JP2009097707A - Bolt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bolt which can be tightened without using a special tool and cannot be loosened after being tightened, but which is allowed to be loosened in an emergency. <P>SOLUTION: A bolt comprises a first bolt having a through-hole in the center, a second bolt made up of a second bolt shaft which is slidably inserted into the through-hole drilled into the first bolt shaft and is longer than the first bolt and of a second serration provided to one end of the second bolt shaft, and a lock part provided to a second bolt shaft end on an opposite side to the second serration. A first locking part functioning as a locking part in one rotation direction and not functioning as a locking part in the reverse rotation direction is formed on a head part of the first bolt. A second locking part locked in the first locking part provided to the first bolt to turn the first bolt in one direction only is formed on a surface facing the fist bolt head of the second serration. A maximum diameter of the lock part is made wider than a hole diameter of the through-hole and narrower than a diameter of the first bolt shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bolt that is screwed to an object to be fastened, and more particularly to a bolt that is difficult to be removed from the object to be fastened once screwed to the object to be fastened.

Various bolts that are difficult to remove from a fastened object after connecting two or more fastened objects such as a bolt for attaching a license plate to a vehicle and a bolt for attaching a groove lid to a U-shaped groove have been proposed.
For example, Patent Document 1 includes a bolt and a nut, and a washer is inserted between the nut and the object to be fastened. When the nut fastens the object to be fastened to the joint surface of the washer and the nut, the washer rotates. A bolt nut having a wedge-shaped slope that does not serve as a locking portion when the nut is rotated in the reverse direction and prevents the nut from loosening by biting a sharp fitting line provided on the washer into the fastened object is disclosed. However, with such a structure, there is a problem that the processing cost of the washer is increased, and when the fastened object is hard, it cannot be dealt with.

  Further, Patent Document 2 discloses an apparatus for preventing theft by separating a bolt and a fastening material for fastening the bolt, attaching them with screw members, and removing the nut after attaching the nut to an object to be fastened. ing. However, in such a configuration, there are disadvantages such as a tightening operation of the nut and a removing operation of the nut, increasing the number of work steps, and if the forgetting to remove the nut, the role of preventing theft is lost.

  Further, in Patent Document 3, an umbrella-shaped flange portion is provided at the head of the screw shaft, and a turning operation portion is provided at the upper end of the flange portion through a breakable squeezing portion. When the torque is applied to the bent portion, a configuration is disclosed in which the bent portion is broken and no further force is applied to the object to be fastened and the umbrella portion is not loosened because no tool is applied. However, in such a configuration, there is a problem that the bolt cannot be loosened even if the bolt has to be loosened.

Utility Model Registration No. 3092753 Japanese Patent Laid-Open No. 10-37939 JP 2003-343537 A

  The present invention relates to a bolt that can be tightened without using a special tool and can be loosened as necessary even after tightening.

  The first bolt of the present invention is slidably inserted into a first bolt composed of a bolt shaft having a through hole in the center, and a through hole formed in the first bolt shaft. A second bolt comprising a long second bolt shaft and a second serration provided at one end of the second bolt shaft, and a lock provided at the second bolt shaft end opposite to the second serration of the second bolt And the first bolt head has a first locking portion that becomes a locking portion when rotating in one direction and does not become a locking portion when rotated in the reverse direction, and the second serration The surface facing the head of the first bolt has a second locking portion that locks with the first locking portion provided on the first bolt and rotates the first bolt only in one direction. The maximum diameter of the lock portion is larger than the diameter of the through hole, and is larger than the diameter of the first bolt shaft. It is characterized in that the small.

  The second bolt of the present invention includes a first bolt comprising a first bolt shaft having a through hole in the center and a first serration provided at one end of the bolt shaft, and a through hole formed in the first bolt shaft. A second bolt comprising a second bolt shaft longer than the length of the first bolt and a second serration provided at one end of the second bolt shaft; and a second bolt of the second bolt A locking part provided at the end of the second bolt shaft opposite to the serration. The head of the first serration becomes a locking part when rotating in one direction, and does not become a locking part when rotating in the reverse direction. The first serration of the second serration facing the first serration is engaged with the first serration provided on the first serration, and the first serration is rotated only in one direction. A second locking portion that moves, the locking portion Maximum diameter is characterized by less than the diameter of the first bolt larger than the diameter of the through hole.

