JP2013249944A - Locking nut/bolt and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locking nut/bolt which reliably exhibits a locking effect by a slight working, and to provide a method of manufacturing the locking nut/bolt.SOLUTION: A locking nut/bolt is characterized in that a protruded part or a wavy part formed with a height of at most an inter-gap distance between thread faces in the axial direction of the thread faces facing each other during a locking operation gets stranded or gets over a protruded part or a wavy part formed with a height of at most the inter-gap distance between the thread faces in the axial direction of the thread faces, in the nut and bolt that has not a reduced diameter part. A method of manufacturing the locking nut is characterized in that the protruded part is formed with respect to the axial direction by directly pushing or dumping a thread face against the nut protruding from a guide part of an automatic nut tapping machine.

Description

  The present invention relates to a locking nut / bolt and a manufacturing method.

Ordinary nuts and bolts gradually loosened due to various causes such as continuous vibration. For this reason, nuts used in machinery must be periodically tightened or nuts having a locking function must be used, and various locking methods have been developed. As part of the main system, a double nut that simply tightens two nuts in succession, an eccentric taper double nut that uses an eccentric nut (Patent Document 1), a castle nut that is used in combination with a cotter pin (Patent Document 2), There is a precision lock nut (Patent Document 3) that attaches another screw to the nut.

Japanese Patent Laid-Open No. 06-337012 Noto 312955 Publication US Patent Publication 005454674A1

When manufacturing the conventional locking nut as described above, there are the following three disadvantages compared to the normal nut manufacturing.
・ Manufacturing process ・ Number of components ・ Manufacturing cost In addition, there are the following three demerits even during fastening work.
・ Elimination of loosening prevention effect due to work mistakes, damage to some parts, etc. ・ Extension of work time by using special fastening methods or special tools ・ Working costs The above six shortcomings are considered a trade-off with the loosening prevention effect. Although it should be, it can be reduced by changing the locking method to the conventional one. The present invention eliminates all of the above six demerits by means of making the locking nuts and bolts manufacturing method and tightening work almost the same as ordinary nuts and bolts, and ensures that the nuts and bolts are loosened by a small amount of processing. An object of the present invention is to provide a locking nut / bolt that exhibits a locking effect.

The locking nut / bolt of the present invention has the following characteristics.
1. Convex or corrugated portion formed in the axial direction on the thread surface of the male or female screw, or convex or corrugated portion formed in the axial direction on the thread surface of the female or male screw facing during the tightening operation The feature is that the club rides on or gets over.
2. During tightening work, when both screw surfaces are in the locked state, the operator can detect through the tool.

The manufacturing method of the locking nut / bolt of the present invention includes the following steps.
1. There is a step of forming a convex portion by pressing or striking the screw surface of the nut coming out from the guide portion of the automatic nut tapping machine during or after completion of threading.
2. There is a step of securing a space for forming the convex portion again by moving the nut on which the convex portion has been formed from the position at the time of formation.

By adopting the nuts and bolts of the present invention, a number of advantages as described below can be obtained as compared with the conventional anti-loosening product, though the structure is very simple.

In the first place, it is considered that the nut stays at the initial position due to the static friction generated between the bolt screw surface and the member to be fastened due to the pretension at the time of fastening, and only holds the looseness.
The nut / bolt and the object to be fastened are continuously subjected to vibrations in all directions, and will be repeatedly deformed and restored slightly in each direction, but the thread surface near the bolt head and the vicinity of the tip. Since this is a continuous surface even though the amount of deformation is different from that of the screw surface, it slides so as to scoop the screw surface of the nut that is in close contact. Naturally, since the resistance is less in the anti-fastening direction, if the above-described state is extended for a long time, the loosening proceeds until it can be visually observed. In other words, if the looseness due to vibration is due to the breaking of static friction of the entire screw surface caused by repeated slight displacement of the screw surface, which is considered to be the cause, the first trigger is `` Slight displacement of the screw surface '' If it is securely stopped, vibration loosening (rotational loosening) will never occur. “Slight displacement of the thread surface” can be stopped with a slight force.

