Fastening member, bonded joint, and method for manufacturing bonded joint

Abstract

This fastening member comprises a body portion, a first end portion, a second end portion, a first linking portion, and a second linking portion. A part of the body portion that is adjacent to the first linking portion and the first linking portion have outer diameters with different values. The outer diameters of the first end portion and the first linking portion are smaller than the outer diameter of the part of the body portion adjacent to the first linking portion. A part of the body portion that is adjacent to the second linking portion and the second end portion have outer diameters with different values. The thicknesses of the first end portion and the first linking portion as viewed from the axial direction are smaller than the thickness of the body portion.

Description

Fastening member, joint, and method for manufacturing joint

[0001] The present disclosure relates to a fastening member for screwing in a bolt portion of a towing hook, a joining joint between the fastening member and an object to be joined, and an automobile component with the fastening member.

[0002] Patent Document 1 discloses an eyebolt nut as a fastening member for screwing in a bolt portion of a towing hook. This eyebolt nut has a cylindrical portion and an umbrella-shaped portion. The rear surface of the umbrella-shaped portion is joined to a mounting surface of an automobile component.

[0003] Japanese Patent Application Laid-Open No. 2013-099999

[0004] An object of the present disclosure is to provide a joint joint of a new structure in which a fastening member for screwing in a bolt portion of a towing hook is joined to an automotive component, an automotive component with a fastening member, and a fastening member of a new structure to be used therewith.

[0005] The gist of the present disclosure is as follows.

[0006] <1> A fastening member having a threaded hole extending in an axial direction, comprising: a main body portion extending in the axial direction; a first end portion on one side of the main body portion in the axial direction; a second end portion on the other side of the main body portion in the axial direction; a first connecting portion connecting the main body portion to the first end portion; and a second connecting portion connecting the main body portion to the second end portion, wherein the threaded hole is provided in at least one of the main body portion or the second end portion, wherein, in the axial direction, a portion of the main body portion adjacent to the first connecting portion and the first connecting portion have different outer diameters, the outer diameters of the first end portion and the first connecting portion are smaller than the outer diameter of the portion of the main body portion adjacent to the first connecting portion, the outer diameters of the portion of the main body portion adjacent to the second connecting portion and the second end have different outer diameters, and the thickness of the first end portion and the first connecting portion as viewed in the axial direction is thinner than the thickness of the main body portion.

[0007] <2> The fastening member according to <1>, wherein the second end portion and the second connecting portion have a thickness greater than the thickness of the first end portion and the first connecting portion.

[0008] <3> The fastening member described in <1> or <2>, wherein, in the axial direction, an outer diameter of a portion of the second end portion adjacent to the second connecting portion is larger than an outer diameter of each of a portion of the main body portion adjacent to the second connecting portion and the second connecting portion.

[0009] <4> The fastening member according to any one of <1> to <3>, wherein, in the axial direction, the outer diameter of a portion of the second end portion adjacent to the second connecting portion and the second connecting portion is smaller than the outer diameter of a portion of the main body portion adjacent to the second connecting portion, and the thickness of each of the second end portion and the second connecting portion as viewed in the axial direction is thinner than the thickness of the main body portion.

[0010] <5> The fastening member according to any one of <1> to <3>, wherein the shapes of the circumferential surfaces of the main body portion and the second connecting portion are uniform along the axial direction.

[0011] <6> The fastening member according to any one of <1> to <5>, wherein the main body portion has a main body through hole that is a through hole extending in the axial direction, the first end portion and the first connecting portion have first through holes that communicate with the main body through hole in the axial direction, the minimum value of the diameter of the first through hole as viewed in the axial direction is larger than the maximum value of the diameter of the main body through hole, and when the main body portion has a screw hole, the main body through hole has a threaded portion.

[0012] <7> The fastening member according to any one of <1> to <6>, wherein the main body portion has a main body through hole that is a through hole extending in the axial direction, the second end portion and the second connecting portion have second through holes that communicate with the main body through hole in the axial direction, the minimum value of the diameter of the second through hole as viewed in the axial direction is larger than the maximum value of the diameter of the main body through hole, if the main body portion has a screw hole, the main body through hole has a threaded portion, and if the second end portion has the screw hole, the second through hole has a threaded portion.

[0013] <8> A joint joint comprising objects to be joined and a fastening member joined to the objects to be joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, wherein the first plate portion has a first hole, and the second plate portion has a second hole, and the fastening member is a fastening member having a threaded hole extending in an axial direction, and comprising: a main body portion extending in the axial direction, a first end portion on one side in the axial direction of the main body portion, a second end portion on the other side in the axial direction of the main body portion, a first connecting portion connecting the main body portion to the first end portion, and a second connecting portion connecting the main body portion to the second end portion, wherein the threaded hole is in at least one of the main body portion or the second end portion, wherein the first end portion is arranged on one side in the axial direction with respect to the first plate portion, and the second end portion is arranged on the other side in the axial direction with respect to the second plate portion, the first connecting portion is arranged inside the first hole, and the second connecting portion is arranged inside the second hole, and the main body portion is arranged between the first plate portion and the second plate portion, A joint joint in which, in the axial direction, the outer diameter of the first connecting portion is smaller than the outer diameter of a portion of the main body portion adjacent to the first connecting portion, the thickness of the first connecting portion is thinner than the thickness of a portion of the main body portion adjacent to the first connecting portion, the outer diameter of the first end portion is larger than the diameter of the first hole, the main body portion and the first end portion sandwich the peripheral portion of the first hole in the first plate portion from both axial sides, and the outer diameter of the second end portion is larger than the diameter of the second hole, and the peripheral portion of the second hole is supported by the second end portion.

[0014] <9> The joint described in <8>, wherein the outer diameter of the second connecting portion is smaller than the outer diameter of a portion of the main body portion adjacent to the second connecting portion, the thickness of the second connecting portion is thinner than the thickness of a portion of the main body portion adjacent to the second connecting portion, the outer diameter of the second end portion is larger than the diameter of the second hole, and the main body portion and the second end portion clamp the peripheral portion of the second hole in the second plate portion from both axial sides.

[0015] <10> The joined joint according to <8> or <9>, wherein the object to be joined is an automobile part, the automobile part having a closed cross-section structure in which a hat-shaped first plate and a substantially flat second plate are joined, the first plate having a top plate portion, a pair of vertical plate portions, and a pair of flange portions, the second plate having an opposing portion opposing the top plate portion and a pair of joining portions joined to the pair of flange portions, the top plate portion being the first plate portion, the opposing portion being the second plate portion, and the plate thickness of the first plate being greater than the plate thickness of the second plate.

[0016] <11> The joint according to any one of <8> to <10>, wherein the first hole has a polygonal shape.

