JPH11270529A - Special bolt, special nut, fastening device, and connecting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out rotation by only a special tool. SOLUTION: In a special bolt 10, a screw groove is arranged on one end part of a shaft part 11, and a trancated conical head part 12 whose outer diameter is formed in a shape gradually smaller toward a tip end side apart from the shaft part 11 is formed concentrically with the shaft part 11 on the other end part of the shaft part 11. An engaging recessed part 12a of a cross section pentangular shape whose respective comer parts 12c are composed in a circular arc shape is arranged in a condition opened to a tip end surface of the head part 12. A truncated cone shaped projection part 12e whose outer diameter is formed in a shape gradually smaller toward a tip end side is arranged in the engaging recessed part 12a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the connection of steel materials,
Special bolts and nuts that are used to connect steel pipes and are rotated only by special tools, fastening devices composed of these special bolts and special nuts, and connections using special bolts and special nuts Regarding the structure.

[0002]

2. Description of the Related Art Generally, a hexagonal bolt having a hexagonal column-shaped head and a hexagonal column-shaped hexagonal nut are used as bolts and nuts constituting a fastening device used for connecting steel materials or steel pipes. . Such a hexagon bolt and a hexagon nut are respectively rotated by a general tool such as a spanner and a wrench, and are mutually tightened by being rotated by a general tool.

[0003]

When steel materials are connected by means of a hexagon bolt and a hexagon nut, the head of the hexagon bolt or the hexagon nut is exposed to the outside so that it is rotated by a tool such as a spanner. It is necessary to be in a state. Therefore, the head portion of the hexagon bolt or the hexagon nut is exposed to the outside at the connection portion between the steel materials.

When the head of the hexagon bolt or the hexagon nut is exposed as described above, if the third party easily approaches the connection portion, the third party may use a wrench or the like. There is a possibility that the head of the hexagon bolt or the hexagon nut is easily rotated by a general tool, and the fastening state of the hexagon bolt and the hexagon nut is loosened. In particular, when steel materials forming towers, bridges, etc. are fastened with hexagon bolts and hexagon nuts, if the fastening state is loosened by a third party, there is a risk of a major accident such as collapse of the tower, bridge, etc. There is.

The present invention has been made to solve such a problem, and its purpose is to make it impossible to rotate easily with a commonly used general tool, and therefore to rotate easily with a third party. Another object of the present invention is to provide a special bolt and a special nut which are not likely to be damaged, and a fastening device constituted by the special bolt and the special nut. Another object of the present invention is to provide a connection structure in which the connection state of steel materials and the like is not easily canceled by a third party when steel materials and the like are connected by bolts and nuts rotated by a general tool. It is in.

[0006]

According to a first aspect of the present invention, there is provided a special bolt according to the first aspect of the present invention, wherein one end of the special bolt is provided with a thread groove at an end opposite to the shaft. A frustoconical head whose outer diameter is gradually reduced toward the side is provided concentrically with the shaft portion, and the front end portion of this head has a circular cross section with a corner portion formed in an arc shape. A pentagonal engaging recess is provided in an open state on the distal end surface of the head, and a frustoconical projection having an outer diameter that gradually decreases toward the distal end is provided in the engaging concave portion. It is characterized by having.

The special nut according to the present invention has a truncated cone shape whose outer diameter decreases gradually toward the distal end, and has a thread groove on an inner peripheral surface at an axial center portion excluding a distal end portion. Is formed, and an engaging hole portion having a regular pentagonal cross section in which a corner portion is formed in an arc shape is formed at a distal end portion continuous with the female screw portion, and the female screw portion is formed. It is characterized by being provided concentrically.

The special nut according to the third aspect has a cylindrical shape having a constant outer diameter, and has a female screw portion having a thread groove formed on an inner peripheral surface except for one end portion. An engaging hole having a regular pentagonal cross section and a corner formed in an arc shape is provided concentrically with the female screw at an end portion continuous with the female screw.

According to a fourth aspect of the present invention, there is provided a fastening device, wherein the threaded portion of the shaft portion of the special bolt according to the first aspect is provided with a female threaded portion of the special nut according to the second or third aspect of the present invention. The special bolt is screw-coupled to the distal end of the shaft.

According to a fourth aspect of the present invention, a pair of members are connected to each other by a fastening device including a bolt and a nut, and a cover member for covering the head of the bolt in the fastening device is a special tool. Are fastened to mutually connected members by a fastening device constituted by a special bolt rotated only by a special tool and a special nut rotated only by a special tool.

