Multistage cushioning friction type impact resistant anchor rod

Abstract

This utility model provides a multi-stage buffer friction-type impact-resistant anchor bolt, including a rod body. The rod body is composed of an anchoring section, a pressure-relief section, a friction section, and a standard section, arranged sequentially from top to bottom. A conical anchor head is fixed to the top of the anchoring section. The anchoring section is fixedly connected to the pressure-relief section, the pressure-relief section is fixedly connected to the friction section, and the friction section is fixedly connected to the standard section. A mating component is installed on the standard section. This utility model, through the mating arrangement between the various structures and the use of a multi-stage structural arrangement, improves the practicality of the overall device.

Description

Technical Field

[0001] This utility model relates to the technical field of mine support equipment, specifically to a multi-stage buffer friction-type impact-resistant anchor bolt. Background Technology

[0002] With the depletion of shallow resources, the mining depth of coal and metal mines has been increasing year by year (some mines exceed 1,000 meters in depth), leading to a significant increase in ground stress and a heightened risk of rockburst. Complex geological conditions, such as faults, folds, and hard roofs, easily trigger stress concentrations, which, when combined with mining disturbances, are more likely to trigger rockbursts. In deep mining, tunnel excavation, and slope reinforcement projects, rock masses are frequently threatened by high-intensity, instantaneous dynamic loads generated by stress concentration, rock bursts, and mine tremors. In recent years, coal mining technology has gradually improved, and rock bolts have become a key method for rockburst prevention and control by reinforcing the surrounding rock, improving stress distribution, and absorbing impact energy. The method involves anchor bolts forming an "anchored load-bearing body" with the surrounding rock, improving the overall strength and deformation resistance of the surrounding rock. Traditional anchor bolts (such as threaded steel anchor bolts) have a single energy absorption mode, relying solely on the material's own strength to resist impact. When the instantaneous deformation of the surrounding rock exceeds the yield limit of the bolt (usually 0.2%-0.5% strain), brittle fracture is likely to occur. Furthermore, it is impossible to visually indicate whether the anchor bolt has undergone energy absorption and sliding, which is not conducive to subsequent roadway maintenance and safety monitoring. Existing anchor bolts only absorb energy through tensile plastic deformation of the bolt body, resulting in low energy absorption density (approximately 10-15 kJ / m). After plastic deformation, the anchor bolt cannot be reset, leading to permanent failure of the support system, requiring complete replacement. Therefore, based on the above problems, the present invention provides a multi-stage buffer friction-type impact-resistant anchor bolt. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a multi-stage buffer friction-type impact-resistant anchor bolt, which solves the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: A multi-stage buffer friction-type impact-resistant anchor bolt includes a rod body, which is composed of an anchoring section, a pressure-relief section, a friction section, and a standard section from top to bottom. A conical anchor head is fixed at the top of the anchoring section. The anchoring section is fixedly connected to the pressure-relief section, the pressure-relief section is fixedly connected to the friction section, the friction section is fixedly connected to the standard section, and a mating component is installed on the standard section.

[0005] Furthermore, the outer surface of the anchoring section is provided with deep threads.

[0006] Furthermore, the pressure-relief section is uniformly provided with several annular closed sawtooth grooves, and each annular closed sawtooth groove is filled with polyurethane-carbon fiber composite material.

[0007] Furthermore, the outer surface of the friction section is provided with shallow threads, and a fixing ring is fixedly provided on the friction section. A friction ring is provided above the fixing ring, and the friction ring is sleeved on the friction section. A pre-tightening spring is provided between the friction ring and the fixing ring, and the pre-tightening spring is sleeved on the outer periphery of the friction section.

[0008] Furthermore, limit slots are provided on both sides of the friction section, and a limit block is slidably provided in each limit slot, and each limit block is fixedly connected to the inner wall of the friction ring.

