Expanded-base mechanical anchor bolt

Abstract

The utility model discloses an expanded-base mechanical anchor bolt, and relates to the technical field of anchor bolts. The device comprises a screw rod, a first expansion head is arranged on the lower end face of the screw rod, an expansion cylinder and a nut matched with threads are sleeved on the peripheral side of the screw rod, and an elastic supporting piece is arranged on the peripheral side of the expansion cylinder; a plurality of expansion grooves and a plurality of deformation grooves are evenly formed in the peripheral side of the expansion cylinder, the expansion grooves penetrate through the lower end face of the expansion cylinder, a second expansion head is arranged on the peripheral side of the screw, and the first expansion head and the second expansion head are each of a circular-truncated-cone-shaped structure. According to the multi-stage anchor bolt, the circular truncated cone-shaped structures of the first expansion head and the second expansion head on the screw rod are matched with the expansion groove and the deformation groove of the expansion barrel, so that multi-stage anchoring is achieved, the synergistic effect of preliminary expansion and middle section synchronous expansion is conveniently formed, and the overall stability of the anchor bolt is improved; the part, corresponding to the upper half part of the deformation groove, of the expansion cylinder uniformly deforms layer by layer.

Description

Technical Field

[0001] This utility model belongs to the field of anchor bolts, specifically, it relates to an expanded-base mechanical anchor bolt. Background Technology

[0002] An enlarged-hole anchor bolt is a type of mechanical anchor bolt that achieves anchoring by using a key between the enlarged hole at the bottom of the anchor hole and the anchor bolt expansion member.

[0003] Chinese Patent No. CN216278854U discloses a self-expanding mechanical anchor bolt, comprising: an expansion sleeve, an expansion plate installed at one end of the expansion sleeve, and an anchor rod passing through the expansion sleeve and the expansion plate. The anchor rod includes a threaded part and a smooth part. An expansion head is installed at the end of the smooth part near the expansion plate, and a nut is connected to the end of the threaded part away from the expansion head. A cavity is formed on both sides of the smooth part, and a spring is fixed inside the cavity. A movable block is connected to one end of the spring, and a limit block is fixed at the end of the movable block away from the spring.

[0004] The mechanical anchor bolt with a self-expanding bottom disclosed in the application relies mainly on the rigid engagement of the limiting block and the limiting groove for the connection between the anchor bolt and the expansion sleeve. However, in actual applications, when the anchor bolt is subjected to vibration, it is easy to cause the limiting block to disengage from the limiting groove, resulting in slippage between the expansion sleeve and the anchor bolt. In addition, during installation, the smooth part of the anchor bolt and the expansion sleeve are prone to misalignment, causing the movable block to jam, which further affects the fixing effect of the anchor bolt. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide an expanded-base mechanical anchor bolt, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by this utility model is as follows:

[0007] A type of expansion-bottom mechanical anchor bolt includes: a screw rod, a first expansion head provided on the lower end face of the screw rod, an expansion cylinder sleeved on the periphery and a nut threadedly fitted thereon, the expansion cylinder being located between the nut and the first expansion head, the nut being located above the first expansion head, and an elastic support member being provided on the periphery of the expansion cylinder;

[0008] The expansion cylinder is uniformly provided with multiple expansion grooves and multiple deformation grooves on its periphery. Both expansion grooves and deformation grooves are connected to the inner cavity of the expansion cylinder. The expansion grooves penetrate the lower end face of the expansion cylinder, and the deformation grooves are located above the expansion grooves. A second expansion head is provided on the periphery of the screw. Both the first expansion head and the second expansion head are frustum-shaped structures. Multiple triangular pressure blocks are provided on the inner wall side of the expansion cylinder. The triangular pressure blocks are located between two adjacent deformation grooves. The second expansion head is located below the triangular pressure blocks, and the triangular pressure blocks correspond to the upper half of the deformation grooves.

[0009] Optionally, a flat washer is fitted around the screw, located between the nut and the expansion cylinder, and the diameter of the flat washer is larger than the diameter of the nut and the expansion cylinder.

[0010] Optionally, a spring washer is fitted around the screw, with the spring washer located between the nut and the flat washer.

[0011] Optionally, the elastic support includes a connecting ring located on the periphery of the expansion cylinder, which is located between the expansion groove and the deformation groove. Multiple storage boxes are evenly arranged on the periphery of the connecting ring, with each storage box corresponding to the deformation groove. A stepped support block is elastically fitted on the side of the storage box away from the connecting ring, with the stepped support block gradually increasing in thickness from bottom to top.

