Stainless steel expansion screw

Abstract

The utility model belongs to the technical field of expansion screws, and specifically discloses a stainless steel expansion screw which comprises a cylinder and a sleeve arranged outside the cylinder, and the bottom end of the sleeve is provided with an expansion part for improving anchoring effect; the expansion part comprises a plurality of expansion petals arranged at intervals in the circumferential direction, gaps are formed between the adjacent expansion petals, the end of each expansion petal is provided with an outwardly protruding arc-shaped ring, the outer side of the arc-shaped ring is provided with a protruding part for embedding an installation base body, the expansion part further comprises a plurality of groups of auxiliary anchoring members distributed in the circumferential direction, each group of auxiliary anchoring members comprises a plurality of sharp cones, the auxiliary anchoring members are arranged between the adjacent arc-shaped rings, one end of the cylinder is provided with a threaded part, and the other end of the cylinder is provided with a guide head part for expanding the expansion part, the protruding part on the outer side of the arc-shaped ring of the utility model is synchronously embedded into the inner wall of the base material along with the extrusion of the arc-shaped ring, the protruding part can penetrate into the inside of the base material, axial tension can be effectively resisted, and the expansion screw can be prevented from loosening due to external force.

Description

Technical Field

[0001] This application relates to the field of expansion screw technology, and more specifically, to a stainless steel expansion screw. Background Technology

[0002] Expansion bolts are mechanical fasteners specifically designed for strong fixing on hard, unthreaded substrates such as concrete, brick walls, and stone. Their core advantage lies in using the principle of physical expansion to transform a loose fit into a tight locking state, thereby providing reliable tensile and shear force bearing capacity.

[0003] Traditional expansion screws have a smooth surface at the expansion point. After installation, they rely solely on the radial compressive stress generated by the expansion to form a surface contact friction anchor between the expansion component and the hole wall of the substrate. There is no additional anti-pull-out structure such as physical interlocking, and the anchoring effect depends on the initial friction force. During long-term use, the initial compressive stress between the expansion component and the substrate will decrease due to factors such as material creep and the generation of micro gaps at the interface, resulting in a decrease in the coefficient of friction. Ultimately, the effective anchoring force cannot be maintained, leading to screw loosening and failure. Utility Model Content

[0004] To address the aforementioned problems, this application provides a stainless steel expansion screw.

[0005] The stainless steel expansion bolt provided in this application adopts the following technical solution: A stainless steel expansion bolt includes a column and a sleeve sleeved on the outside of the column, the bottom end of the sleeve having an expansion portion for improving the anchoring effect. The expansion section includes multiple expansion petals spaced apart circumferentially, with gaps formed between adjacent expansion petals. Each expansion petal has an outwardly protruding arc-shaped ring at its end, and a protrusion for embedding into the mounting base is provided on the outer side of the arc-shaped ring.

[0006] Through the above technical solution, the protrusion on the outer side of the arc ring is embedded into the inner wall of the substrate simultaneously with the compression of the arc ring. The protrusion can penetrate deep into the substrate, effectively resisting axial tension and preventing the expansion screw from loosening due to external force.

[0007] Furthermore, the expansion section also includes multiple sets of auxiliary anchors distributed circumferentially, each set of auxiliary anchors containing multiple pointed cones.

[0008] Through the above technical solution, the pointed cone on the auxiliary anchor penetrates into the interior of the substrate, forming multiple dispersed piercing anchor points. The combined force of these points and the interlocking action of the protrusion further enhances the connection strength between the expansion screw and the substrate, while resisting lateral or oblique forces.

[0009] Furthermore, auxiliary anchors are placed between adjacent arc-shaped rings.

[0010] Furthermore, one end of the column is provided with a threaded portion, and the other end is provided with a guide head for expanding the expansion portion.

[0011] Furthermore, a fastener is provided on the threaded part, and a pressure-bearing gasket is provided between the fastener and the top of the sleeve.

[0012] Furthermore, the sleeve and the expansion section are integrally molded structures.

[0013] With the above technical solution, since the sleeve and expansion part adopt an integral molding structure, compared with the split structure, gaps or weak stress points at the splicing of parts can be avoided.

[0014] Furthermore, the taper of the guide head is greater than the taper of the corresponding position of the internal channel of the sleeve.

