JP2012127494A - Bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loosening prevention bolt having a simple configuration and capable of reliably preventing loosening and of being repeatedly used in a wide range of construction processes, and to provide a loosening prevention bolt capable of reliably preventing loosening even for use in a place with strong temperature differences and for use in a place with strong vibrations and of being repeatedly used in a wide range of construction processes.SOLUTION: The loosening preventing bolt includes a bolt body, a sub bolt, and a diameter expanding member on which a friction member is mounted in need. In the bolt body, a shaft hole is formed at least one end of a shaft core part so as to become a space of a circular truncated cone shape in which the end part of the shaft hole is enlarged as coming closer to the distal end, one or more of slits are formed from the distal end in the distal end part of the shaft part where the space with the circular truncated cone shape is formed, the diameter expanding member is arranged in the space of the bolt body and has side faces with the circular truncated cone shape abutting on the inner wall of the space and enlarging the diameter of the space, the sub bolt is inserted into the shaft hole arranged in the bolt body and moves the diameter expanding member in a direction for enlarging the diameter of the space of the bolt body and provides diameter enlarging force to the space of the bolt body.

Description

  The present invention relates to a bolt having a locking function.

  Between the male threaded portion of the bolt and the female threaded portion that is screwed to the male threaded portion, the screw is screwed through the spiral strips / grooves provided on both screw portions, and the frictional force acting between the surfaces of the spiral strips / grooves Thus, the mutual rotation is stopped and the fixing relation is maintained. However, the frictional force generated between the spiral strip and the groove surface is only generated on the smooth gradient surface, and the gradient surfaces slip due to expansion, contraction, vibration, etc. due to temperature changes applied to both screw parts over a long period of time. The fixing condition between the male and female screw parts may be broken, and the bolt may loosen and fall off, causing an accident.

  Accordingly, various bolts having a locking function for preventing accidents of this type have been proposed.

For example, as shown in FIG. 26, the locking bolt disclosed in Patent Document 1 includes a headed bolt 1201 and a disk-shaped receiving member 1204. The headed bolt 1201 is concentric with the bolt shaft core on the lower surface of the tip. A convex portion 1202 having a truncated cone shape is formed, and a concave portion 1205 symmetrical to the convex portion 1202 is formed on the upper surface of the disc-shaped receiving member 1204. The convex portion 1202 and the concave portion 1205 are The bolt is surely locked by being slightly eccentric and applying a large shear stress in a direction perpendicular to the axial direction to the bolt.
However, in the locking bolt with such a configuration, the disc-shaped receiving member 1204 is inserted into the bottomed screw hole in advance, and the convex portion 1202 of the bolt 1201 is fitted into the concave portion 1205 of the disc-shaped receiving member 1204. Must be matched with the position where the disk-shaped receiving member 1204 is inserted, and the dimensional management of the bolt is a problem.

Japanese Patent Laid-Open No. 10-37936

SUMMARY OF THE INVENTION An object of the present invention is to provide a locking bolt that can be reliably prevented with a simple structure, has a wide construction range, and can be used repeatedly.
Another object of the present invention is to provide a locking bolt that can be used repeatedly in a wide range of construction that can reliably prevent loosening even when used in locations with a large temperature difference or in locations with severe vibration. And

  The bolt of the present invention is a bolt composed of a bolt main body, a sub bolt, and a diameter-expanding member. The bolt main body has a shaft hole at least at one end of the shaft core portion, and the end of the shaft hole is the tip. Is formed so as to become a frustoconical space that is wider, and one or more slits are formed at the tip of the shaft portion where the frustoconical space is formed from the tip, and The diameter member is disposed in the space of the bolt body, has a truncated cone side surface that abuts against the inner wall of the space and expands the space, and the auxiliary bolt is inserted into a shaft hole provided in the bolt body. The diameter-expanding member is moved in the direction of expanding the space of the bolt body to apply a diameter expansion force to the space of the bolt body.

  The bolt of the present invention is a bolt comprising a bolt main body, a diameter-expanding member, a friction member, and a sub bolt, and the bolt main body has a shaft hole at least at one end of its shaft core portion, The end of the shaft hole is formed so as to become a frustoconical space that is widened as the end is closer to the tip, and one or more slits from the tip are formed at the tip of the shaft portion where the truncated cone space is formed. The expanding member is disposed in the space of the bolt body, and has a frustoconical side surface that abuts against the inner wall of the space to expand the space, the frustoconical side surface, and the frustoconical shape. A friction member holding portion for holding a friction member inserted between the friction member, the friction member is held by the friction member holding portion, and the auxiliary bolt is inserted into a shaft hole provided in the bolt body. The diameter-expanding member is moved in the direction of expanding the diameter of the space of the bolt body to To grant the expanded force in the space of the belt body.

It is preferable that the diameter-expanding member is disposed in the frustoconical space of the bolt body and is configured to prevent shaft rotation with respect to the bolt body by an anti-rotation function.
Moreover, it is preferable to provide a slit in the diameter-expanding member.

  The bolt main body is composed of a bolt main body and an auxiliary bolt, and the bolt main body is provided with a shaft hole in an axial core portion thereof, and becomes a frustoconical space that is wider as the end portion of the shaft hole is closer to the tip. One or more slits are formed in the circumferential direction of the tip end shaft hole in which the frustoconical space is formed, and the auxiliary bolt is inserted into the bolt main shaft hole in a non-rotatable manner. The auxiliary bolt end portion may be provided with a screw portion for screwing the auxiliary bolt equipped with the diameter-expanding member.

  The bolt according to the present invention is preferably provided with a sub-bolt protrusion preventing member that prevents the sub-bolt from coming out of the bolt body.

In the bolt of the present invention, after the male screw portion of the bolt is fastened to the female screw portion of the article to be fastened, the rear end space of the bolt body is pushed out by the diameter-expanding member, so that the male screw portion is firmly coupled to the female screw portion. It is possible to provide a locking bolt that does not loosen for a long time.
Further, the bolt of the present invention, after tightening the male screw portion of the bolt to the female screw portion of the fastened object, the rear end portion space of the bolt body is pushed out by the diameter expanding member, so the male screw portion is firmly coupled to the female screw portion, In addition, there is a friction member between the diameter-expanding member and the space of the bolt body, so there is no loosening between the two due to vibration or temperature change, even in environments where vibration or temperature change is severe for a long time. The present invention has an excellent effect that can provide a locking bolt that does not loosen.

In the bolt of the present invention, after the bolt shaft of the bolt is inserted into the through hole of the object to be fastened, the rear end portion space of the bolt body is pushed out by the diameter expanding member. Therefore, it is possible to provide a locking bolt that does not loosen between the two.
In the bolt of the present invention, after the bolt shaft of the bolt is inserted into the through hole of the object to be fastened, the rear end portion space of the bolt body is pushed out by the diameter expanding member. In addition, since there is a friction member between the diameter-expanding member and the space of the bolt body, there is no relaxation between the two due to vibration or temperature change, and there is no long-term vibration or temperature change. It has an excellent effect capable of providing a locking bolt that does not loosen even in a severe environment.

  In the bolt of the present invention, after the bolt shaft of the bolt is inserted into the through hole of the object to be fastened, the rear end portion space of the bolt body is pushed out by the diameter expanding member. In addition, there is a friction member between the diameter-expanding member and the space of the bolt body, and the diameter-expanding member is provided with a slit, so that the diameter-expanding member and the sub bolt are also firmly coupled. Therefore, the bolts for anti-theft are not loosened by vibration or temperature change between them, and they are not loosened even in long-term vibration and severe temperature change environments, and the secondary bolt is prevented from rotating. As a result, it is possible to provide an effective locking bolt, which has an excellent effect.

It is a figure which shows the volt | bolt of 1st Embodiment, (a) is a top view, (b) is a partially cutaway side view, (c) is a bottom view. It is a figure which shows the volt | bolt main body in 1st Embodiment, (a) is a top view, (b) is a front view, (c) is a bottom view, (d) is XX sectional drawing of (a). It is a side view which shows the subbolt of 1st Embodiment. It is a figure which shows a diameter-expanding member, (a) is a top view, (b) is a side view, (c) is a bottom view, (d)-(f) is a side view which shows an application example. It is a figure which shows the use condition which attached the volt | bolt of 1st Embodiment to the to-be-fastened object, (a) is the state screwed in the bottomed screw hole, (b) is the state screwed in the penetration screw hole, ( c) shows a state in which a bolt is inserted into a through-hole of a fastened object that does not have a threaded portion and the fastened object is coupled.

The bolt of 2nd Embodiment is shown, (a) is a partially cutaway side view of a bolt, (b) is a side view which shows the state which attached the enlarged diameter member to the subbolt, (c) is a latching body. It is a top view which shows the nut as. It is a partial cutaway side view which shows the structure of the volt | bolt of 3rd Embodiment in a use state. It is a partial cutaway side view which shows the structure of the volt | bolt of 4th Embodiment in a use condition. It is a partial cutaway side view which shows the structure of the volt | bolt of 5th Embodiment in a use condition. It is a figure which shows the volt | bolt of 6th Embodiment, (a) is a top view, (b) is a partially cutaway side view, (c) is a bottom view.

It is a figure which shows a diameter-expanding member, (a) is a top view, (b) is a side view, (c) is a bottom view, (d)-(f) is a side view which shows an application example. It is a figure which shows the use condition which attached the volt | bolt of 6th Embodiment to the to-be-fastened object, (a) is the state screwed to the bottomed screw hole, (b) is the state screwed to the through screw hole, ( c) shows a state in which a bolt is inserted into a through-hole of a fastened object that does not have a threaded portion and the fastened object is coupled. The bolt of 7th Embodiment is shown, (a) is a partially cutaway side view of a bolt, (b) is a side view which shows the state which attached the enlarged diameter member to the subbolt, (c) is a latching body. It is a top view which shows the nut as. It is a partial cutaway side view which shows the structure of the volt | bolt of 8th Embodiment in a use condition. It is a partial cutaway side view which shows the structure of the volt | bolt of 9th Embodiment in a use condition.

It is a partially cutaway side view which shows the structure of the volt | bolt of 10th Embodiment in a use condition. It is a figure which shows the volt | bolt of 11th Embodiment, (a) is a top view, (b) is a partially cutaway side view, (c) is a bottom view. It is a figure which shows a diameter expansion member, (a) is a top view, (b) (b1) is sectional drawing of a side surface, (c) is a bottom view, (d)-(f) (d1)-(f1) are application. It is a side view which shows an example. It is a side view which shows the other application example of a diameter expansion member, (a) (a1) is a side view, (b) is a partially expanded explanatory view of (a). It is a figure which shows the volt | bolt of 12th Embodiment, (a) is a top view, (b) is a partially cutaway side view, (c) is a bottom view. It is a figure which shows the volt | bolt of 13th Embodiment, (a) is a top view, (b) is a partially cutaway side view, (c) is a bottom view.

