Expansion nut structure for furniture and expansion screw

Abstract

The utility model relates to the field of furniture connecting structures, in particular to an expansion nut structure and an expansion screw for furniture, which comprise a fixed end, the fixed end is in threaded connection with an expansion bolt, an expansion end is arranged on one side, away from the expansion bolt, of the fixed end, a top piece is arranged in the expansion end, and an abutting end is arranged on one side, close to the expansion bolt, of the fixed end. The diameter of the abutting end is larger than that of the fixed end, and the expansion bolt abuts against the top piece in the process that the expansion bolt is screwed into the fixed end, and the abutting end is embedded between the two abutting faces. According to the design of the abutting end, the flexibility of wood materials and the expansion or contraction characteristic under the environment change are considered, the surface damage or structural deformation of the wood is avoided by reasonably adjusting the size and shape of the nut structure, meanwhile, the abutting end adapts to the size change of the wood under different environment conditions, and the service life of the wood is prolonged. And therefore, the binding surface of the wooden furniture can be protected in the use process.

Description

Technical Field

[0001] The present application relates to the field of furniture connection structures, and specifically to an expansion nut structure and an expansion screw for furniture. Background Art

[0002] In the prior art, bolt structures used in furniture generally consist of a bolt and a nut. A hole is drilled in the component to be mounted, the screw head is placed on the outside of a thin-walled panel, a stud is inserted into the hole, and the nut is tightened onto the stud to secure the bolt structure. The stud end is then threaded to connect to decorative components such as a hook for decorative or practical purposes.

[0003] In addition, during the use of the connecting structural components of furniture, there is a nut structure that is embedded in the two connecting surfaces of the wood. Specifically, the Chinese patent application number CN221170279U discloses an expansion nut structure and an expansion screw, and specifically discloses a nut structure that can protect the bolt threads during use. In addition to the problems of unidirectional rotation and loosening described therein, there are some other problems when the nut structure is embedded in the two connecting surfaces of wooden furniture. First, wooden materials are usually soft and susceptible to physical damage. When the nut structure is embedded in the wooden material, if the outer diameter of the nut is too large or the embedding force is too strong, it may cause damage to the wood surface or deformation of the wood structure, affecting the appearance and stability of the furniture.

[0004] Secondly, wood materials expand or contract under varying environmental conditions, such as changes in humidity. This can cause the gap between the nut structure and the wood embedded in the wooden joint surface to change, thereby affecting the tightness of the connection and the stability of the overall structure. Finally, conditions such as frequent use, the placement of heavy objects, and vibration and impact on wooden furniture can create continuous squeezing pressure on the nut structure, placing higher demands on the nut's ability to maintain a continuous connection.

[0005] Therefore, there is an urgent need for an expansion nut connection structure that can protect the joint surface of wooden furniture during use. Summary of the Invention

[0006] The present application aims to provide an expansion nut structure for furniture, which is used to protect the bonding surface of wooden furniture during use; and also to provide an expansion screw for furniture, which is used to improve the ability of the expansion screw to resist dynamic pressure.

[0007] This application is implemented through the following technical solutions:

[0008] Disclosed is an expansion nut structure for furniture, comprising a fixed end, which is threadedly connected to an expansion bolt; an expansion end is provided on the side of the fixed end away from the expansion bolt; a top plate is provided inside the expansion end; an abutment end is provided on the side of the fixed end close to the expansion bolt; the diameter of the abutment end is larger than the diameter of the fixed end; when the expansion bolt is screwed into the fixed end, it abuts against the top plate and the abutment end is embedded between the two abutment surfaces.

[0009] Furthermore, after the expansion nut is embedded in the mounting hole, the movement of the expansion bolt and the top plate can achieve bidirectional interlocking of the embedding portion and the abutting end in the mounting hole.

[0010] Furthermore, the expansion end includes a plurality of hooks, which are distributed in a circular array based on the central axis of the expansion end. The expansion nut is fixed to the expansion bolt by embedding the hooks in the furniture corresponding to the abutment surface.

[0011] Furthermore, the hook includes a flip portion and a fitting portion, the flip portion and the fixed end are integrally formed, the fitting portion and the flip portion are fixedly connected, and the fitting portion is connected and fixed to the abutting surface by movement of the expansion bolt and the top plate.

[0012] Furthermore, the included angle between the flip portion and the engaging portion is less than 90 degrees, and after the expansion nut is embedded in the mounting hole, the dynamic pressure is resisted through the included angle.

