JPS6261807B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to locking nuts, particularly torque-enhancing locking nuts, and methods of manufacturing such nuts.

Conventionally, various torque increasing type locking nuts have been proposed. For example, an annular flat plate is fixed to the upper surface of the nut body opposite to the seating surface, and an arcuate projection extending radially inward is provided on the inner peripheral surface of the annular flat plate, and the nut is screwed into this arcuate projection. A locking nut is known that prevents the nut from loosening by contacting and interfering with the male threaded surface of the bolt.

However, in this type of locking nut, the wall thickness of the annular flat plate is thinner than the thread pitch of the male thread of the bolt, so even if the tip of the arcuate protrusion comes into contact with the male thread surface, there will be a large amount of friction. no force can be generated between the tip of the arcuate protrusion and the external thread surface;
It is difficult to obtain such a reliable nut loosening effect.

The present invention has been made in view of the above points,
The purpose is to provide a locking nut that can generate a relatively large frictional force with the male threaded surface of a threaded member such as a bolt, and can provide a reliable locking effect.

According to the invention, the objective is to provide a nut body;
It consists of a recess formed on the upper surface of the nut body opposite to the seat surface of the nut body, and an annular body disposed within the recess, and the annular body has an inner circumferential surface of the annular body. an inner peripheral part having an internal thread coaxially with the internal thread of the nut body and having the same nominal diameter and pitch, and an inner peripheral part that extends outward from this inner peripheral part; It has an elongated annular conical thin-walled portion and an outer peripheral portion that is integrally connected to the annular conical thin-walled portion and is fixed to the peripheral edge of the recessed portion, and has a bottom surface and a front portion of the recessed portion. The nut is in contact with a surface of the inner periphery facing the bottom surface thereof, and the female thread of the nut body and the female thread of the inner periphery are relatively different in phase. Achieved by Natsuto.

Therefore, when the locking nut of the present invention is screwed into a threaded member having a male thread, such as a bolt, the female thread on the inner circumference, which is out of phase with the female thread on the nut body, is connected to the female thread on the nut body. As a result of the inner circumferential portion being returned in the opposite direction to the relative movement direction so as to be screwed together with the female thread into the male thread of the screwing member, the thin portion, especially the annular conical thin wall portion, is elastically deformed, and the female thread and the male thread are screwed together. A relatively large frictional force can be generated between the nut and the screw, and a reliable effect of preventing the nut from loosening can be achieved.

Furthermore, the present invention relates to a method of manufacturing a locking nut having the above-mentioned configuration, and this manufacturing method includes the following steps:
a step of providing a recessed portion in the upper surface of the nut material opposite to the seating surface having the screw pilot hole; an inner peripheral portion having the screw pilot hole; and an annular conical thin wall portion integrally extending outward from the inner peripheral portion; arranging an annular body including an outer circumferential portion connected to the annular conical thin-walled portion in the recess; and spacing the lower surface of the inner circumferential portion a predetermined distance from the bottom surface of the recess; a step of fixing it around the inner circumference of the annular body, a step of forming a continuous internal thread in the prepared hole of the nut material and the prepared hole of the inner circumference of the annular body, and a step of fixing the inner circumference of the annular body to the bottom surface of the recessed part. moving the inner periphery of the annular body relative to the outer periphery until the inner periphery of the annular body contacts the inner periphery of the annular body, thereby making the female thread formed in the nut material and the female thread formed in the inner periphery different in phase; It is characterized by consisting of.

By manufacturing the locking nut in this way, it is possible to accurately form a female thread on the inner periphery of the nut material and the annular body, and it is also possible to form a female thread accurately on the inner periphery of the nut material and the annular body. The inner periphery can be moved relatively in the axial direction, that is, pushed in the axial direction with a press machine, until the lower surfaces come into contact, and the desired phase difference is imparted to the female thread formed in the nut material and the female thread formed on the inner periphery. Even in the case of mass production, there is no variation in the phase difference between individual locking nuts, and a large number of locking nuts can be efficiently manufactured.

Hereinafter, preferred embodiments of the present invention will be explained based on the drawings.