In the connecting structure according to a fifth aspect, the special bolt is the special bolt according to the first aspect, and the special nut is the special nut according to the second or third aspect.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1A is a side view showing an embodiment of a fastening device according to the present invention constituted by a special bolt and a special nut according to the present invention, and FIG. 1B is a partially broken front view thereof. It is. The fastening device 30 has a special bolt 10 rotated only by a special tool and a special nut 20 rotated only by a special tool.

The special bolt 10 has a shaft portion 1 extending linearly.
1 is provided with a head 12 at one end. A screw groove 11a is provided at a far end of the head portion 12 of the shaft portion 11, and a special nut 20 is screw-connected to the screw groove 11a.

The head 12 of the special bolt 10 has a truncated conical shape arranged concentrically with the shaft 11,
The outer diameter gradually decreases toward the distal end face away from 1. The continuous portion of the base end surface and the outer peripheral surface of the head 12 that is continuous with the shaft portion 11 is formed in an arc shape.

An engagement recess 12a is formed in the distal end portion of the head 12 and is open at the distal end surface. This engagement recess 1
Reference numeral 2 a denotes a pentagonal cross section which is concentric with the outer peripheral surface of the head 12, and the bottom surface 12 b is a flat surface orthogonal to the axis of the shaft 11. Each corner 12c of the engaging recess 12a is formed in an arc shape. The inner surface 12d between the adjacent corners 12c is formed in an arc shape slightly bulging outward.

A bottom surface 12b is provided at the axial center of the engagement recess 12a.
A protruding portion 12e in the shape of a truncated cone protruding so that the outer diameter gradually decreases from the top to the tip side is provided concentrically with the bottom surface 12b. The tip surface of the projection 12e is
It is located on the same plane as the tip surface of the head 12a.

FIG. 2A is a partially cutaway front view of the special nut 20, and FIG. 2B is a side view thereof. The special nut 20 has a truncated cone shape whose outer diameter decreases gradually toward the distal end, and has a screw thread on its inner peripheral surface except for the distal end whose outer diameter decreases. The female screw portion 21 provided with the groove is provided concentrically with the outer peripheral surface. In addition, a female screw 21
And an engagement hole 22 having a diameter larger than that of the female screw portion 21 penetrates. The engaging hole 22 has a regular pentagonal cross section, and each of the corner portions 22a has an arc shape. The inner side surface 22b between the adjacent corner portions 22a is formed in an arc shape slightly bulging outward.

The special nut 20 is screwed into the thread groove 11a in the shaft 11 of the special bolt 10 so that the front end of the special nut 10 having the reduced outer diameter is located on the front end side of the shaft 11 of the special nut 10. Be combined.

The special bolt 10 is provided in the engagement recess 1 of the head 12.
The special nut 20 is rotated by a special tool fitted in an aligned state, and the special nut 20 is also rotated by a special tool fitted in the engagement hole 22 in an aligned state.

FIG. 3A is a longitudinal sectional view of a special tool 60 for rotating the special bolt 10 and the special nut 20, and FIG.
(B) is a side view thereof. The special tool 60 has a hexagonal prism-shaped tool main body 61 and a head 62 provided at one end of the tool main body 61.

The head portion 62 is a head 1 of the special bolt 10.
2 has a regular pentagonal column shape having an outer peripheral surface aligned with the inner peripheral surface of the engaging concave portion 12a, and has, at its axial center, an inner diameter capable of fitting to the projection 12e of the head 12 of the special bolt 10. Is provided. The through hole 63 has a constant inner diameter over the entire length of the special tool 60, and the tool main body 61 also passes through the shaft center.

The head 12 of the special bolt 10 has a truncated conical shape with a smaller diameter as it approaches the tip.
Even when a normal tool such as a wrench or a spanner is engaged, the tool is easily disengaged toward the distal end without engaging with the head 12. Similarly, since the special nut 20 is screwed to the special bolt 10 such that the small-diameter distal end surface of the truncated cone is located on the distal end side of the special bolt 10, a special wrench, a spanner, etc. When the tool is engaged with the special nut 20, the tool is easily pulled out to the tip side of the special bolt 10 without engaging with the special nut 20.

Therefore, in the fastening device 30 constituted by the special bolt 10 and the special nut 20, the special bolt 10 and the special nut 20 are not rotated by commercially available tools such as a wrench, a spanner, and a chain wrench. And a special bolt 10 and a special nut 20
There is no danger that the fastening state can be loosened by a third party who does not have the special tool 60 that can rotate each of them.

