A constant resistance large deformation anchor cable support system for coal mine roadway

Abstract

The present application relates to a kind of constant resistance large deformation anchor supporting system for coal mine roadway, including multiple hierarchical constant resistance self-adapting pressure-relief anchor body arranged in array and longitudinal collaborative support network connected between the same column anchor body, anchor body is realized by the two-stage limiting and friction structure between the first-stage core barrel, second-stage core barrel and shell in its interior, two-stage constant resistance pressure-relief of first low and then high, make supporting resistance and roof deformation stage self-adapting match, collaborative network is connected by W steel band the tray of the same column anchor, and pre-compression spring damping element is arranged between adjacent tray, realize the dynamic transmission and buffer of supporting load, improve the overall resistance to local damage capacity, in addition, system also integrates displacement overrun monitoring component and self-generating mechanism, for long time, wireless monitoring and early warning to anchor core displacement are carried out.The present application realizes the self-adapting and collaboration of supporting, improves the supporting reliability and safety of the protected roadway in the process of cutting roof pressure relief.

Description

Technical Field

[0001] This invention relates to the field of coal mine roadway technology, and in particular to a constant resistance large deformation anchor cable support system for coal mine roadways. Background Technology

[0002] In coal mining, underground mining is the primary method, mainly using long-arm mining. Coal pillars are left to maintain the mining roadways. Under these conditions, a significant amount of coal resources are wasted; coal pillar losses typically account for about 40% of the total coal loss in the mine. Furthermore, during underground mining, intense mining pressure often causes severe deformation and damage to adjacent roadways, such as floor heave, sidewall shrinkage, and shotcrete cracking. Stress also concentrates on the retained protective coal pillars, placing the surrounding rock in a high-stress environment and causing large deformations, seriously affecting mine safety. The roof-cutting and pressure-relief pillarless self-forming roadway technology eliminates the need for section coal pillars. By implementing directional pre-splitting blasting on the roadway roof, the stress transmission path is cut off, achieving the goal of protecting adjacent roadways. This effectively solves the problem of tight replacement, recovers the protective coal pillars, reduces stress concentration, and lowers safety risks. Roadways adjacent to the longwall face are often subjected to the combined effects of in-situ stress, bearing pressure, and dynamic pressure from mining. Dynamic pressure has the greatest impact on roadway stability, and it arises from the collapse of overlying rock in the goaf during mining operations, causing pressure to be transmitted towards adjacent roadways. Therefore, to fundamentally reduce or eliminate the impact of dynamic pressure from adjacent longwall faces on roadway stability, it is necessary to cut off the stress transmission path in the goaf roof. Simultaneously, grouting anchors and cables should be installed in the protected roadways to improve the self-supporting capacity and dynamic pressure resistance of the surrounding rock, achieving coupled support. Constant-resistance, high-deformation anchor cables that absorb energy from the surrounding rock should be used to reinforce the roof of the protected roadways. These constant-resistance anchor cables absorb the elastic strain energy in the surrounding rock, thereby reducing the stress acting on the floor and controlling the deformation of the protected roadways.

[0003] Existing constant-resistance large deformation anchor cables mostly adopt a single constant-resistance value design, such as 350kN. Their working principle is that when the axial force reaches the preset constant-resistance value, the constant-resistance device slips to release energy. However, the deformation of the surrounding rock usually goes through multiple stages of severe-moderate-stable. A single constant-resistance value is difficult to match the entire process. In the initial severe deformation, an excessively high constant-resistance value may cause the support to bear the ultimate load too early and be damaged. In the later stage of deformation, an excessively low constant-resistance value is not enough to provide sufficient restraint force, resulting in continuous rheology of the protected roadway. The existing pressure relief method may cause the energy release to be too concentrated or insufficient, making it difficult to achieve a good match between the support resistance and the roof deformation energy, and the pressure relief mode is rigid. In addition, currently, multiple anchor cables in the roadway are often connected by rigid or hinged methods such as W steel strips and steel beams. However, rigid connections force the displacement of local overload points to be transferred to adjacent anchor cables, which may cause adjacent anchor cables to be pulled, disrupt their own reasonable pressure relief rhythm, and even trigger cascading failures. Traditional connection methods lack elastic buffers and damping energy dissipation components, making it difficult to flexibly redistribute force flow according to load distribution. The overall system integrity depends on the strength of the components. In addition, online monitoring of anchor cable conditions (stress and displacement) is the key to predicting roadway stability. Downhole monitoring sensors generally rely on wired power supply or batteries. Wired power supply is complex, costly, and easily damaged, while battery power supply has a limited lifespan and requires frequent replacement in long-term support scenarios, making maintenance difficult and unsafe. Existing monitoring focuses more on anchor cable load or roadway surface displacement, lacking a dedicated, long-term, in-situ monitoring method for whether abnormal slippage (i.e., locking failure) occurs in the core load-bearing component (steel strand) of the anchor cable after the constant resistance is completely locked. Summary of the Invention

[0004] In view of the above problems, the present invention provides a constant resistance large deformation anchor cable support system for coal mine roadways to solve the problems mentioned in the background art.

