JP2001003915A - Locking nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fastening between a bolt and a nut from unfastened by integrally forming a locking nut body with the nut in the central axial direction via a thin-wall connecting part, continuously engraving female screws in their inside faces, and fracturing a connecting part by a fastening torque exceeding a nut fastening torque. SOLUTION: A shaft part 41 of a bolt 40 is inserted in insertion holes of fastening counter-members W1, W2, an integrally formed nut 20, a thin-wall connecting part 30, a female screw continuously engraved in a locking nut body 10 are threadly engaged around the shaft part 41, and the members W1, W2 are fastened between the head part of the bolt 50 and the nut 20. When the nut body 10 is fastened by a torque of the fastening torque of the nut 20 or more, the connecting part 30 is fractured and deformed inward and the female screw inside the connecting part 30 deeply eats into a female screw in the shaft part 41 as shown in an arrow. This constitution can prevent the rotation in the loosening direction even if trying to loosen the nut body 10 and the nut 20. The nut body is thus prevented from loosened even by a large force so that the fastening is prevented from unfastened unless the bolt and nut are fractured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking nut and, more particularly, to a locking nut which cannot be released once a bolt and nut have been fastened.

[0002]

2. Description of the Related Art Bolts and nuts are often used for fastening in various fields such as steel towers and bridges. Normally, for bolts and nuts, the bolt shaft part is inserted into the insertion hole of the member to be fastened, the female screw of the nut is screwed into the male screw of the bolt, and the multiple members to be tightened are tightened between the bolt head and the nut. Is done.

In such bolts and nuts, vibration, thermal expansion,
Since there is a possibility that the fastening may be loosened due to a change over time or the like, various methods for preventing loosening have been proposed. For example,
A method using a bending washer or a lock wire, a method using a double nut (JP-A-6-26512, etc.), and the like are known.

[0004]

However, all of the above-mentioned conventional locking methods are devised on the premise that bolts and nuts are reused, and if the bolts or nuts are intentionally turned with excessive force, There is a problem that the fastening can be released by turning the bolt or nut in the loosening direction.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a locking nut in which once a bolt and a nut are fastened, the fastening cannot be released.

[0006]

SUMMARY OF THE INVENTION Accordingly, a locking nut according to the present invention is a locking nut for competing with a nut for fastening a member to be fastened to the head of a bolt to prevent the fastening from loosening. A lock nut body is integrally formed in the central axis direction of the nut and the bolt via a thin connecting portion, and a female screw is continuously engraved on the inner surface of the loosening nut body, the thin connecting portion and the nut. With the tightening torque exceeding the tightening torque of the nut, the thin connecting portion is broken, and at least the female screw inside the thin connecting portion is deformed, bites into the male screw of the bolt, and loosening of the fastening is prevented. It is characterized by doing so.

One of the features of the present invention is that after the tightening of the nut is completed, a larger tightening torque is applied to break the thin connecting portion, deform the female screw inside the thin connecting portion, and bite into the male screw of the bolt. It is in the point that I tried to do it.
As a result, even if a loosening torque large enough to loosen the nut acts, the bolt and nut cannot be loosened because the locking nut itself cannot rotate in the loosening direction.
Unless the bolt, nut or locking nut body is broken, the fastening will not be released. If the locking nut body strongly competes with the nut with a tightening torque equal to or greater than the fastening torque of the nut, the loosening of the fastening can be more reliably performed.

Further, the female screw is cut inward in the thin connecting portion. However, when the thin connecting portion is deformed inward when the thin connecting portion is broken so as to bite into the male screw of the bolt, the female screw is not necessarily required. There is no.

That is, the loosening lock nut according to the present invention comprises:
In a locking nut that performs locking of fastening by competing with a nut that fastens a member to be fastened between the bolt head and the locking nut body, the locking nut body is connected to the nut and the bolt through a thin connecting portion in the center axis direction. It is formed integrally, and the female screw of both is engraved so as to be continuous on the inner surface of the locking nut body and the nut, and the thin connecting portion is broken by a tightening torque exceeding the tightening torque of the nut. In addition, at least the thin connecting portion is deformed inward and bites into the male screw of the bolt, so that loosening of the fastening is prevented.

