A sleeve structure for realizing low-damping sliding and magnetic attraction function

Abstract

The utility model relates to a sleeve structure realizing low-damping sliding and magnetic attraction function belongs to furniture support device technical field. Including mutually nested inner tube and outer tube, inner tube and outer tube are all integrative injection molding structure, the outer wall of inner tube is equipped with a plurality of wave convex, and the both sides of wave convex are equipped with limiting rib, and inner tube passes through wave convex and the inner wall interference fit of outer tube, and the height of limiting rib is the maximum height after wave convex interference deformation, wave convex and the limiting rib of both sides form Z point structure, and the oil storage groove is equipped on wave convex and limiting rib all. The utility model discloses through integrative injection molding inner and outer tube cooperation wave convex and limiting rib structure, and combines oil storage groove design, and effectively solved the problem that traditional steel sleeve processing is complex, and the cooperation gap is unstable and the sliding damping is uneven.

Description

Technical Field

[0001] This utility model relates to the field of furniture support device technology, and in particular to a sleeve structure that realizes low-damping sliding and magnetic attraction functions. Background Technology

[0002] Currently, the support structure (such as table legs) of furniture such as height-adjustable desks mostly adopts a sleeve structure of steel square or round tubes, usually designed as a two- or three-section nested form (thicker at the top and thinner at the bottom or thinner at the top and thicker at the bottom), and plastic sheets are installed in the nested parts to achieve relative sliding and reduce wobbling. However, this traditional steel tubing structure has many key problems, such as: the production of steel table legs requires multiple processes such as cutting, bending, welding, stamping, and spraying, which not only requires a large investment in specialized equipment but also extends the production cycle; at the same time, the cost of steel itself, processing costs, and logistics and transportation costs are high, weakening the product's market competitiveness; controlling the dimensional accuracy tolerance of steel pipes is difficult, and fluctuations in parameters such as fitting clearance and friction directly affect performance; to ensure quality, automated measuring equipment is required for online inspection, increasing equipment costs, and the high rework rate leads to low production efficiency; the large number of parts and the complicated assembly process require specialized technicians to operate, increasing labor and training costs; the complex process extends the production cycle of individual products and reduces overall production efficiency; when the table is raised to its highest position, the traditional steel tubing structure exhibits significant back-and-forth and left-and-right swaying, affecting the user experience and even posing a safety hazard to valuable or fragile items placed on it, etc.

[0003] Therefore, there is an urgent need to develop a sleeve structure that can achieve low-damping sliding and magnetic attraction functions to solve the above-mentioned technical problems. Utility Model Content

[0004] The present invention provides a sleeve structure that realizes low-damping sliding and magnetic attraction functions, which adopts the following technical solution, including an inner tube and an outer tube nested together, wherein the inner tube and the outer tube are integral injection molded structures; The outer wall of the inner tube is provided with multiple wave-shaped protrusions, and limiting ribs are provided on both sides of the wave-shaped protrusions. The inner tube is interference-fitted with the inner wall of the outer tube through the wave-shaped protrusions. The height of the limiting ribs is the maximum height of the wave-shaped protrusions after interference deformation. The wave-shaped protrusions and the limiting ribs on both sides form a Z-point structure. The waveform protrusions are provided with oil storage grooves.

[0005] Furthermore, a connecting plate is provided at the bottom of the waveform protrusions and the limiting ribs.

[0006] Furthermore, the waveform protrusion is elliptical or streamlined, the height of the waveform protrusion is 2-4mm, and the interference deformation is 0.3-1.2mm.

[0007] Furthermore, both the outer and inner tubes have chamfered ends.

[0008] Furthermore, limiting blocks are provided at both the upper and lower ends of the inner wall of the outer tube to limit the inner tube and prevent it from falling off.

[0009] Furthermore, the inner wall at the bottom of the outer tube is provided with multiple sets of radial reinforcing ribs.

[0010] Furthermore, a thickened ring or reinforcing pad is provided at the connection between the bottom of the outer tube and the table leg.

[0011] Furthermore, it also includes a magnetic attraction structure, wherein a strong magnet is embedded in a predetermined position on the inner wall of the outer tube.

