WO1994001687A1

WO1994001687A1 - Part mounting device and method

Info

Publication number: WO1994001687A1
Application number: PCT/JP1993/000908
Authority: WO
Inventors: Nobuharu Naito; Katsumi Yamada; Seiichi Toyonaga; Kimikazu Nakamura; Tatuya Ogawa
Original assignee: Nippon Pop Rivets And Fasteners Ltd.; Toyota Motor Corporation; Emhart Inc.
Priority date: 1992-07-03
Filing date: 1993-07-02
Publication date: 1994-01-20

Abstract

A part mounting device (1) comprises a bolt (3) welded to a panel (2) and a hollow collar (6) for securing a part (5) disposed on a vehicle body to the panel with a blank hole (4) put over the bolt. The collar (6) comprises in turn a flange which is larger than the part blank hole (4) and a trunk portion (9) which is tightly secured to the bolt, and the inside diameter of the trunk portion is originally formed slightly larger than the outside diameter of the bolt. However, when the collar flange (8) is press-fitted while it presses a part against the panel, the inside diameter of the trunk portion (9) is reduced so that the trunk portion is secured to the bolt (3). Thus, the trunk portion can be tightly secured without any skill by press-fitting the collar flange, whereby a part can be mounted on a panel such as a vehicle body panel by an operation made only from one side. Moreover, the part so mounted can easily be dismounted and re-mounted by rotating the collar.

Description

Description Component mounting device and method Technical field

The present invention relates to an apparatus and a method for attaching components to a panel such as a vehicle body panel using a bolt as a screw member.

Background art

When assembling parts to the car body panel, weld a nut to the car body panel or bracket, screw the part to the car body panel with bolts, or weld a weld bolt to the car body panel or bracket, and attach the part to the car body panel. I was screwing it with a nut. The installation of these parts requires bolts or nuts to be screwed, and this is usually done using an impact wrench.Therefore, skilled workers are required to prevent excessive fastening or insufficient fastening. In addition, it was difficult to manage and control the fastening torque.

Although parts are not attached to the vehicle body panel, Japanese Utility Model Publication No. 48-28991 and Japanese Patent Application Laid-Open No. 57-69108 disclose one of two panels to be connected. When a bolt is inserted from one side and a hollow collar is passed through the bolt shaft part that has come out on the other side, and this collar is pressed with two panels pressed by a tool, the inner diameter of the body becomes smaller. A structure is disclosed in which both panels are reduced in diameter and fixed to bolts to connect both panels.

However, the connection device described in the above publication requires the work from both sides of the panel, in which bolts are attached from one side of the panel, and a collar is inserted into and fastened to the bolt shaft from the other side of the panel. And When attaching parts to the car body panel, Due to the specialty of the flannel, work from both sides is almost impossible.

In addition, Japanese Patent Application Laid-Open No. 61-144445 discloses a method of fixing a workpiece in which a pin member is mounted with a tubular collar. The method described in this publication also requires work from both sides of the panel, in which the pin member is attached from one side of the panel, and the collar is penetrated and fastened to the shaft of the pin from the other side of the panel. . Further, in US Pat. No. 5,171,115, a pin member is fixed to a panel, A method is disclosed in which a flange is formed on a flange, and a part is brought into contact with the flange, and a collar is mounted on the tip of a pin member from another side of the part and fixed. With this fixing method, the force that can fix the component from one side of the panel using the pin member protruding from the panel, and the collar cannot be removed after fixing. Therefore, the parts could not be removed.

Disclosure of the invention

Therefore, an object of the present invention is to eliminate the necessity of managing the torque at the time of fastening without skill, and to attach a part to a panel such as a vehicle body panel by one side operation. An object of the present invention is to provide a device and a method for attaching a component to a panel in which a component can be easily removed.

To achieve this object, according to the present invention, a bolt and a hollow collar are provided, and the collar has a body portion to be fastened to the bolt, and the inner diameter of the body portion is initially larger than the outer diameter of the bolt. When the body is crimped, a part mounting device is provided in which the inside diameter of the body is reduced and the body is fixed to a bolt. This device has a bolt fixed to a panel, and the component has a pilot hole with a bolt. It is placed on the panel in a state where it penetrates, and it is crimped with the empty body pressed against the panel side, the inner diameter of the body is reduced and fixed to the bolt, and the part is attached to the panel. Features.

