Coal rock failure acoustic emission three-dimensional real-time positioning and early warning device

Abstract

This invention belongs to the technical field of mine safety monitoring equipment, and relates to a three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage. It includes a sensor mounting mechanism, an acoustic emission sensor, a signal acquisition and processing unit, a three-dimensional positioning unit, and an early warning unit. The sensor mounting mechanism includes a mounting rod, a sensor compartment, and an outer sleeve. The outer sleeve is fitted around the sensor compartment and has an annular protrusion and an expansion groove. In its free state, the outer diameter of the annular protrusion is larger than the borehole diameter. A threaded drive mechanism is provided between the sensor compartment and the outer sleeve. When the mounting rod is rotated, the outer sleeve moves axially and expands radially, causing the annular protrusion to press against the borehole wall. The sensor compartment also has a coupling agent injection mechanism triggered by the movement of the outer sleeve, injecting coupling agent into the mounting cavity to fill the gap between the sensor and the cavity wall. This invention completes anchoring and injection simultaneously through a single rotational action, making operation simple, anchoring reliable, and coupling effect good. Furthermore, the sensor can be recycled and reused.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine safety monitoring equipment, in particular to a coal rock damage acoustic emission three-dimensional real-time positioning and early warning device. BACKGROUND

[0002] The coal rock damage acoustic emission three-dimensional real-time positioning and early warning device can directly display the position and development trend of the rupture, automatically triggers the early warning before the instability and damage, and provides a real-time monitoring means for mine dynamic disasters, and ensures the safety production.

[0003] In the coal rock damage acoustic emission monitoring system, the installation quality of the sensor directly determines the reliability of signal acquisition and positioning accuracy. The existing sensor installation method mainly adopts grouting fixation, that is, the sensor is packaged in the hole by injecting cement mortar in the drill hole. This method has obvious defects: the grouting process is complex, the slurry needs to be prepared on site and wait for solidification, and the installation efficiency is low; the slurry is easy to flow out in the upward hole or horizontal hole, resulting in poor coupling and serious signal attenuation; more importantly, the grouting fixation is a one-time irreversible installation, the sensor cannot be recycled, when the monitoring area changes with the mining and excavation, the installed sensor is permanently abandoned, causing equipment waste, greatly increasing the long-term monitoring cost, and the original design only considers the static load tension, without considering the coupling requirement that the sensor needs to be closely attached to the hole wall to transmit weak vibration signals.

[0004] In view of this, the present application provides a coal rock damage acoustic emission three-dimensional real-time positioning and early warning device, which solves the above technical problems. SUMMARY

[0005] This part aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part and the abstract and title of the specification to avoid obscuring the purpose of this part, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] A coal rock damage acoustic emission three-dimensional real-time positioning and early warning device, comprising: A sensor mounting mechanism, comprising: A mounting rod; A sensor cabin fixedly connected to the front end of the mounting rod, and an installation cavity is arranged in the sensor cabin; An outer sleeve is sleeved on the outer periphery of the sensor cabin, and at least two annular protrusions are arranged on the outer periphery of the outer sleeve, and an expansion slot is formed on the side wall of the outer sleeve to form a radially expandable open ring structure; In its free state, the outer diameter of the annular protrusion of the outer sleeve is larger than the diameter of the hole to be drilled. A drive mechanism is provided between the sensor compartment and the outer sleeve. When the mounting rod rotates, it drives the outer sleeve to move axially and expand radially, so that the annular protrusion abuts against the borehole wall. The sensor compartment is also equipped with a coupling agent injection mechanism triggered by the axial movement of the outer sleeve; An acoustic emission sensor is disposed within the mounting cavity; The signal acquisition and processing unit is connected to the acoustic emission sensor; A three-dimensional positioning unit is connected to the signal acquisition and processing unit; The early warning unit is connected to the three-dimensional positioning unit.

[0007] Preferably, the outer diameter of the annular protrusion in its free state is 0.3-2 mm larger than the borehole diameter.

[0008] Preferably, the drive mechanism includes an external thread disposed on the outer peripheral surface of the sensor compartment and an internal thread disposed on the inner peripheral surface of the outer sleeve.

[0009] Preferably, the sensor compartment includes a rear threaded section and a smooth front expansion section, the external thread is provided on the rear threaded section, and the front expansion section is a smooth conical surface with a diameter that gradually increases from back to front.

