Friction-reducing patch and metal lock nut

Abstract

The utility model discloses an improvement to the existing metal locking nut, relates to a friction-increasing piece (1) for increasing friction, characterized in that: no tab (3) is arranged on one side of the inner ring (6) of the ring seat piece, and at least one tab (3) in the form of a sector (4), a crescent (5) or an eccentric circle (26) is arranged on the other side, forming an asymmetric friction-increasing piece (1). The friction-increasing piece (1) is riveted and pressed on the step (14), forming a new metal locking nut (13). The anti-loosening method is that the friction-increasing piece (1) pushes and squeezes the external thread (24) of the bolt to one side horizontally and axially, so that the internal thread (23) of the metal locking nut is decentered on the external thread (24) of the bolt, the gap (22) is fully inclined, and the screw is expanded to form two sawtooth wave peak and valley tooth engagement. With the increase of the pre-tightening force, the friction coefficient is increased, the friction force is very large, and the anti-loosening performance is greatly improved. The anti-loosening technology and product are used for the anti-loosening and fastening of various vibrating mechanical equipment and facilities.

Description

Technical Field

[0001] This utility model relates to the field of anti-loosening fasteners, and in particular to friction-enhancing plates for increasing friction on metal lock nuts, metal lock nuts, and methods for preventing loosening. Background Technology

[0002] The existing ISO 7719 standard is a standard for all-metal hexagonal lock nuts, such as the "Metal Insert Hexagonal Lock Nut" disclosed in Chinese patent CN2045034U. Its feature is that a special spring plate is fixed in the nut body, and there is a pressing step at the top of the nut for fixing the spring plate. The spring plate has two or more "U"-shaped grooves with the opening direction facing inward. The included angle between the two sides of the "U"-shaped groove is not greater than 90°. The spring plate is pressed and fixed under the pressing step at the top of the nut body. The spring sheet described here undergoes elastic deformation during tightening, increasing the contact area and friction. During vibration, the elastic restoring force of the spring sheet counteracts the loosening tendency. Since it serves to increase the friction between the nut and bolt, it is referred to as a "friction enhancer" in this case. Due to its radially symmetrical structure, the unfolding of the nut's internal thread and the bolt's external thread is actually two parallel helical tooth surfaces. This inevitably leads to slippage under strong vibration conditions, causing the nut to loosen and turn. In actual testing, with an amplitude of ±0.8mm, a frequency of 12.5Hz, a preload of 68KN, and 2000 vibrations, only about 20% of the residual axial force remains, which is far from meeting the requirements for fastening and preventing loosening of mechanical equipment and facilities under strong vibration.

[0003] For example, the locking method of DIN980-V type nuts, with the end face designed as an ellipse, or a three-point contact, or the above-mentioned two-point locking design on the side, are all based on the axially symmetrical structural design of the nut. They cannot change the fact that the friction force is evenly distributed on the circumferential side due to the axially symmetrical design, which causes the internal thread of the nut and the external thread of the bolt to spiral, slip, and loosen. Utility Model Content

[0004] To overcome the shortcomings of the prior art, this invention aims to provide a friction-enhancing plate, a metal lock nut, and a method for preventing loosening, which can significantly improve the anti-loosening performance under strong vibration conditions and ensure that the internal thread of the nut is firmly locked on the external thread of the bolt without rotation, slippage, or loosening.

[0005] The friction-enhancing plate provided in this case consists of an annular ring seat plate and a convex plate. The concave arc of the convex plate faces the axis of the metal locking nut. The convex arc of the convex plate is integrally connected with the inner ring of the annular ring seat plate. Its characteristic is that:

[0006] On one side of the inner ring of the annular ring seat, there are no protrusions; on the other side of the inner ring of the annular ring seat, there is at least one protrusion, which is connected to each other to form a friction-enhancing plate. The friction-enhancing plate is asymmetrical.

[0007] The protrusion may be fan-shaped, crescent-shaped, or eccentrically circular;

[0008] The outer periphery of the friction-enhancing plate is such that it can be radially embedded within the inner riveting edge of one end of the nut.

