JPS6143568B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lock nuts, and more particularly to torque-enhancing lock nuts. Conventionally, various torque increasing type lock nuts have been proposed. For example, an annular thin plate is fixed to the upper surface of the nut body that faces the seat surface, and an arcuate projection protruding radially inward on the inner peripheral surface of the annular thin plate is attached to the male thread surface of the threaded member into which the nut is screwed. contact and interfere with
A locking nut is known that is configured to prevent the nut from loosening. However, in such a lock nut, the thickness of the annular flat plate is not so thick compared to the thread pitch of the threaded member, so the tip of the arcuate protrusion only partially contacts the male threaded surface of the threaded member. Therefore, it is difficult to obtain such a reliable locking effect. The present invention has been made in view of the above points,
The purpose is to provide a lock nut that can have a reliable locking effect. According to the present invention, the object is to provide an annular plate having an inner ring part and an outer ring part, the inner ring part and the outer ring part being integrally connected by an elastic intermediate coupling part; It consists of a nut body that holds the outer ring part of the plate in a fixed state on the upper surface facing the seat surface, and the inner circumferential surface of the inner ring part has at least one female thread of the same pitch as the female thread of the nut. Achieved by a lock nut which is formed with a pitch of at least 100 mm, and is arranged such that the lower end of the female thread is discontinuous with the upper end of the female thread of the nut body. be done. That is, the lock nut of the present invention is equipped with a thick annular plate having a thickness of one thread or more in place of the annular thin plate, and this annular plate has the following features. (1) The annular plate has a female thread on the inner peripheral surface of the inner ring portion, and the terminal end of this female thread is disposed as discontinuously as possible with respect to the upper terminal end of the female thread of the nut body. When this female thread is screwed into the male thread of the threaded member, the female thread and the male thread make strong contact over the entire surface. (2) The contact pressure at the contact surface between the female thread and the male thread is (3) The annular plate is functionally separated into an elastically deformable part and a non-elastically deformable part, and this elastically deformable part returns to its original state when the lock nut is unscrewed. (4) A radial groove is formed on the upper surface of the outer ring part of the annular plate, and a part of the nut body engages with the groove, so that the outer ring part is securely attached to the nut body. Fixed. Hereinafter, the present invention will be explained based on preferred specific examples. The lock nut 1 according to the present invention consists of a nut body 2 and an annular plate 3, and the nut body 2 has a cylindrical portion 6 on an upper surface 5 facing the seat surface 4.
The annular plate 3 is securely held within the cylindrical portion 6. The annular plate 3 includes an inner ring part 7, an outer ring part 8, and an elastic intermediate joint part 9, and the inner ring part 7 and the outer ring part 8 are integrally connected by the elastic intermediate joint part 9. The elastic intermediate coupling part 9 may be formed thin by providing an annular groove between the inner ring part 7 and the outer ring part 8, and this annular groove 10 extends upward from the lower surface of the plate 3 as shown in FIG. The distal end thereof is rounded and extends in an annular shape in the circumferential direction of the plate 3. A female thread 12 having the same shape and dimensions as the female thread 11 of the nut body 2 is formed on the inner peripheral surface of the inner ring portion 7, and the female thread 12 has a diameter of at least 1 pitch or more, preferably within the range of 1 to 2 pitches. It is formed of. A plurality of, for example, four, radial grooves 13 are formed on the upper surface of the outer ring portion 8, and a portion of the upper surface 5 of the nut body 2 is engaged with these grooves 13. That is, the annular plate 3 is placed in the cylindrical part 6, and then the cylindrical part 6 is bent into an annular shape to clamp the outer ring part 8 of the plate 3, and the position of the bent cylindrical part 6 corresponding to the groove 13 is The portion 14 located at is swaged into the groove 13. Due to the engagement of the portion 14 in the groove 13, the outer ring part 8 is completely fixed to the cylindrical part 6, and the plate 3 is held on the upper surface 5 of the nut body 2. The annular plate 3 is prevented from coming off in the axial direction by the outer ring part 8 being clamped between the cylindrical part 6 and the upper surface 5 with respect to the nut body 2, and the groove 1
3 is engaged by the portion 14 to prevent rotation. The female threads 11 of the nut body 2 and the female threads 12 of the plate 3 have the same nominal diameter and pitch, and are separately threaded. The lower end 15 of the screw 12 is disposed discontinuously with respect to the upper end 16 of the internal thread 11, preferably at an angle of 20° to 70° clockwise or 30° counterclockwise when viewed from above the nut.
It is preferable to prevent the plate 3 from coming off and rotating relative to the nut body 2 while being rotated over a range of 100 degrees. That is, the relative positions of the female threads 11 and 12 need to be set in a state where the female threads 11 of the nut body and the female threads 12 of the annular plate 3 are deviated from each other without forming a continuous spiral. When the lock nut 1 is screwed into a threaded member, for example, a bolt, the elastic intermediate connecting part 9 deforms within the range of elastic deformation, and the female thread 12 is screwed into the bolt, causing excessively strong contact with the threaded surface of the bolt. The relative position needs to be set so that 12 does not seize on the male thread of the bolt. The annular plate 3 is preferably made of carbon steel, alloy steel, or stainless steel, and is preferably formed to have a high elastic modulus by heat treatment or work hardening treatment. When the lock nut 1 according to the present invention configured as described above is screwed into a screwing member, for example, a bolt,
