JPH11351226A - Bolt and nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a nut from being detached from once-tightened bolt and nut. SOLUTION: A first contour part 2-1 and a second contour part 2-2 are successively arranged from a head part side, the inequality 11 >12 is at least satisfied for the diameters of the first and second contour parts, where 11 is the diameter of the first contour part 2-1, 12 is the diameter of the second contour part 2-2, the rotational direction of a screw groove cut in circumferential edges of the respective contour parts 2-1, 2-2 is opposite to each other, first and second nuts 3-1, 3-2 corresponding to the contour parts 2-1, 2-2 are provided, and a connecting means is provided between nuts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt and a nut which cannot be removed after tightening.

[0002]

2. Description of the Related Art Generally, when a structure or a material is firmly fixed to a structure or a structure, it is common to use bolts and nuts to tighten the structure. Conventionally, a bolt having a head is provided with a right-hand thread, and a nut to be screwed into the bolt is inserted and rotated to firmly fix an object to be fastened between the head and the nut.

However, the fixing method described above may be loosened under the influence of weather conditions such as temperature and physical conditions such as vibration. To address this, use spring washers, double locking nuts,
It is well known that there are already various techniques such as inserting a toothed washer nut and a split pin into a bolt, and the like.

[0004]

In the above-mentioned prior art, for example, in the case of a double nut, it is hard to loosen under ordinary natural phenomena and hardly comes off, but it can be removed artificially. When inserting a split pin into a bolt, for example, if the split pin is removed with a hammer, the split pin is artificially removed in the same manner as described above.

The present invention has been made to solve the above-mentioned problems, and not only does it not loosen due to natural phenomena,
The purpose is to provide bolts and nuts that cannot be removed artificially.

[0006]

According to a first aspect of the present invention, a bolt / nut has a first outer portion and a second outer portion in order from the head side, and the diameter of the front first outer portion is l _1. When the diameter of the second outer portion is l ₂ , at least l ₁
> While the outer diameter relationship l _2, before the opposite directions to the rotational direction of the screw groove bored in the periphery of the outer portion, the first,
The first and second nuts corresponding to the respective second outer portions are provided, and a connecting means is provided between the nuts. Therefore, since both nuts are connected, when one of the nuts is to be removed, the other connected nut is tightened and cannot be removed.

According to a second aspect of the present invention, there is provided a bolt / nut according to the first aspect, wherein the rotation direction of the thread groove of the first outer portion is a right-handed screw or a left-handed screw, and the screw groove of the second outer portion is. The direction of rotation was left-handed or right-handed.

[0008] In the bolt / nut according to the third aspect of the present invention, in the first aspect, a connection portion having no thread groove is provided between the first outer portion and the second outer portion.

According to a fourth aspect of the present invention, in the bolt / nut according to the first aspect, the connecting means provided between each of the first and second nuts has a notch formed in a corresponding nut surface. And a spring washer connecting the cuts.

According to a fifth aspect of the present invention, there is provided a bolt / nut according to the first aspect, wherein the connecting means provided between the first and second nuts comprises a tongue formed on a corresponding nut surface. A convex portion having a piece and a concave portion having a step portion for locking the tongue piece.

According to a sixth aspect of the present invention, there is provided the bolt and nut according to the first aspect, wherein the connecting means provided between the first and second nuts is a hole formed in a corresponding nut surface. And a pin inserted by a spring into each of the holes.

According to a seventh aspect of the present invention, in the first aspect, the connecting means provided between the first and second nuts is bonded or welded.

[0013]

FIG. 1 is a structural view showing an embodiment of a bolt and nut according to the present invention. In FIG. 1, FIG. 1A shows the overall shape of a bolt, 1 is a head, and 2 is a bolt, which are integrally formed.

The bolt 2 has a first outer portion 2 having an outer diameter l _1.
-1 and a second outer portion having an outer diameter l ₂ 2-2 and there therebetween and a connecting portion 2-3 connecting these, first, second
Have a relationship of l ₁ > l ₂ .