In the bolt, it is preferable that the first bolt shaft and the first serration are integrally formed.
In the bolt, it is preferable that the first bolt shaft and the first serration are formed separately, and the first serration is fixed to a tip portion of the first bolt shaft.

In the bolt, it is preferable that the second bolt shaft and the second serration are integrally formed.
In the bolt, it is preferable that the second bolt shaft and the second serration are formed separately, and the second serration is fixed to a tip portion of the second bolt shaft.

In the bolt, a second locking portion for locking the first bolt on the surface facing the first serration of the second serration and rotating the first bolt It is preferable that the washer is fixed.
In the bolt, it is preferable that the head of the first bolt has a concave portion or a convex portion that engages with a third tool and allows the first bolt to rotate.

In the first bolt, it is preferable that a head of the first bolt has an arc shape and the locking portion is provided on the arc-shaped surface.
In the second bolt, it is preferable that the head of the first serration has an arc shape, and the locking portion is provided on the arc-shaped surface.
It is preferable that a spring member is inserted between the bottom portion of the first bolt and the lock portion.

  Once the bolt of the present invention has been tightened, it cannot be loosened or removed.If necessary, the second bolt is damaged and removed. There is an effect that can be judged at a glance.

Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows one embodiment of the first bolt 100 of the present invention. The first bolt 100 shown in the first embodiment is composed of a first bolt 1, a second bolt 2, and a lock portion 3. Has been.
The first bolt 1 includes a bolt shaft 11 having a through hole 12 formed in the center, and a spiral groove 13 is formed on the surface of the bolt shaft 11. A head portion of the bolt shaft 11 is formed with a first locking portion (14) which becomes a locking portion when rotating in one direction and does not become a locking portion when rotating in the opposite direction. The first locking portion (14) shown in FIG. 1 includes a plurality of contact surfaces 14 (locking portions to be engaged) provided radially from the center of the bolt shaft in the radial direction. The contact surface 14 is composed of a raised surface 141 and an inclined surface 142 that is lowered to a wedge-shaped inclined surface of the inclined cone surface with the raised surface 141 as a vertex, and a second locking portion 24 formed on the second bolt 2 described later. The first bolt is rotated only in one direction and is rotated idly with respect to the rotational force in the reverse direction.

  The second bolt shaft 2 is slidably inserted into a through hole 12 drilled in the first bolt shaft 11 and has a length L2 longer than the length L1 of the first bolt shaft 11. 21 and a second serration 25 provided at one end of the second bolt shaft 21. The second bolt shaft 21 and the second serration 25 may be formed integrally, or may be formed separately and joined (fixed).

The surface of the second serration 25 facing the first locking portion 14 provided on the first bolt head is locked to the first locking portion 14 provided on the first bolt so that the first serration is A second locking portion (24) that rotates only in one direction (the direction in which the bolt is tightened) is formed. The second locking portion 24 is in contact with the contact surface 141 of the first locking portion 14 as shown in the figure, and a contact portion 241 that applies a rotational force in one direction to the contact surface 141 of the first locking portion 14. The inclined surface 242 is lowered in the shape of a wedge-shaped slope with an oblique conical surface with the corresponding contact portion 241 as the apex, and meshes with the first locking portion 14 to rotate the first bolt 1 in one direction and in the opposite direction. Is configured to run idle.
The locking portions 14 and 24 will be further described in detail with reference to FIG.
Although the cut surfaces (contact portions) 141 and 241 are formed as the locking portions 14 and 24, they may be formed as a cut surface and a protruding surface cut vertically in a triangular shape instead of the cut surfaces.

The lock portion 3 is attached to the bottom of the second bolt to prevent the second bolt 2 from coming off from the first bolt 1, and thus the lock portion 3 is formed in the through hole 12 provided in the first bolt 1. The diameter is larger than the diameter of the first bolt and smaller than the diameter of the first bolt. Since it is sufficient for the lock portion 3 to play a role of preventing the second bolt 2 from falling out of the first bolt 1, the shape thereof is not limited to the circular shape shown in the figure, and can be formed in a polygonal shape, a rod shape, etc. The two bolts 2 can be attached by screwing, welding, bonding with an adhesive, or the like.
The first bolt 1 and the second bolt 2 are formed by inserting the bolt shaft 21 of the second bolt into the through hole 12 of the first bolt 1 and attaching the lock portion 3 to the bottom of the second bolt shaft 21. The bolt 100 can be configured. In the figure, reference numeral 26 denotes a range mounting hole into which a range for rotating the second bolt 2 is inserted.

