Blind Nut and Mounting Structure Thereof

Abstract

A Blind nut may be mounted on a hole of a mounted member. The blind nut includes a main body with a plastically deformable material and a nut member with a relatively harder material. The main body has a cylindrical first tubular portion and a second hexagonal and cylindrical tubular portion provided adjacent to first tubular member. A flange is provided adjacent the second tubular member. Nut member includes a short cylindrical nut base member. Nut tubular members are adjacent nut base member and have a smaller outer diameter than that of the nut base member. A female threaded pass-through hole extends across the length of the nut member. The nut cylinder members are inside the first tubular member and the second tubular member; and the lower edge of the main body tubular member is in contact with a step member of the nut base member and welded thereto.

Claims

1. Blind nut, which is to be mounted onto the mounting hole of a mounted member, comprising: a main body, that is formed with a plastically deformable soft material, having a main body tubular member, and a flange provided on an edge of the main body tubular member, onto which center holes are formed; and a nut member, formed with a hard material, having a short cylindrical nut base member having a circumferential step on the upper surface thereof, and nut cylinder members provided adjacent to the step and having outer diameters smaller than that of the nut base, onto which a pass-through hole having a female screw is formed; wherein the nut cylinder members of the nut member are provided inside the main body tubular member of the main body; and the lower edge portion of the main body tubular member is in contact and coupled with the step of the nut base.

2. Blind nut of claim 1, wherein the nut member and the main body tubular member of the main body are inserted into the mounting hole of the mounted member, a part of the main body tubular member is plastically deformed to be enlarged and the mounted member is sandwiched between the deformed enlarged-diameter member and the flange to mount the blind nut onto the mounted member.

3. Blind nut of claim 1, wherein the lower edge surface of the main body tubular member is coupled with the step of the nut base member by means of welding.

4. Blind nut of claim 1, wherein the main body tubular member has a first tubular member which is distant from the flange and takes a cylindrical shape; and a second tubular member, which is close to the flange, the cross-section of which takes a hexagonal or square cylindrical shape.

5. Blind nut of claim 1, wherein the outer surface of the main body tubular member adjacent to the flange is knurled.

6. Blind nut of claim 1, wherein the pass-through hole of the nut member possesses an inner diameter which is constant across the entire nut member, and the female screw is formed across the entire pass-through hole.

7. Blind nut of claim 1, wherein the nut cylinder members of the nut member comprise a first cylinder member which is provided adjacent to the nut base; and a second cylinder member which is provided adjacent to the first cylinder member with an outer diameter that is smaller than that of the first cylinder member.

8. Structure in which the blind nut is mounted onto the mounting hole of the mounted member, wherein the blind nut comprises: a main body, formed with a plastically deformable soft material, which has a main body tubular member and a flange provided on an edge of the main body tubular member, onto which center holes are formed; and a nut member, formed with a hard material, which possesses a short cylindrical nut base member having a circumferential step on the upper surface thereof, and nut cylinder members provided adjacent to the step having a smaller outer diameter than that of the nut base, and onto which a pass-through hole having a female screw is formed; wherein the nut cylinder members of the nut member are provided inside the main body tubular member of the main body, the lower edge surface of the main body tubular member is in contact with and coupled with the step of the nut base; the nut member and the main body tubular member of the main body are inserted into the mounting hole of the mounted member, and the mounted member is sandwiched between the enlarged-diameter member formed by enlarging a part of the main body tubular member and the flange for the blind nut to be mounted onto the mounted member.

9. Structure according to claim 8, wherein the diameter-enlarged member of the main body tubular member is enlarged right above the lower edge surface of the main body tubular member.

10. Structure according to claims 8, wherein the male screw of the shank of the bolt engages with the female screw of the nut member, and the mounting member is sandwiched and mounted between the flange of the main body and the head of the bolt.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1A is a cross-sectional view showing the state in which the traditional blind nut is set on the mounted member.

[0044] FIG. 1B is a cross-sectional view showing the blind nut mounted on the mounted member.

[0045] FIG. 2 is an oblique view showing the main body of the blind nut of a working example of the present invention.

[0046] FIG. 3 is a top view of the main body shown in FIG. 2.

