Anchoring agent deviation-preventing device for coal mine roof support

Abstract

The application discloses an anchoring agent deviation-preventing device for coal mine roof supporting and a construction method, and belongs to the technical field of coal mine supporting equipment. The device comprises a thin-walled cylindrical shell, a sawtooth holder, a central columnar hole of the sawtooth holder and single-face teeth of the sawtooth holder. The sawtooth holder is arranged in the thin-walled cylindrical shell and is integrally formed, the central columnar hole is coaxially arranged and is used for sleeving the tail end of the anchoring agent, the end face of the sawtooth holder towards the insertion end of the anchor rod is provided with the single-face teeth which are uniformly distributed in the circumferential direction, and the device is integrally formed by using the breakable engineering plastic. The thin-walled cylindrical shell is used for completing the radial direction guiding and limiting of the anchoring agent, the sawtooth holder is used for realizing the axial direction limiting of the anchoring agent, a hollow long pipe is not needed, the conveying and installation of the anchoring agent are realized, and the deviation and displacement of the anchoring agent during operation can be avoided. The matched construction method simplifies the anchoring process of the anchor rod, improves the anchoring construction efficiency, engineering quality and operation safety and reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mine supporting equipment, in particular to an anchoring agent deviation prevention device for coal mine roof supporting, and also relates to a coal mine roof anchoring agent deviation prevention construction method based on the device. BACKGROUND

[0002] Coal mine underground roof supporting is a core link to ensure the safety of coal mining operation, and the anchor rod supporting technology has become one of the mainstream technical forms of coal mine roadway roof supporting in China due to its high supporting strength, strong adaptability to surrounding rock, convenient construction and low comprehensive cost. In the anchor rod supporting system, the anchoring agent is a core functional component to realize the bonding of the anchor rod body and the roadway surrounding rock and to transfer the supporting stress. The installation positioning accuracy, axial and radial stability of the anchoring agent in the anchor rod drilling hole directly determine the ultimate anchoring force of the anchor rod, the bearing capacity of the supporting system and even the safety level of the underground roof operation.

[0003] At present, the anchoring agent installation operation of the coal mine underground roof anchor rod drilling hole often adopts the construction technology of hollow long pipe auxiliary conveying under the condition of separation layer of the roof rock stratum. The operation process is as follows: first, the hollow long pipe is stretched into the preset anchor rod hole along the axial direction until the front end of the hollow long pipe reaches the hole bottom position of the anchor rod hole; then the anchoring agent is sent into the inner cavity of the hollow long pipe, so that the anchoring agent is arranged along the axial direction of the drilling hole; then the front end surface of the anchor rod body is used to press against the tail end of the outermost anchoring agent to limit the anchoring agent from falling along the axial direction of the drilling hole, and the hollow long pipe is completely pulled out from the anchor rod hole; finally, the anchor rod body is rotated and pushed to the hole bottom by the anchor rod drilling machine, so that the anchor rod body breaks the packaging shell of the anchoring agent, the resin and curing agent in the anchoring agent are fully mixed and reacted and filled in the annular gap between the anchor rod body and the drilling hole wall, and after the anchoring agent is completely cured, the anchoring installation operation of the anchor rod is completed. The core role of the hollow long pipe is to limit the conveying path and radial movement range of the anchoring agent to ensure that the anchoring agent can be smoothly sent to the hole bottom position along the drilling hole.

[0004] However, the existing device and construction technology still have some deficiencies in the use process: 1. Anchoring agents are prone to deviation and movement. On the one hand, during the extraction of the hollow tube from the borehole, the inner wall of the tube is prone to friction with the anchoring agent's encapsulation shell, causing the anchoring agent to shift. This makes it impossible to ensure that the anchoring agent is always in the axial position of the borehole, which in turn leads to uneven filling after the subsequent anchoring agent is squeezed out, insufficient effective anchoring section length of the anchor rod, and ultimately, failure of the anchoring force of the anchor rod. On the other hand, when multiple anchoring agents are installed in series, the axial gravity of the front anchoring agent near the bottom of the hole will directly act on the rear anchoring agent, causing the rear anchoring agent to be axially compressed and enter the delamination gap of the coal mine roof strata. This reduces the effective filling amount of anchoring agent in the borehole, and the designed anchoring section length cannot be guaranteed, ultimately leading to anchor rod anchoring failure, instability of the roof support system, and even safety accidents.