[0013] Preferably, the included angle between the flip portion and the engaging portion is in a range of 65 degrees to 80 degrees.

[0014] Furthermore, the expansion nut structure also includes a fixing portion arranged on the outer peripheral surface of the flip portion.

[0015] Furthermore, the fixing portion is a plurality of parallel strip-shaped protrusions.

[0016] Preferably, the fixing portion is a plurality of parallel strip-shaped protrusions arranged at intervals.

[0017] Preferably, the fixing portion is a plurality of obliquely arranged strip-shaped protrusions.

[0018] Furthermore, a surface of the abutting end away from the expansion end is a concave surface or a convex surface, and during the embedding process of the expansion nut in the furniture, the concave surface or the convex surface is reversely engaged with the abutting surface.

[0019] An expansion screw for furniture includes an expansion nut structure embedded in a furniture mounting hole. During installation, an abutting end engages with two abutting surfaces. The expansion screw also includes an expansion bolt. During screwing of the expansion bolt, the expansion end is fixed in the mounting hole through a top plate.

[0020] Compared with the prior art, this application has the following advantages and beneficial effects:

[0021] 1. The present invention provides an abutment end with a diameter larger than that of the fixed end on one side of the expansion bolt. The design of the abutment end allows the expansion bolt to lock the nut structure and embed the abutment end between the two abutment surfaces when the expansion bolt is screwed in, thereby enhancing the bite force between the nut and the contact surface of the furniture and improving the stability of the connection. The abutment end design also takes into account the softness of the wood material and its expansion or contraction characteristics under environmental changes. By reasonably adjusting the size and shape of the nut structure, damage to the wood surface or structural deformation is avoided. At the same time, it also adapts to the dimensional changes of the wood under different environmental conditions, thereby protecting the contact surface of the wooden furniture during use.

[0022] 2. This application utilizes the pushing force of the top plate to achieve a tight fit between the engaging portion and the abutting surface of the furniture. This design cleverly utilizes the force generated when the expansion bolt is screwed in. The top plate pushes the engaging portion of the hook outward, allowing the hook to be firmly embedded in the abutting surface of the furniture. Due to the synergistic effect of the flip portion and the engaging portion, the expansion nut can not only resist static loads, but also withstand dynamic pressures that may be encountered by furniture during use, such as the placement of heavy objects or vibration shocks.

[0023] 3. The angle of this application can also be regarded as a "barb". When the furniture is subjected to continuous pressure, the bolt tends to move outward due to the reaction force. In this process, it may drive the expansion nut to move toward the mounting hole. The "barb" structure can fix the nut structure to the mounting hole, thereby effectively reducing the probability of loosening. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation of the embodiments of the present application. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the expansion nut for this application;

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of the expansion nut of this application;

[0027] Figure 3 This is a schematic diagram of the structure of the expansion screw for this application;

[0028] Figure 4 This is a schematic diagram of the structure of Example 3 of the present application;

[0029] Figure 5 This is a schematic diagram of the structure of Example 4 of the present application;

[0030] Figure 6 This is a structural diagram of Example 5 of the present application;

[0031] Figure 7This is a structural diagram of the expansion nut embedded in the mounting hole of this application;

[0032] Figure 8 This is a schematic diagram of the structure of the expansion nut interlocking in the mounting hole of Example 2 of the present application;

[0033] Figure 9 This is a schematic diagram of the "barb" structure of the expansion nut of Example 3 of the present application;

[0034] Figure 10 This is a structural schematic diagram of the expansion nut of Example 10 of the present application.

[0035] Markings and corresponding parts names in the accompanying drawings:

[0036] 1-fixed end, 2-expansion end, 3-expansion bolt, 4-top plate, 5-butt end, 6-fixed part;

[0037] 21-hook;

[0038] 211- flipping portion, 212- fitting portion. DETAILED DESCRIPTION

[0039] To make the purpose, technical solutions, and advantages of this application more clearly understood, the present application is further described in detail below in conjunction with the examples and accompanying drawings. The illustrative embodiments of this application and their descriptions are only used to explain this application and are not intended to limit this application. It should be noted that this application is already in the actual development and use stage.

[0040] In order to make the technical solution of this application clearer, the professional terms involved in this application are explained here;

[0041] In this application, the term "abutment surface" refers to the surface between two structures that are connected and fastened by expansion screws;

[0042] In this application, the term "mounting hole" refers to a hole-like structure preset on a structure to be connected and fastened, such as a stepped hole pre-opened on the fastening surface of furniture.

