as described above, the drill 130 is fitted into the fitting portion 120, and the fitting portion 120 keeps the axis S of the drill 130 extending in a direction overlapping the crimped portion 19. Therefore, the operator P can easily align the tip 133 of the drill 130 with the center of the crimped portion 19 by simply sliding the shank 131 of the drill 130 relative to the fitting portion 120 while it remains fitted into the fitting portion 120 (see FIGS. 10 and 11).

[0048] Once the tip 133 of the drill 130 is positioned in the center of the crimped portion 19 in this manner, the drill 130 is then rotated around the tip 133 of the drill 130 as the rotation center so that the shaft portion 131 is perpendicular to the cabin exterior surface 11A of the trim board 11. The drill 130 is then driven to break the crimped portion 19. This releases the fastening, making it possible to disassemble the ornament board 13 and the middle board 14.

[0049] In this way, when the shaft portion 131 of the drill 130 is inserted into the insertion portion 120 and the tip 133 is abutted against the outer surface 11A of the vehicle interior, even if the tip 133 of the drill 130 is positioned in a position offset from the crimping portion 19, the axis S of the drill 130 is maintained so as to extend in a direction overlapping with the crimping portion 19 when inserted into the insertion portion 120, so the tip 133 of the drill 130 can be easily aligned with the center of the crimping portion 19.

[0050] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, but can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0051] (1) In the above embodiment, the insertion portion 20 is configured such that the dimension L1 between the two protrusions 21, 21 that rise side by side from the outer surface 11A of the vehicle cabin in a direction along the outer periphery of the crimping portion 19 is equal to or smaller than the diameter D of the shank 31 of the drill 30. However, the insertion portion may also be configured such that the dimension between the two protrusions is equal to the diameter D of the shank of the drill, allowing the entire shank to be inserted.

[0052] (2) As shown in FIG. 14, the fitting portion 220 may have a round rod-shaped protrusion 221, and as shown in FIG. 15, the fitting portion 320 may have a semi-spherical protrusion 321.

[0053] (3) Furthermore, as shown in FIG. 16, the fitting portion 420 may be formed by providing a recessed cutout portion 422 along the outer peripheral surface of the drill shaft portion at the end of the protruding side of the standing wall 421 rising from the outer surface 11A of the vehicle cabin.

[0054] (4) Furthermore, the technology disclosed in this specification is not limited to the vehicle door trim 10, but can be modified and applied to other vehicle interior materials such as pillar garnishes, ceiling materials, console boxes, dashboards, various instrument panels, deck trims, etc., as well as vehicle interior materials for trains, airplanes, ships, etc., and applications other than vehicle interior materials. [Explanation of symbols]

[0055] 10: Door trim (fastening structure) 11, 111: Trim board (fastening structure) 11A: Vehicle interior outer surface (first surface) 13: Ornament board (second plate member) 14: Middle board (first plate member) 17: Mounting boss 18: Boss insertion hole 19, 19A, 19B, 19C: Crimping portion 20, 20A, 20B, 20C, 120, 220, 320, 420: Insertion portion 21, 21A, 21B, 21C, 121, 221, 321: Protrusion portion 30, 130: Drill 31, 131: Shank portion 32, 132: Tip portion 33, 133: Tip 421: Standing wall 422: Notch portion

Claims

1. A fastening structure in which a plate-shaped first plate member and a second plate member are fastened together by a crimping portion that is crimped in a state in which an attachment boss protruding from a plate surface of the first plate member is inserted into a boss insertion hole provided in the second plate member, a fitting portion formed on a first surface of the plate surface of the fastening structure, on which the crimped portion is arranged, at a position adjacent to the crimped portion, protruding from the first surface, and into which a shank of a drill for breaking the crimped portion can be fitted; A fastening structure in which, when the shaft portion is fitted into the fitting portion, the axis of the shaft portion intersects the first surface obliquely and overlaps the crimping portion.

2. The fastening structure described in claim 1, wherein the insertion portion is configured by two protrusions that rise side by side from the first surface in a direction along the outer periphery of the crimping portion, and the dimension between the protrusions is less than the diameter of the shank of the drill.

3. The fastening structure according to claim 1 or claim 2, wherein the insertion portion is configured by providing a concave cutout portion cut along the outer peripheral surface of the shank portion of the drill at the end of the protruding side of a standing wall rising from the first surface.

4. the first plate member and the second plate member are fastened together by a plurality of the crimping portions, 3. A fastening structure as described in claim 1 or claim 2, wherein when a plurality of imaginary concentric circles are set, passing through each of the fastening portions, with one point at the end of the fastening structure as the center of the concentric circles, each of the insertion portions is arranged between the center of the concentric circles and each of the fastening portions.

5. The fastening structure according to claim 4 , wherein the fitting portion is provided across the first plate member and the second plate member.

6. 3. A method for disassembling a fastening structure according to claim 1 or 2 into the first plate member and the second plate member, comprising: a step of fitting the shank of the drill into the fitting portion and bringing the tip of the drill into contact with the first surface; a step of sliding the shank portion relative to the fitting portion to align the tip of the drill so that it is positioned at a center portion of the crimped portion; rotating the drill around the tip of the drill as a rotation center so that the shank is disposed perpendicular to the first surface; and a step of driving the drill to destroy the crimped portion and release the fastening between the first plate member and the second plate member.

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