The first outer part 2-1 and the second outer part 2
If the first external portion 2-1 side is a right-hand screw (in the direction of clockwise tightening), for example, the second external portion 2-2 is a left-hand screw (counterclockwise). Direction to tighten around).

FIG. 1B is a view showing the configuration of a nut for the bolt. Since 3-1 is a nut on the first outer portion 2-1 side, the nut has a right-hand thread inside (in addition, FIG. Since the nut 3-1 is referred to as a first nut, 3-2 is a nut on the side of the second outer portion 2-2, and has a left-hand thread therein. 2 nuts).

FIG. 2 is a view for explaining a use state. A bolt hole (not shown) is formed in the two fixed members 4-1 and 4-2, and the bolt 2 is inserted through the hole. The first nut 3-1 is rotated clockwise and tightened, and then the second nut 3-2 is rotated counterclockwise and tightened.

As described above, simply turning the first nut clockwise and then turning the second nut counterclockwise removes the second nut by turning it clockwise. ,
Furthermore, if the second nut is rotated counterclockwise thereafter, it can be artificially (easy) removed.

As described above, an object of the present invention is to provide a bolt / nut which cannot be removed artificially. By fixing the nuts to each other, the second nut is rotated clockwise. Then, since the second nut and the first nut are fixed, the first nut rotates clockwise, and the first nut is tightened. As a result, the first nut can be absolutely removed. It is something that has disappeared.

The reason why the outer diameter of the first outer part 2-1 and the second outer part 2-2 is l ₁ > l ₂ in the above embodiment is as follows.
When a right screw and a left screw are cut on one bolt, the first nut for tightening the first outer part 2-1 becomes the second outer part 2-
2 cannot be passed.

The first outer part 2-1 and the second outer part 2
The reason why the connecting portion 2-3 is provided between the fixing member 4 and the fixing member 4 is as follows.
This is because, when tightening -1 and 4-2, a degree of freedom is provided between them to facilitate the tightening. That is, a buffer zone is provided between the right screw and the left screw.

According to the present embodiment, when removing the nut, the procedure is to remove the first nut after removing the second nut. However, the first and second nuts are fixed. When the second nut is rotated in a direction to remove, the first nut integrated with the second nut is rotated in a tightening direction,
You can never remove the nut from the bolt.

FIG. 3 is a configuration diagram showing another embodiment. In FIG. 3, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, the structural feature is that the first and second nuts are fixed by modifying the structure of each nut 3-1 and 3-2 and interposing a spring washer between the nuts. (Connected).

In FIG. 3A, reference numeral 5 denotes a spring washer,
FIG. 3B shows the entire shape of the spring washer. 6-
Reference numerals 1 and 6-2 denote flange portions provided on the nut, on the upper surface of the first nut 3-1 (the surface facing outward when the nut is tightened), and on the second nut 3-2. Is provided on the lower surface thereof (the surface facing inward when the nut is tightened).

FIG. 4 is a structural view of the first nut.
4A is a cross-sectional view of FIG. 4A taken along a plane center line, and FIG.
-1 is provided. Note that reference numeral 7 denotes a notch, which will be described later.

FIG. 4 (c) is a plan view as viewed from the top of FIG. 4 (a), and FIG. 4 (d) is a perspective view of FIG. 4 (c).
In FIG. 4C, four cuts 7 are provided, for example, at every 90 ° inside the flange 6-1 provided in a circular shape. FIG.
In (d), the cut 7 is shown three-dimensionally.

An open end of a spring washer described later enters the step formed by the cut. In the above description, only the notch provided on the upper surface of the first nut has been described.
A cut similar to that described above (the direction of the step formed by the cut is the opposite direction) is also formed on the bottom surface of the nut.

FIG. 5 is a diagram for explaining the operation, in which the first nut (hereinafter, referred to as nut A) has a right-hand thread and the second nut (hereinafter, referred to as nut B) has a left-hand thread. . First, after tightening the nut A, the spring washer 5 is sandwiched, and the nut B is tightened and rotated (X direction, clockwise).