[0043] Example 1:

[0044] Please refer to the attached Figures 1 to 3 A furniture expansion nut structure includes a fixed end 1, which is threadedly connected to an expansion bolt 3. An expansion end 2 is provided on the side of the fixed end 1 away from the expansion bolt 3, and a top plate 4 is provided inside the expansion end 2. An abutment end 5 is provided on the side of the fixed end 1 close to the expansion bolt 3. The diameter of the abutment end 5 is larger than the diameter of the fixed end 1. When the expansion bolt 3 is screwed into the fixed end 1, it abuts against the top plate 4 and the abutment end 5 is embedded between the two abutment surfaces.

[0045] In the process of using the connecting structural components of furniture, there is also a nut structure embedded in the two connecting surfaces of wood. Specifically, the Chinese patent application number CN221170279U discloses an expansion nut structure and an expansion screw, which specifically discloses a nut structure that can protect the bolt thread during use. In addition to the problems of unidirectional rotation and loosening described therein, when the nut structure is embedded in the two connecting surfaces of wooden furniture, some other problems will be encountered. First, wooden materials are usually soft and easily damaged by physical damage, such as the attached Figure 7 As shown in the figure, the wood material corresponding to the nut structure is not shown, and the extrusion hole that appears in the wood material on the corresponding side of the expansion bolt 3 is caused by the pressure of the fixed end during engagement; when the nut structure is engaged with the wood material, if the outer diameter of the nut is too large or the engagement force is too strong, it may cause damage to the wood surface or deformation of the wood structure, affecting the appearance and stability of the furniture.

[0046] Based on the above problems, the applicant proposed an expansion nut structure for furniture. First, the structure includes a fixed end 1, which is threadedly connected to the expansion bolt 3 to ensure a tight fit between the nut and the bolt. An expansion end 2 is designed on the side of the fixed end 1 away from the expansion bolt 3. In particular, a top plate 4 is provided in the expansion end 2. The design of the top plate 4 allows the expansion bolt 3 to expand the expansion end 2 through the movement of the top plate 4 during the screwing process, so that the expansion end 2 can be tightly embedded in the material to achieve firm anchoring.

[0047] In addition, an abutment end 5 with a diameter larger than that of the fixed end 1 is provided on the side of the fixed end 1 close to the expansion bolt 3. The design of the abutment end 5 enables the expansion bolt 3 to lock the nut structure and embed the abutment end 5 between the two abutment surfaces when the expansion bolt 3 is screwed in, thereby enhancing the bite force between the nut and the contact surface of the furniture and improving the stability of the connection; the design of the abutment end 5 also takes into account the softness of the wood material and the expansion or contraction characteristics under environmental changes. By reasonably adjusting the size and shape of the nut structure, damage to the wood surface or structural deformation is avoided, and it also adapts to the size changes of the wood under different environmental conditions.

[0048] The applicant's design also pays special attention to the continuous squeezing force on the nut structure when the furniture is frequently used or when heavy objects are placed. By setting the angle between the flip portion 211 and the interlocking portion 212 to be less than 90 degrees, especially the preferred range of 65 to 80 degrees, the expansion nut can resist dynamic pressure through this angle after being embedded, providing better impact resistance. At the same time, the design of the hook 21, including the flip portion 211 and the interlocking portion 212, enables the expansion nut to be more firmly embedded in the furniture, further improving the reliability of the connection. Finally, the applicant also provides designs for different fixing parts 6, such as parallel strip protrusions, parallel and staggered strip protrusions, and inclined strip protrusions. These designs increase the friction between the expansion nut and the contact surface of the furniture, further ensuring the fixing effect of the nut.

[0049] It should also be noted that in the existing field of connection structures, the bolt and nut connection structure is relatively mature and fixed, and it is difficult to produce major pioneering improvements. Therefore, technical personnel generally have problems with the maturity of bolt connections. Under the premise of this problem, technical personnel find it difficult to consider other possibilities, which hinders the further improvement and development of the bolt connection structure. Specifically, after the bolt and nut are engaged and locked, when wooden furniture is subjected to a certain dynamic extrusion force, the nut will generate a large pressure on the contact surface of the wooden furniture, thereby damaging the contact surface. When the contact surface is damaged, the range of movement of the nut increases, further causing the gap between the two contact surfaces to increase. On this basis, the applicant increases the contact surface between the nut and the wooden furniture through the structure of the abutment end 5, thereby playing a role in dispersing pressure. When subjected to dynamic pressure, the pressure can also be shared through structures such as the buckle and the fixing portion 6. The above effect overcomes the above technical prejudice to a certain extent and solves the problem of low dynamic stability of the connection bolt, with outstanding substantive features and significant progress.