It is a partially cutaway side view which shows the structure of the volt | bolt of 14th Embodiment in a use condition. It is a partially cutaway side view which shows the structure of the volt | bolt of 15th Embodiment in a use condition. It is a partially cutaway side view which shows the structure of the volt | bolt of 16th Embodiment in a use condition. It is a partially cutaway side view which shows the structure of the volt | bolt of 17th Embodiment in a use condition. It is a partially cutaway side view illustrating a conventional locking bolt.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 shows a bolt 10 according to a first embodiment of the present invention. The bolt 10 includes a bolt body 11, a sub bolt 21, and a diameter-expanding member (so-called top) 31.

The bolt body will be described.
2A and 2B show the bolt body 11, where FIG. 2A is a top view, FIG. 2B is a side view, FIG. 2C is a bottom view, and FIG. 2D is a cross-sectional view taken along line XX shown in FIG.

The bolt main body 11 is a head tightening bolt including a hexagonal or circular head 12 (in the figure, a hexagon is displayed) and a cylindrical shaft portion 13 formed integrally with the head 12.
If the side surface of the head 12 is hexagonal as shown in the figure, it becomes a tool engaging portion, and if it is circular, a hexagonal recess 16 is formed in the top surface of the head 12 to form a tool system joint. In FIG. 2, the side surface is hexagonal and the recess 16 is formed in a circular shape.
A spiral groove (male thread portion) 14 is engraved on at least the tip portion of the outer peripheral surface of the shaft portion 13.

A shaft hole 15 for receiving a sub bolt 21 described later is provided in the shaft core portion of the bolt body 11. In the direction of the head 12 of the shaft hole 15, a recess 16 is formed for rotatably accommodating the head of the sub bolt 21, and the end of the shaft hole 15 (opposite to the head) becomes wider toward the tip. A space 17 having a truncated cone shape (hereinafter referred to as a truncated cone shape) is formed.
Further, one or a plurality of slits 18 are provided at the end portion of the shaft portion 13 in which the frustoconical space 17 is formed from the tip thereof toward the head portion 12. The optimum number of slits is about 2 to 4.

The sub bolt will be described.
As shown in FIG. 3, the sub bolt 21 includes a locking head portion 22 and a fastening shaft portion 23 formed integrally with the locking head portion 22. The sub bolt 21 is accommodated in the shaft hole 15 provided in the bolt main body 11 as shown in FIG. When the sub bolt 21 is stored in the shaft hole 15 of the bolt main body 11, the locking head 22 is rotatably stored in the recess 16 provided in the head 12 of the bolt main body 11. The locking head 22 is formed in a shape capable of locking a tool for rotating the auxiliary bolt 21. For example, if the concave portion 16 is circular, the side surface of the locking head 22 is polygonal (for example, hexagonal), and if the concave portion 16 is polygonal, a polygonal depression or minus [ −] Or a plus (+) groove is formed. In FIG. 3, the polygonal depression 24 is indicated by a dotted line.
The length of the fastening shaft portion 23 of the sub bolt 21 is preferably designed to be substantially the same as or slightly shorter than the length of the shaft hole 15 of the bolt body 11.
A threaded portion 25 that connects a diameter-expanding member 31 to be described later is engraved at the distal end portion (the side opposite to the head portion 22) of the fastening shaft portion 23.

The diameter expanding member will be described.
The diameter-expanding member 31 is inserted into the frustoconical space 17 provided in the bolt body 11 and plays a role of pushing and expanding the tip threaded portion of the bolt body 11 outward when moved by the sub bolt 21.
The diameter-expanding member 31 has a truncated cone shape as shown in FIG. The side surface 32 of the diameter-expanding member 31 is formed in a truncated frustoconical shape that eliminates the top of the cone in accordance with the inclination angle of the frustoconical space 17 provided in the bolt body 11. The diameter-expanding member 31 has a frustoconical part at least in part, and the frustoconical side surface 32 abuts exclusively on the side surface of the space 17 to expand the diameter of the space 17. Just do it.
The diameter-expanding member 31 is screwed with the auxiliary bolt 21. In the present embodiment, a screw hole 33 (connection hole) that is screwed into the screw portion 25 (see FIG. 3) of the sub bolt 21 is screwed to the shaft core portion of the diameter-expanding member 31.

Further, the frustoconical side surface 32 is provided with an anti-rotation function if necessary. The anti-rotation function is provided with a wing 35 as shown in FIG. 4A to FIG. 4C fitted into the slit 18 provided in the bolt body 11, and provided with a pin 36 as shown in FIG. Then, a knurling process 37 or the like as shown in FIG.
The rotation preventing function is provided in the diameter-expanding member 31 in this way because the diameter-expanding member 31 rotates when the diameter-expanding member 31 screwed into the sub-bolt 21 is rotated and moved. This is to prevent it. The mechanism for preventing the rotation of the diameter-expanding member 31 may be any configuration as long as it can perform the function of preventing the diameter-expanding member 31 from rotating. In the present embodiment, the wing 35 is formed separately, and the wing 35 is fitted and fixed to an axially extending slit formed in the side surface of the diameter-expanding member 31. The number of slits (the number of wings 35) (or the number of pins 36) is preferably matched to the number of one or more slits 18 provided in the bolt body 11.
In addition, if the length (axial direction dimension) of the diameter-expanding member 31 is lengthened, the ratio of the diameter expansion with respect to the unit movement amount can be decreased, adjustment is easy, and a finer diameter expansion (applying a loosening prevention force) becomes possible. . Further, when it is desired to increase the diameter expansion range, the angle of the inclined surface of the diameter expansion member 31 is preferably increased.

FIG. 4 (f) shows an embodiment in which the diameter-expanding member 31 is made longer than the other embodiments and the side surface is inclined in two stages.
The ratio of the diameter expansion to the movement amount of the diameter expansion member 31 is determined by the shape of the diameter expansion member 31, particularly the angle of the truncated cone side surface 32. As shown in FIG. 4 (f), when the length (axial dimension) of the diameter-expanding member 31 is increased, the ratio of the diameter expansion with respect to the unit movement amount can be reduced. The inclination angle of the side surface of 31 may be increased.

As described above, as a rotation preventing function, instead of the wing 35, as shown in FIG. 4D, the side surface of the diameter expanding member 31 is engaged with the slit 18 of the bolt body 11 to prevent the rotation. The pin (locking protrusion) 36 may be erected at a position corresponding to the slit 18.
Further, in place of such a locking projection, in order to prevent rotation of the diameter-expanding member 31 inserted in the space 17, as shown in FIG. 37 may be applied. Unevenness due to knurl processing is the anti-rotation function. This method can obtain the effect of preventing rotation by a simple method.

An explanation will be given for the assembly of the bolt.
Next, the assembly of the bolt in this embodiment will be specifically described.
As shown in FIG. 1, the auxiliary bolt 21 is inserted into the shaft hole 15 formed in the shaft portion 13 of the bolt body 11. The fastening shaft portion 23 of the sub bolt 21 is slidably inserted into the shaft hole 15, and the locking head portion 22 formed integrally with the upper end of the fastening shaft portion 23 is accommodated in the recess 16 of the bolt body 11.
Next, the diameter-expanding member 31 is screwed to the end of the fastening shaft portion 23 of the sub bolt 21. Since the length of the fastening shaft portion 23 of the sub bolt 21 is substantially the same as or slightly shorter than the length of the shaft hole 15 of the bolt body 11, the diameter expanding member 31 is inserted from the lower end of the bolt body 11. The screw hole 33 of the diameter-expanding member 31 can be screwed into the screw portion 25 screwed to the shaft portion 23 of the sub bolt 21. At this time, the wing 35 provided on the diameter expanding member 31 is fitted into the slit 18 provided at the lower end of the bolt body 11. By fitting the wings 35 into the slit 18, when the auxiliary bolt 21 is rotated to pull up the enlarged member 31, the enlarged member 31 is prevented from rotating, and the enlarged member 31 follows the rotation of the auxiliary bolt 21. Move up (down).

The auxiliary bolt 21 has a locking head portion 22 in a cylindrical shape with a diameter larger than that of the shaft hole 15, and a fastening shaft portion 23 extends from the center thereof. Accordingly, the locking head 22 functions as a locking body that contacts with the bottom surface of the recess 16 of the bolt body 11 as a seating surface, and the diameter-expanding member 31 that is screwed into the end of the fastening shaft portion 23 is replaced with the shaft portion 23. The tension to be pulled up through is generated.
In this way, the auxiliary bolt 21 is inserted into the shaft hole 15 of the bolt body, and the auxiliary bolt 21 is rotated with a tool (not shown) in a state where the diameter-expanding member 31 is screwed to the end of the end portion of the axial portion 23 of the auxiliary bolt 21. Thus, the diameter-expanding member 31 is pulled up in the head 22 direction and temporarily fixed to complete the assembly of the bolt 10.

  As described above, the auxiliary bolt 21 is inserted into the shaft hole 15 of the bolt body, and the auxiliary bolt 21 is rotated in a state in which the enlarged diameter member 31 is screwed to the end of the shaft portion 23 of the auxiliary bolt 21. In a state where 31 is pulled up (temporarily fixed), the bolt 10 is used as described later in the same manner as a normal bolt.

  In this embodiment, the bolt main body 11, the sub bolt 21, and the diameter-expanding member 31 are preferably made of metal such as iron or stainless steel, but can also be made of hard plastic having sufficient rigidity. In addition, although the direction of the screw of the screw part 25 of the sub bolt 21 is the same general right screw as that of the spiral groove 14 of the bolt body 11, it may be a reverse screw at all.

The usage state will be described.
The example which fastens the to-be-fastened object by the volt | bolt 10 of this embodiment is demonstrated.
FIG. 5A shows a state in which two fastening objects A and B are fastened with the bolt 10 of the present embodiment.
First, as described above, the auxiliary bolt 21 is passed through the shaft hole 15 of the bolt main body 11, the diameter-expanding member 31 is screwed into the distal end portion of the fastening shaft portion 23, and lightly screwed to temporarily fix the bolt 10. (See FIG. 1 (b)). In this state, the tip of the threaded portion 14 of the bolt body 11 does not bulge radially outward (does not expand), and can be handled in the same manner as a normal bolt because it maintains the normal dimensions.

  In order to join the two fastened objects A and B with the assembled bolt 10, as shown in FIG. 5A, the base side cover with a spiral groove cut into the male threaded portion 14 of the bolt body 11 is cut. The bolt body 11 is screwed into the threaded portion B1 of the fastener B. Although not shown, in principle, a spring washer is used. When screwing, the bolts 10 are tightened with a wrench or the like, the lower part of the bolt head 12 is brought into contact with the surface of the object A to be fastened, and the objects A and B are fastened with a normal tightening strength.