[0012] Furthermore, the surface of the strong magnet sheet is provided with a nickel plating layer or an epoxy resin coating, and the thickness of the strong magnet sheet is 1.5-3mm.

[0013] In summary, this utility model has the following beneficial technical effects: 1. This utility model features elliptical or streamlined wave-shaped protrusions (2-4mm in height, 0.3-1.2mm in interference deformation) that are interference-fitted with the outer tube. Low-damping sliding is achieved through controllable micro-deformation, reducing frictional resistance. The height of the limiting rib is 1-3mm, which is the maximum height of the wave-shaped protrusion after interference deformation, preventing excessive deformation of the protrusion. This dual control of the swaying amount solves the problem of lifting and swaying in traditional steel pipes.

[0014] 2. The oil storage groove of this utility model stores lubricant, further reducing sliding friction, reducing wear, extending service life, and improving the user's smoothness of use.

[0015] 3. The sleeve structure provided by this utility model, which realizes low-damping sliding and magnetic attraction functions, effectively solves the problems of complex processing, unstable fitting clearance and uneven sliding damping of traditional steel sleeves by using an integrally injection-molded inner and outer tube with a wave-shaped protrusion and limiting rib structure, combined with an oil storage groove design. It has the advantages of simplifying the production process, reducing manufacturing costs, improving sliding stability and integrating magnetic attraction function. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the inner tube structure of this utility model; Figure 3 This is a utility model Figure 2 Enlarged view A; Figure 4 This is a schematic diagram of the Z-point structure of this utility model; Figure 5 This is a schematic diagram of the maximum displacement connection between the inner and outer tubes of this utility model. Figure 6 This is a utility model Figure 5 Enlarged image B; Figure 7 This is a schematic diagram of the minimum displacement connection between the inner and outer tubes of this utility model; Figure 8 This is the utility model Figure 7 Enlarged image C; Figure 9 This is a schematic diagram of another embodiment of the present invention.

[0017] Explanation of reference numerals in the attached drawings: 1. Outer tube; 2. Inner tube; 3. Wave-shaped protrusion; 4. Limiting rib; 5. Oil storage groove; 6. Connecting plate; 7. Limiting block; 8. Z-point structure. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings.

[0019] like Figures 1 to 4 A specific embodiment of a sleeve structure for achieving low-damping sliding and magnetic attraction functions is shown, comprising an inner tube 2 and an outer tube 1 nested together, both of which are integrally injection molded structures. The outer wall of the inner tube 2 has multiple corrugated protrusions 3, with limiting ribs 4 on both sides of the corrugated protrusions 3. A connecting plate 6 is provided at the bottom of the corrugated protrusions 3 and the limiting ribs 4, strengthening the connection between the corrugated protrusions 3 and the limiting ribs 4 and the outer wall of the inner tube 2, preventing breakage or fatigue damage during long-term use. The inner tube 2 is interference-fitted with the inner wall of the outer tube 1 through the corrugated protrusions 3, and the height of the limiting ribs 4 is lower than the maximum height of the corrugated protrusions 3. The corrugated protrusions 3 and the limiting ribs 4 on both sides form a Z-point structure 8. Oil storage grooves 5 are provided on the corrugated protrusions 3, and oil storage grooves 5 may also be provided on the limiting ribs 4.

[0020] Specifically, the injection-molded inner tube 2 and outer tube 1 achieve precise mating dimensions, reducing the tolerance accumulation problem of traditional steel pipes. The corrugated protrusions 3 on the outer wall of the inner tube 2 undergo elastic deformation upon contact with the inner wall of the outer tube 1, forming evenly distributed contact points, ensuring axial positioning accuracy while reducing sliding friction. The design of the limiting rib 4 being lower than the corrugated protrusions 3 not only ensures that the inner tube 2 transmits contact force only through the corrugated protrusions 3 during sliding, avoiding direct friction between the limiting rib 4 and the inner wall of the outer tube 1, but also prevents excessive deformation of the corrugated protrusions 3, providing dual control over the amount of sway and solving the lifting and swaying problem of traditional steel pipes. The continuous undulating shape of the Z-point structure 8 generates a dynamic contact pressure distribution during sliding, compensating for any minor deformations that may exist in the injection-molded part. The oil reservoir 5 is filled with lubricating medium during assembly and continuously releases lubricating material as the inner tube 2 slides, forming a stable oil film layer, further reducing sliding friction, decreasing wear, extending service life, and improving user experience.

