JPH11351219A - Nut and bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nut or a bolt capable of being tightened/loosened only by an exclusive tool. SOLUTION: A nut 10 is provided with an approximately circular bearing surface in contact with an article 41 to be tightened, a female screw part 14 formed orthogonal to the bearing surface 12, an approximately circular upper surface 16 opposite to the bearing surface 12, and a side surface 18 comprising a surface of revolution of a line or a curve to connect the bearing surface 12 to the upper surface 16, the diameter of the section of the bearing surface 12 and a part in the vicinity thereof is maximum, and the diameter of the upper surface 16 is minimum. The nut 10 may be provided with one or a plurality of recessed streaks to be connected from the upper surface 16 to the bearing surface 12 on the side surface 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut and a bolt, and more particularly to a nut and a bolt which cannot be loosened unless a special tool is used.

[0002]

2. Description of the Related Art Today, a large number of bolts and nuts are used in a building or civil engineering structure, and some of the bolts and nuts are left exposed even after the completion of the structure. For example, many bridges such as suspension bridges, power transmission towers and the like, railway rail fastening parts, and the like. These not only reduce construction costs, but also check for loose bolts and nuts due to relaxation, vibration, etc. in inspection work that is performed as appropriate, and repair them quickly, or replace bolts and nuts with replacement of parts during maintenance. The bolts and nuts are left exposed for replacement or the like.

However, in such a bolt connection, when a predetermined number or more of bolts and nuts are removed at the same time, the fastened bolts are sheared or broken by the action of an external force such as the own weight or wind force. hand,
The structure will be destroyed. In addition, in the friction joining, if a certain number or more of bolts and nuts are loosened at the same time, the friction joining force is reduced at a stretch, and there is a risk that the bolt is sheared. For this reason, protection fences and the like are generally provided to protect the facilities so that only those involved can enter.

[0004] However, bolts and nuts used for such bridges and steel towers are not originally intended to be loosened or removed for the purpose of destruction or dismantling based on human or malicious intent. Bolts and general tools
It was possible to loosen and remove the nut.
Therefore, in order to protect against destructive activities and mischief, bolts and nuts or members to be fastened are fixed by welding,
Alternatively, processing such as fixing bolts and nuts with resin or the like is performed.

[0005]

However, if the fastening portion is loosened due to relaxation or the like if it is fixed by welding or resin, it cannot be retightened. Also, when the fastening member becomes old or deteriorated,
Even if the members need to be replaced, there arises a problem that they cannot be disassembled.

The inventors of the present invention have made intensive studies and studies in order to provide bolts and nuts which can be tightened or loosened only by special tools, and as a result, have conceived the nut and bolt according to the present invention. That's what happened.

[0007]

The gist of the nut according to the present invention is as follows: a substantially circular seat surface which comes into contact with an object to be fastened; a female screw portion formed in a direction perpendicular to the seat surface;
A substantially circular upper surface facing the seat surface, a side surface comprising a linear or curved rotating surface connecting the seat surface and the upper surface is provided, and a diameter of a cross section of the seat surface or the vicinity thereof is the largest, The diameter of the upper surface may be at a minimum.

Further, in such a nut, at least one minute concave or convex is formed on the side surface.

Further, in such a nut, the side surface is provided with one or a plurality of concave stripes connected from the upper surface to the seat surface.

Further, in such a nut, the concave streak is formed such that an engagement surface substantially perpendicular to the direction is formed in the tightening direction, and a slant surface oblique to the direction is formed in the loosening direction. .

The gist of the bolt according to the present invention is as follows: a bolt having a male thread at at one end and a bolt having a head formed at one end of the bolt;
The head has a substantially circular seat surface in contact with the workpiece, a female screw portion formed in a direction perpendicular to the seat surface, a substantially circular upper surface facing the seat surface, and the seat surface. A side surface comprising a straight or curved rotating surface connecting the upper surface, a diameter of a cross section of the seat surface or the vicinity thereof is the largest, a diameter of the upper surface is the smallest, and the side surface is a seat surface from the upper surface. To provide one or a plurality of concave streaks leading to.

