Flangeless blind nut and its fastening method

Abstract

The present invention provides a blind nut fastening structure that does not leave any protruding shapes on the surface of the member to be attached after the blind nut is fastened, and that can be fastened regardless of the thickness of the member to be attached. [Solution] The flangeless blind nut comprises a female threaded portion and a hollow tubular portion that can be plastically deformed, the tubular portion having a constant outer diameter corresponding to the inner diameter of the member to be attached. The member to be attached is made of a material weaker than the blind nut. When the mounting member is attached to the member to be attached, the end of the tubular portion opposite to the female threaded portion is located inside the mounting hole of the member to be attached, the tubular portion located outside the mounting hole of the member to be attached is plastically deformed, while the tubular portion located inside the mounting hole bites into the member to be attached, thereby fastening the blind nut to the member to be attached, and the mounting member is attached to the member to be attached by the bolt screwing into the female threaded portion.

Description

Technical Field

[0001] The present invention relates to a blind nut. In particular, it relates to a blind nut that can be fastened to a mounting member without a flange.

Background Art

[0002] Conventional blind nuts include a flange at one end, a tubular portion extending from the flange, and a female screw portion following the tubular portion. The flange is mainly responsible for positioning on the mounting member and receiving the reaction force during fastening. With this blind nut inserted into the mounting hole of the mounting member with the female screw portion and the tubular portion, a fastening tool is used to buckle and expand the diameter of the tubular portion, and the mounting member is sandwiched between the expanded tubular portion and the flange for fastening. Therefore, conventional blind nuts have a range of plate thicknesses that can be fastened, and a separately designed blind nut is required for plate thicknesses outside this range.

[0003] Moreover, in the surface of the mounting member after fastening with a conventional blind nut, there is a convex shape due to the flange. As a result, it is impossible to make the mounting member adhere closely to the mounting member. For example, in cases where airtight or watertight performance is required between the mounting member and the mounting member and close adhesion is necessary, countersinking is required. Also, when it is desired to increase the fastening strength between the mounting member and the mounting member, and when it is desired to reduce the dimensions after fastening of the outer surface of the mounting member and the outer surface of the mounting member, countersinking is also required.

[0004] As shown in Patent Document 1, there are also nuts without a flange that causes the convex shape. However, the nut of Patent Document 1 forms a flange due to the deformation of the cylindrical wall of the nut when fastening to the mounting member, so a convex shape is formed on the surface of the mounting member after fastening. Further, the nut of Patent Document 1 cannot be attached to a mounting member having a thickness exceeding the length of the cylindrical wall, and it is necessary to prepare a separately designed nut according to the thickness of the mounting member.

[0005] Therefore, in fastening components to be attached using blind nuts, there was a need for a design that would prevent any protruding shapes from appearing on the surface of the component after the blind nut has been fastened, and a design that would allow fastening regardless of the thickness of the component to be attached. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 56-66515 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a blind nut and a method for fastening the blind nut that do not leave any protruding shapes on the surface of the member to be attached after fastening the blind nut, and that can be fastened regardless of the thickness of the member to be attached. [Means for solving the problem]

[0008] To achieve this objective, the present invention provides a flangeless blind nut comprising a hollow tubular portion and a female threaded portion. The flangeless blind nut is fastened to the mounting member using a fastening tool, and after fastening, there are no protruding shapes on the surface of the mounting member.

[0009] One aspect of the present invention is, A method of fastening a flangeless blind nut to a mounting member using a fastening tool, and then attaching a mounting member to the mounting member with a bolt, The member to be mounted has a mounting hole, and the mounting member has a mounting hole, The blind nut comprises a female threaded portion with an internal female thread formed thereon, and a hollow tubular portion adjacent to the female threaded portion, wherein the tubular portion has a constant outer diameter corresponding to the diameter of the mounting hole of the mounting member, The fastening tool comprises a flange portion having an outer diameter larger than the inner diameter of the mounting hole, a shaft portion extending from the flange portion and having a male threaded portion at its tip, and a contact portion extending from the flange portion to the outside of the shaft portion in the direction of the male threaded portion, having an outer diameter that can be inserted into the mounting hole, and configured to abut against the tubular portion. The aforementioned method, The steps include: attaching the blind nut to the fastening tool by screwing the female thread portion of the tubular portion into the male thread portion of the fastening tool, and bringing the end of the tubular portion opposite to the female thread portion into contact with the contact portion of the fastening tool; With the blind nut attached to the fastening tool, the blind nut is inserted into the mounting hole of the mounting member until the flange portion of the fastening tool contacts the mounting member. The steps include: pulling the blind nut towards the fastening tool while the contact portion of the fastening tool presses against the end of the tubular portion, causing the tubular portion located outside the mounting hole to plastically deform, and causing the tubular portion located inside the mounting hole to bite into the mounting member, thereby fastening the blind nut to the mounting member; The steps include removing the fastening tool while the blind nut is fastened to the member to be attached, The method comprises the step of using the bolt to attach the mounting member to the mounting member through the mounting hole of the mounting member.