[0010] Preferably, the cross-section of the annular protrusion is serrated, with the front side of the serration being an inclined surface and the rear side being a vertical surface.

[0011] Preferably, the front end of the sensor compartment is provided with a guide head, which is conical and its maximum outer diameter is less than or equal to the outer diameter of the outer sleeve when it is in the retracted state.

[0012] Preferably, the mounting rod is composed of multiple rod sections that are detachably connected in sequence.

[0013] Preferably, the rear end of the sensor compartment is provided with a through hole for leading out sensor signal lines.

[0014] Preferably, the coupling agent injection mechanism includes: The storage chamber located at the front of the sensor compartment is pre-filled with coupling agent; The liquid injection channel connects the storage chamber and the installation cavity, and its inlet end is provided with a ruptureable sealing membrane; The pressure block is movably disposed in the storage chamber, with its top extending into the moving path of the outer sleeve; A return spring is provided in the storage chamber, with one end abutting against the bottom of the storage chamber and the other end abutting against the pressure block, applying an outward elastic force to the pressure block; When the pressure block is pressed by the outer sleeve, it moves into the storage chamber and squeezes the coupling agent, causing the coupling agent to break through the sealing membrane and be injected into the installation cavity through the injection channel.

[0015] Preferably, there are two storage chambers, symmetrically distributed on both sides of the axis of the sensor compartment.

[0016] The beneficial effects of this invention are: This invention, through the cooperation of a pre-tightened outer sleeve and a threaded drive mechanism, allows operators to simultaneously achieve axial movement, radial expansion anchoring, and coupling agent injection of the outer sleeve with a single action of continuously rotating the mounting rod, greatly simplifying the on-site installation process. Because the internal and external threads remain engaged throughout, the driving force is controllable throughout the process, allowing operators to precisely control the forward and backward position of the outer sleeve. As the outer sleeve moves along the front smooth conical surface, it is gradually expanded, with expansion occurring synchronously with the drive, ensuring precise and reliable anchoring timing. The serrated design of the annular protrusion creates a mechanical self-locking mechanism on its rear side, becoming increasingly tighter after anchoring, significantly improving vibration resistance and anti-retraction capabilities. The coupling agent injection mechanism is triggered by the movement of the outer sleeve, simultaneously injecting coupling agent into the mounting cavity during anchoring, completely eliminating the air gap between the sensor and the cavity wall, ensuring high-fidelity transmission of acoustic emission signals. Reverse rotation of the mounting rod allows the outer sleeve to retract and retract, achieving reversible recovery of the sensor and mounting mechanism, significantly reducing long-term monitoring costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. 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.

[0018] in: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 Exploded structural diagram of the present invention; Figure 4 for Figure 3 Enlarged view at point B in the middle; Figure 5 This is a schematic diagram of the cross-sectional structure of the present invention; Figure 6 for Figure 5 Enlarged view at point C; Figure 7 A schematic diagram of the internal connection structure of the sensor compartment; Figure 8 for Figure 7 Enlarged view at point D; Figure 9 for Figure 8 Enlarged view of point E in the middle.

[0019] In the picture: 1. Mounting rod; 11. Rod section; 2. Sensor compartment; 21. Mounting cavity; 22. Rear threaded section; 23. Front expansion section; 3. Outer sleeve; 31. Annular protrusion; 311. Inclined surface; 312. Vertical surface; 32. Expansion groove; 4. Drive mechanism; 41. External thread; 42. Internal thread; 5. Coupling agent injection mechanism; 51. Storage chamber; 52. Injection channel; 53. Sealing membrane; 54. Pressure block; 55. Return spring; 6. Acoustic emission sensor; 7. Guide head; 8. Wire hole. Detailed Implementation