[0005] The specific technical solution is as follows: A constant resistance, large deformation anchor cable support system for coal mine roadways includes: The graded constant resistance adaptive pressure relief anchor cable body is arranged in an array on the roof of the roadway it protects. The graded constant resistance adaptive pressure relief anchor cable body includes steel strands, outer shell, tray and multi-stage core cylinder assembly set in the outer shell. The multi-stage core cylinder assembly provides adaptive pressure relief function through graded sliding between multi-stage core cylinders. A longitudinally coordinated support network is connected between the graded constant resistance adaptive yielding anchor cable bodies arranged along the direction of the protected roadway. The longitudinally coordinated support network includes W-shaped steel strips and preloaded spring damping elements. The lower end face of the W-shaped steel strip is provided with a slide rail along its length direction. The side of the tray is provided with a sliding element that cooperates with the slide rail. The preloaded spring damping element is connected between two adjacent trays on the same W-shaped steel strip. It is used to transfer and buffer the load between adjacent graded constant resistance adaptive yielding anchor cable bodies to achieve dynamic coordination of support load.

[0006] Furthermore, it also includes a displacement over-limit monitoring component, which includes a detection housing detachably disposed on the lower end face of the tray and a displacement detection mechanism disposed inside the detection housing for detecting the displacement of the multi-stage core cylinder assembly.

[0007] Furthermore, the multi-stage core assembly includes a primary core and a secondary core; the inner ring of the primary core is connected to the tail end of the steel strand via a lock; the secondary core is sleeved on the outer ring of the primary core, and a first limiting and friction assembly is provided between the primary core and the secondary core; the outer shell is sleeved on the outer ring of the secondary core, and a second limiting and friction assembly is provided between the outer shell and the secondary core.

[0008] Furthermore, the first limiting and friction assembly includes a first friction pad disposed between the first-stage core cylinder and the second-stage core cylinder, a first annular shoulder coaxially disposed at the lower end of the outer wall of the first-stage core cylinder, and a first annular groove coaxially disposed on the inner wall of the second-stage core cylinder that cooperates with the first annular shoulder, and the axial length of the first annular groove is greater than the axial length of the first annular shoulder.

[0009] Furthermore, the second limiting and friction assembly includes a second friction pad disposed between the outer shell and the secondary core cylinder, a second annular shoulder coaxially disposed at the lower end of the outer wall of the secondary core cylinder, and a second annular groove coaxially disposed on the inner wall of the outer shell and cooperating with the second annular shoulder, wherein the axial length of the second annular groove is greater than the axial length of the second annular shoulder.

[0010] Furthermore, the axial friction between the primary core and the secondary core is less than the axial friction between the secondary core and the outer shell.

[0011] Furthermore, the pallet is a square steel plate, and the pallet is integrally formed with the bottom end of the outer shell or connected by welding or flange connection.

[0012] Furthermore, the pre-compression spring damping component includes a first housing disposed on the lower end face of the W steel strip, and a damper and a pre-compression spring disposed within the first housing. The pre-compression spring is sleeved outside the piston rod of the damper. The length direction of the first housing is arranged along the length direction of the W steel strip. A first movable block and a second movable block are slidably disposed at both ends of the first housing along its length direction. The end faces of the first movable block and the second movable block that are close to each other are respectively connected to the two ends of the damper. The end faces of the first movable block and the second movable block that are far from each other are respectively hinged to two adjacent trays through a first connector and a second connector.

[0013] Furthermore, the damper is a hydraulic damper or a viscous damper.

[0014] Furthermore, the W steel strip is provided with a plurality of first through holes running vertically along its length to allow the outer casing to pass through, and the size of the first through holes is smaller than the size of the tray.

[0015] Furthermore, two parallel C-shaped channel steels are symmetrically arranged on the left and right sides of the lower end face of the W steel strip along its length direction to form the slide rail, and the preloaded spring damping element is located between the two C-shaped channel steels.

[0016] Furthermore, the sliding element is one of a sliding block or a roller.

[0017] Furthermore, the upper end face of the detection housing is connected to the tray via a connector. The connector includes snap-fit ​​strips on both longitudinal ends of the tray and inverted L-shaped snap-fit ​​plates adapted to the snap-fit ​​strips on both longitudinal ends of the upper end face of the detection housing. The vertical section of the inverted L-shaped snap-fit ​​plate is also provided with fastening bolts for locking the inverted L-shaped snap-fit ​​plate to the snap-fit ​​strip.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a constant resistance large deformation anchor cable support system for coal mine roadways. By setting different constant resistance values ​​in the graded constant resistance adaptive yielding anchor cable body, it realizes two-stage sliding and final locking, transforming the single constant resistance into an adaptive yielding mode with low resistance followed by high resistance and graded response. This enables the support resistance to adaptively match different stages of roof deformation, avoiding initial overload damage and providing strong support in the later stages. It solves the problem of rigidity and difficulty in adapting to deformation stages in the traditional constant resistance anchor cable resistance mode, and improves the reliability of the support and the long-term stability of the protected roadway.

