Bidirectional shaped charge blasting roof-cutting pressure relief method and system for coal mine tunnel

Abstract

The invention relates to a bidirectional shaped charge blasting top-cutting pressure relief method and system for a coal mine roadway, the system comprises a head shaped charge pipe, a plurality of trailing shaped charge pipes, a spacing adjusting mechanism and a synchronous detonation network, the head shaped charge pipe integrates cutting, sensing and crawling functions and can continuously move upwards in a blast hole autonomously, and the tail shaped charge pipe is connected with the synchronous detonation network. A V-shaped guide groove is synchronously cut, continuous lithology data are collected, a V-shaped protruding edge is arranged on the outer side of the trailing energy-gathering pipe and matched with the V-shaped guide groove to achieve circumferential positioning, a distance adjusting mechanism adjusts the distance between the energy-gathering pipes through winding and unwinding of a cable according to the lithology data, optimization of charge distribution is achieved, and a synchronous detonating network is synchronized based on a high-precision clock. And all the electronic detonators are controlled to be detonated in sequence within microsecond-level precision. According to the method, integrated operation of geological exploration, parameter self-adaptive adjustment and precise blasting is achieved, the technical problems that the joint cutting direction deviation is large, the charging parameters are not matched with the lithology, and the blasting cooperation effect is poor are solved, and the reliability and economical efficiency of top cutting pressure relief are improved.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a bidirectional shaped charge blasting method and system for roof cutting and pressure relief in 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. This method leads to a significant waste of coal resources; 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 remaining 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-relieving 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.

[0003] Currently, the main technology for roof cutting and pressure relief in coal mines adopts the bidirectional shaped charge blasting method. In existing technologies, this generally involves directly placing a bidirectional shaped charge tube into the blast hole, aligning the two shaped charge holes with the cutting direction. The principle is that after the explosive detonates, the shock wave first acts directly on the hole wall corresponding to the bidirectional shaped charge hole, creating initial cracks. Subsequently, under the action of the explosive gases, a static stress field is formed around the blast hole and its wall. Under the action of this static stress field, the blast hole experiences radial compressive stress. Guided by the shaped charge holes, the explosive gases rush into the initial micro-cracks created by the shock wave. This creates a wedge effect, generating tension in the direction perpendicular to the fracture to achieve the purpose of cutting. However, in practice, it has been found that the installation of bidirectional shaped charge tubes mainly relies on manual operation, making it difficult to ensure the precise alignment of the shaped charge hole directions of all shaped charge tubes in a hole tens of meters deep. This seriously affects the smoothness and continuity of the cut. Furthermore, when the shock wave first acts on the hole wall corresponding to the bidirectional shaped charge hole, the impact force of the shock wave acting on the hole wall through the bidirectional shaped charge hole is dispersed due to the smoothness of the hole wall, which can easily lead to a limited initial fracture opening, ultimately resulting in an unsatisfactory cut or even failure. In addition, the current technology usually uses bidirectional shaped charge tubes with the same spacing throughout the entire blast hole, and the amount of explosive charge inside each bidirectional shaped charge tube is also the same. However, the lithology of the roof of actual coal mine roadways often varies significantly in the longitudinal direction. Uniform charging parameters are difficult to adapt to this variation, which can easily lead to incomplete cutting due to insufficient energy in hard rock layers, and excessive damage to the roof due to excessive energy in weak rock layers. In addition, when multiple bidirectional shaped charge tubes are detonated, the traditional method often uses detonating detonators, which is simple and reliable, but it is difficult to achieve precise micro-delay detonation and to form the best superposition effect of stress waves. Summary of the Invention

[0004] In view of the above problems, the present invention provides a bidirectional shaped charge blasting roof cutting and pressure relief method and system for coal mine roadways, so as to solve the problems mentioned in the background art.

[0005] The specific technical solution is as follows: A bidirectional shaped charge blasting roof cutting and pressure relief method for coal mine roadways, characterized by comprising the following steps: S1 connects the head-mounted shaped charge tube to several trailing shaped charge tubes in series, and places the head control cabin at the opening of the blast hole. It controls the cutting components inside the head-mounted shaped charge tube to work. At the same time, with the help of tools or built-in crawling components, the head-mounted shaped charge tube is driven to move upward along the axial direction of the blast hole inside the blast hole, thereby cutting two symmetrical guide structures on the blast hole wall. The sensing unit inside the head-mounted shaped charge tube is used to synchronously collect lithological and location data of the inner wall of the blast hole, and construct a lithological distribution file for the entire section of the blast hole. S2, the subsequent trailing energy tubes are circumferentially positioned by the limiting protrusions embedded in the guide structure and follow the head energy tube upward until the head energy tube is moved to the designated position. S3, the main controller calculates and determines the target spacing of each shaped charge tube and the amount of explosive required to fill each shaped charge tube based on the lithology distribution file; S4, pumping the corresponding amount of emulsion explosive into the head shaped charge tube and each tail shaped charge tube from top to bottom; S5, the main controller drives each spacing adjustment mechanism to move from top to bottom in sequence, adjusting each energy-concentrating tube to the target spacing in sequence; S6, the main controller broadcasts a time synchronization signal to the head shaped charge tube and the electronic detonator modules built into each tail shaped charge tube via the communication bus and synchronizes them. Then, it sends a command containing an absolute detonation timestamp to each electronic detonator module individually. When the local clock of each electronic detonator module reaches its respective absolute detonation timestamp, it independently triggers detonation.