[0047] FIG. 4 is a front view of the main body shown in FIG. 2.

[0048] FIG. 5 is a bottom view of the main body shown in FIG. 2.

[0049] FIG. 6 is a cross-sectional view along the A-A line shown in FIG. 4 of the main body shown in FIG. 2.

[0050] FIG. 7 is an oblique view showing the nut member of the blind nut of a working example of the present invention.

[0051] FIG. 8 is a top view of the nut member shown in FIG. 7.

[0052] FIG. 9 is a front view of the nut member shown in FIG. 7.

[0053] FIG. 10 is a cross-sectional view along the A-A line shown in FIG. 9 of the nut member shown in FIG. 7.

[0054] FIG. 11 is an oblique view showing the state in which the nut member shown in FIG. 7 is not yet inserted into the main body shown in the main body shown in FIG. 2.

[0055] FIG. 12 is an oblique view depicting the state in which the nut member shown in FIG. 7 is inserted into the main body shown in the main body as illustrated in FIG. 2.

[0056] FIG. 13 is a top view of the blind nut shown in FIG. 12.

[0057] FIG. 14 is a front view of the blind nut shown in FIG. 12.

[0058] FIG. 15 is a cross-sectional view along the A-A line shown in FIG. 14 of the blind nut shown in FIG. 12.

[0059] FIG. 16 is a cross-sectional view showing the state in which the blind nut is mounted onto the mounted member.

[0060] FIG. 17 is a cross-sectional view showing the state in which another mounting member is mounted by means of a bolt onto the blind nut which has been mounted onto the mounted member.

DETAILED DESCRIPTION OF THE INVENTION

[0061] An explanation of blind nut 10 of a working example of the present invention shall be given below with reference to the drawings. FIGS. 2 to 6 show main body 20 of blind nut 10, and FIGS. 7 to 10 show nut member 30 of blind nut 10. FIG. 11 shows the state in which main body 20 and nut member 30 are not yet coupled, and FIGS. 12 to 15 show the state in which main body 20 and nut member 30 are coupled. FIG. 16 shows the state in which blind nut 10 is mounted onto mounted member 41, and FIG. 17 shows the state in which mounting member 42 is mounted by means of bolt 45 onto blind nut 10 which has been mounted onto mounted member 41.

[0062] Blind nut 10 of a working example of the present invention comprises main body 20, which is formed with a plastically deformable material such as metal and the like; and nut member 30, which is formed with a rigid material such as metal and the like. As shown in FIG. 11, nut member 30 is inserted from the lower side of main body 20, and the lower edge surface of main body 20 and step 31a of nut base 31 of nut member 30 are welded by means of laser welding to form blind nut 10.

[0063] Blind nut 10, which has been formed in an integrated manner, is inserted into mounting hole 43 of mounted member 41; the diameters of first tubular member 21 and second tubular member 22 of main body 20 are enlarged by utilizing the fastening tool to mount blind nut 10 onto mounting hole 43. Subsequently, bolt 45 is caused to be screwed onto female screw 37 of nut member 30 in order to mount mounting member 42 onto blind nut 10.

[0064] An explanation regarding main body 20 of blind nut 10 shall be given below, with reference to FIGS. 2 to 6. FIG. 2 is an oblique view showing main body 20 of blind nut 10. FIG. 3 is a top view, FIG. 4 is a front view, and FIG. 5 is a bottom view, respectively. FIG. 6 is a cross-sectional view along the A-A line shown in FIG. 4 of main body 20.

[0065] Main body 20 is formed with a plastically deformable material such as metal, and the like. Main body 20 possesses first tubular member 21 on one edge thereof. First tubular member 21 takes a cylindrical shape, and first center hole 25 of which the cross-sectional surface takes a circular shape is formed thereon. The outer diameter of first tubular member 21 is smaller than the inner diameter of mounting hole 43 of mounted member 41. The inner diameter of first tubular member 21 is either equivalent to or slightly larger than that the outer diameter of first cylinder member 32 of nut member 30 in order to receive first cylinder member 32. Alternatively, the inner diameter of first tubular member 21 may be designed to be slightly smaller than the outer diameter of first cylinder member 32 of nut member 30 so that first cylinder member 32 of nut member 30 is pressed in.