[0012] Optionally, the storage box has an extension block on the lower part of the side away from the step support block. The extension block is located below the connecting ring and is engaged in the corresponding expansion slot.

[0013] Optionally, a sliding post is provided on the upper part of the side of the stepped support block near the storage box, and the sliding post passes horizontally through the corresponding storage box.

[0014] Optionally, a limiting circular plate is provided on the end face of the sliding column away from the stepped support block, and the limiting circular plate is located between the storage box and the expansion cylinder.

[0015] Optionally, multiple springs are installed between the stepped support block and one side of the inner wall of the storage box. The springs are located below the sliding column and are distributed vertically at equal intervals.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time:

[0017] The frustum-shaped structure of the first and second expansion heads on the screw, combined with the expansion groove and deformation groove of the expansion cylinder, enables multi-stage anchoring. This facilitates the synergistic effect of initial expansion and synchronous expansion in the middle section, improving the overall stability of the anchor bolt. Through the layered arrangement of triangular pressure blocks and the synchronous extrusion of the second expansion head, the upper part of the expansion cylinder corresponding to the deformation groove deforms uniformly layer by layer, enhancing the uniformity and firmness of the anchoring. At the same time, the elastic support component provides positioning constraints for the expansion cylinder, reducing offset and improving the installation accuracy of the anchor bolt and its adaptability to the drilling diameter.

[0018] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0020] In the picture:

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of the anchor bolt;

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of the anchor bolt;

[0023] Figure 3 This is a cross-sectional structural diagram of the storage box.

[0024] The attached diagram lists the components represented by each number as follows:

[0025] 1. Screw; 2. Nut; 3. Expansion cylinder; 4. Expansion groove; 5. Extension block; 6. First expansion head; 7. Storage box; 8. Spring; 9. Step support block; 10. Sliding column; 11. Limiting circular plate; 12. Flat washer; 13. Triangular pressure block; 14. Second expansion head; 15. Deformation groove; 16. Connecting ring.

[0026] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0027] 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.

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Expanded-base mechanical anchors, as an important branch of mechanical anchoring, primarily utilize the principle of mechanical expansion to form a keyed structure within the substrate cavity, achieving a high-load-bearing anchoring effect. These anchors are widely used in applications such as building curtain wall fixing, bridge structural reinforcement, and industrial equipment base installation. Their core design typically includes an anchor rod, expansion components, and fastening assemblies. Depending on the expansion method, common types include expansion sleeve type, segmented expansion type, and composite expanded-base type. For example, expansion sleeve type anchors usually consist of an anchor rod with a tapered head and a metal sleeve with an outer slot. During installation, rotating the nut drives the anchor rod to move, forcing the tapered head into the sleeve, causing the lower end of the sleeve to expand outward along an axial cut, forming a tight contact with the hole wall. Segmented expansion type uses multiple independent metal plates surrounding the end of the anchor rod. As the anchor rod moves, a beveled structure pushes the metal plates apart to achieve multi-point anchoring. Despite the diverse design forms, existing technologies generally face problems such as insufficient connection stability between the anchor rod and the expansion components, limited vibration resistance, and weak long-term impact resistance.

[0030] In practical applications, traditional expanded-base anchor bolts rely on friction or simple interlocking structures to achieve linkage between the anchor rod and the expansion sleeve. While this design can meet basic requirements under static loads, it is prone to relative displacement due to vibration or impact under dynamic conditions. For example, when the anchor bolt is subjected to periodic external forces, minute slippage between the anchor rod and the sleeve can gradually weaken the initial anchoring force and even lead to anchoring failure. Some improved solutions attempt to add protrusions or grooves to the anchor rod surface to enhance mechanical engagement, but due to the lack of an elastic reset mechanism, the connection strength may still decrease after long-term use due to material wear or plastic deformation. Furthermore, as a key component that directly bears the reaction force of the matrix, the structural strength and deformation resistance of the expansion sleeve directly affect the anchor bolt's lifespan. In existing technologies, the sleeve is mostly made of a single metal material and expands through a slotted design. However, when there are pores or embedded gravel in the concrete matrix, local areas of the sleeve are prone to cracking due to stress concentration. Especially under frequent impact loads, the expanded area may undergo permanent deformation, resulting in a reduction in the anchoring contact area.