[0005] 2. The anchor bolt anchoring process is cumbersome and inefficient. Existing processes require additional steps such as positioning and removing hollow long tubes, extending the working cycle of a single anchor bolt. In large-scale, high-volume anchor bolt support operations underground, this increases the labor intensity of construction workers and also increases on-site labor and time costs.

[0006] 3. The existing hollow tubes need to be reused repeatedly, which makes on-site material management difficult. During transportation and installation, there are safety risks such as falling objects causing injury and tool damage. At the same time, the hollow tubes used for a long time are prone to deformation and wear, which further affects the delivery accuracy of the anchoring agent and the safety of the operation. Summary of the Invention

[0007] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, this invention provides an anchoring agent anti-deviation device for coal mine roof support, comprising a thin-walled cylindrical shell and a sawtooth support coaxially arranged, wherein the sawtooth support has a central columnar hole coaxial with the thin-walled cylindrical shell; the sawtooth support is fixedly arranged in the internal cavity of the thin-walled cylindrical shell, and the sawtooth support and the thin-walled cylindrical shell are integrally formed, the sawtooth support dividing the internal cavity of the thin-walled cylindrical shell into an anchoring agent receiving cavity on the bottom side of the hole and an anchor rod pushing cavity on the side; the sawtooth support faces the anchor rod pushing cavity. The end face is provided with circumferentially evenly distributed serrated single-sided teeth, the tips of which face the anchor rod insertion direction; the central columnar hole of the serrated support is used to fit the tail end of the anchoring agent to be installed; the outer diameter of the thin-walled cylindrical shell is adapted to the diameter of the anchor rod hole to be constructed, and its outer wall can fit against the hole wall of the anchor rod hole; the anti-deviation device is made of crushable engineering plastic in one piece to ensure that the structure remains intact during the delivery of the anchoring agent and can be crushed when the anchor rod is rotated and pushed forward.

[0008] Furthermore, the sawtooth support is a bidirectional axial limiting structure with two axial end faces facing the bottom of the hole and the anchor bolt side respectively; the end face facing the bottom of the hole constitutes an anchoring agent blocking surface, used to restrict the axial movement of the anchoring agent towards the anchor bolt hole opening; the end face facing the anchor bolt side constitutes an anchor bolt guide positioning surface, providing initial positioning for anchor bolt advancement.

[0009] Furthermore, the diameter of the central columnar hole of the sawtooth bracket is larger than the outer diameter of the metal sealing ring at the end of the anchoring agent to be installed.

[0010] Furthermore, the inner diameter of the thin-walled cylindrical shell is larger than the outer diameter of the anchoring agent to be installed.

[0011] Furthermore, the fractured engineering plastic is a brittle engineering plastic, which can maintain structural stability during the delivery of the anchoring agent, and can withstand the axial gravity and delivery friction of the anchoring agent without deformation or damage; under the axial extrusion impact force of the rotating propulsion of the anchor rod, it can undergo brittle fracture, and the broken fragments are solidified inside the borehole along with the anchoring agent, without affecting the anchoring performance of the anchor rod.

[0012] On the other hand, the present invention provides a construction method for preventing deviation of coal mine roof anchoring agent, which is based on the above-mentioned anti-deviation device for coal mine roof support anchoring agent, and includes the following steps: 1. Preparation before construction: Check the structural integrity of the anti-deviation device, confirm that the saw tooth support is firmly connected to the thin-walled cylindrical shell, and that the teeth on one side of the saw tooth support are undamaged. Match the anti-deviation device and the corresponding type of anchoring agent with the specifications of the anchor bolt hole. 2. Pre-assembly: The tail end of the anchoring agent is coaxially inserted into the central cylindrical hole of the sawtooth bracket of the anti-deviation device, so that the main body of the anchoring agent is housed in the anchoring agent receiving cavity at the bottom of the hole of the thin-walled cylindrical shell, thus completing the pre-assembly of the anchoring agent and the anti-deviation device to form an integrated conveying unit. 3. In-hole delivery: The pre-assembled integral delivery unit is directly delivered into the preset anchor bolt hole until the top of the integral delivery unit reaches the bottom of the anchor bolt hole. During the delivery process, the outer wall of the thin-walled cylindrical shell fits against the hole wall of the anchor bolt hole, and the anchoring agent is radially guided and limited throughout the process to prevent radial deviation and axial movement of the anchoring agent. 4. Anchor bolt rotation and compression anchoring: Align the front end of the anchor bolt with the central columnar hole of the sawtooth support and insert it into the anchor bolt hole. Drive the anchor bolt to rotate and advance it towards the bottom of the hole through the anchor bolt drilling machine. After the front end of the anchor bolt contacts the single tooth of the sawtooth support, the sawtooth support is broken under the force of rotation and advancement. The anchor bolt continues to advance forward and squeezes through the encapsulation shell of the anchoring agent, so that the resin and curing agent in the anchoring agent can be fully mixed and reacted. 5. Curing Completion: After the anchoring agent has fully cured, the anchoring installation of a single anchor rod is completed. The broken anti-deviation device is cured in the borehole along with the anchoring agent and does not need to be removed.

