A pre-buried adjustable expansion depth expansion bolt assembly

Abstract

The application discloses a pre-buried adjustable expansion depth expansion bolt assembly and belongs to the technical field of expansion bolts, which comprises a spring pad, a flat pad, a pre-buried sleeve, a hexagonal nut, an expansion sleeve, an expansion cone, an adjusting screw rod and a sealing end cover. In order to overcome the defects of the prior art, such as the damage to the concrete structure and the internal steel bars caused by the post-construction of the expansion bolt, the fixed and unadjustable expansion depth of the pre-buried anchor bolt, the jamming of the adjusting mechanism caused by the cement seepage due to the unreliable sealing of the plastic film during the pouring process, and the loosening of the anchoring force under long-term vibration, the application provides the pre-buried adjustable expansion depth expansion bolt assembly, so that the expansion depth of the expansion bolt on the market can be flexibly adjusted according to the actual wall thickness or the size of the decorative layer under the premise of pre-buried installation, the problems of the poor stability of the sealing end cover during the pouring process, the cement leakage caused by the poor stability of the sealing end cover, the single anchoring force between the expansion sleeve and the concrete and the insufficient long-term reliability of the expansion sleeve and the concrete are solved.

Description

Technical Field

[0001] This invention belongs to the field of expansion bolt technology, specifically referring to a pre-embedded expansion bolt assembly with adjustable expansion depth. Background Technology

[0002] Currently, most expansion bolts used in building anchoring are post-installed structures. This involves drilling holes in hardened concrete or masonry, inserting the expansion tube into the holes, and then tightening the nut to move the bolt outwards, pulling the cone or sleeve to radially expand the expansion tube, achieving anchoring through friction. However, this post-installation method has significant drawbacks: the drilling process easily damages internal reinforcing steel, and can cause concrete cracking in thin-walled structures or edge areas; furthermore, the anchoring depth is limited by the hole depth, making it impossible to flexibly adjust according to the actual wall thickness or the size of subsequent decorative layers. In addition, while some pre-embedded anchors avoid the post-drilling problem, their expansion depth is fixed and cannot be adjusted according to site conditions after the concrete has hardened, resulting in poor adaptability.

[0003] Another common problem is the reliability of the seal during pouring. Some embedded parts use plastic film as a temporary cover, which is easily ruptured or deformed by cement slurry during concrete pouring. This causes cement to seep into the casing, contaminating the threads and sliding mating surfaces, ultimately causing the adjustment mechanism to jam and the expansion function to fail. Meanwhile, the anchoring force of existing expansion bolts mainly relies on the friction between the expansion tube and the hole wall, which is prone to loosening under long-term vibration or load changes. While embedded parts have mechanical embedding capabilities, they cannot simultaneously meet the requirements of adjustable expansion depth and reliable anchoring. Therefore, it is necessary to design an expansion bolt assembly that can be pre-installed to avoid post-drilling damage, allows for adjustment of the expansion depth as needed, and possesses good sealing performance and reliable anchoring force. Summary of the Invention

[0004] To address the aforementioned issues and overcome the shortcomings of existing expansion bolts, such as easy damage to concrete structures and internal reinforcing bars during post-installation, fixed and unadjustable expansion depth of pre-embedded anchors, unreliable sealing of plastic film during pouring leading to cement seepage and jamming of the adjustment mechanism, and anchoring force relying mainly on friction which is prone to loosening under long-term vibration, this invention provides a pre-embedded adjustable expansion bolt assembly. This effectively solves the problems of current market expansion bolts being unable to flexibly adjust the expansion depth according to the actual wall thickness or decorative layer size under the premise of pre-embedded installation, poor stability of the sealing end cap during pouring leading to cement leakage, and the single anchoring force between the expansion sleeve and concrete with insufficient long-term reliability.

