Cross-section layer large-dip-angle fully mechanized coal mining face rib caving prevention method

Abstract

The invention relates to the technical field of mine construction, in particular to a cross-section layer large-dip-angle fully mechanized coal mining face wall caving prevention method which comprises a wall caving prevention equipment anti-skid cooperative system which is an integrated system composed of a hydraulic support, a scraper conveyor, an inclined anti-skid mechanism and an anti-skid hydraulic machine. The device is used for achieving anti-skid, anti-falling and posture cooperative adjustment of the device in the pseudo-inclined dip mining slope adjustment process. The hydraulic support is rigidly connected through the externally-arranged anti-skid hydraulic machine, the linkage influence of sliding-down of the scraper conveyor is counteracted, and the hydraulic support is prevented from toppling over; the built-in anti-skid hydraulic machine corrects the deviation of the connecting rod and protects the hydraulic support from being damaged; the anti-skidding, anti-falling and anti-caving effects of the fully-mechanized coal mining equipment in effective mining of the large-dip-angle working face are achieved through layout adjustment of the pseudo-dip dynamic adaptive fault and the fully-mechanized coal mining equipment anti-skidding system, the mining efficiency of the working face is improved, the equipment sliding-down possibility is reduced, and the technical problems existing in the large-dip-angle fully-mechanized coal mining process are solved.

Description

Technical Field

[0001] The invention relates to the technical field of mine construction, in particular to a method for preventing rock spalling in a fully mechanized mining working face with a large dip angle in a section layer. Background Art

[0002] With the continuous development of mining technology and engineering science, fully mechanized mining has become the mainstream process for mining steeply inclined coal seams. This technical system was originally designed to address the need for anti-slip control of working face equipment, using an upward-facing pseudo-inclined working face layout as its basic mining solution. However, engineering practice has shown that this mining method presents several technical challenges in actual application: First, the inclination of the coal seam significantly reduces coal wall stability, which can easily lead to spalling accidents; second, due to geological conditions, the hydraulic supports exhibit a non-linear, jagged shape, affecting the overall stability of the support system; and finally, during mining, scattered coal is prone to rolling due to gravity, posing a safety hazard to the working face. These issues are even more pronounced during fault crossings.

[0003] In order to effectively solve this type of problem, a large number of sites have adopted the coal mining technology of advancing along the true inclination direction. This technology arranges the working face at a certain angle to the true inclination direction of the coal seam. It has strong adaptability to the mining of large-angle coal seams and forms a static layout mode with a fixed downward pseudo-inclination angle. The conventional angle is 10°-15°. Although mechanized coal mining can be achieved, it cannot be dynamically adjusted according to real-time parameters such as fault drop and coal body fragmentation. Engineering practice shows that when the shear stress of the coal wall exceeds 15MPa, if it passes through the fault fracture zone, the static layout is likely to lead to uneven force on the hydraulic support and excessive sliding of the scraper, which in turn causes spalling accidents. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preventing spalling in a fully mechanized mining working face with a large inclination angle in a section layer, so as to solve the technical defects mentioned above.

[0005] In order to achieve the above effects, the technical solution adopted by the present invention is: a method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer, comprising the following steps:

[0006] Step 1: Pseudo-inclined mining layout: The transport tunnel at the tail of the shearer is arranged above the return air tunnel at the head of the shearer along the inclination direction of the coal seam, creating a vertical height difference between the two. This allows the actual advancing direction of the working face to form an angle with the direction of the coal seam, thereby reducing the inclination of the working face along the advancing direction. This establishes a pseudo-inclined dynamic advancing system based on real-time correction of fault parameters, effectively reducing the equivalent inclination angle of the shearer's operating trajectory.

[0007] Step 2: Real-time perception of fault parameters: A geological radar is deployed in the advanced support section of the working face. The radar wave reflection signal is used to identify the fault interface and output the fault direction, drop, and horizontal length of the broken zone. A strain-type cutting resistance sensor and an image recognition module for coal fragmentation are built into the shearer's rocker arm. The strain-type cutting resistance sensor provides real-time feedback on the mechanical resistance during coal wall cutting, reflecting changes in coal strength. The coal fragmentation is identified through images, and the average particle size of coal blocks is identified through images. The proportion of broken coal is calculated, and the coal wall integrity is inverted.

[0008] Step 3: Calculation of layout parameters: Based on at least 5 working faces with similar geological conditions, collect several sets of stress correlation analysis data, where the stress correlation analysis data include fault drop, fracture zone length and pitch-pseudo-oblique angle. After regression analysis, according to the formula The coal wall shear stress τ is calculated and controlled to be ≤15MPa. The correction formula for the pitch-down pseudo-slope angle is derived: α 初始 -α 修正 The result is recorded as the angle correction Δα, combined with the working surface length L 面 , calculate Δh=L by trigonometric function 面 sin(Δα) simultaneously directly outputs the angle correction value Δα adjustment instruction, which is then linked to the anti-skid coordination system of the anti-skid equipment. By adjusting the extension and contraction of the anti-skid hydraulic press and the tension of the oblique anti-skid mechanism, the tilt angle of the equipment is maintained consistent with the pitch angle.

