An expansion rivet nut

Abstract

The utility model discloses an expansion rivet nut, including nut body and hexagon bolt, the nut body includes the nut board of setting at the top, the bottom fixed connection ring of nut board, the bottom staggered distribution of connection ring has four groups first expansion arm and connecting column, one side middle part fixed with second expansion arm of connecting column, the bottom fixed base of connecting column, the top center position fixed screw rod of base, through " once expansion pre -fixed " design, can establish the preliminary occlusion of nut body and board before rotating hexagon bolt, thoroughly avoided the synchronous rotation problem of traditional expansion nut because of the lack of pre -tightening force, need not additional tool fixed nut body, has simplified the installation process, reduced the operation difficulty, has improved assembly efficiency significantly.

Description

Technical Field

[0001] This utility model relates to the field of riveting nut technology, specifically an expansion riveting nut. Background Technology

[0002] In the field of mechanical manufacturing and structural connection, expansion rivet nuts are widely used as efficient fastening components in threaded connections of sheet metal, profiles, and other base materials. They work by axially moving internal components, driving radial plastic deformation of the external expansion part, thereby tightly engaging with a pre-set through hole in the base material to form a secure internal thread connection point.

[0003] However, a common problem affecting operational efficiency and reliability exists in the installation process of some existing expansion-type riveting nuts: when the mounting bolt is initially screwed into the nut body, and its tapered front end just begins to insert into the expansion section of the expansion nut, the preload between the expansion nut and the wall of the through hole in the base body has not yet been established. In this critical state, the rotational torque applied to the mounting bolt is easily transmitted directly to the nut body through the threaded joint, causing the entire nut body to rotate synchronously within the through hole in the base body, i.e., "slippage." To address this, we propose an expansion-type riveting nut. Utility Model Content

[0004] To achieve the above objectives, this utility model provides the following technical solution: an expansion-type riveting nut, comprising: a nut body and a hexagonal bolt, wherein the nut body includes a nut plate disposed at the top end, a connecting ring is fixed at the bottom end of the nut plate, four sets of first expansion arms and connecting posts are staggered at the bottom end of the connecting ring, a second expansion arm is fixed at the middle of one side of the connecting post, a base is fixed at the bottom of the connecting post, and a screw is fixed at the center of the top end of the base; the hexagonal bolt includes a rotating plate disposed at the top end, a pressing rod is fixed at the center of the bottom end of the rotating plate, and the pressing rod has an internal thread.

[0005] As a preferred embodiment of this utility model, the nut body is cylindrical with an insertion hole inside, and the compression rod fits into the insertion hole.

[0006] In a preferred embodiment of this invention, the internal thread is threadedly connected to the screw.

[0007] As a preferred embodiment of the present invention, the bottom end of the extrusion rod is wedge-shaped, the inner sides of the first expansion arm and the second expansion arm are inclined inward, and the wedge-shaped structure abuts against the first expansion arm and the second expansion arm.

[0008] As a preferred embodiment of this utility model, the first expansion arm is located axially above the screw, and the second expansion arm is located axially to the side of the screw.

[0009] As a preferred embodiment of this utility model, the bottom ends of the first expansion arm and the second expansion arm are configured to be thinner on the outer side and thicker on the inner side.

[0010] As a preferred embodiment of this utility model, the first expansion arm and the second expansion arm are elastic structures.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (i) Solving the slippage problem and improving installation efficiency: Through the "one-time expansion pre-fixing" design, the nut body and the plate can be initially engaged before rotating the hexagonal bolt, which completely avoids the problem of synchronous rotation caused by insufficient pre-tightening force of traditional expansion nuts. No additional tools are needed to fix the nut body, simplifying the installation process, reducing the difficulty of operation, and significantly improving assembly efficiency.

[0013] (II) Double-layer expansion structure with stronger fastening: The first expansion arm and the second expansion arm are designed with axial layering and circumferential staggering. The double-layer expansion structure forms independent mechanical engagement with the hole wall of the plate. Compared with the traditional single-layer expansion structure, the contact area of ​​the connection point is larger and the engagement force is more uniform, which effectively improves the pull-out resistance and torque resistance of the connection and avoids loosening during long-term use. Attached Figure Description

[0014] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a three-dimensional structural diagram of the nut body of this utility model;

[0017] Figure 3 This is a three-dimensional structural diagram of the hexagonal bolt of this utility model;

[0018] Figure 4 This is a schematic front sectional view of the present invention;

[0019] Figure 5 This is a top cross-sectional view of the nut body of this utility model.

