JPH0979245A - Screwing structure, double screw and female screw forming jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screwing structure which can be applied even for a small screw, which is not released from locking even when a turn is generated in a same direction as that in a main unit screw. SOLUTION: A structure comprises the first female screw 31 formed in a mounted body 29, second female screw 33 having the same center axis to the first female screw 31 with an internal diameter smaller than the first female screw 31 and formed in a tip end of the first female screw 31 with a tightening direction reverse to the first female screw 31 and a double screw 11 having a male screw part 13 screwed to the first female screw 31 and also screwing a locking screw 19 screwed to the second female screw 33 to the center of the male screw part 13. The male screw part 13 is inserted to a through hole 35, formed in a mounting body 27, and screwed to the first female screw 31, so as to secure the mounting body 27 to the mounted body 29. Then, in this condition, the locking screw 19 is screwed to the second female screw 33 in a reverse direction to a screwing direction of the male screw part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw structure for fixing an attachment body to an adherend, a double screw used in the screw structure, and a female screw for screwing the double screw. Regarding the ingredients.

[0002]

2. Description of the Related Art A bolt is one of the typical screw parts. Further, the bolt is a general screw-in bolt having a head at one end and a screw at the other end. After the threaded bolt penetrates the attachment body, the tip side is screwed into the adherend to fix the attachment body and the adherend. Further, a small screw or the like is used instead of the bolt to fix the small attachment body. The small screws are roughly classified into those with a slot for tightening with a so-called minus screwdriver, and those with a cross hole for tightening with a cross-shaped screwdriver.
Further, these small screws are classified into a pan small screw, a plate small screw, a round plate small screw, a flat small screw and the like depending on the shape of the head.

These screws are prevented from loosening mainly by friction between the head and the mounting body when the mounting body is fastened to the adherend. However, due to such frictional force alone, the screw may gradually loosen due to vibration and the like, and in the worst case, the screw may drop out. Therefore, conventionally, the loosening of the screw is prevented by various methods. For example, as such a locking structure, as shown in FIG. 6, by screwing a small screw 3 in the bolt center axis direction onto the bolt head 1 and tightening the small screw 3 after screwing the bolt, It is known that the small screw 3 is pressed against the surface of the mounting body 5 and the frictional force regulates the rotation of the bolt head 1 to prevent the bolt from loosening.

[0004]

However, in the above-described conventional locking structure, since the bolt head 1 must be provided with the small screw 3, only a bolt having a relatively large head can be adopted. There wasn't. In other words, if the head is small, such as a small countersunk screw, and the lower surface of the screw head is an inverted conical shape, the head does not contact the mounting body on the surface perpendicular to the screwing direction, so it cannot be used. Became. Further, in the above-described loosening prevention structure, the small screw 3 is extremely smaller than the main body screw, so that a special screwdriver is required and there is a problem that workability is poor. Further, the above-described loosening prevention structure cannot be adopted for the mounting body 5 which is not scratched because the small screw 3 is pressed against the surface of the mounting body 5. Since the loosening prevention small screw 3 is also tightened in the same direction as the bolt, if the counterclockwise rotation occurs due to vibration or the like, it becomes impossible to prevent the loosening of the bolt. The present invention has been made in view of the above situation, and it is possible to employ a small screw such as a flat head screw that does not contact the mounting body in a plane in which the head is perpendicular to the screwing direction. An object of the present invention is to provide a screwing structure and a double screw in which the loosening prevention is not released even if the rotation occurs, and to reliably prevent the loosening and to adopt the loosening prevention structure in the small screw.

