Never-loosening screw assembly

Abstract

The utility model discloses a screw assembly capable of never loosening. When the screw is vibrated, the screw can loosen slowly in a few and many manner, which is the root cause that the traditional screw is easy to loosen. The screw assembly comprises a bolt 1, a gasket 2, a spring gasket 3, a meshing piece 4 and a nut 5, the bolt 1 is provided with a groove A, the meshing piece 4 is provided with a protruding beam A1 and a meshing face B, and one face of the nut 5 is provided with a meshing face B1. According to the anti-loosening principle, when the nut 5 is screwed, the meshing piece 4 and the nut 5 are tightly wedged into a whole due to the pre-tightening force and the interaction of the meshing faces, the meshing piece 4 is inevitably driven to rotate together if the nut 5 is loosened, and the meshing piece 4 does not rotate absolutely under the action of the groove A and the protruding beam A1. The loosening force of vibration on the screw is far smaller than the peak value rotating force needed when the protrusions on the occlusal face meet with the protrusions on the occlusal face. Therefore, the aim of never loosening is fulfilled from the structural principle.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical fastening, in particular to a screw assembly. Background Art

[0002] The screw is a major invention in the industrial history. It is a tool for fastening machine parts step by step by using the physical and mathematical principles of the circular rotation of the inclined plane of an object and friction. People have invented various methods to prevent the screw from loosening, such as using double nuts, adding spring washers, applying screw glue, embedding a nylon anti-loosening ring in the nut, adding a check nut outside, etc. However, these methods cannot fundamentally prevent loosening from the structural principle, so the anti-loosening effect is not very ideal. For example, the Chinese invention patent with the publication number CN117212321A, "discloses a screw that never loosens, relating to the technical field of screw fastening. It includes a screw body, the screw body includes a screw thread section and a square limit protrusion at the end of the screw, a conventional nut, a positioning sleeve, and the bottom of the barrel-shaped positioning sleeve has a square limit hole, the size of the hole is the same as that of the end square positioning protrusion, and a six-sided clamp. The present invention uses the limit protrusion and the positioning sleeve to achieve never loosening. When the nut is tightened, the circular positioning sleeve is pressed into a hexagon to hold the nut tightly by the clamp to achieve never loosening". However, this design can only be disassembled destructively, which is not conducive to the recycling of screws. Currently, the better solutions for solving screw loosening on the market are the Hard Lock nut from Japan and the Nord-Lock anti-loosening washer invented in Sweden. Refer to the homepage of the Hard Lock company, www.hardlock-nut.cn, "It consists of two types of nuts, convex and concave. First, tighten the convex nut eccentrically processed according to the wedge principle, and then tighten the concave nut processed concentrically that plays the role of a locking nut. The entire threaded part of the convex nut presses on one side of the bolt, and the entire threaded part of the concave nut presses on the threaded part on the opposite side of the bolt. That is to say, by using the wedge technology, the bolt and the anti-loosening nut can form a state of being completely integrated like welding". However, this kind of nut has different eccentric amounts corresponding to different sizes and materials, and has strict requirements for materials, processes, etc. Refer to Baidu Encyclopedia, baike.baidu.com / item / nord-lock / 627089?fr=ge_ala, "The original Nord-Lock anti-loosening washer consists of a pair of tooth surface washers that bite each other, one side is a wedge-shaped tooth surface, and the other side is a radial fine tooth. When tightening the fastener, the wedge-shaped teeth are locked, and at the same time, the radial fine teeth on the outer surface of the washer will bite the fastener and the clamped part, and clear indentation marks will be formed on the fastener and the clamped part. Because the wedge surface angle α is greater than the thread lead angle β, the wedge locking effect prevents the rotation and loosening of the fastener". However, the Nord-Lock anti-loosening washer has a drawback, that is, it requires a relatively large pre-tightening force, which will produce indentation marks on the surface of the fixed part and damage the fixed part to a certain extent. Summary of the Invention

[0003] In order to overcome the technical problems in the prior art, such as screws being prone to loosening, inconvenient for disassembly and recycling, high requirements for materials and processes, large requirements for pre-tightening force, and indentations being generated on the surface of the fixed parts, the present utility model invents a screw assembly that never loosens. Based on the original screw kit including bolts, washers, spring washers, and nuts, improvements have been made. The inventor found that the advantage of a screw is that it can gradually tighten the mechanical parts of an object, but this is also the fundamental reason why it is prone to loosening when subjected to vibration. When subjected to vibration, the screw will gradually loosen bit by bit and accumulate slowly!