Such special bolts 10 and special nuts 20 can be used in place of commonly used hexagon bolts and hexagon nuts, respectively. In addition, since a normal hexagon nut is screwed into the screw groove 11a of the special bolt 10, for example, the special bolt 10 is used instead of the hexagon bolt for the embedded hexagon nut. You may. In this case, since the hexagon nut is in a state of being embedded, the hexagon nut cannot be rotated by engaging with a normal tool, and the head 12 of the special bolt 10 cannot be rotated. Special tool 60
Therefore, a third party who does not have the six special tools cannot remove the special bolt 10.

Similarly, the special nut 20 may be screwed to the hexagonal bolt with the head embedded. Also in this case, a third party who does not have the special tool 60 cannot remove the special nut 20. Further, the special nut 20 may be screw-coupled to the hexagon bolt after the hexagon nut is screw-coupled to the hexagon bolt. In this case, a third party who does not have the special tool 60 cannot remove the special nut 20, and therefore cannot remove the hexagon nut.

When the special nut 20 is further screwed to the special bolt 10 or the hexagon nut screwed to the hexagon bolt, a cylindrical sleeve is provided so that the hexagon nut is not rotated by a normal tool such as a spanner. In the fitted state, the special nut 20 may be screw-connected to the bolt.

FIG. 4 is a partially cutaway front view showing another example of the special nut. This special nut 20 is
A cylindrical skirt portion 23 is provided integrally with the female screw portion 21 at an end on the far side of the engagement hole portion 22 in FIG.
In such a special nut 20, if the special nut 20 is screw-coupled to a hexagon nut screwed to a bolt, and if the skirt portion 23 covers the hexagon nut, the hexagon nut itself is used. Cannot be rotated by a normal tool.

The special nut 20 does not need to have a truncated conical shape, and may be, for example, a cylindrical shape having a constant outer diameter as shown in FIG. Also in this case, a female screw portion 21 is provided on the inner peripheral surface except for one end portion of the special nut, and the female screw portion 21 is concentric with the female screw portion 21 at one end portion. An engagement hole portion 22 having a larger diameter than that is provided. The engaging hole 22 has a regular pentagonal cross section, and each of the corners has an arc shape. The inner side surface between the adjacent corner portions is formed in an arc shape slightly bulging outward.

As shown in FIG. 5, such a special nut 20 is prevented from being loosened by rotating the hexagon nut 52 in a fastening device in which a hexagon nut 52 is screwed to a normal hexagon bolt 51. Used to In this case, the cylindrical special nut protection sleeve 56 is attached to the hexagon nut 52 with the cylindrical hexagon nut protection sleeve 55 fitted thereto.
Is fitted to. The special nut protection sleeve 56 has an inner diameter such that the special nut 20 is fitted therein, and has a bottom surface provided with a through hole at the lower end surface thereof. Then, the bottom surface of the special nut protection sleeve 56 is brought into contact with the upper end surface of the hexagon nut protection sleeve 55, and the hex bolt is inserted so that the special nut 20 is fitted into the special bolt protection sleeve 56. The special nut 20 is screwed to 51.

As a result, the special nut 20 is engaged with the special nut protective sleeve 56, and the special nut 20 has a constant outer diameter by a usual tool such as a spanner. There is no risk of rotation.
The hexagon nut 52 is also provided with a hexagon nut protection sleeve 55.
Since it is fitted inside, there is no possibility of being rotated by a normal tool such as a spanner. The hexagon nut protection sleeve 55 is a special nut 2 screwed to the hexagon bolt 51.
The hexagon nut protection sleeve 55 is secured by the special nut protection sleeve 56
There is no risk of being removed.

As described above, the special bolt 10 and the special nut 20 of the present invention can be used in the existing connection structure using the hexagon bolt and the hexagon nut, in place of either the hexagon bolt or the hexagon nut. With a short time and simple operation, it is possible to prevent a third party from removing bolts and nuts in existing equipment.

FIG. 6A is a perspective view showing a connection structure of angle irons utilizing the property that the special bolt 10 and the special nut 20 in the fastening device 30 shown in FIG. FIG. 6 (b)
FIG. In this connection structure, as shown in FIG. 6C, a pair of long plate-shaped side plates 41 are integrated with each other in a state where they are abutted with each other so as to form a right-angled corner portion 42. The ends of the steel 40 are overlapped with each other. Each angle iron 40 is overlapped with a corner of the other angle iron 40 fitted in a corner 42 of one angle iron 40.

