JPS6053204B2 - double locking nut - Google Patents

Description

[Detailed description of the invention] The present invention relates to a double locking nut.

Locking nuts are torque increasing nuts that are tightened while interfering with the bolt male thread from the beginning when screwed onto the bolt, and interference pressure between the bolt male thread and the bolt male thread when screwed onto the bolt with a predetermined axial force. There is a free-rotating type nut that is attached. A free-rotating nut does not require a large torque while being screwed onto a bolt, and it is relatively easy to control the torque when the nut is completely screwed onto a bolt. The double locking nut of the present invention is a free-rotating nut.

The conventional free-rotating double nut consists of two nuts.
When screwing onto a bolt, it is necessary to screw in two nuts separately, which is difficult to work with, and when tightening a large number of nuts, the tightening force tends to vary for each nut, making it difficult to ensure accuracy. It is difficult to tighten nuts.
Furthermore, the height of the double nut itself is higher than that of a normal nut. The present invention has been made in view of the above points, and its objectives are to:
To provide a double free-rotating type locking nut which can integrate two nuts into one body and can provide a reliable locking effect by using a double locking mechanism in combination.

That is, the double locking nut of the present invention has first and second nuts that are brought into contact with each other and overlapped, and is provided at the center of the contact surface of the first nut, and the female thread of the nut is provided at the center of the contact surface of the first nut. A recess is formed to be slightly eccentric with respect to the axis of The protrusion fitted into the hole and the contact surfaces of the first and second nuts are provided so as to correspond to each other, and the lead angle of the female thread is formed so as to surround the protrusion. Provided on the abutment surfaces of the first and second nuts so as to correspond to each other, respectively, in order to connect the spiral surfaces extending at slightly different angles with the starting and ending ends of the spiral surfaces. It is characterized by consisting of a connected surface.

Therefore, according to the double locking nut of the present invention, the first
Also, the second nut can be pre-polymerized and integrated into a bolt and then screwed onto the bolt, tightened like a single nut, and then the first and second nuts can be rotated relative to each other. , can apply double interference pressure in the axial and radial directions between the bolt and nut, and has good workability, and even when tightening a large number of nuts, the tightening force of each individual nut is not so much. No variation occurs.

Furthermore, the difference in nut height can be reduced as compared to a normal nut, and a lightweight double locking nut can therefore be provided. Preferred aspects of the double locking nut of the present invention are as follows. A specific example will be explained based on the attached drawings. Figures 1 to 7
The double locking nut 1 shown in the figure consists of an upper nut 2 as a first nut and a lower nut 3 as a second nut, and the upper nut 2 and the lower nut 3 can be integrated. The lower surface of the upper nut 2 is a flat surface 4 that is horizontal to the seating surface of the double nut 1. From the flat surface 4, the axis of the nut 2 is centered, in the helical direction of the female thread 8 of the nut, and from the lead angle of the female screw 8. The flat surface 4 and the spiral surface 5 are connected by a locking surface 6 perpendicular to the seat surface of the nut 3 on the one hand. A recess 7 is formed in the center of the lower surface of the upper nut 2, and the flat surface 4, spiral surface 5, and locking surface 6 are provided on the lower surface of the peripheral wall of the recess 7. The center of the recess 7 is slightly eccentric from the axis of the nut 2 by ε, and a female thread 8 is formed above the upper surface of the recess 7 on the inner circumferential surface of the upper nut 2, centered on the axis. . An annular chamfered portion 9 is formed at the portion where the upper surface of the concave portion 7 and the female thread 8 are connected.The lower nut 3 has a flat male spiral surface 5 and a locking surface 6 on the upper surface of the upper nut 2. A flat surface 10, a spiral surface 11, and a locking surface 12 are formed in the center of the lower nut 3, and the flat surface 10, spiral surface 11, and locking surface 12 correspond to the lower nut 3 and the saw body, respectively. It surrounds the protrusion 13 which is provided in a protruding manner.

The protrusion 13 corresponds to the recess 7 of the upper nut 2, has a center slightly eccentric from the axis of the lower nut 3 by E, and has an outer diameter that almost matches the diameter of the recess 7. are doing. The flat surfaces 4, 10 and the locking surfaces 6, 12 constitute a connecting surface. Similar to the upper nut 2, the spiral surface 11 gradually extends from the flat surface 10 in the helical direction of the female thread 14 of the lower nut 3 and at an angle slightly larger than the lead angle of the thumb screw 14, centering on the axis of the lower nut 3. The flat surface 1 is connected again via the locking surface 12 which is inclined and perpendicular to the seat surface of the lower nut 3.
Connected to 0. A female thread 14 of the lower nut 3 similar to the female thread 8 is formed within the protrusion 13 . An annular chamfered portion is also formed on the seat surface 15 of the lower nut 3 adjacent to the female thread 14. In the double locking nut 1 constructed as described above, the protruding portion 13 of the lower nut 3 is inserted into the recess 7 of the upper nut 2 in an intermediate fit state, and the upper nut 2 and the lower nut 3 are separated from each other. The hexagonal peripheral surfaces match and are integrated like a single nut.