[0004] The technical solution adopted by the present utility model is: a screw assembly that never loosens, including a bolt, a washer, a spring washer, a biting member, and a nut. The bolt is provided with a slot; the biting member is provided with a protruding beam and a biting surface; one side of the nut is provided with a biting surface. Further, the slot on the bolt corresponds to the protruding beam on the biting member, and the two fit and can slide; the shapes of the cross-sections of the slot and the protruding beam include a rectangle, a triangle, a semi-circle, and a composite shape of a rectangle on the top and a triangle on the bottom. Further, one side of the biting member is smooth, and the other side is a biting surface, which corresponds to the biting surface of the biting nut, and the two fit. Further, the inner ring of the biting member is a smooth structure without threads, and its circular inner diameter corresponds to the threaded outer diameter of the bolt, and the two fit and can slide. Further, based on a conventional nut, one side of the nut is set as a biting surface, which corresponds to the biting surface of the biting member, and the two fit. Further, the biting surfaces of the biting member and the nut are designed as an annular structure that diverges in the radial direction and is centrosymmetric with alternating concave and convex; the number of concave and convex structures and the depth of the grooves are increased or decreased according to the manufacturing requirements of the screw. Further, another design scheme for the biting surfaces of the biting member and the nut is that the annular biting surface of the biting member is evenly distributed with grooves not larger than a semi-spherical shape, and the annular biting surface of the nut is evenly distributed with protrusions not larger than a semi-spherical shape, and the two correspond and fit with each other; if the biting surface on the biting member is designed as a convex structure, then the biting surface on the nut is designed as a groove structure; the number of concave and convex structures and the depth of the grooves are increased or decreased according to the manufacturing requirements of the screw. Further, the spring washer is a C-shaped spring washer or a multi-turn spring washer.

[0005] The present utility model designs a screw assembly with a special structure. From its technical features, the beneficial effects brought by the present utility model can be obtained: 1. The possibility of screw loosening is eliminated from the design principle; 2. It can be repeatedly disassembled and used; 3. It has low requirements for materials, manufacturing processes, etc.; 4. A large pre-tightening force is not required to achieve anti-loosening, thus preventing physical damage to the surface of the fixed parts by the screw. Brief Description of the Drawings

[0006] Figure 1 It is a three-dimensional perspective schematic diagram of Embodiment 1 of the present utility model;

[0007] Figure 2 It is a three - dimensional perspective schematic diagram of another perspective of the first embodiment of the present utility model;

[0008] Figure 3 It is a three - dimensional perspective schematic diagram of the second embodiment of the present utility model;

[0009] Figure 4 It is a three - dimensional perspective schematic diagram of another perspective of the second embodiment of the present utility model;

[0010] Figure 5 They are typical types of the cross - sectional shapes of the slot on the bolt and the protruding beam on the engaging member;

[0011] Figure 6 It is a three - dimensional perspective schematic diagram of the engaging surface structure of the first embodiment;

[0012] Figure 7 It is a three - dimensional perspective side schematic diagram of the engaging surface structure of the first embodiment;

[0013] In the figure: 1. Bolt, 2. Washer, 3. Spring washer, 4. Engaging member, 5. Nut, A. Slot, A1. Protruding beam, B. Engaging surface, B1. Engaging surface, C. Slot, C1. Protruding beam, D. Engaging surface, D1. Engaging surface, a. Rectangular cross - section, b. Triangular cross - section, c. Semi - circular cross - section, d. Composite cross - section with a rectangular upper part and a triangular lower part. Detailed implementation manners