[0019] (2) The present invention provides a constant resistance large deformation anchor cable support system for coal mine roadways. By setting up a longitudinal collaborative support network, when uneven deformation of the roof causes a sudden increase in the load of a certain anchor cable, the sinking of its tray will compress the preloaded spring damping component connected to it. The reaction force generated by the preloaded spring damping component can act on the adjacent tray, thereby actively transferring part of the excess load to the adjacent anchor cables for sharing. At the same time, the damper can consume the impact kinetic energy, changing the drawback of the traditional rigid connection forcibly transmitting displacement, realizing the flexible transmission and dynamic balance of force, and coupling multiple independent anchor cables into an organic whole that can adjust the load. This not only prevents the premature failure of a single anchor cable caused by local overload, but also enhances the ability of the entire support section to resist local damage and dynamic pressure impact, and improves the overall safety of the system.

[0020] (3) The present invention provides a constant resistance large deformation anchor cable support system for coal mine roadways. By setting up a displacement over-limit monitoring component, the traction rope is directly connected to the first-stage core cylinder. By detecting the extension and contraction of the traction rope, the system can directly monitor when the anchor cable experiences pressure slippage or abnormal deformation, thus realizing the function of moving from passive support to active early warning and improving the safety of the protected roadway.

[0021] (4) The present invention provides a constant resistance large deformation anchor cable support system for coal mine roadways. By setting up a self-generating mechanism, the pendulum responds to low-frequency large vibrations. The pendulum swings with a large amplitude and strong magnetic force, which can effectively drive the elastic cantilever beam. The elastic cantilever beam itself can resonate to respond to high-frequency small vibrations. The pendulum response may be delayed, but the high-frequency vibrations directly in the enclosed chamber will be transmitted to the fixed end of the elastic cantilever beam through the annular base, causing the high-order resonance of the elastic cantilever beam. The piezoelectric sheet can also generate electricity. The fin plate can further capture small vibrations and can convert multi-directional vibration energy into electrical energy, which is stored in the battery to power the entire monitoring module, eliminating the dependence on external wiring or periodic battery replacement. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 This is a schematic diagram of the graded constant resistance adaptive pressure relief anchor cable structure of the present invention.

[0024] Figure 3 This is a schematic diagram of the top-cutting support in the prior art of this invention.

[0025] Figure 4 This is a schematic diagram of the longitudinal collaborative support network distribution of the present invention.

[0026] Figure 5 This is a schematic diagram of the longitudinal collaborative support network structure of the present invention.

[0027] Figure 6 This is a schematic diagram of the preloaded spring damping component of the present invention.

[0028] Figure 7 This is a schematic diagram of the W-steel strip structure of the present invention.

[0029] Figure 8 This is a schematic diagram of the displacement over-limit monitoring component of the present invention.

[0030] Figure 9 This is a schematic diagram of the displacement over-limit monitoring component of the present invention from another angle.

[0031] Figure 10 This is a schematic diagram of the self-generating mechanism of the present invention.

[0032] Figure 11This is a schematic diagram showing the location distribution of the piezoelectric power generation units of the present invention.

[0033] Figure 12 This is the present invention. Figure 10 A magnified view of part A.

[0034] In the diagram: 1. Protected roadway; 2. Graded constant resistance adaptive yielding anchor cable body; 21. Steel strand; 22. Shell; 23. Tray; 24. Primary core tube; 25. Secondary core tube; 26. Lock; 27. First annular shoulder; 28. First annular groove; 29. ​​Second annular shoulder; 210. Second annular groove; 3. Longitudinal coordinated support network; 31. W-shaped steel strip; 32. Sliding component; 33. Pre-compression spring damping component; 331. First shell; 332. Damper; 333. Pre-compression spring; 334. First movable block; 335. Second movable block; 336. First connector; 337. Second connector; 34. Slide rail; 35. First through hole; 4. Displacement overload Limited monitoring components; 41. Detection housing; 42. Connector; 421. Clip strip; 422. Inverted L-shaped clip plate; 423. Fastening bolt; 43. Winding drum; 44. Traction rope; 45. Support plate; 46. Tensioner; 47. Fixed pulley; 48. Microprocessor; 49. Wireless transmission module; 5. Self-generating mechanism; 51. Enclosed chamber; 52. Pendulum; 53. Ring drive magnet; 54. Ring base; 55. Piezoelectric power generation unit; 551. Elastic cantilever beam; 552. Permanent magnet drive block; 553. Piezoelectric ceramic sheet; 554. Fin plate; 56. Magnetic guide ring; 6. Direct roof; 7. Coal seam; 8. Floor; 9. Goaf; 10. Cut; 11. Old roof. Detailed Implementation

[0035] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] Example 1 This invention discloses a constant resistance large deformation anchor cable support system for coal mine roadways, comprising multiple graded constant resistance adaptive pressure relief anchor cables 2 arranged in an array on the roof of the roadway 1 being protected, and a longitudinal collaborative support network 3 connecting the graded constant resistance adaptive pressure relief anchor cables 2 arranged in the same column along the direction of the roadway 1 being protected.