The nut body 2 is screwed onto the bolt, and the annular plate 3
The female thread 12 of the inner ring part 7 is screwed into the male thread of the bolt while interfering with the elastic intermediate coupling part 9 of the bolt which is elastically deformed and the inner ring part 7 is displaced relative to the outer ring part 8. match. An annular plate 3 set so that the female thread 11 and the female thread 12 form a discontinuous spiral, that is, the phase is changed in advance with respect to the female thread 11.
When the female thread 12 is screwed into the bolt, the female thread 12 strongly contacts the male thread of the bolt due to the elastic deformation of the elastic intermediate coupling portion 9, thereby preventing the lock nut 1 from loosening. That is, the internal thread 1 formed on the inner circumferential surface of the inner ring portion 7
2 has a thread of at least one pitch, and as a result, the lock nut 1 is in strong contact with the flank of the male thread of the bolt to which it is screwed, and has a relatively large contact surface with the male thread. can have a reliable locking effect. By the way, the annular plate 3 has an inner ring part 7 having a female thread 12 formed on its inner peripheral surface, and a state in which the female thread 12 of the inner ring part 7 and the female thread 11 of the nut body 2 do not form a continuous spiral. an outer ring portion 8 positioned to fix the annular plate 3 on the nut body 2;
It consists of an elastic intermediate connecting part 9 that integrally connects the inner ring part 7 and the outer ring part 8, and when the lock nut 1 is screwed onto the bolt, the female thread 12 is connected to the elastic intermediate joint part 9 so that the female thread 12 is screwed with the male thread of the bolt. The coupling portion 9 is elastically deformed and the inner ring portion 7 is displaced in the rotational direction and the axial direction. Due to the elastic deformation of the elastic intermediate joint 9, the female thread 12 comes into strong contact with the male thread surface of the bolt, but if the contact pressure between the female thread 12 and the male thread is too strong, the elastic intermediate joint 9 may be plastically deformed. The screw 12 may seize into the male thread. In addition, the lower end 15 of the female thread 12 is connected to the female thread 11.
When the nut 1 is screwed onto the bolt with the nut 1 fixed at a certain angle clockwise with respect to the upper end 16, the upper flank of the female thread 12 of the annular plate 3 and the bolt There is contact interference with the lower flank of the male thread. When the nut 1 is tightened in this state, the inner ring portion 7 is pushed downward, but the downward movement of the inner ring portion 7 is restricted by the upper surface 5 of the nut body 2. Therefore, when the phase is shifted clockwise, a large friction torque is generated even if the set angle is small. Conversely, when the nut 1 is screwed onto the bolt with the lower end 15 fixed at a certain angle counterclockwise with respect to the upper end 16, the lower flank of the female thread 12 of the annular plate 3 The upper flank of the bolt's male thread contacts and interferes. In this state Natsu 1
When the inner ring part 7 is tightened, the inner ring part 7 is pushed upward, but in this case, the inner ring part 7 is not restricted by the upper surface 5 and can move upward, so the set angle must be relatively large to maintain the predetermined friction torque. does not reach. Therefore, in the present invention, the lower end 1 of the female thread 12
5, that is, the part of the female thread 12 adjacent to the lower surface of the plate 3 is connected to the upper end 16 of the female thread 11, that is,
The relative positions of the female threads 11 and 12 are determined by rotating the part adjacent to the upper surface 5 by 20° to 70° clockwise or 30° to 100° counterclockwise. It is set. However, the present invention is not limited to this, and the terminal end 15 is displaced in the axial direction relative to the terminal end 16, and the terminal end 15 and the terminal end 16 are arranged on the same vertical line, and the terminal end 15 is disposed relative to the terminal end 16. An annular plate 3 may be mounted on the nut body 2 to make it discontinuous, or the terminal end 15 may be displaced in the axial direction as well as in the rotational direction with respect to the terminal end 16, and the annular plate 3 may be mounted on the nut body 2. Based on the elastic deformation of the elastic intermediate coupling portion 9, the female thread 12 will strongly contact the male thread of the bolt, and the elastic portion 9 will not be plastically deformed and the female thread 12 will not seize into the male thread. The lock nut 1 may be configured as follows. Further, according to the lock nut of the present invention, when the lock nut 1 is screwed onto a threaded member such as a bolt, the elastic intermediate joint portion 9 is formed thin and deforms within the range of elastic deformation. When it is removed from the threaded member, the elastic intermediate coupling part 9 can be restored to its original state and the internal thread 12 of the inner ring part 7 can be returned to its initial position. The results of a friction torque test and a loosening test of the lock nut of the present invention are shown below. The annular plate is made of S45C material that has been heat-treated by quenching and tempering.
M20 and M16 coarse or fine threads are used. The phase change angle is the lower end 1 of the female thread 12.
5 and the upper end 16 of the female thread 11, and the clockwise direction is indicated by + and the counterclockwise direction is indicated by - when viewed from the top surface of the nut. The friction torque test is conducted based on ISO2320, and the loosening test is conducted based on NAS3350.

