JP2000329127A - Removal preventing device for fixed nut and mounting jig exclusively used for the fixed nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removal preventing device being a device to prevent the occurrence of removal of a bolt and nut, used in a structure, such as an iron tower and a bridge, by a malicious outsider and a collapse accident, and especially for a fixed nut where a bolt, like an anchor bolt, fixed to a support member and which is used for fastening by threadedly engaging with the screw shaft part of a bolt. SOLUTION: This device comprises a fixing nut 11 on the outer peripheral surface of which a male screw part 14 is situated and having an end part on the fastening side on which a flange part 15 is mounted, and a cylindrical cover 12 covering a fixed nut 11 and covering the whole of the fixing nut 11 with a given gap S therebetween and provided at the inside with a lock stepped part 18 engaged with the flange part 15. When the fixing nut 11 is inserted in the gap S and fastened by a mounting jig for exclusive use threadedly engaged with the male screw part 14, the cylindrical cover 12 is locked and held in a moving state between the fixing nut 11 and a member 2 to be fastened through the lock stepped part 18 engaged with the flange part 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing the removal of a fixing nut suitable for use in assembling structures such as power transmission towers, bridges, and the like, and to a dedicated fixing jig for the fixing nut.

[0002]

2. Description of the Related Art Bolts and nuts used for structures such as steel towers and bridges are removed by malicious outsiders.
In order to prevent a collapse accident from occurring, various types of bolt / nut removal prevention devices that cannot be removed with a normal rotating tool such as a commercially-available spanner have been proposed. Generally, the bolts and nuts fastened are often covered with a cylindrical cover (for example, see Japanese Utility Model Registration No. 3053700).

[0003]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of preventing accidents as described above. In particular, a bolt such as an anchor bolt is fixed to a supporting member, and a screw shaft portion of the bolt is screwed. An object of the present invention is to provide a device for preventing a fixing nut from being used for fastening together and a dedicated mounting jig for the fixing nut.

[0004]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a method for screwing a member to be fastened to a support member, such as an anchor bolt, by fastening the member to be fastened to the support member. A device for preventing removal of a fixing nut to be fixed, wherein an external thread portion is provided on an outer peripheral surface,
A fixing nut provided with a flange portion at an end on a tightening side, and fitted on the fixing nut, covering the whole of the fixing nut with a predetermined gap on the outer periphery, and engaging with the flange portion on the inside When the fixing nut is tightened by a dedicated mounting jig that is inserted into the gap and screwed into the male screw portion, the cylindrical cover is It is characterized in that it is configured to be movably locked and held between the fixed nut and the member to be fastened via the locking step that engages with the flange portion. Therefore, the fixing nut cannot be removed by inserting a normal rotating tool such as a wrench into the gap between the fixing nut and the cylindrical cover.

[0005] In the exclusive mounting jig according to the present invention, a screw hole that is screwed into the male screw portion of the fixed nut is provided through an inner peripheral surface of a cylindrical body that can be inserted into the gap. This is a cylindrical jig provided with an engaging portion of a rotary tool on an outer periphery of an end portion of a cylindrical body.

[0006] Further, the exclusive mounting jig according to the present invention includes:
2. A receiving hole in which the screw shaft of the mounting bolt according to claim 1 is loosely fitted at a tip end of the cylindrical jig and a screw shaft having a male screw screwed into the screw hole of the cylindrical jig. And a holding screw jig provided with a head for engaging a rotary tool at a rear end portion of the screw shaft portion, and when attaching the fixing nut, the cylindrical jig is In a state where a gap is provided between the male screw portion of the fixing nut and the flange portion, the screw shaft portion of the holding screw jig is screwed into the cylindrical jig, and the screw shaft portion In a state where the distal end portion is pressed against the upper end surface of the fixing nut, the fixing nut is further rotated by rotating the holding screw jig in a tightening direction, and after the tightening is completed, the holding screw jig is loosened. By rotating in the direction, the cylindrical jig is removed without rotating with the fixing nut. It is configured to be.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of use in which a member to be fastened 2 is mounted and fixed to a support member 1 using a device 10 for preventing the removal of a fixing nut according to the present invention. The mounting bolt 3 has its screw shaft portion 4 penetrating the support member 1 and is fixed to the support member 1 in a non-removable state by welding 5 or other appropriate fixing means.

The detachment preventing device 10 includes a specially shaped fixing nut 11, a cylindrical cover 12 which is fitted on the fixing nut 11, and which covers the whole of the fixing nut 11 with a predetermined gap (S) on its outer periphery. It is composed of

As shown in FIG. 2, a fixing nut 11 is provided on an outer peripheral surface of a cylindrical nut body 13 with a male screw portion 14.
, A flange portion 15 is provided at an end of the nut body 13 on the tightening side, and a guide cylindrical portion 16 having a height A is provided below the flange portion 15. On the other hand, as shown in FIG. 3, the cylindrical cover 12 is formed along the inner peripheral surface of the lower end portion of the cylindrical body 17 having an inner diameter slightly larger than the outer diameter of the flange portion 15 of the fixing nut 11. An annular locking step 18 that is locked to the lower side of 15 is provided. The inner diameter of the locking step 18 is slightly larger than the outer diameter of the guide cylinder 16 of the fixed nut 11, and the height B is formed slightly lower than the height A of the guide cylinder 16.

