JP2003166519A - Plastic locking nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic locking nut of which the whole body is made of a simple elastic resin material in a low cost, which has an excellent locking effect, and further of which screwing work can be easily carried out. <P>SOLUTION: The screw hole 12 of a resin-made nut 10 molded of an elastic resin material is formed of the first female screw 13 with a complete thread formed from the bearing surface 11 side to the intermediate section and the second female screw 14 with a incomplete thread continuously extending to the first female screw 13. A male screw 31 fitted to the female screw 13 is screwed in the second female screw 14 to form a female screw 16 with a complete thread to obtain a locking effect. As the second female screw 14 is formed in a female screw with a complete thread, the inner diameter B of the second female screw 14 is formed a little smaller than the inner diameter A of the first female screw 13. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin locking nut having a locking function.

[0002]

2. Description of the Related Art Various types of locking nuts have been proposed for a long time. Among them, the most typical locking nuts made of resin material are
As shown in FIG. 7, it is a nylon insert locking nut having a structure in which a nylon ring 3 is inserted and fixed on the top of the screw hole 2 of the metal nut 1. When a male screw such as a bolt is screwed into the screw hole 2 from the seating surface 4 side of the loosening nut, a female screw is formed on the inner peripheral portion of the nylon ring 3 by the male screw, and the formed female screw closely contacts the male screw. By producing a large frictional force, the loosening prevention effect is exhibited.

[0003]

However, the above-mentioned conventional nylon insert locking nut is a metal nut 1.
It is composed of two parts, the nylon ring 3 and the nylon ring 3 and has a drawback that the manufacturing cost is high. Further, the screwing resistance when screwing the male screw into the nylon ring 3 was large, and the screwing operation was difficult as compared with a normal nut.

The present invention has been made in view of the above points, and while the whole nut can be molded at a low cost by molding a single elastic resin material, an excellent anti-loosening effect can be obtained and a screwing operation can be performed. An object of the present invention is to provide a resin locking nut that can be easily used.

[0005]

In order to achieve the above object, the present invention provides a screw nut of a resin nut formed of an elastic resin material, which has a complete thread formed from a seat surface side to an intermediate portion. It is characterized in that it is formed from a first female screw portion and a second female screw portion having an incomplete thread continuous with the first female screw portion, and a male screw thread-fitted to the first female screw portion having a complete screw thread is formed. A screwing-in effect is obtained by screwing into the second female thread portion of the incomplete thread to form a female thread of the complete thread. The second
In order to form the female screw portion into a female screw having a complete thread, it is desirable that the inner diameter of the second female screw portion is formed to be slightly smaller than the inner diameter of the first female screw portion. When the elastic resin material is relatively soft, it is also possible to replace the second female screw portion of the incomplete screw thread with a normal screw pilot hole and form a female screw of the complete screw thread in the screw pilot hole. is there.

The resin material for molding the locking nut of the present invention is preferably a reinforced plastic material of nylon resin.

The resin lock nut according to the present invention is more effective when used as a double nut in combination with a standard metal nut. In this case, the object to be fastened is secured by the metal nut to secure a predetermined axial force, and the resin locking nut of the present invention is configured to prevent the return rotation of the metal nut.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vertical sectional front view of a resin lock nut according to the present invention. The lock nut 10 is formed of an elastic resin material such as a nylon resin. The elastic resin material is preferably a resin material obtained by impregnating a reinforcing material such as glass fiber with a synthetic resin material. The screw hole 12 of the loosening prevention nut 10 has a seat surface 11
1st female threaded portion 13 with complete thread from
Is formed on the second female screw portion 14 which is continuous with the first female screw 13 and extends to the top of the second female screw portion 14 having an incomplete thread, and the second female screw portion 14 can be easily formed into a complete thread as described later. For this reason, the inner diameter B of the second female screw portion 14 is formed to be slightly smaller than the inner diameter A of the first female screw portion 13.

As described above, the first female screw portion 1 having a complete thread
Resin locking nut 1 having a screw hole 12 composed of a third female thread portion 14 having an incomplete thread and continuous with the third thread portion 3.
0 can be manufactured at low cost by using the internal thread molding core 20 shown in FIG. The female thread molding core 20 is
A first male screw portion 21 having a complete thread and a second male screw portion 22 having an incomplete thread formed up to the tip continuously from the first male screw portion 21 are provided at the tip of the round shaft. The thread forming core 20
As shown in FIG. 3, it is set between the molding dies 23 and 24, the resin material is injected into the molding recess 25 to mold the nut 10, and then the core 20 is rotated in the screw loosening direction.
When pulled out from the nut 10, the resin locking nut 1 having a screw hole 12 composed of a first female thread portion 13 of a complete thread and a second female thread portion 14 of an incomplete thread shown in FIG.
0 is obtained.