[0020] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] Example 1: like Figures 1-9 As shown, a three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage includes: The sensor mounting mechanism includes: Mounting rod 1; The sensor compartment 2 is fixedly connected to the front end of the mounting rod 1, and has a mounting cavity 21 inside. The outer sleeve 3 is fitted around the outer periphery of the sensor compartment 2. The outer periphery surface of the outer sleeve 3 is provided with at least two annular protrusions 31, and its sidewall is provided with an expansion groove 32 that allows the outer sleeve 3 to form a radially expandable open-ring structure. When the outer sleeve 3 is in a free state, the outer diameter of its annular protrusion 31 is larger than the diameter of the hole to be drilled. A drive mechanism 4 is provided between the sensor compartment 2 and the outer sleeve 3. When the mounting rod 1 rotates, it drives the outer sleeve 3 to move axially and expand radially, so that the annular protrusion 31 abuts against the borehole wall. The sensor compartment 2 is also equipped with a coupling agent injection mechanism 5 triggered by the axial movement of the outer sleeve 3; Acoustic emission sensor 6 is disposed inside mounting cavity 21; The signal acquisition and processing unit is connected to the acoustic emission sensor 6; The three-dimensional positioning unit is connected to the signal acquisition and processing unit; The early warning unit is connected to the three-dimensional positioning unit.

[0022] The outer diameter of the annular protrusion 31 in its free state is 0.3-2 mm larger than the borehole diameter.

[0023] The drive mechanism 4 includes an external thread 41 on the outer peripheral surface of the sensor compartment 2 and an internal thread 42 on the inner peripheral surface of the outer sleeve 3.

[0024] The cross-section of the annular protrusion 31 is serrated, with the front side of the serration being an inclined surface 311 and the rear side being a vertical surface 312.

[0025] like Figures 1-9 As shown, the three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage in this embodiment includes a sensor installation mechanism, an acoustic emission sensor 6, a signal acquisition and processing unit, a three-dimensional positioning unit, and an early warning unit.

[0026] The sensor mounting mechanism includes a mounting rod 1, a sensor compartment 2, and an outer retaining sleeve 3. The mounting rod 1, made of seamless steel tubing, is used to push the entire mechanism to the predetermined drilling depth. The sensor compartment 2 is fixedly connected to the front end of the mounting rod 1, and its interior has a mounting cavity 21 for accommodating the acoustic emission sensor 6.

[0027] The outer sleeve 3 is fitted around the outer periphery of the sensor compartment 2. The outer periphery of the outer sleeve 3 has two axially arranged annular protrusions 31. The cross-section of each annular protrusion 31 is serrated, with a sloping front surface 311 and a vertical rear surface 312. Multiple through-hole expansion grooves 32 are axially distributed along the sidewalls of the outer sleeve 3. These expansion grooves 32 create a radially expandable open-loop structure for the outer sleeve 3; that is, the outer sleeve 3 resembles a circular ring with slits, capable of elastically opening and closing in the radial direction.

[0028] In its free state, the outer diameter of the annular protrusion 31 of the outer sleeve 3 is 1 mm larger than the diameter of the borehole to be drilled. This means that the outer sleeve 3 must be pushed before it can be inserted into the borehole. After the outer sleeve 3 is inserted into the borehole, the annular protrusion 31 always remains in contact with the borehole wall, generating a stable initial frictional force.

[0029] A drive mechanism 4 is provided between the sensor compartment 2 and the outer sleeve 3. In this embodiment, the drive mechanism 4 includes an external thread 41 provided on the outer peripheral surface of the sensor compartment 2 and an internal thread 42 provided on the inner peripheral surface of the outer sleeve 3, both of which are equal pitch threads.

[0030] The sensor compartment 2 is also equipped with a coupling agent injection mechanism 5, which is triggered by the axial movement of the outer sleeve 3. Its specific structure will be described in detail in subsequent embodiments.

[0031] Acoustic emission sensor 6 is installed inside mounting cavity 21 to collect acoustic emission signals generated by coal and rock fracturing. Signal acquisition and processing unit is connected to acoustic emission sensor 6, amplifying, filtering, and performing analog-to-digital conversion on the raw signal. Three-dimensional positioning unit is connected to signal acquisition and processing unit, using a time-difference positioning algorithm to calculate the three-dimensional coordinates of the coal and rock fracturing source in real time. Early warning unit is connected to three-dimensional positioning unit, issuing graded early warning signals based on the positioning results and preset early warning criteria.

[0032] In this embodiment, through the design of the pre-tightening outer sleeve 3 and the cooperation of the threaded drive mechanism 4, the device can achieve reliable mechanical anchoring of the sensor in deep holes; the coupling agent injection mechanism 5 ensures good acoustic coupling between the sensor and the mounting cavity 21; high-quality signal acquisition provides a data foundation for subsequent accurate positioning and reliable early warning. The entire device, from physical installation to signal acquisition and data processing, forms a complete monitoring and early warning chain.