[0017] <12> A method for manufacturing a joined joint in which objects to be joined and a fastening member are joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, the first plate portion having a first hole and the second plate portion having a second hole, the fastening member having: a threaded hole extending in an axial direction, a main body portion extending in the axial direction, a first end portion on one side in the axial direction of the main body portion, a second end portion on the other side in the axial direction of the main body portion, a first connecting portion connecting the main body portion to the first end portion, and a second connecting portion connecting the main body portion to the second end portion, the threaded hole being in at least one of the main body portion or the second end portion, and in the axial direction, a portion of the main body portion adjacent to the first connecting portion and the first connecting portion have different outer diameters, and the portion of the first end portion adjacent to the first connecting portion and the first connecting portion have smaller outer diameters than the portion of the main body portion adjacent to the first connecting portion, the outer diameters of a portion of the main body portion adjacent to the second connecting portion and the second end portion are different values; the thicknesses of the first end portion and the first connecting portion as viewed in the axial direction are thinner than the thickness of the main body portion; the manufacturing method includes a step of preparing the objects to be joined and the fastening member, a first step, and a second step; in the first step, the first end portion is arranged on one axial side of the first plate portion, and the second end portion is arranged on the other axial side of the second plate portion, the first connecting portion is arranged inside the first hole, the second connecting portion is arranged inside the second hole, the main body portion is arranged between the first plate portion and the second plate portion, and the portion of the main body portion adjacent to the first connecting portion contacts the peripheral portion of the first hole in the first plate portion from the other axial side, a crimping preparation state in which a portion of the second end portion adjacent to the second connecting portion contacts a peripheral portion of the second hole in the second plate portion from the other axial side, or a portion of the main body portion adjacent to the second connecting portion contacts a peripheral portion of the second hole in the second plate portion from one axial side,In the second step, the fastening member is electrically heated and pressurized from both axial sides in the crimping preparation state to deform the first end portion to form a deformed portion, and the peripheral portion of the first hole in the first plate portion is clamped from both axial sides by the main body portion and the deformed portion.

[0018] <13> The method for manufacturing a joined joint described in <12>, wherein the fastening member has an outer diameter of a portion of the second end portion adjacent to the second connecting portion that is larger than the outer diameters of the portion of the main body portion adjacent to the second connecting portion and the second connecting portion, the outer diameter of the second end portion is larger than the diameter of the second hole, and in the crimping preparation state, the portion of the second end portion adjacent to the second connecting portion contacts the peripheral portion of the second hole in the second plate portion from the other axial side.

[0019] <14> The method for manufacturing a joined joint according to <12> or <13>, wherein the fastening member has an outer diameter of a portion of the second end adjacent to the second connecting portion and the second connecting portion that is smaller than an outer diameter of a portion of the main body that is adjacent to the second connecting portion; each of the second end and the second connecting portion as viewed in the axial direction is thinner than the thickness of the main body; in the crimping preparation state, the portion of the main body that is adjacent to the second connecting portion contacts a peripheral portion of the second hole in the second plate portion from one axial side; and in the second step, further, by applying electrical heat and pressure to the fastening member from both axial sides in the crimping preparation state, the second end is deformed to form a second deformed portion, and the peripheral portion of the second hole in the second plate portion is clamped from both axial sides by the main body portion and the second deformed portion.

[0020] Fig. 1 is a perspective view showing a fastening member of an embodiment; Fig. 2 is a cross-sectional view showing a fastening member of an embodiment; Fig. 3 is a cross-sectional view showing an automobile member of an embodiment; Fig. 4 is a cross-sectional view showing a state in which the fastening member is placed on the automobile member (crimping preparation state); Fig. 5 is a cross-sectional view showing a state in which the fastening member is joined to the automobile member (joint joint); Fig. 6 is a diagram showing a modified first hole; Fig. 7 is a cross-sectional view corresponding to Fig. 4 showing a modified fastening member; Fig. 8 is a cross-sectional view corresponding to Fig. 5 showing a modified joint joint.

[0021] Hereinafter, embodiments of the present disclosure will be described.

[0022] First, a preferred embodiment of the fastening member 10 will be described with reference to FIGS. 1 and 2. FIG.

[0023] The fastening member 10 is preferably used by being joined to an automobile component 20 (see FIG. 3). For example, the fastening member 10 is a fastening member (also called a towing nut) for screwing in a bolt portion of a towing hook (not shown). The towing hook is a hook used to tow an automobile.

[0024] The fastening member 10 includes a shaft portion 11 , a flange portion 12 , and a crimped portion 13 .

[0025] The shaft portion 11 has a cylindrical shape. A circular through-hole 11A is formed in the shaft portion 11, penetrating the shaft portion 11. Therefore, the shaft portion 11 can also be said to have a cylindrical shape. The through-hole 11A of the shaft portion 11 is a screw hole (not shown).

[0026] The flange portion 12 is provided on the other axial side of the shaft portion 11. The flange portion 12 has a cylindrical shape formed coaxially with the shaft portion 11. The outer diameter R2 of the flange portion 12 is larger than the outer diameter R1 of the shaft portion 11. A circular through-hole 12A is formed in the flange portion 12 and penetrates the flange portion 12. Therefore, the flange portion 12 can also be said to be cylindrical. The through-hole 12A of the flange portion 12 is formed coaxially with the through-hole 11A of the shaft portion 11 and is connected to the through-hole 11A of the shaft portion 11. In this embodiment, the through-hole 12A of the flange portion 12 is not a threaded hole, but this is not limiting. The inner diameter r2 of the flange portion 12 is larger than the inner diameter r1 of the shaft portion 11 (maximum diameter, root diameter of the threaded hole).

[0027] The crimped portion 13 is provided on one axial side of the shaft portion 11. The crimped portion 13 has a cylindrical shape formed coaxially with the shaft portion 11. The outer diameter R3 of the crimped portion 13 is smaller than the outer diameter R1 of the shaft portion 11. A circular through-hole 13A is formed in the crimped portion 13 and penetrates the crimped portion 13. Therefore, the crimped portion 13 can also be said to be cylindrical. The through-hole 13A of the crimped portion 13 is formed coaxially with the through-hole 11A of the shaft portion 11 and is connected to the through-hole 11A of the shaft portion 11. Therefore, the through-hole 11A of the shaft portion 11, the through-hole 12A of the flange portion 12, and the through-hole 13A of the crimped portion 13 form through-holes 11A, 12A, and 13A that penetrate the fastening member 10 in the axial direction. In this embodiment, the through-hole 13A of the crimped portion 13 is not a screw hole, but this is not limiting. In this embodiment, the inner diameter r3 of the crimped portion 13 is larger than the inner diameter r1 (maximum diameter, root diameter of the screw hole) of the shank 11, but is not limited to this. The thickness of the crimped portion 13 ((R3-r3) / 2) is smaller than the thickness of the shank 11 ((R1-r1) / 2).

[0028] The entire fastening member 10 is integrally formed from the same material, for example, steel.

[0029] A first end face 14 is formed on one axial end face of the shaft portion 11. When the fastening member 10 is viewed from one axial side, the first end face 14 of the shaft portion 11 is a surface formed around the crimped portion 13 and is a surface that extends in an annular shape.

[0030] A second end face 15 is formed on one axial end face of the flange portion 12. The second end face 15 of the flange portion 12 is a surface formed around the shank 11 when the fastening member 10 is viewed from one axial side, and is a surface that extends in an annular shape.

[0031] (Automobile member 20) The "joined object" in this disclosure is preferably a member having a closed cross-sectional structure with two plate-like members facing each other. The crimped portion 13 of the fastening member 10 is crimped to one of the two plate-like members and joined, the flange portion 12 is supported by the other, and the shaft portion 11 is fixed between the two plate-like members. Using Figure 3, an automobile member 20 will be described as an example of a preferred embodiment of the "joined object."

[0032] The automobile component 20 is, for example, a frame component (bumper reinforcement component) extending in the vehicle width direction at the front or rear end of the automobile, but may be another automobile component. For example, the automobile component 10 may be a component for supporting a battery box mounted on the automobile. In this case, the fastening member 10 is used to fasten the battery box.