The locking nut 1 shown in FIG. 1 is provided with an annular recess 5 in the upper surface 4 of the nut body 2 facing the seat surface 3, and an annular body 6 is disposed within the recess 5. Teru. The annular body 6 defines an inner circumferential surface of the annular body 6, and includes an inner circumferential portion 8 having a female thread 7 and an annular conical thin-walled portion integrally extending outward from the inner circumferential portion 8. , and a thin annular flange portion 11 as an outer peripheral portion 10 integrally connected to the thin portion 9. Flange part 1
1 is fixed to the nut body 2 around the recess 5.

The nut body 2 has a cylindrical portion 12 projecting integrally extending upward from the upper surface 4, and the cylindrical portion 12 and the recess 5 are arranged concentrically with respect to the female thread 13 of the nut body 2. ing. The inner diameter of the cylindrical portion 12 is larger than the diameter of the recess 5, and a stepped portion 14 is provided between the cylindrical portion 12 and the recess 5. These recesses 5, step portions 14, and cylindrical portions 12 constitute a recess portion. Further, the peripheral edge of the recessed portion includes a stepped portion 14 and a cylindrical portion 12.

The flange part 11 of the annular body 6 is placed on the step part 14, and by caulking the cylindrical part 12 inward, the flange part 11 of the annular body 6 is placed between the step part 14 and the cylindrical part 12, that is, the peripheral edge of the recessed part. The flange portion 11 is clamped and fixed to the nut body 2.

The female thread 13 and the female thread 7 are formed to have the same nominal diameter and pitch. Then, the inner peripheral part 8 is moved relative to the flange part 11 in the axial direction of the female thread, and the stepped part 14 and the cylindrical part 12 of the flange part 11 are moved.
By bending and deforming the thin walled portion 9 that is not held between the female threads in the axial direction of the female thread and elongating it into a conical shape, the phases of the female thread 13 and the female thread 7 are made different.

In particular, it is preferable that the locking nut 1 be manufactured by the following process.

(i) An annular recess 5 and a cylindrical portion 12 are provided on the upper surface 4 of the nut body 2 opposite the seat surface 3 of the nut material 16 having a screw pilot hole 15 (see Fig. 3); (ii) a screw pilot hole An annular body 6 (see FIG. ) is arranged in the recess 5, and the flange part 11 is placed on the step part 14.
(iii) Place the lower surface 18 of the inner peripheral part 8 facing the bottom surface 19 of the recess 5 at a predetermined distance from the bottom surface 19 of the recess 5 (for example, a distance equivalent to about 1/2 pitch of a female thread). ) apart from the flange portion 11 in the recess 5.
(iv) crimp the cylindrical part 12 inwardly and downwardly to clamp the flange part 11 between the cylindrical part 12 and the stepped part 14 (see Fig. 6); (iv) the nut material 16; (v) Female threads 1 of the nut material 16 (nut body 2) are formed continuously in the pilot hole 15 of the nut and the pilot hole 17 of the inner peripheral part 8 using a tap or the like (see Fig. 7).
The lower surface 18 of the inner circumferential portion 8 is made such that the phase of the female thread 7 of the inner circumferential portion 8 differs by the distance (for example, 1/2 pitch of the female thread).
until it abuts or contacts the bottom surface 19 of the recess 5.
The inner peripheral part 8 is moved relative to the flange part 11 downward in the axial direction of the female thread, and the flange part 11 is
The thin portion 9 not held between the cylindrical portion 12 and the stepped portion 14 is bent downward in the axial direction of the female thread (see FIG. 1).

Prior to the steps (i) to (v) above, nut material 1
A chamfered portion 20 is formed in the prepared hole 15 on the bottom surface 3 side of the inner peripheral portion 8, and a chamfered portion 21 is formed in the prepared hole 17 on the lower surface 18 side of the inner peripheral portion 8. In addition, chamfering is performed at a predetermined angle between the step portion 14 and the recess 5 to form an inclined surface 22, so that the thin portion 9 is bent downward in the axial direction of the female thread in the step (v). Compensate for.