The notch may have any shape as long as it can be broken with a tightening torque equal to or higher than the tightening torque of the nut. For example, a notch can be formed between the locking body and the nut so as to extend all the way around the rotation direction or a part thereof.

If there is a gap between the locking nut body and the nut, rainwater may enter between the male and female screws through the gap between the nut and the nut, causing rust. In such a case, it is preferable to provide a caulking material in the thin connecting portion.

The number of the locking nut bodies may be one,
A plurality of locking nut bodies may be formed integrally with the bolt center axis direction through cutouts.

In the above description, the locking nut body is formed integrally with the nut. However, the locking nut body is formed separately, and the projection corresponding to the above-mentioned thin connecting portion and the biting portion corresponding to the internal thread therein are formed on the locking nut. It may be formed so that the protrusion is deformed with a tightening torque equal to or greater than the fastening torque so that the biting portion is bitten into the male screw of the bolt.

That is, the locking nut according to the present invention is a locking nut which competes with a nut for fastening a member to be fastened to the head of a bolt to prevent the fastening from loosening.
A projection is provided on at least one edge of the locking nut body in the direction of the center axis of the bolt, and an inner surface side of the projection has a thread shape having the same height as the female screw of the locking nut body. The protrusion is deformed inward with a tightening torque exceeding a predetermined tightening torque of the nut of the locking nut body, and the biting portion bites into the male screw of the bolt, and is fastened. Characterized in that slack is prevented.

Further, as in the case of the thin connecting portion, the projection may be deformed inward so as to bite into the male screw of the bolt.

That is, the locking nut according to the present invention is a locking nut which competes with a nut for fastening a member to be fastened to a head of a bolt to prevent the fastening from loosening.
At least one edge of the locking nut body has a projection projecting in the direction of the center axis of the bolt, and the locking nut has a fastening torque exceeding a predetermined fastening torque of the nut. The bolt is deformed to bite into the male screw of the bolt to prevent loosening of the fastening.

The projection may be in any form as long as it can be deformed inward with a tightening torque higher than the tightening torque of the nut so that the biting portion can bite into the male screw of the bolt. For example, a plurality of protrusions may be formed on the edge of the locking nut body at predetermined intervals in the circumferential direction, or the protrusions may be formed to extend around the entire circumference of at least one edge of the locking nut body. You may.

It is important to surely deform the projection inward when tightening the locking nut. Therefore, the locking nut is preferably used in combination with a nut having a seating surface formed on at least one end edge of the projection to abut the projection and deform the projection inward.

[0019]

According to the present invention, according to the present invention, the biting portion of the female screw or the projection inside the notch bites into the male screw of the bolt with a tightening torque higher than the fastening torque, and the bolt is intentionally excessively overpowered.・ Even if you try to loosen the fastening of the nut, the locking nut body will not loosen and will not be released unless the bolt, nut or lock nut body is broken, and will be removed without your knowledge of the bolt / nut fastening. Can be reliably prevented.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific examples shown in the accompanying drawings. 1 to 4 show a preferred embodiment of a locking nut according to the present invention. The locking nut body 10 is formed integrally with the nut 20 via the thin connecting portion 30, and the locking nut body 10, the nut 2
Female threads are engraved on the inner peripheral surfaces of the 0 and thin connecting portions 30 so as to be continuous.

The thin connecting portion 30 extends in the circumferential direction over the entire length, and is formed to have a thickness such that the thin connecting portion 30 is broken by a tightening torque higher than the tightening torque of the nut 20.

