JPH0716093Y2 - Double lock nut - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double lock nut having two nuts, one for fastening and one for locking.

[0002]

2. Description of the Related Art As a lock nut for preventing loosening of a fastening nut, for example, as shown in FIG. 6, a ring A made of synthetic resin is fitted to a thread portion B of a lock nut N1, and the lock nut N1 is fastened to the ring A. When the screw is screwed into the bolt in the state facing toward the side, the thread on the ring A is threaded by the thread on the bolt side, thereby increasing the fastening force between the bolt and the lock nut N1 and surely preventing loosening. A lock nut (hereinafter,
The former is called a lock nut).

As a lock nut having a similar purpose, a double lock nut (hereinafter referred to as the latter double lock nut) in which a fastening nut N2 and a lock nut N3 are integrated as shown in FIG. 7 is also known. It is (special public Sho 4
7-43429 gazette). This is because the groove C is formed in the boundary between the fastening nut N2 and the lock nut N3 so that both nuts N
Form a thin wall between N2 and N3.
3 is screwed into the bolt, and the tightening nut N2 is tightened to a predetermined depth. Then, when the lock nut N3 is further tightened, the tightening torque by the lock nut N3 exceeds the predetermined value, so that the lock nut N3 is tightened at the cutting line X. The lock nut N3 is cut from the nut N2 so that the lock nut N3 functions to prevent loosening.

[0004]

However, the former lock nut described above has a drawback that it cannot be reused once it is used and the ring A is screwed.
Similarly, the latter double lock nut cannot be reused once it is used and the nuts N2 and N3 are separated.

[0005] Further, in the latter Dabururo' click nut, in addition to the forging process, it is formed by cutting a groove C, and must be shaped to be expected a groove innermost is reliably cut by rolling, There is a problem that processing becomes complicated and cost rises. It is also possible that the shape of the cut surface becomes uneven in the circumferential direction, which impedes the uniform transmission of tightening torque and makes the lock function unstable. If tightening stops halfway, the tightening torque of the lock nut may increase and cutting may occur at the cutting line X. Even if foreign matter is removed, the double lock nut cannot be used and a new double lock nut must be used. I will have to do it.

In addition, in the latter double lock nut, since both nuts N2 and N3 are separated, both nuts N2 and N3 are separated.
Since the thickness of the connecting portion between the nuts 2 and N3 is thin, the area of the contact surface between the two nuts N2 and N3 after separation is also small, and therefore the transmission of the tightening torque by the lock nut N3 may be uncertain. .

Therefore, the present invention is reusable and can exert a reliable locking function , and further
The challenge is to provide a double lock nut with excellent workability .

That is, the present invention is a double lock nut formed by coaxially connecting two nuts, and one end portion of the connecting side end surface is provided with a circular base portion having a divergent shape.
On the end face of the other nut on the connecting side, a thin annular projection having an inner diameter slightly larger than the circular base portion is formed,
In addition, the annular projection is fitted into the circular base portion, and the two nuts are reduced in diameter so as to be individually rotatable and are engaged with the circular base portion.

And, in particular, a circular base is provided on the end face on the connecting side.
In the nut provided, the end surface around the circular base portion is a tapered surface that is inclined from the outer peripheral end of the nut toward the circular base portion toward the end surface opposite to the nut.

According to the above construction , since the two nuts are individually rotatably connected by the engagement of the circular base portion and the annular protrusion, one of the nuts is used as a fastening nut and the other nut is used. It is possible to lock the fastening nut by using the nut as a lock nut and tightening the lock nut after fastening the fastening nut.

Especially, in a nut having a circular base,
In this case, since the end surface around the circular base is tapered , the direction in which both nuts are in close contact with each other with the annular projection of the other nut fitted in the circular base of the nut
When a force is applied to the annular projection , the annular projection abuts the tapered surface by this force, and is curved inwardly guided by the tapered surface to engage the circular base portion, and the curved shape and the divergence of the circular base portion. Depending on the shape, both nuts will be securely retained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

The double lock nut 1 according to the present invention is
As is clear from FIGS. 1 to 4, the fastening nut 2 and the lock nut 3 are coaxially and individually rotatably connected. That is, the fastening nut 2 is formed with a circular base portion 5 coaxial with the screw hole 4 on the end face on the connecting side when the fastening nut 2 is formed by forging. In that case, the circular base portion 5 is formed in a divergent shape so that the peripheral surface 5a of the circular base portion 5 is an outwardly inclined surface (see FIG. 5) and the circumference of the circular base portion 5 is The shape of the connection-side end surface is formed into a tapered surface 6 that is inclined from the outer peripheral end of the nut to the circular base portion 5 toward the end surface opposite to the nut.

Further, in the lock nut 3, at the time of forming by the press working, an inner diameter which is coaxial with the screw hole 7 and is slightly larger than the outer diameter of the tip of the circular base portion 5 is formed on the end face of the connecting side. The ring-shaped protrusion 8 having a thin thickness (thickness capable of being deformed and deformed by caulking, which will be described later) is formed. In addition, the lengths of the screw holes 4 and 7 of the fastening nut 2 and the lock nut 3 are L1> L2 as shown in FIG.
The length L1 of the screw hole 7 in the lock nut 3 is made longer.