[0009] The thickness h of the friction-enhancing plate is 1 / 10 to 1 / 2 of the pitch of the internal thread of the metal lock nut, including 1 / 10 or 1 / 2;

[0010] The inner diameter of the friction-enhancing ring is larger than the large diameter D of the internal thread of the metal lock nut;

[0011] The inner radius of the protrusion on the friction-enhancing plate is smaller than the small diameter d of the internal thread of the metal lock nut;

[0012] The curvature of the convex piece is π / 6 to 5π / 6;

[0013] Preferably, the curvature of the convex piece is π / 3 to 2π / 3;

[0014] The friction-enhancing sheet is made of elastic metal;

[0015] The elastic metal can be stainless steel, silicon manganese spring steel, carbon spring steel, titanium alloy, low manganese spring steel, or chromium vanadium steel.

[0016] The structure of the metal locking nut processed from the aforementioned friction-enhancing plate is characterized in that: the circumference of the friction-enhancing plate is radially embedded in the inward riveting edge at one end of the metal locking nut body, between the plate and the step of the metal locking nut body, and is fixed by riveting. The inner diameter of the inward riveting edge is just large enough to accommodate the outer diameter of the friction-enhancing plate, and is radially riveted. The thickness of the friction-enhancing plate is sufficient to be axially riveted between the inward riveting edge at one end of the metal locking nut and the step, so that it cannot rotate or loosen when the metal locking nut is pre-tightened.

[0017] The installation and use structure of the metal lock nut described in this case is as follows: the tail end of the bolt is passed through the screw holes of the lower and upper fasteners, and the metal lock nut described in this case is screwed on the exposed tail end of the bolt. The annular plane of one end of the metal lock nut contacts the surface around the screw hole of the upper fastener and is pre-tightened.

[0018] The anti-loosening method of the metal lock nut described in this case is as follows: the inner arc-shaped edge of the upper protrusion of the pre-tightened metal lock nut is tightly opened by the pre-tightened bolt external thread, squeezing the uppermost engagement bolt external thread, and exerting a certain downward frictional pressure axially. At the same time, because the inner radius of the protrusion is less than 1 / 2 of the large diameter D of the internal thread of the metal lock nut, if the thread clearance is negligible, that is, less than 1 / 2 of the outer diameter of the peak of the bolt external thread, the bolt is pushed to one side laterally. At this time, the metal lock nut and the bolt are not coaxial, and the thread is misaligned. The locking mechanism involves the metal lock nut tilting on the bolt due to downward frictional pressure and asymmetrical thrust to one side. Within the permissible range of the gap between the internal thread of the metal lock nut and the external thread of the bolt, one side is higher than the other, allowing for a significant tilt. This tilting causes the internal thread of the metal lock nut and the external thread of the bolt to unfold into two sawtooth-like, staggered meshing teeth. As the preload increases, the coefficient of friction becomes very high, resulting in a large frictional force between the two, thus significantly improving the anti-loosening performance.

[0019] Compared with the existing technology, this utility model does not add any parts or increase any cost. Instead, it removes the convex piece on the other side of the symmetrical structure and replaces it with an asymmetrical friction-enhancing plate structure. The friction is changed from parallel threaded rubbing friction to sawtooth wave peak-valley staggered tooth meshing. The friction force increases with the preload and tends to be infinite. This locking structure makes the asymmetrical metal lock nut lock on the bolt. Its anti-loosening performance is significantly improved by several times compared with the existing symmetrical metal lock nut, and an unexpected anti-loosening effect is achieved. Attached Figure Description

[0020] Figure 1 This is one of the front views of the friction-enhancing sheet described in this utility model;

[0021] Figure 2 yes Figure 1 The left view;

[0022] Figure 3 yes Figure 1 The right view;

[0023] Figure 4 yes Figure 1 A perspective view of the metal locking nut of the friction-enhancing plate;

[0024] Figure 5 This is a utility model Figure 4 Front view of the metal lock nut;

[0025] Figure 6 yes Figure 5 Top view;

[0026] Figure 7 This is the second front view of the friction-enhancing sheet described in this utility model;

[0027] Figure 8 yes Figure 7 The left view;

[0028] Figure 9 yes Figure 7 The right view;

[0029] Figure 10 yes Figure 7 A perspective view of the metal locking nut of the friction-enhancing plate;