[0006] A bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways includes: The head-shaped charge tube has, from top to bottom, a head control compartment, a cutting mechanism compartment, and a head charge compartment. The head control compartment contains a sensing unit for control, communication, positioning, and continuous detection of lithology and location. The cutting mechanism compartment has symmetrically arranged windows on its tube wall, and each window has a rotatable cutting element inside for cutting along the cutting direction on the blast hole wall to form a guide structure. The head charge compartment has multiple sets of first shaped charge holes symmetrically arranged on its side wall, and a first pumping pipe is provided at the lower end of the head charge compartment. A plurality of trailing energy focusing tubes are provided, each of which has multiple sets of second energy focusing holes symmetrically arranged on its sidewall. The outer side of each trailing energy focusing tube is also provided with a limiting protrusion that cooperates with the guide structure. Each trailing energy focusing tube is provided with a second pumping tube inside. The upper end of the first second pumping tube is connected to the lower end of the first pumping tube, and the upper ends of the remaining second pumping tubes are connected to the lower end of the second pumping tube above it. Each second pumping tube is also provided with a three-way solenoid valve. A spacing adjustment mechanism is provided between the head charge compartment and the first trailing shaped charge tube, as well as between adjacent trailing shaped charge tubes. The spacing adjustment mechanism includes a worm gear pair driven by a second motor, a drum coaxially connected to the worm gear, and a cable wound on the drum. One end of the cable is connected to the next adjacent trailing shaped charge tube.

[0007] Furthermore, it also includes a synchronous detonation network, comprising a main controller located at the opening of the blast hole and electronic detonator modules respectively located in the head shaped charge tube and the tail shaped charge tube. The main controller is connected to each electronic detonator module via a communication bus for clock synchronization, issuing absolute detonation time commands, and controlling detonation.

[0008] Furthermore, the sensing unit includes a battery, a main control chip, a wireless communication module, a gyroscope, a dual-axis tilt sensor, an acoustic scanning probe for continuous lithology detection, and a position encoder for recording relative position.

[0009] Furthermore, the cutting component includes a cutting disc and a first motor for driving the cutting disc to rotate. The cutting disc is a V-shaped diamond cutting disc, and the V-shaped cutting edges of the two cutting discs are opposite each other. The ends of the two cutting discs that are far apart from each other can cut the inner walls on both sides of the area where the cutting plane is located in the blast hole. The guiding structure is a V-shaped guide groove that matches the V-shaped cutting edge, and the limiting protrusion is a V-shaped protrusion that cooperates with the V-shaped guide groove.

[0010] Furthermore, a one-way inlet valve is provided at the lower end of the first pumping pipe, and a first connector that mates with the upper end of the second pumping pipe is coaxially provided at the lower end of the first pumping pipe; a second connector that mates with the upper end of the second pumping pipe is coaxially provided at the lower end of the second pumping pipe; the first pumping pipe and the first second pumping pipe are connected in series through the first connector, and several second pumping pipes are connected in series sequentially through the second connector, for sequentially pumping emulsion explosives into the head charge chamber and several trailing shaped charge tubes.

[0011] Furthermore, the spacing adjustment mechanism also includes a length detector for detecting the release length of the cable, wherein the length detector is a rotary encoder disposed on the drum.

[0012] Furthermore, the spacing adjustment mechanism also includes an upper connector located on the lower end face of the head charge chamber and the tail charge tube, and a lower connector located on the upper end face of the tail charge tube. A flexible protective sleeve for allowing the cable and communication bus to pass through the interior is connected between the upper connector and the lower connector.

[0013] Furthermore, the cable is a steel wire rope or Kevlar fiber rope, with one end connected to a drum and the other end connected to a lower connector via a flexible protective sleeve.

[0014] Furthermore, the communication bus is a four-core cable, of which two cores form a differential data bus and the other two cores are power lines.

[0015] Furthermore, the main controller has a built-in clock source, and the electronic detonator module includes a unique ID address, a calibrable local clock, and an initiation capacitor. The main controller is used to broadcast a clock synchronization signal to all electronic detonator modules before detonation and to issue encrypted instructions containing the absolute detonation time to each module. Each electronic detonator module autonomously performs detonation based on the synchronized local clock at the absolute detonation time.

[0016] Furthermore, a limiting sleeve is coaxially provided on the lower end face of the head charge chamber and each of the trailing shaped charge tubes, and a limiting sleeve that is clearance-fitted with the limiting sleeve is coaxially provided on the upper end face of each of the trailing shaped charge tubes.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a bidirectional shaped charge blasting roof cutting and pressure relief method and system for coal mine roadways. By setting a cutting mechanism chamber on the head shaped charge tube, two continuous guide structures are cut on the inner wall of the blast hole by the cutting component. This facilitates the alignment of the shaped charge angles of each shaped charge tube through the limiting protrusion, ensuring that the axes of all first and second shaped charge holes from the hole opening to the hole bottom are located in the same preset plane, thereby ensuring the consistency of the direction of the blast shaped charge jet and improving the flatness and continuity of the roof cut. Moreover, the shock wave during blasting can act on the guide structure corresponding to the shaped charge hole, making it easier for the impact force of the shock wave to be concentrated at the guide structure position, thus ensuring the opening of the initial crack.