[0038] refer to Figure 1 and 2The graded constant resistance adaptive pressure relief anchor cable body 2 includes steel strand 21, outer shell 22, tray 23 and multi-stage core cylinder assembly disposed in the outer shell 22. The multi-stage core cylinder assembly provides adaptive pressure relief function through graded sliding between multi-stage core cylinders.

[0039] Furthermore, as a specific implementation method, refer to Figure 2 The multi-stage core assembly includes a primary core 24 and a secondary core 25; the inner ring of the primary core 24 is connected to the tail end of the steel strand 21 via a lock 26; the secondary core 25 is sleeved on the outer ring of the primary core 24, and a first limiting and friction assembly is provided between the primary core 24 and the secondary core 25; the outer shell 22 is sleeved on the outer ring of the secondary core 25, and a second limiting and friction assembly is provided between the outer shell 22 and the secondary core 25.

[0040] Furthermore, as a specific implementation method, refer to Figure 2 The first limiting and friction assembly includes a first friction pad disposed between the first-stage core cylinder 24 and the second-stage core cylinder 25, a first annular shoulder 27 coaxially disposed at the lower end of the outer wall of the first-stage core cylinder 24, and a first annular groove 28 coaxially disposed on the inner wall of the second-stage core cylinder 25 and cooperating with the first annular shoulder 27, wherein the axial length of the first annular groove 28 is greater than the axial length of the first annular shoulder 27.

[0041] Furthermore, as a specific implementation method, refer to Figure 2 The second limiting and friction assembly includes a second friction pad disposed between the outer shell 22 and the secondary core cylinder 25, a second annular shoulder 29 coaxially disposed at the lower end of the outer wall of the secondary core cylinder 25, and a second annular groove 210 coaxially disposed on the inner wall of the outer shell 22 and cooperating with the second annular shoulder 29, wherein the axial length of the second annular groove 210 is greater than the axial length of the second annular shoulder 29.

[0042] The axial friction between the primary core cylinder 24 and the secondary core cylinder 25 is less than the axial friction between the secondary core cylinder 25 and the outer shell 22. The axial friction between the primary core cylinder 24 and the secondary core cylinder 25 is 250-300 kN, preferably 280 kN; the axial friction between the secondary core cylinder 25 and the outer shell 22 is 350-400 kN, preferably 350 kN.

[0043] Furthermore, as a specific implementation, the tray 23 is a square steel plate, and the tray 23 is integrally formed with the bottom end of the outer shell 22 or connected by welding or flange connection.

[0044] In conventional coal mining, as the longwall face advances, a long arm beam is formed. This long arm beam generates significant dynamic pressure during its downward movement, and simultaneously, it is more likely to generate substantial supporting pressure, which acts on adjacent roadways. This places the roadways in a dynamic pressure-affected zone, making them prone to deformation and damage such as sidewall heave, floor heave, and shotcrete detachment. (Reference) Figure 3 As shown, the structure includes the floor 8, the protected roadway 1, the coal seam 7, and the old roof 11. By using roof-cutting and pressure-reducing roadway protection, the long-arm beam is transformed into a short-arm beam, cutting off the stress transmission path of the roof. At the same time, the expansive properties of gangue are used to fill the goaf 9, support the overlying strata of the goaf, and the short-arm beam, limiting the subsidence and rotation of the immediate roof 6, reducing the dynamic pressure of mining and the support pressure, so that the adjacent roadways of the working face are outside the influence range of the dynamic pressure of mining, thereby ensuring the stability of the roadway. In roof-cutting and pressure-reducing roadway protection, pre-splitting blasting technology is often used at the cut 10 position, and constant resistance large deformation anchor cables are used on the top of the protected roadway 1 to achieve pressure relief support.