[0009] Furthermore, the mating component includes a buffer sleeve, which is sleeved through the standard section. A locking nut is provided on one side of the buffer sleeve and threaded onto the standard section. An end cap is provided on the other side of the buffer sleeve. A plurality of butterfly spring groups are evenly arranged between the end cap and the buffer sleeve and are fixedly connected by the plurality of butterfly spring groups. An adaptive tray is provided on one side of the end cap, and a spherical washer is fitted at the end of the adaptive tray away from the end cap. The spherical washer, the adaptive tray, and the end cap are all sleeved on the standard section.

[0010] This invention provides a multi-stage buffer friction-type impact-resistant anchor bolt. Compared with the prior art, it has the following advantages: This utility model allows the pressure section to achieve primary energy absorption through groove filling with composite material, the friction section to achieve secondary energy dissipation through sliding friction between a movable friction ring and a pre-tightening spring, and the buffer sleeve to provide tertiary buffering through a nonlinear butterfly spring assembly. Through its multi-stage design, this anchor bolt can greatly increase its practicality. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the front cross-sectional structure of the present invention; Figure 2 This diagram shows a cross-sectional view of the friction ring and the limiting groove of this invention. The figure shows: 1. Rod body; 2. Friction ring; 3. Annular closed sawtooth groove; 4. Locking nut; 5. Spherical washer; 6. Adaptive tray; 7. Butterfly spring assembly; 8. Conical anchor head; 9. Anchoring section; 10. Pressure relief section; 11. Friction section; 12. Standard section; 13. End cap; 14. Buffer sleeve; 15. Limiting groove; 16. Preload spring. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model are described clearly and completely. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0014] Example To address the technical problems in the background section, a multi-stage buffer friction-type impact-resistant anchor bolt is proposed as follows: Combination Figure 1-2 As shown, the present invention provides a multi-stage buffer friction-type impact-resistant anchor rod, including a rod body 1. The rod body 1 is composed of an anchoring section 9, a pressure-relief section 10, a friction section 11, and a standard section 12 from top to bottom. A conical anchor head 8 is fixed at the top of the anchoring section 9 for piercing and anchoring the resin anchoring agent. The anchoring section 9 is fixedly connected to the pressure-relief section 10, the pressure-relief section 10 is fixedly connected to the friction section 11, the friction section 11 is fixedly connected to the standard section 12, and a mating part is installed on the standard section 12.

[0015] The outer surface of the anchoring section 9 is provided with deep threads. Several annular closed sawtooth grooves 3 are evenly formed on the compression section 10, with a groove depth of 5 mm and a spacing of 10 mm. Each annular closed sawtooth groove 3 is filled with polyurethane-carbon fiber composite material. The compression modulus is 800 MPa, with 15% chopped carbon fiber by volume, 5% nano-silica added, a porosity of <2%, and a compression resilience of ≥90%. The edges of the sawtooth grooves are laser-strengthened, resulting in a residual compressive stress ≥500 MPa and a fatigue life increased by 3 times.

[0016] The outer surface of the friction section 11 is provided with shallow threads, and a fixed ring is fixedly provided on the friction section 11. A friction ring 2 is provided above the fixed ring and is sleeved on the friction section 11. A pre-tightening spring 16 is provided between the friction ring 2 and the fixed ring and is sleeved on the outer periphery of the friction section 11.

[0017] Both sides of the friction section 11 are provided with limit slots 15, and each limit slot 15 is provided with a limit block that slides in it. Each limit block is fixed to the inner wall of the friction ring 2. The friction ring is made of copper-based powder metallurgy material with a friction coefficient of 0.2 and a preload spring stiffness of 30kN / mm. The sliding threshold (50-200kN) can be continuously adjusted by rotating the adjusting nut, with an error of <±5%. The preload spring 3 adopts a variable pitch design (pitch 8-12mm), with an initial stiffness of 30kN / mm. When compressed by 50%, the stiffness increases non-linearly to 80kN / mm.