[0005]

Means for Solving the Problems In order to achieve the above object, the structure of a screwing structure according to the present invention has a first female screw formed on an adherend and a center of the first female screw. A second female screw, which is a shaft and has an inner diameter smaller than that of the first female screw, is formed at the tip of the first female screw and has a tightening direction opposite to that of the first female screw; and the first female screw. A penetrating hole formed in the mounting body, which has a male screw part that is screwed to the second screw, and a locking screw that is screwed to the second female screw, and a double screw that is screwed to the center of the male screw part. By inserting the male screw portion into the hole and screwing the male screw portion into the first female screw, the attachment body is fixed to the adherend, and in this state, the locking screw is attached to the male body. It is characterized in that the second female screw is screwed in a direction opposite to the screwing direction of the screw portion. In the screwed structure configured as described above, when the male screw portion tries to rotate counterclockwise due to vibration or the like, at the same time, the male screw portion does not react with the loosening prevention screw screwed to the adherend. Trying to rotate clockwise. At this time, since the loosening prevention screw and the male screw portion are screwed with the reverse screw, the male screw portion is rotated in the tightening direction with respect to the loosening prevention screw, and is rotated in the counterclockwise direction (loosening action). ) Will be blocked.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a screwing structure, a double screw and a female screw forming jig according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing a screwing structure according to the present invention, and FIG. 2 is a sectional view of a double screw used in FIG. In the screw structure according to the present invention, the double screw 11 shown in FIG. 2 is used. The double screw 11 is a bolt,
The same can be applied to any of a small pan screw, a small countersunk screw, a round plate small screw, a flat small screw, and the like. In the present embodiment, the case where the double screw 11 is adopted as a bolt will be described as an example.

The outer shape of the double screw 11 is formed in the same manner as a normal screw-in bolt. That is, the head portion 15 is formed at one end of the male screw portion 13 and the screw 17 is formed at the other end. A locking screw 19 is screwed in the center of the male screw portion 13 in the central axis direction. A screw 21 is formed over the entire length of the loosening prevention screw 19, and the screw 21 is a reverse screw with respect to the screw 17 of the male screw portion 13. The loosening prevention screw 19 is attached to the male screw portion 13 by screwing with the reverse female screw 23 formed at the center of the male screw portion 13.
Further, the loosening prevention screw 19 is formed to be equal to or slightly shorter than the entire length of the male screw portion 13.

The head, which is one end of the loosening prevention screw 19, is provided with a slot or a cross hole 25 so that the head can be rotated by a screwdriver. The screwdriver hole formed in the head of the loosening prevention screw 19 may be a hexagonal hole that can be rotated by a hexagonal wrench or the like, in addition to the above-mentioned slot and cross hole 25. Therefore, the loosening prevention screw 19 is rotated in the counterclockwise direction so that the tip of the locking screw 19 projects from the male screw portion 13.

A screwing structure for fixing the mounting body to the adherend by using the double screw 11 thus constructed will be described. FIG.
As shown in FIG. 1, the adherend 29 has a screw 17 of the male screw portion 13.
A female screw 31 that is screwed with is formed. Further, a female screw 33 to which the loosening prevention screw 19 is screwed is attached to the bottom of the female screw 31.
Are formed in the same center as the female screw 31. Mounting body 27
A through hole 35 having an inner diameter larger than the outer shape of the male screw portion 13 of the double screw 11 is formed in the double screw 11.
The male screw portion 13 is rotatably inserted into the member 5.

The double screw 11 inserted through the mounting body 27 is
First, the male screw portion 13 is rotated clockwise to be screwed into the female screw 31 of the adherend 29. The male screw portion 13 is completely screwed into the adherend 29, and the attachment body 27 is clamped between the head portion 30 of the male screw portion 13 and the adherend 29 to be fastened.

Then, the loosening prevention screw 19 is rotated counterclockwise by using a small screwdriver 32. The loosening prevention screw 19 rotated counterclockwise is projected from the tip of the male screw portion 13 and is screwed to the female screw 33 formed on the adherend 29. The locking screw 19 is screwed into the female screw 33 to a predetermined depth. The loosening prevention screw 19 is a female screw 33.
Even if it is not screwed in until it reaches the bottom portion, the later-described loosening-preventing effect is produced. However, it is preferable to integrally fix the adherend 29 to the adherend 29 in the state where the bottom portion is reached. . That is, in such a state, the loosening prevention screw 19 has a function like a stud bolt integrated with the adherend 29.