Next, in order to prevent loosening, a rotating tool (for example, a hexagonal wrench) (not shown) is applied to the head 22 of the sub bolt 21 to rotate the sub bolt 21 and screwed into the end of the sub bolt 21. The diameter-expanding member 31 is pulled up. When the diameter expanding member 31 is pulled up toward the locking head 22, the stress on the side surface 32 of the diameter expanding member 31 is applied to the space 17. Since the space 17 is provided with the slit 18, the space 17 is pushed outward and the diameter of the lower portion of the shaft portion 13 of the bolt body 11 is increased. By expanding the diameter of the shaft portion 13, the spiral groove (male thread portion) 14 is firmly brought into contact with the thread portion (spiral groove) B 1 of the article B to be fastened. The bolt 10 cannot be loosened by the force of the tool that rotates the portion 12.
Accordingly, the diameter-expanding member 31 expands (expands) the tip of the threaded portion of the bolt body 11 and exhibits a strong locking effect. As a result, the bolt can be reliably prevented from loosening, and the bolt 10 and the fastened object A can be prevented. , B is loose and does not rotate in the direction of disengagement.

  In the present embodiment, the diameter-expanding member 31 is pulled up by the sub-bolt 21 and the diameter-expanding member 31 is fixed in the space 17 of the bolt main body, and then the sub-bolt 21 can be rotated and removed in the direction opposite to the tightening. It is. That is, the auxiliary bolt 21 can be separated from the enlarged diameter member 31 by rotating the auxiliary bolt 21 in a direction opposite to the direction in which the enlarged diameter member 31 is tightened. Even if the auxiliary bolt 21 is removed from the diameter-expanding member 31, the diameter-expanding member 31 is fixed to the bolt body, so that it does not hinder the bolt locking function. By removing the auxiliary bolt in this way, the auxiliary bolt disappears from the bolt, so that an effect of preventing the operator from forgetting to tighten the auxiliary bolt is also exhibited. If necessary, the removed sub bolt 21 can be used again.

  It is also preferable that the auxiliary bolt is cut at a predetermined position when a force equal to or greater than a certain torque is applied. That is, by providing a notch in the head 22 of the auxiliary bolt and rotating the auxiliary bolt at the tip thereof, it breaks when a force exceeding a certain torque is applied to the head, and an excessive force is applied to the diameter expanding member 31. It can be configured not to join. By separating the head of the sub bolt in this way, the head of the sub bolt is removed from the bolt, and thus an effect of preventing the operator from forgetting to tighten the sub bolt is also exhibited.

  The embodiment shown in FIG. 5B is an example in which the length of the bolt shaft portion 13 is longer than the thickness of the objects A and B to be fastened. The assembly of the bolt and the screwing to the fastened object are the same as in the case of FIG. In FIG. 5 (b), the end of the end portion of the shaft portion 13 of the bolt main body 11 penetrates from the article B to be fastened. Therefore, when the diameter-expanding member 31 is pulled up, the tip end portion of the bolt main body 11 is expanded in diameter, and the bolt tip penetrating the object to be fastened is opened, and the loosening prevention effect is obtained more strongly. In the case of an application intended for the through screw hole of FIG. 5B, a more appropriate loosening prevention effect can be obtained by using the diameter expanding member 31 having the shape shown in FIG.

  That is, in the diameter-expanding member 31 of FIG. 4 (f), for example, a pier in which the top of the cone having an apex angle of 30 degrees is removed, for example, in a manner in which the top of the cone having an apex angle of 30 degrees is eliminated. A wing 35 is fixed to a truncated cone-shaped main body portion (the angle is exaggerated in the drawing) on the side peripheral surface having a constriction formed with the upper bottom portion of the cone. In this way, by providing an angle to the inclination and expanding the tip of the bolt at a larger angle, the loosening prevention effect is further improved. Moreover, by comprising in this way, also in the site | part where it is difficult to mount | wear with the nut from the back side, the outstanding effect which can be firmly screwed without using a nut is exhibited.

  In the above-described embodiment, the outer periphery of the locking head portion 22 of the sub bolt 21 is formed in a hexagonal shape as the tool engaging portion of the sub bolt 21 and can be rotated by a spanner or the like. Of course, it may be a depression or a minus or plus groove into which a minus or plus driver can be inserted. In any case, the tool engaging portion may have any shape as long as the auxiliary bolt 21 can be rotated. In addition, the bolt main body 11 may have a shape other than the hexagonal shape as a tool engaging portion for rotating the bolt main body 11.

In the locking bolt of the above-described embodiment, after tightening the male threaded portion of the bolt to the female threaded portion of the object to be fastened, the rear end space of the bolt main body is pushed and expanded by the diameter expanding member, and the male threaded portion is firmly coupled to the female threaded portion. Although the object to be fastened is firmly coupled, as shown in FIG. 5 (c), the female screw part is not provided in the fastened part, and the length of the bolt shaft part 13 is set to the length of the through hole of the objects to be fastened A and B. The portion where the bolt shaft portion 13 is exposed from the fastened object B is larger than the diameter of the through hole by extending the rear end space 17 of the bolt body 11 with the diameter-expanding member 31 and expanding the rear space. It can also comprise so that a to-be-fastened object may be couple | bonded firmly by expanding in diameter. That is, it can be configured to add the role of a nut to the expanded diameter portion.
In this embodiment, the screw portion 14 is provided on the shaft portion 13 of the bolt main body 11, but a configuration in which the screw portion is not provided is also possible.

[Second Embodiment]
It is attached to the assembly of the sub bolt and the bolt.
A second embodiment of the bolt will be described with reference to FIG.
6A and 6B show a bolt 210 according to the second embodiment, in which FIG. 6A is a partially cutaway side view, FIG. 6B is a side view of a sub-bolt 221 with an enlarged member attached, and FIG. It is a top view of the nut 251 as.
The second embodiment is the same as the first embodiment except that the sub bolt 221 is different from the first embodiment. Therefore, the same portions are denoted by the same reference numerals and detailed description thereof is omitted.
In the second embodiment, the auxiliary bolt 221 includes a nut 251 and a fastening shaft portion 223. The fastening shaft portion 223 has a screw portion 225 cut at least at the tip end portion, and a nut 251 is screwed into the screw portion 225. A diameter expanding member 31 is provided at the rear end of the fastening shaft portion 223. The fastening shaft portion 223 and the diameter-expanding member 31 are formed integrally with each other, or separately formed and attached by bonding, screwing, or the like.

In the assembly of the bolt according to the second embodiment, the screw body 225 side of the fastening shaft portion 223 in which the diameter expanding member 31 is attached to the rear end end portion of the fastening shaft portion 223 in the shaft hole 15 of the bolt body 11 is connected to the bolt body 11. Is inserted from the side opposite to the head 12, and the tip is projected into a recess 16 provided in the head 12 of the bolt body 11. Next, the nut 251 is screwed onto the protruding end of the fastening shaft portion 223, and temporarily assembled to complete the assembly.
The fastening shaft portion 223 and the nut 251 can be screwed together first, and then the diameter expanding member 31 can be assembled to the fastening shaft portion 223.

The usage will be explained.
As in the first embodiment, after the object to be fastened is screwed with the bolt 210, the nut 251 is tightened from the head 12 side of the bolt main body 11. By tightening the nut 251, the diameter expanding member 31 is pulled up in the space 17 at the tip of the bolt body 11. When the diameter expanding member 31 is pulled up, the stress on the side surface 32 of the diameter expanding member 31 is applied to the space 17. Since the slit 17 is provided in the space 17, the space 17 is pushed outward and the shaft portion 13 of the bolt body 11 is expanded in diameter. By expanding the diameter of the shaft portion 13, the spiral groove (male thread portion) 14 is firmly brought into contact with the object to be fastened, and even if the bolt body 11 is rotated in the direction of removing the bolt body 11, The bolt 10 cannot be loosened.
Therefore, as a result of the diameter-expanding member 31 expanding the diameter of the threaded portion of the bolt body 11 (widening) and exhibiting a strong locking effect, loosening of the bolt can be reliably prevented.

  The loosening-prevention bolt of the second embodiment has a rear end space of a bolt main body, to which the object to be fastened is screwed with a bolt, is expanded by a diameter-expanding member, and the male screw portion is firmly coupled to the female screw portion. Although firmly coupled, as described in the first embodiment (see FIG. 5), after inserting the bolt shaft into the through hole of the fastened object without providing the bolt shaft portion and the threaded portion in the fastened object, The rear end space of the bolt body can be expanded by a diameter increasing member, and the rear end space of the bolt shaft can be firmly joined to the through hole of the fastened object to join the fastened object. Furthermore, the bolt shaft is fastened by expanding the rear space of the bolt body by expanding the rear end space of the bolt body by increasing the length of the bolt shaft longer than the length of the through hole of the object to be fastened. The part exposed from the object becomes larger than the diameter of the through hole, i.e., enlarged. Portion becomes the role of the nut, it is possible to firmly couple the fastened object.

[Third Embodiment]
A bolt 310 according to the third embodiment will be described with reference to FIG.
FIG. 7 is a partially cutaway side view showing the bolt 310 of the third embodiment.
The bolt body will be described.
In the third embodiment, the bolt body 311 includes a hexagonal or circular head 312 (in the figure, a hexagon is displayed) and a columnar shaft portion 313 integrally formed with the head 312. Head tightening bolt.
If the side surface of the head 312 is hexagonal as shown in the figure, it becomes a tool engaging portion, and if it is circular, a hexagonal groove (not shown) or a plus or minus groove is drilled on the top surface of the head 12 to provide a tool system. Form a joint.
A spiral groove (threaded portion) 314 is engraved on at least the tip portion of the outer peripheral surface of the shaft portion 313.
A shaft hole 315 (a bottomed hole is shown in the figure, but it may be a through hole) that accommodates a sub bolt 321 described later from the end of the bolt body 311 opposite to the head 312 toward the head. Is provided. The end of the shaft hole 315 (opposite to the head) is formed into a frusto-conical frustoconical space (hereinafter referred to as a frustoconical shape) space 317 that is wider toward the tip. A thread portion 355 is engraved.

  Further, the end of the bolt body shaft portion 313 in which the truncated cone space 317 is formed has one or more slits 318 (similar to the slit 18 in FIG. 2) from the tip toward the body head 312. Are omitted). The number of slits 318 is optimally about 2 to 4.

The sub bolt will be described.
As shown in FIG. 7, the auxiliary bolt 321 has a fastening head portion 357 and a fastening shaft portion 359 provided integrally with the locking head portion 357 and provided with a screw portion 358 that is screwed into the screw portion 355 at least at the tip. It is made up of. The sub bolt 321 is accommodated in a shaft hole 315 provided in the bolt body 311 as shown in FIG.
The length of the fastening shaft portion 359 of the sub bolt 321 is preferably designed to be substantially the same as or slightly shorter than the length of the shaft hole 315 of the bolt body 311.