  In order to couple the two fastened objects A and B with the first bolt, as shown in FIG. 2, the spiral groove 13B that is screwed into the spiral groove 13 of the first bolt 1 is cut on both of the fastened objects A and B. The first bolt 1 is screwed into the spiral groove 13B. When screwing, for example, a hexagonal range (not shown) is inserted into the hexagonal groove 26 provided at the head of the second bolt and turned so that the locking portion 24 provided on the second serration is provided on the first bolt. The first bolt 1 is rotated by meshing with the portion 14, the first bolt 1 is screwed into the spiral groove 13 </ b> B of the article (A), B to be fastened, and the articles A and B are fastened.

  Once the object to be fastened is screwed once with the first bolt as shown in FIG. 2, the first locking is achieved even if the second serration is rotated in the removal direction (the direction opposite to the tightening direction) to remove this connection. The portion 14 and the second locking portion 24 are idle, so that the rotational force of the second serration is not applied to the first bolt, and the first bolt 1 does not rotate in the direction of disengagement. It cannot be removed.

  As described above, the length L2 of the second bolt shaft 21 is longer than the length L1 of the first bolt shaft 11 by H as shown in FIGS. Although the length H can be designed arbitrarily, it is preferable that the length H be longer than the length h at which the engagement between the first locking portion 14 and the second locking portion 24 is removed as shown in the figure.

To release the connection between the objects A and B to be fastened, the second bolt 2 is pulled upward as shown in FIG. By pulling up the second bolt 2 upward, a gap of length h is formed between the first bolt 1 and the second serration 25. The second bolt shaft 21 is cut using this gap. By cutting the second bolt shaft 21, the head of the first bolt appears and engages with a third tool (driver, wrench, etc.) provided on the head to rotate the first bolt. The third tool is attached to the concave portion or the convex portion, and the first bolt 1 is removed from the object to be fastened by rotating in the direction in which the first bolt is removed (the direction opposite to the attaching direction). Examples of the recess include a polygonal hole that fits a polygonal wrench, a minus or plus groove into which a minus or plus driver can be inserted, and a plurality of depressions. The convex portion is a rod-like or polygonal column that can be hooked on the convex portion and turn the first bolt 1. In order to protect the object to be fastened from theft, nothing is provided on the head of the first bolt 1 to prevent the rotation of the bolt by the third tool. In addition, when the second bolt 2 is damaged due to fraud or the like, it is found that there is no second bolt when viewed from the outside, and thus it is also possible to monitor theft prevention.
In addition, this invention is not limited to the said embodiment, The change in the range which does not change the main point of invention is possible variously.

  FIG. 3 shows a second embodiment of the present invention. A second bolt 200 shown in the second embodiment includes a first bolt shaft 11 having a through hole 12 in the center and a head of the bolt shaft 11. A first bolt 10 comprising a first serration 16 provided on the first bolt shaft 11 and a second bolt L1 which is slidably inserted into a through-hole 12 drilled in the first bolt shaft 11 and which is longer than a length L1 of the first bolt 10. Of the second bolt shaft 21 and the second serration 25 provided on the head of the second bolt shaft 21, and the second bolt 20 on the opposite side of the second serration 25. It is comprised with the lock | rock part 3 provided in the 2nd volt | bolt shaft end (butt | face part).

The head portion of the first serration 16 has a first locking portion 14 that becomes a locking portion when rotating in one direction and does not become a locking portion when rotated in the reverse direction. On the surface facing 16, there is a second locking portion 24 that locks with the first locking portion 14 provided on the first serration 16 and rotates the first serration in one direction. The shape of the locking portions 14, 24 is the same as that of the first embodiment as shown in FIG.
Since the shape and size of the lock portion 3 are the same as those in the first embodiment, detailed description thereof is omitted.

As described above, in the second bolt 200 of the second embodiment, the first bolt 10 in the second bolt 200 is different from the first bolt 1 of the first bolt 100 in the first embodiment.
The first serration 16 constituting the first bolt 10 is formed integrally with the first bolt shaft 11 by forging, for example, or in a separate process on the head of the bolt shaft 11 in which the spiral groove 13 is inscribed at a predetermined location. The molded first serration 16 is fixed by welding, bonding with an adhesive, shrink fitting, or the like. The first bolt shaft 11 and the first serration 16 are separated from each other by procuring a commercially available long screw rod as the first bolt shaft 11, cutting it to a predetermined length, and drilling through holes. This is because the first serration 16 can be easily manufactured by pressing, and can be manufactured and provided at low cost by joining (fixing) the two.