Further, in the bolt, the concave streak has an engagement surface substantially perpendicular to the tightening direction and a slant surface oblique to the direction in the loosening direction. .

[0013]

Next, an embodiment of a nut according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, a nut 10 according to one embodiment includes a substantially circular seating surface 12 that contacts an object to be fastened,
Female screw 1 formed in a direction perpendicular to the seating surface 12
4, a substantially circular upper surface 16 facing the seat surface 12, and a side surface 18 formed of a linear or curved rotating surface connecting one point on the outer periphery of the seat surface 12 and one point on the outer periphery of the upper surface 16; In this example, the shape is a truncated cone as a whole. The diameter of the cross section of the seat surface 12 or the vicinity of the seat surface 12 is maximum, and the diameter of the upper surface 16 is minimum. Therefore, the nut 10 is formed of a rotating body that is not caught at all on the outer peripheral side surface.

As shown in FIG. 2, a bolt 20 used for the nut 10 has a head portion 22 formed in a hemispherical shape, and is circumferentially attached to a tip of a male screw portion 26 formed on a shaft portion 24. A torque shear type bolt in which a so-called pin tail 30 is formed through the formed V-shaped groove (notch) 28 is preferably used. Here, the cross-sectional shape of the notch 28 is determined so as to be cut when a predetermined torque or more acts thereon. In addition, pin tail 30
Is provided with a plurality of projections 31 substantially parallel to the axial direction on the outer circumference, for example, a hexagonal, double hexagonal 12-point (point) or the like, or an odd-numbered projection such as a pentagon or an eleven-angle, and a general-purpose socket or It is fitted into a dedicated socket and serves as a reaction force receiver when tightening the nut. This pintail 3
0 will be discarded when notch 28 is cut. Alternatively, the wrench may be torque-controlled so that the notch 28 is left without being broken, and when the wrench is used for retightening later, the wrench is broken at the notch 28 and the pin tail 30 may be discarded.

On the other hand, the electric socket 32 includes an outer socket 34 fitted to the nut 10, an inner socket 36 fitted to the pin tail 30 of the bolt 20,
And an eject pin 38, and the outer socket 34
The inner socket 36 and the inner socket 36 are configured to be relatively rotated in opposite directions by a planetary gear mechanism or the like. The outer socket 34 is provided on the side 1 of the nut 10.
8 and the inner socket 36 is formed so as to be fitted to the pin tail 30 of the bolt 20. A slight frictional resistance is applied between the outer socket 34 and the side surface 18 of the nut 10, and it is difficult to receive a reaction force sufficient to obtain the predetermined tightening force and shear the pin tail 30 by the notch 28. Can not. For this reason, a pin 39 that is engaged with another member (not shown) is provided outside the outer socket 34. By engaging the pin 39 with another member, the outer socket 34 is prevented from idling. It is configured to receive a reaction force.

Using the nut 10 and the bolt 20 described above, as shown in FIG. 2, the shaft portion 24 of the bolt 20 is inserted into the holes formed in the members to be fastened 40, 41, and then the male screw portion 26 is formed. Screw the nut 10. Next, the outer socket 34 and the inner socket 36 of the electric socket 32 are fitted to the pin tails 30 of the nut 10 and the bolt 20, respectively, and the pins 39 of the outer socket 34 are engaged with other members. Turn on the switch while pressing slightly on the nut 10 toward 32,
The outer socket 34 and the inner socket 36 are rotated in opposite directions. As a result, since the outer socket 34 is not rotated by the pin 39, the inner socket 36 and the bolt 20 rotate in the tightening direction. On the other hand, the nut 10 is tightened by the male screw portion 26 until the seat surface 12 contacts the member 41 to be fastened by the frictional force with the outer socket 34, and then the nut 10 is tightened by the frictional force between the seat surface 12 and the member 41 to be fastened. Stops, and the male screw portion 26 of the bolt 20 is tightened.

