A narrow coal pillar bidirectional counter-anchor device and a use method thereof

Abstract

The present application belongs to the technical field of coal pillar anchoring, and proposes a narrow coal pillar bidirectional counter-anchor device, which comprises: a sleeve rod configured to pass through a drill hole on a coal pillar; an anchor claw mechanism comprising a support unit connected to the sleeve rod, at least one anchor claw connected to the support unit, and the anchor claw on the side away from the sleeve rod connected to the support unit through an elastic unit; an inner rotating rod arranged in the sleeve rod, one end of the inner rotating rod being clamped with the anchor claw to switch the anchor claw between an expanded state and a contracted state; wherein in the contracted state, the inner rotating rod is clamped with the end of the anchor claw, and in the expanded state, the inner rotating rod is separated from the end of the anchor claw to drive the anchor claw to expand by the elastic unit; the present application can complete the construction of the counter-anchor device on one side of the coal pillar, and the operation is simple and convenient; through the rubber sleeve ring and the threaded fixed end sleeved on the sleeve rod, harmful gases can enter the section along the empty tunnel from the gap between the anchor rod and the drill hole, eliminating safety hazards and ensuring the safety of workers.

Description

Technical Field

[0001] This invention belongs to the field of coal pillar anchoring technology, and particularly relates to a bidirectional anchoring device for narrow coal pillars and its usage method. Background Technology

[0002] Small coal pillar roadway excavation has become the main method for normal face continuity in most mining areas of my country. After the upper section of the working face is mined, a stress reduction zone appears due to the influence of support pressure. In roadway excavation along the goaf in the stress reduction zone, although the surrounding rock is in a stress reduction zone, secondary fractures are developed in the coal body, resulting in severe strength damage. Both sides of the small coal pillar are prone to loosening and breaking. During the roadway excavation process, it is necessary to explore a method for controlling the attitude stability of the coal pillar with bidirectional anchoring, taking into account the fracture characteristics of the coal body on the sidewalls of the coal pillar.

[0003] Existing sidewall support methods for narrow coal pillars in gob-side excavation mainly focus on high-strength threaded steel anchor bolts and long anchor cable reinforcement. These support methods are all unidirectional restraint supports. In gob-side excavation with low coal seam fracture development and minimal deformation on both sides of the small coal pillar, they can provide significant resistance, maintain the integrity of the small coal pillar, and effectively control deformation and instability. However, after the upper section of the working face has been mined, and the coal side anchors have retracted, and the edges of the small coal pillar are prone to loosening and fracturing, these support methods cannot effectively control the coal pillar's posture, easily leading to significant deformation and instability on the coal pillar side during gob-side excavation.

[0004] However, some existing bidirectional tie rod devices cannot be installed on one side of the coal pillar, making operation difficult; moreover, they cannot prevent harmful gases such as methane from the goaf of the upper section of the working face from entering the goaf excavation roadway of this section through the gap between the anchor and the borehole, posing certain safety hazards. Summary of the Invention

[0005] The purpose of this invention is to provide a bidirectional anchoring device for narrow coal pillars and its usage method to solve the problems of high operational difficulty and certain safety hazards mentioned above.

[0006] To achieve the above objectives, the present invention provides the following solution: a narrow coal pillar bidirectional anchoring device, comprising:

[0007] The outer rod is configured to pass through a borehole in the coal pillar;

[0008] An anchor claw mechanism includes a support unit connected to the outer sleeve rod, at least one anchor claw being connected to the support unit, and the side of the anchor claw away from the outer sleeve rod being connected to the support unit via an elastic unit;

[0009] An inner rotating rod is disposed inside the outer rotating rod, and one end of the inner rotating rod is engaged with the anchor claw so that the anchor claw can switch between an extended state and a retracted state.

[0010] In the retracted state, the inner rotating rod is engaged with the end of the anchor claw; in the extended state, the inner rotating rod is separated from the end of the anchor claw, so that the elastic unit drives the anchor claw to extend.