[0015] In summary, this application includes at least one of the following beneficial technical effects: (1) The protrusion on the outer side of the arc ring of this utility model is embedded into the inner wall of the substrate at the same time as the arc ring is squeezed. The protrusion can penetrate into the interior of the substrate, effectively resisting axial tension and preventing the expansion screw from loosening due to external force. (2) The pointed cone on the auxiliary anchor of this utility model penetrates into the interior of the substrate to form multiple dispersed piercing anchor points. The combined force is formed with the biting action of the protrusion to further enhance the connection strength between the expansion screw and the substrate, while resisting lateral or oblique forces. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the overall column structure of this utility model; Figure 4 This is a cross-sectional view of the present invention; Figure 5 For the present utility model Figure 1 Enlarged view of the structure at point A in the middle.

[0017] Explanation of reference numerals in the attached drawings: 1. Column; 2. Sleeve; 3. Pressure bearing gasket; 4. Expansion flap; 5. Threaded part; 6. Guide head; 7. Fastener; 8. Auxiliary anchor; 9. Arc ring; 10. Protrusion. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0019] Reference Figures 1-5 A stainless steel expansion bolt includes a column 1 and a sleeve 2 sleeved on the outside of the column 1. The bottom end of the sleeve 2 is provided with an expansion portion for improving the anchoring effect. The expansion section includes a plurality of expansion petals 4 spaced apart in the circumferential direction, with gaps formed between adjacent expansion petals 4. Each expansion petal 4 has an outwardly protruding arc-shaped ring 9 at its end, and a protrusion 10 for embedding into the mounting base is provided on the outer side of the arc-shaped ring 9.

[0020] Before installation, the sleeve 2 is pre-fitted onto the outside of the column 1 to form a pre-assembled structure. The whole assembly is aligned with the pre-drilled holes on the substrate to ensure that the axis of each component is consistent with the axis of the hole, thus completing the initial positioning. Then, the sleeve 2 is placed into the pre-drilled holes in the substrate.

[0021] After the sleeve 2 is inserted into the hole, the fastener 7 is rotated. Because the top of the column 1 is provided with a threaded part 5 and is threadedly connected to the fastener 7, the column 1 moves upward when the fastener 7 is rotated. The column 1 drives the guide head 6 to move upward. Since the taper of the guide head 6 is greater than the taper of the corresponding position of the internal channel of the sleeve 2, the tapered surface of the guide head 6 can generate a radially outward spreading force on the inner wall of the expansion part at the bottom of the sleeve 2. This spreading force continues to increase as the relative displacement between the sleeve 2 and the column 1 increases. At this time, the multiple expansion petals 4 arranged circumferentially in the expansion part begin to expand synchronously and slowly towards the inner wall of the hole in the substrate because there is a gap between adjacent expansion petals 4.

[0022] The protrusion 10 on the outer side of the arc ring 9 is inserted into the inner wall of the substrate simultaneously with the compression of the arc ring 9. The protrusion 10 can penetrate deep into the substrate, effectively resisting axial tension and preventing the expansion screw from loosening due to external force.

[0023] It should be noted that the number of pointed cones on the auxiliary anchor 8 and the number of circumferentially distributed protrusions 10 are not subject to fixed limitations; in actual design and production, they can be adaptively adjusted according to the material characteristics of the mounting base, the preset load-bearing requirements of the screws, and the usage environment.

[0024] Reference Figures 1-5 The expansion section also includes multiple sets of auxiliary anchors 8 distributed circumferentially, each set of auxiliary anchors 8 containing multiple pointed cones, and the auxiliary anchors 8 are disposed between adjacent arc-shaped rings 9.

[0025] Multiple sets of auxiliary anchors 8, located between adjacent arc-shaped rings 9 and distributed circumferentially, pierce the inner wall of the substrate synchronously with the expansion of the expansion flap 4. The sharp structure of the pointed cone allows the protrusion on the outer side of the arc-shaped ring to easily embed into the inner wall of the substrate synchronously with the compression of the arc-shaped ring. The protrusion can penetrate deep into the interior of the substrate, effectively resisting axial tensile force and preventing the expansion screw from loosening due to external force.

[0026] Reference Figures 3-4 One end of the column 1 is provided with a threaded part 5, and the other end is provided with a guide head 6 for expanding the expansion part. A fastener 7 is provided on the threaded part 5, and a pressure-bearing gasket 3 is provided between the fastener 7 and the top of the sleeve 2.

[0027] Reference Figures 1-2 The sleeve 2 and the expansion part are integrally formed, and the taper of the guide head 6 is greater than the taper of the corresponding position of the internal channel of the sleeve 2.