[0010] Preferably, the insertion step is adjustable so that the blind nut is inserted into the mounting hole of the mounting member such that the end of the tubular portion is located within the mounting hole of the mounting member.

[0011] Preferably, the end of the tubular portion is tapered, and when the blind nut is pulled towards the fastening tool, the tapered shape of the end of the tubular portion supports the member to be attached.

[0012] Preferably, the flange portion of the fastening tool is equipped with an extrusion mechanism, and when the male threaded portion of the fastening tool is rotated in a direction to remove the fastening tool from the blind nut, the extrusion mechanism causes the flange portion to press against the member to be attached, thereby removing the fastening tool.

[0013] Preferably, the member to be attached is made of a material that is weaker than the blind nut.

[0014] Preferably, the mounting hole of the mounting member is tetrahedral or hexagonal.

[0015] Preferably, the outer surface of the tubular portion is machined (for example, by serration) to engage with the mounting hole.

[0016] Another aspect of the present invention is, A structure in which a mounting member is attached to a mounting member by a blind nut and bolt without a flange, The aforementioned blind nut is A female threaded portion with an internal thread formed therein, A hollow tubular portion adjacent to the female thread portion that is capable of plastic deformation and Equipped with, The tubular portion has a constant outer diameter corresponding to the inner diameter of the member to be attached. The mounting member is made of a material that is weaker than the blind nut. In the state in which the mounting member is attached to the member to be mounted, The end of the tubular portion opposite to the female thread portion is located inside the mounting hole of the mounting member. The tubular portion of the member to be mounted, located outside the mounting hole, is plastically deformed, while the tubular portion located inside the mounting hole is biting into the member to be mounted, thereby fastening the blind nut to the member to be mounted. The bolt passes through the mounting hole of the mounting member, the mounting hole of the member to be mounted, and the tubular portion, and is screwed with the female screw portion, so that the mounting member is mounted on the member to be mounted.

Advantages of the Invention

[0017] According to the present invention, there is no convex shape on the surface of the member to be mounted after fastening the blind nut, and it is possible to fasten using the blind nut regardless of the thickness of the member to be mounted.

Brief Description of the Drawings

[0018] [Figure 1] It is a cross-sectional view of a blind nut without a flange according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view of a state where a blind nut without a flange according to an embodiment of the present invention is attached to a fastening tool. <0OO0099>It is a cross-sectional view of a state where the blind nut without a flange attached to the fastening tool as shown in FIG. 2 is inserted into the mounting hole of the member to be mounted. [Figure 4] It is a cross-sectional view showing a state where the tubular portion of the blind nut without a flange is plastically deformed using a fastening tool and fastened to the member to be mounted. [Figure 5] It is a cross-sectional view showing a state where the fastening tool is removed from the state shown in FIG. 4, and the blind nut without a flange is fastened to the member to be mounted. <00001OS>It is a cross-sectional view of a structure in which a mounting member is fixed to a member to be mounted on which a blind nut without a flange according to an embodiment of the present invention is fastened, using a bolt. [Figure 7] As a modification, it is a cross-sectional view showing a state where a blind nut without a flange is fastened to a member to be mounted when the fastening tool includes an extrusion mechanism and the end portion of the tubular portion is tapered.

Mode for Carrying Out the Invention

[0019] Embodiments of the present invention will be described below with reference to the drawings.

[0020] [Configuration of flangeless blind nuts] Figure 1 is a cross-sectional view of a flangeless blind nut 10 according to one embodiment of the present disclosure. The flangeless blind nut 10 comprises a female threaded portion 14 with an internal thread formed on the inside of one end, and a hollow tubular portion 12 adjacent to the female threaded portion.