[0009] Step 4: Execute dynamic layout correction: When the coal wall stress monitoring value τ>15MPa, start dynamic correction, automatically reduce the pseudo-inclination angle by 3°-5°, and simultaneously reduce the height difference between the transport lane and the return air lane by 0.8-1.2m; during the adjustment process, the scraper conveyor push sensor feedbacks the push angle every 5 seconds, and the lane inclinometer feedbacks the actual inclination angle α every 10 seconds 实测 , when α 实测 With α 修正 When the error is ≤±0.5° and the height error is ≤±0.1m, the adjustment is determined to be in place and the slope adjustment is stopped; if the error exceeds the threshold, the adjustment is automatically made.

[0010] Preferably, in the step one, when the cutting resistance suddenly changes and increases by more than 30% within ten seconds, or the coal body fragmentation is greater than 60%, it is determined that the fault influence zone has been entered, and the fault parameters are corrected by linking the geological radar data; if the cutting resistance increase is less than 10% and the coal body fragmentation is less than 40% within 30 consecutive minutes, it is determined that the fault influence zone has been exited. After exiting, the pseudo-oblique angle is restored to the normal value at a rate of 0.5° / min, and the height difference between the transport tunnel and the return air tunnel is simultaneously increased.

[0011] Preferably, in step three, α 修正It is expressed as the corrected pitch pseudo-slant angle, with a value range of 5°-15°, α 初始 It is expressed as the conventional pseudo-oblique angle, with a value range of 10°-15°. k is expressed as the correction coefficient, which is determined in sections according to the uniaxial compressive strength of the coal seam.

[0012] Preferably, in step three, the uniaxial compressive strength of the coal seam is less than 20 MPa, and the value of k is 5; the uniaxial compressive strength of the coal seam is between 20-40 MPa, and the value of k is 3; the uniaxial compressive strength of the coal seam is greater than 40 MPa, and the value of k is 2.

[0013] Preferably, in step 4, if the angle increases by 2°, the hydraulic press pushes the bracket toward the head of the machine to ensure that the bracket arrangement angle is consistent with the pitch pseudo-oblique angle.

[0014] Preferably, it also includes an anti-skid coordination system for equipment to prevent spalling. The anti-skid coordination system for equipment to prevent spalling refers to an integrated system composed of a hydraulic support, a scraper conveyor, an inclined anti-skid mechanism and an anti-skid hydraulic press, which is used to achieve anti-skid, anti-falling and posture coordinated adjustment of the equipment during the slope adjustment process of downward and pseudo-inclined mining. The hydraulic support is located on one side of the scraper conveyor, and the scraper conveyor is connected to the inside of each hydraulic support through a connecting rod. An inclined anti-skid mechanism is also provided between the scraper conveyor and the hydraulic support located on one side; "external" anti-skid hydraulic presses are provided between two adjacent hydraulic supports and on the outside of the hydraulic supports; one end of the connecting rod is connected to the inside of the hydraulic support, and an "internal" anti-skid hydraulic press is also provided between the inside of the hydraulic support and the connecting rod.

[0015] Preferably, the inclined anti-skid mechanism includes a scraper conveyor connector, an iron chain, a tension monitoring system, a retractable hydraulic rod and a hydraulic support connector, one end of the scraper conveyor connector is connected to the iron chain, and the other end of the iron chain is connected to the tension monitoring system, a retractable hydraulic rod is provided on one side of the tension monitoring system, and a hydraulic support connector is provided at one end of the retractable hydraulic rod, and one end of the hydraulic support connector is connected to the interior of the hydraulic support.

[0016] Preferably, the telescopic hydraulic rod consists of a connecting block, a telescopic rod, a sealing ring, a telescopic piston, a liquid-gas mixing sleeve and a monitoring system. One end of the telescopic rod and the liquid-gas mixing sleeve is provided with a connecting block, and the other end of the telescopic rod is fixedly provided with a telescopic piston. The surface of the telescopic piston is slidably connected to the interior of the liquid-gas mixing sleeve. A monitoring system is provided at one end of the liquid-gas mixing sleeve and located outside the telescopic rod, and a sealing ring is provided between the surface of the telescopic rod and the interior of the monitoring system.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By dynamically adapting the layout of the fault to the dip angle, the dip angle Δα is corrected in real time, and the equivalent dip fluctuation is controlled within ±2°, reducing the shear stress concentration in the coal wall. Real-time perception of fault parameters can accurately identify the cause of the spalling and initiate layout correction in advance. Dynamic adjustment of the dip angle and the height difference of the roadway ensures that the coal wall stress is always within a controllable range.