[0020] In the diagram: 1. Nut body; 11. Nut plate; 12. Connecting ring; 13. First expansion arm; 14. Connecting column; 15. Second expansion arm; 16. Insertion hole; 17. Base; 18. Screw; 2. Hex bolt; 21. Rotating plate; 22. Extrusion rod; 23. Internal thread. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example

[0023] Please see Figure 1-5 The present invention provides the following technical solution: an expansion-type riveting nut, comprising: a nut body 1 and a hexagonal bolt 2. The nut body 1 includes a nut plate 11 disposed at the top end, a connecting ring 12 fixed at the bottom end of the nut plate 11, four sets of first expansion arms 13 and connecting posts 14 staggered at the bottom end of the connecting ring 12, a second expansion arm 15 fixed at the middle of one side of the connecting post 14, a base 17 fixed at the bottom of the connecting post 14, and a screw 18 fixed at the center of the top end of the base 17; the hexagonal bolt 2 includes a rotating plate 21 disposed at the top end, a pressing rod 22 fixed at the center of the bottom end of the rotating plate 21, and an internal thread 23 provided inside the pressing rod 22.

[0024] In order to ensure the coaxiality of the hexagonal bolt 2 and the nut body 1 during assembly, avoid uneven force on the expansion arm due to assembly misalignment, and provide stable axial guidance for the extrusion rod 22 to ensure accurate and controllable subsequent expansion action, in this embodiment, as a preferred technical solution of the present invention, the nut body 1 is cylindrical and has an insertion hole 16 inside, and the extrusion rod 22 fits into the insertion hole 16.

[0025] In order to achieve axial feeding of the extrusion rod 22 through threaded transmission, so that the extrusion rod 22 can continuously apply extrusion force to the expansion arm, provide a power transmission path for secondary expansion and strengthening fixation, and at the same time establish axial preload of the threaded pair to improve the overall connection stability, in this embodiment, as a preferred technical solution of the present invention, the internal thread 23 is threadedly connected to the screw 18.

[0026] In order to convert the axial pressure of the extrusion rod 22 into radial extrusion force, the wedge structure and the inner inclined surface of the expansion arm are adapted to achieve precise extrusion drive of the first expansion arm 13 and the second expansion arm 15, ensuring that the expansion arm can generate radial deformation in a preset direction. In this embodiment, as a preferred technical solution of the present invention, the bottom end of the extrusion rod 22 is wedge-shaped, the inner sides of the first expansion arm 13 and the second expansion arm 15 are inclined inward, and the wedge structure abuts against the first expansion arm 13 and the second expansion arm 15.

[0027] In order to make the first expansion arm 13 and the second expansion arm 15 form a layered distribution in the axial direction, realize the double-layer fixing logic of "pre-fixing + secondary reinforcement", and at the same time, the circumferential staggered layout can allow the expansion biting force to cover more directions, avoid connection blind spots, and improve the anti-torque capability, in this embodiment, as a preferred technical solution of the present invention, the first expansion arm 13 is located above the screw 18 in the axial direction, and the second expansion arm 15 is located to the side of the screw 18 in the axial direction.

[0028] In order to optimize the mechanical properties of the expansion arms and enable them to easily engage with the inner wall of the plate when subjected to radial extrusion force, in this embodiment, as a preferred technical solution of the present invention, the bottom ends of the first expansion arm 13 and the second expansion arm 15 are set to be thinner on the outer side and thicker on the inner side.

[0029] In order to ensure that the expansion arm can form an effective mechanical engagement with the inner wall of the hole in the plate after expansion, the design extends beyond the outer contour of the connecting post 14, so that the expansion arm can be embedded in the tiny gap of the hole wall in the plate or generate slight extrusion deformation, establish a stable connection engagement point, and prevent the nut body 1 from being displaced relative to the plate. In this embodiment, as a preferred technical solution of the present invention, the first expansion arm 13 and the second expansion arm 15 are elastic structures.

