JP2575066Y2 - nut - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut used for a bolt coated with rust prevention or the like.

[0002]

2. Description of the Related Art In the fields of automobiles, construction, machinery, and the like, when manufacturing products, members are connected to each other using a large number of bolts and nuts.
Since it is necessary to apply rust-preventive coating to each member, temporarily fix bolts to one member, then apply rust-preventive painting to the entire member together with the bolts, and then apply rust-preventive painting to the bolts separately. The other member is inserted and the nut is screwed together to connect the two members.

[0003] In such a case, if the thread portion of the bolt is coated, the ordinary nut cannot be smoothly screwed into the bolt with a normal nut. Also, as the nut is screwed together, the coating on the external thread of the bolt is peeled off and enters the gap between the external thread of the bottle and the internal thread of the nut being screwed. It becomes increasingly difficult to twist and screw the bolts. Nevertheless, forcibly screwing the bolts and nuts causes inconveniences such as crushing of the bolts and nuts of the screw portion and breakage of the bolts.

[0004] Therefore, as a nut used for the above-mentioned bolt, conventionally, a prepared hole is formed in a nut material in a triangular shape, and a female screw is formed in the formed triangular prepared hole.
The pilot hole is drilled in a normal circular shape, and after a female screw is cut into this pilot hole, the screw shaft direction from the bottom surface to the top surface of the nut material is placed at several places in the circumferential direction of the thread part of the female screw. Is known in which a concave groove is separately formed by cutting. Such a na
For Tsu bets, a configuration having a concave groove on Jikukata toward the portion of the female thread
When screwing into the painted bolt,
The coating peeled from the bolts is introduced into the female groove.
Therefore, the twisting operation of the nut can be performed without any trouble .

[0005]

[Problems to be Solved by the Invention] However, in the case of the above-mentioned nut, since the groove is formed only in the screw axis direction, the coating film introduced into the groove of the nut at the time of screwing the nut is screwed. It is difficult to discharge from the nut, so while the screw is screwed into the nut, the coating film accumulated in the groove enters the gap between the male screw of the bolt and the female screw of the nut being screwed. In some cases, the screwing of the nut was hindered. In addition, when a triangular pilot hole is drilled in the nut material as in the above nut, or after the female screw is carved, it is separately cut to form a groove in the screw axis direction. Since the manufacturing process is more complicated than that of the nut, the manufacturing cost is increased, and there is a disadvantage that the nut is expensive.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to form a groove for introducing a peeling coating film provided on a nut in a spiral shape. Accordingly, it is an object of the present invention to provide a nut in which the coating film introduced into the groove is easily discharged to the outside of the nut when the nut is screwed together and the groove can be easily formed.

That is, in order to achieve the above object, the present invention is formed by a trapezoidal screw engraving tap T1.
The same direction as the trapezoidal screw 51 and the screwing direction of the tap T1
Formed by tapping screw T2
And a screw 5 formed by the tap T1.
The first screw groove 52 is used as the groove 5 for introducing a release coating.
The screw formed by the top T2 is a female screw 3, and
The trapezoidal screw 51 has a root diameter d equal to the root diameter D of the female screw 3.
And the pitch p is larger than the pitch P of the female screw 3.
It is formed in .

[0008]

[Function] Because the nut is screwed into the painted bolt, the coating applied to the threaded part of the bolt is peeled off by friction with the female thread of the nut. Then, it is introduced into the groove of the nut. The coating film introduced into the groove moves in the groove in the direction of twisting of the nut along with the twisting of the nut, and is discharged outward from the top surface of the nut. In this case, since the movement of the coating film in the groove is promoted by the twisting action of the nut, the coating film is quickly discharged outward from the top surface of the nut and does not stay in the groove. Therefore, it is difficult for the coating film moving in the concave groove to enter the gap between the male screw of the bolt and the female screw of the nut being screwed, so that the screw screwing of the nut is not hindered. I can do it. And the nut is recessed as well as the female thread.
Since the groove part is also formed by tapping, it is easy to manufacture,
Therefore, it can be provided at low cost.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, A is a hexagonal nut, and a female screw 3 is carved in a circular pilot hole 2 drilled in the center of a metal nut material 1. The release coating introduction groove 5 is screwed in the same direction as the spiral direction of the female screw 3 and at a pitch p that is twice the pitch P of the female screw 3.