[0021] Specifically, the wave-shaped protrusion 3 will rub against the inner wall of the outer tube 1 during use, which may lead to wear over time. Therefore, the wave-shaped protrusion 3 in this invention uses a material with good wear resistance, such as modified PA, PAGF, or POM materials with added PTFE or silicone oil. At the same time, special treatments, such as hardening treatment or coating with a wear-resistant layer, are applied to the inner wall of the outer tube 1 and the oil storage groove 5 to effectively improve wear resistance.

[0022] Furthermore, the waveform protrusion 3 undergoes micro-deformation during each sliding process, which may lead to fatigue failure with prolonged use. The maximum stress and strain of the waveform protrusion 3 should be determined through finite element analysis. It should be ensured that its stress level under normal operating conditions is well below the material's fatigue limit; a safety factor of at least 2.5 is recommended. Simultaneously, optimizing the shape and size of the protrusion can reduce stress concentration and improve fatigue life.

[0023] Specifically, the inner wall of the outer tube 1 has an inwardly thickened gradient structure at the transition from the non-load-bearing to the load-bearing section, and the outer wall of the inner tube 2 also has an inwardly thickened gradient structure at the transition from the non-load-bearing to the load-bearing section. The transition angle of the gradient structure is 10°-20°, and the transition angle is controlled within the range of 10°-20°. This ensures the smooth, non-jamming sliding function of the Z-point structure 8 and sufficient strength to avoid stress concentration. The inward thickening design of the outer wall of the inner tube 2 can be achieved by using a rib structure instead of uniform thickening, which can reduce material usage and product weight while maintaining strength. The number and distribution of the ribs should be optimized according to the stress conditions.

[0024] Specifically, the wall thickness of non-load-bearing parts can be controlled at 1.5-2.0mm, while the wall thickness of load-bearing parts can be appropriately increased to 2.5-3.0mm.

[0025] Specifically, when the inner tube 2 and the outer tube 1 adopt a square tube structure, each surface of the inner tube is provided with 4 sets of Z-point structures composed of wave-shaped protrusions and limiting ribs; when the inner tube 2 and the outer tube 1 adopt a round tube structure (not shown in the figure), the outer wall of the inner tube 2 is evenly distributed with 6-8 sets of Z-point structures 8 composed of wave-shaped protrusions 3 and limiting ribs 4.

[0026] In a preferred embodiment, the inner tube 2 and the outer tube 1 adopt a square tube structure, the waveform protrusion 3 is elliptical or streamlined, the height of the waveform protrusion 3 is 2-4mm, the interference deformation is 0.3-1.2mm, the height of the limiting rib 4 is 1-3mm, that is, the maximum height of the waveform protrusion after interference deformation, and the ends of the outer tube 1 and the inner tube 2 are provided with chamfers.

[0027] Specifically, the elliptical or streamlined shape refers to the smooth curve shape without sharp edges of the waveform protrusion 3. This shape enables the contact area between the waveform protrusion 3 and the inner wall of the outer tube 1 to form a continuously changing pressure distribution, avoiding sudden changes in sliding resistance caused by local stress concentration.

[0028] Specifically, the height of the corrugated protrusion 3 is 2-4mm, and the interference deformation is 0.3-1.2mm. This height range can maintain the frictional force of the interference fit through elastic deformation, while avoiding a surge in assembly resistance due to excessive material compression. The height of the limiting rib 4 is 1-3mm, which is the maximum height after the interference deformation of the corrugated protrusion. This not only ensures that the contact force is transmitted only through the corrugated protrusion 3 when the inner tube 2 slides, avoiding direct friction between the limiting rib 4 and the inner wall of the outer tube 1, but also prevents excessive deformation of the corrugated protrusion 3. This dual control of the amount of sway solves the problem of swaying during the lifting and lowering of traditional steel pipes.

[0029] Specifically, the ends of the outer tube 1 and the inner tube 2 are chamfered to form a bevel or arc transition. During the nesting process, the bevel guides the tube body to slide axially, reducing the assembly resistance caused by burrs or processing errors at the tube ends.