[0031] Regarding the optimization of impact resistance, some existing technologies attempt to add a protective layer or buffer structure to the outside of the expansion sleeve. For example, rubber or polymer materials are used to wrap the sleeve to absorb external impact energy, or metal reinforcing rings are added to disperse stress. However, such designs often face problems such as material aging, failure of adhesion to the substrate, or increased structural weight. Rubber buffer layers are prone to hardening and cracking in humid or high-temperature environments, losing their elastic buffering function; the weld points between the metal reinforcing ring and the sleeve are prone to fatigue cracks under repeated impacts, thus becoming weak points in the structure. In addition, the expansion action of traditional anchors usually relies on the unidirectional thrust generated by the rotation of the nut, lacking dynamic feedback adjustment of the expansion process. When the substrate hardness is uneven or there are deviations in the drilling, the anchor may over-expand on one side and under-expand on the other side due to uneven expansion resistance, resulting in an unbalanced distribution of anchoring force, or even causing sleeve to twist and deform.

[0032] Another common challenge lies in the insufficient self-adjustment capability during anchor installation. For example, when there is a slight tilt or diameter deviation in the base hole, the rigid structure of traditional anchors may lead to uneven contact between the expansion component and the hole wall, and some areas may fail to form an effective locking key. Some designs attempt to improve adaptability through multi-segment expansion heads or flexible connection structures, but due to the lack of an effective radial constraint mechanism, the expanded sleeve may spring back, reducing its fit with the hole wall. In addition, the limiting structure of existing anchors mostly uses fixed grooves or pins for locking. Such rigid designs are prone to causing difficulties in aligning the anchor rod and sleeve when there are installation deviations or base deformation, and may even lead to jamming, affecting construction efficiency.

[0033] Material selection and manufacturing processes also significantly impact anchor bolt performance. For example, low-cost anchor bolts are often made of ordinary carbon steel, which, while meeting general strength requirements, is prone to corrosion in humid or corrosive environments, leading to obstructed expansion joint movement or reduced structural strength. Some high-specification products use stainless steel or surface coatings to improve corrosion resistance, but this significantly increases costs, limiting their widespread application. On the other hand, the slit or segment design of the expansion joint requires precise control of processing accuracy. Uneven slit widths or burrs on the edges may cause stress concentration during expansion, accelerating fatigue damage.

[0034] In summary, while existing expanded-base mechanical anchors achieve their foundation anchoring function, they still suffer from common problems such as insufficient stability in the connection between the anchor bolt and the expansion component, weak resistance to dynamic loads, limited impact resistance and structural durability, and room for improvement in installation adaptability. Especially in complex environments or under long-term vibration conditions, the performance of anchors degrades rapidly, limiting their application in high-reliability engineering. Therefore, breakthroughs are urgently needed in structural design, material optimization, and dynamic adjustment mechanisms to comprehensively improve the mechanical properties and environmental adaptability of anchors.

[0035] Please see Figure 1-3As shown, this embodiment provides a bottom-expanding mechanical anchor bolt, including: a screw 1, a first expansion head 6 provided on the lower end face of the screw 1, an expansion cylinder 3 sleeved on the periphery and a nut 2 threadedly engaged, the expansion cylinder 3 being located between the nut 2 and the first expansion head 6, the nut 2 being located above the first expansion head 6, and an elastic support member being provided on the periphery of the expansion cylinder 3;

[0036] The expansion cylinder 3 is evenly provided with multiple expansion grooves 4 and multiple deformation grooves 15 on its periphery. Both the expansion grooves 4 and the deformation grooves 15 are connected to the inner cavity of the expansion cylinder 3. The expansion grooves 4 penetrate the lower end face of the expansion cylinder 3, and the deformation grooves 15 are located above the expansion grooves 4. The screw 1 is provided with a second expansion head 14 on its periphery. Both the first expansion head 6 and the second expansion head 14 are frustoconical structures. The inner wall of the expansion cylinder 3 is provided with multiple triangular pressure blocks 13. The triangular pressure blocks 13 are located between two adjacent deformation grooves 15. The second expansion head 14 is located below the triangular pressure blocks 13. The triangular pressure blocks 13 correspond to the upper half of the deformation grooves 15.