Further, according to the present invention, it is composed of a bolt and a hollow collar, wherein the collar has a body portion fastened to the bolt, and the inner diameter of the body portion is initially formed larger than the outer diameter of the bolt. When the body is crimped, there is provided a component mounting method in which the inside diameter of the body is reduced and the body is fixed to the bolt. In this method, the bolt is fixed to the panel, the part is inserted, and the pilot hole passes through the bolt. The collar is pressed against the panel side with the collar pressed against the panel side to reduce the inner diameter of the collar, whereby the collar is fixed to the bolt and the part is mounted on the panel. And

In the present invention, the bolt can be welded to the panel. Further, the bolt can be fixed to the panel by crimping. Further, as the bolt, a blind rivet comprising a mandrel and a sleeve provided adjacent to the large-diameter head of the mandrel and capable of being attached to the panel by pulling out the mandrel and buckling the sleeve is used. When crimping the blind rivet on the body Can be mounted on a panel.

The collar may be formed of metal, or may be a combination of metal and plastic. In addition, a tool engaging portion such as a hexagon may be formed in the collar in advance, but may be formed when the collar body is crimped. The collar can be crimped from the radially outer side of the collar body in the diameter reducing direction. Alternatively, it may be performed by pressing the collar in the axial direction, and when the collar is deformed in the radial direction by this pressing, the deformation of the collar in the radial direction is restricted, thereby reducing the inner diameter of the collar. A tool engaging portion such as a hexagon can be formed while making the diameter.

Further, according to the present invention, a bolt portion having an external thread formed in the middle, a nut portion provided on the outer surface of the bolt portion, and a nut portion and a bolt portion provided between the nut portion and the head portion of the bolt portion are provided. Using a plastic coupling member consisting of a bent portion connecting the panel, the bolt portion is pulled out from the nut portion, the bent portion is bent, and the panel and the component are clamped by the bent portion and the nut portion, and the component is clamped by this clamping. A component mounting apparatus and method characterized by being mounted on a panel is provided, which also makes it possible not only to perform one-sided mounting of the panel but also to easily remove components.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a half sectional front view of a component mounting apparatus according to the present invention.

FIG. 2 is an explanatory view showing a state in which a collar is fastened to a bolt.

Figure 3 (A) and (B), _c FIG. 4 is a front view of various modifications of the bolt (A) ~ (C) are cross-sectional views of various modifications of the collar.

FIGS. 5 (A) and (B) show an embodiment of a component mounting apparatus using yet another bolt, wherein (A) shows a state before mounting and (B) shows a state after mounting. is there.

FIGS. 6 (A) and (B) show an embodiment of a component mounting apparatus using still another collar, wherein (A) shows a state before mounting and (B) shows a state after mounting. is there.

FIGS. 7 (A) and (B) are views showing still another modification in which bolts are fixed to a panel.

8 (A) to 8 (C) are views showing still another embodiment using a blind rivet as a bolt.

FIG. 9 shows yet another embodiment of the present invention, in which a collar is formed using a fastening tool. FIG. 6 is a view showing a state in which a hexagon is formed on the outer surface while reducing the diameter of.

10 (A) and (B) show the embodiment of FIG. 9 with the fastening tool removed, (A) shows the state before the collar is crimped, and (B) shows the state after the collar is crimped. Fig. 11 (A) and (B) are cross-sectional views taken along the line A-A of Fig. 9, (A) is before the collar is crimped, and (B) is after the collar is crimped. FIG.

FIGS. 12 (A) to 12 (C) show still another embodiment of the present invention using a plastic connecting member. FIG. 12 (A) shows a state before mounting components on a panel, and FIG. Fig. 3C is a diagram showing a state after components are mounted on the panel, and Fig. 3C is a diagram showing a state where components are removed from the panel.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the component mounting apparatus of the present invention. The component mounting device 1 includes a bolt 3 such as a body bolt or a stud bolt welded to a panel 2 such as a vehicle body panel, and a component 5 disposed on the panel 2 with a pilot hole 4 penetrating the bolt 3. A hollow collar 6 fixed to 2. The collar 6 is formed of a metal such as aluminum or stainless steel. The collar 6 comprises a flange 8 which is larger than the pilot hole 4 of the part 5 and a body 9 which is fastened to the bolt 3; in this embodiment, furthermore, the side between the flange 8 and the body 9 A hexagonal tool engaging portion 10 is formed when viewed from above. A tool such as a wrench is engaged with the tool engaging portion 10 to facilitate rotation for removal after fastening. The flange 8 becomes unnecessary if it is larger than the pilot hole 4 of the outer diameter component of the body 9.