[0030] In addition, limit blocks 7 are provided at the upper and lower ends of the inner wall of the outer tube 1 to limit the inner tube 2 and prevent it from falling off.

[0031] Specifically, such as Figures 5-8 As shown, when the inner tube 2 slides to the top limit position inside the outer tube 1, the Z-point structure 8 on the inner tube contacts the upper limit block 7 to form a mechanical block; when it slides to the bottom limit position, the Z-point structure 8 on the inner tube 2 contacts the lower limit block 7 to form a mechanical block. While maintaining the sliding fit clearance between the inner and outer tubes, a rigid termination point for axial movement is formed, achieving the anti-fall-off function without the need for additional frictional resistance.

[0032] In other preferred embodiments, the inner wall of the inner tube 2 is provided with multiple sets of radial reinforcing ribs to enhance the overall yield strength of the device. The size of the reinforcing ribs is preferably suitable for the mold. A thickened ring or reinforcing pad (not shown in the figure) is provided at the connection between the inner tube and the table leg.

[0033] Specifically, the bending stress borne by the inner tube 2 during the lifting and lowering process is transferred to the entire tube body through radial stiffeners, and the spacing angle between adjacent stiffeners makes the stress distribution more uniform. When the inner tube 2 is in a high position, the circumferentially spaced stiffeners form a multi-point support structure, suppressing the plastic deformation of the tube wall caused by local stress.

[0034] Specifically, the inner wall of the inner tube 2 is provided with a multi-point support and fixing structure that is assembled with the lead screw nut and the motor. The multi-point support and fixing structure includes 3-4 support points, which are connected to the inner wall of the inner tube by reinforcing ribs.

[0035] Specifically, the core concept of this utility model lies in utilizing advanced injection molding technology to integrally injection mold the inner tube 2 and its required support structures (such as through holes, screw holes, screw pillars, etc.) in one piece. During the design process, mold development is strictly based on the actual installation positions and precise dimensions of components such as motors, lead screws, and wires, ensuring accurate matching of all reserved holes and support points. This utility model employs a high-precision integrated injection molding process, aiming to seamlessly integrate the inner tube 2 body with all necessary internal support structures (including but not limited to component mounting through holes, threaded fastening holes, and positioning screw pillars). Customized mold development is based on detailed dimensional analysis and spatial layout planning of core components (such as high-performance motors, precision lead screw transmission mechanisms, and electrical connection harnesses). This integrated design not only significantly simplifies the assembly process and effectively reduces production costs, but also fundamentally improves the overall structural integrity and reliability of the system by reducing the number of parts. This solution is particularly suitable for applications with high requirements for lightweighting and cost-effectiveness, while also meeting the structural stability requirements under medium load conditions.

[0036] Specifically, the advantages of integrated injection molding solutions lie in their high production efficiency, relatively low manufacturing cost, and ability to achieve complex geometries. To ensure sufficient structural strength and dimensional stability, high-performance engineering plastics must be selected, and the mold must be meticulously designed to avoid deformation or stress concentration that may occur during injection molding. This invention performs exceptionally well in low-to-medium load applications where cost and weight are critical.

[0037] Furthermore, it should be noted that the lead screw nut in this invention integrates a plastic-coated one-way bearing, designed to provide superior structural self-locking capability. This ensures that the lead screw drive system can reliably maintain its position under external loads or vibrations, preventing accidental rotation or displacement. By precisely encapsulating the one-way bearing within the nut body, not only is space utilization optimized, but the bearing is also effectively protected from external environmental influences, thereby extending its service life and improving the overall stability and safety of the system. This self-locking mechanism is crucial for applications requiring precise position holding and high operational safety.

[0038] In other preferred embodiments, a magnetic attraction structure is also included. The magnetic attraction structure is a strong magnet sheet that is encapsulated in a predetermined position on the inner wall of the outer tube 1 by an insert injection molding process. The surface of the strong magnet sheet is provided with a nickel plating layer or an epoxy resin coating. The thickness of the strong magnet sheet is 1.5-3mm. A locking structure, such as a boss or a groove, is provided around the strong magnet sheet to prevent the strong magnet sheet from loosening during use.

