JPH066730U - Double lock nut - Google Patents

Abstract

(57) [Summary] [Purpose] A double lock nut in which a fastening nut and a lock nut are individually rotatably connected to each other, which enables reuse of the double lock nut and improves workability. And, try to suppress the cost increase. [Structure] A circular base portion 5 having a flared shape is formed on a fastening nut 2, and an end face shape around the circular base portion 5 is formed into a tapered surface 6, while an annular thin protrusion 8 is formed on a lock nut 3. The nuts 2 and 3 are crimped while the annular projection 8 is fitted to the circular base 5, and the diameter of the annular projection 8 is reduced by the taper surface 6, and the annular projection 8 is engaged and removed. Stop.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a double lock nut having two nuts for fastening and locking.

[0002]

[Prior art]

 As a lock nut for preventing the fastening nut from loosening, for example, as shown in FIG. 6, a synthetic resin ring A is fitted to the thread portion B of the lock nut N1, and the lock nut N1 is oriented toward the tightening side. When it is screwed into the bolt in this state, the ring A is threaded by the thread on the bolt side, increasing the fastening force between the bolt and the lock nut N1, and providing a reliable locking effect. There is known a lock nut (hereinafter, referred to as the former lock nut) adapted to be used.

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. (See Japanese Patent Publication No. 47-43429). This is because a groove C is formed in the boundary between the fastening nut N2 and the lock nut N3 to form a thin portion between the nuts N2 and N3, and both nuts N2 and N3 are screwed into a bolt, and the fastening nut N2 is When the lock nut N3 is further tightened from the state of being tightened to a predetermined depth, the tightening torque by the lock nut N3 exceeds a predetermined value, so that the lock nut N3 is cut from the fastening nut N2 at the cutting line X. The lock nut N3 functions to prevent loosening.

[0004]

[Problems to be solved by the device]

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

Further, in the latter double lot nut, it is necessary to form the groove C by a cutting process in addition to the forging process, and form the groove C by the rolling process so as to surely cut the inside of the groove. However, there is a problem that the processing becomes complicated and the cost increases. It is also possible that the shape of the cut surface becomes uneven in the circumferential direction and the uniform tightening torque transmission is hindered and the locking function becomes unstable, and foreign matter adheres to the bolt side. If tightening of the nut 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. You will have to use a lock nut.

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

Therefore, an object of the present invention is to provide a double lock nut that can be reused and can exert a reliable locking function.

[0008]

[Means for Solving the Problems]

 That is, the device according to claim 1 of the present invention (hereinafter referred to as the first device) is a double lock nut formed by coaxially connecting two nuts, and one of the nuts has a connecting side end surface. , A circular base with a divergent shape is projected, and a thin annular projection with an inner diameter slightly larger than that of the above circular base is formed on the end surface of the other nut on the connecting side. The projection is fitted to the circular base portion, and the two nuts are internally reduced in diameter so as to be individually rotatable and are engaged with the circular base portion.

Further, according to a second aspect of the present invention (hereinafter, referred to as a second aspect), an end surface around the circular base portion of a nut having a circular base portion on a connection side end surface is a circular base portion from a nut outer peripheral end. It is characterized in that it is a taper surface that inclines toward the end face side on the opposite side of the nut.

[0010]

[Action]

 According to the first aspect of the invention, 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 is used. The nut can be used as a lock nut, and the fastening nut can be locked by tightening the lock nut after fastening the fastening nut.

Further, according to the second aspect of the invention, since the connecting side end surface of the nut having the circular base portion is formed into a tapered surface shape, the nut having the circular base portion is fitted with the annular projection of the other nut. If both nuts are caulked, the caulking force causes the annular projection to contact the taper surface, and the taper surface guides it to curve inwardly to engage the circular base portion, and the curved shape and circular shape. Both nuts are securely prevented from coming off due to the diverging shape of the base portion.

[0012]

【Example】

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

In the double lock nut 1 according to the present invention, as apparent from FIGS. 1 to 4, the fastening nut 2 and the lock nut 3 are coaxially and rotatably connected to each other. That is, the fastening nut 2 is formed with a circular base portion 5 coaxial with the screw hole 4 at 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, and the peripheral surface 5a of the circular base portion 5 is formed as an outwardly inclined surface (see FIG. 5). The end surface of the connecting side is formed into a tapered surface 6 that is inclined from the outer peripheral end of the nut toward 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 that 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 wall 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 should be L1> L2 as shown in FIG. 3, so that the length L1 of the screw hole 7 in the lock nut 3 should be longer. Constitute.