[0005] The technical solution adopted by this invention is as follows: This invention provides a pre-embedded adjustable expansion bolt assembly, including a spring washer, a flat washer, a pre-embedded sleeve, a hexagonal nut, an expansion sleeve, an expansion cone, an adjusting screw, and a sealing end cap. The sealing end cap is sleeved on the outer wall of the end of the pre-embedded sleeve that is embedded in cement. The sealing end cap prevents the pre-embedded sleeve from being sealed by cement when it is embedded in cement, thus ensuring the stability of the pre-embedded sleeve structure. The spring washer is in contact with the end of the pre-embedded sleeve away from cement. The flat washer is in contact with the spring washer. The hexagonal nut is in contact with the flat washer. The expansion sleeve engages and slides in a straight line inside the pre-embedded sleeve. The expansion cone engages and slides in a straight line inside the expansion sleeve. The two ends of the adjusting screw are respectively engaged with the expansion cone and the hexagonal nut, and the thread grooves at both ends of the adjusting screw are in the same direction but have different pitches.

[0006] Furthermore, the pre-embedded sleeve is a cylindrical straight pipe with both ends inclined towards the center. The pre-embedded sleeve has a longitudinal gap A on the side near the cement. The outer wall of the pre-embedded sleeve is provided with a rib ring. The rib ring is a curved ring structure with a curved opening facing away from the cement, which can prevent the pre-embedded sleeve from being pulled out of the pre-embedded area by external force.

[0007] Furthermore, the hexagonal nut is provided with a skirt-shaped clamping plate, which has a longitudinal slit. The longitudinal slit helps the operator to pass the skirt-shaped clamping plate through the small hole at the center of the spring washer and flat washer, and clamp it onto the inner wall of the pre-embedded sleeve. The end of the skirt-shaped clamping plate engages and is fixed with the side wall of the pre-embedded sleeve that is inclined towards the center at the top.

[0008] Furthermore, the sealing end cap is composed of multiple arc-shaped plates spliced ​​together. The adjacent sets of arc-shaped plates are bonded together by hot-melting rigid plastic ropes. The plastic ropes have a triangular notch on the side away from the center of the sealing end cap. The notch on the side of the plastic rope away from the center of the sealing end cap not only ensures that the plastic ropes connect to the sealing end cap, but also makes it easier for the plastic ropes to break when the pre-embedded sleeve expands outward. When the pre-embedded sleeve is expanded by the expansion sleeve, the sealing end cap will not fix the shape of the pre-embedded sleeve.

[0009] Furthermore, the adjusting screw is composed of bolt P, bolt Q and connecting column. The two ends of the connecting column are fixedly connected to bolt P and bolt Q respectively, and the thread directions of bolt P and bolt Q are the same, but the pitch of the thread on the surface of bolt P is greater than the pitch of the thread on the surface of bolt Q.

[0010] Furthermore, the expansion sleeve includes an expansion deformation tube and a contact fixing tube, both of which are cylindrical structures. The connection between the expansion deformation tube and the contact fixing tube is rounded. The outer wall of the contact fixing tube has a rough curved surface. The inner wall of the expansion deformation tube has an inner conical surface on the side near the sealing end cap, which contacts and cooperates with the expansion cone. The outer wall of the expansion deformation tube has a trapezoidal prism. The expansion deformation tube has a gap that penetrates both the inner and outer walls.

[0011] Preferably, the horizontal cross-section of the gap A is set as a triangle, and the gap A penetrates the inner and outer walls of the pre-embedded sleeve. The triangular cross-section of the gap A can prevent external cement from entering the pre-embedded sleeve, and can also ensure that the trapezoidal prism slides along the gap A. When the expansion sleeve expands, the trapezoidal prism passes through the pre-embedded sleeve and contacts the cement, thereby improving the overall stability of the expansion screw.