For example, when the two members W1 and W2 are fastened, bolts 4 are inserted into the through holes of the members W1 and W2.
0 is inserted through the washer 50 through the washer 50, and the nut 20 is inserted into the shaft 41 of the bolt 40 through the washer 50.
The thin connection portion 30 and the female screw of the locking nut body 10 are screwed together, the nut 20 is tightened to a predetermined fastening torque, and the two fastened members W1 and W2 are fastened between the head of the bolt 50 and the nut 20. . FIG. 3 shows this state.
In some cases, the washer 50 is not used.

When the nut 20 is tightened with a predetermined fastening torque, the locking nut body 10 is tightened with a torque greater than the fastening torque of the nut 20. Then, as shown in FIG. 4, the thin connecting portion 30 is broken and deformed inward, and the female screw inside the thin connecting portion 30
As shown by the arrow (a) in FIG.

In this state, even if an attempt is made to loosen the locking nut body 10 and the nut 20, the thin connecting portion 30 deformed and biting into the male screw of the bolt shaft portion moves in the loosening direction of the locking nut body 10 and the nut 20. Of the bolt 40 and the nut 20 are not disconnected.

FIG. 5 shows a modification of the above embodiment. FIG.
FIG. 5A shows the shape of the thin connecting portion 30 of the above embodiment,
(B) to (e) show modifications of the thin connecting portion 30 of the above embodiment, and the thin connecting portion 30 extends partially in the circumferential direction as shown in (b) to (e) of FIG. Shape and the thin connecting portion 30
Can be set.

FIG. 6 shows a second embodiment of the locking nut according to the present invention.
An embodiment will be described. In this example, the internal thread is not engraved on the inner surface of the thin connecting portion 30, but the internal thread is engraved on the inner surface of the locking nut 10 and the nut 20 so as to be continuous between them.

In this embodiment, no female screw is formed inside the thin connecting portion 30. However, if the locking nut body 10 is tightened with a torque higher than the fastening torque of the nut 20, the thin connecting portion 30 is broken, When the locking nut 10 is tightened, the broken thin connecting portion 30 is deformed and a part thereof is deformed inward and bites into the male screw of the bolt shaft portion, so that the same operation and effect as in the above embodiment can be obtained. it can.

FIG. 7 shows a third embodiment of the locking nut according to the present invention.
An embodiment will be described. In this example, the caulking material 60 is inserted into the thin connecting portion 30. Thereby, after the locking nut body 10 is tightened, the locking nut body 10 is tightened.
Rainwater can be prevented from entering between the male and female screws from the gap between the nut and the nut 20, and the generation of rust and the fatigue of the material can be prevented. Also, if the caulking material 60 is colored red or blue, the caulking material 60 is compressed and oozes out when the locking nut body 10 is tightened to prevent loosening. Will be understood.

FIG. 8 shows a fourth embodiment of the locking nut according to the present invention.
An embodiment will be described. In this example, the two locking nut bodies 10 and 10 are integrated with the nut 20 via the two thin connecting portions 30 and 30. In this way, by providing the two locking nuts 10, 10 and the thin connecting portions 30, 30, the locking of the bolts and nuts can be more reliably performed.

FIGS. 9 to 12 show a fifth embodiment of a locking nut according to the present invention. In this example, the locking nut body 10 is provided separately from the nut 20, and a plurality of projections 70 are provided at one end edge of the locking nut body 10 at substantially equal intervals. A threaded biting portion 71 is formed on the inner side of. On the other hand,
A seating surface 2 that can abut the projection 70 is provided at both ends of the nut 20.
1, 21 are formed.

In order to prevent the bolt 40 and the nut 20 from being loosened, the nut 20 is fastened to the shaft of the bolt 40 with a predetermined torque, and then the locking nut body 10 is screwed into the bolt shaft. As shown in FIG.
Is screwed until it comes into contact with the bearing surface 21 of the nut 20,
When the locking nut body 10 is tightened with a torque greater than the fastening torque of the nut 20, the projections 70.
Is deformed inward by the seat surface 21 of the
1 bites into the male screw of the bolt shaft as shown by the arrow in FIG. Thus, similarly to the first embodiment, loosening of the connection between the bolt 40 and the nut 20 can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a preferred embodiment of a locking nut according to the present invention.