[0033] The automotive component 20 includes a first member 21 and a second member 22. The first member 21 is hat-shaped. Specifically, the first member 21 has a top plate portion 21A, a pair of vertical plate portions 21B, and a pair of flange portions 21C. The second member 22 is generally flat. The second member 22 has a facing portion 22A facing the top plate portion 21A and a pair of joining portions 22B joined to the pair of flange portions 21C. As a result, the automotive component 20 has a closed cross-sectional structure extending in a direction perpendicular to the plane of the drawing. In the illustrated example, the thickness of the second member 22 is smaller than the thickness of the first member 21. The first member 21 and the second member 22 are, for example, steel plates. Either or both of the first member 21 and the second member 22 may be high-tensile steel plates of 1800 MPa or more, or may be hot-stamped steel plates. The automobile member 20 is disposed, for example, in a position in which the second member 22 side (the lower side in FIG. 3 ) of the first member 21 and the second member 22 faces outward in the vehicle longitudinal direction.

[0034] A first hole 23 is formed in the top plate portion 21A of the first member 21. The first hole 23 is circular. A diameter d1 of the first hole 23 is slightly larger than the outer diameter R3 of the crimped portion 13 and smaller than the outer diameter R1 of the shaft portion 11. Hereinafter, the top plate portion 21A of the first member 21 may be referred to as the first plate portion 21A. A second hole 24 is formed in the opposing portion 22A of the second member 22. The second hole 24 is circular. A diameter d2 of the second hole 24 is slightly larger than the outer diameter R1 of the shaft portion 11 and smaller than the outer diameter R2 of the flange portion 12. Hereinafter, the opposing portion 22A of the second member 22 may be referred to as the second plate portion 22A.

[0035] (Joining Method, Manufacturing Method) Next, a method for joining the fastening member 10, that is, a method for manufacturing an automobile component 30 with a fastening member (also referred to as a joint 30), will be described with reference to FIGS.

[0036] The joining method of the fastening member 10 generally involves the following steps: First step: The fastening member 10 is placed in a predetermined position relative to the automobile component 20 (a crimping preparation state, see FIG. 4). Second step: A crimping step is carried out in the crimping preparation state to obtain an automobile component 30 with the fastening member (a joint 30) (see FIG. 5).

[0037] In the first step, the fastening member 10 is inserted into the interior of the automotive member 20 from the second hole 24 side of the automotive member 20, with the crimped portion 13 side leading. Specifically, the crimped portion 13 and shank 11 of the fastening member 10 are passed through the second hole 24 of the automotive member 20, and the crimped portion 13 is then passed through the first hole 23 so that the tip end 13a of the crimped portion 13 protrudes from the first surface 21A1 of the first plate portion 21A. In addition, the first end surface 14 of the shank 11 of the fastening member 10 is brought into contact with the second surface 21A2 of the top plate portion 21A.

[0038] The crimping preparation state shown in FIG. 4 will be described in detail as follows. The root portion 13b of the crimping portion 13 is positioned within the first hole 23. The portion of the crimping portion 13 other than the root portion 13b (tip portion 13a) protrudes from the first hole 23 toward the first surface 21A1 of the first plate portion 21A and is located on the first surface 21A1 side of the first plate portion 21A. The first end surface 14 of the shaft portion 11 contacts the second surface 21A2 of the first plate portion 21A. The first end surface 14 of the shaft portion 11 contacts the peripheral portion of the first hole 23 in the first plate portion 21A. The root portion 11b (the end portion on the other axial side) of the shaft portion 11 is positioned within the second hole 24. The majority of the shaft portion 11 (general portion 11a) excluding the root portion 11b is located inside the automotive component 20. In other words, the general portion 11a of the shaft portion 11 is located between the first member 21 and the second member 22. The flange portion 12 is located outside the automobile member 20. In other words, the flange portion 12 is disposed on the other axial side of the second member 22. The second end surface 15 of the flange portion 12 is in contact with or close to the second surface 22A2 of the second plate portion 22A. The second end surface 15 of the flange portion 12 is in contact with or close to the peripheral portion of the second hole 24 in the second plate portion 22A.

[0039] Hereinafter, the general portion 11a of the shank 11 will be referred to as the main body 11a, the tip 13a of the crimped portion 13 as the first end 13a, the root 13b of the crimped portion 13 as the first connecting portion 13b, the root 11b of the shank 11 as the second connecting portion 11b, and the flange 12 as the second end 12. Using these designations, the structure of the fastening member 10 can be restated as follows. The main body 11a has a first end surface 14. The first end 13a constitutes one axial end of the fastening member 10. The first connecting portion 13b connects the main body 11a and the first end 13a. The second end 12 constitutes the other axial end of the fastening member 10. The second connecting portion 11b connects the main body 11a and the second end 12. At least one of the main body 11a and the second end 12 has a screw hole. In the axial direction, the outer diameters of the portion of the main body portion 11a adjacent to the first connecting portion 13b and the first connecting portion 13a are different. Furthermore, in the axial direction, the outer diameters of the first end portion 13a and the first connecting portion 13a are smaller than the outer diameter of the portion of the main body portion 11a adjacent to the first connecting portion 13b. With this configuration, in the crimping preparation state, the first end portion 13a is positioned on one axial side of the first plate portion 21A, and the portion of the main body portion 11a adjacent to the first connecting portion 13a can be in contact with the peripheral portion of the first hole 23 in the first plate portion 21A from the other axial side. Furthermore, in the axial direction, the outer diameters of the portion of the main body portion 11a adjacent to the second connecting portion 11b and the second end portion 12 are different. With this configuration, in the crimping preparation state, the portion of the second end portion 12 adjacent to the second connecting portion 11b can be in contact with the peripheral portion of the second hole 23 in the second plate portion 22A from the other axial side. Alternatively, a portion of the main body 11a adjacent to the second connecting portion 11b can be in contact with the peripheral edge of the second hole 23 in the second plate portion 22A from one axial side. That is, according to the present disclosure, in the crimping preparation state, it is possible to fix the fastening member in a state in which it is in contact with and supported by both of the two opposing plate-like members.

[0040] In the second step, the crimping process is performed in a crimping preparation state. The crimping process here refers to a process in which the fastening member 10 is sandwiched between a pair of electrodes 40 on both axial sides and subjected to electrical heating and pressure. The crimping process locally deforms the crimped portion 13. This is because the crimped portion 13 has a thinner wall thickness (smaller cross-sectional area) than the shank portion 11 and the flange portion 12, so it has lower strength and is locally heated and softened by electrical current. Specifically, when the fastening member 10 is electrically heated in the axial direction, the current density in the crimped portion 13, which is thinner than the shank portion 11, is higher than that in the shank portion 11. This allows the crimped portion 13 to be efficiently heated and softened faster than other regions. This configuration enables the crimped portion 13 to be deformed in a short time. Here, the thickness of the crimped portion 13 is (R3 - r3) / 2, the thickness of the shank 11 is (R1 - r1) / 2, and the thickness of the flange 12 is (R2 - r2) / 2. As shown in FIG. 2, R3 is the outer diameter of the crimped portion 13, r3 is the inner diameter of the crimped portion 13, R1 is the outer diameter of the shank 11, and r1 is the inner diameter (maximum diameter) of the shank. The thickness of the crimped portion 13 is preferably 80% or less of the thickness of the shank 11. If the outer diameter or inner diameter is not uniform in the axial direction, the thickness is defined by the maximum value. For example, if the inner diameter r3 of the crimped portion 13 is not uniform, the thickness of the crimped portion 13 is considered to be (R3 - r3min) / 2. If this value is smaller than the thicknesses of the shank 11 and flange 12, the crimping can be performed appropriately. Hereinafter, the deformed crimped portion 13 shown in Figure 5 may be referred to as the deformed portion 13. The electrode material may be, for example, chromium copper, alumina-dispersed copper, or beryllium copper, but is not limited to these, and a wide variety of electrode materials for resistance welding may be used. The outer diameter of the electrode may be equal to or greater than the outer diameter of the crimped portion 13, and is preferably equal to or greater than the outer diameter of the flange portion 12. The shape of the electrode tip may be flat or rounded. In the latter case, if the electrode radius is too small, a temperature distribution is likely to occur in the radial direction of the traction nut, so an electrode radius of 100 mm or greater is preferred.