[0021] In one embodiment, the outer surface of the tubular portion 12 may be processed (for example, serrated) to engage with the mounting hole of the mounting member when fastening to the mounting member. The flangeless blind nut 10 according to the present invention is typically used to fasten to a mounting member made of aluminum or other material that is weaker than a flangeless blind nut 10, but the serration on the outer surface of the tubular portion 12 makes it possible to make the engagement with the mounting hole stronger. As will be described later, the tubular portion 12 includes a portion that plastically deforms and expands in diameter when fastened to the mounting member 30. In order to facilitate the plastic deformation of the tubular portion 12 during fastening, the wall thickness of the tubular portion 12 may be designed to be thinner than the wall thickness of the female thread portion 14. In this regard, the outer surface from the tubular portion 12 to the female thread portion 14 has a constant straight shape, and the inner diameter of the tubular portion 12 may be designed to be substantially larger than the inner diameter of the female thread portion 14.

[0022] [Configuration of fastening tools] Figure 2 shows the state in which the flangeless blind nut 10 is mounted on the fastening tool 20, as a preliminary step before fastening the flangeless blind nut 10 to the member to be fastened. The fastening tool 20 comprises a flange portion 24 having an outer diameter larger than the inner diameter of the mounting hole of the member to be fastened, a shaft portion 28 extending from the flange portion 24 and having a male thread portion 22 at its tip 34, and a contact portion 26 extending from the flange portion 24 in the direction of the male thread portion 22, having an outer diameter that can be inserted into the mounting hole, and configured to abut against the end 16 of the tubular portion 12. The shaft portion 28 has an outer diameter smaller than the inner diameter of the tubular portion 12, and the male thread portion 22 is formed to be screwable with the female thread portion 14.

[0023] [Installation method using flangeless blind nuts] A method for attaching a mounting member to a mounting member using the flangeless blind nut 10 shown in Figure 1 will be described. First, the flangeless blind nut 10 is attached to the fastening tool 20 as shown in Figure 2. At this time, the tubular portion 12 has a constant outer diameter corresponding to the diameter of the mounting hole of the member to be mounted. The flangeless blind nut 10 is attached to the fastening tool 20 by screwing the female thread portion 14 onto the male thread portion 22 of the fastening tool 20 and bringing the end portion 16 of the tubular portion 12 opposite to the female thread portion 14 into contact with the contact portion 26 of the fastening tool 20.

[0024] Next, as shown in Figure 2, the flangeless blind nut 10 attached to the fastening tool 20 is inserted into the mounting hole 32 of the member to be mounted 30. Figure 3 shows the state in which the flangeless blind nut 10 attached to the fastening tool 20 is inserted into the mounting hole 32 of the member to be mounted 30. The tubular portion 12 has a constant outer diameter corresponding to the inner diameter of the mounting hole 32 of the member to be mounted 30. The flangeless blind nut 10 attached to the fastening tool 20 is inserted until the flange portion 24 of the fastening tool 20 abuts against the outer surface of the member to be mounted 30, and in this case, the end portion 16 of the tubular portion 12 is located inside the mounting hole 32 of the member to be mounted 30.

[0025] Here, the position of the end portion 16 relative to the mounting hole 32 may be adjusted by setting the distance 36 from the flange portion 24 to the tip of the contact portion 26 of the fastening tool 20. In other words, it is not necessary to prepare a flangeless blind nut 10 having a corresponding length according to the thickness of the member to be mounted 30, and by setting the distance 36 from the flange portion 24 to the tip of the contact portion 26 of the fastening tool 20 according to the thickness of the member to be mounted 30, it is possible to adjust so that the end portion 16 of the tubular portion 12 is located inside the mounting hole 32 of the member to be mounted 30. According to this embodiment, it is possible to adjust so that the end portion 16 of the tubular portion 12 is located inside the mounting hole 32 of the member to be mounted 30 regardless of the thickness of the member to be mounted 30, and it is also possible to configure it so that there is no protruding shape of the blind nut on the surface of the member to be mounted 30.