When the torque between the outer socket 34 and the inner socket 36, that is, the pin tail 30 of the bolt 20 exceeds a predetermined value, the socket of the electric socket 32 is set to stop. The nut 10 can be tightened without cutting the pin tail 30. In the bolt 20 and the nut 10 tightened in this manner, the side surface 18 of the nut 10 has a truncated cone shape, and even if the side surface 18 is to be gripped with a pipe wrench 42 or the like of a general-purpose tool, the side surface 18 slides on an inclined slope. Thus, the nut 10 cannot be turned. on the other hand,
The nut 10 can be loosened or removed by reversing the pin tail 30 using the electric socket 32, which is the dedicated tool described above.

Further, the torque between the outer socket 34 and the inner socket 36, that is, the pin tail 30 of the bolt 20, is increased to a certain value or more by further tightening the nut 10 tightened with a constant torque as described above. When this occurs, the notch 28 is cut, and the tightening operation is completed as shown in FIG. The cut pin tail 30 is discharged to the outside from the inner socket 36 by the eject pin 38. After the bolt 20 and the nut 10 are tightened as described above, the nut 10 cannot be removed. That is, the bolt 20
The pin tail 30 provided at is not cut,
The side 18 of the nut 10 has a frustoconical shape and the side 1
If you try to grip 8 with a general-purpose tool such as a pipe wrench 42,
The nut 10 cannot be turned because it slips on the inclined slope.

As described above, one embodiment of the nut according to the present invention has been described in detail, but the present invention is not limited to the above embodiment.

For example, as shown in FIG.
It is also possible to form the position where the maximum outer diameter of the surface becomes the seat surface 12. The embodiment shown in FIG.
In the present embodiment, the position of the seating surface 12 is set to the maximum outer diameter, while the position where the maximum outer diameter is located near the portion. By setting the position of the maximum outer diameter on the seating surface 12 in this manner, it is possible to completely eliminate gripping the nut 10 with a pipe wrench or the like.

Further, as shown in FIG.
It is also possible to provide a disk-shaped projection 44 protruding in the radial direction in the vicinity of. The thickness of the convex portion 44 is about 1 to 5 mm
With such a degree, it is almost impossible to grip the outer periphery of the convex portion 44 with a pipe wrench, and the nut 10 cannot be loosened.

Further, as shown in FIG. 4C, the side surface 46 of the nut 10 can be formed in a hemispherical shape.
Alternatively, as shown in FIG.
It is also possible to form 6 into a drum shape as a whole and depressed. In any case, once the nut 10 is once tightened and the pin tail 30 of the bolt 20 is cut, the side surface 46 of the nut 10 cannot be loosened by grasping it with a general-purpose tool such as a pipe wrench. Cannot be loosened.

As shown in FIG. 5, it is also preferable that the planar shape of the nut 48 is formed to be an ellipse close to a circle (the drawing is exaggerated for the sake of explanation).
If the difference between the major axis and the minor axis of the ellipse is large, it can be grasped and loosened with a general-purpose tool such as a pipe wrench, while if the difference between the major axis and the minor axis is small, a general-purpose tool such as a pipe wrench can be used. Even if you can grab it, you can't rotate it. Further, by using a special tool in which the shape of the socket is formed in conformity with the shape of the nut 48, it becomes possible to retighten and loosen the nut.

Although not shown, the nut may be formed in a polygonal shape such as a triangular shape or a pentagonal shape close to a circle. Each of the shapes needs to have a shape close to a circle such that a general-purpose tool such as a pipe wrench cannot grasp and loosen the side surface of the nut. In other words, if at least one minute concave or convex portion is formed on the side of the nut, the nut cannot be loosened with a general-purpose tool, and the nut should be tightened or loosened only with a special tool. Can be.

Next, it is also possible to form one or a plurality of concave stripes extending from the upper surface 16 to the seat surface 12 on the side surfaces 18 and 46 of the various nuts 10 and 48 described above. That is, FIG.
As shown in FIG. 5, one or a plurality of ridges 54 are formed on the side surface 52 of the nut 50 having a truncated conical shape so as to be connected to the seat surface 12 from the upper surface 16. An engagement surface 56 is formed, and a slant surface 58 is formed in the loosening direction at an angle to the direction.