The method of fixing the nut using a wire or a pin has a great psychological sense of safety in terms of appearance, but it cannot be denied that it has a rather high function in terms of the function of preventing loosening and the cost.
There are many other types of locking methods that increase the coefficient of friction, but it seems that it is more reliable to lock both the nuts and bolts by processing. In this method, convex portions are provided in the axial direction (vertical direction) with respect to the thread surface, and the convex portions of both nuts and bolts (hereinafter referred to as lock portions) at the time of fastening are faced to each other on the thread surface and locked. Therefore, as seen in other methods, it is not “a state where it is difficult to loosen due to friction” but a state where it does not loosen
Thus, a highly reliable product can be manufactured.

The advantages of the above method are listed as follows.
・ With regard to the manufacturing process, it is only necessary to add one process to the processing flow using equipment for manufacturing ordinary nuts such as automatic nut tapping machines, so existing manufacturing equipment can be utilized. Suitable for mass product manufacturing. As a result, it can be offered as a very inexpensive product compared to the conventional anti-loosening product.
-It looks the same as normal nuts and bolts in appearance, so it is lighter and space-saving than double nuts. For this reason, in the event of an emergency such as a shortage of normal nuts or bolts at the work site, it may be possible to use this type of nut or bolt together.
・ As long as consideration is given to the difference in the expansion rate of the material, it is more resistant to use at high temperatures than nylon nuts and screw locks.
・ Even if there is a slight decrease in the fastening force, the lock part is more resistant to loosening than the other parts of the threaded surface by the height of the protrusion. Therefore, even in the case of the loosening due to the relaxation of the stress and the loosening of the depression, including the loosening due to the difference in expansion coefficient as described above, the effect of preventing the loosening will continue to a certain extent.
・ Since the projecting parts face each other on the threaded surface, tightening more than necessary increases the amount of elastic deformation of the threaded surface.As a result, the projecting part becomes an obstacle and it becomes difficult to tighten any further. Next, an overtorque prevention effect can be expected. Therefore, the proper tightening force is not normally exceeded, and loosening due to the yielding of the screw is less likely to occur.
・ Initial loosening cannot occur due to the structure.
・ No additional tightening is required, resulting in work cost reduction.
-Since no other parts are required in addition to nuts and bolts, it is advantageous in terms of preventing loss during manufacturing and management and fastening operations.
・ Since the fastening method and the tools to be used are already existing, the operator is particularly conscious, remembers new procedures, and does not need to take the trouble of education, so the overall work cost can be reduced.
・ The life of the locking function, such as initial failure and abrasion of the convex part due to repeated use, can be easily discriminated by the presence or absence of a click feeling. Easy to grasp.
・ Even if the fastening operation is finished at a halfway position where there is no click feeling, when the loosening occurs, the thread surface slides to the lock part provided before the current position and is engaged. By stopping or fitting, the effect of preventing loosening will continue to be exhibited.

It is explanatory drawing which showed the mechanism of the locking prevention in Embodiment 1 of this invention. It is explanatory drawing which showed the example of the locking shape in Embodiment 2 of this invention. It is explanatory drawing of the locking nut manufacturing method 1 in Embodiment 4 of this invention. It is explanatory drawing of the locking nut manufacturing method 2 in Embodiment 5 of this invention.

A locking nut / bolt and a manufacturing method according to an embodiment of the present invention will be described below with reference to the drawings. Example 1 is the principle of the present invention, Example 2 is various shapes, Example 3 is a bolt manufacturing example of the present invention, Example 4 is a nut manufacturing example 1 of the present invention, and Example 5 is a nut manufacturing example of the present invention. It becomes description of 2.