In the component mounting device 1 shown in FIG. 1, the component 5 is mounted on the panel 2 by the following method. The inner diameter of the body 9 of the collar 6 is formed slightly larger than the outer diameter of the bolt 3 at first, so that the bolt 3 can be easily inserted. Therefore, the arrangement of the part 5 on the panel 2 and the passage of the collar 6 to the bolt 3 can be easily performed from one side of the panel 2, that is, from the top in the figure. In order to fasten the collar 6 to the bolt 3, as shown in Fig. 2, grip the torso 9 of the collar 6 with the nose grip 13 of the same or similar tool as the blind rivet setting tool 1 2 And insert the tip of bolt 3 into the jaw 14 of the tool. Grasp and operate tool 1 and 2. Jaw 14 acts to pull out bolt 3, but bolt 3 is firmly welded to the panel and remains fixed, and the reaction causes grip 13 to move collar 6 to panel 2 The collar body 9 is crimped while pressing to the side, and the inner diameter of the body part 9 is narrowed down according to the screw shape of the bolt 3 to reduce the diameter, whereby the collar 6 is fixed to the bolt 3 and the part 5 Is attached to panel 2. In the experiment, an axial force of 600 kgf was obtained as a fixing force. C This corresponds to a case where the M6 bolt and nut were fastened with a torque of 80 kgfcm.

FIG. 3 shows a modification of the bolt used. (A) of FIG. 3 shows a type in which the thread above the bolt 3 is removed, and the upper part 16 is a pulling part by the jaw 14, so that the jaw can be easily gripped. FIG. 3 (B) shows a drill type weld bolt 17 which has a large pull-out resistance and can obtain a higher fastening force.

FIG. 4 shows a modification of the collar. The collar 6 shown in (A) of FIG. 4 is provided with an engagement ring 19 for the bolt 6 on the upper part, so that when the bolt 3 is fastened, the collar 3 can be temporarily fixed. it can. The collar 20 in (B) of FIG. 4 includes an inner plastic part 21 and an outer metal part 22. By forming in this manner, advantages such as a reduction in the weight of the collar and an easy reduction in diameter for fastening to the bolt 3 are obtained. Further, a locking claw may be formed in the inner plastic portion 21, whereby the same temporary fixing function as the collar 6 in (A) can be obtained. The collar 6 in (C) of FIG. 4 is configured so that the washer 23 can be attached to the lower end side. According to this, the collar 6 can be pre-attached to the part 5, and there is the convenience that the part 5 can be attached to the bolt 3. If the engaging ring 19 is provided on the roller 6, the part 5 can be formed.

FIG. 5 shows still another modification of the bolt 3. As shown in FIG. 5A, a constriction 25 is provided at an intermediate height position of the bolt 3, and the jaw 14 at the time of fastening is formed. Due to the pulling force, as shown in (B), the upper part of the constriction 25 is broken to remove unnecessary or obstructive protrusions.

FIG. 6 shows yet another variation of the color, in which color 26 is As shown in (A) of Fig. 6, no hexagonal portion is formed on the body before fastening, but by tightening the nose grip 14 of the tool at the time of fastening, As shown, a hexagonal tool engaging portion 27 is formed.

7 (A) and (B) show another example of fixing a bolt to panel 2. FIG. FIG. 7 (A) shows a state in which the clinch bolt 30 is fixed to the panel 2 by crimping, and FIG. 7 (B) shows a state in which the bolt 31 is fixed to the plastic part 31 of the panel 2. It shows the state that is being done. In the case of (B), the bolt 32 may be fixed by press-fitting, or the bolt 32 may be fixed by insert molding.