[0018] (2) The present invention provides a bidirectional shaped charge blasting method and system for cutting and depressurizing roofs in coal mine roadways. By setting up a sensing unit, continuous lithological distribution data is acquired synchronously during the upward cutting process. The main controller calculates and determines the charging spacing and charge amount of each shaped charge tube based on this data. Subsequently, the actual distance between adjacent shaped charge tubes is dynamically adjusted by controlling each spacing adjustment mechanism. This allows the spacing to be reduced and the charge energy to be concentrated in hard rock strata, while the spacing to be increased and the energy to be dispersed in soft rock strata. This achieves the matching of explosive energy distribution with the properties of the rock strata, ensuring the cutting effect while avoiding excessive or insufficient damage to the roof strata and reducing the unit consumption of explosives.

[0019] (3) The present invention provides a bidirectional shaped charge blasting roof cutting and pressure relief method and system for coal mine roadways. By setting up a synchronous detonation network, the main controller performs microsecond-level clock synchronization on all electronic detonator modules before detonation through the communication bus and issues a unique absolute detonation timestamp. Each electronic detonator module independently keeps time and triggers autonomously. By setting micro-differential detonation times for detonators at different positions along the borehole, the shaped charge tubes at different intervals tend to detonate at the same time, thereby achieving optimal superposition of controlled explosion stress waves in space and time, enhancing the driving force of directional fracture, and thus obtaining a longer effective cut and a more regular cross-section.

[0020] (4) The present invention provides a bidirectional shaped charge blasting method and system for cutting the top and relieving pressure in coal mine roadways. By setting a crawling component between the cutting mechanism compartment and the head charge compartment, and by controlling the alternating anchoring and release of the first radial clamping mechanism and the second radial clamping mechanism, and cooperating with the forward and reverse rotation of the double threaded screw, the cutting mechanism compartment and the head control compartment can be driven to achieve continuous upward movement without external traction. Compared with intermittent or jumping movement, continuous crawling ensures that the acoustic scanning probe installed in the head control compartment can perform uninterrupted scanning of the borehole wall at a constant speed, thereby obtaining a continuous lithological profile with no data loss and high resolution, providing an accurate data basis for subsequent spacing optimization and detonation parameter design. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the present invention.

[0023] Figure 3 This is a schematic diagram of the head-type energy-concentrating tube structure of the present invention.

[0024] Figure 4 This is a schematic diagram of the cutting mechanism compartment structure of the present invention.

[0025] Figure 5 This is a schematic diagram of the spacing adjustment mechanism of the present invention.

[0026] Figure 6 This is a schematic diagram of the tail-following focusing tube structure of the present invention.

[0027] Figure 7 This is a schematic diagram of the V-shaped convex ridge structure of the present invention.

[0028] Figure 8 This is a schematic diagram of the crawling component structure of the present invention.

[0029] Figure 9 This is a schematic diagram of the first crawling and anchoring cabin structure of the present invention.

[0030] Figure 10 This is a schematic diagram of the first radial clamping mechanism of the present invention.

[0031] Figure 11 This is a schematic diagram of the second crawling and anchoring cabin structure of the present invention.

[0032] Figure 12 This is a schematic diagram of the second radial clamping mechanism of the present invention.