[0033] Example 2: like Figures 1-4 As shown, a three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage is provided. The sensor compartment 2 includes a rear threaded part 22 and a smooth front expansion part 23. The external thread 41 is provided in the rear threaded part 22, and the front expansion part 23 is a smooth conical surface with a diameter that gradually increases from back to front.

[0034] Based on Example 1, this example further optimizes the structure of the sensor compartment 2. For example... Figure 2 As shown, the sensor compartment 2 includes a rear threaded section 22 and a front expansion section 23.

[0035] The rear threaded section 22 is a cylinder of equal diameter, with an external thread 41 on its outer circumference, which engages with the internal thread 42 of the outer ferrule 3 to achieve drive. The front expansion section 23 is a smooth conical surface without threads, and its diameter gradually increases from rear to front.

[0036] Phase 1: The operator rotates the mounting rod 1, causing the sensor compartment 2 to rotate accordingly. Due to the initial frictional force, the outer sleeve 3 tends to remain relatively stationary, moving forward along the thread of the rear threaded portion 22. At this time, the outer sleeve 3 is in a retracted state, with the annular protrusion 31 maintaining slight contact with the bore wall.

[0037] Second stage: The outer sleeve 3 continues to move forward, gradually entering the area of ​​the front expansion section 23. At this time, the internal thread 42 of the outer sleeve 3 still engages with the external thread 41 of the rear threaded section 22, and the driving relationship continues. As the outer sleeve 3 moves forward, its front end (the part away from the thread engagement section) begins to contact the smooth conical surface with a gradually increasing diameter.

[0038] Phase 3: The operator continues to rotate mounting rod 1, and outer clamp 3 continues to move forward. During this process: The rear end of the outer sleeve 3 (the part with the internal thread 42) is always engaged with the rear threaded part 22, and continuously receives driving force; The front end of the outer card sleeve 3 is gradually expanded by the smooth conical surface of the front expansion part 23; The outer sleeve 3 is an open-loop elastic structure that undergoes elastic deformation, with the rear end maintaining its original diameter and the front end gradually expanding. As the front end expands, the annular protrusion 31 is gradually pressed into the borehole wall; When the outer sleeve 3 moves to the foremost end of the front expansion section 23, the annular protrusion 31 is fully embedded in the borehole wall, and the vertical surface 312 of the serrated protrusion forms a self-locking mechanism to prevent the outer sleeve 3 from retracting.

[0039] Fourth stage: When retrieval is required, the operator rotates the mounting rod 1 in the reverse direction. The sensor compartment 2 rotates in the reverse direction, driving the outer retaining sleeve 3 to move backward. As the outer retaining sleeve 3 retracts, its front end gradually disengages from the conical area of ​​the front expansion section 23 and enters the smaller diameter rear section area. The outer retaining sleeve 3 contracts under its own elasticity, and the annular protrusion 31 disengages from the hole wall. During the retraction of the outer retaining sleeve 3, its internal thread 42 remains engaged with the rear threaded section 22 until it returns to its initial position.

[0040] This design simplifies the operation process by simultaneously achieving axial movement, radial expansion anchoring, and coupling agent injection of the outer sleeve 3 through a single rotation of the mounting rod 1. Since the external thread 41 and internal thread 42 remain engaged, the driving force is controllable throughout the process, allowing operators to control the forward and backward position of the outer sleeve 3 via rotation. Expansion, a natural consequence of the outer sleeve 3 moving along the front expansion section 23, occurs synchronously with the driving process, ensuring reliable anchoring timing. The serrated design of the annular protrusion 31 creates a mechanical self-locking mechanism on its rear vertical surface 312, tightening further after anchoring and enhancing anchoring reliability. Reverse rotation of the mounting rod 1 causes the outer sleeve 3 to retract along the rear thread section 22, disengaging the annular protrusion 31 from the borehole wall, enabling reversible recovery of the acoustic emission sensor 6 and the mounting mechanism, effectively reducing long-term operating costs.