(A) to (C) of FIG. 8 show still another embodiment of the present invention. In this embodiment, the bolts 34 are formed by blind rivets. Bolts 3 4 consist of a mandrel 3 5, known as a blind rivet, and a sleeve 3 7 provided adjacent to the large diameter head 36 of the mandrel, forming a mandrel head 3 6 When the mandrel 35 is removed with the blind rivet fastening tool by inserting it into the hole of the panel 38 together with the sleeve 37, the sleeve 37 is deformed so as to expand and can be attached to the panel. In the present invention, the mandrel 35 has a portion exposed from the sleeve 37 and a screw 39 formed above and below the portion. Also, the illustrated sleeve 37 does not have a flange to be formed on the side opposite to the mandrel head. This is to prevent bolts 34, forces to be attached to panel 38, and to be attached to parts 40. Therefore, if the pilot hole 41 of the component 39 is large in diameter, a flange smaller in diameter than the hole may be formed in the sleeve 37. Further, as in the other embodiments, the hollow collar 42 is lightly engaged with the screw 39 of the mandrel 35 of the bolt 34. A tool engagement portion 43 such as a hexagon is formed below the collar 42.

In order to fasten the collar 42 to the bolt 34 while fastening the bolt 34 to the panel 38, as shown in FIG. 8 (B), a mandrel 35 This causes the sleeve 37 to deform so as to expand, while the collar 42 is also compressed radially inward from the top, and the inner diameter of the collar is narrowed down to match the thread shape of the screw 39 The diameter is reduced to form an internal thread. This behavior The operation is performed until the mandrel 35 is broken, and the bolt 34 is fastened to the panel 38. At the same time, the collar 42 is fixed to the bolt 34, and the part 40 is attached to the panel 38. To remove the part 40, simply apply a tool to the tool engagement part 43 of the collar 42 and rotate the collar 42, as shown in Fig. 8 (C), and re-attach. 5 can also be done by turning the color 4 2.

9 to 11 show still another embodiment of the present invention. This embodiment relates to an improvement in the hexagonal narrowing of the body of the collar 26 in FIG. As shown in Fig. 6, when crimping the collar, it was sometimes difficult to reduce both the diameter of a single hole and narrow it down to a hexagon because the amount of deformation of the collar material was small. Book

10 In the embodiment, the collar 45 has a ring shape, the diameter before crimping is formed smaller than the effective diameter after crimping, and the axial height before crimping is formed higher than the height after crimping. Has been done. Further, the fastening tool 46 includes a hexagonal member 47 extending from the outer periphery to the tip and surrounding the collar 45, and a pusher 48 pressing the collar 45 against the panel 2 and the component 5. Is provided. The state before the crimping of the collar is shown in (A) and (A) of FIG. 10 and (A) of FIG. 11, and the collar 45 has a small diameter ring shape inscribed in the hexagonal member 47. It is the shape of.

To attach part 5 to panel 2, hold collar 45 at the end of hexagonal member 47 of fastening tool 46, insert bolt 45 into bolt 3, and connect collar 45 to part 5. Face. At this time, the jaws 49 of the fastening tool 46 hold the tip of the bolt 3.

Then, the pusher 48 contacts the upper surface of the collar 45 so as to press it. When the fastening tool is actuated, the jaws 49 operate to pull the bolt 3 upward, and the bolt 3 remains fixed to the panel 2, so that the reaction of the pusher 48 to the upper surface of the collar 45 Press strongly from With this pressing force, the collar 45 is deformed so as to have a lower height, as shown in FIG. 10 (B), and as shown in FIG. 11 (B).

₂₅ , the inner diameter is reduced to form a female screw according to the screw thread shape of the bolt 3, and the portion of the outer surface that expands radially outward is regulated by a hexagonal member 47, and is formed into a hexagon. It is formed. The material of the collar 45 may not be metal as long as it can be deformed. In this embodiment, the deformation of the collar 45 into a hexagon and the engagement with the bolt are sufficiently satisfactory. Since the plastic material can be deformed by heating, the plastic material can be heated and deformed, the range of color materials can be expanded, and the diameter of the collar before crimping can be reduced. Can be accommodated, and the entire collar can be made smaller, so that the length of the bolt can be reduced.

5 FIGS. 12 (A) to (C) show still another embodiment of the present invention. As shown in (A), in this embodiment, parts 53 are attached to panel 52 by means of a joining member 51 made of plastic, instead of attaching parts to the panel by a combination of a bolt and a color. . The connecting member 51 includes a bolt portion 55 extending vertically in the center and a male screw 54 formed in the middle, and a nut provided on an outer surface of the bolt portion 55.