The first embodiment will be described below.
In the present invention, a slight convex portion is formed in the axial direction with respect to the screw surfaces of both nuts and bolts, and the convex portions are provided on the screw surfaces that are in contact with each other during the fastening operation.
FIG. 1-1 shows a state immediately before the lock portions of the thread surfaces of the nuts and bolts being fitted come into contact with each other. The arrow on the right side indicates the traveling direction of each thread surface during fitting. When the screw surface A moves to the left, which is the fastening direction of the present embodiment, the lock portion comes into contact with the lock portion provided on the screw surface B. Then, the fastening operator will feel a stronger resistance than before contact, but if the force is applied as it is, the lock parts will get over each other as shown in FIG. 1-2, and the threaded surface around the lock part will also be deformed. To do. The deformation acts as if an elastic body is incorporated and presses the lock portion. At this time, since the elasticity of both screw surfaces can be used, the amount of elastic deformation of one screw surface can be ½ the height required to engage (the height of the hook between the lock portions). become. If force is applied continuously, as shown in Fig. 1-3, a click sensation is generated at the same time that the lock part is completely overcome. If it is attempted to move in the non-fastening direction, a strong resistance will occur. It will occur.

Since the maximum static frictional force is greater than the dynamic frictional force, an extremely small locking part can be used if it is possible to prevent slippage caused on the screw surface due to minute deformation of the nut, bolt, and fastening member due to vibration so that this will not be disturbed. However, it is effective to maintain the tightened state. For this reason, the nuts and bolts in the locked state as shown in Fig. 1-3 will not loosen the static friction unless they are intentionally applied in the "turning direction (rotating direction around the axis)". It is thought that it does not occur. Therefore, it is theoretically never necessary to have a screw surface with a height higher than the range where it can get over the convex surface facing the surface due to deformation of the screw caused by vibration, impact, etc. The nuts and bolts will not loosen.

The lock part can be formed without difficulty by using the part that is loosely fitted between the thread faces, but even if the lock part is slightly larger than the above distance, it is tightened. There is no problem in practical use because the loose work is only slightly tight. However, if another lock portion is formed directly above or below one screw thread in the axial direction, there is a high possibility that the space necessary for elastic deformation cannot be ensured and the device cannot be used. For example, when a plurality of lock portions are formed on a straight line in the axial direction with respect to the bolt, it is desirable that a space of one screw thread or more is provided without being continuous.

In FIG. 1, it is expressed that there is a large gap between the convex portion and the other thread surface. However, the gap is for facilitating the understanding of the figure, and the convex vertex is not fitted during fitting. The state may always be in contact with the other thread surface.

FIG. 2 shows three patterns as other examples of the shape of the lock portion.
The pattern A (A in FIG. 2) has a higher locking portion formed on the screw surface A than the screw surface B, thereby further improving the reliability of the locking function.

The pattern B (B in FIG. 2) is configured to be fitted to the small lock portion of the screw surface B by providing a small recess in the center of the lock portion formed on the screw surface A. If there is a certain amount of tightening torque, it will not slide in the tightening direction when vibration occurs, so make sure that the convex part of the thread surface is clamped by the two convex parts of the other thread surface as in this pattern. Although the static friction cannot be broken at least, it is desirable to realize this structure when there is a demand for fixing the nut at an intermediate position of the bolt.

As shown in pattern C (C in FIG. 2), the lock part formed on the threaded surface A has a wedge shape so that it can only be turned in the fastening direction, and once removed, it will not turn in the anti-fastening direction. A product having a function can be manufactured.

In any of the above three patterns, it is desirable that the screw surface A be on the bolt side where the shape processing can be performed relatively freely.

The bolt manufacturing method according to the principle of the present invention can be most easily implemented by changing the transfer pattern of the rolling die to one that is screwed into the shape of the lock portion.
If it is necessary to provide multiple lock parts, it should be provided on the bolt side thread surface that can be processed together at the same time, and it will take some time compared to normal manufacturing, and the yield on the nut side thread surface will be reduced. It is desirable to keep a few places.

The nut according to the principle of the present invention can be manufactured by using an NC lathe and the like, and a lock portion having a finer shape can be engraved. However, as shown in FIG. Manufacture can be performed simply by adding A and a roller part for moving a processed nut. The convex forming tool A is a small hammer-like instrument with a sharp tip for forming a lock portion by pressing or striking against the thread surface of the nut bottom, and at a certain timing. It is assumed that it can be operated or controlled by sensor processing. In the convex portion forming processing tool A of the present embodiment, a dot-like or linear convex portion can be provided on the nut screw surface by rotating about 90 degrees. Processing of the lock portion is performed by pressing or striking the thread surface of the nut with the convex forming tool A from the facing direction to the nut that is coming out from the guide portion of the automatic nut tapping machine or after completion of threading. Can also be automated.

