JPS62151615A - Locknut and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a locking nut and a method for manufacturing the same.

(Prior Art) In a so-called bolt-nut fastening structure, various self-tightening locking nuts have been proposed in order to prevent a nut fastened to a bolt from loosening or falling off.

For example, what is disclosed in Japanese Utility Model Application Publication No. 54-98443 is a screw cap that is screwed onto the neck of a footwear, but a female screw that is screwed into a male screw formed on the outer peripheral surface of the neck is inserted into the inside of the cap. When providing the stripes on the circumferential surface, an elastic protrusion is further integrally connected to the tip of the thread of this female screw at a height such that the tip is pressed against the outer circumferential surface of the neck when the cap is screwed onto the neck. I have V.

In addition, in Japanese Patent Application Laid-open No. 50-157759, a female thread carved in the center hole of a nut has a partially deformed cross section that is incompletely engaged with the normal thread spacing +7+F. Because of this, the bottom of the screw valley is shallower than other parts,
The deformed cross section is created by changing the angle of the inclined side surface inside the screw, increasing the width (6 and height) of the screw thread, or locally changing the pitch interval of the screw thread.

(Problem to be Solved by the Invention) However, in the former method, if the cap structure is made of synthetic resin, the elastic protrusion is pressed against the neck of the bottle using the elastic force of the synthetic resin itself. Although it is possible to expect a loosening effect by using this method, it is generally not applicable to nuts that are made of metal. This is because metal nuts, which cannot be expected to have the elasticity of the synthetic resin, were developed in 1984-9844.
If a protrusion similar to the one described in Publication No. 3 is provided at the tip of the thread of the female thread, the crimp between the nut and the bolt will be strong and 1.
1. The nut must be rotated with a strong force from the beginning to the end of tightening. Therefore,
It is not something that can be put into practical use with the ff1l bottom.

In addition, in the latter method, the threaded portion of the deformed cross section is only partially provided, so the former method does not have any drawbacks. Since the frictional resistance caused by incomplete engagement persists from the beginning of tightening to the end of tightening, the resistance during tightening is also large and workability is still poor.

Furthermore, in order to create a deformed cross section in the latter method, the thread root is made locally shallow as shown in the previous example (e), and the shape of the screw exit surface is locally changed, etc.; Because the shape of the thread root or the thread pitch interval changes locally, it is not possible to open a female thread using a tap, and a special thread cutting process is required. As an example of this special thread cutting method, the publication discloses that a core mold is produced in which a part of the thread of the thread is incompletely engaged with the normal thread spacing cross section, and this is used to cut the thread into the oak 1. We have proposed a nut manufacturing method similar to a type of caulking process, in which an external force is applied to the nut in the direction of its central axis after the nut is inserted into the nut, thereby carving a female thread. Even if it is suitable,
It cannot be adopted in any other way.

Furthermore, the method is inefficient and completely ignores economic effects.

In view of the above-mentioned points, the present invention allows the tightening work of bolts from 1 to 10 to be carried out easily, and can accurately prevent loosening by simply applying strong force temporarily just before the completion of tightening. The object of this invention is to provide a nut that can hold an IJ, and a further object is to provide a method for manufacturing a nut that can efficiently and inexpensively manufacture such locking nuts 1 to 1.

(Means for solving the problem) That is, the locking nut according to the first invention of the present application has a
~ The female threads on the inner periphery of the center hole of the nut body are carved at the same pitch interval over the entire length and with the root diameters aligned, and among the female threads, the threads in a predetermined range at one end of the nut body are carved. It is characterized in that the top protrudes further into the center hole than the thread of the rounded part.

In addition, the method for manufacturing a loosening +l=map according to the second invention of the present application is for manufacturing the locking nut according to the first invention, in which one end of the nut body is used as a pilot hole opened in the center of the nut body. A prepared hole having a small diameter part is formed in a predetermined range, and a tap is inserted into this prepared hole from the side opposite to the small diameter part to cut a female thread in the entire prepared hole including the small diameter part, and as the tap The tap is characterized in that it has a relief groove between the cutting blades arranged at constant pitch intervals, and the diameter of the tap shaft at the bottom of the relief groove is approximately equal to the inner diameter of the small diameter portion.

(Function) According to the second invention, a tap is inserted into the small hole of the nut main body from the side opposite to the small diameter portion, and as the 1 (11) thread is cut into the prepared hole, the small diameter portion becomes thinner. When a female thread is cut in the small diameter part, the small diameter part wall thickness that protrudes inward escapes into the relief groove between the tap cutting edges, and this remains as a bulge at the small diameter part thread crest. Compared to the screw cut in the pilot hole of the part, the screw in the small diameter part is cut with the same pitch interval and the same root diameter, but the thread crest protrudes inward by the amount of the bulge.