[0011] Preferably, the outer sleeve rod is sleeved and threaded to the outside of the inner rotating rod, and a top block is fixed at one end of the inner rotating rod, the top block abutting against the anchor claw.

[0012] Preferably, it further includes:

[0013] An anchor claw contraction sheath is fixed to one end of the outer sleeve rod; two anchor claws are provided and are rotatably connected to the anchor claw contraction sheath via a rotating shaft; the support unit is fixed to the end of the anchor claw contraction sheath away from the coal pillar via a connecting rod.

[0014] Preferably, the anchor claw contraction sheath is further provided with a backstop structure, which is fixed inside the anchor claw contraction sheath near one end of the anchor claw to restrict the rotation of the anchor claw.

[0015] Preferably, the anchor claw is further provided with a receiving cavity, and a telescopic claw block is slidably connected in the receiving cavity. An inner spring is fixedly connected between the telescopic claw block and the receiving cavity, and the side of the telescopic claw block away from the inner spring contacts the top block.

[0016] Preferably, the elastic unit includes two springs, one end of which is fixed to the support unit, and the other end is fixed to the anchor claw on the side away from the outer sleeve rod.

[0017] Preferably, the outer sleeve rod is further provided with a threaded fixing end at the end away from the anchor claw contraction sheath, the threaded fixing end comprising:

[0018] The tray, fitted onto the outer sleeve rod at the end furthest from the anchor claw contraction sheath, contacts the coal pillar;

[0019] The nut is threaded onto the outer sleeve rod at the end away from the anchor claw contraction sheath and contacts the side of the tray away from the anchor claw contraction sheath.

[0020] Preferably, the tray has an annular protrusion on the side near the coal pillar, and the annular protrusion has a chamfer on the side near the coal pillar. The annular protrusion is inserted into the drill hole and closes the drill hole on the coal pillar.

[0021] Preferably, the outer sleeve rod is further provided with a protrusion, and a rubber collar is fixed on one side of the protrusion. The protrusion is used to limit the rubber collar, and the rubber collar is used to close the drill hole.

[0022] A method for using a narrow coal pillar bidirectional anchoring device, the construction steps of which include:

[0023] Insert the outer sleeve rod into the drilled position on the coal pillar, and extend the anchor claw contraction sheath through the end of the drill hole;

[0024] Fix the outer rod and rotate the inner rod. The inner rod presses against the top block, and the top block presses against the telescopic claw block to retract into the receiving cavity. The anchor claw automatically opens under the action of the spring.

[0025] Pull the end of the outer sleeve rod to move the entire tie rod inward along the borehole axis toward the roadway until the anchor claw is pressed against the coal pillar wall.

[0026] Place the tray and nut on the end of the outer rod, and then tighten the nut.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] This invention controls the anchor claw at the other end of the anchor claw by directly controlling the outer sleeve rod, enabling the construction of the tie rod device to be completed on one side of the coal pillar. The operation is simple and convenient. The rubber sleeve and threaded fixing end fitted on the outer sleeve rod can effectively prevent harmful gases such as methane from the goaf of the upper section of the working face from entering the goaf excavation roadway of this section through the gap between the anchor rod and the borehole, eliminating safety hazards and ensuring the safety of workers. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure when the anchor claw is deployed;

[0032] Figure 3 This is a schematic diagram of the connection structure between the anchor device and the coal pillar;

[0033] Figure 4 This is a schematic diagram showing the full cross-section of the anchor device from the front view.