A plurality of through-holes 43 having the same inner diameter are provided in each of the mutually overlapping side plate portions 41 at each end of each angle iron 40. Each side plate 41 has four through holes 43 along one side edge,
Three through-holes 43 along the other side edge are respectively provided along the longitudinal direction. The angle irons 40 are mutually overlapped so that the through holes 43 provided in the respective side plates 41 are aligned with each other.

The other through-holes 43 except for the two through-holes 43 located on both sides of the four through-holes 43 arranged along the far side edge of the corner 42 of each side plate 41 are usually provided. Hexagonal bolts 51 are respectively inserted.
Each hexagonal bolt 51 is inserted so that the head 51a comes into contact with each side plate 41 of the angle steel 40 stacked on the inside, and the hexagonal bolt 51 is aligned with each side plate 41 of the angle steel 40 stacked on the outside. Each through hole 43 is inserted. Then, a normal hexagon nut 5 is attached to the tip of each hexagon bolt 51 through which each side plate 41 of the angle iron 40 stacked on the outside is inserted.
2 (see FIG. 5B) are screw-connected.
Thereby, the mutually overlapped ends of each angle iron 40 are mutually connected.

The angle iron 40 superposed on the inner side has the shape shown in FIG.
As shown in (a) and (b), a cover member 5 made of an angle steel having a cross section similar to that of the angle iron 40 is provided.
3 are fitted. The cover member 53 has a length substantially equal to the length of each end of the angle irons 40 overlapped with each other, and all the hexagons connecting the angle irons 40 overlapped with each other by the cover member 53. Head 51a of bolt 51
Is covered.

The cover member 53 does not have the hexagonal bolts 51 of the angle iron 40 stacked inside inserted therein.
Four elongated holes 53a extending in the horizontal direction are provided so as to face the two through holes 43.

As shown in FIGS. 6A and 6B, the special bolts 10 shown in FIG. 1 are inserted into the respective through holes 53a of the cover member 53 from the inside of the cover member 53. The head 12 is in contact with the cover member 53. The shaft portions 11 of the special bolts 10 are inserted through the aligned through holes 43 of the angle steels 40 overlapped with each other, and the thread grooves 11a of the shaft portions 11 protruding from the outer angle steels 40. Are screwed with special nuts 20, respectively.

In such an angle steel connection structure, the cover member 53 is screwed to the four special bolts 10 rotated only by the special tool 60 and each of the special bolts 10, and each of the special bolts 10 is Only rotated 4
Is attached to the angle irons 40 which are overlapped with each other by the two special nuts 20, so that the cover member 53
Can be removed only by an operator having a special tool 60 capable of rotating each special bolt 10 and each special nut 20.

The cover member 53 is provided with a head 51a of a hexagonal bolt 51 connecting the angle irons 40 stacked one on another.
In the state where the cover member 53 is not removed, the head 51a of each hexagon bolt 51 cannot be rotated by engaging a tool such as a normal wrench with the head member 51a. Neither can the 51 be removed from each of the aligned through holes 43 in the angle irons 40 stacked one on top of the other. A hexagon nut 52 screwed to each hexagon bolt 51 is attached to each side plate portion 4 of the angle iron 40 superposed on the outside.
Since it is exposed along 1, it can be rotated with a normal wrench or the like. Therefore, although it is possible for a third party to remove each hex nut 52, each hex bolt 51 from which each hex nut 52 has been removed can be used.
Since the head portion 51a is covered by the cover member 53, the head portion 51a cannot be removed from the through hole 43 of the angle iron 40. As a result, each hexagon bolt 51
The connected state of the ends of the angle irons 40 overlapped with each other is maintained.

As described above, the special tool 6 capable of rotating the special bolt 10 and the special nut 20 respectively.
0 only, special bolt 10 and special nut 20
It is not easy to remove the cover member 53 since the fastening state of
It is not easy to release the connection between them.

In such a connection structure, in an existing facility in which the angle irons 40 are mutually connected by a plurality of hexagon bolts and hexagon nuts, four hexagon bolts and hexagon nuts at predetermined positions are replaced with special bolts 10. In addition, since it is only necessary to attach the cover member 53 instead of the special nut 20, it is possible to easily prevent a third party from removing the nut and the bolt in the existing equipment.