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 to the circular base portion 5, and then both nuts are struck by an appropriate means. Give and crimp. By this caulking, the tip of the annular projection 8 is guided by the taper surface 6 and deformed inward as shown in FIG. 6, so that the annular projection 8 is reduced in diameter and is prevented from coming off in the circular base portion 5. Is engaged with. However, the engagement should be performed loosely without hindering the individual rotation of the nuts 2 and 3, and the circular base portion 5 should come into light contact with the end surface of the lock nut 3, or Make sure that a small gap is formed as shown in.

In such a double lock nut 1, the nuts 2 and 3 are screwed into a bolt (not shown), and the fastening nut 2 is tightened to a predetermined depth, and then the lock nut 3 is further tightened to tighten the fastening nut 2. When the circular base portion 5 is brought into pressure contact with the fastening nut 2, a tightening torque is applied to the fastening nut 2 via the circular base portion 5, so that the locking function is exerted. Further, as described above, the length L 1 of the screw hole 7 on the lock nut 3 side is longer than the length L 2 of the screw hole 4 of the fastening nut 2, so that the tightening force by the lock nut 3 increases. It can prevent loosening surely.

By the way, in the double lock nut 1 of the present invention, the fastening nut 2 and the lock nut 3 are independent of each other, and the nuts 2 and 3 are engaged with each other by the circular base portion 5 and the annular projection 8. They are only connected together. Therefore, unlike the conventional nuts shown in FIGS. 6 and 7, the ring C is not threaded or the fastening nut N2 and the lock nut N3 are not deformed by use. It can be reused without inconvenience.

Further, the double lock nut 1 can be obtained only by caulking the two nuts 2 and 3 manufactured by the forging process using the taper surface 6 formed on the fastening nut 2, so that the process is simple. It is possible to suppress the cost increase.

In addition, since 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, the fastening nut 2 is locked, a relatively large contact is made. Thus, torque transmission can be performed on the surface, and the torque transmission becomes reliable, so that a good locking function can be expected.

Furthermore, since the fastening nut 2 and the lock nut 3 are rotatably connected to each other, if foreign matter adheres to the bolt side and the tightening of the fastening nut 2 is hindered, the foreign matter is removed. If both nuts 2 and 3 are tightened after removal, it can be used without problems.

In the above embodiment, 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 circular base portion 5 has a bulge. The engagement with the annular projection 8 may be made possible by doing so.

[0022]

[Effect of device]

 As is clear from the above description, according to the present invention, two nuts that are independently manufactured are also rotatably connected to each other by the engagement of the circular base portion and the annular protrusion to form the double lock nut. Since it is made and it does not cause deformation etc. due to use, it can be reused, and since it does not require cutting or rolling, it improves workability and keeps costs low. it can.

Further, even if 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, and the nut is not wasted.

In addition, the tightening torque of the lock-side nut is added to lock the nut on the fastening side while both nuts are in contact with each other on the circular base, so that the torque transmission is relatively large. The surface can be evenly and reliably carried out in the circumferential direction, and a good locking function can be expected.

Further, since the connecting side end surface of the nut having the circular base portion is formed into a tapered surface, if both nuts are caulked from the state where the annular protrusion of the other nut is fitted to the circular base portion of the nut. The caulking force causes the annular projection to come into contact with the tapered surface, and the tapered surface guides the annular projection to bend inward and engage 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 can be 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 (2)

[Scope of utility model registration request] 1. A double lock nut formed by coaxially connecting two nuts, wherein a conical end portion of one nut has a circular base portion projecting from the end surface on the connecting side, and the end surface on the connecting side of the other nut. Is formed with a thin annular protrusion having an inner diameter slightly larger than that of the circular base portion, and the annular protrusion is fitted to the circular base portion, and the two nuts can rotate individually. The double lock nut is characterized in that the diameter is reduced inwardly and is engaged with the circular base portion. 2. A nut having a circular base portion on the end face on the connecting side has an end surface around the circular base portion which is a tapered surface inclined from the outer peripheral end of the nut to the circular base portion toward the end surface opposite to the nut. The double lock nut according to claim 1, wherein