  In order to couple the two fastened objects A and B with the second bolt 200, as shown in FIG. 3E, the spiral groove 13 of the first bolt 1 is at least placed on the fastened object B. The spiral groove 13B that is screwed into the first groove 1 is cut, and the first bolt 1 is screwed into the spiral groove 13B. When screwing, for example, a hexagonal range (not shown) is inserted into the hexagonal groove 26 provided at the head of the second bolt and turned so that the locking portion 24 provided on the second serration is provided on the first bolt. The first bolt 1 is rotated by meshing with the portion 14, the first bolt 10 is screwed into the spiral groove 13 </ b> B of the fastened object (A,) B, and the lower portion of the first serration 16 is brought into contact with the surface of the fastened object A. The fastened objects A and B are fastened.

  Since the anti-theft measures and the like in the second embodiment are the same as those in the first embodiment, detailed description thereof is omitted. When the second bolt 200 is used particularly for theft prevention, the thickness of the first serration 16 is made as thin as possible, and the outer shape thereof is circular, conical, or umbrella-shaped, and is associated with a spanner or the like. In addition, it is necessary to have a structure that prevents the first bolt from rotating as much as possible.

FIG. 5 shows a third embodiment of the present invention. The third embodiment is the same as the second embodiment except for the configuration of the second serration 25 in the second embodiment described above. The same parts as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
As shown in FIG. 5, the second serration 25 includes a flange portion 251 and a washer 252. The flange portion 251 is integrally formed with the second bolt shaft 21 or manufactured in a separate process and fixed to the bolt shaft 21, and the washer 252 is formed by press molding or the like to form the lower surface of the flange portion 251, that is, the first serration 16. And the second locking portion 24 are fixed by an adhesive or welding so that they face each other.
In the third embodiment, the second serration 25 is separated into the flange portion 251 and the washer 252. For the portion having the flange portion 251 on the bolt shaft 21, for example, a commercially available bolt can be used as it is, and the flange portion 251 of this bolt is pressed. This is because it can be provided at low cost by fixing the washer 252 created by molding or the like.

  In the present invention, the first bolt shaft and the second bolt shaft are made of a metal such as iron or stainless steel, and the first serration, the second serration, and the washer formed in a separate process from the bolt shaft are made of the same metal as the bolt shaft or a hard plastic. Can be created.

  FIG. 6 shows a fourth embodiment. In the fourth embodiment, the head portion of the first serration 16 provided on the first bolt shaft 11 is formed in a semicircular convex shape, and the locking portion 14 is formed in this portion. Is formed. The locking portion 14 can be easily formed by cutting a semicircular peripheral portion into a straight line. The locking portion 24 provided on the second serration 25 of the second bolt 20 is a semicircular recess that matches the shape of the head of the first bolt shaft 11 so that the locking portion 24 meshes with the locking portion 14. It is configured. Thus, by making the first bolt head a semicircular convex shape, it becomes difficult to hook the tool when removing the first bolt, and the effect for preventing theft is further improved. Although FIG. 6 has been described as a modified example of the second bolt 200, it is needless to say that it can be applied to the first bolt 100 as it is.

  FIG. 7 shows a fifth embodiment of the bolt of the present invention, showing the use state of the bolt of the present invention by taking the second bolt 200 as an example, and shows a state in which a nut 40 is screwed to the first buttocks. ing. For example, when the objects to be fastened A and B are assembled with the bolt of the present invention and the nut 40 is assembled in a state in which the nut 40 cannot be rotated, the nut 40 may be used without engraving the screw groove on the fastened object. Is possible.

  FIG. 8 also shows a sixth embodiment of the bolt of the present invention. A spring member (for example, a helical spring) is provided between the bottom of the first bolt 1 and the lock portion 3 attached to the second bolt in the above embodiment. ) 50 is inserted. By inserting the spring member 50 in this way, the gap between the engaging portions of the first bolt and the second bolt is always closed by the repulsive force of the spring member, and the object to be fastened is In the coupled state, the movement of the second bolt is suppressed so that it does not move. For example, it can be used without generating noise when used in a place where vibration occurs.