At least one female thread 7 is formed on the inner circumferential portion 8.
It is formed to have a thread surface that is larger than a pitch.

The annular body 6 shown in FIG. 5 corresponds to the annular body 6 placed in the recess 5 of the nut body 2 in FIG. and is inclined conically at an angle corresponding to angle α. Of course, this angle α can be adjusted as desired. It is preferable that the annular body 6 is made of a material that is more easily deformed elastically than the nut body 2. Further, it is better to heat-treat the annular body 6 and the nut body 2 separately in advance.

The locking nut 1 configured as above is
It is screwed into a threaded member such as a bolt that has a male thread. After screwing the female thread 13 of the nut body 2 onto the male thread, when the nut body 2 is further screwed into the screwing member, the tip of the screwing member will fit into the chamfered part of the inner circumference 8 of the annular body 6. 21 and presses the inner circumferential portion 8 upward, and the thin portion 9, which has previously been bent downward in the axial direction, is elastically bent and deformed upward. When the female thread 7 of the inner circumferential portion 8 is screwed together with the female thread 13, interference pressure is applied to the male thread via the female thread 7 based on the elastic deformation of the thin portion 9, and the female thread 7 A relatively large frictional force is generated between the external thread and the external thread. At this time, the female thread 13 contacts and interferes with the male thread together with the female thread 7, and a relatively large frictional force is generated between the female thread 13 and the male thread.

In this way, the frictional force can provide a reliable locking effect of the locking nut 1.

Moreover, since the frictional force can be generated based on the elastic deformation of the thin-walled portion 9, the frictional force does not decrease that much even if the locking nut 1 is repeatedly engaged and disengaged with the threaded member. First, even if the locking nut 1 is used repeatedly, the locking effect of the locking nut 1 can be maintained.

In the specific example described above, the thin portion 9 is bent downward in the axial direction of the female thread, but the thin portion 9 may be bent upward in the axial direction to shift the phase between the female thread 13 and the female thread 7. In this case, from the inner peripheral part 8 to the thin part 9
is formed by extending outward and upward, and in order to shift the phase between the female thread 13 and the female thread 7, an upward force in the axial direction is applied to the thin wall portion 9, and the thin wall portion 9 extends outward substantially horizontally. The thin portion 9 may be plastically bent and deformed as shown in FIG.

8 to 11 show other embodiments of the locking nut 1 of the present invention.

In this specific example, the nut material 1 of the nut body 2
The inner diameter of the cylindrical portion 30 provided on the upper surface 4 of the annular body 6 is the same as the diameter of the recess 31 (see FIG. 9), and the annular body 6 integrally extends outward from the inner peripheral portion 8 of the annular body 6. It has a thin wall portion 9 and an outer peripheral portion 10, that is, an annular thick wall portion 32, which is integrally connected to the thin wall portion 9 and integrally extends outward from the thin wall portion 9.
As shown in FIG.
8 is raised by a predetermined distance (for example, a distance corresponding to 1/2 pitch of the female thread). Note that the cylindrical portion 30 and the recess 31 constitute a recess portion.

The locking nut 1 of this specific example can also be manufactured by substantially the same steps as the steps (i) to (v) of the above specific example, so it will not be described in detail here.

The annular body 6 shown in FIG. 10 is placed in the recess 31 of the nut material 16 shown in FIG. 33 and the cylindrical portion 30, and is fixed to the nut material 16. In this state, the outer circumferential surface of the thick portion 32 is in surface contact with the inner circumferential surface of the recess 31 . And Natsuto material 1
In order to form continuous internal threads 13 and 7 in the pre-threaded hole 15 of 6 and the pre-threaded hole 17 of the inner peripheral part 8, and to shift the phase of the female thread 13 and the female thread 7, as shown in FIG. The inner circumferential portion 8 is moved relative to the thick portion 32 downward in the axial direction of the female thread until the lower surface 18 of the inner circumferential portion 8 facing the bottom surface 33 of the recess 31 comes into contact with the bottom surface 33 of the recess 31. The thin portion 9 is bent downward in the axial direction of the female thread, and the thin portion 9 is expanded into a conical shape. The annular body 6 shown in FIG. 11 corresponds to the annular body 6 arranged in the recess 31 of the nut body 2 in FIG. It is inclined conically at an angle corresponding to angle α. The thin portion 9 may be bent upward in the axial direction of the female thread 7. Of course, as shown in FIG. 11, the annular body 6 with the internal thread 7 formed in advance on the inner peripheral portion 8 is placed in the recess 31 of the nut body 2 in which the internal thread 13 is formed in advance, and the annular body 6 is The thick portion 32 may be fixed to the nut body 2 by caulking the cylindrical portion 30 so as to sandwich the thick portion 32 between the cylindrical portion 30 and the bottom surface 33 of the recess 31. On this occasion,
In order to shift the phase between the female thread 7 and the female thread 13, the angle α is adjusted to a desired angle before or after the caulking.