Fig. 3-1 shows that a nut that has not yet been threaded and entered from the hopper falls into the guide and is pushed into the blade of the vent shank tap by a push rod, and the nut that has been tapped is discharged from the end of the blade. This is a state where the lock portion is processed by the convex forming tool A on the nut.

In order to form two locations at the same time, use a two-protrusion forming tool A having a gap about the diameter of the shank, and move it so as to sandwich the shank, or in FIG. Another method is also conceivable in which another convex forming tool is installed at the bottom of the guide and cooperated.

Fig. 3-2 shows that the convex forming tool A moves, secures a discharge path for the processed nut, the next nut is pushed into the blade, and the nut after the locking portion is pushed from the guide in Fig. 3-1. It is in a state of riding on the roller part.

FIG. 3C shows a state in which the roller portion pushes out the nut that has been processed with the lock portion, thereby creating a space for processing the next nut with the convex forming tool A. Although not expressed in FIG. 3, in fact, there is a processed nut that has been processed immediately before and is directed to the tap housing. Therefore, if there is no roller portion, the nut is connected in a rosary manner and the lock portion cannot be processed.

In the case of an automatic nut screw stand in which the shank part and the tap housing itself move left and right, at the timing when the shank part comes out of the guide, the projection forming tool A is tapped from the guide side, contrary to FIG. The lock part can be machined by striking the nut screw surface that was tapped last in the direction of the side.

FIG. 4 shows a state in which the tapping completion nut discharged from the end of the blade portion is pressed or hit with the convex forming tool A in the same manner as in FIG. The difference is that a bent shank tap having a rod-shaped convex forming tool B is used at an appropriate location around the portion where the end of the blade portion changes to the shank portion.

The convex forming tool B is a rod-shaped tool for forming a lock portion with respect to the thread surface inside the nut by pressing or striking the nut from the outside, and the width of the thread of the blade portion. And the size must be less than the height. It is also important to install the screw tapping nut in a position where it can be smoothly advanced. The timing of formation depends on the convex forming tool A outside the nut. However, in the case of the present embodiment, since the lock portion processing by the convex portion forming processing tool B on the nut internal thread surface is intended, the tip of the convex portion forming processing tool A does not necessarily have a sharp head.

In the fourth embodiment, the lock portion can be formed only on the screw surface of the nut bottom portion. However, the lock portion can be formed at an arbitrary position on the screw surface inside the nut by the method of this embodiment. At that time, depending on the operation timing of the convex portion forming processed portion A, not only a convex shape but also a wavy lock portion can be formed on the screw surface.

The nuts and bolts of the present invention are different from conventional loosening prevention systems that increase the coefficient of friction, and both of them are surely produced while generating a click feeling by a slightly sized lock part or wave-like part protruding from each other. Because it is locked and held by the elasticity of each material at the same time, there is no displacement between the male and female screws even in the continuous vibration in any direction, up, down, left, right, and left, thus preventing loosening It is useful as a nut and bolt. In addition, the method of manufacturing a locking nut / bolt according to the present invention is useful for manufacturing a nut / bolt having a function of preventing loosening.

110 Thread surface A
120 Thread surface B
130 Convex part (lock part)
210 Pattern A
220 Pattern B
230 Pattern C
310 Push rod 320 Hopper 330 Guide 340 Convex forming tool A (for nut bottom)
350 Bent shank tap 360 Tap housing 370 Nut 380 Blade part 390 Roller part 410 Convex part forming tool B (for inside of nut)