[0041] Example 3: like Figure 1 and Figure 5As shown, a three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage is provided. A guide head 7 is installed at the front end of the sensor compartment 2. The guide head 7 is conical, and its maximum outer diameter is less than or equal to the outer diameter of the outer sleeve 3 in its retracted state. The conical structure of the guide head 7 guides the sensor compartment 2 during the pushing process, allowing it to smoothly enter the borehole and avoiding jamming caused by burrs at the borehole opening or uneven borehole walls. Simultaneously, since the maximum outer diameter of the guide head 7 does not exceed the outer diameter of the outer sleeve 3 in its retracted state, a gap remains between the guide head 7 and the borehole wall after the outer sleeve 3 expands and anchors, preventing interference with the anchoring effect.

[0042] Mounting rod 1 is composed of multiple rod sections 11 that are detachably connected in sequence. In this embodiment, adjacent rod sections 11 are connected by threads, and each rod section 11 is 1 meter long. During on-site installation, the appropriate number of rod sections 11 can be selected and connected according to the drilling depth.

[0043] Adaptable to different hole depths: The drilling depth in coal mines varies from a few meters to tens of meters. The modular design allows one set of installation mechanisms to be applicable to various depths without the need to customize installation rods of different lengths for different depths.

[0044] Easy to transport and carry: The length of a single rod section 11 is moderate, making it easy to transport and carry in narrow underground tunnels.

[0045] Flexible on-site adjustments: If the drilling depth does not meet expectations, the number of rod sections 11 can be increased or decreased at any time without having to return to the ground for replacement.

[0046] Protection: Used to protect the signal line leading out to acoustic emission sensor 6.

[0047] The rear end of the sensor compartment 2 is provided with a wire hole 8 for leading out the sensor signal line. The wire hole 8 allows the signal line to be led out from the rear end of the sensor compartment 2, avoiding compression or wear of the signal line during installation. At the same time, the diameter of the wire hole 8 matches the diameter of the signal line, and after installation, it can be filled with sealant to further protect the signal line and prevent moisture from entering the mounting cavity 21.

[0048] Example 4: like Figures 5-9 As shown, a three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage includes a coupling agent injection mechanism 5 comprising: Storage chamber 51 located at the front end of sensor compartment 2 is pre-filled with coupling agent; The liquid injection channel 52 connects the storage chamber 51 and the installation cavity 21, and its inlet end is provided with a ruptureable sealing membrane 53. The pressure block 54 is movably disposed in the storage chamber 51, with its top extending into the moving path of the outer sleeve 3; The return spring 55 is located inside the storage chamber 51, with one end abutting against the bottom of the storage chamber 51 and the other end abutting against the pressure block 54, applying an outward elastic force to the pressure block 54; When the pressure block 54 is pressed by the outer sleeve 3, it moves into the storage chamber 51 and squeezes the coupling agent, causing the coupling agent to break through the sealing membrane 53 and be injected into the installation cavity 21 through the injection channel 52.

[0049] There are two storage chambers 51, which are symmetrically distributed on both sides of the axis of the sensor compartment 2.

[0050] This embodiment describes in detail the specific structure and working principle of the coupling agent injection mechanism 5. The coupling agent injection mechanism 5 includes a storage chamber 51, an injection channel 52, a sealing membrane 53, a pressure block 54, and a return spring 55.

[0051] Storage chamber 51 is located at the front end of sensor compartment 2, inside the front expansion section 23. In this embodiment, two storage chambers 51 are provided, symmetrically distributed on both sides of the axis of sensor compartment 2. Each storage chamber 51 is pre-filled with sufficient acoustic coupling agent. In this embodiment, non-curing silicone grease is selected as the coupling agent, which has good acoustic impedance matching with the coal and rock mass and the metal compartment, and excellent long-term stability.

[0052] The injection channel 52 connects the storage chamber 51 and the mounting cavity 21. The inlet end of the injection channel 52 (i.e. the end connected to the storage chamber 51) is provided with a ruptureable sealing membrane 53. In this embodiment, an aluminum foil with a thickness of 0.05 mm is used as the sealing membrane 53.

[0053] The pressure block 54 is movably disposed within the storage chamber 51, with its top extending out of the storage chamber 51 and positioned on the moving path of the outer sleeve 3. The return spring 55 is disposed within the storage chamber 51, with one end abutting against the bottom of the storage chamber 51 and the other end abutting against the bottom of the pressure block 54, and always applies an upward elastic force to the pressure block 54.

