Expansion type anchor rod for coal mine

Abstract

The invention relates to the technical field of coal mine supporting, and discloses an expansion type anchor rod for a coal mine, which comprises a rod body, a plurality of triggering mechanisms, a plurality of expansion mechanisms and a plurality of supporting rods, a plurality of groups of sliding grooves are formed in the surface of the rod body along the longitudinal axis at equal intervals, the plurality of sliding grooves are not perpendicular to one another, the plurality of triggering mechanisms are respectively arranged in the sliding grooves, and the plurality of expansion mechanisms are arranged on the surface of the rod body at equal intervals. And the percussion mechanism is arranged in the rod body and is matched with the execution distance of the expansion mechanism in a working state to execute a radial expansion action so as to fix the interior of the coal mine hole. Through the arrangement of the percussion mechanism, the chemical anchor bolt is protected in real time when the chemical anchor bolt is fed into a hole, and after the pull rope relieves limitation on the abutting ring, the pre-pressing spring releases kinetic energy and pushes the abutting ring to linearly accelerate to linearly pop out the chemical anchor bolt, so that it is ensured that the chemical anchor bolt can accurately reach the bottom of the hole; and offset and debonding during manual stuffing are reduced.

Description

Technical Field

[0001] This invention relates to the field of coal mine support technology, specifically to an expandable anchor bolt for coal mines. Background Technology

[0002] As the lifeline of underground coal mining, the smoothness and stability of roadways directly affect the safe and efficient production of coal mines. Statistics show that the total length of roadways excavated annually in my country's state-owned coal mines exceeds 12,000 kilometers, with a bolt support rate exceeding 80%. However, with the continuous increase in mining depth, the surrounding rock in underground roadways is under high stress for extended periods. High ground pressure leads to deformation and instability of the surrounding rock, and may even induce dynamic disasters such as rockbursts, seriously threatening safe production. If substantial breakthroughs cannot be achieved in bolt support technology under complex geological conditions, its application rate will be difficult to increase, and mine production efficiency will be greatly limited.

[0003] While existing rock bolt support technology can utilize the original rock stress to achieve active support, it exposes its serious defects in soft and fractured rock layers. The loose rock mass makes it difficult for traditional rock bolts to be effectively fixed, resulting in a significant reduction in actual support effect. The mainstream technology relies on single-point end anchoring (anchoring agent + tray + nut fixing), which can only locally enhance frictional resistance and cannot solve the problem of the lack of overall anchoring force in soft rock layers. Summary of the Invention

[0004] The purpose of this invention is to provide an expansion bolt for coal mines to solve the problem of weak overall anchoring in soft rock strata, which leads to a lack of force, as mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an expandable anchor bolt for coal mines, comprising a rod body, wherein a plurality of sliding grooves are equidistantly formed on the surface of the rod body along its longitudinal axis, the plurality of sliding grooves being non-perpendicular to each other; a plurality of triggering mechanisms are respectively disposed inside each of the sliding grooves; a plurality of expansion mechanisms are equidistantly disposed on the surface of the rod body and respectively located near the sliding grooves on the rod body; a firing mechanism is disposed inside the rod body, which, in the working state, performs a radial expansion action in conjunction with the execution distance of the expansion mechanisms to fix the interior of the coal mine borehole; and a control mechanism is disposed inside the rod body on the side away from the firing mechanism, the control mechanism comprising a rotating ring rotatably connected inside the rod body, wherein a directional slot is formed inside the rotating ring, and a pull rod is slidably connected inside the directional slot.

[0006] Preferably, the triggering mechanism includes a limiting block slidably connected inside the slide groove, a movable ring fixedly connected to one side of the limiting block, an inner ring fixedly connected to the other side of the limiting block, and a pressure groove formed on the inner wall of the inner ring.

[0007] Preferably, the expansion mechanism includes a threaded ring threaded to the surface of the rod and near the slide groove. The surface of the threaded ring is provided with several sets of arc-shaped slots at equal intervals. Each arc-shaped slot is hinged to an arc-shaped plate at its edge. The surface of the arc-shaped plate is provided with an annular slot. A rubber band is sleeved inside the annular slot. Each arc-shaped plate is provided with an oblique slot near the axis of the threaded ring.

[0008] Preferably, the contact surface between the arc-shaped plate and the moving ring is curved, and the flipping action is generated by applying pressure through the moving ring during operation.

[0009] Preferably, multiple arc-shaped plates together form an axially shortening cone along the circumferential surface of the threaded ring, with the minimum radius end near the oblique groove and the maximum radius end extending away from the oblique groove.