[0034] Among them, 1. Outer rod; 2. Anchor claw contraction sheath; 2-1. Anchor claw; 3. Connecting rod; 4. Support unit; 5. Spring; 6. Anti-reverse structure; 7. Rubber ring; 8. Coal pillar; 9. Tray; 10. Nut; 11. Drill hole; 12. Inner rotating rod; 13. Top block; 14. Telescopic claw block; 15. Rotating shaft; 16. Inner spring; 17. Protrusion. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example: Refer to Figures 1-4 A narrow coal pillar bidirectional anchoring device includes: an outer rod 1 configured to pass through a drill hole 11 in the coal pillar 8; an anchor claw mechanism including a support unit 4 connected to the outer rod 1, at least one anchor claw 2-1 connected to the support unit 4, the side of the anchor claw 2-1 away from the outer rod 1 being connected to the support unit 4 via an elastic unit; and an inner rotating rod 12 disposed inside the outer rod 1, one end of the inner rotating rod 12 engaging with the anchor claw 2-1 to switch between an extended state and a retracted state; wherein, in the retracted state, the inner rotating rod 12 engages with the end of the anchor claw 2-1, and in the extended state, the inner rotating rod 12 separates from the end of the anchor claw 2-1, so that the elastic unit drives the anchor claw 2-1 to extend.

[0038] This invention controls the anchor claw 2-1 of the other end of the anchor claw by directly controlling the outer sleeve rod, which allows the construction of the tie-down device to be completed on one side of the coal pillar 8. The operation is simple and convenient. The rubber ring 7 and the threaded fixing end fitted on the outer sleeve rod 1 can effectively prevent harmful gases such as methane from the goaf of the upper section working face from entering the goaf excavation roadway of this section through the gap between the anchor rod and the borehole, eliminating safety hazards and ensuring the safety of workers.

[0039] The outer sleeve rod 1 is threaded onto the outside of the inner rotating rod 12. A top block 13 is fixed to one end of the inner rotating rod 12, and the top block 13 abuts against the anchor claw 2-1. It also includes: an anchor claw contraction sheath 2, fixed to one end of the outer sleeve rod 1; two anchor claws 2-1 are provided, rotatably connected to the anchor claw contraction sheath 2 via a rotating shaft 15; the support unit 4 is fixed to the end of the anchor claw contraction sheath 2 away from the coal pillar 8 via a connecting rod 3; furthermore, a portion of the outer sleeve rod 1 and the inner rotating rod 12 are threaded together to ensure that they do not detach from each other.

[0040] The inner rotating rod 12 has a rotatable part at the end away from the anchor claw locking part. The rotatable part is formed by cutting several flat surfaces at the end of the inner rotating rod 12 away from the anchor claw locking part. When rotating, the inner rotating rod 12 can be twisted by clamping the flat surfaces of the rotatable part with a vise or other tools.

[0041] An anti-reverse structure 6 is also provided inside the anchor claw contraction sheath 2. The anti-reverse structure 6 is fixed inside the anchor claw contraction sheath 2 near the end of the anchor claw 2-1 and is used to limit the rotation of the anchor claw 2-1.

[0042] An anchor claw 2-1 also has a receiving cavity, and a telescopic claw block 14 is slidably connected in the receiving cavity. An inner spring 16 is fixedly connected between the telescopic claw block 14 and the receiving cavity. The side of the telescopic claw block 14 away from the inner spring 16 contacts the top block 13.

[0043] The elastic unit includes two springs 5, one end of which is fixed to the support unit 4, and the other end is fixed to the anchor claw 2-1 on the side away from the outer sleeve rod 1.

[0044] The outer rod 1 is also provided with a threaded fixing end at the end away from the anchor claw contraction sheath 2. The threaded fixing end includes: a tray 9, which is sleeved on the outer rod 1 at the end away from the anchor claw contraction sheath 2 and contacts the coal pillar 8; and a nut 10, which is threadedly connected to the outer rod 1 at the end away from the anchor claw contraction sheath 2 and contacts the side of the tray 9 away from the anchor claw contraction sheath 2.

[0045] Among them, the shape of the anchor claw 2-1 is an upward sloping edge on the top and a horizontal straight edge on the bottom. Its function is to maintain the good mechanical posture of the anchor claw 2-1 so that it can fit well against the wall of the coal pillar 8. The thickness of the anchor claw 2-1 is 5-8mm and the length is 100-150mm.