[0019] 2. The external anti-skid hydraulic press controls the fluctuation of the coal wall support force caused by the tilting of the hydraulic support within ±5% through the rigid connection support group, eliminating the cause of coal spalling from the equipment end; the internal anti-skid hydraulic press corrects the offset of the connecting rod to protect the hydraulic support from damage; the inclined anti-skid mechanism dynamically balances the downward force of the conveyor through the retractable hydraulic rod and the tension monitoring system, greatly reducing the "up and down" amplitude of the equipment.

[0020] 3. Through the integration of fault parameter perception, geological radar and in-process detection, dynamic adaptation under complex geological conditions is achieved. Layout parameter calculation is based on big data regression of similar working faces, combined with corrections such as coal seam strength and burial depth, making the technology adaptable to diverse working conditions such as large inclinations of 35°-55° and fault drops of 2-8m. Equipment installation and control processes are standardized to reduce the difficulty of on-site implementation. Whether in old mining areas with complex faults or new mines in large-angle coal seams, this solution can achieve coordinated control of anti-slab and equipment anti-slip, breaking through the limitations of traditional technologies on geological conditions and significantly improving the universality and reliability of large-angle fully mechanized mining technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only represent some embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a flow chart of a method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the working surface in a plan view and a pseudo-inclined view according to an embodiment of the present invention;

[0024] Figure 3 2. It is a top view of the anti-skid cooperative system structure of the anti-slip equipment according to an embodiment of the present invention;

[0025] Figure 4 Schematic diagram of the anti-skid coordination system structure of the anti-slip device according to an embodiment of the present invention;

[0026] Figure 5 This is a side view of the hydraulic support structure according to an embodiment of the present invention;

[0027] Figure 6 is a schematic diagram of the structure of an oblique anti-slip mechanism according to an embodiment of the present invention;

[0028] Figure 7 is a schematic diagram of a telescopic hydraulic rod structure according to an embodiment of the present invention;

[0029] Figure 8 It is a schematic diagram of the layout of the fully mechanized mining equipment of the downward pseudo-inclined working face of the present invention;

[0030] Figure 9 It is a schematic diagram of force analysis of the oblique anti-skid mechanism and equipment of the present invention.

[0031] In the figure, 1. Scraper conveyor; 2. Inclined anti-skid mechanism; 3. Connecting rod; 4. "Built-in" anti-skid hydraulic press; 5. Hydraulic support; 6. "External" anti-skid hydraulic press; 7. Liquid-gas mixing sleeve; 8. Scraper conveyor connector; 9. Iron chain; 10. Tension monitoring system; 11. Retractable hydraulic rod; 12. Hydraulic support connector; 13. Connecting block; 14. Retractable rod; 15. Sealing ring; 16. Monitoring system; 17. Retractable piston; 18. Return air channel; 19. Coal mining machine; 20. Transport channel; 21. Transfer machine. DETAILED DESCRIPTION

[0032] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] See also Figures 1 to 8 As shown, this embodiment discloses a method for preventing spalling in a fully-mechanized mining face with a large dip angle in a section layer, comprising the following steps:

[0035] Step 1. Layout of downward pseudo-inclined mining: Arrange the transport tunnel where the tail of the coal mining machine is located above the return air tunnel of the machine head along the inclination direction of the coal seam, so that the two form a vertical height difference, and let the actual advancement direction of the working face form an angle with the direction of the coal seam, thereby reducing the inclination of the working face along the advancement direction, and build a pseudo-inclined dynamic advancement system based on real-time correction of fault parameters, effectively reducing the equivalent inclination of the coal mining machine's operating trajectory, and the working face is arranged in a downward pseudo-inclined straight line, changing the large inclination to pseudo-inclined mining, reducing the inclination of the mining working face, realizing mechanized coal mining, and effectively avoiding injuries caused by coal wall fragments, thereby replacing the upward pseudo-inclined large-angle coal mining technology.

[0036] Step 2: Real-time perception of fault parameters: Deploy geological radar in the advance support section of the working face, identify the fault interface through radar wave reflection signals, output the fault direction, drop and horizontal length of the broken zone, and install a strain-type cutting resistance sensor and an image recognition module for coal body fragmentation on the rocker arm of the coal mining machine. The strain-type cutting resistance sensor provides real-time feedback on the mechanical resistance during coal wall cutting, reflecting changes in coal body strength. The coal body fragmentation is identified through images, and the average particle size of coal blocks is identified through images. The proportion of broken coal body is calculated, and the integrity of the coal wall is inverted.