Then, after the nuts 2 and 3 are separated from each other in FIG. 4, the annular projection 8 of the lock nut 3 is fitted on the circular base portion 5, and then the nuts 2 and 3 are brought into close contact with each other by an appropriate means. If you add force, to this power
More tip end of the annular projection 8 is guided by the tapered surface 6 deforms inwardly as shown in FIG. 5, therefore the annular projection 8 is reduced in diameter, is engaged in a state retaining the carousel 5 . However, the engagement is performed loosely without hindering the rotation of the nuts 2 and 3, and the circular base portion 5 is brought into light contact with the end surface of the lock nut 3, or as shown in FIG. Make sure that a small gap is formed.

In such a double lock nut 1, the nuts 2 and 3 are screwed into bolts (not shown), and the fastening nut 2 is tightened to a predetermined depth. When the base portion 5 is brought into pressure contact, a tightening torque is applied to the fastening nut 2 via the circular base portion 5, and the lock function is exerted. Also, as described above, the lock nut 3
The length L1 of the side screw hole 7 is the screw hole 4 of the fastening nut 2
Is longer than the length L2 of the lock nut 3
The tightening force due to increases, and it is possible to securely prevent loosening.

By the way, the double lock nut 1 of the present invention
In the above, the fastening nut 2 and the lock nut 3 are independent of each other, and the nuts 2 and 3 are merely connected by the engagement of the circular base portion 5 and the annular projection 8. . Therefore, unlike the conventional nut shown in FIGS. 6 and 7, there is no deformation such that the ring C is screwed by use or the fastening nut N2 and the lock nut N3 are disconnected. It can be reused without inconvenience.

Further, the tape formed on the fastening nut 2 is
By using the flat surface 6, both nuts 2 and 3 are
Simply apply force in the direction of close contact and these nuts
Since the double lock nut 1 is obtained by connecting 2 and 3 , the processing is simplified and the cost increase can be suppressed.

In addition, the tightening torque of the lock nut 3 is applied while the nuts 2 and 3 are in contact with each other on the circular base portion 5 to lock the fastening nut 2, so that a relatively large contact surface is obtained. The torque can be transmitted, the torque can be surely transmitted, and a good lock function can be expected.

Further, the fastening nut 2 and the lock nut 3
Since and are individually rotatably connected, if foreign matter adheres to the bolt side and tightening of the fastening nut 2 is hindered, it is possible to tighten both nuts 2 and 3 after removing the foreign matter. Can be used.

In the embodiment described above, the peripheral surface 5a of the circular base portion 5 is an inclined surface as shown in FIG. 5, but instead of this, the peripheral surface of the distal end of the circular base portion 5 has a bulge. By doing so, the engagement with the annular protrusion 8 may be performed.

[0022]

As is apparent from the above description, according to the present invention, two nuts, which are independently manufactured, are also rotatably connected to each other by the engagement of the circular base and the annular projection. The double lock nut is made, and it does not cause deformation etc. due to use, so it can be reused and does not require cutting work or rolling work, so workability is improved and cost is kept low. be able to.

Further, even when a foreign substance adheres to the bolt when the bolt is tightened and the tightening is hindered, if the foreign substance is removed, the tightening can be restarted without any inconvenience.
Waste of nuts is eliminated.

In addition, the tightening torque of the lock-side nut is applied while both nuts are in contact with each other on the circular base portion to lock the nut on the tightening side, so that the torque transmission is relatively large. The surface is uniformly and surely performed in the circumferential direction, and a good lock function can be expected.

Further, in a nut having a circular base portion
Since the end surface around the circular base is tapered,
With the circular protrusion of the other nut fitted to the circular base of the nut, apply a force in the direction to bring both nuts into close contact with each other.
With this force, the annular projection abuts the tapered surface by this force, is curved inwardly guided by the tapered surface and engages with the circular base portion, and depending on the curved shape and the divergent shape of the circular base portion. , Both nuts will be prevented from coming off. Therefore, the two nuts can be easily connected, the workability is further improved, and the cost increase can be suppressed.

[Brief description of drawings]

FIG. 1 is a plan view of a double nut according to the present invention.

FIG. 2 is a front view of the double nut.

FIG. 3 is a sectional view of the double nut.

FIG. 4 is an exploded view of the double nut.

FIG. 5 is an explanatory diagram when connecting the nuts.

FIG. 6 is a sectional view of a conventional example.

FIG. 7 is a front view of another conventional example.

[Explanation of symbols]

 1 Double lock nut 2 Tightening nut 3 Lock nut 5 Circular base 6 Tapered surface 8 Annular protrusion

Claims (1)

[Scope of utility model registration request] 1. A double lock nut formed by coaxially connecting two nuts, wherein an end face of one of the nuts on the connecting side is provided with a circular base portion having a diverging shape , and the circular base is provided.
The end face around the part is
It is a tapered surface that inclines toward the end surface on the opposite side
In addition, a thin annular protrusion having an inner diameter slightly larger than the circular base portion is formed on the end surface of the other nut on the coupling side, and the annular protrusion is fitted to the circular base portion. Inside by being pressed against the above tapered surface
Is reduced in diameter, shape the two nuts can rotate individually
Double lock nut, which is engaged with the circular base portion in a stationary state .