JP2651364B2 - Locking nut structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a locking nut.
More specifically, the present invention relates to a locking nut structure for screwing a work by screwing it to a bolt inserted into the work, the loosening being prevented by a pitch difference and a spring effect to securely tighten the work.

[0002]

2. Description of the Related Art Conventionally, when a bolt 6 inserted into a workpiece is tightened, a locking nut structure screwed to the bolt 6 includes:
Taiwanese new patent (utility model registration) No. 691
No. 22 "Union type locking nut" is available. As shown in FIGS. 5 and 6, the lock nut structure includes a nut unit 4 including a main nut 41 and a sub nut 42 instead of a normal combination of a nut and a lock nut. The main nut 41 is provided with a cylindrical projecting portion having a threaded portion 412 formed at the center of one side thereof. On the other hand, the sub-nut 42 is provided with a small-diameter screw hole 421 that is screwed with the bolt 6.
1 is provided with a large-diameter threaded hole 422 that extends on the same axis as that of the main thread 41 and is screwed with the male threaded part 412. 41
It is formed slightly longer than 2. Further, in the nut unit 4, the screw pitches of the large and small screw portions can be set to be slightly different.

[0003] The main nut 41 and the sub nut 4
When each of the nuts 2 is tightened to the bolt 6, first, the main nut 41 is screwed into the bolt 6, and then the large diameter screw hole 422 and the small diameter screw hole 421 of the sub nut 42 are
The male nut 412 and the bolt 6 are screwed together at the same time. By screwing the main nut 41 to the bolt 6 as described above, a first-stage screw tightening effect is produced. Also, the sub nut 42 is connected to the main nut 4
1 and the bolt 6 and the sub nut 42
Is screwed into the main nut 41 so that the bolt 6
Not only does the contact area with the nut increase, but also the action of tightening the sub nut 42 to the main nut 41 is added, so that a second-stage screw tightening effect is obtained. Further, the pitch of the large-diameter screw hole 422 of the sub nut 42 screwed to the external thread 412 of the main nut 41 and the pitch of the small-diameter screw hole 421 of the sub nut 42 screwed to the bolt 6. Are different, the screw hole 4 of the main nut 41 with respect to the large diameter screw hole 422 of the sub nut 42
Due to the pitch difference between the bolt 11 and the bolt 6, the screw tightening distance of the larger pitch is larger than that of the smaller pitch in the same tightening rotation, so that the third stage screw tightening effect by the larger pitch can be obtained. Therefore, in the nut unit 4, a superior screw tightening effect can be obtained between the main nut 41, the sub nut 42, and the bolt 6 than the conventional lock nut.

[0004]

However, although the "combination type locking nut" shown in FIGS. 5 and 6 has an effect of preventing the bolt from loosening more than the conventional one, it has a problem in terms of the screw tightening effect. Not enough. As a result of further studies by the inventor, in addition to the above-mentioned action due to the pitch difference between the main nut, sub nut and bolt, by providing a reliable spring action against vibration, etc., the main nut is provided. It has been found that a better screw tightening effect occurs between the nut, sub-nut and bolt.
In view of this point, the present invention combines the main nut, the sub nut and the bolt with an appropriate mode of spring action to produce an excellent screw tightening effect, and furthermore, a reinforcing action to make a strong press contact by the screw tightening effect. It is an object of the present invention to provide a bolt locking nut structure capable of imparting a bolt.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a cylindrical projection having a threaded portion formed on the outer peripheral surface thereof at the center of one end surface and a screw hole provided. The screw thickness on the effective diameter of the screw hole is set to be larger than the difference between the radius of the screw root of the screw hole and the radius of the screw root of the external thread portion, and the radius of the screw root of the screw hole. A main nut, a first screw hole, and a second screw hole smaller in diameter than the first screw hole are provided continuously in the axial direction. The main thread of the main nut and the first screw hole of the sub nut are set to the same size that can be screwed together, and the screw hole of the main nut and the sub screw・
The second screw hole of the nut has the same size to which the same bolt can be screwed, and the pitch of the external thread of the main nut is set smaller than the pitch of the screw hole of the main nut. The present invention provides a locking nut structure.