BRIEF DESCRIPTION OF THE DRAWINGS It shows 1st embodiment of this invention, (a) is a top view, (b) is a front view, (c) is a bottom view, (d) is a sectional view on the aa line. It is a partially cutaway front view which shows the state which attached the volt | bolt to his coupling thing. FIG. 2 shows a second embodiment of the present invention, in which (a) is a top view, (b) is a front view, (c) is a bottom view, (d) is a cross-sectional view along the line aa, and (e) is used. It is explanatory drawing which shows a state. The 1st volt | bolt in 2nd embodiment of this invention is shown, (a) is a top view, (b) is a front view, (c) is a bottom view, (d) is a bb sectional view taken on the line. . FIGS. 3A and 3B show a third embodiment of the present invention, in which FIG. 3A is a top view, FIG. 3B is a front view, FIG. 3C is a bottom view, and FIG. It is a front view which shows 4th embodiment of this invention. It is a partially cutaway front view showing a fifth embodiment of the present invention. It is a partially cutaway front view showing a sixth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st bolt 2 2nd bolt 3 Lock part 10 1st bolt 11 1st bolt shaft 12 Through-hole 13 Spiral groove 13B Spiral grooves 14 and 24 Locking part 14 First locking part 16 First serration 20 Second bolt 21 Second bolt shaft 24 Second locking portion 25 Second serration 26 Square groove 40 Nut 50 Spring member 100 First bolt 141 Abutting surface 142 Inclined surface 200 Second bolt 241 Abutting portion 242 Inclining surface 251 Flange portion 252 Washer A Fastened object B Fastened object

Claims (11)

A first bolt comprising a first bolt shaft having a through hole in the center;
A second bolt shaft that is slidably inserted into a through-hole formed in the first bolt shaft and is longer than the length of the first bolt, and a second serration provided at one end of the second bolt shaft. The second bolt,
A lock provided on the second bolt shaft end opposite to the second serration of the second bolt;
Consists of
On the head of the first bolt, a first locking portion is formed which becomes a locking portion when rotating in one direction and does not become a locking portion when rotating in the reverse direction,
A second surface of the second serration that faces the head of the first bolt is locked to a first locking portion provided on the first bolt, and the second bolt rotates only in one direction. A locking part is formed,
The maximum diameter of the lock portion is a bolt larger than the diameter of the through hole and smaller than the diameter of the first bolt shaft. A first bolt comprising a first bolt shaft having a through hole in the center and a first serration provided at one end of the bolt shaft;
A second bolt shaft that is slidably inserted into a through-hole formed in the first bolt shaft and is longer than the length of the first bolt, and a second serration provided at one end of the second bolt shaft. The second bolt,
A lock provided on the second bolt shaft end opposite to the second serration of the second bolt;
Consists of
On the head of the first serration, there is a first locking portion that becomes a locking portion when rotating in one direction and does not become a locking portion when rotated in the reverse direction,
A second engaging portion that engages with a first engaging portion provided on the first serration and rotates the first serration only in one direction on a surface of the second serration facing the first serration. Have
The maximum diameter of the lock portion is a bolt larger than the diameter of the through hole and smaller than the diameter of the first bolt shaft.   The bolt according to claim 2, wherein the first bolt shaft and the first serration are integrally formed.     The bolt according to claim 2, wherein the first bolt shaft and the first serration are formed separately, and the first serration is fixed to a tip portion of the first bolt shaft.     The bolt according to claim 2, wherein the second bolt shaft and the second serration are integrally formed.   The bolt according to claim 1 or 2, wherein the second bolt shaft and the second serration are formed separately, and the second serration is fixed to a tip portion of the second bolt shaft.   A second locking portion for locking the first bolt in one direction by locking the first locking portion provided on the first serration on a surface of the second serration facing the first serration. The bolt according to claim 1 or 2, wherein a washer having the same is fixed.   The bolt according to claim 1 or 2, wherein a concave portion or a convex portion that engages with a third tool and makes the first bolt rotatable is formed on a head portion of the first bolt.   The bolt according to claim 1, wherein a head portion of the first bolt is arc-shaped, and the first locking portion is provided on the arc-shaped surface.   The bolt according to claim 2, wherein a head of the first serration has an arc shape, and the first locking portion is provided on the arc-shaped surface.   The bolt according to claim 1 or 2, wherein a spring member is inserted between a bottom portion of the first bolt and the lock portion.

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