[0012] Furthermore, the expansion cone is designed as a hollow cone structure. The diameter of the expansion cone is small on the side near the sealing end cap, and the diameter is large at the other end. A through threaded hole is provided in the center of the expansion cone. The threaded hole on the expansion cone engages with the bolt post Q. The outer wall of the expansion cone is provided with a longitudinal protrusion to prevent it from rotating with the adjusting screw. The inner wall of the expansion deformation tube is provided with a longitudinal groove. The longitudinal protrusion engages and slides in the longitudinal groove. The longitudinal protrusion and the longitudinal groove are tightly fitted. Without the influence of external force, the expansion cone will move the expansion sleeve together into the depth of the pre-embedded sleeve under the influence of the frictional resistance between the longitudinal protrusion and the longitudinal groove.

[0013] Furthermore, the outer wall of the pre-embedded sleeve at the end furthest from the pre-embedded depth is provided with a thread A, and a nut A is provided at the thread. A pressing groove is provided in the side wall area of ​​the pre-embedded sleeve where the thread A is located. A triangular pressing piece is provided in the pressing groove. A resistance-increasing clamp is provided below the pressing piece. A spring reset is provided between the pressing piece and the inner wall of the pre-embedded sleeve. The resistance-increasing clamp is pressed and fixed to the outer wall of the contact fixing tube. After the expansion sleeve reaches the desired expansion depth, the nut A is rotated along the thread A to squeeze the pressing piece, so that the resistance-increasing clamp clamps the contact fixing tube. Then, the adjusting screw is rotated again, and the expansion sleeve no longer moves. The expansion cone moves and squeezes the expansion deformation tube. The trapezoidal prism squeezes and passes through the gap A. The pre-embedded sleeve squeezes the pre-embedded area, and the trapezoidal prism contacts the pre-embedded area to achieve expansion and fixation at a specific depth.

[0014] Furthermore, the connecting surfaces of the skirt-shaped clamping plate and the pre-embedded sleeve are respectively provided with clamping blocks and clamping grooves to ensure the relative stability between the pre-embedded sleeve and the hexagonal nut when the adjusting screw rotates.

[0015] This solution provides a pre-embedded expansion bolt assembly with adjustable expansion depth, which has the following advantages:

[0016] (1) The sealing end cap used in this application is composed of multiple arc-shaped plates bonded together by hot-melt bonding with rigid plastic ropes. The plastic ropes have a triangular notch on the side away from the center, which can prevent cement mortar from entering and does not restrict the expansion deformation of the expansion screws. Compared with the traditional plastic film sealing method, this structure has higher overall stability when the pre-embedded sleeve is poured with concrete. It can effectively prevent cement slurry from entering the pre-embedded sleeve and avoid contamination of the threads and sliding surfaces. When the expansion sleeve is squeezed and expanded by the expansion cone, the plastic rope will break precisely along the triangular notch, and the sealing end cap will separate by itself. This ensures the sealing reliability during pouring and does not hinder the normal expansion action of the expansion sleeve, which significantly improves the success rate of pre-embedded construction and the long-term working reliability of the components.

[0017] (2) This application sets the threads at both ends of the adjusting screw to be in the same direction but with different pitches (the pitch of bolt post P is greater than the pitch of bolt post Q), and with the tight sliding fit between the longitudinal protrusion on the outer wall of the expansion cone and the longitudinal groove on the inner wall of the expansion sleeve, the expansion sleeve and the expansion cone move together into the depth of the pre-embedded sleeve when the adjusting screw is rotated, and the moving speed can be precisely controlled; the operator only needs to rotate the corresponding number of turns according to the required expansion depth to position the expansion sleeve at any axial position in the pre-embedded sleeve, and then tighten the nut A to make the pressing plate drive the resistance increasing clamp to clamp the contact fixed pipe, thereby truly realizing the stepless adjustment of the expansion depth, which can flexibly adapt to different wall thicknesses or decorative layer conditions, and overcome the defect that the depth of traditional pre-embedded parts is not adjustable;