[0006]

In the locking nut structure according to the present invention, the thickness of the screw hole of the main nut on the effective diameter of each screw is determined by the radius of the screw root of the screw hole and the male screw. The protrusion of the main nut is moderately elastically deformed because the difference between the radius of the thread valley and the radius of the screw hole is smaller than the radius of the thread. After the main nut is screwed into the bolt and the work is clamped and fixed, the first screw hole of the sub nut is further screwed into the external thread of the main nut. Then, when the main nut and the sub nut are screwed together, the difference in pitch between the two screw holes of the sub nut causes a difference in the screw advance distance, and the protrusion is deformed at the screw contact surface. The male screw part and the first screw hole are more tightly pressed As a result, the torsional stress around the axis of the bolt increases, it does not rotate with some vibration, and the main nut can reinforce the screwing pressure on the main nut through the male thread portion, which facilitates Can be prevented from loosening.

[0007]

Next, the present invention will be described in detail with reference to the embodiments shown in the drawings. As shown in FIG. 1, the locking nut structure according to the embodiment of the present invention has a configuration including a main nut 1 and a sub nut 2. The main nut 1 has a cylindrical projection 12 having a diameter smaller than that of the main body 11 protruding from one end face of the cylindrical main body 11.
An external thread 120 is provided on the outer peripheral surface of the cylindrical projection 12. The main body 11 and the protruding portion 12 are provided with screw holes 13 communicating from one end to the other end of the axis. The sub-nut 2 has two screw holes having different hole diameters along its axis, namely, a first screw hole 210 having a relatively large diameter and a second screw hole 220 having a relatively small diameter. Are provided continuously along the axis thereof.

The first screw hole 210 of the sub nut 2
Are formed in the same size that can be screwed together with the external thread portion 120 of the protruding portion 12 of the main nut 1. The second screw hole 220 of the sub nut 2
Are formed in the same size that can be screwed into the screw hole 13 of the main nut. On the other hand, the main nut 1
The pitch of the male screw portion 120 in the protrusion 12 is set smaller than the pitch of the screw hole 13 of the main nut 1. That is, in this embodiment, the first screw hole 210 of the sub nut 2 and the male screw portion 12 of the main nut 1 are provided.
While 0 is the same pitch, the second screw hole 220 of the sub nut 2 is the same pitch as the screw hole 13 of the main nut, and the former pitch is set smaller than the latter pitch. .

FIG. 2 is an enlarged view of a main part F of FIG. As shown in FIG. 2, the screw hole 13 of the main nut 1 is provided.
Is set to be larger than the difference Y between the radius M of the thread root of the screw hole 13 and the radius N of the thread root of the external thread portion 120 of the main nut 1. And the root radius M of the screw hole 13 is
Is set to be smaller than the trough radius N. As a result, the wall thickness cross section of the projecting portion 12 of the main nut 1 assumes a thin wave shape. When the male screw portion 120 is torsionally rotated, the projecting portion 12 is easily deformed. By the elastic deformation action of the portion 12, the pressing and tightening of the main nut 1 against the bolt 3 via the wall surface of the protruding portion 12 can be strengthened.