[0054] Initial state: During the process of the sensor mounting mechanism being pushed into the borehole, the return spring 55 lifts the pressure block 54, causing its top to extend out of the storage chamber 51. At this time, the pressure block 54 is located on the moving path of the front end of the outer sleeve 3, but the outer sleeve 3 has not yet come into contact with the pressure block 54. The sealing membrane 53 remains intact, and the coupling agent is sealed inside the storage chamber 51.

[0055] Triggering injection stage: When the outer sleeve 3 moves forward along the front expansion section 23, its front end face gradually approaches the pressure block 54. The outer sleeve 3 continues to move forward, and its front end face presses against the top of the pressure block 54, overcoming the elastic force of the reset spring 55 and pressing the pressure block 54 into the storage chamber 51.

[0056] As the pressure block 54 moves downward, it compresses the volume within the storage chamber 51, causing the coupling agent pressure to rise rapidly. When the pressure reaches the rupture threshold of the sealing membrane 53, the sealing membrane 53 ruptures instantaneously, and the coupling agent is injected into the mounting cavity 21 through the injection channel 52 under pressure.

[0057] Filling Stage: The couplant injected into the mounting cavity 21 flows within the cavity, gradually filling the gap between the acoustic emission sensor 6 and the inner wall of the mounting cavity 21. To ensure uniform filling, a spiral guide groove (not shown in the figure) can be provided on the inner wall of the mounting cavity 21 to guide the couplant to flow uniformly from back to front and from circumference to center. During the flow, the couplant pushes the air in the cavity out through the tiny gap at the front end of the sensor or the wire hole 8, achieving bubble-free filling.

[0058] When the outer sleeve 3 moves to the foremost end of the front expansion section 23, the pressure block 54 is pressed to its lowest point, and the coupling agent in the storage chamber 51 has been squeezed out. At this time, the mounting cavity 21 is completely filled with coupling agent, and the acoustic emission sensor 6 is evenly coated with coupling agent.

[0059] Reset Phase: When sensor retrieval is required, the mounting rod 1 is rotated in the reverse direction to move the outer retaining sleeve 3 backward. After the outer retaining sleeve 3 disengages from the pressure block 54, the reset spring 55 pushes the pressure block 54 upward, restoring it to its extended state. Residual coupling agent in the storage chamber 51 is retained for reuse during the next installation.

[0060] This embodiment employs two symmetrically distributed storage chambers 51. The two storage chambers 51 have identical structures, each with its own independent pressure block 54, return spring 55, injection channel 52, and sealing membrane 53.

[0061] During installation, the front end of the outer sleeve 3 simultaneously presses against two pressure blocks 54, and the two storage chambers 51 are simultaneously compressed, ruptured, and injected.

[0062] The benefits of the dual storage compartment 51 design: Balanced force: When the two pressure blocks 54 are pressed against the outer sleeve 3 at the same time, the force is symmetrically distributed, avoiding the generation of skew torque in the sensor compartment 2 and ensuring the stability of the anchoring process.

[0063] Double capacity: The total capacity of the coupling agent is doubled, which is sufficient to completely fill the mounting cavity 21 with an appropriate margin to ensure the filling effect.

[0064] Mutual backup: If the sealing membrane 53 of one of the storage chambers 51 breaks prematurely due to an accident or the injection channel 52 is blocked, the other storage chamber 51 can still complete the injection task independently, which improves the reliability of the system.

[0065] The effect of coupling agent injection mechanism 5: Mechanical linkage, no additional power required: The injection action is entirely driven by the movement of the outer sleeve 3, without the need for motors, hydraulics or manual operation. The structure is simple and inherently safe, and it is suitable for underground coal mine environments.

[0066] The injection timing is controllable: the injection action occurs synchronously with the anchoring movement of the outer sleeve 3, and the rupture pressure design of the sealing membrane 53 ensures that the injection occurs at a specific stage in the anchoring process, so that the coupling agent is not lost too early during the pushing process, nor is the coupling effect affected too late.

[0067] The recyclable design reduces operating costs: the coupling agent is non-curing silicone grease, allowing the sensor to be easily removed from the mounting cavity 21; the return spring 55 automatically resets the pressure block 54, and residual coupling agent in the storage chamber 51 can be reused. Compared with traditional grouting installation methods, both the sensor and the mounting mechanism in this solution are reusable, significantly reducing long-term monitoring costs.