[0018] The mating components include a buffer sleeve 14, which is fitted through the standard section 12. A locking nut 4 is provided on one side of the buffer sleeve 14, threaded onto the standard section 12. An end cap 13 is provided on the other side of the buffer sleeve 14. Several butterfly spring groups 7 are evenly distributed between the end cap 13 and the buffer sleeve 14 and are fixedly connected by these groups. An adaptive tray 6 is provided on one side of the end cap 13. A spherical washer 5 is fitted at the end of the adaptive tray 6 away from the end cap 13. The butterfly spring groups exhibit non-linear stiffness characteristics. The adaptive tray 6 contacts the surrounding rock through the spherical washer 5. The spherical washer 5, the adaptive tray 6, and the end cap 13 are all fitted onto the standard section 12. The spherical washer 5 is a hemispherical structure with a diameter of 50mm and a spherical radius of 30mm. The center diameter of the adaptive tray 6 is 25mm, and its coaxiality error with the rod axis is ≤0.1mm.

[0019] Working principle: A conical anchor head 8 is fixed at the top of the anchoring section 9 to pierce and anchor the resin anchoring agent; The annular closed sawtooth groove 3 (groove depth 5mm, spacing 10mm) on the compression section 10 is filled with polyurethane-carbon fiber composite material, which absorbs the energy of compression deformation and impact (accounting for 30%-40%), thus achieving primary energy absorption. The friction section 11 includes a friction ring 2, a preload spring 16, and a limiting groove 15, etc. When the friction ring slides, it dissipates secondary energy (accounting for 40%-50%) through frictional heat generation. The buffer sleeve is fixed to the end of the rod and has two sets of eight-piece butterfly spring stacked inside. The initial stiffness is 50KN / mm, and the stiffness increases to 120KN / mm when the compression is >30%, thus achieving three-level buffering.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0021] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A multi-stage buffer friction-type impact-resistant anchor bolt, characterized in that: The rod (1) is composed of an anchoring section (9), a pressure relief section (10), a friction section (11) and a standard section (12) from top to bottom. A tapered anchor head (8) is fixed at the top of the anchoring section (9). The anchoring section (9) is fixed to the pressure relief section (10). The pressure relief section (10) is fixed to the friction section (11). The friction section (11) is fixed to the standard section (12). A mating part is installed on the standard section (12).

2. The multi-stage buffer friction-type impact-resistant anchor bolt according to claim 1, characterized in that: The outer surface of the anchoring section (9) is provided with deep threads.

3. The multi-stage buffer friction-type impact-resistant anchor bolt according to claim 1, characterized in that: The pressure relief section (10) is provided with a number of annular closed sawtooth grooves (3), and each annular closed sawtooth groove (3) is filled with polyurethane-carbon fiber composite material.

4. The multi-stage buffer friction-type impact-resistant anchor bolt according to claim 1, characterized in that: The outer surface of the friction section (11) is provided with shallow threads, and a fixing ring is fixed on the friction section (11). A friction ring (2) is provided above the fixing ring. The friction ring (2) is sleeved on the friction section (11). A pre-tightening spring (16) is provided between the friction ring (2) and the fixing ring. The pre-tightening spring (16) is sleeved on the outer periphery of the friction section (11).

5. The multi-stage buffer friction-type impact-resistant anchor bolt according to claim 4, characterized in that: Both sides of the friction section (11) are provided with limiting slots (15), and each limiting slot (15) is provided with a limiting block that slides in it. Each limiting block is fixed to the inner wall of the friction ring (2).

6. The multi-stage buffer friction-type impact-resistant anchor bolt according to claim 1, characterized in that: The fitting components include a buffer sleeve (14), which is sleeved through the standard section (12). A locking nut (4) is provided on one side of the buffer sleeve (14), and the locking nut (4) is threaded onto the standard section (12). An end cap (13) is provided on the other side of the buffer sleeve (14). Several butterfly spring groups (7) are evenly arranged between the end cap (13) and the buffer sleeve (14) and are fixedly connected by several butterfly spring groups (7). An adaptive tray (6) is provided on one side of the end cap (13). A spherical washer (5) is provided at the end of the adaptive tray (6) away from the end cap (13). The spherical washer (5), the adaptive tray (6), and the end cap (13) are all sleeved on the standard section (12).

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