[0045] This invention achieves two-stage constant resistance pressure relief through two-stage limiting and friction between the primary core cylinder 24 and the secondary core cylinder 25, and between the secondary core cylinder 25 and the outer shell 22. When the pressure on the top plate is low, the system provides high-rigidity support. When the pressure exceeds the first-stage threshold, the first-stage slippage occurs, whereby the first annular shoulder 27 of the primary core cylinder 24 moves within the first annular groove 28 of the secondary core cylinder 25, releasing energy with lower constant resistance. When the pressure continues to increase and exceeds the second-stage threshold, the second-stage slippage occurs, whereby the second annular shoulder 29 of the secondary core cylinder 25 moves within the second annular groove 210 of the outer shell 22, continuing to relieve pressure with higher constant resistance, ultimately achieving mechanical locking. This design allows the support resistance to adaptively match different stages of top plate deformation, avoiding initial overload damage and providing strong support in the later stages.

[0046] refer to Figure 4 and Figure 5 The longitudinal coordinated support network 3 includes a W-shaped steel strip 31 and a preloaded spring damping element 33. The lower end face of the W-shaped steel strip 31 is provided with a slide rail 34 along its length direction. The side of the tray 23 is provided with a sliding element 32 that cooperates with the slide rail 34. The preloaded spring damping element 33 is connected between two adjacent trays 23 on the same W-shaped steel strip 31, and is used to transfer and buffer the load between adjacent graded constant resistance adaptive yielding anchor cable bodies 2 to realize dynamic coordination of support load.

[0047] Furthermore, as a specific implementation method, refer to Figure 5 and Figure 6The pre-compression spring damping component 33 includes a first housing 331 disposed on the lower end face of the W steel strip 31, and a damper 332 and a pre-compression spring 333 disposed within the first housing 331. The pre-compression spring 333 is sleeved outside the piston rod of the damper 332. The length direction of the first housing 331 is arranged along the length direction of the W steel strip 31. A first movable block 334 and a second movable block 335 are slidably disposed at both ends of the first housing 331 along its length direction. The end faces of the first movable block 334 and the second movable block 335 that are close to each other are respectively connected to the two ends of the damper 332. The end faces of the first movable block 334 and the second movable block 335 that are far from each other are respectively hinged to the two adjacent trays 23 through a first connector 336 and a second connector 337. The load between the two trays 23 can be transmitted to the damper 332 and the pre-compression spring 333 through the first connector 336, the second connector 337, the first movable block 334, and the second movable block 335, respectively, so as to realize the transfer and buffering of the load between adjacent graded constant resistance adaptive yielding anchor cable bodies 2, and realize the dynamic coordination of the support load.

[0048] The damper 332 is a hydraulic damper or a viscous damper.

[0049] refer to Figure 7 The W steel strip 31 has several first through holes 35 that are sequentially provided along its length for the outer shell 22 to pass through, and the size of the first through holes 35 is smaller than the size of the tray 23.

[0050] The lower end face of the W steel strip 31 is symmetrically provided with two parallel C-shaped channel steels on the left and right sides along its length direction, forming the slide rail 34, and the preloaded spring damping member 33 is located between the two C-shaped channel steels.

[0051] The sliding element 32 is one of a sliding block or a roller.

[0052] Two or three graded constant resistance adaptive yielding anchor cable bodies 2 in the same column are connected by W steel strip 31, and adjacent trays 23 are connected by preloaded spring damping element 33. When a single anchor cable is subjected to excessive force, the displacement of its tray 23 will push and pull the trays 23 of the adjacent anchor cable through the preloaded spring damping element 33, thereby actively transferring part of the load to the adjacent anchor cable, realizing the dynamic balance and redistribution of the support load, improving the integrity of the support system and its resistance to local damage, and the damper 332 can effectively consume impact energy.

[0053] Furthermore, as one implementation method, refer to Figure 1 and Figure 8It also includes a displacement over-limit monitoring component 4, which includes a detection housing 41 detachably disposed on the lower end face of the tray 23 and a displacement detection mechanism disposed inside the detection housing 41 for detecting the displacement of the multi-stage core cylinder assembly.

[0054] Furthermore, as a specific implementation method, refer to Figure 8 The upper end face of the detection housing 41 is connected to the tray 23 via a connector 42. The connector 42 includes a snap-fit ​​strip 421 disposed on both longitudinal end faces of the tray 23 and an inverted L-shaped snap-fit ​​plate 422 disposed on both longitudinal end faces of the upper end face of the detection housing 41 and adapted to the snap-fit ​​strip 421. The vertical section of the inverted L-shaped snap-fit ​​plate 422 is also provided with a fastening bolt 423 for locking the inverted L-shaped snap-fit ​​plate 422 to the snap-fit ​​strip 421.

[0055] Example 2 This invention discloses a constant resistance, large deformation anchor cable support system for coal mine roadways, with reference to... Figure 2 , Figure 8 and Figure 9 Based on Embodiment 1, the displacement detection mechanism includes a winding drum 43 disposed inside the detection housing 41, a traction rope 44 wound on the winding drum 43, and a rotary encoder for detecting the release length of the traction rope 44. One end of the traction rope 44 is connected to the winding drum 43, and the other end of the traction rope 44 extends through the second through hole to the outside of the detection housing 41 and is connected to the lower end of the first-stage core cylinder 24.