[0068] Work process: Step 1 (On-site preparation): The drilling location and depth were determined according to the monitoring plan, and a drilling rig was used to drill the borehole. The borehole diameter was designed to be 42mm to match the sensor mounting mechanism. The surface debris at the borehole opening was cleaned in preparation for installation.

[0069] Step 2 (Preparation of sensor mounting mechanism): In a safe area on the surface or downhole, install the acoustic emission sensor 6 into the mounting cavity 21 of the sensor compartment 2, with the sensor signal line leading out from the wiring hole 8. Check that the coupling agent in both storage chambers 51 is sufficient and that the sealing membrane 53 is intact. According to the drilling depth, connect the corresponding number of rod sections 11 in sequence to form the mounting rod 1.

[0070] Step 3 (Institutional Push): The operator holds the installation rod 1 and slowly pushes the entire mechanism into the borehole. Because the outer diameter (43mm) of the annular protrusion 31 of the outer sleeve 3 in its free state is larger than the borehole diameter (42mm), the outer sleeve 3 is compressed and inserted into the borehole. During the pushing process, the annular protrusion 31 maintains contact with the borehole wall under the action of elastic restoring force, generating a stable initial frictional force. The guide head 7 guides the mechanism forward smoothly, avoiding jamming.

[0071] Step 4 (Rotational Anchoring and Coupling Agent Injection): Once the sensor compartment 2 is pushed to the predetermined depth, the operator uses a wrench outside the hole to continuously rotate the mounting rod 1 in the forward direction.

[0072] Mounting rod 1 drives sensor compartment 2 to rotate. Due to the initial frictional force, outer sleeve 3 tends to remain relatively stationary, and moves forward along the thread of the rear threaded portion 22. At this time, the internal thread 42 of outer sleeve 3 always maintains engagement with the external thread 41 of the rear threaded portion 22, and the driving relationship continues.

[0073] The outer sleeve 3 continues to move forward, gradually entering the area of ​​the front expansion section 23. As the outer sleeve 3 moves forward, its front end begins to contact the smooth conical surface with a gradually increasing diameter. As an open-ring elastic structure, the front end of the outer sleeve 3 is gradually expanded by the conical surface, and the annular protrusion 31 is gradually pressed into the borehole wall.

[0074] At the same time, the front end of the outer sleeve 3 gradually approaches and finally presses against the top of the pressure block 54 of the two storage chambers 51, pressing the pressure block 54 into the storage chamber 51. The pressure block 54 squeezes the coupling agent, which is injected into the mounting cavity 21 through the injection channel 52, evenly filling the gap between the acoustic emission sensor 6 and the mounting cavity 21, and pushing the air out from the front end of the sensor.

[0075] The operator continues to rotate the mounting rod 1 until the outer sleeve 3 moves to the front end of the front expansion section 23. At this time, the annular protrusion 31 is fully embedded in the borehole wall, and the vertical surface 312 of the serrated protrusion forms a self-locking mechanism; the mounting cavity 21 is completely filled with coupling agent, and the acoustic emission sensor 6 is evenly wrapped with coupling agent.

[0076] Step 5 (Signal Acquisition and Location Early Warning): After installation, the acoustic emission sensor 6 begins operation. When the coal and rock mass fractures, the resulting acoustic emission signal is collected by the acoustic emission sensor 6 and transmitted to the signal acquisition and processing unit via a signal line. The signal acquisition and processing unit amplifies, filters, and performs analog-to-digital conversion on the signal before uploading the digital signal to the three-dimensional positioning unit.

[0077] The three-dimensional positioning unit employs the Geiger positioning algorithm based on ray tracing, combined with a pre-established wave velocity field model, to calculate the three-dimensional coordinates of the rupture source in real time and dynamically display the rupture location and energy on the three-dimensional model. When the energy, frequency, or spatial concentration of the rupture event exceeds a preset threshold, the early warning unit issues a tiered early warning signal, notifying relevant personnel through the underground broadcast system, audible and visual alarms, or the mine's integrated automation platform.