[0010] Preferably, the firing mechanism includes a carrier ring fixedly connected to the inside of the rod body, a spring fixedly connected inside the carrier ring, a stop ring fixedly connected to the end of the spring, a pull rope fixedly connected to one side of the stop ring, and a chemical anchor bolt provided on the other side of the pull rope.

[0011] Preferably, the pull rope is in contact with the pull rod, and the pull rope is broken by the pull rod when the pull rod moves away from the direction of the chemical anchor bolt to a set distance.

[0012] Preferably, the pull rod maintains a gap with the pressure groove in the initial state, and slides down in a direction along the inside of the pressure groove under the driving force in the working state, and its sliding trajectory is constrained by the inner cavity of the pressure groove.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] (1) By setting the firing mechanism, the chemical anchor is protected in real time when it is sent into the hole. When the pull rope releases the restriction on the abutment ring, the preload spring will release kinetic energy and push the abutment ring to accelerate linearly and pop the chemical anchor out in a straight line, ensuring that the chemical anchor can accurately reach the bottom of the hole and reduce the deviation and detachment caused by manual insertion.

[0015] (2) By cooperating with the triggering mechanism and the expansion mechanism on the surface of the rod, the rod is pre-positioned before being sent into the hole to ensure the initial position is accurate. When it is sent into the hole, it is self-locked to effectively resist external interference, prevent position deviation, ensure accurate delivery to the target area, and finely control the radial expansion of the target expansion area to avoid support instability caused by excessive or weak expansion effect. In conjunction with the firing mechanism and the control mechanism, the overall reliability of the support system is greatly improved. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the cross-sectional structure of the rod body of the present invention;

[0018] Figure 3 This is a schematic diagram showing the disassembled structure of the triggering mechanism and the expansion mechanism of the present invention;

[0019] Figure 4 This is a schematic diagram of the second-view structure of the triggering mechanism and expansion mechanism of the present invention.

[0020] Figure 5 This is a schematic diagram of the isolated structure of the triggering mechanism and the expansion mechanism of the present invention;

[0021] Figure 6 This is a schematic diagram of the isolated second-view structure of the triggering mechanism and expansion mechanism of the present invention;

[0022] Figure 7 This is a schematic diagram of the cross-sectional structure of the firing mechanism of the present invention;

[0023] Figure 8 This is a schematic diagram of the cross-sectional structure of the triggering mechanism of the present invention.

[0024] In the diagram: 100, rod; 101, slide groove; 200, triggering mechanism; 201, limiting block; 202, moving ring; 203, inner ring; 204, compression groove; 300, expansion mechanism; 301, threaded ring; 302, arc-shaped groove; 303, arc-shaped plate; 304, rubber band; 305, oblique groove; 500, firing mechanism; 501, carrier ring; 502, spring; 503, stop ring; 504, pull rope; 505, chemical anchor; 600, control mechanism; 601, rotating ring; 602, pull rod. Detailed Implementation

[0025] 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.

[0026] Please see Figure 1-8This invention provides a technical solution: an expandable anchor bolt for coal mines, comprising a rod body 100, with a plurality of grooves 101 equidistantly formed on the surface of the rod body 100 along its longitudinal axis, the grooves 101 being non-perpendicular to each other; a plurality of triggering mechanisms 200 respectively disposed inside each groove 101; a plurality of expansion mechanisms 300 equidistantly disposed on the surface of the rod body 100, respectively located on the rod body 100 near the grooves 101; a firing mechanism 500 disposed inside the rod body 100, which, in working condition, performs radial expansion action in conjunction with the execution distance of the expansion mechanisms 300 to fix the interior of the coal mine borehole; and a control mechanism 600 disposed inside the rod body 100 on the side away from the firing mechanism 500. The control mechanism 600 includes a rotating ring 601 rotatably connected inside the rod body 100, the rotating ring 601 having a directional slot, and a pull rod 602 slidably connected inside the directional slot.

[0027] During use, the firing mechanism 500 on the rod 100 is directed towards the inside of the drilled hole, with the firing mechanism 500 facing the hole. (See reference...) Figure 3 The slide grooves 101 are staggered and equidistant along the length of the rod 100, ensuring that after the pull rod 602 rotates once inside the rotating ring 601, all the trigger mechanisms 200 inside the slide grooves 101 can rotate and pull back. When the pull rod 602 drives the last set of trigger mechanisms 200 to contact the expansion mechanism 300, the multi-stage expansion effect is completed.