[0026] Next, the flangeless blind nut 10 is fastened to the mounting member 30 using the fastening tool 20. Figure 4 is a cross-sectional view showing how the tubular portion 12 of the flangeless blind nut 10 is plastically deformed using the fastening tool 20 to fasten it to the mounting member 30. From the state shown in Figure 3, the flangeless blind nut 10 is pulled towards the flange portion 24 of the fastening tool 20, while the contact portion 26 of the fastening tool 20 presses against the end portion 16 of the tubular portion 12. In this case, the action of pulling the flangeless blind nut 10 towards the flange portion 24 of the fastening tool 20 may be achieved by using a mechanism that slides the shaft portion 28 in the direction of pulling the flangeless blind nut 10 without rotating the male thread portion 22 of the fastening tool 20, or the fastening tool 20 may be configured to pull the flangeless blind nut 10 in conjunction with the rotation of the male thread portion 22 of the fastening tool 20. This causes the tubular portion 12 located outside the mounting hole 32 to plastically deform and expand in diameter, while the tubular portion 12 located inside the mounting hole 32 bites into the mounting member 30, thereby fastening the flangeless blind nut 10 to the mounting member 30.

[0027] In one embodiment, the mounting member 30 may be made of a material that is weaker than the flangeless blind nut 10 (for example, aluminum extrusion).

[0028] In one embodiment, the mounting hole 32 of the mounting member 30 may be tetrahedral or hexagonal in order to prevent the flangeless blind nut 10 from rotating together during fastening.

[0029] In one embodiment, the outer surface of the tubular portion 12 of the flangeless blind nut 10 may be processed (for example, serrated) to make the engagement with the surface of the mounting hole 32 stronger.

[0030] Next, as shown in Figure 5, the fastening tool 20 is removed from the state shown in Figure 4. In this case, as described above, the tubular portion 12 located inside the mounting hole 32 is biting into the mounting member 30, and the flangeless blind nut 10 and the mounting member 30 are fastened together. Furthermore, because the end portion 16 of the flangeless blind nut 10 is located inside the mounting hole 32 of the mounting member 30, there is no convex shape on the surface of the mounting member 30.

[0031] Next, the mounting member 72 is attached to the mounting member 70 using the bolt 74. Figure 6 is a cross-sectional view of a structure in which the mounting member 72 is fixed to the mounting member 70 (for example, an aluminum extruded case) to which the flangeless blind nut 10 is fastened, using the bolt 74. The mounting member 72 has a mounting hole, and the mounting member 72 can be attached to the mounting member 70 by passing the shaft of the bolt 74 through the mounting hole of the mounting member 72, and then inserting it into the mounting hole of the mounting member 70 and the tubular portion 12 of the flangeless blind nut 10 and screwing it into the female thread portion 14.

[0032] Since there is no protruding shape due to the flangeless blind nut 10 on the surface of the mounting member 70 that contacts the mounting member 72, the mounting member 70 and the mounting member 72 can be fixed in close contact. With this configuration, it is possible to apply a sealant between the mounting member 70 and the mounting member 72 to ensure close contact and maintain airtightness and watertightness.

[0033] [Differentiation] Figure 7 is a cross-sectional view showing a state in which a flangeless blind nut is fastened to a mounting member, as another embodiment in which the fastening tool is equipped with an extrusion mechanism and the end of the tubular portion is tapered.

[0034] In the embodiment shown in Figure 7, the end 16 of the flangeless blind nut 10 is tapered, and when the flangeless blind nut 10 is pulled towards the flange portion of the fastening tool 60, the tapered shape of the end 16 of the tubular portion 12 makes it easier for the member to be attached 30 to be supported. The portion of the tubular portion 12 located inside the mounting hole 32 bites more securely into the member to be attached 30, enabling a stronger fastening.

[0035] Furthermore, in the embodiment shown in Figure 7, the fastening tool 60 with an extrusion mechanism is equipped with an extrusion mechanism 62 to prevent the fastening tool 60 with an extrusion mechanism from biting into the flangeless blind nut 10 after fastening. The extrusion mechanism 62 is configured such that when the male threaded portion 22 of the fastening tool 60 is rotated in the direction to remove the fastening tool 60 with an extrusion mechanism from the flangeless blind nut 10 after fastening, it presses against the member to be attached 30. With this configuration, the fastening tool 60 with an extrusion mechanism can be removed without the contact portion of the fastening tool 60 biting into the flangeless blind nut 10.