For the nut 50, more preferably, the torque shear type bolt described in the above embodiment is used. The nut 50 is provided on the inner surface of the outer socket 60 of the electric socket 32 corresponding to the nut 50.
And one or a plurality of projections to be engaged with the engagement surface 56 of the hologram. Therefore, the outer socket 60
Is rotated in the direction in which the nut 50 is tightened, the projection of the outer socket 60 engages with the engagement surface 56 of the nut 50, and the nut 50 rotates in the tightening direction and is tightened. Conversely, when the outer socket 60 is rotated in a direction in which the nut 50 is loosened, the projection of the outer socket 60 slides on the slope 58 of the nut 50 and acts in a direction to come off the nut 50. Therefore, when the outer socket 60 is reversed while strongly pressing the electric socket 32 against the nut 50 side, the nut 50 can be loosened.

The fastening operation using the nut 50 and the bolt 20 according to this embodiment is performed as shown in FIG.
After the shaft portion 24 of the bolt 20 is inserted into the holes formed in the members to be fastened 40, 41, the nut 50 is inserted into the male screw portion 26.
Screw. Next, the outer socket 60 and the inner socket 36 of the electric socket 32 are respectively
After the electric socket 32 is turned on, the outer socket 60 and the inner socket 36 are relatively rotated in opposite directions. As a result, usually, the outer socket 60 rotates and the nut 50 is tightened to the bolt 20, while the inner socket 36 and the pin tail 30 of the bolt 20 act as a reaction force receiver. Then, the nut 50 is tightened to the male screw portion 26 by the rotational force of the outer socket 34 until the seat surface 12 contacts the member 41 to be fastened, and then the nut 50 is tightened by the frictional force between the seat surface 12 and the member 41 to be fastened. It stops, and the male screw portion 26 of the bolt 20 is tightened.

When the torque between the outer socket 60 and the inner socket 36, that is, the pin tail 30 of the bolt 20 exceeds a preset value, the socket of the electric socket 32 is set to stop. The nut 50 can be tightened without cutting the pin tail 30. In the bolt 20 and the nut 50 tightened in this manner, the side surface 52 of the nut 50 has a truncated cone shape, and even if the side surface 52 is gripped by the pipe wrench 42 of a general-purpose tool, the side surface 52 slides on the inclined slope. , The nut 50 cannot be turned. On the other hand, by rotating the nut 50 and the pin tail 30 in the reverse direction using the electric socket 32 which is the above-described dedicated tool,
The nut 50 can be loosened or removed.

Further, the torque between the outer socket 60 and the inner socket 36, that is, the pin tail 30 of the bolt 20 is increased to a predetermined value or more by further tightening the nut 50 tightened with a constant torque as described above. When this occurs, the notch 28 is cut, and the tightening operation is completed as shown in FIG. The cut pin tail 30 is discharged to the outside from the inner socket 36 by the eject pin 38. After the bolt 20 and the nut 50 are tightened as described above, the nut 50 cannot be removed. That is, the bolt 20
The pin tail 30 provided at is not cut,
The side surface 18 of the nut 50 has a truncated cone shape,
Even if the user tries to grip the 8 with the pipe wrench 42 of a general-purpose tool, the user slips on the inclined slope and cannot turn the nut 10. The electric wrench 32, which is a special tool, cannot be used because the pin tail 30 serving as a reaction force receiving member is not cut.

Next, as shown in FIG. 9, the side surfaces 18, 46 of the various nuts 10, 48 described above are placed on the seat surface 1 from the upper surface 16.
Nut 64 formed with one or more concave streaks 62 leading to 2
Can also be configured. That is, one or a plurality of the concave streaks 62 are formed in the tightening direction and the loosening direction, and the engaging surface 66 substantially perpendicular to the direction is formed on the side surface 6 of the truncated cone-shaped nut 64.
8 will be formed. The pair of engagement surfaces 66 forming one concave streak 62 need not be parallel, and may have a slope.

Therefore, in this nut 64,
It is possible to tighten or loosen by an electric socket having a dedicated outer socket. However, it goes without saying that, depending on the pipe wrench of a general-purpose tool, it cannot be loosened or tightened as described above.