[0037] Multiple triangular pressure blocks 13 are vertically divided into multiple layers, so that the second expansion head 14 can simultaneously squeeze each layer of triangular pressure blocks 13.

[0038] One application of this embodiment is as follows: In use, the screw 1 and the expansion cylinder 3 are first inserted into the pre-drilled mounting hole. If the diameter of the mounting hole is large, the elastic support can be inserted into the mounting hole at the same time, and the elastic support can be used to provide initial positioning by adhering to the hole wall. When the nut 2 is tightened, the nut 2 drives the screw 1 to move upward, forcing the frustum-shaped structure of the first expansion head 6 to push into the lower end of the expansion cylinder 3. Since the expansion grooves 4 are distributed through the lower end of the expansion cylinder 3, the lower end of the expansion cylinder 3 is squeezed outward by the first expansion head 6 to form a preliminary anchoring. At the same time, the second expansion on the screw 1 The first expansion head 14 presses upward against the triangular pressure block 13 on the inner wall of the expansion cylinder 3. The frustum surface of the second expansion head 14 squeezes the triangular pressure block 13 outward, causing the upper half of the expansion cylinder 3 corresponding to the deformation groove 15 to deform and expand outward, further increasing the contact pressure between the expansion cylinder 3 and the hole wall. During this process, the second expansion head 14 can squeeze the triangular pressure block 13 layer by layer from bottom to top, and the lower triangular pressure block 13 is used to stop and limit the second expansion head 14. The lower end of the expansion cylinder 3 corresponding to the expansion groove 4 and the upper half of the deformation groove 15 partially expand to form a multi-stage anchoring. It should be noted that all electrical equipment involved in this application can be powered by a battery or an external power source.

[0039] The frustum-shaped structure of the first expansion head 6 and the second expansion head 14 on the screw 1, combined with the expansion groove 4 and deformation groove 15 of the expansion cylinder 3, enables multi-stage anchoring, facilitating the synergistic effect of initial expansion and mid-section synchronous expansion, thereby improving the overall stability of the anchor bolt. Through the layered arrangement of the triangular pressure block 13 and the synchronous extrusion of the second expansion head 14, the upper part of the expansion cylinder 3 corresponding to the deformation groove 15 deforms uniformly layer by layer, enhancing the uniformity and firmness of the anchoring. At the same time, the elastic support member provides positioning constraints for the expansion cylinder 3, reducing offset and improving the installation accuracy of the anchor bolt and its adaptability to the drilling diameter.

[0040] like Figure 1 , 2 As shown, in this embodiment, a flat washer 12 is sleeved around the screw 1. The flat washer 12 is located between the nut 2 and the expansion cylinder 3. The diameter of the flat washer 12 is larger than the diameter of the nut 2 and the expansion cylinder 3. The flat washer 12 disperses the direct pressure of the nut 2 on the expansion cylinder 3, reduces the risk of deformation at the upper end of the expansion cylinder 3, and facilitates the protection of the structural integrity of the expansion cylinder 3.

[0041] like Figure 2 As shown, in this embodiment, a spring washer is sleeved around the screw 1. The spring washer is located between the nut 2 and the flat washer 12. The spring washer reduces the risk of the nut 2 retraction caused by external load and improves the long-term fastening reliability of the anchor bolt.

[0042] like Figure 1-3 As shown, the elastic support member in this embodiment includes a connecting ring 16, which is located on the periphery of the expansion cylinder 3. The expansion cylinder 3 is located between the expansion groove 4 and the deformation groove 15. A plurality of storage boxes 7 are evenly arranged on the periphery of the connecting ring 16. The storage boxes 7 correspond to the deformation groove 15. A stepped support block 9 is elastically fitted on the side of the storage box 7 away from the connecting ring 16. The stepped support block 9 gradually thickens from bottom to top. Through the cooperation of the connecting ring 16, the storage box 7 and the stepped support block 9, the gradually thickening structure of the stepped support block 9 can adapt to the shape of the hole wall of different diameters, thereby improving the fit between the elastic support member and the hole wall.

[0043] like Figure 2 As shown, in this embodiment, the storage box 7 is provided with an extension block 5 on the lower part of the side away from the step support block 9. The extension block 5 is located below the connecting ring 16 and is snapped into the corresponding expansion groove 4. By snapping the extension block 5 into the expansion groove 4, it is convenient to position and install the elastic support on the expansion cylinder 3, thereby ensuring that the expansion cylinder 3 is located between the expansion groove 4 and the deformation groove 15, and aligning the storage box 7 with the deformation groove 15.