[0033] In the diagram: 1. Blasting hole; 2. Head-mounted shaped charge tube; 21. Head-mounted control compartment; 22. Cutting mechanism compartment; 221. Window; 222. First motor; 223. Cutting disc; 224. Motor housing; 23. Head-mounted charge compartment; 231. First shaped charge hole; 232. First pumping pipe; 233. One-way liquid inlet valve; 234. First connector; 24. First crawling and anchoring compartment; 241. Third motor; 242. Double-threaded lead screw; 243. First ball bearing nut block; 244. Second ball bearing nut block; 245. First connecting rod; 246. Second connecting rod; 247. First radial clamping mechanism; 2471. First arc-shaped clamping plate; 2472. First electric cylinder; 25. Second crawling and anchoring compartment; 25 1. Fourth motor; 252. Drive shaft; 253. First bevel gear; 254. Second radial clamping mechanism; 2541. Second lead screw; 2542. Third ball bearing nut block; 2543. Second arc-shaped clamping plate; 2544. Third connecting rod; 2545. Second bevel gear; 3. Follower energy-concentrating tube; 31. Second energy-concentrating hole; 32. V-shaped convex rib; 33. Second pumping pipe; 34. Three-way solenoid valve; 35. Second connector; 4. Spacing adjustment mechanism; 41. Second motor; 42. Worm gear pair; 43. Drum; 44. Cable; 46. Upper connector; 47. Lower connector; 48. Flexible protective sleeve; 5. Ruptureable sealing membrane; 6. V-shaped guide groove; 7. Limiting sleeve; 8. Limiting sleeve. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] Example 1 This invention discloses a bidirectional shaped charge blasting method for roof cutting and pressure relief in coal mine roadways, with reference to... Figure 1 This includes the following steps: S1, connect the head-type energy-concentrating tube 2 in series with several subsequent tail-type energy-concentrating tubes 3, and place the head control cabin 21 at the opening of the blast hole 1. Control the cutting components inside the head-type energy-concentrating tube 2 to work. At the same time, with the help of tools or built-in crawling components, drive the head-type energy-concentrating tube 2 to move upward along the axial direction of the blast hole 1 inside the blast hole 1, so as to cut two symmetrical guide structures on the hole wall of the blast hole 1. Simultaneously collect the lithology and location data of the inner wall of the blast hole 1 using the sensing unit inside the head-type energy-concentrating tube 2, and construct the lithology distribution file of the entire section of the blast hole 1. S2, the subsequent trailing energy tubes 3 are circumferentially positioned by the limiting protrusion embedded in the guide structure and follow the head energy tube 2 upward until the head energy tube 2 is moved to the designated position. S3, the main controller calculates and determines the target spacing of each shaped charge tube and the amount of explosive required to fill each shaped charge tube based on the lithology distribution file; S4, pumping the corresponding amount of emulsion explosive into the head shaped charge tube 2 and each tail shaped charge tube 3 from top to bottom; S5, the main controller drives each spacing adjustment mechanism 4 to move from top to bottom in sequence, and adjusts each energy-concentrating tube to the target spacing in sequence; S6, the main controller broadcasts a time synchronization signal to the electronic detonator modules built into the head shaped charge tube 2 and each trailing shaped charge tube 3 via the communication bus and synchronizes them. Then, it sends an instruction containing an absolute detonation timestamp to each electronic detonator module individually. When the local clock of each electronic detonator module reaches its respective absolute detonation timestamp, it independently triggers detonation.

[0037] Example 2 This invention discloses a bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways, with reference to... Figure 2 Based on Embodiment 1, it also includes a head-type shaped charge tube 2, a tail-type shaped charge tube 3, a spacing adjustment mechanism 4, and a synchronous detonation network.

[0038] refer to Figure 3 , Figure 4 and Figure 5The head-mounted shaped charge tube 2 contains, from top to bottom, a head control compartment 21, a cutting mechanism compartment 22, and a head charge compartment 23. The upper end of the head control compartment 21 is hemispherical, and it houses a sensing unit for control, communication, positioning, and continuous detection of lithology and location. The cutting mechanism compartment 22 has symmetrically arranged windows 221 on its wall, each window 221 having a rotatable cutting element inside for cutting along the slit direction on the wall of the blast hole 1 to form a guiding structure. The head charge compartment 23... The sidewalls are symmetrically provided with multiple sets of first energy-concentrating holes 231. The lower end of the head loading chamber 23 is provided with a first pumping pipe 232. The lower end of the first pumping pipe 232 is provided with a one-way liquid inlet valve 233. The lower port of the first pumping pipe 232 is coaxially provided with a first connector 234 that mates with the upper port of the second pumping pipe 33. The sensing unit includes a battery, a main control chip, a wireless communication module, a gyroscope, a dual-axis tilt sensor, an acoustic scanning probe for continuous lithological detection, and a position encoder for recording relative positions. The cutting component includes a cutting disc 223 and a first motor 222 for driving the cutting disc 223 to rotate. The cutting disc 223 is a V-shaped diamond cutting disc, and the V-shaped cutting edges of the two cutting discs 223 are opposite each other. The ends of the two cutting discs 223 that are far apart from each other can cut the inner walls on both sides of the area where the cutting plane is located in the blast hole 1. The guiding structure is a V-shaped guide groove 6 that matches the V-shaped cutting edge. The acoustic scanning probe makes rigid contact with the borehole wall 1, continuously exciting and receiving acoustic waves during the upward cutting process. The position encoder records the absolute depth of the head control chamber 21 relative to the borehole opening, thus establishing a one-to-one correspondence between acoustic wave data and position. The cutting depth of the V-shaped guide groove 6 is typically 2-5 mm, providing a preferential path for the subsequent shaped jet of the blast, reducing the energy required for blasting. The cutting disc 223 rotates at high speed and contacts the borehole wall under the drive of the first motor 222. As the entire tubing string moves upward, the cutting disc 223 cuts two continuous V-shaped guide grooves 6 in the borehole wall. During this process, the acoustic scanning probe collects the acoustic wave propagation velocity of the rock mass in real time (directly related to rock hardness). All data is transmitted wirelessly to the main controller at the borehole opening in real time. The V-shaped guide groove 6 formed by mechanical cutting provides a physical guiding reference for the subsequent tailing energy-concentrating tube 3, fundamentally solving the problem of large errors in manual alignment of the energy-concentrating direction. Moreover, the shock wave during blasting can act on the V-shaped guide groove 6 corresponding to the energy-concentrating hole, making it easier for the impact force of the shock wave to concentrate at the position of the V-shaped guide groove 6, thus ensuring the opening of the initial crack.