[0050] It should be noted that the expansion end 2 includes a plurality of hooks 21, which are distributed in a circular array based on the central axis of the expansion end 2. The expansion nut is fixed to the expansion bolt 3 by embedding the hooks 21 in the furniture corresponding to the abutment surface.

[0051] It should also be noted that the hooks 21 are arranged in a circular array around the central axis of the expansion end 2. This design ensures that when the expansion nut is inserted into the furniture, the hooks 21 are evenly distributed on the abutment surface, providing consistent engagement force in all directions. This layout not only helps to improve the connection stability between the nut and the furniture, but also, due to the uniform distribution of the hooks 21, it can reduce localized pressure on the furniture material, avoiding surface damage or structural deformation caused by concentrated pressure.

[0052] In addition, the design of the hook 21 allows the expansion nut to work in conjunction with the expansion bolt 3 during the installation process. By screwing the expansion bolt 3, the top plate 4 is pushed, so that the hook 21 can be tightly engaged with the abutting surface of the furniture. This engagement not only improves the fixing strength of the nut, but also enhances its ability to resist dynamic pressure, especially when the furniture is subjected to heavy objects or is frequently used, and can maintain the stability and reliability of the connection.

[0053] It should be noted that the hook 21 includes a flipping portion 211 and a fitting portion 212. The flipping portion 211 is integrally formed with the fixed end 1. The fitting portion 212 is fixedly connected to the flipping portion 211. The fitting portion 212 is connected and fixed to the abutting surface by moving the expansion bolt 3 and the top plate 4.

[0054] It should also be noted that the flip portion 211 is integrally formed with the fixed end 1, ensuring the integrity and stability of the structure. The interlocking portion 212 is fixedly connected to the flip portion 211 to form the overall structure of the hook 21. This design allows the hook 21 to tightly interlock with the furniture's abutting surface through the pushing force of the top plate 4 when the expansion bolt 3 is screwed in. This design cleverly utilizes the force generated when the expansion bolt 3 is screwed in, pushing the interlocking portion 212 of the hook 21 outward through the top plate 4, allowing the hook 21 to be firmly embedded in the furniture's abutting surface. Due to the synergistic effect of the flip portion 211 and the interlocking portion 212, the expansion nut can not only resist static loads, but also withstand dynamic pressures that the furniture may encounter during use, such as the placement of heavy objects or vibration shocks.

[0055] It should also be noted that the Figure 7 The expansion nut structure in the figure is a closed structure, that is, the structure when it is produced. In the closed state, the diameter of the expansion end 2 is smaller than the diameter of the fixed end 1, so as to facilitate the rapid installation of the expansion nut structure in the mounting hole.

[0056] Example 2:

[0057] This embodiment only describes the parts that are different from the embodiment 1. Specifically, as shown in the attached Figures 6 and 7After the expansion nut is inserted into the mounting hole, the movement of the expansion bolt 3 and the top plate 4 enables bidirectional interlocking between the engaging portion 212 and the abutting end 5 within the mounting hole. In light of the aforementioned issues, the applicant has also discovered during use that conventional expansion nut structures are prone to loosening when subjected to dynamic pressure within the mounting holes of wooden furniture, such as wooden recliners and beds. This loosening problem is partly due to material limitations of wooden furniture, but another important reason is the reduced engagement ability of conventional expansion nut structures within the mounting holes. In this regard, the abutment end 5 proposed by the applicant can not only protect the abutment surface, but also achieve "interlocking" in the mounting hole. Specifically, it can be understood that the expansion screw will pre-make a mounting hole between the two abutment surfaces when in use. In this regard, the expansion nut in this embodiment is pre-set with a mounting hole with a step when in use, that is, a step hole. The step hole matches the size and depth of the abutment end 5, and the expansion nut structure is knocked into the mounting hole. At this time, the abutment end 5 and the step hole are completely filled, which largely avoids the damage of the expansion nut to the step hole in the axial direction; further, when the expansion bolt 3 is screwed into the expansion nut, the opening and closing of the expansion end 2 is achieved through the top plate 4, and the hook 21 is engaged in the wooden furniture material corresponding to the mounting hole. In the process of flipping the flip part 211 of the hook 21, the axial distance between the hook 21 and the abutment end 5 becomes shorter, thereby achieving two-way interlocking in the mounting hole, further enhancing the ability of the expansion nut to resist dynamic pressure, and also increasing the fastening ability of the expansion nut to the furniture corresponding to the mounting hole.