In the connection structure shown in FIG. 6, the special bolt 10 and the special nut 20 shown in FIGS. 1 and 2 are used.
The special bolt and the special nut that are rotated only by the special tool 60 are not limited to the zero and the special nut 20.

Further, in such a connection structure, in order to prevent the exposed hexagon nut 52 from being removed from the hexagon bolt 51, the skirt 23 shown in FIG.
May be screwed to the tip of the hexagonal bolt 51, respectively, and each hexagonal nut 51 may be covered with the skirt 23 of the special bolt 20. Thus, the skirt portion 2 of each special bolt 20
When each of the hexagon nuts 52 is covered by 3, the hexagon nuts 52 cannot be removed with a normal tool. Further, as shown in FIG. 5, a column-shaped special nut 20, a special nut protection sleeve 56 and a hexagon nut protection sleeve 55 may be used.

[0045]

Since the special bolt and the special nut of the present invention are each rotated only by a special tool, there is no possibility of rotation by a third party who does not have the special tool. Therefore, the fastening device constituted by one or both of the special bolt and the special nut is not likely to be easily released by a third party.

Further, in the connection structure of the present invention, the heads of the bolts connecting the members are covered by the cover member attached by the special bolt and the special nut which are respectively rotated only by the special tools. A third party who does not have a special tool cannot easily cancel the fastening state between members by bolts.

[Brief description of the drawings]

1A is a side view showing an example of an embodiment of a fastening device of the present invention using a special bolt of the present invention and a special nut of the present invention, and FIG. 1B is a partially cutaway front view thereof. It is.

FIG. 2 (a) is a partially cutaway front view of a special nut 20 of the present invention used in the fastening device, and FIG. 2 (b) is a side view thereof.

3A is a partially cutaway front view showing an example of a special tool capable of rotating a special bolt and a special nut of the present invention, and FIG. 3B is a side view thereof.

FIG. 4 is a partially cutaway front view showing another example of the special nut of the present invention.

FIG. 5 is a perspective view showing a use state of still another example of the special nut of the present invention.

6 (a) is a perspective view showing an example of an embodiment of a connecting structure of the present invention, FIG. 6 (b) is a cross-sectional view thereof, and FIG.
It is a perspective view in the state where the cover member in the connection structure was removed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Special bolt 11 Shaft part 11a Screw groove 12 Head 12a Engaging concave part 12b Bottom surface 12c Corner part 12d Inner side surface 12e Projection part 20 Special nut 21 Female screw part 22 Engaging hole part 22a Corner part 22b Inner side surface 23 Skirt part 30 Fastening Device 40 Angle iron 51 Hex bolt 52 Hex nut 60 Special tool

Claims (6)

[Claims] 1. A truncated cone-shaped head having an outer diameter gradually decreasing toward an end farther away from the shaft at an end opposite to the shaft having a thread groove at one end. Is provided concentrically with the shaft, and at the tip side of this head,
An engaging recess having a regular pentagonal cross section in which each corner is formed in an arc shape is provided in an open state on the distal end surface of the head, and the outer diameter is sequentially increased in the engaging recess toward the distal end. A special bolt having a reduced truncated cone-shaped projection. 2. A female thread portion having a frusto-conical shape whose outer diameter is gradually reduced toward the distal end, and having a thread groove formed on an inner peripheral surface at an axial center portion excluding the distal end portion. While being formed, in the tip side part which is continuous with this female screw part,
A special nut, characterized in that an engaging hole having a regular pentagonal cross section and a corner portion formed in an arc shape is provided concentrically with a female screw portion. 3. A female screw portion having a cylindrical shape with a constant outer diameter and having a thread groove formed on an inner peripheral surface excluding one end portion, and an end continuous with the female screw portion. A special nut, characterized in that an engaging hole having a regular pentagonal cross section and a corner portion formed in an arc shape is provided concentrically with the female screw portion. 4. The special screw according to claim 1, wherein the screw groove of the shaft portion has a female screw portion of the special nut according to claim 2 or 3, wherein the engagement hole portion is a tip end of the shaft portion of the special bolt. A fastening device characterized by being screw-connected. 5. A pair of members are mutually connected by a fastening device constituted by bolts and nuts,
The cover member covering the head of the bolt in the fastening device is fastened to the interconnected members by a fastening device constituted by a special bolt rotated only by the special tool and a special nut rotated only by the special tool. Connection structure characterized by being made. 6. The connecting structure according to claim 4, wherein the special bolt is the special bolt according to claim 1, and the special nut is the special nut according to claim 2 or 3.