The diameter expanding member will be described.
The diameter-expanding member 31 is inserted into a frustoconical space 317 provided in the bolt main body 311 and plays a role of expanding the tip screw portion 314 of the bolt main body 311 outward when moved by the sub bolt 321.
A through hole 338 is provided at the center of the diameter expanding member 31. The size of the through hole 338 is set such that the auxiliary bolt 321 can be inserted. Since other configurations are the same as those shown in FIG. 4 described in the first embodiment, detailed description thereof is omitted.

The assembly and usage of the bolt will be explained.
Next, the assembly and use method of the bolt in this embodiment will be specifically described.
As shown in FIG. 7, the bolt main body 311 is inserted through the through holes of the objects A and B to be fastened. The length of the shaft portion 313 of the bolt body 311 is designed to be substantially the same as the length of the through holes of the objects A and B to be fastened. In addition, in FIG. 7 which shows this embodiment, the thread part B1 is formed in the inner peripheral wall of the through-hole of the to-be-fastened object B. FIG.
In this embodiment, the head 312 of the bolt body 311 is rotated with a tool, the bolt body 311 is inserted into the through-hole of the article A to be fastened, and is screwed into the threaded portion B1 of the article B to be fastened. B is concluded.
Next, the diameter-expanding member 31 is inserted into the fastening shaft portion 353 of the sub-bolt 321, the diameter-expanding member 31 is fitted together with the sub-bolt 321 in the space 317 provided in the bolt main body, and the sub-bolt 321 is tightened to the bolt main body 311. The diameter member 31 is moved to the back of the space 317. At this time, the wing 35 (see FIG. 4) provided on the diameter-expanding member 31 is fitted into the slit 18 (see FIG. 2) provided at the lower end of the bolt body 311. By inserting the blades 35 into the slit 18 and rotating the auxiliary bolt 321 to draw the enlarged member 31 into the bolt body, the enlarged member 31 is prevented from rotating, and the enlarged member 31 is rotated by the auxiliary bolt 321. Move to follow.

As described above, the auxiliary bolt 321 is inserted into the shaft hole 315 of the bolt body 311 and the auxiliary bolt is rotated by a tool (not shown), whereby the diameter-expanding member 31 is pulled up in the head 312 direction. The force applied to the frustoconical side surface of the diameter-expanding member 31 by pulling up the diameter-expanding member 31 is in the direction of expanding the diameter of the truncated cone-shaped space 317 of the bolt body, that is, the tip portion of the shaft portion 313 of the bolt body 311. Acts in a direction to spread from the inner side to the outer peripheral side.
In this way, the side surface of the diameter expanding member 31 moves so as to push the tip portion of the shaft portion 313 of the bolt body 311 from the inside to the outer periphery side, and the end portion of the bolt body 311 is expanded by the diameter expanding member 31 to be covered. By being pressed against the threaded portion B1 of the fastening object B, the bolt body 311 is firmly fixed to the object to be fastened, and does not loosen for a long time.

[Fourth Embodiment]
A loosening prevention bolt 410 according to the fourth embodiment will be described with reference to FIG.
The bolt body will be described.
In the fourth embodiment, unlike the bolt main body 11 of the first embodiment, the bolt main body 411 does not have a head and includes only a cylindrical shaft portion 413. Screw portions 414 are engraved on at least both ends of the bolt body 411.
Moreover, the bottomed shaft hole 453 is provided in both ends similarly to the said 3rd Embodiment. The shaft hole 453 may be a through hole.
The opening end of the shaft hole 453 is formed in a truncated cone space 417 as in the first and third embodiments, and a threaded portion 414 is engraved at the tip. One or more slits 18 (see FIG. 2) are provided from the tip toward the center. The optimum number of slits is about 2 to 4.
Nuts 451 that are screwed into the threaded portions 414 are provided on the threaded portions 414 at both ends of the bolt body 411.

The auxiliary bolt will be described.
The auxiliary bolt 421 has the same configuration as the auxiliary bolt 321 described in the third embodiment as shown in FIG. Moreover, since the diameter-expanding member 31 is also the same as that of the third embodiment, the same reference numerals are given and detailed description thereof is omitted.

The usage will be explained.
FIG. 8 is a partial cross-sectional view of the bolt 410 according to the fourth embodiment in use.
The bolt body 411 is passed through the through-holes of the objects A and B to be fastened. At this time, both ends of the bolt main body 411 (both ends where the screw portions 414 are formed) protrude from the surfaces of the fastened objects A and B to substantially the same extent.
A nut 451 having a spiral groove screwed to the threaded portion 414 on the inner peripheral surface is attached to the threaded portion 414 of each projecting end of the bolt body 411 with a washer 452 interposed therebetween, and the fastened objects A and B are attached. Tighten and fix.
Next, the diameter-expanding member 31 (for example, the same shape as FIG. 4 (f)) is inserted into the frustoconical space 417 at both ends of the bolt body 411 from the outside, and the auxiliary bolt 321 is passed through the connection hole of the diameter-expanding member 31. Then, the auxiliary bolt 321 is rotated with a tool or the like.

When the auxiliary bolt 321 is rotated and screwed into the shaft hole 453, the diameter-expanding member 31 is prevented from rotating by a rotation preventing function such as a blade that engages with a slit (not shown) of the bolt body as in the first embodiment. Configure as follows. Further, the diameter-expanding member 31 is pushed inward by the locking head 357 of the sub bolt 321 and moves inwardly in the frustoconical space 417. Therefore, the end of the bolt main body 411 is expanded in diameter and strongly pressed against the inner peripheral wall of the nut 451, and both are firmly coupled.
By performing the operation of tightening the sub bolt 321 simultaneously or alternately on the fastened object A side and the fastened object B side, the fastened objects A and B are fastened, and the bolts are firmly fixed without loosening. Is done.
The fourth embodiment is particularly effective when applied to the fastened objects A and B having through holes larger than the outer diameter of the bolt body 411 as shown in FIG.

[Fifth Embodiment]
A loosening prevention bolt 510 according to the fifth embodiment will be described with reference to FIG.
It is attached to the bolt body.
The bolt main body 511 of the fifth embodiment includes a bolt main body 561 that is substantially the same as the bolt main body 11 described in the first embodiment, and an auxiliary bolt 571 that is inserted into the shaft hole 565 of the bolt main body 561.
A concave portion 566 is formed in the head 562 of the bolt main body 561 so that a head 572 of an auxiliary bolt 571 described later can be stored in a non-rotatable manner.
The auxiliary bolt 571 includes a head portion 572 and a shaft portion 573, and a shaft hole 575 is provided at a tip portion of the shaft portion 573, and a screw portion 574 is provided in the shaft hole 575. The length of the shaft portion 573 is shorter than the length of the bolt main body 561, and is designed to have a length that can exhibit the function of the diameter-expanding member 31 described later.

A recess 566 provided in the head 562 of the bolt main body 561 is formed so as to house the head 572 of the auxiliary bolt 571 and to prevent the head 572 from rotating. For example, if the head portion 562 of the bolt main body 561 is formed in a hexagonal shape, it is formed in a hexagonal concave portion 566 corresponding to the shape, and the auxiliary bolt 571 is inserted into the shaft hole 565 of the bolt main body 561. The head 572 is housed in a non-rotatable manner. In addition, since the shape of the recessed part 566 provided in a head is enough if it can accommodate the main body 561 of a bolt so that rotation is impossible, the shape etc. are arbitrary.
The sub-bolt 521 is the same as the sub-bolt 321 described in the third embodiment, and the diameter-expanding member 31 and the nut 551 are the same as in the above-described embodiment.

It explains with use.
First, the bolt main body 561 is inserted into the through holes of the objects A and B to be fastened. Next, the nut 551 is screwed onto the tip of the shaft portion 563 of the bolt main body 561 protruding from the fastened object, the nut 551 is tightened, and the fastened objects A and B are fastened. In this state, the auxiliary bolt 571 is inserted into the shaft hole 565 of the bolt main body 561, and the head 572 of the auxiliary bolt 571 is inserted so as to be received in the recess 566 of the bolt main body 561.

Next, the auxiliary bolt 571 is inserted into the rear end of the auxiliary bolt 571, the auxiliary bolt 521 is inserted into the truncated cone-shaped space 567 of the bolt main body 561, and the enlarged member 31 (for example, having the same shape as FIG. 4F). Insert it so that it fits, and rotate the secondary bolt with a tool.
By rotating the auxiliary bolt 521 and screwing it into the shaft hole 575, the diameter-expanding member 31 is pushed by the locking head 572 of the auxiliary bolt 521 and moves inward in the frustoconical space 567. Therefore, the diameter of the end of the bolt main body 511 is increased and strongly pressed against the inner peripheral wall of the nut 551, and both are firmly coupled.
As shown in FIG. 9, the fifth embodiment is particularly effective when applied to the fastened objects A and B having through holes larger than the outer diameter of the bolt main body 511.

  The loosening prevention bolts of the fourth and fifth embodiments are such that, after the objects to be fastened are coupled by the bolt main bodies 411 and 511 and the nuts 451 and 551, the rear end space of the bolt main body is expanded by the diameter-expanding member. However, without providing the nut 451, the end space of the bolt main body is expanded by a diameter expanding member so that the end space is larger than the diameter of the through-hole of the object to be fastened. As a result, as described with reference to FIG. 5C of the first embodiment, the bolt shaft portion cannot be pulled out from the through-hole of the fastened object, and thus the fastened object can be fastened.

The locking bolt does not loosen for normal use. However, if the expansion / contraction force due to the temperature difference acts on the bolt, or if severe vibrations act for a long time, loosening occurs between the sub bolt and the diameter expanding member, and the force to expand the space of the bolt body is weakened. In the worst case, there is a concern that the tightening force of the non-fastened material fastened with the bolts may be lowered and loosening may occur.
Therefore, when there is a concern about application in a place where there is a concern that the bolt may loosen due to use in an environment with a large temperature difference or vibration, the bolt of the following embodiment is used.

[Sixth Embodiment]
FIG. 10 shows a sixth embodiment of the present invention. A bolt 600 includes a bolt body 11, a sub bolt 21, a diameter-expanding member (so-called top) 31, and a friction member 41.

A bolt main body and a sub bolt will be described.
Since the bolt main body 11 and the sub bolt 21 are the same as those in the first embodiment, detailed description thereof is omitted.