[0028] Since the sleeve 2 and the expansion part adopt an integral molding structure, compared with the split structure, gaps or weak stress points at the splicing of parts can be avoided.

[0029] During the process of the guide head 6 opening the expansion petals 4, the integrally molded structure ensures that the opening force can be evenly transmitted to each expansion petal 4, so that the deformation amplitude of all expansion petals 4 is consistent. The arc ring 9, the protrusion 10 and the auxiliary anchor 8 contact the substrate synchronously, avoiding anchoring failure due to uneven local deformation.

[0030] Working principle: Before installation, the sleeve 2 is pre-fitted onto the outside of the column 1 to form a pre-assembled structure. The entire structure is aligned with the pre-drilled holes on the substrate to ensure that the axis of each component is consistent with the axis of the hole to complete the initial positioning. Then the sleeve 2 is placed into the hole of the substrate.

[0031] After the sleeve 2 is in place, rotate the fastener 7 on the threaded part 5 of the column 1. Since the fastener 7 and the threaded part 5 are connected by threads, the rotation will drive the column 1 to move upward, and the column 1 will simultaneously drive the guide head 6 at its end to move upward.

[0032] Because the taper of the guide head 6 is greater than the taper of the corresponding position of the internal channel of the sleeve 2, the upward-moving guide head 6 will generate a radially outward spreading force on the inner wall of the expansion portion at the bottom of the sleeve 2, and this spreading force increases with the increase of the relative displacement between the column 1 and the sleeve 2. The multiple expansion petals 4 arranged circumferentially in the expansion portion, due to the gap reserved between adjacent expansion petals 4, expand synchronously and slowly towards the inner wall of the substrate hole under the action of the spreading force. During the expansion of the expansion petal 4, the arc-shaped ring 9 protruding outward at its end moves outward with the deformation, and the protrusion 10 on the outer side of the arc-shaped ring 9 is simultaneously embedded into the inner wall of the substrate to resist axial tension and prevent the screw from loosening; at the same time, multiple sets of auxiliary anchors 8 located between adjacent arc-shaped rings 9 and distributed circumferentially pierce into the inner wall of the substrate synchronously with the expansion of the expansion petal 4, forming dispersed piercing anchor points, which, together with the interlocking action of the protrusion 10, enhance the connection strength and resist lateral or oblique forces.

[0033] In addition, the sleeve 2 and the expansion part are integrally formed, which can avoid the splicing gaps and stress weak points of the split structure. When the guide head 6 opens the expansion petals 4, it can evenly transmit the opening force to each expansion petal 4, ensuring that the deformation amplitude of all expansion petals 4 is consistent, so that the arc ring 9, the protrusion 10 and the auxiliary anchor 8 can contact the substrate synchronously, and finally achieve stable anchoring of the screw and the substrate.

[0034] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A stainless steel expansion screw, characterized in that, include: The column (1) and the sleeve (2) sleeved outside the column (1), wherein the bottom end of the sleeve (2) is provided with an expansion portion for improving the anchoring effect; The expansion portion includes a plurality of expansion petals (4) spaced apart in the circumferential direction, with gaps formed between adjacent expansion petals (4), and each expansion petal (4) has an outwardly protruding arc-shaped ring (9) at its end, and the outer side of the arc-shaped ring (9) has a protrusion (10) for embedding into the mounting base.

2. The stainless steel expansion screw according to claim 1, characterized in that: The expansion section also includes multiple sets of auxiliary anchors (8) distributed circumferentially, each set of auxiliary anchors (8) containing multiple pointed cones.

3. A stainless steel expansion screw according to claim 2, characterized in that: The auxiliary anchor (8) is disposed between adjacent arc-shaped rings (9).

4. A stainless steel expansion screw according to claim 1, characterized in that: One end of the column (1) is provided with a threaded part (5), and the other end is provided with a guide head (6) for opening the expansion part.

5. A stainless steel expansion screw according to claim 4, characterized in that: The threaded part (5) is provided with a fastener (7), and a pressure-bearing gasket (3) is provided between the fastener (7) and the top of the sleeve (2).

6. A stainless steel expansion screw according to claim 1, characterized in that: The sleeve (2) and the expansion part are integrally formed.

7. A stainless steel expansion screw according to claim 4, characterized in that: The taper of the guide head (6) is greater than the taper of the corresponding position of the internal channel of the sleeve (2).

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