[0056] The axial direction of the winding drum 43 is horizontally arranged in the longitudinal direction. Rotating rods are coaxially arranged at both ends of the winding drum 43. The rotating rods are connected to the lower inner end of the detection housing 41 through bearings and support plates 45. One of the support plates 45 is also provided with a tensioning member 46 for keeping the traction rope 44 in a taut state.

[0057] The tensioning member 46 includes a second housing disposed on the upper end of the support plate 45 and a coil spring disposed inside the second housing. The outer fixed end of the coil spring is connected to the second housing, and the inner free end of the coil spring is connected to the rotating rod.

[0058] The second through hole is located at the lower end of one side of the detection housing 41 near the steel strand 21, and a fixed pulley 47 for turning the traction rope 44 is provided on this side above the second through hole.

[0059] The detection housing 41 is also equipped with a microprocessor 48 and a wireless transmission module 49. The microprocessor 48 is electrically connected to the rotary encoder and is configured to make judgments based on the displacement data and its rate of change monitored by the rotary encoder. When the displacement change or rate of change exceeds a preset threshold, the microprocessor 48 controls the wireless transmission module 49 to send an early warning signal.

[0060] Furthermore, as one embodiment, the first housing 331 is also provided with a displacement sensor for detecting the extension and retraction of the piston rod of the damper 332. The displacement sensor is signal-connected to the microprocessor 48 and is used to provide the microprocessor 48 with displacement data reflecting the load transfer state between adjacent graded constant resistance adaptive yielding anchor bodies 2.

[0061] Furthermore, as one implementation method, it also includes a ground monitoring platform and several roadway gateways deployed in the protected roadway 1. The roadway gateways are able to receive data sent by the wireless transmission module 49 and transmit it to the ground monitoring platform via the network. The ground monitoring platform is able to provide early warnings on the status of the entire roadway support system.

[0062] By measuring the release length of the traction rope 44 connected to the primary core cylinder 24, the absolute displacement of the steel strands 21 inside the anchor cable and the primary core cylinder 24 is monitored. This allows for the determination of whether the graded constant resistance adaptive yielding anchor cable body 2 has experienced abnormal slippage, i.e., locking failure, enabling long-term, in-situ monitoring. Additionally, it can monitor whether the constant resistance device slips after final locking and the amount of slippage. The microprocessor 48, by analyzing the displacement of the primary core cylinder 24, can issue an early warning when the graded constant resistance adaptive yielding anchor cable body 2 experiences abnormal slippage (such as locking failure or continuous creep), thus transitioning from passive support to active early warning and improving the safety of the protected roadway 1. Analyzing the displacement data of the damper 332 in the collaborative network with the displacement data of the primary core cylinder 24 allows for a more comprehensive assessment of the support system's working status, improving the reliability of condition diagnosis.

[0063] Example 3 According to the working principle of the embodiment, since at least one displacement over-limit monitoring component 4 needs to be installed at the lower end of each tray 23, and each displacement over-limit monitoring component 4 needs to be provided with a separate power supply module, it is easy to cause difficulties and messes in wiring within the protected roadway 1. In addition, during coal mining, the coal mine roadway will generate a certain amount of vibration due to the operation of underground equipment (such as drilling rigs, coal mining machines, and coal conveyors) and blasting. There are also self-generating structures in the prior art that utilize the vibration of the protected roadway 1 to generate electricity, but most of them have strict requirements on the direction of vibration, while the vibration of the protected roadway 1 is multi-directional and disordered, resulting in low energy collection efficiency.

[0064] This invention discloses a constant resistance, large deformation anchor cable support system for coal mine roadways, with reference to... Figure 8 , Figure 10 , Figure 11 and Figure 12 Based on Embodiment 2, the displacement over-limit monitoring component 4 further includes several self-generating mechanisms 5 disposed at the upper end of the detection housing 41, which are used to convert the vibration energy of the protected roadway 1 into electrical energy; the self-generating mechanism 5 includes a closed chamber 51, a pendulum 52 suspended at the upper end of the closed chamber 51, an annular driving magnet 53 coaxially disposed at the equator position of the pendulum 52, and an annular base 54 disposed on the inner wall of the closed chamber 51; a plurality of piezoelectric power generation units 55 are evenly distributed along the circumference on the inner side of the annular base 54, and the piezoelectric power generation unit 55 includes an elastic cantilever beam 551, a permanent magnet driving block 552 disposed at the free end of the elastic cantilever beam 551, and a piezoelectric ceramic sheet 553 attached to the elastic cantilever beam 551.

[0065] The annular driving magnet 53 is radially magnetized and is coaxial with the annular base 54 when static. The magnetic pole direction of the permanent magnet driving block 552 is radially repulsive to that of the annular driving magnet 53.