The diameter expanding member will be described.
The diameter-expanding member 31 is inserted into the frustoconical space 17 provided in the bolt body 11 and plays a role of pushing and expanding the tip threaded portion of the bolt body 11 outward when moved by the sub bolt 21.
The diameter-expanding member 31 has a truncated cone shape as shown in FIG. The side surface 32 of the diameter-expanding member 31 is formed in a truncated frustoconical shape that eliminates the top of the cone in accordance with the inclination angle of the frustoconical space 17 provided in the bolt body 11. The diameter-expanding member 31 has a frustoconical part at least in part, and the frustoconical side surface 32 abuts exclusively on the side surface of the space 17 to expand the diameter of the space 17. Just do it.
The diameter-expanding member 31 is screwed with the auxiliary bolt 21. In the present embodiment, a screw hole 33 (connection hole) that is screwed into the screw portion 25 of the sub bolt 21 is screwed to the shaft core portion of the diameter expanding member 31.

  In the circumferential direction of the frustoconical side surface 32 of the diameter-expanding member 31, a friction member 41 (an elastic O-ring, or a circular spring member divided into two or a plurality of parts if necessary) to be described later is attached. A member holding portion (hereinafter sometimes referred to as a groove) 34 is formed. The shape of the friction member holding portion (which may be hereinafter expressed as a groove in the present embodiment) 34 is preferably drilled together with the shape of the friction member 41.

Further, the frustoconical side surface 32 is provided with an anti-rotation function if necessary. The anti-rotation function is provided with a wing 35 as shown in FIG. 11A to 11C fitted in the slit 18 provided in the bolt body 11, and provided with a pin 36 as shown in FIG. Then, a knurling process 37 as shown in FIG.
The rotation preventing function is provided in the diameter-expanding member 31 in this way because the diameter-expanding member 31 rotates when the diameter-expanding member 31 screwed into the sub-bolt 21 is rotated and moved. This is to prevent it. Note that the mechanism for preventing the rotation of the diameter-expanding member 31 only needs to perform the function of preventing the diameter-expanding member 31 from rotating. In the present embodiment, the wing 35 is formed separately, and the wing 35 is fitted and fixed to an axially extending slit formed in the side surface of the diameter-expanding member 31. The number of slits (the number of wings 35) (or the number of pins 36) is preferably matched to the number of one or more slits 18 provided in the bolt body 11.
In addition, if the length (axial direction dimension) of the diameter-expanding member 31 is lengthened, the ratio of the diameter expansion with respect to the unit movement amount can be decreased, adjustment is easy, and a finer diameter expansion (applying a loosening prevention force) becomes possible. . Further, when it is desired to increase the diameter expansion range, the angle of the inclined surface of the diameter expansion member 31 is preferably increased.

FIG. 11 (f) shows an embodiment in which the length of the diameter-expanding member 31 is made longer than that of the other embodiments and the side surface is inclined in two stages.
The ratio of the diameter expansion to the movement amount of the diameter expansion member 31 is determined by the shape of the diameter expansion member 31, particularly the angle of the truncated cone side surface 32. As shown in FIG. 4 (f), when the length (axial dimension) of the diameter-expanding member 31 is increased, the ratio of the diameter expansion with respect to the unit movement amount can be reduced. The inclination angle of the side surface of 31 may be increased.

As described above, as a rotation preventing function, instead of the wing 35, as shown in FIG. 11 (d), as a locking means for engaging the slit 18 of the bolt main body 11 on the side surface of the diameter expanding member 31 and preventing the rotation. The pin (locking protrusion) 36 may be erected at a position corresponding to the slit 18.
Further, in place of such a locking projection, in order to prevent rotation of the diameter-expanding member 31 inserted in the space 17, as shown in FIG. 37 may be applied. Unevenness due to knurl processing is the anti-rotation function. This method can obtain the effect of preventing rotation by a simple method.

The friction member will be described.
The friction member 41 is composed of an elastic O-ring, or a circular spring member divided into two or a plurality of parts if necessary. Any friction member 41 may be used as long as it is sandwiched between the space 17 and the truncated cone side surface 32 and effectively prevents the diameter-expanding member 31 from falling off the bolt body 11.
The friction member 41 is attached to a groove (friction member holding portion) 34 formed in the diameter-expanding member 31 and is compressed or deformed when the diameter-expanding member 31 is pushed into the space 17 of the main body 11 together with the diameter-expanding member 31 so that the diameter-expanding member 31 becomes long-term. It serves to prevent the bolt from falling off. Therefore, even if the friction member 41 is not an O-ring or a leaf spring, it can be employed regardless of the material and shape as long as it plays the role.

An explanation will be given for the assembly of the bolt.
Next, the assembly of the bolt in this embodiment will be specifically described.
As shown in FIG. 10, the auxiliary bolt 21 is inserted into the shaft hole 15 formed in the shaft portion 13 of the bolt body 11. The fastening shaft portion 23 of the sub bolt 21 is slidably inserted into the shaft hole 15, and the locking head portion 22 formed integrally with the upper end of the fastening shaft portion 23 is accommodated in the head recess portion 16 of the bolt body 11. .
Next, the diameter-expanding member 31 in which the friction member 41 (for example, an O-ring 42) is mounted in the groove 34 of the diameter-expanding member 31 is screwed to the tip end of the fastening shaft portion 23 of the sub bolt 21. Since the length of the fastening shaft portion 23 of the sub bolt 21 is substantially the same as or slightly shorter than the length of the shaft hole 15 of the bolt body 11, the diameter expanding member 31 is inserted from the lower end of the bolt body 11. The screw hole 33 of the diameter-expanding member 31 can be screwed into the screw portion 25 screwed to the shaft portion 23 of the sub bolt 21. At this time, the wing 35 provided on the diameter expanding member 31 is fitted into the slit 18 provided at the lower end of the bolt body 11. By fitting the wings 35 into the slit 18, when the auxiliary bolt 21 is rotated to pull up the enlarged member 31, the enlarged member 31 is prevented from rotating, and the enlarged member 31 follows the rotation of the auxiliary bolt 21. Move up (down).

The auxiliary bolt 21 has a locking head portion 22 in a cylindrical shape with a diameter larger than that of the shaft hole 15, and a fastening shaft portion 23 extends from the center thereof. Therefore, the locking head 22 functions as a locking body that contacts with the bottom surface of the head recess 16 of the bolt body 11 as a seating surface, and the diameter-expanding member 31 that is screwed into the end of the fastening shaft portion 23 is connected to the shaft. A tension to be pulled up through the portion 23 is generated.
In this way, the auxiliary bolt 21 is inserted into the shaft hole 15 of the bolt body, and the auxiliary bolt 21 is rotated with a tool (not shown) in a state where the diameter-expanding member 31 is screwed to the end of the end portion of the axial portion 23 of the auxiliary bolt 21. Thus, the diameter-expanding member 31 is pulled up in the head 22 direction and temporarily fixed to complete the assembly of the bolt 10.

  As described above, the auxiliary bolt 21 is inserted into the shaft hole 15 of the bolt body, and the auxiliary bolt 21 is rotated in a state in which the enlarged diameter member 31 is screwed to the end of the shaft portion 23 of the auxiliary bolt 21. In a state where 31 is pulled up (temporarily fixed), the bolt 10 is used as described later in the same manner as a normal bolt.

  In this embodiment, the bolt main body 11, the sub bolt 21, and the diameter-expanding member 31 are preferably made of metal such as iron or stainless steel, but can also be made of hard plastic having sufficient rigidity. In addition, although the direction of the screw of the screw part 25 of the sub bolt 21 is the same general right screw as that of the screw part 14 of the bolt main body 11, it may be a reverse screw at all.

  The friction member 41 may be formed of an elastic member such as the O-ring 42, or may be a ring-shaped leaf spring divided into two. When the leaf spring 43 (friction member 41) is employed, the outside of the leaf spring 43 bites into the side surface of the space 17 as shown in an enlarged view in FIG. 14 to be described later, and the diameter-expanding member 31 can be firmly fixed to the bolt body. ,preferable.

The usage state will be described.
The example which fastens the to-be-fastened object with the volt | bolt 600 of this embodiment is demonstrated.
FIG. 12A shows a state in which two fastening objects A and B are fastened with the bolt 600 of the present embodiment.
First, as described above, the auxiliary bolt 21 is passed through the shaft hole 15 of the bolt body 11, and the diameter-expanding member 31 with the friction member 41 mounted on the tip end portion of the fastening shaft portion 23 is screwed and lightly screwed and temporarily fixed. Assemble the bolt 600. (See FIG. 10B). In this state, the tip of the threaded portion 14 of the bolt body 11 does not bulge radially outward (does not expand), and can be handled in the same manner as a normal bolt because it maintains the normal dimensions.

  In order to join two objects to be fastened A and B with the assembled bolt 600, as shown in FIG. 12A, the base side fastening with a spiral groove cut into the male threaded portion 14 of the bolt main body 11 is cut. The bolt body 11 is screwed into the threaded portion B1 of the object B. Although not shown, in principle, a spring washer is used. When screwing, the bolt 600 is tightened with a wrench or the like, the lower part of the bolt head 12 is brought into contact with the surface of the object A to be fastened, and the objects A and B are fastened with a normal tightening strength.

Next, in order to prevent loosening, a rotating tool (for example, a hexagonal wrench) (not shown) is applied to the head 22 of the sub bolt 21 to rotate the sub bolt 21 and screwed into the end of the sub bolt 21. The diameter-expanding member 31 is pulled up. When the diameter expanding member 31 is pulled up toward the locking head 22, the stress on the side surface 32 of the diameter expanding member 31 is applied to the space 17. Since the space 17 is provided with the slit 18, the space 17 is pushed outward and the diameter of the lower portion of the shaft portion 13 of the bolt body 11 is increased. By expanding the diameter of the shaft portion 13, the spiral groove (male thread portion) 14 is firmly brought into contact with the thread portion (spiral groove) B 1 of the article B to be fastened. The bolt 600 cannot be loosened by the force of the tool rotating the portion 12.
Furthermore, in this embodiment, the friction member 41 is fitted into the diameter-expanding member 31, and the friction member 41 firmly couples the bolt body 11 and the diameter-expanding member 31, so that expansion and contraction due to temperature change over time, excessive vibration, etc. However, the diameter-expanding member 31 does not fall off from the bolt body.
Therefore, as a result of the diameter-expanding member 31 expanding the diameter of the threaded portion of the bolt main body 11 and exhibiting a strong locking effect, the bolt main body 11 and the diameter-expanding member can be reliably prevented. 31 is firmly coupled with the friction member 41, so that even when strong vibration is applied, the coupling between the bolt 600 and the objects A and B to be fastened is not loosened and does not rotate in the direction of disengagement.

  In the present embodiment, the diameter-expanding member 31 is pulled up by the sub-bolt 21 and the diameter-expanding member 31 is fixed in the space 17 of the bolt main body, and then the sub-bolt 21 can be rotated and removed in the direction opposite to the tightening. It is. That is, the auxiliary bolt 21 can be separated from the enlarged diameter member 31 by rotating the auxiliary bolt 21 in a direction opposite to the direction in which the enlarged diameter member 31 is tightened. Even if the auxiliary bolt 21 is removed from the enlarged member 31, the enlarged member 31 is firmly fixed to the bolt body by the frictional force of the friction member 41 (or by biting into the bolt body like a leaf spring). This will not interfere with the bolt locking function. By removing the auxiliary bolt in this way, the auxiliary bolt disappears from the bolt, so that an effect of preventing the operator from forgetting to tighten the auxiliary bolt is also exhibited. If necessary, the removed sub bolt 21 can be used again.