[0039] refer to Figure 2 , Figure 6 and Figure 7The trailing shaped charge tubes 3 are provided in multiple units. Each trailing shaped charge tube 3 has multiple sets of second shaped charge holes 31 symmetrically arranged on its sidewall. The outer surface of each trailing shaped charge tube 3 is also provided with a limiting protrusion that cooperates with the guide structure. Each trailing shaped charge tube 3 is provided with a second pumping pipe 33 inside. The upper end of the first second pumping pipe 33 is connected to the lower end of the first pumping pipe 232, and the upper ends of the remaining second pumping pipes 33 are connected to the lower ends of their respective upstream second pumping pipes 33. Each second pumping pipe 33 is also provided with a three-way solenoid valve 34 for connecting the upper and lower pipes when pumping emulsion explosives. The pumping is completed and then shut off; the limiting protrusion is a V-shaped protrusion 32 that mates with the V-shaped guide groove 6, used to embed into the V-shaped guide groove 6 when the following shaped charge tube 3 moves upward, to achieve circumferential positioning; the lower end of the second pumping tube 33 is coaxially provided with a second connector 35 that mates with the upper end of the second pumping tube 33; the first pumping tube 232 and the first second pumping tube 33 are connected in series through the first connector 234, and several second pumping tubes 33 are connected in series in sequence through the second connector 35, used to pump emulsion explosives into the head charge chamber 23 and several following shaped charge tubes 3 in sequence. When the trailing shaped charge tube 3 enters the blast hole 1, the V-shaped protrusion 32 is confined within the V-shaped guide groove 6, ensuring that the shaped charge direction of all the second shaped charge holes 31 of the trailing shaped charge tubes 3 is consistent with the cutting plane; the first pumping pipe 232 and the second pumping pipe 33 are connected in series to form a continuous and closed delivery channel from the hole opening to the bottom of the hole. The three-way solenoid valve 34 is opened during loading and closed after loading to prevent the explosive from flowing back.

[0040] Furthermore, as one implementation method, refer to Figure 5 and Figure 6 Each of the head-mounted propellant compartment 23 and the lower end face of each trailing shaped charge tube 3 is coaxially provided with a limiting sleeve 7, and each of the trailing shaped charge tubes 3 is coaxially provided with a limiting sleeve 8 that is clearance-fitted with the limiting sleeve 7 on the upper end face of the limiting sleeve 7. Their function is to provide rigid support and radial positioning during initial placement and upward movement, and to disengage from each other during spacing adjustments.

[0041] Furthermore, as one implementation method, refer to Figure 5 and Figure 7 Each of the first energy-concentrating holes 231 and the second energy-concentrating hole 31 is further provided with a ruptureable sealing membrane 5. The ruptureable sealing membrane 5 is made of polyester film, and its burst pressure is much lower than the detonation pressure of the explosive, but sufficient to withstand the static pressure when the emulsion explosive is pumped.

[0042] refer to Figure 3 , Figure 5 and Figure 6The spacing adjustment mechanism 4 is located between the head charge chamber 23 and the first trailing shaped charge tube 3, as well as between adjacent trailing shaped charge tubes 3. The spacing adjustment mechanism 4 includes a worm gear pair 42 driven by a second motor 41, a drum 43 coaxially connected to the worm gear, and a cable 44 wound on the drum 43. One end of the cable 44 is connected to the next adjacent trailing shaped charge tube 3. The spacing adjustment mechanism 4 also includes a length detector for detecting the release length of the cable 44. The length detector is located between the head charge chamber 23 and the first trailing shaped charge tube 3, and between adjacent trailing shaped charge tubes 3. The rotary encoder is mounted on the drum 43. The spacing adjustment mechanism 4 also includes an upper connector 46 located on the lower end face of the head charging chamber 23 and the trailing energy-concentrating tube 3, and a lower connector 47 located on the upper end face of the trailing energy-concentrating tube 3. A flexible protective sleeve 48 is connected between the upper connector 46 and the lower connector 47 to allow the cable 44 and communication bus to pass through the interior. The cable 44 is a steel wire rope or Kevlar fiber rope, with one end connected to the drum 43 and the other end connected to the lower connector 47 via the flexible protective sleeve 48. Initially, when the limiting sleeves 7 and limiting sleeves 8 are inserted, the head energy-concentrating tube 2 and several trailing energy-concentrating tubes 3 form a strip-shaped cylinder, and the cable 44 of the spacing adjustment mechanism 4 is in a tightened state. The rotary encoder calculates the release length of the cable 44 by measuring the rotation angle of the drum 43. The main controller adjusts each spacing to the target value by controlling the second motor 41. The self-locking characteristic of the worm gear pair 42 ensures that after adjustment, it can resist the gravity of the following shaped charge tube 3 without continuous power supply, maintaining a stable spacing. After the following shaped charge tube 3 follows the head shaped charge tube 2 to its position, it begins pumping emulsion explosive. After pumping is completed, the main controller sends target length commands to each spacing adjustment mechanism 4 from top to bottom according to the lithology distribution file. The corresponding second motor 41 starts, releasing the cable 44, and the flexible protective sleeve 48 extends accordingly. The rotary encoder provides real-time feedback. After the target length is reached, the second motor 41 stops, the worm gear self-locks, and the following shaped charge tube 3 is suspended in the new position. After all spacing adjustment mechanisms 4 have completed their actions, the head shaped charge tube 2 and several following shaped charge tubes 3 present a non-uniform, lithology-matched shape in the borehole. In hard rock sections, the spacing is reduced and the explosive charge is concentrated to enhance the power; in soft rock sections, the spacing is increased and the explosive charge is dispersed to avoid excessive crushing, improve blasting efficiency, and reduce explosive consumption per unit.For example, the entire length of blast hole 1 is divided into five sections, from the borehole opening to the bottom, namely section one, section two, section three, section four, and section five. The average value of the acoustic wave scanning probe data for each section is taken as the average acoustic velocity for that section. Based on the average acoustic velocity, the lithology is divided into three cases: a section with an average acoustic velocity less than or equal to 2000 m / s is considered a weak rock layer; a section with an average acoustic velocity between 2000 and 3000 m / s is considered a weak rock layer; and a section with an average acoustic velocity between 2000 and 3000 m / s is considered a weak rock layer. The rock strata are defined as follows: a velocity between 100 m / s and 3000 m / s is considered a standard rock stratum; a velocity greater than or equal to 3000 m / s is considered a hard rock stratum; several trailing shaped charge tubes 3 located within the standard rock stratum are spaced 200-400 mm apart, with the charge being the standard amount; several trailing shaped charge tubes 3 located within the soft rock stratum are spaced 400-600 mm apart, with the charge being 85% of the standard amount; several trailing shaped charge tubes 3 located within the hard rock stratum are spaced 0-200 mm apart, with the charge being 120% of the standard amount. The charge amount of each shaped charge tube is monitored by the flow valve in the pumping emulsion explosive device.