[0018] (3) This application features a trapezoidal prism on the outer wall of the expansion sleeve and a longitudinal gap with a triangular horizontal cross-section at the front end of the pre-embedded sleeve. When the expansion cone compresses the expansion sleeve to expand radially, the trapezoidal prism can smoothly slide out along the triangular gap and directly press against the concrete wall. At the same time, the cross-sectional structure of the triangular gap can effectively prevent cement from seeping in during pouring and also provide a directional expansion channel for the trapezoidal prism. In addition, the rib ring on the outer wall of the pre-embedded sleeve is designed as a curved ring structure with a curved opening facing away from the cement, which enhances the pull-out resistance of the sleeve in the concrete. The synergistic effect of the above structures means that the anchoring force comes from both the direct compression between the expansion sleeve and the concrete and the mechanical embedding of the pre-embedded sleeve itself, which greatly improves the overall anchoring reliability and vibration resistance. Attached Figure Description

[0019] Figure 1 A perspective view of a pre-embedded adjustable expansion bolt assembly provided by the present invention;

[0020] Figure 2 A perspective sectional view of a pre-embedded adjustable expansion bolt assembly provided by the present invention;

[0021] Figure 3An exploded view of an embedded adjustable expansion bolt assembly provided for this invention;

[0022] Figure 4 A front view of a pre-embedded adjustable expansion bolt assembly provided by the present invention;

[0023] Figure 5 Right view of a pre-embedded adjustable expansion bolt assembly provided by the present invention;

[0024] Figure 6 A left sectional view of an embedded adjustable expansion bolt assembly provided by the present invention;

[0025] Figure 7 A front sectional view of an embedded adjustable expansion bolt assembly provided by the present invention;

[0026] Figure 8 A schematic diagram showing the spatial positions of the spring washer, flat washer, and hexagonal nut;

[0027] Figure 9 for Figure 2 A magnified view of part A in the middle;

[0028] Figure 10 This is a three-dimensional sectional view of the expansion sleeve;

[0029] Figure 11 This is a three-dimensional view of an expanding cone.

[0030] Among them, 1. Spring washer, 2. Flat washer, 3. Embedded sleeve, 4. Hexagonal nut, 5. Expansion sleeve, 6. Expansion cone, 7. Adjusting screw, 8. Sealing end cap, 301. Rib ring, 302. Gap A, 401. Skirt-shaped clamping plate, 801. Plastic rope, 701. Bolt post P, 702. Bolt post Q, 703. Connecting post, 501. Expansion deformation tube, 502. Contact fixing tube, 503. Trapezoidal prism, 601. Longitudinal convex ridge, 602. Longitudinal groove, 311. Thread A, 312. Nut A, 313. Pressing groove, 314. Pressing plate, 315. Resistance increasing clamp.

[0031] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] like Figures 1-11 As shown, the present invention provides a pre-embedded adjustable expansion bolt assembly, including a spring washer 1, a flat washer 2, a pre-embedded sleeve 3, a hexagonal nut 4, an expansion sleeve 5, an expansion cone 6, an adjusting screw 7, and a sealing end cap 8. The sealing end cap 8 is sleeved on the outer wall of the end of the pre-embedded sleeve 3 that is embedded in the cement. The spring washer 1 is in contact with the end of the pre-embedded sleeve 3 away from the cement. The flat washer 2 is in contact with the spring washer 1. The hexagonal nut 4 is in contact with the flat washer 2. The expansion sleeve 5 engages and slides in a straight line inside the pre-embedded sleeve 3. The expansion cone 6 engages and slides in a straight line inside the expansion sleeve 5. The two ends of the adjusting screw 7 are respectively engaged with the expansion cone 6 and the hexagonal nut 4, and the thread grooves at both ends of the adjusting screw 7 are in the same direction but have different pitches.

[0035] The pre-embedded sleeve 3 is a cylindrical straight pipe with both ends inclined towards the center. The pre-embedded sleeve 3 has a longitudinal gap A302 on the side close to the cement. The outer wall of the pre-embedded sleeve 3 is provided with a rib ring 301, which is a curved ring structure with a curved opening towards the side far from the cement.