> A bend portion 58 connecting the nut portion and the bolt portion between the nut portion 56 and the head portion 57 at the lower end of the nut portion 56 and the bolt portion 55. The bolt portion 55 has an upper grip portion 60 and a small diameter portion 61 between the grip portion and the male screw, in addition to the lower end side head portion 57 and the intermediate male screw 54. The nut portion 56 has an outer surface formed, for example, in a hexagonal shape so that it can be engaged with a tool such as a wrench, and the inner surface has a projection 6 2 that engages with the male is screw 54 of the bolt portion. Are formed. The nut portion 56 has a thin-walled portion 63 formed slightly above the connecting portion with the bent portion 58 so that the nut portion 56 can be separated into an upper portion and a lower portion. Have been. The bent portion 58 is formed of a flexible arm extending parallel to the outside of the bolt portion 55, and in the illustrated example, a pair is provided with the bolt portion 55 interposed therebetween.

20 To attach the component 53 to the panel 52 using the coupling member 51 having such a configuration, insert the head 57 of the coupling member 51 into the holes of the panel 52 and the component 53, The flange 64 of the nut part 56 is brought into contact with the part 53. Next, as shown by an arrow 65 in FIG. 12 (B), the grip portion 60 is pulled with a tool such as a blind rivet fastening tool. This pulling force causes the middle portion of the bent portion 58 to protrude outward in the radial direction,

₂ 5 The protruding bent portion 58 contacts the panel surface. When the grip portion 60 is further pulled, the bent portion 58 increases the bending, and the bolt portion 55 breaks at the small diameter portion 61. The nut portion 56 engages with the male screw 54, and the bent portion 58 and the nut flange 64 pinch the panel 52 with the component 53, and the component is attached to the panel. Can be In addition, the pulling force of the tool, that is, the force to bend the bent portion 58, is equivalent to the breaking of the small diameter portion 61. It can be determined by the resistance, and the operator does not need to adjust the pulling force of the tool. Fig. 12 (C) shows the case where the part 53 is removed from the panel 52. c That is, if the nut part 56 is rotated, the nut part 56 becomes the male screw of the bolt part 55.

Move up along 5 4. On the other hand, even if the nut portion 56 is rotated, the lower portion 66 of the nut portion connected to the bent portion 58 acts to prevent the rotation, so that it is broken at the thin portion 63 and the upper portion is broken. Only the nut body moves upward, and the lower part of the nut

6 6 remains in the bolt portion 55 while being engaged with the male screw 54. Therefore, the bent portion 58 also remains bent and remains attached to the panel 52. The part 53 can be easily removed because the flange 64 of the nut part 55 is eliminated. Next, by rotating the nut portion 56 against the external thread of the bolt portion 55, the component 53 can be attached to the panel 52.

According to this embodiment, it goes without saying that the component is attached from one side of the panel, but the force to bend the bent portion 58 is determined by the selection of the breaking resistance of the broken portion of the shaft portion, and the operator pulls. There is no need to adjust the pulling force of the tool, and no skill in torque management of screws is required. In addition, parts can be easily removed and re-attached easily, and since they are molded from plastic, there is no need for protection measures and damage to parts is reduced.

Industrial applicability

ADVANTAGE OF THE INVENTION According to this invention, it can be fastened from one side of a panel only by operation of a fastening tool, without requiring skill like fastening of a bolt and a nut. The fastening force at this time may be set by a tool without depending on the skill of the operator, and the management of the fastening torque such as bolts and nuts is not required. In addition, parts can be attached to the panel by working from one side, and the parts that have been attached by collar cultivation can be easily removed.

The present invention may be embodied in various other forms without departing from its spirit or essential characteristics. Therefore, the above-described embodiment is merely an example in every aspect, and should not be construed as limiting. The scope of the present invention is defined by the appended claims, and is not restricted by the specification text. Further, all modifications and changes belonging to the equivalent range of Claims φ are within the scope of the present invention.

Claims

The scope of the claims

1. A collar comprising a bolt and a hollow collar, wherein the collar has a body portion to be fastened to the bolt, and an inner diameter of the body portion is initially formed larger than an outer diameter of the bolt. In a component mounting device in which the inner diameter is reduced and fixed to the bolt, the bolt is fixed to the panel, the component is placed on the panel with its pilot hole penetrating the bolt, and the collar body is attached to the panel. A part mounting device, wherein the part is mounted on a panel by being press-bonded while being pressed to the side, the inner diameter of the body part is reduced and fixed to a bolt.