  It is also preferable that the auxiliary bolt is cut at a predetermined position when a force equal to or greater than a certain torque is applied. That is, by providing a notch in the head 22 of the auxiliary bolt and rotating the auxiliary bolt at the tip thereof, it breaks when a force exceeding a certain torque is applied to the head, and an excessive force is applied to the diameter expanding member 31. It can be configured not to join. By separating the head of the sub bolt in this way, the head of the sub bolt is removed from the bolt, and thus an effect of preventing the operator from forgetting to tighten the sub bolt is also exhibited.

  The embodiment shown in FIG. 12B is an example in which the length of the bolt shaft portion 13 is longer than the thickness of the objects A and B to be fastened. The assembly of the bolt and the screwing to the fastened object are the same as in the case of FIG. In FIG. 12 (b), the end of the end portion of the shaft portion 13 of the bolt main body 11 penetrates from the article B to be fastened. Therefore, when the diameter-expanding member 31 is pulled up, the tip end portion of the bolt main body 11 is expanded in diameter, and the bolt tip penetrating the object to be fastened is opened, and the loosening prevention effect is obtained more strongly. In the case of an application intended for the through screw hole in FIG. 12B, a more appropriate loosening prevention effect can be obtained by using the diameter-expanding member 31 having the shape shown in FIG.

  That is, in the diameter-expanding member 31 shown in FIG. 11 (f), for example, a pier in which the apex of the cone having an apex angle of 30 degrees is made continuous with the lower bottom of the conical cone from which the apex of the cone having an apex angle of 8 degrees is eliminated. A wing 35 is fixed to a truncated cone-shaped main body portion (the angle is exaggerated in the drawing) on the side peripheral surface having a constriction formed with the upper bottom portion of the cone. In this way, by providing an angle to the inclination and expanding the tip of the bolt at a larger angle, the loosening prevention effect is further improved. Moreover, by comprising in this way, also in the site | part where it is difficult to mount | wear with the nut from the back side, the outstanding effect which can be firmly screwed without using a nut is exhibited.

  In the above-described embodiment, the outer periphery of the locking head portion 22 of the sub bolt 21 is formed in a hexagonal shape as the tool engaging portion of the sub bolt 21 and can be rotated by a spanner or the like. Of course, it may be a depression or a minus or plus groove into which a minus or plus driver can be inserted. In any case, the tool engaging portion may have any shape as long as the auxiliary bolt 21 can be rotated. In addition, the bolt main body 11 may have a shape other than the hexagonal shape as a tool engaging portion for rotating the bolt main body 11.

In the locking bolt of the above-described embodiment, after tightening the male threaded portion of the bolt to the female threaded portion of the object to be fastened, the rear end space of the bolt main body is pushed and expanded by the diameter expanding member, and the male threaded portion is firmly coupled to the female threaded portion. Although the object to be fastened is firmly coupled, as shown in FIG. 12 (c), the female screw part is not provided in the fastened part, and the length of the bolt shaft part 13 is set to the length of the through hole of the objects to be fastened A and B. The portion where the bolt shaft portion 13 is exposed from the fastened object B is larger than the diameter of the through hole by extending the rear end space 17 of the bolt body 11 with the diameter-expanding member 31 and expanding the rear space. It can also comprise so that a to-be-fastened object may be couple | bonded firmly by expanding in diameter. That is, it can be configured to add the role of a nut to the expanded diameter portion.
In this embodiment, the screw portion 14 is provided on the shaft portion 13 of the bolt body, but a configuration in which the screw portion is not provided is also possible.
Furthermore, since there is a friction member between the expanded member and the space of the bolt body, there is no loosening between the two due to vibration or temperature change. Has the effect of preventing loosening.

[Seventh Embodiment]
It is attached to the assembly of the sub bolt and the bolt.
A seventh embodiment of the loosening prevention bolt will be described with reference to FIG.
13A and 13B show a bolt 700 according to the seventh embodiment, in which FIG. 13A is a partially cutaway side view, FIG. 13B is a side view of a sub-bolt 221 to which an enlarged member is attached, and FIG. It is a top view.
The seventh embodiment is the same as the sixth embodiment except that the auxiliary bolt 221 is different from the sixth embodiment. Therefore, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.
In the seventh embodiment, the sub-bolt 221 includes a nut 251 and a fastening shaft portion 223. The fastening shaft portion 223 has a screw portion 225 cut at least at the tip end portion, and a nut 251 is screwed into the screw portion 225. A diameter-expanding member 31 with a friction member 41 is provided at the rear end of the fastening shaft portion 223. Note that the fastening shaft portion 223 and the diameter-expanding member 31 are both created integrally or separately and attached by bonding, screwing, or the like.

The bolt 700 according to the seventh embodiment is assembled in such a manner that the screw portion 225 side of the fastening shaft portion 223 in which the diameter-expanding member 31 is attached to the rear end end portion of the fastening shaft portion 223 in the shaft hole 15 of the bolt body 11. 11 is inserted from the side opposite to the head 12, and its tip is projected into a recess 16 provided in the head 12 of the bolt body 11. Next, the nut 251 is screwed onto the protruding end of the fastening shaft portion 223, and temporarily assembled to complete the assembly.
The fastening shaft portion 223 and the nut 251 may be first screwed together, and then assembled as a configuration in which the diameter-expanding member 31 with the friction member 41 attached is attached to the fastening shaft portion.

The usage will be explained.
Similarly to the sixth embodiment, after the object to be fastened is screwed with the bolt 700, the nut 251 is tightened from the head 12 side of the bolt body 11. By tightening the nut 251, the diameter expanding member 31 is pulled up in the space 17 at the tip of the bolt body 11. When the diameter expanding member 31 is pulled up, the stress on the side surface 32 of the diameter expanding member 31 is applied to the space 17. Since the slit 17 is provided in the space 17, the space 17 is pushed outward and the shaft portion 13 of the bolt body 11 is expanded in diameter. By expanding the diameter of the shaft portion 13, the spiral groove (male thread portion) 14 is firmly brought into contact with the object to be fastened, and even if the bolt body 11 is rotated in the direction of removing the bolt body 11, The bolt 700 cannot be loosened. Furthermore, in this embodiment, the friction member 41 is fitted into the diameter-expanding member 31, and the friction member 41 firmly couples the bolt body 11 and the diameter-expanding member 31, so that expansion and contraction due to temperature change over time, excessive vibration, etc. However, the diameter-expanding member 31 does not fall off from the bolt body.
Therefore, as a result of the diameter-expanding member 31 expanding the diameter of the threaded portion of the bolt body 11 (widening) and exhibiting a strong locking effect, loosening of the bolt can be reliably prevented. Since the bolt main body 11 and the diameter-expanding member 31 are firmly coupled with the friction member 41 interposed therebetween, the bolt 700 and the object to be fastened are loosened and rotated in the direction of disengagement even when strong vibration is applied. There is no.

  In the seventh embodiment, the loosening-stop bolts are used to expand the rear end space of the bolt main body to which the object to be fastened is screwed by the bolt, and the male screw part is firmly coupled to the female screw part. Although firmly connected, as described in the sixth embodiment (see FIG. 12), after inserting the bolt shaft into the through hole of the fastened object without providing the bolt shaft portion and the threaded portion in the fastened object, The rear end space of the bolt body can be expanded by a diameter increasing member, and the rear end space of the bolt shaft can be firmly joined to the through hole of the fastened object to join the fastened object. Furthermore, the bolt shaft is fastened by expanding the rear space of the bolt body by expanding the rear end space of the bolt body by increasing the length of the bolt shaft longer than the length of the through hole of the object to be fastened. The part exposed from the object becomes larger than the diameter of the through hole, i.e., enlarged. Portion becomes the role of the nut, it is possible to firmly couple the fastened object. In addition, there is a friction member between the diameter-expanding member and the space of the bolt body, so there is no loosening between the two due to vibration or temperature change. It also has a locking bolt effect that does not loosen.

[Eighth Embodiment]
FIG. 14 is a partially cutaway side view showing the bolt 800 of the eighth embodiment.
A loosening prevention bolt 800 of the eighth embodiment will be described with reference to FIG.
Since the eighth embodiment is the same as the third embodiment except that the diameter-expanding member is different from the third embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.
Since the diameter-expanding member and the friction member are the same as those in the sixth embodiment, detailed description is omitted.

The assembly and usage of the bolt will be explained.
Next, the assembly and use method of the bolt 800 in this embodiment will be specifically described.
As shown in FIG. 14, the bolt body 311 is inserted through the through holes of the objects A and B to be fastened. The length of the shaft portion 313 of the bolt body 311 is designed to be substantially the same as the length of the through holes of the objects A and B to be fastened. In addition, in FIG. 14 which shows this embodiment, the thread part B1 is formed in the inner peripheral wall of the through-hole of the to-be-fastened object B. FIG.
In this embodiment, the head 312 of the bolt body 311 is rotated with a tool, the bolt body 311 is inserted into the through holes of the objects A and B, and the objects A and B are fastened.
Next, the enlarged member 31 with the friction member 41 made of a spring member is inserted into the fastening shaft portion 353 of the auxiliary bolt 321, and the enlarged member 31 is fitted together with the auxiliary bolt 321 in the space 317 provided in the bolt body. Is tightened to the bolt body 311 to move the diameter-expanding member 31 to the back of the space 317. At this time, the wing 35 (see FIG. 11) provided on the diameter-expanding member 31 is fitted into the slit 18 provided at the lower end of the bolt body 311. By inserting the wings 35 into the slit 18, the auxiliary bolt 321 is rotated to draw the enlarged member 31 into the bolt body, whereby the enlarged member 31 is prevented from rotating and the enlarged member 31 is rotated by the auxiliary bolt 321. Move following the movement.