[0043] The synchronized detonation network includes a main controller located at the opening of the blast hole 1 and electronic detonator modules respectively located in the head shaped charge tube 2 and the tail shaped charge tube 3. The main controller is connected to each electronic detonator module via a communication bus for clock synchronization, issuing absolute detonation time commands, and controlling detonation. The communication bus is a four-core cable, with two cores forming a differential data bus and the other two cores being power lines. The main controller has a built-in clock source, and each electronic detonator module includes a unique ID address, a calibrable local clock, and a detonation capacitor. The main controller broadcasts a clock synchronization signal to all electronic detonator modules before detonation and issues encrypted commands containing the absolute detonation time to each module. Each electronic detonator module autonomously detonates at the absolute detonation time based on its synchronized local clock. The main controller employs a precision time protocol algorithm to periodically broadcast synchronization messages. These messages contain the precise timestamp of the master clock. Each electronic detonator module records the local time of message arrival and compensates for network transmission delays through a delayed request-response mechanism, thereby synchronizing its local TCXO clock with the master clock to the microsecond level. After synchronization, the main controller sends a future absolute detonation time individually to each electronic detonator module. The microprocessor inside each electronic detonator module continuously compares its local clock with this absolute time, maintaining independent timekeeping. After the detonation command is enabled, the detonation capacitors of all electronic detonator modules are charged. After that, the detonation network no longer needs to transmit any timing signals. Each electronic detonator module waits for its own clock to complete the preset countdown. When the local clock of the electronic detonator module reaches its unique absolute detonation moment, its internal switching circuit immediately activates, detonating the semiconductor bridge and the main charge. Since all clocks have been synchronized in advance, the detonation actions of each module unfold in the designed sequence on the time axis, thereby achieving the simultaneous detonation of each shaped charge tube at different intervals. The microsecond-level synchronization accuracy enables the stress wave to achieve optimal superposition at the designed position, enhancing the directional fracture effect.

[0044] Example 3 This invention discloses a bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways, with reference to... Figure 8 , Figure 9 and Figure 11Based on Embodiment 2, the head-mounted energy-concentrating tube 2 is further provided with a crawling component between the cutting mechanism chamber 22 and the head-mounted explosive loading chamber 23. The crawling component includes a first crawling and anchoring chamber 24 and a second crawling and anchoring chamber 25 arranged vertically. A double-threaded screw 242 driven by a third motor 241 is coaxially arranged within the first crawling and anchoring chamber 24. The pitch ratio of the upper and lower threads of the double-threaded screw 242 is 1:2, and it is respectively fitted with a first ball bearing nut block 243 and a second ball bearing nut block 244. The first ball bearing nut block 243 is connected to the cutting mechanism chamber 22 via a first connecting rod 245, and the second ball bearing nut block 244 is connected to the first crawling and anchoring chamber 25 via a second connecting rod 246. The second crawling and anchoring chamber 24 is connected to the first crawling and anchoring chamber 25. At least two sets of first radial clamping mechanisms 247 are provided along the axial direction on the inner wall of the first crawling and anchoring chamber 24. A transmission shaft 252 driven by a fourth motor 251 is coaxially provided inside the second crawling and anchoring chamber 25. At least two sets of second radial clamping mechanisms 254 are provided along the axial direction on the inner wall of the second crawling and anchoring chamber 25, which are respectively connected to the transmission shaft 252. Through the alternating anchoring of the first radial clamping mechanism 247 and the second radial clamping mechanism 254 and the forward and reverse rotation of the double threaded screw 242, the head control chamber 21 is driven to continuously move upward in the blast hole 1, ensuring the continuity of detection by the acoustic scanning probe installed inside the head control chamber 21.

