A curved surface variable tooth type anti-loosening nut

Abstract

The present invention discloses a curved surface variable tooth type anti-loosening nut, which relates to the technical field of anti-loosening nuts, and comprises a nut body, wherein an internal thread is provided on the inner wall of the nut body, and the internal thread is used for matching and connecting with an external thread; an anti-loosening inclined surface is provided on the thread inclined surface below the root of the internal thread, and the anti-loosening inclined surface is a quadratic curved surface structure. The curved surface variable tooth type anti-loosening nut provided by the present invention has good anti-loosening performance and a wide range of applications.

Description

Technical Field

[0001] The invention relates to the technical field of anti-loosening nuts, in particular to a curved surface variable tooth type anti-loosening nut. Background Art

[0002] Currently, there are many types of nuts with anti-loosening performance. Among them, variable tooth anti-loosening nuts are a kind of fasteners with good anti-loosening performance and reusability, and have been widely used. At present, the variable tooth angles of variable tooth anti-loosening nuts are mostly linear plane types. When the threaded connection is working, the contact angle between the large diameter top of the external thread and the variable tooth surface of the internal thread will not change. This angle is closely related to the performance of the anti-loosening nut. The smaller the contact angle, the better the anti-loosening performance. However, a small angle will also bring some unfavorable factors, that is, the working range of the variable tooth surface that produces the anti-loosening effect will also be reduced, and the tolerance requirements for the external thread are higher. The inclination angle of the variable tooth anti-loosening nuts that are currently widely used is mostly 30°, such as Figure 1 and Figure 2 As shown, its basic thread angle is 60°, and its anti-loosening inclined surface is a plane with an angle of 30° to the center line. Its characteristic is that when the top of the external thread moves on this surface, their angle will not change, which can basically meet the medium tolerance thread pair connection cooperation. A certain inclination angle will also have a certain effect on the anti-loosening performance of anti-loosening nuts of different materials. At present, the conventional 30° angle variable tooth anti-loosening nut has a certain effect on the anti-loosening performance of fasteners such as stainless steel materials. Reducing the inclination angle can improve the anti-loosening performance, but the working surface range of the variable tooth type is narrowed, and the tolerance requirements for the matching thread are higher. Once the major diameter of the external thread deviates from the tolerance range, the anti-loosening performance may fail. Therefore, there is a contradiction between the anti-loosening performance and the scope of application of the linear variable tooth anti-loosening nut. Summary of the invention

[0003] The purpose of the present invention is to provide a curved surface variable tooth anti-loosening nut to solve the problems existing in the above-mentioned prior art, so as to achieve good anti-loosening performance and a wide range of applications.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a curved variable tooth anti-loosening nut, comprising a nut body, an inner wall of the nut body is provided with an internal thread, the internal thread is used for matching and connecting with an external thread; an anti-loosening inclined surface is provided on the thread inclined surface below the tooth bottom of the internal thread, and the anti-loosening inclined surface is a quadratic curved surface structure.

[0006] Optionally, the angle between the tangent plane at the contact point between the quadratic curved surface structure of the anti-loosening slope and the major diameter of the external thread and the major diameter crest of the external thread gradually decreases from the starting end to the end end of the quadratic curved surface structure.

[0007] Compared with the prior art, the present invention has achieved the following technical effects:

[0008] The present invention adopts a curved anti-loosening bevel. When the bolt enters the anti-loosening nut, the angle between the contact point of the top of the external thread and the anti-loosening bevel of the internal thread of the anti-loosening nut is a changing process. In the initial stage of the external thread entering, this contact angle is relatively large. Although the anti-loosening performance coefficient at this time is smaller than that of the usual flat variable tooth anti-loosening nut, the fastener is usually not in the final working area in this area, which will not affect the actual anti-loosening performance coefficient, but can expand the tolerance redundancy of the matching external thread. As the bolt is continuously tightened, this contact angle will continue to decrease. The smaller angle can increase the anti-loosening performance coefficient of the anti-loosening nut. As the top of the external thread gradually enters the final working area, the curved variable tooth anti-loosening nut can obtain better anti-loosening performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0010] Figure 1 It is a schematic diagram of the thread structure of a plane variable thread type anti-loosening nut in the prior art;