As described above, the auxiliary bolt 321 is inserted into the shaft hole 315 of the bolt body 311 and the auxiliary bolt is rotated by a tool (not shown), whereby the diameter-expanding member 31 is pulled up in the head 312 direction. The force applied to the frustoconical side surface of the diameter-expanding member 31 by pulling up the diameter-expanding member 31 is in the direction of expanding the diameter of the truncated cone-shaped space 317 of the bolt body, that is, the tip portion of the shaft portion 313 of the bolt body 311. Acts in a direction to spread from the inner side to the outer peripheral side.
Thus, when the side surface of the diameter expanding member 31 moves so as to push the tip portion of the shaft portion 313 of the bolt main body 311 from the inside to the outer peripheral side, the friction member 41 fitted into the diameter expanding member 31 becomes a member of the diameter expanding member 31. The friction member 41 made of a spring member sandwiched between the side surface and the side surface of the truncated conical space 317 of the bolt body 311 is pressed so that the outer periphery bites into the space 317 of the bolt body as schematically shown in the enlarged view. Then, the diameter-expanding member 31 is fixed to the side surface of the space portion. For this reason, the diameter-expanding member 31 is firmly fixed to the space 317, so that it does not fall off even under vibrations or severe temperature changes.
In this way, the end portion of the bolt body 311 is pushed and expanded by the diameter-expanding member 31, and the bolt body 311 is firmly fixed to the fastened object by being pressed against the through hole of the fastened object B, and loosens for a long time. There is nothing. Moreover, since the edge part of the bolt main body 311 is expanded, the role of a nut can also be played simultaneously.

[Ninth Embodiment]
FIG. 15 is a partially cutaway side view showing the bolt 900 of the ninth embodiment.
Since the ninth embodiment is the same as the fourth embodiment, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.
Further, since the diameter-expanding member and the friction member are the same as those in the sixth embodiment, detailed description thereof is omitted.

The usage will be explained.
FIG. 15 is a partial cross-sectional view of the bolt 900 according to the ninth embodiment in use.
The bolt body 411 is passed through the through-holes of the objects A and B to be fastened. At this time, both ends of the bolt main body 411 (both ends where the screw portions 414 are formed) protrude from the surfaces of the fastened objects A and B to substantially the same extent.
A nut 451 having a spiral groove screwed to the threaded portion 414 on the inner peripheral surface is attached to the threaded portion 414 of each projecting end of the bolt body 411 with a washer 452 interposed therebetween, and the fastened objects A and B are attached. Tighten and fix.
Next, a diameter-expanding member 31 (for example, having the same shape as FIG. 11 (f)) with the friction member 41 attached is inserted into the frustoconical space 417 at both ends of the bolt body 411. The auxiliary bolt 321 is inserted through the connecting hole, and the auxiliary bolt 321 is rotated with a tool or the like.

When the auxiliary bolt 321 is rotated and screwed into the shaft hole 453, the diameter-expanding member 31 is prevented from rotating by a rotation preventing function such as a blade that engages with a slit (not shown) of the bolt body as in the first embodiment. Configure as follows. Further, the diameter-expanding member 31 is pushed inward by the locking head 357 of the sub bolt 321 and moves inwardly in the frustoconical space 417. Therefore, the end of the bolt main body 411 is expanded in diameter and strongly pressed against the inner peripheral wall of the nut 451, and the friction member 41 enters between the inner wall of the nut 451 and the expanded diameter member 31, and both are firmly coupled. .
By performing the operation of tightening the sub bolt 321 simultaneously or alternately on the fastened object A side and the fastened object B side, the fastened objects A and B are fastened, and the bolts are firmly fixed without loosening. Is done.
The ninth embodiment is particularly effective when applied to fastened objects A and B having through holes larger than the outer diameter of the bolt body 411 as shown in FIG.

[Tenth embodiment]
FIG. 16 is a partially cutaway side view showing the bolt 1000 of the tenth embodiment.
The tenth embodiment is the same as the fifth embodiment except that the diameter-expanding member is different from the fifth embodiment. Therefore, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.
Further, since the diameter-expanding member and the friction member are the same as those in the sixth embodiment, detailed description thereof is omitted.

It explains with use.
First, the bolt main body 561 is inserted into the through holes of the objects A and B to be fastened. Next, the nut 551 is screwed onto the tip of the shaft portion 563 of the bolt main body 561 protruding from the fastened object, the nut 551 is tightened, and the fastened objects A and B are fastened. In this state, the auxiliary bolt 571 is inserted into the shaft hole 565 of the bolt main body 561, and the head 572 of the auxiliary bolt 571 is stored in the recess 566 of the bolt main body 561.

Next, the auxiliary bolt 571 is inserted with the auxiliary bolt 521 inserted through the enlarged member 31 having the friction member 41 fitted into the rear end thereof into the truncated cone-shaped space 567 of the bolt main body 561 and the enlarged member 31 (for example, FIG. 11 (f)). Insert so that the same shape) fits in, and rotate the sub bolt with a tool or the like.
By rotating the sub bolt 521 and screwing it into the shaft hole 575, the diameter expanding member 31 is pushed by the locking head 571 of the sub bolt 521 so that the diameter expanding member 31 moves inwardly in the frustoconical space 567. Moving. Therefore, the end of the bolt main body 511 is expanded in diameter and strongly pressed against and pressed against the inner peripheral wall of the nut 551, and the friction member 41 enters between the inner wall of the nut 551 and the expanded diameter member 31, and the two are firmly coupled. To do.
The tenth embodiment is also particularly effective when applied to fastened objects A and B having through holes larger than the outer diameter of the bolt main body 511 as shown.

  In the bolts of the ninth and tenth embodiments, the bolted bodies are joined by the bolt main bodies 411 and 511 and the nuts 451 and 551, and then the rear end space of the bolt main body is expanded by the diameter-expanding member, and the male screw portion is the nut Although the nut 451 is not provided, the end space of the bolt main body is expanded by the diameter-expanding member and the end space is expanded larger than the diameter of the through-hole of the fastened object without providing the nut 451. Thus, as described with reference to FIG. 12C of the sixth embodiment, the bolt shaft portion cannot be pulled out from the through-hole of the fastened object, and thus the fastened object can be fastened. In addition, there is a friction member between the diameter-expanding member and the space of the bolt body, so there is no loosening between the two due to vibration or temperature change. It also has a locking bolt effect that does not loosen.

[Eleventh embodiment]
FIG. 17 is a partially cutaway side view showing the bolt 1100 of the eleventh embodiment.
The eleventh embodiment is the same as the fifth embodiment except that the diameter-expanding member is different from the fifth embodiment. Therefore, the same portions are denoted by the same reference numerals, and detailed description thereof is omitted.

It attaches and demonstrates to a diameter-expansion member.
FIG. 18 shows a diameter-expanding member, which is different from the diameter-expanding member 31 shown in FIG. 11 in that one or more slits 45 are provided in the diameter-expanding member. Although described in detail, the same portions as those of the diameter-expanding member 31 shown in FIG. 18 shows an embodiment in which the slit 45 is provided in the diameter-expanding member 31 having the friction member 41 shown in FIG. 11, but it is needless to say that the present invention can be applied to the diameter-expanding member 31 shown in FIG.
The diameter-expanding member 31 is inserted into the truncated cone-shaped space 17 provided in the bolt body 11, and has the function of expanding the tip screw portion of the bolt body 11 outward when moved by the sub bolt 21. The same as the diameter-expanding member 31.

The diameter-expanding member 31 of this embodiment has a truncated cone shape as shown in FIG. The side surface 32 of the diameter-expanding member 31 is formed in a truncated frustoconical shape that eliminates the top of the cone in accordance with the inclination angle of the frustoconical space 17 provided in the bolt body 11. The diameter-expanding member 31 has a frustoconical part at least in part, and the frustoconical side surface 32 abuts exclusively on the side surface of the space 17 to expand the diameter of the space 17. Just do it.
The diameter-expanding member 31 is screwed with the auxiliary bolt 21. In the present embodiment, a screw hole 33 (connection hole) that is screwed into the screw portion 25 of the sub bolt 21 is screwed to the shaft core portion of the diameter expanding member 31.

Further, the frustoconical side surface 32 is provided with an anti-rotation function if necessary. The anti-rotation function is provided with a wing 35 as shown in FIG. 18A to 18C fitted into the slit 18 provided in the bolt body 11, and provided with a pin 36 as shown in FIG. Then, a knurling process 37 or the like as shown in FIG.
The rotation preventing function is provided in the diameter-expanding member 31 in this way because the diameter-expanding member 31 rotates when the diameter-expanding member 31 screwed into the sub-bolt 21 is rotated and moved. This is to prevent it. The mechanism for preventing the rotation of the diameter-expanding member 31 may be any configuration as long as it can perform the function of preventing the diameter-expanding member 31 from rotating.

In the present embodiment, one or more slits 45 are provided in the diameter expanding member 31. As shown in the figure, the slit 45 is provided from the top to the bottom or from the bottom to the top in the longitudinal direction of the diameter increasing member.
FIG. 18B shows an embodiment in which slits 45 are provided in the diameter-expanding member 31 having the wings 35 from the top to the bottom. (B1) is an embodiment in which slits 45 are provided from the bottom to the top.
FIG. 18D shows an embodiment in which slits 45 are provided in the diameter-expanding member 31 having the pins 36 from top to bottom. (D1) is an embodiment in which slits 45 are provided from the bottom to the top.

FIG. 18E shows an embodiment in which slits 45 are provided on the diameter-expanded member 31 that has been subjected to the knurling process 37 from the top to the bottom. (E1) is an embodiment in which slits 45 are provided from the bottom to the top.
FIG. 18 (f) is an embodiment in which slits 45 are provided from the top to the bottom in the enlarged diameter member 31 having a step on the side surface, and FIG. 18 (f 1) is provided with the slits 45 in the enlarged diameter member 31 from the bottom to the top. This is an example.

FIG. 19A shows an embodiment in which slits 45 are provided in the diameter-expanding member 31 from the top to the bottom, and the diameter of the side surface corresponding to the slit is slightly increased. (A1) is an embodiment in which a slit 45 is provided from the bottom to the top and the diameter of the side surface corresponding to the slit is slightly increased. FIG. 19 (b) is an enlarged explanatory view of FIG. 19 (a).
18 and 19 have been described with respect to the embodiment in which the friction member 41 is added to the diameter-expanding member 31, but it is of course effective to provide a slit in the diameter-expanding member that does not have the friction member shown in FIG. is there.

A description will be given according to the use state.
The use state will be described with reference to an embodiment showing a state in which two objects to be fastened A and B (see FIG. 12A) are fastened with a bolt 1100 shown in FIG.
First, the auxiliary bolt 21 is passed through the shaft hole 15 of the bolt main body 11, the diameter-expanding member 31 is screwed into the distal end portion of the fastening shaft portion 23, and lightly screwed and temporarily fixed to assemble the bolt 1100. (See FIG. 17B). In this state, the tip of the threaded portion 14 of the bolt body 11 does not bulge radially outward (does not expand), and can be handled in the same manner as a normal bolt because it maintains the normal dimensions.

  In order to join the two fastening objects A and B with the assembled bolt 1100, as shown in FIG. 12 (a), the base side fastening with a spiral groove cut into the male threaded portion 14 of the bolt body 11 is cut. The bolt body 11 is screwed into the threaded portion B1 of the object B. When screwing, the bolts 1100 are tightened with a wrench or the like, the lower part of the bolt head 12 is brought into contact with the surface of the object A to be fastened, and the objects A and B are fastened with normal tightening strength.