[0066] Second tubular member 22 is provided adjacent to the upper portion of first tubular member 21. The cross-sectional surface of second tubular member 22 takes a hexagonal shape, and second center hole 26 is provided thereon. The outer cross-sectional surface takes a hexagonal shape, and the apexes thereof are chamfered. The cross-sectional surface of second center hole 26 takes a hexagonal shape with rounded corners. The overall shape of second tubular member 22 is a hexagonal cylinder. The size of second tubular member 22 is small enough to be inserted in mounting hole 43 of mounted member 41. First tubular member 21 and second tubular member 22 are parts that are to be plastically deformed in order to enlarge the diameters thereof when they are mounted onto mounted member 41.

[0067] In this working example of the present invention, the cross-sectional surface of second tubular member 22 is hexagonal; however, it may be square or circular. If the cross-sectional surface of second tubular member 22 is designed to be circular, the surface may be knurled to prevent rotation.

[0068] Mounting hole 43 of mounted member 41 may be hexagonal to match the shape of second tubular member 22; it may also be square or circular.

[0069] Main body 20 possesses flange 24, which is provided adjacent to the upper portion of second tubular member 22. The cross-sectional surface of flange 24 is circular on its outer surface; and second center hole 26 on its inner surface is hexagonal. In other words, second center hole 26 with a hexagonal cross-sectional surface is formed in the area extending from flange 24 to second tubular member 22. The outer diameter of flange 24 is larger than the outer diameter of second tubular member 22 and larger than the inner diameter of mounting hole 43 of mounted member 41. Main body 20 is overall axially symmetrical around the center axis.

[0070] An explanation concerning nut member 30 of blind nut 10 is provided below with reference to FIGS. 7 to 10. FIG. 7 is an oblique view showing nut member 30, FIG. 8 is a top view and FIG. 9 is a front view, respectively. FIG. 10 is a cross-sectional view along the A-A line shown in FIG. 9 of nut member 30.

[0071] Nut member 30 is formed using a rigid material such as metal, and the like. Nut member 30 comprises circular nut base member 31, and nut cylinder members, which are provided adjacent to the upper portion of nut base member 31. Nut cylinder members are separated into first cylinder member 32 and second cylinder member 33, which is provided adjacent to the upper portion of first cylinder member 32.

[0072] Nut base member 31 of nut member 30 takes a cylindrical shape. The outer diameter of nut base member 31 is approximately equal to the outer diameter of first tubular member 21 of main body 20.

[0073] The outer diameter of first cylinder member 32 is smaller than the outer diameter of nut base member 31. The outer diameter of first cylinder member 32 is either approx.-imately equal to or slightly smaller than the inner diameter of first tubular member 21 of main body 20; alternatively, it is slightly larger in a manner so as to be pressed in. First tubular member 21 of main body 20 is primarily provided in the area surrounding first cylinder member 32. Circumferential step 31a of nut base member 31 receives the lower edge of first tubular member 21 of main body 20. The length of first cylinder member 32 is approximately the same as the length of first tubular member 21 of main body 20.

[0074] Second cylinder member 33 takes a circular shape approximately the same as the shape of first cylinder member 32. The outer diameter of second cylinder member 33 is slightly smaller than the outer diameter of first cylinder member 32. Nut base member 31, first cylinder member 32 and second cylinder member 33 share the same central axis.

[0075] When nut member 30 is combined with main body 20, second tubular member 22 of main body 20 is primarily provided in the area surrounding second cylinder member 33. The outer surface of second cylinder member 33 and hexagonally-shaped second center hole 26 of second tubular member 22 are provided so as to be slightly spaced from one another.

[0076] The length of second cylinder member 33 is less than the length of second tubular member 22 of main body 20. When main body 20 and nut member 30 are combined as shown in FIG. 15, the upper edge of second cylinder member 33 is located at the middle height in the height direction of second tubular member 22.

[0077] In this working example of the present invention, the cylinder members of nut member 30 are separated into first cylinder member 32 and second cylinder member 33. However, first cylinder member 32 and second cylinder member 33 may have the same outer diameter and be constituted as one integrated nut cylinder member.