[0037] Specifically, when the cutting resistance suddenly changes and increases by more than 30% within ten seconds, or the coal body fragmentation is greater than 60%, it is determined to have entered the fault influence zone, and the fault parameters are corrected by linking the geological radar data; if the cutting resistance increase is less than 10% and the coal body fragmentation is less than 40% within 30 consecutive minutes, it is determined to have exited the fault influence zone. After exiting, the pitch-pseudo-oblique angle is restored to the normal value (10°-15°) at a rate of 0.5° / min, and the height difference between the transport tunnel and the return air tunnel is simultaneously increased (0.1m / min) to avoid stress mutation.

[0038] Step 3: Calculation of layout parameters: Based on at least 5 working faces with similar geological conditions, collect several sets of stress correlation analysis data, where the stress correlation analysis data include fault drop, fracture zone length and pitch-pseudo-oblique angle. After regression analysis, according to the formula The coal wall shear stress τ is calculated, where γ represents the coal body bulk density. According to the "Code for Geological Exploration of Coal Deposits" (GB / T12719-2023) and combined with the coal seam burial depth correction, γ = 10 + 0.002·M, M represents the coal seam burial depth, h represents the mining height, and the value is 2-4m, α represents the pitch-pseudo-oblique angle, and the initial value is 10°-15°, H represents the fault drop, and L represents the length of the fracture zone.

[0039] Control the coal wall shear stress τ≤15MPa and derive the correction formula for the pitch pseudo-inclined angle: where α 修正 It is expressed as the corrected pitch pseudo-slant angle, with a value range of 5°-15°, α 初始 It is expressed as the conventional pseudo-oblique angle, with a value range of 10°-15°. k is expressed as the correction coefficient, which is determined in sections according to the uniaxial compressive strength of the coal seam.

[0040] α 初始 -α 修正 The result is recorded as the angle correction Δα, combined with the working surface length L 面 , calculate Δh=L by trigonometric function 面sin(Δα) and directly output the angle correction value Δα adjustment instruction at the same time, which is linked to the anti-skid collaborative system of the anti-skid equipment to execute. By adjusting the extension and contraction of the anti-skid hydraulic press and the tension of the oblique anti-skid mechanism, the tilt angle of the equipment is maintained consistent with the pitch-down pseudo-oblique angle.

[0041] Specifically, if the uniaxial compressive strength of the coal seam is less than 20 MPa, the value of k is 5; if the uniaxial compressive strength of the coal seam is between 20-40 MPa, the value of k is 3; if the uniaxial compressive strength of the coal seam is greater than 40 MPa, the value of k is 2.

[0042] Step 4: Execute dynamic layout correction: When the scraper conveyor slides more than 0.3m, the measured value of coal wall shear stress increases by 8MPa on average. Therefore, the sliding amount is controlled within 0.1m by the inclined anti-skid mechanism, which can reduce the risk of spalling by more than 60%. When the coal wall stress monitoring value τ>15MPa, the dynamic correction is started, and the pseudo-inclined angle is automatically reduced by 3°-5°, and the height difference between the transport lane and the return air lane is simultaneously reduced by 0.8-1.2m. During the adjustment process, the scraper conveyor push sensor feedbacks the push angle every 5s, and the lane inclinometer feedbacks the actual inclination angle α every 10s. 实测 , when α 实测 With α 修正 When the error is ≤±0.5° and the height error is ≤±0.1m, the adjustment is determined to be in place and the slope adjustment is stopped; if the error exceeds the threshold, the adjustment is automatically made.

[0043] By installing an "external" anti-skid hydraulic press between the hydraulic supports, multiple supports are rigidly connected into a whole through the expansion and contraction of the hydraulic press. When the pitch-down pseudo-oblique angle is adjusted, the "external" anti-skid hydraulic press expands and contracts synchronously to maintain the overall inclination angle of the support group and prevent a single support from tipping over due to angle changes. An "internal" anti-skid hydraulic press is installed between the hydraulic support and the connecting rod. The two ends of the "internal" anti-skid hydraulic press respectively support the hydraulic support and the connecting rod, and a buffer pad is set on the contact surface. After the pitch-down pseudo-oblique angle is adjusted, the tension generated by the angle change of the scraper conveyor will be transmitted to the hydraulic support through the connecting rod. The "internal" anti-skid hydraulic press offsets the tension deviation through real-time pushing to ensure that the angle between the connecting rod and the scraper conveyor matches the pitch-down pseudo-oblique angle, avoiding angle rebound due to uneven force.