The first embodiment will be described below.
In the present invention, a slight convex portion is formed in the axial direction with respect to the screw surfaces of both nuts and bolts, and the convex portions are provided on the screw surfaces that are in contact with each other during the fastening operation.
FIG. 1-1 shows a state immediately before the lock portions of the thread surfaces of the nuts and bolts being fitted come into contact with each other. The arrow on the right side indicates the traveling direction of each thread surface during fitting. When the screw surface A moves to the left, which is the fastening direction of the present embodiment, the lock portion comes into contact with the lock portion provided on the screw surface B. Then, the fastening operator will feel a stronger resistance than before contact, but if the force is applied as it is, the lock parts will get over each other as shown in FIG. 1-2, and the threaded surface around the lock part will also be deformed. To do. The deformation acts as if an elastic body is incorporated and presses the lock portion. At this time, since it is possible to use the elasticity of both the screw surface, Maseru already at half the distance of one of the elastic deformation of the screw surface height required to engage (height caught locking portions) thing also Ru can. If force is further applied, as shown in Fig. 1-3, a click sensation is generated at the same time that the lock part is completely overcome, and if it is moved in the non-fastening direction contrary to the past, strong resistance is obtained. Will occur.

The nut according to the principle of the present invention can be manufactured by using an NC lathe and the like, and a lock portion having a finer shape can be engraved. However, as shown in FIG. Manufacture can be performed simply by adding A and a roller part for moving a processed nut. The convexity forming processing tool A is a tool having a sharp tip for forming a lock portion by pressing or striking against the thread surface of the nut bottom, and operates at a fixed timing, The operation can be controlled by sensor processing. In the convex portion forming processing tool A of the present embodiment, a dot-like or linear convex portion can be provided on the nut screw surface by rotating about 90 degrees. Processing of the lock portion is performed by pressing or striking the thread surface of the nut with the convex forming tool A from the facing direction to the nut that is coming out from the guide portion of the automatic nut tapping machine or after completion of threading. Can also be automated.

In the fourth embodiment, the lock portion can be formed only on the screw surface of the nut bottom portion. However, the lock portion can be formed at an arbitrary position on the screw surface inside the nut by the method of this embodiment. At that time, depending on the operation timing of the convex forming tool A, not only the convex shape but also the wavy lock portion can be formed on the screw surface.

The locking nut / bolt of the present invention has the following characteristics.
In bolt nut without a reduced径雌threaded portion against the axial direction of the threaded surface of the male thread or female thread, empty gaps distance between screw surface facing the該螺Ko
The protrusions or corrugations formed in the release height of less than, or female thread facing in Shimeyuru work against the axial direction of the threaded surface of the male screw, air gap distance between the screw surfaces facing the該螺Ko Less high
It is characterized in that the convex part or the wavy part formed on the base rides on or gets over.

The manufacturing method of the locking nut / bolt of the present invention includes the following steps.
Exiting from the guide portion of the automatic nut threading machine, the thread surface of the nut directly to the nut after the threading in or threading completed by pressing or hitting, axially pairs
Comprising the step of forming the convex portion to.

The locking nut / bolt of the present invention has the following characteristics.
At least one of the convex portions provided on the threaded surface does not have a reduced diameter female thread when facing each other
In a nut or bolt that is not shaped, a convex part formed at a height equal to or less than the clearance distance between the screw surfaces facing the screw with respect to the axial direction of the screw surface of the male screw or the female screw is tightened. A convex portion formed at a height equal to or less than an air gap distance between the screw surfaces facing the screw rides on or over the axial direction of the screw surface of the facing female screw or the male screw.

The manufacturing method of the locking nut / bolt of the present invention includes the following steps.
When forming the convex part by directly pressing or striking the thread surface of the nut coming out from the guide part of the automatic nut tapping machine against the nut during or after threading.
There is a step of forming a convex portion in the axial direction without cutting .

Claims (4)

Convex or wave-like portions formed in the axial direction on the screw surface of the male screw or female screw, and convex or wave-like portions formed in the axial direction on the screw surface of the female or male screw facing during the tightening operation Locking nuts and bolts characterized by riding on or over. 2. The locking nut / bolt according to claim 1, wherein an operator can sense through a tool when both screw surfaces are locked during a tightening operation. It has a step of forming a convex portion by pressing or striking a screw surface of the nut that comes out from a guide portion of an automatic nut tapping machine during or after threading. A method for manufacturing a locking nut. 4. A method of manufacturing a locking nut according to claim 3, further comprising the step of securing a space for forming the convex portion again by moving the nut having the convex portion formed from the position at the time of formation.

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