[0013] Beneficial effects Compared with the prior art, the present invention has the following advantages: 1. This invention utilizes a thin-walled cylindrical shell, a serrated support, and a central cylindrical hole to eliminate the need for auxiliary delivery and positioning of the anchoring agent via a hollow long tube. This saves on additional steps such as the installation and removal of the hollow long tube, shortens the anchoring cycle of a single anchor bolt, improves the construction efficiency of large-scale downhole anchor bolt support operations, and reduces construction and time costs. By ensuring the anchoring agent adheres to the inner wall of the thin-walled cylindrical shell and the outer wall of the thin-walled cylindrical shell adheres to the borehole wall, radial guidance and positioning of the anchoring agent are achieved. This ensures that the anchoring agent remains at the axial position of the borehole throughout the process, effectively preventing radial deviation of the anchoring agent and solving the problems of easy deviation and poor positioning accuracy of the anchoring agent in traditional processes.

[0014] 2. This invention, through the bidirectional axial limiting structure design of the sawtooth support, can effectively bear the axial gravity of the anchoring agent, avoiding the problem of the anchoring agent being compressed by gravity and entering the rock layer separation gap, ensuring the effective filling amount of anchoring agent in the borehole and the length of the anchoring section, and avoiding the safety hazards of roof support caused by anchoring agent displacement and anchoring failure; at the same time, the single-sided tooth design of the sawtooth support end face can quickly achieve stress concentration when the anchor rod is rotated and advanced, ensuring that the sawtooth support breaks smoothly and will not hinder the advancement and anchoring operation of the anchor rod.

[0015] 3. This invention is made of engineering plastic in one piece, with a simple structure and convenient installation. It can be directly adapted to existing conventional specifications of anchoring agents and anchor bolt drilling, without the need to modify existing anchor bolt drilling machines, anchoring agents and other supporting equipment and materials, and has strong versatility. At the same time, the device is designed for single use, eliminating the need for repeated turnover management and reducing the difficulty of on-site material management.

[0016] 4. The present invention provides a corresponding anchoring agent anti-deviation construction method, which forms a complete technical solution with the device, standardizes the operation process, further ensures the installation and positioning accuracy of the anchoring agent and the anchoring quality of the anchor bolt, simplifies the construction process, reduces the labor intensity of construction personnel, and is suitable for large-scale and large-volume anchor bolt support operations in underground mines.

[0017] Figure 1 This is a schematic diagram of the overall structure of the anchoring agent anti-deviation device of the present invention; Figure 2 This is an axial cross-sectional view of the anchoring agent anti-deviation device of the present invention. Figure 3 This is a top view of the anchoring agent anti-deviation device of the present invention; Figure 4 This is a schematic diagram showing the usage state of the anchoring agent anti-deviation device and the anchoring agent anchor rod of the present invention. Figure 5This is a schematic diagram of the installation of the anchoring agent anti-deviation device and the anchoring agent in the anchor bolt hole of the present invention; Figure 6 This is a flowchart illustrating the construction method of the anchoring agent anti-deviation device of the present invention.

[0018] In the figure: 1. Anchoring agent anti-deviation device; 2. Anchoring agent; 3. Anchor rod; 4. Anchor rod hole; 5. Bottom of hole; 6. Delamination; 11. Thin-walled cylindrical shell; 12. Sawtooth support; 121. Central columnar hole of sawtooth support; 122. Single-sided tooth of sawtooth support. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] The present invention will be further described below with reference to specific embodiments.