[0044] Specifically, if the angle increases by 2°, the hydraulic press pushes the bracket toward the head to ensure that the bracket arrangement angle is consistent with the vertical pseudo-oblique angle, and the deviation between the bracket arrangement angle and the vertical pseudo-oblique angle is controlled within ±0.5° to ensure that the coal wall stress increment is ≤1MP;

[0045] If the hydraulic system of the slope adjustment mechanism fails (pressure loss > 20%), immediately start the emergency mechanical slope adjustment device (such as a manual screw jack) to adjust the angle at a rate of 0.2° / min. At the same time, stop the shearer from cutting and only maintain the scraper conveyor at a low speed (0.5m / min);

[0046] If the stress sensor fails, switch to the "machine vision + historical data fusion" mode: identify the risk of spalling through the coal wall crack image, combine the historical stress data of the previous hour, and adjust the angle according to a 50% safety factor (for example, when the normal angle is 12°, the fault state is adjusted to 9°).

[0047] It should be noted that the layout adjustment of the dynamic adaptive fault of the forward pseudo-oblique described in this application refers to the real-time perception of parameters such as the fault drop H and the length of the broken zone L, and the dynamic adjustment of the forward pseudo-oblique angle according to the formula α correction = α initial - k·H / L to achieve the anti-slabbing control strategy of coal wall stress τ≤15MPa.

[0048] Furthermore, a method for preventing spalling in a high-angle comprehensive mining face in a section layer also includes an equipment anti-skid coordination system for preventing spalling. The equipment anti-skid coordination system for preventing spalling refers to an integrated system composed of a hydraulic support, a scraper conveyor, an inclined anti-skid mechanism and an anti-skid hydraulic press, which is used to achieve anti-skid, anti-falling and coordinated posture adjustment of the equipment during the slope adjustment process of downward pseudo-inclined mining. The inclined anti-skid mechanism indirectly protects the stability of the coal wall by controlling the slippage of the equipment, and is a core component of the anti-skid technical system; the hydraulic support is located on one side of the scraper conveyor, and the scraper conveyor is connected to the inside of each hydraulic support through a connecting rod, and an inclined anti-skid mechanism is also provided between the scraper conveyor and the hydraulic support located on one side; "external" anti-skid hydraulic presses are provided between two adjacent hydraulic supports and on the outside of the hydraulic support; one end of the connecting rod is connected to the inside of the hydraulic support, and an "internal" anti-skid hydraulic press is also provided between the inside of the hydraulic support and the connecting rod.

[0049] Specifically, the inclined anti-skid mechanism includes a scraper conveyor connector, an iron chain, a tension monitoring system, a retractable hydraulic rod and a hydraulic support connector. One end of the scraper conveyor connector is connected to the iron chain, and the other end of the iron chain is connected to the tension monitoring system. A retractable hydraulic rod is provided on one side of the tension monitoring system, and a hydraulic support connector is provided at one end of the retractable hydraulic rod. One end of the hydraulic support connector is connected to the interior of the hydraulic support, and each hydraulic support is reserved for installing a connection point for an anti-skid hydraulic press and an inclined anti-skid structure, and each anti-skid hydraulic press is installed at the reserved point.

[0050] The tension monitoring system includes a tension monitor with a measuring range of 0-50kN and an accuracy of ±0.5kN, which is installed at the connection between the chain and the hydraulic rod; the allowable tension range is 20% F 铁链强度 ≤F 监测 ≤80%·F 铁链强度 , F 铁链强度 is the breaking force of the chain, with a value of 30-50kN; the adjustment logic is ΔL 液压杆 =k 调节 ·(F 监测 -F目标 ), ΔL 液压杆 is the extension and contraction of the hydraulic rod, k 调节 =0.5mm / kN; F 目标 =50%*F 铁链强度 .

[0051] Furthermore, the telescopic hydraulic rod is composed of a connecting block, a telescopic rod, a sealing ring, a telescopic piston, a liquid-gas mixing sleeve and a monitoring system. One end of the telescopic rod and the liquid-gas mixing sleeve is provided with a connecting block, and the other end of the telescopic rod is fixedly provided with a telescopic piston. The surface of the telescopic piston is slidably connected to the interior of the liquid-gas mixing sleeve. A monitoring system is provided at one end of the liquid-gas mixing sleeve and located outside the telescopic rod, and a sealing ring is provided between the surface of the telescopic rod and the interior of the monitoring system.

[0052] Specifically, during the installation of fully mechanized mining equipment for a high-angle working face in a mine, an "external" anti-skid hydraulic press, i.e., an anti-fall device between hydraulic supports, is first installed. Based on existing equipment, the present invention adds several "internal" anti-skid hydraulic presses to each hydraulic support. During the equipment installation process, the hydraulic press telescopic switch is turned on, and the stability of the individual and overall supports is ensured through the interconnection of these hydraulic supports.