At that time, the flat surface 4, spiral surface 5, and locking surface 6 of the upper nut 2 are brought into contact with the flat surface 10, spiral surface 11, and locking surface 13 of the lower nut 3, respectively, and the female thread 8 of the upper nut 2 and The female thread 14 of the lower nut 3 forms a continuous spiral via the annular chamfered portion 9. The locking surface 6 of the upper nut 2 and the locking surface 12 of the lower nut 3 engage with each other in a state of contact when the double nut 1 is screwed onto the bolt B.
The integrated double nut 1 may have approximately the same dimensions as a normal nut. When the integrated double locking nut 1 is screwed onto the bolt B and the tightened object A is tightened, the seat surface 15 of the lower nut 3 comes into contact with the tightened object A, and the nut 1
After it is completely tightened, the lower nut 3 is fixed and the upper nut 2 is rotated in the opposite direction with a predetermined torque.

The recess 7 of the upper nut 2 and the protrusion 13 of the lower nut 3 are formed so that their centers are slightly eccentric by ε from the axes of the nuts 2 and 3, and slightly eccentric by E from the axis of the bolt B. Since they are engaged in position, by rotating the upper nut 2 in the opposite direction around the axis of the bolt B, the inner circumferential surface of the recess 7 turns the outer circumferential surface of the protrusion 13 inward in the radial direction of the bolt B. When pressed, the female thread 14 of the lower nut 2 is screwed into the thread C of the bolt B while interfering with it. At this time, since the recess 7 also receives the reaction force from the protrusion 13, the female thread 8 of the upper nut 2 is also locked in an interfering state with the thread C of the bolt B. Also spiral surface 5
and 11 are formed with an inclination angle slightly larger than the lead angle of the female screws 8 and 14, so the spiral surface 5 presses the spiral surface 11, and the bolt B is inserted between the screws 8 and 14.
A predetermined tightening force by the double nut 1 via the bolt B is reliably applied to the object A to be tightened.
Therefore, the double nut 1 is eccentrically locked to the bolt B in order to apply a predetermined interference pressure to the bolt B in the radial direction via the recess 7 and the projection 13, and the spiral surface 5
Since axial interference pressure is applied to the bolt B through the bolts B and 11, and a predetermined tightening force is reliably applied to the fastened object A, the two Due to the heavy locking mechanism, the double nut 1 does not loosen even due to complex vibrations applied to the fastened object A, and can maintain its locking effect almost permanently.

Furthermore, when the upper nut 2 is rotated in the opposite direction, gaps are formed between the locking surfaces 6 and 12 and between the flat surfaces 4 and 10, but this gap allows the operator to rotate the double nut 1. The interference pressure applied to the bolt B can be identified and the desired locking friction torque can be applied to the double nut 1 within a range that does not destroy the double nut 1 or the bolt B.

In the above specific example, the upper nut 2 has the recess 7 and the lower nut 3 has the protrusion 13, but the upper nut 2 may have the protrusion and the lower nut 3 may have the recess. and 1
0 and the locking surfaces 6 and 12 are simply spiral surfaces 5 and 11.
It may be replaced by a connecting surface that connects.

That is, when the double nut 1 is screwed onto the bolt B, the connecting surfaces engage with each other in the direction of rotation, and when the upper nut 2 is rotated in the opposite direction, they are separated without sliding against each other. It is sufficient if the connecting surface is formed so that the Also double nut 1
After tightening, a pin or the like may be inserted into the gap formed between the locking surfaces 6 and 12 or between the flat surfaces 4 and 10 to securely lock the double nut 1. Instead of the locking surface and the flat surface, a pin or the like may be inserted into the gap between the connecting surfaces. The specific examples shown in FIGS. 8 to 10 are specific examples different from the double nut 1.
Similarly, spiral surfaces 18 and 19 are formed on the upper nut 16 and lower nut 17, but the spiral surfaces 18 and 19 are formed with spirals in the opposite direction to the female threads 20 and 21 of the nuts 16 and 17. . The upper nut 16 has a recess 22 as in the above-described specific example, and the center of the recess 22 is slightly eccentric from the axis of the nut 16 by ε. A female thread 20 is formed above the recess 22. The spiral surface 18 is formed on the lower surface of the peripheral wall of the recess 22, and the spiral surface 18 extends approximately once around the axis of the female thread 20.
They are connected at a connecting surface 23. The lower nut 17 has a protrusion 24 as in the above-described specific example, and the center of the protrusion 24 is slightly eccentric from the axis of the nut 17 by ε.