[0041] FIG. 5 shows an automobile component 30 with a fastening member (a joint 30).

[0042] When the pre-deformed crimped portion 13 (see FIG. 4 ) is used as a reference, the first end 13a is deformed to expand radially outward and radially inward. The first connecting portion 13b is located inside the first hole 23, and its radially outward expansion is suppressed by the first plate portion 21A, so the first connecting portion 13b is deformed to expand radially inward. Of the deformed crimped portion 13, the outer diameter R3a of the first end 13a is larger than the outer diameter R3 of the pre-deformed crimped portion 13 and is also larger than the diameter d1 of the first hole 23. As a result, the peripheral portion of the first hole 23 in the first plate portion 21A is sandwiched between the main body portion 11a and the deformed crimped portion 13 (first end 13a).

[0043] The inner diameter r3a of the crimped portion 13 after deformation is, for example, smaller than the inner diameter r3 of the crimped portion 13 before deformation and larger than the inner diameter r1 (maximum diameter) of the shaft portion 11.

[0044] <Operation and Effect> Next, the operation and effect of this embodiment will be described.

[0045] 1, 2, etc., the fastening member 10 of this embodiment includes a main body portion 11a having an axially extending screw hole (through hole 11A) formed therein, a first end portion 13a constituting one axial end portion of the fastening member 10, a second end portion 12 constituting the other axial end portion of the fastening member 10, a first connecting portion 13b connecting the main body portion 11a to the first end portion 13a, and a second connecting portion 11b connecting the main body portion 11a to the second end portion 12. A first end surface 14 facing toward one axial side is formed on one axial end face of the main body portion 11a. Therefore, by placing the fastening member 10 on the workpieces 20, it can be placed in a predetermined position (a crimping preparation state, see FIG. 4). The predetermined positioning state (crimping preparation state) referred to here means a state in which the first end portion 13a is positioned on one axial side of the first plate portion 21A, and the second end portion 12 is positioned on the other axial side of the second plate portion 22A, and the first end face 14 is in contact with the peripheral portion of the first hole 23 in the first plate portion 21A from the other axial side.

[0046] 4 and 5 , in this embodiment, the first end portion 13a and the first connecting portion 13b are configured to be crimped by a crimping process in which the fastening member 10 is sandwiched from both axial sides between a pair of electrodes 40 and subjected to electrical heating and pressure. Therefore, by performing the crimping process in the crimping preparation state (see FIG. 4 ), the first end portion 13a and the first connecting portion 13b are crimped to form the deforming portion 13 (see FIG. 5 ), and a state can be achieved in which the main body portion 11a and the first end portion 13a of the deforming portion 13 sandwich the peripheral portion of the first hole 23 in the first plate portion 21A from both axial sides. In this way, the fastening member 10 is joined to the joining object 20.

[0047] In this embodiment, as shown in FIG. 5 , the second end 12 and the second connecting portion 11b are configured to be resistant to deformation during the crimping process. Therefore, the joining process is easier than in a configuration in which both the first end 13a and the second end 12 are crimped (see FIGS. 7 and 8 ). This configuration can be achieved by increasing the thickness (cross-sectional area) of the second end 12 and the second connecting portion 11b relative to the thickness of the crimped portion 13, as viewed axially. When the fastening member 10 is electrically heated in the axial direction, the current density in the crimped portion 13, which is thinner than the second end 12 and the second connecting portion 11b, is higher than that in the second end 12 and the second connecting portion 11b. This allows the crimped portion 13 to be efficiently heated and softened faster than other regions. This configuration allows the deformation of the crimped portion 13 and the resulting crimping to be completed before the second end 12 and the second connecting portion 11b soften and deform.

[0048] 4, in this embodiment, the main body 11a is configured to be able to pass through a second hole 24 formed in the object to be joined 20. Therefore, the fastening member 10 can be placed on the automobile member 20 in a state in which the first member 21 and the second member 22 that constitute the automobile member 20 are joined.

[0049] In this embodiment, as shown in FIG. 1 , the shapes of the circumferential surfaces 11S of the main body portion 11a and the second connecting portion 11b are uniform along the axial direction. Therefore, when the main body portion 11a passes through the second hole 24 and the second connecting portion 11b is disposed within the second hole 24, it is easy to ensure the bearing strength of the main body portion 11a and the second connecting portion 11b. "The shapes of the circumferential surfaces 11S of the main body portion 11a and the second connecting portion 11b are uniform along the axial direction" refers to, for example, that the outer diameters of the main body portion 11a and the second connecting portion 11b are constant along the axial direction. Furthermore, in this embodiment, as shown in FIG. 2 , the outer diameter R2 of the second end portion 12 is larger than the outer diameter R1 of the main body portion 11a and the second connecting portion 11b. The value of r2 is selected so that the cross-sectional area (thickness as viewed from the axial direction) of the second end portion 12 is larger than the cross-sectional area (thickness as viewed from the axial direction) of the main body portion and the second connecting portion, and is equal to or greater than r1. This configuration prevents the second end portion 12 from being deformed during the crimping process.

[0050] 4, the first connecting portion 13b and the first end portion 13a are formed in a cylindrical shape. Therefore, compared to a configuration in which the first connecting portion 13b and the first end portion 13a are not formed in a cylindrical shape, the first connecting portion 13b and the first end portion 13a are properly crimped, and the joining reliability is improved. Here, the configuration in which the first connecting portion 13b is not formed in a cylindrical shape means a columnar shape without a through hole.

[0051] In addition, in this embodiment, through holes 11A, 12A, 13A are formed that axially pass through the first end portion 13a, the first connecting portion 13b, the main body portion 11a, the second connecting portion 11b, and the second end portion 12. This makes it easy to manufacture the fastening member 10 using a lathe or the like.

[0052] In this embodiment, the screw holes are formed not only in the portion of the through holes 11A, 12A, and 13A that corresponds to the main body portion 11a but also in the portion that corresponds to the second connecting portion 11b. This allows the portion where the screw holes are formed to be longer, thereby ensuring the fastening strength with the bolt.

[0053] Incidentally, if the inner diameter of the first connecting portion 13b (or the average value if not constant) is larger than the inner diameter of the first end portion 13a (or the average value if not constant), the amount of deformation of the first connecting portion 13b (the root portion 13b of the crimped portion 13) and the portion of the first end portion 13a adjacent to the first connecting portion 13b is likely to be small. If the amount of deformation of the first connecting portion 13b and the portion of the first end portion 13a adjacent to the first connecting portion 13b is small, the peripheral portion of the first hole 23 in the first plate portion 21A may not be properly clamped by the main body portion 11a and the deformed crimped portion 13. In other words, the deformed portion 13 may not have an appropriate shape. Therefore, in this embodiment, as shown in FIG. 2 , the inner diameter r3 of the first connecting portion 13b is constant along the axial direction, the inner diameter r3 of the first end portion 13a is constant along the axial direction, and the inner diameter r3 of the first connecting portion 13b is the same as the inner diameter r3 of the first end portion 13a. Therefore, compared to a configuration in which the inner diameter (average value if not constant) of the first connecting portion 13b is larger than the inner diameter (average value if not constant) of the first end portion 13a, the first connecting portion 13b (root portion 13b of the crimped portion 13) can be sufficiently deformed, and a deformed portion 13 of an appropriate shape can be obtained.