Next, in order to prevent loosening, a rotating tool (for example, a hexagonal wrench) (not shown) is applied to the head 22 of the sub bolt 21 to rotate the sub bolt 21 and screwed into the end of the sub bolt 21. The diameter-expanding member 31 is pulled up. When the diameter-expanding member 31 is pulled up toward the locking head 22, the stress on the side surface 32 of the diameter-expanding member 31 is applied to the space 17. Since the slit 17 is provided in the space 17, the space 17 is pushed outward and the shaft portion 13 of the bolt body 11 is expanded in diameter. By expanding the diameter of the shaft portion 13, the spiral groove (male thread portion) 14 is firmly brought into contact with the thread portion (spiral groove) B 1 of the article B to be fastened. The bolt 1100 cannot be loosened by the force of the tool rotating the portion 12.
On the other hand, as the diameter-expanding member 31 is pulled up toward the locking head 22, the stress on the side surface 32 of the diameter-expanding member 31 is applied in the direction in which the sub bolt 21 is tightened. Since the slit 45 is provided in the diameter expanding member 31, the pressure applied to the diameter expanding member 31 tightens the sub bolt 21 with a strong force, and the shaft portion 23 of the sub bolt 21 is prevented from rotating. The Since the shaft portion 23 of the sub bolt 21 is firmly tightened by the diameter-expanding member 31, even if the sub bolt 21 is rotated in the removing direction, the bolt 1100 is loosened by the force of the tool that rotates the locking head 22 of the sub bolt 21. It is not possible. Therefore, the bolt 1100 of this embodiment can be used effectively for theft prevention.

  In particular, as shown in FIGS. 19 (a) and 19 (a1), specifically, FIG. 19 (b) in an enlarged manner, the diameter of the side surface 32 corresponding to the slit 45 is slightly increased, so that the diameter-expanding member 31 passes through the space 17. The force that tightens the slit 45 is increased by moving after pushing and expanding the space, and the diameter-expanding member 31 is firmly coupled to the fastening shaft portion of the sub bolt. The loosening-preventing effect becomes even more effective when the diameter-expanding member 31 tightens the shaft portion of the sub bolt more firmly.

In the sixth embodiment or the like, a friction member 41 (an elastic O-ring, or a circular spring member divided into two or a plurality of parts if necessary) is mounted in the circumferential direction of the frustoconical side surface 32 of the diameter expanding member 31. did. In this embodiment, since the friction member 41 is firmly joined to the sub bolt 21, the friction member 41 is not necessarily required, but it is more effective to use in view of safety.
In this embodiment, since the sub bolt 21 is fixed by the diameter-expanding member 31, it does not loosen even if vibration or temperature change is applied to the object to be fastened. Since 21 is not removed, it has an excellent effect as an antitheft bolt.

  When the bolt of the present invention is used for theft prevention, for example, it is also effective to change the head shape and recess shape of the bolt main body and the head shape of the auxiliary bolt from the hexagonal shape to the pentagonal shape in each of the above embodiments. It is. Generally, a commercially available tool for rotating a bolt is compatible with a hexagon (even-numbered square). For this reason, a special tool is used as a tool for rotating the bolt by making the head for rotating the bolt or the like using a tool into a pentagonal shape. By making the bolt head a pentagon (an odd-numbered square, a heptagon or a nine-sided is also possible), it can serve as a wing for preventing theft.

[Twelfth and thirteenth embodiments]
As described above, the bolt in the first embodiment has a risk of loosening due to the effects of thermal expansion and contraction and the influence of vibration, and this risk has been eliminated in the sixth embodiment, the eleventh embodiment, and the like. In this embodiment, the secondary bolt is prevented from being loosened with a simple configuration.

This embodiment will be described in the state applied to the first embodiment.
FIG. 20 shows the twelfth embodiment. Since the bolt main body, the sub-bolt, and the diameter-expanding member described in the first embodiment are the same, the same reference numerals are given and detailed description is omitted.
In the present embodiment, a protrusion preventing member 60 is provided for preventing the auxiliary bolt from loosening due to temperature change or vibration during use of the bolt, and coming out.
The protrusion preventing member 60 is provided so as to close the concave portion 16 provided in the head 12 of the bolt main body 11. The protrusion preventing member 60 closes the recess 16 provided in the head portion 12 of the bolt main body 11, so that even if the sub bolt 21 is loosened during use and moves in the direction of protruding from the bolt main body (the protruding direction), the sub bolt 21 The head 22 is configured to be prevented from protruding by being prevented from protruding by the protrusion preventing member 60.

FIG. 20 shows a twelfth embodiment in which the protrusion preventing member 60 prevents the auxiliary bolt from loosening and protruding from the bolt main body. The protrusion preventing member 60 is formed in a lid shape, and the head of the bolt main body 11 is formed. The state fixed to the part 12 with the screw 62 is shown.
In the twelfth embodiment, the protrusion preventing member 60 is formed in a lid shape. However, any shape may be used as long as the auxiliary bolt protrudes, that is, the auxiliary bolt is prevented from rotating and prevented from protruding. . For example, as in the thirteenth embodiment shown in FIG. 21, a plate (projection prevention member 61) bent in a U shape may be arranged so as to cross the concave portion of the bolt main body and fixed to the bolt head 12. .
Alternatively, in the type in which the head 22 of the sub bolt is inserted into the recess 16 of the bolt main body head 12 as shown in FIG. 1, the gap between the recess 16 and the head 22 is filled with a solid member such as a curable resin. Thus, the auxiliary bolt may be configured to be prevented from rotating, and the auxiliary bolt may be fixed to the bolt body by welding or bonding with an adhesive.

[Fourteenth, fifteenth and sixteenth embodiments]
22 and 23 show the fourteenth and fifteenth embodiments of the present invention, in which the head 21 of the bolt body 11 is embedded in the recess A2 provided in the fastened part A. FIG.
In particular, the embodiment shown in FIG. 23 is constructed such that when the lower part of the bolt head is embedded in the article A to be fastened as an inclined surface, the surface of the article to be fastened and the head are not uneven.
FIG. 24 shows a sixteenth embodiment of the present invention, in which the bolt body is composed of a pan screw.

[Seventeenth embodiment]
FIG. 25 shows a seventeenth embodiment of the present invention. The bolt body 411 shown in FIG. 15 is composed of hexagon socket set bolts 412, and a minus or plus groove for rotating the subsidiary bolt is provided on the head 357 of the subsidiary bolt. The configuration is provided.

  Although the fourteenth to seventeenth embodiments are partially different from the above-described embodiments, the essence is the same as that of the above-described embodiments, and thus detailed description thereof is omitted.

  As described above, the present invention has been described with a plurality of embodiments. However, the present invention can be implemented by arbitrarily changing the combination of the bolt main body, the sub bolt, the diameter expanding member, and the friction member described in each embodiment. The present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 Bolt 11 Bolt main body 12 Bolt head 13 Bolt shaft part 14 Spiral groove 15 Shaft hole 16 Head recessed part 17 Rear end space 18 Slit 21 Sub bolt 22 Locking head 23 Fastening shaft part 25 Screw part 31 Diameter expansion member 32 Side surface 32 Frustum-shaped side surface 33 Screw hole 34 Friction member holding part (groove)
35 blades 36 pins 37 knurl processing 41 friction members 45 slits 60 protrusion preventing members 61 protrusion preventing members 210 bolts 221 sub bolts 223 fastening shaft portions 225 screw portions 251 nuts 310 bolts 311 bolt bodies 312 heads 313 bolt body shaft portions 314 spiral grooves 315 Shaft hole 317 frustoconical space 318 Slit 321 Sub bolt 338 Through hole 353 Fastening shaft portion 355 Screw portion 357 Locking head 358 Screw portion 359 Fastening shaft portion 410 Prevention bolt 410 Bolt 411 Bolt body 413 Shaft portion 414 Screw portion 417 Frustum-shaped space 421 Sub bolt 451 Nut 453 Shaft hole 510 Bolt 511 Bolt main body 521 Sub bolt 551 Nut 561 Bolt main body 562 Head 563 Shaft portion 565 Shaft hole 566 Recess 567 Space 571 Auxiliary Belt 572 head 573 shank 574 threaded portion 575 shaft hole 600 volts 700 volts 800 volts 900 volts 1000 volts 1100 volts A fastened object B fastened object B1 threaded portion

Claims (6)

It is a bolt consisting of a bolt body, a sub bolt, and a diameter expanding member,
The bolt body is formed such that a shaft hole is formed in at least one end portion of the shaft core portion, and a frustoconical space is widened as the end portion of the shaft hole is closer to the tip. One or more slits are formed from the tip of the tip of the shaft part formed with
The diameter-expanding member is disposed in the space of the bolt body, and has a truncated conical side surface that abuts against the inner wall of the space and expands the space.
The sub bolt is inserted into a shaft hole provided in the bolt body, and the diameter expanding member is moved in a direction of expanding the space of the bolt body to apply a diameter expanding force to the space of the bolt body. It is a bolt composed of a bolt body, a diameter expanding member, a friction member, and a sub bolt,
The bolt body is formed such that a shaft hole is formed in at least one end portion of the shaft core portion, and a frustoconical space is widened as the end portion of the shaft hole is closer to the tip. One or more slits are formed from the tip of the tip of the shaft part formed with
The diameter-expanding member is disposed in the space of the bolt main body, contacts the inner wall of the space, expands the space, and has a truncated cone-shaped side surface between the truncated cone-shaped side surface and the truncated cone-shaped space. A friction member holding portion that holds the friction member to be inserted;
The friction member is held by the friction member holding portion;
The sub bolt is inserted into a shaft hole provided in the bolt body, and the diameter expanding member is moved in a direction of expanding the space of the bolt body to apply a diameter expanding force to the space of the bolt body.   The said diameter-expansion member is arrange | positioned in the said truncated-cone-shaped space of a volt | bolt main body, and is comprised so that a shaft rotation may be prevented with respect to the said volt | bolt main body by a rotation prevention function. bolt.   The bolt according to claim 1 or 2, wherein a slit is provided in the diameter-expanding member. The bolt body is composed of a bolt main body and an auxiliary bolt,
The bolt main body is provided with a shaft hole in the shaft core portion, and is formed so that the end portion of the shaft hole becomes a frustoconical space that is wider as the end is closer to the tip, thereby forming the frustoconical space. One or more slits are formed in the circumferential direction of the tip end shaft hole,
The auxiliary bolt is inserted into the bolt main shaft hole in a non-rotatable manner, and an auxiliary bolt end portion is provided with a screw portion for screwing the auxiliary bolt with the diameter-expanding member attached thereto. The described bolt.   The bolt according to any one of claims 1 to 5, further comprising a sub-bolt protrusion preventing member that prevents the sub-bolt from slipping out of the bolt body.

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