[0011] Figure 2 It is a schematic structural diagram of a planar variable-thread anti-loosening nut in the prior art after the contact point between the external thread top and the anti-loosening inclined surface is moved;

[0012] Figure 3 It is a schematic diagram of the thread structure of the curved surface variable tooth type anti-loosening nut in the present invention;

[0013] Figure 4 A schematic diagram of the structure of the curved variable tooth anti-loosening nut of the present invention after the contact point between the top of the external thread and the anti-loosening inclined surface is moved;

[0014] Among them, 1 is the internal thread, 2 is the external thread, 3 is the anti-loosening bevel, and 4 is the top of the thread. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] The purpose of the present invention is to provide a curved surface variable tooth anti-loosening nut to solve the problems existing in the above-mentioned prior art, so as to achieve good anti-loosening performance and a wide range of applications.

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The present invention provides a curved surface variable tooth type anti-loosening nut, such as Figure 3 and Figure 4 As shown, it includes a nut body, an internal thread 1 is provided on the inner wall of the nut body, and the internal thread 1 is used to cooperate with the external thread 2; an anti-loosening bevel 3 is provided on the thread bevel below the root of the internal thread 1, and the anti-loosening bevel 3 is a quadratic surface structure. The angle between the tangent plane where the quadratic surface structure of the anti-loosening bevel 3 and the contact point of the major diameter of the external thread 2 and the crest 4 of the major diameter of the external thread gradually decreases from the beginning to the end of the quadratic surface structure. Specifically, the outer layer is a variable tooth type anti-loosening nut thread (with a section line) of the external thread 2, and its basic thread angle is 60°. The anti-loosening bevel 3 of the internal thread 1 is a curved surface. When working, the top of the external thread 2 moves on the anti-loosening bevel 3. When moving, the angle between the contact point of the anti-loosening bevel 3 and the external thread 2 and the vertical plane where the crest 4 of the external thread 2 is located will change, and the angle changes from large to small.

[0019] Compared with the flat variable tooth anti-loosening nut, the quadratic curved surface structure of the present invention can provide a wider working surface for the anti-loosening inclined surface, and as the threaded connection is tightened, the structure can gradually improve the locking state to obtain better anti-loosening performance. The anti-loosening performance of the variable tooth anti-loosening nut depends on the angle between the anti-loosening inclined surface contact point of the external thread 2 in the internal thread 1 and the vertical plane where the top of the major diameter of the external thread 2 is located. Since the anti-loosening inclined surface is different from the traditional straight inclined surface, it is a surface approximating a quadratic curve, which can produce a variable angle. The smaller the angle, the better the anti-loosening performance generated by the contact between the major diameter of the external thread 2 and the anti-loosening inclined surface 3, but the higher the precision requirement for the external thread 2, the worse the applicability. On the contrary, the larger the angle, the smaller the precision requirement for the external thread, the wider the applicability, but the anti-loosening performance generated by the contact between the major diameter of the external thread and the inclined surface becomes worse. The characteristic of the quadratic surface is that at the beginning of the surface, the angle of the surface in the vertical direction relative to the top of the major diameter of the external thread is large, so that the major diameter of the thread can easily enter the anti-loosening bevel. Although the angle between the major diameter of the thread and the anti-loosening bevel 3 is large at this time, the anti-loosening resistance generated is small, but because the nut is usually not in the tightening state at this time, anti-loosening resistance is not needed. As the fastener is continuously tightened, the major diameter of the external thread 2 will extend inward along the curved surface. At the same time, the angle between the top 4 of the major diameter of the external thread 2 and the quadratic curved surface structure of the anti-loosening bevel 3 at the contact point also begins to slowly decrease. At this time, the anti-loosening resistance generated also begins to gradually increase, and the fastener gradually enters the tightening state. The characteristic of the anti-loosening resistance generated by the anti-loosening inclined surface 3 of the quadratic curved surface structure of the curved surface variable tooth anti-loosening nut is that a wider working surface can be provided for the external thread major diameter on the anti-loosening inclined surface. In the initial stage of the fastener working, the angle between the external thread and the variable tooth curved surface contact point relative to the center line is large, and the anti-loosening resistance generated is small. As the fastener is continuously tightened, the contact point between the external thread and the variable tooth curved surface of the fastener deepens, and the angle relative to the vertical center line continues to decrease, and the anti-loosening resistance generated also gradually increases. In other words, as the fastener is tightened, the anti-loosening resistance presents an increasing change process. When the fastener is tightened, its anti-loosening performance also reaches a better state. During the entire working process, the angle between the contact point of the external thread major diameter and the anti-loosening inclined surface is a change process from large to small, and the resistance to prevent the loosening of the thread pair changes from small to large. However, for the currently commonly used flat variable tooth anti-loosening nut, since the anti-loosening inclined surface is a plane, the angle between the contact point of the external thread major diameter and the anti-loosening inclined surface is a constant state during the entire working process, and the resistance coefficient to prevent the loosening of the thread pair is also relatively constant.Although compared with the flat variable tooth anti-loosening nut, the curved variable tooth anti-loosening nut has a larger contact point angle between the major diameter of the external thread and the anti-loosening bevel in the initial state, and the resistance to preventing the loosening of the thread pair is also small, but as the fastener is continuously tightened, the major diameter of the external thread continues to penetrate inward, and the contact point angle between the major diameter of the external thread of the curved variable tooth anti-loosening nut and the anti-loosening bevel begins to decrease, and the resistance to preventing the loosening of the thread pair increases. When the contact point angle between the top of the major diameter of the thread and the anti-loosening bevel is smaller than the bevel angle of the flat variable tooth anti-loosening nut, the resistance to preventing the loosening of the thread pair will exceed the resistance of the flat variable tooth anti-loosening nut to prevent the loosening of the thread pair, thereby obtaining a better anti-loosening effect.