[0036] The hexagonal nut 4 is provided with a skirt-shaped clamping plate 401, which has a longitudinal slit. The end of the skirt-shaped clamping plate 401 is engaged and fixed with the side wall of the pre-embedded sleeve 3 that is inclined towards the center.

[0037] The sealing end cap 8 is composed of multiple arc-shaped plates. Adjacent sets of arc-shaped plates are bonded together by hot-melting rigid plastic ropes 801. The plastic ropes 801 have a triangular notch on one side away from the center of the sealing end cap 8.

[0038] The adjusting screw 7 consists of bolt post P701, bolt post Q702 and connecting post 703. The two ends of the connecting post 703 are fixedly connected to bolt post P701 and bolt post Q702 respectively. The threads of bolt post P701 and bolt post Q702 are in the same direction, but the pitch of the thread on the surface of bolt post P701 is greater than the pitch of the thread on the surface of bolt post Q702.

[0039] The expansion sleeve 5 includes an expansion deformation tube 501 and a contact fixing tube 502. Both the expansion deformation tube 501 and the contact fixing tube 502 are cylindrical structures. The connection between the expansion deformation tube 501 and the contact fixing tube 502 is rounded. The outer wall of the contact fixing tube 502 is rough curved. The inner wall of the expansion deformation tube 501 is provided with an inner conical surface on the side near the sealing end cap 8, which contacts and cooperates with the expansion cone 6. The outer wall of the expansion deformation tube 501 is provided with a trapezoidal prism 503. The expansion deformation tube 501 is provided with a gap that penetrates the inner and outer walls.

[0040] The horizontal cross-section of the gap A302 is set as a triangle, and the gap A302 penetrates the inner and outer walls of the pre-embedded sleeve 3. The triangular cross-section of the gap A302 can prevent external cement from entering the pre-embedded sleeve 3, and can also ensure that the trapezoidal prism 503 slides along the gap A302.

[0041] The expansion cone 6 is designed as a hollow cone structure. The diameter of the expansion cone 6 is small on the side near the sealing end cover 8 and large on the other end. The center of the expansion cone 6 is provided with a through threaded hole. The threaded hole on the expansion cone 6 engages with the bolt post Q702. The outer wall of the expansion cone 6 is provided with a longitudinal protrusion 601 to prevent it from rotating with the adjusting screw 7. The inner wall of the expansion deformation tube 501 is provided with a longitudinal groove 602. The longitudinal protrusion 601 engages and slides in the longitudinal groove 602. The longitudinal protrusion 601 and the longitudinal groove 602 are tightly fitted together.

[0042] The outer wall of the pre-embedded sleeve 3, away from the deep pre-embedded part, is provided with a thread A311 and a nut A312. The side wall area of ​​the pre-embedded sleeve 3 where the thread A311 is located is provided with a pressing groove 313. A triangular pressing piece 314 is provided in the pressing groove 313. A resistance-increasing clamping plate 315 is provided below the pressing piece 314. A spring for resetting is provided between the pressing piece 314 and the inner wall of the pre-embedded sleeve 3. The resistance-increasing clamping plate 315 is pressed and fixed to the outer wall of the contact fixing tube 502.

[0043] The skirt-shaped clamping plate 401 and the pre-embedded sleeve 3 are respectively provided with clamping blocks and clamping grooves on their connection surfaces.

[0044] In practical use, the sealing end cap 8 is fitted onto one end of the pre-embedded sleeve 3. The expansion sleeve 5, expansion cone 6, and adjusting screw 7 are all installed in the pre-embedded sleeve 3. Before use, the expansion sleeve 5 is positioned at one end of the pre-embedded sleeve 3 near the pre-embedded concrete area. Then, the skirt-shaped clamping plate 401 on the hexagonal nut 4 is engaged and fixed on the pre-embedded sleeve 3. This makes it easy to disassemble and assemble before the expansion operation and avoids the loss of parts while waiting for the cement to solidify.