[0078] Step 6 (Recycling): When the monitoring task is completed or the sensor position needs to be adjusted, the operator rotates the mounting rod 1 in the reverse direction. The sensor compartment 2 rotates in the reverse direction, driving the outer sleeve 3 to move backward.

[0079] As the outer sleeve 3 retracts, its front end gradually separates from the conical area of ​​the front expansion section 23 and enters the rear section with a smaller diameter. Under its own elasticity, the outer sleeve 3 contracts, and the annular protrusion 31 disengages from the hole wall. At the same time, the outer sleeve 3 disengages from the pressure block 54, and the return spring 55 pushes the pressure block 54 upward to return it to its original position.

[0080] The outer sleeve 3 continues to retract, its internal thread 42 remaining engaged with the rear threaded portion 22, until it returns to its initial position. The operator pulls the mounting rod 1 outward to remove the entire mechanism from the borehole.

[0081] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage, characterized in that, include: Sensor mounting mechanism, the sensor mounting mechanism comprising: Mounting rod (1); The sensor compartment (2) is fixedly connected to the front end of the mounting rod (1), and has a mounting cavity (21) inside. The outer sleeve (3) is fitted around the outer periphery of the sensor compartment (2). The outer periphery of the outer sleeve (3) is provided with at least two annular protrusions (31), and its sidewall is provided with an expansion groove (32) that allows the outer sleeve (3) to form a radially expandable open-ring structure. In its free state, the outer diameter of the annular protrusion (31) of the outer sleeve (3) is larger than the diameter of the hole to be drilled. A drive mechanism (4) is provided between the sensor compartment (2) and the outer sleeve (3). When the mounting rod (1) rotates, it drives the outer sleeve (3) to move axially and expand radially, so that the annular protrusion (31) abuts against the borehole wall. The sensor compartment (2) is also equipped with a coupling agent injection mechanism (5) triggered by the axial movement of the outer sleeve (3); An acoustic emission sensor (6) is disposed within the mounting cavity (21); The signal acquisition and processing unit is connected to the acoustic emission sensor (6). A three-dimensional positioning unit is connected to the signal acquisition and processing unit; The early warning unit is connected to the three-dimensional positioning unit.

2. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The outer diameter of the annular protrusion (31) in its free state is 0.3-2 mm larger than the borehole diameter.

3. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The drive mechanism (4) includes an external thread (41) on the outer peripheral surface of the sensor compartment (2) and an internal thread (42) on the inner peripheral surface of the outer sleeve (3).

4. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 3, characterized in that, The sensor compartment (2) includes a rear threaded section (22) and a smooth front expansion section (23). The external thread (41) is provided on the rear threaded section (22), and the front expansion section (23) is a smooth conical surface with a diameter that gradually increases from back to front.

5. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The cross-section of the annular protrusion (31) is serrated, with the front side of the serration being an inclined surface (311) and the rear side being a vertical surface (312).

6. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The sensor compartment (2) is provided with a guide head (7) at the front end. The guide head (7) is conical and its maximum outer diameter is less than or equal to the outer diameter of the outer sleeve (3) when it is in the contracted state.

7. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The mounting rod (1) is composed of multiple rod sections (11) that are detachably connected in sequence.

8. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The rear end of the sensor compartment (2) is provided with a wire hole (8) for leading out sensor signal lines.

9. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 1, characterized in that, The coupling agent injection mechanism (5) includes: The storage chamber (51) located at the front end of the sensor compartment (2) is pre-filled with coupling agent; The liquid injection channel (52) connects the storage chamber (51) and the installation cavity (21), and its inlet end is provided with a ruptureable sealing membrane (53). The pressure block (54) is movably disposed in the storage chamber (51), with its top extending into the moving path of the outer sleeve (3); A return spring (55) is provided in the storage chamber (51), with one end abutting the bottom of the storage chamber (51) and the other end abutting the pressure block (54), and applying an outward elastic force to the pressure block (54); When the pressure block (54) is pressed by the outer sleeve (3), it moves into the storage chamber (51) and squeezes the coupling agent, so that the coupling agent breaks through the sealing membrane (53) and is injected into the installation cavity (21) through the injection channel (52).

10. The three-dimensional real-time positioning and early warning device for acoustic emission of coal and rock damage according to claim 9, characterized in that, Two storage chambers (51) are provided, symmetrically distributed on both sides of the axis of the sensor compartment (2).

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