When the cylindrical cover 12 is fitted to the fixing nut 11 having the above structure from the side of the guide cylindrical portion 16 at the lower end, as shown in FIG. Are fitted into the cylindrical body 17 of the cylindrical cover 12 so as to be rotatable and slidable in the axial direction, and the entire fixing nut 11 is covered with the cylindrical cover 12. A predetermined gap (S) is secured between the cylindrical cover 12 and the peripheral surface, and the locking step 18 of the cylindrical cover 12 is locked below the flange 15. The fixing nut 11 to which the cylindrical cover 12 is fitted is attached to the screw shaft 4 of the mounting bolt 3.
And a fixing jig 2 for the fixing nut 11 to be described later.
0 (see FIG. 4), the fixing nut 11
The member 2 to be fastened is supported by the support member 1 at the lower end surface of the guide cylindrical portion 16 of FIG.
Can be tightened and fixed. At this time, the height B of the locking step portion 18 of the cylindrical cover 12 is the height A of the guide cylindrical portion 16.
Since the height is slightly lower, a gap C is generated between the two and the cylindrical body 17 is rotatable and slidable with respect to the flange portion 15. 11 is locked and held in a movable state. Therefore, even if an outsider moves the cylindrical cover 12 in the tightened state of the fixing nut 11, the fixing nut 1
1 cannot be removed, and a rotating tool (not shown) such as a spanner is inserted through the gap (S) to fix the fixing nut 1
1 cannot be removed.

FIGS. 4 and 5 show the fixing nut 11 described above.
FIG. 2 shows a dedicated mounting jig 20 used for mounting the fixing nut 11 of the detachment prevention device 10 composed of a cylindrical cover 12. The exclusive mounting jig 20 is composed of a thin cylindrical body 21 that can be inserted into the gap (S) and an engaging portion 22 of a rotary tool connected to the cylindrical body 21, and penetrates the entirety of the fixing nut 20. Screw hole 23 screwed into outer peripheral male screw portion 14 of 11
Is a cylindrical jig provided. The engaging portion 22 of the cylindrical jig (dedicated mounting jig) 20 is formed in a hexagonal shape in the illustrated example, but is rectangular and other cylindrical tools are engaged to rotate the cylindrical jig 20. Any shape may be used as long as it can be formed.

FIG. 4 shows a state in which the fixing nut 11 is tightened by using the cylindrical jig 20. The cylindrical body 21 of the cylindrical jig 20 is inserted from the gap (S) to fix the screw hole 23. After screwing into the male screw portion 14 of the nut 11 and screwing it until the end face 21 a of the cylindrical body 21 contacts the flange portion 15,
A rotary tool such as a wrench is engaged with the engaging portion 22 so that the cylindrical jig 2
When 0 is rotated, the cylindrical jig 20 and the fixing nut 11 rotate integrally, and the fixing nut 11 is tightened. When the tightening is completed, the cylindrical jig 20 is rotated in a loosening direction and removed from the fixed nut 11 to be in the tightened state shown in FIG.

In order to prevent the fixing nut 11 from rotating together when the cylindrical jig 20 is rotated and removed in the loosening direction, a special mounting jig 30 shown in FIG. 6 is used. preferable.

FIG. 6 shows a state in which the fixing nut 11 is tightened using the special mounting jig 30. The dedicated mounting jig 30 includes the above-described cylindrical jig 20 and a holding screw jig 25 to be assembled to the cylindrical jig 20. The holding screw jig 25 is the male thread 1 of the fixing nut 11.
4 has a screw shaft portion 26 having the same diameter as that of the screw shaft portion 4, and a receiving hole 27 extending in the axial direction from the distal end surface of the screw shaft portion 26 is provided.
The receiving hole 27 has an inner diameter that is slightly larger than the outer diameter of the screw shaft portion 4 of the mounting bolt 3 and is formed at a depth sufficient to receive the screw shaft portion 4 in a loosely fitted state.

When mounting the fixing nut 11 using the above-mentioned dedicated mounting jig 30, first, the screw hole 23 of the cylindrical jig 20 is screwed into the male screw portion 14 of the fixing nut 11, and the cylindrical jig 20 End surface 21a of cylindrical body 21 and flange portion 15
With a constant gap E provided between
5 is screwed into the screw hole 23 of the cylindrical jig 20, and the front end surface 26 a of the screw shaft portion 26 is assembled in a state of being in contact with the upper end surface of the fixing nut 11. In this assembled state, the fixing nut 11 is screwed into the screw shaft portion 4 of the mounting bolt 3, and the fixing nut 11 is tightened by rotating the holding screw jig 25 in the tightening direction.
Fixed to. Next, after the fastening of the fixing nut 11 is completed, when the presser screw jig 25 is rotated in the loosening direction, the pressing force against the fixing nut 11 is released, and the cylindrical jig 20 is also pulled to the loosening side. Therefore, the cylindrical jig 20 can be easily removed without rotating together with the fixing nut 11.