Adjust the angle α of the thin portion 9 shown in FIGS. 5 and 11 as desired, and
You may adjust the phase difference between the two.

Further, the locking nut of the present invention is not limited to hexagonal nuts, and may be applied to nuts of various shapes, for example, even if the nut body has a shape such as a square nut or a round nut. good.

In addition, in order to more securely fix the outer circumference of the annular body around the recess, the inner circumferential surface of the recess, that is, the circumferential wall, is formed into a polygonal shape, and the circumferential surface of the outer circumference of the annular body is fixed around the recess. It may be formed into a polygonal shape corresponding to the shape of the peripheral wall of the nut, and projections or depressions are provided at equal angular intervals on the upper surface of the outer periphery, and a cylindrical portion provided on the upper surface of the nut body is engaged with the projections or depressions. The cylindrical portion may be caulked again as shown in FIG.

Further, in the specific example of the annular body 6 shown in FIG.
However, this annular groove 34 may be formed to have an inverted V-shape in cross section to define a thin portion. Further, this annular groove is not limited to a circular shape, but may be polygonal. In addition, in all specific examples of the annular body, it is not necessary to extend the annular thin wall portion outward from the upper end of the inner circumferential portion, and the annular thin wall portion does not need to extend outward from the intermediate portion or the lower end of the inner circumferential portion in the axial direction. It may be formed to be elongated.

As described above, according to the present invention, the inner peripheral part is moved relative to the outer peripheral part in the axial direction of the female thread, and the female thread of the inner peripheral part is different in phase from the female thread of the nut body. Therefore, when the locking nut of the present invention is screwed onto a bolt, the female thread on the inner circumference and the female thread on the nut body strongly contact and interfere with the male thread of the bolt, achieving a reliable locking effect. obtain.

In addition, in the locking nut of the present invention, when the locking nut is attached to a bolt, for example, the relative phase difference between the female thread of the nut body and the female thread of the inner peripheral portion is As a result, the male thread of the bolt contacts and interferes with the female thread of the inner peripheral portion, and the annular body receives a displacement force along the axial direction of the female thread. The annular body can elastically absorb such displacement force by the annular conical thin-walled portion formed in a dish shape and having rigidity. In other words, the annular conical thin-walled portion formed in a dish shape and having increased rigidity Therefore, the contact interference force between the male thread of the bolt and the female thread of the inner peripheral part can be strongly and elastically maintained, and the male thread of the bolt, the female thread of the inner peripheral part, and the female thread of the nut body can each be maintained strongly and elastically. and the contact interference force can be maintained at a required level, and furthermore, since the surface of the inner circumferential portion facing the bottom surface is in contact with the bottom surface of the recessed portion. , the distance of movement of the annular body caused by the displacement force along the axial direction of the female thread can be regulated within a predetermined range;
In other words, the annular body can be configured to be movable within the elastic limit of the annular conical thin-walled portion, and therefore, the locking nut of the present invention does not prevent the bolt from tightening even if the mounting is repeated. The contact interference force between the inner peripheral portion and the internal thread can be elastically maintained, and the deterioration of the locking effect can be reduced.