[0045] To improve the stability of the pre-embedded sleeve 3 and hexagonal nut 4 during use, the locking blocks and slots inside the pre-embedded sleeve 3 and hexagonal nut 4 are engaged and fixed with each other. Then, the hexagonal nut 4 is fixed with a wrench to improve the relative stability between the pre-embedded sleeve 3 and hexagonal nut 4. Finally, the adjusting screw 7 is rotated.

[0046] The operator uses a tool to rotate the adjusting screw 7. Since the position of the pre-embedded sleeve 3 is fixed, the adjusting screw 7 will move a fixed distance deeper into the pre-embedded sleeve 3 with each rotation. At the same time, due to the different pitches on the surfaces of bolt post P701 and bolt post Q702, bolt post Q702 rotates. Due to the difference in the pitch of the double threads, bolt post Q702 drives the expansion cone 6 to move. The expansion cone 6 moves at a speed less than that of bolt post P701. Due to the frictional resistance between the longitudinal protrusion 601 and the longitudinal groove 602, the expansion sleeve 5 moves together with the expansion cone 6.

[0047] The number of rotations of the adjusting screw 7 is proportional to the depth it enters the pre-embedded sleeve 3. When the expansion sleeve 5 is moved to the appropriate depth, rotate the nut A312 to press the pressing plate 314. The pressing plate 314 slides toward the center of the pre-embedded sleeve 3, and the resistance-increasing clamp 315 clamps and contacts the fixed tube 502, thereby fixing the position of the expansion deformation tube 501.

[0048] Then rotate the adjusting screw 7. At this time, only the expansion cone 6 slides along the inner wall of the expansion sleeve 5. The expansion cone 6 squeezes the inner cone surface of the expansion sleeve 5 and causes the expansion sleeve 5 to expand outward. The trapezoidal prism 503 on the outer wall of the expansion sleeve 5 squeezes the gap A302, causing the gap A302 to open. The pressure between the pre-embedded sleeve 3 and the pre-embedded area increases. The trapezoidal prism 503 contacts the cement in the pre-embedded area, increasing the friction between the trapezoidal prism 503 and the pre-embedded area.

[0049] By repeatedly rotating the adjusting screw 7, the expansion sleeve 5 expands to a greater extent, and the expansion effect becomes more obvious.

[0050] During the process of the pre-embedded sleeve 3 being squeezed and expanded by the expansion sleeve 5, the plastic rope 801 on the sealing end cap 8 is broken, and the sealing end cap 8 will not restrict the expansion of the pre-embedded sleeve 3.

[0051] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0052] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An embedded adjustable expansion bolt assembly, comprising a spring washer (1) and a flat washer (2), wherein the flat washer (2) is in contact with the spring washer (1), characterized in that: It also includes a pre-embedded sleeve (3), a hexagonal nut (4), an expansion sleeve (5), an expansion cone (6), an adjusting screw (7), and a sealing end cap (8). The sealing end cap (8) is fitted onto the outer wall of the end of the pre-embedded sleeve (3) that is embedded in the cement. The spring washer (1) is in contact with the end of the pre-embedded sleeve (3) that is away from the cement. The hexagonal nut (4) is in contact with the flat washer (2). The expansion sleeve (5) engages and slides in a straight line inside the pre-embedded sleeve (3). The expansion cone (6) engages and slides in a straight line inside the expansion sleeve (5). The two ends of the adjusting screw (7) are respectively engaged with the expansion cone (6) and the hexagonal nut (4). The thread grooves at both ends of the adjusting screw (7) are in the same direction but have different pitches.

2. The pre-embedded adjustable expansion bolt assembly according to claim 1, characterized in that: The pre-embedded sleeve (3) is a cylindrical straight pipe with both ends inclined towards the center. The pre-embedded sleeve (3) has a longitudinal gap A (302) on the side close to the cement. The outer wall of the pre-embedded sleeve (3) is provided with a rib ring (301). The rib ring (301) is a curved ring structure with a curved opening towards the side far from the cement.