[0028] The triggering mechanism 200 includes a limiting block 201 that is slidably connected inside the slide groove 101. A movable ring 202 is fixedly connected to one side of the limiting block 201, and an inner ring 203 is fixedly connected to the other side of the limiting block 201. A pressure groove 204 is opened on the inner wall of the inner ring 203.

[0029] During use, the limiting block 201 is first locked inside the slide groove 101. Because the rod 100 needs to be sent into the hole, the limiting block 201 on the rod 100 is in a restricted state before being contacted by the pull rod 602. This prevents the moving ring 202 from accidentally sliding due to premature contact with the expansion mechanism 300. Premature expansion may jam the rod 100, preventing it from being sent to the bottom of the hole. In some environments, the rod 100 needs to be sent into the hole with the help of a mechanical device. The mechanical device may cause the limiting block 201 to loosen. Therefore, it is necessary to lock it through the slide groove 101 before use. The pre-positioning and self-locking characteristics reduce the number of adjustments and difficulty during installation and speed up the construction process.

[0030] The expansion mechanism 300 includes a threaded ring 301 threadedly connected to the surface of the rod 100 and near the slide groove 101. The surface of the threaded ring 301 is provided with several sets of arc-shaped slots 302 at equal intervals. Each arc-shaped slot 302 is hinged to an arc-shaped plate 303 at its edge. The surface of the arc-shaped plate 303 is provided with an annular slot. A rubber band 304 is sleeved inside the annular slot. The pre-positioning and self-locking characteristics reduce the number of adjustments and difficulty during installation and speed up the construction. Each arc-shaped plate 303 is provided with an oblique slot 305 near the axis of the threaded ring 301.

[0031] During use, the threaded ring 301 is threadedly connected to the surface of the rod 100. When the rod 100 is manually or mechanically inserted into the hole, the threaded ring 301, with its pre-determined internal environment, allows for precise orientation of the hole. Typically, a detector is used to predict the internal environment of the drilled hole. With accurate data, such as determining whether certain areas require a larger expansion radius while others do not need excessive expansion to prevent instability, the threaded ring 301 can be precisely oriented on the surface of the rod 100. Due to its threaded characteristics, the threaded ring 301 will not shift position due to external forces when the rod 100 is inserted into the hole, thus preventing weakened support. This achieves precise adjustment of the installation position and controllable expansion radius, particularly in heterogeneous rock formations. For example, in soft and fractured zones, it avoids uniform expansion force causing local rock mass crushing. For areas with strong mining pressure disturbance, it increases the expansion radius of key sections, such as stress concentration areas, to improve tensile strength. When the threaded ring 301 is inserted, it resists lateral friction and vibration, avoiding the "progressive slippage" problem of traditional mechanical anchoring, thus accelerating the support progress. The controllable arc plate 303 controls the expansion radius as needed, such as reducing expansion force in fracture areas, maintaining the integrity of the hole structure, and avoiding excessive expansion pressure of the arc plate 303 in soft rock layers, which could lead to secondary collapse. At the same time, it achieves the effect of segmented coordination. In the initial state, it is only necessary to adjust the threaded ring 301 to the appropriate position and then put it on the surface of the arc plate 303 through the rubber band 304. The operation is simple, the teaching cost is low, and it is suitable for large-scale deployment.

[0032] The contact surface between the arc plate 303 and the moving ring 202 is curved. In the working state, the moving ring 202 applies pressure to generate a flipping action.

[0033] During use, the curved surface design of the arc plate 303 is to make the movement of the moving ring 202 on the arc plate 303 smoother when the curved surfaces of the moving ring 202 come into contact, thus avoiding jamming.

[0034] Multiple arc-shaped plates 303 together form an axially shortening cone along the circumferential surface of the threaded ring 301, with the minimum radius end near the inclined groove 305 and the maximum radius end extending away from the inclined groove 305.

[0035] As the moving ring 202 gradually comes into contact with the arc plate 303, the tilt angle of the arc plate 303 increases axially along the pressure of the moving ring 202, thereby eliminating the off-center load caused by the asynchronous expansion of the single point of the arc plate 303.

[0036] The firing mechanism 500 includes a carrier ring 501 fixedly connected inside the rod body 100. A spring 502 is fixedly connected inside the carrier ring 501. A stop ring 503 is fixedly connected to the end of the spring 502. A pull rope 504 is fixedly connected to one side of the stop ring 503. A chemical anchor 505 is provided on the other side of the pull rope 504.