[0039] Specifically, the arrangement of the strong magnets on the inner wall of the outer tube 1 can be either ring-shaped or dot-matrix-shaped, depending on the actual pipe fitting.

[0040] Specifically, the magnetic structure is integrated with the outer tube through an insert injection molding process, in which the strong magnet is precisely positioned and completely encapsulated inside the tube wall during the injection molding stage.

[0041] In other preferred embodiments, the present invention employs a composite structure of plastic-coated steel plates in a portion of the inner tube to increase load-bearing capacity.

[0042] Specifically, a pre-formed steel plate with pre-machined support features such as through holes, screw holes, and screw studs is precisely placed inside the inner tube mold. Plastic material is then injected into the steel plate to form a robust composite support structure. This significantly improves the inner tube's resistance to bending, torsion, and impact, ensuring stable operation and precise positioning of core components such as the motor and lead screw under high loads or extreme conditions. This solution is ideal for heavy-duty applications, high reliability, and long-life product designs.

[0043] In other preferred embodiments, the magnetic attraction structure is achieved by adding an appropriate proportion of reduced iron powder to the injection molding raw materials of the inner and outer tubes to achieve the magnetic attraction effect.

[0044] Specifically, add an appropriate proportion of reduced iron powder to the injection molding raw material, using reduced iron powder with a particle size of 50-100μm, which is recommended to be 30%-50% of the injection molding raw material. Add a coupling agent to improve the compatibility between the iron powder and the plastic matrix. Mix the injection molding raw material or twin-screw extruder to enable the inner and outer tubes of the injection molded tubes to achieve a magnetic attraction effect.

[0045] This utility model effectively solves the problems of complex processing, unstable fitting clearance and uneven sliding damping of traditional steel sleeves by using an integrally injection-molded inner and outer tube with a corrugated protrusion 3 and a limiting rib 4 structure, combined with an oil storage groove 5 design. It has the advantages of simplifying the production process, reducing manufacturing costs, improving sliding stability and integrating magnetic attraction function.

[0046] Furthermore, it should be noted that there can be multiple inner tubes 2. For example... Figure 9 As shown, there are two inner tubes 2. In this case, the first inner tube is the "outer tube" of the second inner tube, and the second inner tube and the first inner tube are nested together.

[0047] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A sleeve structure that achieves low-damping sliding and magnetic attraction functions, characterized in that, It includes an inner tube (2) and an outer tube (1) nested together, both of which are integral injection molded structures; The outer wall of the inner tube (2) is provided with multiple wave-shaped protrusions (3), and the wave-shaped protrusions (3) are provided with limiting ribs (4) on both sides. The inner tube (2) is press-fitted with the inner wall of the outer tube (1) through the wave-shaped protrusions (3). The height of the limiting ribs (4) is the maximum height of the wave-shaped protrusions (3) after the press-fit deformation. The wave-shaped protrusions (3) and the limiting ribs (4) on both sides form a Z-point structure (8). The waveform protrusion (3) is provided with an oil storage groove (5).

2. The sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that, The bottom of the waveform protrusion (3) and the limiting rib (4) is provided with a connecting plate (6).

3. The sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that, The waveform protrusion (3) is elliptical or streamlined, and the height of the waveform protrusion (3) is 2-4mm, with an interference deformation of 0.3-1.2mm.

4. The sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that... Both the outer tube (1) and the inner tube (2) have chamfered ends.

5. A sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that... The outer tube (1) has limit blocks (7) at both the upper and lower ends of its inner wall to limit the inner tube (2) and prevent it from falling off.

6. A sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that... The inner wall of the inner tube (2) is provided with multiple sets of radial reinforcing ribs.

7. A sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that... The bottom of the outer tube (1) is provided with a thickened ring or a reinforcing pad at the connection between it and the table leg.

8. A sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 1, characterized in that... It also includes a magnetic attraction structure, wherein a strong magnet is embedded in a predetermined position on the inner wall of the outer tube (1).

9. A sleeve structure for achieving low-damping sliding and magnetic attraction functions according to claim 8, characterized in that... The surface of the strong magnet sheet is provided with a nickel plating layer or an epoxy resin coating, and the thickness of the strong magnet sheet is 1.5-3mm.

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