FIGS. 4 and 5 show an example in which the resin locking nut 10 having the above-described structure is screwed into the male screw portion 31 of the standard metal bolt 30 and used to fasten the members to be fastened 32, 33. In the figure, 34 is a washer. Figure 4
Shows a state where the first female screw portion 13 of the complete thread of the locking nut 10 is screw-fitted to the male screw portion 31,
This fitting state is a normal screw fitting, and a fitting gap 15 is generated between the first female screw portion 13 and the male screw portion 31 as well shown in FIG. 4B. There is. Figure 5
From the fitted state of FIG. 4, the locking nut 10 is further screwed into the male threaded portion 31, and the member to be fastened 3 via the washer 34.
It shows a state in which 2, 34 are tightened. In this screwed state, the male screw portion 31 is the first female screw portion 1 with a complete thread.
3 is guided and guided into the second female screw portion 14 having an incomplete thread, and by the upsetting action, the second female screw portion 1
4 is plastically deformed to form a female thread portion 16 having a complete thread. At this time, the inner diameter B of the second female thread portion 14 of the incomplete thread is set to be smaller than the inner diameter A of the first female thread portion 13 of the complete thread, so that the female thread portion of the complete thread by the upsetting action of the male thread portion 31 is formed. 16 can be easily and uniformly molded. The female screw portion 16 formed in this manner is shown in FIG.
As is well shown in (b), the threads of the external thread 31 are substantially completely adhered to each other, and the flank surface of the thread has a very large contact area. As it produces a large frictional force, it has an excellent anti-loosening effect. On the other hand, the locking nut 10 screwed in
Rotate in the return direction and remove it from the male screw part 31,
Since the completely threaded female threaded portion 16 returns to the original second threaded portion 14 of the incomplete thread due to the elastic restoring force,
Even when it is used again, the same locking effect can be obtained.

FIG. 6 shows an example in which the locking nut 10 of the present invention is used as a double nut in combination with a standard metal nut 35. First, the metal nut 35
Is fastened to the male thread portion 31 of the bolt 30 to be fastened to the fastened object 32,
After tightening 33 to secure a predetermined axial force, the loosening prevention nut 10 is screwed into the male screw portion 31 and screwed in. As in the case shown in FIGS. 4 and 5, the second female screw 14 with an incomplete thread is formed. Is molded into the female thread 16 of the complete thread,
It has an excellent anti-loosening effect.

[0012]

As described above, in the resin locking nut of the present invention, the male screw threaded to the first female thread portion of the complete thread formed on the seat surface side is fitted to the first female thread portion. Since it is guided and screwed into the second female screw portion of the incomplete screw thread, the second female screw portion is easily and satisfactorily molded into the female screw portion of the complete screw thread, and exhibits an excellent effect of preventing loosening and screwing resistance. It is very small and can be screwed in very easily, and has excellent workability. Moreover, since the entire nut is molded from the elastic resin material, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a resin locking nut according to the present invention.

FIG. 2 is a front view (a) of the internal thread molding core used for molding the locking nut, and FIG. 2 (b) is an enlarged cross-sectional view of the main part of the core.

FIG. 3 is an explanatory diagram of a forming process of the locking nut of the same.

[Fig. 4] Same as above, showing an example of using the lock nut,
(A) is a vertical cross-sectional front view showing the middle of fitting which is screwed to the male screw part, and (b) is an enlarged sectional view of the same screw fitting part.

[Fig. 5] Same as above, showing an example of using the locking nut,
(A) is a vertical cross-sectional front view showing a state in which screwing into a male screw portion is completed, and (b) is an enlarged sectional view of the same screw-in fitting portion.

FIG. 6 is a vertical sectional front view showing another example of use of the resin locking nut of the present invention.

FIG. 7 is a partially longitudinal front view showing a conventional locking nut.

[Explanation of symbols]

10 Resin locking nut 11 seat 12 screw holes 13 Completely threaded first female thread 14 Second female thread of incomplete thread 15 Mating gap 16 Molded female thread with full thread 30 metal bolts 31 Male thread 32, 33 Fastened member 34 washer 35 Standard Metal Nut

Claims (5)

[Claims] 1. A screw hole of a resin nut molded of an elastic resin material, a first female screw portion of a complete thread provided from a seat surface side to an intermediate portion, and an incomplete portion continuous to the first female screw portion. A resin locking nut, which is formed from a second female thread portion of a thread. 2. The inner diameter of the second female screw portion is formed to be slightly smaller than the inner diameter of the first female screw portion.
The resin lock nut described above. 3. A threaded hole of a resin nut molded of an elastic resin material, a first female threaded portion having a complete thread provided from a seat surface side to an intermediate portion, and a screw thread continuous with the first female threaded portion. A resin locking nut characterized by being formed with a hole. 4. The resin locking nut according to claim 1, 2 or 3, wherein the elastic resin material is a reinforced plastic material. 5. A combination of the resin locking nut according to any one of claims 1 to 4 and a metal nut, wherein the metal nut secures a predetermined axial force by tightening an object to be fastened. An anti-loosening double nut device configured to prevent the return rotation of the metal nut by the resin anti-loosening nut.