[0037] When not in use, the chemical anchor 505 remains inside the rod body 100 to prevent breakage when the rod body 100 is inserted into the borehole. After the pull rope 504 loses its traction, the retaining ring 503 connected to the pull rope 504 is no longer restrained, and the spring 502 connected to the retaining ring 503 loses its restraining force. This, in conjunction with the retaining ring 503, will eject the chemical anchor 505 from inside the rod body 100. The inner wall of the borehole is uneven, and traditional exposed anchors have a high breakage rate due to impact during insertion. The chemical anchor 505 is housed inside the rod 100, forming a physical barrier. The rod 100 preferentially contacts the hole wall. The chemical anchor 505 is not subjected to external impact throughout the process. It is also prone to deviation when manually inserted and may be affected by dust / water flow at the bottom of the hole, resulting in insufficient bonding area. The spring 502 is pre-compressed to store kinetic energy. When released, it pushes the retaining ring 503. Because the spring 502 is restricted, the chemical anchor 505 does not tilt when ejected, reducing the difficulty of operation and improving the anchoring efficiency.

[0038] See Figure 7 During use, when not in use, the chemical anchor 505 is located inside the rod body 100. The carrier ring 501 has a recess, i.e. a groove, which allows part of the chemical anchor 505 to be located inside the carrier ring 501. As the chemical anchor 505 gradually approaches the carrier ring 501, it forces the abutment ring 503 to move toward the inside of the carrier ring 501. At the same time, the abutment ring 503 drives the spring 502 to compress. The two ends of the spring 502 are connected to the abutment ring 503 and the carrier ring 501 respectively. When the spring 502 is compressed, it is constrained by the carrier ring 501 and does not shift to the left or right when subjected to force.

[0039] The pull rope 504 is in contact with the pull rod 602, and when the pull rod 602 moves away from the chemical anchor 505 to a set distance, the pull rope 504 is broken by the pull rod 602.

[0040] In the initial state, the pull rod 602 maintains a gap with the pressure groove 204. In the working state, it is driven by the force to slide down in a direction along the inside of the pressure groove 204, and its sliding trajectory is constrained by the inner cavity of the pressure groove 204.

[0041] Working principle:

[0042] Preparation work: Drill pile holes at the required locations according to the operating procedures. The depth and diameter of the holes must meet the design requirements and should be approximately 100mm longer and larger than the selected rod body's length and diameter. After drilling, clean the holes thoroughly of dust, gravel, and other impurities to ensure that the chemical anchor 505 can fully penetrate into the hole after breaking. Insert the chemical anchor 505 into the groove of the carrier ring 501 according to the specifications and sequence specified in the "Operating Procedures." (Refer to...) Figure 7 After the chemical anchor 505 is placed in the groove of the carrier ring 501, the rod 100 is inserted into the borehole. When the rod 100 gradually sinks into the borehole to the working distance, the rod 100 stops working. At this time, the pull rod 602 on the rotating ring 601 of the operating mechanism 600 is pulled away from the chemical anchor 505. When the pull rope 504 breaks, the abutment ring 503 releases the potential energy of the compressed spring 502, and the abutment ring 503 ejects the chemical anchor 505 into the borehole. Then the rod 100 is pushed forward again for a distance until it can no longer move forward or backward, and the pushing stops. While waiting for the chemical agent inside the chemical anchor 505 to solidify, the rotating ring 601 is operated to continue moving away from the position of the chemical anchor 505. See reference. Figure 4 as well as Figure 3 The compression groove 204 on the inner ring 203 is Z-shaped. In the initial state, the rotating ring 601 drives the pull rod 602 to the compression groove 204 of the first trigger mechanism 200. When the pull rod 602 contacts the Z-shaped compression groove 204 of the inner ring 203, the pull rod 602 rotates. The L-shaped limiting block 201 of the slide 101 is located at the short side of the L-shape of the slide 101. Then, the rotation of the pull rod 602 releases the locking of the limiting block 201, so that the limiting block 201 is inside the long side of the slide 101. Then, the pull rod 602 continues to move away from the chemical anchor 505 inside the rotating ring 601. The pull rod 602 inside the compression groove 204 pulls the inner ring 203 toward the expansion mechanism 300. When the moving ring 202 contacts several arc plates 303, it will force the threaded ring 301 to move away from the chemical anchor 505. Above, the arc plate 303 on the arc groove 302 expands away from the axis of the threaded ring 301 until it expands to a suitable angle, or when the rock and soil inside the hole are too soft, the limiting block 201 connected to the inner ring 203 is moved to the bottom of the L-shaped long side of the slide groove 101 by the operation of the pull rod 602. The width of the moving ring 202 is less than or equal to the width of the inclined groove 305. When the inner ring 203 reaches its maximum stroke, the pull rod 602 is pulled out from the current pressing groove 204 in conjunction with the positioning effect of the rotating ring 601 from the Z-shape, and reaches the next trigger mechanism 200 and expansion mechanism 300. The above operation is repeated. The outward expansion angle of the arc plate 303 can be freely selected, or the inner ring 203 can be pulled to the maximum stroke. When the maximum arc plate 303 is opened to the maximum angle, refer to Figure 6As shown, this is the unopened state. After all the arc-shaped plates 303 have reached their maximum concentric outward rotation through the moving ring 202, the moving ring 202 is pressed against the arc-shaped plates 303 by the elastic band 304, causing the moving ring 202 to contact the inclined slot 305. This limits the movement of the moving ring 202, achieving the effect of expansion while preventing it from resetting. (See following...) Figure 1 and Figure 2 Tighten the tray and nut sequentially on the rod 100 to make the tray fit tightly against the rock surface. The installation of the tray and nut is existing technology and is shown in the figure but not marked. Tighten the rod 100 to the specified preload, and all operations are completed.