At this time, the nut B slips without acting on the spring washer 5 because the nut B is not "tucked".
Does not transmit torque. That is, when the nut B is rotated in the tightening direction, the open end of the spring washer 5 does not catch on the cut, so that the nut B slips and continues to rotate, but when the nut B is rotated in the loosening direction, one end of the spring washer is And the other end face of the spring washer is hooked on the notch on the upper surface of the nut A to fix both nuts.

FIG. 6 illustrates the case where the nut A is actuated (rotated) to prevent or remove the nut A. When the nut A tries to rotate in the loosening direction (Y direction), one open end of the spring washer enters the cut provided on the upper surface of the nut A, and the other open end which has made one round enters the cut of the nut B. For,
A force in the Y-1 direction is applied to the nut B3-2.

However, rotating the nut B3-2 in the Y-1 direction is a rotation in the tightening direction, so that the nut is not loosened until the spring washer is broken, and the nut B3-2 cannot be removed.

FIG. 7 is a view for explaining the case where the nut B3-2 is removed and loosened or removed. When the nut B3-2 is artificially loosened and rotated (Z direction), the rotational force is
From point A in 3-2, the spring washer 5 makes one round to reach point B.
Here, since the force acting on point B is the tightening rotation, the nut B3
-2 does not loosen and does not come off (does not come off).

FIG. 8 is a configuration diagram of still another embodiment. In the present embodiment, the nut A3-1 and the nut B3-2
Is a connection method. That is, FIG.
(B) shows a configuration diagram of the nut A3-1.

As shown in FIG. 8A, the nut A3
After tightening -1, the nut B3-2 is forcibly pushed in while rotating from above to fix the nuts A and B together.

That is, as shown in FIG.
3-1 has a cylindrical portion 3-3 on the upper surface of the nut, a tongue piece 3-4 extending outward from the upper edge, and a plurality of splits 3-5 on the side surface. ing.
The nut B3-2 has a cylindrical shape, and the nut A3-
A projection 3-6 corresponding to the tongue piece 3-4 provided on the upper surface of the device 1 is provided on the entire circumference.

Therefore, when the nut A is rotated clockwise to tighten it, the nut B is rotated counterclockwise to approach the nut A. After the nut B is completely approached, the nut B3-2 is forcibly turned to contact. , The cylindrical portion on the top surface of the nut A approaches,
Through the protruding portion 3-6, enters the space inside, and returns to the original shape to complete the joining. In this case, it is more effective to insert and fix the pin 3-7 between the tongue piece 3-4 and the nut B3-2.

FIG. 9 is a configuration diagram showing still another embodiment. In the present embodiment, the hole 8 provided on the nut B3-2 side
A pin 10 pushed out by a spring 9 is provided therein, and the pin 10 is inserted into any one of a plurality of holes 11 provided in the nut 3-1 to connect (fix) both nuts.

FIG. 9A is an overall view, FIG. 9B is a view of the nut B3-2 viewed from the bottom, and FIG.
FIG. 1 is a view of the device 1 as viewed from above. According to the present embodiment, as a result of connecting both nuts, the nut cannot be removed from the bolt.

FIG. 10 is a configuration diagram showing still another embodiment. In the present embodiment, the bolt is not removed from the head side. And in this example, the head 1 of the bolt
A notch as shown in FIG. 4 is provided in the inside of the bolt, a holding plate 12 described later is provided between the fixing member 4-1, and a spring washer 13 is interposed between the bolt head and the holding plate. Things.

FIG. 10A shows the overall shape.
(B) is a configuration diagram of the holding plate 12. FIG. 10 (b) is a view of the holding plate as viewed from the back side.
As shown in FIG. 3A, a plurality of recesses 12-2 are inserted into the fixed member 4-1 to prevent rotation of the holding plate. These operations are performed as described above, and will not be described. According to the present embodiment, the head of the bolt is not removed.