[0078] Pass-through hole 35 is formed in the area extending from the lower surface of nut base member 31 to the upper surface of second cylinder member 33. The inner diameter of pass-through hole 35 is constant all the way across nut base member 31, first cylinder member 32 and second cylinder member 33. Female screw 37 is formed in the area extending from the upper edge to the lower edge of pass-through hole 35. As stated below, main body 20 and nut member 30 are coupled by means of laser welding, so that the thread of female screw 37 of nut member 30 is not deformed. Due to the foregoing, female screw 37 can be formed all along nut member 30.

[0079] An explanation regarding blind nut 10, in which main body 20 and nut member 30 are combined, is provided below with reference to FIGS. 11 to 15. FIG. 11 is an oblique view showing the state in which nut member 30 is not yet inserted into main body 20. FIG. 12 is an oblique view showing the state in which nut member 30 is inserted into main body 20; FIG. 13 is a top view, and FIG. 14 is a front view thereof, respectively. FIG. 15 is a cross-sectional view along the A-A line shown in FIG. 14 of blind nut 10.

[0080] As shown in FIG. 11, nut member 30 is inserted with the second cylinder member first from first tubular member 21 of main body 20. As shown in FIG. 15, the lower edge of first tubular member 21 is in contact with step 31a of nut base member 31. The inner surface of first tubular member 21 of main body 20 is in contact with the outer peripheral surface of first cylinder member 32 of nut base member 31. Second cylinder 33 of nut base member 31 is provided inside second center hole 26 of main body 20. The cross-sectional surface of second center hole 26 takes a hexagonal shape, and the inner surface of second tubular member 22 is adjacent to second cylinder member 33 of nut member 30 in the central portion of each side of the cross-sectional hexagon. The upper surface of second cylinder 33 is positioned in the middle of the lengthwise direction of second tubular member 22.

[0081] In this state, the lower edge surface of first tubular member 21 of main body 20 and step 31a of nut base member 31 are laser-welded to integrate main body 20 and nut member 30. Only the lower edge surface of first tubular member 21 and step 31a of nut base member 31 are welded. Due to the foregoing, when blind nut 10 is mounted onto mounted member 41, the portion right above the lower edge surface of first tubular member 21 can be plastically deformed, and thus the height of blind nut 10 can be decreased.

[0082] First tubular member 21 and nut base member 31 may be welded by means of welding methods other than laser-welding. Moreover, these members may be coupled by methods other than welding.

[0083] FIG. 16 is a cross-sectional view showing blind nut 10 mounted onto mounted member 41. Mounting hole 43 is formed on mounted member 41. The shape of mounting hole 43 is hexagonal so that second tubular member 22 having the hexagonal cross-sectional surface fits therein.

[0084] Alternatively, if the cross-sectional surface of second tubular member 22 is square or circular, the shape of mounting hole 43 may be matched up with the shape of second tubular member 22 to be square or circular. When blind nut 10 is mounted onto mounted member 41, blind nut 10 is inserted into mounting hole 43 of mounted member 41 with nut base member 31 first. The lower surface of flange 24 is in contact with the outer periphery of mounting hole 43 of mounted member 41.

[0085] The male screw of the screw mandrel of the fastening tool (not shown in the figures) is caused to rotate so as to be engaged with female screw 37 of nut member 30. When the nose piece (not shown in the figures) of the fastening tool comes in contact with the upper surface of flange 24, rotations of the screw mandrel are stopped. [The nose piece is] pulled strongly to the fastening tool without rotating the screw mandrel.

[0086] Nut base member 31 of nut member 30 pushes up first tubular member 21 and second tubular member 22 of main body 20 in an upward direction. First tubular member 21 and second tubular member 22 are plastically deformed to form enlarged-diameter member 22a. Mounted member 41 is sandwiched between the lower surface of flange 24 and enlarged-diameter member 22a. The upper edge surface of second cylinder member 33 of nut member 30 has moved to a height that is approximately the same height as the lower surface of flange 24.

[0087] The outer diameter of second cylinder member 33 is slightly smaller than the outer diameter of first cylinder member 32, and there is a small space between second cylinder member 33 and second center hole 26 of main body 20. Therefore, even when the destination position of the upward movement of second cylinder member 33 is slightly varied, upward movement is possible.