[Table] Yield load indicates the yield load of the bolt, and an extremely excellent lock nut that does not loosen even after a 17-minute impact vibration test is achieved by setting the initial tightening force to 30% or less of the yield load. . Based on the US NAS3350 standard, amplitude ±5.5cm,
An impact vibration test with a barrel stroke of 19 mm was performed for 17 minutes (approximately 3
As a result of continuous operation (10,000 cycles), it did not loosen.

[Brief explanation of the drawing]

Figure 1 is a plan view of the lock nut of the present invention, Figure 2 is a plan view of the lock nut of the present invention;
The figure is a cross-sectional view taken along the line A-A in Figure 1, Figure 3 is a plan view of the circular plate, Figure 4 is a cross-sectional view taken along the line B-B in Figure 3, and Figure 5 is a cross-sectional view of the circular plate shown in Figure 3. It is a back view of a plate. 1... Lock nut, 2... Nut body, 3...
...Annular plate, 5...Top surface, 7...Inner ring part, 8
... Outer ring part, 9 ... Intermediate joint part, 12 ... Female thread.

Claims (1)

[Scope of Claims] 1. An annular plate having an inner ring part and an outer ring part, the inner ring part and the outer ring part being integrally connected by an elastic intermediate joint part, and an outer ring part of the plate. It consists of a nut body that holds the ring part in a fixed state on the upper surface facing the seat surface, and at least one female thread of the same pitch as the female thread of the nut is formed on the inner peripheral surface of the inner ring part. A lock nut, characterized in that the lower end of the female thread on the annular plate is disposed so as to be discontinuous with respect to the upper end of the female thread on the nut body. 2. Rotate the lower end of the female thread of the annular plate relative to the upper end of the female thread of the nut body over a range of 20° to 70° clockwise or 30° to 100° counterclockwise when viewed from above the nut. 2. The lock nut according to claim 1, wherein the outer ring portion of the annular plate is fixed to the upper surface of the nut body in this state. 3. Part of the upper surface of the nut body is engaged with the plurality of radial grooves formed on the upper surface of the outer ring part of the annular plate, and the outer ring part is held in a fixed state on the upper surface of the nut body. A lock nut according to claim 1 or 2.