[0058] Example 3:

[0059] This embodiment only describes the parts that are different from the embodiment 1, as shown in the attached Figure 9 As shown, a is the angle between the flip portion 211 and the interlocking portion 212. Specifically, the angle between the flip portion 211 and the interlocking portion 212 is less than 90 degrees. After the expansion nut is inserted into the mounting hole, it resists dynamic pressure through this angle. The angle between the flip portion 211 and the interlocking portion 212 ranges from 65 degrees to 80 degrees. By designing the angle between the flip portion 211 and the interlocking portion 212, the problem of "rebound" generated by the nut structure after being subjected to dynamic extrusion force is solved. The angle is less than 90 degrees, and specifically controlled within the range of 65 degrees to 80 degrees. This angle is crucial for improving the nut's stability and ability to resist dynamic pressure. First, the angle design of less than 90 degrees allows the hook 21 to achieve greater pressure with a smaller contact area when it is embedded in the abutting surface of the furniture, thereby increasing the friction and bite strength between the nut and the furniture. This structure allows the nut to more effectively resist these dynamic pressures when subjected to external forces, such as furniture vibration or pressure exerted by heavy objects, reducing the nut's loosening or falling off.

[0060] Secondly, the angle is set within a specific range (65 to 80 degrees) in order to balance the embedding force and resistance of the nut. If the angle is too large, the hook 21 may require greater force when embedded, which may cause damage to the furniture material; and if the angle is too small, it may not provide sufficient bite strength to resist dynamic pressure. Therefore, the selection of this range is based on a comprehensive consideration of the characteristics of the furniture material and the use environment. Finally, the above-mentioned angle can also be regarded as a "barb". When the furniture is subjected to continuous pressure, the bolt has a tendency to move outward due to the reaction force. In this process, it may drive the expansion nut to move toward the mounting hole together, and the "barb" structure can fix the nut structure to the mounting hole, thereby effectively reducing the probability of loosening.

[0061] Furthermore, this design takes into account the expansion and contraction characteristics of materials like wood in varying environmental conditions. By maintaining a small angle, the nut maintains a tight connection as the wood expands, while preventing damage from overtightening when the wood contracts. This adaptability ensures that the nut maintains a good connection under varying environmental conditions.

[0062] Example 4:

[0063] This embodiment only describes the parts that are different from the embodiment 1. Specifically, as shown in the attached Figure 4 As shown, the expansion nut structure further includes a fixing portion 6 provided on the outer circumference of the flip portion 211. The fixing portion 6 is a plurality of parallel strip-shaped protrusions.

[0064] It should be noted that by providing a fixing portion 6 on the outer peripheral surface of the flip portion 211, the stability problem in the furniture connection is effectively solved. The fixing portion 6 is designed as a plurality of parallel strip-shaped protrusions. These protrusions increase the friction between the nut and the contact surface of the furniture, thereby improving the fixing strength of the nut. When the expansion bolt 3 is tightened, these strip-shaped protrusions can fit tightly with the furniture material to prevent the nut from rotating or moving when subjected to force, thereby ensuring the reliability of the connection.

[0065] In addition, the design of the fixing portion 6 also takes into account the expansion or contraction that may occur in materials such as wood under different environmental conditions. Through the strip-shaped protrusions on the fixing portion 6, even if the size of the wood changes, the nut can maintain a close fit with the furniture, thereby maintaining the stability of the connection. This design also helps to disperse the pressure of the nut on the furniture material, reduce material damage caused by concentrated pressure, and extend the service life of the furniture.

[0066] Example 5:

[0067] This embodiment only describes the parts that are different from the embodiment 1. Specifically, as shown in the attached Figure 5 As shown, the fixing portion 6 is a plurality of parallel strip-shaped protrusions arranged at intervals.