3. The pre-embedded adjustable expansion bolt assembly according to claim 2, characterized in that: The adjusting screw (7) is composed of bolt post P (701), bolt post Q (702) and connecting post (703). The two ends of the connecting post (703) are fixedly connected to bolt post P (701) and bolt post Q (702) respectively. The thread directions of bolt post P (701) and bolt post Q (702) are the same, but the pitch of the thread on the surface of bolt post P (701) is greater than the pitch of the thread on the surface of bolt post Q (702).

4. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 3, characterized in that: The expansion sleeve (5) includes an expansion deformation tube (501) and a contact fixing tube (502). Both the expansion deformation tube (501) and the contact fixing tube (502) are cylindrical. The connection between the expansion deformation tube (501) and the contact fixing tube (502) is rounded. The outer wall of the contact fixing tube (502) is rough curved. The inner wall of the expansion deformation tube (501) near the sealing end cap (8) is provided with an inner conical surface, which contacts and cooperates with the expansion cone (6). The outer wall of the expansion deformation tube (501) is provided with a trapezoidal prism (503). The expansion deformation tube (501) is provided with a gap that penetrates the inner and outer walls.

5. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 4, characterized in that: The horizontal cross-section of the gap A (302) is set as a triangle, and the gap A (302) penetrates the inner and outer walls of the pre-embedded sleeve (3). The triangular cross-section of the gap A (302) can prevent external cement from entering the pre-embedded sleeve (3) and ensure that the trapezoidal prism (503) slides along the gap A (302).

6. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 5, characterized in that: The expansion cone (6) is a hollow cone structure. The diameter of the expansion cone (6) is small on the side near the sealing end cap (8) and large on the other end. The center of the expansion cone (6) is provided with a through threaded hole. The threaded hole on the expansion cone (6) engages with the bolt column Q (702). The outer wall of the expansion cone (6) is provided with a longitudinal protrusion (601) to prevent it from rotating with the adjusting screw (7). The inner wall of the expansion deformation tube (501) is provided with a longitudinal groove (602). The longitudinal protrusion (601) engages and slides in the longitudinal groove (602). The longitudinal protrusion (601) and the longitudinal groove (602) fit tightly together.

7. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 6, characterized in that: The pre-embedded sleeve (3) has a thread A (311) on the outer wall of the end away from the pre-embedded depth. A nut A (312) is provided at the thread A (311). A pressing groove (313) is provided in the side wall area of ​​the pre-embedded sleeve (3) where the thread A (311) is located. A triangular pressing piece (314) is provided in the pressing groove (313). A resistance-increasing clamp (315) is provided below the pressing piece (314). A spring for resetting is provided between the pressing piece (314) and the inner wall of the pre-embedded sleeve (3). The resistance-increasing clamp (315) is pressed and fixed to the outer wall of the contact fixing tube (502).

8. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 7, characterized in that: The hexagonal nut (4) is provided with a skirt-shaped clamping plate (401), the skirt-shaped clamping plate (401) is provided with a longitudinal slit, and the end of the skirt-shaped clamping plate (401) is engaged and fixed with the side wall of the pre-embedded sleeve (3) that is inclined towards the center.

9. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 8, characterized in that: The sealing end cap (8) is composed of multiple arc-shaped plates spliced ​​together. The two adjacent sets of arc-shaped plates are bonded together by hot-melting hard plastic rope (801). The plastic rope (801) has a triangular notch on one side away from the center of the sealing end cap (8).

10. The pre-embedded adjustable expansion depth expansion bolt assembly according to claim 9, characterized in that: The skirt-shaped card plate (401) and the pre-embedded sleeve (3) are respectively provided with card blocks and card slots on their connection surfaces.

Images