[0036] As described above, one embodiment and examples of the flangeless blind nut and its fastening method according to the present invention have been explained. However, it is easy to understand that the present invention is not limited to the above-described examples, and various modifications can be made thereto. And, as long as these modifications fall within the scope of the matters described in each claim of the patent claims and equivalent matters, they are naturally included within the technical scope of the present invention. The above-described examples utilized a predetermined fastening tool and bolt, but this is merely an example, and the present invention is not limited to this particular example. [Explanation of Symbols]

[0037] 10 Flangeless blind nuts 12 Tubular part 14 Female thread section 16 End 20 Fastening Tools 22 Male threaded section 24 Flange section 26 Contact part 28 Shaft section 30, 70 Mounted Members 32 mounting holes 34 Tip 60 Fastening tool with extrusion mechanism 62 Extrusion mechanism 72 Mounting components 74 volts

Claims

1. A method of fastening a flangeless blind nut to a mounting member using a fastening tool, and then attaching a mounting member to the mounting member with a bolt, The member to be mounted has a mounting hole, and the mounting member has a mounting hole, The blind nut comprises a female threaded portion with an internal female thread formed thereon, and a hollow tubular portion adjacent to the female threaded portion, wherein the tubular portion has a constant outer diameter corresponding to the diameter of the mounting hole of the mounting member, The fastening tool comprises a flange portion having an outer diameter larger than the inner diameter of the mounting hole, a shaft portion extending from the flange portion and having a male threaded portion at its tip, and a contact portion extending from the flange portion to the outside of the shaft portion in the direction of the male threaded portion, having an outer diameter that can be inserted into the mounting hole, and configured to abut against the tubular portion. The aforementioned method, The steps include: attaching the blind nut to the fastening tool by screwing the female thread portion of the tubular portion into the male thread portion of the fastening tool, and bringing the end of the tubular portion opposite to the female thread portion into contact with the contact portion of the fastening tool; With the blind nut attached to the fastening tool, the blind nut is inserted into the mounting hole of the mounting member until the flange portion of the fastening tool contacts the mounting member. The steps include: pulling the blind nut towards the fastening tool while the contact portion of the fastening tool presses against the end of the tubular portion, causing the tubular portion located outside the mounting hole to plastically deform, and causing the tubular portion located inside the mounting hole to bite into the mounting member, thereby fastening the blind nut to the mounting member; The steps include removing the fastening tool while the blind nut is fastened to the member to be attached, A method comprising the step of attaching the mounting member to the mounting member through the mounting hole of the mounting member using the bolt.

2. The aforementioned insertion step is, The blind nut can be adjusted so that its end portion is positioned within the mounting hole of the mounting member, thereby allowing insertion into the mounting hole of the mounting member. The method according to claim 1, characterized by the features described above.

3. The end of the tubular portion is tapered, and when the blind nut is pulled towards the fastening tool, the tapered shape of the end of the tubular portion causes the member to be attached to be supported. The method according to claim 1, characterized by the features described above.

4. The flange portion of the fastening tool is equipped with an extrusion mechanism, and when the male threaded portion of the fastening tool is rotated in the direction of removing the fastening tool from the blind nut, the extrusion mechanism causes the flange portion to press against the member to be attached, thereby removing the fastening tool. The method according to claim 1, characterized by the features described above.

5. The mounting member is formed of a material that is weaker than the blind nut. The method according to claim 1, characterized by the features described above.

6. The mounting hole of the mounting member is tetrahedral or hexagonal. The method according to claim 1, characterized by the features described above.

7. The outer surface of the tubular portion is machined to engage with the mounting hole. The method according to claim 1, characterized in that

8. A structure in which a mounting member is attached to a mounting member by a blind nut and bolt without a flange, The aforementioned blind nut is A female threaded portion with an internal thread formed therein, A hollow tubular portion adjacent to the female thread portion that is capable of plastic deformation and Equipped with, The tubular portion has a constant outer diameter corresponding to the inner diameter of the member to be attached. The mounting member is made of a material that is weaker than the blind nut. In the state in which the mounting member is attached to the member to be mounted, The end of the tubular portion opposite to the female thread portion is located inside the mounting hole of the mounting member. The tubular portion of the member to be mounted, located outside the mounting hole, is plastically deformed, while the tubular portion located inside the mounting hole is biting into the member to be mounted, thereby fastening the blind nut to the member to be mounted. The bolt passes through the mounting hole of the mounting member, the mounting hole of the member to be mounted, and the tubular portion, and is screwed into the female threaded portion, thereby attaching the mounting member to the member to be mounted.

9. The mounting hole of the mounting member is tetrahedral or hexagonal. The structure according to feature 8.

10. The outer surface of the tubular portion is machined to engage with the mounting hole. The structure according to claim 8, characterized in that it is the structure described in claim 8.

Images