[0014] To enable those skilled in the art to better understand the solution of the present utility model, the following will be clearly and completely described with reference to the accompanying drawings. The embodiments and examples described herein are only used to explain the present utility model and are not used to limit the present utility model. A screw assembly that never loosens includes a bolt 1, a washer 2, a spring washer 3, a biting member 4, and a nut 5. Among them, the bolt 1 is provided with a slot A; the biting member 4 is provided with a protruding beam A1 and a biting surface B; one side of the nut 5 is provided with a biting surface B1. Here, the washer 2 and the spring washer 3 are conventional washers. The function of the washer 2 is to protect the surface of the fixed part from damage. The spring washer 3 provides a compression amount when the protrusions meet during the rotation of the biting surface and applies an elastic force to tightly bite the biting member 4 and the nut 5. Further, the slot A on the bolt 1 corresponds to the protruding beam A1 on the biting member 4, and the two fit and can slide; the cross-sectional shapes of the slot A and the protruding beam A1 include a rectangle a, a triangle b, a semi-circle c, and a composite shape d with a rectangle on the top and a triangle on the bottom. In actual screw production, the above shapes are typical shapes, and the cross-sectional shape can be designed into other shapes other than the above four shapes a, b, c, and d according to manufacturing requirements and processes. Further, one side of the biting member 4 is smooth, and the other side is the biting surface B, which corresponds to the biting surface B1 of the biting nut 5, and the two fit. Here, the smooth side of the biting member 4 faces the spring washer 3. Further, the inner circle of the biting member 4 has a smooth structure without threads, and its circular inner diameter corresponds to the threaded outer diameter of the bolt 1, and the two fit and can slide. From the structural characteristics of the biting member 4, it can be seen that the biting member 4 can slide on the bolt 1 but cannot rotate. Further, on the basis of a conventional nut, one side of the nut 5 is set as the biting surface B1, which corresponds to the biting surface B of the biting member 4, and the two fit. Further, the biting surfaces B and B1 of the biting member 4 and the nut 5 are designed as an annular structure that diverges in the radial direction and is centrosymmetric with alternating concave and convex structures. The number of concave and convex structures and the depth of the grooves are increased or decreased according to the screw manufacturing requirements. To better understand this alternating concave and convex biting structure, this structure is specifically separated and referred to Figure 6 and Figure 7, the number of grooves and protrusions is set to 18 respectively. Here, the center point of the engaging surface is located at half of the depth of the entire engaging structure, so that the two relatively engaging surfaces can fit perfectly. Obviously, when manufacturing the screw assembly, this structure should be manufactured on the respective engaging surfaces of the engaging member 4 and the screw 5. When tightening the screw assembly, turn the nut 5. When the protrusion meets and fits with the groove, it can be called a tightening operation. The more the number of the concave-convex structure design, the less the rotation amount of the nut 5 in one tightening operation, and vice versa. The depth of the groove determines the anti-loosening effect. The deeper the groove, the better the anti-loosening effect, and vice versa. Further, another design scheme for the engaging surfaces D and D1 of the engaging member 4 and the nut 5 is that the groove in the shape of no more than a semi-spherical shape is evenly distributed on the annular engaging surface of the engaging member 4, and the protrusion in the shape of no more than a semi-spherical shape is evenly distributed on the annular engaging surface of the nut 5. The two correspond to each other and fit with each other; if the engaging surface on the engaging member 4 is designed as a protrusion, the engaging surface on the nut 5 is designed as a groove; the number of the concave-convex structure and the depth of the groove are increased or decreased according to the screw manufacturing requirements. This is another design of the engaging surface shape. The protrusion and the groove in the shape of no more than a semi-spherical shape fit with each other, and this structure can also play the role of engagement. Similarly, the more the number of the concave-convex structure, the less the rotation amount of the nut in one tightening operation, and vice versa. The smaller the designed semi-spherical shape is than the standard semi-spherical shape, the shallower the groove of the engaging structure is, and the smaller the anti-loosening force is. When it is equal to the semi-spherical shape, the anti-loosening effect is the best. For these two designs of the engaging surfaces, it can be achieved that when the nut 5 is turned, rotation misalignment can occur between the two engaging surfaces. After a certain rotation amount, they will fit again slowly. Further, the spring washer 3 is a C-shaped spring washer or a multi-turn spring washer. If the compressible amount of the C-shaped spring washer meets the required peak compressible amount when the two engaging surfaces meet, the C-shaped spring washer is adopted. The multi-turn spring washer can increase the compressible amount and increase the tightening force. The elastic strength of the spring washer determines the locking force of the screw assembly to a certain extent.

[0015] Example 1

[0016] See Figure 1 and Figure 2 . In this embodiment, the slotted A and the protruding beam A1 adopt a rectangular design. The engaging surfaces B and B1 of the engaging member 4 and the nut 5 adopt an annular structure with alternating concave and convex parts that diverge in the radial direction and are centrosymmetric. The number of grooves and protrusions is 18 each. The spring washer adopts a C-shaped spring washer.

[0017] Example 2

[0018] See Figure 3 and Figure 4In this embodiment, the slotted C and the protruding beam C1 adopt a triangular design. There are 12 semi-spherical grooves evenly distributed on the annular engaging surface D of the engaging member 4, and 12 semi-spherical protrusions evenly distributed on the annular engaging surface D1 of the nut 5. The two correspond to each other and fit together. The spring washer 3 adopts a two-turn spring washer.