Then, in the nut of the first invention of the present application obtained in the above manner, the high part of the thread crest is formed only at the nut 1 to one end of the main body, so that other parts of the nut are Department,
In other words, if the nut is tightened onto the bolt from the lower side of the thread, the nut can be rotated lightly as usual at the beginning of tightening. Then, just before the bolt reaches the high part of the thread crest, apply strong force and tighten the high part of the thread crest (the bulge) toward the bolt, and this thread will come into strong pressure contact with the bolt. Therefore, a large pressure contact force (+! iti friction force) acts between the two, which has a loosening effect);
7.

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

FIG. 1 shows a locking nut 1 according to an embodiment of the first invention of the present application.
shows. This nut 1 is a nut with a seat, and a female thread 4 is formed in the center hole of a main body 3 having a seat 2.

At one end 5 of the female thread 4 (the end opposite to the end where the seat 2 is provided), the top of the thread 6 protrudes inward from the other portion 7. This is shown in more detail in Figure 2.
6 + has a bulging part 8 installed at the top of the thread 6o of the standard dimension shown by the chain line, and the top protrudes inward from the thread 62 of the other part 7 formed to the standard dimension. It is being done.

In addition, the female thread 4 is cut at the same pitch interval over its entire length, the thread 61 part and the thread thread 62 part, and the depth from the thread top of the standard dimension to the thread valley 9, as shown by the chain line, is the valley. The diameter is the same throughout the entire length range mentioned above. Therefore, the screw threads 61 and 62 are shaped so that the thread thread 61 projects more than the thread thread 62 by an amount of eight bulges, with the thread root 9 as a reference.

Further, except for this bulging portion 8, the cross sections of the threads 61 and 62 have the same shape.

When using the nut 1 configured in this way, when the nut 1 is screwed into the bolt from the seat 2 side, it will initially have a standard shape, that is, the thread 62 of the part 7 where the bulge 8 is not provided.
is screwed into the bolt, so the nut rotates in a circle W1 at the beginning of tightening, but when the bolt passes through this part 7 and approaches the end of tightening, the thread 61 with the bulge 8 starts to engage with the bolt. . At this time, the end 5 of the nut 1
As shown in FIG.
The bulging portion 8 is strongly pressed against the valley bottom portion 10a, and a large pressing force (frictional force) acts between the two. Therefore, in the completely tightened state, the nut 1 is prevented from loosening, and the force applied to the nut 1 only needs to be increased just before the tightening is completed as described above.

Next, as an embodiment of the second invention of the present application, a method of manufacturing the locking nut 1 as described above will be described. First, when forming the pilot hole 11 in the nut body 3 as shown in FIG. 4, a small diameter portion 12 is formed on the end 5 side of the pilot hole 11, the diameter of which is reduced below that of the other portion 7. On the other hand, on the side of the tap 13 where a female thread is to be cut with respect to the prepared hole 11, relief grooves are formed at the bottom between the cutting edges 14...14 formed at constant pitch intervals, as shown in an enlarged view in FIG. 15...Engrave 15. In this case, the diameter R1 of the tap shaft drawn on the bottom surface of the relief j415 is set to approximately match the inner diameter R2 of the small diameter portion 12 of the Naramil main body 3. Then, the tap 13 is inserted into the F hole 11 from the opposite side of the small diameter portion 12 while being rotated.

This allows the pilot hole 11 to have a cutting edge 14 that gradually becomes taller.
... At 14, a shallow thread groove is cut at first, and this thread is gradually cut deeper. This is the small diameter portion 12 of the pilot hole 11.
The same is true for , but each cutting edge 14 is provided on the tap 13 side.
Since relief grooves 15...15 are formed between...14, in the small diameter portion 12, the inner part
Even if the thread a escapes into the relief grooves 15...15 and the tap 13 is pulled through the prepared hole 11, the excess material that escaped into the relief groove 15 is not removed, and the bulge at the top of the thread 61 is prevented. It remains as part 8.

In this way, a nut 1 as shown in FIG. 1.2 is manufactured.

In addition, as shown in Fig. 6, the pilot hole 1 in the nut body 3'
A small diameter part 12' is formed at one end of the part 1', and a plurality of holes 12a'...12a' are formed in the small diameter part 12' in the axial direction.
'l was established, and then, as in Fig. 4, f
If you cut the luff thread, the sea urchin [screw 4] shown in Figure 7.
At one end of the screw thread 6', an intermittent bulge 8' is formed in the circumferential direction, resulting in a 4T round (~1' is 15
1 will be given. According to this rat 1', tightening the bolt 1. 'i, the range that is pressed against the root of the Afl thread at J5 of the bolt is smaller than the bulge shown in Fig. It will be done.