[0020] When the external thread is tightened into the variable tooth lock nut, the top of the external thread enters the bottom diameter of the variable tooth lock nut thread. Since the contact point angle of the curved variable tooth lock nut in the bottom area of ​​the thread teeth is greater than that of the flat variable tooth lock nut, the bottom diameter of the curved variable tooth lock nut is larger than that of the flat variable tooth lock nut, and the tolerance requirement for the major diameter of the bolt thread is wider. Although in this area, the contact point angle between the major diameter of the external thread of the curved variable tooth lock nut and the anti-loosening inclined surface is large, and the anti-loosening effect may be relatively poor, but since this area is usually not the final working area of ​​the lock nut, it will not affect the actual performance of the lock nut. As the nut is gradually tightened, the contact point between the top of the external thread and the anti-loosening bevel begins to move, and the contact angle between the major diameter of the external thread of the curved variable tooth type anti-loosening nut and the anti-loosening bevel begins to decrease, and the anti-loosening performance is also improved accordingly; while the contact angle between the major diameter of the external thread of the flat variable tooth type anti-loosening nut and the anti-loosening bevel does not change during the movement, and its anti-loosening performance coefficient does not change. When the angle between the contact point of the major diameter of the external thread of the curved variable tooth type anti-loosening nut and the anti-loosening bevel is reduced to less than the angle of the similar flat variable tooth type anti-loosening nut, the anti-loosening performance coefficient of the curved variable tooth type anti-loosening nut begins to exceed that of the similar flat variable tooth type anti-loosening nut. As the nut is further tightened, the contact point between the major diameter of the top of the external thread and the anti-loosening bevel continues to move downward, and the performance coefficient of the curved variable tooth type anti-loosening nut will be further improved, while the anti-loosening performance coefficient of the flat variable tooth type anti-loosening nut does not change because the contact angle does not change.

[0021] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A curved surface variable tooth type anti-loosening nut, characterized in that: It includes a nut body, an inner wall of which is provided with an internal thread, and the internal thread is used for matching and connecting with an external thread; an anti-loosening inclined surface is provided on the thread inclined surface below the root of the internal thread, and the anti-loosening inclined surface is a quadratic surface structure; the angle between the tangent plane where the contact point between the quadratic surface structure of the anti-loosening inclined surface and the major diameter of the external thread is located and the top of the major diameter of the external thread gradually decreases from the beginning to the end of the quadratic surface structure; the thread angle of the external thread is 60°.

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