[0054] In this embodiment, as shown in FIG. 2, the minimum value r3 (which is a constant value in this embodiment) of the inner diameter r3 of the first connecting portion 13b and the first end portion 13a in the axial direction is greater than the maximum diameter r1 of the screw hole (through hole 11A). This prevents the deformed portion 13 (see FIG. 5), which has deformed so as to expand radially inward, from overlapping with the screw hole 11A as viewed from the axial direction. This is particularly advantageous when the bolt portion of the towing hook is screwed in from one axial side. The difference between the two (r1 and r3) is preferably 1 mm or more, and more preferably 5 mm or more.

[0055] 2 , the inner diameter r2 of the second end 12 is larger than the inner diameter r1 of the main body 11a and the second connecting portion 11b, and the outer diameter R2 of the second end 12 is larger than the outer diameter R1 of the main body 11a and the second connecting portion 11b. Because the inner diameter r2 of the second end 12 is larger than the inner diameter r1 of the main body 11a and the second connecting portion 11b, even if the second end 12 is slightly deformed during the crimping process, the deformed second end 12 and the screw hole 11A are prevented from overlapping each other as viewed in the axial direction. Furthermore, by selecting the value of r2 so that the outer diameter R2 of the second end 12 is larger than the outer diameter R1 of the main body 11a and the second connecting portion 11b and so that the cross-sectional area (thickness as viewed in the axial direction) of the second end 12 is larger than the cross-sectional areas (thickness as viewed in the axial direction) of the main body 11a and the second connecting portion and is equal to or greater than r1, deformation of the second end 12 during the crimping process is prevented. Furthermore, by forming the flange portion 12 with an increased outer diameter R2 of the second end portion 12, the flange portion 12 and the second surface 22A2 of the second plate portion 22A can be brought into contact with each other, which has the effect of preventing tilting of the fastening member 10. This configuration is particularly effective when the difference between R1 and R3 is small.

[0056] Furthermore, in the bonded joint of this embodiment, as shown in FIG. 5 , the first end surface 14 of the main body portion 11a contacts the peripheral portion of the first hole 23 in the first plate portion 21A from the other axial side. The first end portion 13a and the first connecting portion 13b form the deformed portion 13, and the main body portion 11a and the deformed portion 13 sandwich the peripheral portion of the first hole 23 in the first plate portion 21A from both axial sides. This ensures that the workpieces 20 and the fastening member 10 are properly bonded. Whether a portion of a specific bonded joint corresponds to the "deformed portion 13" (the crimped portion 13 deformed by pressure) can be confirmed, for example, by comparing the structure of the portion with that of the main body portion 11a through cross-sectional observation. Furthermore, this can be confirmed by comparing the hardness of the portion with that of the main body portion 11a. In this case, it is desirable to sample the main body portion 11a from the axial center to measure the structure and hardness. For example, the measurement load can be set to 1 kgf or more, and the average values ​​of five or more measurements made on the main body 11a and the crimped portion 13 can be compared to determine whether the difference is HV 10 or more. In the joined joint of this embodiment, as shown in Figure 5, the second connecting portion 11b of the fastening member 10 is disposed within the second hole 24 of the second plate portion 22A, so that the fastening member 10 is prevented from tilting around the joint portion with the first plate portion 21A.

[0057] 3, the thickness of the first member 21 is greater than the thickness of the second member 22. The hat-shaped first member 21 having a greater thickness than the second member 22 can efficiently improve the strength of the automobile member 20. Furthermore, by crimping the fastening member 10 to the first member 21 having a greater thickness, it is easier to ensure joint strength compared to when the fastening member 10 is crimped to the second member 22 having a smaller thickness.

[0058] (Supplementary Explanation) Although the fastening member, the joint, and the automotive component with the fastening member according to the present disclosure have been described above using the embodiments, the present disclosure is not limited to the above-described embodiments.

[0059] In the above embodiment, the first hole 23 and the second hole 24 are described as having circular shapes. However, the shapes of the first hole and the second hole in the present disclosure do not have to be circular. For example, as shown in FIG. 6 , the first hole 23 may have a hexagonal shape. This allows the cylindrical crimping portion 13 (particularly the root portion 13b) to deform to conform to the hexagonal shape of the first hole 23, thereby further suppressing axial rotation of the fastening member 10 relative to the automotive member 20. In this case, the diameter d1 of the first hole 23 can be considered to be the diameter of a circle inscribed in the hexagon formed by the first hole 23, and the diameter d1 of the first hole 23 can be set to be the same as or slightly larger than the outer diameter R3 of the crimping portion 13. Note that the shape of the first hole 23 to achieve this effect is not limited to a hexagon and may be a polygon other than a hexagon (e.g., an octagon). Furthermore, the shape of the first hole 23 may be a shape other than a polygon (a shape that suppresses axial rotation of the fastening member 10 relative to the workpiece 20). Furthermore, when the shape of the first hole 23 is a shape other than a circle, the shape of the crimped portion 13 (as viewed from the axial direction) may be changed to a shape similar to the shape of the first hole 23 .

[0060] In the above embodiment, an example has been described in which the shaft portion 11, the flange portion 12, and the crimped portion 13 are all cylindrical. In other words, in the above embodiment, an example has been described in which the main body portion 11a, the first end portion 13a, the second end portion 12, the first connecting portion 13b, and the second connecting portion 11b are all cylindrical. However, the present disclosure is not limited to this. The main body portion 11a, the first end portion 13a, the second end portion 12, the first connecting portion 13b, and the second connecting portion 11b may each be individually changed to a hexagonal prism shape or another prismatic shape. Note that, for example, if the main body portion 11a is polygonal prism-shaped, the diameter of a circle circumscribing the polygon is considered to be the outer diameter of the main body portion 11a.

[0061] Furthermore, the dimensions of the fastening member 10 and the automotive component 20 described in the above embodiment are not particularly limited. However, the following dimensions are preferred. The bolt portion that can be screwed into the threaded hole formed in the fastening member 10 is, for example, M10 to M30. The thread pitch of the threaded hole formed in the fastening member 10 is, for example, 1.5 to 3.0 mm. The thickness ((R1-r1) / 2) of the shank 11 is preferably 3 to 20 mm, more preferably 5 to 15 mm. The axial dimension of the shank 11 is, for example, 30 to 200 mm. The inner diameter of the flange 12 is preferably equal to or greater than the inner diameter r1 of the shank 11, for example, 0.5 mm larger than the inner diameter of the shank. The outer diameter of the flange 12 is preferably 2 mm or more larger than the outer diameter R1 of the shank 11, taking into account installation tolerances. The axial dimension of the flange 12 is, for example, 2 to 10 mm. The thickness of the crimped portion 13 ((R3-r3) / 2) is, for example, 2 to 10 mm. There are no particular limitations on the axial dimension of the crimped portion 13, but if it is too short, the shape of the deformed portion 13 (see FIG. 5) will be defective, and if it is too long, the shape of the deformed portion 13 will become unstable. If the length of the crimped portion 13 is H and the thickness is T, H / T is preferably in the range of 2 to 10, and more preferably in the range of 3 to 6.