[0030] Figure 11 This is a utility model Figure 10 Front view of the metal lock nut;

[0031] Figure 12 yes Figure 11 Top view;

[0032] Figure 13 This is the third front view of the friction-enhancing sheet described in this utility model;

[0033] Figure 14 yes Figure 13 The left view;

[0034] Figure 15 yes Figure 13 The right view;

[0035] Figure 16 yes Figure 13 A perspective view of the metal locking nut of the friction-enhancing plate;

[0036] Figure 17 This is a utility model Figure 16 Front view of the metal lock nut;

[0037] Figure 18 yes Figure 17 Top view;

[0038] Figure 19 This is a utility model Figure 4 , Figure 10 , Figure 16 A schematic diagram illustrating the structure of the metal lock nut.

[0039] In the picture:

[0040] 1. Friction enhancer plate 2. Left-hand or right-hand thread

[0041] 3. Convex plate 4. Fan-shaped

[0042] 5. Crescent-shaped inner ring of the 6th ring seat plate

[0043] 7. Inward riveting edge 8. Thickness h of the friction-enhancing sheet

[0044] 9. Inner diameter of the ring seat plate 10. Larger diameter D of the nut's internal thread

[0045] 11. Inner radius of the lug 12. Smallest diameter d of the nut's internal thread

[0046] 13. Metal lock nut 14. Step

[0047] 15. Metal lock nut body 16. Bolt

[0048] 17. Bolt head 18. Threaded rod

[0049] 19. Upper fastener 20. Lower fastener

[0050] 21. Screw hole 22. Clearance

[0051] 23. Internal thread of metal lock nut 24. External thread of bolt

[0052] 25. Circular plane 26. Eccentric circle

[0053] 27. Ring seat plate

[0054] α, the angle through the center of the circle corresponding to the convexity of the convex piece. Detailed Implementation

[0055] The present invention will now be further described in conjunction with the accompanying drawings and embodiments:

[0056] This utility model Figure 1 , Figure 7 , Figure 13 In the process, the friction-enhancing plate 1 is composed of an annular ring seat plate 2 and a protrusion plate 3. The concave arc of the protrusion plate 3 faces the axis of the metal locking nut 13, and the convex arc of the protrusion plate 3 is connected to the inner ring 6 of the annular ring seat plate as a whole.

[0057] On one side of the inner ring 6 of the annular ring seat, there are no protrusions; on the other side of the inner ring 6 of the annular ring seat, there is at least one, two, or more protrusions 3, which are connected to each other to form a friction-enhancing plate 1, and the friction-enhancing plate 1 is asymmetrical.

[0058] The protrusions 3 are respectively fan-shaped 4, crescent-shaped 5, or eccentric circle-shaped 26.

[0059] Figure 1 , Figure 2 , Figure 3 The protrusion 3 in the middle is fan-shaped 4, and its inward protrusion is a fan-shaped structure.

[0060] Figure 7 , Figure 8 , Figure 9The protrusion 3 in the middle is crescent-shaped, and its inward protruding part has a crescent-shaped structure.

[0061] Figure 13 , Figure 14 , Figure 15 The convex piece 3 is an eccentric circular shape 26, and its inward protruding part is an eccentric circular structure.

[0062] The outer periphery of the friction-enhancing plate 1 is such that it can be radially embedded within the inner riveted edge 7 at one end of the metal locking nut body 15.

[0063] The thickness h of the friction-enhancing plate 1 is 1 / 10 to 1 / 2 of the pitch of the internal thread 23 of the metal locking nut 13, including 1 / 10 or 1 / 2; such as 1 / 10, 3 / 10, 4 / 1, or 1 / 2.

[0064] The inner diameter 9 of the friction-enhancing plate 1 ring seat is larger than the large diameter D of the internal thread 23 of the metal lock nut.

[0065] The inner radius 11 of the convex plate 3 on the friction-enhancing plate 1 is smaller than the small diameter d of the internal thread 23 of the metal lock nut.

[0066] The radius of the protrusion 3 is π / 6 to 5π / 6, which corresponds to an angle of 30° to 150° through the center of the circle, such as 30°, 60°, 90°, 120°, or 150°; preferably, the radius of the protrusion 3 is π / 3 to 2π / 3, which corresponds to a central angle of 60° to 120°.