[0053] After the connecting rod is connected to the scraper conveyor, open the telescopic switch of the "built-in" anti-skid hydraulic press between the hydraulic support and the connecting rod, and use the "built-in" anti-skid hydraulic press to support the hydraulic support and the connecting rod to ensure that the connecting rod will not deflect under the pulling force of the scraper conveyor. When installing the "built-in" anti-skid hydraulic press between the hydraulic support and the connecting rod, a certain buffer pad should be placed between the contact surface of the "built-in" anti-skid hydraulic press and the connecting rod to prevent deformation of the connecting rod and the base caused by rigid contact between the two.

[0054] After completing the installation of the above-mentioned device, an inclined anti-skid structure is set between the hydraulic support and the scraper conveyor. The inclined anti-skid structure can offset the downward force of the scraper conveyor by applying a certain effective pulling force. At the same time, it should be noted that the inclined anti-skid structure shall not be directly connected with an iron chain. A retractable hydraulic rod should be added to connect it. The retraction amount of the hydraulic rod can be automatically adjusted according to the size of the downward force of the scraper conveyor to ensure that the iron chain will not be affected by continuous high-intensity tension or long-term relaxation, and always maintain a suitable stretching state.

[0055] It is worth noting that this oblique anti-skid mechanism is equipped with an automatic tension monitoring system, which monitors the tension in real time through a tension monitor. When the tension exceeds the pre-set allowable range, the control system receives the signal from the tension monitor and transmits the signal to the monitoring system on the retractable hydraulic rod, which issues an instruction to adjust the hydraulic rod to keep the oblique anti-skid mechanism in a suitable stress state.

[0056] Furthermore, in order to clearly see the effect of this synchronous anti-skid method, the force analysis of the scraper conveyor and the hydraulic support is carried out, such as Figure 9 As shown in the figure, G is the gravity of the scraper conveyor, f is the upward friction force, T is the force generated by the scraper conveyor on the connecting rod when it slides downward, and T z Support force provided for "built-in" anti-skid hydraulic press, T g Provides tension for the tilted anti-skid mechanism.

[0057] It can be seen that the magnitude of the downward force generated by the scraper conveyor is F = G·cosa-f;

[0058] Due to the inclined anti-slip mechanism, T g size, so only T g It is sufficient to provide a force that can offset the downward force, that is:

[0059] T g ·cosb=F=G·cosa-f

[0060] You can get:

[0061]

[0062] When the tilted anti-skid mechanism provides sufficient T g When the force T acting on the connecting rod is small or non-existent, the supporting force T provided by the "built-in" anti-skid hydraulic press is z Will cancel out any T that may exist.

[0063] It can be seen that the synchronous anti-skid method of the fully mechanized mining working face equipment can effectively eliminate the downward force generated by the scraper conveyor in the fully mechanized mining working face with a large inclination angle, and ensure the anti-skid effect of the fully mechanized mining equipment.

[0064] This type of pseudo-inclined mining system for high-angle fully-mechanized mining faces uses dynamic correction of pseudo-inclined angles and adaptive matching technology of fault fracture zones, in conjunction with an inclined anti-skid mechanism, to achieve coordinated control of equipment anti-skid and coal wall anti-slab, thereby improving working face mining efficiency, reducing the possibility of equipment sliding, and solving technical difficulties existing in the high-angle fully-mechanized mining process.

[0065] Adjust the spatial relationship between the tail and head of the coal mining machine, and arrange the transport tunnel above the return air tunnel along the inclination direction of the coal seam to form a vertical height difference; through this dislocation, the actual advancement direction of the working face forms an angle with the direction of the coal seam, thereby reducing the inclination angle of the working face along the advancement direction, forming a controllable pseudo-inclined advancement system, and effectively reducing the equivalent inclination angle of the coal mining machine's operating trajectory.

[0066] It should be noted that during the operation of the equipment, the coal cutting and chute movement should be kept in the same direction to eliminate the stress concentration points on the working face. According to the "up and down" situation of the equipment, the pushing method should be adjusted in time, and a special person should be sent to the site to supervise and control the inclination angle of the equipment to effectively prevent the occurrence of spalling on the working face.

[0067] During the equipment development process, connectors for installing anti-skid hydraulic presses and inclined anti-skid mechanisms are reserved, and each anti-skid hydraulic press is installed at the reserved position;

[0068] During the installation of fully mechanized mining equipment at a high-angle working face in a mine, an "external" anti-skid hydraulic press, i.e., an anti-fall device between hydraulic supports, is first installed. Based on existing equipment, the present invention adds several anti-skid hydraulic presses to each hydraulic support. During the equipment installation process, the hydraulic press telescopic switches are turned on, and the stability of the individual supports and the entire support is ensured by interconnecting these supports.