[0062] Furthermore, as described in the above embodiment, the inner diameter r2 of the flange portion 12 (second end portion 12) is preferably equal to or greater than the inner diameter r1 of the shaft portion 11. However, in a mode in which the towing hook is screwed in from one axial side, the inner diameter r2 of the flange portion 12 (second end portion 12) may be less than the inner diameter r1 of the shaft portion 11. Furthermore, the second end portion 12 does not necessarily have to have a through hole 12A.

[0063] In addition, in the above embodiment, the outer diameter R2 of the flange portion 12 (second end portion 12) is larger than the outer diameter R1 of the shaft portion 11, but the second end portion of the present disclosure is not limited to this. For example, the outer diameter R2 of the second end portion 12 may be the same as the outer diameter R1 of the shaft portion 11. In this case, the second end portion 12 can no longer be called a flange portion 12.

[0064] Furthermore, in the above embodiment, an example has been described in which the fastening member 10 is made of steel, but the fastening member of the present disclosure may be made of a metal other than steel.

[0065] Furthermore, in the above embodiment, an example has been described in which the crimping portion 13 is formed in a cylindrical shape (i.e., an example in which the through hole 13A is formed in the first end portion 13a and the first connecting portion 13b), but the first end portion and the first connecting portion of the present disclosure are not limited to this. For example, the first end portion may be formed in a cylindrical shape, while the first connecting portion may not be formed in a cylindrical shape. Also, for example, both the first end portion and the second connecting portion may not be formed in a cylindrical shape. Furthermore, even if the crimping portion 13 is formed in a cylindrical shape, it may not be completely cylindrical. Here, completely cylindrical means a cylindrical shape in which no slits, holes, etc. are formed in a part of the circumferential direction. In other words, "cylindrical" in the present disclosure includes a shape in which a slit, hole, etc. is formed in a part of the circumferential direction.

[0066] Furthermore, in the above embodiment, an example was described in which the entire through hole 11A of the shaft portion 11 is a threaded hole (i.e., an example in which the entire portions of the through holes 11A, 12A, and 13A corresponding to the main body portion 11a and the second connecting portion 11b are threaded holes), but the threaded holes of the present disclosure are not limited to this. A portion of the through hole 11A of the shaft portion 11 may be a threaded hole. Furthermore, the threaded hole (threading) may not be formed in the through hole 11A of the shaft portion 11, but may be formed only in the through hole 12A of the flange portion 12. Furthermore, it is sufficient that the threaded hole (threading) is formed in at least one of the main body portion, the second connecting portion, or the second end portion.

[0067] In the above embodiment, the inner diameter r3 of the cylindrical crimped portion 13 is constant along the axial direction, but the present disclosure is not limited to this. The inner diameter r3 of the cylindrical crimped portion 13 may increase toward one axial side. In this case, deformation of the crimped portion 13 so as to expand radially inward can be suppressed.

[0068] In the above embodiment, an example has been described in which the fastening member 10 can be inserted from the second hole 24 into a joining object (automobile member 20) in which the relative positions of the first plate portion 21A and the second plate portion 22A are fixed, thereby achieving a crimping preparation state. However, the present disclosure is not limited to this. The fastening member 10 may be first placed on the first member 21, and then the second member 22 may be placed to achieve the crimping preparation state. In this case, as with the fastening member 110 shown in Figures 7 and 8, portions on both axial sides of the fastening member 110 may be configured to be crimped.

[0069] The fastening member 110 shown in FIG. 7 includes a shaft portion 111, a crimped portion 13 on one side of the shaft portion 111 in the axial direction, and a crimped portion 13 on the other side of the shaft portion 111 in the axial direction. Other components having the same functions and functions as those of the above-described embodiment are denoted by the same reference numerals and will not be described again. In this example, the entire shaft portion 111 corresponds to the "main body portion," the tip portion 13a of the crimped portion 13 on one side corresponds to the "first end," the root portion 13b of the crimped portion 13 on one side corresponds to the "first connecting portion," the tip portion 13a of the crimped portion 13 on the other side corresponds to the "second end," and the root portion 13b of the crimped portion 13 on the other side corresponds to the "second connecting portion." Therefore, such a fastening member 110 is also included in the fastening member of the above-described aspect <1>. In this example, not only the first end portion 13a and the first connecting portion 13b but also the second end portion 13a and the second connecting portion 13b are configured to be crimped in the crimping process. Also, as shown in FIG. 7, in this example, the shape of the circumferential surface of the shaft portion 111 (main body portion) is not uniform along the axial direction. The main body portion of the present disclosure also includes those with such shapes. "The shape of the circumferential surface of the shaft portion 111 (main body portion) is uniform along the axial direction" means, for example, that the outer diameter of the shaft portion 111 (main body portion) is constant along the axial direction.

[0070] In the above embodiment, the internal space (through hole 13A) of the cylindrical crimping portion 13 is connected to the screw hole (through hole 11A), but the present disclosure is not limited to this. The screw hole may be open only on the other axial side.

[0071] In addition, in the above embodiment, arc welding is not used to join the fastening member 10 to the automobile component 20, so the time required for joining can be significantly reduced compared to when arc welding is used. Furthermore, the problem of breakage during an automobile collision due to welding defects, etc. can be avoided. However, the joined joint of the present disclosure is not limited to this, and for example, the second connecting portion and the second plate portion of the fastening member may be joined by arc welding.

[0072] Furthermore, in the above embodiment, an example has been described in which the automobile member 20, which is the object to be joined, has a closed cross-sectional structure, but the object to be joined and the automobile member of the present disclosure are not limited to those having a closed cross-sectional structure.

[0073] Furthermore, in the above embodiment, the through hole 13A of the crimped portion 13 is not a threaded hole, but it may be a threaded hole. In this case, inward bulging of the deformed crimped portion 13 can be suppressed. Furthermore, in the above embodiment, no threads are formed on the outer peripheral surface of the crimped portion 13. Since no threads are formed on the outer peripheral surface of the crimped portion 13, outward bulging of the deformed crimped portion 13 can be promoted compared to when threads are formed on the outer peripheral surface of the crimped portion 13. As a result, the deformed crimped portion 13 and the main body portion 11 can sandwich the peripheral portion of the first hole 23 in the first plate portion 21A from both axial sides.

[0074] In the above embodiment, an example (see FIG. 5 ) has been described in which the peripheral portion of the first hole 23 in the first plate portion 21A is sandwiched between the first end surface 14 of the main body portion 11a and the deformed crimped portion 13. However, the present disclosure is not limited to this, and it is sufficient that the peripheral portion of the first hole 23 in the first plate portion 21A is sandwiched between the main body portion 11a and the deformed crimped portion 13. In other words, the main body portion 11a does not necessarily have to have a planar first end surface 14.

[0075] In the above embodiment, the shaft portion 11, the flange portion 12, and the crimped portion 13 have cylindrical outer shapes. However, the present disclosure is not limited to this, and the shaft portion, the flange portion, or the crimped portion may have a polygonal cylindrical outer shape.

[0076] In the above embodiment, the inner diameter of the crimped portion 13 is constant along the axial direction. However, for example, the inner diameter of the crimped portion 13 may gradually increase toward one side in the axial direction. As a result, the thickness of the crimped portion 13 may gradually decrease toward one side in the axial direction.

[0077] (Note) In addition to the above, the following note is also disclosed.