[0019] The working principle of this screw assembly is as follows: Refer to Figure 1 and Figure 2 . The workpiece to be fixed is located between the hexagonal bolt head of the bolt 1 and the washer 2. The spring washer 3, the engaging member 4, and the nut 5 are assembled according to the schematic diagram. During the tightening operation, when the nut 5 is screwed in, since the engaging member 4 is slidably connected to the bolt 1, under the screwing force applied by the nut 5, the engaging member 4 slides and squeezes to drive the spring washer 3 and the washer 2 closer to the workpiece to be fixed. Further, the spring washer 3 is compressed, and the engaging surfaces corresponding to the engaging member 4 and the screw 5 rotate and displace. The screwing force required for the nut 5 gradually increases. When the protrusions on the two engaging surfaces meet, the required screwing force is the largest, and at this time, the compression amount of the spring washer is also the largest. When the protrusion meets and fits with the groove, the screwing force is the smallest, and at this time, the spring washer rebounds to complete a tightening operation; then the nut 5 is further screwed in to start the next tightening operation until the required pre-tightening force is reached, and the tightening operation ends. Since the engaging member 4 can only slide on the bolt 1 and cannot rotate, under the extrusion of the pre-tightening force, and due to the interaction between the engaging surfaces, the engaging member 4 and the nut 5 are tightly engaged together. If the nut 5 is to rotate, it will inevitably drive the engaging member 4 to rotate. However, due to the action of the groove A and the protruding beam A1, the engaging member 4 will never rotate, so that the nut 5 achieves the purpose of never loosening. The loosening force brought by vibration to the screw is much smaller than the peak rotational force required when the protrusions on the engaging surfaces meet, so the loosening of the screw is eliminated in principle. It should be noted that after the tightening operation of the screw assembly is completed, the spring washer 3 has a certain amount of expansion and contraction, so as to provide the spring compression amount required when the protrusions on the engaging surfaces meet, so that the nut 5 can be rotated. When performing the disassembly operation, rotate the nut 5. At this time, a relatively large force needs to be applied to overcome the force brought by the misaligned rotation of the concave-convex structure between the engaging surface B and the engaging surface B1. Especially when the protrusions meet, the required force reaches the peak, and at this time, the compression amount of the spring washer is the largest. When the groove and the protrusion of the engaging surfaces B and B1 fit, the spring washer rebounds, so as to complete a loosening operation; rotate the nut 5 again to perform the next loosening operation until the nut is unscrewed.

[0020] Here, through specific embodiments and two examples are given, the unique structure of the present invention is clearly and completely described, and its mechanical principle of never loosening is clearly pointed out. All equivalent replacements or modifications made through this technical solution and concept are included in the protection scope of the present invention.

Claims

1. A screw assembly that never loosens, comprising a bolt (1), a washer (2), a spring washer (3), a biting member (4), and a nut (5), characterized in that: The bolt (1) is provided with a slot (A); the engaging member (4) is provided with a protruding beam (A1) and an engaging surface B; one side of the nut (5) is provided with an engaging surface B1.

2. The screw assembly that never loosens according to claim 1, wherein The slot (A) on the bolt (1) corresponds to the protruding beam (A1) on the engaging member (4), and the two fit and can slide; the shapes of the cross-sections of the slot (A) and the protruding beam (A1) include a rectangle (a), a triangle (b), a semi-circle (c), and a composite shape (d) with a rectangle on the top and a triangle on the bottom.

3. The screw assembly that never loosens according to claim 1, wherein One side of the engaging member (4) is smooth, and the other side is the engaging surface B, which corresponds to the engaging surface B1 of the nut (5), and the two fit.

4. The screw assembly that never loosens according to claim 1 or 3, characterized in that, The inner ring of the engaging member (4) is a smooth structure without threads, and its circular inner diameter corresponds to the threaded outer diameter of the bolt (1), and the two fit and can slide.

5. The screw assembly that never loosens according to claim 1, characterized in that, Based on a conventional nut, one side of the nut (5) is designed as the engaging surface B1, which corresponds to the engaging surface B of the engaging member (4), and the two fit.

6. The screw assembly that never loosens according to claim 1, characterized in that, The engaging surfaces B and B1 of the engaging member (4) and the nut (5) are designed as an annular structure with alternating concave and convex patterns that diverge in the radial direction and are centrosymmetric; the number of concave and convex structures and the depth of the grooves are increased or decreased according to the manufacturing requirements of the screw.

7. The screw assembly that never loosens according to claim 1, characterized in that, Another design for the engaging surfaces D and D1 of the engaging member (4) and the nut (5) is that the annular engaging surface of the engaging member (4) is evenly distributed with grooves not larger than a semi-spherical shape, and the annular engaging surface of the nut (5) is evenly distributed with protrusions not larger than a semi-spherical shape, and the two correspond and fit with each other; if the engaging surface on the engaging member (4) is designed as a protruding structure, then the engaging surface on the nut (5) is designed as a groove structure; the number of concave and convex structures and the depth of the grooves are increased or decreased according to the manufacturing requirements of the screw.

8. The screw assembly that never loosens according to claim 1, characterized in that, The spring washer (3) is a C-shaped spring washer or a multi-turn spring washer.

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