[0067] The friction enhancer 1 is made of an elastic metal; the elastic metal can be stainless steel, silicon manganese spring steel, carbon spring steel, titanium alloy, low manganese spring steel or chromium vanadium steel; for example, stainless steel can be SUS304 to 316, silicon manganese spring steel can be 60Si2Mn, carbon spring steel can be 65Mn, etc.

[0068] Figure 4 , Figure 10 , Figure 16 The structure consists of friction-enhancing plates 1 with fan-shaped 4, crescent-shaped 5, and eccentric circular 26 protrusions 3, respectively, and an asymmetrical metal locking nut 13.

[0069] The circular periphery of the friction-enhancing piece 1 is radially embedded in the inward riveting edge 7 at one end of the metal locking nut body 15, between the metal locking nut body 15 and the step 14, and is pressed and riveted. The inner diameter of the inward riveting edge 7 is just enough to accommodate the outer diameter of the friction-enhancing piece 1, and is radially riveted. The thickness of the friction-enhancing piece 1 is sufficient to be axially riveted between the inward riveting edge 7 at one end of the metal locking nut 13 and the step 14, so that it cannot rotate or loosen when the metal locking nut 13 is pre-tightened.

[0070] Figure 19The installation and use structure of the asymmetrical metal locking nut 13 in this case is as follows: the tail end of the bolt 16 is passed through the screw hole 21 of the lower fastener 20 and the upper fastener 19, and the asymmetrical metal locking nut 13 of this case is screwed on the exposed tail end of the screw 18. The annular plane 25 of the other end of the metal locking nut 13 contacts the surface around the screw hole 21 of the upper fastener 19 and is pre-tightened.

[0071] like Figure 19 for Figure 4 , Figure 10 , Figure 16 The three methods for preventing loosening of the asymmetrical metal lock nut 13 shown are all based on the same principle: the inner arc-shaped edge of the upper protrusion 3 of the pre-tightened metal lock nut 13 is tightly opened by the pre-tightened bolt external thread 24, squeezing the uppermost engagement bolt external thread 24 of the bolt 16, and exerting a certain downward frictional pressure axially. At the same time, because the inner radius of the protrusion 3 is less than 1 / 2 of the large diameter D of the inner thread 23 of the metal lock nut, and if the thread clearance 22 is negligible, that is, less than 1 / 2 of the outer diameter of the peak of the bolt external thread 24, the screw 18 is pushed to one side laterally. At this time, the metal lock nut 13 and the screw 18 are not... The coaxial, threaded misalignment engagement means that the metal locking nut 13 on the screw 18 is misaligned due to downward frictional pressure and asymmetrical thrust to one side. Within the allowable range of the gap between the internal thread 23 of the metal locking nut and the external thread 24 of the bolt, one side is higher and the other side is lower, allowing for sufficient misalignment. This causes the internal thread 23 of the metal locking nut and the external thread 24 of the bolt to spiral out and engage in a two-toothed, wavy, staggered meshing. As the preload increases, the coefficient of friction becomes very large, resulting in a large frictional force between the two, thus significantly improving the anti-loosening performance.

[0072] According to the ISO16130-2015 standard test for transverse vibration, after 2000 vibrations at an amplitude of ±0.8mm, a frequency of 12.5Hz, and a preload of approximately 68KN, the residual axial force of the symmetrical metal lock nut before the improvement was about 20%, while the residual axial force of the asymmetrical metal lock nut after the improvement was as high as over 90%.

[0073] Compared with the prior art, this utility model does not add any parts or increase any cost. Instead, it removes the convex piece 3 on the other side of the symmetrical structure and replaces it with an asymmetrical friction-enhancing piece 1 structure. The friction is changed from parallel threaded rubbing friction to sawtooth wave peak-valley staggered tooth meshing. The friction force increases with the preload and tends to be infinite. The locking structure makes the asymmetrical metal locking nut 13 lock on the bolt 16. Its anti-loosening performance is significantly improved by several times compared with the existing symmetrical metal locking nuts, and an unexpected anti-loosening effect is achieved.