In the threaded structure in which the mounting body 27 and the adherend 29 are thus fixed to each other, the male screw portion 13 is caused by vibration or the like.
Is rotated counterclockwise, at the same time, the adherend 2
A male screw portion 13 is provided for the loosening prevention screw 19 screwed to the screw 9.
Tries to rotate counterclockwise. At this time, since the loosening prevention screw 19 and the male screw portion 13 are screwed with the reverse screw,
The male screw portion 13 rotates in the tightening direction with respect to the loosening prevention screw 19, and the rotation in the counterclockwise direction is prevented. That is, the male screw portion 13 is prevented from loosening in the counterclockwise direction.

In other words, the male screw portion 1 is assumed.
Assuming a case where the screw 17 is not formed on the outer circumference of 3 and the male screw portion 13 is loosely fitted to the female screw 31, the head of the male screw portion 13 is already in pressure contact with the mounting body 27. Therefore, even if the male screw portion 13 tries to be rotated counterclockwise (tightening direction) with respect to the loosening prevention screw 19, the male screw portion 13 is prevented from being tightened by the head, and the male screw portion 13 is prevented.
This is because the counterclockwise loosening of the whole is prevented.

On the other hand, in order to release the screwing of the double screw 11 in which the loosening is prevented in this way, first, the loosening prevention screw 19 is rotated in the clockwise direction, and the female screw of the adherend 29 is first rotated. Three
Unscrew with 3. After that, the male screw portion 13 is rotated in the counterclockwise direction to release the screw engagement of the male screw portion 13 from the female screw 31 of the adherend 29, similarly to the normal bolt release.

According to the above-described screwing structure, the loosening prevention screw 19 of the reverse screw is screwed into the center of the male screw portion 13, and the loosening prevention screw 19 is attached to the adherend 29 after the male screw portion 13 is screwed. Since it is screwed into the formed female screw 33, even when the male screw portion 13 tries to rotate counterclockwise due to vibration or the like, this rotation is reliably prevented by the loosening prevention screw 19. be able to.

The double screw 11 used in this structure is also used.
According to this, since the locking screw 19 is screwed into the center of the male screw portion 13, a large installation space for the locking screw 19 can be secured, and a relatively large locking screw 19 can be secured.
Therefore, the locking screw 19 can be rotated by a normal screwdriver.

Further, since the loosening prevention screw 19 is screwed into the female screw 33 formed on the bottom portion of the female screw 31 of the adherend 29, a small screw provided on the conventional bolt head (see FIG. 6).
As described above, the surface of the mounting body 27 is not scratched.

Since the double screw 11 is screwed with the locking screw 19 at the center of the male screw portion 13, it can be easily applied to a countersunk screw or the like in which the lower surface of the screw head has an inverted conical shape. You can

Next, a jig for forming the female screws 31, 33 with which the double screw 11 is screwed will be described. FIG. 3 is a sectional view showing a jig for forming a female screw having a screw structure according to the present invention, and FIG. 4 is a sectional view showing a state at the time of forming a female screw,
FIG. 5 is a sectional view showing the female screw which has been formed. In the above-described double screw 11, the female screw 31 and the female screw 33 need to be formed at the same center. Therefore, in order to manually form the female screw 31 and the female screw 33, the female screw forming jig 41 shown in FIG. 3 is used.

In the internal thread forming jig 41, an internal tap 45 for the internal thread 33 is screwed into the center of an external tap 43 for the internal thread 31. A through hole 47 is formed in the outer tap 43 and the inner tap 45 in a direction orthogonal to the central axis, and a handle bar 49 for rotating the female screw forming jig 41 is detachably inserted into the through hole 47. . Further, another through hole 51 into which the handle bar 49 is inserted is formed on the upper end side of the internal tap 45.