[0021] This embodiment provides a coal mine roof support anchoring agent anti-deviation device, the core structure of which includes a thin-walled cylindrical shell 11 and a sawtooth support 12 arranged coaxially. The sawtooth support 12 has a central columnar hole 121 that is coaxial with the thin-walled cylindrical shell 11.

[0022] The sawtooth support 12 is arranged in the internal cavity of the thin-walled cylindrical shell 11, and the sawtooth support 12 and the thin-walled cylindrical shell 11 are integrally formed. The sawtooth support 12 divides the internal cavity of the thin-walled cylindrical shell 11 into a bottom-side anchoring agent receiving cavity and an anchor rod side pushing cavity. The end face of the sawtooth support 12 facing the anchor rod side pushing cavity is provided with circumferentially evenly distributed sawtooth support single-sided teeth 122, and the tips of the sawtooth support single-sided teeth 122 face the anchor rod insertion direction. The central columnar hole 121 of the sawtooth support 12 is used to fit on the tail end of the anchoring agent 2 to be installed, so as to realize the radial limit of the anchoring agent 2. The outer diameter of the thin-walled cylindrical shell 11 is adapted to the hole diameter of the anchor rod hole 4 to be constructed, and its outer wall can fit with the hole wall of the anchor rod hole 4, so as to realize the radial guidance of the anchoring agent 2 during the delivery process. The anti-deviation device 1 is made of crushable engineering plastic integrally molded to ensure that the structure remains intact during the delivery of the anchoring agent 2 and can be crushed when the anchor rod 3 is rotated and pushed.

[0023] Furthermore, the sawtooth support 12 is a bidirectional axial limiting structure. The anchoring agent 2 to be installed is coaxially housed in the anchoring agent receiving cavity on the bottom side of the hole, and its tail end is inserted into the central columnar hole 121. The end face of the sawtooth support 12 facing the bottom side of the hole restricts the axial movement of the anchoring agent 2 towards the anchor hole opening 4. The end face of the sawtooth support 12 facing the anchor side provides initial positioning for the advancement of the anchor 3.

[0024] Furthermore, the diameter of the central columnar hole 121 of the sawtooth bracket is larger than the outer diameter of the metal sealing ring at the end of the anchoring agent 2 to be installed, ensuring that the tail end of the anchoring agent 2 can be smoothly fitted into the central columnar hole 121 to achieve a stable limiting fit.

[0025] Furthermore, the inner diameter of the thin-walled cylindrical shell 11 is larger than the outer diameter of the anchoring agent 2 to be installed, so that the anchoring agent 2 can be completely contained in the inner cavity of the thin-walled cylindrical shell 11, achieving full radial protection and limiting.

[0026] Furthermore, the fracturing engineering plastic is an engineering plastic that can maintain structural stability during the delivery of the anchoring agent 2, and can withstand the axial gravity of the anchoring agent 2 and the friction during the delivery process without deformation or damage; it can fracture under the axial extrusion force of the rotating propulsion of the anchor rod 3, without hindering the propulsion of the anchor rod 3 or the mixing and solidification of the anchoring agent 2. The broken material can be solidified in the borehole along with the anchoring agent 2 without affecting the anchoring force of the anchor rod.

[0027] Based on the above device, this embodiment also provides a construction method for preventing deviation of coal mine roof anchoring agent. The specific operation process is as follows: 1. Preparation before construction: check the structural integrity of the anti-deviation device (1), confirm that the saw tooth support (12) is firmly connected to the thin-walled cylindrical shell (11) without cracks or damage, and that the single-sided teeth (122) of the saw tooth support are not damaged; select an anti-deviation device (1) of suitable size and an anchoring agent (2) that meets the design model requirements according to the specifications of the anchor hole (4) to be constructed.

[0028] 2. Pre-assembly: The tail end of the anchoring agent (2) is coaxially inserted into the central columnar hole (121) of the sawtooth support (12) of the anti-deviation device (1), so that the main body of the anchoring agent (2) is contained in the anchoring agent accommodating cavity at the bottom of the hole of the thin-walled cylindrical shell (11); the axial and radial limiting constraints of the anchoring agent (2) are completed by means of the sawtooth support (12), and the assembly is formed into an integral delivery unit.