[0045] Furthermore, as a specific implementation method, refer to Figure 9 and Figure 10 Each set of the first radial clamping mechanism 247 includes several first clamping members arranged sequentially at equal intervals around the axial direction of the first crawling and anchoring chamber 24. Each first clamping member includes a first arc-shaped clamping plate 2471 coaxially disposed on the outer side of the first crawling and anchoring chamber 24. A first electric cylinder 2472 is provided on the inner wall of the first crawling and anchoring chamber 24 to move the first arc-shaped clamping plate 2471 radially. While performing the anchoring function, the first radial clamping mechanism 247 can detect the coaxiality of the cutting mechanism chamber 22 and the blast hole 1 using a gyroscope and a dual-axis tilt sensor. The coaxiality of the cutting mechanism chamber 22 can be adjusted by controlling the extension or retraction of each first electric cylinder 2472.

[0046] Furthermore, as a specific implementation method, refer to Figure 11 and Figure 12Each set of second radial clamping mechanisms 254 includes several second clamping members arranged sequentially at equal intervals around the axial direction of the second crawling and anchoring chamber 25. The second clamping member includes a second lead screw 2541 arranged radially along the second crawling and anchoring chamber 25 and a second arc-shaped clamping plate 2543 coaxially arranged on the outer side of the second crawling and anchoring chamber 25. A third ball nut block 2542 is adapted on the second lead screw 2541. The third ball nut block 2542 is connected to the inner side of the second arc-shaped clamping plate 2543 through a third connecting rod 2544. A second bevel gear 2545 is coaxially arranged at one end of the second lead screw 2541 away from the second arc-shaped clamping plate 2543. A first bevel gear 253 that meshes with several second bevel gears 2545 is coaxially arranged at both ends of the transmission shaft 252.

[0047] Furthermore, as a specific implementation method, refer to Figure 9 The lower end face of the cutting mechanism compartment 22 is provided with a motor receiving slot 224 for accommodating the third motor 241.

[0048] When the second crawling and anchoring chamber 25 is anchored to the inner wall of the blast hole 1 through several sets of second clamping mechanisms, the rotation of the double threaded screw 242 causes the second ball nut block 244 and the first ball nut block 243 to move downwards, and the second ball nut block 244 moves downwards faster than the first ball nut block 243. Since the second crawling and anchoring chamber 25 is anchored to the blast hole 1, it pushes the first crawling and anchoring chamber 24, as well as the upper cutting mechanism chamber 22 and the head control chamber 21, to move upwards. The upward movement is the displacement of the second ball nut block 244 minus the displacement of the first ball nut block 243. When the second ball nut block 244... When the system moves to its lowest position, the first clamping mechanism anchors to the inner wall of the blast hole 1, and the second clamping mechanism releases its anchorage. The reversal of the double-threaded screw 242 causes the second ball bearing nut block 244 and the first ball bearing nut block 243 to move upwards. Since the first crawling and anchoring chamber 24 is anchored to the blast hole 1, it pushes the cutting mechanism chamber 22 and the head control chamber 21 upwards. The upward movement is equal to the displacement of the first ball bearing nut block 243. The upward movement of the second ball bearing nut block 244 causes the second crawling and anchoring chamber 25 to move closer to the first crawling and anchoring chamber 24. This cycle repeats, enabling the cutting mechanism chamber 22 to advance continuously. No longer relying on external drill rods or ropes for traction, the system possesses autonomous movement capabilities. Continuous crawling results in continuous, uninterrupted acoustic scanning data, leading to higher accuracy in the geological model.

[0049] 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.

[0050] 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 method for bidirectional shaped charge blasting roof cutting and pressure relief in coal mine roadways, characterized in that, Includes the following steps: S1, connect the head-shaped energy tube (2) in series with several subsequent tail-shaped energy tubes (3), and place the head control cabin (21) at the opening of the blast hole (1), control the cutting component inside the head-shaped energy tube (2) to work, and at the same time drive the head-shaped energy tube (2) to move upward along the axial direction of the blast hole (1) inside the blast hole (1) with the help of tools or built-in crawling components, so as to cut two symmetrical guide structures on the hole wall of the blast hole (1), and use the sensing unit inside the head-shaped energy tube (2) to synchronously collect the lithology and location data of the inner wall of the blast hole (1) to construct the lithology distribution file of the entire section of the blast hole (1); S2, the subsequent trailing energy tubes (3) are circumferentially positioned by the limiting protrusion embedded in the guide structure and follow the head energy tube (2) upward until the head energy tube (2) is displaced to the designated position; S3, the main controller calculates and determines the target spacing of each shaped charge tube and the amount of explosive required to fill each shaped charge tube based on the lithology distribution file; S4, pumping the corresponding amount of emulsion explosive into the head shaped charge tube (2) and each trailing shaped charge tube (3) from top to bottom; S5, the main controller drives each spacing adjustment mechanism (4) to move from top to bottom in sequence, and adjusts each energy-concentrating tube to the target spacing in sequence; S6, the main controller broadcasts a time synchronization signal to the electronic detonator modules built into the head shaped charge tube (2) and each trailing shaped charge tube (3) via the communication bus and synchronizes them. Then, it sends an instruction containing an absolute detonation timestamp to each electronic detonator module individually. When the local clock of each electronic detonator module reaches its respective absolute detonation timestamp, it independently triggers detonation.