FIG. 11 is a configuration diagram showing still another embodiment. According to the present embodiment, each nut is subjected to engagement processing (trapping) so that once engaged, it does not come off. As described above, when the first nut 3-1 is engaged by 14-1 and 14-2, it does not rotate in the tightening direction of the first nut 3-1. According to the present embodiment, the nut cannot be removed from the bolt.

Although various types of connecting means have been described above, the present invention is not limited to these, and it is a matter of course that the natural connecting means may be a resin or other fixing method such as welding.

[0043]

As described above, according to the present invention, the outer diameters of the first outer portion and the second outer portion of the bolt are changed, and the rotation directions of the thread grooves of the outer portion are reversed.
And because it was configured to connect the two nuts after tightening,
The following effects are obtained. (A) It is not removed artificially. (B) Safety can be ensured. (C) The initial tightening state and performance can be maintained without being loosened. (D) Work, maintenance, management and maintenance costs for preventing loosening are reduced. (E) As described above, it can be used for bolts and nuts for joints of railway rails, power transmission towers, oil pipelines, gas pipelines and the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a bolt and nut according to the present invention.

FIG. 2 is a diagram showing a use state of FIG. 1;

FIG. 3 is a diagram showing a method of connecting the nuts.

FIG. 4 is a diagram showing a configuration of a nut.

FIG. 5 is a view for explaining how to transmit the force of the nut when tightening.

FIG. 6 is a view for explaining how a force is transmitted when one nut (inside) is turned to prevent loosening or removal.

FIG. 7 is a view for explaining how to transmit a force when the other nut (outside) is turned to prevent or remove looseness.

FIG. 8 is a view showing another embodiment of a method of connecting the nuts.

FIG. 9 is a view showing still another embodiment of a method of connecting the nuts.

FIG. 10 is a diagram showing an embodiment in which a bolt is not removed from the head side.

FIG. 11 is a view showing still another embodiment of a method of connecting the nuts.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Head 2 bolt 2-1 1st external part 2-2 2nd external part 2-3 Connection part 3-1 1st nut 3-2 2nd nut 4-1 and 4-2 Fixed part 5, 13 Spring Washer 6-1, 6-2 Flange 7 Notch 8,11 Hole 9 Spring 10 Pin 12-1 Convex 12-2 Concave 14-1,14-2 Engagement

Claims (7)

[Claims] 1. A first external part and a second external part in this order from the head side. When the diameter of the front first external part is l ₁ and the diameter of the second external part is l ₂ , at least each diameter is at least one. l ₁ > l ₂ , and the rotation directions of the thread grooves formed in the peripheral edge of the front outer portions are set to be opposite to each other, and the first and second outer portions correspond to the first and second outer portions. 2. A bolt and nut, wherein two nuts are provided, and a connecting means is provided between the nuts. 2. The bolt and nut according to claim 1, wherein the direction of rotation of the thread groove of the first outer portion is a right-handed screw or a left-handed screw, and the direction of rotation of the thread groove of the second outer portion is a left-handed screw or a right-handed screw. Bolts and nuts characterized by: 3. The bolt and nut according to claim 1, further comprising a connection portion having no thread groove between the first outer portion and the second outer portion. 4. The bolt and nut according to claim 1, wherein the connecting means provided between the first and second nuts is a spring washer for connecting the cuts formed on the respective nut surfaces and the cuts. Bolts and nuts characterized by the following. 5. The bolt / nut according to claim 1, wherein the connecting means provided between the first and second nuts includes a projection having a tongue formed on a corresponding nut surface and the tongue. A bolt / nut characterized by a concave portion having a step portion to be locked. 6. The bolt / nut according to claim 1, wherein the connecting means provided between the first and second nuts is inserted into a corresponding hole formed in each nut surface by a spring. Bolts and nuts characterized by pins. 7. The bolt and nut according to claim 1, wherein the connecting means provided between the first and second nuts is adhesion or welding.