[0046] The anchor claw contraction sheath 2 is shaped as a circular sleeve with two open sections at the top (which facilitates the rotation of the anchor claw) and a fine thread at the bottom that can be connected to the tail of the outer sleeve of the anchor rod. The total outer diameter of the anchor claw contraction sheath 2 is 3-5 mm larger than the diameter of the inner rotating rod 12 and 3-5 mm smaller than the diameter of the drill hole 11. The total length of the anchor claw contraction sheath 2 is 200-250 mm.

[0047] The tray 9 has an annular protrusion on the side near the coal pillar 8. The annular protrusion has a chamfer on the side near the coal pillar 8. The annular protrusion is inserted into the drill hole 11 and seals the drill hole 11 on the coal pillar 8.

[0048] The outer rod 1 is also provided with a protrusion 17, and a rubber collar 7 is fixed on one side of the protrusion 17. The protrusion 17 is used to limit the rubber collar 7, and the rubber collar 7 is used to close the drill hole 11.

[0049] During the installation of the overall device, the protrusion 17 can limit the rubber ring 7, making it less prone to misalignment and ensuring that the rubber ring 7 reaches the designated position smoothly. This allows the device to effectively prevent harmful gases such as methane from entering the goaf tunnel of this section through the gap between the anchor bolt and the borehole, eliminating safety hazards and ensuring the safety of workers.

[0050] In addition, the rubber sleeve 7 is pre-installed on the end of the outer sleeve rod 1 near the anchor claw locking part. The length of the rubber sleeve is 100-400mm, the outer diameter of the rubber sleeve is 2-10mm, and the total diameter of the rubber sleeve is equal to the diameter of the borehole. The function of the rubber sleeve is to prevent toxic gases such as methane from the upper section of the goaf from entering the goaf excavation roadway of this section through the gap between the outer sleeve rod 1 and the borehole 11 after the construction of the outer sleeve rod is completed.

[0051] A method for using a narrow coal pillar bidirectional anchoring device, the construction steps of which include:

[0052] Insert the outer sleeve rod 1 into the borehole 11 on the coal pillar 8, and extend the anchor claw contraction sheath 2 through the end of the borehole 11;

[0053] Fix the outer outer rod 1 and rotate the inner rotating rod 12. The inner rotating rod 12 presses the top block 13, and the top block 13 presses the telescopic claw block 14 to retract into the receiving cavity. The anchor claw 2-1 is automatically opened under the action of the spring 5.

[0054] Specifically, after rotating the inner rotating rod 12, the top block 13 at the end of the inner rotating rod 12 presses the telescopic claw block 14 back into the receiving cavity. At this time, the anchor claw 2-1 immediately rebounds under the tension of the spring 5, causing the anchor claw 2-1 to unfold. After the anchor claw 2-1 unfolds, the telescopic claw block 14 in the receiving cavity pops out again.

[0055] In addition, after the anchor claw 2-1 automatically expands, it contacts the anti-reverse structure 6, and the anchor claw 2-1 reaches a position perpendicular to the anchor claw contraction sheath 2.

[0056] Pull the end of the outer sleeve rod 1 to move the entire tie rod along the borehole 11 axial direction into the roadway until the anchor claw 2-1 is pressed against the coal pillar wall.

[0057] Place the tray 9 and nut 10 on the end of the outer rod 1, and then tighten the nut 10.

[0058] The diameter of borehole 11 is not greater than the diameter of rubber ferrule 7, and the total outer diameter of anchor claw contraction sheath 2 is not greater than the diameter of borehole 11.