FIG. 2 is a sectional view showing the locking nut.

FIG. 3 is a view showing a state before tightening of a locking nut in a bolt and nut fastener using the locking nut.

FIG. 4 is a diagram showing a state after tightening of a locking nut in the bolt and nut fastener.

FIG. 5 is a plan view of a thin connecting portion according to the first embodiment.
It is a figure which shows (a) and its modification (b)-(e).

FIG. 6 is a cross-sectional view of a locking nut according to a second embodiment of the present invention (a) and a plan view of a thin connecting portion (b).
FIG.

FIG. 7 is a front view showing a lock nut according to a third embodiment of the present invention.

FIG. 8 is a plan view (a) and a front view (b) of a thin connecting portion of a locking nut according to a fourth embodiment of the present invention.
FIG.

FIG. 9 is a diagram showing a front configuration (a) and a plan configuration (b) of a locking nut according to a fifth embodiment of the present invention.

FIG. 10 is a view showing the structure of a nut 20 used in combination with the locking nut.

FIG. 11 is a view conceptually showing a state before tightening of the locking nut.

FIG. 12 is a view conceptually showing a state after tightening of the locking nut.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Loose stop nut main body 20 Nut 21 Seat surface 30 Thin connection part 40 Bolt 41 Bolt shaft part 60 Caulking material 70 Projection 71 Biting part

Claims (9)

[Claims] 1. A locking nut for competing with a nut for fastening a member to be fastened between a bolt head and a locking nut, wherein the locking nut body is thin in the direction of the center axis of the nut and the bolt. A female screw is formed continuously on the inner surface of the nut for preventing loosening, the thin connecting portion and the nut, and the thinning is performed with a tightening torque exceeding the tightening torque of the nut. A locking nut, wherein the connecting portion is broken and at least the female screw inside the thin connecting portion is deformed and bites into the male screw of the bolt to prevent loosening of the fastening. 2. A locking nut for locking a fastening member in competition with a nut for fastening a member to be fastened between the bolt head and the nut, wherein the locking nut body is thin in the central axis direction of the nut and the bolt. It is formed integrally via a connecting portion, and the female screw of both is engraved on the inner surface of the nut for preventing loosening and the inner surface of the nut so as to be continuous. A locking nut, wherein at least the thin connecting portion is deformed inward and bites into the male screw of the bolt to prevent loosening of the fastening. 3. The locking nut according to claim 1, wherein the thin connecting portion is formed so as to extend all or a part of a circumferential direction between the locking main body and the nut. 4. The locking nut according to claim 1, wherein a caulking material is provided in the thin connecting portion. 5. A locking nut for locking a fastening member in competition with a nut for fastening a member to be fastened to a head portion of the bolt, wherein at least one end edge of the locking nut body has a projection formed on the bolt. A threaded biting portion having the same height as the female screw of the locking nut body is formed on the inner surface side of the projection, and the nut of the locking nut body is formed on the inner surface side of the projection. Wherein the protrusion is deformed inward with a tightening torque exceeding a predetermined tightening torque so that the biting portion bites into the male screw of the bolt to prevent loosening of the fastening. Lock nut. 6. A locking nut for competing with a nut for fastening a member to be fastened to a head portion of a bolt to prevent loosening of the fastening, wherein at least one end of the locking nut main body has a protrusion on the bolt. The protrusion is deformed inward by a tightening torque exceeding a predetermined tightening torque of the nut of the loosening nut body, bites into the male screw of the bolt, and loosens the tightening. A locking nut characterized in that the nut is prevented. 7. The locking nut according to claim 5, wherein the plurality of protrusions are formed at predetermined intervals in a circumferential direction. 8. The locking nut according to claim 5, wherein the projection is formed so as to extend around the entire periphery of at least one end edge of the locking nut body. 9. The locking nut according to claim 5, wherein the locking nut is used in combination with a nut having at least one end edge formed with a seating surface which abuts the projection to deform the projection inward.