[0043] The contents not described in detail in this description are existing technologies known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An expanding rock bolt for use in coal mines, characterised in that, Include: The rod body (100) is provided with a plurality of groups of sliding grooves (101) equidistantly along its longitudinal axis, and the sliding grooves (101) are not perpendicular to each other; A plurality of trigger mechanisms (200) are respectively arranged in each sliding groove (101); A plurality of expansion mechanisms (300) are equidistantly arranged on the surface of the rod body (100) and are respectively located near the sliding grooves (101) of the rod body (100); A firing mechanism (500) is arranged in the rod body (100) and cooperates with the expansion mechanism (300) to perform a radial expansion action in the working state to fix the inside of the coal mine hole; A control mechanism (600) is arranged on the side away from the firing mechanism (500) in the rod body (100), the control mechanism (600) includes a rotating ring (601) rotatably connected in the rod body (100), a directional slot is formed in the rotating ring (601), and a pull rod (602) is slidably connected in the directional slot.

2. An expanding rock bolt for use in a coal mine according to claim 1 wherein: The trigger mechanism (200) includes a limiting block (201) slidably connected in the sliding groove (101), a moving ring (202) is fixedly connected to one side of the limiting block (201), an inner ring (203) is fixedly connected to the other side of the limiting block (201), and a compression slot (204) is formed in the inner wall of the inner ring (203).

3. An expanding rock bolt for use in a coal mine according to claim 2, characterised in that: The expansion mechanism (300) includes a threaded ring (301) threadedly connected to the surface of the rod body (100) and near the sliding groove (101), a plurality of groups of arc-shaped slots (302) are equidistantly formed on the surface of the threaded ring (301), an arc-shaped plate (303) is hingedly connected to the edge of each arc-shaped slot (302), an annular slot is formed on the surface of the arc-shaped plate (303), a rubber band (304) is sleeved in the annular slot, and an inclined slot (305) is formed near the axis of the threaded ring (301) on each arc-shaped plate (303).

4. An expanding rock bolt for use in a coal mine according to claim 3 wherein: The contact surface between the arc-shaped plate (303) and the moving ring (202) is curved, and the arc-shaped plate (303) is flipped by the compression force of the moving ring (202) in the working state.

5. An expanding rock bolt for use in a coal mine according to claim 4 wherein: A plurality of arc-shaped plates (303) jointly form an axially tapered cone along the circumferential surface of the threaded ring (301), the smallest radius end of the cone is near the inclined slot (305), and the largest radius end of the cone extends away from the inclined slot (305).

6. An expanding rock bolt for use in a coal mine according to claim 5 wherein: The firing mechanism (500) includes a carrier ring (501) fixedly connected in the rod body (100), a spring (502) is fixedly connected in the carrier ring (501), a stop ring (503) is fixedly connected to the end of the spring (502), a pull rope (504) is fixedly connected to one side of the stop ring (503), and a chemical anchor (505) is arranged on the other side of the pull rope (504).

7. An expanding rock bolt for use in a coal mine according to claim 6 wherein: The pull rope (504) is in contact with the pull rod (602), and when the pull rod (602) moves to a set distance away from the chemical anchor (505), the pull rope (504) is pulled off by the pull rod (602).

8. An expanding rock bolt for use in a coal mine according to claim 7, characterised in that: The pull rod (602) is initially kept apart from the pressing notch (204), and in the working state, is driven to slide downward along the inside of the pressing notch (204), and the sliding track is constrained by the inner cavity of the pressing notch (204).

Images