The female thread 21 is similar to the female thread 20 and has a protrusion 24.
It is also formed on the inner peripheral surface of. The spiral surface 19 goes approximately once around the axis of the female thread 21 so as to surround the protrusion 24 , and is connected at a connecting surface 25 . Recess 22
The protrusion 24 is inserted into the screw 20 in an intermediate fit state.
and 21 are made continuous, and the upper nut 16 and the lower nut 1
The double locking nut 26, which is integrated with the bolt 7, is screwed onto a bolt like a single nut and tightened onto the object A to be tightened.

Thereafter, the upper nut 16 is further rotated in the tightening direction with a predetermined torque, and the lower nut 17 and the upper nut 16 are locked in an interfering state with the bolt B by eccentric rotation of the recess 22 about the axis of the bolt B. Ru. In the double nut 26, the spirally inclined angles of the spiral surfaces 18 and 19 are preferably smaller than the lead angles of the screws 20 and 21. Also, the double nut 26 can be formed with substantially the same dimensions as a regular nut. When the protrusion 24 is inserted into the recess 22 in an intermediate fit state, a slight gap is formed between the upper nut 16 and the lower nut 11, but even with such a gap, the locking effect of the double nut 26 is maintained. is effective.

In all of the above-mentioned specific examples, the upper nut and lower nut are integrated by fitting the protrusion into the recess with an intermediate fit, but by fitting the protrusion into the recess with a loose fit, An engaging portion may be provided in the recess and the protrusion to prevent the lower nut from falling off from the upper nut when not in use. Preferably, the aforementioned eccentricity ε is also selected such that the double nut and bolt are deformed within the limits of elastic deformation.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one specific example of the double locking nut according to the present invention when the bolt is screwed together, and FIGS. 2 to 4 are front views of the upper nut of the double nut shown in FIG. 1. , a side view and a bottom view, FIGS. 5 to 7 are respectively a plan view, a front view and a side view of the lower nut of the double nut shown in FIG. 1, and FIG. 8 is a view shown in FIG. 1. An explanatory diagram of a double locking nut according to the present invention other than a specific example when bolts are screwed together, FIG. 9 is a sectional view of the upper nut of the double nut shown in FIG. 8, and FIG. FIG. 3 is a cross-sectional view of the lower nut of the double nut shown in the figure; 1...Double locking nut, 2...Upper nut, 3...Lower nut, 5, 11...
・Spiral surface, 7... Concavity, 13...
・Protrusion.

Claims (1)

[Claims] 1. The first and second nuts are brought into contact with each other and overlapped, and the first nut is provided at the center of the abutment surface of the first nut, and is slightly disposed with respect to the axis of the female thread of the nut. A recess is formed eccentrically in the recess, and a second nut is protruded from the center of the abutting surface of the second nut in order to correspond to the recess, and is fitted into the recess eccentrically like the recess. are provided on the protrusion and the contact surfaces of the first and second nuts to correspond to each other, respectively, and are formed at an angle slightly different from the lead angle of the female thread so as to surround the protrusion. A spiral surface that extends at an angle,
A double locking nut comprising connecting surfaces provided on the contact surfaces of the first and second nuts so as to correspond to each other, respectively, to connect the starting end and the terminal end of the spiral surface. 2. The nut according to claim 1, wherein the connecting surface is formed by a flat surface substantially parallel to the seating surface of the nut and a locking surface substantially perpendicular to the seating surface. . 3. The first and second nuts are each hexagonal nuts, and
3. The nut according to claim 1, wherein the respective hexagonal circumferential surfaces coincide and the internal threads of the first and second nuts define a continuous spiral. 4. The inclination angle of the spiral surface is slightly larger than the lead angle of the female thread, and after the first and second nuts are integrally screwed onto the bolt, the nut located above of the first and second nuts is The nut according to any one of claims 1 to 3, which is rotated relative to the other nut in a direction opposite to the tightening direction. 5. The inclination angle of the spiral surface is slightly smaller than the lead angle of the female thread, and after the first and second nuts are integrally screwed onto the bolt, the nut located above of the first and second nuts is The nut according to any one of claims 1 to 3, which is rotated relative to the other nut in the tightening direction.