Further, as means for preventing the fixing nut 11 from rotating together when the cylindrical jig 20 is removed, the male screw part 14 of the fixing nut 11 and the cylindrical jig 20 screwed to the male screw part 14 are used. It is conceivable that the lead angle of the screw thread of the screw hole 23 is larger than the lead angle of the screw thread of the screw hole 13a of the fixing nut 11. Thus, the male screw portion 14
When the lead angle of the screw thread of the screw hole 23 is increased, the frictional resistance of the screw thread is smaller than the frictional resistance of the screw thread of the screw hole 13a of the fixing nut 11, so that the fixing nut 11 does not rotate together with the cylindrical shape. The jig (dedicated mounting jig) 20 can be easily removed.

FIG. 7 shows another embodiment of the fixing nut removal preventing device 10 according to the present invention. The example is
An example in which a detachment preventing device 10 according to the present invention is further applied to an anchor bolt 3 ′ embedded and fixed in a concrete frame 6, to which a normal double nut 8, 8 is screwed and a member to be fastened 2 is attached and fixed. ing. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

[0019]

As described above, the fixing nut removal preventing device of the present invention cannot remove the fixing nut with a normal rotating tool, and effectively prevents the removal by a malicious outsider. Can be.

Further, the use of the dedicated mounting jig according to the present invention makes it possible to easily and reliably mount the fixing nut.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a use state of a fixing nut removal prevention device according to the present invention.

FIG. 2 is a perspective view of the fixing nut.

FIG. 3 is a sectional perspective view of the tubular cover.

FIG. 4 is a vertical sectional front view showing a use state of a dedicated mounting jig used for mounting the fixing nut.

FIG. 5 is a plan view of the exclusive mounting jig.

FIG. 6 is a longitudinal sectional front view showing a use state of another dedicated mounting jig used for mounting the fixing nut.

FIG. 7 is a vertical sectional front view showing another embodiment of the fixing nut removal preventing device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support member 2 Member to be fastened 3 Mounting bolt 3 'Anchor bolt 4 Screw shaft part 10 Removal prevention device 11 Fixed nut 12 Cylindrical cover 13 Nut main body 14 External male screw part 15 Flange part 16 Guide cylindrical part 17 Cylindrical body 18 Lock Step 20 Dedicated mounting jig (cylindrical jig) 21 Cylindrical body 22 Engaging part 25 Holding screw jig 26 Screw shaft 27 Receiving hole 30 Dedicated mounting jig

Claims (3)

[Claims] 1. A device for preventing removal of a fixing nut, which is screwed to a mounting bolt fixed to a support member like an anchor bolt and tightens and fixes a member to be fastened to the support member, wherein an external thread is provided on an outer peripheral surface. A portion is provided, and a fixing nut provided with a flange portion at an end on the tightening side, is fitted on the fixing nut, covers the entirety of the fixing nut with a predetermined gap on the outer periphery, and When the fixing nut is tightened by a special mounting jig which is inserted into the gap and is screwed to the male screw portion, the cylindrical cover being provided with a locking step portion which engages with the flange portion on the inside. The cylindrical cover is configured to be locked and held in a movable state between the fixing nut and the member to be fastened via the locking step portion engaging with the flange portion. Characteristic solid Prevention device for removal of fixed nut. 2. A screw hole which is screwed into said male thread portion of said fixed nut is provided through an inner peripheral surface of said cylindrical body insertable into said gap according to claim 1. An exclusive jig for fixing a fixed nut comprising a cylindrical jig provided with an engaging portion of a rotary tool on an outer periphery of an end portion. 3. The screw of the mounting bolt according to claim 1, wherein the cylindrical jig according to claim 2 and a screw shaft portion having a male screw screwed into the screw hole of the cylindrical jig. A receiving hole into which the shaft portion is loosely fitted is provided, and a holding screw jig provided with a head for engaging a rotary tool at a rear end of the screw shaft portion. At the time of mounting, the cylindrical jig is screwed into the male screw portion of the fixing nut to provide a gap between the fixing jig and the flange portion, and the screw shaft portion of the holding screw jig is attached to the cylindrical jig. In a state where the tip of the screw shaft portion is pressed against the upper end surface of the fixing nut, the fixing nut is further rotated in the tightening direction to tighten the fixing nut, and the tightening is completed. Thereafter, the cylindrical jig is rotated by rotating the presser screw jig in the loosening direction. Dedicated mounting jig fixing nut, characterized in that it is configured to be removed without the constant nut and co-rotation.