Further, according to the method for manufacturing a locking nut of the present invention, after the lower surface of the inner peripheral part is spaced apart from the bottom surface of the recessed part by a predetermined distance in advance and the outer peripheral part is fixed around the recessed part, , the inner periphery is moved relative to the outer periphery in the axial direction of the female thread until the lower surface of the inner periphery comes into contact with the bottom of the recess. The inner circumference can be relatively moved in the axial direction, that is, pushed in the axial direction by a press machine, until the lower surface of the inner circumference comes into contact with the surface, and the phase difference between the female thread on the inner circumference and the female thread formed on the nut material can be set to a predetermined amount, and even when mass-producing locking nuts, it is possible to prevent variations in the phase difference caused by individual locking nuts, and an efficient method for manufacturing locking nuts is provided. may be provided.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a first specific example of the locking nut of the present invention, FIG. 2 is a plan view of the locking nut shown in FIG. 1, and FIG. Cross-sectional view of the nut material of the locking nut, No. 4
The figure is a sectional view of the annular body before forming the internal thread, FIG. 5 is a sectional view of the annular body after forming the internal thread, and FIGS. 6 and 7 are explanatory diagrams showing the manufacturing process of the locking nut shown in FIG. Fig. 8 is a cross-sectional view of a second specific example of the locking nut of the present invention, Fig. 9 is a cross-sectional view of the nut material of the locking nut shown in Fig. 8, and Fig. 10 is a cross-section of the annular body before forming an internal thread. FIG. 11 is a sectional view of the annular body after the female thread has been formed. 2... Nut body, 5... Recess, 6... Annular body, 7... Female thread, 8... Inner circumference, 9... Thin wall portion, 10... Outer circumference, 13... Female thread.

Claims (1)

[Scope of Claims] 1 Consisting of a nut body, a recessed portion formed on the upper surface of the nut body opposite to the seat surface of the nut body, and an annular body disposed within the recessed portion, the annular body The body defines an inner circumferential surface of the annular body, and an inner circumferential portion having an internal thread formed coaxially and with the same nominal diameter and pitch as the internal thread of the nut main body on the inner circumferential surface; It has an annular conical thin wall portion that integrally extends outward from the inner peripheral portion, and an outer peripheral portion that is integrally connected to the annular conical thin wall portion and is fixed to the peripheral edge of the recessed portion. The bottom surface of the recessed portion and the surface of the inner peripheral portion facing the bottom surface are in contact with each other, and the female threads of the nut body and the female threads of the inner peripheral portion are relatively different in phase. A locking nut that is characterized by: 2. The locking nut according to claim 1, wherein the outer peripheral portion of the annular body is an annular thin-walled flange member that integrally extends outward from the annular conical thin-walled portion. 3. An annular thick-walled member in which the outer peripheral portion of the annular body integrally extends outward from the annular conical thin-walled portion, and the outer peripheral surface of the annular thick-walled member is flush with the inner peripheral surface of the recessed portion. The locking nut according to claim 1, wherein the locking nut is fixed to the peripheral edge of the recessed portion in contact with the recessed portion. 4. Providing a recessed portion on the upper surface of the nut material opposite to the seating surface having the screw pilot hole, an inner peripheral portion having the screw pilot hole, and an annular conical thin wall portion integrally extending outward from the inner peripheral portion. and an outer periphery connected to the annular conical thin-walled portion in the recess, and separating the lower surface of the inner periphery from the bottom surface of the recess by a predetermined distance, and the outer periphery. a step of fixing around the recessed part, a step of forming an internal thread continuous with a prepared hole in the nut material and a prepared hole in the inner circumference of the annular body, and a step in which the lower surface of the inner circumference of the annular body is connected to the recessed part. The inner periphery of the annular body is moved relative to the outer periphery in the axial direction of the female thread until it comes into contact with the bottom surface of the nut material, and the female thread formed in the nut material and the female thread formed on the inner periphery are connected. A method for manufacturing a locking nut comprising the steps of varying the phase of the female thread. 5 When the outer periphery of the annular body is fixed around the recess, the lower surface of the inner periphery should be 1/2 of the female thread from the bottom of the recess.
5. The method of manufacturing a locking nut according to claim 4, wherein the locking nuts are spaced apart by a pitch.