In order to form the coaxial female screw 31 and female screw 33 using this female screw forming jig 41, first, the female screw 31 and the pilot hole 53 for the female screw 33 are first formed on the adherend 29. 55 is formed. Next, the external tap 43 is screwed into the prepared hole 53 by rotating the handle bar 49 to form the female screw 31 for the male screw portion 13. Next, as shown in FIG. 4, after the female screw 31 is formed, the handle bar 49 is pulled out from the outer tap 43 and replaced with the through hole 51 above the inner tap 45, and only the inner tap 45 is rotated counterclockwise. To form a female screw 33 for the loosening prevention screw 19.

After forming the female screw 33, first, the inner tap 45 is housed in the outer tap 43 by rotating clockwise, and then the handle bar 49 is inserted into the through hole 4.
7, and the external tap 43 is rotated counterclockwise to remove it from the female screw 31. Thereby, as shown in FIG. 5, the female screw 31 and the female screw 33 are provided on the same center.
Will be formed on the adherend 29.

According to the female screw forming jig 41, the internal tap 45 is further provided inside the external tap 43, and the internal tap 45 is rotated counterclockwise so that the internal tap 45 can project from the external tap 43. By performing the thread cutting with the internal tap 45 after the thread cutting with the external tap 43, the female screw 31 and the female screw 33 can be formed with high accuracy with the same central axis by a series of operations.

[0024]

As described in detail above, according to the screwing structure of the present invention, the locking screw of the reverse screw is screwed into the center of the male screw portion, and the locking screw is attached to the male screw portion. Since it is decided to screw onto the adherend after screwing,
Even when the male screw portion tries to rotate in the counterclockwise direction, this rotation can be reliably prevented by the loosening prevention screw. Also, with this structure, the locking screw is screwed into the center of the male screw part, so a large installation space for the locking screw can be secured, and it can be used for small screws, and a relatively large Since a set screw can be used, it is also possible to use a normal screwdriver to rotate the loosening set screw.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a screw structure according to the present invention.

FIG. 2 is a cross-sectional view of the double screw used in FIG.

FIG. 3 is a cross-sectional view showing a jig for forming a female screw having a screwing structure according to the present invention.

FIG. 4 is a cross-sectional view showing a state when a female screw is formed.

FIG. 5 is a cross-sectional view showing the formed female screw.

FIG. 6 is a sectional view showing a conventional locking structure.

[Explanation of symbols]

 11 Double Screw 13 Male Screw Part 19 Loosening Prevention Screw 27 Mounting Body 29 Adherent Body 31 First Female Screw 32 Screwdriver 33 Second Female Screw 35 Through Hole 41 Female Screw Forming Tool 43 External Tap 45 Internal Tap 47 First through hole 49 Handle bar 51 Second through hole

Claims (3)

[Claims] 1. A first female screw formed on an adherend, and a tip end of the first female screw having the same central axis as the first female screw and an inner diameter smaller than that of the first female screw. A second female screw which is formed and has a tightening direction opposite to that of the first female screw, and a male screw portion which is screwed to the first female screw and which is screwed with the second female screw to prevent loosening. A double screw having a screw screwed into the center of the male screw part, and the male screw part is inserted into a through hole formed in the mounting body so that the male screw part becomes the first female screw. The mounting body is fixed to the adherend by screwing, and in this state, the locking screw is screwed to the second female screw in a direction opposite to the screwing direction of the male screw portion. Characteristic screw structure. 2. A male screw portion and a male screw portion, which are screwed together at the center of the male screw portion through a female screw cut in a direction opposite to the male screw portion, and a screwdriver is used from the head side of the male screw portion. A double screw, comprising: a locking screw that can be projected from the tip of the male screw portion by being rotated. 3. An external tap forming a first female screw on an adherend, and a screw of the external tap screwed to the center of the external tap via a female screw cut in a direction opposite to the external tap. An internal tap that protrudes from the tip of the external tap to form a second female screw on the adherend by being rotated in a direction opposite to the cutting direction; the external tap screwed to the internal tap; A first through hole formed in a direction intersecting with the central axis of the external tap and the internal tap; a handle bar inserted through the through hole to allow the external tap to rotate; and an upper end side of the internal tap. And a second through hole which is formed in the hole and into which the handle bar can be inserted.