[0059] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A bidirectional anchoring device for narrow coal pillars, characterized in that, include: The outer rod (1) is configured to pass through the borehole (11) on the coal pillar (8); An anchor claw mechanism includes a support unit (4) connected to the outer sleeve rod (1), at least one anchor claw (2-1) is connected to the support unit (4), and the side of the anchor claw (2-1) away from the outer sleeve rod (1) is connected to the support unit (4) through an elastic unit; An inner rotating rod (12) is disposed inside the outer rod (1). One end of the inner rotating rod (12) is engaged with the anchor claw (2-1) so that the anchor claw (2-1) can switch between an extended state and a retracted state. In the retracted state, the inner rotating rod (12) is engaged with the end of the anchor claw (2-1), and in the unfolded state, the inner rotating rod (12) is separated from the end of the anchor claw (2-1), so that the elastic unit drives the anchor claw (2-1) to unfold. The outer sleeve rod (1) is sleeved and threaded to the outside of the inner rotating rod (12). One end of the inner rotating rod (12) is fixed with a top block (13), and the top block (13) abuts against the anchor claw (2-1). An anchor claw contraction sheath (2) is fixed to one end of the outer sleeve rod (1); two anchor claws (2-1) are provided and are rotatably connected to the anchor claw contraction sheath (2) via a rotating shaft (15); the support unit (4) is fixed to the end of the anchor claw contraction sheath (2) away from the coal pillar (8) via a connecting rod (3). The anchor claw (2-1) is also provided with a receiving cavity, and a telescopic claw block (14) is slidably connected in the receiving cavity. An inner spring (16) is fixedly connected between the telescopic claw block (14) and the receiving cavity. The side of the telescopic claw block (14) away from the inner spring (16) contacts the top block (13).

2. The narrow coal pillar bidirectional anchoring device according to claim 1, characterized in that, The anchor claw contraction sheath (2) is also provided with a backstop structure (6), which is fixed inside the anchor claw contraction sheath (2) near one end of the anchor claw (2-1) to restrict the rotation of the anchor claw (2-1).

3. The narrow coal pillar bidirectional anchoring device according to claim 1, characterized in that, The elastic unit includes two springs (5), one end of which is fixed to the support unit (4), and the other end is fixed to the anchor claw (2-1) on the side away from the outer sleeve rod (1).

4. The narrow coal pillar bidirectional anchoring device according to claim 1, characterized in that, The outer sleeve rod (1) is further provided with a threaded fixing end at the end away from the anchor claw contraction sheath (2), the threaded fixing end including: The tray (9) is fitted onto the outer sleeve rod (1) at one end away from the anchor claw contraction sheath (2) and contacts the coal pillar (8); The nut (10) is threaded onto the outer sleeve rod (1) at one end away from the anchor claw contraction sheath (2) and contacts the side of the tray (9) away from the anchor claw contraction sheath (2).

5. A narrow coal pillar bidirectional anchoring device according to claim 4, characterized in that, The tray (9) is provided with an annular protrusion on the side near the coal pillar (8), and the annular protrusion is provided with a chamfer on the side near the coal pillar (8). The annular protrusion is inserted into the drill hole (11) and the annular protrusion closes the drill hole (11) on the coal pillar (8).

6. The narrow coal pillar bidirectional anchoring device according to claim 1, characterized in that, The outer sleeve rod (1) is also provided with a protrusion (17), and a rubber collar (7) is fixed on one side of the protrusion (17). The protrusion (17) is used to limit the rubber collar (7), and the rubber collar (7) is used to close the drill hole (11).

7. A method of using a narrow coal pillar bidirectional anchoring device, for using the narrow coal pillar bidirectional anchoring device as described in claim 3, characterized in that: The construction steps include: Insert the outer sleeve rod (1) into the borehole (11) on the coal pillar (8) and pass the anchor claw shrink sheath (2) through the end of the borehole (11); Fix the outer outer rod (1) and rotate the inner rotating rod (12). The inner rotating rod (12) presses the top block (13), and the top block (13) presses the telescopic claw block (14) to retract into the receiving cavity. The anchor claw (2-1) automatically opens under the action of the spring (5). Pull the end of the outer sleeve rod (1) to move the entire tie rod along the borehole (11) axis into the roadway until the anchor claw (2-1) is pressed against the coal pillar wall; Place the tray (9) and nut (10) on the end of the outer rod (1), and then tighten the nut (10).

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