[0029] 3. In-hole conveying: The assembled conveying unit is attached to the front end of the anchor bolt (3), and the anchor bolt (3) and the conveying unit are inserted into the anchor bolt hole (4). The anchor bolt drilling machine is started to drive the anchor bolt (3) to feed axially. The anchor bolt (3) drives the conveying unit to move axially along the anchor bolt hole (4) until the top of the conveying unit abuts against the bottom (5) of the anchor bolt hole (4). This process does not require the assistance of hollow long tubes for conveying. The outer wall of the thin-walled cylindrical shell (11) fits against the hole wall of the anchor bolt hole (4), constraining the anchoring agent (2) to the borehole axis, preventing the anchoring agent (2) from radially deviating or axially moving, and preventing the anchoring agent (2) from entering the delamination (6) gap of the top rock layer.

[0030] 4. Anchor bolt rotation and compression anchoring: After the overall conveying unit reaches the bottom of the hole (5), the anchor bolt drilling machine continues to drive the anchor bolt (3) to rotate and feed towards the bottom of the hole (5); the front end of the anchor bolt (3) contacts the saw tooth support single-sided tooth (122), and the saw tooth support (12) breaks under the action of rotation-axial compression coupling; the anchor bolt (3) continues to advance and punctures the outer shell of the anchoring agent (2), so that the resin component inside the anchoring agent (2) is fully mixed with the curing agent, and the mixed anchoring agent fills the annular gap between the anchor bolt (3) and the hole wall of the anchor bolt hole (4).

[0031] 5. Curing completion: Once the anchoring agent (2) has completely cured, the single anchor bolt installation is complete; the broken anti-deviation device (1) fragments are sealed inside the anchor bolt hole (4) along with the anchoring agent (2) after curing, without the need for additional dismantling work and without reducing the anchor bolt's anchoring performance.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for preventing deviation of anchoring agent in coal mine roof support, comprising a thin-walled cylindrical shell (11) and a sawtooth support (12) arranged coaxially, wherein the sawtooth support (12) has a central columnar hole (121) coaxial with the thin-walled cylindrical shell (11), characterized in that: The sawtooth support (12) is fixedly arranged in the internal cavity of the thin-walled cylindrical shell (11), and the sawtooth support (12) and the thin-walled cylindrical shell (11) are integrally formed. The sawtooth support (12) divides the internal cavity of the thin-walled cylindrical shell (11) into a hole bottom side anchoring agent receiving cavity and an anchor rod side pushing cavity. The end face of the sawtooth support (12) facing the anchor rod side pushing cavity is provided with circumferentially evenly distributed sawtooth support single-sided teeth (122), and the tooth tips of the sawtooth support single-sided teeth (122) face the anchor rod (3) insertion direction. The sawtooth support (12) has a central columnar hole (121) for fitting onto the tail end of the anchoring agent (2) to be installed; the outer diameter of the thin-walled cylindrical shell (11) is adapted to the diameter of the anchor hole (4) to be constructed, and its outer wall can fit against the hole wall of the anchor hole (4); the anti-deviation device (1) is made of crushable engineering plastic in one piece; the anti-deviation device (1) maintains structural integrity during the delivery of the anchoring agent (2) and can be crushed when the anchor (3) is rotated and pushed forward.

2. The anti-deviation device for anchoring agent used in coal mine roof support according to claim 1, characterized in that, The sawtooth support (12) is a bidirectional axial limiting structure with two axial end faces facing the bottom of the hole (5) and the anchor rod (3) respectively. The end face facing the bottom of the hole (5) forms an anchoring agent blocking surface, which is used to prevent the anchoring agent from moving axially towards the anchor rod hole opening. The end face facing the anchor rod (3) forms an anchor rod guide positioning surface, which provides initial positioning for the advancement of the anchor rod (3).

3. The anti-deviation device for anchoring agent used in coal mine roof support according to claim 1, characterized in that, The diameter of the central columnar hole (121) of the sawtooth bracket (12) is larger than the outer diameter of the metal sealing ring at the end of the anchoring agent (2) to be installed.

4. The anti-deviation device for anchoring agent used in coal mine roof support according to claim 1, characterized in that, The inner diameter of the thin-walled cylindrical shell (11) is larger than the outer diameter of the anchoring agent (2) to be installed.

5. The anti-deviation device for anchoring agent used in coal mine roof support according to claim 1, characterized in that, The fractable engineering plastic can maintain structural stability during the delivery of the anchoring agent (2) and can fracture under the axial extrusion force of the rotating propulsion of the anchor rod (3).

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