2. A bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways, characterized in that, The method of claim 1 is employed, and includes: The head-shaped charge tube (2) has a head control compartment (21), a cutting mechanism compartment (22), and a head charge compartment (23) arranged sequentially from top to bottom. The head control compartment (21) is equipped with a sensing unit for control, communication, positioning, and continuous detection of lithology and position. The cutting mechanism compartment (22) has windows (221) symmetrically opened on its tube wall. Each window (221) has a rotatable cutting component inside, which is used to cut along the cutting direction on the wall of the blast hole (1) to form a guide structure. The head charge compartment (23) has multiple sets of first shaped charge holes (231) symmetrically arranged on its side wall. The head charge compartment (23) has a first pumping pipe (232) at its lower end. A plurality of trailing energy-concentrating tubes (3) are provided, and each trailing energy-concentrating tube (3) has a plurality of sets of second energy-concentrating holes (31) symmetrically provided on its sidewall. The outer side of the trailing energy-concentrating tube (3) is also provided with a limiting protrusion that cooperates with the guide structure. Each trailing energy-concentrating tube (3) is provided with a second pumping tube (33) inside. The upper end of the first second pumping tube (33) is connected to the lower end of the first pumping tube (232). The upper ends of the remaining second pumping tubes (33) are connected to the lower end of the next-level second pumping tube (33). Each second pumping tube (33) is also provided with a three-way solenoid valve (34). The spacing adjustment mechanism (4) is located between the head charge chamber (23) and the first tailing shaped charge tube (3) and between adjacent tailing shaped charge tubes (3). The spacing adjustment mechanism (4) includes a worm gear pair (42) driven by a second motor (41), a drum (43) coaxially connected to the worm gear, and a cable (44) wound on the drum (43). One end of the cable (44) is connected to the next adjacent tailing shaped charge tube (3).

3. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, It also includes a synchronous detonation network, including a main controller located at the opening of the blast hole (1) and electronic detonator modules located in the head shaped charge tube (2) and the tail shaped charge tube (3) respectively. The main controller is connected to each electronic detonator module through a communication bus and is used to perform clock synchronization, issue absolute detonation time commands and control detonation.

4. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, The sensing unit includes a battery, a main control chip, a wireless communication module, a gyroscope, a dual-axis tilt sensor, an acoustic scanning probe for continuous lithology detection, and a position encoder for recording relative position.

5. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, The cutting component includes a cutting disc (223) and a first motor (222) for driving the cutting disc (223) to rotate. The cutting disc (223) is a V-shaped diamond disc, and the V-shaped cutting edges of the two cutting discs (223) are opposite to each other. The ends of the two cutting discs (223) that are far apart from each other can cut the inner walls on both sides of the area where the cutting plane is located in the blast hole (1). The guide structure is a V-shaped guide groove (6) that matches the V-shaped cutting edge, and the limiting protrusion is a V-shaped protrusion (32) that cooperates with the V-shaped guide groove (6).

6. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, The lower end of the first pumping pipe (232) is provided with a one-way liquid inlet valve (233), and the lower port of the first pumping pipe (232) is coaxially provided with a first connector (234) that mates with the upper port of the second pumping pipe (33); the lower port of the second pumping pipe (33) is coaxially provided with a second connector (35) that mates with the upper port of the second pumping pipe (33); the first pumping pipe (232) and the first second pumping pipe (33) are connected in series through the first connector (234), and several second pumping pipes (33) are connected in series in sequence through the second connector (35) for sequentially pumping emulsion explosives into the head charge chamber (23) and several trailing shaped charge tubes (3).

7. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, The spacing adjustment mechanism (4) further includes a length detector for detecting the release length of the cable (44), and the length detector is a rotary encoder disposed on the drum (43).

8. The bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 3, characterized in that, The communication bus is a four-core cable, with two cores forming a differential data bus and the other two cores being power lines.

9. A bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 8, characterized in that, The main controller has a built-in clock source, and the electronic detonator module includes a unique ID address, a calibrable local clock, and an initiation capacitor. The main controller is used to broadcast a clock synchronization signal to all electronic detonator modules before detonation and to issue encrypted instructions containing the absolute detonation time to each module. Each electronic detonator module autonomously performs detonation based on the synchronized local clock at the absolute detonation time.

10. A bidirectional shaped charge blasting roof cutting and pressure relief system for coal mine roadways according to claim 2, characterized in that, The head loading chamber (23) and each of the trailing shaped charge tubes (3) are respectively provided with a limiting sleeve (7) on their lower end surfaces, and each of the trailing shaped charge tubes (3) is respectively provided with a limiting sleeve (8) on its upper end surface that is coaxially fitted with the limiting sleeve (7).

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