To manufacture the nut A, FIGS.
As shown in FIG. 2, after forming a nut material 1 having a circular pilot hole 2 at the center by forging (FIG. 2), a root diameter d is formed in the pilot hole 2 of the nut material 1 by a trapezoidal screw engraving tap T1. The pitch p is smaller than the root diameter D of the female screw 3 and the pitch p is
A trapezoidal screw 51 twice as large as the pitch P is engraved (FIG. 3), and the screw groove 52 becomes the concave groove 5. Then, a tap T2 for forming an internal thread from the same direction as the screwing direction of the tap T1.
And the female screw 3 is engraved (FIG. 4). By manufacturing in this manner, the thread 4 of the female screw 3 is engraved with the pitch p in the same direction as the spiral direction of the female screw 3 and twice the pitch P of the female screw 3. The nut A having the groove 5 for introducing the release coating film is obtained.

Next, a case where the nut A is used for a bolt B coated with rust prevention or the like will be described with reference to FIG. When the nut A is screwed into the bolt B, the coating film 7 applied to the male screw 6 of the bolt B is peeled off by friction with the female screw 3 of the nut A, and the inside of the groove 5 of the nut A is removed. Is introduced to Coating film 7 introduced into groove 5
Moves in the concave groove 5 in the twisting direction of the nut A together with the twisting of the nut A, and is discharged outward from the top surface of the nut A. In this case, since the movement of the coating film 7 in the concave groove 5 is promoted by the twisting action of the nut A, the coating film 7 is quickly discharged outward from the top surface of the nut A, and does not stay in the concave groove 5. . As a result, it is difficult for the coating film 7 moving in the concave groove 5 to enter the gap between the male screw 6 of the bolt B and the female screw 3 of the nut B being screwed together. The twisting and screwing can be performed without any trouble.

In the above embodiment, the case where the concave groove 5 is screwed with the pitch p twice as large as the pitch P of the female screw 3 is shown, but the present invention is not limited to this. However, if the concave groove 5 is screwed at the same pitch as the pitch P of the female screw 3 or less, the portion of the thread 4 cut off by the concave groove 5 increases, so that the tightening strength of the nut A is increased. Will be significantly reduced. On the other hand, when the screw is screwed with a large pitch such as a triple pitch or a quadruple pitch, the portion of the screw thread 4 that is cut off by the concave groove 5 becomes smaller, so that the tightening strength decreases only slightly. On the other hand, the cutting of the groove 5 by the tap cannot be performed efficiently. Therefore, the size of the pitch p of the concave groove 5 is larger than about twice the pitch P of the female screw 3.
As long as the nut is not large, it may be determined in consideration of the purpose, type, size, and the like of the nut.

In the case of the nut A of the above embodiment, the thread 4 is slightly reduced in comparison with the thread of the ordinary nut shown by a two-dot chain line in FIG. Can be used to a lesser extent.

[0014]

[Effect of the invention] As described above, according to the invention,
In the same direction as the spiral direction of the female thread,
Further, since the screw is provided with a pitch larger than the pitch of the female screw, the coating film introduced into the concave groove is easily discharged out of the nut by the twisting action of the nut. Therefore, when the nut is screwed into the screw, the coating film does not stay in the groove. Therefore, the coating film in the groove is between the male screw of the bolt and the female screw of the nut being screwed. Can be prevented from entering the gap of the nut and making it difficult to screw the nut into the screw, and the screw can be smoothly screwed into the bolt coated with rust prevention or the like. Can provide nuts.

According to the invention, the female thread is formed
Of course, release coating introducing groove even, because it cut formed by the tap, will be possible to produce in a normal nut manufacturing and similar steps, bolts therefore painting is applied
Nuts suitable for use with
You.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical sectional view showing an embodiment of the present invention nut.

FIG. 2 is a longitudinal sectional view showing a nut material used when manufacturing the nut of the present invention.

3 is a main part longitudinal sectional view showing a tap used when engraving a trapezoidal screw on the nut material of FIG. 2 and a nut material threaded by the tap;

FIG. 4 is a longitudinal sectional view of a main part showing a tap used when engraving a female thread on the nut material of FIG. 3 and a nut material threaded by the tap;

FIG. 5 is a longitudinal sectional view showing a state in which the nut of the present invention is used for a painted bolt.

[Explanation of symbols]

 A Nut 1 Nut material 2 Prepared hole 3 Female thread 4 Thread 5 Groove for introduction of release coating P Pitch of female thread p Pitch of groove for introduction of release coating

Claims (1)

(57) [Scope of request for utility model registration] 1. A method for forming a trapezoidal screw by tapping a tap T1.
Trapezoidal screw 51 and the same direction as this tap T1
Threaded tapping T2
Formed by this tap T1
The thread groove 52 of the stitch 51 is formed as the groove 5 for introducing a release coating.
The screw formed by the tap T2 is a female screw 3,
The trapezoidal screw 51 has a root diameter d equal to the root diameter of the female screw 3.
Smaller than D, and the pitch p is larger than the pitch P of the female screw 3.
A nut that is also formed large .