[0044] like Figure 3As shown, in this embodiment, the upper part of the stepped support block 9 near the storage box 7 is provided with a sliding column 10. The sliding column 10 passes through the corresponding storage box 7 laterally. By passing through the storage box 7 laterally and connecting the stepped support block 9, the lateral displacement range of the stepped support block 9 is limited, so that the stepped support block 9 can elastically extend and retract only in a preset direction, thereby improving the guiding nature of the elastic support member's support action.

[0045] like Figure 3 As shown, in this embodiment, a limiting circular plate 11 is provided on the end face of the sliding column 10 away from the stepped support block 9. The limiting circular plate 11 is located between the storage box 7 and the expansion cylinder 3. The displacement distance of the sliding column 10 is limited by the limiting circular plate 11, thereby improving the reliability of the support of the stepped support block 9.

[0046] like Figure 3 As shown, in this embodiment, multiple springs 8 are installed between the stepped support block 9 and one side of the inner wall of the storage box 7. The springs 8 are located below the sliding column 10. The multiple springs 8 are vertically equidistant and connected to the stepped support block 9 and the storage box 7 through the springs 8, so that the stepped support block 9 can be kept in contact with the hole wall by using the springs 8.

[0047] This utility model is not limited to the above-described embodiments. Anyone should know that structural changes made under the guidance of this utility model, and any technical solutions that are the same as or similar to this utility model, fall within the protection scope of this utility model. Technical aspects, shapes, and structures not described in detail in this utility model are all publicly known technologies.

Claims

1. A mechanical anchor with an enlarged base, characterized in that, The utility model relates to a screw rod (1) is provided with a first expansion head (6) on the lower end face, is provided with an expansion cylinder (3) on the lateral side, and is provided with a nut (2) through screwing, and the lateral side of the expansion cylinder (3) is provided with elastic supporting parts; The lateral side of the expansion cylinder (3) is uniformly provided with a plurality of expansion grooves (4) and a plurality of deformation grooves (15), the expansion grooves (4) penetrate the lower end face of the expansion cylinder (3), the lateral side of the screw rod (1) is provided with a second expansion head (14), the first expansion head (6) and the second expansion head (14) are both circular truncated cone structures, the inner wall side of the expansion cylinder (3) is provided with a plurality of triangular compression blocks (13), the triangular compression blocks (13) are located between adjacent two deformation grooves (15), and the second expansion head (14) is located below the triangular compression blocks (13). The lateral side of the screw rod (1) is provided with a flat washer (12), and the flat washer (12) is located between the nut (2) and the expansion cylinder (3).

2. A mechanical anchor with an enlarged base according to claim 1, wherein The lateral side of the screw rod (1) is provided with a spring washer, and the spring washer is located between the nut (2) and the flat washer (12).

3. A mechanical anchor of the undercut type according to claim 2, characterized in that The elastic supporting parts include a connecting ring (16), the connecting ring (16) is located on the lateral side of the expansion cylinder (3), the lateral side of the connecting ring (16) is uniformly provided with a plurality of storage boxes (7), the storage boxes (7) correspond to the deformation grooves (15), and the side, away from the connecting ring (16), of the storage boxes (7) is elastically provided with a stepped support block (9).

4. A mechanical anchor of the undercut type according to claim 1, characterized in that The side, away from the stepped support block (9), of the storage box (7) is provided with an extension block (5) at the lower part, and the extension block (5) is clamped in the corresponding expansion groove (4).

5. A mechanical anchor of the undercut type according to claim 4, characterized in that The side, close to the storage box (7), of the stepped support block (9) is provided with a sliding column (10) at the upper part, and the sliding column (10) penetrates the corresponding storage box (7) horizontally.

6. A mechanical anchor of the undercut type according to claim 4, characterized in that The end face, away from the stepped support block (9), of the sliding column (10) is provided with a limiting circular plate (11), and the limiting circular plate (11) is located between the storage box (7) and the expansion cylinder (3).

7. A bulb mechanical anchor according to claim 6, wherein, A plurality of springs (8) are arranged between the stepped support block (9) and the inner wall side of the storage box (7), and the springs (8) are located below the sliding column (10).

8. A mechanical anchor of the undercut type according to claim 1, wherein ​

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