[0078] <1> A fastening member for screwing in a bolt portion of a towing hook, comprising: a main body portion in which a threaded hole extending in the axial direction is formed; a first end portion constituting an end portion on one axial side of the fastening member; a second end portion constituting an end portion on the other axial side of the fastening member; a first connecting portion connecting the main body portion and the first end portion; and a second connecting portion connecting the main body portion and the second end portion, wherein a first end face facing the one axial side is formed on an end face on the one axial side of the main body portion, and the first end portion and the first connecting portion have outer diameters smaller than the outer diameter of the main body portion and have wall thicknesses thinner than the main body portion.

[0079] <2> The fastening member according to <1>, wherein the second end portion and the second connecting portion have a thickness greater than that of the first end portion and the first connecting portion.

[0080] <3> The fastening member according to <1> or <2>, wherein the second end portion has an outer diameter larger than outer diameters of the main body portion and the second connecting portion.

[0081] <4> The fastening member according to any one of <1> to <3>, wherein the shape of the circumferential surface of the main body is uniform along the axial direction.

[0082] <5> The fastening member according to any one of <1> to <3>, wherein a shape of a peripheral surface of the main body portion is uniform along the axial direction, and an outer diameter of the second end portion is larger than an outer diameter of the main body portion.

[0083] <6> The fastening member according to any one of <1> to <5>, wherein the first connecting portion and the first end portion are formed in a cylindrical shape.

[0084] <7> The fastening member according to any one of <1> to <6>, wherein a through hole is formed axially penetrating the first end portion, the first connecting portion, the main body portion, the second connecting portion, and the second end portion, and the screw hole is formed in a portion of the through hole corresponding to the main body portion.

[0085] <8> The fastening member according to <7>, wherein the screw hole is also formed in a portion of the through hole corresponding to the second connecting portion.

[0086] <9> The fastening member according to any one of <6> to <8>, wherein an inner diameter of the first connecting portion is constant along the axial direction, an inner diameter of the first end portion is constant along the axial direction, and an inner diameter of the connecting portion is the same as an inner diameter of the first end portion.

[0087] <10> The fastening member according to any one of <7> to <9>, wherein the minimum axial value of the inner diameter of the first connecting portion and the first end portion is greater than the maximum diameter of the screw hole.

[0088] <11> The fastening member according to any one of <7> to <10>, wherein an inner diameter of the second end portion is larger than an inner diameter of the main body portion, and an outer diameter of the second end portion is larger than an outer diameter of the main body portion.

[0089] <12> A joint including objects to be joined and a fastening member joined to the objects to be joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, wherein a first hole is formed in the first plate portion and a second hole is formed in the second plate portion, and the fastening member includes: a main portion in which a screw hole extending in an axial direction is formed, a first end portion constituting an end portion on one axial side of the fastening member, and a second end portion constituting an end portion on the other axial side of the fastening member, a first connecting portion connecting the main portion and the first end portion, and a second connecting portion connecting the main portion and the second end portion, wherein a first end face facing one axial side is formed on an end face on one axial side of the main portion, the first end portion being arranged on one axial side with respect to the first plate portion, and the second end portion being arranged on the other axial side with respect to the second plate portion, and the first end face is in contact with a peripheral portion of the first hole in the first plate portion from the other axial side, and the first end portion and the first connecting portion are crimped deformation portions, a joint in which the main body portion and the deformation portion sandwich a peripheral portion of the first hole in the first plate portion from both sides in the axial direction.

[0090] <13> The bonded joint according to <12>, wherein the first hole is circular.

[0091] <14> The joint according to <12>, wherein the first hole has a polygonal shape.

[0092] <15> An automobile component with a fastening member, comprising the joint according to any one of <12> to <14>.

[0093] <16> The automotive component with fastening members according to <15>, comprising an automotive component with a closed cross-section structure in which a hat-shaped first plate and a substantially flat second plate are joined, wherein the first plate has a top plate portion, a pair of vertical plate portions, and a pair of flange portions, and the second plate has an opposing portion facing the top plate portion and a pair of joining portions joined to the pair of flange portions, wherein the top plate portion is the first plate portion, the opposing portion is the second plate portion, and the first plate has a thickness greater than that of the second plate.

[0094] <17> A method for manufacturing a joined joint in which objects to be joined and a fastening member are joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, a first hole formed in the first plate portion and a second hole formed in the second plate portion, the fastening member comprising: a main body portion in which a screw hole extending in an axial direction is formed, a first end portion constituting an end portion on one axial side of the fastening member, and a second end portion constituting an end portion on the other axial side of the fastening member, a first connecting portion connecting the main body portion and the first end portion, and a second connecting portion connecting the main body portion and the second end portion, wherein a first end face facing the one axial side is formed on an end face on the one axial side of the main body portion, the manufacturing method includes a first step and a second step, wherein in the first step, a crimping preparation state is established in which the first end portion is arranged on one axial side with respect to the first plate portion and the second end portion is arranged on the other axial side with respect to the second plate portion, and the first end face is in contact with a peripheral portion of the first hole in the first plate portion from the other axial side, In the second step, the fastening member is pressurized from both axial sides in the crimping preparation state to deform the first end portion and the first connecting portion to form a deformed portion, and the main body portion and the deformed portion sandwich the peripheral portion of the first hole in the first plate portion from both axial sides.

[0095] The disclosure of Japanese Patent Application No. 2022-115114, filed on July 19, 2022, is incorporated herein by reference in its entirety.

[0096] DESCRIPTION OF SYMBOLS 10 Fastening member 11A, 12A, 13A Through hole 11 Shank portion 11A Through hole (screw hole) of shaft portion 11a General portion (main body portion) of shaft portion 11b Base portion (second connecting portion) of shaft portion 12 Flange portion (second end portion) 12A Through hole of flange portion 13 Crimped portion, deformed portion 13A Through hole of crimped portion 13a Tip portion (first end portion) of crimped portion 13b Base portion (first connecting portion) of crimped portion 14 First end surface 15 Second end surface 20 Automobile member (object to be joined) 21 First member 21A1 First surface 21A2 Second surface 21A Top plate portion (first plate portion) 21B Vertical plate portion 21C Flange portion 22 Second member 22A Opposing portion (second plate portion) 22B Joint portion 23 First hole 24 Second hole 30 Automotive component with fastening member 40 Electrode R1 Outer diameter of shaft portion R2 Outer diameter of flange portion R3 Outer diameter of crimped portion R3a Outer diameter of deformed portion d1 Diameter of first hole d2 Diameter of second hole r1 Inner diameter of shaft portion r2 Inner diameter of flange portion r3 Inner diameter of crimped portion r3a Inner diameter of deformed portion

Claims

1. A fastening member having a threaded hole extending in an axial direction, comprising: a main body portion extending in the axial direction; a first end portion on one side of the main body portion in the axial direction; a second end portion on the other side of the main body portion in the axial direction; a first connecting portion connecting the main body portion to the first end portion; and a second connecting portion connecting the main body portion to the second end portion, wherein the threaded hole is in at least one of the main body portion or the second end portion, wherein, in the axial direction, the outer diameters of a portion of the main body portion adjacent to the first connecting portion and the first connecting portion are different values, the outer diameters of the first end portion and the first connecting portion are smaller than the outer diameter of the portion of the main body portion adjacent to the first connecting portion, the outer diameters of a portion of the main body portion adjacent to the second connecting portion and the second end portion are different values, and the thickness of the first end portion and the first connecting portion as viewed in the axial direction is thinner than the thickness of the main body portion.