[0068] The parallel strip-shaped protrusions of the fixing portion 6 provide a uniform surface structure, which helps to provide consistent friction between the expansion nut and the contact surface of the furniture, thereby enhancing the fixing stability of the nut. The parallel protrusions make the resistance in all directions evenly distributed when the nut is embedded in the furniture, which is conducive to maintaining the balance and stability of the nut and reducing damage to the furniture caused by excessive local pressure.

[0069] The staggered strip-shaped protrusions in this embodiment provide a more flexible fixing method. This structure allows the nut to be more adaptable when embedded and can better adapt to the irregularities of the furniture surface. The staggered protrusions can provide different degrees of engagement resistance in different directions, which helps to provide better fixing effects under specific usage conditions, such as when bearing uneven loads or when used on materials of different hardness.

[0070] Example 6:

[0071] This embodiment only describes the parts that are different from the embodiment 1. Specifically, as shown in the attached Figure 6 As shown, the fixing portion 6 is a plurality of obliquely arranged strip-shaped protrusions. The obliquely arranged strip-shaped protrusions are a special form of the fixing portion 6, which is characterized in that the protrusions are not perpendicular to the axis of the expansion nut, but are inclined at a certain angle. This design can increase the friction coefficient between the contact surface between the nut and the furniture, improve the fixing force of the nut, and when the nut is subjected to lateral force or dynamic load, the inclined protrusions can provide better anti-slip performance, thereby enhancing the stability of the nut. In addition, the obliquely arranged protrusions may also help guide the expansion nut to distribute force more evenly during the embedding process, reducing local damage to the furniture material.

[0072] Example 7:

[0073] This embodiment only describes the parts that are different from embodiment 1. Specifically, the side of the abutment end 5 away from the expansion end 2 is a concave or convex surface. During the embedding process of the expansion nut in the furniture, the concave or convex surface is reversely engaged with the abutment surface.

[0074] It's important to note that when the expansion nut is inserted into the furniture, the concave or convex surface of the abutment end 5 engages counter-engagingly with the abutment surface of the furniture. This design significantly enhances the strength and stability of the fixation between the nut and the furniture. The concave surface creates a recessed space that the furniture material fills when the nut is inserted, creating a tight mechanical lock. This locking action not only enhances the nut's grip but also absorbs and disperses the dynamic pressure generated during furniture use, minimizing damage to the furniture material.

[0075] Example 8:

[0076] This embodiment only describes the parts that are different from Example 1. Specifically, an expansion screw for furniture includes an expansion nut structure embedded in a furniture mounting hole. During the installation process, the abutment end 5 engages with the two abutment surfaces. The expansion screw also includes an expansion bolt 3. During the screwing process of the expansion bolt 3, the expansion end 2 is fixed in the mounting hole through the top plate 4.

[0077] The core component of the expansion screw is the expansion nut structure embedded in the furniture installation hole. The abutment end 5 of this structure tightly engages with the two abutment surfaces of the furniture during the installation process; it not only ensures a firm connection between the expansion screw and the furniture, but also through the special shape of the abutment end 5, such as concave or convex surface, it forms a reverse bite with the abutment surface of the furniture, further enhancing the stability and tightness of the connection.

[0078] The top plate 4 plays a crucial role in the screwing process of the expansion bolt 3. Working in conjunction with the expansion end 2, it secures the expansion end 2 within the mounting hole, thus fulfilling the expansion screw's anchoring function. This effectively prevents direct contact between the bolt and the inner wall of the expansion end 2, protecting the bolt threads from damage and extending the service life of the expansion screw. Furthermore, the expansion of the expansion end 2 allows the expansion screw to embed tightly into the furniture material, maintaining stability and resisting loosening under both static and dynamic loads.

[0079] Example 9:

[0080] Specifically, the applicant conducted experiments on expansion screws in different implementations and prior art. The present application is the technical solution corresponding to Example 1, and the prior art is an M6 expansion bolt 3. The specific comparison data are as follows:

[0081]

[0082] Based on the above data, the applicant hereby provides a detailed description of the above data, specifically: the above data is the average value taken from no less than 10 cyclic test records, wherein the prior art selects M6 expansion bolts 3, and the present application selects the standard size of M6 expansion bolts 3 to be manufactured, the static load test is the maximum force required for the two to be axially separated under the same conditions of use; the dynamic load test is the number of cycles in which the two are subjected to a 500N force at intervals of 10 seconds under the same conditions of use until obvious loosening occurs; the material damage test is the damage depth of the end face of the wood material after the two are used 10 times under the same conditions of use; the fixation test is the maximum force required for the expansion nuts of the two to generate obvious circumferential rotation through the expansion bolts 3 after being engaged with the wood material. It can be understood that during the above test process, the various performance properties of the expansion screws of the present application are significantly better than those of the prior art.