[0066] The enclosed chamber 51 is cylindrical, and a magnetic ring 56 is coaxially arranged at the upper end of the enclosed chamber 51. The annular driving magnet 53 is coaxial with the magnetic ring 56 and maintains an air gap when static, and the permanent magnet driving block 552 is located in the area of ​​enhanced magnetic field formed by the magnetic ring 56.

[0067] The enclosed chamber 51 is made of a non-magnetic material, and the magnetic ring 56 is made of a soft magnetic material with high saturation magnetic induction intensity.

[0068] The fixed end of the elastic cantilever beam 551 is connected to the inner ring of the annular base 54, and the piezoelectric ceramic sheet 553 is disposed on the upper end face of the elastic cantilever beam 551 near the annular base 54.

[0069] The free end of the elastic cantilever beam 551 is also vertically provided with a fin plate 554, and the permanent magnet drive block 552 is provided on one end face of the fin plate 554 near the annular drive magnet 53.

[0070] The detection housing 41 is also equipped with a storage battery.

[0071] refer to Figure 10The upper middle part of the pendulum 52 is suspended by a flexible titanium alloy wire. The vibration of the protected tunnel 1 can drive the detection housing 41 and the internal sealed chamber 51. The vibration of the sealed chamber 51 can be transmitted to the titanium alloy wire. Since the pendulum 52 has a certain mass, the vibration of the titanium alloy wire is transmitted to the pendulum 52 with a certain lag. Inertia causes the pendulum 52 to produce multi-directional lag swing. The ring drive magnet 53 on the pendulum 52 pushes the permanent magnet drive block 552 at the free end of each elastic cantilever beam 551 through magnetic repulsion, forcing the elastic cantilever beam 551 to bend, thereby causing the piezoelectric ceramic sheet 553 to generate electricity due to strain. The pendulum 52 oscillates in multiple directions under vibration, thereby driving the annular drive magnet 53 to move. Through non-contact magnetic repulsion, it drives the circumferentially arranged elastic cantilever beam 551 to bend. The bending deformation of the elastic cantilever beam 551 causes maximum strain at its root, resulting in compression or stretching deformation of the piezoelectric ceramic sheet 553 attached at this location. Based on the positive piezoelectric effect, alternating high-voltage charges are generated between its upper and lower electrodes, realizing the power generation of the piezoelectric ceramic sheet 553. This method can capture multi-directional, low-frequency vibrations, has high energy conversion efficiency, and is free from mechanical collision and wear, resulting in a long lifespan. The magnetic guide ring 56 transforms the magnetic short-circuit problem caused by the ferromagnetic tray 23 into a magnetic convergence advantage, guiding magnetic lines of force to the permanent magnet drive block 552 area, enhancing the driving magnetic field, and ensuring power generation. This achieves a wiring-free, self-powered function. In addition, the pendulum 52 responds to low-frequency large vibrations, has a large swing amplitude, and strong magnetic force, which can effectively drive the elastic cantilever beam 551. The elastic cantilever beam 551 itself can resonate to respond to high-frequency small vibrations. The pendulum 52 may respond with lag, but the high-frequency vibrations directly from the enclosed chamber 51 will be transmitted to the fixed end of the elastic cantilever beam 551 through the annular base 54, triggering the high-order resonance of the elastic cantilever beam 551. The piezoelectric sheet can also generate electricity, and the fin plate 554 can further capture small vibrations.

[0072] The magnetic ring 56 is made of a soft magnetic material with high saturation magnetic induction intensity (high permeability). When the radially magnetized annular drive magnet 53 is installed below it, the magnetic ring 56 provides an easy path for the magnetic lines of force on the upper surface of the magnet. Most of the magnetic lines of force that would otherwise diverge upwards and be attracted by the ferromagnetic tray 23, forming a magnetic short circuit and being wasted, are actively guided into the interior of the magnetic ring 56. The geometry (annular) of the magnetic ring 56 is designed to conduct the converged magnetic flux along the ring body and concentrate it for radial outward release from its outer cylindrical wall. This is equivalent to converting the relatively dispersed magnetic flux on the upper surface of the magnet... The magnetic field is transformed into a strong radial magnetic field that is highly concentrated and directional at the outer wall of the magnetic ring 56. This enhanced magnetic field covers the area where the permanent magnet drive blocks 552 in the surrounding piezoelectric power generation unit 55 are located. Through the above guidance and convergence, the magnetic ring 56 constructs a directional action area with low magnetic resistance and enhanced magnetic field strength between the annular drive magnet 53 and each permanent magnet drive block 552. When the pendulum 52 drives the annular drive magnet 53 to swing, this enhanced magnetic field can generate a stronger and more stable pulsed magnetic repulsion force on the permanent magnet drive block 552, thereby more effectively driving the cantilever beam 551 to bend and generate electricity.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A constant-resistance, large-deformation anchor cable support system for coal mine roadways, characterized in that, include: The graded constant resistance adaptive pressure relief anchor cable body (2) is arranged in an array on the roof of the protected roadway (1). The graded constant resistance adaptive pressure relief anchor cable body (2) includes steel strand (21), shell (22), tray (23) and multi-stage core cylinder assembly set in the shell (22). The multi-stage core cylinder assembly provides adaptive pressure relief function through graded sliding between multi-stage core cylinders. The longitudinal coordinated support network (3) is connected between the graded constant resistance adaptive yielding anchor bodies (2) arranged along the direction of the protected roadway (1). The longitudinal coordinated support network (3) includes a W steel strip (31) and a preloaded spring damping element (33). The lower end face of the W steel strip (31) is provided with a slide rail (34) along its length direction. The side of the tray (23) is provided with a sliding element (32) that cooperates with the slide rail (34). The preloaded spring damping element (33) is connected between two adjacent trays (23) on the same W steel strip (31) to transfer and buffer the load between adjacent graded constant resistance adaptive yielding anchor bodies (2) and realize the dynamic coordination of the support load.

2. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 1, characterized in that, The multi-stage core tube assembly includes a primary core tube (24) and a secondary core tube (25); the inner ring of the primary core tube (24) is connected to the tail end of the steel strand (21) through a lock (26); the secondary core tube (25) is sleeved on the outer ring of the primary core tube (24), and a first limiting and friction assembly is provided between the primary core tube (24) and the secondary core tube (25); the outer shell (22) is sleeved on the outer ring of the secondary core tube (25), and a second limiting and friction assembly is provided between the outer shell (22) and the secondary core tube (25).

3. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 2, characterized in that, The first limiting and friction assembly includes a first friction pad disposed between the first-stage core cylinder (24) and the second-stage core cylinder (25), a first annular shoulder (27) coaxially disposed at the lower end of the outer wall of the first-stage core cylinder (24), and a first annular groove (28) coaxially disposed on the inner wall of the second-stage core cylinder (25) and cooperating with the first annular shoulder (27), and the axial length of the first annular groove (28) is greater than the axial length of the first annular shoulder (27).

4. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 3, characterized in that, The second limiting and friction assembly includes a second friction pad disposed between the outer shell (22) and the secondary core cylinder (25), a second annular shoulder (29) coaxially disposed at the lower end of the outer wall of the secondary core cylinder (25), and a second annular groove (210) coaxially disposed on the inner wall of the outer shell (22) and cooperating with the second annular shoulder (29), and the axial length of the second annular groove (210) is greater than the axial length of the second annular shoulder (29).

5. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 1, characterized in that, The pallet (23) is a square steel plate, and the pallet (23) is integrally formed with the bottom end of the outer shell (22) or connected by welding or flange connection.

6. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 1, characterized in that, The pre-compression spring damping component (33) includes a first housing (331) disposed on the lower end face of the W steel strip (31) and a damper (332) and a pre-compression spring (333) disposed in the first housing (331). The pre-compression spring (333) is sleeved outside the piston rod of the damper (332). The length direction of the first housing (331) is arranged along the length direction of the W steel strip (31). The first movable block (334) and the second movable block (335) are slidably disposed at both ends of the first housing (331) along its length direction. The end faces of the first movable block (334) and the second movable block (335) that are close to each other are respectively connected to the two ends of the damper (332). The end faces of the first movable block (334) and the second movable block (335) that are far apart from each other are respectively hinged to the two adjacent trays (23) through the first connector (336) and the second connector (337).

7. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 6, characterized in that, The lower end face of the W steel strip (31) is symmetrically provided with two parallel C-shaped channel steels on the left and right sides along its length direction, forming the slide rail (34), and the preloaded spring damping component (33) is located between the two C-shaped channel steels.

8. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 7, characterized in that, The sliding element (32) is one of a sliding block or a roller.

9. A constant resistance large deformation anchor cable support system for coal mine roadways according to any one of claims 1-8, characterized in that, It also includes a displacement over-limit monitoring component (4), which includes a detection housing (41) detachably disposed on the lower end face of the tray (23) and a displacement detection mechanism disposed inside the detection housing (41) for detecting the displacement of the multi-stage core cylinder assembly.

10. The constant resistance large deformation anchor cable support system for coal mine roadways according to claim 9, characterized in that, The upper end face of the detection housing (41) is connected to the tray (23) via a connector (42). The connector (42) includes a snap-fit ​​strip (421) on both longitudinal end faces of the tray (23) and an inverted L-shaped snap-fit ​​plate (422) on both longitudinal end faces of the upper end face of the detection housing (41) that is adapted to the snap-fit ​​strip (421). The vertical section of the inverted L-shaped snap-fit ​​plate (422) is also provided with a fastening bolt (423) for locking the inverted L-shaped snap-fit ​​plate (422) to the snap-fit ​​strip (421).

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