2. The fastening member according to claim 1, wherein the thickness of each of the second end portion and the second connecting portion is greater than the thickness of each of the first end portion and the first connecting portion.

3. A fastening member as described in claim 1 or claim 2, wherein the outer diameter of the portion of the second end portion adjacent to the second connecting portion in the axial direction is larger than the outer diameters of the portion of the main body portion adjacent to the second connecting portion and the second connecting portion.

4. A fastening member as described in claim 1, wherein, in the axial direction, the outer diameters of the portion of the second end portion adjacent to the second connecting portion and the second connecting portion are smaller than the outer diameter of the portion of the main body portion adjacent to the second connecting portion, and the thicknesses of the second end portion and the second connecting portion as viewed in the axial direction are thinner than the thickness of the main body portion.

5. A fastening member according to claim 1 or 2, wherein the shapes of the peripheral surfaces of the main body portion and the second connecting portion are uniform along the axial direction.

6. A fastening member as described in claim 1 or 2, wherein the main body portion has a main body through hole that is a through hole extending in the axial direction, the first end portion and the first connecting portion have first through holes that communicate with the main body through hole in the axial direction, the minimum value of the diameter of the first through hole as viewed in the axial direction is larger than the maximum value of the diameter of the main body through hole, and if the main body portion has a screw hole, the main body through hole has a threaded portion.

7. A fastening member as described in claim 1 or 2, wherein the main body portion has a main body through hole that is a through hole extending in the axial direction, the second end portion and the second connecting portion have second through holes that communicate with the main body through hole in the axial direction, the minimum value of the diameter of the second through hole as viewed in the axial direction is greater than the maximum value of the diameter of the main body through hole, if the main body portion has the screw hole, the main body through hole has a threaded portion, and if the second end portion has the screw hole, the second through hole has a threaded portion.

8. A joint comprising objects to be joined and a fastening member joined to the objects to be joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, wherein the first plate portion has a first hole and the second plate portion has a second hole, the fastening member is a fastening member having a threaded hole extending in an axial direction, and comprising: a main body portion extending in the axial direction, a first end portion on one side in the axial direction of the main body portion, a second end portion on the other side in the axial direction of the main body portion, a first connecting portion connecting the main body portion to the first end portion, and a second connecting portion connecting the main body portion to the second end portion, wherein the threaded hole is in at least one of the main body portion or the second end portion, wherein the first end portion is arranged on one axial side of the first plate portion and the second end portion is arranged on the other axial side of the second plate portion, the first connecting portion is arranged inside the first hole, and the second connecting portion is arranged inside the second hole, and the main body portion is arranged between the first plate portion and the second plate portion, A joint joint in which, in the axial direction, the outer diameter of the first connecting portion is smaller than the outer diameter of a portion of the main body portion adjacent to the first connecting portion, the thickness of the first connecting portion is thinner than the thickness of a portion of the main body portion adjacent to the first connecting portion, the outer diameter of the first end portion is larger than the diameter of the first hole, the main body portion and the first end portion sandwich the peripheral portion of the first hole in the first plate portion from both axial sides, and the outer diameter of the second end portion is larger than the diameter of the second hole, and the peripheral portion of the second hole is supported by the second end portion.

9. A joint as described in claim 8, wherein the outer diameter of the second connecting portion is smaller than the outer diameter of the portion of the main body portion adjacent to the second connecting portion, the thickness of the second connecting portion is thinner than the thickness of the portion of the main body portion adjacent to the second connecting portion, the outer diameter of the second end portion is larger than the diameter of the second hole, and the peripheral portion of the second hole in the second plate portion is clamped from both axial sides by the main body portion and the second end portion.

10. A joint joint as described in claim 8 or 9, wherein the object to be joined is an automobile part, the automobile part having a closed cross-section structure in which a hat-shaped first plate and a substantially flat second plate are joined, the first plate having a top plate portion, a pair of vertical plate portions, and a pair of flange portions, the second plate having an opposing portion opposing the top plate portion and a pair of joining portions joined to the pair of flange portions, the top plate portion being the first plate portion, the opposing portion being the second plate portion, and the thickness of the first plate being greater than the thickness of the second plate.

11. A joint according to claim 8 or 9, wherein the shape of the first hole is polygonal.

12. A method for manufacturing a joined joint in which objects to be joined and a fastening member are joined, wherein the objects to be joined have a first plate portion and a second plate portion facing the first plate portion, the first plate portion having a first hole and the second plate portion having a second hole, the fastening member having a screw hole extending in an axial direction, a main body portion extending in the axial direction, a first end portion on one side of the axial direction of the main body portion, a second end portion on the other side of the axial direction of the main body portion, a first connecting portion connecting the main body portion to the first end portion, and a second connecting portion connecting the main body portion to the second end portion, wherein the screw hole is in at least one of the main body portion or the second end portion, the outer diameters of a portion of the main body portion adjacent to the first connecting portion and the first connecting portion have different values, and the outer diameters of the portion of the first end portion adjacent to the first connecting portion and the first connecting portion are smaller than the outer diameter of the portion of the main body portion adjacent to the first connecting portion, the outer diameters of a portion of the main body portion adjacent to the second connecting portion and the second end portion are different values; the thicknesses of the first end portion and the first connecting portion as viewed in the axial direction are thinner than the thickness of the main body portion; the manufacturing method includes a step of preparing the objects to be joined and the fastening member, a first step, and a second step; in the first step, the first end portion is arranged on one axial side of the first plate portion, and the second end portion is arranged on the other axial side of the second plate portion, the first connecting portion is arranged inside the first hole, the second connecting portion is arranged inside the second hole, the main body portion is arranged between the first plate portion and the second plate portion, and the portion of the main body portion adjacent to the first connecting portion contacts the peripheral portion of the first hole in the first plate portion from the other axial side, a crimping preparation state in which a portion of the second end portion adjacent to the second connecting portion contacts a peripheral portion of the second hole in the second plate portion from the other axial side, or a portion of the main body portion adjacent to the second connecting portion contacts a peripheral portion of the second hole in the second plate portion from one axial side,In the second step, the fastening member is electrically heated and pressurized from both axial sides in the crimping preparation state to deform the first end portion to form a deformed portion, and the peripheral portion of the first hole in the first plate portion is clamped from both axial sides by the main body portion and the deformed portion.

13. A method for manufacturing a joined joint as described in claim 12, wherein the fastening member has an outer diameter of the portion of the second end adjacent to the second connecting portion that is larger than the outer diameters of the portion of the main body that is adjacent to the second connecting portion and the second connecting portion, the outer diameter of the second end is larger than the diameter of the second hole, and in the crimping preparation state, the portion of the second end adjacent to the second connecting portion contacts the peripheral portion of the second hole in the second plate portion from the other axial side.

14. A method for manufacturing a joined joint as set forth in claim 12, wherein the fastening member has an outer diameter of the second connecting portion and a portion of the second end adjacent to the second connecting portion that is smaller than the outer diameter of the portion of the main body adjacent to the second connecting portion, the thickness of each of the second end and the second connecting portion as viewed in the axial direction is thinner than the thickness of the main body, and in the crimping preparation state, the portion of the main body adjacent to the second connecting portion comes into contact with the peripheral portion of the second hole in the second plate portion from one axial side, and in the second step, further, by applying electrical heat and pressure to the fastening member from both axial sides in the crimping preparation state, the second end is deformed to form a second deformed portion, and the peripheral portion of the second hole in the second plate portion is clamped from both axial sides by the main body portion and the second deformed portion.