In the various nuts having a concave streak described above, the whole shape of the nut is not limited to the truncated cone shape illustrated in the drawings, but may be various shapes such as a hemisphere. Further, it is sufficient that at least one concave streak is formed. Further, the concave stripes need not be formed at symmetrical positions, but are preferably formed asymmetrically. By forming the concave strip asymmetrically, it is possible to prevent the diverting of the general-purpose tool.

Next, as shown in FIG. 10, the bolt according to the present invention has a shaft portion 72 having at least one end provided with a male screw portion 70, and a head portion 74 formed at one end of the shaft portion 72. In the bolt 76, the head 74 has a substantially circular seat surface 78 in contact with the workpiece, a substantially circular upper surface 80 facing the seat surface 78, and a rotation of a straight line or a curve connecting the seat surface 78 and the upper surface 80. The side surface 82 has a maximum diameter in the cross section of the seat surface 78 or the vicinity thereof, the diameter of the upper surface 80 is minimum, and the side surface 82 has
8 may be provided with one or more concave stripes 84. Similarly to the nut 64 described above, the bolt 76 according to this embodiment can be tightened or loosened only with a dedicated tool, and cannot be tightened or loosened with a general-purpose tool such as a pipe wrench. The bolt 76 is preferably used for railways, for example, for mounting rails.

In the bolt 76, although not shown, a recess formed on the side surface of the head is formed with an engaging surface substantially perpendicular to the tightening direction, and is formed in the loosening direction. It may be formed with a slope that is oblique to the direction.
In this configuration, the bolt can be rotated in the direction in which the bolt is tightened, even if a special tool is used,
It cannot be rotated in the loosening direction. Further, if the tool is a general-purpose tool, the bolt cannot be tightened.

Although the embodiments of the nut and the bolt according to the present invention have been described above, it goes without saying that the present invention is not limited to the illustrated embodiment. Also, in the use form of the nut, a so-called double nut can be tightened to prevent natural loosening. At this time, it can be used in combination with a conventional nut.

Further, in the bolt according to the present invention,
The present invention can be configured as a torque shear type provided with a pin tail via a notch at the end of the external thread portion, and the present invention can be variously improved, modified, and modified based on the knowledge of those skilled in the art without departing from the spirit of the present invention. The present invention can be implemented in a modified mode.

[0038]

As described above, the nut according to the present invention has a substantially circular seating surface in contact with an object to be fastened, a female screw portion formed in a direction perpendicular to the seating surface, and a substantially circular upper surface facing the seating surface. And a side surface consisting of a straight or curved rotating surface connecting the seat surface and the upper surface, the diameter of the cross section of the seat surface or the vicinity thereof being the largest, and the diameter of the upper surface being the smallest. When the nut is loosened using a general-purpose tool such as a pipe wrench, the tool slides on the side surface of the nut and cannot be loosened.

One or more minute concaves or convexes are formed on the side surface of the nut. For example, by forming the planar shape into a polygon such as an ellipse or a triangle close to a circle, it is tightened or loosened by a special tool. Work can be easily performed.

Further, by providing one or a plurality of concave stripes from the upper surface to the seat surface on the side surface of the nut, the work of tightening or loosening with a special tool can be further facilitated.

Further, in the concave streak formed on the side surface of the nut, an engaging surface substantially perpendicular to the direction is formed in the tightening direction, and an inclined surface oblique to the direction is formed in the loosening direction. Thus, even if the nut can be tightened, it cannot be loosened.

Next, the head of the bolt according to the present invention is composed of a rotating body like the above-mentioned nut, and further has one or a plurality of concave stripes extending from the upper surface to the seat surface on the side surface. The work of tightening or loosening the bolts can be performed only by the special tool.

Also, the concave streak formed on the head of the bolt has an engaging surface substantially perpendicular to the direction in the tightening direction, and an inclined surface oblique to the direction in the loosening direction. With this configuration, even if the bolt can be tightened by a special tool, it cannot be loosened.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a nut according to the present invention, wherein FIG. 1 (a) is a fragmentary front view and FIG. 1 (b) is a plan view.