[0083] Example 10:

[0084] This embodiment only describes the parts that are different from the embodiment 1. Specifically, as shown in the attached Figure 10 As shown, another preferred embodiment of the expansion nut structure in the present application is to set the cross-sectional shape of the abutment end 5 to a polygon. It can be understood that in the aforementioned embodiment, the cross-sectional shape of the abutment end 5 is preferably a circular ring, while in the present embodiment, the cross-sectional shape can be a quadrilateral, a hexagon, an octagon, etc., among which a regular hexagonal structure is more preferred. In terms of the hexagonal cross-sectional shape of the abutment end 5, it can replace the original anti-rotation structure and other structures to a certain extent, thereby preventing it from rotating in the mounting hole. In addition, on the basis of the polygonal structure of the present embodiment, a anti-rotation structure can also be provided on its side to further improve the ability of the expansion nut to be connected and fixed in the mounting hole.

[0085] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of this application in detail. It should be understood that the above are only specific implementation methods of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. An expansion nut structure for furniture, comprising a fixed end (1), the fixed end (1) being threadedly connected to an expansion bolt (3), an expansion end (2) being provided on a side of the fixed end (1) away from the expansion bolt (3), a top plate (4) being provided inside the expansion end (2), and characterized in that: An abutting end (5) is provided on one side of the fixed end (1) close to the expansion bolt (3), and the diameter of the abutting end (5) is larger than the diameter of the fixed end (1). When the expansion bolt (3) is screwed into the fixed end (1), it abuts against the top plate (4) and the abutting end (5) is embedded between the two abutting surfaces. The expansion end (2) includes a plurality of hooks (21), which are distributed in a circular array with the central axis of the expansion end (2) as a reference. The expansion nut is fixed to the expansion bolt (3) by embedding the hooks (21) in the furniture corresponding to the abutment surface. The hook (21) comprises a turning portion (211) and a fitting portion (212); the turning portion (211) and the fixed end (1) are integrally formed; the fitting portion (212) and the turning portion (211) are fixedly connected; the fitting portion (212) is connected and fixed to the abutting surface by movement of the expansion bolt (3) and the top plate (4); The included angle between the turning portion (211) and the engaging portion (212) is less than 90 degrees, and after the expansion nut is embedded in the mounting hole, the dynamic pressure is resisted through the included angle.

2. The expansion nut structure for furniture according to claim 1, characterized in that: After the expansion nut is embedded in the mounting hole, the movement of the expansion bolt (3) and the top plate (4) can achieve bidirectional interlocking of the embedding portion (212) and the abutting end (5) in the mounting hole.

3. The expansion nut structure for furniture according to claim 1, characterized in that: The included angle between the turning portion (211) and the engaging portion (212) ranges from 65 degrees to 80 degrees.

4. The expansion nut structure for furniture according to claim 1, characterized in that: The expansion nut structure further includes a fixing portion (6) arranged on the outer peripheral surface of the flip portion (211).

5. The expansion nut structure for furniture according to claim 4, characterized in that: The fixing portion (6) is a plurality of parallel strip-shaped protrusions.

6. The expansion nut structure for furniture according to claim 4, characterized in that: The fixing portion (6) is a plurality of parallel strip-shaped protrusions arranged at intervals.

7. The expansion nut structure for furniture according to claim 4, characterized in that: The fixing portion (6) is a plurality of obliquely arranged strip-shaped protrusions.

8. The expansion nut structure for furniture according to claim 1, characterized in that: The side of the abutting end (5) away from the expansion end (2) is a concave surface or a convex surface, and the expansion nut is engaged with the abutting surface in the opposite direction through the concave surface or the convex surface during the embedding process in the furniture.

9. An expansion screw for furniture, characterized in that: An expansion nut structure for furniture according to any one of claims 1 to 8 comprises an expansion nut structure embedded in a mounting hole, wherein during installation, the abutting end (5) engages with two abutting surfaces, and the expansion screw further comprises an expansion bolt (3), wherein during screwing of the expansion bolt (3), the expansion end (2) is fixed in the mounting hole via the top plate (4).

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