2. The component mounting device according to claim 1, wherein the bolt is welded to the panel.

3. The component mounting device according to claim 1, wherein the bolt is fixed to the panel by crimping.

4. The bolt comprises a mandrel and a sleeve provided adjacent to the large diameter head of the mandrel and pulling the mandrel causes the sleeve to buckle. 2. The component mounting device according to claim 1, wherein the device comprises a blind rivet that can be mounted on a panel, and the blind rivet is mounted on a panel when the collar body is crimped.

5. The component mounting according to claim 1, wherein the component mounting is made of a solid metal.

6. The component mounting device according to claim 1, wherein the component mounting device is made of a combination of a metal force and a metal.

7. The crimping of the collar is performed by pressing the collar in the axial direction, and when the collar is deformed to increase its outer diameter by the pressing in the axial direction, the collar is pressed outward in the radial direction. 2. The component mounting apparatus according to claim 1, wherein the deformation is restricted to a hexagon, and the inner diameter of the collar is reduced at the same time.

8. The component mounting device according to claim 7, wherein the collar is made of metal or plastic.

9. It consists of a bolt and a hollow collar, and the collar has a body to be fastened to the bolt. An inner diameter of the body portion is initially formed to be larger than an outer diameter of the bolt, and when the body portion is crimped, the inner diameter of the body portion is reduced and fixed to the bolt. And

Place the part on the panel with its pilot hole through the bolt,

5 The body of the collar is pressed against the panel and pressed down to reduce the inside diameter of the body, whereby the collar is fixed to the bolt and the part is attached to the panel

A component mounting method characterized in that:

10. The component mounting method according to claim 9, wherein the bolt is welded to the panel.

_{1 0} parts mounting method according to Claim 9, characterized in that fixing by crimping 11. bolt on the panel.

12. Bolt force, consisting of a mandrel and a sleeve provided adjacent to the large diameter head of the mandrel and buckling the sleeve by withdrawing the mandrel; A blind rivet that can be attached to the

10. The component mounting method according to claim 9, wherein: (5) is mounted on a panel when the collar body is crimped.

13. The component mounting method according to claim 9, wherein the component mounting metal is made of metal.

14. The component mounting method according to claim 20, wherein the collar comprises a combination of metal and plastic.

15. The crimping of the collar is performed by pressing the collar in the axial direction, the crimping of the collar is performed by pressing the collar in the axial direction, and the pressing in the axial direction causes the collar to reduce its outer diameter. When deforming so as to increase the diameter, the deformation outward in the radial direction is restricted to a hexagon, and the inner diameter of the collar is simultaneously reduced.

10. The component mounting method according to claim 9, which is ₂₅ mm.

16. The component mounting method according to claim 15, wherein the collar is made of plastic, and the collar is heated when restricting deformation of the collar in a radially outward direction.

17. A bolt part with an external thread formed in the middle and a nut provided on the outer surface of this bolt part Using a plastic coupling member consisting of a nut part and a bent part that connects the nut part and the bolt part between the nut part and the head part of the bolt part, pulls the bolt part out of the nut part and bends the bent part. The panel and the part are clamped by the bent part and the nut part, and the part is attached to the panel by this clamping.

5 Parts mounting device.

18. A bolt with an external thread formed in the middle, a nut provided on the outer surface of the bolt, and a bend that connects the nut and the bolt between the nut and the head of the bolt. Using a plastic coupling member consisting of

Pull out the bolt part from the nut part and bend the bent part,

, 0 The panel and the part are clamped by the bent part and the nut part, and the part is attached to the panel by this clamping.

A component mounting method characterized in that:

19. A plastic coupling member for use in the component mounting method according to claim 18, wherein a bolt portion having an external thread formed in the middle, and an outer surface of the bolt portion are provided.

₁₅ Nut part, and a bent part between the nut part and the head part of the bolt part that connects the nut part and the bolt part, and the bolt part has a small diameter part that is broken by a certain pulling force. A coupling member characterized in that the nut portion has a thin portion formed at a position slightly away from a connection portion with the bent portion so that the nut portion can be separated into an upper portion and a lower portion.