[0088] When the fastening operation by the fastening tool is completed, the screw mandrel is reversely rotated to cancel engagement with female screw 37 of nut member 30. In this way, blind nut 10 is mounted onto mounted member 41.

[0089] In traditional blind nut 1 shown in FIG. 1(b), female screw 15 is provided below enlarged-diameter member 12a, which increases the overall height of blind nut 1. In the blind nut of the working example of the present invention shown in FIG. 16, female screw 37 of nut member 30 enters the inside of enlarged-diameter member 22a. Although the length of female screw 37 is sufficiently secured, the overall height of blind nut 10 is decreased.

[0090] In a traditional blind nut formed in an integrated manner, the portion to be enlarged and the female screw member to be engaged with a bolt were formed in an integrated manner. Because the portion to be engaged with the female screw was formed with a soft material that would easily be plastically deformed, the portion had to be thick and the outer diameter large.

[0091] In the blind rivet of the working example of the present invention, the portion to be enlarged and the female screw member are separate members; thus, the portion to be enlarged can be formed with a soft material, and the female screw member can be formed with a hard material. Due to the foregoing, the female screw member can be thinner. And also due to the foregoing, the outer diameter of the blind rivet can be decreased.

[0092] Moreover, in the blind nut formed in an integrated manner, the female screw member needed to be quenched. In the blind rivet of the working example of the present invention, the female screw member is formed with a hard material, and, thus, no quenching process is necessary.

[0093] Moreover, as regards a traditional blind rivet consisting of two parts in which the main body is drawn to be coupled with the nut member, it has been possible for the thread of the female screw member of the nut member to become deformed in the drawing process. Because of this, the female screw could not be formed on the portion of the nut member to be coupled with the main body; thus, it has been necessary to separate the coupling portion from the female screw portion, which increased the height.

[0094] In the blind rivet of the working example of the present invention, the main body and the nut member are coupled by means of laser-welding, and, thus, it is not likely that the thread of the female screw of the nut member will be deformed. Wherefore, it is possible for the female screw to be formed along the entire length of the nut member.

[0095] FIG. 16 shows enlarged-diameter member 22a being gradually enlarged. However, as shown in enlarged-diameter member 12a in FIG. 1(b) showing the prior art, enlarged-diameter member 22a may be enlarged to exhibit plastic deformation so as to be crushed in both upward and downward directions.

[0096] FIG. 17 is a cross-sectional view showing the state in which mounting member 42 is mounted by means of bolt 45 onto blind nut 10 which has been mounted onto mounted member 41 shown in FIG. 16. Bolt 45 having head 46 and shank 47 is prepared. The male screw of shank 47 can be engaged with female screw 37 of nut member 30. The position of pass-through hole 36 of nut member 30 and the position of mounting hole 44 of mounting member 42 are aligned to position mounting member 42 on flange 24 of blind nut 10. Shank 47 of bolt 45 is inserted through mounting hole 44 of mounting member 42 into pass-through hole 35 of nut member 30. The male screw provided on shank 47 of bolt 45 is caused to be engaged with female screw 37 of nut member 30 to mount mounting member 42 onto blind nut 10. If mounting hole 43 of mounted member 41 takes a hexagonal shape, when bolt 45 is caused to be engaged, blind nut 10 is supported so as not to rotate within mounting hole 43.

[0097] In FIG. 17, mounting member 42 is mounted on the side of flange 24 of blind nut 10; however, mounting member 42 may also be mounted on the side of nut base member 31 (the lower side in FIG. 17) of blind nut 10, which is the opposite side of the side shown in FIG. 17.

[0098] In the working example of the present invention, the cross-sectional surface of second tubular member 22 is hexagonal. The cross-sectional surface of second tubular member 22 may take other polygonal shapes having other angular numbers. For example, the cross-sectional surface of second tubular member 22 may be square, or the cross-sectional surface of second tubular member 22 may be circular.

[0099] According to the working example of the present invention, it becomes possible to obtain a blind nut with a lower height after it is fastened. It also is possible to obtain a blind nut with a smaller outer diameter and lighter weight. It also is possible to obtain a blind nut that does not require quenching the screw member.