Historically, a pilot hole 11° 11' like J- shown in Figure 4 or Figure 6 is used.
A tap 13' shown in Fig. 8 is attached to the main body 3.3' formed with
, that is, the relief between each cutting edge 1/I'...14' is 15'
...If the female thread is cut using the tap 13' which has small second cutting edges 16'...16' inside the tap 15', a J3 (notch) will be formed at one end of the female thread 4'' as shown in Fig. 9. Thread 6″
A nut 1'' is formed in which a bulged portion 8'' with a forked tip is exposed. According to this nut 1'', when the two fork-shaped projecting pieces 8a'' and 88'' of the bulging portion 8'' come into pressure contact with the bottom of the bolt when the bolt is tightened to By elastically deforming in the direction of approaching each other as shown by arrows a and a, the tightening torque is reduced, and in the tightened state, both projecting pieces F
Due to the outward elastic restoring force of 3a and 3a'', they come into strong pressure contact with the valley bottom of pole I. Therefore, a large loosening prevention effect can be obtained with a small tightening torque of 1 to 100 lbs.

(Effects of the Invention) As detailed above, the first aspect of the present application. In the locking nuts 1 to 1 according to the second invention, since the rotational force at the time of tightening the nut to the pole 1 is reduced as compared to the conventional one, the tightening work can be easily performed. Appropriate loosening can be achieved by applying a large force only immediately before the completion of tightening and pressing the high portion of the thread top against the pole 1.

In addition, this locking nut changes the degree of protrusion of the top of the thread by the presence of the small diameter part of the prepared hole and the relief groove of the tap, and since the thread pitch interval and root diameter are the same, the above-mentioned lower The nut can be manufactured all at once by ordinary tapping of the hole, eliminating the need for special manufacturing methods, making it possible to provide a locking nut at low cost, improving manufacturing efficiency, and making mass production possible.

In particular, according to the nut of the present invention, the dimension R2 of the F hole small diameter portion 12.12' shown in FIG. 4.6 and the tap 1 shown in FIG.
Since the shaft light R1 etc. in the groove part 3 can be set to positive (1), the loosening is reduced compared to the conventional method in which a part of the female thread is deformed by applying plastic working from the outer periphery after completion. There is an advantage in always setting the stopping torque accurately.

The present invention is not limited to the nuts shown in the examples, but can be widely applied to other nuts.

[Brief explanation of drawings]

FIG. 1 shows a locking nut showing an embodiment of the first invention of the present application.
2 is an enlarged sectional view of the main part of Fig. 1, 3
The figure is an enlarged sectional view of the main part of the same large nut in use, Figure 4 is an explanatory diagram showing an embodiment of the method for manufacturing the locking nut of the second invention of the present application, and Figure 5 is the nut used in this fi method. Partial enlargement of the tap; new view, Fig. 6 (a), (b) 1. A sectional view and a plan view showing the shape of the F hole in the second embodiment of the second invention, FIG. 7 is an enlarged sectional view of the main part of the nut according to the embodiment, and FIG. 8 is a third embodiment of the second invention of the present application. FIG. 9 is an enlarged cross-sectional view of the main parts of the tap used in this example. FIG. 1.1', 1''...nut, 4.4', 4''...1
111 threaded part, 6.6', 6"... thread, 8.8
'. 8″...Bulge, 9...Screw valley, 11.11'・
... Pilot hole, 12.12' ... Small diameter part. Fig. 1 Fig. 2 Port Fig. 3 Fig. 4 Fig. 5 +1' Fig. 6 (b) Mi 4' Fig. 8 Fig. 9 ≦ =: S-

Claims (2)

[Claims] (1) The female threads on the inner periphery of the center hole of the nut body are carved at the same pitch interval over the entire length and with the root diameters uniform, and the female threads are carved in a predetermined range at one end of the nut body within the entire length of the female thread. A locking nut characterized in that the top of the thread protrudes further inward from the center hole than the other threads. (2) As a pilot hole opened in the center of the nut body, a pilot hole having a small diameter part is formed in a predetermined range at one end of the nut body, and a tap is inserted into this pilot hole from the side opposite to the small diameter part. In addition to carving a female thread in the entire prepared hole including the small diameter part,
The tap is characterized in that it has a relief groove between the cutting blades arranged at constant pitch intervals, and the tap shaft diameter at the bottom of the relief groove is approximately equal to the inner diameter of the small diameter portion. Manufacturing method for locking nuts.