[0030] In summary, with the help of the above-described technical solution of this utility model,

[0031] Working principle: First, the bottom of the cylindrical nut body 1 is embedded into the pre-drilled hole in the plate, so that the bottom end of the nut plate 11 at the top of the nut body 1 fits tightly against the top surface of the plate, completing the initial axial positioning of the nut body 1 and ensuring that the subsequent expansion structure can accurately act on the hole wall of the plate. The pressing rod 22 of the hexagonal bolt 2 is inserted axially along the insertion hole 16 of the nut body 1. The coaxiality of the insertion process is ensured by utilizing the compatibility between the outer diameter of the pressing rod 22 and the inner diameter of the insertion hole 16. By applying axial force to press the rotating plate 21 of the hexagonal bolt 2, the wedge-shaped structure at the bottom end of the pressing rod 22 gradually penetrates and forms contact with the inner inclined surfaces of the four sets of first expansion arms 13 staggered at the bottom end of the connecting ring 12 of the nut body 1. As the pressing force increases, the radial component of the wedge structure pushes the first expansion arm 13 outward, and the bottom end of the first expansion arm 13 moves outward so that its outer contour exceeds the outer contour of the connecting column 14, tightly embedding into the inner wall of the plate hole, forming a preliminary mechanical engagement, realizing the pre-fixation of the nut body 1 and the plate, effectively avoiding the "slippage" problem of the nut body 1 rotating synchronously when rotating the hexagonal bolt 2 later.

[0032] After pre-fixing, the rotating plate 21 of the hexagonal bolt 2 is rotated by a tool, causing the internal thread 23 of the pressing rod 22 to engage with the screw 18 at the top center of the nut body 1 base 17. As the thread drives the rotation, the pressing rod 22 continuously feeds downwards axially, and its wedge-shaped structure at the bottom penetrates further, contacting the inner inclined surface of the second expansion arm 15 in the middle of one side of the connecting column 14 and applying radial compressive force. Since the second expansion arm 15 is located axially to the side of the screw 18, it expands and deforms outwards under the action of the wedge-shaped structure, and its outer contour at the bottom also exceeds the outer contour of the connecting column 14, forming a secondary mechanical engagement with the inner wall of the plate hole. The first expansion arm 13 and the second expansion arm 15 are distributed vertically and staggered circumferentially in the axial direction. The double-layer expansion structure together forms a multi-point, multi-directional engagement and fixation with the plate hole wall. Simultaneously, the axial preload of the threaded pair further enhances the connection stability, ultimately achieving a firm connection between the nut body 1 and the plate, providing a reliable threaded connection point for the subsequent assembly of external components.

[0033] Finally, it should be noted that, in this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An expansion-type riveting nut, characterized in that, include: The nut body (1) and the hexagonal bolt (2) are provided. The nut body (1) includes a nut plate (11) at the top end. A connecting ring (12) is fixed at the bottom end of the nut plate (11). Four sets of first expansion arms (13) and connecting columns (14) are staggered at the bottom end of the connecting ring (12). A second expansion arm (15) is fixed at the middle of one side of the connecting column (14). A base (17) is fixed at the bottom of the connecting column (14). A screw (18) is fixed at the center of the top end of the base (17). The hexagonal bolt (2) includes a rotating plate (21) at the top end. A pressing rod (22) is fixed at the center of the bottom end of the rotating plate (21). An internal thread (23) is provided inside the pressing rod (22).

2. The expansion-type riveting nut according to claim 1, characterized in that: The nut body (1) is cylindrical and has an insertion hole (16) inside. The compression rod (22) fits into the insertion hole (16).

3. The expansion-type riveting nut according to claim 1, characterized in that: The internal thread (23) is threadedly connected to the screw (18).

4. The expansion-type riveting nut according to claim 1, characterized in that: The bottom end of the extrusion rod (22) has a wedge-shaped structure. The inner sides of the first expansion arm (13) and the second expansion arm (15) are inclined inward, and the wedge-shaped structure abuts against the first expansion arm (13) and the second expansion arm (15).

5. The expansion-type riveting nut according to claim 1, characterized in that: The first expansion arm (13) is located axially above the screw (18), and the second expansion arm (15) is located axially to the side of the screw (18).

6. The expansion-type riveting nut according to claim 1, characterized in that: The bottom ends of the first expansion arm (13) and the second expansion arm (15) are arranged with the outer side being thin and the inner side being thick.

7. The expansion-type riveting nut according to claim 1, characterized in that: The first expansion arm (13) and the second expansion arm (15) are elastic structures.

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