FIG. 2 is an explanatory sectional view for explaining a method of tightening the nut shown in FIG. 1;

3 is an explanatory side view showing a state where a non-fastening member is tightened using the nut shown in FIG. 1;

FIGS. 4 (a) to 4 (d) are fragmentary front views of another embodiment of a nut according to the present invention.

FIG. 5 is a plan view showing still another embodiment of the nut according to the present invention.

FIG. 6 is a view showing still another embodiment of the nut according to the present invention, and FIG. 6 (a) is a fragmentary front view of a main part, and FIG.
Is a plan view.

FIG. 7 is an explanatory sectional view for explaining a method of tightening the nut shown in FIG. 6;

8 is an explanatory side view showing a state where a non-fastening member is tightened using the nut shown in FIG. 6;

FIG. 9 is a view showing still another embodiment of the nut according to the present invention, and FIG. 9 (a) is a fragmentary front view of a main part, and FIG.
Is a plan view.

FIG. 10 is a view showing one embodiment of a bolt according to the present invention, wherein FIG. 10 (a) is a plan view and FIG. 10 (b) is a fragmentary front view of a main part.

[Explanation of symbols]

 10, 48, 50, 64: Nut 12, 78: Seat 14: Female thread 16, 80: Top 18, 46, 52, 68, 82: Side 20, 76: Bolt 22, 74: Head 24, 72: Shafts 26, 70: Male thread 28: Groove (notch) 30: Pin tail 32: Electric socket 34, 60: Outer socket 36: Inner socket 40, 41: Fastened member 42: Pipe wrench 54, 62, 84: Concave strip 56, 66: engagement surface 58: slope

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsuomi Hara 4-1-1-21 Kitahama, Chuo-ku, Osaka-shi, Osaka Prefecture Inside Sumikin Seimitsu Kogyo Co., Ltd. (72) Inventor Shigeru Maeda 4 Kitahama, Chuo-ku, Osaka-shi, Osaka No. 1-21, Sumitomo Sumikin Seimitsu Kogyo Co., Ltd. (72) Inventor Bunkazu Akamine 1-13-8 Yakuin, Chuo-ku, Fukuoka City, Fukuoka Prefecture Inside Nishi Nippon Electric Iron Works Co., Ltd. 1020-1 Todorokicho, Nishi-Nippon Electric Iron Works, Ltd. (72) Inventor Masamichi Soeda Kyushu Hard Rock Industry Co., Ltd. 2-5-2-1, Harunomachi, Yawatahigashi-ku, Kitakyushu-shi, Fukuoka

Claims (6)

[Claims] 1. A substantially circular bearing surface for contacting an object to be fastened,
A female screw portion formed in a direction perpendicular to the seating surface, a substantially circular upper surface facing the seating surface, and a side surface comprising a linear or curved rotating surface connecting the seating surface and the upper surface; A nut characterized in that the diameter of the cross section of the surface or the vicinity thereof has a maximum and the diameter of the upper surface has a minimum. 2. The nut according to claim 1, wherein one or more minute concaves or convexes are formed on the side surface. 3. The nut according to claim 1, wherein the side surface has one or a plurality of concave stripes connected from the upper surface to the seat surface. 4. The concave streak according to claim 1, wherein an engaging surface substantially perpendicular to said direction is formed in a tightening direction, and a slant surface oblique to said direction is formed in a loosening direction. 3. The nut described in 3. 5. A substantially circular seat having a shaft having at least one end provided with a male thread and a head having a head formed at one end of the shaft, wherein the head is in contact with an object to be fastened. And a female screw portion formed in a direction perpendicular to the seat surface,
A substantially circular upper surface facing the seat surface, a side surface comprising a linear or curved rotating surface connecting the seat surface and the upper surface is provided, and a diameter of a cross section of the seat surface or the vicinity thereof is the largest, A bolt having a minimum diameter of an upper surface, and having one or more concave stripes on the side surface from the upper surface to the seat surface. 6. The concave streak according to claim 1, wherein an engaging surface substantially perpendicular to the direction is formed in the tightening direction, and a slant surface oblique to the direction is formed in the loosening direction. 5. The bolt described in 5.