[0074] The friction-enhancing piece 1 described in this case can be stamped in one go using a punch press or cut using a laser cutting machine. Then, the friction-enhancing piece 1 is fixed between the inward riveting edge 7 and the step 14 by a press. The processing and use methods of the improved, asymmetrical, metal locking nut 13 are the same as those of the existing symmetrical ordinary metal locking nuts. They are all mature technologies. Their structure, working principle, material, specifications, and selection methods should be mastered by ordinary technicians in this field, so they will not be repeated here.

[0075] This utility model relates to a friction-enhancing plate 1, a metal locking nut 13, and a method for preventing loosening. It is applicable to the anti-loosening and fastening of vibrating machinery and facilities in fields such as railways, bridges, mines, petrochemicals, aviation, aerospace, shipping, iron towers, wind power, nuclear power, vehicles, military industry, and robotics.

[0076] It should be noted that the terms "front" and "rear"; "large" and "small"; "inner" and "outer"; "left" and "right"; "up" and "down"; "upward" and "downward"; "convex" and "concave"; "high" and "low" used in this utility model to indicate orientation, area, position, or aspect relationship are based on the orientation, area, position, or direction relationship shown in the accompanying drawings. They are only for the convenience of description and simplification. In actual application, the orientation, position, or direction can be interchanged, rotated, or reversed. They do not indicate or imply that the device or part referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "installation" and "connection" should be interpreted broadly. For example, an integrated connection can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this application can be understood through the specific circumstances.

[0077] The above description is merely a preferred embodiment of this case and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this case should be included within the scope of protection of this utility model.

Claims

1. A friction-increasing piece, which is composed of a circular ring-shaped ring seat piece (27) and a tab (3), the concave arc of the tab (3) is directed towards the axis of a metal locking nut (13), and the convex arc of the tab (3) is integrally connected with the inner circle (6) of the circular ring-shaped ring seat piece, characterized in that: on one side of the inner circle (6) of the circular ring-shaped ring seat piece, there is no tab (3); and on the other side of the inner circle (6) of the circular ring-shaped ring seat piece, there is at least one tab (3) integrally connected therewith to form the friction-increasing piece (1), which is asymmetric. The tab (3) is either fan-shaped (4), or crescent-shaped (5), or eccentric circle-shaped (26).

2. The friction enhancing sheet of claim 1 wherein: The outer circumferential edge of the friction-increasing piece (1) is just capable of being radially placed inside the inner turned-in riveting edge (7) of one end of the metal locking nut (13).

3. The friction enhancing sheet of claim 1 wherein: The thickness h (8) of the friction-increasing piece is 1 / 10-1 / 2 of the pitch of the internal thread (23) of the metal locking nut, including 1 / 10 or 1 / 2.

4. The friction enhancing sheet of claim 1 wherein: The inner diameter (9) of the ring seat piece of the friction-increasing piece is greater than the major diameter D of the internal thread (23) of the metal locking nut; and the inner radius (11) of the tab of the friction-increasing piece (1) is less than the minor diameter d of the internal thread (23) of the metal locking nut.

5. The friction enhancing sheet of claim 1 wherein: The arc of the tab is π / 6-5π / 6.

6. The friction enhancing sheet of claim 1 wherein: The material of the friction-increasing piece (1) is elastic metal.

7. The friction enhancing sheet of claim 1 wherein: The elastic metal is stainless steel, silicon-manganese spring steel, carbon spring steel, titanium alloy, low-manganese spring steel or chromium-vanadium steel.

8. The friction enhancing sheet of claim 7, wherein: The circumferential edge of the friction-increasing piece (1) is radially embedded inside the inner turned-in riveting edge (7) of one end of the metal locking nut body (15), between the step (14) of the metal locking nut body (15), and is press-riveted and fixed, wherein the inner diameter of the inner turned-in riveting edge (7) is just capable of embedding the outer diameter of the friction-increasing piece (1) and is radially riveted dead; and the thickness h (8) of the friction-increasing piece satisfies that it can be axially riveted dead between the inner turned-in riveting edge (7) and the step (14) of one end of the metal locking nut (13), and cannot rotate and loosen when the metal locking nut (13) is pre-tightened.

9. A metal lock nut comprising a metal lock nut body (15) and a friction- enhancing sheet (1) as claimed in any one of claims 1 to 8, characterized in that: ​

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