FIG. 3 is a partial longitudinal sectional side view when the main nut 1 of the present invention is screwed to the bolt 6. FIG. As shown in FIG. 3, when screwing the main nut 1 to the bolt 3 to clamp and clamp the workpiece 90, the screw hole 13 of the main nut 1 was first inserted into the workpiece 9. The work piece 90 is screwed onto the bolt 3 and pressed against the washer 31 by the outer end surface of the main body 11 of the main nut 1 to clamp and clamp the workpiece 90 between the washer 31 and the bolt head 32. The main
When the nut 1 is screwed onto the bolt 3, according to the basic principle of screw tightening, a contact force is generated between the contact surfaces of the threads of the bolt and the nut which are caught by each other, and an action of tightening and contacting each other occurs. Therefore, when the screw hole 13 of the main nut 1 and the bolt 3 are screwed together, both the main nut 1 and the bolt 3 are deformed as a whole due to the press-tightening operation. The body 11 of the nut 1 is formed to be thicker, so that the deformation resistance is extremely large,
Since the protruding portion 12 of the nut 1 is formed to be thin, only the main nut 1 is easily deformed, and the tightening can be strengthened. That is, the main nut 1 and the bolt 3
The main nut 1 is pulled by the bolt 3 by the screwing action, and a pressure is generated on the contact surface on the forward side. However, a play gap due to a manufacturing error causes the nuts A, B, and C in FIG. 1
From the root side to the tip side, that is, to the protruding portion 12 side of the main nut 1. Here, as described above, the pitch between the male screw portion 120 of the main nut 1 and the first screw hole 210 of the sub nut 2 is compared with the pitch of the second screw hole 220 of the sub nut 2 and the bolt 3. Since the pitch is slightly reduced, the delay in pitch between the male screw portion 120 and the first screw hole 210 generates a force for pushing the bolt 3 from the distal end to the proximal end side. Therefore, at the front and rear end portions of the protruding portion 12, the tensile stress is generated in the bolt 3 by screwing with the screw hole 13 of the main nut 1 and the second screw hole 220 of the sub nut 2. A compressive stress is applied to the bolt 3 at the threaded portion between the external thread portion 12 of the nut 1 and the first screw hole 210 of the sub nut 2. for that reason,
As shown in FIG. 4, the projecting portion 12 is elastically deformed in a compression direction like a coil spring, and as shown in A ′, B ′, and C ′ in FIG.
The clearance is pressed away and disappears, and the main nut and sub-
The nuts 2 are tightened and pressed against each other to increase the frictional resistance, thereby preventing the main nut 1 from loosening.

As described above, in the present embodiment, when the main nut 1 is screwed with the bolt 3, the cross section in the wall thickness direction of the protrusion 12 has a thin wave shape, such as a coil spring. The work 90 can be further tightened and pressed by the elastic action, and when the sub nut 2 is screwed into the main nut 1, the action of delaying the pitch with the bolt 1 and the protrusion 12 of the main nut 1 can be achieved. Of the main nut and the sub nut 2, there is an action of tightening and pressing each other between the main nut and the sub nut 2, whereby the sub nut 2 has a larger torsional friction resistance due to the main nut 1. As a result, loosening of the main nut 1 can be prevented.

[0012]

In the locking nut structure according to the present invention constructed as described above, the main nut and the sub nut are formed in such a manner that the protrusion of the main nut is formed to be thin so as to be capable of appropriate elastic deformation. -In addition to the better gripping force than before, it has increased torsional resistance and has a tight tightening action to prevent loosening. Further, the press contact with the bolt can be reinforced more than the screw tightening effect of the nut, and the work can be securely clamped and clamped, and an excellent loosening prevention function can be exhibited.

[Brief description of the drawings]

FIG. 1 is an exploded vertical sectional view of a main nut and a sub nut according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part F of FIG.

FIG. 3 is a longitudinal sectional view showing a state in which a main nut is screwed into a bolt.

FIG. 4 is a longitudinal sectional view showing a state where a main nut and a sub nut are screwed into a bolt.

FIG. 5 is an exploded perspective view showing a configuration of a conventional example of a locking nut.

FIG. 6 is a longitudinal sectional view showing a configuration of a conventional example of a locking nut.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main nut 2 Sub nut 11 Main nut main body 12 Projection part 120 Male thread part 13 Screw hole 210 First screw hole 220 Second screw hole

Claims (1)

(57) [Claims] 1. A cylindrical projection having a screw portion (120) formed on an outer peripheral surface thereof is provided at a center portion of one end surface, and a screw hole (13) is provided. The thread thickness (X) on the diameter is calculated by calculating the radius (M) of the thread root of the screw hole (13) and the radius (N) of the thread root of the male thread portion (120).
(Y) and the screw hole (13)
Main nut in which the radius (M) of the thread root of the thread is set smaller than the radius (N) of the thread root of the male thread portion (120).
(1), a first screw hole (210), and the first screw hole (210)
A sub-nut (2) provided with a second screw hole (220) having a smaller diameter continuously in the axial direction; the male thread (120) of the main nut (1) and the sub-nut The first screw hole (210) of (2) is set to the same size that can be screwed together, and
The screw hole (13) of the nut (1) and the second screw hole (220) of the sub-nut (2) are connected to the same bolt (3).
And the pitch of the male thread (120) of the main nut (1) is set smaller than the pitch of the screw hole (13) of the main nut (1). A locking nut structure.