[0069] After the connecting rod is connected to the scraper conveyor, turn on the hydraulic press telescopic switch "built-in" between the hydraulic support and the connecting rod, and use the hydraulic press to support the base and connecting rod to ensure that the connecting rod does not deflect under the pulling force of the conveyor. When installing an anti-slip hydraulic support between the hydraulic support and the connecting rod, a certain buffer pad is also placed between the contact surface of the anti-slip support and the connecting rod to prevent deformation of the connecting rod and base caused by rigid contact between the two.

[0070] After completing the installation of the above-mentioned device, an oblique anti-skid mechanism is set between the hydraulic support and the scraper conveyor. The device can offset the downward force of the scraper conveyor by applying a certain effective pulling force. At the same time, it should be noted that the oblique anti-skid mechanism shall not be directly connected with an iron chain. A retractable hydraulic rod should be added to connect it. The retraction amount of the hydraulic rod can be automatically adjusted according to the size of the downward force of the scraper conveyor to ensure that the chain will not be affected by continuous high-intensity tension or long-term relaxation, and always maintain a suitable stretching state.

[0071] It is worth noting that this oblique anti-skid mechanism is equipped with an automatic tension monitoring system, which monitors the tension in real time through a tension monitor. When the tension exceeds the pre-set allowable range, the control system receives the signal from the tension monitor and transmits the signal to the monitoring system on the retractable hydraulic rod, which issues an instruction to adjust the hydraulic rod to keep the oblique anti-skid mechanism in a suitable stress state.

[0072] In summary, if Figure 8As shown, the present invention adopts the "machine tail to machine head" downward pseudo-inclined mining method to effectively ensure that the spalling phenomenon occurs during the comprehensive mining process, and in response to the "upward and downward movement" phenomenon that may occur in the equipment in this mining method, three different types of devices are arranged and installed in different positions, which can achieve the purpose of anti-slip and anti-falling of the comprehensive mining equipment on the large-angle working face; by adjusting the relative positions of the machine head and tail, a controllable downward pseudo-inclined mining system is established, and according to the on-site conditions, the push and support status are adjusted in time to effectively prevent the working face spalling phenomenon and the "upward and downward movement" problem of the equipment. By installing an "external" anti-skid hydraulic press on the outside of the hydraulic support, each hydraulic support is tightly connected to avoid the sliding of a single or entire hydraulic support due to the sliding of the scraper conveyor. At the same time, the hydraulic support is connected to the conveyor through an inclined anti-skid mechanism, which increases the connection path and improves the stability of the scraper conveyor to a certain extent. By installing a retractable hydraulic rod and a tension monitoring system, the damage rate of the inclined anti-skid mechanism can be reduced. If the scraper conveyor slides significantly, the connecting rod connected to the scraper conveyor will be offset by its action, and in severe cases, the hydraulic support will be damaged. By installing an "internal" anti-skid hydraulic press between the hydraulic support and the connecting rod, the shape of the connecting rod can be corrected, which can effectively prevent the occurrence of this phenomenon and reduce the damage rate of the equipment.

[0073] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0074] The present invention is not limited to the above optional embodiments. Anyone can derive various other forms of products based on the teachings of the present invention. The above specific embodiments should not be construed as limiting the scope of protection of the present invention. The scope of protection of the present invention shall be based on the scope defined in the claims, and the description can be used to interpret the claims.

Claims

1. A method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer, characterized in that: The following steps are involved: Step 1: Pseudo-inclined mining layout: The transport tunnel at the tail of the shearer is arranged above the return air tunnel at the head of the shearer, along the inclination direction of the coal seam. This creates a vertical height difference between the two, allowing the actual advancement direction of the working face to form an angle with the direction of the coal seam, reducing the inclination of the working face along the advancement direction, and establishing a pseudo-inclined dynamic advancement system based on real-time correction of fault parameters. Step 2: Real-time perception of fault parameters: A geological radar is deployed in the advanced support section of the working face. The radar wave reflection signal is used to identify the fault interface and output the fault direction, drop, and horizontal length of the fracture zone. A strain-type cutting resistance sensor and an image recognition module for coal fragmentation are built into the shearer's rocker arm. The strain-type cutting resistance sensor provides real-time feedback on the mechanical resistance during coal wall cutting. The image recognition of coal fragmentation is used to identify the average particle size of coal blocks, calculate the proportion of broken coal, and invert the integrity of the coal wall. Step 3: Calculation of layout parameters: Based on at least 5 working faces with similar geological conditions, collect several sets of stress correlation analysis data, where the stress correlation analysis data include fault drop, fracture zone length and pitch-pseudo-oblique angle. After regression analysis, according to the formula The coal wall shear stress τ is calculated and controlled to be ≤15MPa. The correction formula for the pitch-down pseudo-slope angle is derived: α 初始 -α 修正 The result is recorded as the angle correction Δα, combined with the working surface length L 面 , calculate Δh=L by trigonometric function 面 sin(Δα) simultaneously directly outputs the angle correction value Δα adjustment instruction, which is then linked to the anti-skid coordination system of the anti-skid equipment. By adjusting the extension and contraction of the anti-skid hydraulic press and the tension of the oblique anti-skid mechanism, the tilt angle of the equipment is maintained consistent with the pitch angle. Step 4: Execute dynamic layout correction: When the coal wall stress monitoring value τ>15MPa, start dynamic correction, automatically reduce the pseudo-inclination angle by 3°-5°, and simultaneously reduce the height difference between the transport lane and the return air lane by 0.8-1.2m; during the adjustment process, the scraper conveyor push sensor feedbacks the push angle every 5 seconds, and the lane inclinometer feedbacks the actual inclination angle α every 10 seconds 实测 , when α 实测 With α 修正 When the error is ≤±0.5° and the height error is ≤±0.1m, the adjustment is determined to be in place and the slope adjustment is stopped; if the error exceeds the threshold, the adjustment is automatically made.

2. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 1 is characterized in that: In the step 1, when the cutting resistance suddenly changes and increases by more than 30% within ten seconds, or the coal body fragmentation is greater than 60%, it is determined that the fault has entered the affected area, and the fault parameters are corrected by linking the geological radar data; if the cutting resistance increase is less than 10% and the coal body fragmentation is less than 40% within 30 consecutive minutes, it is determined that the fault has exited the affected area. After exiting, the pitch-pseudo-oblique angle is restored to the normal value at a rate of 0.5° / min, and the height difference between the transport tunnel and the return air tunnel is simultaneously increased.

3. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 1 is characterized in that: In the step 3, α 修正 It is expressed as the corrected pitch pseudo-slant angle, with a value range of 5°-15°, α 初始 It is expressed as the conventional pseudo-oblique angle, with a value range of 10°-15°. k is expressed as the correction coefficient, which is determined in sections according to the uniaxial compressive strength of the coal seam.

4. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 1 is characterized in that: In step three, if the uniaxial compressive strength of the coal seam is less than 20 MPa, the value of k is 5; if the uniaxial compressive strength of the coal seam is between 20-40 MPa, the value of k is 3; if the uniaxial compressive strength of the coal seam is greater than 40 MPa, the value of k is 2.

5. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 1 is characterized in that: In the step 4, if the angle increases by 2°, the hydraulic press pushes the bracket toward the head of the machine to ensure that the bracket arrangement angle is consistent with the pitch pseudo-oblique angle.

6. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 1 is characterized in that: It also includes an anti-skid coordination system for equipment to prevent spalling. The anti-skid coordination system for equipment to prevent spalling refers to an integrated system composed of hydraulic supports, scraper conveyors, inclined anti-skid mechanisms and anti-skid hydraulic presses, which is used to achieve anti-skid, anti-falling and coordinated posture adjustment of equipment during the slope adjustment process of downward and pseudo-inclined mining. The hydraulic support is located on one side of the scraper conveyor, and the scraper conveyor is connected to the inside of each hydraulic support through a connecting rod. An inclined anti-skid mechanism is also provided between the scraper conveyor and the hydraulic support located on one side; "external" anti-skid hydraulic presses are provided between two adjacent hydraulic supports and on the outside of the hydraulic supports; one end of the connecting rod is connected to the inside of the hydraulic support, and an "internal" anti-skid hydraulic press is also provided between the inside of the hydraulic support and the connecting rod.

7. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 6 is characterized in that: The inclined anti-skid mechanism includes a scraper conveyor connector, an iron chain, a tension monitoring system, a retractable hydraulic rod and a hydraulic support connector. One end of the scraper conveyor connector is connected to the iron chain, and the other end of the iron chain is connected to the tension monitoring system. A retractable hydraulic rod is provided on one side of the tension monitoring system, and one end of the retractable hydraulic rod is provided with a hydraulic support connector. One end of the hydraulic support connector is connected to the interior of the hydraulic support.

8. The method for preventing spalling in a fully mechanized mining face with a large dip angle in a section layer according to claim 7 is characterized in that: The telescopic hydraulic rod is composed of a connecting block, a telescopic rod, a sealing ring, a telescopic piston, a liquid-gas mixing sleeve and a monitoring system. One end of the telescopic rod and the liquid-gas mixing sleeve is provided with a connecting block, and the other end of the telescopic rod is fixedly provided with a telescopic piston. The surface of the telescopic piston is slidably connected to the inside of the liquid-gas mixing sleeve. A monitoring system is provided at one end of the liquid-gas mixing sleeve and located outside the telescopic rod, and a sealing ring is provided between the surface of the telescopic rod and the inside of the monitoring system.

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